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 typedef struct _SgenThreadInfo SgenThreadInfo;
  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/sgen/sgen-conf.h"
  35 #include "mono/sgen/sgen-hash-table.h"
  36 #include "mono/sgen/sgen-protocol.h"
  37 #include "mono/sgen/gc-internal-agnostic.h"
  38 #include "mono/sgen/sgen-thread-pool.h"
  39
  40 /* The method used to clear the nursery */
  41 /* Clearing at nursery collections is the safest, but has bad interactions with caches.
  42  * Clearing at TLAB creation is much faster, but more complex and it might expose hard
  43  * to find bugs.
  44  */
  45 typedef enum {
  46         CLEAR_AT_GC,
  47         CLEAR_AT_TLAB_CREATION,
  48         CLEAR_AT_TLAB_CREATION_DEBUG
  49 } NurseryClearPolicy;
  50
  51 NurseryClearPolicy sgen_get_nursery_clear_policy (void);
  52
  53 #if !defined(__MACH__) && !MONO_MACH_ARCH_SUPPORTED && defined(HAVE_PTHREAD_KILL)
  54 #define SGEN_POSIX_STW 1
  55 #endif
  56
  57 /*
  58  * The nursery section uses this struct.
  59  */
  60 typedef struct _GCMemSection GCMemSection;
  61 struct _GCMemSection {
  62         char *data;
  63         char *end_data;
  64         /*
  65          * scan starts is an array of pointers to objects equally spaced in the allocation area
  66          * They let use quickly find pinned objects from pinning pointers.
  67          */
  68         char **scan_starts;
  69         /* in major collections indexes in the pin_queue for objects that pin this section */
  70         size_t pin_queue_first_entry;
  71         size_t pin_queue_last_entry;
  72         size_t num_scan_start;
  73 };
  74
  75 /*
  76  * Recursion is not allowed for the thread lock.
  77  */
  78 #define LOCK_DECLARE(name) mono_mutex_t name
  79 /* if changing LOCK_INIT to something that isn't idempotent, look at
  80    its use in mono_gc_base_init in sgen-gc.c */
  81 #define LOCK_INIT(name) mono_os_mutex_init (&(name))
  82 #define LOCK_GC do { sgen_gc_lock (); } while (0)
  83 #define UNLOCK_GC do { sgen_gc_unlock (); } while (0)
  84
  85 extern MonoCoopMutex sgen_interruption_mutex;
  86
  87 #define LOCK_INTERRUPTION mono_coop_mutex_lock (&sgen_interruption_mutex)
  88 #define UNLOCK_INTERRUPTION mono_coop_mutex_unlock (&sgen_interruption_mutex)
  89
  90 /* FIXME: Use InterlockedAdd & InterlockedAdd64 to reduce the CAS cost. */
  91 #define SGEN_CAS        InterlockedCompareExchange
  92 #define SGEN_CAS_PTR    InterlockedCompareExchangePointer
  93 #define SGEN_ATOMIC_ADD(x,i)    do {                                    \
  94                 int __old_x;                                            \
  95                 do {                                                    \
  96                         __old_x = (x);                                  \
  97                 } while (InterlockedCompareExchange (&(x), __old_x + (i), __old_x) != __old_x); \
  98         } while (0)
  99 #define SGEN_ATOMIC_ADD_P(x,i) do { \
 100                 size_t __old_x;                                            \
 101                 do {                                                    \
 102                         __old_x = (x);                                  \
 103                 } while (InterlockedCompareExchangePointer ((void**)&(x), (void*)(__old_x + (i)), (void*)__old_x) != (void*)__old_x); \
 104         } while (0)
 105
 106 #ifdef HEAVY_STATISTICS
 107 extern guint64 stat_objects_alloced_degraded;
 108 extern guint64 stat_bytes_alloced_degraded;
 109 extern guint64 stat_copy_object_called_major;
 110 extern guint64 stat_objects_copied_major;
 111 #endif
 112
 113 #define SGEN_ASSERT(level, a, ...) do { \
 114         if (G_UNLIKELY ((level) <= SGEN_MAX_ASSERT_LEVEL && !(a))) {    \
 115                 g_error (__VA_ARGS__);  \
 116 } } while (0)
 117
 118 #ifdef HAVE_LOCALTIME_R
 119 # define LOG_TIMESTAMP  \
 120         do {    \
 121                 time_t t;                                                                       \
 122                 struct tm tod;                                                                  \
 123                 time(&t);                                                                       \
 124                 localtime_r(&t, &tod);                                                          \
 125                 strftime(logTime, sizeof(logTime), "%Y-%m-%d %H:%M:%S", &tod);                  \
 126         } while (0)
 127 #else
 128 # define LOG_TIMESTAMP  \
 129         do {    \
 130                 time_t t;                                                                       \
 131                 struct tm *tod;                                                                 \
 132                 time(&t);                                                                       \
 133                 tod = localtime(&t);                                                            \
 134                 strftime(logTime, sizeof(logTime), "%F %T", tod);                               \
 135         } while (0)
 136 #endif
 137
 138 #define SGEN_LOG(level, format, ...) do {      \
 139         if (G_UNLIKELY ((level) <= SGEN_MAX_DEBUG_LEVEL && (level) <= gc_debug_level)) {        \
 140                 char logTime[80];                                                               \
 141                 LOG_TIMESTAMP;                                                                  \
 142                 mono_gc_printf (gc_debug_file, "%s " format "\n", logTime, ##__VA_ARGS__);      \
 143 } } while (0)
 144
 145 #define SGEN_COND_LOG(level, cond, format, ...) do {    \
 146         if (G_UNLIKELY ((level) <= SGEN_MAX_DEBUG_LEVEL && (level) <= gc_debug_level)) {                \
 147                 if (cond) {                                                                             \
 148                         char logTime[80];                                                               \
 149                         LOG_TIMESTAMP;                                                                  \
 150                         mono_gc_printf (gc_debug_file, "%s " format "\n", logTime, ##__VA_ARGS__);      \
 151                 }                                                                                       \
 152 } } while (0)
 153
 154 extern int gc_debug_level;
 155 extern FILE* gc_debug_file;
 156
 157 extern int current_collection_generation;
 158
 159 extern unsigned int sgen_global_stop_count;
 160
 161 #define SGEN_ALIGN_UP_TO(val,align)     (((val) + (align - 1)) & ~(align - 1))
 162 #define SGEN_ALIGN_DOWN_TO(val,align)   ((val) & ~(align - 1))
 163
 164 #define SGEN_ALLOC_ALIGN                8
 165 #define SGEN_ALLOC_ALIGN_BITS   3
 166
 167 /* s must be non-negative */
 168 #define SGEN_CAN_ALIGN_UP(s)            ((s) <= SIZE_MAX - (SGEN_ALLOC_ALIGN - 1))
 169 #define SGEN_ALIGN_UP(s)                SGEN_ALIGN_UP_TO(s, SGEN_ALLOC_ALIGN)
 170 #define SGEN_ALIGN_DOWN(s)              SGEN_ALIGN_DOWN_TO(s, SGEN_ALLOC_ALIGN)
 171
 172 #if SIZEOF_VOID_P == 4
 173 #define ONE_P 1
 174 #else
 175 #define ONE_P 1ll
 176 #endif
 177
 178 static inline guint
 179 sgen_aligned_addr_hash (gconstpointer ptr)
 180 {
 181         return GPOINTER_TO_UINT (ptr) >> 3;
 182 }
 183
 184 #define SGEN_PTR_IN_NURSERY(p,bits,start,end)   (((mword)(p) & ~(((mword)1 << (bits)) - 1)) == (mword)(start))
 185
 186 extern size_t sgen_nursery_size;
 187 extern size_t sgen_nursery_max_size;
 188 extern int sgen_nursery_bits;
 189
 190 extern char *sgen_nursery_start;
 191 extern char *sgen_nursery_end;
 192
 193 static inline MONO_ALWAYS_INLINE gboolean
 194 sgen_ptr_in_nursery (void *p)
 195 {
 196         return SGEN_PTR_IN_NURSERY ((p), sgen_nursery_bits, sgen_nursery_start, sgen_nursery_end);
 197 }
 198
 199 static inline MONO_ALWAYS_INLINE char*
 200 sgen_get_nursery_start (void)
 201 {
 202         return sgen_nursery_start;
 203 }
 204
 205 static inline MONO_ALWAYS_INLINE char*
 206 sgen_get_nursery_end (void)
 207 {
 208         return sgen_nursery_end;
 209 }
 210
 211 /*
 212  * We use the lowest three bits in the vtable pointer of objects to tag whether they're
 213  * forwarded, pinned, and/or cemented.  These are the valid states:
 214  *
 215  * | State            | bits |
 216  * |------------------+------+
 217  * | default          |  000 |
 218  * | forwarded        |  001 |
 219  * | pinned           |  010 |
 220  * | pinned, cemented |  110 |
 221  *
 222  * We store them in the vtable slot because the bits are used in the sync block for other
 223  * purposes: if we merge them and alloc the sync blocks aligned to 8 bytes, we can change
 224  * this and use bit 3 in the syncblock (with the lower two bits both set for forwarded, that
 225  * would be an invalid combination for the monitor and hash code).
 226  */
 227
 228 #include "sgen-tagged-pointer.h"
 229
 230 #define SGEN_VTABLE_BITS_MASK   SGEN_TAGGED_POINTER_MASK
 231
 232 #define SGEN_POINTER_IS_TAGGED_FORWARDED(p)     SGEN_POINTER_IS_TAGGED_1((p))
 233 #define SGEN_POINTER_TAG_FORWARDED(p)           SGEN_POINTER_TAG_1((p))
 234
 235 #define SGEN_POINTER_IS_TAGGED_PINNED(p)        SGEN_POINTER_IS_TAGGED_2((p))
 236 #define SGEN_POINTER_TAG_PINNED(p)              SGEN_POINTER_TAG_2((p))
 237
 238 #define SGEN_POINTER_IS_TAGGED_CEMENTED(p)      SGEN_POINTER_IS_TAGGED_4((p))
 239 #define SGEN_POINTER_TAG_CEMENTED(p)            SGEN_POINTER_TAG_4((p))
 240
 241 #define SGEN_POINTER_UNTAG_VTABLE(p)            SGEN_POINTER_UNTAG_ALL((p))
 242
 243 /* returns NULL if not forwarded, or the forwarded address */
 244 #define SGEN_VTABLE_IS_FORWARDED(vtable) ((GCObject *)(SGEN_POINTER_IS_TAGGED_FORWARDED ((vtable)) ? SGEN_POINTER_UNTAG_VTABLE ((vtable)) : NULL))
 245 #define SGEN_OBJECT_IS_FORWARDED(obj) ((GCObject *)SGEN_VTABLE_IS_FORWARDED (((mword*)(obj))[0]))
 246
 247 #define SGEN_VTABLE_IS_PINNED(vtable) SGEN_POINTER_IS_TAGGED_PINNED ((vtable))
 248 #define SGEN_OBJECT_IS_PINNED(obj) (SGEN_VTABLE_IS_PINNED (((mword*)(obj))[0]))
 249
 250 #define SGEN_OBJECT_IS_CEMENTED(obj) (SGEN_POINTER_IS_TAGGED_CEMENTED (((mword*)(obj))[0]))
 251
 252 /* set the forwarded address fw_addr for object obj */
 253 #define SGEN_FORWARD_OBJECT(obj,fw_addr) do {                           \
 254                 *(void**)(obj) = SGEN_POINTER_TAG_FORWARDED ((fw_addr));        \
 255         } while (0)
 256 #define SGEN_FORWARD_OBJECT_PAR(obj,fw_addr,final_fw_addr) do {                 \
 257                 gpointer old_vtable_word = *(gpointer*)obj;                     \
 258                 gpointer new_vtable_word;                                       \
 259                 final_fw_addr = SGEN_VTABLE_IS_FORWARDED (old_vtable_word);     \
 260                 if (final_fw_addr)                                              \
 261                         break;                                                  \
 262                 new_vtable_word = SGEN_POINTER_TAG_FORWARDED ((fw_addr));       \
 263                 old_vtable_word = InterlockedCompareExchangePointer ((gpointer*)obj, new_vtable_word, old_vtable_word); \
 264                 final_fw_addr = SGEN_VTABLE_IS_FORWARDED (old_vtable_word);     \
 265                 if (!final_fw_addr)                                             \
 266                         final_fw_addr = (fw_addr);                              \
 267         } while (0)
 268 #define SGEN_PIN_OBJECT(obj) do {       \
 269                 *(void**)(obj) = SGEN_POINTER_TAG_PINNED (*(void**)(obj)); \
 270         } while (0)
 271 #define SGEN_CEMENT_OBJECT(obj) do {    \
 272                 *(void**)(obj) = SGEN_POINTER_TAG_CEMENTED (*(void**)(obj)); \
 273         } while (0)
 274 /* Unpins and uncements */
 275 #define SGEN_UNPIN_OBJECT(obj) do {     \
 276                 *(void**)(obj) = SGEN_POINTER_UNTAG_VTABLE (*(void**)(obj)); \
 277         } while (0)
 278
 279 /*
 280  * Since we set bits in the vtable, use the macro to load it from the pointer to
 281  * an object that is potentially pinned.
 282  */
 283 #define SGEN_LOAD_VTABLE(obj)           ((GCVTable)(SGEN_POINTER_UNTAG_ALL (SGEN_LOAD_VTABLE_UNCHECKED ((GCObject *)(obj)))))
 284
 285 /*
 286 List of what each bit on of the vtable gc bits means.
 287 */
 288 enum {
 289         // When the Java bridge has determined an object is "bridged", it uses these two bits to cache that information.
 290         SGEN_GC_BIT_BRIDGE_OBJECT = 1,
 291         SGEN_GC_BIT_BRIDGE_OPAQUE_OBJECT = 2,
 292         SGEN_GC_BIT_FINALIZER_AWARE = 4,
 293 };
 294
 295 void sgen_gc_init (void);
 296
 297 void sgen_os_init (void);
 298
 299 void sgen_update_heap_boundaries (mword low, mword high);
 300
 301 void sgen_check_section_scan_starts (GCMemSection *section);
 302
 303 void sgen_conservatively_pin_objects_from (void **start, void **end, void *start_nursery, void *end_nursery, int pin_type);
 304
 305 gboolean sgen_gc_initialized (void);
 306
 307 /* Keep in sync with description_for_type() in sgen-internal.c! */
 308 enum {
 309         INTERNAL_MEM_PIN_QUEUE,
 310         INTERNAL_MEM_FRAGMENT,
 311         INTERNAL_MEM_SECTION,
 312         INTERNAL_MEM_SCAN_STARTS,
 313         INTERNAL_MEM_FIN_TABLE,
 314         INTERNAL_MEM_FINALIZE_ENTRY,
 315         INTERNAL_MEM_FINALIZE_READY,
 316         INTERNAL_MEM_DISLINK_TABLE,
 317         INTERNAL_MEM_DISLINK,
 318         INTERNAL_MEM_ROOTS_TABLE,
 319         INTERNAL_MEM_ROOT_RECORD,
 320         INTERNAL_MEM_STATISTICS,
 321         INTERNAL_MEM_STAT_PINNED_CLASS,
 322         INTERNAL_MEM_STAT_REMSET_CLASS,
 323         INTERNAL_MEM_GRAY_QUEUE,
 324         INTERNAL_MEM_MS_TABLES,
 325         INTERNAL_MEM_MS_BLOCK_INFO,
 326         INTERNAL_MEM_MS_BLOCK_INFO_SORT,
 327         INTERNAL_MEM_WORKER_DATA,
 328         INTERNAL_MEM_THREAD_POOL_JOB,
 329         INTERNAL_MEM_BRIDGE_DATA,
 330         INTERNAL_MEM_OLD_BRIDGE_HASH_TABLE,
 331         INTERNAL_MEM_OLD_BRIDGE_HASH_TABLE_ENTRY,
 332         INTERNAL_MEM_BRIDGE_HASH_TABLE,
 333         INTERNAL_MEM_BRIDGE_HASH_TABLE_ENTRY,
 334         INTERNAL_MEM_BRIDGE_ALIVE_HASH_TABLE,
 335         INTERNAL_MEM_BRIDGE_ALIVE_HASH_TABLE_ENTRY,
 336         INTERNAL_MEM_TARJAN_BRIDGE_HASH_TABLE,
 337         INTERNAL_MEM_TARJAN_BRIDGE_HASH_TABLE_ENTRY,
 338         INTERNAL_MEM_TARJAN_OBJ_BUCKET,
 339         INTERNAL_MEM_BRIDGE_DEBUG,
 340         INTERNAL_MEM_TOGGLEREF_DATA,
 341         INTERNAL_MEM_CARDTABLE_MOD_UNION,
 342         INTERNAL_MEM_BINARY_PROTOCOL,
 343         INTERNAL_MEM_TEMPORARY,
 344         INTERNAL_MEM_LOG_ENTRY,
 345         INTERNAL_MEM_COMPLEX_DESCRIPTORS,
 346         INTERNAL_MEM_FIRST_CLIENT
 347 };
 348
 349 enum {
 350         GENERATION_NURSERY,
 351         GENERATION_OLD,
 352         GENERATION_MAX
 353 };
 354
 355 #ifdef SGEN_HEAVY_BINARY_PROTOCOL
 356 #define BINARY_PROTOCOL_ARG(x)  ,x
 357 #else
 358 #define BINARY_PROTOCOL_ARG(x)
 359 #endif
 360
 361 void sgen_init_internal_allocator (void);
 362
 363 #define SGEN_DEFINE_OBJECT_VTABLE
 364 #ifdef SGEN_CLIENT_HEADER
 365 #include SGEN_CLIENT_HEADER
 366 #else
 367 #include "metadata/sgen-client-mono.h"
 368 #endif
 369 #undef SGEN_DEFINE_OBJECT_VTABLE
 370
 371 #include "mono/sgen/sgen-descriptor.h"
 372 #include "mono/sgen/sgen-gray.h"
 373
 374 /* the runtime can register areas of memory as roots: we keep two lists of roots,
 375  * a pinned root set for conservatively scanned roots and a normal one for
 376  * precisely scanned roots (currently implemented as a single list).
 377  */
 378 typedef struct _RootRecord RootRecord;
 379 struct _RootRecord {
 380         char *end_root;
 381         SgenDescriptor root_desc;
 382         int source;
 383         const char *msg;
 384 };
 385
 386 enum {
 387         ROOT_TYPE_NORMAL = 0, /* "normal" roots */
 388         ROOT_TYPE_PINNED = 1, /* roots without a GC descriptor */
 389         ROOT_TYPE_WBARRIER = 2, /* roots with a write barrier */
 390         ROOT_TYPE_NUM
 391 };
 392
 393 extern SgenHashTable roots_hash [ROOT_TYPE_NUM];
 394
 395 int sgen_register_root (char *start, size_t size, SgenDescriptor descr, int root_type, int source, const char *msg);
 396 void sgen_deregister_root (char* addr);
 397
 398 typedef void (*IterateObjectCallbackFunc) (GCObject*, size_t, void*);
 399
 400 void sgen_scan_area_with_callback (char *start, char *end, IterateObjectCallbackFunc callback, void *data, gboolean allow_flags, gboolean fail_on_canaries);
 401
 402 /* eventually share with MonoThread? */
 403 /*
 404  * This structure extends the MonoThreadInfo structure.
 405  */
 406 struct _SgenThreadInfo {
 407         SgenClientThreadInfo client_info;
 408
 409         char *tlab_start;
 410         char *tlab_next;
 411         char *tlab_temp_end;
 412         char *tlab_real_end;
 413 };
 414
 415 gboolean sgen_is_worker_thread (MonoNativeThreadId thread);
 416
 417 typedef void (*CopyOrMarkObjectFunc) (GCObject**, SgenGrayQueue*);
 418 typedef void (*ScanObjectFunc) (GCObject *obj, SgenDescriptor desc, SgenGrayQueue*);
 419 typedef void (*ScanVTypeFunc) (GCObject *full_object, char *start, SgenDescriptor desc, SgenGrayQueue* BINARY_PROTOCOL_ARG (size_t size));
 420 typedef void (*ScanPtrFieldFunc) (GCObject *obj, GCObject **ptr, SgenGrayQueue* queue);
 421 typedef gboolean (*DrainGrayStackFunc) (SgenGrayQueue *queue);
 422
 423 typedef struct {
 424         CopyOrMarkObjectFunc copy_or_mark_object;
 425         ScanObjectFunc scan_object;
 426         ScanVTypeFunc scan_vtype;
 427         ScanPtrFieldFunc scan_ptr_field;
 428         /* Drain stack optimized for the above functions */
 429         DrainGrayStackFunc drain_gray_stack;
 430         /*FIXME add allocation function? */
 431 } SgenObjectOperations;
 432
 433 typedef struct
 434 {
 435         SgenObjectOperations *ops;
 436         SgenGrayQueue *queue;
 437 } ScanCopyContext;
 438
 439 #define CONTEXT_FROM_OBJECT_OPERATIONS(ops, queue) ((ScanCopyContext) { (ops), (queue) })
 440
 441 void sgen_report_internal_mem_usage (void);
 442 void sgen_dump_internal_mem_usage (FILE *heap_dump_file);
 443 void sgen_dump_section (GCMemSection *section, const char *type);
 444 void sgen_dump_occupied (char *start, char *end, char *section_start);
 445
 446 void sgen_register_fixed_internal_mem_type (int type, size_t size);
 447
 448 void* sgen_alloc_internal (int type);
 449 void sgen_free_internal (void *addr, int type);
 450
 451 void* sgen_alloc_internal_dynamic (size_t size, int type, gboolean assert_on_failure);
 452 void sgen_free_internal_dynamic (void *addr, size_t size, int type);
 453
 454 void sgen_pin_stats_enable (void);
 455 void sgen_pin_stats_register_object (GCObject *obj, int generation);
 456 void sgen_pin_stats_register_global_remset (GCObject *obj);
 457 void sgen_pin_stats_report (void);
 458
 459 void sgen_sort_addresses (void **array, size_t size);
 460 void sgen_add_to_global_remset (gpointer ptr, GCObject *obj);
 461
 462 int sgen_get_current_collection_generation (void);
 463 gboolean sgen_collection_is_concurrent (void);
 464 gboolean sgen_concurrent_collection_in_progress (void);
 465
 466 typedef struct _SgenFragment SgenFragment;
 467
 468 struct _SgenFragment {
 469         SgenFragment *next;
 470         char *fragment_start;
 471         char *fragment_next; /* the current soft limit for allocation */
 472         char *fragment_end;
 473         SgenFragment *next_in_order; /* We use a different entry for all active fragments so we can avoid SMR. */
 474 };
 475
 476 typedef struct {
 477         SgenFragment *alloc_head; /* List head to be used when allocating memory. Walk with fragment_next. */
 478         SgenFragment *region_head; /* List head of the region used by this allocator. Walk with next_in_order. */
 479 } SgenFragmentAllocator;
 480
 481 void sgen_fragment_allocator_add (SgenFragmentAllocator *allocator, char *start, char *end);
 482 void sgen_fragment_allocator_release (SgenFragmentAllocator *allocator);
 483 void* sgen_fragment_allocator_par_alloc (SgenFragmentAllocator *allocator, size_t size);
 484 void* sgen_fragment_allocator_serial_range_alloc (SgenFragmentAllocator *allocator, size_t desired_size, size_t minimum_size, size_t *out_alloc_size);
 485 void* sgen_fragment_allocator_par_range_alloc (SgenFragmentAllocator *allocator, size_t desired_size, size_t minimum_size, size_t *out_alloc_size);
 486 SgenFragment* sgen_fragment_allocator_alloc (void);
 487 void sgen_clear_allocator_fragments (SgenFragmentAllocator *allocator);
 488 void sgen_clear_range (char *start, char *end);
 489
 490
 491 /*
 492 This is a space/speed compromise as we need to make sure the from/to space check is both O(1)
 493 and only hit cache hot memory. On a 4Mb nursery it requires 1024 bytes, or 3% of your average
 494 L1 cache. On small configs with a 512kb nursery, this goes to 0.4%.
 495
 496 Experimental results on how much space we waste with a 4Mb nursery:
 497
 498 Note that the wastage applies to the half nursery, or 2Mb:
 499
 500 Test 1 (compiling corlib):
 501 9: avg: 3.1k
 502 8: avg: 1.6k
 503
 504 */
 505 #define SGEN_TO_SPACE_GRANULE_BITS 9
 506 #define SGEN_TO_SPACE_GRANULE_IN_BYTES (1 << SGEN_TO_SPACE_GRANULE_BITS)
 507
 508 extern char *sgen_space_bitmap;
 509 extern size_t sgen_space_bitmap_size;
 510
 511 static inline gboolean
 512 sgen_nursery_is_to_space (void *object)
 513 {
 514         size_t idx = ((char*)object - sgen_nursery_start) >> SGEN_TO_SPACE_GRANULE_BITS;
 515         size_t byte = idx >> 3;
 516         size_t bit = idx & 0x7;
 517
 518         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 ());
 519         SGEN_ASSERT (4, byte < sgen_space_bitmap_size, "byte index %zd out of range (%zd)", byte, sgen_space_bitmap_size);
 520
 521         return (sgen_space_bitmap [byte] & (1 << bit)) != 0;
 522 }
 523
 524 static inline gboolean
 525 sgen_nursery_is_from_space (void *object)
 526 {
 527         return !sgen_nursery_is_to_space (object);
 528 }
 529
 530 static inline gboolean
 531 sgen_nursery_is_object_alive (GCObject *obj)
 532 {
 533         /* FIXME put this asserts under a non default level */
 534         g_assert (sgen_ptr_in_nursery (obj));
 535
 536         if (sgen_nursery_is_to_space (obj))
 537                 return TRUE;
 538
 539         if (SGEN_OBJECT_IS_PINNED (obj) || SGEN_OBJECT_IS_FORWARDED (obj))
 540                 return TRUE;
 541
 542         return FALSE;
 543 }
 544
 545 typedef struct {
 546         gboolean is_split;
 547         gboolean is_parallel;
 548
 549         GCObject* (*alloc_for_promotion) (GCVTable vtable, GCObject *obj, size_t objsize, gboolean has_references);
 550         GCObject* (*alloc_for_promotion_par) (GCVTable vtable, GCObject *obj, size_t objsize, gboolean has_references);
 551
 552         SgenObjectOperations serial_ops;
 553         SgenObjectOperations serial_ops_with_concurrent_major;
 554         SgenObjectOperations parallel_ops;
 555
 556         void (*prepare_to_space) (char *to_space_bitmap, size_t space_bitmap_size);
 557         void (*clear_fragments) (void);
 558         SgenFragment* (*build_fragments_get_exclude_head) (void);
 559         void (*build_fragments_release_exclude_head) (void);
 560         void (*build_fragments_finish) (SgenFragmentAllocator *allocator);
 561         void (*init_nursery) (SgenFragmentAllocator *allocator, char *start, char *end);
 562
 563         gboolean (*handle_gc_param) (const char *opt); /* Optional */
 564         void (*print_gc_param_usage) (void); /* Optional */
 565 } SgenMinorCollector;
 566
 567 extern SgenMinorCollector sgen_minor_collector;
 568
 569 void sgen_simple_nursery_init (SgenMinorCollector *collector, gboolean parallel);
 570 void sgen_split_nursery_init (SgenMinorCollector *collector);
 571
 572 /* Updating references */
 573
 574 #ifdef SGEN_CHECK_UPDATE_REFERENCE
 575 gboolean sgen_thread_pool_is_thread_pool_thread (MonoNativeThreadId some_thread);
 576
 577 static inline void
 578 sgen_update_reference (GCObject **p, GCObject *o, gboolean allow_null)
 579 {
 580         if (!allow_null)
 581                 SGEN_ASSERT (0, o, "Cannot update a reference with a NULL pointer");
 582         SGEN_ASSERT (0, !sgen_workers_is_worker_thread (mono_native_thread_id_get ()), "Can't update a reference in the worker thread");
 583         *p = o;
 584 }
 585
 586 #define SGEN_UPDATE_REFERENCE_ALLOW_NULL(p,o)   sgen_update_reference ((GCObject**)(p), (GCObject*)(o), TRUE)
 587 #define SGEN_UPDATE_REFERENCE(p,o)              sgen_update_reference ((GCObject**)(p), (GCObject*)(o), FALSE)
 588 #else
 589 #define SGEN_UPDATE_REFERENCE_ALLOW_NULL(p,o)   (*(GCObject**)(p) = (GCObject*)(o))
 590 #define SGEN_UPDATE_REFERENCE(p,o)              SGEN_UPDATE_REFERENCE_ALLOW_NULL ((p), (o))
 591 #endif
 592
 593 /* Major collector */
 594
 595 typedef void (*sgen_cardtable_block_callback) (mword start, mword size);
 596 void sgen_major_collector_iterate_live_block_ranges (sgen_cardtable_block_callback callback);
 597 void sgen_major_collector_iterate_block_ranges (sgen_cardtable_block_callback callback);
 598
 599 typedef enum {
 600         ITERATE_OBJECTS_SWEEP = 1,
 601         ITERATE_OBJECTS_NON_PINNED = 2,
 602         ITERATE_OBJECTS_PINNED = 4,
 603         ITERATE_OBJECTS_SWEEP_NON_PINNED = ITERATE_OBJECTS_SWEEP | ITERATE_OBJECTS_NON_PINNED,
 604         ITERATE_OBJECTS_SWEEP_PINNED = ITERATE_OBJECTS_SWEEP | ITERATE_OBJECTS_PINNED,
 605         ITERATE_OBJECTS_SWEEP_ALL = ITERATE_OBJECTS_SWEEP | ITERATE_OBJECTS_NON_PINNED | ITERATE_OBJECTS_PINNED
 606 } IterateObjectsFlags;
 607
 608 typedef struct
 609 {
 610         size_t num_scanned_objects;
 611         size_t num_unique_scanned_objects;
 612 } ScannedObjectCounts;
 613
 614 typedef enum {
 615         CARDTABLE_SCAN_GLOBAL = 0,
 616         CARDTABLE_SCAN_MOD_UNION = 1,
 617         CARDTABLE_SCAN_MOD_UNION_PRECLEAN = CARDTABLE_SCAN_MOD_UNION | 2,
 618 } CardTableScanType;
 619
 620 typedef struct _SgenMajorCollector SgenMajorCollector;
 621 struct _SgenMajorCollector {
 622         size_t section_size;
 623         gboolean is_concurrent;
 624         gboolean is_parallel;
 625         gboolean supports_cardtable;
 626         gboolean sweeps_lazily;
 627
 628         void* (*alloc_heap) (mword nursery_size, mword nursery_align);
 629         gboolean (*is_object_live) (GCObject *obj);
 630         GCObject* (*alloc_small_pinned_obj) (GCVTable vtable, size_t size, gboolean has_references);
 631         GCObject* (*alloc_degraded) (GCVTable vtable, size_t size);
 632
 633         SgenObjectOperations major_ops_serial;
 634         SgenObjectOperations major_ops_concurrent_start;
 635         SgenObjectOperations major_ops_concurrent_finish;
 636         SgenObjectOperations major_ops_conc_par_start;
 637         SgenObjectOperations major_ops_conc_par_finish;
 638
 639         GCObject* (*alloc_object) (GCVTable vtable, size_t size, gboolean has_references);
 640         GCObject* (*alloc_object_par) (GCVTable vtable, size_t size, gboolean has_references);
 641         void (*free_pinned_object) (GCObject *obj, size_t size);
 642
 643         /*
 644          * This is used for domain unloading, heap walking from the logging profiler, and
 645          * debugging.  Can assume the world is stopped.
 646          */
 647         void (*iterate_objects) (IterateObjectsFlags flags, IterateObjectCallbackFunc callback, void *data);
 648
 649         void (*free_non_pinned_object) (GCObject *obj, size_t size);
 650         void (*pin_objects) (SgenGrayQueue *queue);
 651         void (*pin_major_object) (GCObject *obj, SgenGrayQueue *queue);
 652         void (*scan_card_table) (CardTableScanType scan_type, ScanCopyContext ctx, int job_index, int job_split_count);
 653         void (*iterate_live_block_ranges) (sgen_cardtable_block_callback callback);
 654         void (*iterate_block_ranges) (sgen_cardtable_block_callback callback);
 655         void (*update_cardtable_mod_union) (void);
 656         void (*init_to_space) (void);
 657         void (*sweep) (void);
 658         gboolean (*have_swept) (void);
 659         void (*finish_sweeping) (void);
 660         void (*free_swept_blocks) (size_t section_reserve);
 661         void (*check_scan_starts) (void);
 662         void (*dump_heap) (FILE *heap_dump_file);
 663         gint64 (*get_used_size) (void);
 664         void (*start_nursery_collection) (void);
 665         void (*finish_nursery_collection) (void);
 666         void (*start_major_collection) (void);
 667         void (*finish_major_collection) (ScannedObjectCounts *counts);
 668         gboolean (*ptr_is_in_non_pinned_space) (char *ptr, char **start);
 669         gboolean (*ptr_is_from_pinned_alloc) (char *ptr);
 670         void (*report_pinned_memory_usage) (void);
 671         size_t (*get_num_major_sections) (void);
 672         size_t (*get_bytes_survived_last_sweep) (void);
 673         gboolean (*handle_gc_param) (const char *opt);
 674         void (*print_gc_param_usage) (void);
 675         void (*post_param_init) (SgenMajorCollector *collector);
 676         gboolean (*is_valid_object) (char *ptr);
 677         GCVTable (*describe_pointer) (char *pointer);
 678         guint8* (*get_cardtable_mod_union_for_reference) (char *object);
 679         long long (*get_and_reset_num_major_objects_marked) (void);
 680         void (*count_cards) (long long *num_total_cards, long long *num_marked_cards);
 681         SgenThreadPool* (*get_sweep_pool) (void);
 682
 683         void (*worker_init_cb) (gpointer worker);
 684 };
 685
 686 extern SgenMajorCollector major_collector;
 687
 688 void sgen_marksweep_init (SgenMajorCollector *collector);
 689 void sgen_marksweep_conc_init (SgenMajorCollector *collector);
 690 void sgen_marksweep_conc_par_init (SgenMajorCollector *collector);
 691 SgenMajorCollector* sgen_get_major_collector (void);
 692 SgenMinorCollector* sgen_get_minor_collector (void);
 693
 694
 695 typedef struct _SgenRememberedSet {
 696         void (*wbarrier_set_field) (GCObject *obj, gpointer field_ptr, GCObject* value);
 697         void (*wbarrier_arrayref_copy) (gpointer dest_ptr, gpointer src_ptr, int count);
 698         void (*wbarrier_value_copy) (gpointer dest, gpointer src, int count, size_t element_size);
 699         void (*wbarrier_object_copy) (GCObject* obj, GCObject *src);
 700         void (*wbarrier_generic_nostore) (gpointer ptr);
 701         void (*record_pointer) (gpointer ptr);
 702         void (*wbarrier_range_copy) (gpointer dest, gpointer src, int count);
 703
 704         void (*start_scan_remsets) (void);
 705
 706         void (*clear_cards) (void);
 707
 708         gboolean (*find_address) (char *addr);
 709         gboolean (*find_address_with_cards) (char *cards_start, guint8 *cards, char *addr);
 710 } SgenRememberedSet;
 711
 712 SgenRememberedSet *sgen_get_remset (void);
 713
 714 /*
 715  * These must be kept in sync with object.h.  They're here for using SGen independently of
 716  * Mono.
 717  */
 718 void mono_gc_wbarrier_arrayref_copy (gpointer dest_ptr, gpointer src_ptr, int count);
 719 void mono_gc_wbarrier_generic_nostore (gpointer ptr);
 720 void mono_gc_wbarrier_generic_store (gpointer ptr, GCObject* value);
 721 void mono_gc_wbarrier_generic_store_atomic (gpointer ptr, GCObject *value);
 722
 723 void sgen_wbarrier_range_copy (gpointer _dest, gpointer _src, int size);
 724
 725 static inline SgenDescriptor
 726 sgen_obj_get_descriptor (GCObject *obj)
 727 {
 728         GCVTable vtable = SGEN_LOAD_VTABLE_UNCHECKED (obj);
 729         SGEN_ASSERT (9, !SGEN_POINTER_IS_TAGGED_ANY (vtable), "Object can't be tagged");
 730         return sgen_vtable_get_descriptor (vtable);
 731 }
 732
 733 static inline SgenDescriptor
 734 sgen_obj_get_descriptor_safe (GCObject *obj)
 735 {
 736         GCVTable vtable = SGEN_LOAD_VTABLE (obj);
 737         return sgen_vtable_get_descriptor (vtable);
 738 }
 739
 740 static mword sgen_client_par_object_get_size (GCVTable vtable, GCObject* o);
 741 static mword sgen_client_slow_object_get_size (GCVTable vtable, GCObject* o);
 742
 743 static inline mword
 744 sgen_safe_object_get_size (GCObject *obj)
 745 {
 746         GCObject *forwarded;
 747         GCVTable vtable = SGEN_LOAD_VTABLE_UNCHECKED (obj);
 748
 749         /*
 750          * Once we load the vtable, we must always use it, in case we are in parallel case.
 751          * Otherwise the object might get forwarded in the meantime and we would read an
 752          * invalid vtable. An object cannot be forwarded for a second time during same GC.
 753          */
 754         if ((forwarded = SGEN_VTABLE_IS_FORWARDED (vtable)))
 755                 return sgen_client_par_object_get_size (SGEN_LOAD_VTABLE (forwarded), obj);
 756         else
 757                 return sgen_client_par_object_get_size ((GCVTable)SGEN_POINTER_UNTAG_ALL (vtable), obj);
 758 }
 759
 760 static inline gboolean
 761 sgen_safe_object_is_small (GCObject *obj, int type)
 762 {
 763         if (type <= DESC_TYPE_MAX_SMALL_OBJ)
 764                 return TRUE;
 765         return SGEN_ALIGN_UP (sgen_safe_object_get_size ((GCObject*)obj)) <= SGEN_MAX_SMALL_OBJ_SIZE;
 766 }
 767
 768 /*
 769  * This variant guarantees to return the exact size of the object
 770  * before alignment. Needed for canary support.
 771  */
 772 static inline guint
 773 sgen_safe_object_get_size_unaligned (GCObject *obj)
 774 {
 775         GCObject *forwarded;
 776
 777         if ((forwarded = SGEN_OBJECT_IS_FORWARDED (obj))) {
 778                 obj = (GCObject*)forwarded;
 779         }
 780
 781         return sgen_client_slow_object_get_size (SGEN_LOAD_VTABLE (obj), obj);
 782 }
 783
 784 #ifdef SGEN_CLIENT_HEADER
 785 #include SGEN_CLIENT_HEADER
 786 #else
 787 #include "metadata/sgen-client-mono.h"
 788 #endif
 789
 790 gboolean sgen_object_is_live (GCObject *obj);
 791
 792 void  sgen_init_fin_weak_hash (void);
 793
 794 /* FIXME: move the toggleref stuff out of here */
 795 void sgen_mark_togglerefs (char *start, char *end, ScanCopyContext ctx);
 796 void sgen_clear_togglerefs (char *start, char *end, ScanCopyContext ctx);
 797
 798 void sgen_process_togglerefs (void);
 799 void sgen_register_test_toggleref_callback (void);
 800
 801 void sgen_mark_bridge_object (GCObject *obj);
 802 void sgen_collect_bridge_objects (int generation, ScanCopyContext ctx);
 803
 804 typedef gboolean (*SgenObjectPredicateFunc) (GCObject *obj, void *user_data);
 805
 806 void sgen_null_links_if (SgenObjectPredicateFunc predicate, void *data, int generation, gboolean track);
 807
 808 gboolean sgen_gc_is_object_ready_for_finalization (GCObject *object);
 809 void sgen_gc_lock (void);
 810 void sgen_gc_unlock (void);
 811
 812 void sgen_queue_finalization_entry (GCObject *obj);
 813 const char* sgen_generation_name (int generation);
 814
 815 void sgen_finalize_in_range (int generation, ScanCopyContext ctx);
 816 void sgen_null_link_in_range (int generation, ScanCopyContext ctx, gboolean track);
 817 void sgen_process_fin_stage_entries (void);
 818 gboolean sgen_have_pending_finalizers (void);
 819 void sgen_object_register_for_finalization (GCObject *obj, void *user_data);
 820
 821 void sgen_finalize_if (SgenObjectPredicateFunc predicate, void *user_data);
 822 void sgen_remove_finalizers_if (SgenObjectPredicateFunc predicate, void *user_data, int generation);
 823 void sgen_set_suspend_finalizers (void);
 824
 825 void sgen_wbroots_iterate_live_block_ranges (sgen_cardtable_block_callback cb);
 826 void sgen_wbroots_scan_card_table (ScanCopyContext ctx);
 827
 828 void sgen_register_disappearing_link (GCObject *obj, void **link, gboolean track, gboolean in_gc);
 829
 830 GCObject* sgen_weak_link_get (void **link_addr);
 831
 832 gboolean sgen_drain_gray_stack (ScanCopyContext ctx);
 833
 834 enum {
 835         SPACE_NURSERY,
 836         SPACE_MAJOR,
 837         SPACE_LOS
 838 };
 839
 840 void sgen_pin_object (GCObject *object, SgenGrayQueue *queue);
 841 void sgen_set_pinned_from_failed_allocation (mword objsize);
 842
 843 void sgen_ensure_free_space (size_t size, int generation);
 844 void sgen_gc_collect (int generation);
 845 void sgen_perform_collection (size_t requested_size, int generation_to_collect, const char *reason, gboolean wait_to_finish, gboolean stw);
 846
 847 int sgen_gc_collection_count (int generation);
 848 /* FIXME: what exactly does this return? */
 849 size_t sgen_gc_get_used_size (void);
 850 size_t sgen_gc_get_total_heap_allocation (void);
 851
 852 /* STW */
 853
 854 void sgen_stop_world (int generation);
 855 void sgen_restart_world (int generation);
 856 gboolean sgen_is_world_stopped (void);
 857
 858 gboolean sgen_set_allow_synchronous_major (gboolean flag);
 859
 860 /* LOS */
 861
 862 typedef struct _LOSObject LOSObject;
 863 struct _LOSObject {
 864         LOSObject *next;
 865         mword size; /* this is the object size, lowest bit used for pin/mark */
 866         guint8 * volatile cardtable_mod_union; /* only used by the concurrent collector */
 867 #if SIZEOF_VOID_P < 8
 868         mword dummy;            /* to align object to sizeof (double) */
 869 #endif
 870         GCObject data [MONO_ZERO_LEN_ARRAY];
 871 };
 872
 873 extern LOSObject *los_object_list;
 874 extern mword los_memory_usage;
 875 extern mword los_memory_usage_total;
 876
 877 void sgen_los_free_object (LOSObject *obj);
 878 void* sgen_los_alloc_large_inner (GCVTable vtable, size_t size);
 879 void sgen_los_sweep (void);
 880 gboolean sgen_ptr_is_in_los (char *ptr, char **start);
 881 void sgen_los_iterate_objects (IterateObjectCallbackFunc cb, void *user_data);
 882 void sgen_los_iterate_live_block_ranges (sgen_cardtable_block_callback callback);
 883 void sgen_los_scan_card_table (CardTableScanType scan_type, ScanCopyContext ctx, int job_index, int job_split_count);
 884 void sgen_los_update_cardtable_mod_union (void);
 885 void sgen_los_count_cards (long long *num_total_cards, long long *num_marked_cards);
 886 gboolean sgen_los_is_valid_object (char *object);
 887 gboolean mono_sgen_los_describe_pointer (char *ptr);
 888 LOSObject* sgen_los_header_for_object (GCObject *data);
 889 mword sgen_los_object_size (LOSObject *obj);
 890 void sgen_los_pin_object (GCObject *obj);
 891 gboolean sgen_los_pin_object_par (GCObject *obj);
 892 gboolean sgen_los_object_is_pinned (GCObject *obj);
 893 void sgen_los_mark_mod_union_card (GCObject *mono_obj, void **ptr);
 894
 895
 896 /* nursery allocator */
 897
 898 void sgen_clear_nursery_fragments (void);
 899 void sgen_nursery_allocator_prepare_for_pinning (void);
 900 void sgen_nursery_allocator_set_nursery_bounds (char *nursery_start, size_t min_size, size_t max_size);
 901 void sgen_resize_nursery (gboolean need_shrink);
 902 mword sgen_build_nursery_fragments (GCMemSection *nursery_section, SgenGrayQueue *unpin_queue);
 903 void sgen_init_nursery_allocator (void);
 904 void sgen_nursery_allocator_init_heavy_stats (void);
 905 void sgen_init_allocator (void);
 906 void* sgen_nursery_alloc (size_t size);
 907 void* sgen_nursery_alloc_range (size_t size, size_t min_size, size_t *out_alloc_size);
 908 gboolean sgen_can_alloc_size (size_t size);
 909 void sgen_nursery_retire_region (void *address, ptrdiff_t size);
 910
 911 void sgen_nursery_alloc_prepare_for_minor (void);
 912 void sgen_nursery_alloc_prepare_for_major (void);
 913
 914 GCObject* sgen_alloc_for_promotion (GCObject *obj, size_t objsize, gboolean has_references);
 915
 916 GCObject* sgen_alloc_obj_nolock (GCVTable vtable, size_t size);
 917 GCObject* sgen_try_alloc_obj_nolock (GCVTable vtable, size_t size);
 918
 919 /* Threads */
 920
 921 void* sgen_thread_register (SgenThreadInfo* info, void *addr);
 922 void sgen_thread_unregister (SgenThreadInfo *p);
 923
 924 /* Finalization/ephemeron support */
 925
 926 static inline gboolean
 927 sgen_major_is_object_alive (GCObject *object)
 928 {
 929         mword objsize;
 930
 931         /* Oldgen objects can be pinned and forwarded too */
 932         if (SGEN_OBJECT_IS_PINNED (object) || SGEN_OBJECT_IS_FORWARDED (object))
 933                 return TRUE;
 934
 935         /*
 936          * FIXME: major_collector.is_object_live() also calculates the
 937          * size.  Avoid the double calculation.
 938          */
 939         objsize = SGEN_ALIGN_UP (sgen_safe_object_get_size (object));
 940         if (objsize > SGEN_MAX_SMALL_OBJ_SIZE)
 941                 return sgen_los_object_is_pinned (object);
 942
 943         return major_collector.is_object_live (object);
 944 }
 945
 946 /*
 947  * This function returns true if @object is either alive or it belongs to the old gen
 948  * and we're currently doing a minor collection.
 949  */
 950 static inline int
 951 sgen_is_object_alive_for_current_gen (GCObject *object)
 952 {
 953         if (sgen_ptr_in_nursery (object))
 954                 return sgen_nursery_is_object_alive (object);
 955
 956         if (current_collection_generation == GENERATION_NURSERY)
 957                 return TRUE;
 958
 959         return sgen_major_is_object_alive (object);
 960 }
 961
 962 int sgen_gc_invoke_finalizers (void);
 963
 964 /* GC handles */
 965
 966 void sgen_init_gchandles (void);
 967
 968 void sgen_null_links_if (SgenObjectPredicateFunc predicate, void *data, int generation, gboolean track);
 969
 970 typedef gpointer (*SgenGCHandleIterateCallback) (gpointer hidden, GCHandleType handle_type, int max_generation, gpointer user);
 971
 972 void sgen_gchandle_iterate (GCHandleType handle_type, int max_generation, SgenGCHandleIterateCallback callback, gpointer user);
 973 void sgen_gchandle_set_target (guint32 gchandle, GCObject *obj);
 974 void sgen_mark_normal_gc_handles (void *addr, SgenUserMarkFunc mark_func, void *gc_data);
 975 gpointer sgen_gchandle_get_metadata (guint32 gchandle);
 976
 977 /* Other globals */
 978
 979 extern GCMemSection *nursery_section;
 980 extern guint32 collect_before_allocs;
 981 extern guint32 verify_before_allocs;
 982 extern gboolean has_per_allocation_action;
 983 extern size_t degraded_mode;
 984 extern int default_nursery_size;
 985 extern guint32 tlab_size;
 986 extern NurseryClearPolicy nursery_clear_policy;
 987 extern gboolean sgen_try_free_some_memory;
 988 extern mword total_promoted_size;
 989 extern mword total_allocated_major;
 990 extern volatile gboolean sgen_suspend_finalizers;
 991 extern MonoCoopMutex gc_mutex;
 992 extern volatile gboolean concurrent_collection_in_progress;
 993
 994 /* Nursery helpers. */
 995
 996 static inline void
 997 sgen_set_nursery_scan_start (char *p)
 998 {
 999         size_t idx = (p - (char*)nursery_section->data) / SGEN_SCAN_START_SIZE;
1000         char *old = nursery_section->scan_starts [idx];
1001         if (!old || old > p)
1002                 nursery_section->scan_starts [idx] = p;
1003 }
1004
1005
1006 /* Object Allocation */
1007
1008 typedef enum {
1009         ATYPE_NORMAL,
1010         ATYPE_VECTOR,
1011         ATYPE_SMALL,
1012         ATYPE_STRING,
1013         ATYPE_NUM
1014 } SgenAllocatorType;
1015
1016 void sgen_clear_tlabs (void);
1017
1018 GCObject* sgen_alloc_obj (GCVTable vtable, size_t size);
1019 GCObject* sgen_alloc_obj_pinned (GCVTable vtable, size_t size);
1020 GCObject* sgen_alloc_obj_mature (GCVTable vtable, size_t size);
1021
1022 /* Debug support */
1023
1024 void sgen_check_remset_consistency (void);
1025 void sgen_check_mod_union_consistency (void);
1026 void sgen_check_major_refs (void);
1027 void sgen_check_whole_heap (gboolean allow_missing_pinning);
1028 void sgen_check_whole_heap_stw (void);
1029 void sgen_check_objref (char *obj);
1030 void sgen_check_heap_marked (gboolean nursery_must_be_pinned);
1031 void sgen_check_nursery_objects_pinned (gboolean pinned);
1032 void sgen_check_for_xdomain_refs (void);
1033 GCObject* sgen_find_object_for_ptr (char *ptr);
1034
1035 void mono_gc_scan_for_specific_ref (GCObject *key, gboolean precise);
1036
1037 void sgen_debug_enable_heap_dump (const char *filename);
1038 void sgen_debug_dump_heap (const char *type, int num, const char *reason);
1039
1040 void sgen_debug_verify_nursery (gboolean do_dump_nursery_content);
1041 void sgen_debug_check_nursery_is_clean (void);
1042
1043 /* Environment variable parsing */
1044
1045 #define MONO_GC_PARAMS_NAME     "MONO_GC_PARAMS"
1046 #define MONO_GC_DEBUG_NAME      "MONO_GC_DEBUG"
1047
1048 void sgen_env_var_error (const char *env_var, const char *fallback, const char *description_format, ...);
1049
1050 /* Utilities */
1051
1052 void sgen_qsort (void *array, size_t count, size_t element_size, int (*compare) (const void*, const void*));
1053 gint64 sgen_timestamp (void);
1054
1055 /*
1056  * Canary (guard word) support
1057  * Notes:
1058  * - CANARY_SIZE must be multiple of word size in bytes
1059  * - Canary space is not included on checks against SGEN_MAX_SMALL_OBJ_SIZE
1060  */
1061
1062 gboolean nursery_canaries_enabled (void);
1063
1064 #define CANARY_SIZE 8
1065 #define CANARY_STRING  "koupepia"
1066
1067 #define CANARIFY_SIZE(size) if (nursery_canaries_enabled ()) {  \
1068                         size = size + CANARY_SIZE;      \
1069                 }
1070
1071 #define CANARIFY_ALLOC(addr,size) if (nursery_canaries_enabled ()) {    \
1072                                 memcpy ((char*) (addr) + (size), CANARY_STRING, CANARY_SIZE);   \
1073                         }
1074
1075 #define CANARY_VALID(addr) (strncmp ((char*) (addr), CANARY_STRING, CANARY_SIZE) == 0)
1076
1077 #define CHECK_CANARY_FOR_OBJECT(addr,fail) if (nursery_canaries_enabled ()) {   \
1078                                 guint size = sgen_safe_object_get_size_unaligned ((GCObject *) (addr)); \
1079                                 char* canary_ptr = (char*) (addr) + size;       \
1080                                 if (!CANARY_VALID(canary_ptr)) {        \
1081                                         char *window_start, *window_end; \
1082                                         window_start = (char*)(addr) - 128; \
1083                                         if (!sgen_ptr_in_nursery (window_start)) \
1084                                                 window_start = sgen_get_nursery_start (); \
1085                                         window_end = (char*)(addr) + 128; \
1086                                         if (!sgen_ptr_in_nursery (window_end)) \
1087                                                 window_end = sgen_get_nursery_end (); \
1088                                         fprintf (stderr, "\nCANARY ERROR - Type:%s Size:%d Address:%p Data:\n", sgen_client_vtable_get_name (SGEN_LOAD_VTABLE ((addr))), size,  (char*) addr); \
1089                                         fwrite (addr, sizeof (char), size, stderr); \
1090                                         fprintf (stderr, "\nCanary zone (next 12 chars):\n"); \
1091                                         fwrite (canary_ptr, sizeof (char), 12, stderr); \
1092                                         fprintf (stderr, "\nOriginal canary string:\n"); \
1093                                         fwrite (CANARY_STRING, sizeof (char), 8, stderr); \
1094                                         for (int x = -8; x <= 8; x++) { \
1095                                                 if (canary_ptr + x < (char*) addr); \
1096                                                         continue; \
1097                                                 if (CANARY_VALID(canary_ptr +x)) \
1098                                                         fprintf (stderr, "\nCANARY ERROR - canary found at offset %d\n", x); \
1099                                         } \
1100                                         fprintf (stderr, "\nSurrounding nursery (%p - %p):\n", window_start, window_end); \
1101                                         fwrite (window_start, sizeof (char), window_end - window_start, stderr); \
1102                                 } }
1103
1104 /*
1105  * This causes the compile to extend the liveness of 'v' till the call to dummy_use
1106  */
1107 static inline void
1108 sgen_dummy_use (gpointer v)
1109 {
1110 #if defined(__GNUC__)
1111         __asm__ volatile ("" : "=r"(v) : "r"(v));
1112 #elif defined(_MSC_VER)
1113         static volatile gpointer ptr;
1114         ptr = v;
1115 #else
1116 #error "Implement sgen_dummy_use for your compiler"
1117 #endif
1118 }
1119
1120 #endif /* HAVE_SGEN_GC */
1121
1122 #endif /* __MONO_SGENGC_H__ */