Ensure special static slots respect alignment. (#20506)

[mono-project.git] / mono / metadata / threads.c

/**
 * \file
 * Thread support internal calls
 *
 * Author:
 *      Dick Porter (dick@ximian.com)
 *      Paolo Molaro (lupus@ximian.com)
 *      Patrik Torstensson (patrik.torstensson@labs2.com)
 *
 * Copyright 2001-2003 Ximian, Inc (http://www.ximian.com)
 * Copyright 2004-2009 Novell, Inc (http://www.novell.com)
 * Copyright 2011 Xamarin, Inc (http://www.xamarin.com)
 * Licensed under the MIT license. See LICENSE file in the project root for full license information.
 */

#include <config.h>

#include <glib.h>
#include <string.h>

#include <mono/metadata/object.h>
#include <mono/metadata/domain-internals.h>
#include <mono/metadata/profiler-private.h>
#include <mono/metadata/threads.h>
#include <mono/metadata/threads-types.h>
#include <mono/metadata/exception.h>
#include <mono/metadata/environment.h>
#include <mono/metadata/monitor.h>
#include <mono/metadata/mono-hash-internals.h>
#include <mono/metadata/gc-internals.h>
#include <mono/metadata/marshal.h>
#include <mono/metadata/runtime.h>
#include <mono/metadata/object-internals.h>
#include <mono/metadata/debug-internals.h>
#include <mono/utils/monobitset.h>
#include <mono/utils/mono-compiler.h>
#include <mono/utils/mono-mmap.h>
#include <mono/utils/mono-membar.h>
#include <mono/utils/mono-time.h>
#include <mono/utils/mono-threads.h>
#include <mono/utils/mono-threads-coop.h>
#include <mono/utils/mono-tls.h>
#include <mono/utils/atomic.h>
#include <mono/utils/mono-memory-model.h>
#include <mono/utils/mono-error-internals.h>
#include <mono/utils/os-event.h>
#include <mono/utils/mono-threads-debug.h>
#include <mono/utils/unlocked.h>
#include <mono/metadata/w32handle.h>
#include <mono/metadata/w32event.h>
#include <mono/metadata/w32mutex.h>

#include <mono/metadata/reflection-internals.h>
#include <mono/metadata/abi-details.h>
#include <mono/metadata/w32error.h>
#include <mono/utils/w32api.h>
#include <mono/utils/mono-os-wait.h>
#include <mono/metadata/exception-internals.h>
#include <mono/utils/mono-state.h>
#include <mono/metadata/w32subset.h>
#include <mono/metadata/mono-config.h>
#include "mono/utils/mono-tls-inline.h"

#ifdef HAVE_SYS_WAIT_H
#include <sys/wait.h>
#endif

#include <signal.h>

#if defined(HOST_WIN32)
#include <objbase.h>
#include <sys/timeb.h>
extern gboolean
mono_native_thread_join_handle (HANDLE thread_handle, gboolean close_handle);
#endif

#if defined(HOST_FUCHSIA)
#include <zircon/syscalls.h>
#endif

#if defined(HOST_ANDROID) && !defined(TARGET_ARM64) && !defined(TARGET_AMD64)
#define USE_TKILL_ON_ANDROID 1
#endif

#ifdef HOST_ANDROID
#include <errno.h>

#ifdef USE_TKILL_ON_ANDROID
extern int tkill (pid_t tid, int signal);
#endif
#endif

#include "icall-decl.h"

/*#define THREAD_DEBUG(a) do { a; } while (0)*/
#define THREAD_DEBUG(a)
/*#define THREAD_WAIT_DEBUG(a) do { a; } while (0)*/
#define THREAD_WAIT_DEBUG(a)
/*#define LIBGC_DEBUG(a) do { a; } while (0)*/
#define LIBGC_DEBUG(a)

#define SPIN_TRYLOCK(i) (mono_atomic_cas_i32 (&(i), 1, 0) == 0)
#define SPIN_LOCK(i) do { \
                                if (SPIN_TRYLOCK (i)) \
                                        break; \
                        } while (1)

#define SPIN_UNLOCK(i) i = 0

#define LOCK_THREAD(thread) lock_thread((thread))
#define UNLOCK_THREAD(thread) unlock_thread((thread))

typedef union {
        gint32 ival;
        gfloat fval;
} IntFloatUnion;

typedef union {
        gint64 ival;
        gdouble fval;
} LongDoubleUnion;
 
typedef struct _StaticDataFreeList StaticDataFreeList;
struct _StaticDataFreeList {
        StaticDataFreeList *next;
        guint32 offset;
        guint32 size;
        gint32 align;
};

typedef struct {
        int idx;
        int offset;
        StaticDataFreeList *freelist;
} StaticDataInfo;

/* Controls access to the 'threads' hash table */
static void mono_threads_lock (void);
static void mono_threads_unlock (void);
static MonoCoopMutex threads_mutex;

/* Controls access to the 'joinable_threads' hash table */
#define joinable_threads_lock() mono_coop_mutex_lock (&joinable_threads_mutex)
#define joinable_threads_unlock() mono_coop_mutex_unlock (&joinable_threads_mutex)
static MonoCoopMutex joinable_threads_mutex;

/* Holds current status of static data heap */
static StaticDataInfo thread_static_info;
static StaticDataInfo context_static_info;

/* The hash of existing threads (key is thread ID, value is
 * MonoInternalThread*) that need joining before exit
 */
static MonoGHashTable *threads=NULL;

/* List of app context GC handles.
 * Added to from mono_threads_register_app_context ().
 */
static GHashTable *contexts = NULL;

/* Cleanup queue for contexts. */
static MonoReferenceQueue *context_queue;

/*
 * Threads which are starting up and they are not in the 'threads' hash yet.
 * When mono_thread_attach_internal is called for a thread, it will be removed from this hash table.
 * Protected by mono_threads_lock ().
 */
static MonoGHashTable *threads_starting_up = NULL;

/* Contains tids */
/* Protected by the threads lock */
static GHashTable *joinable_threads;
static gint32 joinable_thread_count;

/* mono_threads_join_threads will take threads from joinable_threads list and wait for them. */
/* When this happens, the tid is not on the list anymore so mono_thread_join assumes the thread has complete */
/* and will return back to the caller. This could cause a race since caller of join assumes thread has completed */
/* and on some OS it could cause errors. Keeping the tid's currently pending a native thread join call */
/* in a separate table (only affecting callers interested in this internal join detail) and look at that table in mono_thread_join */
/* will close this race. */
static GHashTable *pending_native_thread_join_calls;
static MonoCoopCond pending_native_thread_join_calls_event;

static GHashTable *pending_joinable_threads;
static gint32 pending_joinable_thread_count;

static MonoCoopCond zero_pending_joinable_thread_event;

static void threads_add_pending_joinable_runtime_thread (MonoThreadInfo *mono_thread_info);
static gboolean threads_wait_pending_joinable_threads (uint32_t timeout);
static gchar* thread_dump_dir = NULL;

#define SET_CURRENT_OBJECT   mono_tls_set_thread
#define GET_CURRENT_OBJECT   mono_tls_get_thread

/* function called at thread start */
static MonoThreadStartCB mono_thread_start_cb = NULL;

/* function called at thread attach */
static MonoThreadAttachCB mono_thread_attach_cb = NULL;

/* function called at thread cleanup */
static MonoThreadCleanupFunc mono_thread_cleanup_fn = NULL;

/* The default stack size for each thread */
static guint32 default_stacksize = 0;
#define default_stacksize_for_thread(thread) ((thread)->stack_size? (thread)->stack_size: default_stacksize)

static void context_adjust_static_data (MonoAppContextHandle ctx);
static void mono_free_static_data (gpointer* static_data);
static void mono_init_static_data_info (StaticDataInfo *static_data);
static guint32 mono_alloc_static_data_slot (StaticDataInfo *static_data, guint32 size, guint32 align);
static gboolean mono_thread_resume (MonoInternalThread* thread);
static void async_abort_internal (MonoInternalThread *thread, gboolean install_async_abort);
static void self_abort_internal (MonoError *error);
static void async_suspend_internal (MonoInternalThread *thread, gboolean interrupt);
static void self_suspend_internal (void);

static gboolean
mono_thread_set_interruption_requested_flags (MonoInternalThread *thread, gboolean sync);

MONO_COLD void
mono_set_pending_exception_handle (MonoExceptionHandle exc);

static MonoException*
mono_thread_execute_interruption_ptr (void);

static void
mono_thread_execute_interruption_void (void);

static gboolean
mono_thread_execute_interruption (MonoExceptionHandle *pexc);

static void ref_stack_destroy (gpointer rs);

#if SIZEOF_VOID_P == 4
/* Spin lock for unaligned InterlockedXXX 64 bit functions on 32bit platforms. */
#define mono_interlocked_lock() mono_os_mutex_lock (&interlocked_mutex)
#define mono_interlocked_unlock() mono_os_mutex_unlock (&interlocked_mutex)
static mono_mutex_t interlocked_mutex;
#endif

/* global count of thread interruptions requested */
gint32 mono_thread_interruption_request_flag;

/* Event signaled when a thread changes its background mode */
static MonoOSEvent background_change_event;

static gboolean shutting_down = FALSE;

static gint32 managed_thread_id_counter = 0;

static void
mono_threads_lock (void)
{
        mono_locks_coop_acquire (&threads_mutex, ThreadsLock);
}

static void
mono_threads_unlock (void)
{
        mono_locks_coop_release (&threads_mutex, ThreadsLock);
}


static guint32
get_next_managed_thread_id (void)
{
        return mono_atomic_inc_i32 (&managed_thread_id_counter);
}

/*
 * We separate interruptions/exceptions into either sync (they can be processed anytime,
 * normally as soon as they are set, and are set by the same thread) and async (they can't
 * be processed inside abort protected blocks and are normally set by other threads). We
 * can have both a pending sync and async interruption. In this case, the sync exception is
 * processed first. Since we clean sync flag first, mono_thread_execute_interruption must
 * also handle all sync type exceptions before the async type exceptions.
 */
enum {
        INTERRUPT_SYNC_REQUESTED_BIT = 0x1,
        INTERRUPT_ASYNC_REQUESTED_BIT = 0x2,
        INTERRUPT_REQUESTED_MASK = 0x3,
        ABORT_PROT_BLOCK_SHIFT = 2,
        ABORT_PROT_BLOCK_BITS = 8,
        ABORT_PROT_BLOCK_MASK = (((1 << ABORT_PROT_BLOCK_BITS) - 1) << ABORT_PROT_BLOCK_SHIFT)
};

static int
mono_thread_get_abort_prot_block_count (MonoInternalThread *thread)
{
        gsize state = thread->thread_state;
        return (state & ABORT_PROT_BLOCK_MASK) >> ABORT_PROT_BLOCK_SHIFT;
}

gboolean
mono_threads_is_current_thread_in_protected_block (void)
{
        MonoInternalThread *thread = mono_thread_internal_current ();

        return mono_thread_get_abort_prot_block_count (thread) > 0;
}

void
mono_threads_begin_abort_protected_block (void)
{
        MonoInternalThread *thread = mono_thread_internal_current ();
        gsize old_state, new_state;
        int new_val;
        do {
                old_state = thread->thread_state;

                new_val = ((old_state & ABORT_PROT_BLOCK_MASK) >> ABORT_PROT_BLOCK_SHIFT) + 1;
                //bounds check abort_prot_count
                g_assert (new_val > 0);
                g_assert (new_val < (1 << ABORT_PROT_BLOCK_BITS));

                new_state = old_state + (1 << ABORT_PROT_BLOCK_SHIFT);
        } while (mono_atomic_cas_ptr ((volatile gpointer *)&thread->thread_state, (gpointer)new_state, (gpointer)old_state) != (gpointer)old_state);

        /* Defer async request since we won't be able to process until exiting the block */
        if (new_val == 1 && (new_state & INTERRUPT_ASYNC_REQUESTED_BIT)) {
                mono_atomic_dec_i32 (&mono_thread_interruption_request_flag);
                THREADS_INTERRUPT_DEBUG ("[%d] begin abort protected block old_state %ld new_state %ld, defer tir %d\n", thread->small_id, old_state, new_state, mono_thread_interruption_request_flag);
                if (mono_thread_interruption_request_flag < 0)
                        g_warning ("bad mono_thread_interruption_request_flag state");
        } else {
                THREADS_INTERRUPT_DEBUG ("[%d] begin abort protected block old_state %ld new_state %ld, tir %d\n", thread->small_id, old_state, new_state, mono_thread_interruption_request_flag);
        }
}

static gboolean
mono_thread_state_has_interruption (gsize state)
{
        /* pending exception, self abort */
        if (state & INTERRUPT_SYNC_REQUESTED_BIT)
                return TRUE;

        /* abort, interruption, suspend */
        if ((state & INTERRUPT_ASYNC_REQUESTED_BIT) && !(state & ABORT_PROT_BLOCK_MASK))
                return TRUE;

        return FALSE;
}

gboolean
mono_threads_end_abort_protected_block (void)
{
        MonoInternalThread *thread = mono_thread_internal_current ();
        gsize old_state, new_state;
        int new_val;
        do {
                old_state = thread->thread_state;

                //bounds check abort_prot_count
                new_val = ((old_state & ABORT_PROT_BLOCK_MASK) >> ABORT_PROT_BLOCK_SHIFT) - 1;
                g_assert (new_val >= 0);
                g_assert (new_val < (1 << ABORT_PROT_BLOCK_BITS));

                new_state = old_state - (1 << ABORT_PROT_BLOCK_SHIFT);
        } while (mono_atomic_cas_ptr ((volatile gpointer *)&thread->thread_state, (gpointer)new_state, (gpointer)old_state) != (gpointer)old_state);

        if (new_val == 0 && (new_state & INTERRUPT_ASYNC_REQUESTED_BIT)) {
                mono_atomic_inc_i32 (&mono_thread_interruption_request_flag);
                THREADS_INTERRUPT_DEBUG ("[%d] end abort protected block old_state %ld new_state %ld, restore tir %d\n", thread->small_id, old_state, new_state, mono_thread_interruption_request_flag);
        } else {
                THREADS_INTERRUPT_DEBUG ("[%d] end abort protected block old_state %ld new_state %ld, tir %d\n", thread->small_id, old_state, new_state, mono_thread_interruption_request_flag);
        }

        return mono_thread_state_has_interruption (new_state);
}

static gboolean
mono_thread_get_interruption_requested (MonoInternalThread *thread)
{
        gsize state = thread->thread_state;

        return mono_thread_state_has_interruption (state);
}

/*
 * Returns TRUE is there was a state change
 * We clear a single interruption request, sync has priority.
 */
static gboolean
mono_thread_clear_interruption_requested (MonoInternalThread *thread)
{
        gsize old_state, new_state;
        do {
                old_state = thread->thread_state;

                // no interruption to process
                if (!(old_state & INTERRUPT_SYNC_REQUESTED_BIT) &&
                                (!(old_state & INTERRUPT_ASYNC_REQUESTED_BIT) || (old_state & ABORT_PROT_BLOCK_MASK)))
                        return FALSE;

                if (old_state & INTERRUPT_SYNC_REQUESTED_BIT)
                        new_state = old_state & ~INTERRUPT_SYNC_REQUESTED_BIT;
                else
                        new_state = old_state & ~INTERRUPT_ASYNC_REQUESTED_BIT;
        } while (mono_atomic_cas_ptr ((volatile gpointer *)&thread->thread_state, (gpointer)new_state, (gpointer)old_state) != (gpointer)old_state);

        mono_atomic_dec_i32 (&mono_thread_interruption_request_flag);
        THREADS_INTERRUPT_DEBUG ("[%d] clear interruption old_state %ld new_state %ld, tir %d\n", thread->small_id, old_state, new_state, mono_thread_interruption_request_flag);
        if (mono_thread_interruption_request_flag < 0)
                g_warning ("bad mono_thread_interruption_request_flag state");
        return TRUE;
}

static gboolean
mono_thread_clear_interruption_requested_handle (MonoInternalThreadHandle thread)
{
        // Internal threads are pinned so shallow coop/handle.
        return mono_thread_clear_interruption_requested (mono_internal_thread_handle_ptr (thread));
}

/* Returns TRUE is there was a state change and the interruption can be processed */
static gboolean
mono_thread_set_interruption_requested (MonoInternalThread *thread)
{
        //always force when the current thread is doing it to itself.
        gboolean sync = thread == mono_thread_internal_current ();
        /* Normally synchronous interruptions can bypass abort protection. */
        return mono_thread_set_interruption_requested_flags (thread, sync);
}

/* Returns TRUE if there was a state change and the interruption can be
 * processed.  This variant defers a self abort when inside an abort protected
 * block.  Normally this should only be done when a thread has received an
 * outside indication that it should abort.  (For example when the JIT sets a
 * flag in an finally block.)
 */

static gboolean
mono_thread_set_self_interruption_respect_abort_prot (void)
{
        MonoInternalThread *thread = mono_thread_internal_current ();
        /* N.B. Sets the ASYNC_REQUESTED_BIT for current this thread,
         * which is unusual. */
        return mono_thread_set_interruption_requested_flags (thread, FALSE);
}

/* Returns TRUE if there was a state change and the interruption can be processed. */
static gboolean
mono_thread_set_interruption_requested_flags (MonoInternalThread *thread, gboolean sync)
{
        gsize old_state, new_state;
        do {
                old_state = thread->thread_state;

                //Already set
                if ((sync && (old_state & INTERRUPT_SYNC_REQUESTED_BIT)) ||
                                (!sync && (old_state & INTERRUPT_ASYNC_REQUESTED_BIT)))
                        return FALSE;

                if (sync)
                        new_state = old_state | INTERRUPT_SYNC_REQUESTED_BIT;
                else
                        new_state = old_state | INTERRUPT_ASYNC_REQUESTED_BIT;
        } while (mono_atomic_cas_ptr ((volatile gpointer *)&thread->thread_state, (gpointer)new_state, (gpointer)old_state) != (gpointer)old_state);

        if (sync || !(new_state & ABORT_PROT_BLOCK_MASK)) {
                mono_atomic_inc_i32 (&mono_thread_interruption_request_flag);
                THREADS_INTERRUPT_DEBUG ("[%d] set interruption on [%d] old_state %ld new_state %ld, tir %d\n", mono_thread_internal_current ()->small_id, thread->small_id, old_state, new_state, mono_thread_interruption_request_flag);
        } else {
                THREADS_INTERRUPT_DEBUG ("[%d] set interruption on [%d] old_state %ld new_state %ld, tir deferred %d\n", mono_thread_internal_current ()->small_id, thread->small_id, old_state, new_state, mono_thread_interruption_request_flag);
        }

        return sync || !(new_state & ABORT_PROT_BLOCK_MASK);
}

static MonoNativeThreadId
thread_get_tid (MonoInternalThread *thread)
{
        /* We store the tid as a guint64 to keep the object layout constant between platforms */
        return MONO_UINT_TO_NATIVE_THREAD_ID (thread->tid);
}

static void
free_synch_cs (MonoCoopMutex *synch_cs)
{
        g_assert (synch_cs);
        mono_coop_mutex_destroy (synch_cs);
        g_free (synch_cs);
}

static void
free_longlived_thread_data (void *user_data)
{
        MonoLongLivedThreadData *lltd = (MonoLongLivedThreadData*)user_data;
        free_synch_cs (lltd->synch_cs);

        g_free (lltd);
}

static void
init_longlived_thread_data (MonoLongLivedThreadData *lltd)
{
        mono_refcount_init (lltd, free_longlived_thread_data);
        mono_refcount_inc (lltd);
        /* Initial refcount is 2: decremented once by
         * mono_thread_detach_internal and once by the MonoInternalThread
         * finalizer - whichever one happens later will deallocate. */

        lltd->synch_cs = g_new0 (MonoCoopMutex, 1);
        mono_coop_mutex_init_recursive (lltd->synch_cs);

        mono_memory_barrier ();
}

static void
dec_longlived_thread_data (MonoLongLivedThreadData *lltd)
{
        mono_refcount_dec (lltd);
}

static void
lock_thread (MonoInternalThread *thread)
{
        g_assert (thread->longlived);
        g_assert (thread->longlived->synch_cs);

        mono_coop_mutex_lock (thread->longlived->synch_cs);
}

static void
unlock_thread (MonoInternalThread *thread)
{
        mono_coop_mutex_unlock (thread->longlived->synch_cs);
}

static void
lock_thread_handle (MonoInternalThreadHandle thread)
{
        lock_thread (mono_internal_thread_handle_ptr (thread));
}

static void
unlock_thread_handle (MonoInternalThreadHandle thread)
{
        unlock_thread (mono_internal_thread_handle_ptr (thread));
}

static gboolean
is_appdomainunloaded_exception (MonoClass *klass)
{
#ifdef ENABLE_NETCORE
        return FALSE;
#else
        return klass == mono_class_get_appdomain_unloaded_exception_class ();
#endif
}

static gboolean
is_threadabort_exception (MonoClass *klass)
{
        return klass == mono_defaults.threadabortexception_class;
}

/*
 * A special static data offset (guint32) consists of 3 parts:
 *
 * [0]   6-bit index into the array of chunks.
 * [6]   25-bit offset into the array.
 * [31]  Bit indicating thread or context static.
 */

typedef union {
        struct {
#if G_BYTE_ORDER != G_LITTLE_ENDIAN
                guint32 type : 1;
                guint32 offset : 25;
                guint32 index : 6;
#else
                guint32 index : 6;
                guint32 offset : 25;
                guint32 type : 1;
#endif
        } fields;
        guint32 raw;
} SpecialStaticOffset;

#define SPECIAL_STATIC_OFFSET_TYPE_THREAD 0
#define SPECIAL_STATIC_OFFSET_TYPE_CONTEXT 1

static guint32
MAKE_SPECIAL_STATIC_OFFSET (guint32 index, guint32 offset, guint32 type)
{
        SpecialStaticOffset special_static_offset;
        memset (&special_static_offset, 0, sizeof (special_static_offset));
        special_static_offset.fields.index = index;
        special_static_offset.fields.offset = offset;
        special_static_offset.fields.type = type;
        return special_static_offset.raw;
}

#define ACCESS_SPECIAL_STATIC_OFFSET(x,f) \
        (((SpecialStaticOffset *) &(x))->fields.f)

static gpointer
get_thread_static_data (MonoInternalThread *thread, guint32 offset)
{
        g_assert (ACCESS_SPECIAL_STATIC_OFFSET (offset, type) == SPECIAL_STATIC_OFFSET_TYPE_THREAD);

        int idx = ACCESS_SPECIAL_STATIC_OFFSET (offset, index);
        int off = ACCESS_SPECIAL_STATIC_OFFSET (offset, offset);

        return ((char *) thread->static_data [idx]) + off;
}

static gpointer
get_context_static_data (MonoAppContext *ctx, guint32 offset)
{
        g_assert (ACCESS_SPECIAL_STATIC_OFFSET (offset, type) == SPECIAL_STATIC_OFFSET_TYPE_CONTEXT);

        int idx = ACCESS_SPECIAL_STATIC_OFFSET (offset, index);
        int off = ACCESS_SPECIAL_STATIC_OFFSET (offset, offset);

        return ((char *) ctx->static_data [idx]) + off;
}

static MonoThread**
get_current_thread_ptr_for_domain (MonoDomain *domain, MonoInternalThread *thread)
{
        guint32 offset;

        MONO_STATIC_POINTER_INIT (MonoClassField, current_thread_field)

                current_thread_field = mono_class_get_field_from_name_full (mono_defaults.thread_class, "current_thread", NULL);
                g_assert (current_thread_field);

        MONO_STATIC_POINTER_INIT_END (MonoClassField, current_thread_field)

        ERROR_DECL (thread_vt_error);
        mono_class_vtable_checked (domain, mono_defaults.thread_class, thread_vt_error);
        mono_error_assert_ok (thread_vt_error);
        mono_domain_lock (domain);
        offset = GPOINTER_TO_UINT (g_hash_table_lookup (domain->special_static_fields, current_thread_field));
        mono_domain_unlock (domain);
        g_assert (offset);

        return (MonoThread **)get_thread_static_data (thread, offset);
}

static void
set_current_thread_for_domain (MonoDomain *domain, MonoInternalThread *thread, MonoThread *current)
{
#ifndef ENABLE_NETCORE
        MonoThread **current_thread_ptr = get_current_thread_ptr_for_domain (domain, thread);

        g_assert (current->obj.vtable->domain == domain);

        g_assert (!*current_thread_ptr);
        *current_thread_ptr = current;
#endif
}

static MonoThread*
create_thread_object (MonoDomain *domain, MonoInternalThread *internal)
{
#ifdef ENABLE_NETCORE
        MONO_OBJECT_SETREF_INTERNAL (internal, internal_thread, internal);
        return internal;
#else
        MonoThread *thread;
        MonoVTable *vtable;
        ERROR_DECL (error);

        vtable = mono_class_vtable_checked (domain, mono_defaults.thread_class, error);
        mono_error_assert_ok (error);

        thread = (MonoThread*)mono_object_new_mature (vtable, error);
        /* only possible failure mode is OOM, from which we don't expect to recover. */
        mono_error_assert_ok (error);

        MONO_OBJECT_SETREF_INTERNAL (thread, internal_thread, internal);

        return thread;
#endif
}

static void
init_internal_thread_object (MonoInternalThread *thread)
{
        thread->longlived = g_new0 (MonoLongLivedThreadData, 1);
        init_longlived_thread_data (thread->longlived);

        thread->apartment_state = ThreadApartmentState_Unknown;
        thread->managed_id = get_next_managed_thread_id ();
        if (mono_gc_is_moving ()) {
                thread->thread_pinning_ref = thread;
                MONO_GC_REGISTER_ROOT_PINNING (thread->thread_pinning_ref, MONO_ROOT_SOURCE_THREADING, NULL, "Thread Pinning Reference");
        }

        thread->priority = MONO_THREAD_PRIORITY_NORMAL;

        thread->suspended = g_new0 (MonoOSEvent, 1);
        mono_os_event_init (thread->suspended, TRUE);
}

static MonoInternalThread*
create_internal_thread_object (void)
{
        ERROR_DECL (error);
        MonoInternalThread *thread;
        MonoVTable *vt;

        vt = mono_class_vtable_checked (mono_get_root_domain (), mono_defaults.internal_thread_class, error);
        mono_error_assert_ok (error);
        thread = (MonoInternalThread*) mono_object_new_mature (vt, error);
        /* only possible failure mode is OOM, from which we don't exect to recover */
        mono_error_assert_ok (error);

        init_internal_thread_object (thread);

        return thread;
}

static void
mono_thread_internal_set_priority (MonoInternalThread *internal, MonoThreadPriority priority)
{
        g_assert (internal);

        g_assert (priority >= MONO_THREAD_PRIORITY_LOWEST);
        g_assert (priority <= MONO_THREAD_PRIORITY_HIGHEST);
        g_assert (MONO_THREAD_PRIORITY_LOWEST < MONO_THREAD_PRIORITY_HIGHEST);

#ifdef HOST_WIN32
        BOOL res;
        DWORD last_error;

        g_assert (internal->native_handle);

        MONO_ENTER_GC_SAFE;
        res = SetThreadPriority (internal->native_handle, (int)priority - 2);
        last_error = GetLastError ();
        MONO_EXIT_GC_SAFE;
        if (!res)
                g_error ("%s: SetThreadPriority failed, error %d", __func__, last_error);
#elif defined(HOST_FUCHSIA)
        int z_priority;
        
        if (priority == MONO_THREAD_PRIORITY_LOWEST)
                z_priority = ZX_PRIORITY_LOWEST;
        else if (priority == MONO_THREAD_PRIORITY_BELOW_NORMAL)
                z_priority = ZX_PRIORITY_LOW;
        else if (priority == MONO_THREAD_PRIORITY_NORMAL)
                z_priority = ZX_PRIORITY_DEFAULT;
        else if (priority == MONO_THREAD_PRIORITY_ABOVE_NORMAL)
                z_priority = ZX_PRIORITY_HIGH;
        else if (priority == MONO_THREAD_PRIORITY_HIGHEST)
                z_priority = ZX_PRIORITY_HIGHEST;
        else
                return;
        
        //
        // When this API becomes available on an arbitrary thread, we can use it,
        // not available on current Zircon
        //
#else /* !HOST_WIN32 and not HOST_FUCHSIA */
        pthread_t tid;
        int policy;
        struct sched_param param;
        gint res;

        tid = thread_get_tid (internal);

        MONO_ENTER_GC_SAFE;
        res = pthread_getschedparam (tid, &policy, &param);
        MONO_EXIT_GC_SAFE;
        if (res != 0)
                g_error ("%s: pthread_getschedparam failed, error: \"%s\" (%d)", __func__, g_strerror (res), res);

#ifdef _POSIX_PRIORITY_SCHEDULING
        int max, min;

        /* Necessary to get valid priority range */

        MONO_ENTER_GC_SAFE;
#if defined(__PASE__)
        /* only priorities allowed by IBM i */
        min = PRIORITY_MIN;
        max = PRIORITY_MAX;
#else
        min = sched_get_priority_min (policy);
        max = sched_get_priority_max (policy);
#endif
        MONO_EXIT_GC_SAFE;

        /* Not tunable. Bail out */
        if ((min == -1) || (max == -1))
                return;

        if (max > 0 && min >= 0 && max > min) {
                double srange, drange, sposition, dposition;
                srange = MONO_THREAD_PRIORITY_HIGHEST - MONO_THREAD_PRIORITY_LOWEST;
                drange = max - min;
                sposition = priority - MONO_THREAD_PRIORITY_LOWEST;
                dposition = (sposition / srange) * drange;
                param.sched_priority = (int)(dposition + min);
        } else
#endif
        {
                switch (policy) {
                case SCHED_FIFO:
                case SCHED_RR:
                        param.sched_priority = 50;
                        break;
#ifdef SCHED_BATCH
                case SCHED_BATCH:
#endif
                case SCHED_OTHER:
                        param.sched_priority = 0;
                        break;
                default:
                        g_warning ("%s: unknown policy %d", __func__, policy);
                        return;
                }
        }

        MONO_ENTER_GC_SAFE;
#if defined(__PASE__)
        /* only scheduling param allowed by IBM i */
        res = pthread_setschedparam (tid, SCHED_OTHER, &param);
#else
        res = pthread_setschedparam (tid, policy, &param);
#endif
        MONO_EXIT_GC_SAFE;
        if (res != 0) {
                if (res == EPERM) {
#if !defined(_AIX)
                        /* AIX doesn't like doing this and will spam this every time;
                         * weirdly, i doesn't complain
                         */
                        g_warning ("%s: pthread_setschedparam failed, error: \"%s\" (%d)", __func__, g_strerror (res), res);
#endif
                        return;
                }
                g_error ("%s: pthread_setschedparam failed, error: \"%s\" (%d)", __func__, g_strerror (res), res);
        }
#endif /* HOST_WIN32 */
}

static void 
mono_alloc_static_data (gpointer **static_data_ptr, guint32 offset, void *alloc_key, gboolean threadlocal);

static gboolean
mono_thread_attach_internal (MonoThread *thread, gboolean force_attach, gboolean force_domain)
{
        MonoThreadInfo *info;
        MonoInternalThread *internal;
        MonoDomain *domain, *root_domain;
        guint32 gchandle;

        g_assert (thread);

        info = mono_thread_info_current ();
        g_assert (info);

        internal = thread->internal_thread;
        g_assert (internal);

        /* It is needed to store the MonoInternalThread on the MonoThreadInfo, because of the following case:
         *  - the MonoInternalThread TLS key is destroyed: set it to NULL
         *  - the MonoThreadInfo TLS key is destroyed: calls mono_thread_info_detach
         *    - it calls MonoThreadInfoCallbacks.thread_detach
         *      - mono_thread_internal_current returns NULL -> fails to detach the MonoInternalThread. */
        mono_thread_info_set_internal_thread_gchandle (info, mono_gchandle_new_internal ((MonoObject*) internal, FALSE));

        internal->handle = mono_threads_open_thread_handle (info->handle);
        internal->native_handle = MONO_NATIVE_THREAD_HANDLE_TO_GPOINTER (mono_threads_open_native_thread_handle (info->native_handle));
        internal->tid = MONO_NATIVE_THREAD_ID_TO_UINT (mono_native_thread_id_get ());
        internal->thread_info = info;
        internal->small_id = info->small_id;

        THREAD_DEBUG (g_message ("%s: (%" G_GSIZE_FORMAT ") Setting current_object_key to %p", __func__, mono_native_thread_id_get (), internal));

        SET_CURRENT_OBJECT (internal);

        domain = mono_object_domain (thread);

        mono_thread_push_appdomain_ref (domain);
        if (!mono_domain_set_fast (domain, force_domain)) {
                mono_thread_pop_appdomain_ref ();
                goto fail;
        }

        mono_threads_lock ();

        if (shutting_down && !force_attach) {
                mono_threads_unlock ();
                mono_thread_pop_appdomain_ref ();
                goto fail;
        }

        if (threads_starting_up)
                mono_g_hash_table_remove (threads_starting_up, thread);

        if (!threads) {
                threads = mono_g_hash_table_new_type_internal (NULL, NULL, MONO_HASH_VALUE_GC, MONO_ROOT_SOURCE_THREADING, NULL, "Thread Table");
        }

        /* We don't need to duplicate thread->handle, because it is
         * only closed when the thread object is finalized by the GC. */
        mono_g_hash_table_insert_internal (threads, (gpointer)(gsize)(internal->tid), internal);

        /* We have to do this here because mono_thread_start_cb
         * requires that root_domain_thread is set up. */
        if (thread_static_info.offset || thread_static_info.idx > 0) {
                /* get the current allocated size */
                guint32 offset = MAKE_SPECIAL_STATIC_OFFSET (thread_static_info.idx, thread_static_info.offset, 0);
                mono_alloc_static_data (&internal->static_data, offset, (void *) MONO_UINT_TO_NATIVE_THREAD_ID (internal->tid), TRUE);
        }

        mono_threads_unlock ();

        root_domain = mono_get_root_domain ();

        g_assert (!internal->root_domain_thread);
        if (domain != root_domain)
                MONO_OBJECT_SETREF_INTERNAL (internal, root_domain_thread, create_thread_object (root_domain, internal));
        else
                MONO_OBJECT_SETREF_INTERNAL (internal, root_domain_thread, thread);

        if (domain != root_domain)
                set_current_thread_for_domain (root_domain, internal, internal->root_domain_thread);

        set_current_thread_for_domain (domain, internal, thread);

        THREAD_DEBUG (g_message ("%s: Attached thread ID %" G_GSIZE_FORMAT " (handle %p)", __func__, internal->tid, internal->handle));

        return TRUE;

fail:
        mono_threads_lock ();
        if (threads_starting_up)
                mono_g_hash_table_remove (threads_starting_up, thread);
        mono_threads_unlock ();

        if (!mono_thread_info_try_get_internal_thread_gchandle (info, &gchandle))
                g_error ("%s: failed to get gchandle, info %p", __func__, info);

        mono_gchandle_free_internal (gchandle);

        mono_thread_info_unset_internal_thread_gchandle (info);

        SET_CURRENT_OBJECT(NULL);

        return FALSE;
}

static void
mono_thread_detach_internal (MonoInternalThread *thread)
{
        MonoThreadInfo *info;
        MonoInternalThread *value;
        gboolean removed;
        guint32 gchandle;

        g_assert (mono_thread_internal_is_current (thread));

        g_assert (thread != NULL);
        SET_CURRENT_OBJECT (thread);

        info = thread->thread_info;
        g_assert (info);

        THREAD_DEBUG (g_message ("%s: mono_thread_detach for %p (%" G_GSIZE_FORMAT ")", __func__, thread, (gsize)thread->tid));

        MONO_PROFILER_RAISE (thread_stopping, (thread->tid));

        /*
        * Prevent race condition between thread shutdown and runtime shutdown.
        * Including all runtime threads in the pending joinable count will make
        * sure shutdown will wait for it to get onto the joinable thread list before
        * critical resources have been cleanup (like GC memory). Threads getting onto
        * the joinable thread list should just about to exit and not blocking a potential
        * join call. Owner of threads attached to the runtime but not identified as runtime
        * threads needs to make sure thread detach calls won't race with runtime shutdown.
        */
        threads_add_pending_joinable_runtime_thread (info);

#ifndef HOST_WIN32
        mono_w32mutex_abandon (thread);
#endif

        mono_gchandle_free_internal (thread->abort_state_handle);
        thread->abort_state_handle = 0;

        thread->abort_exc = NULL;
        thread->current_appcontext = NULL;

        LOCK_THREAD (thread);

        thread->state |= ThreadState_Stopped;
        thread->state &= ~ThreadState_Background;

        UNLOCK_THREAD (thread);

        /*
        An interruption request has leaked to cleanup. Adjust the global counter.

        This can happen is the abort source thread finds the abortee (this) thread
        in unmanaged code. If this thread never trips back to managed code or check
        the local flag it will be left set and positively unbalance the global counter.

        Leaving the counter unbalanced will cause a performance degradation since all threads
        will now keep checking their local flags all the time.
        */
        mono_thread_clear_interruption_requested (thread);

        mono_threads_lock ();

        g_assert (threads);

        if (!mono_g_hash_table_lookup_extended (threads, (gpointer)thread->tid, NULL, (gpointer*) &value)) {
                g_error ("%s: thread %p (tid: %p) should not have been removed yet from threads", __func__, thread, thread->tid);
        } else if (thread != value) {
                /* We have to check whether the thread object for the tid is still the same in the table because the
                 * thread might have been destroyed and the tid reused in the meantime, in which case the tid would be in
                 * the table, but with another thread object. */
                g_error ("%s: thread %p (tid: %p) do not match with value %p (tid: %p)", __func__, thread, thread->tid, value, value->tid);
        }

        removed = mono_g_hash_table_remove (threads, (gpointer)thread->tid);
        g_assert (removed);

        mono_threads_unlock ();

        /* Don't close the handle here, wait for the object finalizer
         * to do it. Otherwise, the following race condition applies:
         *
         * 1) Thread exits (and mono_thread_detach_internal() closes the handle)
         *
         * 2) Some other handle is reassigned the same slot
         *
         * 3) Another thread tries to join the first thread, and
         * blocks waiting for the reassigned handle to be signalled
         * (which might never happen).  This is possible, because the
         * thread calling Join() still has a reference to the first
         * thread's object.
         */

        mono_release_type_locks (thread);

        MONO_PROFILER_RAISE (thread_stopped, (thread->tid));
        MONO_PROFILER_RAISE (gc_root_unregister, ((const mono_byte*)(info->stack_start_limit)));
        MONO_PROFILER_RAISE (gc_root_unregister, ((const mono_byte*)(info->handle_stack)));

        /*
         * This will signal async signal handlers that the thread has exited.
         * The profiler callback needs this to be set, so it cannot be done earlier.
         */
        mono_domain_unset ();
        mono_memory_barrier ();

        mono_thread_pop_appdomain_ref ();

        mono_free_static_data (thread->static_data);
        thread->static_data = NULL;
        ref_stack_destroy (thread->appdomain_refs);
        thread->appdomain_refs = NULL;

        g_assert (thread->suspended);
        mono_os_event_destroy (thread->suspended);
        g_free (thread->suspended);
        thread->suspended = NULL;

        if (mono_thread_cleanup_fn)
                mono_thread_cleanup_fn (thread_get_tid (thread));

        mono_memory_barrier ();

        if (mono_gc_is_moving ()) {
                MONO_GC_UNREGISTER_ROOT (thread->thread_pinning_ref);
                thread->thread_pinning_ref = NULL;
        }

        /* There is no more any guarantee that `thread` is alive */
        mono_memory_barrier ();

        SET_CURRENT_OBJECT (NULL);
        mono_domain_unset ();

        if (!mono_thread_info_try_get_internal_thread_gchandle (info, &gchandle))
                g_error ("%s: failed to get gchandle, info = %p", __func__, info);

        mono_gchandle_free_internal (gchandle);

        mono_thread_info_unset_internal_thread_gchandle (info);

        /* Possibly free synch_cs, if the finalizer for InternalThread already
         * ran also. */
        dec_longlived_thread_data (thread->longlived);

        MONO_PROFILER_RAISE (thread_exited, (thread->tid));

        /* Don't need to close the handle to this thread, even though we took a
         * reference in mono_thread_attach (), because the GC will do it
         * when the Thread object is finalised.
         */
}

typedef struct {
        gint32 ref;
        MonoThread *thread;
        MonoObject *start_delegate;
        MonoObject *start_delegate_arg;
        MonoThreadStart start_func;
        gpointer start_func_arg;
        gboolean force_attach;
        gboolean failed;
        MonoCoopSem registered;
} StartInfo;

static void
fire_attach_profiler_events (MonoNativeThreadId tid)
{
        MONO_PROFILER_RAISE (thread_started, ((uintptr_t) tid));

        MonoThreadInfo *info = mono_thread_info_current ();

        MONO_PROFILER_RAISE (gc_root_register, (
                (const mono_byte*)(info->stack_start_limit),
                (char *) info->stack_end - (char *) info->stack_start_limit,
                MONO_ROOT_SOURCE_STACK,
                (void *) tid,
                "Thread Stack"));

        // The handle stack is a pseudo-root similar to the finalizer queues.
        MONO_PROFILER_RAISE (gc_root_register, (
                (const mono_byte*)info->handle_stack,
                1,
                MONO_ROOT_SOURCE_HANDLE,
                (void *) tid,
                "Handle Stack"));
}

static guint32 WINAPI
start_wrapper_internal (StartInfo *start_info, gsize *stack_ptr)
{
        ERROR_DECL (error);
        MonoThreadStart start_func;
        void *start_func_arg;
        gsize tid;
        /* 
         * We don't create a local to hold start_info->thread, so hopefully it won't get pinned during a
         * GC stack walk.
         */
        MonoThread *thread;
        MonoInternalThread *internal;
        MonoObject *start_delegate;
        MonoObject *start_delegate_arg;

        thread = start_info->thread;
        internal = thread->internal_thread;

        THREAD_DEBUG (g_message ("%s: (%" G_GSIZE_FORMAT ") Start wrapper", __func__, mono_native_thread_id_get ()));

        if (!mono_thread_attach_internal (thread, start_info->force_attach, FALSE)) {
                start_info->failed = TRUE;

                mono_coop_sem_post (&start_info->registered);

                if (mono_atomic_dec_i32 (&start_info->ref) == 0) {
                        mono_coop_sem_destroy (&start_info->registered);
                        g_free (start_info);
                }

                return 0;
        }

        mono_thread_internal_set_priority (internal, (MonoThreadPriority)internal->priority);

        tid = internal->tid;

        start_delegate = start_info->start_delegate;
        start_delegate_arg = start_info->start_delegate_arg;
        start_func = start_info->start_func;
        start_func_arg = start_info->start_func_arg;

        /* This MUST be called before any managed code can be
         * executed, as it calls the callback function that (for the
         * jit) sets the lmf marker.
         */

        if (mono_thread_start_cb)
                mono_thread_start_cb (tid, stack_ptr, (gpointer)start_func);

        /* On 2.0 profile (and higher), set explicitly since state might have been
           Unknown */
        if (internal->apartment_state == ThreadApartmentState_Unknown)
                internal->apartment_state = ThreadApartmentState_MTA;

        mono_thread_init_apartment_state ();

        /* Let the thread that called Start() know we're ready */
        mono_coop_sem_post (&start_info->registered);

        if (mono_atomic_dec_i32 (&start_info->ref) == 0) {
                mono_coop_sem_destroy (&start_info->registered);
                g_free (start_info);
        }

        /* start_info is not valid anymore */
        start_info = NULL;

        /* 
         * Call this after calling start_notify, since the profiler callback might want
         * to lock the thread, and the lock is held by thread_start () which waits for
         * start_notify.
         */
        fire_attach_profiler_events ((MonoNativeThreadId) tid);

        /* if the name was set before starting, we didn't invoke the profiler callback */
        // This is a little racy, ok.

        if (internal->name.chars) {

                LOCK_THREAD (internal);

                if (internal->name.chars) {
                        MONO_PROFILER_RAISE (thread_name, (internal->tid, internal->name.chars));
                        mono_native_thread_set_name (MONO_UINT_TO_NATIVE_THREAD_ID (internal->tid), internal->name.chars);
                }

                UNLOCK_THREAD (internal);
        }

        /* start_func is set only for unmanaged start functions */
        if (start_func) {
                start_func (start_func_arg);
        } else {
#ifdef ENABLE_NETCORE
                /* Call a callback in the RuntimeThread class */
                g_assert (start_delegate == NULL);

                MONO_STATIC_POINTER_INIT (MonoMethod, cb)

                        cb = mono_class_get_method_from_name_checked (internal->obj.vtable->klass, "StartCallback", 0, 0, error);
                        g_assert (cb);
                        mono_error_assert_ok (error);

                MONO_STATIC_POINTER_INIT_END (MonoMethod, cb)

                mono_runtime_invoke_checked (cb, internal, NULL, error);
#else
                void *args [1];

                g_assert (start_delegate != NULL);

                /* we may want to handle the exception here. See comment below on unhandled exceptions */
                args [0] = (gpointer) start_delegate_arg;
                mono_runtime_delegate_invoke_checked (start_delegate, args, error);
#endif

                if (!is_ok (error)) {
                        MonoException *ex = mono_error_convert_to_exception (error);

                        g_assert (ex != NULL);
                        MonoClass *klass = mono_object_class (ex);
                        if ((mono_runtime_unhandled_exception_policy_get () != MONO_UNHANDLED_POLICY_LEGACY) &&
                            !is_threadabort_exception (klass)) {
                                mono_unhandled_exception_internal (&ex->object);
                                mono_invoke_unhandled_exception_hook (&ex->object);
                                g_assert_not_reached ();
                        }
                } else {
                        mono_error_cleanup (error);
                }
        }

        /* If the thread calls ExitThread at all, this remaining code
         * will not be executed, but the main thread will eventually
         * call mono_thread_detach_internal() on this thread's behalf.
         */

        THREAD_DEBUG (g_message ("%s: (%" G_GSIZE_FORMAT ") Start wrapper terminating", __func__, mono_native_thread_id_get ()));

        /* Do any cleanup needed for apartment state. This
         * cannot be done in mono_thread_detach_internal since
         * mono_thread_detach_internal could be  called for a
         * thread other than the current thread.
         * mono_thread_cleanup_apartment_state cleans up apartment
         * for the current thead */
        mono_thread_cleanup_apartment_state ();

        mono_thread_detach_internal (internal);

        return 0;
}

static mono_thread_start_return_t WINAPI
start_wrapper (gpointer data)
{
        StartInfo *start_info;
        MonoThreadInfo *info;
        gsize res;

        start_info = (StartInfo*) data;
        g_assert (start_info);

        info = mono_thread_info_attach ();
        info->runtime_thread = TRUE;

        /* Run the actual main function of the thread */
        res = start_wrapper_internal (start_info, (gsize*)info->stack_end);

        mono_thread_info_exit (res);

        g_assert_not_reached ();
}

/*
 * create_thread:
 *
 *   Common thread creation code.
 * LOCKING: Acquires the threads lock.
 */
static gboolean
create_thread (MonoThread *thread, MonoInternalThread *internal, MonoObject *start_delegate, MonoThreadStart start_func, gpointer start_func_arg,
        MonoThreadCreateFlags flags, MonoError *error)
{
        StartInfo *start_info = NULL;
        MonoNativeThreadId tid;
        gboolean ret;
        gsize stack_set_size;

        if (start_delegate)
                g_assert (!start_func && !start_func_arg);
        if (start_func)
                g_assert (!start_delegate);

        if (flags & MONO_THREAD_CREATE_FLAGS_THREADPOOL) {
                g_assert (!(flags & MONO_THREAD_CREATE_FLAGS_DEBUGGER));
                g_assert (!(flags & MONO_THREAD_CREATE_FLAGS_FORCE_CREATE));
        }
        if (flags & MONO_THREAD_CREATE_FLAGS_DEBUGGER) {
                g_assert (!(flags & MONO_THREAD_CREATE_FLAGS_THREADPOOL));
                g_assert (!(flags & MONO_THREAD_CREATE_FLAGS_FORCE_CREATE));
        }

        /*
         * Join joinable threads to prevent running out of threads since the finalizer
         * thread might be blocked/backlogged.
         */
        mono_threads_join_threads ();

        error_init (error);

        mono_threads_lock ();
        if (shutting_down && !(flags & MONO_THREAD_CREATE_FLAGS_FORCE_CREATE)) {
                mono_threads_unlock ();
                mono_error_set_execution_engine (error, "Couldn't create thread. Runtime is shutting down.");
                return FALSE;
        }
        if (threads_starting_up == NULL) {
                threads_starting_up = mono_g_hash_table_new_type_internal (NULL, NULL, MONO_HASH_KEY_VALUE_GC, MONO_ROOT_SOURCE_THREADING, NULL, "Thread Starting Table");
        }
        mono_g_hash_table_insert_internal (threads_starting_up, thread, thread);
        mono_threads_unlock ();

#ifndef ENABLE_NETCORE
        internal->threadpool_thread = flags & MONO_THREAD_CREATE_FLAGS_THREADPOOL;
        if (internal->threadpool_thread)
                mono_thread_set_state (internal, ThreadState_Background);
#endif

        internal->debugger_thread = flags & MONO_THREAD_CREATE_FLAGS_DEBUGGER;

        start_info = g_new0 (StartInfo, 1);
        start_info->ref = 2;
        start_info->thread = thread;
        start_info->start_delegate = start_delegate;
        start_info->start_delegate_arg = thread->start_obj;
        start_info->start_func = start_func;
        start_info->start_func_arg = start_func_arg;
        start_info->force_attach = flags & MONO_THREAD_CREATE_FLAGS_FORCE_CREATE;
        start_info->failed = FALSE;
        mono_coop_sem_init (&start_info->registered, 0);

        if (flags != MONO_THREAD_CREATE_FLAGS_SMALL_STACK)
                stack_set_size = default_stacksize_for_thread (internal);
        else
                stack_set_size = 0;

        if (!mono_thread_platform_create_thread (start_wrapper, start_info, &stack_set_size, &tid)) {
                /* The thread couldn't be created, so set an exception */
                mono_threads_lock ();
                mono_g_hash_table_remove (threads_starting_up, thread);
                mono_threads_unlock ();
                mono_error_set_execution_engine (error, "Couldn't create thread. Error 0x%x", mono_w32error_get_last());
                /* ref is not going to be decremented in start_wrapper_internal */
                mono_atomic_dec_i32 (&start_info->ref);
                ret = FALSE;
                goto done;
        }

        internal->stack_size = (int) stack_set_size;

        THREAD_DEBUG (g_message ("%s: (%" G_GSIZE_FORMAT ") Launching thread %p (%" G_GSIZE_FORMAT ")", __func__, mono_native_thread_id_get (), internal, (gsize)internal->tid));

        /*
         * Wait for the thread to set up its TLS data etc, so
         * theres no potential race condition if someone tries
         * to look up the data believing the thread has
         * started
         */

        mono_coop_sem_wait (&start_info->registered, MONO_SEM_FLAGS_NONE);

        THREAD_DEBUG (g_message ("%s: (%" G_GSIZE_FORMAT ") Done launching thread %p (%" G_GSIZE_FORMAT ")", __func__, mono_native_thread_id_get (), internal, (gsize)internal->tid));

        ret = !start_info->failed;

done:
        if (mono_atomic_dec_i32 (&start_info->ref) == 0) {
                mono_coop_sem_destroy (&start_info->registered);
                g_free (start_info);
        }

        return ret;
}

/**
 * mono_thread_new_init:
 */
void
mono_thread_new_init (intptr_t tid, gpointer stack_start, gpointer func)
{
        if (mono_thread_start_cb) {
                mono_thread_start_cb (tid, stack_start, func);
        }
}

/**
 * mono_threads_set_default_stacksize:
 */
void
mono_threads_set_default_stacksize (guint32 stacksize)
{
        default_stacksize = stacksize;
}

/**
 * mono_threads_get_default_stacksize:
 */
guint32
mono_threads_get_default_stacksize (void)
{
        return default_stacksize;
}

/*
 * mono_thread_create_internal:
 *
 *   ARG should not be a GC reference.
 */
MonoInternalThread*
mono_thread_create_internal (MonoDomain *domain, gpointer func, gpointer arg, MonoThreadCreateFlags flags, MonoError *error)
{
        MonoThread *thread;
        MonoInternalThread *internal;
        gboolean res;

        error_init (error);

        internal = create_internal_thread_object ();

        thread = create_thread_object (domain, internal);

        LOCK_THREAD (internal);

        res = create_thread (thread, internal, NULL, (MonoThreadStart) func, arg, flags, error);
        (void)res;

        UNLOCK_THREAD (internal);

        return_val_if_nok (error, NULL);
        return internal;
}

MonoInternalThreadHandle
mono_thread_create_internal_handle (MonoDomain *domain, gpointer func, gpointer arg, MonoThreadCreateFlags flags, MonoError *error)
{
        // FIXME invert
        return MONO_HANDLE_NEW (MonoInternalThread, mono_thread_create_internal (domain, func, arg, flags, error));
}

/**
 * mono_thread_create:
 */
void
mono_thread_create (MonoDomain *domain, gpointer func, gpointer arg)
{
        MONO_ENTER_GC_UNSAFE;
        ERROR_DECL (error);
        if (!mono_thread_create_checked (domain, func, arg, error))
                mono_error_cleanup (error);
        MONO_EXIT_GC_UNSAFE;
}

gboolean
mono_thread_create_checked (MonoDomain *domain, gpointer func, gpointer arg, MonoError *error)
{
        return (NULL != mono_thread_create_internal (domain, func, arg, MONO_THREAD_CREATE_FLAGS_NONE, error));
}

/**
 * mono_thread_attach:
 */
MonoThread *
mono_thread_attach (MonoDomain *domain)
{
        MonoInternalThread *internal;
        MonoThread *thread;
        MonoThreadInfo *info;
        MonoNativeThreadId tid;

        if (mono_thread_internal_current_is_attached ()) {
                if (domain != mono_domain_get ())
                        mono_domain_set_fast (domain, TRUE);
                /* Already attached */
                return mono_thread_current ();
        }

        info = mono_thread_info_attach ();
        g_assert (info);

        tid=mono_native_thread_id_get ();

        if (mono_runtime_get_no_exec ())
                return NULL;

        internal = create_internal_thread_object ();

        thread = create_thread_object (domain, internal);

        if (!mono_thread_attach_internal (thread, FALSE, TRUE)) {
                /* Mono is shutting down, so just wait for the end */
                for (;;)
                        mono_thread_info_sleep (10000, NULL);
        }

        THREAD_DEBUG (g_message ("%s: Attached thread ID %" G_GSIZE_FORMAT " (handle %p)", __func__, tid, internal->handle));

        if (mono_thread_attach_cb)
                mono_thread_attach_cb (MONO_NATIVE_THREAD_ID_TO_UINT (tid), info->stack_end);

        fire_attach_profiler_events (tid);

        return thread;
}

/**
 * mono_threads_attach_tools_thread:
 *
 * Attach the current thread as a tool thread. DON'T USE THIS FUNCTION WITHOUT READING ALL DISCLAIMERS.
 *
 * A tools thread is a very special kind of thread that needs access to core
 * runtime facilities but should not be counted as a regular thread for high
 * order facilities such as executing managed code or accessing the managed
 * heap.
 *
 * This is intended only for low-level utilities than need to be able to use
 * some low-level runtime facilities when doing things like resolving
 * backtraces in their background processing thread.
 *
 * Note in particular that the thread is not fully attached - it does not have
 * a "current domain" because it cannot run managed code or interact with
 * managed objects.  However it can act on some metadata, and use our low-level
 * locks and the coop thread state machine (ie GC Safe and GC Unsafe
 * transitions make sense).
 */
void
mono_threads_attach_tools_thread (void)
{
        MonoThreadInfo *info = mono_thread_info_attach ();
        g_assert (info);
        mono_thread_info_set_flags (MONO_THREAD_INFO_FLAGS_NO_GC | MONO_THREAD_INFO_FLAGS_NO_SAMPLE);
}

/**
 * mono_thread_detach:
 */
void
mono_thread_detach (MonoThread *thread)
{
        if (thread)
                mono_thread_detach_internal (thread->internal_thread);
}



/**
 * mono_thread_detach_if_exiting:
 *
 * Detach the current thread from the runtime if it is exiting, i.e. it is running pthread dtors.
 * This should be used at the end of embedding code which calls into managed code, and which
 * can be called from pthread dtors, like <code>dealloc:</code> implementations in Objective-C.
 */
mono_bool
mono_thread_detach_if_exiting (void)
{
        if (mono_thread_info_is_exiting ()) {
                MonoInternalThread *thread;

                thread = mono_thread_internal_current ();
                if (thread) {
                        // Switch to GC Unsafe thread state before detaching;
                        // don't expect to undo this switch, hence unbalanced.
                        gpointer dummy;
                        (void) mono_threads_enter_gc_unsafe_region_unbalanced (&dummy);

                        mono_thread_detach_internal (thread);
                        mono_thread_info_detach ();
                        return TRUE;
                }
        }
        return FALSE;
}

gboolean
mono_thread_internal_current_is_attached (void)
{
        MonoInternalThread *internal;

        internal = GET_CURRENT_OBJECT ();
        if (!internal)
                return FALSE;

        return TRUE;
}

/**
 * mono_thread_exit:
 */
void
mono_thread_exit (void)
{
        MonoInternalThread *thread = mono_thread_internal_current ();

        THREAD_DEBUG (g_message ("%s: mono_thread_exit for %p (%" G_GSIZE_FORMAT ")", __func__, thread, (gsize)thread->tid));

        mono_thread_detach_internal (thread);

        /* we could add a callback here for embedders to use. */
        if (mono_thread_get_main () && (thread == mono_thread_get_main ()->internal_thread))
                exit (mono_environment_exitcode_get ());

        mono_thread_info_exit (0);
}

static void
mono_thread_construct_internal (MonoThreadObjectHandle this_obj_handle)
{
        MonoInternalThread * const internal = create_internal_thread_object ();

        internal->state = ThreadState_Unstarted;

        int const thread_gchandle = mono_gchandle_from_handle (MONO_HANDLE_CAST (MonoObject, this_obj_handle), TRUE);

        MonoThreadObject *this_obj = MONO_HANDLE_RAW (this_obj_handle);

        mono_atomic_cas_ptr ((volatile gpointer *)&this_obj->internal_thread, internal, NULL);

        mono_gchandle_free_internal (thread_gchandle);
}

#ifndef ENABLE_NETCORE
void
ves_icall_System_Threading_Thread_ConstructInternalThread (MonoThreadObjectHandle this_obj_handle, MonoError *error)
{
        mono_thread_construct_internal (this_obj_handle);
}
#endif

void
ves_icall_System_Threading_Thread_GetCurrentThread (MonoThread *volatile* thread)
{
        *thread = mono_thread_current ();
}

static MonoInternalThread*
thread_handle_to_internal_ptr (MonoThreadObjectHandle thread_handle)
{
        return MONO_HANDLE_GETVAL(thread_handle, internal_thread); // InternalThreads are always pinned.
}

static void
mono_error_set_exception_thread_state (MonoError *error, const char *exception_message)
{
        mono_error_set_generic_error (error, "System.Threading", "ThreadStateException", "%s", exception_message);
}

static void
mono_error_set_exception_thread_not_started_or_dead (MonoError *error)
{
        mono_error_set_exception_thread_state (error, "Thread has not been started, or is dead.");
}

#ifndef ENABLE_NETCORE
MonoBoolean
ves_icall_System_Threading_Thread_Thread_internal (MonoThreadObjectHandle thread_handle, MonoObjectHandle start_handle, MonoError *error)
{
        MonoInternalThread *internal;
        gboolean res;
        MonoThread *this_obj = MONO_HANDLE_RAW (thread_handle);
        MonoObject *start = MONO_HANDLE_RAW (start_handle);

        THREAD_DEBUG (g_message("%s: Trying to start a new thread: this (%p) start (%p)", __func__, this_obj, start));

        internal = thread_handle_to_internal_ptr (thread_handle);

        if (!internal) {
                mono_thread_construct_internal (thread_handle);
                internal = thread_handle_to_internal_ptr (thread_handle);
                g_assert (internal);
        }

        LOCK_THREAD (internal);

        if ((internal->state & ThreadState_Unstarted) == 0) {
                UNLOCK_THREAD (internal);
                mono_error_set_exception_thread_state (error, "Thread has already been started.");
                return FALSE;
        }

        if ((internal->state & ThreadState_Aborted) != 0) {
                UNLOCK_THREAD (internal);
                return TRUE;
        }

        res = create_thread (this_obj, internal, start, NULL, NULL, MONO_THREAD_CREATE_FLAGS_NONE, error);
        if (!res) {
                UNLOCK_THREAD (internal);
                return FALSE;
        }

        internal->state &= ~ThreadState_Unstarted;

        THREAD_DEBUG (g_message ("%s: Started thread ID %" G_GSIZE_FORMAT " (handle %p)", __func__, tid, thread));

        UNLOCK_THREAD (internal);
        return TRUE;
}
#endif

static
void
mono_thread_name_cleanup (MonoThreadName* name)
{
        MonoThreadName const old_name = *name;
        memset (name, 0, sizeof (*name));
        if (old_name.free)
                g_free (old_name.chars);
}

/*
 * This is called from the finalizer of the internal thread object.
 */
void
ves_icall_System_Threading_InternalThread_Thread_free_internal (MonoInternalThreadHandle this_obj_handle, MonoError *error)
{
        MonoInternalThread *this_obj = mono_internal_thread_handle_ptr (this_obj_handle);
        THREAD_DEBUG (g_message ("%s: Closing thread %p, handle %p", __func__, this_obj, this_obj->handle));

        /*
         * Since threads keep a reference to their thread object while running, by
         * the time this function is called, the thread has already exited/detached,
         * i.e. mono_thread_detach_internal () has ran. The exception is during
         * shutdown, when mono_thread_detach_internal () can be called after this.
         */
        if (this_obj->handle) {
                mono_threads_close_thread_handle (this_obj->handle);
                this_obj->handle = NULL;
        }

        mono_threads_close_native_thread_handle (MONO_GPOINTER_TO_NATIVE_THREAD_HANDLE (this_obj->native_handle));
        this_obj->native_handle = NULL;

        /* Possibly free synch_cs, if the thread already detached also. */
        dec_longlived_thread_data (this_obj->longlived);

        mono_thread_name_cleanup (&this_obj->name);
}

static void
mono_sleep_internal (gint32 ms, MonoBoolean allow_interruption, MonoError *error)
{
        THREAD_DEBUG (g_message ("%s: Sleeping for %d ms", __func__, ms));

        if (mono_thread_current_check_pending_interrupt ())
                return;

        MonoInternalThread * const thread = mono_thread_internal_current ();

        HANDLE_LOOP_PREPARE;

        while (TRUE) {
                gboolean alerted = FALSE;

                mono_thread_set_state (thread, ThreadState_WaitSleepJoin);

                (void)mono_thread_info_sleep (ms, &alerted);

                mono_thread_clr_state (thread, ThreadState_WaitSleepJoin);

                if (!alerted)
                        return;

                if (allow_interruption) {
                        SETUP_ICALL_FRAME;

                        MonoExceptionHandle exc = MONO_HANDLE_NEW (MonoException, NULL);

                        const gboolean interrupt = mono_thread_execute_interruption (&exc);

                        if (interrupt)
                                mono_set_pending_exception_handle (exc);

                        CLEAR_ICALL_FRAME;

                        if (interrupt)
                                return;
                }

                if (ms == MONO_INFINITE_WAIT) // FIXME: !MONO_INFINITE_WAIT
                        continue;
                return;
        }
}

#ifdef ENABLE_NETCORE
void
ves_icall_System_Threading_Thread_Sleep_internal (gint32 ms, MonoBoolean allow_interruption, MonoError *error)
{
        return mono_sleep_internal (ms, allow_interruption, error);
}
#else
void
ves_icall_System_Threading_Thread_Sleep_internal (gint32 ms, MonoError *error)
{
        return mono_sleep_internal (ms, TRUE, error);
}

void
ves_icall_System_Threading_Thread_SpinWait_nop (MonoError *error)
{
}
#endif

#ifndef ENABLE_NETCORE
gint32
ves_icall_System_Threading_Thread_GetDomainID (MonoError *error)
{
        return mono_domain_get()->domain_id;
}
#endif

/**
 * mono_thread_get_name_utf8:
 * \returns the name of the thread in UTF-8.
 * Return NULL if the thread has no name.
 * The returned memory is owned by the caller (g_free it).
 */
char *
mono_thread_get_name_utf8 (MonoThread *thread)
{
        if (thread == NULL)
                return NULL;

        MonoInternalThread *internal = thread->internal_thread;

        // This is a little racy, ok.

        if (internal == NULL || !internal->name.chars)
                return NULL;

        LOCK_THREAD (internal);

        char *tname = (char*)g_memdup (internal->name.chars, internal->name.length + 1);

        UNLOCK_THREAD (internal);

        return tname;
}

/**
 * mono_thread_get_managed_id:
 * \returns the \c Thread.ManagedThreadId value of \p thread.
 * Returns \c -1 if \p thread is NULL.
 */
int32_t
mono_thread_get_managed_id (MonoThread *thread)
{
        if (thread == NULL)
                return -1;

        MonoInternalThread *internal = thread->internal_thread;
        if (internal == NULL)
                return -1;

        int32_t id = internal->managed_id;

        return id;
}

#ifndef ENABLE_NETCORE
MonoStringHandle
ves_icall_System_Threading_Thread_GetName_internal (MonoInternalThreadHandle thread_handle, MonoError *error)
{
        // InternalThreads are always pinned, so shallowly coop-handleize.
        MonoInternalThread * const this_obj = mono_internal_thread_handle_ptr (thread_handle);

        MonoStringHandle str = NULL_HANDLE_STRING;

        // This is a little racy, ok.

        if (this_obj->name.chars) {
                LOCK_THREAD (this_obj);

                if (this_obj->name.chars)
                        str = mono_string_new_utf8_len (mono_domain_get (), this_obj->name.chars, this_obj->name.length, error);

                UNLOCK_THREAD (this_obj);
        }

        return str;
}
#endif

// Unusal function:
//  - MonoError is optional -- failure is usually not interesting, except the documented failure mode for managed callers.
//  - name16 only used on Windows.
//  - name8 is either constant, or g_free'able -- this function always takes ownership and never copies.
//
void
mono_thread_set_name (MonoInternalThread *this_obj,
                      const char* name8, size_t name8_length, const gunichar2* name16,
                      MonoSetThreadNameFlags flags, MonoError *error)
{
        // A special case for the threadpool worker.
        // It sets the name repeatedly, in case it has changed, per-spec,
        // and if not done carefully, this can be a performance problem.
        //
        // This is racy but ok. The name will always be valid (or absent).
        // In an unusual race, the name might briefly not revert to what the spec requires.
        //
        if ((flags & MonoSetThreadNameFlag_RepeatedlyButOptimized) && name8 == this_obj->name.chars) {
                // Length is presumed to match.
                return;
        }

        MonoNativeThreadId tid = 0;

        const gboolean constant = !!(flags & MonoSetThreadNameFlag_Constant);

#if HOST_WIN32 // On Windows, if name8 is supplied, then name16 must be also.
        g_assert (!name8 || name16);
#endif

        LOCK_THREAD (this_obj);

        if (flags & MonoSetThreadNameFlag_Reset) {
                this_obj->flags &= ~MONO_THREAD_FLAG_NAME_SET;
        } else if (this_obj->flags & MONO_THREAD_FLAG_NAME_SET) {
                UNLOCK_THREAD (this_obj);
                
                if (error)
                        mono_error_set_invalid_operation (error, "%s", "Thread.Name can only be set once.");

                if (!constant)
                        g_free ((char*)name8);
                return;
        }

        mono_thread_name_cleanup (&this_obj->name);

        if (name8) {
                this_obj->name.chars = (char*)name8;
                this_obj->name.length = name8_length;
                this_obj->name.free = !constant;
                if (flags & MonoSetThreadNameFlag_Permanent)
                        this_obj->flags |= MONO_THREAD_FLAG_NAME_SET;
        }

        if (!(this_obj->state & ThreadState_Stopped))
                tid = thread_get_tid (this_obj);

        UNLOCK_THREAD (this_obj);

        if (name8 && tid) {
                MONO_PROFILER_RAISE (thread_name, ((uintptr_t)tid, name8));
                mono_native_thread_set_name (tid, name8);
        }

        mono_thread_set_name_windows (this_obj->native_handle, name16);

        mono_free (0); // FIXME keep mono-publib.c in use and its functions exported
}

void 
ves_icall_System_Threading_Thread_SetName_icall (MonoInternalThreadHandle thread_handle, const gunichar2* name16, gint32 name16_length, MonoError* error)
{
        long name8_length = 0;

        char* name8 = name16 ? g_utf16_to_utf8 (name16, name16_length, NULL, &name8_length, NULL) : NULL;

        mono_thread_set_name (mono_internal_thread_handle_ptr (thread_handle),
                name8, (gint32)name8_length, name16, MonoSetThreadNameFlag_Permanent, error);
}

#ifndef ENABLE_NETCORE
/*
 * ves_icall_System_Threading_Thread_GetPriority_internal:
 * @param this_obj: The MonoInternalThread on which to operate.
 *
 * Gets the priority of the given thread.
 * @return: The priority of the given thread.
 */
int
ves_icall_System_Threading_Thread_GetPriority (MonoThreadObjectHandle this_obj, MonoError *error)
{
        gint32 priority;

        MonoInternalThread *internal = thread_handle_to_internal_ptr (this_obj);

        LOCK_THREAD (internal);
        priority = internal->priority;
        UNLOCK_THREAD (internal);

        return priority;
}
#endif

/* 
 * ves_icall_System_Threading_Thread_SetPriority_internal:
 * @param this_obj: The MonoInternalThread on which to operate.
 * @param priority: The priority to set.
 *
 * Sets the priority of the given thread.
 */
void
ves_icall_System_Threading_Thread_SetPriority (MonoThreadObjectHandle this_obj, int priority, MonoError *error)
{
        MonoInternalThread *internal = thread_handle_to_internal_ptr (this_obj);

        LOCK_THREAD (internal);
        internal->priority = priority;
        if (internal->thread_info != NULL)
                mono_thread_internal_set_priority (internal, (MonoThreadPriority)priority);
        UNLOCK_THREAD (internal);
}

/* If the array is already in the requested domain, we just return it,
   otherwise we return a copy in that domain. */
static MonoArrayHandle
byte_array_to_domain (MonoArrayHandle arr, MonoDomain *domain, MonoError *error)
{
        HANDLE_FUNCTION_ENTER ()

        if (MONO_HANDLE_IS_NULL (arr))
                return MONO_HANDLE_NEW (MonoArray, NULL);

        if (MONO_HANDLE_DOMAIN (arr) == domain)
                return arr;

        size_t const size = mono_array_handle_length (arr);

        // Capture arrays into common representation for repetitious code.
        // These two variables could also be an array of size 2 and
        // repetition implemented with a loop.
        struct {
                MonoArrayHandle handle;
                gpointer p;
                guint gchandle;
        }
        source = { arr },
        dest = { mono_array_new_handle (domain, mono_defaults.byte_class, size, error) };
        goto_if_nok (error, exit);

        // Pin both arrays.
        source.p = mono_array_handle_pin_with_size (source.handle, size, 0, &source.gchandle);
        dest.p = mono_array_handle_pin_with_size (dest.handle, size, 0, &dest.gchandle);

        memmove (dest.p, source.p, size);
exit:
        // Unpin both arrays.
        mono_gchandle_free_internal (source.gchandle);
        mono_gchandle_free_internal (dest.gchandle);

        HANDLE_FUNCTION_RETURN_REF (MonoArray, dest.handle)
}

#ifndef ENABLE_NETCORE
MonoArrayHandle
ves_icall_System_Threading_Thread_ByteArrayToRootDomain (MonoArrayHandle arr, MonoError *error)
{
        return byte_array_to_domain (arr, mono_get_root_domain (), error);
}

MonoArrayHandle
ves_icall_System_Threading_Thread_ByteArrayToCurrentDomain (MonoArrayHandle arr, MonoError *error)
{
        return byte_array_to_domain (arr, mono_domain_get (), error);
}
#endif

/**
 * mono_thread_current:
 */
MonoThread *
mono_thread_current (void)
{
#ifdef ENABLE_NETCORE
        return mono_thread_internal_current ();
#else
        MonoDomain *domain = mono_domain_get ();
        MonoInternalThread *internal = mono_thread_internal_current ();
        MonoThread **current_thread_ptr;

        g_assert (internal);
        current_thread_ptr = get_current_thread_ptr_for_domain (domain, internal);

        if (!*current_thread_ptr) {
                g_assert (domain != mono_get_root_domain ());
                *current_thread_ptr = create_thread_object (domain, internal);
        }
        return *current_thread_ptr;
#endif
}

static MonoThreadObjectHandle
mono_thread_current_handle (void)
{
        return MONO_HANDLE_NEW (MonoThreadObject, mono_thread_current ());
}

/* Return the thread object belonging to INTERNAL in the current domain */
static MonoThread *
mono_thread_current_for_thread (MonoInternalThread *internal)
{
#ifdef ENABLE_NETCORE
        return mono_thread_internal_current ();
#else
        MonoDomain *domain = mono_domain_get ();
        MonoThread **current_thread_ptr;

        g_assert (internal);
        current_thread_ptr = get_current_thread_ptr_for_domain (domain, internal);

        if (!*current_thread_ptr) {
                g_assert (domain != mono_get_root_domain ());
                *current_thread_ptr = create_thread_object (domain, internal);
        }
        return *current_thread_ptr;
#endif
}

MonoInternalThread*
mono_thread_internal_current (void)
{
        MonoInternalThread *res = GET_CURRENT_OBJECT ();
        THREAD_DEBUG (g_message ("%s: returning %p", __func__, res));
        return res;
}

MonoInternalThreadHandle
mono_thread_internal_current_handle (void)
{
        return MONO_HANDLE_NEW (MonoInternalThread, mono_thread_internal_current ());
}

static MonoThreadInfoWaitRet
mono_join_uninterrupted (MonoThreadHandle* thread_to_join, gint32 ms, MonoError *error)
{
        MonoThreadInfoWaitRet ret;
        gint32 wait = ms;

        const gint64 start = (ms == -1) ? 0 : mono_msec_ticks ();
        while (TRUE) {
                MONO_ENTER_GC_SAFE;
                ret = mono_thread_info_wait_one_handle (thread_to_join, wait, TRUE);
                MONO_EXIT_GC_SAFE;

                if (ret != MONO_THREAD_INFO_WAIT_RET_ALERTED)
                        return ret;

                MonoException *exc = mono_thread_execute_interruption_ptr ();
                if (exc) {
                        mono_error_set_exception_instance (error, exc);
                        return ret;
                }

                if (ms == -1)
                        continue;

                /* Re-calculate ms according to the time passed */
                const gint32 diff_ms = (gint32)(mono_msec_ticks () - start);
                if (diff_ms >= ms) {
                        ret = MONO_THREAD_INFO_WAIT_RET_TIMEOUT;
                        return ret;
                }
                wait = ms - diff_ms;
        }

        return ret;
}

MonoBoolean
ves_icall_System_Threading_Thread_Join_internal (MonoThreadObjectHandle thread_handle, int ms, MonoError *error)
{
        if (mono_thread_current_check_pending_interrupt ())
                return FALSE;

        // Internal threads are pinned so shallow coop/handle.
        MonoInternalThread * const thread = thread_handle_to_internal_ptr (thread_handle);
        MonoThreadHandle *handle = thread->handle;
        MonoInternalThread *cur_thread = mono_thread_internal_current ();
        gboolean ret = FALSE;

        LOCK_THREAD (thread);
        
        if ((thread->state & ThreadState_Unstarted) != 0) {
                UNLOCK_THREAD (thread);
                
                mono_error_set_exception_thread_state (error, "Thread has not been started.");
                return FALSE;
        }

        UNLOCK_THREAD (thread);

        if (ms == -1)
                ms = MONO_INFINITE_WAIT;
        THREAD_DEBUG (g_message ("%s: joining thread handle %p, %d ms", __func__, handle, ms));

        mono_thread_set_state (cur_thread, ThreadState_WaitSleepJoin);

        ret = mono_join_uninterrupted (handle, ms, error);

        mono_thread_clr_state (cur_thread, ThreadState_WaitSleepJoin);

        if (ret == MONO_THREAD_INFO_WAIT_RET_SUCCESS_0) {
                THREAD_DEBUG (g_message ("%s: join successful", __func__));

                mono_error_assert_ok (error);

                /* Wait for the thread to really exit */
                MonoNativeThreadId tid = thread_get_tid (thread);
                mono_thread_join ((gpointer)(gsize)tid);

                return TRUE;
        }
        
        THREAD_DEBUG (g_message ("%s: join failed", __func__));

        return FALSE;
}

#define MANAGED_WAIT_FAILED 0x7fffffff

static gint32
map_native_wait_result_to_managed (MonoW32HandleWaitRet val, gsize numobjects)
{
        if (val >= MONO_W32HANDLE_WAIT_RET_SUCCESS_0 && val < MONO_W32HANDLE_WAIT_RET_SUCCESS_0 + numobjects) {
                return WAIT_OBJECT_0 + (val - MONO_W32HANDLE_WAIT_RET_SUCCESS_0);
        } else if (val >= MONO_W32HANDLE_WAIT_RET_ABANDONED_0 && val < MONO_W32HANDLE_WAIT_RET_ABANDONED_0 + numobjects) {
                return WAIT_ABANDONED_0 + (val - MONO_W32HANDLE_WAIT_RET_ABANDONED_0);
        } else if (val == MONO_W32HANDLE_WAIT_RET_ALERTED) {
                return WAIT_IO_COMPLETION;
        } else if (val == MONO_W32HANDLE_WAIT_RET_TIMEOUT) {
                return WAIT_TIMEOUT;
        } else if (val == MONO_W32HANDLE_WAIT_RET_TOO_MANY_POSTS) {
                return WAIT_TOO_MANY_POSTS;
        } else if (val == MONO_W32HANDLE_WAIT_RET_NOT_OWNED_BY_CALLER) {
                return WAIT_NOT_OWNED_BY_CALLER;
        } else if (val == MONO_W32HANDLE_WAIT_RET_FAILED) {
                /* WAIT_FAILED in waithandle.cs is different from WAIT_FAILED in Win32 API */
                return MANAGED_WAIT_FAILED;
        } else {
                g_error ("%s: unknown val value %d", __func__, val);
        }
}

gint32
ves_icall_System_Threading_WaitHandle_Wait_internal (gpointer *handles, gint32 numhandles, MonoBoolean waitall, gint32 timeout, MonoError *error)
{
        /* Do this WaitSleepJoin check before creating objects */
        if (mono_thread_current_check_pending_interrupt ())
                return map_native_wait_result_to_managed (MONO_W32HANDLE_WAIT_RET_FAILED, 0);

        MonoInternalThread * const thread = mono_thread_internal_current ();

        mono_thread_set_state (thread, ThreadState_WaitSleepJoin);

        gint64 start = 0;

        if (timeout == -1)
                timeout = MONO_INFINITE_WAIT;
        if (timeout != MONO_INFINITE_WAIT)
                start = mono_msec_ticks ();

        guint32 timeoutLeft = timeout;

        MonoW32HandleWaitRet ret;

        HANDLE_LOOP_PREPARE;

        for (;;) {

                /* mono_w32handle_wait_multiple optimizes the case for numhandles == 1 */
                ret = mono_w32handle_wait_multiple (handles, numhandles, waitall, timeoutLeft, TRUE, error);

                if (ret != MONO_W32HANDLE_WAIT_RET_ALERTED)
                        break;

                SETUP_ICALL_FRAME;

                MonoExceptionHandle exc = MONO_HANDLE_NEW (MonoException, NULL);

                const gboolean interrupt = mono_thread_execute_interruption (&exc);

                if (interrupt)
                        mono_error_set_exception_handle (error, exc);

                CLEAR_ICALL_FRAME;

                if (interrupt)
                        break;

                if (timeout != MONO_INFINITE_WAIT) {
                        gint64 const elapsed = mono_msec_ticks () - start;
                        if (elapsed >= timeout) {
                                ret = MONO_W32HANDLE_WAIT_RET_TIMEOUT;
                                break;
                        }

                        timeoutLeft = timeout - elapsed;
                }
        }

        mono_thread_clr_state (thread, ThreadState_WaitSleepJoin);

        return map_native_wait_result_to_managed (ret, numhandles);
}

#if HAVE_API_SUPPORT_WIN32_SIGNAL_OBJECT_AND_WAIT
gint32
ves_icall_System_Threading_WaitHandle_SignalAndWait_Internal (gpointer toSignal, gpointer toWait, gint32 ms, MonoError *error)
{
        MonoW32HandleWaitRet ret;
        MonoInternalThread *thread = mono_thread_internal_current ();

        if (ms == -1)
                ms = MONO_INFINITE_WAIT;

        if (mono_thread_current_check_pending_interrupt ())
                return map_native_wait_result_to_managed (MONO_W32HANDLE_WAIT_RET_FAILED, 0);

        mono_thread_set_state (thread, ThreadState_WaitSleepJoin);
        
        ret = mono_w32handle_signal_and_wait (toSignal, toWait, ms, TRUE);
        
        mono_thread_clr_state (thread, ThreadState_WaitSleepJoin);

        return map_native_wait_result_to_managed (ret, 1);
}

#endif

gint32 ves_icall_System_Threading_Interlocked_Increment_Int (gint32 *location)
{
        return mono_atomic_inc_i32 (location);
}

gint64 ves_icall_System_Threading_Interlocked_Increment_Long (gint64 *location)
{
#if SIZEOF_VOID_P == 4
        if (G_UNLIKELY ((size_t)location & 0x7)) {
                gint64 ret;
                mono_interlocked_lock ();
                (*location)++;
                ret = *location;
                mono_interlocked_unlock ();
                return ret;
        }
#endif
        return mono_atomic_inc_i64 (location);
}

gint32 ves_icall_System_Threading_Interlocked_Decrement_Int (gint32 *location)
{
        return mono_atomic_dec_i32(location);
}

gint64 ves_icall_System_Threading_Interlocked_Decrement_Long (gint64 * location)
{
#if SIZEOF_VOID_P == 4
        if (G_UNLIKELY ((size_t)location & 0x7)) {
                gint64 ret;
                mono_interlocked_lock ();
                (*location)--;
                ret = *location;
                mono_interlocked_unlock ();
                return ret;
        }
#endif
        return mono_atomic_dec_i64 (location);
}

gint32 ves_icall_System_Threading_Interlocked_Exchange_Int (gint32 *location, gint32 value)
{
        return mono_atomic_xchg_i32(location, value);
}

void
ves_icall_System_Threading_Interlocked_Exchange_Object (MonoObject *volatile*location, MonoObject *volatile*value, MonoObject *volatile*res)
{
        // Coop-equivalency here via pointers to pointers.
        // value and res are to managed frames, location ought to be (or member or global) but it cannot be guaranteed.
        //
        // This also handles generic T case, T constrained to a class.
        //
        // This is not entirely convincing due to lack of volatile in the caller, however coop also
        // presently breaks identity of location and would therefore never work.
        //
        *res = (MonoObject*)mono_atomic_xchg_ptr ((volatile gpointer*)location, *value);
        mono_gc_wbarrier_generic_nostore_internal ((gpointer)location); // FIXME volatile
}

gpointer ves_icall_System_Threading_Interlocked_Exchange_IntPtr (gpointer *location, gpointer value)
{
        return mono_atomic_xchg_ptr(location, value);
}

gfloat ves_icall_System_Threading_Interlocked_Exchange_Single (gfloat *location, gfloat value)
{
        IntFloatUnion val, ret;

        val.fval = value;
        ret.ival = mono_atomic_xchg_i32((gint32 *) location, val.ival);

        return ret.fval;
}

gint64 
ves_icall_System_Threading_Interlocked_Exchange_Long (gint64 *location, gint64 value)
{
#if SIZEOF_VOID_P == 4
        if (G_UNLIKELY ((size_t)location & 0x7)) {
                gint64 ret;
                mono_interlocked_lock ();
                ret = *location;
                *location = value;
                mono_interlocked_unlock ();
                return ret;
        }
#endif
        return mono_atomic_xchg_i64 (location, value);
}

gdouble 
ves_icall_System_Threading_Interlocked_Exchange_Double (gdouble *location, gdouble value)
{
        LongDoubleUnion val, ret;

        val.fval = value;
        ret.ival = (gint64)mono_atomic_xchg_i64((gint64 *) location, val.ival);

        return ret.fval;
}

gint32 ves_icall_System_Threading_Interlocked_CompareExchange_Int(gint32 *location, gint32 value, gint32 comparand)
{
        return mono_atomic_cas_i32(location, value, comparand);
}

gint32 ves_icall_System_Threading_Interlocked_CompareExchange_Int_Success(gint32 *location, gint32 value, gint32 comparand, MonoBoolean *success)
{
        gint32 r = mono_atomic_cas_i32(location, value, comparand);
        *success = r == comparand;
        return r;
}

void
ves_icall_System_Threading_Interlocked_CompareExchange_Object (MonoObject *volatile*location, MonoObject *volatile*value, MonoObject *volatile*comparand, MonoObject *volatile* res)
{
        // Coop-equivalency here via pointers to pointers.
        // value and comparand and res are to managed frames, location ought to be (or member or global) but it cannot be guaranteed.
        //
        // This also handles generic T case, T constrained to a class.
        //
        // This is not entirely convincing due to lack of volatile in the caller, however coop also
        // presently breaks identity of location and would therefore never work.
        //
        *res = (MonoObject*)mono_atomic_cas_ptr ((volatile gpointer*)location, *value, *comparand);
        mono_gc_wbarrier_generic_nostore_internal ((gpointer)location); // FIXME volatile
}

gpointer ves_icall_System_Threading_Interlocked_CompareExchange_IntPtr(gpointer *location, gpointer value, gpointer comparand)
{
        return mono_atomic_cas_ptr(location, value, comparand);
}

gfloat ves_icall_System_Threading_Interlocked_CompareExchange_Single (gfloat *location, gfloat value, gfloat comparand)
{
        IntFloatUnion val, ret, cmp;

        val.fval = value;
        cmp.fval = comparand;
        ret.ival = mono_atomic_cas_i32((gint32 *) location, val.ival, cmp.ival);

        return ret.fval;
}

gdouble
ves_icall_System_Threading_Interlocked_CompareExchange_Double (gdouble *location, gdouble value, gdouble comparand)
{
#if SIZEOF_VOID_P == 8
        LongDoubleUnion val, comp, ret;

        val.fval = value;
        comp.fval = comparand;
        ret.ival = (gint64)mono_atomic_cas_ptr((gpointer *) location, (gpointer)val.ival, (gpointer)comp.ival);

        return ret.fval;
#else
        gdouble old;

        mono_interlocked_lock ();
        old = *location;
        if (old == comparand)
                *location = value;
        mono_interlocked_unlock ();

        return old;
#endif
}

gint64 
ves_icall_System_Threading_Interlocked_CompareExchange_Long (gint64 *location, gint64 value, gint64 comparand)
{
#if SIZEOF_VOID_P == 4
        if (G_UNLIKELY ((size_t)location & 0x7)) {
                gint64 old;
                mono_interlocked_lock ();
                old = *location;
                if (old == comparand)
                        *location = value;
                mono_interlocked_unlock ();
                return old;
        }
#endif
        return mono_atomic_cas_i64 (location, value, comparand);
}

gint32 
ves_icall_System_Threading_Interlocked_Add_Int (gint32 *location, gint32 value)
{
        return mono_atomic_add_i32 (location, value);
}

gint64 
ves_icall_System_Threading_Interlocked_Add_Long (gint64 *location, gint64 value)
{
#if SIZEOF_VOID_P == 4
        if (G_UNLIKELY ((size_t)location & 0x7)) {
                gint64 ret;
                mono_interlocked_lock ();
                *location += value;
                ret = *location;
                mono_interlocked_unlock ();
                return ret;
        }
#endif
        return mono_atomic_add_i64 (location, value);
}

gint64 
ves_icall_System_Threading_Interlocked_Read_Long (gint64 *location)
{
#if SIZEOF_VOID_P == 4
        if (G_UNLIKELY ((size_t)location & 0x7)) {
                gint64 ret;
                mono_interlocked_lock ();
                ret = *location;
                mono_interlocked_unlock ();
                return ret;
        }
#endif
        return mono_atomic_load_i64 (location);
}

void
ves_icall_System_Threading_Interlocked_MemoryBarrierProcessWide (void)
{
        mono_memory_barrier_process_wide ();
}

void
ves_icall_System_Threading_Thread_MemoryBarrier (void)
{
        mono_memory_barrier ();
}

void
ves_icall_System_Threading_Thread_ClrState (MonoInternalThreadHandle this_obj, guint32 state, MonoError *error)
{
        // InternalThreads are always pinned, so shallowly coop-handleize.
        mono_thread_clr_state (mono_internal_thread_handle_ptr (this_obj), (MonoThreadState)state);
}

void
ves_icall_System_Threading_Thread_SetState (MonoInternalThreadHandle thread_handle, guint32 state, MonoError *error)
{
        // InternalThreads are always pinned, so shallowly coop-handleize.
        mono_thread_set_state (mono_internal_thread_handle_ptr (thread_handle), (MonoThreadState)state);
}

guint32
ves_icall_System_Threading_Thread_GetState (MonoInternalThreadHandle thread_handle, MonoError *error)
{
        // InternalThreads are always pinned, so shallowly coop-handleize.
        MonoInternalThread *this_obj = mono_internal_thread_handle_ptr (thread_handle);

        guint32 state;

        LOCK_THREAD (this_obj);
        
        state = this_obj->state;

        UNLOCK_THREAD (this_obj);
        
        return state;
}

void
ves_icall_System_Threading_Thread_Interrupt_internal (MonoThreadObjectHandle thread_handle, MonoError *error)
{
        // Internal threads are pinned so shallow coop/handle.
        MonoInternalThread * const thread = thread_handle_to_internal_ptr (thread_handle);
        MonoInternalThread * const current = mono_thread_internal_current ();

        LOCK_THREAD (thread);

        thread->thread_interrupt_requested = TRUE;
        gboolean const throw_ = current != thread && (thread->state & ThreadState_WaitSleepJoin);

        UNLOCK_THREAD (thread);

        if (throw_)
                async_abort_internal (thread, FALSE);
}

/**
 * mono_thread_current_check_pending_interrupt:
 * Checks if there's a interruption request and set the pending exception if so.
 * \returns true if a pending exception was set
 */
gboolean
mono_thread_current_check_pending_interrupt (void)
{
        MonoInternalThread *thread = mono_thread_internal_current ();
        gboolean throw_ = FALSE;

        LOCK_THREAD (thread);
        
        if (thread->thread_interrupt_requested) {
                throw_ = TRUE;
                thread->thread_interrupt_requested = FALSE;
        }
        
        UNLOCK_THREAD (thread);

        if (throw_) {
                ERROR_DECL (error);
                mono_error_set_thread_interrupted (error);
                mono_error_set_pending_exception (error);
        }
        return throw_;
}

static gboolean
request_thread_abort (MonoInternalThread *thread, MonoObjectHandle *state, gboolean appdomain_unload)
// state is a pointer to a handle in order to be optional,
// and be passed unspecified from functions not using handles.
// When raw pointers is gone, it need not be a pointer,
// though this would still work efficiently.
{
        LOCK_THREAD (thread);

        /* With self abort we always throw a new exception */
        if (thread == mono_thread_internal_current ())
                thread->abort_exc = NULL;

        if (thread->state & (ThreadState_AbortRequested | ThreadState_Stopped))
        {
                UNLOCK_THREAD (thread);
                return FALSE;
        }

        if ((thread->state & ThreadState_Unstarted) != 0) {
                thread->state |= ThreadState_Aborted;
                UNLOCK_THREAD (thread);
                return FALSE;
        }

        thread->state |= ThreadState_AbortRequested;
        if (appdomain_unload)
                thread->flags |= MONO_THREAD_FLAG_APPDOMAIN_ABORT;
        else
                thread->flags &= ~MONO_THREAD_FLAG_APPDOMAIN_ABORT;

        mono_gchandle_free_internal (thread->abort_state_handle);
        thread->abort_state_handle = 0;


        if (state && !MONO_HANDLE_IS_NULL (*state)) {
                thread->abort_state_handle = mono_gchandle_from_handle (*state, FALSE);
                g_assert (thread->abort_state_handle);
        }

        thread->abort_exc = NULL;

        THREAD_DEBUG (g_message ("%s: (%" G_GSIZE_FORMAT ") Abort requested for %p (%" G_GSIZE_FORMAT ")", __func__, mono_native_thread_id_get (), thread, (gsize)thread->tid));

        /* During shutdown, we can't wait for other threads */
        if (!shutting_down)
                /* Make sure the thread is awake */
                mono_thread_resume (thread);

        UNLOCK_THREAD (thread);
        return TRUE;
}

#ifndef ENABLE_NETCORE
void
ves_icall_System_Threading_Thread_Abort (MonoInternalThreadHandle thread_handle, MonoObjectHandle state, MonoError *error)
{
        // InternalThreads are always pinned, so shallowly coop-handleize.
        MonoInternalThread * const thread = mono_internal_thread_handle_ptr (thread_handle);
        gboolean is_self = thread == mono_thread_internal_current ();

        /* For self aborts we always process the abort */
        if (!request_thread_abort (thread, &state, FALSE) && !is_self)
                return;

        if (is_self) {
                self_abort_internal (error);
        } else {
                async_abort_internal (thread, TRUE);
        }
}
#endif

/**
 * mono_thread_internal_abort:
 * Request thread \p thread to be aborted.
 * \p thread MUST NOT be the current thread.
 */
void
mono_thread_internal_abort (MonoInternalThread *thread, gboolean appdomain_unload)
{
        g_assert (thread != mono_thread_internal_current ());

        if (!request_thread_abort (thread, NULL, appdomain_unload))
                return;
        async_abort_internal (thread, TRUE);
}

#ifndef ENABLE_NETCORE
void
ves_icall_System_Threading_Thread_ResetAbort (MonoThreadObjectHandle this_obj, MonoError *error)
{
        MonoInternalThread *thread = mono_thread_internal_current ();
        gboolean was_aborting, is_domain_abort;

        LOCK_THREAD (thread);
        was_aborting = thread->state & ThreadState_AbortRequested;
        is_domain_abort = thread->flags & MONO_THREAD_FLAG_APPDOMAIN_ABORT;

        if (was_aborting && !is_domain_abort)
                thread->state &= ~ThreadState_AbortRequested;
        UNLOCK_THREAD (thread);

        if (!was_aborting) {
                mono_error_set_exception_thread_state (error, "Unable to reset abort because no abort was requested");
                return;
        } else if (is_domain_abort) {
                /* Silently ignore abort resets in unloading appdomains */
                return;
        }

        mono_get_eh_callbacks ()->mono_clear_abort_threshold ();
        thread->abort_exc = NULL;
        mono_gchandle_free_internal (thread->abort_state_handle);
        /* This is actually not necessary - the handle
           only counts if the exception is set */
        thread->abort_state_handle = 0;
}
#endif

void
mono_thread_internal_reset_abort (MonoInternalThread *thread)
{
        LOCK_THREAD (thread);

        thread->state &= ~ThreadState_AbortRequested;

        if (thread->abort_exc) {
                mono_get_eh_callbacks ()->mono_clear_abort_threshold ();
                thread->abort_exc = NULL;
                mono_gchandle_free_internal (thread->abort_state_handle);
                /* This is actually not necessary - the handle
                   only counts if the exception is set */
                thread->abort_state_handle = 0;
        }

        UNLOCK_THREAD (thread);
}

#ifndef ENABLE_NETCORE
MonoObjectHandle
ves_icall_System_Threading_Thread_GetAbortExceptionState (MonoThreadObjectHandle this_obj, MonoError *error)
{
        MonoInternalThread *thread = thread_handle_to_internal_ptr (this_obj);

        if (!thread->abort_state_handle)
                return NULL_HANDLE; // No state. No error.

        // Convert gc handle to coop handle.
        MonoObjectHandle state = mono_gchandle_get_target_handle (thread->abort_state_handle);
        g_assert (MONO_HANDLE_BOOL (state));

        MonoDomain *domain = mono_domain_get ();
        if (MONO_HANDLE_DOMAIN (state) == domain)
                return state; // No need to cross domain, return state directly.

        // Attempt move state cross-domain.
        MonoObjectHandle deserialized = mono_object_xdomain_representation (state, domain, error);

        // If deserialized is null, there must be an error, and vice versa.
        g_assert (is_ok (error) == MONO_HANDLE_BOOL (deserialized));

        if (MONO_HANDLE_BOOL (deserialized))
                return deserialized; // Cross-domain serialization succeeded. Return it.

        // Wrap error in InvalidOperationException.
        ERROR_DECL (error_creating_exception);
        MonoExceptionHandle invalid_op_exc = mono_exception_new_invalid_operation (
                "Thread.ExceptionState cannot access an ExceptionState from a different AppDomain", error_creating_exception);
        mono_error_assert_ok (error_creating_exception);
        g_assert (!is_ok (error) && 1);
        MONO_HANDLE_SET (invalid_op_exc, inner_ex, mono_error_convert_to_exception_handle (error));
        error_init_reuse (error);
        mono_error_set_exception_handle (error, invalid_op_exc);
        g_assert (!is_ok (error) && 2);

        // There is state, but we failed to return it.
        return NULL_HANDLE;
}
#endif

static gboolean
mono_thread_suspend (MonoInternalThread *thread)
{
        LOCK_THREAD (thread);

        if (thread->state & (ThreadState_Unstarted | ThreadState_Aborted | ThreadState_Stopped))
        {
                UNLOCK_THREAD (thread);
                return FALSE;
        }

        if (thread->state & (ThreadState_Suspended | ThreadState_SuspendRequested | ThreadState_AbortRequested))
        {
                UNLOCK_THREAD (thread);
                return TRUE;
        }
        
        thread->state |= ThreadState_SuspendRequested;
        MONO_ENTER_GC_SAFE;
        mono_os_event_reset (thread->suspended);
        MONO_EXIT_GC_SAFE;

        if (thread == mono_thread_internal_current ()) {
                /* calls UNLOCK_THREAD (thread) */
                self_suspend_internal ();
        } else {
                /* calls UNLOCK_THREAD (thread) */
                async_suspend_internal (thread, FALSE);
        }

        return TRUE;
}

#ifndef ENABLE_NETCORE
void
ves_icall_System_Threading_Thread_Suspend (MonoThreadObjectHandle this_obj, MonoError *error)
{
        if (!mono_thread_suspend (thread_handle_to_internal_ptr (this_obj)))
                mono_error_set_exception_thread_not_started_or_dead (error);

}
#endif

/* LOCKING: LOCK_THREAD(thread) must be held */
static gboolean
mono_thread_resume (MonoInternalThread *thread)
{
        if ((thread->state & ThreadState_SuspendRequested) != 0) {
                // g_async_safe_printf ("RESUME (1) thread %p\n", thread_get_tid (thread));
                thread->state &= ~ThreadState_SuspendRequested;
                MONO_ENTER_GC_SAFE;
                mono_os_event_set (thread->suspended);
                MONO_EXIT_GC_SAFE;
                return TRUE;
        }

        if ((thread->state & ThreadState_Suspended) == 0 ||
                (thread->state & ThreadState_Unstarted) != 0 || 
                (thread->state & ThreadState_Aborted) != 0 || 
                (thread->state & ThreadState_Stopped) != 0)
        {
                // g_async_safe_printf ("RESUME (2) thread %p\n", thread_get_tid (thread));
                return FALSE;
        }

        // g_async_safe_printf ("RESUME (3) thread %p\n", thread_get_tid (thread));

        MONO_ENTER_GC_SAFE;
        mono_os_event_set (thread->suspended);
        MONO_EXIT_GC_SAFE;

        if (!thread->self_suspended) {
                UNLOCK_THREAD (thread);

                /* Awake the thread */
                if (!mono_thread_info_resume (thread_get_tid (thread)))
                        return FALSE;

                LOCK_THREAD (thread);
        }

        thread->state &= ~ThreadState_Suspended;

        return TRUE;
}

#ifndef ENABLE_NETCORE
void
ves_icall_System_Threading_Thread_Resume (MonoThreadObjectHandle thread_handle, MonoError *error)
{
        // Internal threads are pinned so shallow coop/handle.
        MonoInternalThread * const internal_thread = thread_handle_to_internal_ptr (thread_handle);
        gboolean exception = FALSE;

        if (!internal_thread) {
                exception = TRUE;
        } else {
                LOCK_THREAD (internal_thread);
                if (!mono_thread_resume (internal_thread))
                        exception = TRUE;
                UNLOCK_THREAD (internal_thread);
        }

        if (exception)
                mono_error_set_exception_thread_not_started_or_dead (error);
}
#endif

gboolean
mono_threads_is_critical_method (MonoMethod *method)
{
        switch (method->wrapper_type) {
        case MONO_WRAPPER_RUNTIME_INVOKE:
        case MONO_WRAPPER_XDOMAIN_INVOKE:
        case MONO_WRAPPER_XDOMAIN_DISPATCH:     
                return TRUE;
        }
        return FALSE;
}

static gboolean
find_wrapper (MonoMethod *m, gint no, gint ilo, gboolean managed, gpointer data)
{
        if (managed)
                return TRUE;

        if (mono_threads_is_critical_method (m)) {
                *((gboolean*)data) = TRUE;
                return TRUE;
        }
        return FALSE;
}

static gboolean 
is_running_protected_wrapper (void)
{
        gboolean found = FALSE;
        mono_stack_walk (find_wrapper, &found);
        return found;
}

/**
 * mono_thread_stop:
 */
void
mono_thread_stop (MonoThread *thread)
{
        MonoInternalThread *internal = thread->internal_thread;

        if (!request_thread_abort (internal, NULL, FALSE))
                return;

        if (internal == mono_thread_internal_current ()) {
                ERROR_DECL (error);
                self_abort_internal (error);
                /*
                This function is part of the embeding API and has no way to return the exception
                to be thrown. So what we do is keep the old behavior and raise the exception.
                */
                mono_error_raise_exception_deprecated (error); /* OK to throw, see note */
        } else {
                async_abort_internal (internal, TRUE);
        }
}

gint8
ves_icall_System_Threading_Thread_VolatileRead1 (void *ptr)
{
        gint8 tmp = *(volatile gint8 *)ptr;
        mono_memory_barrier ();
        return tmp;
}

gint16
ves_icall_System_Threading_Thread_VolatileRead2 (void *ptr)
{
        gint16 tmp = *(volatile gint16 *)ptr;
        mono_memory_barrier ();
        return tmp;
}

gint32
ves_icall_System_Threading_Thread_VolatileRead4 (void *ptr)
{
        gint32 tmp = *(volatile gint32 *)ptr;
        mono_memory_barrier ();
        return tmp;
}

gint64
ves_icall_System_Threading_Thread_VolatileRead8 (void *ptr)
{
        gint64 tmp = *(volatile gint64 *)ptr;
        mono_memory_barrier ();
        return tmp;
}

void *
ves_icall_System_Threading_Thread_VolatileReadIntPtr (void *ptr)
{
        volatile void *tmp = *(volatile void **)ptr;
        mono_memory_barrier ();
        return (void *) tmp;
}

void *
ves_icall_System_Threading_Thread_VolatileReadObject (void *ptr)
{
        volatile MonoObject *tmp = *(volatile MonoObject **)ptr;
        mono_memory_barrier ();
        return (MonoObject *) tmp;
}

double
ves_icall_System_Threading_Thread_VolatileReadDouble (void *ptr)
{
        double tmp = *(volatile double *)ptr;
        mono_memory_barrier ();
        return tmp;
}

float
ves_icall_System_Threading_Thread_VolatileReadFloat (void *ptr)
{
        float tmp = *(volatile float *)ptr;
        mono_memory_barrier ();
        return tmp;
}

gint64
ves_icall_System_Threading_Volatile_Read8 (void *ptr)
{
#if SIZEOF_VOID_P == 4
        if (G_UNLIKELY ((size_t)ptr & 0x7)) {
                gint64 val;
                mono_interlocked_lock ();
                val = *(gint64*)ptr;
                mono_interlocked_unlock ();
                return val;
        }
#endif
        return mono_atomic_load_i64 ((volatile gint64 *)ptr);
}

guint64
ves_icall_System_Threading_Volatile_ReadU8 (void *ptr)
{
#if SIZEOF_VOID_P == 4
        if (G_UNLIKELY ((size_t)ptr & 0x7)) {
                guint64 val;
                mono_interlocked_lock ();
                val = *(guint64*)ptr;
                mono_interlocked_unlock ();
                return val;
        }
#endif
        return (guint64)mono_atomic_load_i64 ((volatile gint64 *)ptr);
}

double
ves_icall_System_Threading_Volatile_ReadDouble (void *ptr)
{
        LongDoubleUnion u;

#if SIZEOF_VOID_P == 4
        if (G_UNLIKELY ((size_t)ptr & 0x7)) {
                double val;
                mono_interlocked_lock ();
                val = *(double*)ptr;
                mono_interlocked_unlock ();
                return val;
        }
#endif

        u.ival = mono_atomic_load_i64 ((volatile gint64 *)ptr);

        return u.fval;
}

void
ves_icall_System_Threading_Thread_VolatileWrite1 (void *ptr, gint8 value)
{
        mono_memory_barrier ();
        *(volatile gint8 *)ptr = value;
}

void
ves_icall_System_Threading_Thread_VolatileWrite2 (void *ptr, gint16 value)
{
        mono_memory_barrier ();
        *(volatile gint16 *)ptr = value;
}

void
ves_icall_System_Threading_Thread_VolatileWrite4 (void *ptr, gint32 value)
{
        mono_memory_barrier ();
        *(volatile gint32 *)ptr = value;
}

void
ves_icall_System_Threading_Thread_VolatileWrite8 (void *ptr, gint64 value)
{
        mono_memory_barrier ();
        *(volatile gint64 *)ptr = value;
}

void
ves_icall_System_Threading_Thread_VolatileWriteIntPtr (void *ptr, void *value)
{
        mono_memory_barrier ();
        *(volatile void **)ptr = value;
}

void
ves_icall_System_Threading_Thread_VolatileWriteObject (void *ptr, MonoObject *value)
{
        mono_memory_barrier ();
        mono_gc_wbarrier_generic_store_internal (ptr, value);
}

void
ves_icall_System_Threading_Thread_VolatileWriteDouble (void *ptr, double value)
{
        mono_memory_barrier ();
        *(volatile double *)ptr = value;
}

void
ves_icall_System_Threading_Thread_VolatileWriteFloat (void *ptr, float value)
{
        mono_memory_barrier ();
        *(volatile float *)ptr = value;
}

void
ves_icall_System_Threading_Volatile_Write8 (void *ptr, gint64 value)
{
#if SIZEOF_VOID_P == 4
        if (G_UNLIKELY ((size_t)ptr & 0x7)) {
                mono_interlocked_lock ();
                *(gint64*)ptr = value;
                mono_interlocked_unlock ();
                return;
        }
#endif

        mono_atomic_store_i64 ((volatile gint64 *)ptr, value);
}

void
ves_icall_System_Threading_Volatile_WriteU8 (void *ptr, guint64 value)
{
#if SIZEOF_VOID_P == 4
        if (G_UNLIKELY ((size_t)ptr & 0x7)) {
                mono_interlocked_lock ();
                *(guint64*)ptr = value;
                mono_interlocked_unlock ();
                return;
        }
#endif

        mono_atomic_store_i64 ((volatile gint64 *)ptr, (gint64)value);
}

void
ves_icall_System_Threading_Volatile_WriteDouble (void *ptr, double value)
{
        LongDoubleUnion u;

#if SIZEOF_VOID_P == 4
        if (G_UNLIKELY ((size_t)ptr & 0x7)) {
                mono_interlocked_lock ();
                *(double*)ptr = value;
                mono_interlocked_unlock ();
                return;
        }
#endif

        u.fval = value;

        mono_atomic_store_i64 ((volatile gint64 *)ptr, u.ival);
}

static void
free_context (void *user_data)
{
        ContextStaticData *data = (ContextStaticData*)user_data;

        mono_threads_lock ();

        /*
         * There is no guarantee that, by the point this reference queue callback
         * has been invoked, the GC handle associated with the object will fail to
         * resolve as one might expect. So if we don't free and remove the GC
         * handle here, free_context_static_data_helper () could end up resolving
         * a GC handle to an actually-dead context which would contain a pointer
         * to an already-freed static data segment, resulting in a crash when
         * accessing it.
         */
        g_hash_table_remove (contexts, GUINT_TO_POINTER (data->gc_handle));

        mono_threads_unlock ();

        mono_gchandle_free_internal (data->gc_handle);
        mono_free_static_data (data->static_data);
        g_free (data);
}

void
mono_threads_register_app_context (MonoAppContextHandle ctx, MonoError *error)
{
        error_init (error);
        mono_threads_lock ();

        //g_print ("Registering context %d in domain %d\n", ctx->context_id, ctx->domain_id);

        if (!contexts)
                contexts = g_hash_table_new (NULL, NULL);

        if (!context_queue)
                context_queue = mono_gc_reference_queue_new_internal (free_context);

        gpointer gch = GUINT_TO_POINTER (mono_gchandle_new_weakref_from_handle (MONO_HANDLE_CAST (MonoObject, ctx)));
        g_hash_table_insert (contexts, gch, gch);

        /*
         * We use this intermediate structure to contain a duplicate pointer to
         * the static data because we can't rely on being able to resolve the GC
         * handle in the reference queue callback.
         */
        ContextStaticData *data = g_new0 (ContextStaticData, 1);
        data->gc_handle = GPOINTER_TO_UINT (gch);
        MONO_HANDLE_SETVAL (ctx, data, ContextStaticData*, data);

        context_adjust_static_data (ctx);
        mono_gc_reference_queue_add_handle (context_queue, ctx, data);

        mono_threads_unlock ();

        MONO_PROFILER_RAISE (context_loaded, (MONO_HANDLE_RAW (ctx)));
}

#ifndef ENABLE_NETCORE
void
ves_icall_System_Runtime_Remoting_Contexts_Context_RegisterContext (MonoAppContextHandle ctx, MonoError *error)
{
        mono_threads_register_app_context (ctx, error);
}
#endif

void
mono_threads_release_app_context (MonoAppContext* ctx, MonoError *error)
{
        /*
         * NOTE: Since finalizers are unreliable for the purposes of ensuring
         * cleanup in exceptional circumstances, we don't actually do any
         * cleanup work here. We instead do this via a reference queue.
         */

        //g_print ("Releasing context %d in domain %d\n", ctx->context_id, ctx->domain_id);

        MONO_PROFILER_RAISE (context_unloaded, (ctx));
}

#ifndef ENABLE_NETCORE
void
ves_icall_System_Runtime_Remoting_Contexts_Context_ReleaseContext (MonoAppContextHandle ctx, MonoError *error)
{
        mono_threads_release_app_context (MONO_HANDLE_RAW (ctx), error); /* FIXME use handles in mono_threads_release_app_context */
}
#endif

void mono_thread_init (MonoThreadStartCB start_cb,
                       MonoThreadAttachCB attach_cb)
{
        mono_coop_mutex_init_recursive (&threads_mutex);

#if SIZEOF_VOID_P == 4
        mono_os_mutex_init (&interlocked_mutex);
#endif
        mono_coop_mutex_init_recursive(&joinable_threads_mutex);

        mono_os_event_init (&background_change_event, FALSE);
        
        mono_coop_cond_init (&pending_native_thread_join_calls_event);
        mono_coop_cond_init (&zero_pending_joinable_thread_event);

        mono_init_static_data_info (&thread_static_info);
        mono_init_static_data_info (&context_static_info);

        mono_thread_start_cb = start_cb;
        mono_thread_attach_cb = attach_cb;

}

static gpointer
thread_attach (MonoThreadInfo *info)
{
        return mono_gc_thread_attach (info);
}

static void
thread_detach (MonoThreadInfo *info)
{
        MonoInternalThread *internal;
        guint32 gchandle;

        /* If a delegate is passed to native code and invoked on a thread we dont
         * know about, marshal will register it with mono_threads_attach_coop, but
         * we have no way of knowing when that thread goes away.  SGen has a TSD
         * so we assume that if the domain is still registered, we can detach
         * the thread */

        g_assert (info);
        g_assert (mono_thread_info_is_current (info));

        if (!mono_thread_info_try_get_internal_thread_gchandle (info, &gchandle))
                return;

        internal = (MonoInternalThread*) mono_gchandle_get_target_internal (gchandle);
        g_assert (internal);

        mono_thread_detach_internal (internal);

        mono_gc_thread_detach (info);
}

static void
thread_detach_with_lock (MonoThreadInfo *info)
{
        mono_gc_thread_detach_with_lock (info);
}

static gboolean
thread_in_critical_region (MonoThreadInfo *info)
{
        return mono_gc_thread_in_critical_region (info);
}

static gboolean
ip_in_critical_region (MonoDomain *domain, gpointer ip)
{
        MonoJitInfo *ji;
        MonoMethod *method;

        /*
         * We pass false for 'try_aot' so this becomes async safe.
         * It won't find aot methods whose jit info is not yet loaded,
         * so we preload their jit info in the JIT.
         */
        ji = mono_jit_info_table_find_internal (domain, ip, FALSE, FALSE);
        if (!ji)
                return FALSE;

        method = mono_jit_info_get_method (ji);
        g_assert (method);

        return mono_gc_is_critical_method (method);
}

static void
thread_flags_changing (MonoThreadInfoFlags old, MonoThreadInfoFlags new_)
{
        mono_gc_skip_thread_changing (!!(new_ & MONO_THREAD_INFO_FLAGS_NO_GC));
}

static void
thread_flags_changed (MonoThreadInfoFlags old, MonoThreadInfoFlags new_)
{
        mono_gc_skip_thread_changed (!!(new_ & MONO_THREAD_INFO_FLAGS_NO_GC));
}

void
mono_thread_callbacks_init (void)
{
        MonoThreadInfoCallbacks cb;

        memset (&cb, 0, sizeof(cb));
        cb.thread_attach = thread_attach;
        cb.thread_detach = thread_detach;
        cb.thread_detach_with_lock = thread_detach_with_lock;
        cb.ip_in_critical_region = ip_in_critical_region;
        cb.thread_in_critical_region = thread_in_critical_region;
        cb.thread_flags_changing = thread_flags_changing;
        cb.thread_flags_changed = thread_flags_changed;
        mono_thread_info_callbacks_init (&cb);
}

/**
 * mono_thread_cleanup:
 */
void
mono_thread_cleanup (void)
{
        /* Wait for pending threads to park on joinable threads list */
        /* NOTE, waiting on this should be extremely rare and will only happen */
        /* under certain specific conditions. */
        gboolean wait_result = threads_wait_pending_joinable_threads (2000);
        if (!wait_result)
                g_warning ("Waiting on threads to park on joinable thread list timed out.");

        mono_threads_join_threads ();

#if !defined(HOST_WIN32)
        /* The main thread must abandon any held mutexes (particularly
         * important for named mutexes as they are shared across
         * processes, see bug 74680.)  This will happen when the
         * thread exits, but if it's not running in a subthread it
         * won't exit in time.
         */
        if (!mono_runtime_get_no_exec ())
                mono_w32mutex_abandon (mono_thread_internal_current ());
#endif

#if 0
        /* This stuff needs more testing, it seems one of these
         * critical sections can be locked when mono_thread_cleanup is
         * called.
         */
        mono_coop_mutex_destroy (&threads_mutex);
        mono_os_mutex_destroy (&interlocked_mutex);
        mono_os_mutex_destroy (&delayed_free_table_mutex);
        mono_os_mutex_destroy (&small_id_mutex);
        mono_coop_cond_destroy (&zero_pending_joinable_thread_event);
        mono_coop_cond_destroy (&pending_native_thread_join_calls_event);
        mono_os_event_destroy (&background_change_event);
#endif
}

void
mono_threads_install_cleanup (MonoThreadCleanupFunc func)
{
        mono_thread_cleanup_fn = func;
}

/**
 * mono_thread_set_manage_callback:
 */
void
mono_thread_set_manage_callback (MonoThread *thread, MonoThreadManageCallback func)
{
        thread->internal_thread->manage_callback = func;
}

G_GNUC_UNUSED
static void print_tids (gpointer key, gpointer value, gpointer user)
{
        /* GPOINTER_TO_UINT breaks horribly if sizeof(void *) >
         * sizeof(uint) and a cast to uint would overflow
         */
        /* Older versions of glib don't have G_GSIZE_FORMAT, so just
         * print this as a pointer.
         */
        g_message ("Waiting for: %p", key);
}

struct wait_data 
{
        MonoThreadHandle *handles[MONO_W32HANDLE_MAXIMUM_WAIT_OBJECTS];
        MonoInternalThread *threads[MONO_W32HANDLE_MAXIMUM_WAIT_OBJECTS];
        guint32 num;
};

static void
wait_for_tids (struct wait_data *wait, guint32 timeout, gboolean check_state_change)
{
        guint32 i;
        MonoThreadInfoWaitRet ret;
        
        THREAD_DEBUG (g_message("%s: %d threads to wait for in this batch", __func__, wait->num));

        /* Add the thread state change event, so it wakes
         * up if a thread changes to background mode. */

        MONO_ENTER_GC_SAFE;
        if (check_state_change)
                ret = mono_thread_info_wait_multiple_handle (wait->handles, wait->num, &background_change_event, FALSE, timeout, TRUE);
        else
                ret = mono_thread_info_wait_multiple_handle (wait->handles, wait->num, NULL, TRUE, timeout, TRUE);
        MONO_EXIT_GC_SAFE;

        if (ret == MONO_THREAD_INFO_WAIT_RET_FAILED) {
                /* See the comment in build_wait_tids() */
                THREAD_DEBUG (g_message ("%s: Wait failed", __func__));
                return;
        }
        
        for( i = 0; i < wait->num; i++)
                mono_threads_close_thread_handle (wait->handles [i]);

        if (ret >= MONO_THREAD_INFO_WAIT_RET_SUCCESS_0 && ret < (MONO_THREAD_INFO_WAIT_RET_SUCCESS_0 + wait->num)) {
                MonoInternalThread *internal;

                internal = wait->threads [ret - MONO_THREAD_INFO_WAIT_RET_SUCCESS_0];

                mono_threads_lock ();
                if (mono_g_hash_table_lookup (threads, (gpointer) internal->tid) == internal)
                        g_error ("%s: failed to call mono_thread_detach_internal on thread %p, InternalThread: %p", __func__, internal->tid, internal);
                mono_threads_unlock ();
        }
}

static void build_wait_tids (gpointer key, gpointer value, gpointer user)
{
        struct wait_data *wait=(struct wait_data *)user;

        if(wait->num<MONO_W32HANDLE_MAXIMUM_WAIT_OBJECTS - 1) {
                MonoInternalThread *thread=(MonoInternalThread *)value;

                /* Ignore background threads, we abort them later */
                /* Do not lock here since it is not needed and the caller holds threads_lock */
                if (thread->state & ThreadState_Background) {
                        THREAD_DEBUG (g_message ("%s: ignoring background thread %" G_GSIZE_FORMAT, __func__, (gsize)thread->tid));
                        return; /* just leave, ignore */
                }
                
                if (mono_gc_is_finalizer_internal_thread (thread)) {
                        THREAD_DEBUG (g_message ("%s: ignoring finalizer thread %" G_GSIZE_FORMAT, __func__, (gsize)thread->tid));
                        return;
                }

                if (thread == mono_thread_internal_current ()) {
                        THREAD_DEBUG (g_message ("%s: ignoring current thread %" G_GSIZE_FORMAT, __func__, (gsize)thread->tid));
                        return;
                }

                if (mono_thread_get_main () && (thread == mono_thread_get_main ()->internal_thread)) {
                        THREAD_DEBUG (g_message ("%s: ignoring main thread %" G_GSIZE_FORMAT, __func__, (gsize)thread->tid));
                        return;
                }

                if (thread->flags & MONO_THREAD_FLAG_DONT_MANAGE) {
                        THREAD_DEBUG (g_message ("%s: ignoring thread %" G_GSIZE_FORMAT "with DONT_MANAGE flag set.", __func__, (gsize)thread->tid));
                        return;
                }

                THREAD_DEBUG (g_message ("%s: Invoking mono_thread_manage callback on thread %p", __func__, thread));
                if ((thread->manage_callback == NULL) || (thread->manage_callback (thread->root_domain_thread) == TRUE)) {
                        wait->handles[wait->num]=mono_threads_open_thread_handle (thread->handle);
                        wait->threads[wait->num]=thread;
                        wait->num++;

                        THREAD_DEBUG (g_message ("%s: adding thread %" G_GSIZE_FORMAT, __func__, (gsize)thread->tid));
                } else {
                        THREAD_DEBUG (g_message ("%s: ignoring (because of callback) thread %" G_GSIZE_FORMAT, __func__, (gsize)thread->tid));
                }
                
                
        } else {
                /* Just ignore the rest, we can't do anything with
                 * them yet
                 */
        }
}

static void
abort_threads (gpointer key, gpointer value, gpointer user)
{
        struct wait_data *wait=(struct wait_data *)user;
        MonoNativeThreadId self = mono_native_thread_id_get ();
        MonoInternalThread *thread = (MonoInternalThread *)value;

        if (wait->num >= MONO_W32HANDLE_MAXIMUM_WAIT_OBJECTS)
                return;

        if (mono_native_thread_id_equals (thread_get_tid (thread), self))
                return;
        if (mono_gc_is_finalizer_internal_thread (thread))
                return;

        if ((thread->flags & MONO_THREAD_FLAG_DONT_MANAGE))
                return;

        wait->handles[wait->num] = mono_threads_open_thread_handle (thread->handle);
        wait->threads[wait->num] = thread;
        wait->num++;

        THREAD_DEBUG (g_print ("%s: Aborting id: %" G_GSIZE_FORMAT "\n", __func__, (gsize)thread->tid));
        mono_thread_internal_abort (thread, FALSE);
}

/** 
 * mono_threads_set_shutting_down:
 *
 * Is called by a thread that wants to shut down Mono. If the runtime is already
 * shutting down, the calling thread is suspended/stopped, and this function never
 * returns.
 */
void
mono_threads_set_shutting_down (void)
{
        MonoInternalThread *current_thread = mono_thread_internal_current ();

        mono_threads_lock ();

        if (shutting_down) {
                mono_threads_unlock ();

                /* Make sure we're properly suspended/stopped */

                LOCK_THREAD (current_thread);

                if (current_thread->state & (ThreadState_SuspendRequested | ThreadState_AbortRequested)) {
                        UNLOCK_THREAD (current_thread);
                        mono_thread_execute_interruption_void ();
                } else {
                        UNLOCK_THREAD (current_thread);
                }

                /*since we're killing the thread, detach it.*/
                mono_thread_detach_internal (current_thread);

                /* Wake up other threads potentially waiting for us */
                mono_thread_info_exit (0);
        } else {
                shutting_down = TRUE;

                /* Not really a background state change, but this will
                 * interrupt the main thread if it is waiting for all
                 * the other threads.
                 */
                MONO_ENTER_GC_SAFE;
                mono_os_event_set (&background_change_event);
                MONO_EXIT_GC_SAFE;

                mono_threads_unlock ();
        }
}

/**
 * mono_thread_manage_internal:
 */
void
mono_thread_manage_internal (void)
{
        MONO_REQ_GC_UNSAFE_MODE;

        struct wait_data wait_data;
        struct wait_data *wait = &wait_data;

        memset (wait, 0, sizeof (struct wait_data));
        /* join each thread that's still running */
        THREAD_DEBUG (g_message ("%s: Joining each running thread...", __func__));
        
        mono_threads_lock ();
        if(threads==NULL) {
                THREAD_DEBUG (g_message("%s: No threads", __func__));
                mono_threads_unlock ();
                return;
        }

        mono_threads_unlock ();
        
        do {
                mono_threads_lock ();
                if (shutting_down) {
                        /* somebody else is shutting down */
                        mono_threads_unlock ();
                        break;
                }
                THREAD_DEBUG (g_message ("%s: There are %d threads to join", __func__, mono_g_hash_table_size (threads));
                        mono_g_hash_table_foreach (threads, print_tids, NULL));
        
                MONO_ENTER_GC_SAFE;
                mono_os_event_reset (&background_change_event);
                MONO_EXIT_GC_SAFE;
                wait->num=0;
                /* We must zero all InternalThread pointers to avoid making the GC unhappy. */
                memset (wait->threads, 0, sizeof (wait->threads));
                mono_g_hash_table_foreach (threads, build_wait_tids, wait);
                mono_threads_unlock ();
                if (wait->num > 0)
                        /* Something to wait for */
                        wait_for_tids (wait, MONO_INFINITE_WAIT, TRUE);
                THREAD_DEBUG (g_message ("%s: I have %d threads after waiting.", __func__, wait->num));
        } while(wait->num>0);

        /* Mono is shutting down, so just wait for the end */
        if (!mono_runtime_try_shutdown ()) {
                /*FIXME mono_thread_suspend probably should call mono_thread_execute_interruption when self interrupting. */
                mono_thread_suspend (mono_thread_internal_current ());
                mono_thread_execute_interruption_void ();
        }

#ifndef ENABLE_NETCORE
        /*
         * Under netcore, we don't abort any threads, just exit.
         * This is not a problem since we don't do runtime cleanup either.
         */
        /* 
         * Remove everything but the finalizer thread and self.
         * Also abort all the background threads
         * */
        do {
                mono_threads_lock ();

                wait->num = 0;
                /*We must zero all InternalThread pointers to avoid making the GC unhappy.*/
                memset (wait->threads, 0, sizeof (wait->threads));
                mono_g_hash_table_foreach (threads, abort_threads, wait);

                mono_threads_unlock ();

                THREAD_DEBUG (g_message ("%s: wait->num is now %d", __func__, wait->num));
                if (wait->num > 0) {
                        /* Something to wait for */
                        wait_for_tids (wait, MONO_INFINITE_WAIT, FALSE);
                }
        } while (wait->num > 0);
#endif
        
        /* 
         * give the subthreads a chance to really quit (this is mainly needed
         * to get correct user and system times from getrusage/wait/time(1)).
         * This could be removed if we avoid pthread_detach() and use pthread_join().
         */
        mono_thread_info_yield ();
}

#ifndef ENABLE_NETCORE
static void
collect_threads_for_suspend (gpointer key, gpointer value, gpointer user_data)
{
        MonoInternalThread *thread = (MonoInternalThread*)value;
        struct wait_data *wait = (struct wait_data*)user_data;

        /* 
         * We try to exclude threads early, to avoid running into the MONO_W32HANDLE_MAXIMUM_WAIT_OBJECTS
         * limitation.
         * This needs no locking.
         */
        if ((thread->state & ThreadState_Suspended) != 0 || 
                (thread->state & ThreadState_Stopped) != 0)
                return;

        if (wait->num<MONO_W32HANDLE_MAXIMUM_WAIT_OBJECTS) {
                wait->handles [wait->num] = mono_threads_open_thread_handle (thread->handle);
                wait->threads [wait->num] = thread;
                wait->num++;
        }
}

/*
 * mono_thread_suspend_all_other_threads:
 *
 *  Suspend all managed threads except the finalizer thread and this thread. It is
 * not possible to resume them later.
 */
void mono_thread_suspend_all_other_threads (void)
{
        struct wait_data wait_data;
        struct wait_data *wait = &wait_data;
        int i;
        MonoNativeThreadId self = mono_native_thread_id_get ();
        guint32 eventidx = 0;
        gboolean starting, finished;

        memset (wait, 0, sizeof (struct wait_data));
        /*
         * The other threads could be in an arbitrary state at this point, i.e.
         * they could be starting up, shutting down etc. This means that there could be
         * threads which are not even in the threads hash table yet.
         */

        /* 
         * First we set a barrier which will be checked by all threads before they
         * are added to the threads hash table, and they will exit if the flag is set.
         * This ensures that no threads could be added to the hash later.
         * We will use shutting_down as the barrier for now.
         */
        g_assert (shutting_down);

        /*
         * We make multiple calls to WaitForMultipleObjects since:
         * - we can only wait for MONO_W32HANDLE_MAXIMUM_WAIT_OBJECTS threads
         * - some threads could exit without becoming suspended
         */
        finished = FALSE;
        while (!finished) {
                /*
                 * Make a copy of the hashtable since we can't do anything with
                 * threads while threads_mutex is held.
                 */
                wait->num = 0;
                /*We must zero all InternalThread pointers to avoid making the GC unhappy.*/
                memset (wait->threads, 0, sizeof (wait->threads));
                mono_threads_lock ();
                mono_g_hash_table_foreach (threads, collect_threads_for_suspend, wait);
                mono_threads_unlock ();

                eventidx = 0;
                /* Get the suspended events that we'll be waiting for */
                for (i = 0; i < wait->num; ++i) {
                        MonoInternalThread *thread = wait->threads [i];

                        if (mono_native_thread_id_equals (thread_get_tid (thread), self)
                             || mono_gc_is_finalizer_internal_thread (thread)
                             || (thread->flags & MONO_THREAD_FLAG_DONT_MANAGE)
                        ) {
                                mono_threads_close_thread_handle (wait->handles [i]);
                                wait->threads [i] = NULL;
                                continue;
                        }

                        LOCK_THREAD (thread);

                        if (thread->state & (ThreadState_Suspended | ThreadState_Stopped)) {
                                UNLOCK_THREAD (thread);
                                mono_threads_close_thread_handle (wait->handles [i]);
                                wait->threads [i] = NULL;
                                continue;
                        }

                        ++eventidx;

                        /* Convert abort requests into suspend requests */
                        if ((thread->state & ThreadState_AbortRequested) != 0)
                                thread->state &= ~ThreadState_AbortRequested;
                        
                        thread->state |= ThreadState_SuspendRequested;
                        MONO_ENTER_GC_SAFE;
                        mono_os_event_reset (thread->suspended);
                        MONO_EXIT_GC_SAFE;

                        /* Signal the thread to suspend + calls UNLOCK_THREAD (thread) */
                        async_suspend_internal (thread, TRUE);

                        mono_threads_close_thread_handle (wait->handles [i]);
                        wait->threads [i] = NULL;
                }
                if (eventidx <= 0) {
                        /* 
                         * If there are threads which are starting up, we wait until they
                         * are suspended when they try to register in the threads hash.
                         * This is guaranteed to finish, since the threads which can create new
                         * threads get suspended after a while.
                         * FIXME: The finalizer thread can still create new threads.
                         */
                        mono_threads_lock ();
                        if (threads_starting_up)
                                starting = mono_g_hash_table_size (threads_starting_up) > 0;
                        else
                                starting = FALSE;
                        mono_threads_unlock ();
                        if (starting)
                                mono_thread_info_sleep (100, NULL);
                        else
                                finished = TRUE;
                }
        }
}
#endif

typedef struct {
        MonoInternalThread *thread;
        MonoStackFrameInfo *frames;
        int nframes, max_frames;
        int nthreads, max_threads;
        MonoInternalThread **threads;
} ThreadDumpUserData;

static gboolean thread_dump_requested;

/* This needs to be async safe */
static gboolean
collect_frame (MonoStackFrameInfo *frame, MonoContext *ctx, gpointer data)
{
        ThreadDumpUserData *ud = (ThreadDumpUserData *)data;

        if (ud->nframes < ud->max_frames) {
                memcpy (&ud->frames [ud->nframes], frame, sizeof (MonoStackFrameInfo));
                ud->nframes ++;
        }

        return FALSE;
}

/* This needs to be async safe */
static SuspendThreadResult
get_thread_dump (MonoThreadInfo *info, gpointer ud)
{
        ThreadDumpUserData *user_data = (ThreadDumpUserData *)ud;
        MonoInternalThread *thread = user_data->thread;

#if 0
/* This no longer works with remote unwinding */
        g_string_append_printf (text, " tid=0x%p this=0x%p ", (gpointer)(gsize)thread->tid, thread);
        mono_thread_internal_describe (thread, text);
        g_string_append (text, "\n");
#endif

        if (thread == mono_thread_internal_current ())
                mono_get_eh_callbacks ()->mono_walk_stack_with_ctx (collect_frame, NULL, MONO_UNWIND_SIGNAL_SAFE, ud);
        else
                mono_get_eh_callbacks ()->mono_walk_stack_with_state (collect_frame, mono_thread_info_get_suspend_state (info), MONO_UNWIND_SIGNAL_SAFE, ud);

        return MonoResumeThread;
}

typedef struct {
        int nthreads, max_threads;

        guint32 *threads;
} CollectThreadsUserData;

typedef struct {
        int nthreads, max_threads;
        MonoNativeThreadId *threads;
} CollectThreadIdsUserData;

static void
collect_thread (gpointer key, gpointer value, gpointer user)
{
        CollectThreadsUserData *ud = (CollectThreadsUserData *)user;
        MonoInternalThread *thread = (MonoInternalThread *)value;

        if (ud->nthreads < ud->max_threads)
                ud->threads [ud->nthreads ++] = mono_gchandle_new_internal (&thread->obj, TRUE);
}

/*
 * Collect running threads into the THREADS array.
 * THREADS should be an array allocated on the stack.
 */
static int
collect_threads (guint32 *thread_handles, int max_threads)
{
        CollectThreadsUserData ud;

        mono_memory_barrier ();
        if (!threads)
                return 0;

        memset (&ud, 0, sizeof (ud));
        /* This array contains refs, but its on the stack, so its ok */
        ud.threads = thread_handles;
        ud.max_threads = max_threads;

        mono_threads_lock ();
        mono_g_hash_table_foreach (threads, collect_thread, &ud);
        mono_threads_unlock ();

        return ud.nthreads;
}

void
mono_gstring_append_thread_name (GString* text, MonoInternalThread* thread)
{
        g_string_append (text, "\n\"");
        char const * const name = thread->name.chars;
        g_string_append (text,               name ? name :
                        thread->threadpool_thread ? "<threadpool thread>" :
                                                    "<unnamed thread>");
        g_string_append (text, "\"");
}

static void
dump_thread (MonoInternalThread *thread, ThreadDumpUserData *ud, FILE* output_file)
{
        GString* text = g_string_new (0);
        int i;

        ud->thread = thread;
        ud->nframes = 0;

        /* Collect frames for the thread */
        if (thread == mono_thread_internal_current ()) {
                get_thread_dump (mono_thread_info_current (), ud);
        } else {
                mono_thread_info_safe_suspend_and_run (thread_get_tid (thread), FALSE, get_thread_dump, ud);
        }

        /*
         * Do all the non async-safe work outside of get_thread_dump.
         */
        mono_gstring_append_thread_name (text, thread);

        for (i = 0; i < ud->nframes; ++i) {
                MonoStackFrameInfo *frame = &ud->frames [i];
                MonoMethod *method = NULL;

                if (frame->type == FRAME_TYPE_MANAGED)
                        method = mono_jit_info_get_method (frame->ji);

                if (method) {
                        gchar *location = mono_debug_print_stack_frame (method, frame->native_offset, frame->domain);
                        g_string_append_printf (text, "  %s\n", location);
                        g_free (location);
                } else {
                        g_string_append_printf (text, "  at <unknown> <0x%05x>\n", frame->native_offset);
                }
        }

        g_fprintf (output_file, "%s", text->str);

#if PLATFORM_WIN32 && TARGET_WIN32 && _DEBUG
        OutputDebugStringA(text->str);
#endif

        g_string_free (text, TRUE);
        fflush (output_file);
}

static void
mono_get_time_of_day (struct timeval *tv) {
#ifdef WIN32
        struct _timeb time;
        _ftime(&time);
        tv->tv_sec = time.time;
        tv->tv_usec = time.millitm * 1000;
#else
        if (gettimeofday (tv, NULL) == -1) {
                g_error ("gettimeofday() failed; errno is %d (%s)", errno, strerror (errno));
        }
#endif
}

static void
mono_local_time (const struct timeval *tv, struct tm *tm) {
#ifdef HAVE_LOCALTIME_R
        localtime_r(&tv->tv_sec, tm);
#else
        time_t const tv_sec = tv->tv_sec; // Copy due to Win32/Posix contradiction.
        *tm = *localtime (&tv_sec);
#endif
}

void
mono_threads_perform_thread_dump (void)
{
        FILE* output_file = NULL;
        ThreadDumpUserData ud;
        guint32 thread_array [128];
        int tindex, nthreads;

        if (!thread_dump_requested)
                return;

        if (thread_dump_dir != NULL) {
                GString* path = g_string_new (0);
                char time_str[80];
                struct timeval tv;
                long ms;
                struct tm tod;
                mono_get_time_of_day (&tv);
                mono_local_time(&tv, &tod);
                strftime(time_str, sizeof(time_str), MONO_STRFTIME_F "_" MONO_STRFTIME_T, &tod);
                ms = tv.tv_usec / 1000;
                g_string_append_printf (path, "%s/%s.%03ld.tdump", thread_dump_dir, time_str, ms);
                output_file = fopen (path->str, "w");
                g_string_free (path, TRUE);
        }
        if (output_file == NULL) {
                g_print ("Full thread dump:\n");
        }

        /* Make a copy of the threads hash to avoid doing work inside threads_lock () */
        nthreads = collect_threads (thread_array, 128);

        memset (&ud, 0, sizeof (ud));
        ud.frames = g_new0 (MonoStackFrameInfo, 256);
        ud.max_frames = 256;

        for (tindex = 0; tindex < nthreads; ++tindex) {
                guint32 handle = thread_array [tindex];
                MonoInternalThread *thread = (MonoInternalThread *) mono_gchandle_get_target_internal (handle);
                dump_thread (thread, &ud, output_file != NULL ? output_file : stdout);
                mono_gchandle_free_internal (handle);
        }

        if (output_file != NULL) {
                fclose (output_file);
        }
        g_free (ud.frames);

        thread_dump_requested = FALSE;
}

#ifndef ENABLE_NETCORE
/* Obtain the thread dump of all threads */
void
ves_icall_System_Threading_Thread_GetStackTraces (MonoArrayHandleOut out_threads_handle, MonoArrayHandleOut out_stack_frames_handle, MonoError *error)
{
        MONO_HANDLE_ASSIGN_RAW (out_threads_handle, NULL);
        MONO_HANDLE_ASSIGN_RAW (out_stack_frames_handle, NULL);

        guint32 handle = 0;

        MonoStackFrameHandle stack_frame_handle = MONO_HANDLE_NEW (MonoStackFrame, NULL);
        MonoReflectionMethodHandle reflection_method_handle = MONO_HANDLE_NEW (MonoReflectionMethod, NULL);
        MonoStringHandle filename_handle = MONO_HANDLE_NEW (MonoString, NULL);
        MonoArrayHandle thread_frames_handle = MONO_HANDLE_NEW (MonoArray, NULL);

        ThreadDumpUserData ud;
        guint32 thread_array [128];
        MonoDomain *domain = mono_domain_get ();
        MonoDebugSourceLocation *location;
        int tindex, nthreads;
        
        MonoArray* out_threads = NULL;
        MonoArray* out_stack_frames = NULL;

        MONO_HANDLE_ASSIGN_RAW (out_threads_handle, NULL);
        MONO_HANDLE_ASSIGN_RAW (out_stack_frames_handle, NULL);

        /* Make a copy of the threads hash to avoid doing work inside threads_lock () */
        nthreads = collect_threads (thread_array, 128);

        memset (&ud, 0, sizeof (ud));
        ud.frames = g_new0 (MonoStackFrameInfo, 256);
        ud.max_frames = 256;

        out_threads = mono_array_new_checked (domain, mono_defaults.thread_class, nthreads, error);
        goto_if_nok (error, leave);
        MONO_HANDLE_ASSIGN_RAW (out_threads_handle, out_threads);
        out_stack_frames = mono_array_new_checked (domain, mono_defaults.array_class, nthreads, error);
        goto_if_nok (error, leave);
        MONO_HANDLE_ASSIGN_RAW (out_stack_frames_handle, out_stack_frames);

        for (tindex = 0; tindex < nthreads; ++tindex) {

                mono_gchandle_free_internal (handle);
                handle = thread_array [tindex];
                MonoInternalThread *thread = (MonoInternalThread *) mono_gchandle_get_target_internal (handle);

                MonoArray *thread_frames;
                int i;

                ud.thread = thread;
                ud.nframes = 0;

                /* Collect frames for the thread */
                if (thread == mono_thread_internal_current ()) {
                        get_thread_dump (mono_thread_info_current (), &ud);
                } else {
                        mono_thread_info_safe_suspend_and_run (thread_get_tid (thread), FALSE, get_thread_dump, &ud);
                }

                mono_array_setref_fast (out_threads, tindex, mono_thread_current_for_thread (thread));

                thread_frames = mono_array_new_checked (domain, mono_defaults.stack_frame_class, ud.nframes, error);
                MONO_HANDLE_ASSIGN_RAW (thread_frames_handle, thread_frames);
                goto_if_nok (error, leave);
                mono_array_setref_fast (out_stack_frames, tindex, thread_frames);

                for (i = 0; i < ud.nframes; ++i) {
                        MonoStackFrameInfo *frame = &ud.frames [i];
                        MonoMethod *method = NULL;
                        MonoStackFrame *sf = (MonoStackFrame *)mono_object_new_checked (domain, mono_defaults.stack_frame_class, error);
                        MONO_HANDLE_ASSIGN_RAW (stack_frame_handle, sf);
                        goto_if_nok (error, leave);

                        sf->native_offset = frame->native_offset;

                        if (frame->type == FRAME_TYPE_MANAGED)
                                method = mono_jit_info_get_method (frame->ji);

                        if (method) {
                                sf->method_address = (gsize) frame->ji->code_start;

                                MonoReflectionMethod *rm = mono_method_get_object_checked (domain, method, NULL, error);
                                MONO_HANDLE_ASSIGN_RAW (reflection_method_handle, rm);
                                goto_if_nok (error, leave);
                                MONO_OBJECT_SETREF_INTERNAL (sf, method, rm);

                                location = mono_debug_lookup_source_location (method, frame->native_offset, domain);
                                if (location) {
                                        sf->il_offset = location->il_offset;

                                        if (location->source_file) {
                                                MonoString *filename = mono_string_new_checked (domain, location->source_file, error);
                                                MONO_HANDLE_ASSIGN_RAW (filename_handle, filename);
                                                goto_if_nok (error, leave);
                                                MONO_OBJECT_SETREF_INTERNAL (sf, filename, filename);
                                                sf->line = location->row;
                                                sf->column = location->column;
                                        }
                                        mono_debug_free_source_location (location);
                                } else {
                                        sf->il_offset = -1;
                                }
                        }
                        mono_array_setref_internal (thread_frames, i, sf);
                }

                mono_gchandle_free_internal (handle);
                handle = 0;
        }

leave:
        mono_gchandle_free_internal (handle);
        g_free (ud.frames);
}
#endif

/**
 * mono_threads_request_thread_dump:
 *
 *   Ask all threads except the current to print their stacktrace to stdout.
 */
void
mono_threads_request_thread_dump (void)
{
        /*The new thread dump code runs out of the finalizer thread. */
        thread_dump_requested = TRUE;
        mono_gc_finalize_notify ();
}

struct ref_stack {
        gpointer *refs;
        gint allocated; /* +1 so that refs [allocated] == NULL */
        gint bottom;
};

typedef struct ref_stack RefStack;

static RefStack *
ref_stack_new (gint initial_size)
{
        RefStack *rs;

        initial_size = MAX (initial_size, 16) + 1;
        rs = g_new0 (RefStack, 1);
        rs->refs = g_new0 (gpointer, initial_size);
        rs->allocated = initial_size;
        return rs;
}

static void
ref_stack_destroy (gpointer ptr)
{
        RefStack *rs = (RefStack *)ptr;

        if (rs != NULL) {
                g_free (rs->refs);
                g_free (rs);
        }
}

static void
ref_stack_push (RefStack *rs, gpointer ptr)
{
        g_assert (rs != NULL);

        if (rs->bottom >= rs->allocated) {
                rs->refs = (void **)g_realloc (rs->refs, rs->allocated * 2 * sizeof (gpointer) + 1);
                rs->allocated <<= 1;
                rs->refs [rs->allocated] = NULL;
        }
        rs->refs [rs->bottom++] = ptr;
}

static void
ref_stack_pop (RefStack *rs)
{
        if (rs == NULL || rs->bottom == 0)
                return;

        rs->bottom--;
        rs->refs [rs->bottom] = NULL;
}

static gboolean
ref_stack_find (RefStack *rs, gpointer ptr)
{
        gpointer *refs;

        if (rs == NULL)
                return FALSE;

        for (refs = rs->refs; refs && *refs; refs++) {
                if (*refs == ptr)
                        return TRUE;
        }
        return FALSE;
}

/*
 * mono_thread_push_appdomain_ref:
 *
 *   Register that the current thread may have references to objects in domain 
 * @domain on its stack. Each call to this function should be paired with a 
 * call to pop_appdomain_ref.
 */
void 
mono_thread_push_appdomain_ref (MonoDomain *domain)
{
        MonoInternalThread *thread = mono_thread_internal_current ();

        if (thread) {
                /* printf ("PUSH REF: %" G_GSIZE_FORMAT " -> %s.\n", (gsize)thread->tid, domain->friendly_name); */
                SPIN_LOCK (thread->lock_thread_id);
                if (thread->appdomain_refs == NULL)
                        thread->appdomain_refs = ref_stack_new (16);
                ref_stack_push ((RefStack *)thread->appdomain_refs, domain);
                SPIN_UNLOCK (thread->lock_thread_id);
        }
}

void
mono_thread_pop_appdomain_ref (void)
{
        MonoInternalThread *thread = mono_thread_internal_current ();

        if (thread) {
                /* printf ("POP REF: %" G_GSIZE_FORMAT " -> %s.\n", (gsize)thread->tid, ((MonoDomain*)(thread->appdomain_refs->data))->friendly_name); */
                SPIN_LOCK (thread->lock_thread_id);
                ref_stack_pop ((RefStack *)thread->appdomain_refs);
                SPIN_UNLOCK (thread->lock_thread_id);
        }
}

gboolean
mono_thread_internal_has_appdomain_ref (MonoInternalThread *thread, MonoDomain *domain)
{
        gboolean res;
        SPIN_LOCK (thread->lock_thread_id);
        res = ref_stack_find ((RefStack *)thread->appdomain_refs, domain);
        SPIN_UNLOCK (thread->lock_thread_id);
        return res;
}

gboolean
mono_thread_has_appdomain_ref (MonoThread *thread, MonoDomain *domain)
{
        return mono_thread_internal_has_appdomain_ref (thread->internal_thread, domain);
}

typedef struct abort_appdomain_data {
        struct wait_data wait;
        MonoDomain *domain;
} abort_appdomain_data;

static void
collect_appdomain_thread (gpointer key, gpointer value, gpointer user_data)
{
        MonoInternalThread *thread = (MonoInternalThread*)value;
        abort_appdomain_data *data = (abort_appdomain_data*)user_data;
        MonoDomain *domain = data->domain;

        if (mono_thread_internal_has_appdomain_ref (thread, domain)) {
                /* printf ("ABORTING THREAD %p BECAUSE IT REFERENCES DOMAIN %s.\n", thread->tid, domain->friendly_name); */

                if(data->wait.num<MONO_W32HANDLE_MAXIMUM_WAIT_OBJECTS) {
                        data->wait.handles [data->wait.num] = mono_threads_open_thread_handle (thread->handle);
                        data->wait.threads [data->wait.num] = thread;
                        data->wait.num++;
                } else {
                        /* Just ignore the rest, we can't do anything with
                         * them yet
                         */
                }
        }
}

/*
 * mono_threads_abort_appdomain_threads:
 *
 *   Abort threads which has references to the given appdomain.
 */
gboolean
mono_threads_abort_appdomain_threads (MonoDomain *domain, int timeout)
{
        abort_appdomain_data user_data;
        gint64 start_time;
        int orig_timeout = timeout;
        int i;

        THREAD_DEBUG (g_message ("%s: starting abort", __func__));

        start_time = mono_msec_ticks ();
        do {
                mono_threads_lock ();

                user_data.domain = domain;
                user_data.wait.num = 0;
                /* This shouldn't take any locks */
                mono_g_hash_table_foreach (threads, collect_appdomain_thread, &user_data);
                mono_threads_unlock ();

                if (user_data.wait.num > 0) {
                        /* Abort the threads outside the threads lock */
                        for (i = 0; i < user_data.wait.num; ++i)
                                mono_thread_internal_abort (user_data.wait.threads [i], TRUE);

                        /*
                         * We should wait for the threads either to abort, or to leave the
                         * domain. We can't do the latter, so we wait with a timeout.
                         */
                        wait_for_tids (&user_data.wait, 100, FALSE);
                }

                /* Update remaining time */
                timeout -= mono_msec_ticks () - start_time;
                start_time = mono_msec_ticks ();

                if (orig_timeout != -1 && timeout < 0)
                        return FALSE;
        }
        while (user_data.wait.num > 0);

        THREAD_DEBUG (g_message ("%s: abort done", __func__));

        return TRUE;
}

/* This is a JIT icall.  This icall is called from a finally block when
 * mono_install_handler_block_guard called by another thread has flipped the
 * finally block's exvar (see mono_find_exvar_for_offset).  In that case, if
 * the finally is in an abort protected block, we must defer the abort
 * exception until we leave the abort protected block.  Otherwise we proceed
 * with a synchronous self-abort.
 */
void
ves_icall_thread_finish_async_abort (void)
{
        /* We were called from the handler block and are about to
         * leave it.  (If we end up postponing the abort because we're
         * in an abort protected block, the unwinder won't run and
         * won't clear the handler block itself which will confuse the
         * unwinder if we're in a try {} catch {} and we throw again.
         * ie, this:
         * static Constructor () {
         *   try {
         *     try {
         *     } finally {
         *       icall (); // Thread.Abort landed here,
         *                 // and caused the handler block to be installed
         *       if (exvar)
         *         ves_icall_thread_finish_async_abort (); // we're here
         *     }
         *     throw E ();
         *   } catch (E) {
         *     // unwinder will get confused here and synthesize a self abort
         *   }
         * }
         *
         * More interestingly, this doesn't only happen with icalls - a JIT
         * trampoline is native code that will cause a handler to be installed.
         * So the above situation can happen with any code in a "finally"
         * clause.
         */
        mono_get_eh_callbacks ()->mono_uninstall_current_handler_block_guard ();
        /* Just set the async interruption requested bit.  Rely on the icall
         * wrapper of this icall to process the thread interruption, respecting
         * any abort protection blocks in our call stack.
         */
        mono_thread_set_self_interruption_respect_abort_prot ();
}

/*
 * mono_thread_get_undeniable_exception:
 *
 *   Return an exception which needs to be raised when leaving a catch clause.
 * This is used for undeniable exception propagation.
 */
MonoException*
mono_thread_get_undeniable_exception (void)
{
        MonoInternalThread *thread = mono_thread_internal_current ();

        if (!(thread && thread->abort_exc && !is_running_protected_wrapper ()))
                return NULL;

        // We don't want to have our exception effect calls made by
        // the catching block

        if (!mono_get_eh_callbacks ()->mono_above_abort_threshold ())
                return NULL;

        /*
         * FIXME: Clear the abort exception and return an AppDomainUnloaded 
         * exception if the thread no longer references a dying appdomain.
         */ 
        thread->abort_exc->trace_ips = NULL;
        thread->abort_exc->stack_trace = NULL;
        return thread->abort_exc;
}

#if MONO_SMALL_CONFIG
#define NUM_STATIC_DATA_IDX 4
static const int static_data_size [NUM_STATIC_DATA_IDX] = {
        64, 256, 1024, 4096
};
#else
#define NUM_STATIC_DATA_IDX 8
static const int static_data_size [NUM_STATIC_DATA_IDX] = {
        1024, 4096, 16384, 65536, 262144, 1048576, 4194304, 16777216
};
#endif

static MonoBitSet *thread_reference_bitmaps [NUM_STATIC_DATA_IDX];
static MonoBitSet *context_reference_bitmaps [NUM_STATIC_DATA_IDX];

static void
mark_slots (void *addr, MonoBitSet **bitmaps, MonoGCMarkFunc mark_func, void *gc_data)
{
        gpointer *static_data = (gpointer *)addr;

        for (int i = 0; i < NUM_STATIC_DATA_IDX; ++i) {
                void **ptr = (void **)static_data [i];

                if (!ptr)
                        continue;

                MONO_BITSET_FOREACH (bitmaps [i], idx, {
                        void **p = ptr + idx;

                        if (*p)
                                mark_func ((MonoObject**)p, gc_data);
                });
        }
}

static void
mark_tls_slots (void *addr, MonoGCMarkFunc mark_func, void *gc_data)
{
        mark_slots (addr, thread_reference_bitmaps, mark_func, gc_data);
}

static void
mark_ctx_slots (void *addr, MonoGCMarkFunc mark_func, void *gc_data)
{
        mark_slots (addr, context_reference_bitmaps, mark_func, gc_data);
}

/*
 *  mono_alloc_static_data
 *
 *   Allocate memory blocks for storing threads or context static data
 */
static void 
mono_alloc_static_data (gpointer **static_data_ptr, guint32 offset, void *alloc_key, gboolean threadlocal)
{
        guint idx = ACCESS_SPECIAL_STATIC_OFFSET (offset, index);
        int i;

        gpointer* static_data = *static_data_ptr;
        if (!static_data) {
                static MonoGCDescriptor tls_desc = MONO_GC_DESCRIPTOR_NULL;
                static MonoGCDescriptor ctx_desc = MONO_GC_DESCRIPTOR_NULL;

                if (mono_gc_user_markers_supported ()) {
                        if (tls_desc == MONO_GC_DESCRIPTOR_NULL)
                                tls_desc = mono_gc_make_root_descr_user (mark_tls_slots);

                        if (ctx_desc == MONO_GC_DESCRIPTOR_NULL)
                                ctx_desc = mono_gc_make_root_descr_user (mark_ctx_slots);
                }

                static_data = (void **)mono_gc_alloc_fixed (static_data_size [0], threadlocal ? tls_desc : ctx_desc,
                        threadlocal ? MONO_ROOT_SOURCE_THREAD_STATIC : MONO_ROOT_SOURCE_CONTEXT_STATIC,
                        alloc_key,
                        threadlocal ? "ThreadStatic Fields" : "ContextStatic Fields");
                *static_data_ptr = static_data;
                static_data [0] = static_data;
        }

        for (i = 1; i <= idx; ++i) {
                if (static_data [i])
                        continue;

                if (mono_gc_user_markers_supported ())
                        static_data [i] = g_malloc0 (static_data_size [i]);
                else
                        static_data [i] = mono_gc_alloc_fixed (static_data_size [i], MONO_GC_DESCRIPTOR_NULL,
                                threadlocal ? MONO_ROOT_SOURCE_THREAD_STATIC : MONO_ROOT_SOURCE_CONTEXT_STATIC,
                                alloc_key,
                                threadlocal ? "ThreadStatic Fields" : "ContextStatic Fields");
        }
}

static void 
mono_free_static_data (gpointer* static_data)
{
        int i;
        for (i = 1; i < NUM_STATIC_DATA_IDX; ++i) {
                gpointer p = static_data [i];
                if (!p)
                        continue;
                /*
                 * At this point, the static data pointer array is still registered with the
                 * GC, so must ensure that mark_tls_slots() will not encounter any invalid
                 * data.  Freeing the individual arrays without first nulling their slots
                 * would make it possible for mark_tls/ctx_slots() to encounter a pointer to
                 * such an already freed array.  See bug #13813.
                 */
                static_data [i] = NULL;
                mono_memory_write_barrier ();
                if (mono_gc_user_markers_supported ())
                        g_free (p);
                else
                        mono_gc_free_fixed (p);
        }
        mono_gc_free_fixed (static_data);
}

/*
 *  mono_init_static_data_info
 *
 *   Initializes static data counters
 */
static void mono_init_static_data_info (StaticDataInfo *static_data)
{
        static_data->idx = 0;
        static_data->offset = 0;
        static_data->freelist = NULL;
}

/*
 *  mono_alloc_static_data_slot
 *
 *   Generates an offset for static data. static_data contains the counters
 *  used to generate it.
 */
static guint32
mono_alloc_static_data_slot (StaticDataInfo *static_data, guint32 size, guint32 align)
{
        if (!static_data->idx && !static_data->offset) {
                /* 
                 * we use the first chunk of the first allocation also as
                 * an array for the rest of the data 
                 */
                static_data->offset = sizeof (gpointer) * NUM_STATIC_DATA_IDX;
        }
        static_data->offset += align - 1;
        static_data->offset &= ~(align - 1);
        if (static_data->offset + size >= static_data_size [static_data->idx]) {
                static_data->idx ++;
                g_assert (size <= static_data_size [static_data->idx]);
                g_assert (static_data->idx < NUM_STATIC_DATA_IDX);
                static_data->offset = 0;
        }
        guint32 offset = MAKE_SPECIAL_STATIC_OFFSET (static_data->idx, static_data->offset, 0);
        static_data->offset += size;
        return offset;
}

/*
 * LOCKING: requires that threads_mutex is held
 */
static void
context_adjust_static_data (MonoAppContextHandle ctx_handle)
{
        MonoAppContext *ctx = MONO_HANDLE_RAW (ctx_handle);
        if (context_static_info.offset || context_static_info.idx > 0) {
                guint32 offset = MAKE_SPECIAL_STATIC_OFFSET (context_static_info.idx, context_static_info.offset, 0);
                mono_alloc_static_data (&ctx->static_data, offset, ctx, FALSE);
                ctx->data->static_data = ctx->static_data;
        }
}

/*
 * LOCKING: requires that threads_mutex is held
 */
static void 
alloc_thread_static_data_helper (gpointer key, gpointer value, gpointer user)
{
        MonoInternalThread *thread = (MonoInternalThread *)value;
        guint32 offset = GPOINTER_TO_UINT (user);

        mono_alloc_static_data (&(thread->static_data), offset, (void *) MONO_UINT_TO_NATIVE_THREAD_ID (thread->tid), TRUE);
}

/*
 * LOCKING: requires that threads_mutex is held
 */
static void
alloc_context_static_data_helper (gpointer key, gpointer value, gpointer user)
{
        MonoAppContext *ctx = (MonoAppContext *) mono_gchandle_get_target_internal (GPOINTER_TO_INT (key));

        if (!ctx)
                return;

        guint32 offset = GPOINTER_TO_UINT (user);
        mono_alloc_static_data (&ctx->static_data, offset, ctx, FALSE);
        ctx->data->static_data = ctx->static_data;
}

static StaticDataFreeList*
search_slot_in_freelist (StaticDataInfo *static_data, guint32 size, gint32 align)
{
        StaticDataFreeList* prev = NULL;
        StaticDataFreeList* tmp = static_data->freelist;
        while (tmp) {
                if (tmp->size == size && tmp->align == align) {
                        if (prev)
                                prev->next = tmp->next;
                        else
                                static_data->freelist = tmp->next;
                        return tmp;
                }
                prev = tmp;
                tmp = tmp->next;
        }
        return NULL;
}

#if SIZEOF_VOID_P == 4
#define ONE_P 1
#else
#define ONE_P 1ll
#endif

static void
update_reference_bitmap (MonoBitSet **sets, guint32 offset, uintptr_t *bitmap, int numbits)
{
        int idx = ACCESS_SPECIAL_STATIC_OFFSET (offset, index);
        if (!sets [idx])
                sets [idx] = mono_bitset_new (static_data_size [idx] / sizeof (uintptr_t), 0);
        MonoBitSet *rb = sets [idx];
        offset = ACCESS_SPECIAL_STATIC_OFFSET (offset, offset);
        offset /= sizeof (uintptr_t);
        /* offset is now the bitmap offset */
        for (int i = 0; i < numbits; ++i) {
                if (bitmap [i / sizeof (uintptr_t)] & (ONE_P << (i & (sizeof (uintptr_t) * 8 -1))))
                        mono_bitset_set_fast (rb, offset + i);
        }
}

static void
clear_reference_bitmap (MonoBitSet **sets, guint32 offset, guint32 size)
{
        int idx = ACCESS_SPECIAL_STATIC_OFFSET (offset, index);
        MonoBitSet *rb = sets [idx];
        offset = ACCESS_SPECIAL_STATIC_OFFSET (offset, offset);
        offset /= sizeof (uintptr_t);
        /* offset is now the bitmap offset */
        for (int i = 0; i < size / sizeof (uintptr_t); i++)
                mono_bitset_clear_fast (rb, offset + i);
}

guint32
mono_alloc_special_static_data (guint32 static_type, guint32 size, guint32 align, uintptr_t *bitmap, int numbits)
{
        g_assert (static_type == SPECIAL_STATIC_THREAD || static_type == SPECIAL_STATIC_CONTEXT);

        StaticDataInfo *info;
        MonoBitSet **sets;

        if (static_type == SPECIAL_STATIC_THREAD) {
                info = &thread_static_info;
                sets = thread_reference_bitmaps;
        } else {
                info = &context_static_info;
                sets = context_reference_bitmaps;
        }

        mono_threads_lock ();

        StaticDataFreeList *item = search_slot_in_freelist (info, size, align);
        guint32 offset;

        if (item) {
                offset = item->offset;
                g_free (item);
        } else {
                offset = mono_alloc_static_data_slot (info, size, align);
        }

        update_reference_bitmap (sets, offset, bitmap, numbits);

        if (static_type == SPECIAL_STATIC_THREAD) {
                /* This can be called during startup */
                if (threads != NULL)
                        mono_g_hash_table_foreach (threads, alloc_thread_static_data_helper, GUINT_TO_POINTER (offset));
        } else {
                if (contexts != NULL)
                        g_hash_table_foreach (contexts, alloc_context_static_data_helper, GUINT_TO_POINTER (offset));

                ACCESS_SPECIAL_STATIC_OFFSET (offset, type) = SPECIAL_STATIC_OFFSET_TYPE_CONTEXT;
        }

        mono_threads_unlock ();

        return offset;
}

gpointer
mono_get_special_static_data_for_thread (MonoInternalThread *thread, guint32 offset)
{
        guint32 static_type = ACCESS_SPECIAL_STATIC_OFFSET (offset, type);

        if (static_type == SPECIAL_STATIC_OFFSET_TYPE_THREAD) {
                return get_thread_static_data (thread, offset);
        } else {
                return get_context_static_data (thread->current_appcontext, offset);
        }
}

gpointer
mono_get_special_static_data (guint32 offset)
{
        return mono_get_special_static_data_for_thread (mono_thread_internal_current (), offset);
}

typedef struct {
        guint32 offset;
        guint32 size;
} OffsetSize;

/*
 * LOCKING: requires that threads_mutex is held
 */
static void 
free_thread_static_data_helper (gpointer key, gpointer value, gpointer user)
{
        MonoInternalThread *thread = (MonoInternalThread *)value;
        OffsetSize *data = (OffsetSize *)user;
        int idx = ACCESS_SPECIAL_STATIC_OFFSET (data->offset, index);
        int off = ACCESS_SPECIAL_STATIC_OFFSET (data->offset, offset);
        char *ptr;

        if (!thread->static_data || !thread->static_data [idx])
                return;
        ptr = ((char*) thread->static_data [idx]) + off;
        mono_gc_bzero_atomic (ptr, data->size);
}

/*
 * LOCKING: requires that threads_mutex is held
 */
static void
free_context_static_data_helper (gpointer key, gpointer value, gpointer user)
{
        MonoAppContext *ctx = (MonoAppContext *) mono_gchandle_get_target_internal (GPOINTER_TO_INT (key));

        if (!ctx)
                return;

        OffsetSize *data = (OffsetSize *)user;
        int idx = ACCESS_SPECIAL_STATIC_OFFSET (data->offset, index);
        int off = ACCESS_SPECIAL_STATIC_OFFSET (data->offset, offset);
        char *ptr;

        if (!ctx->static_data || !ctx->static_data [idx])
                return;

        ptr = ((char*) ctx->static_data [idx]) + off;
        mono_gc_bzero_atomic (ptr, data->size);
}

static void
do_free_special_slot (guint32 offset, guint32 size, gint32 align)
{
        guint32 static_type = ACCESS_SPECIAL_STATIC_OFFSET (offset, type);
        MonoBitSet **sets;
        StaticDataInfo *info;

        if (static_type == SPECIAL_STATIC_OFFSET_TYPE_THREAD) {
                info = &thread_static_info;
                sets = thread_reference_bitmaps;
        } else {
                info = &context_static_info;
                sets = context_reference_bitmaps;
        }

        guint32 data_offset = offset;
        ACCESS_SPECIAL_STATIC_OFFSET (data_offset, type) = 0;
        OffsetSize data = { data_offset, size };

        clear_reference_bitmap (sets, data.offset, data.size);

        if (static_type == SPECIAL_STATIC_OFFSET_TYPE_THREAD) {
                if (threads != NULL)
                        mono_g_hash_table_foreach (threads, free_thread_static_data_helper, &data);
        } else {
                if (contexts != NULL)
                        g_hash_table_foreach (contexts, free_context_static_data_helper, &data);
        }

        if (!mono_runtime_is_shutting_down ()) {
                StaticDataFreeList *item = g_new0 (StaticDataFreeList, 1);

                item->offset = offset;
                item->size = size;
                item->align = align;

                item->next = info->freelist;
                info->freelist = item;
        }
}

static void
do_free_special (gpointer key, gpointer value, gpointer data)
{
        MonoClassField *field = (MonoClassField *)key;
        guint32 offset = GPOINTER_TO_UINT (value);
        gint32 align;
        guint32 size;
        size = mono_type_size (field->type, &align);
        do_free_special_slot (offset, size, align);
}

void
mono_alloc_special_static_data_free (GHashTable *special_static_fields)
{
        mono_threads_lock ();

        g_hash_table_foreach (special_static_fields, do_free_special, NULL);

        mono_threads_unlock ();
}

#ifdef HOST_WIN32
static void
flush_thread_interrupt_queue (void)
{
        /* Consume pending APC calls for current thread.*/
        /* Since this function get's called from interrupt handler it must use a direct */
        /* Win32 API call and can't go through mono_coop_win32_wait_for_single_object_ex */
        /* or it will detect a pending interrupt and not entering the wait call needed */
        /* to consume pending APC's.*/
        MONO_ENTER_GC_SAFE;
        WaitForSingleObjectEx (GetCurrentThread (), 0, TRUE);
        MONO_EXIT_GC_SAFE;
}
#else
static void
flush_thread_interrupt_queue (void)
{
}
#endif

/*
 * mono_thread_execute_interruption
 * 
 * Performs the operation that the requested thread state requires (abort,
 * suspend or stop)
 */
static gboolean
mono_thread_execute_interruption (MonoExceptionHandle *pexc)
{
        gboolean fexc = FALSE;

        // Optimize away frame if caller supplied one.
        if (!pexc) {
                HANDLE_FUNCTION_ENTER ();
                MonoExceptionHandle exc = MONO_HANDLE_NEW (MonoException, NULL);
                fexc = mono_thread_execute_interruption (&exc);
                HANDLE_FUNCTION_RETURN_VAL (fexc);
        }

        MONO_REQ_GC_UNSAFE_MODE;

        MonoInternalThreadHandle thread = mono_thread_internal_current_handle ();
        MonoExceptionHandle exc = MONO_HANDLE_NEW (MonoException, NULL);

        lock_thread_handle (thread);
        gboolean unlock = TRUE;

        /* MonoThread::interruption_requested can only be changed with atomics */
        if (!mono_thread_clear_interruption_requested_handle (thread))
                goto exit;

        MonoThreadObjectHandle sys_thread;
        sys_thread = mono_thread_current_handle ();

        flush_thread_interrupt_queue ();

        /* Clear the interrupted flag of the thread so it can wait again */
        mono_thread_info_clear_self_interrupt ();

        /* If there's a pending exception and an AbortRequested, the pending exception takes precedence */
        MONO_HANDLE_GET (exc, sys_thread, pending_exception);
        if (!MONO_HANDLE_IS_NULL (exc)) {
                // sys_thread->pending_exception = NULL;
                MONO_HANDLE_SETRAW (sys_thread, pending_exception, NULL);
                fexc = TRUE;
                goto exit;
        } else if (MONO_HANDLE_GETVAL (thread, state) & ThreadState_AbortRequested) {
                // Does the thread already have an abort exception?
                // If not, create a new one and set it on demand.
                // exc = thread->abort_exc;
                MONO_HANDLE_GET (exc, thread, abort_exc);
                if (MONO_HANDLE_IS_NULL (exc)) {
                        ERROR_DECL (error);
                        exc = mono_exception_new_thread_abort (error);
                        mono_error_assert_ok (error); // FIXME
                        // thread->abort_exc = exc;
                        MONO_HANDLE_SET (thread, abort_exc, exc);
                }
                fexc = TRUE;
        } else if (MONO_HANDLE_GETVAL (thread, state) & ThreadState_SuspendRequested) {
                /* calls UNLOCK_THREAD (thread) */
                self_suspend_internal ();
                unlock = FALSE;
        } else if (MONO_HANDLE_GETVAL (thread, thread_interrupt_requested)) {
                // thread->thread_interrupt_requested = FALSE
                MONO_HANDLE_SETVAL (thread, thread_interrupt_requested, MonoBoolean, FALSE);
                unlock_thread_handle (thread);
                unlock = FALSE;
                ERROR_DECL (error);
                exc = mono_exception_new_thread_interrupted (error);
                mono_error_assert_ok (error); // FIXME
                fexc = TRUE;
        }
exit:
        if (unlock)
                unlock_thread_handle (thread);

        if (fexc)
                MONO_HANDLE_ASSIGN (*pexc, exc);

        return fexc;
}

static void
mono_thread_execute_interruption_void (void)
{
        (void)mono_thread_execute_interruption (NULL);
}

static MonoException*
mono_thread_execute_interruption_ptr (void)
{
        HANDLE_FUNCTION_ENTER ();
        MonoExceptionHandle exc = MONO_HANDLE_NEW (MonoException, NULL);
        MonoException * const exc_raw = mono_thread_execute_interruption (&exc) ? MONO_HANDLE_RAW (exc) : NULL;
        HANDLE_FUNCTION_RETURN_VAL (exc_raw);
}

/*
 * mono_thread_request_interruption_internal
 *
 * A signal handler can call this method to request the interruption of a
 * thread. The result of the interruption will depend on the current state of
 * the thread. If the result is an exception that needs to be thrown, it is
 * provided as return value.
 */
static gboolean
mono_thread_request_interruption_internal (gboolean running_managed, MonoExceptionHandle *pexc)
{
        MonoInternalThread *thread = mono_thread_internal_current ();

        /* The thread may already be stopping */
        if (thread == NULL)
                return FALSE;

        if (!mono_thread_set_interruption_requested (thread))
                return FALSE;

        if (!running_managed || is_running_protected_wrapper ()) {
                /* Can't stop while in unmanaged code. Increase the global interruption
                   request count. When exiting the unmanaged method the count will be
                   checked and the thread will be interrupted. */

                /* this will awake the thread if it is in WaitForSingleObject 
                   or similar */
#ifdef HOST_WIN32
                mono_win32_interrupt_wait (thread->thread_info, thread->native_handle, (DWORD)thread->tid);
#else
                mono_thread_info_self_interrupt ();
#endif
                return FALSE;
        }
        return mono_thread_execute_interruption (pexc);
}

static void
mono_thread_request_interruption_native (void)
{
        (void)mono_thread_request_interruption_internal (FALSE, NULL);
}

static gboolean
mono_thread_request_interruption_managed (MonoExceptionHandle *exc)
{
        return mono_thread_request_interruption_internal (TRUE, exc);
}

/*This function should be called by a thread after it has exited all of
 * its handle blocks at interruption time.*/
void
mono_thread_resume_interruption (gboolean exec)
{
        MonoInternalThread *thread = mono_thread_internal_current ();
        gboolean still_aborting;

        /* The thread may already be stopping */
        if (thread == NULL)
                return;

        LOCK_THREAD (thread);
        still_aborting = (thread->state & (ThreadState_AbortRequested)) != 0;
        UNLOCK_THREAD (thread);

        /*This can happen if the protected block called Thread::ResetAbort*/
        if (!still_aborting)
                return;

        if (!mono_thread_set_interruption_requested (thread))
                return;

        mono_thread_info_self_interrupt ();

        if (exec) // Ignore the exception here, it will be raised later.
                mono_thread_execute_interruption_void ();
}

gboolean
mono_thread_interruption_requested (void)
{
        if (mono_thread_interruption_request_flag) {
                MonoInternalThread *thread = mono_thread_internal_current ();
                /* The thread may already be stopping */
                if (thread != NULL) 
                        return mono_thread_get_interruption_requested (thread);
        }
        return FALSE;
}

static MonoException*
mono_thread_interruption_checkpoint_request (gboolean bypass_abort_protection)
{
        MonoInternalThread *thread = mono_thread_internal_current ();

        /* The thread may already be stopping */
        if (!thread)
                return NULL;
        if (!mono_thread_get_interruption_requested (thread))
                return NULL;
        if (!bypass_abort_protection && !mono_thread_current ()->pending_exception && is_running_protected_wrapper ())
                return NULL;

        return mono_thread_execute_interruption_ptr ();
}

/*
 * Performs the interruption of the current thread, if one has been requested,
 * and the thread is not running a protected wrapper.
 * Return the exception which needs to be thrown, if any.
 */
MonoException*
mono_thread_interruption_checkpoint (void)
{
        return mono_thread_interruption_checkpoint_request (FALSE);
}

gboolean
mono_thread_interruption_checkpoint_bool (void)
{
        return mono_thread_interruption_checkpoint () != NULL;
}

void
mono_thread_interruption_checkpoint_void (void)
{
        mono_thread_interruption_checkpoint ();
}

/*
 * Performs the interruption of the current thread, if one has been requested.
 * Return the exception which needs to be thrown, if any.
 */
MonoException*
mono_thread_force_interruption_checkpoint_noraise (void)
{
        return mono_thread_interruption_checkpoint_request (TRUE);
}

/*
 * mono_set_pending_exception:
 *
 *   Set the pending exception of the current thread to EXC.
 * The exception will be thrown when execution returns to managed code.
 */
void
mono_set_pending_exception (MonoException *exc)
{
        MonoThread *thread = mono_thread_current ();

        /* The thread may already be stopping */
        if (thread == NULL)
                return;

        MONO_OBJECT_SETREF_INTERNAL (thread, pending_exception, exc);

        mono_thread_request_interruption_native ();
}

/*
 * mono_runtime_set_pending_exception:
 *
 *   Set the pending exception of the current thread to \p exc.
 *   The exception will be thrown when execution returns to managed code.
 *   Can optionally \p overwrite any existing pending exceptions (it's not supported
 *   to overwrite any pending exceptions if the runtime is processing a thread abort request,
 *   in which case the behavior will be undefined).
 *   Return whether the pending exception was set or not.
 *   It will not be set if:
 *   * The thread or runtime is stopping or shutting down
 *   * There already is a pending exception (and \p overwrite is false)
 */
mono_bool
mono_runtime_set_pending_exception (MonoException *exc, mono_bool overwrite)
{
        MonoThread *thread = mono_thread_current ();

        /* The thread may already be stopping */
        if (thread == NULL)
                return FALSE;

        /* Don't overwrite any existing pending exceptions unless asked to */
        if (!overwrite && thread->pending_exception)
                return FALSE;

        MONO_OBJECT_SETREF_INTERNAL (thread, pending_exception, exc);

        mono_thread_request_interruption_native ();

        return TRUE;
}


/*
 * mono_set_pending_exception_handle:
 *
 *   Set the pending exception of the current thread to EXC.
 * The exception will be thrown when execution returns to managed code.
 */
MONO_COLD void
mono_set_pending_exception_handle (MonoExceptionHandle exc)
{
        MonoThread *thread = mono_thread_current ();

        /* The thread may already be stopping */
        if (thread == NULL)
                return;

        MONO_OBJECT_SETREF_INTERNAL (thread, pending_exception, MONO_HANDLE_RAW (exc));

        mono_thread_request_interruption_native ();
}

void 
mono_thread_init_apartment_state (void)
{
#ifdef HOST_WIN32
        MonoInternalThread* thread = mono_thread_internal_current ();

        /* Positive return value indicates success, either
         * S_OK if this is first CoInitialize call, or
         * S_FALSE if CoInitialize already called, but with same
         * threading model. A negative value indicates failure,
         * probably due to trying to change the threading model.
         */
        if (CoInitializeEx(NULL, (thread->apartment_state == ThreadApartmentState_STA) 
                        ? COINIT_APARTMENTTHREADED 
                        : COINIT_MULTITHREADED) < 0) {
                thread->apartment_state = ThreadApartmentState_Unknown;
        }
#endif
}

void 
mono_thread_cleanup_apartment_state (void)
{
#ifdef HOST_WIN32
        MonoInternalThread* thread = mono_thread_internal_current ();

        if (thread && thread->apartment_state != ThreadApartmentState_Unknown) {
                CoUninitialize ();
        }
#endif
}

static void
mono_thread_notify_change_state (MonoThreadState old_state, MonoThreadState new_state)
{
        MonoThreadState diff = old_state ^ new_state;
        if (diff & ThreadState_Background) {
                /* If the thread changes the background mode, the main thread has to
                 * be notified, since it has to rebuild the list of threads to
                 * wait for.
                 */
                MONO_ENTER_GC_SAFE;
                mono_os_event_set (&background_change_event);
                MONO_EXIT_GC_SAFE;
        }
}

void
mono_thread_clear_and_set_state (MonoInternalThread *thread, MonoThreadState clear, MonoThreadState set)
{
        LOCK_THREAD (thread);

        MonoThreadState const old_state = (MonoThreadState)thread->state;
        MonoThreadState const new_state = (old_state & ~clear) | set;
        thread->state = new_state;

        UNLOCK_THREAD (thread);

        mono_thread_notify_change_state (old_state, new_state);
}

void
mono_thread_set_state (MonoInternalThread *thread, MonoThreadState state)
{
        mono_thread_clear_and_set_state (thread, (MonoThreadState)0, state);
}

/**
 * mono_thread_test_and_set_state:
 * Test if current state of \p thread include \p test. If it does not, OR \p set into the state.
 * \returns TRUE if \p set was OR'd in.
 */
gboolean
mono_thread_test_and_set_state (MonoInternalThread *thread, MonoThreadState test, MonoThreadState set)
{
        LOCK_THREAD (thread);
        
        MonoThreadState const old_state = (MonoThreadState)thread->state;

        if ((old_state & test) != 0) {
                UNLOCK_THREAD (thread);
                return FALSE;
        }

        MonoThreadState const new_state = old_state | set;
        thread->state = new_state;

        UNLOCK_THREAD (thread);

        mono_thread_notify_change_state (old_state, new_state);

        return TRUE;
}

void
mono_thread_clr_state (MonoInternalThread *thread, MonoThreadState state)
{
        mono_thread_clear_and_set_state (thread, state, (MonoThreadState)0);
}

gboolean
mono_thread_test_state (MonoInternalThread *thread, MonoThreadState test)
{
        LOCK_THREAD (thread);

        gboolean const ret = ((thread->state & test) != 0);
        
        UNLOCK_THREAD (thread);
        
        return ret;
}

static void
self_interrupt_thread (void *_unused)
{
        MonoException *exc;
        MonoThreadInfo *info;
        MonoContext ctx;

        exc = mono_thread_execute_interruption_ptr ();
        if (!exc) {
                if (mono_threads_are_safepoints_enabled ()) {
                        /* We can return from an async call in coop, as
                         * it's simply called when exiting the safepoint */
                        /* If we're using hybrid suspend, we only self
                         * interrupt if we were running, hence using
                         * safepoints */
                        return;
                }

                g_error ("%s: we can't resume from an async call", __func__);
        }

        info = mono_thread_info_current ();

        /* FIXME using thread_saved_state [ASYNC_SUSPEND_STATE_INDEX] can race with another suspend coming in. */
        ctx = info->thread_saved_state [ASYNC_SUSPEND_STATE_INDEX].ctx;

        mono_raise_exception_with_context (exc, &ctx);
}

static gboolean
mono_jit_info_match (MonoJitInfo *ji, gpointer ip)
{
        if (!ji)
                return FALSE;
        return ji->code_start <= ip && (char*)ip < (char*)ji->code_start + ji->code_size;
}

static gboolean
last_managed (MonoStackFrameInfo *frame, MonoContext *ctx, gpointer data)
{
        MonoJitInfo **dest = (MonoJitInfo **)data;
        *dest = frame->ji;
        return TRUE;
}

static MonoJitInfo*
mono_thread_info_get_last_managed (MonoThreadInfo *info)
{
        MonoJitInfo *ji = NULL;
        if (!info)
                return NULL;

        /*
         * The suspended thread might be holding runtime locks. Make sure we don't try taking
         * any runtime locks while unwinding.
         */
        mono_thread_info_set_is_async_context (TRUE);
        mono_get_eh_callbacks ()->mono_walk_stack_with_state (last_managed, mono_thread_info_get_suspend_state (info), MONO_UNWIND_SIGNAL_SAFE, &ji);
        mono_thread_info_set_is_async_context (FALSE);
        return ji;
}

typedef struct {
        MonoInternalThread *thread;
        gboolean install_async_abort;
        MonoThreadInfoInterruptToken *interrupt_token;
} AbortThreadData;

static SuspendThreadResult
async_abort_critical (MonoThreadInfo *info, gpointer ud)
{
        AbortThreadData *data = (AbortThreadData *)ud;
        MonoInternalThread *thread = data->thread;
        MonoJitInfo *ji = NULL;
        gboolean protected_wrapper;
        gboolean running_managed;

        if (mono_get_eh_callbacks ()->mono_install_handler_block_guard (mono_thread_info_get_suspend_state (info)))
                return MonoResumeThread;

        /*someone is already interrupting it*/
        if (!mono_thread_set_interruption_requested (thread))
                return MonoResumeThread;

        ji = mono_thread_info_get_last_managed (info);
        protected_wrapper = ji && !ji->is_trampoline && !ji->async && mono_threads_is_critical_method (mono_jit_info_get_method (ji));
        running_managed = mono_jit_info_match (ji, MONO_CONTEXT_GET_IP (&mono_thread_info_get_suspend_state (info)->ctx));

        if (!protected_wrapper && running_managed) {
                /*We are in managed code*/
                /*Set the thread to call */
                if (data->install_async_abort)
                        mono_thread_info_setup_async_call (info, self_interrupt_thread, NULL);
                return MonoResumeThread;
        } else {
                /* 
                 * This will cause waits to be broken.
                 * It will also prevent the thread from entering a wait, so if the thread returns
                 * from the wait before it receives the abort signal, it will just spin in the wait
                 * functions in the io-layer until the signal handler calls QueueUserAPC which will
                 * make it return.
                 */
                data->interrupt_token = mono_thread_info_prepare_interrupt (info);

                return MonoResumeThread;
        }
}

static void
async_abort_internal (MonoInternalThread *thread, gboolean install_async_abort)
{
        AbortThreadData data;

        g_assert (thread != mono_thread_internal_current ());

        data.thread = thread;
        data.install_async_abort = install_async_abort;
        data.interrupt_token = NULL;

        mono_thread_info_safe_suspend_and_run (thread_get_tid (thread), TRUE, async_abort_critical, &data);
        if (data.interrupt_token)
                mono_thread_info_finish_interrupt (data.interrupt_token);
        /*FIXME we need to wait for interruption to complete -- figure out how much into interruption we should wait for here*/
}

static void
self_abort_internal (MonoError *error)
{
        HANDLE_FUNCTION_ENTER ();

        error_init (error);

        /* FIXME this is insanely broken, it doesn't cause interruption to happen synchronously
         * since passing FALSE to mono_thread_request_interruption makes sure it returns NULL */

        /*
        Self aborts ignore the protected block logic and raise the TAE regardless. This is verified by one of the tests in mono/tests/abort-cctor.cs.
        */
        MonoExceptionHandle exc = MONO_HANDLE_NEW (MonoException, NULL);
        if (mono_thread_request_interruption_managed (&exc))
                mono_error_set_exception_handle (error, exc);
        else
                mono_thread_info_self_interrupt ();

        HANDLE_FUNCTION_RETURN ();
}

typedef struct {
        MonoInternalThread *thread;
        gboolean interrupt;
        MonoThreadInfoInterruptToken *interrupt_token;
} SuspendThreadData;

static SuspendThreadResult
async_suspend_critical (MonoThreadInfo *info, gpointer ud)
{
        SuspendThreadData *data = (SuspendThreadData *)ud;
        MonoInternalThread *thread = data->thread;
        MonoJitInfo *ji = NULL;
        gboolean protected_wrapper;
        gboolean running_managed;

        ji = mono_thread_info_get_last_managed (info);
        protected_wrapper = ji && !ji->is_trampoline && !ji->async && mono_threads_is_critical_method (mono_jit_info_get_method (ji));
        running_managed = mono_jit_info_match (ji, MONO_CONTEXT_GET_IP (&mono_thread_info_get_suspend_state (info)->ctx));

        if (running_managed && !protected_wrapper) {
                if (mono_threads_are_safepoints_enabled ()) {
                        mono_thread_info_setup_async_call (info, self_interrupt_thread, NULL);
                        return MonoResumeThread;
                } else {
                        thread->state &= ~ThreadState_SuspendRequested;
                        thread->state |= ThreadState_Suspended;
                        return KeepSuspended;
                }
        } else {
                mono_thread_set_interruption_requested (thread);
                if (data->interrupt)
                        data->interrupt_token = mono_thread_info_prepare_interrupt ((MonoThreadInfo *)thread->thread_info);

                return MonoResumeThread;
        }
}

/* LOCKING: called with @thread longlived->synch_cs held, and releases it */
static void
async_suspend_internal (MonoInternalThread *thread, gboolean interrupt)
{
        SuspendThreadData data;

        g_assert (thread != mono_thread_internal_current ());

        // g_async_safe_printf ("ASYNC SUSPEND thread %p\n", thread_get_tid (thread));

        thread->self_suspended = FALSE;

        data.thread = thread;
        data.interrupt = interrupt;
        data.interrupt_token = NULL;

        mono_thread_info_safe_suspend_and_run (thread_get_tid (thread), interrupt, async_suspend_critical, &data);
        if (data.interrupt_token)
                mono_thread_info_finish_interrupt (data.interrupt_token);

        UNLOCK_THREAD (thread);
}

/* LOCKING: called with @thread longlived->synch_cs held, and releases it */
static void
self_suspend_internal (void)
{
        MonoInternalThread *thread;
        MonoOSEvent *event;
        MonoOSEventWaitRet res;

        thread = mono_thread_internal_current ();

        // g_async_safe_printf ("SELF SUSPEND thread %p\n", thread_get_tid (thread));

        thread->self_suspended = TRUE;

        thread->state &= ~ThreadState_SuspendRequested;
        thread->state |= ThreadState_Suspended;

        UNLOCK_THREAD (thread);

        event = thread->suspended;

        MONO_ENTER_GC_SAFE;
        res = mono_os_event_wait_one (event, MONO_INFINITE_WAIT, TRUE);
        g_assert (res == MONO_OS_EVENT_WAIT_RET_SUCCESS_0 || res == MONO_OS_EVENT_WAIT_RET_ALERTED);
        MONO_EXIT_GC_SAFE;
}

static void
suspend_for_shutdown_async_call (gpointer unused)
{
        for (;;)
                mono_thread_info_yield ();
}

static SuspendThreadResult
suspend_for_shutdown_critical (MonoThreadInfo *info, gpointer unused)
{
        mono_thread_info_setup_async_call (info, suspend_for_shutdown_async_call, NULL);
        return MonoResumeThread;
}

void
mono_thread_internal_suspend_for_shutdown (MonoInternalThread *thread)
{
        g_assert (thread != mono_thread_internal_current ());

        mono_thread_info_safe_suspend_and_run (thread_get_tid (thread), FALSE, suspend_for_shutdown_critical, NULL);
}

/**
 * mono_thread_is_foreign:
 * \param thread the thread to query
 *
 * This function allows one to determine if a thread was created by the mono runtime and has
 * a well defined lifecycle or it's a foreign one, created by the native environment.
 *
 * \returns TRUE if \p thread was not created by the runtime.
 */
mono_bool
mono_thread_is_foreign (MonoThread *thread)
{
        mono_bool result;
        MONO_ENTER_GC_UNSAFE;
        MonoThreadInfo *info = (MonoThreadInfo *)thread->internal_thread->thread_info;
        result = (info->runtime_thread == FALSE);
        MONO_EXIT_GC_UNSAFE;
        return result;
}

#ifndef HOST_WIN32
static void
threads_native_thread_join_lock (gpointer tid, gpointer value)
{
        /*
         * Have to cast to a pointer-sized integer first, as we can't narrow
         * from a pointer if pthread_t is an integer smaller than a pointer.
         */
        pthread_t thread = (pthread_t)(intptr_t)tid;
        if (thread != pthread_self ()) {
                MONO_ENTER_GC_SAFE;
                /* This shouldn't block */
                mono_threads_join_lock ();
                mono_native_thread_join (thread);
                mono_threads_join_unlock ();
                MONO_EXIT_GC_SAFE;
        }
}
static void
threads_native_thread_join_nolock (gpointer tid, gpointer value)
{
        pthread_t thread = (pthread_t)(intptr_t)tid;
        MONO_ENTER_GC_SAFE;
        mono_native_thread_join (thread);
        MONO_EXIT_GC_SAFE;
}

static void
threads_add_joinable_thread_nolock (gpointer tid)
{
        g_hash_table_insert (joinable_threads, tid, tid);
}
#else
static void
threads_native_thread_join_lock (gpointer tid, gpointer value)
{
        MonoNativeThreadId thread_id = (MonoNativeThreadId)(guint64)tid;
        HANDLE thread_handle = (HANDLE)value;
        if (thread_id != GetCurrentThreadId () && thread_handle != NULL && thread_handle != INVALID_HANDLE_VALUE) {
                MONO_ENTER_GC_SAFE;
                /* This shouldn't block */
                mono_threads_join_lock ();
                mono_native_thread_join_handle (thread_handle, TRUE);
                mono_threads_join_unlock ();
                MONO_EXIT_GC_SAFE;
        }
}

static void
threads_native_thread_join_nolock (gpointer tid, gpointer value)
{
        HANDLE thread_handle = (HANDLE)value;
        MONO_ENTER_GC_SAFE;
        mono_native_thread_join_handle (thread_handle, TRUE);
        MONO_EXIT_GC_SAFE;
}

static void
threads_add_joinable_thread_nolock (gpointer tid)
{
        g_hash_table_insert (joinable_threads, tid, (gpointer)OpenThread (SYNCHRONIZE, TRUE, (MonoNativeThreadId)(guint64)tid));
}
#endif

static void
threads_add_pending_joinable_thread (gpointer tid)
{
        joinable_threads_lock ();

        if (!pending_joinable_threads)
                pending_joinable_threads = g_hash_table_new (NULL, NULL);

        gpointer orig_key;
        gpointer value;

        if (!g_hash_table_lookup_extended (pending_joinable_threads, tid, &orig_key, &value)) {
                g_hash_table_insert (pending_joinable_threads, tid, tid);
                UnlockedIncrement (&pending_joinable_thread_count);
        }

        joinable_threads_unlock ();
}

static void
threads_add_pending_joinable_runtime_thread (MonoThreadInfo *mono_thread_info)
{
        g_assert (mono_thread_info);

        if (mono_thread_info->runtime_thread) {
                threads_add_pending_joinable_thread ((gpointer)(MONO_UINT_TO_NATIVE_THREAD_ID (mono_thread_info_get_tid (mono_thread_info))));
        }
}

static void
threads_remove_pending_joinable_thread_nolock (gpointer tid)
{
        gpointer orig_key;
        gpointer value;

        if (pending_joinable_threads && g_hash_table_lookup_extended (pending_joinable_threads, tid, &orig_key, &value)) {
                g_hash_table_remove (pending_joinable_threads, tid);
                if (UnlockedDecrement (&pending_joinable_thread_count) == 0)
                        mono_coop_cond_broadcast (&zero_pending_joinable_thread_event);
        }
}

static gboolean
threads_wait_pending_joinable_threads (uint32_t timeout)
{
        if (UnlockedRead (&pending_joinable_thread_count) > 0) {
                joinable_threads_lock ();
                if (timeout == MONO_INFINITE_WAIT) {
                        while (UnlockedRead (&pending_joinable_thread_count) > 0)
                                mono_coop_cond_wait (&zero_pending_joinable_thread_event, &joinable_threads_mutex);
                } else {
                        gint64 start = mono_msec_ticks ();
                        gint64 elapsed = 0;
                        while (UnlockedRead (&pending_joinable_thread_count) > 0 && elapsed < timeout) {
                                mono_coop_cond_timedwait (&zero_pending_joinable_thread_event, &joinable_threads_mutex, timeout - (uint32_t)elapsed);
                                elapsed = mono_msec_ticks () - start;
                        }
                }
                joinable_threads_unlock ();
        }

        return UnlockedRead (&pending_joinable_thread_count) == 0;
}

static void
threads_add_unique_joinable_thread_nolock (gpointer tid)
{
        if (!joinable_threads)
                joinable_threads = g_hash_table_new (NULL, NULL);

        gpointer orig_key;
        gpointer value;

        if (!g_hash_table_lookup_extended (joinable_threads, tid, &orig_key, &value)) {
                threads_add_joinable_thread_nolock (tid);
                UnlockedIncrement (&joinable_thread_count);
        }
}

void
mono_threads_add_joinable_runtime_thread (MonoThreadInfo *thread_info)
{
        g_assert (thread_info);
        MonoThreadInfo *mono_thread_info = thread_info;

        if (mono_thread_info->runtime_thread) {
                gpointer tid = (gpointer)(MONO_UINT_TO_NATIVE_THREAD_ID (mono_thread_info_get_tid (mono_thread_info)));

                joinable_threads_lock ();

                // Add to joinable thread list, if not already included.
                threads_add_unique_joinable_thread_nolock (tid);

                // Remove thread from pending joinable list, if present.
                threads_remove_pending_joinable_thread_nolock (tid);

                joinable_threads_unlock ();

                mono_gc_finalize_notify ();
        }
}

static void
threads_add_pending_native_thread_join_call_nolock (gpointer tid)
{
        if (!pending_native_thread_join_calls)
                pending_native_thread_join_calls = g_hash_table_new (NULL, NULL);

        gpointer orig_key;
        gpointer value;

        if (!g_hash_table_lookup_extended (pending_native_thread_join_calls, tid, &orig_key, &value))
                g_hash_table_insert (pending_native_thread_join_calls, tid, tid);
}

static void
threads_remove_pending_native_thread_join_call_nolock (gpointer tid)
{
        if (pending_native_thread_join_calls)
                g_hash_table_remove (pending_native_thread_join_calls, tid);

        mono_coop_cond_broadcast (&pending_native_thread_join_calls_event);
}

static void
threads_wait_pending_native_thread_join_call_nolock (gpointer tid)
{
        gpointer orig_key;
        gpointer value;

        while (g_hash_table_lookup_extended (pending_native_thread_join_calls, tid, &orig_key, &value)) {
                mono_coop_cond_wait (&pending_native_thread_join_calls_event, &joinable_threads_mutex);
        }
}

/*
 * mono_add_joinable_thread:
 *
 *   Add TID to the list of joinable threads.
 * LOCKING: Acquires the threads lock.
 */
void
mono_threads_add_joinable_thread (gpointer tid)
{
        /*
         * We cannot detach from threads because it causes problems like
         * 2fd16f60/r114307. So we collect them and join them when
         * we have time (in the finalizer thread).
         */
        joinable_threads_lock ();
        threads_add_unique_joinable_thread_nolock (tid);
        joinable_threads_unlock ();

        mono_gc_finalize_notify ();
}

/*
 * mono_threads_join_threads:
 *
 *   Join all joinable threads. This is called from the finalizer thread.
 * LOCKING: Acquires the threads lock.
 */
void
mono_threads_join_threads (void)
{
        GHashTableIter iter;
        gpointer key = NULL;
        gpointer value = NULL;
        gboolean found = FALSE;

        /* Fastpath */
        if (!UnlockedRead (&joinable_thread_count))
                return;

        while (TRUE) {
                joinable_threads_lock ();
                if (found) {
                        // Previous native thread join call completed.
                        threads_remove_pending_native_thread_join_call_nolock (key);
                }
                found = FALSE;
                if (g_hash_table_size (joinable_threads)) {
                        g_hash_table_iter_init (&iter, joinable_threads);
                        g_hash_table_iter_next (&iter, &key, (void**)&value);
                        g_hash_table_remove (joinable_threads, key);
                        UnlockedDecrement (&joinable_thread_count);
                        found = TRUE;

                        // Add to table of tid's with pending native thread join call.
                        threads_add_pending_native_thread_join_call_nolock (key);
                }
                joinable_threads_unlock ();
                if (found)
                        threads_native_thread_join_lock (key, value);
                else
                        break;
        }
}

/*
 * mono_thread_join:
 *
 *   Wait for thread TID to exit.
 * LOCKING: Acquires the threads lock.
 */
void
mono_thread_join (gpointer tid)
{
        gboolean found = FALSE;
        gpointer orig_key;
        gpointer value;

        joinable_threads_lock ();
        if (!joinable_threads)
                joinable_threads = g_hash_table_new (NULL, NULL);

        if (g_hash_table_lookup_extended (joinable_threads, tid, &orig_key, &value)) {
                g_hash_table_remove (joinable_threads, tid);
                UnlockedDecrement (&joinable_thread_count);
                found = TRUE;

                // Add to table of tid's with pending native join call.
                threads_add_pending_native_thread_join_call_nolock (tid);
        }

        if (!found) {
                // Wait for any pending native thread join call not yet completed for this tid.
                threads_wait_pending_native_thread_join_call_nolock (tid);
        }

        joinable_threads_unlock ();

        if (!found)
                return;

        threads_native_thread_join_nolock (tid, value);

        joinable_threads_lock ();
        // Native thread join call completed for this tid.
        threads_remove_pending_native_thread_join_call_nolock (tid);
        joinable_threads_unlock ();
}

void
mono_thread_internal_unhandled_exception (MonoObject* exc)
{
        MonoClass *klass = exc->vtable->klass;
        if (is_threadabort_exception (klass)) {
                mono_thread_internal_reset_abort (mono_thread_internal_current ());
        } else if (!is_appdomainunloaded_exception (klass)
                && mono_runtime_unhandled_exception_policy_get () == MONO_UNHANDLED_POLICY_CURRENT) {
                mono_unhandled_exception_internal (exc);
                if (mono_environment_exitcode_get () == 1) {
                        mono_environment_exitcode_set (255);
                        mono_invoke_unhandled_exception_hook (exc);
                        g_assert_not_reached ();
                }
        }
}

/*
 * mono_threads_attach_coop_internal: called by native->managed wrappers
 *
 *  - @cookie:
 *    - blocking mode: contains gc unsafe transition cookie
 *    - non-blocking mode: contains random data
 *  - @stackdata: semi-opaque struct: stackpointer and function_name
 *  - @return: the original domain which needs to be restored, or NULL.
 */
MonoDomain*
mono_threads_attach_coop_internal (MonoDomain *domain, gpointer *cookie, MonoStackData *stackdata)
{
        MonoDomain *orig;
        MonoThreadInfo *info;
        gboolean external = FALSE;

        orig = mono_domain_get ();

        if (!domain) {
                /* Happens when called from AOTed code which is only used in the root domain. */
                domain = mono_get_root_domain ();
                g_assert (domain);
        }

        /* On coop, when we detached, we moved the thread from  RUNNING->BLOCKING.
         * If we try to reattach we do a BLOCKING->RUNNING transition.  If the thread
         * is fresh, mono_thread_attach() will do a STARTING->RUNNING transition so
         * we're only responsible for making the cookie. */
        if (mono_threads_is_blocking_transition_enabled ())
                external = !(info = mono_thread_info_current_unchecked ()) || !mono_thread_info_is_live (info);

        if (!mono_thread_internal_current ()) {
                mono_thread_attach (domain);

                // #678164
                mono_thread_set_state (mono_thread_internal_current (), ThreadState_Background);
        }

        if (mono_threads_is_blocking_transition_enabled ()) {
                if (external) {
                        /* mono_thread_attach put the thread in RUNNING mode from STARTING, but we need to
                         * return the right cookie. */
                        *cookie = mono_threads_enter_gc_unsafe_region_cookie ();
                } else {
                        /* thread state (BLOCKING|RUNNING) -> RUNNING */
                        *cookie = mono_threads_enter_gc_unsafe_region_unbalanced_internal (stackdata);
                }
        }

        if (orig != domain)
                mono_domain_set_fast (domain, TRUE);

        return orig;
}

/*
 * mono_threads_attach_coop: called by native->managed wrappers
 *
 *  - @dummy:
 *    - blocking mode: contains gc unsafe transition cookie
 *    - non-blocking mode: contains random data
 *    - a pointer to stack, used for some checks
 *  - @return: the original domain which needs to be restored, or NULL.
 */
gpointer
mono_threads_attach_coop (MonoDomain *domain, gpointer *dummy)
{
        MONO_STACKDATA (stackdata);
        stackdata.stackpointer = dummy;
        return mono_threads_attach_coop_internal (domain, dummy, &stackdata);
}

/*
 * mono_threads_detach_coop_internal: called by native->managed wrappers
 *
 *  - @orig: the original domain which needs to be restored, or NULL.
 *  - @stackdata: semi-opaque struct: stackpointer and function_name
 *  - @cookie:
 *    - blocking mode: contains gc unsafe transition cookie
 *    - non-blocking mode: contains random data
 */
void
mono_threads_detach_coop_internal (MonoDomain *orig, gpointer cookie, MonoStackData *stackdata)
{
        MonoDomain *domain = mono_domain_get ();
        g_assert (domain);

        if (orig != domain) {
                if (!orig)
                        mono_domain_unset ();
                else
                        mono_domain_set_fast (orig, TRUE);
        }

        if (mono_threads_is_blocking_transition_enabled ()) {
                /* it won't do anything if cookie is NULL
                 * thread state RUNNING -> (RUNNING|BLOCKING) */
                mono_threads_exit_gc_unsafe_region_unbalanced_internal (cookie, stackdata);
        }
}

/*
 * mono_threads_detach_coop: called by native->managed wrappers
 *
 *  - @orig: the original domain which needs to be restored, or NULL.
 *  - @dummy:
 *    - blocking mode: contains gc unsafe transition cookie
 *    - non-blocking mode: contains random data
 *    - a pointer to stack, used for some checks
 */
void
mono_threads_detach_coop (gpointer orig, gpointer *dummy)
{
        MONO_STACKDATA (stackdata);
        stackdata.stackpointer = dummy;
        mono_threads_detach_coop_internal ((MonoDomain*)orig, *dummy, &stackdata);
}

#if 0
/* Returns TRUE if the current thread is ready to be interrupted. */
gboolean
mono_threads_is_ready_to_be_interrupted (void)
{
        MonoInternalThread *thread;

        thread = mono_thread_internal_current ();
        LOCK_THREAD (thread);
        if (thread->state & (ThreadState_SuspendRequested | ThreadState_AbortRequested)) {
                UNLOCK_THREAD (thread);
                return FALSE;
        }

        if (mono_thread_get_abort_prot_block_count (thread) || mono_get_eh_callbacks ()->mono_current_thread_has_handle_block_guard ()) {
                UNLOCK_THREAD (thread);
                return FALSE;
        }

        UNLOCK_THREAD (thread);
        return TRUE;
}
#endif

void
mono_thread_internal_describe (MonoInternalThread *internal, GString *text)
{
        g_string_append_printf (text, ", thread handle : %p", internal->handle);

        if (internal->thread_info) {
                g_string_append (text, ", state : ");
                mono_thread_info_describe_interrupt_token (internal->thread_info, text);
        }

        if (internal->owned_mutexes) {
                int i;

                g_string_append (text, ", owns : [");
                for (i = 0; i < internal->owned_mutexes->len; i++)
                        g_string_append_printf (text, i == 0 ? "%p" : ", %p", g_ptr_array_index (internal->owned_mutexes, i));
                g_string_append (text, "]");
        }
}

gboolean
mono_thread_internal_is_current (MonoInternalThread *internal)
{
        g_assert (internal);
        return mono_native_thread_id_equals (mono_native_thread_id_get (), MONO_UINT_TO_NATIVE_THREAD_ID (internal->tid));
}

void
mono_set_thread_dump_dir (gchar* dir) {
        thread_dump_dir = dir;
}

#ifdef DISABLE_CRASH_REPORTING
void
mono_threads_summarize_init (void)
{
}

gboolean
mono_threads_summarize (MonoContext *ctx, gchar **out, MonoStackHash *hashes, gboolean silent, gboolean signal_handler_controller, gchar *mem, size_t provided_size)
{
        return FALSE;
}

gboolean
mono_threads_summarize_one (MonoThreadSummary *out, MonoContext *ctx)
{
        return FALSE;
}

#else

static gboolean
mono_threads_summarize_native_self (MonoThreadSummary *out, MonoContext *ctx)
{
        if (!mono_get_eh_callbacks ()->mono_summarize_managed_stack)
                return FALSE;

        memset (out, 0, sizeof (MonoThreadSummary));
        out->ctx = ctx;

        MonoNativeThreadId current = mono_native_thread_id_get();
        out->native_thread_id = (intptr_t) current;

        mono_get_eh_callbacks ()->mono_summarize_unmanaged_stack (out);

        mono_native_thread_get_name (current, out->name, MONO_MAX_SUMMARY_NAME_LEN);

        return TRUE;
}

// Not safe to call from signal handler
gboolean
mono_threads_summarize_one (MonoThreadSummary *out, MonoContext *ctx)
{
        gboolean success = mono_threads_summarize_native_self (out, ctx);

        // Finish this on the same thread

        if (success && mono_get_eh_callbacks ()->mono_summarize_managed_stack)
                mono_get_eh_callbacks ()->mono_summarize_managed_stack (out);

        return success;
}

#define MAX_NUM_THREADS 128
typedef struct {
        gint32 has_owner; // state of this memory

        MonoSemType update; // notify of addition of threads

        int nthreads;
        MonoNativeThreadId thread_array [MAX_NUM_THREADS]; // ids of threads we're dumping

        int nthreads_attached; // Number of threads self-registered
        MonoThreadSummary *all_threads [MAX_NUM_THREADS];

        gboolean silent; // print to stdout
} SummarizerGlobalState;

#if defined(HAVE_KILL) && !defined(HOST_ANDROID) && defined(HAVE_WAITPID) && defined(HAVE_EXECVE) && ((!defined(HOST_DARWIN) && defined(SYS_fork)) || HAVE_FORK)
#define HAVE_MONO_SUMMARIZER_SUPERVISOR 1
#endif

static void
summarizer_supervisor_init (void);

typedef struct {
        MonoSemType supervisor;
        pid_t pid;
        pid_t supervisor_pid;
} SummarizerSupervisorState;

#ifndef HAVE_MONO_SUMMARIZER_SUPERVISOR

void
summarizer_supervisor_init (void)
{
        return;
}

static pid_t
summarizer_supervisor_start (SummarizerSupervisorState *state)
{
        // nonzero, so caller doesn't think it's the supervisor
        return (pid_t) 1;
}

static void
summarizer_supervisor_end (SummarizerSupervisorState *state)
{
        return;
}

#else
static const char *hang_watchdog_path;

void
summarizer_supervisor_init (void)
{
        hang_watchdog_path = g_build_filename (mono_get_config_dir (), "..", "bin", "mono-hang-watchdog", NULL);
        g_assert (hang_watchdog_path);
}

static pid_t
summarizer_supervisor_start (SummarizerSupervisorState *state)
{
        memset (state, 0, sizeof (*state));
        pid_t pid;

        state->pid = getpid();

        /*
        * glibc fork acquires some locks, so if the crash happened inside malloc/free,
        * it will deadlock. Call the syscall directly instead.
        */
#if defined(HOST_ANDROID)
        /* SYS_fork is defined to be __NR_fork which is not defined in some ndk versions */
        // We disable this when we set HAVE_MONO_SUMMARIZER_SUPERVISOR above
        g_assert_not_reached ();
#elif !defined(HOST_DARWIN) && defined(SYS_fork)
        pid = (pid_t) syscall (SYS_fork);
#elif HAVE_FORK
        pid = (pid_t) fork ();
#else
        g_assert_not_reached ();
#endif

        if (pid != 0)
                state->supervisor_pid = pid;
        else {
                char pid_str[20]; // pid is a uint64_t, 20 digits max in decimal form
                sprintf (pid_str, "%" PRIu64, (uint64_t)state->pid);
                const char *const args[] = { hang_watchdog_path, pid_str, NULL };
                execve (args[0], (char * const*)args, NULL); // run 'mono-hang-watchdog [pid]'
                g_async_safe_printf ("Could not exec mono-hang-watchdog, expected on path '%s' (errno %d)\n", hang_watchdog_path, errno);
                exit (1);
        }

        return pid;
}

static void
summarizer_supervisor_end (SummarizerSupervisorState *state)
{
#ifdef HAVE_KILL
        kill (state->supervisor_pid, SIGKILL);
#endif

#if defined (HAVE_WAITPID)
        // Accessed on same thread that sets it.
        int status;
        waitpid (state->supervisor_pid, &status, 0);
#endif
}
#endif

static void
collect_thread_id (gpointer key, gpointer value, gpointer user)
{
        CollectThreadIdsUserData *ud = (CollectThreadIdsUserData *)user;
        MonoInternalThread *thread = (MonoInternalThread *)value;

        if (ud->nthreads < ud->max_threads)
                ud->threads [ud->nthreads ++] = thread_get_tid (thread);
}

static int
collect_thread_ids (MonoNativeThreadId *thread_ids, int max_threads)
{
        CollectThreadIdsUserData ud;

        mono_memory_barrier ();
        if (!threads)
                return 0;

        memset (&ud, 0, sizeof (ud));
        /* This array contains refs, but its on the stack, so its ok */
        ud.threads = thread_ids;
        ud.max_threads = max_threads;

        mono_threads_lock ();
        mono_g_hash_table_foreach (threads, collect_thread_id, &ud);
        mono_threads_unlock ();

        return ud.nthreads;
}

static gboolean
summarizer_state_init (SummarizerGlobalState *state, MonoNativeThreadId current, int *my_index)
{
        gint32 started_state = mono_atomic_cas_i32 (&state->has_owner, 1 /* set */, 0 /* compare */);
        gboolean not_started = started_state == 0;
        if (not_started) {
                state->nthreads = collect_thread_ids (state->thread_array, MAX_NUM_THREADS);
                mono_os_sem_init (&state->update, 0);
        }

        for (int i = 0; i < state->nthreads; i++) {
                if (state->thread_array [i] == current) {
                        *my_index = i;
                        break;
                }
        }

        return not_started;
}

static void
summarizer_signal_other_threads (SummarizerGlobalState *state, MonoNativeThreadId current, int current_idx)
{
        sigset_t sigset, old_sigset;
        sigemptyset(&sigset);
        sigaddset(&sigset, SIGTERM);

        for (int i=0; i < state->nthreads; i++) {
                sigprocmask (SIG_UNBLOCK, &sigset, &old_sigset);

                if (i == current_idx)
                        continue;
        #ifdef HAVE_PTHREAD_KILL
                pthread_kill (state->thread_array [i], SIGTERM);

                if (!state->silent)
                        g_async_safe_printf("Pkilling 0x%" G_GSIZE_FORMAT "x from 0x%" G_GSIZE_FORMAT "x\n", (gsize)MONO_NATIVE_THREAD_ID_TO_UINT (state->thread_array [i]), (gsize)MONO_NATIVE_THREAD_ID_TO_UINT (current));
        #else
                g_error ("pthread_kill () is not supported by this platform");
        #endif
        }
}

// Returns true when there are shared global references to "this_thread"
static gboolean
summarizer_post_dump (SummarizerGlobalState *state, MonoThreadSummary *this_thread, int current_idx)
{
        mono_memory_barrier ();

        gpointer old = mono_atomic_cas_ptr ((volatile gpointer *)&state->all_threads [current_idx], this_thread, NULL);

        if (old == GINT_TO_POINTER (-1)) {
                g_async_safe_printf ("Trying to register response after dumping period ended");
                return FALSE;
        } else if (old != NULL) {
                g_async_safe_printf ("Thread dump raced for thread slot.");
                return FALSE;
        } 

        // We added our pointer
        gint32 count = mono_atomic_inc_i32 ((volatile gint32 *) &state->nthreads_attached);
        if (count == state->nthreads)
                mono_os_sem_post (&state->update);

        return TRUE;
}

// A lockless spinwait with a timeout
// Used in environments where locks are unsafe
//
// If set_pos is true, we wait until the expected number of threads have
// responded and then count that the expected number are set. If it is not true,
// then we wait for them to be unset.
static void
summary_timedwait (SummarizerGlobalState *state, int timeout_seconds)
{
        const gint64 milliseconds_in_second = 1000;
        gint64 timeout_total = milliseconds_in_second * timeout_seconds;

        gint64 end = mono_msec_ticks () + timeout_total;

        while (TRUE) {
                if (mono_atomic_load_i32 ((volatile gint32 *) &state->nthreads_attached) == state->nthreads)
                        break;

                gint64 now = mono_msec_ticks ();
                gint64 remaining = end - now;
                if (remaining <= 0)
                        break;

                mono_os_sem_timedwait (&state->update, remaining, MONO_SEM_FLAGS_NONE);
        }

        return;
}

static MonoThreadSummary *
summarizer_try_read_thread (SummarizerGlobalState *state, int index)
{
        gpointer old_value = NULL;
        gpointer new_value = GINT_TO_POINTER(-1);

        do {
                old_value = state->all_threads [index];
        } while (mono_atomic_cas_ptr ((volatile gpointer *) &state->all_threads [index], new_value, old_value) != old_value);

        MonoThreadSummary *thread = (MonoThreadSummary *) old_value;
        return thread;
}

static void
summarizer_state_term (SummarizerGlobalState *state, gchar **out, gchar *mem, size_t provided_size, MonoThreadSummary *controlling)
{
        // See the array writes
        mono_memory_barrier ();

        MonoThreadSummary *threads [MAX_NUM_THREADS];
        memset (threads, 0, sizeof(threads));

        mono_summarize_timeline_phase_log (MonoSummaryManagedStacks);
        for (int i=0; i < state->nthreads; i++) {
                threads [i] = summarizer_try_read_thread (state, i);
                if (!threads [i])
                        continue;

                // We are doing this dump on the controlling thread because this isn't
                // an async context sometimes. There's still some reliance on malloc here, but it's
                // much more stable to do it all from the controlling thread.
                //
                // This is non-null, checked in mono_threads_summarize
                // with early exit there
                mono_get_eh_callbacks ()->mono_summarize_managed_stack (threads [i]);
        }

        /* The value of the breadcrumb should match the "StackHash" value written by `mono_merp_write_fingerprint_payload` */
        mono_create_crash_hash_breadcrumb (controlling);

        MonoStateWriter writer;
        memset (&writer, 0, sizeof (writer));

        mono_summarize_timeline_phase_log (MonoSummaryStateWriter);
        mono_summarize_native_state_begin (&writer, mem, provided_size);
        for (int i=0; i < state->nthreads; i++) {
                MonoThreadSummary *thread = threads [i];
                if (!thread)
                        continue;

                mono_summarize_native_state_add_thread (&writer, thread, thread->ctx, thread == controlling);
                // Set non-shared state to notify the waiting thread to clean up
                // without having to keep our shared state alive
                mono_atomic_store_i32 (&thread->done, 0x1);
                mono_os_sem_post (&thread->done_wait);
        }
        *out = mono_summarize_native_state_end (&writer);
        mono_summarize_timeline_phase_log (MonoSummaryStateWriterDone);

        mono_os_sem_destroy (&state->update);

        memset (state, 0, sizeof (*state));
        mono_atomic_store_i32 ((volatile gint32 *)&state->has_owner, 0);
}

static void
summarizer_state_wait (MonoThreadSummary *thread)
{
        gint64 milliseconds_in_second = 1000;

        // cond_wait can spuriously wake up, so we need to check
        // done
        while (!mono_atomic_load_i32 (&thread->done))
                mono_os_sem_timedwait (&thread->done_wait, milliseconds_in_second, MONO_SEM_FLAGS_NONE);
}

static gboolean
mono_threads_summarize_execute_internal (MonoContext *ctx, gchar **out, MonoStackHash *hashes, gboolean silent, gchar *working_mem, size_t provided_size, gboolean this_thread_controls)
{
        static SummarizerGlobalState state;

        int current_idx;
        MonoNativeThreadId current = mono_native_thread_id_get ();
        gboolean thread_given_control = summarizer_state_init (&state, current, &current_idx);

        g_assert (this_thread_controls == thread_given_control);

        if (state.nthreads == 0) {
                if (!silent)
                        g_async_safe_printf("No threads attached to runtime.\n");
                memset (&state, 0, sizeof (state));
                return FALSE;
        }

        if (this_thread_controls) {
                g_assert (working_mem);

                mono_summarize_timeline_phase_log (MonoSummarySuspendHandshake);
                state.silent = silent;
                summarizer_signal_other_threads (&state, current, current_idx);
                mono_summarize_timeline_phase_log (MonoSummaryUnmanagedStacks);
        }

        MonoStateMem mem;
        gboolean success = mono_state_alloc_mem (&mem, (long) current, sizeof (MonoThreadSummary));
        if (!success)
                return FALSE;

        MonoThreadSummary *this_thread = (MonoThreadSummary *) mem.mem;

        if (mono_threads_summarize_native_self (this_thread, ctx)) {
                // Init the synchronization between the controlling thread and the 
                // providing thread
                mono_os_sem_init (&this_thread->done_wait, 0);

                // Store a reference to our stack memory into global state
                gboolean success = summarizer_post_dump (&state, this_thread, current_idx);
                if (!success && !state.silent)
                        g_async_safe_printf("Thread 0x%" G_GSIZE_FORMAT "x reported itself.\n", (gsize)MONO_NATIVE_THREAD_ID_TO_UINT (current));
        } else if (!state.silent) {
                g_async_safe_printf("Thread 0x%" G_GSIZE_FORMAT "x couldn't report itself.\n", (gsize)MONO_NATIVE_THREAD_ID_TO_UINT (current));
        }

        // From summarizer, wait and dump.
        if (this_thread_controls) {
                if (!state.silent)
                        g_async_safe_printf("Entering thread summarizer pause from 0x%" G_GSIZE_FORMAT "x\n", (gsize)MONO_NATIVE_THREAD_ID_TO_UINT (current));

                // Wait up to 2 seconds for all of the other threads to catch up
                summary_timedwait (&state, 2);

                if (!state.silent)
                        g_async_safe_printf("Finished thread summarizer pause from 0x%" G_GSIZE_FORMAT "x.\n", (gsize)MONO_NATIVE_THREAD_ID_TO_UINT (current));

                // Dump and cleanup all the stack memory
                summarizer_state_term (&state, out, working_mem, provided_size, this_thread);
        } else {
                // Wait here, keeping our stack memory alive
                // for the dumper
                summarizer_state_wait (this_thread);
        }

        // FIXME: How many threads should be counted?
        if (hashes)
                *hashes = this_thread->hashes;

        mono_state_free_mem (&mem);

        return TRUE;
}

void
mono_threads_summarize_init (void)
{
        summarizer_supervisor_init ();
}

gboolean
mono_threads_summarize_execute (MonoContext *ctx, gchar **out, MonoStackHash *hashes, gboolean silent, gchar *working_mem, size_t provided_size)
{
        gboolean result;
        gboolean already_async = mono_thread_info_is_async_context ();
        if (!already_async)
                mono_thread_info_set_is_async_context (TRUE);
        result = mono_threads_summarize_execute_internal (ctx, out, hashes, silent, working_mem, provided_size, FALSE);
        if (!already_async)
                mono_thread_info_set_is_async_context (FALSE);
        return result;
}

gboolean 
mono_threads_summarize (MonoContext *ctx, gchar **out, MonoStackHash *hashes, gboolean silent, gboolean signal_handler_controller, gchar *mem, size_t provided_size)
{
        if (!mono_get_eh_callbacks ()->mono_summarize_managed_stack)
                return FALSE;

        // The staggered values are due to the need to use inc_i64 for the first value
        static gint64 next_pending_request_id = 0;
        static gint64 request_available_to_run = 1;
        gint64 this_request_id = mono_atomic_inc_i64 ((volatile gint64 *) &next_pending_request_id);

        // This is a global queue of summary requests. 
        // It's not safe to signal a thread while they're in the
        // middle of a dump. Dladdr is not reentrant. It's the one lock
        // we rely on being able to take. 
        //
        // We don't use it in almost any other place in managed code, so 
        // our problem is in the stack dumping code racing with the signalling code.
        //
        // A dump is wait-free to the degree that it's not going to loop indefinitely.
        // If we're running from a crash handler block, we're not in any position to 
        // wait for an in-flight dump to finish. If we crashed while dumping, we cannot dump.
        // We should simply return so we can die cleanly.
        //
        // signal_handler_controller should be set only from a handler that expects itself to be the only
        // entry point, where the runtime already being dumping means we should just give up

        gboolean success = FALSE;

        while (TRUE) {
                gint64 next_request_id = mono_atomic_load_i64 ((volatile gint64 *) &request_available_to_run);

                if (next_request_id == this_request_id) {
                        gboolean already_async = mono_thread_info_is_async_context ();
                        if (!already_async)
                                mono_thread_info_set_is_async_context (TRUE);

                        SummarizerSupervisorState synch;
                        if (summarizer_supervisor_start (&synch)) {
                                g_assert (mem);
                                success = mono_threads_summarize_execute_internal (ctx, out, hashes, silent, mem, provided_size, TRUE);
                                summarizer_supervisor_end (&synch);
                        }

                        if (!already_async)
                                mono_thread_info_set_is_async_context (FALSE);

                        // Only the thread that gets the ticket can unblock future dumpers.
                        mono_atomic_inc_i64 ((volatile gint64 *) &request_available_to_run);
                        break;
                } else if (signal_handler_controller) {
                        // We're done. We can't do anything.
                        g_async_safe_printf ("Attempted to dump for critical failure when already in dump. Error reporting crashed?");
                        mono_summarize_double_fault_log ();
                        break;
                } else {
                        if (!silent)
                                g_async_safe_printf ("Waiting for in-flight dump to complete.");
                        sleep (2);
                }
        }

        return success;
}

#endif

#ifdef ENABLE_NETCORE
void
ves_icall_System_Threading_Thread_StartInternal (MonoThreadObjectHandle thread_handle, MonoError *error)
{
        MonoThread *internal = MONO_HANDLE_RAW (thread_handle);
        gboolean res;

        THREAD_DEBUG (g_message("%s: Trying to start a new thread: this (%p)", __func__, internal));

#ifdef DISABLE_THREADS
        mono_error_set_not_supported (error, NULL);
        return;
#endif

        LOCK_THREAD (internal);

        if ((internal->state & ThreadState_Unstarted) == 0) {
                UNLOCK_THREAD (internal);
                mono_error_set_exception_thread_state (error, "Thread has already been started.");
                return;
        }

        if ((internal->state & ThreadState_Aborted) != 0) {
                UNLOCK_THREAD (internal);
                return;
        }

        res = create_thread (internal, internal, NULL, NULL, NULL, MONO_THREAD_CREATE_FLAGS_NONE, error);
        if (!res) {
                UNLOCK_THREAD (internal);
                return;
        }

        internal->state &= ~ThreadState_Unstarted;

        THREAD_DEBUG (g_message ("%s: Started thread ID %" G_GSIZE_FORMAT " (handle %p)", __func__, (gsize)internal->tid, internal->handle));

        UNLOCK_THREAD (internal);
}

void
ves_icall_System_Threading_Thread_InitInternal (MonoThreadObjectHandle thread_handle, MonoError *error)
{
        MonoThread *internal = MONO_HANDLE_RAW (thread_handle);

        // Need to initialize thread objects created from managed code
        init_internal_thread_object (internal);
        internal->state = ThreadState_Unstarted;
        MONO_OBJECT_SETREF_INTERNAL (internal, internal_thread, internal);
}

guint64
ves_icall_System_Threading_Thread_GetCurrentOSThreadId (MonoError *error)
{
        return mono_native_thread_os_id_get ();
}

gint32
ves_icall_System_Threading_Thread_GetCurrentProcessorNumber (MonoError *error)
{
        return mono_native_thread_processor_id_get ();
}

#endif