mono/sgen/sgen-gc.h

   1 /*
   2  * sgen-gc.c: Simple generational GC.
   3  *
   4  * Copyright 2001-2003 Ximian, Inc
   5  * Copyright 2003-2010 Novell, Inc.
   6  * Copyright 2011 Xamarin Inc (http://www.xamarin.com)
   7  * Copyright (C) 2012 Xamarin Inc
   8  *
   9  * Licensed under the MIT license. See LICENSE file in the project root for full license information.
  10  */
  11 #ifndef __MONO_SGENGC_H__
  12 #define __MONO_SGENGC_H__
  13
  14 /* pthread impl */
  15 #include "config.h"
  16
  17 #ifdef HAVE_SGEN_GC
  18
  19 typedef struct _SgenThreadInfo SgenThreadInfo;
  20 #undef THREAD_INFO_TYPE
  21 #define THREAD_INFO_TYPE SgenThreadInfo
  22
  23 #include <glib.h>
  24 #include <stdio.h>
  25 #ifdef HAVE_PTHREAD_H
  26 #include <pthread.h>
  27 #endif
  28 #include <stdint.h>
  29 #include "mono/utils/mono-compiler.h"
  30 #include "mono/utils/atomic.h"
  31 #include "mono/utils/mono-os-mutex.h"
  32 #include "mono/utils/mono-coop-mutex.h"
  33 #include "mono/sgen/sgen-conf.h"
  34 #include "mono/sgen/sgen-hash-table.h"
  35 #include "mono/sgen/sgen-protocol.h"
  36 #include "mono/sgen/gc-internal-agnostic.h"
  37
  38 /* The method used to clear the nursery */
  39 /* Clearing at nursery collections is the safest, but has bad interactions with caches.
  40  * Clearing at TLAB creation is much faster, but more complex and it might expose hard
  41  * to find bugs.
  42  */
  43 typedef enum {
  44         CLEAR_AT_GC,
  45         CLEAR_AT_TLAB_CREATION,
  46         CLEAR_AT_TLAB_CREATION_DEBUG
  47 } NurseryClearPolicy;
  48
  49 NurseryClearPolicy sgen_get_nursery_clear_policy (void);
  50
  51 #if !defined(__MACH__) && !MONO_MACH_ARCH_SUPPORTED && defined(HAVE_PTHREAD_KILL)
  52 #define SGEN_POSIX_STW 1
  53 #endif
  54
  55 /*
  56  * The nursery section uses this struct.
  57  */
  58 typedef struct _GCMemSection GCMemSection;
  59 struct _GCMemSection {
  60         char *data;
  61         mword size;
  62         /* pointer where more data could be allocated if it fits */
  63         char *next_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 InterlockedAdd & InterlockedAdd64 to reduce the CAS cost. */
  92 #define SGEN_CAS        InterlockedCompareExchange
  93 #define SGEN_CAS_PTR    InterlockedCompareExchangePointer
  94 #define SGEN_ATOMIC_ADD(x,i)    do {                                    \
  95                 int __old_x;                                            \
  96                 do {                                                    \
  97                         __old_x = (x);                                  \
  98                 } while (InterlockedCompareExchange (&(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 (InterlockedCompareExchangePointer ((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 #ifndef HOST_WIN32
 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), "%Y-%m-%d %H:%M:%S", &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), "%F %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) <= gc_debug_level)) {        \
 141                 char logTime[80];                                                               \
 142                 LOG_TIMESTAMP;                                                                  \
 143                 mono_gc_printf (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) <= gc_debug_level)) {                \
 148                 if (cond) {                                                                             \
 149                         char logTime[80];                                                               \
 150                         LOG_TIMESTAMP;                                                                  \
 151                         mono_gc_printf (gc_debug_file, "%s " format "\n", logTime, ##__VA_ARGS__);      \
 152                 }                                                                                       \
 153 } } while (0)
 154
 155 extern int gc_debug_level;
 156 extern FILE* gc_debug_file;
 157
 158 extern int 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 #ifdef USER_CONFIG
 188
 189 /* good sizes are 512KB-1MB: larger ones increase a lot memzeroing time */
 190 #define DEFAULT_NURSERY_SIZE (sgen_nursery_size)
 191 extern size_t sgen_nursery_size;
 192 /* The number of trailing 0 bits in DEFAULT_NURSERY_SIZE */
 193 #define DEFAULT_NURSERY_BITS (sgen_nursery_bits)
 194 extern int sgen_nursery_bits;
 195
 196 #else
 197
 198 #define DEFAULT_NURSERY_SIZE (4*1024*1024)
 199 #define DEFAULT_NURSERY_BITS 22
 200
 201 #endif
 202
 203 extern char *sgen_nursery_start;
 204 extern char *sgen_nursery_end;
 205
 206 static inline MONO_ALWAYS_INLINE gboolean
 207 sgen_ptr_in_nursery (void *p)
 208 {
 209         return SGEN_PTR_IN_NURSERY ((p), DEFAULT_NURSERY_BITS, sgen_nursery_start, sgen_nursery_end);
 210 }
 211
 212 static inline MONO_ALWAYS_INLINE char*
 213 sgen_get_nursery_start (void)
 214 {
 215         return sgen_nursery_start;
 216 }
 217
 218 static inline MONO_ALWAYS_INLINE char*
 219 sgen_get_nursery_end (void)
 220 {
 221         return sgen_nursery_end;
 222 }
 223
 224 /*
 225  * We use the lowest three bits in the vtable pointer of objects to tag whether they're
 226  * forwarded, pinned, and/or cemented.  These are the valid states:
 227  *
 228  * | State            | bits |
 229  * |------------------+------+
 230  * | default          |  000 |
 231  * | forwarded        |  001 |
 232  * | pinned           |  010 |
 233  * | pinned, cemented |  110 |
 234  *
 235  * We store them in the vtable slot because the bits are used in the sync block for other
 236  * purposes: if we merge them and alloc the sync blocks aligned to 8 bytes, we can change
 237  * this and use bit 3 in the syncblock (with the lower two bits both set for forwarded, that
 238  * would be an invalid combination for the monitor and hash code).
 239  */
 240
 241 #include "sgen-tagged-pointer.h"
 242
 243 #define SGEN_VTABLE_BITS_MASK   SGEN_TAGGED_POINTER_MASK
 244
 245 #define SGEN_POINTER_IS_TAGGED_FORWARDED(p)     SGEN_POINTER_IS_TAGGED_1((p))
 246 #define SGEN_POINTER_TAG_FORWARDED(p)           SGEN_POINTER_TAG_1((p))
 247
 248 #define SGEN_POINTER_IS_TAGGED_PINNED(p)        SGEN_POINTER_IS_TAGGED_2((p))
 249 #define SGEN_POINTER_TAG_PINNED(p)              SGEN_POINTER_TAG_2((p))
 250
 251 #define SGEN_POINTER_IS_TAGGED_CEMENTED(p)      SGEN_POINTER_IS_TAGGED_4((p))
 252 #define SGEN_POINTER_TAG_CEMENTED(p)            SGEN_POINTER_TAG_4((p))
 253
 254 #define SGEN_POINTER_UNTAG_VTABLE(p)            SGEN_POINTER_UNTAG_ALL((p))
 255
 256 /* returns NULL if not forwarded, or the forwarded address */
 257 #define SGEN_VTABLE_IS_FORWARDED(vtable) ((GCObject *)(SGEN_POINTER_IS_TAGGED_FORWARDED ((vtable)) ? SGEN_POINTER_UNTAG_VTABLE ((vtable)) : NULL))
 258 #define SGEN_OBJECT_IS_FORWARDED(obj) ((GCObject *)SGEN_VTABLE_IS_FORWARDED (((mword*)(obj))[0]))
 259
 260 #define SGEN_VTABLE_IS_PINNED(vtable) SGEN_POINTER_IS_TAGGED_PINNED ((vtable))
 261 #define SGEN_OBJECT_IS_PINNED(obj) (SGEN_VTABLE_IS_PINNED (((mword*)(obj))[0]))
 262
 263 #define SGEN_OBJECT_IS_CEMENTED(obj) (SGEN_POINTER_IS_TAGGED_CEMENTED (((mword*)(obj))[0]))
 264
 265 /* set the forwarded address fw_addr for object obj */
 266 #define SGEN_FORWARD_OBJECT(obj,fw_addr) do {                           \
 267                 *(void**)(obj) = SGEN_POINTER_TAG_FORWARDED ((fw_addr));        \
 268         } while (0)
 269 #define SGEN_FORWARD_OBJECT_PAR(obj,fw_addr,final_fw_addr) do {                 \
 270                 gpointer old_vtable_word = *(gpointer*)obj;                     \
 271                 gpointer new_vtable_word;                                       \
 272                 final_fw_addr = SGEN_VTABLE_IS_FORWARDED (old_vtable_word);     \
 273                 if (final_fw_addr)                                              \
 274                         break;                                                  \
 275                 new_vtable_word = SGEN_POINTER_TAG_FORWARDED ((fw_addr));       \
 276                 old_vtable_word = InterlockedCompareExchangePointer ((gpointer*)obj, new_vtable_word, old_vtable_word); \
 277                 final_fw_addr = SGEN_VTABLE_IS_FORWARDED (old_vtable_word);     \
 278                 if (!final_fw_addr)                                             \
 279                         final_fw_addr = (fw_addr);                              \
 280         } while (0)
 281 #define SGEN_PIN_OBJECT(obj) do {       \
 282                 *(void**)(obj) = SGEN_POINTER_TAG_PINNED (*(void**)(obj)); \
 283         } while (0)
 284 #define SGEN_CEMENT_OBJECT(obj) do {    \
 285                 *(void**)(obj) = SGEN_POINTER_TAG_CEMENTED (*(void**)(obj)); \
 286         } while (0)
 287 /* Unpins and uncements */
 288 #define SGEN_UNPIN_OBJECT(obj) do {     \
 289                 *(void**)(obj) = SGEN_POINTER_UNTAG_VTABLE (*(void**)(obj)); \
 290         } while (0)
 291
 292 /*
 293  * Since we set bits in the vtable, use the macro to load it from the pointer to
 294  * an object that is potentially pinned.
 295  */
 296 #define SGEN_LOAD_VTABLE(obj)           ((GCVTable)(SGEN_POINTER_UNTAG_ALL (SGEN_LOAD_VTABLE_UNCHECKED ((GCObject *)(obj)))))
 297
 298 /*
 299 List of what each bit on of the vtable gc bits means.
 300 */
 301 enum {
 302         // When the Java bridge has determined an object is "bridged", it uses these two bits to cache that information.
 303         SGEN_GC_BIT_BRIDGE_OBJECT = 1,
 304         SGEN_GC_BIT_BRIDGE_OPAQUE_OBJECT = 2,
 305         SGEN_GC_BIT_FINALIZER_AWARE = 4,
 306 };
 307
 308 void sgen_gc_init (void);
 309
 310 void sgen_os_init (void);
 311
 312 void sgen_update_heap_boundaries (mword low, mword high);
 313
 314 void sgen_check_section_scan_starts (GCMemSection *section);
 315
 316 void sgen_conservatively_pin_objects_from (void **start, void **end, void *start_nursery, void *end_nursery, int pin_type);
 317
 318 gboolean sgen_gc_initialized (void);
 319
 320 /* Keep in sync with description_for_type() in sgen-internal.c! */
 321 enum {
 322         INTERNAL_MEM_PIN_QUEUE,
 323         INTERNAL_MEM_FRAGMENT,
 324         INTERNAL_MEM_SECTION,
 325         INTERNAL_MEM_SCAN_STARTS,
 326         INTERNAL_MEM_FIN_TABLE,
 327         INTERNAL_MEM_FINALIZE_ENTRY,
 328         INTERNAL_MEM_FINALIZE_READY,
 329         INTERNAL_MEM_DISLINK_TABLE,
 330         INTERNAL_MEM_DISLINK,
 331         INTERNAL_MEM_ROOTS_TABLE,
 332         INTERNAL_MEM_ROOT_RECORD,
 333         INTERNAL_MEM_STATISTICS,
 334         INTERNAL_MEM_STAT_PINNED_CLASS,
 335         INTERNAL_MEM_STAT_REMSET_CLASS,
 336         INTERNAL_MEM_GRAY_QUEUE,
 337         INTERNAL_MEM_MS_TABLES,
 338         INTERNAL_MEM_MS_BLOCK_INFO,
 339         INTERNAL_MEM_MS_BLOCK_INFO_SORT,
 340         INTERNAL_MEM_WORKER_DATA,
 341         INTERNAL_MEM_THREAD_POOL_JOB,
 342         INTERNAL_MEM_BRIDGE_DATA,
 343         INTERNAL_MEM_OLD_BRIDGE_HASH_TABLE,
 344         INTERNAL_MEM_OLD_BRIDGE_HASH_TABLE_ENTRY,
 345         INTERNAL_MEM_BRIDGE_HASH_TABLE,
 346         INTERNAL_MEM_BRIDGE_HASH_TABLE_ENTRY,
 347         INTERNAL_MEM_BRIDGE_ALIVE_HASH_TABLE,
 348         INTERNAL_MEM_BRIDGE_ALIVE_HASH_TABLE_ENTRY,
 349         INTERNAL_MEM_TARJAN_BRIDGE_HASH_TABLE,
 350         INTERNAL_MEM_TARJAN_BRIDGE_HASH_TABLE_ENTRY,
 351         INTERNAL_MEM_TARJAN_OBJ_BUCKET,
 352         INTERNAL_MEM_BRIDGE_DEBUG,
 353         INTERNAL_MEM_TOGGLEREF_DATA,
 354         INTERNAL_MEM_CARDTABLE_MOD_UNION,
 355         INTERNAL_MEM_BINARY_PROTOCOL,
 356         INTERNAL_MEM_TEMPORARY,
 357         INTERNAL_MEM_LOG_ENTRY,
 358         INTERNAL_MEM_COMPLEX_DESCRIPTORS,
 359         INTERNAL_MEM_FIRST_CLIENT
 360 };
 361
 362 enum {
 363         GENERATION_NURSERY,
 364         GENERATION_OLD,
 365         GENERATION_MAX
 366 };
 367
 368 #ifdef SGEN_HEAVY_BINARY_PROTOCOL
 369 #define BINARY_PROTOCOL_ARG(x)  ,x
 370 #else
 371 #define BINARY_PROTOCOL_ARG(x)
 372 #endif
 373
 374 void sgen_init_internal_allocator (void);
 375
 376 #define SGEN_DEFINE_OBJECT_VTABLE
 377 #ifdef SGEN_CLIENT_HEADER
 378 #include SGEN_CLIENT_HEADER
 379 #else
 380 #include "metadata/sgen-client-mono.h"
 381 #endif
 382 #undef SGEN_DEFINE_OBJECT_VTABLE
 383
 384 #include "mono/sgen/sgen-descriptor.h"
 385 #include "mono/sgen/sgen-gray.h"
 386
 387 /* the runtime can register areas of memory as roots: we keep two lists of roots,
 388  * a pinned root set for conservatively scanned roots and a normal one for
 389  * precisely scanned roots (currently implemented as a single list).
 390  */
 391 typedef struct _RootRecord RootRecord;
 392 struct _RootRecord {
 393         char *end_root;
 394         SgenDescriptor root_desc;
 395         int source;
 396         const char *msg;
 397 };
 398
 399 enum {
 400         ROOT_TYPE_NORMAL = 0, /* "normal" roots */
 401         ROOT_TYPE_PINNED = 1, /* roots without a GC descriptor */
 402         ROOT_TYPE_WBARRIER = 2, /* roots with a write barrier */
 403         ROOT_TYPE_NUM
 404 };
 405
 406 extern SgenHashTable roots_hash [ROOT_TYPE_NUM];
 407
 408 int sgen_register_root (char *start, size_t size, SgenDescriptor descr, int root_type, int source, const char *msg);
 409 void sgen_deregister_root (char* addr);
 410
 411 typedef void (*IterateObjectCallbackFunc) (GCObject*, size_t, void*);
 412
 413 void sgen_scan_area_with_callback (char *start, char *end, IterateObjectCallbackFunc callback, void *data, gboolean allow_flags, gboolean fail_on_canaries);
 414
 415 /* eventually share with MonoThread? */
 416 /*
 417  * This structure extends the MonoThreadInfo structure.
 418  */
 419 struct _SgenThreadInfo {
 420         SgenClientThreadInfo client_info;
 421
 422         char *tlab_start;
 423         char *tlab_next;
 424         char *tlab_temp_end;
 425         char *tlab_real_end;
 426 };
 427
 428 gboolean sgen_is_worker_thread (MonoNativeThreadId thread);
 429
 430 typedef void (*CopyOrMarkObjectFunc) (GCObject**, SgenGrayQueue*);
 431 typedef void (*ScanObjectFunc) (GCObject *obj, SgenDescriptor desc, SgenGrayQueue*);
 432 typedef void (*ScanVTypeFunc) (GCObject *full_object, char *start, SgenDescriptor desc, SgenGrayQueue* BINARY_PROTOCOL_ARG (size_t size));
 433 typedef void (*ScanPtrFieldFunc) (GCObject *obj, GCObject **ptr, SgenGrayQueue* queue);
 434 typedef gboolean (*DrainGrayStackFunc) (SgenGrayQueue *queue);
 435
 436 typedef struct {
 437         CopyOrMarkObjectFunc copy_or_mark_object;
 438         ScanObjectFunc scan_object;
 439         ScanVTypeFunc scan_vtype;
 440         ScanPtrFieldFunc scan_ptr_field;
 441         /* Drain stack optimized for the above functions */
 442         DrainGrayStackFunc drain_gray_stack;
 443         /*FIXME add allocation function? */
 444 } SgenObjectOperations;
 445
 446 typedef struct
 447 {
 448         SgenObjectOperations *ops;
 449         SgenGrayQueue *queue;
 450 } ScanCopyContext;
 451
 452 #define CONTEXT_FROM_OBJECT_OPERATIONS(ops, queue) ((ScanCopyContext) { (ops), (queue) })
 453
 454 void sgen_report_internal_mem_usage (void);
 455 void sgen_dump_internal_mem_usage (FILE *heap_dump_file);
 456 void sgen_dump_section (GCMemSection *section, const char *type);
 457 void sgen_dump_occupied (char *start, char *end, char *section_start);
 458
 459 void sgen_register_fixed_internal_mem_type (int type, size_t size);
 460
 461 void* sgen_alloc_internal (int type);
 462 void sgen_free_internal (void *addr, int type);
 463
 464 void* sgen_alloc_internal_dynamic (size_t size, int type, gboolean assert_on_failure);
 465 void sgen_free_internal_dynamic (void *addr, size_t size, int type);
 466
 467 void sgen_pin_stats_enable (void);
 468 void sgen_pin_stats_register_object (GCObject *obj, int generation);
 469 void sgen_pin_stats_register_global_remset (GCObject *obj);
 470 void sgen_pin_stats_report (void);
 471
 472 void sgen_sort_addresses (void **array, size_t size);
 473 void sgen_add_to_global_remset (gpointer ptr, GCObject *obj);
 474
 475 int sgen_get_current_collection_generation (void);
 476 gboolean sgen_collection_is_concurrent (void);
 477 gboolean sgen_concurrent_collection_in_progress (void);
 478
 479 typedef struct _SgenFragment SgenFragment;
 480
 481 struct _SgenFragment {
 482         SgenFragment *next;
 483         char *fragment_start;
 484         char *fragment_next; /* the current soft limit for allocation */
 485         char *fragment_end;
 486         SgenFragment *next_in_order; /* We use a different entry for all active fragments so we can avoid SMR. */
 487 };
 488
 489 typedef struct {
 490         SgenFragment *alloc_head; /* List head to be used when allocating memory. Walk with fragment_next. */
 491         SgenFragment *region_head; /* List head of the region used by this allocator. Walk with next_in_order. */
 492 } SgenFragmentAllocator;
 493
 494 void sgen_fragment_allocator_add (SgenFragmentAllocator *allocator, char *start, char *end);
 495 void sgen_fragment_allocator_release (SgenFragmentAllocator *allocator);
 496 void* sgen_fragment_allocator_serial_alloc (SgenFragmentAllocator *allocator, size_t size);
 497 void* sgen_fragment_allocator_par_alloc (SgenFragmentAllocator *allocator, size_t size);
 498 void* sgen_fragment_allocator_serial_range_alloc (SgenFragmentAllocator *allocator, size_t desired_size, size_t minimum_size, size_t *out_alloc_size);
 499 void* sgen_fragment_allocator_par_range_alloc (SgenFragmentAllocator *allocator, size_t desired_size, size_t minimum_size, size_t *out_alloc_size);
 500 SgenFragment* sgen_fragment_allocator_alloc (void);
 501 void sgen_clear_allocator_fragments (SgenFragmentAllocator *allocator);
 502 void sgen_clear_range (char *start, char *end);
 503
 504
 505 /*
 506 This is a space/speed compromise as we need to make sure the from/to space check is both O(1)
 507 and only hit cache hot memory. On a 4Mb nursery it requires 1024 bytes, or 3% of your average
 508 L1 cache. On small configs with a 512kb nursery, this goes to 0.4%.
 509
 510 Experimental results on how much space we waste with a 4Mb nursery:
 511
 512 Note that the wastage applies to the half nursery, or 2Mb:
 513
 514 Test 1 (compiling corlib):
 515 9: avg: 3.1k
 516 8: avg: 1.6k
 517
 518 */
 519 #define SGEN_TO_SPACE_GRANULE_BITS 9
 520 #define SGEN_TO_SPACE_GRANULE_IN_BYTES (1 << SGEN_TO_SPACE_GRANULE_BITS)
 521
 522 extern char *sgen_space_bitmap;
 523 extern size_t sgen_space_bitmap_size;
 524
 525 static inline gboolean
 526 sgen_nursery_is_to_space (void *object)
 527 {
 528         size_t idx = ((char*)object - sgen_nursery_start) >> SGEN_TO_SPACE_GRANULE_BITS;
 529         size_t byte = idx >> 3;
 530         size_t bit = idx & 0x7;
 531
 532         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 ());
 533         SGEN_ASSERT (4, byte < sgen_space_bitmap_size, "byte index %zd out of range (%zd)", byte, sgen_space_bitmap_size);
 534
 535         return (sgen_space_bitmap [byte] & (1 << bit)) != 0;
 536 }
 537
 538 static inline gboolean
 539 sgen_nursery_is_from_space (void *object)
 540 {
 541         return !sgen_nursery_is_to_space (object);
 542 }
 543
 544 static inline gboolean
 545 sgen_nursery_is_object_alive (GCObject *obj)
 546 {
 547         /* FIXME put this asserts under a non default level */
 548         g_assert (sgen_ptr_in_nursery (obj));
 549
 550         if (sgen_nursery_is_to_space (obj))
 551                 return TRUE;
 552
 553         if (SGEN_OBJECT_IS_PINNED (obj) || SGEN_OBJECT_IS_FORWARDED (obj))
 554                 return TRUE;
 555
 556         return FALSE;
 557 }
 558
 559 typedef struct {
 560         gboolean is_split;
 561
 562         GCObject* (*alloc_for_promotion) (GCVTable vtable, GCObject *obj, size_t objsize, gboolean has_references);
 563
 564         SgenObjectOperations serial_ops;
 565         SgenObjectOperations serial_ops_with_concurrent_major;
 566
 567         void (*prepare_to_space) (char *to_space_bitmap, size_t space_bitmap_size);
 568         void (*clear_fragments) (void);
 569         SgenFragment* (*build_fragments_get_exclude_head) (void);
 570         void (*build_fragments_release_exclude_head) (void);
 571         void (*build_fragments_finish) (SgenFragmentAllocator *allocator);
 572         void (*init_nursery) (SgenFragmentAllocator *allocator, char *start, char *end);
 573
 574         gboolean (*handle_gc_param) (const char *opt); /* Optional */
 575         void (*print_gc_param_usage) (void); /* Optional */
 576 } SgenMinorCollector;
 577
 578 extern SgenMinorCollector sgen_minor_collector;
 579
 580 void sgen_simple_nursery_init (SgenMinorCollector *collector);
 581 void sgen_split_nursery_init (SgenMinorCollector *collector);
 582
 583 /* Updating references */
 584
 585 #ifdef SGEN_CHECK_UPDATE_REFERENCE
 586 gboolean sgen_thread_pool_is_thread_pool_thread (MonoNativeThreadId some_thread);
 587
 588 static inline void
 589 sgen_update_reference (GCObject **p, GCObject *o, gboolean allow_null)
 590 {
 591         if (!allow_null)
 592                 SGEN_ASSERT (0, o, "Cannot update a reference with a NULL pointer");
 593         SGEN_ASSERT (0, !sgen_thread_pool_is_thread_pool_thread (mono_native_thread_id_get ()), "Can't update a reference in the worker thread");
 594         *p = o;
 595 }
 596
 597 #define SGEN_UPDATE_REFERENCE_ALLOW_NULL(p,o)   sgen_update_reference ((GCObject**)(p), (GCObject*)(o), TRUE)
 598 #define SGEN_UPDATE_REFERENCE(p,o)              sgen_update_reference ((GCObject**)(p), (GCObject*)(o), FALSE)
 599 #else
 600 #define SGEN_UPDATE_REFERENCE_ALLOW_NULL(p,o)   (*(GCObject**)(p) = (GCObject*)(o))
 601 #define SGEN_UPDATE_REFERENCE(p,o)              SGEN_UPDATE_REFERENCE_ALLOW_NULL ((p), (o))
 602 #endif
 603
 604 /* Major collector */
 605
 606 typedef void (*sgen_cardtable_block_callback) (mword start, mword size);
 607 void sgen_major_collector_iterate_live_block_ranges (sgen_cardtable_block_callback callback);
 608 void sgen_major_collector_iterate_block_ranges (sgen_cardtable_block_callback callback);
 609
 610 typedef enum {
 611         ITERATE_OBJECTS_SWEEP = 1,
 612         ITERATE_OBJECTS_NON_PINNED = 2,
 613         ITERATE_OBJECTS_PINNED = 4,
 614         ITERATE_OBJECTS_SWEEP_NON_PINNED = ITERATE_OBJECTS_SWEEP | ITERATE_OBJECTS_NON_PINNED,
 615         ITERATE_OBJECTS_SWEEP_PINNED = ITERATE_OBJECTS_SWEEP | ITERATE_OBJECTS_PINNED,
 616         ITERATE_OBJECTS_SWEEP_ALL = ITERATE_OBJECTS_SWEEP | ITERATE_OBJECTS_NON_PINNED | ITERATE_OBJECTS_PINNED
 617 } IterateObjectsFlags;
 618
 619 typedef struct
 620 {
 621         size_t num_scanned_objects;
 622         size_t num_unique_scanned_objects;
 623 } ScannedObjectCounts;
 624
 625 typedef enum {
 626         CARDTABLE_SCAN_GLOBAL = 0,
 627         CARDTABLE_SCAN_MOD_UNION = 1,
 628         CARDTABLE_SCAN_MOD_UNION_PRECLEAN = CARDTABLE_SCAN_MOD_UNION | 2,
 629 } CardTableScanType;
 630
 631 typedef struct _SgenMajorCollector SgenMajorCollector;
 632 struct _SgenMajorCollector {
 633         size_t section_size;
 634         gboolean is_concurrent;
 635         gboolean is_parallel;
 636         gboolean needs_thread_pool;
 637         gboolean supports_cardtable;
 638         gboolean sweeps_lazily;
 639
 640         void* (*alloc_heap) (mword nursery_size, mword nursery_align, int nursery_bits);
 641         gboolean (*is_object_live) (GCObject *obj);
 642         GCObject* (*alloc_small_pinned_obj) (GCVTable vtable, size_t size, gboolean has_references);
 643         GCObject* (*alloc_degraded) (GCVTable vtable, size_t size);
 644
 645         SgenObjectOperations major_ops_serial;
 646         SgenObjectOperations major_ops_concurrent_start;
 647         SgenObjectOperations major_ops_concurrent_finish;
 648         SgenObjectOperations major_ops_conc_par_start;
 649         SgenObjectOperations major_ops_conc_par_finish;
 650
 651         GCObject* (*alloc_object) (GCVTable vtable, size_t size, gboolean has_references);
 652         GCObject* (*alloc_object_par) (GCVTable vtable, size_t size, gboolean has_references);
 653         void (*free_pinned_object) (GCObject *obj, size_t size);
 654
 655         /*
 656          * This is used for domain unloading, heap walking from the logging profiler, and
 657          * debugging.  Can assume the world is stopped.
 658          */
 659         void (*iterate_objects) (IterateObjectsFlags flags, IterateObjectCallbackFunc callback, void *data);
 660
 661         void (*free_non_pinned_object) (GCObject *obj, size_t size);
 662         void (*pin_objects) (SgenGrayQueue *queue);
 663         void (*pin_major_object) (GCObject *obj, SgenGrayQueue *queue);
 664         void (*scan_card_table) (CardTableScanType scan_type, ScanCopyContext ctx, int job_index, int job_split_count);
 665         void (*iterate_live_block_ranges) (sgen_cardtable_block_callback callback);
 666         void (*iterate_block_ranges) (sgen_cardtable_block_callback callback);
 667         void (*update_cardtable_mod_union) (void);
 668         void (*init_to_space) (void);
 669         void (*sweep) (void);
 670         gboolean (*have_swept) (void);
 671         void (*finish_sweeping) (void);
 672         void (*free_swept_blocks) (size_t section_reserve);
 673         void (*check_scan_starts) (void);
 674         void (*dump_heap) (FILE *heap_dump_file);
 675         gint64 (*get_used_size) (void);
 676         void (*start_nursery_collection) (void);
 677         void (*finish_nursery_collection) (void);
 678         void (*start_major_collection) (void);
 679         void (*finish_major_collection) (ScannedObjectCounts *counts);
 680         gboolean (*ptr_is_in_non_pinned_space) (char *ptr, char **start);
 681         gboolean (*ptr_is_from_pinned_alloc) (char *ptr);
 682         void (*report_pinned_memory_usage) (void);
 683         size_t (*get_num_major_sections) (void);
 684         size_t (*get_bytes_survived_last_sweep) (void);
 685         gboolean (*handle_gc_param) (const char *opt);
 686         void (*print_gc_param_usage) (void);
 687         void (*post_param_init) (SgenMajorCollector *collector);
 688         gboolean (*is_valid_object) (char *ptr);
 689         GCVTable (*describe_pointer) (char *pointer);
 690         guint8* (*get_cardtable_mod_union_for_reference) (char *object);
 691         long long (*get_and_reset_num_major_objects_marked) (void);
 692         void (*count_cards) (long long *num_total_cards, long long *num_marked_cards);
 693
 694         void (*worker_init_cb) (gpointer worker);
 695 };
 696
 697 extern SgenMajorCollector major_collector;
 698
 699 void sgen_marksweep_init (SgenMajorCollector *collector);
 700 void sgen_marksweep_conc_init (SgenMajorCollector *collector);
 701 void sgen_marksweep_conc_par_init (SgenMajorCollector *collector);
 702 SgenMajorCollector* sgen_get_major_collector (void);
 703
 704
 705 typedef struct _SgenRememberedSet {
 706         void (*wbarrier_set_field) (GCObject *obj, gpointer field_ptr, GCObject* value);
 707         void (*wbarrier_arrayref_copy) (gpointer dest_ptr, gpointer src_ptr, int count);
 708         void (*wbarrier_value_copy) (gpointer dest, gpointer src, int count, size_t element_size);
 709         void (*wbarrier_object_copy) (GCObject* obj, GCObject *src);
 710         void (*wbarrier_generic_nostore) (gpointer ptr);
 711         void (*record_pointer) (gpointer ptr);
 712
 713         void (*scan_remsets) (ScanCopyContext ctx);
 714
 715         void (*clear_cards) (void);
 716
 717         void (*finish_minor_collection) (void);
 718         gboolean (*find_address) (char *addr);
 719         gboolean (*find_address_with_cards) (char *cards_start, guint8 *cards, char *addr);
 720 } SgenRememberedSet;
 721
 722 SgenRememberedSet *sgen_get_remset (void);
 723
 724 /*
 725  * These must be kept in sync with object.h.  They're here for using SGen independently of
 726  * Mono.
 727  */
 728 void mono_gc_wbarrier_arrayref_copy (gpointer dest_ptr, gpointer src_ptr, int count);
 729 void mono_gc_wbarrier_generic_nostore (gpointer ptr);
 730 void mono_gc_wbarrier_generic_store (gpointer ptr, GCObject* value);
 731 void mono_gc_wbarrier_generic_store_atomic (gpointer ptr, GCObject *value);
 732
 733 void sgen_wbarrier_value_copy_bitmap (gpointer _dest, gpointer _src, int size, unsigned bitmap);
 734
 735 static inline SgenDescriptor
 736 sgen_obj_get_descriptor (GCObject *obj)
 737 {
 738         GCVTable vtable = SGEN_LOAD_VTABLE_UNCHECKED (obj);
 739         SGEN_ASSERT (9, !SGEN_POINTER_IS_TAGGED_ANY (vtable), "Object can't be tagged");
 740         return sgen_vtable_get_descriptor (vtable);
 741 }
 742
 743 static inline SgenDescriptor
 744 sgen_obj_get_descriptor_safe (GCObject *obj)
 745 {
 746         GCVTable vtable = SGEN_LOAD_VTABLE (obj);
 747         return sgen_vtable_get_descriptor (vtable);
 748 }
 749
 750 static mword sgen_client_par_object_get_size (GCVTable vtable, GCObject* o);
 751 static mword sgen_client_slow_object_get_size (GCVTable vtable, GCObject* o);
 752
 753 static inline mword
 754 sgen_safe_object_get_size (GCObject *obj)
 755 {
 756         GCObject *forwarded;
 757         GCVTable vtable = SGEN_LOAD_VTABLE_UNCHECKED (obj);
 758
 759         /*
 760          * Once we load the vtable, we must always use it, in case we are in parallel case.
 761          * Otherwise the object might get forwarded in the meantime and we would read an
 762          * invalid vtable. An object cannot be forwarded for a second time during same GC.
 763          */
 764         if ((forwarded = SGEN_VTABLE_IS_FORWARDED (vtable)))
 765                 return sgen_client_par_object_get_size (SGEN_LOAD_VTABLE (forwarded), obj);
 766         else
 767                 return sgen_client_par_object_get_size ((GCVTable)SGEN_POINTER_UNTAG_ALL (vtable), obj);
 768 }
 769
 770 static inline gboolean
 771 sgen_safe_object_is_small (GCObject *obj, int type)
 772 {
 773         if (type <= DESC_TYPE_MAX_SMALL_OBJ)
 774                 return TRUE;
 775         return SGEN_ALIGN_UP (sgen_safe_object_get_size ((GCObject*)obj)) <= SGEN_MAX_SMALL_OBJ_SIZE;
 776 }
 777
 778 /*
 779  * This variant guarantees to return the exact size of the object
 780  * before alignment. Needed for canary support.
 781  */
 782 static inline guint
 783 sgen_safe_object_get_size_unaligned (GCObject *obj)
 784 {
 785         GCObject *forwarded;
 786
 787         if ((forwarded = SGEN_OBJECT_IS_FORWARDED (obj))) {
 788                 obj = (GCObject*)forwarded;
 789         }
 790
 791         return sgen_client_slow_object_get_size (SGEN_LOAD_VTABLE (obj), obj);
 792 }
 793
 794 #ifdef SGEN_CLIENT_HEADER
 795 #include SGEN_CLIENT_HEADER
 796 #else
 797 #include "metadata/sgen-client-mono.h"
 798 #endif
 799
 800 gboolean sgen_object_is_live (GCObject *obj);
 801
 802 void  sgen_init_fin_weak_hash (void);
 803
 804 /* FIXME: move the toggleref stuff out of here */
 805 void sgen_mark_togglerefs (char *start, char *end, ScanCopyContext ctx);
 806 void sgen_clear_togglerefs (char *start, char *end, ScanCopyContext ctx);
 807
 808 void sgen_process_togglerefs (void);
 809 void sgen_register_test_toggleref_callback (void);
 810
 811 void sgen_mark_bridge_object (GCObject *obj);
 812 void sgen_collect_bridge_objects (int generation, ScanCopyContext ctx);
 813
 814 typedef gboolean (*SgenObjectPredicateFunc) (GCObject *obj, void *user_data);
 815
 816 void sgen_null_links_if (SgenObjectPredicateFunc predicate, void *data, int generation, gboolean track);
 817
 818 gboolean sgen_gc_is_object_ready_for_finalization (GCObject *object);
 819 void sgen_gc_lock (void);
 820 void sgen_gc_unlock (void);
 821
 822 void sgen_queue_finalization_entry (GCObject *obj);
 823 const char* sgen_generation_name (int generation);
 824
 825 void sgen_finalize_in_range (int generation, ScanCopyContext ctx);
 826 void sgen_null_link_in_range (int generation, ScanCopyContext ctx, gboolean track);
 827 void sgen_process_fin_stage_entries (void);
 828 gboolean sgen_have_pending_finalizers (void);
 829 void sgen_object_register_for_finalization (GCObject *obj, void *user_data);
 830
 831 void sgen_finalize_if (SgenObjectPredicateFunc predicate, void *user_data);
 832 void sgen_remove_finalizers_if (SgenObjectPredicateFunc predicate, void *user_data, int generation);
 833 void sgen_set_suspend_finalizers (void);
 834
 835 void sgen_register_disappearing_link (GCObject *obj, void **link, gboolean track, gboolean in_gc);
 836
 837 GCObject* sgen_weak_link_get (void **link_addr);
 838
 839 gboolean sgen_drain_gray_stack (ScanCopyContext ctx);
 840
 841 enum {
 842         SPACE_NURSERY,
 843         SPACE_MAJOR,
 844         SPACE_LOS
 845 };
 846
 847 void sgen_pin_object (GCObject *object, SgenGrayQueue *queue);
 848 void sgen_set_pinned_from_failed_allocation (mword objsize);
 849
 850 void sgen_ensure_free_space (size_t size, int generation);
 851 void sgen_gc_collect (int generation);
 852 void sgen_perform_collection (size_t requested_size, int generation_to_collect, const char *reason, gboolean wait_to_finish, gboolean stw);
 853
 854 int sgen_gc_collection_count (int generation);
 855 /* FIXME: what exactly does this return? */
 856 size_t sgen_gc_get_used_size (void);
 857 size_t sgen_gc_get_total_heap_allocation (void);
 858
 859 /* STW */
 860
 861 void sgen_stop_world (int generation);
 862 void sgen_restart_world (int generation);
 863 gboolean sgen_is_world_stopped (void);
 864
 865 gboolean sgen_set_allow_synchronous_major (gboolean flag);
 866
 867 /* LOS */
 868
 869 typedef struct _LOSObject LOSObject;
 870 struct _LOSObject {
 871         LOSObject *next;
 872         mword size; /* this is the object size, lowest bit used for pin/mark */
 873         guint8 * volatile cardtable_mod_union; /* only used by the concurrent collector */
 874 #if SIZEOF_VOID_P < 8
 875         mword dummy;            /* to align object to sizeof (double) */
 876 #endif
 877         GCObject data [MONO_ZERO_LEN_ARRAY];
 878 };
 879
 880 extern LOSObject *los_object_list;
 881 extern mword los_memory_usage;
 882 extern mword los_memory_usage_total;
 883
 884 void sgen_los_free_object (LOSObject *obj);
 885 void* sgen_los_alloc_large_inner (GCVTable vtable, size_t size);
 886 void sgen_los_sweep (void);
 887 gboolean sgen_ptr_is_in_los (char *ptr, char **start);
 888 void sgen_los_iterate_objects (IterateObjectCallbackFunc cb, void *user_data);
 889 void sgen_los_iterate_live_block_ranges (sgen_cardtable_block_callback callback);
 890 void sgen_los_scan_card_table (CardTableScanType scan_type, ScanCopyContext ctx, int job_index, int job_split_count);
 891 void sgen_los_update_cardtable_mod_union (void);
 892 void sgen_los_count_cards (long long *num_total_cards, long long *num_marked_cards);
 893 gboolean sgen_los_is_valid_object (char *object);
 894 gboolean mono_sgen_los_describe_pointer (char *ptr);
 895 LOSObject* sgen_los_header_for_object (GCObject *data);
 896 mword sgen_los_object_size (LOSObject *obj);
 897 void sgen_los_pin_object (GCObject *obj);
 898 gboolean sgen_los_pin_object_par (GCObject *obj);
 899 gboolean sgen_los_object_is_pinned (GCObject *obj);
 900 void sgen_los_mark_mod_union_card (GCObject *mono_obj, void **ptr);
 901
 902
 903 /* nursery allocator */
 904
 905 void sgen_clear_nursery_fragments (void);
 906 void sgen_nursery_allocator_prepare_for_pinning (void);
 907 void sgen_nursery_allocator_set_nursery_bounds (char *nursery_start, char *nursery_end);
 908 mword sgen_build_nursery_fragments (GCMemSection *nursery_section, SgenGrayQueue *unpin_queue);
 909 void sgen_init_nursery_allocator (void);
 910 void sgen_nursery_allocator_init_heavy_stats (void);
 911 void sgen_init_allocator (void);
 912 char* sgen_nursery_alloc_get_upper_alloc_bound (void);
 913 void* sgen_nursery_alloc (size_t size);
 914 void* sgen_nursery_alloc_range (size_t size, size_t min_size, size_t *out_alloc_size);
 915 gboolean sgen_can_alloc_size (size_t size);
 916 void sgen_nursery_retire_region (void *address, ptrdiff_t size);
 917
 918 void sgen_nursery_alloc_prepare_for_minor (void);
 919 void sgen_nursery_alloc_prepare_for_major (void);
 920
 921 GCObject* sgen_alloc_for_promotion (GCObject *obj, size_t objsize, gboolean has_references);
 922
 923 GCObject* sgen_alloc_obj_nolock (GCVTable vtable, size_t size);
 924 GCObject* sgen_try_alloc_obj_nolock (GCVTable vtable, size_t size);
 925
 926 /* Threads */
 927
 928 void* sgen_thread_register (SgenThreadInfo* info, void *addr);
 929 void sgen_thread_unregister (SgenThreadInfo *p);
 930
 931 /* Finalization/ephemeron support */
 932
 933 static inline gboolean
 934 sgen_major_is_object_alive (GCObject *object)
 935 {
 936         mword objsize;
 937
 938         /* Oldgen objects can be pinned and forwarded too */
 939         if (SGEN_OBJECT_IS_PINNED (object) || SGEN_OBJECT_IS_FORWARDED (object))
 940                 return TRUE;
 941
 942         /*
 943          * FIXME: major_collector.is_object_live() also calculates the
 944          * size.  Avoid the double calculation.
 945          */
 946         objsize = SGEN_ALIGN_UP (sgen_safe_object_get_size (object));
 947         if (objsize > SGEN_MAX_SMALL_OBJ_SIZE)
 948                 return sgen_los_object_is_pinned (object);
 949
 950         return major_collector.is_object_live (object);
 951 }
 952
 953 /*
 954  * This function returns true if @object is either alive or it belongs to the old gen
 955  * and we're currently doing a minor collection.
 956  */
 957 static inline int
 958 sgen_is_object_alive_for_current_gen (GCObject *object)
 959 {
 960         if (sgen_ptr_in_nursery (object))
 961                 return sgen_nursery_is_object_alive (object);
 962
 963         if (current_collection_generation == GENERATION_NURSERY)
 964                 return TRUE;
 965
 966         return sgen_major_is_object_alive (object);
 967 }
 968
 969 int sgen_gc_invoke_finalizers (void);
 970
 971 /* GC handles */
 972
 973 void sgen_init_gchandles (void);
 974
 975 void sgen_null_links_if (SgenObjectPredicateFunc predicate, void *data, int generation, gboolean track);
 976
 977 typedef gpointer (*SgenGCHandleIterateCallback) (gpointer hidden, GCHandleType handle_type, int max_generation, gpointer user);
 978
 979 void sgen_gchandle_iterate (GCHandleType handle_type, int max_generation, SgenGCHandleIterateCallback callback, gpointer user);
 980 void sgen_gchandle_set_target (guint32 gchandle, GCObject *obj);
 981 void sgen_mark_normal_gc_handles (void *addr, SgenUserMarkFunc mark_func, void *gc_data);
 982 gpointer sgen_gchandle_get_metadata (guint32 gchandle);
 983
 984 /* Other globals */
 985
 986 extern GCMemSection *nursery_section;
 987 extern guint32 collect_before_allocs;
 988 extern guint32 verify_before_allocs;
 989 extern gboolean has_per_allocation_action;
 990 extern size_t degraded_mode;
 991 extern int default_nursery_size;
 992 extern guint32 tlab_size;
 993 extern NurseryClearPolicy nursery_clear_policy;
 994 extern gboolean sgen_try_free_some_memory;
 995 extern mword total_promoted_size;
 996 extern mword total_allocated_major;
 997 extern volatile gboolean sgen_suspend_finalizers;
 998 extern MonoCoopMutex gc_mutex;
 999
1000 /* Nursery helpers. */
1001
1002 static inline void
1003 sgen_set_nursery_scan_start (char *p)
1004 {
1005         size_t idx = (p - (char*)nursery_section->data) / SGEN_SCAN_START_SIZE;
1006         char *old = nursery_section->scan_starts [idx];
1007         if (!old || old > p)
1008                 nursery_section->scan_starts [idx] = p;
1009 }
1010
1011
1012 /* Object Allocation */
1013
1014 typedef enum {
1015         ATYPE_NORMAL,
1016         ATYPE_VECTOR,
1017         ATYPE_SMALL,
1018         ATYPE_STRING,
1019         ATYPE_NUM
1020 } SgenAllocatorType;
1021
1022 void sgen_clear_tlabs (void);
1023
1024 GCObject* sgen_alloc_obj (GCVTable vtable, size_t size);
1025 GCObject* sgen_alloc_obj_pinned (GCVTable vtable, size_t size);
1026 GCObject* sgen_alloc_obj_mature (GCVTable vtable, size_t size);
1027
1028 /* Debug support */
1029
1030 void sgen_check_remset_consistency (void);
1031 void sgen_check_mod_union_consistency (void);
1032 void sgen_check_major_refs (void);
1033 void sgen_check_whole_heap (gboolean allow_missing_pinning);
1034 void sgen_check_whole_heap_stw (void);
1035 void sgen_check_objref (char *obj);
1036 void sgen_check_heap_marked (gboolean nursery_must_be_pinned);
1037 void sgen_check_nursery_objects_pinned (gboolean pinned);
1038 void sgen_check_for_xdomain_refs (void);
1039 GCObject* sgen_find_object_for_ptr (char *ptr);
1040
1041 void mono_gc_scan_for_specific_ref (GCObject *key, gboolean precise);
1042
1043 void sgen_debug_enable_heap_dump (const char *filename);
1044 void sgen_debug_dump_heap (const char *type, int num, const char *reason);
1045
1046 void sgen_debug_verify_nursery (gboolean do_dump_nursery_content);
1047 void sgen_debug_check_nursery_is_clean (void);
1048
1049 /* Environment variable parsing */
1050
1051 #define MONO_GC_PARAMS_NAME     "MONO_GC_PARAMS"
1052 #define MONO_GC_DEBUG_NAME      "MONO_GC_DEBUG"
1053
1054 void sgen_env_var_error (const char *env_var, const char *fallback, const char *description_format, ...);
1055
1056 /* Utilities */
1057
1058 void sgen_qsort (void *array, size_t count, size_t element_size, int (*compare) (const void*, const void*));
1059 gint64 sgen_timestamp (void);
1060
1061 /*
1062  * Canary (guard word) support
1063  * Notes:
1064  * - CANARY_SIZE must be multiple of word size in bytes
1065  * - Canary space is not included on checks against SGEN_MAX_SMALL_OBJ_SIZE
1066  */
1067
1068 gboolean nursery_canaries_enabled (void);
1069
1070 #define CANARY_SIZE 8
1071 #define CANARY_STRING  "koupepia"
1072
1073 #define CANARIFY_SIZE(size) if (nursery_canaries_enabled ()) {  \
1074                         size = size + CANARY_SIZE;      \
1075                 }
1076
1077 #define CANARIFY_ALLOC(addr,size) if (nursery_canaries_enabled ()) {    \
1078                                 memcpy ((char*) (addr) + (size), CANARY_STRING, CANARY_SIZE);   \
1079                         }
1080
1081 #define CANARY_VALID(addr) (strncmp ((char*) (addr), CANARY_STRING, CANARY_SIZE) == 0)
1082
1083 #define CHECK_CANARY_FOR_OBJECT(addr,fail) if (nursery_canaries_enabled ()) {   \
1084                                 guint size = sgen_safe_object_get_size_unaligned ((GCObject *) (addr)); \
1085                                 char* canary_ptr = (char*) (addr) + size;       \
1086                                 if (!CANARY_VALID(canary_ptr)) {        \
1087                                         char *window_start, *window_end; \
1088                                         window_start = (char*)(addr) - 128; \
1089                                         if (!sgen_ptr_in_nursery (window_start)) \
1090                                                 window_start = sgen_get_nursery_start (); \
1091                                         window_end = (char*)(addr) + 128; \
1092                                         if (!sgen_ptr_in_nursery (window_end)) \
1093                                                 window_end = sgen_get_nursery_end (); \
1094                                         fprintf (stderr, "\nCANARY ERROR - Type:%s Size:%d Address:%p Data:\n", sgen_client_vtable_get_name (SGEN_LOAD_VTABLE ((addr))), size,  (char*) addr); \
1095                                         fwrite (addr, sizeof (char), size, stderr); \
1096                                         fprintf (stderr, "\nCanary zone (next 12 chars):\n"); \
1097                                         fwrite (canary_ptr, sizeof (char), 12, stderr); \
1098                                         fprintf (stderr, "\nOriginal canary string:\n"); \
1099                                         fwrite (CANARY_STRING, sizeof (char), 8, stderr); \
1100                                         for (int x = -8; x <= 8; x++) { \
1101                                                 if (canary_ptr + x < (char*) addr); \
1102                                                         continue; \
1103                                                 if (CANARY_VALID(canary_ptr +x)) \
1104                                                         fprintf (stderr, "\nCANARY ERROR - canary found at offset %d\n", x); \
1105                                         } \
1106                                         fprintf (stderr, "\nSurrounding nursery (%p - %p):\n", window_start, window_end); \
1107                                         fwrite (window_start, sizeof (char), window_end - window_start, stderr); \
1108                                 } }
1109
1110 /*
1111  * This causes the compile to extend the liveness of 'v' till the call to dummy_use
1112  */
1113 static inline void
1114 sgen_dummy_use (gpointer v)
1115 {
1116 #if defined(__GNUC__)
1117         __asm__ volatile ("" : "=r"(v) : "r"(v));
1118 #elif defined(_MSC_VER)
1119         static volatile gpointer ptr;
1120         ptr = v;
1121 #else
1122 #error "Implement sgen_dummy_use for your compiler"
1123 #endif
1124 }
1125
1126 #endif /* HAVE_SGEN_GC */
1127
1128 #endif /* __MONO_SGENGC_H__ */