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
 120 #define SGEN_LOG(level, format, ...) do {      \
 121         if (G_UNLIKELY ((level) <= SGEN_MAX_DEBUG_LEVEL && (level) <= gc_debug_level)) {        \
 122                 mono_gc_printf (gc_debug_file, format "\n", ##__VA_ARGS__);     \
 123 } } while (0)
 124
 125 #define SGEN_COND_LOG(level, cond, format, ...) do {    \
 126         if (G_UNLIKELY ((level) <= SGEN_MAX_DEBUG_LEVEL && (level) <= gc_debug_level)) {        \
 127                 if (cond)       \
 128                         mono_gc_printf (gc_debug_file, format "\n", ##__VA_ARGS__);     \
 129 } } while (0)
 130
 131 extern int gc_debug_level;
 132 extern FILE* gc_debug_file;
 133
 134 extern int current_collection_generation;
 135
 136 extern unsigned int sgen_global_stop_count;
 137
 138 #define SGEN_ALIGN_UP_TO(val,align)     (((val) + (align - 1)) & ~(align - 1))
 139 #define SGEN_ALIGN_DOWN_TO(val,align)   ((val) & ~(align - 1))
 140
 141 #define SGEN_ALLOC_ALIGN                8
 142 #define SGEN_ALLOC_ALIGN_BITS   3
 143
 144 /* s must be non-negative */
 145 #define SGEN_CAN_ALIGN_UP(s)            ((s) <= SIZE_MAX - (SGEN_ALLOC_ALIGN - 1))
 146 #define SGEN_ALIGN_UP(s)                SGEN_ALIGN_UP_TO(s, SGEN_ALLOC_ALIGN)
 147 #define SGEN_ALIGN_DOWN(s)              SGEN_ALIGN_DOWN_TO(s, SGEN_ALLOC_ALIGN)
 148
 149 #if SIZEOF_VOID_P == 4
 150 #define ONE_P 1
 151 #else
 152 #define ONE_P 1ll
 153 #endif
 154
 155 static inline guint
 156 sgen_aligned_addr_hash (gconstpointer ptr)
 157 {
 158         return GPOINTER_TO_UINT (ptr) >> 3;
 159 }
 160
 161 #define SGEN_PTR_IN_NURSERY(p,bits,start,end)   (((mword)(p) & ~((1 << (bits)) - 1)) == (mword)(start))
 162
 163 #ifdef USER_CONFIG
 164
 165 /* good sizes are 512KB-1MB: larger ones increase a lot memzeroing time */
 166 #define DEFAULT_NURSERY_SIZE (sgen_nursery_size)
 167 extern size_t sgen_nursery_size;
 168 /* The number of trailing 0 bits in DEFAULT_NURSERY_SIZE */
 169 #define DEFAULT_NURSERY_BITS (sgen_nursery_bits)
 170 extern int sgen_nursery_bits;
 171
 172 #else
 173
 174 #define DEFAULT_NURSERY_SIZE (4*1024*1024)
 175 #define DEFAULT_NURSERY_BITS 22
 176
 177 #endif
 178
 179 extern char *sgen_nursery_start;
 180 extern char *sgen_nursery_end;
 181
 182 static inline MONO_ALWAYS_INLINE gboolean
 183 sgen_ptr_in_nursery (void *p)
 184 {
 185         return SGEN_PTR_IN_NURSERY ((p), DEFAULT_NURSERY_BITS, sgen_nursery_start, sgen_nursery_end);
 186 }
 187
 188 static inline MONO_ALWAYS_INLINE char*
 189 sgen_get_nursery_start (void)
 190 {
 191         return sgen_nursery_start;
 192 }
 193
 194 static inline MONO_ALWAYS_INLINE char*
 195 sgen_get_nursery_end (void)
 196 {
 197         return sgen_nursery_end;
 198 }
 199
 200 /*
 201  * We use the lowest three bits in the vtable pointer of objects to tag whether they're
 202  * forwarded, pinned, and/or cemented.  These are the valid states:
 203  *
 204  * | State            | bits |
 205  * |------------------+------+
 206  * | default          |  000 |
 207  * | forwarded        |  001 |
 208  * | pinned           |  010 |
 209  * | pinned, cemented |  110 |
 210  *
 211  * We store them in the vtable slot because the bits are used in the sync block for other
 212  * purposes: if we merge them and alloc the sync blocks aligned to 8 bytes, we can change
 213  * this and use bit 3 in the syncblock (with the lower two bits both set for forwarded, that
 214  * would be an invalid combination for the monitor and hash code).
 215  */
 216
 217 #include "sgen-tagged-pointer.h"
 218
 219 #define SGEN_VTABLE_BITS_MASK   SGEN_TAGGED_POINTER_MASK
 220
 221 #define SGEN_POINTER_IS_TAGGED_FORWARDED(p)     SGEN_POINTER_IS_TAGGED_1((p))
 222 #define SGEN_POINTER_TAG_FORWARDED(p)           SGEN_POINTER_TAG_1((p))
 223
 224 #define SGEN_POINTER_IS_TAGGED_PINNED(p)        SGEN_POINTER_IS_TAGGED_2((p))
 225 #define SGEN_POINTER_TAG_PINNED(p)              SGEN_POINTER_TAG_2((p))
 226
 227 #define SGEN_POINTER_IS_TAGGED_CEMENTED(p)      SGEN_POINTER_IS_TAGGED_4((p))
 228 #define SGEN_POINTER_TAG_CEMENTED(p)            SGEN_POINTER_TAG_4((p))
 229
 230 #define SGEN_POINTER_UNTAG_VTABLE(p)            SGEN_POINTER_UNTAG_ALL((p))
 231
 232 /* returns NULL if not forwarded, or the forwarded address */
 233 #define SGEN_VTABLE_IS_FORWARDED(vtable) ((GCVTable *)(SGEN_POINTER_IS_TAGGED_FORWARDED ((vtable)) ? SGEN_POINTER_UNTAG_VTABLE ((vtable)) : NULL))
 234 #define SGEN_OBJECT_IS_FORWARDED(obj) ((GCObject *)SGEN_VTABLE_IS_FORWARDED (((mword*)(obj))[0]))
 235
 236 #define SGEN_VTABLE_IS_PINNED(vtable) SGEN_POINTER_IS_TAGGED_PINNED ((vtable))
 237 #define SGEN_OBJECT_IS_PINNED(obj) (SGEN_VTABLE_IS_PINNED (((mword*)(obj))[0]))
 238
 239 #define SGEN_OBJECT_IS_CEMENTED(obj) (SGEN_POINTER_IS_TAGGED_CEMENTED (((mword*)(obj))[0]))
 240
 241 /* set the forwarded address fw_addr for object obj */
 242 #define SGEN_FORWARD_OBJECT(obj,fw_addr) do {                           \
 243                 *(void**)(obj) = SGEN_POINTER_TAG_FORWARDED ((fw_addr));        \
 244         } while (0)
 245 #define SGEN_PIN_OBJECT(obj) do {       \
 246                 *(void**)(obj) = SGEN_POINTER_TAG_PINNED (*(void**)(obj)); \
 247         } while (0)
 248 #define SGEN_CEMENT_OBJECT(obj) do {    \
 249                 *(void**)(obj) = SGEN_POINTER_TAG_CEMENTED (*(void**)(obj)); \
 250         } while (0)
 251 /* Unpins and uncements */
 252 #define SGEN_UNPIN_OBJECT(obj) do {     \
 253                 *(void**)(obj) = SGEN_POINTER_UNTAG_VTABLE (*(void**)(obj)); \
 254         } while (0)
 255
 256 /*
 257  * Since we set bits in the vtable, use the macro to load it from the pointer to
 258  * an object that is potentially pinned.
 259  */
 260 #define SGEN_LOAD_VTABLE(obj)           ((GCVTable)(SGEN_POINTER_UNTAG_ALL (SGEN_LOAD_VTABLE_UNCHECKED ((GCObject *)(obj)))))
 261
 262 /*
 263 List of what each bit on of the vtable gc bits means.
 264 */
 265 enum {
 266         SGEN_GC_BIT_BRIDGE_OBJECT = 1,
 267         SGEN_GC_BIT_BRIDGE_OPAQUE_OBJECT = 2,
 268         SGEN_GC_BIT_FINALIZER_AWARE = 4,
 269 };
 270
 271 void sgen_gc_init (void);
 272
 273 void sgen_os_init (void);
 274
 275 void sgen_update_heap_boundaries (mword low, mword high);
 276
 277 void sgen_check_section_scan_starts (GCMemSection *section);
 278
 279 void sgen_conservatively_pin_objects_from (void **start, void **end, void *start_nursery, void *end_nursery, int pin_type);
 280
 281 /* Keep in sync with description_for_type() in sgen-internal.c! */
 282 enum {
 283         INTERNAL_MEM_PIN_QUEUE,
 284         INTERNAL_MEM_FRAGMENT,
 285         INTERNAL_MEM_SECTION,
 286         INTERNAL_MEM_SCAN_STARTS,
 287         INTERNAL_MEM_FIN_TABLE,
 288         INTERNAL_MEM_FINALIZE_ENTRY,
 289         INTERNAL_MEM_FINALIZE_READY,
 290         INTERNAL_MEM_DISLINK_TABLE,
 291         INTERNAL_MEM_DISLINK,
 292         INTERNAL_MEM_ROOTS_TABLE,
 293         INTERNAL_MEM_ROOT_RECORD,
 294         INTERNAL_MEM_STATISTICS,
 295         INTERNAL_MEM_STAT_PINNED_CLASS,
 296         INTERNAL_MEM_STAT_REMSET_CLASS,
 297         INTERNAL_MEM_GRAY_QUEUE,
 298         INTERNAL_MEM_MS_TABLES,
 299         INTERNAL_MEM_MS_BLOCK_INFO,
 300         INTERNAL_MEM_MS_BLOCK_INFO_SORT,
 301         INTERNAL_MEM_WORKER_DATA,
 302         INTERNAL_MEM_THREAD_POOL_JOB,
 303         INTERNAL_MEM_BRIDGE_DATA,
 304         INTERNAL_MEM_OLD_BRIDGE_HASH_TABLE,
 305         INTERNAL_MEM_OLD_BRIDGE_HASH_TABLE_ENTRY,
 306         INTERNAL_MEM_BRIDGE_HASH_TABLE,
 307         INTERNAL_MEM_BRIDGE_HASH_TABLE_ENTRY,
 308         INTERNAL_MEM_BRIDGE_ALIVE_HASH_TABLE,
 309         INTERNAL_MEM_BRIDGE_ALIVE_HASH_TABLE_ENTRY,
 310         INTERNAL_MEM_TARJAN_BRIDGE_HASH_TABLE,
 311         INTERNAL_MEM_TARJAN_BRIDGE_HASH_TABLE_ENTRY,
 312         INTERNAL_MEM_TARJAN_OBJ_BUCKET,
 313         INTERNAL_MEM_BRIDGE_DEBUG,
 314         INTERNAL_MEM_TOGGLEREF_DATA,
 315         INTERNAL_MEM_CARDTABLE_MOD_UNION,
 316         INTERNAL_MEM_BINARY_PROTOCOL,
 317         INTERNAL_MEM_TEMPORARY,
 318         INTERNAL_MEM_FIRST_CLIENT
 319 };
 320
 321 enum {
 322         GENERATION_NURSERY,
 323         GENERATION_OLD,
 324         GENERATION_MAX
 325 };
 326
 327 #ifdef SGEN_HEAVY_BINARY_PROTOCOL
 328 #define BINARY_PROTOCOL_ARG(x)  ,x
 329 #else
 330 #define BINARY_PROTOCOL_ARG(x)
 331 #endif
 332
 333 void sgen_init_internal_allocator (void);
 334
 335 #define SGEN_DEFINE_OBJECT_VTABLE
 336 #ifdef SGEN_CLIENT_HEADER
 337 #include SGEN_CLIENT_HEADER
 338 #else
 339 #include "metadata/sgen-client-mono.h"
 340 #endif
 341 #undef SGEN_DEFINE_OBJECT_VTABLE
 342
 343 #include "mono/sgen/sgen-descriptor.h"
 344 #include "mono/sgen/sgen-gray.h"
 345
 346 /* the runtime can register areas of memory as roots: we keep two lists of roots,
 347  * a pinned root set for conservatively scanned roots and a normal one for
 348  * precisely scanned roots (currently implemented as a single list).
 349  */
 350 typedef struct _RootRecord RootRecord;
 351 struct _RootRecord {
 352         char *end_root;
 353         SgenDescriptor root_desc;
 354         int source;
 355         const char *msg;
 356 };
 357
 358 enum {
 359         ROOT_TYPE_NORMAL = 0, /* "normal" roots */
 360         ROOT_TYPE_PINNED = 1, /* roots without a GC descriptor */
 361         ROOT_TYPE_WBARRIER = 2, /* roots with a write barrier */
 362         ROOT_TYPE_NUM
 363 };
 364
 365 extern SgenHashTable roots_hash [ROOT_TYPE_NUM];
 366
 367 int sgen_register_root (char *start, size_t size, SgenDescriptor descr, int root_type, int source, const char *msg);
 368 void sgen_deregister_root (char* addr);
 369
 370 typedef void (*IterateObjectCallbackFunc) (GCObject*, size_t, void*);
 371
 372 void sgen_scan_area_with_callback (char *start, char *end, IterateObjectCallbackFunc callback, void *data, gboolean allow_flags, gboolean fail_on_canaries);
 373
 374 /* eventually share with MonoThread? */
 375 /*
 376  * This structure extends the MonoThreadInfo structure.
 377  */
 378 struct _SgenThreadInfo {
 379         SgenClientThreadInfo client_info;
 380
 381         char **tlab_next_addr;
 382         char **tlab_start_addr;
 383         char **tlab_temp_end_addr;
 384         char **tlab_real_end_addr;
 385
 386 #ifndef HAVE_KW_THREAD
 387         char *tlab_start;
 388         char *tlab_next;
 389         char *tlab_temp_end;
 390         char *tlab_real_end;
 391 #endif
 392 };
 393
 394 gboolean sgen_is_worker_thread (MonoNativeThreadId thread);
 395
 396 typedef void (*CopyOrMarkObjectFunc) (GCObject**, SgenGrayQueue*);
 397 typedef void (*ScanObjectFunc) (GCObject *obj, SgenDescriptor desc, SgenGrayQueue*);
 398 typedef void (*ScanVTypeFunc) (GCObject *full_object, char *start, SgenDescriptor desc, SgenGrayQueue* BINARY_PROTOCOL_ARG (size_t size));
 399 typedef void (*ScanPtrFieldFunc) (GCObject *obj, GCObject **ptr, SgenGrayQueue* queue);
 400 typedef gboolean (*DrainGrayStackFunc) (SgenGrayQueue *queue);
 401
 402 typedef struct {
 403         CopyOrMarkObjectFunc copy_or_mark_object;
 404         ScanObjectFunc scan_object;
 405         ScanVTypeFunc scan_vtype;
 406         ScanPtrFieldFunc scan_ptr_field;
 407         /* Drain stack optimized for the above functions */
 408         DrainGrayStackFunc drain_gray_stack;
 409         /*FIXME add allocation function? */
 410 } SgenObjectOperations;
 411
 412 typedef struct
 413 {
 414         SgenObjectOperations *ops;
 415         SgenGrayQueue *queue;
 416 } ScanCopyContext;
 417
 418 #define CONTEXT_FROM_OBJECT_OPERATIONS(ops, queue) ((ScanCopyContext) { (ops), (queue) })
 419
 420 void sgen_report_internal_mem_usage (void);
 421 void sgen_dump_internal_mem_usage (FILE *heap_dump_file);
 422 void sgen_dump_section (GCMemSection *section, const char *type);
 423 void sgen_dump_occupied (char *start, char *end, char *section_start);
 424
 425 void sgen_register_fixed_internal_mem_type (int type, size_t size);
 426
 427 void* sgen_alloc_internal (int type);
 428 void sgen_free_internal (void *addr, int type);
 429
 430 void* sgen_alloc_internal_dynamic (size_t size, int type, gboolean assert_on_failure);
 431 void sgen_free_internal_dynamic (void *addr, size_t size, int type);
 432
 433 void sgen_pin_stats_enable (void);
 434 void sgen_pin_stats_register_object (GCObject *obj, size_t size);
 435 void sgen_pin_stats_register_global_remset (GCObject *obj);
 436 void sgen_pin_stats_print_class_stats (void);
 437
 438 void sgen_sort_addresses (void **array, size_t size);
 439 void sgen_add_to_global_remset (gpointer ptr, GCObject *obj);
 440
 441 int sgen_get_current_collection_generation (void);
 442 gboolean sgen_collection_is_concurrent (void);
 443 gboolean sgen_concurrent_collection_in_progress (void);
 444
 445 typedef struct _SgenFragment SgenFragment;
 446
 447 struct _SgenFragment {
 448         SgenFragment *next;
 449         char *fragment_start;
 450         char *fragment_next; /* the current soft limit for allocation */
 451         char *fragment_end;
 452         SgenFragment *next_in_order; /* We use a different entry for all active fragments so we can avoid SMR. */
 453 };
 454
 455 typedef struct {
 456         SgenFragment *alloc_head; /* List head to be used when allocating memory. Walk with fragment_next. */
 457         SgenFragment *region_head; /* List head of the region used by this allocator. Walk with next_in_order. */
 458 } SgenFragmentAllocator;
 459
 460 void sgen_fragment_allocator_add (SgenFragmentAllocator *allocator, char *start, char *end);
 461 void sgen_fragment_allocator_release (SgenFragmentAllocator *allocator);
 462 void* sgen_fragment_allocator_serial_alloc (SgenFragmentAllocator *allocator, size_t size);
 463 void* sgen_fragment_allocator_par_alloc (SgenFragmentAllocator *allocator, size_t size);
 464 void* sgen_fragment_allocator_serial_range_alloc (SgenFragmentAllocator *allocator, size_t desired_size, size_t minimum_size, size_t *out_alloc_size);
 465 void* sgen_fragment_allocator_par_range_alloc (SgenFragmentAllocator *allocator, size_t desired_size, size_t minimum_size, size_t *out_alloc_size);
 466 SgenFragment* sgen_fragment_allocator_alloc (void);
 467 void sgen_clear_allocator_fragments (SgenFragmentAllocator *allocator);
 468 void sgen_clear_range (char *start, char *end);
 469
 470
 471 /*
 472 This is a space/speed compromise as we need to make sure the from/to space check is both O(1)
 473 and only hit cache hot memory. On a 4Mb nursery it requires 1024 bytes, or 3% of your average
 474 L1 cache. On small configs with a 512kb nursery, this goes to 0.4%.
 475
 476 Experimental results on how much space we waste with a 4Mb nursery:
 477
 478 Note that the wastage applies to the half nursery, or 2Mb:
 479
 480 Test 1 (compiling corlib):
 481 9: avg: 3.1k
 482 8: avg: 1.6k
 483
 484 */
 485 #define SGEN_TO_SPACE_GRANULE_BITS 9
 486 #define SGEN_TO_SPACE_GRANULE_IN_BYTES (1 << SGEN_TO_SPACE_GRANULE_BITS)
 487
 488 extern char *sgen_space_bitmap;
 489 extern size_t sgen_space_bitmap_size;
 490
 491 static inline gboolean
 492 sgen_nursery_is_to_space (void *object)
 493 {
 494         size_t idx = ((char*)object - sgen_nursery_start) >> SGEN_TO_SPACE_GRANULE_BITS;
 495         size_t byte = idx >> 3;
 496         size_t bit = idx & 0x7;
 497
 498         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 ());
 499         SGEN_ASSERT (4, byte < sgen_space_bitmap_size, "byte index %zd out of range (%zd)", byte, sgen_space_bitmap_size);
 500
 501         return (sgen_space_bitmap [byte] & (1 << bit)) != 0;
 502 }
 503
 504 static inline gboolean
 505 sgen_nursery_is_from_space (void *object)
 506 {
 507         return !sgen_nursery_is_to_space (object);
 508 }
 509
 510 static inline gboolean
 511 sgen_nursery_is_object_alive (GCObject *obj)
 512 {
 513         /* FIXME put this asserts under a non default level */
 514         g_assert (sgen_ptr_in_nursery (obj));
 515
 516         if (sgen_nursery_is_to_space (obj))
 517                 return TRUE;
 518
 519         if (SGEN_OBJECT_IS_PINNED (obj) || SGEN_OBJECT_IS_FORWARDED (obj))
 520                 return TRUE;
 521
 522         return FALSE;
 523 }
 524
 525 typedef struct {
 526         gboolean is_split;
 527
 528         GCObject* (*alloc_for_promotion) (GCVTable vtable, GCObject *obj, size_t objsize, gboolean has_references);
 529
 530         SgenObjectOperations serial_ops;
 531
 532         void (*prepare_to_space) (char *to_space_bitmap, size_t space_bitmap_size);
 533         void (*clear_fragments) (void);
 534         SgenFragment* (*build_fragments_get_exclude_head) (void);
 535         void (*build_fragments_release_exclude_head) (void);
 536         void (*build_fragments_finish) (SgenFragmentAllocator *allocator);
 537         void (*init_nursery) (SgenFragmentAllocator *allocator, char *start, char *end);
 538
 539         gboolean (*handle_gc_param) (const char *opt); /* Optional */
 540         void (*print_gc_param_usage) (void); /* Optional */
 541 } SgenMinorCollector;
 542
 543 extern SgenMinorCollector sgen_minor_collector;
 544
 545 void sgen_simple_nursery_init (SgenMinorCollector *collector);
 546 void sgen_split_nursery_init (SgenMinorCollector *collector);
 547
 548 /* Updating references */
 549
 550 #ifdef SGEN_CHECK_UPDATE_REFERENCE
 551 gboolean sgen_thread_pool_is_thread_pool_thread (MonoNativeThreadId some_thread);
 552
 553 static inline void
 554 sgen_update_reference (GCObject **p, GCObject *o, gboolean allow_null)
 555 {
 556         if (!allow_null)
 557                 SGEN_ASSERT (0, o, "Cannot update a reference with a NULL pointer");
 558         SGEN_ASSERT (0, !sgen_thread_pool_is_thread_pool_thread (mono_native_thread_id_get ()), "Can't update a reference in the worker thread");
 559         *p = o;
 560 }
 561
 562 #define SGEN_UPDATE_REFERENCE_ALLOW_NULL(p,o)   sgen_update_reference ((GCObject**)(p), (GCObject*)(o), TRUE)
 563 #define SGEN_UPDATE_REFERENCE(p,o)              sgen_update_reference ((GCObject**)(p), (GCObject*)(o), FALSE)
 564 #else
 565 #define SGEN_UPDATE_REFERENCE_ALLOW_NULL(p,o)   (*(GCObject**)(p) = (GCObject*)(o))
 566 #define SGEN_UPDATE_REFERENCE(p,o)              SGEN_UPDATE_REFERENCE_ALLOW_NULL ((p), (o))
 567 #endif
 568
 569 /* Major collector */
 570
 571 typedef void (*sgen_cardtable_block_callback) (mword start, mword size);
 572 void sgen_major_collector_iterate_live_block_ranges (sgen_cardtable_block_callback callback);
 573
 574 typedef enum {
 575         ITERATE_OBJECTS_SWEEP = 1,
 576         ITERATE_OBJECTS_NON_PINNED = 2,
 577         ITERATE_OBJECTS_PINNED = 4,
 578         ITERATE_OBJECTS_ALL = ITERATE_OBJECTS_NON_PINNED | ITERATE_OBJECTS_PINNED,
 579         ITERATE_OBJECTS_SWEEP_NON_PINNED = ITERATE_OBJECTS_SWEEP | ITERATE_OBJECTS_NON_PINNED,
 580         ITERATE_OBJECTS_SWEEP_PINNED = ITERATE_OBJECTS_SWEEP | ITERATE_OBJECTS_PINNED,
 581         ITERATE_OBJECTS_SWEEP_ALL = ITERATE_OBJECTS_SWEEP | ITERATE_OBJECTS_NON_PINNED | ITERATE_OBJECTS_PINNED
 582 } IterateObjectsFlags;
 583
 584 typedef struct
 585 {
 586         size_t num_scanned_objects;
 587         size_t num_unique_scanned_objects;
 588 } ScannedObjectCounts;
 589
 590 typedef enum {
 591         CARDTABLE_SCAN_GLOBAL = 0,
 592         CARDTABLE_SCAN_MOD_UNION = 1,
 593         CARDTABLE_SCAN_MOD_UNION_PRECLEAN = CARDTABLE_SCAN_MOD_UNION | 2,
 594 } CardTableScanType;
 595
 596 typedef struct _SgenMajorCollector SgenMajorCollector;
 597 struct _SgenMajorCollector {
 598         size_t section_size;
 599         gboolean is_concurrent;
 600         gboolean needs_thread_pool;
 601         gboolean supports_cardtable;
 602         gboolean sweeps_lazily;
 603
 604         void* (*alloc_heap) (mword nursery_size, mword nursery_align, int nursery_bits);
 605         gboolean (*is_object_live) (GCObject *obj);
 606         GCObject* (*alloc_small_pinned_obj) (GCVTable vtable, size_t size, gboolean has_references);
 607         GCObject* (*alloc_degraded) (GCVTable vtable, size_t size);
 608
 609         SgenObjectOperations major_ops_serial;
 610         SgenObjectOperations major_ops_concurrent_start;
 611         SgenObjectOperations major_ops_concurrent_finish;
 612
 613         GCObject* (*alloc_object) (GCVTable vtable, size_t size, gboolean has_references);
 614         void (*free_pinned_object) (GCObject *obj, size_t size);
 615
 616         /*
 617          * This is used for domain unloading, heap walking from the logging profiler, and
 618          * debugging.  Can assume the world is stopped.
 619          */
 620         void (*iterate_objects) (IterateObjectsFlags flags, IterateObjectCallbackFunc callback, void *data);
 621
 622         void (*free_non_pinned_object) (GCObject *obj, size_t size);
 623         void (*pin_objects) (SgenGrayQueue *queue);
 624         void (*pin_major_object) (GCObject *obj, SgenGrayQueue *queue);
 625         void (*scan_card_table) (CardTableScanType scan_type, ScanCopyContext ctx);
 626         void (*iterate_live_block_ranges) (sgen_cardtable_block_callback callback);
 627         void (*update_cardtable_mod_union) (void);
 628         void (*init_to_space) (void);
 629         void (*sweep) (void);
 630         gboolean (*have_swept) (void);
 631         void (*finish_sweeping) (void);
 632         void (*free_swept_blocks) (size_t allowance);
 633         void (*check_scan_starts) (void);
 634         void (*dump_heap) (FILE *heap_dump_file);
 635         gint64 (*get_used_size) (void);
 636         void (*start_nursery_collection) (void);
 637         void (*finish_nursery_collection) (void);
 638         void (*start_major_collection) (void);
 639         void (*finish_major_collection) (ScannedObjectCounts *counts);
 640         gboolean (*ptr_is_in_non_pinned_space) (char *ptr, char **start);
 641         gboolean (*ptr_is_from_pinned_alloc) (char *ptr);
 642         void (*report_pinned_memory_usage) (void);
 643         size_t (*get_num_major_sections) (void);
 644         size_t (*get_bytes_survived_last_sweep) (void);
 645         gboolean (*handle_gc_param) (const char *opt);
 646         void (*print_gc_param_usage) (void);
 647         void (*post_param_init) (SgenMajorCollector *collector);
 648         gboolean (*is_valid_object) (char *ptr);
 649         GCVTable (*describe_pointer) (char *pointer);
 650         guint8* (*get_cardtable_mod_union_for_reference) (char *object);
 651         long long (*get_and_reset_num_major_objects_marked) (void);
 652         void (*count_cards) (long long *num_total_cards, long long *num_marked_cards);
 653 };
 654
 655 extern SgenMajorCollector major_collector;
 656
 657 void sgen_marksweep_init (SgenMajorCollector *collector);
 658 void sgen_marksweep_fixed_init (SgenMajorCollector *collector);
 659 void sgen_marksweep_par_init (SgenMajorCollector *collector);
 660 void sgen_marksweep_fixed_par_init (SgenMajorCollector *collector);
 661 void sgen_marksweep_conc_init (SgenMajorCollector *collector);
 662 SgenMajorCollector* sgen_get_major_collector (void);
 663
 664
 665 typedef struct _SgenRememberedSet {
 666         void (*wbarrier_set_field) (GCObject *obj, gpointer field_ptr, GCObject* value);
 667         void (*wbarrier_arrayref_copy) (gpointer dest_ptr, gpointer src_ptr, int count);
 668         void (*wbarrier_value_copy) (gpointer dest, gpointer src, int count, size_t element_size);
 669         void (*wbarrier_object_copy) (GCObject* obj, GCObject *src);
 670         void (*wbarrier_generic_nostore) (gpointer ptr);
 671         void (*record_pointer) (gpointer ptr);
 672
 673         void (*scan_remsets) (ScanCopyContext ctx);
 674
 675         void (*clear_cards) (void);
 676
 677         void (*finish_minor_collection) (void);
 678         gboolean (*find_address) (char *addr);
 679         gboolean (*find_address_with_cards) (char *cards_start, guint8 *cards, char *addr);
 680 } SgenRememberedSet;
 681
 682 SgenRememberedSet *sgen_get_remset (void);
 683
 684 /*
 685  * These must be kept in sync with object.h.  They're here for using SGen independently of
 686  * Mono.
 687  */
 688 void mono_gc_wbarrier_arrayref_copy (gpointer dest_ptr, gpointer src_ptr, int count);
 689 void mono_gc_wbarrier_generic_nostore (gpointer ptr);
 690 void mono_gc_wbarrier_generic_store (gpointer ptr, GCObject* value);
 691 void mono_gc_wbarrier_generic_store_atomic (gpointer ptr, GCObject *value);
 692
 693 void sgen_wbarrier_value_copy_bitmap (gpointer _dest, gpointer _src, int size, unsigned bitmap);
 694
 695 static inline SgenDescriptor
 696 sgen_obj_get_descriptor (GCObject *obj)
 697 {
 698         GCVTable vtable = SGEN_LOAD_VTABLE_UNCHECKED (obj);
 699         SGEN_ASSERT (9, !SGEN_POINTER_IS_TAGGED_ANY (vtable), "Object can't be tagged");
 700         return sgen_vtable_get_descriptor (vtable);
 701 }
 702
 703 static inline SgenDescriptor
 704 sgen_obj_get_descriptor_safe (GCObject *obj)
 705 {
 706         GCVTable vtable = SGEN_LOAD_VTABLE (obj);
 707         return sgen_vtable_get_descriptor (vtable);
 708 }
 709
 710 static mword sgen_client_par_object_get_size (GCVTable vtable, GCObject* o);
 711 static mword sgen_client_slow_object_get_size (GCVTable vtable, GCObject* o);
 712
 713 static inline mword
 714 sgen_safe_object_get_size (GCObject *obj)
 715 {
 716        GCObject *forwarded;
 717
 718        if ((forwarded = SGEN_OBJECT_IS_FORWARDED (obj)))
 719                obj = forwarded;
 720
 721        return sgen_client_par_object_get_size (SGEN_LOAD_VTABLE (obj), obj);
 722 }
 723
 724 static inline gboolean
 725 sgen_safe_object_is_small (GCObject *obj, int type)
 726 {
 727         if (type <= DESC_TYPE_MAX_SMALL_OBJ)
 728                 return TRUE;
 729         return SGEN_ALIGN_UP (sgen_safe_object_get_size ((GCObject*)obj)) <= SGEN_MAX_SMALL_OBJ_SIZE;
 730 }
 731
 732 /*
 733  * This variant guarantees to return the exact size of the object
 734  * before alignment. Needed for canary support.
 735  */
 736 static inline guint
 737 sgen_safe_object_get_size_unaligned (GCObject *obj)
 738 {
 739         GCObject *forwarded;
 740
 741         if ((forwarded = SGEN_OBJECT_IS_FORWARDED (obj))) {
 742                 obj = (GCObject*)forwarded;
 743         }
 744
 745         return sgen_client_slow_object_get_size (SGEN_LOAD_VTABLE (obj), obj);
 746 }
 747
 748 #ifdef SGEN_CLIENT_HEADER
 749 #include SGEN_CLIENT_HEADER
 750 #else
 751 #include "metadata/sgen-client-mono.h"
 752 #endif
 753
 754 gboolean sgen_object_is_live (GCObject *obj);
 755
 756 void  sgen_init_fin_weak_hash (void);
 757
 758 /* FIXME: move the toggleref stuff out of here */
 759 void sgen_mark_togglerefs (char *start, char *end, ScanCopyContext ctx);
 760 void sgen_clear_togglerefs (char *start, char *end, ScanCopyContext ctx);
 761
 762 void sgen_process_togglerefs (void);
 763 void sgen_register_test_toggleref_callback (void);
 764
 765 void sgen_mark_bridge_object (GCObject *obj);
 766 void sgen_collect_bridge_objects (int generation, ScanCopyContext ctx);
 767
 768 typedef gboolean (*SgenObjectPredicateFunc) (GCObject *obj, void *user_data);
 769
 770 void sgen_null_links_if (SgenObjectPredicateFunc predicate, void *data, int generation, gboolean track);
 771
 772 gboolean sgen_gc_is_object_ready_for_finalization (GCObject *object);
 773 void sgen_gc_lock (void);
 774 void sgen_gc_unlock (void);
 775
 776 void sgen_queue_finalization_entry (GCObject *obj);
 777 const char* sgen_generation_name (int generation);
 778
 779 void sgen_finalize_in_range (int generation, ScanCopyContext ctx);
 780 void sgen_null_link_in_range (int generation, ScanCopyContext ctx, gboolean track);
 781 void sgen_process_fin_stage_entries (void);
 782 gboolean sgen_have_pending_finalizers (void);
 783 void sgen_object_register_for_finalization (GCObject *obj, void *user_data);
 784
 785 int sgen_gather_finalizers_if (SgenObjectPredicateFunc predicate, void *user_data, GCObject **out_array, int out_size);
 786 void sgen_remove_finalizers_if (SgenObjectPredicateFunc predicate, void *user_data, int generation);
 787
 788 void sgen_register_disappearing_link (GCObject *obj, void **link, gboolean track, gboolean in_gc);
 789
 790 GCObject* sgen_weak_link_get (void **link_addr);
 791
 792 gboolean sgen_drain_gray_stack (ScanCopyContext ctx);
 793
 794 enum {
 795         SPACE_NURSERY,
 796         SPACE_MAJOR,
 797         SPACE_LOS
 798 };
 799
 800 void sgen_pin_object (GCObject *object, SgenGrayQueue *queue);
 801 void sgen_set_pinned_from_failed_allocation (mword objsize);
 802
 803 void sgen_ensure_free_space (size_t size, int generation);
 804 void sgen_gc_collect (int generation);
 805 void sgen_perform_collection (size_t requested_size, int generation_to_collect, const char *reason, gboolean wait_to_finish);
 806
 807 int sgen_gc_collection_count (int generation);
 808 /* FIXME: what exactly does this return? */
 809 size_t sgen_gc_get_used_size (void);
 810 size_t sgen_gc_get_total_heap_allocation (void);
 811
 812 /* STW */
 813
 814 typedef struct {
 815         int generation;
 816         const char *reason;
 817         gboolean is_overflow;
 818         gint64 total_time;
 819         gint64 stw_time;
 820 } GGTimingInfo;
 821
 822 void sgen_stop_world (int generation);
 823 void sgen_restart_world (int generation, GGTimingInfo *timing);
 824 gboolean sgen_is_world_stopped (void);
 825
 826 gboolean sgen_set_allow_synchronous_major (gboolean flag);
 827
 828 /* LOS */
 829
 830 typedef struct _LOSObject LOSObject;
 831 struct _LOSObject {
 832         LOSObject *next;
 833         mword size; /* this is the object size, lowest bit used for pin/mark */
 834         guint8 * volatile cardtable_mod_union; /* only used by the concurrent collector */
 835 #if SIZEOF_VOID_P < 8
 836         mword dummy;            /* to align object to sizeof (double) */
 837 #endif
 838         GCObject data [MONO_ZERO_LEN_ARRAY];
 839 };
 840
 841 extern LOSObject *los_object_list;
 842 extern mword los_memory_usage;
 843
 844 void sgen_los_free_object (LOSObject *obj);
 845 void* sgen_los_alloc_large_inner (GCVTable vtable, size_t size);
 846 void sgen_los_sweep (void);
 847 gboolean sgen_ptr_is_in_los (char *ptr, char **start);
 848 void sgen_los_iterate_objects (IterateObjectCallbackFunc cb, void *user_data);
 849 void sgen_los_iterate_live_block_ranges (sgen_cardtable_block_callback callback);
 850 void sgen_los_scan_card_table (CardTableScanType scan_type, ScanCopyContext ctx);
 851 void sgen_los_update_cardtable_mod_union (void);
 852 void sgen_los_count_cards (long long *num_total_cards, long long *num_marked_cards);
 853 gboolean sgen_los_is_valid_object (char *object);
 854 gboolean mono_sgen_los_describe_pointer (char *ptr);
 855 LOSObject* sgen_los_header_for_object (GCObject *data);
 856 mword sgen_los_object_size (LOSObject *obj);
 857 void sgen_los_pin_object (GCObject *obj);
 858 gboolean sgen_los_object_is_pinned (GCObject *obj);
 859 void sgen_los_mark_mod_union_card (GCObject *mono_obj, void **ptr);
 860
 861
 862 /* nursery allocator */
 863
 864 void sgen_clear_nursery_fragments (void);
 865 void sgen_nursery_allocator_prepare_for_pinning (void);
 866 void sgen_nursery_allocator_set_nursery_bounds (char *nursery_start, char *nursery_end);
 867 mword sgen_build_nursery_fragments (GCMemSection *nursery_section, SgenGrayQueue *unpin_queue);
 868 void sgen_init_nursery_allocator (void);
 869 void sgen_nursery_allocator_init_heavy_stats (void);
 870 void sgen_init_allocator (void);
 871 char* sgen_nursery_alloc_get_upper_alloc_bound (void);
 872 void* sgen_nursery_alloc (size_t size);
 873 void* sgen_nursery_alloc_range (size_t size, size_t min_size, size_t *out_alloc_size);
 874 gboolean sgen_can_alloc_size (size_t size);
 875 void sgen_nursery_retire_region (void *address, ptrdiff_t size);
 876
 877 void sgen_nursery_alloc_prepare_for_minor (void);
 878 void sgen_nursery_alloc_prepare_for_major (void);
 879
 880 GCObject* sgen_alloc_for_promotion (GCObject *obj, size_t objsize, gboolean has_references);
 881
 882 GCObject* sgen_alloc_obj_nolock (GCVTable vtable, size_t size);
 883 GCObject* sgen_try_alloc_obj_nolock (GCVTable vtable, size_t size);
 884
 885 /* Threads */
 886
 887 void* sgen_thread_register (SgenThreadInfo* info, void *addr);
 888 void sgen_thread_unregister (SgenThreadInfo *p);
 889
 890 /* Finalization/ephemeron support */
 891
 892 static inline gboolean
 893 sgen_major_is_object_alive (GCObject *object)
 894 {
 895         mword objsize;
 896
 897         /* Oldgen objects can be pinned and forwarded too */
 898         if (SGEN_OBJECT_IS_PINNED (object) || SGEN_OBJECT_IS_FORWARDED (object))
 899                 return TRUE;
 900
 901         /*
 902          * FIXME: major_collector.is_object_live() also calculates the
 903          * size.  Avoid the double calculation.
 904          */
 905         objsize = SGEN_ALIGN_UP (sgen_safe_object_get_size (object));
 906         if (objsize > SGEN_MAX_SMALL_OBJ_SIZE)
 907                 return sgen_los_object_is_pinned (object);
 908
 909         return major_collector.is_object_live (object);
 910 }
 911
 912 /*
 913  * This function returns true if @object is either alive or it belongs to the old gen
 914  * and we're currently doing a minor collection.
 915  */
 916 static inline int
 917 sgen_is_object_alive_for_current_gen (GCObject *object)
 918 {
 919         if (sgen_ptr_in_nursery (object))
 920                 return sgen_nursery_is_object_alive (object);
 921
 922         if (current_collection_generation == GENERATION_NURSERY)
 923                 return TRUE;
 924
 925         return sgen_major_is_object_alive (object);
 926 }
 927
 928 int sgen_gc_invoke_finalizers (void);
 929
 930 /* GC handles */
 931
 932 void sgen_init_gchandles (void);
 933
 934 void sgen_null_links_if (SgenObjectPredicateFunc predicate, void *data, int generation, gboolean track);
 935
 936 typedef gpointer (*SgenGCHandleIterateCallback) (gpointer hidden, GCHandleType handle_type, int max_generation, gpointer user);
 937
 938 void sgen_gchandle_iterate (GCHandleType handle_type, int max_generation, SgenGCHandleIterateCallback callback, gpointer user);
 939 void sgen_gchandle_set_target (guint32 gchandle, GCObject *obj);
 940 void sgen_mark_normal_gc_handles (void *addr, SgenUserMarkFunc mark_func, void *gc_data);
 941 gpointer sgen_gchandle_get_metadata (guint32 gchandle);
 942
 943 /* Other globals */
 944
 945 extern GCMemSection *nursery_section;
 946 extern guint32 collect_before_allocs;
 947 extern guint32 verify_before_allocs;
 948 extern gboolean has_per_allocation_action;
 949 extern size_t degraded_mode;
 950 extern int default_nursery_size;
 951 extern guint32 tlab_size;
 952 extern NurseryClearPolicy nursery_clear_policy;
 953 extern gboolean sgen_try_free_some_memory;
 954
 955 extern MonoCoopMutex gc_mutex;
 956
 957 /* Nursery helpers. */
 958
 959 static inline void
 960 sgen_set_nursery_scan_start (char *p)
 961 {
 962         size_t idx = (p - (char*)nursery_section->data) / SGEN_SCAN_START_SIZE;
 963         char *old = nursery_section->scan_starts [idx];
 964         if (!old || old > p)
 965                 nursery_section->scan_starts [idx] = p;
 966 }
 967
 968
 969 /* Object Allocation */
 970
 971 typedef enum {
 972         ATYPE_NORMAL,
 973         ATYPE_VECTOR,
 974         ATYPE_SMALL,
 975         ATYPE_STRING,
 976         ATYPE_NUM
 977 } SgenAllocatorType;
 978
 979 void sgen_init_tlab_info (SgenThreadInfo* info);
 980 void sgen_clear_tlabs (void);
 981
 982 GCObject* sgen_alloc_obj (GCVTable vtable, size_t size);
 983 GCObject* sgen_alloc_obj_pinned (GCVTable vtable, size_t size);
 984 GCObject* sgen_alloc_obj_mature (GCVTable vtable, size_t size);
 985
 986 /* Debug support */
 987
 988 void sgen_check_consistency (void);
 989 void sgen_check_mod_union_consistency (void);
 990 void sgen_check_major_refs (void);
 991 void sgen_check_whole_heap (gboolean allow_missing_pinning);
 992 void sgen_check_whole_heap_stw (void);
 993 void sgen_check_objref (char *obj);
 994 void sgen_check_heap_marked (gboolean nursery_must_be_pinned);
 995 void sgen_check_nursery_objects_pinned (gboolean pinned);
 996 void sgen_check_for_xdomain_refs (void);
 997 GCObject* sgen_find_object_for_ptr (char *ptr);
 998
 999 void mono_gc_scan_for_specific_ref (GCObject *key, gboolean precise);
1000
1001 void sgen_debug_enable_heap_dump (const char *filename);
1002 void sgen_debug_dump_heap (const char *type, int num, const char *reason);
1003
1004 void sgen_debug_verify_nursery (gboolean do_dump_nursery_content);
1005 void sgen_debug_check_nursery_is_clean (void);
1006
1007 /* Environment variable parsing */
1008
1009 #define MONO_GC_PARAMS_NAME     "MONO_GC_PARAMS"
1010 #define MONO_GC_DEBUG_NAME      "MONO_GC_DEBUG"
1011
1012 void sgen_env_var_error (const char *env_var, const char *fallback, const char *description_format, ...);
1013
1014 /* Utilities */
1015
1016 void sgen_qsort (void *base, size_t nel, size_t width, int (*compar) (const void*, const void*));
1017 gint64 sgen_timestamp (void);
1018
1019 /*
1020  * Canary (guard word) support
1021  * Notes:
1022  * - CANARY_SIZE must be multiple of word size in bytes
1023  * - Canary space is not included on checks against SGEN_MAX_SMALL_OBJ_SIZE
1024  */
1025
1026 gboolean nursery_canaries_enabled (void);
1027
1028 #define CANARY_SIZE 8
1029 #define CANARY_STRING  "koupepia"
1030
1031 #define CANARIFY_SIZE(size) if (nursery_canaries_enabled ()) {  \
1032                         size = size + CANARY_SIZE;      \
1033                 }
1034
1035 #define CANARIFY_ALLOC(addr,size) if (nursery_canaries_enabled ()) {    \
1036                                 memcpy ((char*) (addr) + (size), CANARY_STRING, CANARY_SIZE);   \
1037                         }
1038
1039 #define CANARY_VALID(addr) (strncmp ((char*) (addr), CANARY_STRING, CANARY_SIZE) == 0)
1040
1041 #define CHECK_CANARY_FOR_OBJECT(addr,fail) if (nursery_canaries_enabled ()) {   \
1042                                 char* canary_ptr = (char*) (addr) + sgen_safe_object_get_size_unaligned ((GCObject *) (addr));  \
1043                                 if (!CANARY_VALID(canary_ptr)) {        \
1044                                         char canary_copy[CANARY_SIZE +1];       \
1045                                         strncpy (canary_copy, canary_ptr, CANARY_SIZE); \
1046                                         canary_copy[CANARY_SIZE] = 0;   \
1047                                         if ((fail))                     \
1048                                                 g_error ("CORRUPT CANARY:\naddr->%p\ntype->%s\nexcepted->'%s'\nfound->'%s'\n", (char*) addr, sgen_client_vtable_get_name (SGEN_LOAD_VTABLE ((addr))), CANARY_STRING, canary_copy); \
1049                                         else                            \
1050                                                 g_warning ("CORRUPT CANARY:\naddr->%p\ntype->%s\nexcepted->'%s'\nfound->'%s'\n", (char*) addr, sgen_client_vtable_get_name (SGEN_LOAD_VTABLE ((addr))), CANARY_STRING, canary_copy); \
1051                                 } }
1052
1053 /*
1054  * This causes the compile to extend the liveness of 'v' till the call to dummy_use
1055  */
1056 static inline void
1057 sgen_dummy_use (gpointer v)
1058 {
1059 #if defined(__GNUC__)
1060         __asm__ volatile ("" : "=r"(v) : "r"(v));
1061 #elif defined(_MSC_VER)
1062         static volatile gpointer ptr;
1063         ptr = v;
1064 #else
1065 #error "Implement sgen_dummy_use for your compiler"
1066 #endif
1067 }
1068
1069 #endif /* HAVE_SGEN_GC */
1070
1071 #endif /* __MONO_SGENGC_H__ */