2 * sgen-gc.c: Simple generational GC.
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
9 * This library is free software; you can redistribute it and/or
10 * modify it under the terms of the GNU Library General Public
11 * License 2.0 as published by the Free Software Foundation;
13 * This library is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16 * Library General Public License for more details.
18 * You should have received a copy of the GNU Library General Public
19 * License 2.0 along with this library; if not, write to the Free
20 * Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
22 #ifndef __MONO_SGENGC_H__
23 #define __MONO_SGENGC_H__
30 typedef struct _SgenThreadInfo SgenThreadInfo;
31 #define THREAD_INFO_TYPE SgenThreadInfo
38 #include <mono/utils/mono-compiler.h>
39 #include <mono/utils/mono-threads.h>
40 #include <mono/utils/dtrace.h>
41 #include <mono/utils/mono-logger-internal.h>
42 #include <mono/utils/atomic.h>
43 #include <mono/utils/mono-mutex.h>
44 #include <mono/metadata/class-internals.h>
45 #include <mono/metadata/object-internals.h>
46 #include <mono/metadata/sgen-conf.h>
47 #include <mono/metadata/sgen-archdep.h>
48 #include <mono/metadata/sgen-descriptor.h>
49 #include <mono/metadata/sgen-gray.h>
50 #include <mono/metadata/sgen-hash-table.h>
52 /* The method used to clear the nursery */
53 /* Clearing at nursery collections is the safest, but has bad interactions with caches.
54 * Clearing at TLAB creation is much faster, but more complex and it might expose hard
59 CLEAR_AT_TLAB_CREATION
62 NurseryClearPolicy sgen_get_nursery_clear_policy (void) MONO_INTERNAL;
64 #define SGEN_TV_DECLARE(name) gint64 name
65 #define SGEN_TV_GETTIME(tv) tv = mono_100ns_ticks ()
66 #define SGEN_TV_ELAPSED(start,end) (int)((end-start) / 10)
67 #define SGEN_TV_ELAPSED_MS(start,end) ((SGEN_TV_ELAPSED((start),(end)) + 500) / 1000)
69 #if !defined(__MACH__) && !MONO_MACH_ARCH_SUPPORTED && defined(HAVE_PTHREAD_KILL)
70 #define SGEN_POSIX_STW 1
73 /* eventually share with MonoThread? */
75 * This structure extends the MonoThreadInfo structure.
77 struct _SgenThreadInfo {
80 This is set to TRUE when STW fails to suspend a thread, most probably because the
81 underlying thread is dead.
84 volatile int in_critical_region;
87 This is set the argument of mono_gc_set_skip_thread.
89 A thread that knowingly holds no managed state can call this
90 function around blocking loops to reduce the GC burden by not
96 void *stack_start_limit;
97 char **tlab_next_addr;
98 char **tlab_start_addr;
99 char **tlab_temp_end_addr;
100 char **tlab_real_end_addr;
101 gpointer runtime_data;
103 #ifdef SGEN_POSIX_STW
104 /* This is -1 until the first suspend. */
106 /* FIXME: kill this, we only use signals on systems that have rt-posix, which doesn't have issues with duplicates. */
107 unsigned int stop_count; /* to catch duplicate signals. */
110 gpointer stopped_ip; /* only valid if the thread is stopped */
111 MonoDomain *stopped_domain; /* dsto */
113 /*FIXME pretty please finish killing ARCH_NUM_REGS */
115 MonoContext ctx; /* ditto */
117 gpointer regs[ARCH_NUM_REGS]; /* ditto */
120 #ifndef HAVE_KW_THREAD
129 * The nursery section uses this struct.
131 typedef struct _GCMemSection GCMemSection;
132 struct _GCMemSection {
135 /* pointer where more data could be allocated if it fits */
139 * scan starts is an array of pointers to objects equally spaced in the allocation area
140 * They let use quickly find pinned objects from pinning pointers.
143 /* in major collections indexes in the pin_queue for objects that pin this section */
144 void **pin_queue_start;
145 int pin_queue_num_entries;
146 unsigned int num_scan_start;
150 * Recursion is not allowed for the thread lock.
152 #define LOCK_DECLARE(name) mono_mutex_t name
153 /* if changing LOCK_INIT to something that isn't idempotent, look at
154 its use in mono_gc_base_init in sgen-gc.c */
155 #define LOCK_INIT(name) mono_mutex_init (&(name))
156 #define LOCK_GC do { \
157 mono_mutex_lock (&gc_mutex); \
160 #define TRYLOCK_GC (mono_mutex_trylock (&gc_mutex) == 0)
161 #define UNLOCK_GC do { \
162 mono_mutex_unlock (&gc_mutex); \
163 MONO_GC_UNLOCKED (); \
166 extern LOCK_DECLARE (sgen_interruption_mutex);
168 #define LOCK_INTERRUPTION mono_mutex_lock (&sgen_interruption_mutex)
169 #define UNLOCK_INTERRUPTION mono_mutex_unlock (&sgen_interruption_mutex)
171 /* FIXME: Use InterlockedAdd & InterlockedAdd64 to reduce the CAS cost. */
172 #define SGEN_CAS_PTR InterlockedCompareExchangePointer
173 #define SGEN_ATOMIC_ADD(x,i) do { \
177 } while (InterlockedCompareExchange (&(x), __old_x + (i), __old_x) != __old_x); \
179 #define SGEN_ATOMIC_ADD_P(x,i) do { \
183 } while (InterlockedCompareExchangePointer ((void**)&(x), (void*)(__old_x + (i)), (void*)__old_x) != (void*)__old_x); \
188 /* we intercept pthread_create calls to know which threads exist */
189 #define USE_PTHREAD_INTERCEPT 1
192 #ifdef HEAVY_STATISTICS
193 #define HEAVY_STAT(x) x
195 extern long long stat_objects_alloced_degraded;
196 extern long long stat_bytes_alloced_degraded;
197 extern long long stat_copy_object_called_major;
198 extern long long stat_objects_copied_major;
200 #define HEAVY_STAT(x)
203 #define SGEN_ASSERT(level, a, ...) do { \
204 if (G_UNLIKELY ((level) <= SGEN_MAX_ASSERT_LEVEL && !(a))) { \
205 g_error (__VA_ARGS__); \
209 #define SGEN_LOG(level, format, ...) do { \
210 if (G_UNLIKELY ((level) <= SGEN_MAX_DEBUG_LEVEL && (level) <= gc_debug_level)) { \
211 mono_gc_printf (gc_debug_file, format, ##__VA_ARGS__); \
214 #define SGEN_COND_LOG(level, cond, format, ...) do { \
215 if (G_UNLIKELY ((level) <= SGEN_MAX_DEBUG_LEVEL && (level) <= gc_debug_level)) { \
217 mono_gc_printf (gc_debug_file, format, ##__VA_ARGS__); \
220 #define SGEN_LOG_DO(level, fun) do { \
221 if (G_UNLIKELY ((level) <= SGEN_MAX_DEBUG_LEVEL && (level) <= gc_debug_level)) { \
225 extern int gc_debug_level;
226 extern FILE* gc_debug_file;
228 extern int current_collection_generation;
230 extern unsigned int sgen_global_stop_count;
232 extern gboolean bridge_processing_in_progress;
234 extern int num_ready_finalizers;
236 #define SGEN_ALLOC_ALIGN 8
237 #define SGEN_ALLOC_ALIGN_BITS 3
239 #define SGEN_ALIGN_UP(s) (((s)+(SGEN_ALLOC_ALIGN-1)) & ~(SGEN_ALLOC_ALIGN-1))
242 * The link pointer is hidden by negating each bit. We use the lowest
243 * bit of the link (before negation) to store whether it needs
244 * resurrection tracking.
246 #define HIDE_POINTER(p,t) ((gpointer)(~((gulong)(p)|((t)?1:0))))
247 #define REVEAL_POINTER(p) ((gpointer)((~(gulong)(p))&~3L))
249 #ifdef SGEN_ALIGN_NURSERY
250 #define SGEN_PTR_IN_NURSERY(p,bits,start,end) (((mword)(p) & ~((1 << (bits)) - 1)) == (mword)(start))
252 #define SGEN_PTR_IN_NURSERY(p,bits,start,end) ((char*)(p) >= (start) && (char*)(p) < (end))
257 /* good sizes are 512KB-1MB: larger ones increase a lot memzeroing time */
258 #define DEFAULT_NURSERY_SIZE (sgen_nursery_size)
259 extern int sgen_nursery_size MONO_INTERNAL;
260 #ifdef SGEN_ALIGN_NURSERY
261 /* The number of trailing 0 bits in DEFAULT_NURSERY_SIZE */
262 #define DEFAULT_NURSERY_BITS (sgen_nursery_bits)
263 extern int sgen_nursery_bits MONO_INTERNAL;
268 #define DEFAULT_NURSERY_SIZE (4*1024*1024)
269 #ifdef SGEN_ALIGN_NURSERY
270 #define DEFAULT_NURSERY_BITS 22
275 #ifndef SGEN_ALIGN_NURSERY
276 #define DEFAULT_NURSERY_BITS -1
279 extern char *sgen_nursery_start MONO_INTERNAL;
280 extern char *sgen_nursery_end MONO_INTERNAL;
282 static MONO_ALWAYS_INLINE gboolean
283 sgen_ptr_in_nursery (void *p)
285 return SGEN_PTR_IN_NURSERY ((p), DEFAULT_NURSERY_BITS, sgen_nursery_start, sgen_nursery_end);
288 static MONO_ALWAYS_INLINE char*
289 sgen_get_nursery_start (void)
291 return sgen_nursery_start;
294 static MONO_ALWAYS_INLINE char*
295 sgen_get_nursery_end (void)
297 return sgen_nursery_end;
300 /* Structure that corresponds to a MonoVTable: desc is a mword so requires
301 * no cast from a pointer to an integer
308 /* these bits are set in the object vtable: we could merge them since an object can be
309 * either pinned or forwarded but not both.
310 * We store them in the vtable slot because the bits are used in the sync block for
311 * other purposes: if we merge them and alloc the sync blocks aligned to 8 bytes, we can change
312 * this and use bit 3 in the syncblock (with the lower two bits both set for forwarded, that
313 * would be an invalid combination for the monitor and hash code).
314 * The values are already shifted.
315 * The forwarding address is stored in the sync block.
317 #define SGEN_FORWARDED_BIT 1
318 #define SGEN_PINNED_BIT 2
319 #define SGEN_VTABLE_BITS_MASK 0x3
321 /* returns NULL if not forwarded, or the forwarded address */
322 #define SGEN_OBJECT_IS_FORWARDED(obj) (((mword*)(obj))[0] & SGEN_FORWARDED_BIT ? (void*)(((mword*)(obj))[0] & ~SGEN_VTABLE_BITS_MASK) : NULL)
323 #define SGEN_OBJECT_IS_PINNED(obj) (((mword*)(obj))[0] & SGEN_PINNED_BIT)
325 /* set the forwarded address fw_addr for object obj */
326 #define SGEN_FORWARD_OBJECT(obj,fw_addr) do { \
327 ((mword*)(obj))[0] = (mword)(fw_addr) | SGEN_FORWARDED_BIT; \
329 #define SGEN_PIN_OBJECT(obj) do { \
330 ((mword*)(obj))[0] |= SGEN_PINNED_BIT; \
332 #define SGEN_UNPIN_OBJECT(obj) do { \
333 ((mword*)(obj))[0] &= ~SGEN_PINNED_BIT; \
337 * Since we set bits in the vtable, use the macro to load it from the pointer to
338 * an object that is potentially pinned.
340 #define SGEN_LOAD_VTABLE(addr) ((*(mword*)(addr)) & ~SGEN_VTABLE_BITS_MASK)
342 #if defined(SGEN_GRAY_OBJECT_ENQUEUE) || SGEN_MAX_DEBUG_LEVEL >= 9
343 #define GRAY_OBJECT_ENQUEUE sgen_gray_object_enqueue
344 #define GRAY_OBJECT_DEQUEUE(queue,o) ((o) = sgen_gray_object_dequeue ((queue)))
346 #define GRAY_OBJECT_ENQUEUE(queue,o) do { \
347 if (G_UNLIKELY (!(queue)->first || (queue)->first->end == SGEN_GRAY_QUEUE_SECTION_SIZE)) \
348 sgen_gray_object_enqueue ((queue), (o)); \
350 (queue)->first->objects [(queue)->first->end++] = (o); \
353 #define GRAY_OBJECT_DEQUEUE(queue,o) do { \
354 if (!(queue)->first) \
356 else if (G_UNLIKELY ((queue)->first->end == 1)) \
357 (o) = sgen_gray_object_dequeue ((queue)); \
359 (o) = (queue)->first->objects [--(queue)->first->end]; \
364 List of what each bit on of the vtable gc bits means.
367 SGEN_GC_BIT_BRIDGE_OBJECT = 1,
370 /* the runtime can register areas of memory as roots: we keep two lists of roots,
371 * a pinned root set for conservatively scanned roots and a normal one for
372 * precisely scanned roots (currently implemented as a single list).
374 typedef struct _RootRecord RootRecord;
381 ROOT_TYPE_NORMAL = 0, /* "normal" roots */
382 ROOT_TYPE_PINNED = 1, /* roots without a GC descriptor */
383 ROOT_TYPE_WBARRIER = 2, /* roots with a write barrier */
387 extern SgenHashTable roots_hash [ROOT_TYPE_NUM];
389 typedef void (*IterateObjectCallbackFunc) (char*, size_t, void*);
391 int sgen_thread_handshake (BOOL suspend) MONO_INTERNAL;
392 gboolean sgen_suspend_thread (SgenThreadInfo *info) MONO_INTERNAL;
393 gboolean sgen_resume_thread (SgenThreadInfo *info) MONO_INTERNAL;
394 void sgen_wait_for_suspend_ack (int count) MONO_INTERNAL;
395 void sgen_os_init (void) MONO_INTERNAL;
397 gboolean sgen_is_worker_thread (MonoNativeThreadId thread) MONO_INTERNAL;
399 void sgen_update_heap_boundaries (mword low, mword high) MONO_INTERNAL;
401 void sgen_scan_area_with_callback (char *start, char *end, IterateObjectCallbackFunc callback, void *data, gboolean allow_flags) MONO_INTERNAL;
402 void sgen_check_section_scan_starts (GCMemSection *section) MONO_INTERNAL;
404 /* Keep in sync with description_for_type() in sgen-internal.c! */
406 INTERNAL_MEM_PIN_QUEUE,
407 INTERNAL_MEM_FRAGMENT,
408 INTERNAL_MEM_SECTION,
409 INTERNAL_MEM_SCAN_STARTS,
410 INTERNAL_MEM_FIN_TABLE,
411 INTERNAL_MEM_FINALIZE_ENTRY,
412 INTERNAL_MEM_FINALIZE_READY_ENTRY,
413 INTERNAL_MEM_DISLINK_TABLE,
414 INTERNAL_MEM_DISLINK,
415 INTERNAL_MEM_ROOTS_TABLE,
416 INTERNAL_MEM_ROOT_RECORD,
417 INTERNAL_MEM_STATISTICS,
418 INTERNAL_MEM_STAT_PINNED_CLASS,
419 INTERNAL_MEM_STAT_REMSET_CLASS,
420 INTERNAL_MEM_GRAY_QUEUE,
421 INTERNAL_MEM_MS_TABLES,
422 INTERNAL_MEM_MS_BLOCK_INFO,
423 INTERNAL_MEM_MS_BLOCK_INFO_SORT,
424 INTERNAL_MEM_EPHEMERON_LINK,
425 INTERNAL_MEM_WORKER_DATA,
426 INTERNAL_MEM_WORKER_JOB_DATA,
427 INTERNAL_MEM_BRIDGE_DATA,
428 INTERNAL_MEM_BRIDGE_HASH_TABLE,
429 INTERNAL_MEM_BRIDGE_HASH_TABLE_ENTRY,
430 INTERNAL_MEM_BRIDGE_ALIVE_HASH_TABLE,
431 INTERNAL_MEM_BRIDGE_ALIVE_HASH_TABLE_ENTRY,
432 INTERNAL_MEM_JOB_QUEUE_ENTRY,
433 INTERNAL_MEM_TOGGLEREF_DATA,
434 INTERNAL_MEM_CARDTABLE_MOD_UNION,
435 INTERNAL_MEM_BINARY_PROTOCOL,
445 #ifdef SGEN_BINARY_PROTOCOL
446 #define BINARY_PROTOCOL_ARG(x) ,x
448 #define BINARY_PROTOCOL_ARG(x)
451 void sgen_init_internal_allocator (void) MONO_INTERNAL;
453 typedef struct _ObjectList ObjectList;
459 typedef void (*CopyOrMarkObjectFunc) (void**, SgenGrayQueue*);
460 typedef void (*ScanObjectFunc) (char*, SgenGrayQueue*);
461 typedef void (*ScanVTypeFunc) (char*, mword desc, SgenGrayQueue* BINARY_PROTOCOL_ARG (size_t size));
465 ScanObjectFunc scan_func;
466 CopyOrMarkObjectFunc copy_func;
467 SgenGrayQueue *queue;
470 void sgen_report_internal_mem_usage (void) MONO_INTERNAL;
471 void sgen_dump_internal_mem_usage (FILE *heap_dump_file) MONO_INTERNAL;
472 void sgen_dump_section (GCMemSection *section, const char *type) MONO_INTERNAL;
473 void sgen_dump_occupied (char *start, char *end, char *section_start) MONO_INTERNAL;
475 void sgen_register_moved_object (void *obj, void *destination) MONO_INTERNAL;
477 void sgen_register_fixed_internal_mem_type (int type, size_t size) MONO_INTERNAL;
479 void* sgen_alloc_internal (int type) MONO_INTERNAL;
480 void sgen_free_internal (void *addr, int type) MONO_INTERNAL;
482 void* sgen_alloc_internal_dynamic (size_t size, int type, gboolean assert_on_failure) MONO_INTERNAL;
483 void sgen_free_internal_dynamic (void *addr, size_t size, int type) MONO_INTERNAL;
485 void** sgen_find_optimized_pin_queue_area (void *start, void *end, int *num) MONO_INTERNAL;
486 void sgen_find_section_pin_queue_start_end (GCMemSection *section) MONO_INTERNAL;
487 void sgen_pin_objects_in_section (GCMemSection *section, ScanCopyContext ctx) MONO_INTERNAL;
489 void sgen_pin_stats_register_object (char *obj, size_t size);
490 void sgen_pin_stats_register_global_remset (char *obj);
491 void sgen_pin_stats_print_class_stats (void);
493 void sgen_sort_addresses (void **array, int size) MONO_INTERNAL;
494 void sgen_add_to_global_remset (gpointer ptr, gpointer obj) MONO_INTERNAL;
496 int sgen_get_current_collection_generation (void) MONO_INTERNAL;
497 gboolean sgen_collection_is_parallel (void) MONO_INTERNAL;
498 gboolean sgen_collection_is_concurrent (void) MONO_INTERNAL;
499 gboolean sgen_concurrent_collection_in_progress (void) MONO_INTERNAL;
502 CopyOrMarkObjectFunc copy_or_mark_object;
503 ScanObjectFunc scan_object;
504 ScanVTypeFunc scan_vtype;
505 /*FIXME add allocation function? */
506 } SgenObjectOperations;
508 SgenObjectOperations *sgen_get_current_object_ops (void) MONO_INTERNAL;
510 typedef struct _SgenFragment SgenFragment;
512 struct _SgenFragment {
514 char *fragment_start;
515 char *fragment_next; /* the current soft limit for allocation */
517 SgenFragment *next_in_order; /* We use a different entry for all active fragments so we can avoid SMR. */
521 SgenFragment *alloc_head; /* List head to be used when allocating memory. Walk with fragment_next. */
522 SgenFragment *region_head; /* List head of the region used by this allocator. Walk with next_in_order. */
523 } SgenFragmentAllocator;
525 void sgen_fragment_allocator_add (SgenFragmentAllocator *allocator, char *start, char *end) MONO_INTERNAL;
526 void sgen_fragment_allocator_release (SgenFragmentAllocator *allocator) MONO_INTERNAL;
527 void* sgen_fragment_allocator_serial_alloc (SgenFragmentAllocator *allocator, size_t size) MONO_INTERNAL;
528 void* sgen_fragment_allocator_par_alloc (SgenFragmentAllocator *allocator, size_t size) MONO_INTERNAL;
529 void* sgen_fragment_allocator_serial_range_alloc (SgenFragmentAllocator *allocator, size_t desired_size, size_t minimum_size, size_t *out_alloc_size) MONO_INTERNAL;
530 void* sgen_fragment_allocator_par_range_alloc (SgenFragmentAllocator *allocator, size_t desired_size, size_t minimum_size, size_t *out_alloc_size) MONO_INTERNAL;
531 SgenFragment* sgen_fragment_allocator_alloc (void) MONO_INTERNAL;
532 void sgen_clear_allocator_fragments (SgenFragmentAllocator *allocator) MONO_INTERNAL;
533 void sgen_clear_range (char *start, char *end) MONO_INTERNAL;
537 This is a space/speed compromise as we need to make sure the from/to space check is both O(1)
538 and only hit cache hot memory. On a 4Mb nursery it requires 1024 bytes, or 3% of your average
539 L1 cache. On small configs with a 512kb nursery, this goes to 0.4%.
541 Experimental results on how much space we waste with a 4Mb nursery:
543 Note that the wastage applies to the half nursery, or 2Mb:
545 Test 1 (compiling corlib):
550 #define SGEN_TO_SPACE_GRANULE_BITS 9
551 #define SGEN_TO_SPACE_GRANULE_IN_BYTES (1 << SGEN_TO_SPACE_GRANULE_BITS)
553 extern char *sgen_space_bitmap MONO_INTERNAL;
554 extern int sgen_space_bitmap_size MONO_INTERNAL;
556 static inline gboolean
557 sgen_nursery_is_to_space (char *object)
559 int idx = (object - sgen_nursery_start) >> SGEN_TO_SPACE_GRANULE_BITS;
563 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 ());
564 SGEN_ASSERT (4, byte < sgen_space_bitmap_size, "byte index %d out of range", byte, sgen_space_bitmap_size);
566 return (sgen_space_bitmap [byte] & (1 << bit)) != 0;
569 static inline gboolean
570 sgen_nursery_is_from_space (char *object)
572 return !sgen_nursery_is_to_space (object);
575 static inline gboolean
576 sgen_nursery_is_object_alive (char *obj)
578 /* FIXME put this asserts under a non default level */
579 g_assert (sgen_ptr_in_nursery (obj));
581 if (sgen_nursery_is_to_space (obj))
584 if (SGEN_OBJECT_IS_PINNED (obj) || SGEN_OBJECT_IS_FORWARDED (obj))
593 char* (*alloc_for_promotion) (MonoVTable *vtable, char *obj, size_t objsize, gboolean has_references);
594 char* (*par_alloc_for_promotion) (MonoVTable *vtable, char *obj, size_t objsize, gboolean has_references);
596 SgenObjectOperations serial_ops;
597 SgenObjectOperations parallel_ops;
599 void (*prepare_to_space) (char *to_space_bitmap, int space_bitmap_size);
600 void (*clear_fragments) (void);
601 SgenFragment* (*build_fragments_get_exclude_head) (void);
602 void (*build_fragments_release_exclude_head) (void);
603 void (*build_fragments_finish) (SgenFragmentAllocator *allocator);
604 void (*init_nursery) (SgenFragmentAllocator *allocator, char *start, char *end);
606 gboolean (*handle_gc_param) (const char *opt); /* Optional */
607 void (*print_gc_param_usage) (void); /* Optional */
608 } SgenMinorCollector;
610 extern SgenMinorCollector sgen_minor_collector;
612 void sgen_simple_nursery_init (SgenMinorCollector *collector) MONO_INTERNAL;
613 void sgen_split_nursery_init (SgenMinorCollector *collector) MONO_INTERNAL;
615 typedef void (*sgen_cardtable_block_callback) (mword start, mword size);
616 void sgen_major_collector_iterate_live_block_ranges (sgen_cardtable_block_callback callback) MONO_INTERNAL;
618 typedef struct _SgenMajorCollector SgenMajorCollector;
619 struct _SgenMajorCollector {
621 gboolean is_parallel;
622 gboolean is_concurrent;
623 gboolean supports_cardtable;
624 gboolean sweeps_lazily;
627 * This is set to TRUE if the sweep for the last major
628 * collection has been completed.
630 gboolean *have_swept;
632 * This is set to TRUE by the sweep if the next major
633 * collection should be synchronous (for evacuation). For
634 * non-concurrent collectors, this should be NULL.
636 gboolean *want_synchronous_collection;
638 void* (*alloc_heap) (mword nursery_size, mword nursery_align, int nursery_bits);
639 gboolean (*is_object_live) (char *obj);
640 void* (*alloc_small_pinned_obj) (MonoVTable *vtable, size_t size, gboolean has_references);
641 void* (*alloc_degraded) (MonoVTable *vtable, size_t size);
643 SgenObjectOperations major_ops;
644 SgenObjectOperations major_concurrent_ops;
646 void* (*alloc_object) (MonoVTable *vtable, int size, gboolean has_references);
647 void* (*par_alloc_object) (MonoVTable *vtable, int size, gboolean has_references);
648 void (*free_pinned_object) (char *obj, size_t size);
649 void (*iterate_objects) (gboolean non_pinned, gboolean pinned, IterateObjectCallbackFunc callback, void *data);
650 void (*free_non_pinned_object) (char *obj, size_t size);
651 void (*find_pin_queue_start_ends) (SgenGrayQueue *queue);
652 void (*pin_objects) (SgenGrayQueue *queue);
653 void (*pin_major_object) (char *obj, SgenGrayQueue *queue);
654 void (*scan_card_table) (gboolean mod_union, SgenGrayQueue *queue);
655 void (*iterate_live_block_ranges) (sgen_cardtable_block_callback callback);
656 void (*update_cardtable_mod_union) (void);
657 void (*init_to_space) (void);
658 void (*sweep) (void);
659 void (*check_scan_starts) (void);
660 void (*dump_heap) (FILE *heap_dump_file);
661 gint64 (*get_used_size) (void);
662 void (*start_nursery_collection) (void);
663 void (*finish_nursery_collection) (void);
664 void (*start_major_collection) (void);
665 void (*finish_major_collection) (void);
666 void (*have_computed_minor_collection_allowance) (void);
667 gboolean (*ptr_is_in_non_pinned_space) (char *ptr, char **start);
668 gboolean (*obj_is_from_pinned_alloc) (char *obj);
669 void (*report_pinned_memory_usage) (void);
670 int (*get_num_major_sections) (void);
671 gboolean (*handle_gc_param) (const char *opt);
672 void (*print_gc_param_usage) (void);
673 gboolean (*is_worker_thread) (MonoNativeThreadId thread);
674 void (*post_param_init) (SgenMajorCollector *collector);
675 void* (*alloc_worker_data) (void);
676 void (*init_worker_thread) (void *data);
677 void (*reset_worker_data) (void *data);
678 gboolean (*is_valid_object) (char *object);
679 MonoVTable* (*describe_pointer) (char *pointer);
680 guint8* (*get_cardtable_mod_union_for_object) (char *object);
681 long long (*get_and_reset_num_major_objects_marked) (void);
684 extern SgenMajorCollector major_collector;
686 void sgen_marksweep_init (SgenMajorCollector *collector) MONO_INTERNAL;
687 void sgen_marksweep_fixed_init (SgenMajorCollector *collector) MONO_INTERNAL;
688 void sgen_marksweep_par_init (SgenMajorCollector *collector) MONO_INTERNAL;
689 void sgen_marksweep_fixed_par_init (SgenMajorCollector *collector) MONO_INTERNAL;
690 void sgen_marksweep_conc_init (SgenMajorCollector *collector) MONO_INTERNAL;
691 SgenMajorCollector* sgen_get_major_collector (void) MONO_INTERNAL;
695 void (*wbarrier_set_field) (MonoObject *obj, gpointer field_ptr, MonoObject* value);
696 void (*wbarrier_set_arrayref) (MonoArray *arr, gpointer slot_ptr, MonoObject* value);
697 void (*wbarrier_arrayref_copy) (gpointer dest_ptr, gpointer src_ptr, int count);
698 void (*wbarrier_value_copy) (gpointer dest, gpointer src, int count, MonoClass *klass);
699 void (*wbarrier_object_copy) (MonoObject* obj, MonoObject *src);
700 void (*wbarrier_generic_nostore) (gpointer ptr);
701 void (*record_pointer) (gpointer ptr);
703 void (*finish_scan_remsets) (void *start_nursery, void *end_nursery, SgenGrayQueue *queue);
705 void (*prepare_for_major_collection) (void);
707 void (*finish_minor_collection) (void);
708 gboolean (*find_address) (char *addr);
709 gboolean (*find_address_with_cards) (char *cards_start, guint8 *cards, char *addr);
712 SgenRemeberedSet *sgen_get_remset (void) MONO_INTERNAL;
714 static guint /*__attribute__((noinline)) not sure if this hint is a good idea*/
715 slow_object_get_size (MonoVTable *vtable, MonoObject* o)
717 MonoClass *klass = vtable->klass;
720 * We depend on mono_string_length_fast and
721 * mono_array_length_fast not using the object's vtable.
723 if (klass == mono_defaults.string_class) {
724 return sizeof (MonoString) + 2 * mono_string_length_fast ((MonoString*) o) + 2;
725 } else if (klass->rank) {
726 MonoArray *array = (MonoArray*)o;
727 size_t size = sizeof (MonoArray) + klass->sizes.element_size * mono_array_length_fast (array);
728 if (G_UNLIKELY (array->bounds)) {
729 size += sizeof (mono_array_size_t) - 1;
730 size &= ~(sizeof (mono_array_size_t) - 1);
731 size += sizeof (MonoArrayBounds) * klass->rank;
735 /* from a created object: the class must be inited already */
736 return klass->instance_size;
741 * This function can be called on an object whose first word, the
742 * vtable field, is not intact. This is necessary for the parallel
746 sgen_par_object_get_size (MonoVTable *vtable, MonoObject* o)
748 mword descr = (mword)vtable->gc_descr;
749 mword type = descr & 0x7;
751 if (type == DESC_TYPE_RUN_LENGTH || type == DESC_TYPE_SMALL_BITMAP) {
752 mword size = descr & 0xfff8;
753 if (size == 0) /* This is used to encode a string */
754 return sizeof (MonoString) + 2 * mono_string_length_fast ((MonoString*) o) + 2;
756 } else if (type == DESC_TYPE_VECTOR) {
757 int element_size = ((descr) >> VECTOR_ELSIZE_SHIFT) & MAX_ELEMENT_SIZE;
758 MonoArray *array = (MonoArray*)o;
759 size_t size = sizeof (MonoArray) + element_size * mono_array_length_fast (array);
761 if (descr & VECTOR_KIND_ARRAY) {
762 size += sizeof (mono_array_size_t) - 1;
763 size &= ~(sizeof (mono_array_size_t) - 1);
764 size += sizeof (MonoArrayBounds) * vtable->klass->rank;
769 return slow_object_get_size (vtable, o);
773 sgen_safe_object_get_size (MonoObject *obj)
777 if ((forwarded = SGEN_OBJECT_IS_FORWARDED (obj)))
778 obj = (MonoObject*)forwarded;
780 return sgen_par_object_get_size ((MonoVTable*)SGEN_LOAD_VTABLE (obj), obj);
783 const char* sgen_safe_name (void* obj) MONO_INTERNAL;
785 gboolean sgen_object_is_live (void *obj) MONO_INTERNAL;
787 void sgen_init_fin_weak_hash (void) MONO_INTERNAL;
789 gboolean sgen_need_bridge_processing (void) MONO_INTERNAL;
790 void sgen_bridge_reset_data (void) MONO_INTERNAL;
791 void sgen_bridge_processing_stw_step (void) MONO_INTERNAL;
792 void sgen_bridge_processing_finish (int generation) MONO_INTERNAL;
793 void sgen_register_test_bridge_callbacks (const char *bridge_class_name) MONO_INTERNAL;
794 gboolean sgen_is_bridge_object (MonoObject *obj) MONO_INTERNAL;
795 gboolean sgen_is_bridge_class (MonoClass *class) MONO_INTERNAL;
796 void sgen_mark_bridge_object (MonoObject *obj) MONO_INTERNAL;
797 void sgen_bridge_register_finalized_object (MonoObject *object) MONO_INTERNAL;
798 void sgen_bridge_describe_pointer (MonoObject *object) MONO_INTERNAL;
800 void sgen_scan_togglerefs (char *start, char *end, ScanCopyContext ctx) MONO_INTERNAL;
801 void sgen_process_togglerefs (void) MONO_INTERNAL;
803 typedef mono_bool (*WeakLinkAlivePredicateFunc) (MonoObject*, void*);
805 void sgen_null_links_with_predicate (int generation, WeakLinkAlivePredicateFunc predicate, void *data) MONO_INTERNAL;
807 gboolean sgen_gc_is_object_ready_for_finalization (void *object) MONO_INTERNAL;
808 void sgen_gc_lock (void) MONO_INTERNAL;
809 void sgen_gc_unlock (void) MONO_INTERNAL;
810 void sgen_gc_event_moves (void) MONO_INTERNAL;
812 void sgen_queue_finalization_entry (MonoObject *obj) MONO_INTERNAL;
813 const char* sgen_generation_name (int generation) MONO_INTERNAL;
815 void sgen_collect_bridge_objects (int generation, ScanCopyContext ctx) MONO_INTERNAL;
816 void sgen_finalize_in_range (int generation, ScanCopyContext ctx) MONO_INTERNAL;
817 void sgen_null_link_in_range (int generation, gboolean before_finalization, ScanCopyContext ctx) MONO_INTERNAL;
818 void sgen_null_links_for_domain (MonoDomain *domain, int generation) MONO_INTERNAL;
819 void sgen_remove_finalizers_for_domain (MonoDomain *domain, int generation) MONO_INTERNAL;
820 void sgen_process_fin_stage_entries (void) MONO_INTERNAL;
821 void sgen_process_dislink_stage_entries (void) MONO_INTERNAL;
822 void sgen_register_disappearing_link (MonoObject *obj, void **link, gboolean track, gboolean in_gc) MONO_INTERNAL;
824 gboolean sgen_drain_gray_stack (int max_objs, ScanCopyContext ctx) MONO_INTERNAL;
832 void sgen_pin_object (void *object, SgenGrayQueue *queue) MONO_INTERNAL;
833 void sgen_parallel_pin_or_update (void **ptr, void *obj, MonoVTable *vt, SgenGrayQueue *queue) MONO_INTERNAL;
834 void sgen_set_pinned_from_failed_allocation (mword objsize) MONO_INTERNAL;
836 void sgen_ensure_free_space (size_t size) MONO_INTERNAL;
837 void sgen_perform_collection (size_t requested_size, int generation_to_collect, const char *reason, gboolean wait_to_finish) MONO_INTERNAL;
838 gboolean sgen_has_critical_method (void) MONO_INTERNAL;
839 gboolean sgen_is_critical_method (MonoMethod *method) MONO_INTERNAL;
846 gboolean is_overflow;
847 SGEN_TV_DECLARE (total_time);
848 SGEN_TV_DECLARE (stw_time);
849 SGEN_TV_DECLARE (bridge_time);
852 int sgen_stop_world (int generation) MONO_INTERNAL;
853 int sgen_restart_world (int generation, GGTimingInfo *timing) MONO_INTERNAL;
857 typedef struct _LOSObject LOSObject;
860 mword size; /* this is the object size, lowest bit used for pin/mark */
861 guint8 *cardtable_mod_union; /* only used by the concurrent collector */
862 #if SIZEOF_VOID_P < 8
863 mword dummy; /* to align object to sizeof (double) */
865 char data [MONO_ZERO_LEN_ARRAY];
868 #define ARRAY_OBJ_INDEX(ptr,array,elem_size) (((char*)(ptr) - ((char*)(array) + G_STRUCT_OFFSET (MonoArray, vector))) / (elem_size))
870 extern LOSObject *los_object_list;
871 extern mword los_memory_usage;
873 void sgen_los_free_object (LOSObject *obj) MONO_INTERNAL;
874 void* sgen_los_alloc_large_inner (MonoVTable *vtable, size_t size) MONO_INTERNAL;
875 void sgen_los_sweep (void) MONO_INTERNAL;
876 gboolean sgen_ptr_is_in_los (char *ptr, char **start) MONO_INTERNAL;
877 void sgen_los_iterate_objects (IterateObjectCallbackFunc cb, void *user_data) MONO_INTERNAL;
878 void sgen_los_iterate_live_block_ranges (sgen_cardtable_block_callback callback) MONO_INTERNAL;
879 void sgen_los_scan_card_table (gboolean mod_union, SgenGrayQueue *queue) MONO_INTERNAL;
880 void sgen_los_update_cardtable_mod_union (void) MONO_INTERNAL;
881 void sgen_major_collector_scan_card_table (SgenGrayQueue *queue) MONO_INTERNAL;
882 gboolean sgen_los_is_valid_object (char *object) MONO_INTERNAL;
883 gboolean mono_sgen_los_describe_pointer (char *ptr) MONO_INTERNAL;
884 LOSObject* sgen_los_header_for_object (char *data) MONO_INTERNAL;
885 mword sgen_los_object_size (LOSObject *obj) MONO_INTERNAL;
886 void sgen_los_pin_object (char *obj) MONO_INTERNAL;
887 void sgen_los_unpin_object (char *obj) MONO_INTERNAL;
888 gboolean sgen_los_object_is_pinned (char *obj) MONO_INTERNAL;
891 /* nursery allocator */
893 void sgen_clear_nursery_fragments (void) MONO_INTERNAL;
894 void sgen_nursery_allocator_prepare_for_pinning (void) MONO_INTERNAL;
895 void sgen_nursery_allocator_set_nursery_bounds (char *nursery_start, char *nursery_end) MONO_INTERNAL;
896 mword sgen_build_nursery_fragments (GCMemSection *nursery_section, void **start, int num_entries, SgenGrayQueue *unpin_queue) MONO_INTERNAL;
897 void sgen_init_nursery_allocator (void) MONO_INTERNAL;
898 void sgen_nursery_allocator_init_heavy_stats (void) MONO_INTERNAL;
899 void sgen_alloc_init_heavy_stats (void) MONO_INTERNAL;
900 char* sgen_nursery_alloc_get_upper_alloc_bound (void) MONO_INTERNAL;
901 void* sgen_nursery_alloc (size_t size) MONO_INTERNAL;
902 void* sgen_nursery_alloc_range (size_t size, size_t min_size, size_t *out_alloc_size) MONO_INTERNAL;
903 MonoVTable* sgen_get_array_fill_vtable (void) MONO_INTERNAL;
904 gboolean sgen_can_alloc_size (size_t size) MONO_INTERNAL;
905 void sgen_nursery_retire_region (void *address, ptrdiff_t size) MONO_INTERNAL;
907 void sgen_nursery_alloc_prepare_for_minor (void) MONO_INTERNAL;
908 void sgen_nursery_alloc_prepare_for_major (void) MONO_INTERNAL;
910 char* sgen_alloc_for_promotion (char *obj, size_t objsize, gboolean has_references) MONO_INTERNAL;
911 char* sgen_par_alloc_for_promotion (char *obj, size_t objsize, gboolean has_references) MONO_INTERNAL;
915 extern MonoNativeTlsKey thread_info_key;
917 #ifdef HAVE_KW_THREAD
918 extern __thread SgenThreadInfo *sgen_thread_info;
919 extern __thread char *stack_end;
922 #ifdef HAVE_KW_THREAD
923 #define TLAB_ACCESS_INIT
924 #define IN_CRITICAL_REGION sgen_thread_info->in_critical_region
926 #define TLAB_ACCESS_INIT SgenThreadInfo *__thread_info__ = mono_native_tls_get_value (thread_info_key)
927 #define IN_CRITICAL_REGION (__thread_info__->in_critical_region)
930 #ifndef DISABLE_CRITICAL_REGION
932 #ifdef HAVE_KW_THREAD
933 #define IN_CRITICAL_REGION sgen_thread_info->in_critical_region
935 #define IN_CRITICAL_REGION (__thread_info__->in_critical_region)
938 /* Enter must be visible before anything is done in the critical region. */
939 #define ENTER_CRITICAL_REGION do { mono_atomic_store_acquire (&IN_CRITICAL_REGION, 1); } while (0)
941 /* Exit must make sure all critical regions stores are visible before it signal the end of the region.
942 * We don't need to emit a full barrier since we
944 #define EXIT_CRITICAL_REGION do { mono_atomic_store_release (&IN_CRITICAL_REGION, 0); } while (0)
948 #ifdef HAVE_KW_THREAD
949 #define EMIT_TLS_ACCESS(mb,member,key) do { \
950 mono_mb_emit_byte ((mb), MONO_CUSTOM_PREFIX); \
951 mono_mb_emit_byte ((mb), CEE_MONO_TLS); \
952 mono_mb_emit_i4 ((mb), (key)); \
956 #if defined(__APPLE__) || defined (HOST_WIN32)
957 #define EMIT_TLS_ACCESS(mb,member,key) do { \
958 mono_mb_emit_byte ((mb), MONO_CUSTOM_PREFIX); \
959 mono_mb_emit_byte ((mb), CEE_MONO_TLS); \
960 mono_mb_emit_i4 ((mb), TLS_KEY_SGEN_THREAD_INFO); \
961 mono_mb_emit_icon ((mb), G_STRUCT_OFFSET (SgenThreadInfo, member)); \
962 mono_mb_emit_byte ((mb), CEE_ADD); \
963 mono_mb_emit_byte ((mb), CEE_LDIND_I); \
966 #define EMIT_TLS_ACCESS(mb,member,key) do { g_error ("sgen is not supported when using --with-tls=pthread.\n"); } while (0)
973 extern GCMemSection *nursery_section;
974 extern int stat_major_gcs;
975 extern guint32 collect_before_allocs;
976 extern guint32 verify_before_allocs;
977 extern gboolean has_per_allocation_action;
978 extern int degraded_mode;
979 extern int default_nursery_size;
980 extern guint32 tlab_size;
981 extern NurseryClearPolicy nursery_clear_policy;
983 extern LOCK_DECLARE (gc_mutex);
985 extern int do_pin_stats;
987 /* Nursery helpers. */
990 sgen_set_nursery_scan_start (char *p)
992 int idx = (p - (char*)nursery_section->data) / SGEN_SCAN_START_SIZE;
993 char *old = nursery_section->scan_starts [idx];
995 nursery_section->scan_starts [idx] = p;
999 /* Object Allocation */
1007 } SgenAllocatorType;
1009 void sgen_init_tlab_info (SgenThreadInfo* info);
1010 void sgen_clear_tlabs (void);
1011 void sgen_set_use_managed_allocator (gboolean flag);
1012 gboolean sgen_is_managed_allocator (MonoMethod *method);
1013 gboolean sgen_has_managed_allocator (void);
1017 void sgen_check_consistency (void);
1018 void sgen_check_mod_union_consistency (void);
1019 void sgen_check_major_refs (void);
1020 void sgen_check_whole_heap (gboolean allow_missing_pinning);
1021 void sgen_check_whole_heap_stw (void) MONO_INTERNAL;
1022 void sgen_check_objref (char *obj);
1023 void sgen_check_major_heap_marked (void) MONO_INTERNAL;
1024 void sgen_check_nursery_objects_pinned (gboolean pinned) MONO_INTERNAL;
1026 /* Write barrier support */
1029 * This causes the compile to extend the liveness of 'v' till the call to dummy_use
1032 sgen_dummy_use (gpointer v) {
1033 #if defined(__GNUC__)
1034 __asm__ volatile ("" : "=r"(v) : "r"(v));
1035 #elif defined(_MSC_VER)
1041 #error "Implement sgen_dummy_use for your compiler"
1045 /* Environment variable parsing */
1047 #define MONO_GC_PARAMS_NAME "MONO_GC_PARAMS"
1048 #define MONO_GC_DEBUG_NAME "MONO_GC_DEBUG"
1050 gboolean sgen_parse_environment_string_extract_number (const char *str, glong *out) MONO_INTERNAL;
1051 void sgen_env_var_error (const char *env_var, const char *fallback, const char *description_format, ...) MONO_INTERNAL;
1053 #endif /* HAVE_SGEN_GC */
1055 #endif /* __MONO_SGENGC_H__ */