mono/sgen/sgen-gc.h

   1 /**
   2  * \file
   3  * Simple generational GC.
   4  *
   5  * Copyright 2001-2003 Ximian, Inc
   6  * Copyright 2003-2010 Novell, Inc.
   7  * Copyright 2011 Xamarin Inc (http://www.xamarin.com)
   8  * Copyright (C) 2012 Xamarin Inc
   9  *
  10  * Licensed under the MIT license. See LICENSE file in the project root for full license information.
  11  */
  12 #ifndef __MONO_SGENGC_H__
  13 #define __MONO_SGENGC_H__
  14
  15 /* pthread impl */
  16 #include "config.h"
  17
  18 #ifdef HAVE_SGEN_GC
  19
  20 #include <mono/utils/mono-forward-internal.h>
  21 #undef THREAD_INFO_TYPE
  22 #define THREAD_INFO_TYPE SgenThreadInfo
  23
  24 #include <glib.h>
  25 #include <stdio.h>
  26 #ifdef HAVE_PTHREAD_H
  27 #include <pthread.h>
  28 #endif
  29 #include <stdint.h>
  30 #include "mono/utils/mono-compiler.h"
  31 #include "mono/utils/atomic.h"
  32 #include "mono/utils/mono-os-mutex.h"
  33 #include "mono/utils/mono-coop-mutex.h"
  34 #include "mono/utils/ward.h"
  35 #include "mono/sgen/sgen-conf.h"
  36 #include "mono/sgen/sgen-hash-table.h"
  37 #include "mono/sgen/sgen-protocol.h"
  38 #include "mono/sgen/gc-internal-agnostic.h"
  39 #include "mono/sgen/sgen-thread-pool.h"
  40
  41 /* The method used to clear the nursery */
  42 /* Clearing at nursery collections is the safest, but has bad interactions with caches.
  43  * Clearing at TLAB creation is much faster, but more complex and it might expose hard
  44  * to find bugs.
  45  */
  46 typedef enum {
  47         CLEAR_AT_GC,
  48         CLEAR_AT_TLAB_CREATION,
  49         CLEAR_AT_TLAB_CREATION_DEBUG
  50 } NurseryClearPolicy;
  51
  52 NurseryClearPolicy sgen_get_nursery_clear_policy (void);
  53
  54 #if !defined(__MACH__) && !MONO_MACH_ARCH_SUPPORTED && defined(HAVE_PTHREAD_KILL)
  55 #define SGEN_POSIX_STW 1
  56 #endif
  57
  58 /*
  59  * The nursery section uses this struct.
  60  */
  61 typedef struct _GCMemSection GCMemSection;
  62 struct _GCMemSection {
  63         char *data;
  64         char *end_data;
  65         /*
  66          * scan starts is an array of pointers to objects equally spaced in the allocation area
  67          * They let use quickly find pinned objects from pinning pointers.
  68          */
  69         char **scan_starts;
  70         /* in major collections indexes in the pin_queue for objects that pin this section */
  71         size_t pin_queue_first_entry;
  72         size_t pin_queue_last_entry;
  73         size_t num_scan_start;
  74 };
  75
  76 /*
  77  * Recursion is not allowed for the thread lock.
  78  */
  79 #define LOCK_DECLARE(name) mono_mutex_t name
  80 /* if changing LOCK_INIT to something that isn't idempotent, look at
  81    its use in mono_gc_base_init in sgen-gc.c */
  82 #define LOCK_INIT(name) mono_os_mutex_init (&(name))
  83 #define LOCK_GC do { sgen_gc_lock (); } while (0)
  84 #define UNLOCK_GC do { sgen_gc_unlock (); } while (0)
  85
  86 extern MonoCoopMutex sgen_interruption_mutex;
  87
  88 #define LOCK_INTERRUPTION mono_coop_mutex_lock (&sgen_interruption_mutex)
  89 #define UNLOCK_INTERRUPTION mono_coop_mutex_unlock (&sgen_interruption_mutex)
  90
  91 /* FIXME: Use mono_atomic_add_i32 & mono_atomic_add_i64 to reduce the CAS cost. */
  92 #define SGEN_CAS        mono_atomic_cas_i32
  93 #define SGEN_CAS_PTR    mono_atomic_cas_ptr
  94 #define SGEN_ATOMIC_ADD(x,i)    do {                                    \
  95                 int __old_x;                                            \
  96                 do {                                                    \
  97                         __old_x = (x);                                  \
  98                 } while (mono_atomic_cas_i32 (&(x), __old_x + (i), __old_x) != __old_x); \
  99         } while (0)
 100 #define SGEN_ATOMIC_ADD_P(x,i) do { \
 101                 size_t __old_x;                                            \
 102                 do {                                                    \
 103                         __old_x = (x);                                  \
 104                 } while (mono_atomic_cas_ptr ((void**)&(x), (void*)(__old_x + (i)), (void*)__old_x) != (void*)__old_x); \
 105         } while (0)
 106
 107 #ifdef HEAVY_STATISTICS
 108 extern guint64 stat_objects_alloced_degraded;
 109 extern guint64 stat_bytes_alloced_degraded;
 110 extern guint64 stat_copy_object_called_major;
 111 extern guint64 stat_objects_copied_major;
 112 #endif
 113
 114 #define SGEN_ASSERT(level, a, ...) do { \
 115         if (G_UNLIKELY ((level) <= SGEN_MAX_ASSERT_LEVEL && !(a))) {    \
 116                 g_error (__VA_ARGS__);  \
 117 } } while (0)
 118
 119 #ifdef HAVE_LOCALTIME_R
 120 # define LOG_TIMESTAMP  \
 121         do {    \
 122                 time_t t;                                                                       \
 123                 struct tm tod;                                                                  \
 124                 time(&t);                                                                       \
 125                 localtime_r(&t, &tod);                                                          \
 126                 strftime(logTime, sizeof(logTime), MONO_STRFTIME_F " " MONO_STRFTIME_T, &tod);  \
 127         } while (0)
 128 #else
 129 # define LOG_TIMESTAMP  \
 130         do {    \
 131                 time_t t;                                                                       \
 132                 struct tm *tod;                                                                 \
 133                 time(&t);                                                                       \
 134                 tod = localtime(&t);                                                            \
 135                 strftime(logTime, sizeof(logTime), MONO_STRFTIME_F " " MONO_STRFTIME_T, tod);   \
 136         } while (0)
 137 #endif
 138
 139 #define SGEN_LOG(level, format, ...) do {      \
 140         if (G_UNLIKELY ((level) <= SGEN_MAX_DEBUG_LEVEL && (level) <= sgen_gc_debug_level)) {   \
 141                 char logTime[80];                                                               \
 142                 LOG_TIMESTAMP;                                                                  \
 143                 mono_gc_printf (sgen_gc_debug_file, "%s " format "\n", logTime, ##__VA_ARGS__); \
 144 } } while (0)
 145
 146 #define SGEN_COND_LOG(level, cond, format, ...) do {    \
 147         if (G_UNLIKELY ((level) <= SGEN_MAX_DEBUG_LEVEL && (level) <= sgen_gc_debug_level)) {           \
 148                 if (cond) {                                                                             \
 149                         char logTime[80];                                                               \
 150                         LOG_TIMESTAMP;                                                                  \
 151                         mono_gc_printf (sgen_gc_debug_file, "%s " format "\n", logTime, ##__VA_ARGS__); \
 152                 }                                                                                       \
 153 } } while (0)
 154
 155 extern int sgen_gc_debug_level;
 156 extern FILE* sgen_gc_debug_file;
 157
 158 extern int sgen_current_collection_generation;
 159
 160 extern unsigned int sgen_global_stop_count;
 161
 162 #define SGEN_ALIGN_UP_TO(val,align)     (((val) + (align - 1)) & ~(align - 1))
 163 #define SGEN_ALIGN_DOWN_TO(val,align)   ((val) & ~(align - 1))
 164
 165 #define SGEN_ALLOC_ALIGN                8
 166 #define SGEN_ALLOC_ALIGN_BITS   3
 167
 168 /* s must be non-negative */
 169 #define SGEN_CAN_ALIGN_UP(s)            ((s) <= SIZE_MAX - (SGEN_ALLOC_ALIGN - 1))
 170 #define SGEN_ALIGN_UP(s)                SGEN_ALIGN_UP_TO(s, SGEN_ALLOC_ALIGN)
 171 #define SGEN_ALIGN_DOWN(s)              SGEN_ALIGN_DOWN_TO(s, SGEN_ALLOC_ALIGN)
 172
 173 #if SIZEOF_VOID_P == 4
 174 #define ONE_P 1
 175 #else
 176 #define ONE_P 1ll
 177 #endif
 178
 179 static inline guint
 180 sgen_aligned_addr_hash (gconstpointer ptr)
 181 {
 182         return GPOINTER_TO_UINT (ptr) >> 3;
 183 }
 184
 185 #define SGEN_PTR_IN_NURSERY(p,bits,start,end)   (((mword)(p) & ~(((mword)1 << (bits)) - 1)) == (mword)(start))
 186
 187 extern size_t sgen_nursery_size;
 188 extern size_t sgen_nursery_max_size;
 189 extern int sgen_nursery_bits;
 190
 191 extern char *sgen_nursery_start;
 192 extern char *sgen_nursery_end;
 193
 194 static inline MONO_ALWAYS_INLINE gboolean
 195 sgen_ptr_in_nursery (void *p)
 196 {
 197         return SGEN_PTR_IN_NURSERY ((p), sgen_nursery_bits, sgen_nursery_start, sgen_nursery_end);
 198 }
 199
 200 static inline MONO_ALWAYS_INLINE char*
 201 sgen_get_nursery_start (void)
 202 {
 203         return sgen_nursery_start;
 204 }
 205
 206 static inline MONO_ALWAYS_INLINE char*
 207 sgen_get_nursery_end (void)
 208 {
 209         return sgen_nursery_end;
 210 }
 211
 212 /*
 213  * We use the lowest three bits in the vtable pointer of objects to tag whether they're
 214  * forwarded, pinned, and/or cemented.  These are the valid states:
 215  *
 216  * | State            | bits |
 217  * |------------------+------+
 218  * | default          |  000 |
 219  * | forwarded        |  001 |
 220  * | pinned           |  010 |
 221  * | pinned, cemented |  110 |
 222  *
 223  * We store them in the vtable slot because the bits are used in the sync block for other
 224  * purposes: if we merge them and alloc the sync blocks aligned to 8 bytes, we can change
 225  * this and use bit 3 in the syncblock (with the lower two bits both set for forwarded, that
 226  * would be an invalid combination for the monitor and hash code).
 227  */
 228
 229 #include "sgen-tagged-pointer.h"
 230
 231 #define SGEN_VTABLE_BITS_MASK   SGEN_TAGGED_POINTER_MASK
 232
 233 #define SGEN_POINTER_IS_TAGGED_FORWARDED(p)     SGEN_POINTER_IS_TAGGED_1((p))
 234 #define SGEN_POINTER_TAG_FORWARDED(p)           SGEN_POINTER_TAG_1((p))
 235
 236 #define SGEN_POINTER_IS_TAGGED_PINNED(p)        SGEN_POINTER_IS_TAGGED_2((p))
 237 #define SGEN_POINTER_TAG_PINNED(p)              SGEN_POINTER_TAG_2((p))
 238
 239 #define SGEN_POINTER_IS_TAGGED_CEMENTED(p)      SGEN_POINTER_IS_TAGGED_4((p))
 240 #define SGEN_POINTER_TAG_CEMENTED(p)            SGEN_POINTER_TAG_4((p))
 241
 242 #define SGEN_POINTER_UNTAG_VTABLE(p)            SGEN_POINTER_UNTAG_ALL((p))
 243
 244 /* returns NULL if not forwarded, or the forwarded address */
 245 #define SGEN_VTABLE_IS_FORWARDED(vtable) ((GCObject *)(SGEN_POINTER_IS_TAGGED_FORWARDED ((vtable)) ? SGEN_POINTER_UNTAG_VTABLE ((vtable)) : NULL))
 246 #define SGEN_OBJECT_IS_FORWARDED(obj) ((GCObject *)SGEN_VTABLE_IS_FORWARDED (((mword*)(obj))[0]))
 247
 248 #define SGEN_VTABLE_IS_PINNED(vtable) SGEN_POINTER_IS_TAGGED_PINNED ((vtable))
 249 #define SGEN_OBJECT_IS_PINNED(obj) (SGEN_VTABLE_IS_PINNED (((mword*)(obj))[0]))
 250
 251 #define SGEN_OBJECT_IS_CEMENTED(obj) (SGEN_POINTER_IS_TAGGED_CEMENTED (((mword*)(obj))[0]))
 252
 253 /* set the forwarded address fw_addr for object obj */
 254 #define SGEN_FORWARD_OBJECT(obj,fw_addr) do {                           \
 255                 *(void**)(obj) = SGEN_POINTER_TAG_FORWARDED ((fw_addr));        \
 256         } while (0)
 257 #define SGEN_FORWARD_OBJECT_PAR(obj,fw_addr,final_fw_addr) do {                 \
 258                 gpointer old_vtable_word = *(gpointer*)obj;                     \
 259                 gpointer new_vtable_word;                                       \
 260                 final_fw_addr = SGEN_VTABLE_IS_FORWARDED (old_vtable_word);     \
 261                 if (final_fw_addr)                                              \
 262                         break;                                                  \
 263                 new_vtable_word = SGEN_POINTER_TAG_FORWARDED ((fw_addr));       \
 264                 old_vtable_word = mono_atomic_cas_ptr ((gpointer*)obj, new_vtable_word, old_vtable_word); \
 265                 final_fw_addr = SGEN_VTABLE_IS_FORWARDED (old_vtable_word);     \
 266                 if (!final_fw_addr)                                             \
 267                         final_fw_addr = (fw_addr);                              \
 268         } while (0)
 269 #define SGEN_PIN_OBJECT(obj) do {       \
 270                 *(void**)(obj) = SGEN_POINTER_TAG_PINNED (*(void**)(obj)); \
 271         } while (0)
 272 #define SGEN_CEMENT_OBJECT(obj) do {    \
 273                 *(void**)(obj) = SGEN_POINTER_TAG_CEMENTED (*(void**)(obj)); \
 274         } while (0)
 275 /* Unpins and uncements */
 276 #define SGEN_UNPIN_OBJECT(obj) do {     \
 277                 *(void**)(obj) = SGEN_POINTER_UNTAG_VTABLE (*(void**)(obj)); \
 278         } while (0)
 279
 280 /*
 281  * Since we set bits in the vtable, use the macro to load it from the pointer to
 282  * an object that is potentially pinned.
 283  */
 284 #define SGEN_LOAD_VTABLE(obj)           ((GCVTable)(SGEN_POINTER_UNTAG_ALL (SGEN_LOAD_VTABLE_UNCHECKED ((GCObject *)(obj)))))
 285
 286 /*
 287 List of what each bit on of the vtable gc bits means.
 288 */
 289 enum {
 290         // When the Java bridge has determined an object is "bridged", it uses these two bits to cache that information.
 291         SGEN_GC_BIT_BRIDGE_OBJECT = 1,
 292         SGEN_GC_BIT_BRIDGE_OPAQUE_OBJECT = 2,
 293         SGEN_GC_BIT_FINALIZER_AWARE = 4,
 294 };
 295
 296 void sgen_gc_init (void)
 297     MONO_PERMIT (need (sgen_lock_gc));
 298
 299 void sgen_os_init (void);
 300
 301 void sgen_update_heap_boundaries (mword low, mword high);
 302
 303 void sgen_check_section_scan_starts (GCMemSection *section);
 304
 305 void sgen_conservatively_pin_objects_from (void **start, void **end, void *start_nursery, void *end_nursery, int pin_type);
 306
 307 gboolean sgen_gc_initialized (void);
 308
 309 /* Keep in sync with description_for_type() in sgen-internal.c! */
 310 enum {
 311         INTERNAL_MEM_PIN_QUEUE,
 312         INTERNAL_MEM_FRAGMENT,
 313         INTERNAL_MEM_SECTION,
 314         INTERNAL_MEM_SCAN_STARTS,
 315         INTERNAL_MEM_FIN_TABLE,
 316         INTERNAL_MEM_FINALIZE_ENTRY,
 317         INTERNAL_MEM_FINALIZE_READY,
 318         INTERNAL_MEM_DISLINK_TABLE,
 319         INTERNAL_MEM_DISLINK,
 320         INTERNAL_MEM_ROOTS_TABLE,
 321         INTERNAL_MEM_ROOT_RECORD,
 322         INTERNAL_MEM_STATISTICS,
 323         INTERNAL_MEM_STAT_PINNED_CLASS,
 324         INTERNAL_MEM_STAT_REMSET_CLASS,
 325         INTERNAL_MEM_STAT_GCHANDLE_CLASS,
 326         INTERNAL_MEM_GRAY_QUEUE,
 327         INTERNAL_MEM_MS_TABLES,
 328         INTERNAL_MEM_MS_BLOCK_INFO,
 329         INTERNAL_MEM_MS_BLOCK_INFO_SORT,
 330         INTERNAL_MEM_WORKER_DATA,
 331         INTERNAL_MEM_THREAD_POOL_JOB,
 332         INTERNAL_MEM_BRIDGE_DATA,
 333         INTERNAL_MEM_OLD_BRIDGE_HASH_TABLE,
 334         INTERNAL_MEM_OLD_BRIDGE_HASH_TABLE_ENTRY,
 335         INTERNAL_MEM_BRIDGE_HASH_TABLE,
 336         INTERNAL_MEM_BRIDGE_HASH_TABLE_ENTRY,
 337         INTERNAL_MEM_BRIDGE_ALIVE_HASH_TABLE,
 338         INTERNAL_MEM_BRIDGE_ALIVE_HASH_TABLE_ENTRY,
 339         INTERNAL_MEM_TARJAN_BRIDGE_HASH_TABLE,
 340         INTERNAL_MEM_TARJAN_BRIDGE_HASH_TABLE_ENTRY,
 341         INTERNAL_MEM_TARJAN_OBJ_BUCKET,
 342         INTERNAL_MEM_BRIDGE_DEBUG,
 343         INTERNAL_MEM_TOGGLEREF_DATA,
 344         INTERNAL_MEM_CARDTABLE_MOD_UNION,
 345         INTERNAL_MEM_BINARY_PROTOCOL,
 346         INTERNAL_MEM_TEMPORARY,
 347         INTERNAL_MEM_LOG_ENTRY,
 348         INTERNAL_MEM_COMPLEX_DESCRIPTORS,
 349         INTERNAL_MEM_FIRST_CLIENT
 350 };
 351
 352 enum {
 353         GENERATION_NURSERY,
 354         GENERATION_OLD,
 355         GENERATION_MAX
 356 };
 357
 358 #ifdef SGEN_HEAVY_BINARY_PROTOCOL
 359 #define BINARY_PROTOCOL_ARG(x)  ,x
 360 #else
 361 #define BINARY_PROTOCOL_ARG(x)
 362 #endif
 363
 364 void sgen_init_internal_allocator (void);
 365
 366 #define SGEN_DEFINE_OBJECT_VTABLE
 367 #ifdef SGEN_CLIENT_HEADER
 368 #include SGEN_CLIENT_HEADER
 369 #else
 370 #include "metadata/sgen-client-mono.h"
 371 #endif
 372 #undef SGEN_DEFINE_OBJECT_VTABLE
 373
 374 #include "mono/sgen/sgen-descriptor.h"
 375 #include "mono/sgen/sgen-gray.h"
 376
 377 /* the runtime can register areas of memory as roots: we keep two lists of roots,
 378  * a pinned root set for conservatively scanned roots and a normal one for
 379  * precisely scanned roots (currently implemented as a single list).
 380  */
 381 typedef struct _RootRecord RootRecord;
 382 struct _RootRecord {
 383         char *end_root;
 384         SgenDescriptor root_desc;
 385         int source;
 386         const char *msg;
 387 };
 388
 389 enum {
 390         ROOT_TYPE_NORMAL = 0, /* "normal" roots */
 391         ROOT_TYPE_PINNED = 1, /* roots without a GC descriptor */
 392         ROOT_TYPE_WBARRIER = 2, /* roots with a write barrier */
 393         ROOT_TYPE_NUM
 394 };
 395
 396 extern SgenHashTable sgen_roots_hash [ROOT_TYPE_NUM];
 397
 398 int sgen_register_root (char *start, size_t size, SgenDescriptor descr, int root_type, MonoGCRootSource source, void *key, const char *msg)
 399         MONO_PERMIT (need (sgen_lock_gc));
 400 void sgen_deregister_root (char* addr)
 401         MONO_PERMIT (need (sgen_lock_gc));
 402
 403 typedef void (*IterateObjectCallbackFunc) (GCObject*, size_t, void*);
 404
 405 void sgen_scan_area_with_callback (char *start, char *end, IterateObjectCallbackFunc callback, void *data, gboolean allow_flags, gboolean fail_on_canaries);
 406
 407 /* eventually share with MonoThread? */
 408 /*
 409  * This structure extends the MonoThreadInfo structure.
 410  */
 411 struct _SgenThreadInfo {
 412         SgenClientThreadInfo client_info;
 413
 414         char *tlab_start;
 415         char *tlab_next;
 416         char *tlab_temp_end;
 417         char *tlab_real_end;
 418
 419         /* Total bytes allocated by this thread in its lifetime so far. */
 420         gint64 total_bytes_allocated;
 421 };
 422
 423 gboolean sgen_is_worker_thread (MonoNativeThreadId thread);
 424
 425 typedef void (*CopyOrMarkObjectFunc) (GCObject**, SgenGrayQueue*);
 426 typedef void (*ScanObjectFunc) (GCObject *obj, SgenDescriptor desc, SgenGrayQueue*);
 427 typedef void (*ScanVTypeFunc) (GCObject *full_object, char *start, SgenDescriptor desc, SgenGrayQueue* BINARY_PROTOCOL_ARG (size_t size));
 428 typedef void (*ScanPtrFieldFunc) (GCObject *obj, GCObject **ptr, SgenGrayQueue* queue);
 429 typedef gboolean (*DrainGrayStackFunc) (SgenGrayQueue *queue);
 430
 431 typedef struct {
 432         CopyOrMarkObjectFunc copy_or_mark_object;
 433         ScanObjectFunc scan_object;
 434         ScanVTypeFunc scan_vtype;
 435         ScanPtrFieldFunc scan_ptr_field;
 436         /* Drain stack optimized for the above functions */
 437         DrainGrayStackFunc drain_gray_stack;
 438         /*FIXME add allocation function? */
 439 } SgenObjectOperations;
 440
 441 typedef struct
 442 {
 443         SgenObjectOperations *ops;
 444         SgenGrayQueue *queue;
 445 } ScanCopyContext;
 446
 447 // error C4576: a parenthesized type followed by an initializer list is a non-standard explicit type conversion
 448 // An inline function or constructor would work here too.
 449 #ifdef _MSC_VER
 450 #define MONO_MSC_WARNING_SUPPRESS(warn, body) __pragma (warning (suppress:warn)) body
 451 #else
 452 #define MONO_MSC_WARNING_SUPPRESS(warn, body) body
 453 #endif
 454 #define CONTEXT_FROM_OBJECT_OPERATIONS(ops, queue) MONO_MSC_WARNING_SUPPRESS (4576, ((ScanCopyContext) { (ops), (queue) }))
 455
 456 void sgen_report_internal_mem_usage (void);
 457 void sgen_dump_internal_mem_usage (FILE *heap_dump_file);
 458 void sgen_dump_section (GCMemSection *section, const char *type);
 459 void sgen_dump_occupied (char *start, char *end, char *section_start);
 460
 461 void sgen_register_fixed_internal_mem_type (int type, size_t size);
 462
 463 void* sgen_alloc_internal (int type);
 464 void sgen_free_internal (void *addr, int type);
 465
 466 void* sgen_alloc_internal_dynamic (size_t size, int type, gboolean assert_on_failure);
 467 void sgen_free_internal_dynamic (void *addr, size_t size, int type);
 468
 469 void sgen_pin_stats_enable (void);
 470 void sgen_pin_stats_register_object (GCObject *obj, int generation);
 471 void sgen_pin_stats_register_global_remset (GCObject *obj);
 472 void sgen_pin_stats_report (void);
 473
 474 void sgen_gchandle_stats_enable (void);
 475 void sgen_gchandle_stats_report (void);
 476
 477 void sgen_sort_addresses (void **array, size_t size);
 478 void sgen_add_to_global_remset (gpointer ptr, GCObject *obj);
 479
 480 int sgen_get_current_collection_generation (void);
 481 gboolean sgen_collection_is_concurrent (void);
 482 gboolean sgen_get_concurrent_collection_in_progress (void);
 483
 484 void sgen_set_bytes_allocated_attached (guint64 bytes);
 485 void sgen_increment_bytes_allocated_detached (guint64 bytes);
 486
 487 typedef struct _SgenFragment SgenFragment;
 488
 489 struct _SgenFragment {
 490         SgenFragment *next;
 491         char *fragment_start;
 492         char *fragment_next; /* the current soft limit for allocation */
 493         char *fragment_end;
 494         SgenFragment *next_in_order; /* We use a different entry for all active fragments so we can avoid SMR. */
 495 };
 496
 497 typedef struct {
 498         SgenFragment *alloc_head; /* List head to be used when allocating memory. Walk with fragment_next. */
 499         SgenFragment *region_head; /* List head of the region used by this allocator. Walk with next_in_order. */
 500 } SgenFragmentAllocator;
 501
 502 void sgen_fragment_allocator_add (SgenFragmentAllocator *allocator, char *start, char *end);
 503 void sgen_fragment_allocator_release (SgenFragmentAllocator *allocator);
 504 void* sgen_fragment_allocator_par_alloc (SgenFragmentAllocator *allocator, size_t size);
 505 void* sgen_fragment_allocator_serial_range_alloc (SgenFragmentAllocator *allocator, size_t desired_size, size_t minimum_size, size_t *out_alloc_size);
 506 void* sgen_fragment_allocator_par_range_alloc (SgenFragmentAllocator *allocator, size_t desired_size, size_t minimum_size, size_t *out_alloc_size);
 507 SgenFragment* sgen_fragment_allocator_alloc (void);
 508 void sgen_clear_allocator_fragments (SgenFragmentAllocator *allocator);
 509 void sgen_clear_range (char *start, char *end);
 510
 511
 512 /*
 513 This is a space/speed compromise as we need to make sure the from/to space check is both O(1)
 514 and only hit cache hot memory. On a 4Mb nursery it requires 1024 bytes, or 3% of your average
 515 L1 cache. On small configs with a 512kb nursery, this goes to 0.4%.
 516
 517 Experimental results on how much space we waste with a 4Mb nursery:
 518
 519 Note that the wastage applies to the half nursery, or 2Mb:
 520
 521 Test 1 (compiling corlib):
 522 9: avg: 3.1k
 523 8: avg: 1.6k
 524
 525 */
 526 #define SGEN_TO_SPACE_GRANULE_BITS 9
 527 #define SGEN_TO_SPACE_GRANULE_IN_BYTES (1 << SGEN_TO_SPACE_GRANULE_BITS)
 528
 529 extern char *sgen_space_bitmap;
 530 extern size_t sgen_space_bitmap_size;
 531
 532 static inline gboolean
 533 sgen_nursery_is_to_space (void *object)
 534 {
 535         size_t idx = ((char*)object - sgen_nursery_start) >> SGEN_TO_SPACE_GRANULE_BITS;
 536         size_t byte = idx >> 3;
 537         size_t bit = idx & 0x7;
 538
 539         SGEN_ASSERT (4, sgen_ptr_in_nursery (object), "object %p is not in nursery [%p - %p]", object, sgen_get_nursery_start (), sgen_get_nursery_end ());
 540         SGEN_ASSERT (4, byte < sgen_space_bitmap_size, "byte index %zd out of range (%zd)", byte, sgen_space_bitmap_size);
 541
 542         return (sgen_space_bitmap [byte] & (1 << bit)) != 0;
 543 }
 544
 545 static inline gboolean
 546 sgen_nursery_is_from_space (void *object)
 547 {
 548         return !sgen_nursery_is_to_space (object);
 549 }
 550
 551 static inline gboolean
 552 sgen_nursery_is_object_alive (GCObject *obj)
 553 {
 554         /* FIXME put this asserts under a non default level */
 555         g_assert (sgen_ptr_in_nursery (obj));
 556
 557         if (sgen_nursery_is_to_space (obj))
 558                 return TRUE;
 559
 560         if (SGEN_OBJECT_IS_PINNED (obj) || SGEN_OBJECT_IS_FORWARDED (obj))
 561                 return TRUE;
 562
 563         return FALSE;
 564 }
 565
 566 typedef struct {
 567         gboolean is_split;
 568         gboolean is_parallel;
 569
 570         GCObject* (*alloc_for_promotion) (GCVTable vtable, GCObject *obj, size_t objsize, gboolean has_references);
 571         GCObject* (*alloc_for_promotion_par) (GCVTable vtable, GCObject *obj, size_t objsize, gboolean has_references);
 572
 573         SgenObjectOperations serial_ops;
 574         SgenObjectOperations serial_ops_with_concurrent_major;
 575         SgenObjectOperations parallel_ops;
 576         SgenObjectOperations parallel_ops_with_concurrent_major;
 577
 578         void (*prepare_to_space) (char *to_space_bitmap, size_t space_bitmap_size);
 579         void (*clear_fragments) (void);
 580         SgenFragment* (*build_fragments_get_exclude_head) (void);
 581         void (*build_fragments_release_exclude_head) (void);
 582         void (*build_fragments_finish) (SgenFragmentAllocator *allocator);
 583         void (*init_nursery) (SgenFragmentAllocator *allocator, char *start, char *end);
 584
 585         gboolean (*handle_gc_param) (const char *opt); /* Optional */
 586         void (*print_gc_param_usage) (void); /* Optional */
 587 } SgenMinorCollector;
 588
 589 extern SgenMinorCollector sgen_minor_collector;
 590
 591 void sgen_simple_nursery_init (SgenMinorCollector *collector, gboolean parallel);
 592 void sgen_split_nursery_init (SgenMinorCollector *collector);
 593
 594 /* Updating references */
 595
 596 #ifdef SGEN_CHECK_UPDATE_REFERENCE
 597 gboolean sgen_thread_pool_is_thread_pool_thread (MonoNativeThreadId some_thread);
 598
 599 static inline void
 600 sgen_update_reference (GCObject **p, GCObject *o, gboolean allow_null)
 601 {
 602         if (!allow_null)
 603                 SGEN_ASSERT (0, o, "Cannot update a reference with a NULL pointer");
 604         SGEN_ASSERT (0, !sgen_workers_is_worker_thread (mono_native_thread_id_get ()), "Can't update a reference in the worker thread");
 605         *p = o;
 606 }
 607
 608 #define SGEN_UPDATE_REFERENCE_ALLOW_NULL(p,o)   sgen_update_reference ((GCObject**)(p), (GCObject*)(o), TRUE)
 609 #define SGEN_UPDATE_REFERENCE(p,o)              sgen_update_reference ((GCObject**)(p), (GCObject*)(o), FALSE)
 610 #else
 611 #define SGEN_UPDATE_REFERENCE_ALLOW_NULL(p,o)   (*(GCObject**)(p) = (GCObject*)(o))
 612 #define SGEN_UPDATE_REFERENCE(p,o)              SGEN_UPDATE_REFERENCE_ALLOW_NULL ((p), (o))
 613 #endif
 614
 615 /* Major collector */
 616
 617 typedef void (*sgen_cardtable_block_callback) (mword start, mword size);
 618 void sgen_major_collector_iterate_live_block_ranges (sgen_cardtable_block_callback callback);
 619 void sgen_major_collector_iterate_block_ranges (sgen_cardtable_block_callback callback);
 620
 621 typedef enum {
 622         ITERATE_OBJECTS_SWEEP = 1,
 623         ITERATE_OBJECTS_NON_PINNED = 2,
 624         ITERATE_OBJECTS_PINNED = 4,
 625         ITERATE_OBJECTS_SWEEP_NON_PINNED = ITERATE_OBJECTS_SWEEP | ITERATE_OBJECTS_NON_PINNED,
 626         ITERATE_OBJECTS_SWEEP_PINNED = ITERATE_OBJECTS_SWEEP | ITERATE_OBJECTS_PINNED,
 627         ITERATE_OBJECTS_SWEEP_ALL = ITERATE_OBJECTS_SWEEP | ITERATE_OBJECTS_NON_PINNED | ITERATE_OBJECTS_PINNED
 628 } IterateObjectsFlags;
 629
 630 typedef struct
 631 {
 632         size_t num_scanned_objects;
 633         size_t num_unique_scanned_objects;
 634 } ScannedObjectCounts;
 635
 636 typedef enum {
 637         CARDTABLE_SCAN_GLOBAL = 0,
 638         CARDTABLE_SCAN_MOD_UNION = 1,
 639         CARDTABLE_SCAN_MOD_UNION_PRECLEAN = CARDTABLE_SCAN_MOD_UNION | 2,
 640 } CardTableScanType;
 641
 642 typedef struct _SgenMajorCollector SgenMajorCollector;
 643 struct _SgenMajorCollector {
 644         size_t section_size;
 645         gboolean is_concurrent;
 646         gboolean is_parallel;
 647         gboolean supports_cardtable;
 648         gboolean sweeps_lazily;
 649
 650         void* (*alloc_heap) (mword nursery_size, mword nursery_align);
 651         gboolean (*is_object_live) (GCObject *obj);
 652         GCObject* (*alloc_small_pinned_obj) (GCVTable vtable, size_t size, gboolean has_references);
 653         GCObject* (*alloc_degraded) (GCVTable vtable, size_t size);
 654
 655         SgenObjectOperations major_ops_serial;
 656         SgenObjectOperations major_ops_concurrent_start;
 657         SgenObjectOperations major_ops_concurrent_finish;
 658         SgenObjectOperations major_ops_conc_par_start;
 659         SgenObjectOperations major_ops_conc_par_finish;
 660
 661         GCObject* (*alloc_object) (GCVTable vtable, size_t size, gboolean has_references);
 662         GCObject* (*alloc_object_par) (GCVTable vtable, size_t size, gboolean has_references);
 663         void (*free_pinned_object) (GCObject *obj, size_t size);
 664
 665         /*
 666          * This is used for domain unloading, heap walking from the logging profiler, and
 667          * debugging.  Can assume the world is stopped.
 668          */
 669         void (*iterate_objects) (IterateObjectsFlags flags, IterateObjectCallbackFunc callback, void *data);
 670
 671         void (*free_non_pinned_object) (GCObject *obj, size_t size);
 672         void (*pin_objects) (SgenGrayQueue *queue);
 673         void (*pin_major_object) (GCObject *obj, SgenGrayQueue *queue);
 674         void (*scan_card_table) (CardTableScanType scan_type, ScanCopyContext ctx, int job_index, int job_split_count, int block_count);
 675         void (*iterate_live_block_ranges) (sgen_cardtable_block_callback callback);
 676         void (*iterate_block_ranges) (sgen_cardtable_block_callback callback);
 677         void (*update_cardtable_mod_union) (void);
 678         void (*init_to_space) (void);
 679         void (*sweep) (void);
 680         gboolean (*have_swept) (void);
 681         void (*finish_sweeping) (void);
 682         void (*free_swept_blocks) (size_t section_reserve);
 683         void (*check_scan_starts) (void);
 684         void (*dump_heap) (FILE *heap_dump_file);
 685         gint64 (*get_used_size) (void);
 686         void (*start_nursery_collection) (void);
 687         void (*finish_nursery_collection) (void);
 688         void (*start_major_collection) (void);
 689         void (*finish_major_collection) (ScannedObjectCounts *counts);
 690         gboolean (*ptr_is_in_non_pinned_space) (char *ptr, char **start);
 691         gboolean (*ptr_is_from_pinned_alloc) (char *ptr);
 692         void (*report_pinned_memory_usage) (void);
 693         size_t (*get_num_major_sections) (void);
 694         size_t (*get_bytes_survived_last_sweep) (void);
 695         gboolean (*handle_gc_param) (const char *opt);
 696         void (*print_gc_param_usage) (void);
 697         void (*post_param_init) (SgenMajorCollector *collector);
 698         gboolean (*is_valid_object) (char *ptr);
 699         GCVTable (*describe_pointer) (char *pointer);
 700         guint8* (*get_cardtable_mod_union_for_reference) (char *object);
 701         long long (*get_and_reset_num_major_objects_marked) (void);
 702         void (*count_cards) (long long *num_total_cards, long long *num_marked_cards);
 703         void (*init_block_free_lists) (gpointer *list_p);
 704 };
 705
 706 extern SgenMajorCollector sgen_major_collector;
 707
 708 void sgen_marksweep_init (SgenMajorCollector *collector);
 709 void sgen_marksweep_conc_init (SgenMajorCollector *collector);
 710 void sgen_marksweep_conc_par_init (SgenMajorCollector *collector);
 711 SgenMajorCollector* sgen_get_major_collector (void);
 712 SgenMinorCollector* sgen_get_minor_collector (void);
 713
 714
 715 typedef struct _SgenRememberedSet {
 716         void (*wbarrier_set_field) (GCObject *obj, gpointer field_ptr, GCObject* value);
 717         void (*wbarrier_arrayref_copy) (gpointer dest_ptr, gconstpointer src_ptr, int count);
 718         void (*wbarrier_value_copy) (gpointer dest, gconstpointer src, int count, size_t element_size);
 719         void (*wbarrier_object_copy) (GCObject* obj, GCObject *src);
 720         void (*wbarrier_generic_nostore) (gpointer ptr);
 721         void (*record_pointer) (gpointer ptr);
 722         void (*wbarrier_range_copy) (gpointer dest, gconstpointer src, int count);
 723
 724         void (*start_scan_remsets) (void);
 725
 726         void (*clear_cards) (void);
 727
 728         gboolean (*find_address) (char *addr);
 729         gboolean (*find_address_with_cards) (char *cards_start, guint8 *cards, char *addr);
 730 } SgenRememberedSet;
 731
 732 SgenRememberedSet *sgen_get_remset (void);
 733
 734 /*
 735  * These must be kept in sync with object.h.  They're here for using SGen independently of
 736  * Mono.
 737  */
 738 void mono_gc_wbarrier_arrayref_copy (gpointer dest_ptr, /*const*/ void* src_ptr, int count);
 739 void mono_gc_wbarrier_generic_nostore (gpointer ptr);
 740 void mono_gc_wbarrier_generic_store (gpointer ptr, GCObject* value);
 741 void mono_gc_wbarrier_generic_store_atomic (gpointer ptr, GCObject *value);
 742
 743 void sgen_wbarrier_range_copy (gpointer _dest, gconstpointer _src, int size);
 744
 745 static inline SgenDescriptor
 746 sgen_obj_get_descriptor (GCObject *obj)
 747 {
 748         GCVTable vtable = SGEN_LOAD_VTABLE_UNCHECKED (obj);
 749         SGEN_ASSERT (9, !SGEN_POINTER_IS_TAGGED_ANY (vtable), "Object can't be tagged");
 750         return sgen_vtable_get_descriptor (vtable);
 751 }
 752
 753 static inline SgenDescriptor
 754 sgen_obj_get_descriptor_safe (GCObject *obj)
 755 {
 756         GCVTable vtable = SGEN_LOAD_VTABLE (obj);
 757         return sgen_vtable_get_descriptor (vtable);
 758 }
 759
 760 static mword sgen_client_par_object_get_size (GCVTable vtable, GCObject* o);
 761 static mword sgen_client_slow_object_get_size (GCVTable vtable, GCObject* o);
 762
 763 static inline mword
 764 sgen_safe_object_get_size (GCObject *obj)
 765 {
 766         GCObject *forwarded;
 767         GCVTable vtable = SGEN_LOAD_VTABLE_UNCHECKED (obj);
 768
 769         /*
 770          * Once we load the vtable, we must always use it, in case we are in parallel case.
 771          * Otherwise the object might get forwarded in the meantime and we would read an
 772          * invalid vtable. An object cannot be forwarded for a second time during same GC.
 773          */
 774         if ((forwarded = SGEN_VTABLE_IS_FORWARDED (vtable)))
 775                 return sgen_client_par_object_get_size (SGEN_LOAD_VTABLE (forwarded), obj);
 776         else
 777                 return sgen_client_par_object_get_size ((GCVTable)SGEN_POINTER_UNTAG_ALL (vtable), obj);
 778 }
 779
 780 static inline gboolean
 781 sgen_safe_object_is_small (GCObject *obj, int type)
 782 {
 783         if (type <= DESC_TYPE_MAX_SMALL_OBJ)
 784                 return TRUE;
 785         return SGEN_ALIGN_UP (sgen_safe_object_get_size ((GCObject*)obj)) <= SGEN_MAX_SMALL_OBJ_SIZE;
 786 }
 787
 788 /*
 789  * This variant guarantees to return the exact size of the object
 790  * before alignment. Needed for canary support.
 791  */
 792 static inline guint
 793 sgen_safe_object_get_size_unaligned (GCObject *obj)
 794 {
 795         GCObject *forwarded;
 796
 797         if ((forwarded = SGEN_OBJECT_IS_FORWARDED (obj))) {
 798                 obj = (GCObject*)forwarded;
 799         }
 800
 801         return sgen_client_slow_object_get_size (SGEN_LOAD_VTABLE (obj), obj);
 802 }
 803
 804 #ifdef SGEN_CLIENT_HEADER
 805 #include SGEN_CLIENT_HEADER
 806 #else
 807 #include "metadata/sgen-client-mono.h"
 808 #endif
 809
 810 gboolean sgen_object_is_live (GCObject *obj);
 811
 812 void  sgen_init_fin_weak_hash (void);
 813
 814 void sgen_register_obj_with_weak_fields (GCObject *obj);
 815
 816 /* FIXME: move the toggleref stuff out of here */
 817 void sgen_mark_togglerefs (char *start, char *end, ScanCopyContext ctx);
 818 void sgen_clear_togglerefs (char *start, char *end, ScanCopyContext ctx);
 819
 820 void sgen_process_togglerefs (void);
 821 void sgen_register_test_toggleref_callback (void);
 822
 823 void sgen_mark_bridge_object (GCObject *obj)
 824         MONO_PERMIT (need (sgen_gc_locked));
 825 void sgen_collect_bridge_objects (int generation, ScanCopyContext ctx)
 826         MONO_PERMIT (need (sgen_gc_locked));
 827
 828 typedef gboolean (*SgenObjectPredicateFunc) (GCObject *obj, void *user_data);
 829
 830 void sgen_null_links_if (SgenObjectPredicateFunc predicate, void *data, int generation, gboolean track)
 831         MONO_PERMIT (need (sgen_gc_locked, sgen_world_stopped));
 832
 833 gboolean sgen_gc_is_object_ready_for_finalization (GCObject *object);
 834 void sgen_gc_lock (void) MONO_PERMIT (use (sgen_lock_gc), grant (sgen_gc_locked), revoke (sgen_lock_gc));
 835 void sgen_gc_unlock (void) MONO_PERMIT (use (sgen_gc_locked), revoke (sgen_gc_locked), grant (sgen_lock_gc));
 836
 837 void sgen_queue_finalization_entry (GCObject *obj);
 838 const char* sgen_generation_name (int generation);
 839
 840 void sgen_finalize_in_range (int generation, ScanCopyContext ctx)
 841         MONO_PERMIT (need (sgen_gc_locked));
 842 void sgen_null_link_in_range (int generation, ScanCopyContext ctx, gboolean track)
 843         MONO_PERMIT (need (sgen_gc_locked, sgen_world_stopped));
 844 void sgen_process_fin_stage_entries (void)
 845         MONO_PERMIT (need (sgen_gc_locked));
 846 gboolean sgen_have_pending_finalizers (void);
 847
 848 typedef void (*SGenFinalizationProc)(gpointer, gpointer); // same as MonoFinalizationProc, GC_finalization_proc
 849
 850 void sgen_object_register_for_finalization (GCObject *obj, SGenFinalizationProc user_data)
 851         MONO_PERMIT (need (sgen_lock_gc));
 852
 853 void sgen_finalize_if (SgenObjectPredicateFunc predicate, void *user_data)
 854         MONO_PERMIT (need (sgen_lock_gc));
 855 void sgen_remove_finalizers_if (SgenObjectPredicateFunc predicate, void *user_data, int generation);
 856 void sgen_set_suspend_finalizers (void);
 857
 858 void sgen_wbroots_iterate_live_block_ranges (sgen_cardtable_block_callback cb);
 859 void sgen_wbroots_scan_card_table (ScanCopyContext ctx);
 860
 861 void sgen_register_disappearing_link (GCObject *obj, void **link, gboolean track, gboolean in_gc);
 862
 863 GCObject* sgen_weak_link_get (void **link_addr);
 864
 865 gboolean sgen_drain_gray_stack (ScanCopyContext ctx);
 866
 867 enum {
 868         SPACE_NURSERY,
 869         SPACE_MAJOR,
 870         SPACE_LOS
 871 };
 872
 873 void sgen_pin_object (GCObject *object, SgenGrayQueue *queue);
 874 void sgen_set_pinned_from_failed_allocation (mword objsize);
 875
 876 void sgen_ensure_free_space (size_t size, int generation)
 877         MONO_PERMIT (need (sgen_gc_locked, sgen_stop_world));
 878 void sgen_gc_collect (int generation)
 879         MONO_PERMIT (need (sgen_lock_gc, sgen_stop_world));
 880 void sgen_perform_collection (size_t requested_size, int generation_to_collect, const char *reason, gboolean wait_to_finish, gboolean stw)
 881         MONO_PERMIT (need (sgen_gc_locked, sgen_stop_world));
 882
 883 int sgen_gc_collection_count (int generation);
 884 /* FIXME: what exactly does this return? */
 885 size_t sgen_gc_get_used_size (void)
 886         MONO_PERMIT (need (sgen_lock_gc));
 887 size_t sgen_gc_get_total_heap_allocation (void);
 888
 889 /* STW */
 890
 891 void sgen_stop_world (int generation, gboolean serial_collection)
 892         MONO_PERMIT (need (sgen_gc_locked), use (sgen_stop_world), grant (sgen_world_stopped), revoke (sgen_stop_world));
 893 void sgen_restart_world (int generation, gboolean serial_collection)
 894         MONO_PERMIT (need (sgen_gc_locked), use (sgen_world_stopped), revoke (sgen_world_stopped), grant (sgen_stop_world));
 895 gboolean sgen_is_world_stopped (void);
 896
 897 gboolean sgen_set_allow_synchronous_major (gboolean flag);
 898
 899 /* LOS */
 900
 901 typedef struct _LOSObject LOSObject;
 902 struct _LOSObject {
 903         LOSObject *next;
 904         mword size; /* this is the object size, lowest bit used for pin/mark */
 905         guint8 * volatile cardtable_mod_union; /* only used by the concurrent collector */
 906 #if SIZEOF_VOID_P < 8
 907         mword dummy;            /* to align object to sizeof (double) */
 908 #endif
 909         GCObject data [MONO_ZERO_LEN_ARRAY];
 910 };
 911
 912 extern LOSObject *sgen_los_object_list;
 913 extern mword sgen_los_memory_usage;
 914 extern mword sgen_los_memory_usage_total;
 915
 916 void sgen_los_free_object (LOSObject *obj);
 917 void* sgen_los_alloc_large_inner (GCVTable vtable, size_t size)
 918         MONO_PERMIT (need (sgen_gc_locked, sgen_stop_world));
 919 void sgen_los_sweep (void);
 920 gboolean sgen_ptr_is_in_los (char *ptr, char **start);
 921 void sgen_los_iterate_objects (IterateObjectCallbackFunc cb, void *user_data);
 922 void sgen_los_iterate_live_block_ranges (sgen_cardtable_block_callback callback);
 923 void sgen_los_scan_card_table (CardTableScanType scan_type, ScanCopyContext ctx, int job_index, int job_split_count);
 924 void sgen_los_update_cardtable_mod_union (void);
 925 void sgen_los_count_cards (long long *num_total_cards, long long *num_marked_cards);
 926 gboolean sgen_los_is_valid_object (char *object);
 927 gboolean mono_sgen_los_describe_pointer (char *ptr);
 928 LOSObject* sgen_los_header_for_object (GCObject *data);
 929 mword sgen_los_object_size (LOSObject *obj);
 930 void sgen_los_pin_object (GCObject *obj);
 931 gboolean sgen_los_pin_object_par (GCObject *obj);
 932 gboolean sgen_los_object_is_pinned (GCObject *obj);
 933 void sgen_los_mark_mod_union_card (GCObject *mono_obj, void **ptr);
 934
 935
 936 /* nursery allocator */
 937
 938 void sgen_clear_nursery_fragments (void);
 939 void sgen_nursery_allocator_prepare_for_pinning (void);
 940 void sgen_nursery_allocator_set_nursery_bounds (char *nursery_start, size_t min_size, size_t max_size);
 941 void sgen_resize_nursery (gboolean need_shrink);
 942 mword sgen_build_nursery_fragments (GCMemSection *nursery_section);
 943 void sgen_init_nursery_allocator (void);
 944 void sgen_nursery_allocator_init_heavy_stats (void);
 945 void sgen_init_allocator (void);
 946 void* sgen_nursery_alloc (size_t size);
 947 void* sgen_nursery_alloc_range (size_t size, size_t min_size, size_t *out_alloc_size);
 948 gboolean sgen_can_alloc_size (size_t size);
 949 void sgen_nursery_retire_region (void *address, ptrdiff_t size);
 950
 951 void sgen_nursery_alloc_prepare_for_minor (void);
 952 void sgen_nursery_alloc_prepare_for_major (void);
 953
 954 GCObject* sgen_alloc_for_promotion (GCObject *obj, size_t objsize, gboolean has_references);
 955
 956 GCObject* sgen_alloc_obj_nolock (GCVTable vtable, size_t size)
 957         MONO_PERMIT (need (sgen_gc_locked, sgen_stop_world));
 958 GCObject* sgen_try_alloc_obj_nolock (GCVTable vtable, size_t size);
 959
 960 /* Threads */
 961
 962 void* sgen_thread_attach (SgenThreadInfo* info);
 963 void sgen_thread_detach_with_lock (SgenThreadInfo *p);
 964
 965 /* Finalization/ephemeron support */
 966
 967 static inline gboolean
 968 sgen_major_is_object_alive (GCObject *object)
 969 {
 970         mword objsize;
 971
 972         /* Oldgen objects can be pinned and forwarded too */
 973         if (SGEN_OBJECT_IS_PINNED (object) || SGEN_OBJECT_IS_FORWARDED (object))
 974                 return TRUE;
 975
 976         /*
 977          * FIXME: major_collector.is_object_live() also calculates the
 978          * size.  Avoid the double calculation.
 979          */
 980         objsize = SGEN_ALIGN_UP (sgen_safe_object_get_size (object));
 981         if (objsize > SGEN_MAX_SMALL_OBJ_SIZE)
 982                 return sgen_los_object_is_pinned (object);
 983
 984         return sgen_major_collector.is_object_live (object);
 985 }
 986
 987
 988 /*
 989  * If the object has been forwarded it means it's still referenced from a root.
 990  * If it is pinned it's still alive as well.
 991  * A LOS object is only alive if we have pinned it.
 992  * Return TRUE if @obj is ready to be finalized.
 993  */
 994 static inline gboolean
 995 sgen_is_object_alive (GCObject *object)
 996 {
 997         if (sgen_ptr_in_nursery (object))
 998                 return sgen_nursery_is_object_alive (object);
 999
1000         return sgen_major_is_object_alive (object);
1001 }
1002
1003
1004 /*
1005  * This function returns true if @object is either alive or it belongs to the old gen
1006  * and we're currently doing a minor collection.
1007  */
1008 static inline int
1009 sgen_is_object_alive_for_current_gen (GCObject *object)
1010 {
1011         if (sgen_ptr_in_nursery (object))
1012                 return sgen_nursery_is_object_alive (object);
1013
1014         if (sgen_current_collection_generation == GENERATION_NURSERY)
1015                 return TRUE;
1016
1017         return sgen_major_is_object_alive (object);
1018 }
1019
1020 int sgen_gc_invoke_finalizers (void)
1021         MONO_PERMIT (need (sgen_lock_gc));
1022
1023 /* GC handles */
1024
1025 void sgen_init_gchandles (void);
1026
1027 void sgen_null_links_if (SgenObjectPredicateFunc predicate, void *data, int generation, gboolean track)
1028         MONO_PERMIT (need (sgen_gc_locked));
1029
1030 typedef gpointer (*SgenGCHandleIterateCallback) (gpointer hidden, GCHandleType handle_type, int max_generation, gpointer user);
1031
1032 guint32 sgen_gchandle_new (GCObject *obj, gboolean pinned);
1033 guint32 sgen_gchandle_new_weakref (GCObject *obj, gboolean track_resurrection);
1034 void sgen_gchandle_iterate (GCHandleType handle_type, int max_generation, SgenGCHandleIterateCallback callback, gpointer user)
1035         MONO_PERMIT (need (sgen_world_stopped));
1036 void sgen_gchandle_set_target (guint32 gchandle, GCObject *obj);
1037 void sgen_mark_normal_gc_handles (void *addr, SgenUserMarkFunc mark_func, void *gc_data)
1038         MONO_PERMIT (need (sgen_world_stopped));
1039 void sgen_gc_handles_report_roots (SgenUserReportRootFunc mark_func, void *gc_data)
1040         MONO_PERMIT (need (sgen_world_stopped));
1041 gpointer sgen_gchandle_get_metadata (guint32 gchandle);
1042 GCObject *sgen_gchandle_get_target (guint32 gchandle);
1043 void sgen_gchandle_free (guint32 gchandle);
1044
1045 /* Other globals */
1046
1047 extern GCMemSection *sgen_nursery_section;
1048 extern guint32 sgen_collect_before_allocs;
1049 extern guint32 sgen_verify_before_allocs;
1050 extern gboolean sgen_has_per_allocation_action;
1051 extern size_t sgen_degraded_mode;
1052 extern int default_nursery_size;
1053 extern guint32 sgen_tlab_size;
1054 extern NurseryClearPolicy sgen_nursery_clear_policy;
1055 extern gboolean sgen_try_free_some_memory;
1056 extern mword sgen_total_promoted_size;
1057 extern mword sgen_total_allocated_major;
1058 extern volatile gboolean sgen_suspend_finalizers;
1059 extern MonoCoopMutex sgen_gc_mutex;
1060 extern volatile gboolean sgen_concurrent_collection_in_progress;
1061
1062 /* Nursery helpers. */
1063
1064 static inline void
1065 sgen_set_nursery_scan_start (char *p)
1066 {
1067         size_t idx = (p - (char*)sgen_nursery_section->data) / SGEN_SCAN_START_SIZE;
1068         char *old = sgen_nursery_section->scan_starts [idx];
1069         if (!old || old > p)
1070                 sgen_nursery_section->scan_starts [idx] = p;
1071 }
1072
1073
1074 /* Object Allocation */
1075
1076 typedef enum {
1077         ATYPE_NORMAL,
1078         ATYPE_VECTOR,
1079         ATYPE_SMALL,
1080         ATYPE_STRING,
1081         ATYPE_NUM
1082 } SgenAllocatorType;
1083
1084 void sgen_clear_tlabs (void);
1085 void sgen_update_allocation_count (void);
1086 guint64 sgen_get_total_allocated_bytes (MonoBoolean precise);
1087
1088 GCObject* sgen_alloc_obj (GCVTable vtable, size_t size)
1089         MONO_PERMIT (need (sgen_lock_gc, sgen_stop_world));
1090 GCObject* sgen_alloc_obj_pinned (GCVTable vtable, size_t size)
1091         MONO_PERMIT (need (sgen_lock_gc, sgen_stop_world));
1092 GCObject* sgen_alloc_obj_mature (GCVTable vtable, size_t size)
1093         MONO_PERMIT (need (sgen_lock_gc, sgen_stop_world));
1094
1095 /* Debug support */
1096
1097 void sgen_check_remset_consistency (void);
1098 void sgen_check_mod_union_consistency (void);
1099 void sgen_check_major_refs (void);
1100 void sgen_check_whole_heap (gboolean allow_missing_pinning);
1101 void sgen_check_whole_heap_stw (void)
1102         MONO_PERMIT (need (sgen_gc_locked, sgen_stop_world));
1103 void sgen_check_objref (char *obj);
1104 void sgen_check_heap_marked (gboolean nursery_must_be_pinned);
1105 void sgen_check_nursery_objects_untag (void);
1106 void sgen_check_for_xdomain_refs (void);
1107 GCObject* sgen_find_object_for_ptr (char *ptr);
1108
1109 void mono_gc_scan_for_specific_ref (GCObject *key, gboolean precise);
1110
1111 void sgen_debug_enable_heap_dump (const char *filename);
1112 void sgen_debug_dump_heap (const char *type, int num, const char *reason);
1113
1114 void sgen_debug_verify_nursery (gboolean do_dump_nursery_content);
1115 void sgen_debug_check_nursery_is_clean (void);
1116
1117 /* Environment variable parsing */
1118
1119 #define MONO_GC_PARAMS_NAME     "MONO_GC_PARAMS"
1120 #define MONO_GC_DEBUG_NAME      "MONO_GC_DEBUG"
1121
1122 void sgen_env_var_error (const char *env_var, const char *fallback, const char *description_format, ...);
1123
1124 /* Utilities */
1125
1126 void sgen_qsort (void *const array, const size_t count, const size_t element_size, int (*compare) (const void*, const void*));
1127 gint64 sgen_timestamp (void);
1128
1129 /*
1130  * Canary (guard word) support
1131  * Notes:
1132  * - CANARY_SIZE must be multiple of word size in bytes
1133  * - Canary space is not included on checks against SGEN_MAX_SMALL_OBJ_SIZE
1134  */
1135
1136 gboolean sgen_nursery_canaries_enabled (void);
1137
1138 #define CANARY_SIZE 8
1139 #define CANARY_STRING  "koupepia"
1140
1141 #define CANARIFY_SIZE(size) if (sgen_nursery_canaries_enabled ()) {     \
1142                         size = size + CANARY_SIZE;      \
1143                 }
1144
1145 #define CANARIFY_ALLOC(addr,size) if (sgen_nursery_canaries_enabled ()) {       \
1146                                 memcpy ((char*) (addr) + (size), CANARY_STRING, CANARY_SIZE);   \
1147                         }
1148
1149 #define CANARY_VALID(addr) (strncmp ((char*) (addr), CANARY_STRING, CANARY_SIZE) == 0)
1150
1151 void
1152 sgen_check_canary_for_object (gpointer addr);
1153
1154 guint64 sgen_get_precise_allocation_count (void);
1155
1156 #define CHECK_CANARY_FOR_OBJECT(addr, ignored) \
1157         (sgen_nursery_canaries_enabled () ? sgen_check_canary_for_object (addr) : (void)0)
1158
1159 /*
1160  * This causes the compile to extend the liveness of 'v' till the call to dummy_use
1161  */
1162 static inline void
1163 sgen_dummy_use (gpointer v)
1164 {
1165 #if defined(_MSC_VER) || defined(HOST_WASM)
1166         static volatile gpointer ptr;
1167         ptr = v;
1168 #elif defined(__GNUC__)
1169         __asm__ volatile ("" : "=r"(v) : "r"(v));
1170 #else
1171 #error "Implement sgen_dummy_use for your compiler"
1172 #endif
1173 }
1174
1175 #endif /* HAVE_SGEN_GC */
1176
1177 #endif /* __MONO_SGENGC_H__ */