[System] Tweak socket test

[mono-project.git] / mono / profiler / mono-profiler-log.c

/*
 * mono-profiler-log.c: mono log profiler
 *
 * Authors:
 *   Paolo Molaro (lupus@ximian.com)
 *   Alex Rønne Petersen (alexrp@xamarin.com)
 *
 * Copyright 2010 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 <mono/metadata/assembly.h>
#include <mono/metadata/debug-helpers.h>
#include "../metadata/metadata-internals.h"
#include <mono/metadata/mono-config.h>
#include <mono/metadata/mono-gc.h>
#include <mono/metadata/mono-perfcounters.h>
#include <mono/metadata/profiler.h>
#include <mono/utils/atomic.h>
#include <mono/utils/hazard-pointer.h>
#include <mono/utils/lock-free-alloc.h>
#include <mono/utils/lock-free-queue.h>
#include <mono/utils/mono-conc-hashtable.h>
#include <mono/utils/mono-counters.h>
#include <mono/utils/mono-linked-list-set.h>
#include <mono/utils/mono-membar.h>
#include <mono/utils/mono-mmap.h>
#include <mono/utils/mono-os-mutex.h>
#include <mono/utils/mono-os-semaphore.h>
#include <mono/utils/mono-threads.h>
#include <mono/utils/mono-threads-api.h>
#include "mono-profiler-log.h"

#ifdef HAVE_DLFCN_H
#include <dlfcn.h>
#endif
#include <fcntl.h>
#ifdef HAVE_LINK_H
#include <link.h>
#endif
#ifdef HAVE_UNISTD_H
#include <unistd.h>
#endif
#if defined(__APPLE__)
#include <mach/mach_time.h>
#endif
#include <netinet/in.h>
#ifdef HAVE_SYS_MMAN_H
#include <sys/mman.h>
#endif
#include <sys/socket.h>
#if defined (HAVE_SYS_ZLIB)
#include <zlib.h>
#endif

#ifdef HAVE_SCHED_GETAFFINITY
#  ifndef GLIBC_HAS_CPU_COUNT
static int
CPU_COUNT(cpu_set_t *set)
{
        int i, count = 0;

        for (int i = 0; i < CPU_SETSIZE; i++)
                if (CPU_ISSET(i, set))
                        count++;
        return count;
}
#  endif
#endif

#define BUFFER_SIZE (4096 * 16)

/* Worst-case size in bytes of a 64-bit value encoded with LEB128. */
#define LEB128_SIZE 10

/* Size of a value encoded as a single byte. */
#undef BYTE_SIZE // mach/i386/vm_param.h on OS X defines this to 8, but it isn't used for anything.
#define BYTE_SIZE 1

/* Size in bytes of the event prefix (ID + time). */
#define EVENT_SIZE (BYTE_SIZE + LEB128_SIZE)

static volatile gint32 runtime_inited;
static volatile gint32 in_shutdown;

static gboolean no_counters;
static int nocalls = 0;
static int notraces = 0;
static int use_zip = 0;
static int do_report = 0;
static int do_heap_shot = 0;
static int max_call_depth = 100;
static int command_port = 0;
static int heapshot_requested = 0;
static int sample_freq = 0;
static int do_mono_sample = 0;
static int do_debug = 0;
static int do_coverage = 0;
static gboolean only_coverage;
static gboolean debug_coverage = FALSE;
static MonoProfileSamplingMode sampling_mode = MONO_PROFILER_STAT_MODE_PROCESS;
static int max_allocated_sample_hits;

// Statistics for internal profiler data structures.
static gint32 sample_allocations_ctr,
              buffer_allocations_ctr;

// Statistics for profiler events.
static gint32 sync_points_ctr,
              heap_objects_ctr,
              heap_starts_ctr,
              heap_ends_ctr,
              heap_roots_ctr,
              gc_events_ctr,
              gc_resizes_ctr,
              gc_allocs_ctr,
              gc_moves_ctr,
              gc_handle_creations_ctr,
              gc_handle_deletions_ctr,
              finalize_begins_ctr,
              finalize_ends_ctr,
              finalize_object_begins_ctr,
              finalize_object_ends_ctr,
              image_loads_ctr,
              image_unloads_ctr,
              assembly_loads_ctr,
              assembly_unloads_ctr,
              class_loads_ctr,
              class_unloads_ctr,
              method_entries_ctr,
              method_exits_ctr,
              method_exception_exits_ctr,
              method_jits_ctr,
              code_buffers_ctr,
              exception_throws_ctr,
              exception_clauses_ctr,
              monitor_contentions_ctr,
              monitor_acquisitions_ctr,
              monitor_failures_ctr,
              thread_starts_ctr,
              thread_ends_ctr,
              thread_names_ctr,
              domain_loads_ctr,
              domain_unloads_ctr,
              domain_names_ctr,
              context_loads_ctr,
              context_unloads_ctr,
              sample_ubins_ctr,
              sample_usyms_ctr,
              sample_hits_ctr,
              counter_descriptors_ctr,
              counter_samples_ctr,
              perfcounter_descriptors_ctr,
              perfcounter_samples_ctr,
              coverage_methods_ctr,
              coverage_statements_ctr,
              coverage_classes_ctr,
              coverage_assemblies_ctr;

static MonoLinkedListSet profiler_thread_list;

/*
 * file format:
 * [header] [buffer]*
 *
 * The file is composed by a header followed by 0 or more buffers.
 * Each buffer contains events that happened on a thread: for a given thread
 * buffers that appear later in the file are guaranteed to contain events
 * that happened later in time. Buffers from separate threads could be interleaved,
 * though.
 * Buffers are not required to be aligned.
 *
 * header format:
 * [id: 4 bytes] constant value: LOG_HEADER_ID
 * [major: 1 byte] [minor: 1 byte] major and minor version of the log profiler
 * [format: 1 byte] version of the data format for the rest of the file
 * [ptrsize: 1 byte] size in bytes of a pointer in the profiled program
 * [startup time: 8 bytes] time in milliseconds since the unix epoch when the program started
 * [timer overhead: 4 bytes] approximate overhead in nanoseconds of the timer
 * [flags: 4 bytes] file format flags, should be 0 for now
 * [pid: 4 bytes] pid of the profiled process
 * [port: 2 bytes] tcp port for server if != 0
 * [args size: 4 bytes] size of args
 * [args: string] arguments passed to the profiler
 * [arch size: 4 bytes] size of arch
 * [arch: string] architecture the profiler is running on
 * [os size: 4 bytes] size of os
 * [os: string] operating system the profiler is running on
 *
 * The multiple byte integers are in little-endian format.
 *
 * buffer format:
 * [buffer header] [event]*
 * Buffers have a fixed-size header followed by 0 or more bytes of event data.
 * Timing information and other values in the event data are usually stored
 * as uleb128 or sleb128 integers. To save space, as noted for each item below,
 * some data is represented as a difference between the actual value and
 * either the last value of the same type (like for timing information) or
 * as the difference from a value stored in a buffer header.
 *
 * For timing information the data is stored as uleb128, since timing
 * increases in a monotonic way in each thread: the value is the number of
 * nanoseconds to add to the last seen timing data in a buffer. The first value
 * in a buffer will be calculated from the time_base field in the buffer head.
 *
 * Object or heap sizes are stored as uleb128.
 * Pointer differences are stored as sleb128, instead.
 *
 * If an unexpected value is found, the rest of the buffer should be ignored,
 * as generally the later values need the former to be interpreted correctly.
 *
 * buffer header format:
 * [bufid: 4 bytes] constant value: BUF_ID
 * [len: 4 bytes] size of the data following the buffer header
 * [time_base: 8 bytes] time base in nanoseconds since an unspecified epoch
 * [ptr_base: 8 bytes] base value for pointers
 * [obj_base: 8 bytes] base value for object addresses
 * [thread id: 8 bytes] system-specific thread ID (pthread_t for example)
 * [method_base: 8 bytes] base value for MonoMethod pointers
 *
 * event format:
 * [extended info: upper 4 bits] [type: lower 4 bits]
 * [time diff: uleb128] nanoseconds since last timing
 * [data]*
 * The data that follows depends on type and the extended info.
 * Type is one of the enum values in mono-profiler-log.h: TYPE_ALLOC, TYPE_GC,
 * TYPE_METADATA, TYPE_METHOD, TYPE_EXCEPTION, TYPE_MONITOR, TYPE_HEAP.
 * The extended info bits are interpreted based on type, see
 * each individual event description below.
 * strings are represented as a 0-terminated utf8 sequence.
 *
 * backtrace format:
 * [num: uleb128] number of frames following
 * [frame: sleb128]* mum MonoMethod* as a pointer difference from the last such
 * pointer or the buffer method_base
 *
 * type alloc format:
 * type: TYPE_ALLOC
 * exinfo: flags: TYPE_ALLOC_BT
 * [ptr: sleb128] class as a byte difference from ptr_base
 * [obj: sleb128] object address as a byte difference from obj_base
 * [size: uleb128] size of the object in the heap
 * If the TYPE_ALLOC_BT flag is set, a backtrace follows.
 *
 * type GC format:
 * type: TYPE_GC
 * exinfo: one of TYPE_GC_EVENT, TYPE_GC_RESIZE, TYPE_GC_MOVE, TYPE_GC_HANDLE_CREATED[_BT],
 * TYPE_GC_HANDLE_DESTROYED[_BT], TYPE_GC_FINALIZE_START, TYPE_GC_FINALIZE_END,
 * TYPE_GC_FINALIZE_OBJECT_START, TYPE_GC_FINALIZE_OBJECT_END
 * if exinfo == TYPE_GC_RESIZE
 *      [heap_size: uleb128] new heap size
 * if exinfo == TYPE_GC_EVENT
 *      [event type: byte] GC event (MONO_GC_EVENT_* from profiler.h)
 *      [generation: byte] GC generation event refers to
 * if exinfo == TYPE_GC_MOVE
 *      [num_objects: uleb128] number of object moves that follow
 *      [objaddr: sleb128]+ num_objects object pointer differences from obj_base
 *      num is always an even number: the even items are the old
 *      addresses, the odd numbers are the respective new object addresses
 * if exinfo == TYPE_GC_HANDLE_CREATED[_BT]
 *      [handle_type: uleb128] GC handle type (System.Runtime.InteropServices.GCHandleType)
 *      upper bits reserved as flags
 *      [handle: uleb128] GC handle value
 *      [objaddr: sleb128] object pointer differences from obj_base
 *      If exinfo == TYPE_GC_HANDLE_CREATED_BT, a backtrace follows.
 * if exinfo == TYPE_GC_HANDLE_DESTROYED[_BT]
 *      [handle_type: uleb128] GC handle type (System.Runtime.InteropServices.GCHandleType)
 *      upper bits reserved as flags
 *      [handle: uleb128] GC handle value
 *      If exinfo == TYPE_GC_HANDLE_DESTROYED_BT, a backtrace follows.
 * if exinfo == TYPE_GC_FINALIZE_OBJECT_{START,END}
 *      [object: sleb128] the object as a difference from obj_base
 *
 * type metadata format:
 * type: TYPE_METADATA
 * exinfo: one of: TYPE_END_LOAD, TYPE_END_UNLOAD (optional for TYPE_THREAD and TYPE_DOMAIN)
 * [mtype: byte] metadata type, one of: TYPE_CLASS, TYPE_IMAGE, TYPE_ASSEMBLY, TYPE_DOMAIN,
 * TYPE_THREAD, TYPE_CONTEXT
 * [pointer: sleb128] pointer of the metadata type depending on mtype
 * if mtype == TYPE_CLASS
 *      [image: sleb128] MonoImage* as a pointer difference from ptr_base
 *      [name: string] full class name
 * if mtype == TYPE_IMAGE
 *      [name: string] image file name
 * if mtype == TYPE_ASSEMBLY
 *      [name: string] assembly name
 * if mtype == TYPE_DOMAIN && exinfo == 0
 *      [name: string] domain friendly name
 * if mtype == TYPE_CONTEXT
 *      [domain: sleb128] domain id as pointer
 * if mtype == TYPE_THREAD && exinfo == 0
 *      [name: string] thread name
 *
 * type method format:
 * type: TYPE_METHOD
 * exinfo: one of: TYPE_LEAVE, TYPE_ENTER, TYPE_EXC_LEAVE, TYPE_JIT
 * [method: sleb128] MonoMethod* as a pointer difference from the last such
 * pointer or the buffer method_base
 * if exinfo == TYPE_JIT
 *      [code address: sleb128] pointer to the native code as a diff from ptr_base
 *      [code size: uleb128] size of the generated code
 *      [name: string] full method name
 *
 * type exception format:
 * type: TYPE_EXCEPTION
 * exinfo: TYPE_THROW_BT flag or one of: TYPE_CLAUSE
 * if exinfo == TYPE_CLAUSE
 *      [clause type: byte] MonoExceptionEnum enum value
 *      [clause index: uleb128] index of the current clause
 *      [method: sleb128] MonoMethod* as a pointer difference from the last such
 *      pointer or the buffer method_base
 * else
 *      [object: sleb128] the exception object as a difference from obj_base
 *      if exinfo has TYPE_THROW_BT set, a backtrace follows.
 *
 * type runtime format:
 * type: TYPE_RUNTIME
 * exinfo: one of: TYPE_JITHELPER
 * if exinfo == TYPE_JITHELPER
 *      [type: byte] MonoProfilerCodeBufferType enum value
 *      [buffer address: sleb128] pointer to the native code as a diff from ptr_base
 *      [buffer size: uleb128] size of the generated code
 *      if type == MONO_PROFILER_CODE_BUFFER_SPECIFIC_TRAMPOLINE
 *              [name: string] buffer description name
 *
 * type monitor format:
 * type: TYPE_MONITOR
 * exinfo: TYPE_MONITOR_BT flag and one of: MONO_PROFILER_MONITOR_(CONTENTION|FAIL|DONE)
 * [object: sleb128] the lock object as a difference from obj_base
 * if exinfo.low3bits == MONO_PROFILER_MONITOR_CONTENTION
 *      If the TYPE_MONITOR_BT flag is set, a backtrace follows.
 *
 * type heap format
 * type: TYPE_HEAP
 * exinfo: one of TYPE_HEAP_START, TYPE_HEAP_END, TYPE_HEAP_OBJECT, TYPE_HEAP_ROOT
 * if exinfo == TYPE_HEAP_OBJECT
 *      [object: sleb128] the object as a difference from obj_base
 *      [class: sleb128] the object MonoClass* as a difference from ptr_base
 *      [size: uleb128] size of the object on the heap
 *      [num_refs: uleb128] number of object references
 *      each referenced objref is preceded by a uleb128 encoded offset: the
 *      first offset is from the object address and each next offset is relative
 *      to the previous one
 *      [objrefs: sleb128]+ object referenced as a difference from obj_base
 *      The same object can appear multiple times, but only the first time
 *      with size != 0: in the other cases this data will only be used to
 *      provide additional referenced objects.
 * if exinfo == TYPE_HEAP_ROOT
 *      [num_roots: uleb128] number of root references
 *      [num_gc: uleb128] number of major gcs
 *      [object: sleb128] the object as a difference from obj_base
 *      [root_type: byte] the root_type: MonoProfileGCRootType (profiler.h)
 *      [extra_info: uleb128] the extra_info value
 *      object, root_type and extra_info are repeated num_roots times
 *
 * type sample format
 * type: TYPE_SAMPLE
 * exinfo: one of TYPE_SAMPLE_HIT, TYPE_SAMPLE_USYM, TYPE_SAMPLE_UBIN, TYPE_SAMPLE_COUNTERS_DESC, TYPE_SAMPLE_COUNTERS
 * if exinfo == TYPE_SAMPLE_HIT
 *      [thread: sleb128] thread id as difference from ptr_base
 *      [count: uleb128] number of following instruction addresses
 *      [ip: sleb128]* instruction pointer as difference from ptr_base
 *      [mbt_count: uleb128] number of managed backtrace frames
 *      [method: sleb128]* MonoMethod* as a pointer difference from the last such
 *      pointer or the buffer method_base (the first such method can be also indentified by ip, but this is not neccessarily true)
 * if exinfo == TYPE_SAMPLE_USYM
 *      [address: sleb128] symbol address as a difference from ptr_base
 *      [size: uleb128] symbol size (may be 0 if unknown)
 *      [name: string] symbol name
 * if exinfo == TYPE_SAMPLE_UBIN
 *      [address: sleb128] address where binary has been loaded
 *      [offset: uleb128] file offset of mapping (the same file can be mapped multiple times)
 *      [size: uleb128] memory size
 *      [name: string] binary name
 * if exinfo == TYPE_SAMPLE_COUNTERS_DESC
 *      [len: uleb128] number of counters
 *      for i = 0 to len
 *              [section: uleb128] section of counter
 *              if section == MONO_COUNTER_PERFCOUNTERS:
 *                      [section_name: string] section name of counter
 *              [name: string] name of counter
 *              [type: byte] type of counter
 *              [unit: byte] unit of counter
 *              [variance: byte] variance of counter
 *              [index: uleb128] unique index of counter
 * if exinfo == TYPE_SAMPLE_COUNTERS
 *      while true:
 *              [index: uleb128] unique index of counter
 *              if index == 0:
 *                      break
 *              [type: byte] type of counter value
 *              if type == string:
 *                      if value == null:
 *                              [0: uleb128] 0 -> value is null
 *                      else:
 *                              [1: uleb128] 1 -> value is not null
 *                              [value: string] counter value
 *              else:
 *                      [value: uleb128/sleb128/double] counter value, can be sleb128, uleb128 or double (determined by using type)
 *
 * type coverage format
 * type: TYPE_COVERAGE
 * exinfo: one of TYPE_COVERAGE_METHOD, TYPE_COVERAGE_STATEMENT, TYPE_COVERAGE_ASSEMBLY, TYPE_COVERAGE_CLASS
 * if exinfo == TYPE_COVERAGE_METHOD
 *  [assembly: string] name of assembly
 *  [class: string] name of the class
 *  [name: string] name of the method
 *  [signature: string] the signature of the method
 *  [filename: string] the file path of the file that contains this method
 *  [token: uleb128] the method token
 *  [method_id: uleb128] an ID for this data to associate with the buffers of TYPE_COVERAGE_STATEMENTS
 *  [len: uleb128] the number of TYPE_COVERAGE_BUFFERS associated with this method
 * if exinfo == TYPE_COVERAGE_STATEMENTS
 *  [method_id: uleb128] an the TYPE_COVERAGE_METHOD buffer to associate this with
 *  [offset: uleb128] the il offset relative to the previous offset
 *  [counter: uleb128] the counter for this instruction
 *  [line: uleb128] the line of filename containing this instruction
 *  [column: uleb128] the column containing this instruction
 * if exinfo == TYPE_COVERAGE_ASSEMBLY
 *  [name: string] assembly name
 *  [guid: string] assembly GUID
 *  [filename: string] assembly filename
 *  [number_of_methods: uleb128] the number of methods in this assembly
 *  [fully_covered: uleb128] the number of fully covered methods
 *  [partially_covered: uleb128] the number of partially covered methods
 *    currently partially_covered will always be 0, and fully_covered is the
 *    number of methods that are fully and partially covered.
 * if exinfo == TYPE_COVERAGE_CLASS
 *  [name: string] assembly name
 *  [class: string] class name
 *  [number_of_methods: uleb128] the number of methods in this class
 *  [fully_covered: uleb128] the number of fully covered methods
 *  [partially_covered: uleb128] the number of partially covered methods
 *    currently partially_covered will always be 0, and fully_covered is the
 *    number of methods that are fully and partially covered.
 *
 * type meta format:
 * type: TYPE_META
 * exinfo: one of: TYPE_SYNC_POINT
 * if exinfo == TYPE_SYNC_POINT
 *      [type: byte] MonoProfilerSyncPointType enum value
 */

// Pending data to be written to the log, for a single thread.
// Threads periodically flush their own LogBuffers by calling safe_send
typedef struct _LogBuffer LogBuffer;
struct _LogBuffer {
        // Next (older) LogBuffer in processing queue
        LogBuffer *next;

        uint64_t time_base;
        uint64_t last_time;
        uintptr_t ptr_base;
        uintptr_t method_base;
        uintptr_t last_method;
        uintptr_t obj_base;
        uintptr_t thread_id;

        // Bytes allocated for this LogBuffer
        int size;

        // Start of currently unused space in buffer
        unsigned char* cursor;

        // Pointer to start-of-structure-plus-size (for convenience)
        unsigned char* buf_end;

        // Start of data in buffer. Contents follow "buffer format" described above.
        unsigned char buf [1];
};

typedef struct {
        MonoLinkedListSetNode node;

        // Convenience pointer to the profiler structure.
        MonoProfiler *profiler;

        // Was this thread added to the LLS?
        gboolean attached;

        // The current log buffer for this thread.
        LogBuffer *buffer;

        // Methods referenced by events in `buffer`, see `MethodInfo`.
        GPtrArray *methods;

        // Current call depth for enter/leave events.
        int call_depth;

        // Indicates whether this thread is currently writing to its `buffer`.
        gboolean busy;

        // Has this thread written a thread end event to `buffer`?
        gboolean ended;
} MonoProfilerThread;

static uintptr_t
thread_id (void)
{
        return (uintptr_t) mono_native_thread_id_get ();
}

static uintptr_t
process_id (void)
{
#ifdef HOST_WIN32
        return (uintptr_t) GetCurrentProcessId ();
#else
        return (uintptr_t) getpid ();
#endif
}

#ifdef __APPLE__
static mach_timebase_info_data_t timebase_info;
#elif defined (HOST_WIN32)
static LARGE_INTEGER pcounter_freq;
#endif

#define TICKS_PER_SEC 1000000000LL

static uint64_t
current_time (void)
{
#ifdef __APPLE__
        uint64_t time = mach_absolute_time ();

        time *= timebase_info.numer;
        time /= timebase_info.denom;

        return time;
#elif defined (HOST_WIN32)
        LARGE_INTEGER value;

        QueryPerformanceCounter (&value);

        return value.QuadPart * TICKS_PER_SEC / pcounter_freq.QuadPart;
#elif defined (CLOCK_MONOTONIC)
        struct timespec tspec;

        clock_gettime (CLOCK_MONOTONIC, &tspec);

        return ((uint64_t) tspec.tv_sec * TICKS_PER_SEC + tspec.tv_nsec);
#else
        struct timeval tv;

        gettimeofday (&tv, NULL);

        return ((uint64_t) tv.tv_sec * TICKS_PER_SEC + tv.tv_usec * 1000);
#endif
}

static int timer_overhead;

static void
init_time (void)
{
#ifdef __APPLE__
        mach_timebase_info (&timebase_info);
#elif defined (HOST_WIN32)
        QueryPerformanceFrequency (&pcounter_freq);
#endif

        uint64_t time_start = current_time ();

        for (int i = 0; i < 256; ++i)
                current_time ();

        uint64_t time_end = current_time ();

        timer_overhead = (time_end - time_start) / 256;
}

/*
 * These macros should be used when writing an event to a log buffer. They take
 * care of a bunch of stuff that can be repetitive and error-prone, such as
 * acquiring/releasing the buffer lock, incrementing the event counter,
 * expanding the log buffer, processing requests, etc. They also create a scope
 * so that it's harder to leak the LogBuffer pointer, which can be problematic
 * as the pointer is unstable when the buffer lock isn't acquired.
 */

#define ENTER_LOG(COUNTER, BUFFER, SIZE) \
        do { \
                MonoProfilerThread *thread__ = PROF_TLS_GET (); \
                if (thread__->attached) \
                        buffer_lock (); \
                g_assert (!thread__->busy && "Why are we trying to write a new event while already writing one?"); \
                thread__->busy = TRUE; \
                InterlockedIncrement ((COUNTER)); \
                LogBuffer *BUFFER = ensure_logbuf_unsafe (thread__, (SIZE))

#define EXIT_LOG_EXPLICIT(SEND, REQUESTS) \
                thread__->busy = FALSE; \
                if ((SEND)) \
                        send_log_unsafe (TRUE); \
                if (thread__->attached) \
                        buffer_unlock (); \
                if ((REQUESTS)) \
                        process_requests (); \
        } while (0)

// Pass these to EXIT_LOG_EXPLICIT () for easier reading.
#define DO_SEND TRUE
#define NO_SEND FALSE
#define DO_REQUESTS TRUE
#define NO_REQUESTS FALSE

#define EXIT_LOG EXIT_LOG_EXPLICIT (DO_SEND, DO_REQUESTS)

static volatile gint32 buffer_rwlock_count;
static volatile gpointer buffer_rwlock_exclusive;

// Can be used recursively.
static void
buffer_lock (void)
{
        /*
         * If the thread holding the exclusive lock tries to modify the
         * reader count, just make it a no-op. This way, we also avoid
         * invoking the GC safe point macros below, which could break if
         * done from a thread that is currently the initiator of STW.
         *
         * In other words, we rely on the fact that the GC thread takes
         * the exclusive lock in the gc_event () callback when the world
         * is about to stop.
         */
        if (InterlockedReadPointer (&buffer_rwlock_exclusive) != (gpointer) thread_id ()) {
                MONO_ENTER_GC_SAFE;

                while (InterlockedReadPointer (&buffer_rwlock_exclusive))
                        mono_thread_info_yield ();

                InterlockedIncrement (&buffer_rwlock_count);

                MONO_EXIT_GC_SAFE;
        }

        mono_memory_barrier ();
}

static void
buffer_unlock (void)
{
        mono_memory_barrier ();

        // See the comment in buffer_lock ().
        if (InterlockedReadPointer (&buffer_rwlock_exclusive) == (gpointer) thread_id ())
                return;

        g_assert (InterlockedRead (&buffer_rwlock_count) && "Why are we trying to decrement a zero reader count?");

        InterlockedDecrement (&buffer_rwlock_count);
}

// Cannot be used recursively.
static void
buffer_lock_excl (void)
{
        gpointer tid = (gpointer) thread_id ();

        g_assert (InterlockedReadPointer (&buffer_rwlock_exclusive) != tid && "Why are we taking the exclusive lock twice?");

        MONO_ENTER_GC_SAFE;

        while (InterlockedCompareExchangePointer (&buffer_rwlock_exclusive, tid, 0))
                mono_thread_info_yield ();

        while (InterlockedRead (&buffer_rwlock_count))
                mono_thread_info_yield ();

        MONO_EXIT_GC_SAFE;

        mono_memory_barrier ();
}

static void
buffer_unlock_excl (void)
{
        mono_memory_barrier ();

        g_assert (InterlockedReadPointer (&buffer_rwlock_exclusive) && "Why is the exclusive lock not held?");
        g_assert (InterlockedReadPointer (&buffer_rwlock_exclusive) == (gpointer) thread_id () && "Why does another thread hold the exclusive lock?");
        g_assert (!InterlockedRead (&buffer_rwlock_count) && "Why are there readers when the exclusive lock is held?");

        InterlockedWritePointer (&buffer_rwlock_exclusive, NULL);
}

typedef struct _BinaryObject BinaryObject;
struct _BinaryObject {
        BinaryObject *next;
        void *addr;
        char *name;
};

struct _MonoProfiler {
        FILE* file;
#if defined (HAVE_SYS_ZLIB)
        gzFile gzfile;
#endif
        char *args;
        uint64_t startup_time;
        int pipe_output;
        int command_port;
        int server_socket;
        int pipes [2];
        MonoNativeThreadId helper_thread;
        MonoNativeThreadId writer_thread;
        MonoNativeThreadId dumper_thread;
        volatile gint32 run_writer_thread;
        MonoLockFreeAllocSizeClass writer_entry_size_class;
        MonoLockFreeAllocator writer_entry_allocator;
        MonoLockFreeQueue writer_queue;
        MonoSemType writer_queue_sem;
        MonoConcurrentHashTable *method_table;
        mono_mutex_t method_table_mutex;
        volatile gint32 run_dumper_thread;
        MonoLockFreeQueue dumper_queue;
        MonoSemType dumper_queue_sem;
        MonoLockFreeAllocSizeClass sample_size_class;
        MonoLockFreeAllocator sample_allocator;
        MonoLockFreeQueue sample_reuse_queue;
        BinaryObject *binary_objects;
        GPtrArray *coverage_filters;
};

typedef struct {
        MonoLockFreeQueueNode node;
        GPtrArray *methods;
        LogBuffer *buffer;
} WriterQueueEntry;

#define WRITER_ENTRY_BLOCK_SIZE (mono_pagesize ())

typedef struct {
        MonoMethod *method;
        MonoJitInfo *ji;
        uint64_t time;
} MethodInfo;

#ifdef HOST_WIN32

#define PROF_TLS_SET(VAL) (TlsSetValue (profiler_tls, (VAL)))
#define PROF_TLS_GET() ((MonoProfilerThread *) TlsGetValue (profiler_tls))
#define PROF_TLS_INIT() (profiler_tls = TlsAlloc ())
#define PROF_TLS_FREE() (TlsFree (profiler_tls))

static DWORD profiler_tls;

#elif HAVE_KW_THREAD

#define PROF_TLS_SET(VAL) (profiler_tls = (VAL))
#define PROF_TLS_GET() (profiler_tls)
#define PROF_TLS_INIT()
#define PROF_TLS_FREE()

static __thread MonoProfilerThread *profiler_tls;

#else

#define PROF_TLS_SET(VAL) (pthread_setspecific (profiler_tls, (VAL)))
#define PROF_TLS_GET() ((MonoProfilerThread *) pthread_getspecific (profiler_tls))
#define PROF_TLS_INIT() (pthread_key_create (&profiler_tls, NULL))
#define PROF_TLS_FREE() (pthread_key_delete (profiler_tls))

static pthread_key_t profiler_tls;

#endif

static char*
pstrdup (const char *s)
{
        int len = strlen (s) + 1;
        char *p = (char *) g_malloc (len);
        memcpy (p, s, len);
        return p;
}

static void *
alloc_buffer (int size)
{
        return mono_valloc (NULL, size, MONO_MMAP_READ | MONO_MMAP_WRITE | MONO_MMAP_ANON | MONO_MMAP_PRIVATE, MONO_MEM_ACCOUNT_PROFILER);
}

static void
free_buffer (void *buf, int size)
{
        mono_vfree (buf, size, MONO_MEM_ACCOUNT_PROFILER);
}

static LogBuffer*
create_buffer (uintptr_t tid)
{
        LogBuffer* buf = (LogBuffer *) alloc_buffer (BUFFER_SIZE);

        InterlockedIncrement (&buffer_allocations_ctr);

        buf->size = BUFFER_SIZE;
        buf->time_base = current_time ();
        buf->last_time = buf->time_base;
        buf->buf_end = (unsigned char *) buf + buf->size;
        buf->cursor = buf->buf;
        buf->thread_id = tid;

        return buf;
}

/*
 * Must be called with the reader lock held if thread is the current thread, or
 * the exclusive lock if thread is a different thread. However, if thread is
 * the current thread, and init_thread () was called with add_to_lls = FALSE,
 * then no locking is necessary.
 */
static void
init_buffer_state (MonoProfilerThread *thread)
{
        thread->buffer = create_buffer (thread->node.key);
        thread->methods = NULL;
}

static void
clear_hazard_pointers (MonoThreadHazardPointers *hp)
{
        mono_hazard_pointer_clear (hp, 0);
        mono_hazard_pointer_clear (hp, 1);
        mono_hazard_pointer_clear (hp, 2);
}

static MonoProfilerThread *
init_thread (MonoProfiler *prof, gboolean add_to_lls)
{
        MonoProfilerThread *thread = PROF_TLS_GET ();

        /*
         * Sometimes we may try to initialize a thread twice. One example is the
         * main thread: We initialize it when setting up the profiler, but we will
         * also get a thread_start () callback for it. Another example is when
         * attaching new threads to the runtime: We may get a gc_alloc () callback
         * for that thread's thread object (where we initialize it), soon followed
         * by a thread_start () callback.
         *
         * These cases are harmless anyhow. Just return if we've already done the
         * initialization work.
         */
        if (thread)
                return thread;

        thread = g_malloc (sizeof (MonoProfilerThread));
        thread->node.key = thread_id ();
        thread->profiler = prof;
        thread->attached = add_to_lls;
        thread->call_depth = 0;
        thread->busy = 0;
        thread->ended = FALSE;

        init_buffer_state (thread);

        /*
         * Some internal profiler threads don't need to be cleaned up
         * by the main thread on shutdown.
         */
        if (add_to_lls) {
                MonoThreadHazardPointers *hp = mono_hazard_pointer_get ();
                g_assert (mono_lls_insert (&profiler_thread_list, hp, &thread->node) && "Why can't we insert the thread in the LLS?");
                clear_hazard_pointers (hp);
        }

        PROF_TLS_SET (thread);

        return thread;
}

// Only valid if init_thread () was called with add_to_lls = FALSE.
static void
deinit_thread (MonoProfilerThread *thread)
{
        g_assert (!thread->attached && "Why are we manually freeing an attached thread?");

        g_free (thread);
        PROF_TLS_SET (NULL);
}

// Only valid if init_thread () was called with add_to_lls = FALSE.
static LogBuffer *
ensure_logbuf_unsafe (MonoProfilerThread *thread, int bytes)
{
        LogBuffer *old = thread->buffer;

        if (old && old->cursor + bytes + 100 < old->buf_end)
                return old;

        LogBuffer *new_ = create_buffer (thread->node.key);
        new_->next = old;
        thread->buffer = new_;

        return new_;
}

static void
encode_uleb128 (uint64_t value, uint8_t *buf, uint8_t **endbuf)
{
        uint8_t *p = buf;

        do {
                uint8_t b = value & 0x7f;
                value >>= 7;

                if (value != 0) /* more bytes to come */
                        b |= 0x80;

                *p ++ = b;
        } while (value);

        *endbuf = p;
}

static void
encode_sleb128 (intptr_t value, uint8_t *buf, uint8_t **endbuf)
{
        int more = 1;
        int negative = (value < 0);
        unsigned int size = sizeof (intptr_t) * 8;
        uint8_t byte;
        uint8_t *p = buf;

        while (more) {
                byte = value & 0x7f;
                value >>= 7;

                /* the following is unnecessary if the
                 * implementation of >>= uses an arithmetic rather
                 * than logical shift for a signed left operand
                 */
                if (negative)
                        /* sign extend */
                        value |= - ((intptr_t) 1 <<(size - 7));

                /* sign bit of byte is second high order bit (0x40) */
                if ((value == 0 && !(byte & 0x40)) ||
                    (value == -1 && (byte & 0x40)))
                        more = 0;
                else
                        byte |= 0x80;

                *p ++= byte;
        }

        *endbuf = p;
}

static void
emit_byte (LogBuffer *logbuffer, int value)
{
        logbuffer->cursor [0] = value;
        logbuffer->cursor++;

        g_assert (logbuffer->cursor <= logbuffer->buf_end && "Why are we writing past the buffer end?");
}

static void
emit_value (LogBuffer *logbuffer, int value)
{
        encode_uleb128 (value, logbuffer->cursor, &logbuffer->cursor);

        g_assert (logbuffer->cursor <= logbuffer->buf_end && "Why are we writing past the buffer end?");
}

static void
emit_time (LogBuffer *logbuffer, uint64_t value)
{
        uint64_t tdiff = value - logbuffer->last_time;
        encode_uleb128 (tdiff, logbuffer->cursor, &logbuffer->cursor);
        logbuffer->last_time = value;

        g_assert (logbuffer->cursor <= logbuffer->buf_end && "Why are we writing past the buffer end?");
}

static void
emit_event_time (LogBuffer *logbuffer, int event, uint64_t time)
{
        emit_byte (logbuffer, event);
        emit_time (logbuffer, time);
}

static void
emit_event (LogBuffer *logbuffer, int event)
{
        emit_event_time (logbuffer, event, current_time ());
}

static void
emit_svalue (LogBuffer *logbuffer, int64_t value)
{
        encode_sleb128 (value, logbuffer->cursor, &logbuffer->cursor);

        g_assert (logbuffer->cursor <= logbuffer->buf_end && "Why are we writing past the buffer end?");
}

static void
emit_uvalue (LogBuffer *logbuffer, uint64_t value)
{
        encode_uleb128 (value, logbuffer->cursor, &logbuffer->cursor);

        g_assert (logbuffer->cursor <= logbuffer->buf_end && "Why are we writing past the buffer end?");
}

static void
emit_ptr (LogBuffer *logbuffer, void *ptr)
{
        if (!logbuffer->ptr_base)
                logbuffer->ptr_base = (uintptr_t) ptr;

        emit_svalue (logbuffer, (intptr_t) ptr - logbuffer->ptr_base);

        g_assert (logbuffer->cursor <= logbuffer->buf_end && "Why are we writing past the buffer end?");
}

static void
emit_method_inner (LogBuffer *logbuffer, void *method)
{
        if (!logbuffer->method_base) {
                logbuffer->method_base = (intptr_t) method;
                logbuffer->last_method = (intptr_t) method;
        }

        encode_sleb128 ((intptr_t) ((char *) method - (char *) logbuffer->last_method), logbuffer->cursor, &logbuffer->cursor);
        logbuffer->last_method = (intptr_t) method;

        g_assert (logbuffer->cursor <= logbuffer->buf_end && "Why are we writing past the buffer end?");
}

static void
register_method_local (MonoMethod *method, MonoJitInfo *ji)
{
        MonoProfilerThread *thread = PROF_TLS_GET ();

        if (!mono_conc_hashtable_lookup (thread->profiler->method_table, method)) {
                MethodInfo *info = (MethodInfo *) g_malloc (sizeof (MethodInfo));

                info->method = method;
                info->ji = ji;
                info->time = current_time ();

                GPtrArray *arr = thread->methods ? thread->methods : (thread->methods = g_ptr_array_new ());
                g_ptr_array_add (arr, info);
        }
}

static void
emit_method (LogBuffer *logbuffer, MonoMethod *method)
{
        register_method_local (method, NULL);
        emit_method_inner (logbuffer, method);
}

static void
emit_obj (LogBuffer *logbuffer, void *ptr)
{
        if (!logbuffer->obj_base)
                logbuffer->obj_base = (uintptr_t) ptr >> 3;

        emit_svalue (logbuffer, ((uintptr_t) ptr >> 3) - logbuffer->obj_base);

        g_assert (logbuffer->cursor <= logbuffer->buf_end && "Why are we writing past the buffer end?");
}

static void
emit_string (LogBuffer *logbuffer, const char *str, size_t size)
{
        size_t i = 0;
        if (str) {
                for (; i < size; i++) {
                        if (str[i] == '\0')
                                break;
                        emit_byte (logbuffer, str [i]);
                }
        }
        emit_byte (logbuffer, '\0');
}

static void
emit_double (LogBuffer *logbuffer, double value)
{
        int i;
        unsigned char buffer[8];
        memcpy (buffer, &value, 8);
#if G_BYTE_ORDER == G_BIG_ENDIAN
        for (i = 7; i >= 0; i--)
#else
        for (i = 0; i < 8; i++)
#endif
                emit_byte (logbuffer, buffer[i]);
}

static char*
write_int16 (char *buf, int32_t value)
{
        int i;
        for (i = 0; i < 2; ++i) {
                buf [i] = value;
                value >>= 8;
        }
        return buf + 2;
}

static char*
write_int32 (char *buf, int32_t value)
{
        int i;
        for (i = 0; i < 4; ++i) {
                buf [i] = value;
                value >>= 8;
        }
        return buf + 4;
}

static char*
write_int64 (char *buf, int64_t value)
{
        int i;
        for (i = 0; i < 8; ++i) {
                buf [i] = value;
                value >>= 8;
        }
        return buf + 8;
}

static char *
write_header_string (char *p, const char *str)
{
        size_t len = strlen (str) + 1;

        p = write_int32 (p, len);
        strcpy (p, str);

        return p + len;
}

static void
dump_header (MonoProfiler *profiler)
{
        const char *args = profiler->args;
        const char *arch = mono_config_get_cpu ();
        const char *os = mono_config_get_os ();

        char *hbuf = g_malloc (
                sizeof (gint32) /* header id */ +
                sizeof (gint8) /* major version */ +
                sizeof (gint8) /* minor version */ +
                sizeof (gint8) /* data version */ +
                sizeof (gint8) /* word size */ +
                sizeof (gint64) /* startup time */ +
                sizeof (gint32) /* timer overhead */ +
                sizeof (gint32) /* flags */ +
                sizeof (gint32) /* process id */ +
                sizeof (gint16) /* command port */ +
                sizeof (gint32) + strlen (args) + 1 /* arguments */ +
                sizeof (gint32) + strlen (arch) + 1 /* architecture */ +
                sizeof (gint32) + strlen (os) + 1 /* operating system */
        );
        char *p = hbuf;

        p = write_int32 (p, LOG_HEADER_ID);
        *p++ = LOG_VERSION_MAJOR;
        *p++ = LOG_VERSION_MINOR;
        *p++ = LOG_DATA_VERSION;
        *p++ = sizeof (void *);
        p = write_int64 (p, ((uint64_t) time (NULL)) * 1000);
        p = write_int32 (p, timer_overhead);
        p = write_int32 (p, 0); /* flags */
        p = write_int32 (p, process_id ());
        p = write_int16 (p, profiler->command_port);
        p = write_header_string (p, args);
        p = write_header_string (p, arch);
        p = write_header_string (p, os);

#if defined (HAVE_SYS_ZLIB)
        if (profiler->gzfile) {
                gzwrite (profiler->gzfile, hbuf, p - hbuf);
        } else
#endif
        {
                fwrite (hbuf, p - hbuf, 1, profiler->file);
                fflush (profiler->file);
        }

        g_free (hbuf);
}

/*
 * Must be called with the reader lock held if thread is the current thread, or
 * the exclusive lock if thread is a different thread. However, if thread is
 * the current thread, and init_thread () was called with add_to_lls = FALSE,
 * then no locking is necessary.
 */
static void
send_buffer (MonoProfilerThread *thread)
{
        WriterQueueEntry *entry = mono_lock_free_alloc (&thread->profiler->writer_entry_allocator);
        entry->methods = thread->methods;
        entry->buffer = thread->buffer;

        mono_lock_free_queue_node_init (&entry->node, FALSE);

        mono_lock_free_queue_enqueue (&thread->profiler->writer_queue, &entry->node);
        mono_os_sem_post (&thread->profiler->writer_queue_sem);
}

static void
free_thread (gpointer p)
{
        MonoProfilerThread *thread = p;

        if (!thread->ended) {
                /*
                 * The thread is being cleaned up by the main thread during
                 * shutdown. This typically happens for internal runtime
                 * threads. We need to synthesize a thread end event.
                 */

                InterlockedIncrement (&thread_ends_ctr);

                LogBuffer *buf = ensure_logbuf_unsafe (thread,
                        EVENT_SIZE /* event */ +
                        BYTE_SIZE /* type */ +
                        LEB128_SIZE /* tid */
                );

                emit_event (buf, TYPE_END_UNLOAD | TYPE_METADATA);
                emit_byte (buf, TYPE_THREAD);
                emit_ptr (buf, (void *) thread->node.key);
        }

        send_buffer (thread);

        g_free (thread);
}

static void
remove_thread (MonoProfilerThread *thread)
{
        MonoThreadHazardPointers *hp = mono_hazard_pointer_get ();

        if (mono_lls_remove (&profiler_thread_list, hp, &thread->node))
                mono_thread_hazardous_try_free (thread, free_thread);

        clear_hazard_pointers (hp);
}

static void
dump_buffer (MonoProfiler *profiler, LogBuffer *buf)
{
        char hbuf [128];
        char *p = hbuf;

        if (buf->next)
                dump_buffer (profiler, buf->next);

        if (buf->cursor - buf->buf) {
                p = write_int32 (p, BUF_ID);
                p = write_int32 (p, buf->cursor - buf->buf);
                p = write_int64 (p, buf->time_base);
                p = write_int64 (p, buf->ptr_base);
                p = write_int64 (p, buf->obj_base);
                p = write_int64 (p, buf->thread_id);
                p = write_int64 (p, buf->method_base);

#if defined (HAVE_SYS_ZLIB)
                if (profiler->gzfile) {
                        gzwrite (profiler->gzfile, hbuf, p - hbuf);
                        gzwrite (profiler->gzfile, buf->buf, buf->cursor - buf->buf);
                } else
#endif
                {
                        fwrite (hbuf, p - hbuf, 1, profiler->file);
                        fwrite (buf->buf, buf->cursor - buf->buf, 1, profiler->file);
                        fflush (profiler->file);
                }
        }

        free_buffer (buf, buf->size);
}

static void
dump_buffer_threadless (MonoProfiler *profiler, LogBuffer *buf)
{
        for (LogBuffer *iter = buf; iter; iter = iter->next)
                iter->thread_id = 0;

        dump_buffer (profiler, buf);
}

static void
process_requests (void)
{
        if (heapshot_requested)
                mono_gc_collect (mono_gc_max_generation ());
}

// Only valid if init_thread () was called with add_to_lls = FALSE.
static void
send_log_unsafe (gboolean if_needed)
{
        MonoProfilerThread *thread = PROF_TLS_GET ();

        if (!if_needed || (if_needed && thread->buffer->next)) {
                if (!thread->attached)
                        for (LogBuffer *iter = thread->buffer; iter; iter = iter->next)
                                iter->thread_id = 0;

                send_buffer (thread);
                init_buffer_state (thread);
        }
}

// Assumes that the exclusive lock is held.
static void
sync_point_flush (void)
{
        g_assert (InterlockedReadPointer (&buffer_rwlock_exclusive) == (gpointer) thread_id () && "Why don't we hold the exclusive lock?");

        MONO_LLS_FOREACH_SAFE (&profiler_thread_list, MonoProfilerThread, thread) {
                g_assert (thread->attached && "Why is a thread in the LLS not attached?");

                send_buffer (thread);
                init_buffer_state (thread);
        } MONO_LLS_FOREACH_SAFE_END
}

// Assumes that the exclusive lock is held.
static void
sync_point_mark (MonoProfilerSyncPointType type)
{
        g_assert (InterlockedReadPointer (&buffer_rwlock_exclusive) == (gpointer) thread_id () && "Why don't we hold the exclusive lock?");

        ENTER_LOG (&sync_points_ctr, logbuffer,
                EVENT_SIZE /* event */ +
                LEB128_SIZE /* type */
        );

        emit_event (logbuffer, TYPE_META | TYPE_SYNC_POINT);
        emit_byte (logbuffer, type);

        EXIT_LOG_EXPLICIT (NO_SEND, NO_REQUESTS);

        send_log_unsafe (FALSE);
}

// Assumes that the exclusive lock is held.
static void
sync_point (MonoProfilerSyncPointType type)
{
        sync_point_flush ();
        sync_point_mark (type);
}

static int
gc_reference (MonoObject *obj, MonoClass *klass, uintptr_t size, uintptr_t num, MonoObject **refs, uintptr_t *offsets, void *data)
{
        /* account for object alignment in the heap */
        size += 7;
        size &= ~7;

        ENTER_LOG (&heap_objects_ctr, logbuffer,
                EVENT_SIZE /* event */ +
                LEB128_SIZE /* obj */ +
                LEB128_SIZE /* klass */ +
                LEB128_SIZE /* size */ +
                LEB128_SIZE /* num */ +
                num * (
                        LEB128_SIZE /* offset */ +
                        LEB128_SIZE /* ref */
                )
        );

        emit_event (logbuffer, TYPE_HEAP_OBJECT | TYPE_HEAP);
        emit_obj (logbuffer, obj);
        emit_ptr (logbuffer, klass);
        emit_value (logbuffer, size);
        emit_value (logbuffer, num);

        uintptr_t last_offset = 0;

        for (int i = 0; i < num; ++i) {
                emit_value (logbuffer, offsets [i] - last_offset);
                last_offset = offsets [i];
                emit_obj (logbuffer, refs [i]);
        }

        EXIT_LOG_EXPLICIT (DO_SEND, NO_REQUESTS);

        return 0;
}

static unsigned int hs_mode_ms = 0;
static unsigned int hs_mode_gc = 0;
static unsigned int hs_mode_ondemand = 0;
static unsigned int gc_count = 0;
static uint64_t last_hs_time = 0;
static gboolean do_heap_walk = FALSE;

static void
heap_walk (MonoProfiler *profiler)
{
        ENTER_LOG (&heap_starts_ctr, logbuffer,
                EVENT_SIZE /* event */
        );

        emit_event (logbuffer, TYPE_HEAP_START | TYPE_HEAP);

        EXIT_LOG_EXPLICIT (DO_SEND, NO_REQUESTS);

        mono_gc_walk_heap (0, gc_reference, NULL);

        ENTER_LOG (&heap_ends_ctr, logbuffer,
                EVENT_SIZE /* event */
        );

        emit_event (logbuffer, TYPE_HEAP_END | TYPE_HEAP);

        EXIT_LOG_EXPLICIT (DO_SEND, NO_REQUESTS);
}

static void
gc_roots (MonoProfiler *prof, int num, void **objects, int *root_types, uintptr_t *extra_info)
{
        ENTER_LOG (&heap_roots_ctr, logbuffer,
                EVENT_SIZE /* event */ +
                LEB128_SIZE /* num */ +
                LEB128_SIZE /* collections */ +
                num * (
                        LEB128_SIZE /* object */ +
                        LEB128_SIZE /* root type */ +
                        LEB128_SIZE /* extra info */
                )
        );

        emit_event (logbuffer, TYPE_HEAP_ROOT | TYPE_HEAP);
        emit_value (logbuffer, num);
        emit_value (logbuffer, mono_gc_collection_count (mono_gc_max_generation ()));

        for (int i = 0; i < num; ++i) {
                emit_obj (logbuffer, objects [i]);
                emit_byte (logbuffer, root_types [i]);
                emit_value (logbuffer, extra_info [i]);
        }

        EXIT_LOG_EXPLICIT (DO_SEND, NO_REQUESTS);
}

static void
gc_event (MonoProfiler *profiler, MonoGCEvent ev, int generation)
{
        ENTER_LOG (&gc_events_ctr, logbuffer,
                EVENT_SIZE /* event */ +
                BYTE_SIZE /* gc event */ +
                BYTE_SIZE /* generation */
        );

        emit_event (logbuffer, TYPE_GC_EVENT | TYPE_GC);
        emit_byte (logbuffer, ev);
        emit_byte (logbuffer, generation);

        EXIT_LOG_EXPLICIT (NO_SEND, NO_REQUESTS);

        switch (ev) {
        case MONO_GC_EVENT_START:
                if (generation == mono_gc_max_generation ())
                        gc_count++;

                uint64_t now = current_time ();

                if (hs_mode_ms && (now - last_hs_time) / 1000 * 1000 >= hs_mode_ms)
                        do_heap_walk = TRUE;
                else if (hs_mode_gc && !(gc_count % hs_mode_gc))
                        do_heap_walk = TRUE;
                else if (hs_mode_ondemand)
                        do_heap_walk = heapshot_requested;
                else if (!hs_mode_ms && !hs_mode_gc && generation == mono_gc_max_generation ())
                        do_heap_walk = TRUE;
                break;
        case MONO_GC_EVENT_PRE_STOP_WORLD_LOCKED:
                /*
                 * Ensure that no thread can be in the middle of writing to
                 * a buffer when the world stops...
                 */
                buffer_lock_excl ();
                break;
        case MONO_GC_EVENT_POST_STOP_WORLD:
                /*
                 * ... So that we now have a consistent view of all buffers.
                 * This allows us to flush them. We need to do this because
                 * they may contain object allocation events that need to be
                 * committed to the log file before any object move events
                 * that will be produced during this GC.
                 */
                sync_point (SYNC_POINT_WORLD_STOP);
                break;
        case MONO_GC_EVENT_PRE_START_WORLD:
                if (do_heap_shot && do_heap_walk) {
                        heap_walk (profiler);

                        do_heap_walk = FALSE;
                        heapshot_requested = 0;
                        last_hs_time = current_time ();
                }
                break;
        case MONO_GC_EVENT_POST_START_WORLD_UNLOCKED:
                /*
                 * Similarly, we must now make sure that any object moves
                 * written to the GC thread's buffer are flushed. Otherwise,
                 * object allocation events for certain addresses could come
                 * after the move events that made those addresses available.
                 */
                sync_point_mark (SYNC_POINT_WORLD_START);

                /*
                 * Finally, it is safe to allow other threads to write to
                 * their buffers again.
                 */
                buffer_unlock_excl ();
                break;
        default:
                break;
        }
}

static void
gc_resize (MonoProfiler *profiler, int64_t new_size)
{
        ENTER_LOG (&gc_resizes_ctr, logbuffer,
                EVENT_SIZE /* event */ +
                LEB128_SIZE /* new size */
        );

        emit_event (logbuffer, TYPE_GC_RESIZE | TYPE_GC);
        emit_value (logbuffer, new_size);

        EXIT_LOG_EXPLICIT (DO_SEND, NO_REQUESTS);
}

// If you alter MAX_FRAMES, you may need to alter SAMPLE_BLOCK_SIZE too.
#define MAX_FRAMES 32

typedef struct {
        int count;
        MonoMethod* methods [MAX_FRAMES];
        int32_t il_offsets [MAX_FRAMES];
        int32_t native_offsets [MAX_FRAMES];
} FrameData;

static int num_frames = MAX_FRAMES;

static mono_bool
walk_stack (MonoMethod *method, int32_t native_offset, int32_t il_offset, mono_bool managed, void* data)
{
        FrameData *frame = (FrameData *)data;
        if (method && frame->count < num_frames) {
                frame->il_offsets [frame->count] = il_offset;
                frame->native_offsets [frame->count] = native_offset;
                frame->methods [frame->count++] = method;
                //printf ("In %d %s at %d (native: %d)\n", frame->count, mono_method_get_name (method), il_offset, native_offset);
        }
        return frame->count == num_frames;
}

/*
 * a note about stack walks: they can cause more profiler events to fire,
 * so we need to make sure they don't happen after we started emitting an
 * event, hence the collect_bt/emit_bt split.
 */
static void
collect_bt (FrameData *data)
{
        data->count = 0;
        mono_stack_walk_no_il (walk_stack, data);
}

static void
emit_bt (MonoProfiler *prof, LogBuffer *logbuffer, FrameData *data)
{
        /* FIXME: this is actually tons of data and we should
         * just output it the first time and use an id the next
         */
        if (data->count > num_frames)
                printf ("bad num frames: %d\n", data->count);
        emit_value (logbuffer, data->count);
        //if (*p != data.count) {
        //      printf ("bad num frames enc at %d: %d -> %d\n", count, data.count, *p); printf ("frames end: %p->%p\n", p, logbuffer->cursor); exit(0);}
        while (data->count) {
                emit_method (logbuffer, data->methods [--data->count]);
        }
}

static void
gc_alloc (MonoProfiler *prof, MonoObject *obj, MonoClass *klass)
{
        init_thread (prof, TRUE);

        int do_bt = (nocalls && InterlockedRead (&runtime_inited) && !notraces) ? TYPE_ALLOC_BT : 0;
        FrameData data;
        uintptr_t len = mono_object_get_size (obj);
        /* account for object alignment in the heap */
        len += 7;
        len &= ~7;

        if (do_bt)
                collect_bt (&data);

        ENTER_LOG (&gc_allocs_ctr, logbuffer,
                EVENT_SIZE /* event */ +
                LEB128_SIZE /* klass */ +
                LEB128_SIZE /* obj */ +
                LEB128_SIZE /* size */ +
                (do_bt ? (
                        LEB128_SIZE /* count */ +
                        data.count * (
                                LEB128_SIZE /* method */
                        )
                ) : 0)
        );

        emit_event (logbuffer, do_bt | TYPE_ALLOC);
        emit_ptr (logbuffer, klass);
        emit_obj (logbuffer, obj);
        emit_value (logbuffer, len);

        if (do_bt)
                emit_bt (prof, logbuffer, &data);

        EXIT_LOG;
}

static void
gc_moves (MonoProfiler *prof, void **objects, int num)
{
        ENTER_LOG (&gc_moves_ctr, logbuffer,
                EVENT_SIZE /* event */ +
                LEB128_SIZE /* num */ +
                num * (
                        LEB128_SIZE /* object */
                )
        );

        emit_event (logbuffer, TYPE_GC_MOVE | TYPE_GC);
        emit_value (logbuffer, num);

        for (int i = 0; i < num; ++i)
                emit_obj (logbuffer, objects [i]);

        EXIT_LOG_EXPLICIT (DO_SEND, NO_REQUESTS);
}

static void
gc_handle (MonoProfiler *prof, int op, int type, uintptr_t handle, MonoObject *obj)
{
        int do_bt = nocalls && InterlockedRead (&runtime_inited) && !notraces;
        FrameData data;

        if (do_bt)
                collect_bt (&data);

        gint32 *ctr = op == MONO_PROFILER_GC_HANDLE_CREATED ? &gc_handle_creations_ctr : &gc_handle_deletions_ctr;

        ENTER_LOG (ctr, logbuffer,
                EVENT_SIZE /* event */ +
                LEB128_SIZE /* type */ +
                LEB128_SIZE /* handle */ +
                (op == MONO_PROFILER_GC_HANDLE_CREATED ? (
                        LEB128_SIZE /* obj */
                ) : 0) +
                (do_bt ? (
                        LEB128_SIZE /* count */ +
                        data.count * (
                                LEB128_SIZE /* method */
                        )
                ) : 0)
        );

        if (op == MONO_PROFILER_GC_HANDLE_CREATED)
                emit_event (logbuffer, (do_bt ? TYPE_GC_HANDLE_CREATED_BT : TYPE_GC_HANDLE_CREATED) | TYPE_GC);
        else if (op == MONO_PROFILER_GC_HANDLE_DESTROYED)
                emit_event (logbuffer, (do_bt ? TYPE_GC_HANDLE_DESTROYED_BT : TYPE_GC_HANDLE_DESTROYED) | TYPE_GC);
        else
                g_assert_not_reached ();

        emit_value (logbuffer, type);
        emit_value (logbuffer, handle);

        if (op == MONO_PROFILER_GC_HANDLE_CREATED)
                emit_obj (logbuffer, obj);

        if (do_bt)
                emit_bt (prof, logbuffer, &data);

        EXIT_LOG;
}

static void
finalize_begin (MonoProfiler *prof)
{
        ENTER_LOG (&finalize_begins_ctr, buf,
                EVENT_SIZE /* event */
        );

        emit_event (buf, TYPE_GC_FINALIZE_START | TYPE_GC);

        EXIT_LOG;
}

static void
finalize_end (MonoProfiler *prof)
{
        ENTER_LOG (&finalize_ends_ctr, buf,
                EVENT_SIZE /* event */
        );

        emit_event (buf, TYPE_GC_FINALIZE_END | TYPE_GC);

        EXIT_LOG;
}

static void
finalize_object_begin (MonoProfiler *prof, MonoObject *obj)
{
        ENTER_LOG (&finalize_object_begins_ctr, buf,
                EVENT_SIZE /* event */ +
                LEB128_SIZE /* obj */
        );

        emit_event (buf, TYPE_GC_FINALIZE_OBJECT_START | TYPE_GC);
        emit_obj (buf, obj);

        EXIT_LOG;
}

static void
finalize_object_end (MonoProfiler *prof, MonoObject *obj)
{
        ENTER_LOG (&finalize_object_ends_ctr, buf,
                EVENT_SIZE /* event */ +
                LEB128_SIZE /* obj */
        );

        emit_event (buf, TYPE_GC_FINALIZE_OBJECT_END | TYPE_GC);
        emit_obj (buf, obj);

        EXIT_LOG;
}

static char*
push_nesting (char *p, MonoClass *klass)
{
        MonoClass *nesting;
        const char *name;
        const char *nspace;
        nesting = mono_class_get_nesting_type (klass);
        if (nesting) {
                p = push_nesting (p, nesting);
                *p++ = '/';
                *p = 0;
        }
        name = mono_class_get_name (klass);
        nspace = mono_class_get_namespace (klass);
        if (*nspace) {
                strcpy (p, nspace);
                p += strlen (nspace);
                *p++ = '.';
                *p = 0;
        }
        strcpy (p, name);
        p += strlen (name);
        return p;
}

static char*
type_name (MonoClass *klass)
{
        char buf [1024];
        char *p;
        push_nesting (buf, klass);
        p = (char *) g_malloc (strlen (buf) + 1);
        strcpy (p, buf);
        return p;
}

static void
image_loaded (MonoProfiler *prof, MonoImage *image, int result)
{
        if (result != MONO_PROFILE_OK)
                return;

        const char *name = mono_image_get_filename (image);
        int nlen = strlen (name) + 1;

        ENTER_LOG (&image_loads_ctr, logbuffer,
                EVENT_SIZE /* event */ +
                BYTE_SIZE /* type */ +
                LEB128_SIZE /* image */ +
                nlen /* name */
        );

        emit_event (logbuffer, TYPE_END_LOAD | TYPE_METADATA);
        emit_byte (logbuffer, TYPE_IMAGE);
        emit_ptr (logbuffer, image);
        memcpy (logbuffer->cursor, name, nlen);
        logbuffer->cursor += nlen;

        EXIT_LOG;
}

static void
image_unloaded (MonoProfiler *prof, MonoImage *image)
{
        const char *name = mono_image_get_filename (image);
        int nlen = strlen (name) + 1;

        ENTER_LOG (&image_unloads_ctr, logbuffer,
                EVENT_SIZE /* event */ +
                BYTE_SIZE /* type */ +
                LEB128_SIZE /* image */ +
                nlen /* name */
        );

        emit_event (logbuffer, TYPE_END_UNLOAD | TYPE_METADATA);
        emit_byte (logbuffer, TYPE_IMAGE);
        emit_ptr (logbuffer, image);
        memcpy (logbuffer->cursor, name, nlen);
        logbuffer->cursor += nlen;

        EXIT_LOG;
}

static void
assembly_loaded (MonoProfiler *prof, MonoAssembly *assembly, int result)
{
        if (result != MONO_PROFILE_OK)
                return;

        char *name = mono_stringify_assembly_name (mono_assembly_get_name (assembly));
        int nlen = strlen (name) + 1;

        ENTER_LOG (&assembly_loads_ctr, logbuffer,
                EVENT_SIZE /* event */ +
                BYTE_SIZE /* type */ +
                LEB128_SIZE /* assembly */ +
                nlen /* name */
        );

        emit_event (logbuffer, TYPE_END_LOAD | TYPE_METADATA);
        emit_byte (logbuffer, TYPE_ASSEMBLY);
        emit_ptr (logbuffer, assembly);
        memcpy (logbuffer->cursor, name, nlen);
        logbuffer->cursor += nlen;

        EXIT_LOG;

        mono_free (name);
}

static void
assembly_unloaded (MonoProfiler *prof, MonoAssembly *assembly)
{
        char *name = mono_stringify_assembly_name (mono_assembly_get_name (assembly));
        int nlen = strlen (name) + 1;

        ENTER_LOG (&assembly_unloads_ctr, logbuffer,
                EVENT_SIZE /* event */ +
                BYTE_SIZE /* type */ +
                LEB128_SIZE /* assembly */ +
                nlen /* name */
        );

        emit_event (logbuffer, TYPE_END_UNLOAD | TYPE_METADATA);
        emit_byte (logbuffer, TYPE_ASSEMBLY);
        emit_ptr (logbuffer, assembly);
        memcpy (logbuffer->cursor, name, nlen);
        logbuffer->cursor += nlen;

        EXIT_LOG;

        mono_free (name);
}

static void
class_loaded (MonoProfiler *prof, MonoClass *klass, int result)
{
        if (result != MONO_PROFILE_OK)
                return;

        char *name;

        if (InterlockedRead (&runtime_inited))
                name = mono_type_get_name (mono_class_get_type (klass));
        else
                name = type_name (klass);

        int nlen = strlen (name) + 1;
        MonoImage *image = mono_class_get_image (klass);

        ENTER_LOG (&class_loads_ctr, logbuffer,
                EVENT_SIZE /* event */ +
                BYTE_SIZE /* type */ +
                LEB128_SIZE /* klass */ +
                LEB128_SIZE /* image */ +
                nlen /* name */
        );

        emit_event (logbuffer, TYPE_END_LOAD | TYPE_METADATA);
        emit_byte (logbuffer, TYPE_CLASS);
        emit_ptr (logbuffer, klass);
        emit_ptr (logbuffer, image);
        memcpy (logbuffer->cursor, name, nlen);
        logbuffer->cursor += nlen;

        EXIT_LOG;

        if (runtime_inited)
                mono_free (name);
        else
                g_free (name);
}

static void
class_unloaded (MonoProfiler *prof, MonoClass *klass)
{
        char *name;

        if (InterlockedRead (&runtime_inited))
                name = mono_type_get_name (mono_class_get_type (klass));
        else
                name = type_name (klass);

        int nlen = strlen (name) + 1;
        MonoImage *image = mono_class_get_image (klass);

        ENTER_LOG (&class_unloads_ctr, logbuffer,
                EVENT_SIZE /* event */ +
                BYTE_SIZE /* type */ +
                LEB128_SIZE /* klass */ +
                LEB128_SIZE /* image */ +
                nlen /* name */
        );

        emit_event (logbuffer, TYPE_END_UNLOAD | TYPE_METADATA);
        emit_byte (logbuffer, TYPE_CLASS);
        emit_ptr (logbuffer, klass);
        emit_ptr (logbuffer, image);
        memcpy (logbuffer->cursor, name, nlen);
        logbuffer->cursor += nlen;

        EXIT_LOG;

        if (runtime_inited)
                mono_free (name);
        else
                g_free (name);
}

static void process_method_enter_coverage (MonoProfiler *prof, MonoMethod *method);

static void
method_enter (MonoProfiler *prof, MonoMethod *method)
{
        process_method_enter_coverage (prof, method);

        if (!only_coverage && PROF_TLS_GET ()->call_depth++ <= max_call_depth) {
                ENTER_LOG (&method_entries_ctr, logbuffer,
                        EVENT_SIZE /* event */ +
                        LEB128_SIZE /* method */
                );

                emit_event (logbuffer, TYPE_ENTER | TYPE_METHOD);
                emit_method (logbuffer, method);

                EXIT_LOG;
        }
}

static void
method_leave (MonoProfiler *prof, MonoMethod *method)
{
        if (!only_coverage && --PROF_TLS_GET ()->call_depth <= max_call_depth) {
                ENTER_LOG (&method_exits_ctr, logbuffer,
                        EVENT_SIZE /* event */ +
                        LEB128_SIZE /* method */
                );

                emit_event (logbuffer, TYPE_LEAVE | TYPE_METHOD);
                emit_method (logbuffer, method);

                EXIT_LOG;
        }
}

static void
method_exc_leave (MonoProfiler *prof, MonoMethod *method)
{
        if (!only_coverage && !nocalls && --PROF_TLS_GET ()->call_depth <= max_call_depth) {
                ENTER_LOG (&method_exception_exits_ctr, logbuffer,
                        EVENT_SIZE /* event */ +
                        LEB128_SIZE /* method */
                );

                emit_event (logbuffer, TYPE_EXC_LEAVE | TYPE_METHOD);
                emit_method (logbuffer, method);

                EXIT_LOG;
        }
}

static void
method_jitted (MonoProfiler *prof, MonoMethod *method, MonoJitInfo *ji, int result)
{
        if (result != MONO_PROFILE_OK)
                return;

        register_method_local (method, ji);

        process_requests ();
}

static void
code_buffer_new (MonoProfiler *prof, void *buffer, int size, MonoProfilerCodeBufferType type, void *data)
{
        char *name;
        int nlen;

        if (type == MONO_PROFILER_CODE_BUFFER_SPECIFIC_TRAMPOLINE) {
                name = (char *) data;
                nlen = strlen (name) + 1;
        } else {
                name = NULL;
                nlen = 0;
        }

        ENTER_LOG (&code_buffers_ctr, logbuffer,
                EVENT_SIZE /* event */ +
                BYTE_SIZE /* type */ +
                LEB128_SIZE /* buffer */ +
                LEB128_SIZE /* size */ +
                (name ? (
                        nlen /* name */
                ) : 0)
        );

        emit_event (logbuffer, TYPE_JITHELPER | TYPE_RUNTIME);
        emit_byte (logbuffer, type);
        emit_ptr (logbuffer, buffer);
        emit_value (logbuffer, size);

        if (name) {
                memcpy (logbuffer->cursor, name, nlen);
                logbuffer->cursor += nlen;
        }

        EXIT_LOG;
}

static void
throw_exc (MonoProfiler *prof, MonoObject *object)
{
        int do_bt = (nocalls && InterlockedRead (&runtime_inited) && !notraces) ? TYPE_THROW_BT : 0;
        FrameData data;

        if (do_bt)
                collect_bt (&data);

        ENTER_LOG (&exception_throws_ctr, logbuffer,
                EVENT_SIZE /* event */ +
                LEB128_SIZE /* object */ +
                (do_bt ? (
                        LEB128_SIZE /* count */ +
                        data.count * (
                                LEB128_SIZE /* method */
                        )
                ) : 0)
        );

        emit_event (logbuffer, do_bt | TYPE_EXCEPTION);
        emit_obj (logbuffer, object);

        if (do_bt)
                emit_bt (prof, logbuffer, &data);

        EXIT_LOG;
}

static void
clause_exc (MonoProfiler *prof, MonoMethod *method, int clause_type, int clause_num)
{
        ENTER_LOG (&exception_clauses_ctr, logbuffer,
                EVENT_SIZE /* event */ +
                BYTE_SIZE /* clause type */ +
                LEB128_SIZE /* clause num */ +
                LEB128_SIZE /* method */
        );

        emit_event (logbuffer, TYPE_EXCEPTION | TYPE_CLAUSE);
        emit_byte (logbuffer, clause_type);
        emit_value (logbuffer, clause_num);
        emit_method (logbuffer, method);

        EXIT_LOG;
}

static void
monitor_event (MonoProfiler *profiler, MonoObject *object, MonoProfilerMonitorEvent event)
{
        int do_bt = (nocalls && InterlockedRead (&runtime_inited) && !notraces && event == MONO_PROFILER_MONITOR_CONTENTION) ? TYPE_MONITOR_BT : 0;
        FrameData data;

        if (do_bt)
                collect_bt (&data);

        gint32 *ctr;

        switch (event) {
        case MONO_PROFILER_MONITOR_CONTENTION:
                ctr = &monitor_contentions_ctr;
                break;
        case MONO_PROFILER_MONITOR_DONE:
                ctr = &monitor_acquisitions_ctr;
                break;
        case MONO_PROFILER_MONITOR_FAIL:
                ctr = &monitor_failures_ctr;
                break;
        default:
                g_assert_not_reached ();
                break;
        }

        ENTER_LOG (ctr, logbuffer,
                EVENT_SIZE /* event */ +
                LEB128_SIZE /* object */ +
                (do_bt ? (
                        LEB128_SIZE /* count */ +
                        data.count * (
                                LEB128_SIZE /* method */
                        )
                ) : 0)
        );

        emit_event (logbuffer, (event << 4) | do_bt | TYPE_MONITOR);
        emit_obj (logbuffer, object);

        if (do_bt)
                emit_bt (profiler, logbuffer, &data);

        EXIT_LOG;
}

static void
thread_start (MonoProfiler *prof, uintptr_t tid)
{
        init_thread (prof, TRUE);

        ENTER_LOG (&thread_starts_ctr, logbuffer,
                EVENT_SIZE /* event */ +
                BYTE_SIZE /* type */ +
                LEB128_SIZE /* tid */
        );

        emit_event (logbuffer, TYPE_END_LOAD | TYPE_METADATA);
        emit_byte (logbuffer, TYPE_THREAD);
        emit_ptr (logbuffer, (void*) tid);

        EXIT_LOG;
}

static void
thread_end (MonoProfiler *prof, uintptr_t tid)
{
        ENTER_LOG (&thread_ends_ctr, logbuffer,
                EVENT_SIZE /* event */ +
                BYTE_SIZE /* type */ +
                LEB128_SIZE /* tid */
        );

        emit_event (logbuffer, TYPE_END_UNLOAD | TYPE_METADATA);
        emit_byte (logbuffer, TYPE_THREAD);
        emit_ptr (logbuffer, (void*) tid);

        EXIT_LOG_EXPLICIT (NO_SEND, NO_REQUESTS);

        MonoProfilerThread *thread = PROF_TLS_GET ();

        thread->ended = TRUE;
        remove_thread (thread);

        PROF_TLS_SET (NULL);
}

static void
thread_name (MonoProfiler *prof, uintptr_t tid, const char *name)
{
        int len = strlen (name) + 1;

        ENTER_LOG (&thread_names_ctr, logbuffer,
                EVENT_SIZE /* event */ +
                BYTE_SIZE /* type */ +
                LEB128_SIZE /* tid */ +
                len /* name */
        );

        emit_event (logbuffer, TYPE_METADATA);
        emit_byte (logbuffer, TYPE_THREAD);
        emit_ptr (logbuffer, (void*)tid);
        memcpy (logbuffer->cursor, name, len);
        logbuffer->cursor += len;

        EXIT_LOG;
}

static void
domain_loaded (MonoProfiler *prof, MonoDomain *domain, int result)
{
        if (result != MONO_PROFILE_OK)
                return;

        ENTER_LOG (&domain_loads_ctr, logbuffer,
                EVENT_SIZE /* event */ +
                BYTE_SIZE /* type */ +
                LEB128_SIZE /* domain id */
        );

        emit_event (logbuffer, TYPE_END_LOAD | TYPE_METADATA);
        emit_byte (logbuffer, TYPE_DOMAIN);
        emit_ptr (logbuffer, (void*)(uintptr_t) mono_domain_get_id (domain));

        EXIT_LOG;
}

static void
domain_unloaded (MonoProfiler *prof, MonoDomain *domain)
{
        ENTER_LOG (&domain_unloads_ctr, logbuffer,
                EVENT_SIZE /* event */ +
                BYTE_SIZE /* type */ +
                LEB128_SIZE /* domain id */
        );

        emit_event (logbuffer, TYPE_END_UNLOAD | TYPE_METADATA);
        emit_byte (logbuffer, TYPE_DOMAIN);
        emit_ptr (logbuffer, (void*)(uintptr_t) mono_domain_get_id (domain));

        EXIT_LOG;
}

static void
domain_name (MonoProfiler *prof, MonoDomain *domain, const char *name)
{
        int nlen = strlen (name) + 1;

        ENTER_LOG (&domain_names_ctr, logbuffer,
                EVENT_SIZE /* event */ +
                BYTE_SIZE /* type */ +
                LEB128_SIZE /* domain id */ +
                nlen /* name */
        );

        emit_event (logbuffer, TYPE_METADATA);
        emit_byte (logbuffer, TYPE_DOMAIN);
        emit_ptr (logbuffer, (void*)(uintptr_t) mono_domain_get_id (domain));
        memcpy (logbuffer->cursor, name, nlen);
        logbuffer->cursor += nlen;

        EXIT_LOG;
}

static void
context_loaded (MonoProfiler *prof, MonoAppContext *context)
{
        ENTER_LOG (&context_loads_ctr, logbuffer,
                EVENT_SIZE /* event */ +
                BYTE_SIZE /* type */ +
                LEB128_SIZE /* context id */ +
                LEB128_SIZE /* domain id */
        );

        emit_event (logbuffer, TYPE_END_LOAD | TYPE_METADATA);
        emit_byte (logbuffer, TYPE_CONTEXT);
        emit_ptr (logbuffer, (void*)(uintptr_t) mono_context_get_id (context));
        emit_ptr (logbuffer, (void*)(uintptr_t) mono_context_get_domain_id (context));

        EXIT_LOG;
}

static void
context_unloaded (MonoProfiler *prof, MonoAppContext *context)
{
        ENTER_LOG (&context_unloads_ctr, logbuffer,
                EVENT_SIZE /* event */ +
                BYTE_SIZE /* type */ +
                LEB128_SIZE /* context id */ +
                LEB128_SIZE /* domain id */
        );

        emit_event (logbuffer, TYPE_END_UNLOAD | TYPE_METADATA);
        emit_byte (logbuffer, TYPE_CONTEXT);
        emit_ptr (logbuffer, (void*)(uintptr_t) mono_context_get_id (context));
        emit_ptr (logbuffer, (void*)(uintptr_t) mono_context_get_domain_id (context));

        EXIT_LOG;
}

typedef struct {
        MonoMethod *method;
        MonoDomain *domain;
        void *base_address;
        int offset;
} AsyncFrameInfo;

typedef struct {
        MonoLockFreeQueueNode node;
        MonoProfiler *prof;
        uint64_t time;
        uintptr_t tid;
        void *ip;
        int count;
        AsyncFrameInfo frames [MONO_ZERO_LEN_ARRAY];
} SampleHit;

static mono_bool
async_walk_stack (MonoMethod *method, MonoDomain *domain, void *base_address, int offset, void *data)
{
        SampleHit *sample = (SampleHit *) data;

        if (sample->count < num_frames) {
                int i = sample->count;

                sample->frames [i].method = method;
                sample->frames [i].domain = domain;
                sample->frames [i].base_address = base_address;
                sample->frames [i].offset = offset;

                sample->count++;
        }

        return sample->count == num_frames;
}

#define SAMPLE_SLOT_SIZE(FRAMES) (sizeof (SampleHit) + sizeof (AsyncFrameInfo) * (FRAMES - MONO_ZERO_LEN_ARRAY))
#define SAMPLE_BLOCK_SIZE (mono_pagesize ())

static void
enqueue_sample_hit (gpointer p)
{
        SampleHit *sample = p;

        mono_lock_free_queue_node_unpoison (&sample->node);
        mono_lock_free_queue_enqueue (&sample->prof->dumper_queue, &sample->node);
        mono_os_sem_post (&sample->prof->dumper_queue_sem);
}

static void
mono_sample_hit (MonoProfiler *profiler, unsigned char *ip, void *context)
{
        /*
         * Please note: We rely on the runtime loading the profiler with
         * MONO_DL_EAGER (RTLD_NOW) so that references to runtime functions within
         * this function (and its siblings) are resolved when the profiler is
         * loaded. Otherwise, we would potentially invoke the dynamic linker when
         * invoking runtime functions, which is not async-signal-safe.
         */

        if (InterlockedRead (&in_shutdown))
                return;

        SampleHit *sample = (SampleHit *) mono_lock_free_queue_dequeue (&profiler->sample_reuse_queue);

        if (!sample) {
                /*
                 * If we're out of reusable sample events and we're not allowed to
                 * allocate more, we have no choice but to drop the event.
                 */
                if (InterlockedRead (&sample_allocations_ctr) >= max_allocated_sample_hits)
                        return;

                sample = mono_lock_free_alloc (&profiler->sample_allocator);
                sample->prof = profiler;
                mono_lock_free_queue_node_init (&sample->node, TRUE);

                InterlockedIncrement (&sample_allocations_ctr);
        }

        sample->count = 0;
        mono_stack_walk_async_safe (&async_walk_stack, context, sample);

        sample->time = current_time ();
        sample->tid = thread_id ();
        sample->ip = ip;

        mono_thread_hazardous_try_free (sample, enqueue_sample_hit);
}

static uintptr_t *code_pages = 0;
static int num_code_pages = 0;
static int size_code_pages = 0;
#define CPAGE_SHIFT (9)
#define CPAGE_SIZE (1 << CPAGE_SHIFT)
#define CPAGE_MASK (~(CPAGE_SIZE - 1))
#define CPAGE_ADDR(p) ((p) & CPAGE_MASK)

static uintptr_t
add_code_page (uintptr_t *hash, uintptr_t hsize, uintptr_t page)
{
        uintptr_t i;
        uintptr_t start_pos;
        start_pos = (page >> CPAGE_SHIFT) % hsize;
        i = start_pos;
        do {
                if (hash [i] && CPAGE_ADDR (hash [i]) == CPAGE_ADDR (page)) {
                        return 0;
                } else if (!hash [i]) {
                        hash [i] = page;
                        return 1;
                }
                /* wrap around */
                if (++i == hsize)
                        i = 0;
        } while (i != start_pos);
        /* should not happen */
        printf ("failed code page store\n");
        return 0;
}

static void
add_code_pointer (uintptr_t ip)
{
        uintptr_t i;
        if (num_code_pages * 2 >= size_code_pages) {
                uintptr_t *n;
                uintptr_t old_size = size_code_pages;
                size_code_pages *= 2;
                if (size_code_pages == 0)
                        size_code_pages = 16;
                n = (uintptr_t *) g_calloc (sizeof (uintptr_t) * size_code_pages, 1);
                for (i = 0; i < old_size; ++i) {
                        if (code_pages [i])
                                add_code_page (n, size_code_pages, code_pages [i]);
                }
                if (code_pages)
                        g_free (code_pages);
                code_pages = n;
        }
        num_code_pages += add_code_page (code_pages, size_code_pages, ip & CPAGE_MASK);
}

/* ELF code crashes on some systems. */
//#if defined(HAVE_DL_ITERATE_PHDR) && defined(ELFMAG0)
#if 0
static void
dump_ubin (MonoProfiler *prof, const char *filename, uintptr_t load_addr, uint64_t offset, uintptr_t size)
{
        int len = strlen (filename) + 1;

        ENTER_LOG (&sample_ubins_ctr, logbuffer,
                EVENT_SIZE /* event */ +
                LEB128_SIZE /* load address */ +
                LEB128_SIZE /* offset */ +
                LEB128_SIZE /* size */ +
                nlen /* file name */
        );

        emit_event (logbuffer, TYPE_SAMPLE | TYPE_SAMPLE_UBIN);
        emit_svalue (logbuffer, load_addr);
        emit_uvalue (logbuffer, offset);
        emit_uvalue (logbuffer, size);
        memcpy (logbuffer->cursor, filename, len);
        logbuffer->cursor += len;

        EXIT_LOG_EXPLICIT (DO_SEND, NO_REQUESTS);
}
#endif

static void
dump_usym (MonoProfiler *prof, const char *name, uintptr_t value, uintptr_t size)
{
        int len = strlen (name) + 1;

        ENTER_LOG (&sample_usyms_ctr, logbuffer,
                EVENT_SIZE /* event */ +
                LEB128_SIZE /* value */ +
                LEB128_SIZE /* size */ +
                len /* name */
        );

        emit_event (logbuffer, TYPE_SAMPLE | TYPE_SAMPLE_USYM);
        emit_ptr (logbuffer, (void*)value);
        emit_value (logbuffer, size);
        memcpy (logbuffer->cursor, name, len);
        logbuffer->cursor += len;

        EXIT_LOG_EXPLICIT (DO_SEND, NO_REQUESTS);
}

/* ELF code crashes on some systems. */
//#if defined(ELFMAG0)
#if 0

#if SIZEOF_VOID_P == 4
#define ELF_WSIZE 32
#else
#define ELF_WSIZE 64
#endif
#ifndef ElfW
#define ElfW(type)      _ElfW (Elf, ELF_WSIZE, type)
#define _ElfW(e,w,t)    _ElfW_1 (e, w, _##t)
#define _ElfW_1(e,w,t)  e##w##t
#endif

static void
dump_elf_symbols (MonoProfiler *prof, ElfW(Sym) *symbols, int num_symbols, const char *strtab, void *load_addr)
{
        int i;
        for (i = 0; i < num_symbols; ++i) {
                const char* sym;
                sym =  strtab + symbols [i].st_name;
                if (!symbols [i].st_name || !symbols [i].st_size || (symbols [i].st_info & 0xf) != STT_FUNC)
                        continue;
                //printf ("symbol %s at %d\n", sym, symbols [i].st_value);
                dump_usym (sym, (uintptr_t)load_addr + symbols [i].st_value, symbols [i].st_size);
        }
}

static int
read_elf_symbols (MonoProfiler *prof, const char *filename, void *load_addr)
{
        int fd, i;
        void *data;
        struct stat statb;
        uint64_t file_size;
        ElfW(Ehdr) *header;
        ElfW(Shdr) *sheader;
        ElfW(Shdr) *shstrtabh;
        ElfW(Shdr) *symtabh = NULL;
        ElfW(Shdr) *strtabh = NULL;
        ElfW(Sym) *symbols = NULL;
        const char *strtab;
        int num_symbols;

        fd = open (filename, O_RDONLY);
        if (fd < 0)
                return 0;
        if (fstat (fd, &statb) != 0) {
                close (fd);
                return 0;
        }
        file_size = statb.st_size;
        data = mmap (NULL, file_size, PROT_READ, MAP_PRIVATE, fd, 0);
        close (fd);
        if (data == MAP_FAILED)
                return 0;
        header = data;
        if (header->e_ident [EI_MAG0] != ELFMAG0 ||
                        header->e_ident [EI_MAG1] != ELFMAG1 ||
                        header->e_ident [EI_MAG2] != ELFMAG2 ||
                        header->e_ident [EI_MAG3] != ELFMAG3 ) {
                munmap (data, file_size);
                return 0;
        }
        sheader = (void*)((char*)data + header->e_shoff);
        shstrtabh = (void*)((char*)sheader + (header->e_shentsize * header->e_shstrndx));
        strtab = (const char*)data + shstrtabh->sh_offset;
        for (i = 0; i < header->e_shnum; ++i) {
                //printf ("section header: %d\n", sheader->sh_type);
                if (sheader->sh_type == SHT_SYMTAB) {
                        symtabh = sheader;
                        strtabh = (void*)((char*)data + header->e_shoff + sheader->sh_link * header->e_shentsize);
                        /*printf ("symtab section header: %d, .strstr: %d\n", i, sheader->sh_link);*/
                        break;
                }
                sheader = (void*)((char*)sheader + header->e_shentsize);
        }
        if (!symtabh || !strtabh) {
                munmap (data, file_size);
                return 0;
        }
        strtab = (const char*)data + strtabh->sh_offset;
        num_symbols = symtabh->sh_size / symtabh->sh_entsize;
        symbols = (void*)((char*)data + symtabh->sh_offset);
        dump_elf_symbols (symbols, num_symbols, strtab, load_addr);
        munmap (data, file_size);
        return 1;
}
#endif

/* ELF code crashes on some systems. */
//#if defined(HAVE_DL_ITERATE_PHDR) && defined(ELFMAG0)
#if 0
static int
elf_dl_callback (struct dl_phdr_info *info, size_t size, void *data)
{
        MonoProfiler *prof = data;
        char buf [256];
        const char *filename;
        BinaryObject *obj;
        char *a = (void*)info->dlpi_addr;
        int i, num_sym;
        ElfW(Dyn) *dyn = NULL;
        ElfW(Sym) *symtab = NULL;
        ElfW(Word) *hash_table = NULL;
        ElfW(Ehdr) *header = NULL;
        const char* strtab = NULL;
        for (obj = prof->binary_objects; obj; obj = obj->next) {
                if (obj->addr == a)
                        return 0;
        }
        filename = info->dlpi_name;
        if (!filename)
                return 0;
        if (!info->dlpi_addr && !filename [0]) {
                int l = readlink ("/proc/self/exe", buf, sizeof (buf) - 1);
                if (l > 0) {
                        buf [l] = 0;
                        filename = buf;
                }
        }
        obj = g_calloc (sizeof (BinaryObject), 1);
        obj->addr = (void*)info->dlpi_addr;
        obj->name = pstrdup (filename);
        obj->next = prof->binary_objects;
        prof->binary_objects = obj;
        //printf ("loaded file: %s at %p, segments: %d\n", filename, (void*)info->dlpi_addr, info->dlpi_phnum);
        a = NULL;
        for (i = 0; i < info->dlpi_phnum; ++i) {
                //printf ("segment type %d file offset: %d, size: %d\n", info->dlpi_phdr[i].p_type, info->dlpi_phdr[i].p_offset, info->dlpi_phdr[i].p_memsz);
                if (info->dlpi_phdr[i].p_type == PT_LOAD && !header) {
                        header = (ElfW(Ehdr)*)(info->dlpi_addr + info->dlpi_phdr[i].p_vaddr);
                        if (header->e_ident [EI_MAG0] != ELFMAG0 ||
                                        header->e_ident [EI_MAG1] != ELFMAG1 ||
                                        header->e_ident [EI_MAG2] != ELFMAG2 ||
                                        header->e_ident [EI_MAG3] != ELFMAG3 ) {
                                header = NULL;
                        }
                        dump_ubin (prof, filename, info->dlpi_addr + info->dlpi_phdr[i].p_vaddr, info->dlpi_phdr[i].p_offset, info->dlpi_phdr[i].p_memsz);
                } else if (info->dlpi_phdr[i].p_type == PT_DYNAMIC) {
                        dyn = (ElfW(Dyn) *)(info->dlpi_addr + info->dlpi_phdr[i].p_vaddr);
                }
        }
        if (read_elf_symbols (prof, filename, (void*)info->dlpi_addr))
                return 0;
        if (!info->dlpi_name || !info->dlpi_name[0])
                return 0;
        if (!dyn)
                return 0;
        for (i = 0; dyn [i].d_tag != DT_NULL; ++i) {
                if (dyn [i].d_tag == DT_SYMTAB) {
                        if (symtab && do_debug)
                                printf ("multiple symtabs: %d\n", i);
                        symtab = (ElfW(Sym) *)(a + dyn [i].d_un.d_ptr);
                } else if (dyn [i].d_tag == DT_HASH) {
                        hash_table = (ElfW(Word) *)(a + dyn [i].d_un.d_ptr);
                } else if (dyn [i].d_tag == DT_STRTAB) {
                        strtab = (const char*)(a + dyn [i].d_un.d_ptr);
                }
        }
        if (!hash_table)
                return 0;
        num_sym = hash_table [1];
        dump_elf_symbols (prof, symtab, num_sym, strtab, (void*)info->dlpi_addr);
        return 0;
}

static int
load_binaries (MonoProfiler *prof)
{
        dl_iterate_phdr (elf_dl_callback, prof);
        return 1;
}
#else
static int
load_binaries (MonoProfiler *prof)
{
        return 0;
}
#endif

static const char*
symbol_for (uintptr_t code)
{
#ifdef HAVE_DLADDR
        void *ip = (void*)code;
        Dl_info di;
        if (dladdr (ip, &di)) {
                if (di.dli_sname)
                        return di.dli_sname;
        } else {
        /*      char **names;
                names = backtrace_symbols (&ip, 1);
                if (names) {
                        const char* p = names [0];
                        g_free (names);
                        return p;
                }
                */
        }
#endif
        return NULL;
}

static void
dump_unmanaged_coderefs (MonoProfiler *prof)
{
        int i;
        const char* last_symbol;
        uintptr_t addr, page_end;

        if (load_binaries (prof))
                return;
        for (i = 0; i < size_code_pages; ++i) {
                const char* sym;
                if (!code_pages [i] || code_pages [i] & 1)
                        continue;
                last_symbol = NULL;
                addr = CPAGE_ADDR (code_pages [i]);
                page_end = addr + CPAGE_SIZE;
                code_pages [i] |= 1;
                /* we dump the symbols for the whole page */
                for (; addr < page_end; addr += 16) {
                        sym = symbol_for (addr);
                        if (sym && sym == last_symbol)
                                continue;
                        last_symbol = sym;
                        if (!sym)
                                continue;
                        dump_usym (prof, sym, addr, 0); /* let's not guess the size */
                        //printf ("found symbol at %p: %s\n", (void*)addr, sym);
                }
        }
}

static int
mono_cpu_count (void)
{
#ifdef PLATFORM_ANDROID
        /* Android tries really hard to save power by powering off CPUs on SMP phones which
         * means the normal way to query cpu count returns a wrong value with userspace API.
         * Instead we use /sys entries to query the actual hardware CPU count.
         */
        int count = 0;
        char buffer[8] = {'\0'};
        int present = open ("/sys/devices/system/cpu/present", O_RDONLY);
        /* Format of the /sys entry is a cpulist of indexes which in the case
         * of present is always of the form "0-(n-1)" when there is more than
         * 1 core, n being the number of CPU cores in the system. Otherwise
         * the value is simply 0
         */
        if (present != -1 && read (present, (char*)buffer, sizeof (buffer)) > 3)
                count = strtol (((char*)buffer) + 2, NULL, 10);
        if (present != -1)
                close (present);
        if (count > 0)
                return count + 1;
#endif

#if defined(HOST_ARM) || defined (HOST_ARM64)

        /* ARM platforms tries really hard to save power by powering off CPUs on SMP phones which
         * means the normal way to query cpu count returns a wrong value with userspace API. */

#ifdef _SC_NPROCESSORS_CONF
        {
                int count = sysconf (_SC_NPROCESSORS_CONF);
                if (count > 0)
                        return count;
        }
#endif

#else

#ifdef HAVE_SCHED_GETAFFINITY
        {
                cpu_set_t set;
                if (sched_getaffinity (getpid (), sizeof (set), &set) == 0)
                        return CPU_COUNT (&set);
        }
#endif
#ifdef _SC_NPROCESSORS_ONLN
        {
                int count = sysconf (_SC_NPROCESSORS_ONLN);
                if (count > 0)
                        return count;
        }
#endif

#endif /* defined(HOST_ARM) || defined (HOST_ARM64) */

#ifdef USE_SYSCTL
        {
                int count;
                int mib [2];
                size_t len = sizeof (int);
                mib [0] = CTL_HW;
                mib [1] = HW_NCPU;
                if (sysctl (mib, 2, &count, &len, NULL, 0) == 0)
                        return count;
        }
#endif
#ifdef HOST_WIN32
        {
                SYSTEM_INFO info;
                GetSystemInfo (&info);
                return info.dwNumberOfProcessors;
        }
#endif

        static gboolean warned;

        if (!warned) {
                g_warning ("Don't know how to determine CPU count on this platform; assuming 1");
                warned = TRUE;
        }

        return 1;
}

typedef struct MonoCounterAgent {
        MonoCounter *counter;
        // MonoCounterAgent specific data :
        void *value;
        size_t value_size;
        short index;
        short emitted;
        struct MonoCounterAgent *next;
} MonoCounterAgent;

static MonoCounterAgent* counters;
static int counters_index = 1;
static mono_mutex_t counters_mutex;

static void
counters_add_agent (MonoCounter *counter)
{
        if (InterlockedRead (&in_shutdown))
                return;

        MonoCounterAgent *agent, *item;

        mono_os_mutex_lock (&counters_mutex);

        for (agent = counters; agent; agent = agent->next) {
                if (agent->counter == counter) {
                        agent->value_size = 0;
                        if (agent->value) {
                                g_free (agent->value);
                                agent->value = NULL;
                        }
                        goto done;
                }
        }

        agent = (MonoCounterAgent *) g_malloc (sizeof (MonoCounterAgent));
        agent->counter = counter;
        agent->value = NULL;
        agent->value_size = 0;
        agent->index = counters_index++;
        agent->emitted = 0;
        agent->next = NULL;

        if (!counters) {
                counters = agent;
        } else {
                item = counters;
                while (item->next)
                        item = item->next;
                item->next = agent;
        }

done:
        mono_os_mutex_unlock (&counters_mutex);
}

static mono_bool
counters_init_foreach_callback (MonoCounter *counter, gpointer data)
{
        counters_add_agent (counter);
        return TRUE;
}

static void
counters_init (MonoProfiler *profiler)
{
        mono_os_mutex_init (&counters_mutex);

        mono_counters_on_register (&counters_add_agent);
        mono_counters_foreach (counters_init_foreach_callback, NULL);
}

static void
counters_emit (MonoProfiler *profiler)
{
        MonoCounterAgent *agent;
        int len = 0;
        int size =
                EVENT_SIZE /* event */ +
                LEB128_SIZE /* len */
        ;

        mono_os_mutex_lock (&counters_mutex);

        for (agent = counters; agent; agent = agent->next) {
                if (agent->emitted)
                        continue;

                size +=
                        LEB128_SIZE /* section */ +
                        strlen (mono_counter_get_name (agent->counter)) + 1 /* name */ +
                        BYTE_SIZE /* type */ +
                        BYTE_SIZE /* unit */ +
                        BYTE_SIZE /* variance */ +
                        LEB128_SIZE /* index */
                ;

                len++;
        }

        if (!len)
                goto done;

        ENTER_LOG (&counter_descriptors_ctr, logbuffer, size);

        emit_event (logbuffer, TYPE_SAMPLE_COUNTERS_DESC | TYPE_SAMPLE);
        emit_value (logbuffer, len);

        for (agent = counters; agent; agent = agent->next) {
                const char *name;

                if (agent->emitted)
                        continue;

                name = mono_counter_get_name (agent->counter);
                emit_value (logbuffer, mono_counter_get_section (agent->counter));
                emit_string (logbuffer, name, strlen (name) + 1);
                emit_byte (logbuffer, mono_counter_get_type (agent->counter));
                emit_byte (logbuffer, mono_counter_get_unit (agent->counter));
                emit_byte (logbuffer, mono_counter_get_variance (agent->counter));
                emit_value (logbuffer, agent->index);

                agent->emitted = 1;
        }

        EXIT_LOG_EXPLICIT (DO_SEND, NO_REQUESTS);

done:
        mono_os_mutex_unlock (&counters_mutex);
}

static void
counters_sample (MonoProfiler *profiler, uint64_t timestamp)
{
        MonoCounterAgent *agent;
        MonoCounter *counter;
        int type;
        int buffer_size;
        void *buffer;
        int size;

        counters_emit (profiler);

        buffer_size = 8;
        buffer = g_calloc (1, buffer_size);

        mono_os_mutex_lock (&counters_mutex);

        size =
                EVENT_SIZE /* event */
        ;

        for (agent = counters; agent; agent = agent->next) {
                size +=
                        LEB128_SIZE /* index */ +
                        BYTE_SIZE /* type */ +
                        mono_counter_get_size (agent->counter) /* value */
                ;
        }

        size +=
                LEB128_SIZE /* stop marker */
        ;

        ENTER_LOG (&counter_samples_ctr, logbuffer, size);

        emit_event_time (logbuffer, TYPE_SAMPLE_COUNTERS | TYPE_SAMPLE, timestamp);

        for (agent = counters; agent; agent = agent->next) {
                size_t size;

                counter = agent->counter;

                size = mono_counter_get_size (counter);

                if (size > buffer_size) {
                        buffer_size = size;
                        buffer = g_realloc (buffer, buffer_size);
                }

                memset (buffer, 0, buffer_size);

                g_assert (mono_counters_sample (counter, buffer, size));

                type = mono_counter_get_type (counter);

                if (!agent->value) {
                        agent->value = g_calloc (1, size);
                        agent->value_size = size;
                } else {
                        if (type == MONO_COUNTER_STRING) {
                                if (strcmp (agent->value, buffer) == 0)
                                        continue;
                        } else {
                                if (agent->value_size == size && memcmp (agent->value, buffer, size) == 0)
                                        continue;
                        }
                }

                emit_uvalue (logbuffer, agent->index);
                emit_byte (logbuffer, type);
                switch (type) {
                case MONO_COUNTER_INT:
#if SIZEOF_VOID_P == 4
                case MONO_COUNTER_WORD:
#endif
                        emit_svalue (logbuffer, *(int*)buffer - *(int*)agent->value);
                        break;
                case MONO_COUNTER_UINT:
                        emit_uvalue (logbuffer, *(guint*)buffer - *(guint*)agent->value);
                        break;
                case MONO_COUNTER_TIME_INTERVAL:
                case MONO_COUNTER_LONG:
#if SIZEOF_VOID_P == 8
                case MONO_COUNTER_WORD:
#endif
                        emit_svalue (logbuffer, *(gint64*)buffer - *(gint64*)agent->value);
                        break;
                case MONO_COUNTER_ULONG:
                        emit_uvalue (logbuffer, *(guint64*)buffer - *(guint64*)agent->value);
                        break;
                case MONO_COUNTER_DOUBLE:
                        emit_double (logbuffer, *(double*)buffer);
                        break;
                case MONO_COUNTER_STRING:
                        if (size == 0) {
                                emit_byte (logbuffer, 0);
                        } else {
                                emit_byte (logbuffer, 1);
                                emit_string (logbuffer, (char*)buffer, size);
                        }
                        break;
                default:
                        g_assert_not_reached ();
                }

                if (type == MONO_COUNTER_STRING && size > agent->value_size) {
                        agent->value = g_realloc (agent->value, size);
                        agent->value_size = size;
                }

                if (size > 0)
                        memcpy (agent->value, buffer, size);
        }
        g_free (buffer);

        emit_value (logbuffer, 0);

        EXIT_LOG_EXPLICIT (DO_SEND, NO_REQUESTS);

        mono_os_mutex_unlock (&counters_mutex);
}

typedef struct _PerfCounterAgent PerfCounterAgent;
struct _PerfCounterAgent {
        PerfCounterAgent *next;
        int index;
        char *category_name;
        char *name;
        int type;
        gint64 value;
        guint8 emitted;
        guint8 updated;
        guint8 deleted;
};

static PerfCounterAgent *perfcounters = NULL;

static void
perfcounters_emit (MonoProfiler *profiler)
{
        PerfCounterAgent *pcagent;
        int len = 0;
        int size =
                EVENT_SIZE /* event */ +
                LEB128_SIZE /* len */
        ;

        for (pcagent = perfcounters; pcagent; pcagent = pcagent->next) {
                if (pcagent->emitted)
                        continue;

                size +=
                        LEB128_SIZE /* section */ +
                        strlen (pcagent->category_name) + 1 /* category name */ +
                        strlen (pcagent->name) + 1 /* name */ +
                        BYTE_SIZE /* type */ +
                        BYTE_SIZE /* unit */ +
                        BYTE_SIZE /* variance */ +
                        LEB128_SIZE /* index */
                ;

                len++;
        }

        if (!len)
                return;

        ENTER_LOG (&perfcounter_descriptors_ctr, logbuffer, size);

        emit_event (logbuffer, TYPE_SAMPLE_COUNTERS_DESC | TYPE_SAMPLE);
        emit_value (logbuffer, len);

        for (pcagent = perfcounters; pcagent; pcagent = pcagent->next) {
                if (pcagent->emitted)
                        continue;

                emit_value (logbuffer, MONO_COUNTER_PERFCOUNTERS);
                emit_string (logbuffer, pcagent->category_name, strlen (pcagent->category_name) + 1);
                emit_string (logbuffer, pcagent->name, strlen (pcagent->name) + 1);
                emit_byte (logbuffer, MONO_COUNTER_LONG);
                emit_byte (logbuffer, MONO_COUNTER_RAW);
                emit_byte (logbuffer, MONO_COUNTER_VARIABLE);
                emit_value (logbuffer, pcagent->index);

                pcagent->emitted = 1;
        }

        EXIT_LOG_EXPLICIT (DO_SEND, NO_REQUESTS);
}

static gboolean
perfcounters_foreach (char *category_name, char *name, unsigned char type, gint64 value, gpointer user_data)
{
        PerfCounterAgent *pcagent;

        for (pcagent = perfcounters; pcagent; pcagent = pcagent->next) {
                if (strcmp (pcagent->category_name, category_name) != 0 || strcmp (pcagent->name, name) != 0)
                        continue;
                if (pcagent->value == value)
                        return TRUE;

                pcagent->value = value;
                pcagent->updated = 1;
                pcagent->deleted = 0;
                return TRUE;
        }

        pcagent = g_new0 (PerfCounterAgent, 1);
        pcagent->next = perfcounters;
        pcagent->index = counters_index++;
        pcagent->category_name = g_strdup (category_name);
        pcagent->name = g_strdup (name);
        pcagent->type = (int) type;
        pcagent->value = value;
        pcagent->emitted = 0;
        pcagent->updated = 1;
        pcagent->deleted = 0;

        perfcounters = pcagent;

        return TRUE;
}

static void
perfcounters_sample (MonoProfiler *profiler, uint64_t timestamp)
{
        PerfCounterAgent *pcagent;
        int len = 0;
        int size;

        mono_os_mutex_lock (&counters_mutex);

        /* mark all perfcounters as deleted, foreach will unmark them as necessary */
        for (pcagent = perfcounters; pcagent; pcagent = pcagent->next)
                pcagent->deleted = 1;

        mono_perfcounter_foreach (perfcounters_foreach, perfcounters);

        perfcounters_emit (profiler);

        size =
                EVENT_SIZE /* event */
        ;

        for (pcagent = perfcounters; pcagent; pcagent = pcagent->next) {
                if (pcagent->deleted || !pcagent->updated)
                        continue;

                size +=
                        LEB128_SIZE /* index */ +
                        BYTE_SIZE /* type */ +
                        LEB128_SIZE /* value */
                ;

                len++;
        }

        if (!len)
                goto done;

        size +=
                LEB128_SIZE /* stop marker */
        ;

        ENTER_LOG (&perfcounter_samples_ctr, logbuffer, size);

        emit_event_time (logbuffer, TYPE_SAMPLE_COUNTERS | TYPE_SAMPLE, timestamp);

        for (pcagent = perfcounters; pcagent; pcagent = pcagent->next) {
                if (pcagent->deleted || !pcagent->updated)
                        continue;
                emit_uvalue (logbuffer, pcagent->index);
                emit_byte (logbuffer, MONO_COUNTER_LONG);
                emit_svalue (logbuffer, pcagent->value);

                pcagent->updated = 0;
        }

        emit_value (logbuffer, 0);

        EXIT_LOG_EXPLICIT (DO_SEND, NO_REQUESTS);

done:
        mono_os_mutex_unlock (&counters_mutex);
}

static void
counters_and_perfcounters_sample (MonoProfiler *prof)
{
        uint64_t now = current_time ();

        counters_sample (prof, now);
        perfcounters_sample (prof, now);
}

#define COVERAGE_DEBUG(x) if (debug_coverage) {x}
static mono_mutex_t coverage_mutex;
static MonoConcurrentHashTable *coverage_methods = NULL;
static MonoConcurrentHashTable *coverage_assemblies = NULL;
static MonoConcurrentHashTable *coverage_classes = NULL;

static MonoConcurrentHashTable *filtered_classes = NULL;
static MonoConcurrentHashTable *entered_methods = NULL;
static MonoConcurrentHashTable *image_to_methods = NULL;
static MonoConcurrentHashTable *suppressed_assemblies = NULL;
static gboolean coverage_initialized = FALSE;

static GPtrArray *coverage_data = NULL;
static int previous_offset = 0;

typedef struct {
        MonoLockFreeQueueNode node;
        MonoMethod *method;
} MethodNode;

typedef struct {
        int offset;
        int counter;
        char *filename;
        int line;
        int column;
} CoverageEntry;

static void
free_coverage_entry (gpointer data, gpointer userdata)
{
        CoverageEntry *entry = (CoverageEntry *)data;
        g_free (entry->filename);
        g_free (entry);
}

static void
obtain_coverage_for_method (MonoProfiler *prof, const MonoProfileCoverageEntry *entry)
{
        int offset = entry->iloffset - previous_offset;
        CoverageEntry *e = g_new (CoverageEntry, 1);

        previous_offset = entry->iloffset;

        e->offset = offset;
        e->counter = entry->counter;
        e->filename = g_strdup(entry->filename ? entry->filename : "");
        e->line = entry->line;
        e->column = entry->col;

        g_ptr_array_add (coverage_data, e);
}

static char *
parse_generic_type_names(char *name)
{
        char *new_name, *ret;
        int within_generic_declaration = 0, generic_members = 1;

        if (name == NULL || *name == '\0')
                return g_strdup ("");

        if (!(ret = new_name = (char *) g_calloc (strlen (name) * 4 + 1, sizeof (char))))
                return NULL;

        do {
                switch (*name) {
                        case '<':
                                within_generic_declaration = 1;
                                break;

                        case '>':
                                within_generic_declaration = 0;

                                if (*(name - 1) != '<') {
                                        *new_name++ = '`';
                                        *new_name++ = '0' + generic_members;
                                } else {
                                        memcpy (new_name, "&lt;&gt;", 8);
                                        new_name += 8;
                                }

                                generic_members = 0;
                                break;

                        case ',':
                                generic_members++;
                                break;

                        default:
                                if (!within_generic_declaration)
                                        *new_name++ = *name;

                                break;
                }
        } while (*name++);

        return ret;
}

static int method_id;
static void
build_method_buffer (gpointer key, gpointer value, gpointer userdata)
{
        MonoMethod *method = (MonoMethod *)value;
        MonoProfiler *prof = (MonoProfiler *)userdata;
        MonoClass *klass;
        MonoImage *image;
        char *class_name;
        const char *image_name, *method_name, *sig, *first_filename;
        guint i;

        previous_offset = 0;
        coverage_data = g_ptr_array_new ();

        mono_profiler_coverage_get (prof, method, obtain_coverage_for_method);

        klass = mono_method_get_class (method);
        image = mono_class_get_image (klass);
        image_name = mono_image_get_name (image);

        sig = mono_signature_get_desc (mono_method_signature (method), TRUE);
        class_name = parse_generic_type_names (mono_type_get_name (mono_class_get_type (klass)));
        method_name = mono_method_get_name (method);

        if (coverage_data->len != 0) {
                CoverageEntry *entry = (CoverageEntry *)coverage_data->pdata[0];
                first_filename = entry->filename ? entry->filename : "";
        } else
                first_filename = "";

        image_name = image_name ? image_name : "";
        sig = sig ? sig : "";
        method_name = method_name ? method_name : "";

        ENTER_LOG (&coverage_methods_ctr, logbuffer,
                EVENT_SIZE /* event */ +
                strlen (image_name) + 1 /* image name */ +
                strlen (class_name) + 1 /* class name */ +
                strlen (method_name) + 1 /* method name */ +
                strlen (sig) + 1 /* signature */ +
                strlen (first_filename) + 1 /* first file name */ +
                LEB128_SIZE /* token */ +
                LEB128_SIZE /* method id */ +
                LEB128_SIZE /* entries */
        );

        emit_event (logbuffer, TYPE_COVERAGE_METHOD | TYPE_COVERAGE);
        emit_string (logbuffer, image_name, strlen (image_name) + 1);
        emit_string (logbuffer, class_name, strlen (class_name) + 1);
        emit_string (logbuffer, method_name, strlen (method_name) + 1);
        emit_string (logbuffer, sig, strlen (sig) + 1);
        emit_string (logbuffer, first_filename, strlen (first_filename) + 1);

        emit_uvalue (logbuffer, mono_method_get_token (method));
        emit_uvalue (logbuffer, method_id);
        emit_value (logbuffer, coverage_data->len);

        EXIT_LOG_EXPLICIT (DO_SEND, NO_REQUESTS);

        for (i = 0; i < coverage_data->len; i++) {
                CoverageEntry *entry = (CoverageEntry *)coverage_data->pdata[i];

                ENTER_LOG (&coverage_statements_ctr, logbuffer,
                        EVENT_SIZE /* event */ +
                        LEB128_SIZE /* method id */ +
                        LEB128_SIZE /* offset */ +
                        LEB128_SIZE /* counter */ +
                        LEB128_SIZE /* line */ +
                        LEB128_SIZE /* column */
                );

                emit_event (logbuffer, TYPE_COVERAGE_STATEMENT | TYPE_COVERAGE);
                emit_uvalue (logbuffer, method_id);
                emit_uvalue (logbuffer, entry->offset);
                emit_uvalue (logbuffer, entry->counter);
                emit_uvalue (logbuffer, entry->line);
                emit_uvalue (logbuffer, entry->column);

                EXIT_LOG_EXPLICIT (DO_SEND, NO_REQUESTS);
        }

        method_id++;

        g_free (class_name);

        g_ptr_array_foreach (coverage_data, free_coverage_entry, NULL);
        g_ptr_array_free (coverage_data, TRUE);
        coverage_data = NULL;
}

/* This empties the queue */
static guint
count_queue (MonoLockFreeQueue *queue)
{
        MonoLockFreeQueueNode *node;
        guint count = 0;

        while ((node = mono_lock_free_queue_dequeue (queue))) {
                count++;
                mono_thread_hazardous_try_free (node, g_free);
        }

        return count;
}

static void
build_class_buffer (gpointer key, gpointer value, gpointer userdata)
{
        MonoClass *klass = (MonoClass *)key;
        MonoLockFreeQueue *class_methods = (MonoLockFreeQueue *)value;
        MonoImage *image;
        char *class_name;
        const char *assembly_name;
        int number_of_methods, partially_covered;
        guint fully_covered;

        image = mono_class_get_image (klass);
        assembly_name = mono_image_get_name (image);
        class_name = mono_type_get_name (mono_class_get_type (klass));

        assembly_name = assembly_name ? assembly_name : "";
        number_of_methods = mono_class_num_methods (klass);
        fully_covered = count_queue (class_methods);
        /* We don't handle partial covered yet */
        partially_covered = 0;

        ENTER_LOG (&coverage_classes_ctr, logbuffer,
                EVENT_SIZE /* event */ +
                strlen (assembly_name) + 1 /* assembly name */ +
                strlen (class_name) + 1 /* class name */ +
                LEB128_SIZE /* no. methods */ +
                LEB128_SIZE /* fully covered */ +
                LEB128_SIZE /* partially covered */
        );

        emit_event (logbuffer, TYPE_COVERAGE_CLASS | TYPE_COVERAGE);
        emit_string (logbuffer, assembly_name, strlen (assembly_name) + 1);
        emit_string (logbuffer, class_name, strlen (class_name) + 1);
        emit_uvalue (logbuffer, number_of_methods);
        emit_uvalue (logbuffer, fully_covered);
        emit_uvalue (logbuffer, partially_covered);

        EXIT_LOG_EXPLICIT (DO_SEND, NO_REQUESTS);

        g_free (class_name);
}

static void
get_coverage_for_image (MonoImage *image, int *number_of_methods, guint *fully_covered, int *partially_covered)
{
        MonoLockFreeQueue *image_methods = (MonoLockFreeQueue *)mono_conc_hashtable_lookup (image_to_methods, image);

        *number_of_methods = mono_image_get_table_rows (image, MONO_TABLE_METHOD);
        if (image_methods)
                *fully_covered = count_queue (image_methods);
        else
                *fully_covered = 0;

        // FIXME: We don't handle partially covered yet.
        *partially_covered = 0;
}

static void
build_assembly_buffer (gpointer key, gpointer value, gpointer userdata)
{
        MonoAssembly *assembly = (MonoAssembly *)value;
        MonoImage *image = mono_assembly_get_image (assembly);
        const char *name, *guid, *filename;
        int number_of_methods = 0, partially_covered = 0;
        guint fully_covered = 0;

        name = mono_image_get_name (image);
        guid = mono_image_get_guid (image);
        filename = mono_image_get_filename (image);

        name = name ? name : "";
        guid = guid ? guid : "";
        filename = filename ? filename : "";

        get_coverage_for_image (image, &number_of_methods, &fully_covered, &partially_covered);

        ENTER_LOG (&coverage_assemblies_ctr, logbuffer,
                EVENT_SIZE /* event */ +
                strlen (name) + 1 /* name */ +
                strlen (guid) + 1 /* guid */ +
                strlen (filename) + 1 /* file name */ +
                LEB128_SIZE /* no. methods */ +
                LEB128_SIZE /* fully covered */ +
                LEB128_SIZE /* partially covered */
        );

        emit_event (logbuffer, TYPE_COVERAGE_ASSEMBLY | TYPE_COVERAGE);
        emit_string (logbuffer, name, strlen (name) + 1);
        emit_string (logbuffer, guid, strlen (guid) + 1);
        emit_string (logbuffer, filename, strlen (filename) + 1);
        emit_uvalue (logbuffer, number_of_methods);
        emit_uvalue (logbuffer, fully_covered);
        emit_uvalue (logbuffer, partially_covered);

        EXIT_LOG_EXPLICIT (DO_SEND, NO_REQUESTS);
}

static void
dump_coverage (MonoProfiler *prof)
{
        if (!coverage_initialized)
                return;

        COVERAGE_DEBUG(fprintf (stderr, "Coverage: Started dump\n");)
        method_id = 0;

        mono_os_mutex_lock (&coverage_mutex);
        mono_conc_hashtable_foreach (coverage_assemblies, build_assembly_buffer, NULL);
        mono_conc_hashtable_foreach (coverage_classes, build_class_buffer, NULL);
        mono_conc_hashtable_foreach (coverage_methods, build_method_buffer, prof);
        mono_os_mutex_unlock (&coverage_mutex);

        COVERAGE_DEBUG(fprintf (stderr, "Coverage: Finished dump\n");)
}

static void
process_method_enter_coverage (MonoProfiler *prof, MonoMethod *method)
{
        MonoClass *klass;
        MonoImage *image;

        if (!coverage_initialized)
                return;

        klass = mono_method_get_class (method);
        image = mono_class_get_image (klass);

        if (mono_conc_hashtable_lookup (suppressed_assemblies, (gpointer) mono_image_get_name (image)))
                return;

        mono_os_mutex_lock (&coverage_mutex);
        mono_conc_hashtable_insert (entered_methods, method, method);
        mono_os_mutex_unlock (&coverage_mutex);
}

static MonoLockFreeQueueNode *
create_method_node (MonoMethod *method)
{
        MethodNode *node = (MethodNode *) g_malloc (sizeof (MethodNode));
        mono_lock_free_queue_node_init ((MonoLockFreeQueueNode *) node, FALSE);
        node->method = method;

        return (MonoLockFreeQueueNode *) node;
}

static gboolean
coverage_filter (MonoProfiler *prof, MonoMethod *method)
{
        MonoError error;
        MonoClass *klass;
        MonoImage *image;
        MonoAssembly *assembly;
        MonoMethodHeader *header;
        guint32 iflags, flags, code_size;
        char *fqn, *classname;
        gboolean has_positive, found;
        MonoLockFreeQueue *image_methods, *class_methods;
        MonoLockFreeQueueNode *node;

        g_assert (coverage_initialized && "Why are we being asked for coverage filter info when we're not doing coverage?");

        COVERAGE_DEBUG(fprintf (stderr, "Coverage filter for %s\n", mono_method_get_name (method));)

        flags = mono_method_get_flags (method, &iflags);
        if ((iflags & 0x1000 /*METHOD_IMPL_ATTRIBUTE_INTERNAL_CALL*/) ||
            (flags & 0x2000 /*METHOD_ATTRIBUTE_PINVOKE_IMPL*/)) {
                COVERAGE_DEBUG(fprintf (stderr, "   Internal call or pinvoke - ignoring\n");)
                return FALSE;
        }

        // Don't need to do anything else if we're already tracking this method
        if (mono_conc_hashtable_lookup (coverage_methods, method)) {
                COVERAGE_DEBUG(fprintf (stderr, "   Already tracking\n");)
                return TRUE;
        }

        klass = mono_method_get_class (method);
        image = mono_class_get_image (klass);

        // Don't handle coverage for the core assemblies
        if (mono_conc_hashtable_lookup (suppressed_assemblies, (gpointer) mono_image_get_name (image)) != NULL)
                return FALSE;

        if (prof->coverage_filters) {
                /* Check already filtered classes first */
                if (mono_conc_hashtable_lookup (filtered_classes, klass)) {
                        COVERAGE_DEBUG(fprintf (stderr, "   Already filtered\n");)
                        return FALSE;
                }

                classname = mono_type_get_name (mono_class_get_type (klass));

                fqn = g_strdup_printf ("[%s]%s", mono_image_get_name (image), classname);

                COVERAGE_DEBUG(fprintf (stderr, "   Looking for %s in filter\n", fqn);)
                // Check positive filters first
                has_positive = FALSE;
                found = FALSE;
                for (guint i = 0; i < prof->coverage_filters->len; ++i) {
                        char *filter = (char *)g_ptr_array_index (prof->coverage_filters, i);

                        if (filter [0] == '+') {
                                filter = &filter [1];

                                COVERAGE_DEBUG(fprintf (stderr, "   Checking against +%s ...", filter);)

                                if (strstr (fqn, filter) != NULL) {
                                        COVERAGE_DEBUG(fprintf (stderr, "matched\n");)
                                        found = TRUE;
                                } else
                                        COVERAGE_DEBUG(fprintf (stderr, "no match\n");)

                                has_positive = TRUE;
                        }
                }

                if (has_positive && !found) {
                        COVERAGE_DEBUG(fprintf (stderr, "   Positive match was not found\n");)

                        mono_os_mutex_lock (&coverage_mutex);
                        mono_conc_hashtable_insert (filtered_classes, klass, klass);
                        mono_os_mutex_unlock (&coverage_mutex);
                        g_free (fqn);
                        g_free (classname);

                        return FALSE;
                }

                for (guint i = 0; i < prof->coverage_filters->len; ++i) {
                        // FIXME: Is substring search sufficient?
                        char *filter = (char *)g_ptr_array_index (prof->coverage_filters, i);
                        if (filter [0] == '+')
                                continue;

                        // Skip '-'
                        filter = &filter [1];
                        COVERAGE_DEBUG(fprintf (stderr, "   Checking against -%s ...", filter);)

                        if (strstr (fqn, filter) != NULL) {
                                COVERAGE_DEBUG(fprintf (stderr, "matched\n");)

                                mono_os_mutex_lock (&coverage_mutex);
                                mono_conc_hashtable_insert (filtered_classes, klass, klass);
                                mono_os_mutex_unlock (&coverage_mutex);
                                g_free (fqn);
                                g_free (classname);

                                return FALSE;
                        } else
                                COVERAGE_DEBUG(fprintf (stderr, "no match\n");)

                }

                g_free (fqn);
                g_free (classname);
        }

        COVERAGE_DEBUG(fprintf (stderr, "   Handling coverage for %s\n", mono_method_get_name (method));)
        header = mono_method_get_header_checked (method, &error);
        mono_error_cleanup (&error);

        mono_method_header_get_code (header, &code_size, NULL);

        assembly = mono_image_get_assembly (image);

        // Need to keep the assemblies around for as long as they are kept in the hashtable
        // Nunit, for example, has a habit of unloading them before the coverage statistics are
        // generated causing a crash. See https://bugzilla.xamarin.com/show_bug.cgi?id=39325
        mono_assembly_addref (assembly);

        mono_os_mutex_lock (&coverage_mutex);
        mono_conc_hashtable_insert (coverage_methods, method, method);
        mono_conc_hashtable_insert (coverage_assemblies, assembly, assembly);
        mono_os_mutex_unlock (&coverage_mutex);

        image_methods = (MonoLockFreeQueue *)mono_conc_hashtable_lookup (image_to_methods, image);

        if (image_methods == NULL) {
                image_methods = (MonoLockFreeQueue *) g_malloc (sizeof (MonoLockFreeQueue));
                mono_lock_free_queue_init (image_methods);
                mono_os_mutex_lock (&coverage_mutex);
                mono_conc_hashtable_insert (image_to_methods, image, image_methods);
                mono_os_mutex_unlock (&coverage_mutex);
        }

        node = create_method_node (method);
        mono_lock_free_queue_enqueue (image_methods, node);

        class_methods = (MonoLockFreeQueue *)mono_conc_hashtable_lookup (coverage_classes, klass);

        if (class_methods == NULL) {
                class_methods = (MonoLockFreeQueue *) g_malloc (sizeof (MonoLockFreeQueue));
                mono_lock_free_queue_init (class_methods);
                mono_os_mutex_lock (&coverage_mutex);
                mono_conc_hashtable_insert (coverage_classes, klass, class_methods);
                mono_os_mutex_unlock (&coverage_mutex);
        }

        node = create_method_node (method);
        mono_lock_free_queue_enqueue (class_methods, node);

        return TRUE;
}

#define LINE_BUFFER_SIZE 4096
/* Max file limit of 128KB */
#define MAX_FILE_SIZE 128 * 1024
static char *
get_file_content (FILE *stream)
{
        char *buffer;
        ssize_t bytes_read;
        long filesize;
        int res, offset = 0;

        res = fseek (stream, 0, SEEK_END);
        if (res < 0)
          return NULL;

        filesize = ftell (stream);
        if (filesize < 0)
          return NULL;

        res = fseek (stream, 0, SEEK_SET);
        if (res < 0)
          return NULL;

        if (filesize > MAX_FILE_SIZE)
          return NULL;

        buffer = (char *) g_malloc ((filesize + 1) * sizeof (char));
        while ((bytes_read = fread (buffer + offset, 1, LINE_BUFFER_SIZE, stream)) > 0)
                offset += bytes_read;

        /* NULL terminate our buffer */
        buffer[filesize] = '\0';
        return buffer;
}

static char *
get_next_line (char *contents, char **next_start)
{
        char *p = contents;

        if (p == NULL || *p == '\0') {
                *next_start = NULL;
                return NULL;
        }

        while (*p != '\n' && *p != '\0')
                p++;

        if (*p == '\n') {
                *p = '\0';
                *next_start = p + 1;
        } else
                *next_start = NULL;

        return contents;
}

static void
init_suppressed_assemblies (void)
{
        char *content;
        char *line;
        FILE *sa_file;

        suppressed_assemblies = mono_conc_hashtable_new (g_str_hash, g_str_equal);
        sa_file = fopen (SUPPRESSION_DIR "/mono-profiler-log.suppression", "r");
        if (sa_file == NULL)
                return;

        /* Don't need to free @content as it is referred to by the lines stored in @suppressed_assemblies */
        content = get_file_content (sa_file);
        if (content == NULL) {
                g_error ("mono-profiler-log.suppression is greater than 128kb - aborting\n");
        }

        while ((line = get_next_line (content, &content))) {
                line = g_strchomp (g_strchug (line));
                /* No locking needed as we're doing initialization */
                mono_conc_hashtable_insert (suppressed_assemblies, line, line);
        }

        fclose (sa_file);
}

static void
coverage_init (MonoProfiler *prof)
{
        g_assert (!coverage_initialized && "Why are we initializing coverage twice?");

        COVERAGE_DEBUG(fprintf (stderr, "Coverage initialized\n");)

        mono_os_mutex_init (&coverage_mutex);
        coverage_methods = mono_conc_hashtable_new (NULL, NULL);
        coverage_assemblies = mono_conc_hashtable_new (NULL, NULL);
        coverage_classes = mono_conc_hashtable_new (NULL, NULL);
        filtered_classes = mono_conc_hashtable_new (NULL, NULL);
        entered_methods = mono_conc_hashtable_new (NULL, NULL);
        image_to_methods = mono_conc_hashtable_new (NULL, NULL);
        init_suppressed_assemblies ();

        coverage_initialized = TRUE;
}

static void
unref_coverage_assemblies (gpointer key, gpointer value, gpointer userdata)
{
        MonoAssembly *assembly = (MonoAssembly *)value;
        mono_assembly_close (assembly);
}

static void
free_sample_hit (gpointer p)
{
        mono_lock_free_free (p, SAMPLE_BLOCK_SIZE);
}

static void
cleanup_reusable_samples (MonoProfiler *prof)
{
        SampleHit *sample;

        while ((sample = (SampleHit *) mono_lock_free_queue_dequeue (&prof->sample_reuse_queue)))
                mono_thread_hazardous_try_free (sample, free_sample_hit);
}

static void
log_shutdown (MonoProfiler *prof)
{
        InterlockedWrite (&in_shutdown, 1);

        if (!no_counters)
                counters_and_perfcounters_sample (prof);

        dump_coverage (prof);

        char c = 1;

        if (write (prof->pipes [1], &c, 1) != 1) {
                fprintf (stderr, "Could not write to pipe: %s\n", strerror (errno));
                exit (1);
        }

        mono_native_thread_join (prof->helper_thread);

        mono_os_mutex_destroy (&counters_mutex);

        MonoCounterAgent *mc_next;

        for (MonoCounterAgent *cur = counters; cur; cur = mc_next) {
                mc_next = cur->next;
                g_free (cur);
        }

        PerfCounterAgent *pc_next;

        for (PerfCounterAgent *cur = perfcounters; cur; cur = pc_next) {
                pc_next = cur->next;
                g_free (cur);
        }

        /*
         * Ensure that we empty the LLS completely, even if some nodes are
         * not immediately removed upon calling mono_lls_remove (), by
         * iterating until the head is NULL.
         */
        while (profiler_thread_list.head) {
                MONO_LLS_FOREACH_SAFE (&profiler_thread_list, MonoProfilerThread, thread) {
                        g_assert (thread->attached && "Why is a thread in the LLS not attached?");

                        remove_thread (thread);
                } MONO_LLS_FOREACH_SAFE_END
        }

        /*
         * Ensure that all threads have been freed, so that we don't miss any
         * buffers when we shut down the writer thread below.
         */
        mono_thread_hazardous_try_free_all ();

        InterlockedWrite (&prof->run_dumper_thread, 0);
        mono_os_sem_post (&prof->dumper_queue_sem);
        mono_native_thread_join (prof->dumper_thread);
        mono_os_sem_destroy (&prof->dumper_queue_sem);

        InterlockedWrite (&prof->run_writer_thread, 0);
        mono_os_sem_post (&prof->writer_queue_sem);
        mono_native_thread_join (prof->writer_thread);
        mono_os_sem_destroy (&prof->writer_queue_sem);

        /*
         * Free all writer queue entries, and ensure that all sample hits will be
         * added to the sample reuse queue.
         */
        mono_thread_hazardous_try_free_all ();

        cleanup_reusable_samples (prof);

        /*
         * Finally, make sure that all sample hits are freed. This should cover all
         * hazardous data from the profiler. We can now be sure that the runtime
         * won't later invoke free functions in the profiler library after it has
         * been unloaded.
         */
        mono_thread_hazardous_try_free_all ();

        g_assert (!InterlockedRead (&buffer_rwlock_count) && "Why is the reader count still non-zero?");
        g_assert (!InterlockedReadPointer (&buffer_rwlock_exclusive) && "Why does someone still hold the exclusive lock?");

#if defined (HAVE_SYS_ZLIB)
        if (prof->gzfile)
                gzclose (prof->gzfile);
#endif
        if (prof->pipe_output)
                pclose (prof->file);
        else
                fclose (prof->file);

        mono_conc_hashtable_destroy (prof->method_table);
        mono_os_mutex_destroy (&prof->method_table_mutex);

        if (coverage_initialized) {
                mono_os_mutex_lock (&coverage_mutex);
                mono_conc_hashtable_foreach (coverage_assemblies, unref_coverage_assemblies, prof);
                mono_os_mutex_unlock (&coverage_mutex);

                mono_conc_hashtable_destroy (coverage_methods);
                mono_conc_hashtable_destroy (coverage_assemblies);
                mono_conc_hashtable_destroy (coverage_classes);
                mono_conc_hashtable_destroy (filtered_classes);

                mono_conc_hashtable_destroy (entered_methods);
                mono_conc_hashtable_destroy (image_to_methods);
                mono_conc_hashtable_destroy (suppressed_assemblies);
                mono_os_mutex_destroy (&coverage_mutex);
        }

        PROF_TLS_FREE ();

        g_free (prof->args);
        g_free (prof);
}

static char*
new_filename (const char* filename)
{
        time_t t = time (NULL);
        int pid = process_id ();
        char pid_buf [16];
        char time_buf [16];
        char *res, *d;
        const char *p;
        int count_dates = 0;
        int count_pids = 0;
        int s_date, s_pid;
        struct tm *ts;
        for (p = filename; *p; p++) {
                if (*p != '%')
                        continue;
                p++;
                if (*p == 't')
                        count_dates++;
                else if (*p == 'p')
                        count_pids++;
                else if (*p == 0)
                        break;
        }
        if (!count_dates && !count_pids)
                return pstrdup (filename);
        snprintf (pid_buf, sizeof (pid_buf), "%d", pid);
        ts = gmtime (&t);
        snprintf (time_buf, sizeof (time_buf), "%d%02d%02d%02d%02d%02d",
                1900 + ts->tm_year, 1 + ts->tm_mon, ts->tm_mday, ts->tm_hour, ts->tm_min, ts->tm_sec);
        s_date = strlen (time_buf);
        s_pid = strlen (pid_buf);
        d = res = (char *) g_malloc (strlen (filename) + s_date * count_dates + s_pid * count_pids);
        for (p = filename; *p; p++) {
                if (*p != '%') {
                        *d++ = *p;
                        continue;
                }
                p++;
                if (*p == 't') {
                        strcpy (d, time_buf);
                        d += s_date;
                        continue;
                } else if (*p == 'p') {
                        strcpy (d, pid_buf);
                        d += s_pid;
                        continue;
                } else if (*p == '%') {
                        *d++ = '%';
                        continue;
                } else if (*p == 0)
                        break;
                *d++ = '%';
                *d++ = *p;
        }
        *d = 0;
        return res;
}

static void
add_to_fd_set (fd_set *set, int fd, int *max_fd)
{
        /*
         * This should only trigger for the basic FDs (server socket, pipes) at
         * startup if for some mysterious reason they're too large. In this case,
         * the profiler really can't function, and we're better off printing an
         * error and exiting.
         */
        if (fd >= FD_SETSIZE) {
                fprintf (stderr, "File descriptor is out of bounds for fd_set: %d\n", fd);
                exit (1);
        }

        FD_SET (fd, set);

        if (*max_fd < fd)
                *max_fd = fd;
}

static void *
helper_thread (void *arg)
{
        MonoProfiler *prof = (MonoProfiler *) arg;

        mono_threads_attach_tools_thread ();
        mono_native_thread_set_name (mono_native_thread_id_get (), "Profiler helper");

        MonoProfilerThread *thread = init_thread (prof, FALSE);

        GArray *command_sockets = g_array_new (FALSE, FALSE, sizeof (int));

        while (1) {
                fd_set rfds;
                int max_fd = -1;

                FD_ZERO (&rfds);

                add_to_fd_set (&rfds, prof->server_socket, &max_fd);
                add_to_fd_set (&rfds, prof->pipes [0], &max_fd);

                for (gint i = 0; i < command_sockets->len; i++)
                        add_to_fd_set (&rfds, g_array_index (command_sockets, int, i), &max_fd);

                struct timeval tv = { .tv_sec = 1, .tv_usec = 0 };

                // Sleep for 1sec or until a file descriptor has data.
                if (select (max_fd + 1, &rfds, NULL, NULL, &tv) == -1) {
                        if (errno == EINTR)
                                continue;

                        fprintf (stderr, "Error in mono-profiler-log server: %s", strerror (errno));
                        exit (1);
                }

                if (!no_counters)
                        counters_and_perfcounters_sample (prof);

                buffer_lock_excl ();

                sync_point (SYNC_POINT_PERIODIC);

                buffer_unlock_excl ();

                // Are we shutting down?
                if (FD_ISSET (prof->pipes [0], &rfds)) {
                        char c;
                        read (prof->pipes [0], &c, 1);
                        break;
                }

                for (gint i = 0; i < command_sockets->len; i++) {
                        int fd = g_array_index (command_sockets, int, i);

                        if (!FD_ISSET (fd, &rfds))
                                continue;

                        char buf [64];
                        int len = read (fd, buf, sizeof (buf) - 1);

                        if (len == -1)
                                continue;

                        if (!len) {
                                // The other end disconnected.
                                g_array_remove_index (command_sockets, i);
                                close (fd);

                                continue;
                        }

                        buf [len] = 0;

                        if (!strcmp (buf, "heapshot\n") && hs_mode_ondemand) {
                                // Rely on the finalization callbacks invoking process_requests ().
                                heapshot_requested = 1;
                                mono_gc_finalize_notify ();
                        }
                }

                if (FD_ISSET (prof->server_socket, &rfds)) {
                        int fd = accept (prof->server_socket, NULL, NULL);

                        if (fd != -1) {
                                if (fd >= FD_SETSIZE)
                                        close (fd);
                                else
                                        g_array_append_val (command_sockets, fd);
                        }
                }
        }

        for (gint i = 0; i < command_sockets->len; i++)
                close (g_array_index (command_sockets, int, i));

        g_array_free (command_sockets, TRUE);

        send_log_unsafe (FALSE);
        deinit_thread (thread);

        mono_thread_info_detach ();

        return NULL;
}

static void
start_helper_thread (MonoProfiler* prof)
{
        if (pipe (prof->pipes) == -1) {
                fprintf (stderr, "Cannot create pipe: %s\n", strerror (errno));
                exit (1);
        }

        prof->server_socket = socket (PF_INET, SOCK_STREAM, 0);

        if (prof->server_socket == -1) {
                fprintf (stderr, "Cannot create server socket: %s\n", strerror (errno));
                exit (1);
        }

        struct sockaddr_in server_address;

        memset (&server_address, 0, sizeof (server_address));
        server_address.sin_family = AF_INET;
        server_address.sin_addr.s_addr = INADDR_ANY;
        server_address.sin_port = htons (prof->command_port);

        if (bind (prof->server_socket, (struct sockaddr *) &server_address, sizeof (server_address)) == -1) {
                fprintf (stderr, "Cannot bind server socket on port %d: %s\n", prof->command_port, strerror (errno));
                close (prof->server_socket);
                exit (1);
        }

        if (listen (prof->server_socket, 1) == -1) {
                fprintf (stderr, "Cannot listen on server socket: %s\n", strerror (errno));
                close (prof->server_socket);
                exit (1);
        }

        socklen_t slen = sizeof (server_address);

        if (getsockname (prof->server_socket, (struct sockaddr *) &server_address, &slen)) {
                fprintf (stderr, "Could not get assigned port: %s\n", strerror (errno));
                close (prof->server_socket);
                exit (1);
        }

        prof->command_port = ntohs (server_address.sin_port);

        if (!mono_native_thread_create (&prof->helper_thread, helper_thread, prof)) {
                fprintf (stderr, "Could not start helper thread\n");
                close (prof->server_socket);
                exit (1);
        }
}

static void
free_writer_entry (gpointer p)
{
        mono_lock_free_free (p, WRITER_ENTRY_BLOCK_SIZE);
}

static gboolean
handle_writer_queue_entry (MonoProfiler *prof)
{
        WriterQueueEntry *entry;

        if ((entry = (WriterQueueEntry *) mono_lock_free_queue_dequeue (&prof->writer_queue))) {
                if (!entry->methods)
                        goto no_methods;

                gboolean wrote_methods = FALSE;

                /*
                 * Encode the method events in a temporary log buffer that we
                 * flush to disk before the main buffer, ensuring that all
                 * methods have metadata emitted before they're referenced.
                 *
                 * We use a 'proper' thread-local buffer for this as opposed
                 * to allocating and freeing a buffer by hand because the call
                 * to mono_method_full_name () below may trigger class load
                 * events when it retrieves the signature of the method. So a
                 * thread-local buffer needs to exist when such events occur.
                 */
                for (guint i = 0; i < entry->methods->len; i++) {
                        MethodInfo *info = (MethodInfo *) g_ptr_array_index (entry->methods, i);

                        if (mono_conc_hashtable_lookup (prof->method_table, info->method))
                                goto free_info; // This method already has metadata emitted.

                        /*
                         * Other threads use this hash table to get a general
                         * idea of whether a method has already been emitted to
                         * the stream. Due to the way we add to this table, it
                         * can easily happen that multiple threads queue up the
                         * same methods, but that's OK since eventually all
                         * methods will be in this table and the thread-local
                         * method lists will just be empty for the rest of the
                         * app's lifetime.
                         */
                        mono_os_mutex_lock (&prof->method_table_mutex);
                        mono_conc_hashtable_insert (prof->method_table, info->method, info->method);
                        mono_os_mutex_unlock (&prof->method_table_mutex);

                        char *name = mono_method_full_name (info->method, 1);
                        int nlen = strlen (name) + 1;
                        void *cstart = info->ji ? mono_jit_info_get_code_start (info->ji) : NULL;
                        int csize = info->ji ? mono_jit_info_get_code_size (info->ji) : 0;

                        ENTER_LOG (&method_jits_ctr, logbuffer,
                                EVENT_SIZE /* event */ +
                                LEB128_SIZE /* method */ +
                                LEB128_SIZE /* start */ +
                                LEB128_SIZE /* size */ +
                                nlen /* name */
                        );

                        emit_event_time (logbuffer, TYPE_JIT | TYPE_METHOD, info->time);
                        emit_method_inner (logbuffer, info->method);
                        emit_ptr (logbuffer, cstart);
                        emit_value (logbuffer, csize);

                        memcpy (logbuffer->cursor, name, nlen);
                        logbuffer->cursor += nlen;

                        EXIT_LOG_EXPLICIT (NO_SEND, NO_REQUESTS);

                        mono_free (name);

                        wrote_methods = TRUE;

                free_info:
                        g_free (info);
                }

                g_ptr_array_free (entry->methods, TRUE);

                if (wrote_methods) {
                        dump_buffer_threadless (prof, PROF_TLS_GET ()->buffer);
                        init_buffer_state (PROF_TLS_GET ());
                }

        no_methods:
                dump_buffer (prof, entry->buffer);

                mono_thread_hazardous_try_free (entry, free_writer_entry);

                return TRUE;
        }

        return FALSE;
}

static void *
writer_thread (void *arg)
{
        MonoProfiler *prof = (MonoProfiler *)arg;

        mono_threads_attach_tools_thread ();
        mono_native_thread_set_name (mono_native_thread_id_get (), "Profiler writer");

        dump_header (prof);

        MonoProfilerThread *thread = init_thread (prof, FALSE);

        while (InterlockedRead (&prof->run_writer_thread)) {
                mono_os_sem_wait (&prof->writer_queue_sem, MONO_SEM_FLAGS_NONE);
                handle_writer_queue_entry (prof);
        }

        /* Drain any remaining entries on shutdown. */
        while (handle_writer_queue_entry (prof));

        free_buffer (thread->buffer, thread->buffer->size);
        deinit_thread (thread);

        mono_thread_info_detach ();

        return NULL;
}

static void
start_writer_thread (MonoProfiler* prof)
{
        InterlockedWrite (&prof->run_writer_thread, 1);

        if (!mono_native_thread_create (&prof->writer_thread, writer_thread, prof)) {
                fprintf (stderr, "Could not start writer thread\n");
                exit (1);
        }
}

static void
reuse_sample_hit (gpointer p)
{
        SampleHit *sample = p;

        mono_lock_free_queue_node_unpoison (&sample->node);
        mono_lock_free_queue_enqueue (&sample->prof->sample_reuse_queue, &sample->node);
}

static gboolean
handle_dumper_queue_entry (MonoProfiler *prof)
{
        SampleHit *sample;

        if ((sample = (SampleHit *) mono_lock_free_queue_dequeue (&prof->dumper_queue))) {
                for (int i = 0; i < sample->count; ++i) {
                        MonoMethod *method = sample->frames [i].method;
                        MonoDomain *domain = sample->frames [i].domain;
                        void *address = sample->frames [i].base_address;

                        if (!method) {
                                g_assert (domain && "What happened to the domain pointer?");
                                g_assert (address && "What happened to the instruction pointer?");

                                MonoJitInfo *ji = mono_jit_info_table_find (domain, (char *) address);

                                if (ji)
                                        sample->frames [i].method = mono_jit_info_get_method (ji);
                        }
                }

                ENTER_LOG (&sample_hits_ctr, logbuffer,
                        EVENT_SIZE /* event */ +
                        BYTE_SIZE /* type */ +
                        LEB128_SIZE /* tid */ +
                        LEB128_SIZE /* count */ +
                        1 * (
                                LEB128_SIZE /* ip */
                        ) +
                        LEB128_SIZE /* managed count */ +
                        sample->count * (
                                LEB128_SIZE /* method */
                        )
                );

                emit_event_time (logbuffer, TYPE_SAMPLE | TYPE_SAMPLE_HIT, sample->time);
                emit_byte (logbuffer, SAMPLE_CYCLES);
                emit_ptr (logbuffer, (void *) sample->tid);
                emit_value (logbuffer, 1);

                // TODO: Actual native unwinding.
                for (int i = 0; i < 1; ++i) {
                        emit_ptr (logbuffer, sample->ip);
                        add_code_pointer ((uintptr_t) sample->ip);
                }

                /* new in data version 6 */
                emit_uvalue (logbuffer, sample->count);

                for (int i = 0; i < sample->count; ++i)
                        emit_method (logbuffer, sample->frames [i].method);

                EXIT_LOG_EXPLICIT (DO_SEND, NO_REQUESTS);

                mono_thread_hazardous_try_free (sample, reuse_sample_hit);

                dump_unmanaged_coderefs (prof);
        }

        return FALSE;
}

static void *
dumper_thread (void *arg)
{
        MonoProfiler *prof = (MonoProfiler *)arg;

        mono_threads_attach_tools_thread ();
        mono_native_thread_set_name (mono_native_thread_id_get (), "Profiler dumper");

        MonoProfilerThread *thread = init_thread (prof, FALSE);

        while (InterlockedRead (&prof->run_dumper_thread)) {
                mono_os_sem_wait (&prof->dumper_queue_sem, MONO_SEM_FLAGS_NONE);
                handle_dumper_queue_entry (prof);
        }

        /* Drain any remaining entries on shutdown. */
        while (handle_dumper_queue_entry (prof));

        send_log_unsafe (FALSE);
        deinit_thread (thread);

        mono_thread_info_detach ();

        return NULL;
}

static void
start_dumper_thread (MonoProfiler* prof)
{
        InterlockedWrite (&prof->run_dumper_thread, 1);

        if (!mono_native_thread_create (&prof->dumper_thread, dumper_thread, prof)) {
                fprintf (stderr, "Could not start dumper thread\n");
                exit (1);
        }
}

static void
register_counter (const char *name, gint32 *counter)
{
        mono_counters_register (name, MONO_COUNTER_UINT | MONO_COUNTER_PROFILER | MONO_COUNTER_MONOTONIC, counter);
}

static void
runtime_initialized (MonoProfiler *profiler)
{
        InterlockedWrite (&runtime_inited, 1);

        register_counter ("Sample events allocated", &sample_allocations_ctr);
        register_counter ("Log buffers allocated", &buffer_allocations_ctr);

        register_counter ("Event: Sync points", &sync_points_ctr);
        register_counter ("Event: Heap objects", &heap_objects_ctr);
        register_counter ("Event: Heap starts", &heap_starts_ctr);
        register_counter ("Event: Heap ends", &heap_ends_ctr);
        register_counter ("Event: Heap roots", &heap_roots_ctr);
        register_counter ("Event: GC events", &gc_events_ctr);
        register_counter ("Event: GC resizes", &gc_resizes_ctr);
        register_counter ("Event: GC allocations", &gc_allocs_ctr);
        register_counter ("Event: GC moves", &gc_moves_ctr);
        register_counter ("Event: GC handle creations", &gc_handle_creations_ctr);
        register_counter ("Event: GC handle deletions", &gc_handle_deletions_ctr);
        register_counter ("Event: GC finalize starts", &finalize_begins_ctr);
        register_counter ("Event: GC finalize ends", &finalize_ends_ctr);
        register_counter ("Event: GC finalize object starts", &finalize_object_begins_ctr);
        register_counter ("Event: GC finalize object ends", &finalize_object_ends_ctr);
        register_counter ("Event: Image loads", &image_loads_ctr);
        register_counter ("Event: Image unloads", &image_unloads_ctr);
        register_counter ("Event: Assembly loads", &assembly_loads_ctr);
        register_counter ("Event: Assembly unloads", &assembly_unloads_ctr);
        register_counter ("Event: Class loads", &class_loads_ctr);
        register_counter ("Event: Class unloads", &class_unloads_ctr);
        register_counter ("Event: Method entries", &method_entries_ctr);
        register_counter ("Event: Method exits", &method_exits_ctr);
        register_counter ("Event: Method exception leaves", &method_exception_exits_ctr);
        register_counter ("Event: Method JITs", &method_jits_ctr);
        register_counter ("Event: Code buffers", &code_buffers_ctr);
        register_counter ("Event: Exception throws", &exception_throws_ctr);
        register_counter ("Event: Exception clauses", &exception_clauses_ctr);
        register_counter ("Event: Monitor contentions", &monitor_contentions_ctr);
        register_counter ("Event: Monitor acquisitions", &monitor_acquisitions_ctr);
        register_counter ("Event: Monitor failures", &monitor_failures_ctr);
        register_counter ("Event: Thread starts", &thread_starts_ctr);
        register_counter ("Event: Thread ends", &thread_ends_ctr);
        register_counter ("Event: Thread names", &thread_names_ctr);
        register_counter ("Event: Domain loads", &domain_loads_ctr);
        register_counter ("Event: Domain unloads", &domain_unloads_ctr);
        register_counter ("Event: Domain names", &domain_names_ctr);
        register_counter ("Event: Context loads", &context_loads_ctr);
        register_counter ("Event: Context unloads", &context_unloads_ctr);
        register_counter ("Event: Sample binaries", &sample_ubins_ctr);
        register_counter ("Event: Sample symbols", &sample_usyms_ctr);
        register_counter ("Event: Sample hits", &sample_hits_ctr);
        register_counter ("Event: Counter descriptors", &counter_descriptors_ctr);
        register_counter ("Event: Counter samples", &counter_samples_ctr);
        register_counter ("Event: Performance counter descriptors", &perfcounter_descriptors_ctr);
        register_counter ("Event: Performance counter samples", &perfcounter_samples_ctr);
        register_counter ("Event: Coverage methods", &coverage_methods_ctr);
        register_counter ("Event: Coverage statements", &coverage_statements_ctr);
        register_counter ("Event: Coverage classes", &coverage_classes_ctr);
        register_counter ("Event: Coverage assemblies", &coverage_assemblies_ctr);

        counters_init (profiler);

        /*
         * We must start the helper thread before the writer thread. This is
         * because the helper thread sets up the command port which is written to
         * the log header by the writer thread.
         */
        start_helper_thread (profiler);
        start_writer_thread (profiler);
        start_dumper_thread (profiler);
}

static MonoProfiler*
create_profiler (const char *args, const char *filename, GPtrArray *filters)
{
        MonoProfiler *prof;
        char *nf;
        int force_delete = 0;
        prof = (MonoProfiler *) g_calloc (1, sizeof (MonoProfiler));

        prof->args = pstrdup (args);
        prof->command_port = command_port;
        if (filename && *filename == '-') {
                force_delete = 1;
                filename++;
        }
        if (!filename) {
                if (do_report)
                        filename = "|mprof-report -";
                else
                        filename = "output.mlpd";
                nf = (char*)filename;
        } else {
                nf = new_filename (filename);
                if (do_report) {
                        int s = strlen (nf) + 32;
                        char *p = (char *) g_malloc (s);
                        snprintf (p, s, "|mprof-report '--out=%s' -", nf);
                        g_free (nf);
                        nf = p;
                }
        }
        if (*nf == '|') {
                prof->file = popen (nf + 1, "w");
                prof->pipe_output = 1;
        } else if (*nf == '#') {
                int fd = strtol (nf + 1, NULL, 10);
                prof->file = fdopen (fd, "a");
        } else {
                if (force_delete)
                        unlink (nf);
                prof->file = fopen (nf, "wb");
        }
        if (!prof->file) {
                fprintf (stderr, "Cannot create profiler output: %s\n", nf);
                exit (1);
        }

#if defined (HAVE_SYS_ZLIB)
        if (use_zip)
                prof->gzfile = gzdopen (fileno (prof->file), "wb");
#endif

        /*
         * If you hit this assert while increasing MAX_FRAMES, you need to increase
         * SAMPLE_BLOCK_SIZE as well.
         */
        g_assert (SAMPLE_SLOT_SIZE (MAX_FRAMES) * 2 < LOCK_FREE_ALLOC_SB_USABLE_SIZE (SAMPLE_BLOCK_SIZE));

        // FIXME: We should free this stuff too.
        mono_lock_free_allocator_init_size_class (&prof->sample_size_class, SAMPLE_SLOT_SIZE (num_frames), SAMPLE_BLOCK_SIZE);
        mono_lock_free_allocator_init_allocator (&prof->sample_allocator, &prof->sample_size_class, MONO_MEM_ACCOUNT_PROFILER);

        mono_lock_free_queue_init (&prof->sample_reuse_queue);

        g_assert (sizeof (WriterQueueEntry) * 2 < LOCK_FREE_ALLOC_SB_USABLE_SIZE (WRITER_ENTRY_BLOCK_SIZE));

        // FIXME: We should free this stuff too.
        mono_lock_free_allocator_init_size_class (&prof->writer_entry_size_class, sizeof (WriterQueueEntry), WRITER_ENTRY_BLOCK_SIZE);
        mono_lock_free_allocator_init_allocator (&prof->writer_entry_allocator, &prof->writer_entry_size_class, MONO_MEM_ACCOUNT_PROFILER);

        mono_lock_free_queue_init (&prof->writer_queue);
        mono_os_sem_init (&prof->writer_queue_sem, 0);

        mono_lock_free_queue_init (&prof->dumper_queue);
        mono_os_sem_init (&prof->dumper_queue_sem, 0);

        mono_os_mutex_init (&prof->method_table_mutex);
        prof->method_table = mono_conc_hashtable_new (NULL, NULL);

        if (do_coverage)
                coverage_init (prof);
        prof->coverage_filters = filters;

        prof->startup_time = current_time ();
        return prof;
}

static void
usage (int do_exit)
{
        printf ("Log profiler version %d.%d (format: %d)\n", LOG_VERSION_MAJOR, LOG_VERSION_MINOR, LOG_DATA_VERSION);
        printf ("Usage: mono --profile=log[:OPTION1[,OPTION2...]] program.exe\n");
        printf ("Options:\n");
        printf ("\thelp                 show this usage info\n");
        printf ("\t[no]alloc            enable/disable recording allocation info\n");
        printf ("\t[no]calls            enable/disable recording enter/leave method events\n");
        printf ("\theapshot[=MODE]      record heap shot info (by default at each major collection)\n");
        printf ("\t                     MODE: every XXms milliseconds, every YYgc collections, ondemand\n");
        printf ("\tcounters             sample counters every 1s\n");
        printf ("\tsample[=TYPE]        use statistical sampling mode (by default cycles/100)\n");
        printf ("\t                     TYPE: cycles,instr,cacherefs,cachemiss,branches,branchmiss\n");
        printf ("\t                     TYPE can be followed by /FREQUENCY\n");
        printf ("\tmaxframes=NUM        collect up to NUM stack frames\n");
        printf ("\tcalldepth=NUM        ignore method events for call chain depth bigger than NUM\n");
        printf ("\toutput=FILENAME      write the data to file FILENAME (-FILENAME to overwrite)\n");
        printf ("\toutput=|PROGRAM      write the data to the stdin of PROGRAM\n");
        printf ("\t                     %%t is subtituted with date and time, %%p with the pid\n");
        printf ("\treport               create a report instead of writing the raw data to a file\n");
        printf ("\tzip                  compress the output data\n");
        printf ("\tport=PORTNUM         use PORTNUM for the listening command server\n");
        printf ("\tcoverage             enable collection of code coverage data\n");
        printf ("\tcovfilter=ASSEMBLY   add an assembly to the code coverage filters\n");
        printf ("\t                     add a + to include the assembly or a - to exclude it\n");
        printf ("\t                     filter=-mscorlib\n");
        printf ("\tcovfilter-file=FILE  use FILE to generate the list of assemblies to be filtered\n");
        if (do_exit)
                exit (1);
}

static const char*
match_option (const char* p, const char *opt, char **rval)
{
        int len = strlen (opt);
        if (strncmp (p, opt, len) == 0) {
                if (rval) {
                        if (p [len] == '=' && p [len + 1]) {
                                const char *opt = p + len + 1;
                                const char *end = strchr (opt, ',');
                                char *val;
                                int l;
                                if (end == NULL) {
                                        l = strlen (opt);
                                } else {
                                        l = end - opt;
                                }
                                val = (char *) g_malloc (l + 1);
                                memcpy (val, opt, l);
                                val [l] = 0;
                                *rval = val;
                                return opt + l;
                        }
                        if (p [len] == 0 || p [len] == ',') {
                                *rval = NULL;
                                return p + len + (p [len] == ',');
                        }
                        usage (1);
                } else {
                        if (p [len] == 0)
                                return p + len;
                        if (p [len] == ',')
                                return p + len + 1;
                }
        }
        return p;
}

static void
set_sample_freq (char *val)
{
        do_mono_sample = 1;
        sample_freq = 100;

        if (!val)
                return;

        char *p = val;

        // Is it only the frequency (new option style)?
        if (isdigit (*p))
                goto parse;

        // Skip the sample type for backwards compatibility.
        while (isalpha (*p))
                p++;

        // Skip the forward slash only if we got a sample type.
        if (p != val && *p == '/') {
                p++;

                char *end;

        parse:
                sample_freq = strtoul (p, &end, 10);

                if (p == end)
                        usage (1);

                p = end;
        }

        if (*p)
                usage (1);

        g_free (val);
}

static void
set_hsmode (char* val, int allow_empty)
{
        char *end;
        unsigned int count;
        if (allow_empty && !val)
                return;
        if (strcmp (val, "ondemand") == 0) {
                hs_mode_ondemand = 1;
                g_free (val);
                return;
        }
        count = strtoul (val, &end, 10);
        if (val == end)
                usage (1);
        if (strcmp (end, "ms") == 0)
                hs_mode_ms = count;
        else if (strcmp (end, "gc") == 0)
                hs_mode_gc = count;
        else
                usage (1);
        g_free (val);
}

/*
 * declaration to silence the compiler: this is the entry point that
 * mono will load from the shared library and call.
 */
extern void
mono_profiler_startup (const char *desc);

extern void
mono_profiler_startup_log (const char *desc);

/*
 * this is the entry point that will be used when the profiler
 * is embedded inside the main executable.
 */
void
mono_profiler_startup_log (const char *desc)
{
        mono_profiler_startup (desc);
}

void
mono_profiler_startup (const char *desc)
{
        MonoProfiler *prof;
        GPtrArray *filters = NULL;
        char *filename = NULL;
        const char *p;
        const char *opt;
        int calls_enabled = 0;
        int allocs_enabled = 0;
        int events = MONO_PROFILE_GC|MONO_PROFILE_ALLOCATIONS|
                MONO_PROFILE_GC_MOVES|MONO_PROFILE_CLASS_EVENTS|MONO_PROFILE_THREADS|
                MONO_PROFILE_ENTER_LEAVE|MONO_PROFILE_JIT_COMPILATION|MONO_PROFILE_EXCEPTIONS|
                MONO_PROFILE_MONITOR_EVENTS|MONO_PROFILE_MODULE_EVENTS|MONO_PROFILE_GC_ROOTS|
                MONO_PROFILE_INS_COVERAGE|MONO_PROFILE_APPDOMAIN_EVENTS|MONO_PROFILE_CONTEXT_EVENTS|
                MONO_PROFILE_ASSEMBLY_EVENTS|MONO_PROFILE_GC_FINALIZATION;

        max_allocated_sample_hits = mono_cpu_count () * 1000;

        p = desc;
        if (strncmp (p, "log", 3))
                usage (1);
        p += 3;
        if (*p == ':')
                p++;
        for (; *p; p = opt) {
                char *val;
                if (*p == ',') {
                        opt = p + 1;
                        continue;
                }
                if ((opt = match_option (p, "help", NULL)) != p) {
                        usage (0);
                        continue;
                }
                if ((opt = match_option (p, "calls", NULL)) != p) {
                        calls_enabled = 1;
                        continue;
                }
                if ((opt = match_option (p, "nocalls", NULL)) != p) {
                        events &= ~MONO_PROFILE_ENTER_LEAVE;
                        nocalls = 1;
                        continue;
                }
                if ((opt = match_option (p, "alloc", NULL)) != p) {
                        allocs_enabled = 1;
                        continue;
                }
                if ((opt = match_option (p, "noalloc", NULL)) != p) {
                        events &= ~MONO_PROFILE_ALLOCATIONS;
                        events &= ~MONO_PROFILE_GC_MOVES;
                        continue;
                }
                if ((opt = match_option (p, "nocounters", NULL)) != p) {
                        no_counters = TRUE;
                        continue;
                }
                if ((opt = match_option (p, "time", &val)) != p) {
                        // For backwards compatibility.
                        if (strcmp (val, "fast") && strcmp (val, "null"))
                                usage (1);
                        g_free (val);
                        continue;
                }
                if ((opt = match_option (p, "report", NULL)) != p) {
                        do_report = 1;
                        continue;
                }
                if ((opt = match_option (p, "debug", NULL)) != p) {
                        do_debug = 1;
                        continue;
                }
                if ((opt = match_option (p, "sampling-real", NULL)) != p) {
                        sampling_mode = MONO_PROFILER_STAT_MODE_REAL;
                        continue;
                }
                if ((opt = match_option (p, "sampling-process", NULL)) != p) {
                        sampling_mode = MONO_PROFILER_STAT_MODE_PROCESS;
                        continue;
                }
                if ((opt = match_option (p, "heapshot", &val)) != p) {
                        events &= ~MONO_PROFILE_ALLOCATIONS;
                        events &= ~MONO_PROFILE_GC_MOVES;
                        events &= ~MONO_PROFILE_ENTER_LEAVE;
                        nocalls = 1;
                        do_heap_shot = 1;
                        set_hsmode (val, 1);
                        continue;
                }
                if ((opt = match_option (p, "sample", &val)) != p) {
                        events &= ~MONO_PROFILE_ALLOCATIONS;
                        events &= ~MONO_PROFILE_GC_MOVES;
                        events &= ~MONO_PROFILE_ENTER_LEAVE;
                        nocalls = 1;
                        set_sample_freq (val);
                        continue;
                }
                if ((opt = match_option (p, "zip", NULL)) != p) {
                        use_zip = 1;
                        continue;
                }
                if ((opt = match_option (p, "output", &val)) != p) {
                        filename = val;
                        continue;
                }
                if ((opt = match_option (p, "port", &val)) != p) {
                        char *end;
                        command_port = strtoul (val, &end, 10);
                        g_free (val);
                        continue;
                }
                if ((opt = match_option (p, "maxframes", &val)) != p) {
                        char *end;
                        num_frames = strtoul (val, &end, 10);
                        if (num_frames > MAX_FRAMES)
                                num_frames = MAX_FRAMES;
                        g_free (val);
                        notraces = num_frames == 0;
                        continue;
                }
                if ((opt = match_option (p, "maxsamples", &val)) != p) {
                        char *end;
                        max_allocated_sample_hits = strtoul (val, &end, 10);
                        if (!max_allocated_sample_hits)
                                max_allocated_sample_hits = G_MAXINT32;
                        g_free (val);
                        continue;
                }
                if ((opt = match_option (p, "calldepth", &val)) != p) {
                        char *end;
                        max_call_depth = strtoul (val, &end, 10);
                        g_free (val);
                        continue;
                }
                if ((opt = match_option (p, "counters", NULL)) != p) {
                        // For backwards compatibility.
                        continue;
                }
                if ((opt = match_option (p, "coverage", NULL)) != p) {
                        do_coverage = 1;
                        events |= MONO_PROFILE_ENTER_LEAVE;
                        debug_coverage = (g_getenv ("MONO_PROFILER_DEBUG_COVERAGE") != NULL);
                        continue;
                }
                if ((opt = match_option (p, "onlycoverage", NULL)) != p) {
                        only_coverage = TRUE;
                        continue;
                }
                if ((opt = match_option (p, "covfilter-file", &val)) != p) {
                        FILE *filter_file;
                        char *line, *content;

                        if (filters == NULL)
                                filters = g_ptr_array_new ();

                        filter_file = fopen (val, "r");
                        if (filter_file == NULL) {
                                fprintf (stderr, "Unable to open %s\n", val);
                                exit (0);
                        }

                        /* Don't need to free content as it is referred to by the lines stored in @filters */
                        content = get_file_content (filter_file);
                        if (content == NULL)
                                fprintf (stderr, "WARNING: %s is greater than 128kb - ignoring\n", val);

                        while ((line = get_next_line (content, &content)))
                                g_ptr_array_add (filters, g_strchug (g_strchomp (line)));

                        fclose (filter_file);
                        continue;
                }
                if ((opt = match_option (p, "covfilter", &val)) != p) {
                        if (filters == NULL)
                                filters = g_ptr_array_new ();

                        g_ptr_array_add (filters, val);
                        continue;
                }
                if (opt == p) {
                        usage (0);
                        exit (0);
                }
        }

        if (calls_enabled) {
                events |= MONO_PROFILE_ENTER_LEAVE;
                nocalls = 0;
        }

        if (allocs_enabled) {
                events |= MONO_PROFILE_ALLOCATIONS;
                events |= MONO_PROFILE_GC_MOVES;
        }

        // Only activate the bare minimum events the profiler needs to function.
        if (only_coverage) {
                if (!do_coverage) {
                        fprintf (stderr, "The onlycoverage option is only valid when paired with the coverage option\n");
                        exit (1);
                }

                no_counters = TRUE;
                events = MONO_PROFILE_GC | MONO_PROFILE_THREADS | MONO_PROFILE_ENTER_LEAVE | MONO_PROFILE_INS_COVERAGE;
        }

        init_time ();

        PROF_TLS_INIT ();

        prof = create_profiler (desc, filename, filters);
        if (!prof) {
                PROF_TLS_FREE ();
                return;
        }

        mono_lls_init (&profiler_thread_list, NULL);

        init_thread (prof, TRUE);

        mono_profiler_install (prof, log_shutdown);
        mono_profiler_install_gc (gc_event, gc_resize);
        mono_profiler_install_allocation (gc_alloc);
        mono_profiler_install_gc_moves (gc_moves);
        mono_profiler_install_gc_roots (gc_handle, gc_roots);
        mono_profiler_install_gc_finalize (finalize_begin, finalize_object_begin, finalize_object_end, finalize_end);
        mono_profiler_install_appdomain (NULL, domain_loaded, domain_unloaded, NULL);
        mono_profiler_install_appdomain_name (domain_name);
        mono_profiler_install_context (context_loaded, context_unloaded);
        mono_profiler_install_class (NULL, class_loaded, class_unloaded, NULL);
        mono_profiler_install_module (NULL, image_loaded, image_unloaded, NULL);
        mono_profiler_install_assembly (NULL, assembly_loaded, assembly_unloaded, NULL);
        mono_profiler_install_thread (thread_start, thread_end);
        mono_profiler_install_thread_name (thread_name);
        mono_profiler_install_enter_leave (method_enter, method_leave);
        mono_profiler_install_jit_end (method_jitted);
        mono_profiler_install_code_buffer_new (code_buffer_new);
        mono_profiler_install_exception (throw_exc, method_exc_leave, clause_exc);
        mono_profiler_install_monitor (monitor_event);
        mono_profiler_install_runtime_initialized (runtime_initialized);
        if (do_coverage)
                mono_profiler_install_coverage_filter (coverage_filter);

        if (do_mono_sample && sample_freq) {
                events |= MONO_PROFILE_STATISTICAL;
                mono_profiler_set_statistical_mode (sampling_mode, sample_freq);
                mono_profiler_install_statistical (mono_sample_hit);
        }

        mono_profiler_set_events ((MonoProfileFlags)events);
}