2 * sgen-gc.c: Simple generational GC.
5 * Paolo Molaro (lupus@ximian.com)
6 * Rodrigo Kumpera (kumpera@gmail.com)
8 * Copyright 2005-2011 Novell, Inc (http://www.novell.com)
9 * Copyright 2011 Xamarin Inc (http://www.xamarin.com)
11 * Thread start/stop adapted from Boehm's GC:
12 * Copyright (c) 1994 by Xerox Corporation. All rights reserved.
13 * Copyright (c) 1996 by Silicon Graphics. All rights reserved.
14 * Copyright (c) 1998 by Fergus Henderson. All rights reserved.
15 * Copyright (c) 2000-2004 by Hewlett-Packard Company. All rights reserved.
17 * THIS MATERIAL IS PROVIDED AS IS, WITH ABSOLUTELY NO WARRANTY EXPRESSED
18 * OR IMPLIED. ANY USE IS AT YOUR OWN RISK.
20 * Permission is hereby granted to use or copy this program
21 * for any purpose, provided the above notices are retained on all copies.
22 * Permission to modify the code and to distribute modified code is granted,
23 * provided the above notices are retained, and a notice that the code was
24 * modified is included with the above copyright notice.
27 * Copyright 2001-2003 Ximian, Inc
28 * Copyright 2003-2010 Novell, Inc.
29 * Copyright 2011 Xamarin, Inc.
31 * Permission is hereby granted, free of charge, to any person obtaining
32 * a copy of this software and associated documentation files (the
33 * "Software"), to deal in the Software without restriction, including
34 * without limitation the rights to use, copy, modify, merge, publish,
35 * distribute, sublicense, and/or sell copies of the Software, and to
36 * permit persons to whom the Software is furnished to do so, subject to
37 * the following conditions:
39 * The above copyright notice and this permission notice shall be
40 * included in all copies or substantial portions of the Software.
42 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
43 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
44 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
45 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
46 * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
47 * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
48 * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
51 * Important: allocation provides always zeroed memory, having to do
52 * a memset after allocation is deadly for performance.
53 * Memory usage at startup is currently as follows:
55 * 64 KB internal space
57 * We should provide a small memory config with half the sizes
59 * We currently try to make as few mono assumptions as possible:
60 * 1) 2-word header with no GC pointers in it (first vtable, second to store the
62 * 2) gc descriptor is the second word in the vtable (first word in the class)
63 * 3) 8 byte alignment is the minimum and enough (not true for special structures (SIMD), FIXME)
64 * 4) there is a function to get an object's size and the number of
65 * elements in an array.
66 * 5) we know the special way bounds are allocated for complex arrays
67 * 6) we know about proxies and how to treat them when domains are unloaded
69 * Always try to keep stack usage to a minimum: no recursive behaviour
70 * and no large stack allocs.
72 * General description.
73 * Objects are initially allocated in a nursery using a fast bump-pointer technique.
74 * When the nursery is full we start a nursery collection: this is performed with a
76 * When the old generation is full we start a copying GC of the old generation as well:
77 * this will be changed to mark&sweep with copying when fragmentation becomes to severe
78 * in the future. Maybe we'll even do both during the same collection like IMMIX.
80 * The things that complicate this description are:
81 * *) pinned objects: we can't move them so we need to keep track of them
82 * *) no precise info of the thread stacks and registers: we need to be able to
83 * quickly find the objects that may be referenced conservatively and pin them
84 * (this makes the first issues more important)
85 * *) large objects are too expensive to be dealt with using copying GC: we handle them
86 * with mark/sweep during major collections
87 * *) some objects need to not move even if they are small (interned strings, Type handles):
88 * we use mark/sweep for them, too: they are not allocated in the nursery, but inside
89 * PinnedChunks regions
95 *) we could have a function pointer in MonoClass to implement
96 customized write barriers for value types
98 *) investigate the stuff needed to advance a thread to a GC-safe
99 point (single-stepping, read from unmapped memory etc) and implement it.
100 This would enable us to inline allocations and write barriers, for example,
101 or at least parts of them, like the write barrier checks.
102 We may need this also for handling precise info on stacks, even simple things
103 as having uninitialized data on the stack and having to wait for the prolog
104 to zero it. Not an issue for the last frame that we scan conservatively.
105 We could always not trust the value in the slots anyway.
107 *) modify the jit to save info about references in stack locations:
108 this can be done just for locals as a start, so that at least
109 part of the stack is handled precisely.
111 *) test/fix endianess issues
113 *) Implement a card table as the write barrier instead of remembered
114 sets? Card tables are not easy to implement with our current
115 memory layout. We have several different kinds of major heap
116 objects: Small objects in regular blocks, small objects in pinned
117 chunks and LOS objects. If we just have a pointer we have no way
118 to tell which kind of object it points into, therefore we cannot
119 know where its card table is. The least we have to do to make
120 this happen is to get rid of write barriers for indirect stores.
123 *) Get rid of write barriers for indirect stores. We can do this by
124 telling the GC to wbarrier-register an object once we do an ldloca
125 or ldelema on it, and to unregister it once it's not used anymore
126 (it can only travel downwards on the stack). The problem with
127 unregistering is that it needs to happen eventually no matter
128 what, even if exceptions are thrown, the thread aborts, etc.
129 Rodrigo suggested that we could do only the registering part and
130 let the collector find out (pessimistically) when it's safe to
131 unregister, namely when the stack pointer of the thread that
132 registered the object is higher than it was when the registering
133 happened. This might make for a good first implementation to get
134 some data on performance.
136 *) Some sort of blacklist support? Blacklists is a concept from the
137 Boehm GC: if during a conservative scan we find pointers to an
138 area which we might use as heap, we mark that area as unusable, so
139 pointer retention by random pinning pointers is reduced.
141 *) experiment with max small object size (very small right now - 2kb,
142 because it's tied to the max freelist size)
144 *) add an option to mmap the whole heap in one chunk: it makes for many
145 simplifications in the checks (put the nursery at the top and just use a single
146 check for inclusion/exclusion): the issue this has is that on 32 bit systems it's
147 not flexible (too much of the address space may be used by default or we can't
148 increase the heap as needed) and we'd need a race-free mechanism to return memory
149 back to the system (mprotect(PROT_NONE) will still keep the memory allocated if it
150 was written to, munmap is needed, but the following mmap may not find the same segment
153 *) memzero the major fragments after restarting the world and optionally a smaller
156 *) investigate having fragment zeroing threads
158 *) separate locks for finalization and other minor stuff to reduce
161 *) try a different copying order to improve memory locality
163 *) a thread abort after a store but before the write barrier will
164 prevent the write barrier from executing
166 *) specialized dynamically generated markers/copiers
168 *) Dynamically adjust TLAB size to the number of threads. If we have
169 too many threads that do allocation, we might need smaller TLABs,
170 and we might get better performance with larger TLABs if we only
171 have a handful of threads. We could sum up the space left in all
172 assigned TLABs and if that's more than some percentage of the
173 nursery size, reduce the TLAB size.
175 *) Explore placing unreachable objects on unused nursery memory.
176 Instead of memset'ng a region to zero, place an int[] covering it.
177 A good place to start is add_nursery_frag. The tricky thing here is
178 placing those objects atomically outside of a collection.
180 *) Allocation should use asymmetric Dekker synchronization:
181 http://blogs.oracle.com/dave/resource/Asymmetric-Dekker-Synchronization.txt
182 This should help weak consistency archs.
190 #ifdef HAVE_PTHREAD_H
193 #ifdef HAVE_SEMAPHORE_H
194 #include <semaphore.h>
205 #define _XOPEN_SOURCE
208 #include "metadata/sgen-gc.h"
209 #include "metadata/metadata-internals.h"
210 #include "metadata/class-internals.h"
211 #include "metadata/gc-internal.h"
212 #include "metadata/object-internals.h"
213 #include "metadata/threads.h"
214 #include "metadata/sgen-cardtable.h"
215 #include "metadata/sgen-ssb.h"
216 #include "metadata/sgen-protocol.h"
217 #include "metadata/sgen-archdep.h"
218 #include "metadata/sgen-bridge.h"
219 #include "metadata/mono-gc.h"
220 #include "metadata/method-builder.h"
221 #include "metadata/profiler-private.h"
222 #include "metadata/monitor.h"
223 #include "metadata/threadpool-internals.h"
224 #include "metadata/mempool-internals.h"
225 #include "metadata/marshal.h"
226 #include "metadata/runtime.h"
227 #include "metadata/sgen-cardtable.h"
228 #include "metadata/sgen-pinning.h"
229 #include "metadata/sgen-workers.h"
230 #include "utils/mono-mmap.h"
231 #include "utils/mono-time.h"
232 #include "utils/mono-semaphore.h"
233 #include "utils/mono-counters.h"
234 #include "utils/mono-proclib.h"
235 #include "utils/mono-memory-model.h"
236 #include "utils/mono-logger-internal.h"
238 #include <mono/utils/mono-logger-internal.h>
239 #include <mono/utils/memcheck.h>
241 #if defined(__MACH__)
242 #include "utils/mach-support.h"
245 #define OPDEF(a,b,c,d,e,f,g,h,i,j) \
249 #include "mono/cil/opcode.def"
255 #undef pthread_create
257 #undef pthread_detach
260 * ######################################################################
261 * ######## Types and constants used by the GC.
262 * ######################################################################
265 /* 0 means not initialized, 1 is initialized, -1 means in progress */
266 static gint32 gc_initialized = 0;
267 /* If set, do a minor collection before every X allocation */
268 guint32 collect_before_allocs = 0;
269 /* If set, do a heap consistency check before each minor collection */
270 static gboolean consistency_check_at_minor_collection = FALSE;
271 /* If set, check that there are no references to the domain left at domain unload */
272 static gboolean xdomain_checks = FALSE;
273 /* If not null, dump the heap after each collection into this file */
274 static FILE *heap_dump_file = NULL;
275 /* If set, mark stacks conservatively, even if precise marking is possible */
276 static gboolean conservative_stack_mark = FALSE;
277 /* If set, do a plausibility check on the scan_starts before and after
279 static gboolean do_scan_starts_check = FALSE;
280 static gboolean nursery_collection_is_parallel = FALSE;
281 static gboolean disable_minor_collections = FALSE;
282 static gboolean disable_major_collections = FALSE;
283 gboolean do_pin_stats = FALSE;
284 static gboolean do_verify_nursery = FALSE;
285 static gboolean do_dump_nursery_content = FALSE;
287 #ifdef HEAVY_STATISTICS
288 long long stat_objects_alloced_degraded = 0;
289 long long stat_bytes_alloced_degraded = 0;
291 long long stat_copy_object_called_nursery = 0;
292 long long stat_objects_copied_nursery = 0;
293 long long stat_copy_object_called_major = 0;
294 long long stat_objects_copied_major = 0;
296 long long stat_scan_object_called_nursery = 0;
297 long long stat_scan_object_called_major = 0;
299 long long stat_nursery_copy_object_failed_from_space = 0;
300 long long stat_nursery_copy_object_failed_forwarded = 0;
301 long long stat_nursery_copy_object_failed_pinned = 0;
303 static int stat_wbarrier_set_field = 0;
304 static int stat_wbarrier_set_arrayref = 0;
305 static int stat_wbarrier_arrayref_copy = 0;
306 static int stat_wbarrier_generic_store = 0;
307 static int stat_wbarrier_set_root = 0;
308 static int stat_wbarrier_value_copy = 0;
309 static int stat_wbarrier_object_copy = 0;
312 int stat_minor_gcs = 0;
313 int stat_major_gcs = 0;
315 static long long stat_pinned_objects = 0;
317 static long long time_minor_pre_collection_fragment_clear = 0;
318 static long long time_minor_pinning = 0;
319 static long long time_minor_scan_remsets = 0;
320 static long long time_minor_scan_pinned = 0;
321 static long long time_minor_scan_registered_roots = 0;
322 static long long time_minor_scan_thread_data = 0;
323 static long long time_minor_finish_gray_stack = 0;
324 static long long time_minor_fragment_creation = 0;
326 static long long time_major_pre_collection_fragment_clear = 0;
327 static long long time_major_pinning = 0;
328 static long long time_major_scan_pinned = 0;
329 static long long time_major_scan_registered_roots = 0;
330 static long long time_major_scan_thread_data = 0;
331 static long long time_major_scan_alloc_pinned = 0;
332 static long long time_major_scan_finalized = 0;
333 static long long time_major_scan_big_objects = 0;
334 static long long time_major_finish_gray_stack = 0;
335 static long long time_major_free_bigobjs = 0;
336 static long long time_major_los_sweep = 0;
337 static long long time_major_sweep = 0;
338 static long long time_major_fragment_creation = 0;
340 int gc_debug_level = 0;
342 static gboolean debug_print_allowance = FALSE;
346 mono_gc_flush_info (void)
348 fflush (gc_debug_file);
353 * Define this to allow the user to change the nursery size by
354 * specifying its value in the MONO_GC_PARAMS environmental
355 * variable. See mono_gc_base_init for details.
357 #define USER_CONFIG 1
359 #define TV_DECLARE SGEN_TV_DECLARE
360 #define TV_GETTIME SGEN_TV_GETTIME
361 #define TV_ELAPSED SGEN_TV_ELAPSED
362 #define TV_ELAPSED_MS SGEN_TV_ELAPSED_MS
364 #define ALIGN_TO(val,align) ((((guint64)val) + ((align) - 1)) & ~((align) - 1))
366 NurseryClearPolicy nursery_clear_policy = CLEAR_AT_TLAB_CREATION;
368 /* the runtime can register areas of memory as roots: we keep two lists of roots,
369 * a pinned root set for conservatively scanned roots and a normal one for
370 * precisely scanned roots (currently implemented as a single list).
372 typedef struct _RootRecord RootRecord;
378 #define object_is_forwarded SGEN_OBJECT_IS_FORWARDED
379 #define object_is_pinned SGEN_OBJECT_IS_PINNED
380 #define pin_object SGEN_PIN_OBJECT
381 #define unpin_object SGEN_UNPIN_OBJECT
383 #define ptr_in_nursery(p) (SGEN_PTR_IN_NURSERY ((p), DEFAULT_NURSERY_BITS, nursery_start, nursery_end))
385 #define LOAD_VTABLE SGEN_LOAD_VTABLE
388 safe_name (void* obj)
390 MonoVTable *vt = (MonoVTable*)LOAD_VTABLE (obj);
391 return vt->klass->name;
394 #define safe_object_get_size mono_sgen_safe_object_get_size
397 mono_sgen_safe_name (void* obj)
399 return safe_name (obj);
403 * ######################################################################
404 * ######## Global data.
405 * ######################################################################
407 LOCK_DECLARE (gc_mutex);
408 static int gc_disabled = 0;
410 static gboolean use_cardtable;
414 /* good sizes are 512KB-1MB: larger ones increase a lot memzeroing time */
415 #define DEFAULT_NURSERY_SIZE (default_nursery_size)
416 int default_nursery_size = (1 << 22);
417 #ifdef SGEN_ALIGN_NURSERY
418 /* The number of trailing 0 bits in DEFAULT_NURSERY_SIZE */
419 #define DEFAULT_NURSERY_BITS (default_nursery_bits)
420 static int default_nursery_bits = 22;
425 #define DEFAULT_NURSERY_SIZE (4*1024*1024)
426 #ifdef SGEN_ALIGN_NURSERY
427 #define DEFAULT_NURSERY_BITS 22
432 #ifndef SGEN_ALIGN_NURSERY
433 #define DEFAULT_NURSERY_BITS -1
436 #define MIN_MINOR_COLLECTION_ALLOWANCE (DEFAULT_NURSERY_SIZE * 4)
438 #define SCAN_START_SIZE SGEN_SCAN_START_SIZE
440 static mword pagesize = 4096;
441 static mword nursery_size;
442 int degraded_mode = 0;
444 static mword bytes_pinned_from_failed_allocation = 0;
446 static mword total_alloc = 0;
447 /* use this to tune when to do a major/minor collection */
448 static mword memory_pressure = 0;
449 static mword minor_collection_allowance;
450 static int minor_collection_sections_alloced = 0;
453 /* GC Logging stats */
454 static int last_major_num_sections = 0;
455 static int last_los_memory_usage = 0;
456 static gboolean major_collection_happened = FALSE;
458 GCMemSection *nursery_section = NULL;
459 static mword lowest_heap_address = ~(mword)0;
460 static mword highest_heap_address = 0;
462 static LOCK_DECLARE (interruption_mutex);
463 static LOCK_DECLARE (pin_queue_mutex);
465 #define LOCK_PIN_QUEUE mono_mutex_lock (&pin_queue_mutex)
466 #define UNLOCK_PIN_QUEUE mono_mutex_unlock (&pin_queue_mutex)
468 typedef struct _FinalizeReadyEntry FinalizeReadyEntry;
469 struct _FinalizeReadyEntry {
470 FinalizeReadyEntry *next;
474 typedef struct _EphemeronLinkNode EphemeronLinkNode;
476 struct _EphemeronLinkNode {
477 EphemeronLinkNode *next;
486 int current_collection_generation = -1;
489 * The link pointer is hidden by negating each bit. We use the lowest
490 * bit of the link (before negation) to store whether it needs
491 * resurrection tracking.
493 #define HIDE_POINTER(p,t) ((gpointer)(~((gulong)(p)|((t)?1:0))))
494 #define REVEAL_POINTER(p) ((gpointer)((~(gulong)(p))&~3L))
496 /* objects that are ready to be finalized */
497 static FinalizeReadyEntry *fin_ready_list = NULL;
498 static FinalizeReadyEntry *critical_fin_list = NULL;
500 static EphemeronLinkNode *ephemeron_list;
502 static int num_ready_finalizers = 0;
503 static int no_finalize = 0;
506 ROOT_TYPE_NORMAL = 0, /* "normal" roots */
507 ROOT_TYPE_PINNED = 1, /* roots without a GC descriptor */
508 ROOT_TYPE_WBARRIER = 2, /* roots with a write barrier */
512 /* registered roots: the key to the hash is the root start address */
514 * Different kinds of roots are kept separate to speed up pin_from_roots () for example.
516 static SgenHashTable roots_hash [ROOT_TYPE_NUM] = {
517 SGEN_HASH_TABLE_INIT (INTERNAL_MEM_ROOTS_TABLE, INTERNAL_MEM_ROOT_RECORD, sizeof (RootRecord), mono_aligned_addr_hash, NULL),
518 SGEN_HASH_TABLE_INIT (INTERNAL_MEM_ROOTS_TABLE, INTERNAL_MEM_ROOT_RECORD, sizeof (RootRecord), mono_aligned_addr_hash, NULL),
519 SGEN_HASH_TABLE_INIT (INTERNAL_MEM_ROOTS_TABLE, INTERNAL_MEM_ROOT_RECORD, sizeof (RootRecord), mono_aligned_addr_hash, NULL)
521 static mword roots_size = 0; /* amount of memory in the root set */
523 #define GC_ROOT_NUM 32
526 void *objects [GC_ROOT_NUM];
527 int root_types [GC_ROOT_NUM];
528 uintptr_t extra_info [GC_ROOT_NUM];
532 notify_gc_roots (GCRootReport *report)
536 mono_profiler_gc_roots (report->count, report->objects, report->root_types, report->extra_info);
541 add_profile_gc_root (GCRootReport *report, void *object, int rtype, uintptr_t extra_info)
543 if (report->count == GC_ROOT_NUM)
544 notify_gc_roots (report);
545 report->objects [report->count] = object;
546 report->root_types [report->count] = rtype;
547 report->extra_info [report->count++] = (uintptr_t)((MonoVTable*)LOAD_VTABLE (object))->klass;
551 * The current allocation cursors
552 * We allocate objects in the nursery.
553 * The nursery is the area between nursery_start and nursery_end.
554 * nursery_frag_real_end points to the end of the currently used nursery fragment.
555 * nursery_first_pinned_start points to the start of the first pinned object in the nursery
556 * nursery_last_pinned_end points to the end of the last pinned object in the nursery
557 * At the next allocation, the area of the nursery where objects can be present is
558 * between MIN(nursery_first_pinned_start, first_fragment_start) and
559 * MAX(nursery_last_pinned_end, nursery_frag_real_end)
561 static char *nursery_start = NULL;
562 static char *nursery_end = NULL;
563 static char *nursery_alloc_bound = NULL;
565 MonoNativeTlsKey thread_info_key;
567 #ifdef HAVE_KW_THREAD
568 __thread SgenThreadInfo *thread_info;
569 __thread gpointer *store_remset_buffer;
570 __thread long store_remset_buffer_index;
571 __thread char *stack_end;
572 __thread long *store_remset_buffer_index_addr;
575 /* The size of a TLAB */
576 /* The bigger the value, the less often we have to go to the slow path to allocate a new
577 * one, but the more space is wasted by threads not allocating much memory.
579 * FIXME: Make this self-tuning for each thread.
581 guint32 tlab_size = (1024 * 4);
583 #define MAX_SMALL_OBJ_SIZE SGEN_MAX_SMALL_OBJ_SIZE
585 /* Functions supplied by the runtime to be called by the GC */
586 static MonoGCCallbacks gc_callbacks;
588 #define ALLOC_ALIGN SGEN_ALLOC_ALIGN
589 #define ALLOC_ALIGN_BITS SGEN_ALLOC_ALIGN_BITS
591 #define ALIGN_UP SGEN_ALIGN_UP
593 #define MOVED_OBJECTS_NUM 64
594 static void *moved_objects [MOVED_OBJECTS_NUM];
595 static int moved_objects_idx = 0;
597 /* Vtable of the objects used to fill out nursery fragments before a collection */
598 static MonoVTable *array_fill_vtable;
600 #ifdef SGEN_DEBUG_INTERNAL_ALLOC
601 MonoNativeThreadId main_gc_thread = NULL;
605 * ######################################################################
606 * ######## Heap size accounting
607 * ######################################################################
610 static mword max_heap_size = ((mword)0)- ((mword)1);
611 static mword soft_heap_limit = ((mword)0) - ((mword)1);
612 static mword allocated_heap;
614 /*Object was pinned during the current collection*/
615 static mword objects_pinned;
618 mono_sgen_release_space (mword size, int space)
620 allocated_heap -= size;
624 available_free_space (void)
626 return max_heap_size - MIN (allocated_heap, max_heap_size);
630 mono_sgen_try_alloc_space (mword size, int space)
632 if (available_free_space () < size)
635 allocated_heap += size;
636 mono_runtime_resource_check_limit (MONO_RESOURCE_GC_HEAP, allocated_heap);
641 init_heap_size_limits (glong max_heap, glong soft_limit)
644 soft_heap_limit = soft_limit;
649 if (max_heap < soft_limit) {
650 fprintf (stderr, "max-heap-size must be at least as large as soft-heap-limit.\n");
654 if (max_heap < nursery_size * 4) {
655 fprintf (stderr, "max-heap-size must be at least 4 times larger than nursery size.\n");
658 max_heap_size = max_heap - nursery_size;
662 * ######################################################################
663 * ######## Macros and function declarations.
664 * ######################################################################
668 align_pointer (void *ptr)
670 mword p = (mword)ptr;
671 p += sizeof (gpointer) - 1;
672 p &= ~ (sizeof (gpointer) - 1);
676 typedef SgenGrayQueue GrayQueue;
678 /* forward declarations */
679 static int stop_world (int generation);
680 static int restart_world (int generation);
681 static void scan_thread_data (void *start_nursery, void *end_nursery, gboolean precise, GrayQueue *queue);
682 static void scan_from_registered_roots (CopyOrMarkObjectFunc copy_func, char *addr_start, char *addr_end, int root_type, GrayQueue *queue);
683 static void scan_finalizer_entries (CopyOrMarkObjectFunc copy_func, FinalizeReadyEntry *list, GrayQueue *queue);
684 static void report_finalizer_roots (void);
685 static void report_registered_roots (void);
686 static void find_pinning_ref_from_thread (char *obj, size_t size);
687 static void update_current_thread_stack (void *start);
688 static void collect_bridge_objects (CopyOrMarkObjectFunc copy_func, char *start, char *end, int generation, GrayQueue *queue);
689 static void finalize_in_range (CopyOrMarkObjectFunc copy_func, char *start, char *end, int generation, GrayQueue *queue);
690 static void process_fin_stage_entries (void);
691 static void null_link_in_range (CopyOrMarkObjectFunc copy_func, char *start, char *end, int generation, gboolean before_finalization, GrayQueue *queue);
692 static void null_links_for_domain (MonoDomain *domain, int generation);
693 static void process_dislink_stage_entries (void);
695 static void pin_from_roots (void *start_nursery, void *end_nursery, GrayQueue *queue);
696 static int pin_objects_from_addresses (GCMemSection *section, void **start, void **end, void *start_nursery, void *end_nursery, GrayQueue *queue);
697 static void finish_gray_stack (char *start_addr, char *end_addr, int generation, GrayQueue *queue);
698 static gboolean need_major_collection (mword space_needed);
699 static void major_collection (const char *reason);
701 static void mono_gc_register_disappearing_link (MonoObject *obj, void **link, gboolean track, gboolean in_gc);
702 static gboolean mono_gc_is_critical_method (MonoMethod *method);
704 void mono_gc_scan_for_specific_ref (MonoObject *key, gboolean precise);
706 static void init_stats (void);
708 static int mark_ephemerons_in_range (CopyOrMarkObjectFunc copy_func, char *start, char *end, GrayQueue *queue);
709 static void clear_unreachable_ephemerons (CopyOrMarkObjectFunc copy_func, char *start, char *end, GrayQueue *queue);
710 static void null_ephemerons_for_domain (MonoDomain *domain);
712 SgenMajorCollector major_collector;
713 static GrayQueue gray_queue;
715 static SgenRemeberedSet remset;
718 #define WORKERS_DISTRIBUTE_GRAY_QUEUE (mono_sgen_collection_is_parallel () ? mono_sgen_workers_get_distribute_gray_queue () : &gray_queue)
720 static SgenGrayQueue*
721 mono_sgen_workers_get_job_gray_queue (WorkerData *worker_data)
723 return worker_data ? &worker_data->private_gray_queue : WORKERS_DISTRIBUTE_GRAY_QUEUE;
727 is_xdomain_ref_allowed (gpointer *ptr, char *obj, MonoDomain *domain)
729 MonoObject *o = (MonoObject*)(obj);
730 MonoObject *ref = (MonoObject*)*(ptr);
731 int offset = (char*)(ptr) - (char*)o;
733 if (o->vtable->klass == mono_defaults.thread_class && offset == G_STRUCT_OFFSET (MonoThread, internal_thread))
735 if (o->vtable->klass == mono_defaults.internal_thread_class && offset == G_STRUCT_OFFSET (MonoInternalThread, current_appcontext))
737 if (mono_class_has_parent_fast (o->vtable->klass, mono_defaults.real_proxy_class) &&
738 offset == G_STRUCT_OFFSET (MonoRealProxy, unwrapped_server))
740 /* Thread.cached_culture_info */
741 if (!strcmp (ref->vtable->klass->name_space, "System.Globalization") &&
742 !strcmp (ref->vtable->klass->name, "CultureInfo") &&
743 !strcmp(o->vtable->klass->name_space, "System") &&
744 !strcmp(o->vtable->klass->name, "Object[]"))
747 * at System.IO.MemoryStream.InternalConstructor (byte[],int,int,bool,bool) [0x0004d] in /home/schani/Work/novell/trunk/mcs/class/corlib/System.IO/MemoryStream.cs:121
748 * at System.IO.MemoryStream..ctor (byte[]) [0x00017] in /home/schani/Work/novell/trunk/mcs/class/corlib/System.IO/MemoryStream.cs:81
749 * at (wrapper remoting-invoke-with-check) System.IO.MemoryStream..ctor (byte[]) <IL 0x00020, 0xffffffff>
750 * at System.Runtime.Remoting.Messaging.CADMethodCallMessage.GetArguments () [0x0000d] in /home/schani/Work/novell/trunk/mcs/class/corlib/System.Runtime.Remoting.Messaging/CADMessages.cs:327
751 * at System.Runtime.Remoting.Messaging.MethodCall..ctor (System.Runtime.Remoting.Messaging.CADMethodCallMessage) [0x00017] in /home/schani/Work/novell/trunk/mcs/class/corlib/System.Runtime.Remoting.Messaging/MethodCall.cs:87
752 * at System.AppDomain.ProcessMessageInDomain (byte[],System.Runtime.Remoting.Messaging.CADMethodCallMessage,byte[]&,System.Runtime.Remoting.Messaging.CADMethodReturnMessage&) [0x00018] in /home/schani/Work/novell/trunk/mcs/class/corlib/System/AppDomain.cs:1213
753 * at (wrapper remoting-invoke-with-check) System.AppDomain.ProcessMessageInDomain (byte[],System.Runtime.Remoting.Messaging.CADMethodCallMessage,byte[]&,System.Runtime.Remoting.Messaging.CADMethodReturnMessage&) <IL 0x0003d, 0xffffffff>
754 * at System.Runtime.Remoting.Channels.CrossAppDomainSink.ProcessMessageInDomain (byte[],System.Runtime.Remoting.Messaging.CADMethodCallMessage) [0x00008] in /home/schani/Work/novell/trunk/mcs/class/corlib/System.Runtime.Remoting.Channels/CrossAppDomainChannel.cs:198
755 * at (wrapper runtime-invoke) object.runtime_invoke_CrossAppDomainSink/ProcessMessageRes_object_object (object,intptr,intptr,intptr) <IL 0x0004c, 0xffffffff>
757 if (!strcmp (ref->vtable->klass->name_space, "System") &&
758 !strcmp (ref->vtable->klass->name, "Byte[]") &&
759 !strcmp (o->vtable->klass->name_space, "System.IO") &&
760 !strcmp (o->vtable->klass->name, "MemoryStream"))
762 /* append_job() in threadpool.c */
763 if (!strcmp (ref->vtable->klass->name_space, "System.Runtime.Remoting.Messaging") &&
764 !strcmp (ref->vtable->klass->name, "AsyncResult") &&
765 !strcmp (o->vtable->klass->name_space, "System") &&
766 !strcmp (o->vtable->klass->name, "Object[]") &&
767 mono_thread_pool_is_queue_array ((MonoArray*) o))
773 check_reference_for_xdomain (gpointer *ptr, char *obj, MonoDomain *domain)
775 MonoObject *o = (MonoObject*)(obj);
776 MonoObject *ref = (MonoObject*)*(ptr);
777 int offset = (char*)(ptr) - (char*)o;
779 MonoClassField *field;
782 if (!ref || ref->vtable->domain == domain)
784 if (is_xdomain_ref_allowed (ptr, obj, domain))
788 for (class = o->vtable->klass; class; class = class->parent) {
791 for (i = 0; i < class->field.count; ++i) {
792 if (class->fields[i].offset == offset) {
793 field = &class->fields[i];
801 if (ref->vtable->klass == mono_defaults.string_class)
802 str = mono_string_to_utf8 ((MonoString*)ref);
805 g_print ("xdomain reference in %p (%s.%s) at offset %d (%s) to %p (%s.%s) (%s) - pointed to by:\n",
806 o, o->vtable->klass->name_space, o->vtable->klass->name,
807 offset, field ? field->name : "",
808 ref, ref->vtable->klass->name_space, ref->vtable->klass->name, str ? str : "");
809 mono_gc_scan_for_specific_ref (o, TRUE);
815 #define HANDLE_PTR(ptr,obj) check_reference_for_xdomain ((ptr), (obj), domain)
818 scan_object_for_xdomain_refs (char *start, mword size, void *data)
820 MonoDomain *domain = ((MonoObject*)start)->vtable->domain;
822 #include "sgen-scan-object.h"
825 static gboolean scan_object_for_specific_ref_precise = TRUE;
828 #define HANDLE_PTR(ptr,obj) do { \
829 if ((MonoObject*)*(ptr) == key) { \
830 g_print ("found ref to %p in object %p (%s) at offset %td\n", \
831 key, (obj), safe_name ((obj)), ((char*)(ptr) - (char*)(obj))); \
836 scan_object_for_specific_ref (char *start, MonoObject *key)
840 if ((forwarded = SGEN_OBJECT_IS_FORWARDED (start)))
843 if (scan_object_for_specific_ref_precise) {
844 #include "sgen-scan-object.h"
846 mword *words = (mword*)start;
847 size_t size = safe_object_get_size ((MonoObject*)start);
849 for (i = 0; i < size / sizeof (mword); ++i) {
850 if (words [i] == (mword)key) {
851 g_print ("found possible ref to %p in object %p (%s) at offset %td\n",
852 key, start, safe_name (start), i * sizeof (mword));
859 mono_sgen_scan_area_with_callback (char *start, char *end, IterateObjectCallbackFunc callback, void *data, gboolean allow_flags)
861 while (start < end) {
865 if (!*(void**)start) {
866 start += sizeof (void*); /* should be ALLOC_ALIGN, really */
871 if (!(obj = SGEN_OBJECT_IS_FORWARDED (start)))
877 size = ALIGN_UP (safe_object_get_size ((MonoObject*)obj));
879 callback (obj, size, data);
886 scan_object_for_specific_ref_callback (char *obj, size_t size, MonoObject *key)
888 scan_object_for_specific_ref (obj, key);
892 check_root_obj_specific_ref (RootRecord *root, MonoObject *key, MonoObject *obj)
896 g_print ("found ref to %p in root record %p\n", key, root);
899 static MonoObject *check_key = NULL;
900 static RootRecord *check_root = NULL;
903 check_root_obj_specific_ref_from_marker (void **obj)
905 check_root_obj_specific_ref (check_root, check_key, *obj);
909 scan_roots_for_specific_ref (MonoObject *key, int root_type)
915 SGEN_HASH_TABLE_FOREACH (&roots_hash [root_type], start_root, root) {
916 mword desc = root->root_desc;
920 switch (desc & ROOT_DESC_TYPE_MASK) {
921 case ROOT_DESC_BITMAP:
922 desc >>= ROOT_DESC_TYPE_SHIFT;
925 check_root_obj_specific_ref (root, key, *start_root);
930 case ROOT_DESC_COMPLEX: {
931 gsize *bitmap_data = mono_sgen_get_complex_descriptor_bitmap (desc);
932 int bwords = (*bitmap_data) - 1;
933 void **start_run = start_root;
935 while (bwords-- > 0) {
936 gsize bmap = *bitmap_data++;
937 void **objptr = start_run;
940 check_root_obj_specific_ref (root, key, *objptr);
944 start_run += GC_BITS_PER_WORD;
948 case ROOT_DESC_USER: {
949 MonoGCRootMarkFunc marker = mono_sgen_get_user_descriptor_func (desc);
950 marker (start_root, check_root_obj_specific_ref_from_marker);
953 case ROOT_DESC_RUN_LEN:
954 g_assert_not_reached ();
956 g_assert_not_reached ();
958 } SGEN_HASH_TABLE_FOREACH_END;
965 mono_gc_scan_for_specific_ref (MonoObject *key, gboolean precise)
970 scan_object_for_specific_ref_precise = precise;
972 mono_sgen_scan_area_with_callback (nursery_section->data, nursery_section->end_data,
973 (IterateObjectCallbackFunc)scan_object_for_specific_ref_callback, key, TRUE);
975 major_collector.iterate_objects (TRUE, TRUE, (IterateObjectCallbackFunc)scan_object_for_specific_ref_callback, key);
977 mono_sgen_los_iterate_objects ((IterateObjectCallbackFunc)scan_object_for_specific_ref_callback, key);
979 scan_roots_for_specific_ref (key, ROOT_TYPE_NORMAL);
980 scan_roots_for_specific_ref (key, ROOT_TYPE_WBARRIER);
982 SGEN_HASH_TABLE_FOREACH (&roots_hash [ROOT_TYPE_PINNED], ptr, root) {
983 while (ptr < (void**)root->end_root) {
984 check_root_obj_specific_ref (root, *ptr, key);
987 } SGEN_HASH_TABLE_FOREACH_END;
991 need_remove_object_for_domain (char *start, MonoDomain *domain)
993 if (mono_object_domain (start) == domain) {
994 DEBUG (4, fprintf (gc_debug_file, "Need to cleanup object %p\n", start));
995 binary_protocol_cleanup (start, (gpointer)LOAD_VTABLE (start), safe_object_get_size ((MonoObject*)start));
1002 process_object_for_domain_clearing (char *start, MonoDomain *domain)
1004 GCVTable *vt = (GCVTable*)LOAD_VTABLE (start);
1005 if (vt->klass == mono_defaults.internal_thread_class)
1006 g_assert (mono_object_domain (start) == mono_get_root_domain ());
1007 /* The object could be a proxy for an object in the domain
1009 if (mono_class_has_parent_fast (vt->klass, mono_defaults.real_proxy_class)) {
1010 MonoObject *server = ((MonoRealProxy*)start)->unwrapped_server;
1012 /* The server could already have been zeroed out, so
1013 we need to check for that, too. */
1014 if (server && (!LOAD_VTABLE (server) || mono_object_domain (server) == domain)) {
1015 DEBUG (4, fprintf (gc_debug_file, "Cleaning up remote pointer in %p to object %p\n",
1017 ((MonoRealProxy*)start)->unwrapped_server = NULL;
1022 static MonoDomain *check_domain = NULL;
1025 check_obj_not_in_domain (void **o)
1027 g_assert (((MonoObject*)(*o))->vtable->domain != check_domain);
1031 scan_for_registered_roots_in_domain (MonoDomain *domain, int root_type)
1035 check_domain = domain;
1036 SGEN_HASH_TABLE_FOREACH (&roots_hash [root_type], start_root, root) {
1037 mword desc = root->root_desc;
1039 /* The MonoDomain struct is allowed to hold
1040 references to objects in its own domain. */
1041 if (start_root == (void**)domain)
1044 switch (desc & ROOT_DESC_TYPE_MASK) {
1045 case ROOT_DESC_BITMAP:
1046 desc >>= ROOT_DESC_TYPE_SHIFT;
1048 if ((desc & 1) && *start_root)
1049 check_obj_not_in_domain (*start_root);
1054 case ROOT_DESC_COMPLEX: {
1055 gsize *bitmap_data = mono_sgen_get_complex_descriptor_bitmap (desc);
1056 int bwords = (*bitmap_data) - 1;
1057 void **start_run = start_root;
1059 while (bwords-- > 0) {
1060 gsize bmap = *bitmap_data++;
1061 void **objptr = start_run;
1063 if ((bmap & 1) && *objptr)
1064 check_obj_not_in_domain (*objptr);
1068 start_run += GC_BITS_PER_WORD;
1072 case ROOT_DESC_USER: {
1073 MonoGCRootMarkFunc marker = mono_sgen_get_user_descriptor_func (desc);
1074 marker (start_root, check_obj_not_in_domain);
1077 case ROOT_DESC_RUN_LEN:
1078 g_assert_not_reached ();
1080 g_assert_not_reached ();
1082 } SGEN_HASH_TABLE_FOREACH_END;
1084 check_domain = NULL;
1088 check_for_xdomain_refs (void)
1092 mono_sgen_scan_area_with_callback (nursery_section->data, nursery_section->end_data,
1093 (IterateObjectCallbackFunc)scan_object_for_xdomain_refs, NULL, FALSE);
1095 major_collector.iterate_objects (TRUE, TRUE, (IterateObjectCallbackFunc)scan_object_for_xdomain_refs, NULL);
1097 for (bigobj = los_object_list; bigobj; bigobj = bigobj->next)
1098 scan_object_for_xdomain_refs (bigobj->data, bigobj->size, NULL);
1102 clear_domain_process_object (char *obj, MonoDomain *domain)
1106 process_object_for_domain_clearing (obj, domain);
1107 remove = need_remove_object_for_domain (obj, domain);
1109 if (remove && ((MonoObject*)obj)->synchronisation) {
1110 void **dislink = mono_monitor_get_object_monitor_weak_link ((MonoObject*)obj);
1112 mono_gc_register_disappearing_link (NULL, dislink, FALSE, TRUE);
1119 clear_domain_process_minor_object_callback (char *obj, size_t size, MonoDomain *domain)
1121 if (clear_domain_process_object (obj, domain))
1122 memset (obj, 0, size);
1126 clear_domain_process_major_object_callback (char *obj, size_t size, MonoDomain *domain)
1128 clear_domain_process_object (obj, domain);
1132 clear_domain_free_major_non_pinned_object_callback (char *obj, size_t size, MonoDomain *domain)
1134 if (need_remove_object_for_domain (obj, domain))
1135 major_collector.free_non_pinned_object (obj, size);
1139 clear_domain_free_major_pinned_object_callback (char *obj, size_t size, MonoDomain *domain)
1141 if (need_remove_object_for_domain (obj, domain))
1142 major_collector.free_pinned_object (obj, size);
1146 * When appdomains are unloaded we can easily remove objects that have finalizers,
1147 * but all the others could still be present in random places on the heap.
1148 * We need a sweep to get rid of them even though it's going to be costly
1150 * The reason we need to remove them is because we access the vtable and class
1151 * structures to know the object size and the reference bitmap: once the domain is
1152 * unloaded the point to random memory.
1155 mono_gc_clear_domain (MonoDomain * domain)
1157 LOSObject *bigobj, *prev;
1162 process_fin_stage_entries ();
1163 process_dislink_stage_entries ();
1165 mono_sgen_clear_nursery_fragments ();
1167 if (xdomain_checks && domain != mono_get_root_domain ()) {
1168 scan_for_registered_roots_in_domain (domain, ROOT_TYPE_NORMAL);
1169 scan_for_registered_roots_in_domain (domain, ROOT_TYPE_WBARRIER);
1170 check_for_xdomain_refs ();
1173 mono_sgen_scan_area_with_callback (nursery_section->data, nursery_section->end_data,
1174 (IterateObjectCallbackFunc)clear_domain_process_minor_object_callback, domain, FALSE);
1176 /*Ephemerons and dislinks must be processed before LOS since they might end up pointing
1177 to memory returned to the OS.*/
1178 null_ephemerons_for_domain (domain);
1180 for (i = GENERATION_NURSERY; i < GENERATION_MAX; ++i)
1181 null_links_for_domain (domain, i);
1183 /* We need two passes over major and large objects because
1184 freeing such objects might give their memory back to the OS
1185 (in the case of large objects) or obliterate its vtable
1186 (pinned objects with major-copying or pinned and non-pinned
1187 objects with major-mark&sweep), but we might need to
1188 dereference a pointer from an object to another object if
1189 the first object is a proxy. */
1190 major_collector.iterate_objects (TRUE, TRUE, (IterateObjectCallbackFunc)clear_domain_process_major_object_callback, domain);
1191 for (bigobj = los_object_list; bigobj; bigobj = bigobj->next)
1192 clear_domain_process_object (bigobj->data, domain);
1195 for (bigobj = los_object_list; bigobj;) {
1196 if (need_remove_object_for_domain (bigobj->data, domain)) {
1197 LOSObject *to_free = bigobj;
1199 prev->next = bigobj->next;
1201 los_object_list = bigobj->next;
1202 bigobj = bigobj->next;
1203 DEBUG (4, fprintf (gc_debug_file, "Freeing large object %p\n",
1205 mono_sgen_los_free_object (to_free);
1209 bigobj = bigobj->next;
1211 major_collector.iterate_objects (TRUE, FALSE, (IterateObjectCallbackFunc)clear_domain_free_major_non_pinned_object_callback, domain);
1212 major_collector.iterate_objects (FALSE, TRUE, (IterateObjectCallbackFunc)clear_domain_free_major_pinned_object_callback, domain);
1214 if (G_UNLIKELY (do_pin_stats)) {
1215 if (domain == mono_get_root_domain ())
1216 mono_sgen_pin_stats_print_class_stats ();
1223 * mono_sgen_add_to_global_remset:
1225 * The global remset contains locations which point into newspace after
1226 * a minor collection. This can happen if the objects they point to are pinned.
1228 * LOCKING: If called from a parallel collector, the global remset
1229 * lock must be held. For serial collectors that is not necessary.
1232 mono_sgen_add_to_global_remset (gpointer ptr)
1234 remset.record_pointer (ptr);
1238 * mono_sgen_drain_gray_stack:
1240 * Scan objects in the gray stack until the stack is empty. This should be called
1241 * frequently after each object is copied, to achieve better locality and cache
1245 mono_sgen_drain_gray_stack (GrayQueue *queue, int max_objs)
1249 if (current_collection_generation == GENERATION_NURSERY) {
1250 ScanObjectFunc scan_func = mono_sgen_get_minor_scan_object ();
1253 GRAY_OBJECT_DEQUEUE (queue, obj);
1256 DEBUG (9, fprintf (gc_debug_file, "Precise gray object scan %p (%s)\n", obj, safe_name (obj)));
1257 scan_func (obj, queue);
1262 if (mono_sgen_collection_is_parallel () && mono_sgen_workers_is_distributed_queue (queue))
1266 for (i = 0; i != max_objs; ++i) {
1267 GRAY_OBJECT_DEQUEUE (queue, obj);
1270 DEBUG (9, fprintf (gc_debug_file, "Precise gray object scan %p (%s)\n", obj, safe_name (obj)));
1271 major_collector.major_scan_object (obj, queue);
1273 } while (max_objs < 0);
1279 * Addresses from start to end are already sorted. This function finds
1280 * the object header for each address and pins the object. The
1281 * addresses must be inside the passed section. The (start of the)
1282 * address array is overwritten with the addresses of the actually
1283 * pinned objects. Return the number of pinned objects.
1286 pin_objects_from_addresses (GCMemSection *section, void **start, void **end, void *start_nursery, void *end_nursery, GrayQueue *queue)
1291 void *last_obj = NULL;
1292 size_t last_obj_size = 0;
1295 void **definitely_pinned = start;
1297 mono_sgen_nursery_allocator_prepare_for_pinning ();
1299 while (start < end) {
1301 /* the range check should be reduntant */
1302 if (addr != last && addr >= start_nursery && addr < end_nursery) {
1303 DEBUG (5, fprintf (gc_debug_file, "Considering pinning addr %p\n", addr));
1304 /* multiple pointers to the same object */
1305 if (addr >= last_obj && (char*)addr < (char*)last_obj + last_obj_size) {
1309 idx = ((char*)addr - (char*)section->data) / SCAN_START_SIZE;
1310 g_assert (idx < section->num_scan_start);
1311 search_start = (void*)section->scan_starts [idx];
1312 if (!search_start || search_start > addr) {
1315 search_start = section->scan_starts [idx];
1316 if (search_start && search_start <= addr)
1319 if (!search_start || search_start > addr)
1320 search_start = start_nursery;
1322 if (search_start < last_obj)
1323 search_start = (char*)last_obj + last_obj_size;
1324 /* now addr should be in an object a short distance from search_start
1325 * Note that search_start must point to zeroed mem or point to an object.
1329 if (!*(void**)search_start) {
1330 /* Consistency check */
1332 for (frag = nursery_fragments; frag; frag = frag->next) {
1333 if (search_start >= frag->fragment_start && search_start < frag->fragment_end)
1334 g_assert_not_reached ();
1338 search_start = (void*)ALIGN_UP ((mword)search_start + sizeof (gpointer));
1341 last_obj = search_start;
1342 last_obj_size = ALIGN_UP (safe_object_get_size ((MonoObject*)search_start));
1344 if (((MonoObject*)last_obj)->synchronisation == GINT_TO_POINTER (-1)) {
1345 /* Marks the beginning of a nursery fragment, skip */
1347 DEBUG (8, fprintf (gc_debug_file, "Pinned try match %p (%s), size %zd\n", last_obj, safe_name (last_obj), last_obj_size));
1348 if (addr >= search_start && (char*)addr < (char*)last_obj + last_obj_size) {
1349 DEBUG (4, fprintf (gc_debug_file, "Pinned object %p, vtable %p (%s), count %d\n", search_start, *(void**)search_start, safe_name (search_start), count));
1350 binary_protocol_pin (search_start, (gpointer)LOAD_VTABLE (search_start), safe_object_get_size (search_start));
1351 pin_object (search_start);
1352 GRAY_OBJECT_ENQUEUE (queue, search_start);
1353 if (G_UNLIKELY (do_pin_stats))
1354 mono_sgen_pin_stats_register_object (search_start, last_obj_size);
1355 definitely_pinned [count] = search_start;
1360 /* skip to the next object */
1361 search_start = (void*)((char*)search_start + last_obj_size);
1362 } while (search_start <= addr);
1363 /* we either pinned the correct object or we ignored the addr because
1364 * it points to unused zeroed memory.
1370 //printf ("effective pinned: %d (at the end: %d)\n", count, (char*)end_nursery - (char*)last);
1371 if (mono_profiler_get_events () & MONO_PROFILE_GC_ROOTS) {
1372 GCRootReport report;
1374 for (idx = 0; idx < count; ++idx)
1375 add_profile_gc_root (&report, definitely_pinned [idx], MONO_PROFILE_GC_ROOT_PINNING | MONO_PROFILE_GC_ROOT_MISC, 0);
1376 notify_gc_roots (&report);
1378 stat_pinned_objects += count;
1383 mono_sgen_pin_objects_in_section (GCMemSection *section, GrayQueue *queue)
1385 int num_entries = section->pin_queue_num_entries;
1387 void **start = section->pin_queue_start;
1389 reduced_to = pin_objects_from_addresses (section, start, start + num_entries,
1390 section->data, section->next_data, queue);
1391 section->pin_queue_num_entries = reduced_to;
1393 section->pin_queue_start = NULL;
1399 mono_sgen_pin_object (void *object, GrayQueue *queue)
1401 if (mono_sgen_collection_is_parallel ()) {
1403 /*object arrives pinned*/
1404 mono_sgen_pin_stage_ptr (object);
1408 SGEN_PIN_OBJECT (object);
1409 mono_sgen_pin_stage_ptr (object);
1411 if (G_UNLIKELY (do_pin_stats))
1412 mono_sgen_pin_stats_register_object (object, safe_object_get_size (object));
1414 GRAY_OBJECT_ENQUEUE (queue, object);
1415 binary_protocol_pin (object, (gpointer)LOAD_VTABLE (object), safe_object_get_size (object));
1418 /* Sort the addresses in array in increasing order.
1419 * Done using a by-the book heap sort. Which has decent and stable performance, is pretty cache efficient.
1422 mono_sgen_sort_addresses (void **array, int size)
1427 for (i = 1; i < size; ++i) {
1430 int parent = (child - 1) / 2;
1432 if (array [parent] >= array [child])
1435 tmp = array [parent];
1436 array [parent] = array [child];
1437 array [child] = tmp;
1443 for (i = size - 1; i > 0; --i) {
1446 array [i] = array [0];
1452 while (root * 2 + 1 <= end) {
1453 int child = root * 2 + 1;
1455 if (child < end && array [child] < array [child + 1])
1457 if (array [root] >= array [child])
1461 array [root] = array [child];
1462 array [child] = tmp;
1470 * Scan the memory between start and end and queue values which could be pointers
1471 * to the area between start_nursery and end_nursery for later consideration.
1472 * Typically used for thread stacks.
1475 conservatively_pin_objects_from (void **start, void **end, void *start_nursery, void *end_nursery, int pin_type)
1478 while (start < end) {
1479 if (*start >= start_nursery && *start < end_nursery) {
1481 * *start can point to the middle of an object
1482 * note: should we handle pointing at the end of an object?
1483 * pinning in C# code disallows pointing at the end of an object
1484 * but there is some small chance that an optimizing C compiler
1485 * may keep the only reference to an object by pointing
1486 * at the end of it. We ignore this small chance for now.
1487 * Pointers to the end of an object are indistinguishable
1488 * from pointers to the start of the next object in memory
1489 * so if we allow that we'd need to pin two objects...
1490 * We queue the pointer in an array, the
1491 * array will then be sorted and uniqued. This way
1492 * we can coalesce several pinning pointers and it should
1493 * be faster since we'd do a memory scan with increasing
1494 * addresses. Note: we can align the address to the allocation
1495 * alignment, so the unique process is more effective.
1497 mword addr = (mword)*start;
1498 addr &= ~(ALLOC_ALIGN - 1);
1499 if (addr >= (mword)start_nursery && addr < (mword)end_nursery)
1500 mono_sgen_pin_stage_ptr ((void*)addr);
1501 if (G_UNLIKELY (do_pin_stats)) {
1502 if (ptr_in_nursery (addr))
1503 mono_sgen_pin_stats_register_address ((char*)addr, pin_type);
1505 DEBUG (6, if (count) fprintf (gc_debug_file, "Pinning address %p from %p\n", (void*)addr, start));
1510 DEBUG (7, if (count) fprintf (gc_debug_file, "found %d potential pinned heap pointers\n", count));
1514 * Debugging function: find in the conservative roots where @obj is being pinned.
1516 static G_GNUC_UNUSED void
1517 find_pinning_reference (char *obj, size_t size)
1521 char *endobj = obj + size;
1523 SGEN_HASH_TABLE_FOREACH (&roots_hash [ROOT_TYPE_NORMAL], start, root) {
1524 /* if desc is non-null it has precise info */
1525 if (!root->root_desc) {
1526 while (start < (char**)root->end_root) {
1527 if (*start >= obj && *start < endobj) {
1528 DEBUG (0, fprintf (gc_debug_file, "Object %p referenced in pinned roots %p-%p\n", obj, start, root->end_root));
1533 } SGEN_HASH_TABLE_FOREACH_END;
1535 find_pinning_ref_from_thread (obj, size);
1539 * The first thing we do in a collection is to identify pinned objects.
1540 * This function considers all the areas of memory that need to be
1541 * conservatively scanned.
1544 pin_from_roots (void *start_nursery, void *end_nursery, GrayQueue *queue)
1548 DEBUG (2, fprintf (gc_debug_file, "Scanning pinned roots (%d bytes, %d/%d entries)\n", (int)roots_size, roots_hash [ROOT_TYPE_NORMAL].num_entries, roots_hash [ROOT_TYPE_PINNED].num_entries));
1549 /* objects pinned from the API are inside these roots */
1550 SGEN_HASH_TABLE_FOREACH (&roots_hash [ROOT_TYPE_PINNED], start_root, root) {
1551 DEBUG (6, fprintf (gc_debug_file, "Pinned roots %p-%p\n", start_root, root->end_root));
1552 conservatively_pin_objects_from (start_root, (void**)root->end_root, start_nursery, end_nursery, PIN_TYPE_OTHER);
1553 } SGEN_HASH_TABLE_FOREACH_END;
1554 /* now deal with the thread stacks
1555 * in the future we should be able to conservatively scan only:
1556 * *) the cpu registers
1557 * *) the unmanaged stack frames
1558 * *) the _last_ managed stack frame
1559 * *) pointers slots in managed frames
1561 scan_thread_data (start_nursery, end_nursery, FALSE, queue);
1565 CopyOrMarkObjectFunc func;
1567 } UserCopyOrMarkData;
1569 static MonoNativeTlsKey user_copy_or_mark_key;
1572 init_user_copy_or_mark_key (void)
1574 mono_native_tls_alloc (&user_copy_or_mark_key, NULL);
1578 set_user_copy_or_mark_data (UserCopyOrMarkData *data)
1580 mono_native_tls_set_value (user_copy_or_mark_key, data);
1584 single_arg_user_copy_or_mark (void **obj)
1586 UserCopyOrMarkData *data = mono_native_tls_get_value (user_copy_or_mark_key);
1588 data->func (obj, data->queue);
1592 * The memory area from start_root to end_root contains pointers to objects.
1593 * Their position is precisely described by @desc (this means that the pointer
1594 * can be either NULL or the pointer to the start of an object).
1595 * This functions copies them to to_space updates them.
1597 * This function is not thread-safe!
1600 precisely_scan_objects_from (CopyOrMarkObjectFunc copy_func, void** start_root, void** end_root, char* n_start, char *n_end, mword desc, GrayQueue *queue)
1602 switch (desc & ROOT_DESC_TYPE_MASK) {
1603 case ROOT_DESC_BITMAP:
1604 desc >>= ROOT_DESC_TYPE_SHIFT;
1606 if ((desc & 1) && *start_root) {
1607 copy_func (start_root, queue);
1608 DEBUG (9, fprintf (gc_debug_file, "Overwrote root at %p with %p\n", start_root, *start_root));
1609 mono_sgen_drain_gray_stack (queue, -1);
1615 case ROOT_DESC_COMPLEX: {
1616 gsize *bitmap_data = mono_sgen_get_complex_descriptor_bitmap (desc);
1617 int bwords = (*bitmap_data) - 1;
1618 void **start_run = start_root;
1620 while (bwords-- > 0) {
1621 gsize bmap = *bitmap_data++;
1622 void **objptr = start_run;
1624 if ((bmap & 1) && *objptr) {
1625 copy_func (objptr, queue);
1626 DEBUG (9, fprintf (gc_debug_file, "Overwrote root at %p with %p\n", objptr, *objptr));
1627 mono_sgen_drain_gray_stack (queue, -1);
1632 start_run += GC_BITS_PER_WORD;
1636 case ROOT_DESC_USER: {
1637 UserCopyOrMarkData data = { copy_func, queue };
1638 MonoGCRootMarkFunc marker = mono_sgen_get_user_descriptor_func (desc);
1639 set_user_copy_or_mark_data (&data);
1640 marker (start_root, single_arg_user_copy_or_mark);
1641 set_user_copy_or_mark_data (NULL);
1644 case ROOT_DESC_RUN_LEN:
1645 g_assert_not_reached ();
1647 g_assert_not_reached ();
1652 reset_heap_boundaries (void)
1654 lowest_heap_address = ~(mword)0;
1655 highest_heap_address = 0;
1659 mono_sgen_update_heap_boundaries (mword low, mword high)
1664 old = lowest_heap_address;
1667 } while (SGEN_CAS_PTR ((gpointer*)&lowest_heap_address, (gpointer)low, (gpointer)old) != (gpointer)old);
1670 old = highest_heap_address;
1673 } while (SGEN_CAS_PTR ((gpointer*)&highest_heap_address, (gpointer)high, (gpointer)old) != (gpointer)old);
1676 static unsigned long
1677 prot_flags_for_activate (int activate)
1679 unsigned long prot_flags = activate? MONO_MMAP_READ|MONO_MMAP_WRITE: MONO_MMAP_NONE;
1680 return prot_flags | MONO_MMAP_PRIVATE | MONO_MMAP_ANON;
1684 * Allocate a big chunk of memory from the OS (usually 64KB to several megabytes).
1685 * This must not require any lock.
1688 mono_sgen_alloc_os_memory (size_t size, int activate)
1690 void *ptr = mono_valloc (0, size, prot_flags_for_activate (activate));
1693 total_alloc += size;
1698 /* size must be a power of 2 */
1700 mono_sgen_alloc_os_memory_aligned (mword size, mword alignment, gboolean activate)
1702 void *ptr = mono_valloc_aligned (size, alignment, prot_flags_for_activate (activate));
1705 total_alloc += size;
1711 * Free the memory returned by mono_sgen_alloc_os_memory (), returning it to the OS.
1714 mono_sgen_free_os_memory (void *addr, size_t size)
1716 mono_vfree (addr, size);
1718 total_alloc -= size;
1722 * Allocate and setup the data structures needed to be able to allocate objects
1723 * in the nursery. The nursery is stored in nursery_section.
1726 alloc_nursery (void)
1728 GCMemSection *section;
1733 if (nursery_section)
1735 DEBUG (2, fprintf (gc_debug_file, "Allocating nursery size: %lu\n", (unsigned long)nursery_size));
1736 /* later we will alloc a larger area for the nursery but only activate
1737 * what we need. The rest will be used as expansion if we have too many pinned
1738 * objects in the existing nursery.
1740 /* FIXME: handle OOM */
1741 section = mono_sgen_alloc_internal (INTERNAL_MEM_SECTION);
1743 g_assert (nursery_size == DEFAULT_NURSERY_SIZE);
1744 alloc_size = nursery_size;
1745 #ifdef SGEN_ALIGN_NURSERY
1746 data = major_collector.alloc_heap (alloc_size, alloc_size, DEFAULT_NURSERY_BITS);
1748 data = major_collector.alloc_heap (alloc_size, 0, DEFAULT_NURSERY_BITS);
1750 nursery_start = data;
1751 nursery_end = nursery_start + nursery_size;
1752 mono_sgen_update_heap_boundaries ((mword)nursery_start, (mword)nursery_end);
1753 DEBUG (4, fprintf (gc_debug_file, "Expanding nursery size (%p-%p): %lu, total: %lu\n", data, data + alloc_size, (unsigned long)nursery_size, (unsigned long)total_alloc));
1754 section->data = section->next_data = data;
1755 section->size = alloc_size;
1756 section->end_data = nursery_end;
1757 scan_starts = (alloc_size + SCAN_START_SIZE - 1) / SCAN_START_SIZE;
1758 section->scan_starts = mono_sgen_alloc_internal_dynamic (sizeof (char*) * scan_starts, INTERNAL_MEM_SCAN_STARTS);
1759 section->num_scan_start = scan_starts;
1760 section->block.role = MEMORY_ROLE_GEN0;
1761 section->block.next = NULL;
1763 nursery_section = section;
1765 mono_sgen_nursery_allocator_set_nursery_bounds (nursery_start, nursery_end);
1769 mono_gc_get_nursery (int *shift_bits, size_t *size)
1771 *size = nursery_size;
1772 #ifdef SGEN_ALIGN_NURSERY
1773 *shift_bits = DEFAULT_NURSERY_BITS;
1777 return nursery_start;
1781 mono_gc_set_current_thread_appdomain (MonoDomain *domain)
1783 SgenThreadInfo *info = mono_thread_info_current ();
1785 /* Could be called from sgen_thread_unregister () with a NULL info */
1788 info->stopped_domain = domain;
1793 mono_gc_precise_stack_mark_enabled (void)
1795 return !conservative_stack_mark;
1799 mono_gc_get_logfile (void)
1801 return mono_sgen_get_logfile ();
1805 report_finalizer_roots_list (FinalizeReadyEntry *list)
1807 GCRootReport report;
1808 FinalizeReadyEntry *fin;
1811 for (fin = list; fin; fin = fin->next) {
1814 add_profile_gc_root (&report, fin->object, MONO_PROFILE_GC_ROOT_FINALIZER, 0);
1816 notify_gc_roots (&report);
1820 report_finalizer_roots (void)
1822 report_finalizer_roots_list (fin_ready_list);
1823 report_finalizer_roots_list (critical_fin_list);
1826 static GCRootReport *root_report;
1829 single_arg_report_root (void **obj)
1832 add_profile_gc_root (root_report, *obj, MONO_PROFILE_GC_ROOT_OTHER, 0);
1836 precisely_report_roots_from (GCRootReport *report, void** start_root, void** end_root, mword desc)
1838 switch (desc & ROOT_DESC_TYPE_MASK) {
1839 case ROOT_DESC_BITMAP:
1840 desc >>= ROOT_DESC_TYPE_SHIFT;
1842 if ((desc & 1) && *start_root) {
1843 add_profile_gc_root (report, *start_root, MONO_PROFILE_GC_ROOT_OTHER, 0);
1849 case ROOT_DESC_COMPLEX: {
1850 gsize *bitmap_data = mono_sgen_get_complex_descriptor_bitmap (desc);
1851 int bwords = (*bitmap_data) - 1;
1852 void **start_run = start_root;
1854 while (bwords-- > 0) {
1855 gsize bmap = *bitmap_data++;
1856 void **objptr = start_run;
1858 if ((bmap & 1) && *objptr) {
1859 add_profile_gc_root (report, *objptr, MONO_PROFILE_GC_ROOT_OTHER, 0);
1864 start_run += GC_BITS_PER_WORD;
1868 case ROOT_DESC_USER: {
1869 MonoGCRootMarkFunc marker = mono_sgen_get_user_descriptor_func (desc);
1870 root_report = report;
1871 marker (start_root, single_arg_report_root);
1874 case ROOT_DESC_RUN_LEN:
1875 g_assert_not_reached ();
1877 g_assert_not_reached ();
1882 report_registered_roots_by_type (int root_type)
1884 GCRootReport report;
1888 SGEN_HASH_TABLE_FOREACH (&roots_hash [root_type], start_root, root) {
1889 DEBUG (6, fprintf (gc_debug_file, "Precise root scan %p-%p (desc: %p)\n", start_root, root->end_root, (void*)root->root_desc));
1890 precisely_report_roots_from (&report, start_root, (void**)root->end_root, root->root_desc);
1891 } SGEN_HASH_TABLE_FOREACH_END;
1892 notify_gc_roots (&report);
1896 report_registered_roots (void)
1898 report_registered_roots_by_type (ROOT_TYPE_NORMAL);
1899 report_registered_roots_by_type (ROOT_TYPE_WBARRIER);
1903 scan_finalizer_entries (CopyOrMarkObjectFunc copy_func, FinalizeReadyEntry *list, GrayQueue *queue)
1905 FinalizeReadyEntry *fin;
1907 for (fin = list; fin; fin = fin->next) {
1910 DEBUG (5, fprintf (gc_debug_file, "Scan of fin ready object: %p (%s)\n", fin->object, safe_name (fin->object)));
1911 copy_func (&fin->object, queue);
1916 generation_name (int generation)
1918 switch (generation) {
1919 case GENERATION_NURSERY: return "nursery";
1920 case GENERATION_OLD: return "old";
1921 default: g_assert_not_reached ();
1927 stw_bridge_process (void)
1929 mono_sgen_bridge_processing_stw_step ();
1933 bridge_process (void)
1935 mono_sgen_bridge_processing_finish ();
1938 CopyOrMarkObjectFunc
1939 mono_sgen_get_copy_object (void)
1941 if (current_collection_generation == GENERATION_NURSERY) {
1942 if (mono_sgen_collection_is_parallel ())
1943 return major_collector.copy_object;
1945 return major_collector.nopar_copy_object;
1947 return major_collector.copy_or_mark_object;
1952 mono_sgen_get_minor_scan_object (void)
1954 g_assert (current_collection_generation == GENERATION_NURSERY);
1956 if (mono_sgen_collection_is_parallel ())
1957 return major_collector.minor_scan_object;
1959 return major_collector.nopar_minor_scan_object;
1963 mono_sgen_get_minor_scan_vtype (void)
1965 g_assert (current_collection_generation == GENERATION_NURSERY);
1967 if (mono_sgen_collection_is_parallel ())
1968 return major_collector.minor_scan_vtype;
1970 return major_collector.nopar_minor_scan_vtype;
1974 finish_gray_stack (char *start_addr, char *end_addr, int generation, GrayQueue *queue)
1979 int done_with_ephemerons, ephemeron_rounds = 0;
1981 CopyOrMarkObjectFunc copy_func = mono_sgen_get_copy_object ();
1984 * We copied all the reachable objects. Now it's the time to copy
1985 * the objects that were not referenced by the roots, but by the copied objects.
1986 * we built a stack of objects pointed to by gray_start: they are
1987 * additional roots and we may add more items as we go.
1988 * We loop until gray_start == gray_objects which means no more objects have
1989 * been added. Note this is iterative: no recursion is involved.
1990 * We need to walk the LO list as well in search of marked big objects
1991 * (use a flag since this is needed only on major collections). We need to loop
1992 * here as well, so keep a counter of marked LO (increasing it in copy_object).
1993 * To achieve better cache locality and cache usage, we drain the gray stack
1994 * frequently, after each object is copied, and just finish the work here.
1996 mono_sgen_drain_gray_stack (queue, -1);
1998 DEBUG (2, fprintf (gc_debug_file, "%s generation done\n", generation_name (generation)));
2001 Reset bridge data, we might have lingering data from a previous collection if this is a major
2002 collection trigged by minor overflow.
2004 We must reset the gathered bridges since their original block might be evacuated due to major
2005 fragmentation in the meanwhile and the bridge code should not have to deal with that.
2007 mono_sgen_bridge_reset_data ();
2010 * Walk the ephemeron tables marking all values with reachable keys. This must be completely done
2011 * before processing finalizable objects or non-tracking weak hamdle to avoid finalizing/clearing
2012 * objects that are in fact reachable.
2014 done_with_ephemerons = 0;
2016 done_with_ephemerons = mark_ephemerons_in_range (copy_func, start_addr, end_addr, queue);
2017 mono_sgen_drain_gray_stack (queue, -1);
2019 } while (!done_with_ephemerons);
2021 mono_sgen_scan_togglerefs (copy_func, start_addr, end_addr, queue);
2022 if (generation == GENERATION_OLD)
2023 mono_sgen_scan_togglerefs (copy_func, nursery_start, nursery_end, queue);
2025 if (mono_sgen_need_bridge_processing ()) {
2026 collect_bridge_objects (copy_func, start_addr, end_addr, generation, queue);
2027 if (generation == GENERATION_OLD)
2028 collect_bridge_objects (copy_func, nursery_start, nursery_end, GENERATION_NURSERY, queue);
2029 mono_sgen_drain_gray_stack (queue, -1);
2033 We must clear weak links that don't track resurrection before processing object ready for
2034 finalization so they can be cleared before that.
2036 null_link_in_range (copy_func, start_addr, end_addr, generation, TRUE, queue);
2037 if (generation == GENERATION_OLD)
2038 null_link_in_range (copy_func, start_addr, end_addr, GENERATION_NURSERY, TRUE, queue);
2041 /* walk the finalization queue and move also the objects that need to be
2042 * finalized: use the finalized objects as new roots so the objects they depend
2043 * on are also not reclaimed. As with the roots above, only objects in the nursery
2044 * are marked/copied.
2045 * We need a loop here, since objects ready for finalizers may reference other objects
2046 * that are fin-ready. Speedup with a flag?
2050 fin_ready = num_ready_finalizers;
2051 finalize_in_range (copy_func, start_addr, end_addr, generation, queue);
2052 if (generation == GENERATION_OLD)
2053 finalize_in_range (copy_func, nursery_start, nursery_end, GENERATION_NURSERY, queue);
2055 if (fin_ready != num_ready_finalizers)
2058 /* drain the new stack that might have been created */
2059 DEBUG (6, fprintf (gc_debug_file, "Precise scan of gray area post fin\n"));
2060 mono_sgen_drain_gray_stack (queue, -1);
2061 } while (fin_ready != num_ready_finalizers);
2063 if (mono_sgen_need_bridge_processing ())
2064 g_assert (num_loops <= 1);
2067 * This must be done again after processing finalizable objects since CWL slots are cleared only after the key is finalized.
2069 done_with_ephemerons = 0;
2071 done_with_ephemerons = mark_ephemerons_in_range (copy_func, start_addr, end_addr, queue);
2072 mono_sgen_drain_gray_stack (queue, -1);
2074 } while (!done_with_ephemerons);
2077 * Clear ephemeron pairs with unreachable keys.
2078 * We pass the copy func so we can figure out if an array was promoted or not.
2080 clear_unreachable_ephemerons (copy_func, start_addr, end_addr, queue);
2083 DEBUG (2, fprintf (gc_debug_file, "Finalize queue handling scan for %s generation: %d usecs %d ephemeron roundss\n", generation_name (generation), TV_ELAPSED (atv, btv), ephemeron_rounds));
2086 * handle disappearing links
2087 * Note we do this after checking the finalization queue because if an object
2088 * survives (at least long enough to be finalized) we don't clear the link.
2089 * This also deals with a possible issue with the monitor reclamation: with the Boehm
2090 * GC a finalized object my lose the monitor because it is cleared before the finalizer is
2093 g_assert (mono_sgen_gray_object_queue_is_empty (queue));
2095 null_link_in_range (copy_func, start_addr, end_addr, generation, FALSE, queue);
2096 if (generation == GENERATION_OLD)
2097 null_link_in_range (copy_func, start_addr, end_addr, GENERATION_NURSERY, FALSE, queue);
2098 if (mono_sgen_gray_object_queue_is_empty (queue))
2100 mono_sgen_drain_gray_stack (queue, -1);
2103 g_assert (mono_sgen_gray_object_queue_is_empty (queue));
2107 mono_sgen_check_section_scan_starts (GCMemSection *section)
2110 for (i = 0; i < section->num_scan_start; ++i) {
2111 if (section->scan_starts [i]) {
2112 guint size = safe_object_get_size ((MonoObject*) section->scan_starts [i]);
2113 g_assert (size >= sizeof (MonoObject) && size <= MAX_SMALL_OBJ_SIZE);
2119 check_scan_starts (void)
2121 if (!do_scan_starts_check)
2123 mono_sgen_check_section_scan_starts (nursery_section);
2124 major_collector.check_scan_starts ();
2128 scan_from_registered_roots (CopyOrMarkObjectFunc copy_func, char *addr_start, char *addr_end, int root_type, GrayQueue *queue)
2132 SGEN_HASH_TABLE_FOREACH (&roots_hash [root_type], start_root, root) {
2133 DEBUG (6, fprintf (gc_debug_file, "Precise root scan %p-%p (desc: %p)\n", start_root, root->end_root, (void*)root->root_desc));
2134 precisely_scan_objects_from (copy_func, start_root, (void**)root->end_root, addr_start, addr_end, root->root_desc, queue);
2135 } SGEN_HASH_TABLE_FOREACH_END;
2139 mono_sgen_dump_occupied (char *start, char *end, char *section_start)
2141 fprintf (heap_dump_file, "<occupied offset=\"%td\" size=\"%td\"/>\n", start - section_start, end - start);
2145 mono_sgen_dump_section (GCMemSection *section, const char *type)
2147 char *start = section->data;
2148 char *end = section->data + section->size;
2149 char *occ_start = NULL;
2151 char *old_start = NULL; /* just for debugging */
2153 fprintf (heap_dump_file, "<section type=\"%s\" size=\"%lu\">\n", type, (unsigned long)section->size);
2155 while (start < end) {
2159 if (!*(void**)start) {
2161 mono_sgen_dump_occupied (occ_start, start, section->data);
2164 start += sizeof (void*); /* should be ALLOC_ALIGN, really */
2167 g_assert (start < section->next_data);
2172 vt = (GCVTable*)LOAD_VTABLE (start);
2175 size = ALIGN_UP (safe_object_get_size ((MonoObject*) start));
2178 fprintf (heap_dump_file, "<object offset=\"%d\" class=\"%s.%s\" size=\"%d\"/>\n",
2179 start - section->data,
2180 vt->klass->name_space, vt->klass->name,
2188 mono_sgen_dump_occupied (occ_start, start, section->data);
2190 fprintf (heap_dump_file, "</section>\n");
2194 dump_object (MonoObject *obj, gboolean dump_location)
2196 static char class_name [1024];
2198 MonoClass *class = mono_object_class (obj);
2202 * Python's XML parser is too stupid to parse angle brackets
2203 * in strings, so we just ignore them;
2206 while (class->name [i] && j < sizeof (class_name) - 1) {
2207 if (!strchr ("<>\"", class->name [i]))
2208 class_name [j++] = class->name [i];
2211 g_assert (j < sizeof (class_name));
2214 fprintf (heap_dump_file, "<object class=\"%s.%s\" size=\"%d\"",
2215 class->name_space, class_name,
2216 safe_object_get_size (obj));
2217 if (dump_location) {
2218 const char *location;
2219 if (ptr_in_nursery (obj))
2220 location = "nursery";
2221 else if (safe_object_get_size (obj) <= MAX_SMALL_OBJ_SIZE)
2225 fprintf (heap_dump_file, " location=\"%s\"", location);
2227 fprintf (heap_dump_file, "/>\n");
2231 dump_heap (const char *type, int num, const char *reason)
2236 fprintf (heap_dump_file, "<collection type=\"%s\" num=\"%d\"", type, num);
2238 fprintf (heap_dump_file, " reason=\"%s\"", reason);
2239 fprintf (heap_dump_file, ">\n");
2240 fprintf (heap_dump_file, "<other-mem-usage type=\"mempools\" size=\"%ld\"/>\n", mono_mempool_get_bytes_allocated ());
2241 mono_sgen_dump_internal_mem_usage (heap_dump_file);
2242 fprintf (heap_dump_file, "<pinned type=\"stack\" bytes=\"%zu\"/>\n", mono_sgen_pin_stats_get_pinned_byte_count (PIN_TYPE_STACK));
2243 /* fprintf (heap_dump_file, "<pinned type=\"static-data\" bytes=\"%d\"/>\n", pinned_byte_counts [PIN_TYPE_STATIC_DATA]); */
2244 fprintf (heap_dump_file, "<pinned type=\"other\" bytes=\"%zu\"/>\n", mono_sgen_pin_stats_get_pinned_byte_count (PIN_TYPE_OTHER));
2246 fprintf (heap_dump_file, "<pinned-objects>\n");
2247 for (list = mono_sgen_pin_stats_get_object_list (); list; list = list->next)
2248 dump_object (list->obj, TRUE);
2249 fprintf (heap_dump_file, "</pinned-objects>\n");
2251 mono_sgen_dump_section (nursery_section, "nursery");
2253 major_collector.dump_heap (heap_dump_file);
2255 fprintf (heap_dump_file, "<los>\n");
2256 for (bigobj = los_object_list; bigobj; bigobj = bigobj->next)
2257 dump_object ((MonoObject*)bigobj->data, FALSE);
2258 fprintf (heap_dump_file, "</los>\n");
2260 fprintf (heap_dump_file, "</collection>\n");
2264 mono_sgen_register_moved_object (void *obj, void *destination)
2266 g_assert (mono_profiler_events & MONO_PROFILE_GC_MOVES);
2268 /* FIXME: handle this for parallel collector */
2269 g_assert (!mono_sgen_collection_is_parallel ());
2271 if (moved_objects_idx == MOVED_OBJECTS_NUM) {
2272 mono_profiler_gc_moves (moved_objects, moved_objects_idx);
2273 moved_objects_idx = 0;
2275 moved_objects [moved_objects_idx++] = obj;
2276 moved_objects [moved_objects_idx++] = destination;
2282 static gboolean inited = FALSE;
2287 mono_counters_register ("Minor fragment clear", MONO_COUNTER_GC | MONO_COUNTER_LONG, &time_minor_pre_collection_fragment_clear);
2288 mono_counters_register ("Minor pinning", MONO_COUNTER_GC | MONO_COUNTER_LONG, &time_minor_pinning);
2289 mono_counters_register ("Minor scan remembered set", MONO_COUNTER_GC | MONO_COUNTER_LONG, &time_minor_scan_remsets);
2290 mono_counters_register ("Minor scan pinned", MONO_COUNTER_GC | MONO_COUNTER_LONG, &time_minor_scan_pinned);
2291 mono_counters_register ("Minor scan registered roots", MONO_COUNTER_GC | MONO_COUNTER_LONG, &time_minor_scan_registered_roots);
2292 mono_counters_register ("Minor scan thread data", MONO_COUNTER_GC | MONO_COUNTER_LONG, &time_minor_scan_thread_data);
2293 mono_counters_register ("Minor finish gray stack", MONO_COUNTER_GC | MONO_COUNTER_LONG, &time_minor_finish_gray_stack);
2294 mono_counters_register ("Minor fragment creation", MONO_COUNTER_GC | MONO_COUNTER_LONG, &time_minor_fragment_creation);
2296 mono_counters_register ("Major fragment clear", MONO_COUNTER_GC | MONO_COUNTER_LONG, &time_major_pre_collection_fragment_clear);
2297 mono_counters_register ("Major pinning", MONO_COUNTER_GC | MONO_COUNTER_LONG, &time_major_pinning);
2298 mono_counters_register ("Major scan pinned", MONO_COUNTER_GC | MONO_COUNTER_LONG, &time_major_scan_pinned);
2299 mono_counters_register ("Major scan registered roots", MONO_COUNTER_GC | MONO_COUNTER_LONG, &time_major_scan_registered_roots);
2300 mono_counters_register ("Major scan thread data", MONO_COUNTER_GC | MONO_COUNTER_LONG, &time_major_scan_thread_data);
2301 mono_counters_register ("Major scan alloc_pinned", MONO_COUNTER_GC | MONO_COUNTER_LONG, &time_major_scan_alloc_pinned);
2302 mono_counters_register ("Major scan finalized", MONO_COUNTER_GC | MONO_COUNTER_LONG, &time_major_scan_finalized);
2303 mono_counters_register ("Major scan big objects", MONO_COUNTER_GC | MONO_COUNTER_LONG, &time_major_scan_big_objects);
2304 mono_counters_register ("Major finish gray stack", MONO_COUNTER_GC | MONO_COUNTER_LONG, &time_major_finish_gray_stack);
2305 mono_counters_register ("Major free big objects", MONO_COUNTER_GC | MONO_COUNTER_LONG, &time_major_free_bigobjs);
2306 mono_counters_register ("Major LOS sweep", MONO_COUNTER_GC | MONO_COUNTER_LONG, &time_major_los_sweep);
2307 mono_counters_register ("Major sweep", MONO_COUNTER_GC | MONO_COUNTER_LONG, &time_major_sweep);
2308 mono_counters_register ("Major fragment creation", MONO_COUNTER_GC | MONO_COUNTER_LONG, &time_major_fragment_creation);
2310 mono_counters_register ("Number of pinned objects", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_pinned_objects);
2312 #ifdef HEAVY_STATISTICS
2313 mono_counters_register ("WBarrier set field", MONO_COUNTER_GC | MONO_COUNTER_INT, &stat_wbarrier_set_field);
2314 mono_counters_register ("WBarrier set arrayref", MONO_COUNTER_GC | MONO_COUNTER_INT, &stat_wbarrier_set_arrayref);
2315 mono_counters_register ("WBarrier arrayref copy", MONO_COUNTER_GC | MONO_COUNTER_INT, &stat_wbarrier_arrayref_copy);
2316 mono_counters_register ("WBarrier generic store called", MONO_COUNTER_GC | MONO_COUNTER_INT, &stat_wbarrier_generic_store);
2317 mono_counters_register ("WBarrier set root", MONO_COUNTER_GC | MONO_COUNTER_INT, &stat_wbarrier_set_root);
2318 mono_counters_register ("WBarrier value copy", MONO_COUNTER_GC | MONO_COUNTER_INT, &stat_wbarrier_value_copy);
2319 mono_counters_register ("WBarrier object copy", MONO_COUNTER_GC | MONO_COUNTER_INT, &stat_wbarrier_object_copy);
2321 mono_counters_register ("# objects allocated degraded", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_objects_alloced_degraded);
2322 mono_counters_register ("bytes allocated degraded", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_bytes_alloced_degraded);
2324 mono_counters_register ("# copy_object() called (nursery)", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_copy_object_called_nursery);
2325 mono_counters_register ("# objects copied (nursery)", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_objects_copied_nursery);
2326 mono_counters_register ("# copy_object() called (major)", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_copy_object_called_major);
2327 mono_counters_register ("# objects copied (major)", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_objects_copied_major);
2329 mono_counters_register ("# scan_object() called (nursery)", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_scan_object_called_nursery);
2330 mono_counters_register ("# scan_object() called (major)", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_scan_object_called_major);
2332 mono_counters_register ("# nursery copy_object() failed from space", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_nursery_copy_object_failed_from_space);
2333 mono_counters_register ("# nursery copy_object() failed forwarded", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_nursery_copy_object_failed_forwarded);
2334 mono_counters_register ("# nursery copy_object() failed pinned", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_nursery_copy_object_failed_pinned);
2336 mono_sgen_nursery_allocator_init_heavy_stats ();
2337 mono_sgen_alloc_init_heavy_stats ();
2343 static gboolean need_calculate_minor_collection_allowance;
2345 static int last_collection_old_num_major_sections;
2346 static mword last_collection_los_memory_usage = 0;
2347 static mword last_collection_old_los_memory_usage;
2348 static mword last_collection_los_memory_alloced;
2351 reset_minor_collection_allowance (void)
2353 need_calculate_minor_collection_allowance = TRUE;
2357 try_calculate_minor_collection_allowance (gboolean overwrite)
2359 int num_major_sections, num_major_sections_saved, save_target, allowance_target;
2360 mword los_memory_saved, new_major, new_heap_size;
2363 g_assert (need_calculate_minor_collection_allowance);
2365 if (!need_calculate_minor_collection_allowance)
2368 if (!*major_collector.have_swept) {
2370 minor_collection_allowance = MIN_MINOR_COLLECTION_ALLOWANCE;
2374 num_major_sections = major_collector.get_num_major_sections ();
2376 num_major_sections_saved = MAX (last_collection_old_num_major_sections - num_major_sections, 0);
2377 los_memory_saved = MAX (last_collection_old_los_memory_usage - last_collection_los_memory_usage, 1);
2379 new_major = num_major_sections * major_collector.section_size;
2380 new_heap_size = new_major + last_collection_los_memory_usage;
2383 * FIXME: Why is save_target half the major memory plus half the
2384 * LOS memory saved? Shouldn't it be half the major memory
2385 * saved plus half the LOS memory saved? Or half the whole heap
2388 save_target = (new_major + los_memory_saved) / 2;
2391 * We aim to allow the allocation of as many sections as is
2392 * necessary to reclaim save_target sections in the next
2393 * collection. We assume the collection pattern won't change.
2394 * In the last cycle, we had num_major_sections_saved for
2395 * minor_collection_sections_alloced. Assuming things won't
2396 * change, this must be the same ratio as save_target for
2397 * allowance_target, i.e.
2399 * num_major_sections_saved save_target
2400 * --------------------------------- == ----------------
2401 * minor_collection_sections_alloced allowance_target
2405 allowance_target = (mword)((double)save_target * (double)(minor_collection_sections_alloced * major_collector.section_size + last_collection_los_memory_alloced) / (double)(num_major_sections_saved * major_collector.section_size + los_memory_saved));
2407 minor_collection_allowance = MAX (MIN (allowance_target, num_major_sections * major_collector.section_size + los_memory_usage), MIN_MINOR_COLLECTION_ALLOWANCE);
2409 if (new_heap_size + minor_collection_allowance > soft_heap_limit) {
2410 if (new_heap_size > soft_heap_limit)
2411 minor_collection_allowance = MIN_MINOR_COLLECTION_ALLOWANCE;
2413 minor_collection_allowance = MAX (soft_heap_limit - new_heap_size, MIN_MINOR_COLLECTION_ALLOWANCE);
2416 if (debug_print_allowance) {
2417 mword old_major = last_collection_old_num_major_sections * major_collector.section_size;
2419 fprintf (gc_debug_file, "Before collection: %ld bytes (%ld major, %ld LOS)\n",
2420 old_major + last_collection_old_los_memory_usage, old_major, last_collection_old_los_memory_usage);
2421 fprintf (gc_debug_file, "After collection: %ld bytes (%ld major, %ld LOS)\n",
2422 new_heap_size, new_major, last_collection_los_memory_usage);
2423 fprintf (gc_debug_file, "Allowance: %ld bytes\n", minor_collection_allowance);
2426 if (major_collector.have_computed_minor_collection_allowance)
2427 major_collector.have_computed_minor_collection_allowance ();
2429 need_calculate_minor_collection_allowance = FALSE;
2433 need_major_collection (mword space_needed)
2435 mword los_alloced = los_memory_usage - MIN (last_collection_los_memory_usage, los_memory_usage);
2436 return (space_needed > available_free_space ()) ||
2437 minor_collection_sections_alloced * major_collector.section_size + los_alloced > minor_collection_allowance;
2441 mono_sgen_need_major_collection (mword space_needed)
2443 return need_major_collection (space_needed);
2447 reset_pinned_from_failed_allocation (void)
2449 bytes_pinned_from_failed_allocation = 0;
2453 mono_sgen_set_pinned_from_failed_allocation (mword objsize)
2455 bytes_pinned_from_failed_allocation += objsize;
2459 mono_sgen_collection_is_parallel (void)
2461 switch (current_collection_generation) {
2462 case GENERATION_NURSERY:
2463 return nursery_collection_is_parallel;
2464 case GENERATION_OLD:
2465 return major_collector.is_parallel;
2467 g_assert_not_reached ();
2472 mono_sgen_nursery_collection_is_parallel (void)
2474 return nursery_collection_is_parallel;
2481 } FinishRememberedSetScanJobData;
2484 job_finish_remembered_set_scan (WorkerData *worker_data, void *job_data_untyped)
2486 FinishRememberedSetScanJobData *job_data = job_data_untyped;
2488 remset.finish_scan_remsets (job_data->heap_start, job_data->heap_end, mono_sgen_workers_get_job_gray_queue (worker_data));
2493 CopyOrMarkObjectFunc func;
2497 } ScanFromRegisteredRootsJobData;
2500 job_scan_from_registered_roots (WorkerData *worker_data, void *job_data_untyped)
2502 ScanFromRegisteredRootsJobData *job_data = job_data_untyped;
2504 scan_from_registered_roots (job_data->func,
2505 job_data->heap_start, job_data->heap_end,
2506 job_data->root_type,
2507 mono_sgen_workers_get_job_gray_queue (worker_data));
2514 } ScanThreadDataJobData;
2517 job_scan_thread_data (WorkerData *worker_data, void *job_data_untyped)
2519 ScanThreadDataJobData *job_data = job_data_untyped;
2521 scan_thread_data (job_data->heap_start, job_data->heap_end, TRUE,
2522 mono_sgen_workers_get_job_gray_queue (worker_data));
2526 verify_scan_starts (char *start, char *end)
2530 for (i = 0; i < nursery_section->num_scan_start; ++i) {
2531 char *addr = nursery_section->scan_starts [i];
2532 if (addr > start && addr < end)
2533 fprintf (gc_debug_file, "NFC-BAD SCAN START [%d] %p for obj [%p %p]\n", i, addr, start, end);
2538 verify_nursery (void)
2540 char *start, *end, *cur, *hole_start;
2542 if (!do_verify_nursery)
2545 /*This cleans up unused fragments */
2546 mono_sgen_nursery_allocator_prepare_for_pinning ();
2548 hole_start = start = cur = nursery_start;
2554 if (!*(void**)cur) {
2555 cur += sizeof (void*);
2559 if (object_is_forwarded (cur))
2560 fprintf (gc_debug_file, "FORWARDED OBJ %p\n", cur);
2561 else if (object_is_pinned (cur))
2562 fprintf (gc_debug_file, "PINNED OBJ %p\n", cur);
2564 ss = safe_object_get_size ((MonoObject*)cur);
2565 size = ALIGN_UP (safe_object_get_size ((MonoObject*)cur));
2566 verify_scan_starts (cur, cur + size);
2567 if (do_dump_nursery_content) {
2568 if (cur > hole_start)
2569 fprintf (gc_debug_file, "HOLE [%p %p %d]\n", hole_start, cur, (int)(cur - hole_start));
2570 fprintf (gc_debug_file, "OBJ [%p %p %d %d %s %d]\n", cur, cur + size, (int)size, (int)ss, mono_sgen_safe_name ((MonoObject*)cur), (gpointer)LOAD_VTABLE (cur) == mono_sgen_get_array_fill_vtable ());
2575 fflush (gc_debug_file);
2579 * Collect objects in the nursery. Returns whether to trigger a major
2583 collect_nursery (size_t requested_size)
2585 gboolean needs_major;
2586 size_t max_garbage_amount;
2588 FinishRememberedSetScanJobData frssjd;
2589 ScanFromRegisteredRootsJobData scrrjd_normal, scrrjd_wbarrier;
2590 ScanThreadDataJobData stdjd;
2591 mword fragment_total;
2592 TV_DECLARE (all_atv);
2593 TV_DECLARE (all_btv);
2597 if (disable_minor_collections)
2602 mono_perfcounters->gc_collections0++;
2604 current_collection_generation = GENERATION_NURSERY;
2606 reset_pinned_from_failed_allocation ();
2608 binary_protocol_collection (GENERATION_NURSERY);
2609 check_scan_starts ();
2613 nursery_next = mono_sgen_nursery_alloc_get_upper_alloc_bound ();
2614 /* FIXME: optimize later to use the higher address where an object can be present */
2615 nursery_next = MAX (nursery_next, nursery_end);
2617 nursery_alloc_bound = nursery_next;
2619 DEBUG (1, fprintf (gc_debug_file, "Start nursery collection %d %p-%p, size: %d\n", stat_minor_gcs, nursery_start, nursery_next, (int)(nursery_next - nursery_start)));
2620 max_garbage_amount = nursery_next - nursery_start;
2621 g_assert (nursery_section->size >= max_garbage_amount);
2623 /* world must be stopped already */
2624 TV_GETTIME (all_atv);
2627 /* Pinning no longer depends on clearing all nursery fragments */
2628 mono_sgen_clear_current_nursery_fragment ();
2631 time_minor_pre_collection_fragment_clear += TV_ELAPSED_MS (atv, btv);
2634 check_for_xdomain_refs ();
2636 nursery_section->next_data = nursery_next;
2638 major_collector.start_nursery_collection ();
2640 try_calculate_minor_collection_allowance (FALSE);
2642 mono_sgen_gray_object_queue_init (&gray_queue);
2643 mono_sgen_workers_init_distribute_gray_queue ();
2646 mono_stats.minor_gc_count ++;
2648 if (remset.prepare_for_minor_collection)
2649 remset.prepare_for_minor_collection ();
2651 process_fin_stage_entries ();
2652 process_dislink_stage_entries ();
2654 /* pin from pinned handles */
2655 mono_sgen_init_pinning ();
2656 mono_profiler_gc_event (MONO_GC_EVENT_MARK_START, 0);
2657 pin_from_roots (nursery_start, nursery_next, WORKERS_DISTRIBUTE_GRAY_QUEUE);
2658 /* identify pinned objects */
2659 mono_sgen_optimize_pin_queue (0);
2660 mono_sgen_pinning_setup_section (nursery_section);
2661 mono_sgen_pin_objects_in_section (nursery_section, WORKERS_DISTRIBUTE_GRAY_QUEUE);
2664 time_minor_pinning += TV_ELAPSED_MS (btv, atv);
2665 DEBUG (2, fprintf (gc_debug_file, "Finding pinned pointers: %d in %d usecs\n", mono_sgen_get_pinned_count (), TV_ELAPSED (btv, atv)));
2666 DEBUG (4, fprintf (gc_debug_file, "Start scan with %d pinned objects\n", mono_sgen_get_pinned_count ()));
2668 if (consistency_check_at_minor_collection)
2669 mono_sgen_check_consistency ();
2671 mono_sgen_workers_start_all_workers ();
2674 * Perform the sequential part of remembered set scanning.
2675 * This usually involves scanning global information that might later be produced by evacuation.
2677 if (remset.begin_scan_remsets)
2678 remset.begin_scan_remsets (nursery_start, nursery_next, WORKERS_DISTRIBUTE_GRAY_QUEUE);
2680 mono_sgen_workers_start_marking ();
2682 frssjd.heap_start = nursery_start;
2683 frssjd.heap_end = nursery_next;
2684 mono_sgen_workers_enqueue_job (job_finish_remembered_set_scan, &frssjd);
2686 /* we don't have complete write barrier yet, so we scan all the old generation sections */
2688 time_minor_scan_remsets += TV_ELAPSED_MS (atv, btv);
2689 DEBUG (2, fprintf (gc_debug_file, "Old generation scan: %d usecs\n", TV_ELAPSED (atv, btv)));
2691 if (!mono_sgen_collection_is_parallel ())
2692 mono_sgen_drain_gray_stack (&gray_queue, -1);
2694 if (mono_profiler_get_events () & MONO_PROFILE_GC_ROOTS)
2695 report_registered_roots ();
2696 if (mono_profiler_get_events () & MONO_PROFILE_GC_ROOTS)
2697 report_finalizer_roots ();
2699 time_minor_scan_pinned += TV_ELAPSED_MS (btv, atv);
2701 /* registered roots, this includes static fields */
2702 scrrjd_normal.func = mono_sgen_collection_is_parallel () ? major_collector.copy_object : major_collector.nopar_copy_object;
2703 scrrjd_normal.heap_start = nursery_start;
2704 scrrjd_normal.heap_end = nursery_next;
2705 scrrjd_normal.root_type = ROOT_TYPE_NORMAL;
2706 mono_sgen_workers_enqueue_job (job_scan_from_registered_roots, &scrrjd_normal);
2708 scrrjd_wbarrier.func = mono_sgen_collection_is_parallel () ? major_collector.copy_object : major_collector.nopar_copy_object;
2709 scrrjd_wbarrier.heap_start = nursery_start;
2710 scrrjd_wbarrier.heap_end = nursery_next;
2711 scrrjd_wbarrier.root_type = ROOT_TYPE_WBARRIER;
2712 mono_sgen_workers_enqueue_job (job_scan_from_registered_roots, &scrrjd_wbarrier);
2715 time_minor_scan_registered_roots += TV_ELAPSED_MS (atv, btv);
2718 stdjd.heap_start = nursery_start;
2719 stdjd.heap_end = nursery_next;
2720 mono_sgen_workers_enqueue_job (job_scan_thread_data, &stdjd);
2723 time_minor_scan_thread_data += TV_ELAPSED_MS (btv, atv);
2726 if (mono_sgen_collection_is_parallel ()) {
2727 while (!mono_sgen_gray_object_queue_is_empty (WORKERS_DISTRIBUTE_GRAY_QUEUE)) {
2728 mono_sgen_workers_distribute_gray_queue_sections ();
2732 mono_sgen_workers_join ();
2734 if (mono_sgen_collection_is_parallel ())
2735 g_assert (mono_sgen_gray_object_queue_is_empty (&gray_queue));
2737 finish_gray_stack (nursery_start, nursery_next, GENERATION_NURSERY, &gray_queue);
2739 time_minor_finish_gray_stack += TV_ELAPSED_MS (btv, atv);
2740 mono_profiler_gc_event (MONO_GC_EVENT_MARK_END, 0);
2743 * The (single-threaded) finalization code might have done
2744 * some copying/marking so we can only reset the GC thread's
2745 * worker data here instead of earlier when we joined the
2748 mono_sgen_workers_reset_data ();
2750 if (objects_pinned) {
2751 mono_sgen_optimize_pin_queue (0);
2752 mono_sgen_pinning_setup_section (nursery_section);
2755 /* walk the pin_queue, build up the fragment list of free memory, unmark
2756 * pinned objects as we go, memzero() the empty fragments so they are ready for the
2759 mono_profiler_gc_event (MONO_GC_EVENT_RECLAIM_START, 0);
2760 fragment_total = mono_sgen_build_nursery_fragments (nursery_section, nursery_section->pin_queue_start, nursery_section->pin_queue_num_entries);
2761 if (!fragment_total)
2764 /* Clear TLABs for all threads */
2765 mono_sgen_clear_tlabs ();
2767 mono_profiler_gc_event (MONO_GC_EVENT_RECLAIM_END, 0);
2769 time_minor_fragment_creation += TV_ELAPSED_MS (atv, btv);
2770 DEBUG (2, fprintf (gc_debug_file, "Fragment creation: %d usecs, %lu bytes available\n", TV_ELAPSED (atv, btv), (unsigned long)fragment_total));
2772 if (consistency_check_at_minor_collection)
2773 mono_sgen_check_major_refs ();
2775 major_collector.finish_nursery_collection ();
2777 TV_GETTIME (all_btv);
2778 mono_stats.minor_gc_time_usecs += TV_ELAPSED (all_atv, all_btv);
2781 dump_heap ("minor", stat_minor_gcs - 1, NULL);
2783 /* prepare the pin queue for the next collection */
2784 mono_sgen_finish_pinning ();
2785 if (fin_ready_list || critical_fin_list) {
2786 DEBUG (4, fprintf (gc_debug_file, "Finalizer-thread wakeup: ready %d\n", num_ready_finalizers));
2787 mono_gc_finalize_notify ();
2789 mono_sgen_pin_stats_reset ();
2791 g_assert (mono_sgen_gray_object_queue_is_empty (&gray_queue));
2793 if (remset.finish_minor_collection)
2794 remset.finish_minor_collection ();
2796 check_scan_starts ();
2798 binary_protocol_flush_buffers (FALSE);
2800 /*objects are late pinned because of lack of memory, so a major is a good call*/
2801 needs_major = need_major_collection (0) || objects_pinned;
2802 current_collection_generation = -1;
2809 mono_sgen_collect_nursery_no_lock (size_t requested_size)
2811 gint64 gc_start_time;
2813 mono_profiler_gc_event (MONO_GC_EVENT_START, 0);
2814 gc_start_time = mono_100ns_ticks ();
2817 collect_nursery (requested_size);
2820 mono_trace_message (MONO_TRACE_GC, "minor gc took %d usecs", (mono_100ns_ticks () - gc_start_time) / 10);
2821 mono_profiler_gc_event (MONO_GC_EVENT_END, 0);
2826 FinalizeReadyEntry *list;
2827 } ScanFinalizerEntriesJobData;
2830 job_scan_finalizer_entries (WorkerData *worker_data, void *job_data_untyped)
2832 ScanFinalizerEntriesJobData *job_data = job_data_untyped;
2834 scan_finalizer_entries (major_collector.copy_or_mark_object,
2836 mono_sgen_workers_get_job_gray_queue (worker_data));
2840 major_do_collection (const char *reason)
2842 LOSObject *bigobj, *prevbo;
2843 TV_DECLARE (all_atv);
2844 TV_DECLARE (all_btv);
2847 /* FIXME: only use these values for the precise scan
2848 * note that to_space pointers should be excluded anyway...
2850 char *heap_start = NULL;
2851 char *heap_end = (char*)-1;
2852 int old_next_pin_slot;
2853 ScanFromRegisteredRootsJobData scrrjd_normal, scrrjd_wbarrier;
2854 ScanThreadDataJobData stdjd;
2855 ScanFinalizerEntriesJobData sfejd_fin_ready, sfejd_critical_fin;
2857 mono_perfcounters->gc_collections1++;
2859 reset_pinned_from_failed_allocation ();
2861 last_collection_old_num_major_sections = major_collector.get_num_major_sections ();
2864 * A domain could have been freed, resulting in
2865 * los_memory_usage being less than last_collection_los_memory_usage.
2867 last_collection_los_memory_alloced = los_memory_usage - MIN (last_collection_los_memory_usage, los_memory_usage);
2868 last_collection_old_los_memory_usage = los_memory_usage;
2871 //count_ref_nonref_objs ();
2872 //consistency_check ();
2874 binary_protocol_collection (GENERATION_OLD);
2875 check_scan_starts ();
2876 mono_sgen_gray_object_queue_init (&gray_queue);
2877 mono_sgen_workers_init_distribute_gray_queue ();
2880 DEBUG (1, fprintf (gc_debug_file, "Start major collection %d\n", stat_major_gcs));
2882 mono_stats.major_gc_count ++;
2884 /* world must be stopped already */
2885 TV_GETTIME (all_atv);
2888 /* Pinning depends on this */
2889 mono_sgen_clear_nursery_fragments ();
2892 time_major_pre_collection_fragment_clear += TV_ELAPSED_MS (atv, btv);
2894 nursery_section->next_data = nursery_end;
2895 /* we should also coalesce scanning from sections close to each other
2896 * and deal with pointers outside of the sections later.
2899 if (major_collector.start_major_collection)
2900 major_collector.start_major_collection ();
2902 *major_collector.have_swept = FALSE;
2903 reset_minor_collection_allowance ();
2906 check_for_xdomain_refs ();
2908 /* Remsets are not useful for a major collection */
2909 remset.prepare_for_major_collection ();
2911 process_fin_stage_entries ();
2912 process_dislink_stage_entries ();
2915 mono_sgen_init_pinning ();
2916 DEBUG (6, fprintf (gc_debug_file, "Collecting pinned addresses\n"));
2917 pin_from_roots ((void*)lowest_heap_address, (void*)highest_heap_address, WORKERS_DISTRIBUTE_GRAY_QUEUE);
2918 mono_sgen_optimize_pin_queue (0);
2921 * pin_queue now contains all candidate pointers, sorted and
2922 * uniqued. We must do two passes now to figure out which
2923 * objects are pinned.
2925 * The first is to find within the pin_queue the area for each
2926 * section. This requires that the pin_queue be sorted. We
2927 * also process the LOS objects and pinned chunks here.
2929 * The second, destructive, pass is to reduce the section
2930 * areas to pointers to the actually pinned objects.
2932 DEBUG (6, fprintf (gc_debug_file, "Pinning from sections\n"));
2933 /* first pass for the sections */
2934 mono_sgen_find_section_pin_queue_start_end (nursery_section);
2935 major_collector.find_pin_queue_start_ends (WORKERS_DISTRIBUTE_GRAY_QUEUE);
2936 /* identify possible pointers to the insize of large objects */
2937 DEBUG (6, fprintf (gc_debug_file, "Pinning from large objects\n"));
2938 for (bigobj = los_object_list; bigobj; bigobj = bigobj->next) {
2940 gboolean profile_roots = mono_profiler_get_events () & MONO_PROFILE_GC_ROOTS;
2941 GCRootReport report;
2943 if (mono_sgen_find_optimized_pin_queue_area (bigobj->data, (char*)bigobj->data + bigobj->size, &dummy)) {
2944 binary_protocol_pin (bigobj->data, (gpointer)LOAD_VTABLE (bigobj->data), safe_object_get_size (bigobj->data));
2945 pin_object (bigobj->data);
2946 /* FIXME: only enqueue if object has references */
2947 GRAY_OBJECT_ENQUEUE (WORKERS_DISTRIBUTE_GRAY_QUEUE, bigobj->data);
2948 if (G_UNLIKELY (do_pin_stats))
2949 mono_sgen_pin_stats_register_object ((char*) bigobj->data, safe_object_get_size ((MonoObject*) bigobj->data));
2950 DEBUG (6, fprintf (gc_debug_file, "Marked large object %p (%s) size: %lu from roots\n", bigobj->data, safe_name (bigobj->data), (unsigned long)bigobj->size));
2953 add_profile_gc_root (&report, bigobj->data, MONO_PROFILE_GC_ROOT_PINNING | MONO_PROFILE_GC_ROOT_MISC, 0);
2956 notify_gc_roots (&report);
2958 /* second pass for the sections */
2959 mono_sgen_pin_objects_in_section (nursery_section, WORKERS_DISTRIBUTE_GRAY_QUEUE);
2960 major_collector.pin_objects (WORKERS_DISTRIBUTE_GRAY_QUEUE);
2961 old_next_pin_slot = mono_sgen_get_pinned_count ();
2964 time_major_pinning += TV_ELAPSED_MS (atv, btv);
2965 DEBUG (2, fprintf (gc_debug_file, "Finding pinned pointers: %d in %d usecs\n", mono_sgen_get_pinned_count (), TV_ELAPSED (atv, btv)));
2966 DEBUG (4, fprintf (gc_debug_file, "Start scan with %d pinned objects\n", mono_sgen_get_pinned_count ()));
2968 major_collector.init_to_space ();
2970 #ifdef SGEN_DEBUG_INTERNAL_ALLOC
2971 main_gc_thread = mono_native_thread_self ();
2974 mono_sgen_workers_start_all_workers ();
2975 mono_sgen_workers_start_marking ();
2977 if (mono_profiler_get_events () & MONO_PROFILE_GC_ROOTS)
2978 report_registered_roots ();
2980 time_major_scan_pinned += TV_ELAPSED_MS (btv, atv);
2982 /* registered roots, this includes static fields */
2983 scrrjd_normal.func = major_collector.copy_or_mark_object;
2984 scrrjd_normal.heap_start = heap_start;
2985 scrrjd_normal.heap_end = heap_end;
2986 scrrjd_normal.root_type = ROOT_TYPE_NORMAL;
2987 mono_sgen_workers_enqueue_job (job_scan_from_registered_roots, &scrrjd_normal);
2989 scrrjd_wbarrier.func = major_collector.copy_or_mark_object;
2990 scrrjd_wbarrier.heap_start = heap_start;
2991 scrrjd_wbarrier.heap_end = heap_end;
2992 scrrjd_wbarrier.root_type = ROOT_TYPE_WBARRIER;
2993 mono_sgen_workers_enqueue_job (job_scan_from_registered_roots, &scrrjd_wbarrier);
2996 time_major_scan_registered_roots += TV_ELAPSED_MS (atv, btv);
2999 stdjd.heap_start = heap_start;
3000 stdjd.heap_end = heap_end;
3001 mono_sgen_workers_enqueue_job (job_scan_thread_data, &stdjd);
3004 time_major_scan_thread_data += TV_ELAPSED_MS (btv, atv);
3007 time_major_scan_alloc_pinned += TV_ELAPSED_MS (atv, btv);
3009 if (mono_profiler_get_events () & MONO_PROFILE_GC_ROOTS)
3010 report_finalizer_roots ();
3012 /* scan the list of objects ready for finalization */
3013 sfejd_fin_ready.list = fin_ready_list;
3014 mono_sgen_workers_enqueue_job (job_scan_finalizer_entries, &sfejd_fin_ready);
3016 sfejd_critical_fin.list = critical_fin_list;
3017 mono_sgen_workers_enqueue_job (job_scan_finalizer_entries, &sfejd_critical_fin);
3020 time_major_scan_finalized += TV_ELAPSED_MS (btv, atv);
3021 DEBUG (2, fprintf (gc_debug_file, "Root scan: %d usecs\n", TV_ELAPSED (btv, atv)));
3024 time_major_scan_big_objects += TV_ELAPSED_MS (atv, btv);
3026 if (major_collector.is_parallel) {
3027 while (!mono_sgen_gray_object_queue_is_empty (WORKERS_DISTRIBUTE_GRAY_QUEUE)) {
3028 mono_sgen_workers_distribute_gray_queue_sections ();
3032 mono_sgen_workers_join ();
3034 #ifdef SGEN_DEBUG_INTERNAL_ALLOC
3035 main_gc_thread = NULL;
3038 if (major_collector.is_parallel)
3039 g_assert (mono_sgen_gray_object_queue_is_empty (&gray_queue));
3041 /* all the objects in the heap */
3042 finish_gray_stack (heap_start, heap_end, GENERATION_OLD, &gray_queue);
3044 time_major_finish_gray_stack += TV_ELAPSED_MS (btv, atv);
3047 * The (single-threaded) finalization code might have done
3048 * some copying/marking so we can only reset the GC thread's
3049 * worker data here instead of earlier when we joined the
3052 mono_sgen_workers_reset_data ();
3054 if (objects_pinned) {
3055 /*This is slow, but we just OOM'd*/
3056 mono_sgen_pin_queue_clear_discarded_entries (nursery_section, old_next_pin_slot);
3057 mono_sgen_optimize_pin_queue (0);
3058 mono_sgen_find_section_pin_queue_start_end (nursery_section);
3062 reset_heap_boundaries ();
3063 mono_sgen_update_heap_boundaries ((mword)nursery_start, (mword)nursery_end);
3065 /* sweep the big objects list */
3067 for (bigobj = los_object_list; bigobj;) {
3068 if (object_is_pinned (bigobj->data)) {
3069 unpin_object (bigobj->data);
3070 mono_sgen_update_heap_boundaries ((mword)bigobj->data, (mword)bigobj->data + bigobj->size);
3073 /* not referenced anywhere, so we can free it */
3075 prevbo->next = bigobj->next;
3077 los_object_list = bigobj->next;
3079 bigobj = bigobj->next;
3080 mono_sgen_los_free_object (to_free);
3084 bigobj = bigobj->next;
3088 time_major_free_bigobjs += TV_ELAPSED_MS (atv, btv);
3090 mono_sgen_los_sweep ();
3093 time_major_los_sweep += TV_ELAPSED_MS (btv, atv);
3095 major_collector.sweep ();
3098 time_major_sweep += TV_ELAPSED_MS (atv, btv);
3100 /* walk the pin_queue, build up the fragment list of free memory, unmark
3101 * pinned objects as we go, memzero() the empty fragments so they are ready for the
3104 if (!mono_sgen_build_nursery_fragments (nursery_section, nursery_section->pin_queue_start, nursery_section->pin_queue_num_entries))
3107 /* Clear TLABs for all threads */
3108 mono_sgen_clear_tlabs ();
3111 time_major_fragment_creation += TV_ELAPSED_MS (btv, atv);
3113 TV_GETTIME (all_btv);
3114 mono_stats.major_gc_time_usecs += TV_ELAPSED (all_atv, all_btv);
3117 dump_heap ("major", stat_major_gcs - 1, reason);
3119 /* prepare the pin queue for the next collection */
3120 mono_sgen_finish_pinning ();
3122 if (fin_ready_list || critical_fin_list) {
3123 DEBUG (4, fprintf (gc_debug_file, "Finalizer-thread wakeup: ready %d\n", num_ready_finalizers));
3124 mono_gc_finalize_notify ();
3126 mono_sgen_pin_stats_reset ();
3128 g_assert (mono_sgen_gray_object_queue_is_empty (&gray_queue));
3130 try_calculate_minor_collection_allowance (TRUE);
3132 minor_collection_sections_alloced = 0;
3133 last_collection_los_memory_usage = los_memory_usage;
3135 major_collector.finish_major_collection ();
3137 check_scan_starts ();
3139 binary_protocol_flush_buffers (FALSE);
3141 //consistency_check ();
3143 return bytes_pinned_from_failed_allocation > 0;
3147 major_collection (const char *reason)
3149 gboolean need_minor_collection;
3151 if (disable_major_collections) {
3152 collect_nursery (0);
3156 major_collection_happened = TRUE;
3157 current_collection_generation = GENERATION_OLD;
3158 need_minor_collection = major_do_collection (reason);
3159 current_collection_generation = -1;
3161 if (need_minor_collection)
3162 collect_nursery (0);
3166 sgen_collect_major_no_lock (const char *reason)
3168 gint64 gc_start_time;
3170 mono_profiler_gc_event (MONO_GC_EVENT_START, 1);
3171 gc_start_time = mono_100ns_ticks ();
3173 major_collection (reason);
3175 mono_trace_message (MONO_TRACE_GC, "major gc took %d usecs", (mono_100ns_ticks () - gc_start_time) / 10);
3176 mono_profiler_gc_event (MONO_GC_EVENT_END, 1);
3180 * When deciding if it's better to collect or to expand, keep track
3181 * of how much garbage was reclaimed with the last collection: if it's too
3183 * This is called when we could not allocate a small object.
3185 static void __attribute__((noinline))
3186 minor_collect_or_expand_inner (size_t size)
3188 int do_minor_collection = 1;
3190 g_assert (nursery_section);
3191 if (do_minor_collection) {
3192 gint64 total_gc_time, major_gc_time = 0;
3194 mono_profiler_gc_event (MONO_GC_EVENT_START, 0);
3195 total_gc_time = mono_100ns_ticks ();
3198 if (collect_nursery (size)) {
3199 mono_profiler_gc_event (MONO_GC_EVENT_START, 1);
3200 major_gc_time = mono_100ns_ticks ();
3202 major_collection ("minor overflow");
3204 /* keep events symmetric */
3205 major_gc_time = mono_100ns_ticks () - major_gc_time;
3206 mono_profiler_gc_event (MONO_GC_EVENT_END, 1);
3208 DEBUG (2, fprintf (gc_debug_file, "Heap size: %lu, LOS size: %lu\n", (unsigned long)total_alloc, (unsigned long)los_memory_usage));
3211 total_gc_time = mono_100ns_ticks () - total_gc_time;
3213 mono_trace_message (MONO_TRACE_GC, "overflow major gc took %d usecs minor gc took %d usecs", total_gc_time / 10, (total_gc_time - major_gc_time) / 10);
3215 mono_trace_message (MONO_TRACE_GC, "minor gc took %d usecs", total_gc_time / 10);
3217 /* this also sets the proper pointers for the next allocation */
3218 if (!mono_sgen_can_alloc_size (size)) {
3219 /* TypeBuilder and MonoMethod are killing mcs with fragmentation */
3220 DEBUG (1, fprintf (gc_debug_file, "nursery collection didn't find enough room for %zd alloc (%d pinned)\n", size, mono_sgen_get_pinned_count ()));
3221 mono_sgen_dump_pin_queue ();
3224 mono_profiler_gc_event (MONO_GC_EVENT_END, 0);
3226 //report_internal_mem_usage ();
3230 mono_sgen_minor_collect_or_expand_inner (size_t size)
3232 minor_collect_or_expand_inner (size);
3236 * ######################################################################
3237 * ######## Memory allocation from the OS
3238 * ######################################################################
3239 * This section of code deals with getting memory from the OS and
3240 * allocating memory for GC-internal data structures.
3241 * Internal memory can be handled with a freelist for small objects.
3247 G_GNUC_UNUSED static void
3248 report_internal_mem_usage (void)
3250 printf ("Internal memory usage:\n");
3251 mono_sgen_report_internal_mem_usage ();
3252 printf ("Pinned memory usage:\n");
3253 major_collector.report_pinned_memory_usage ();
3257 * ######################################################################
3258 * ######## Finalization support
3259 * ######################################################################
3263 * this is valid for the nursery: if the object has been forwarded it means it's
3264 * still refrenced from a root. If it is pinned it's still alive as well.
3265 * Return TRUE if @obj is ready to be finalized.
3267 #define object_is_fin_ready(obj) (!object_is_pinned (obj) && !object_is_forwarded (obj))
3271 mono_sgen_gc_is_object_ready_for_finalization (void *object)
3273 return !major_collector.is_object_live (object) && object_is_fin_ready (object);
3277 has_critical_finalizer (MonoObject *obj)
3281 if (!mono_defaults.critical_finalizer_object)
3284 class = ((MonoVTable*)LOAD_VTABLE (obj))->klass;
3286 return mono_class_has_parent_fast (class, mono_defaults.critical_finalizer_object);
3290 queue_finalization_entry (MonoObject *obj) {
3291 FinalizeReadyEntry *entry = mono_sgen_alloc_internal (INTERNAL_MEM_FINALIZE_READY_ENTRY);
3292 entry->object = obj;
3293 if (has_critical_finalizer (obj)) {
3294 entry->next = critical_fin_list;
3295 critical_fin_list = entry;
3297 entry->next = fin_ready_list;
3298 fin_ready_list = entry;
3303 object_is_reachable (char *object, char *start, char *end)
3305 /*This happens for non nursery objects during minor collections. We just treat all objects as alive.*/
3306 if (object < start || object >= end)
3308 return !object_is_fin_ready (object) || major_collector.is_object_live (object);
3311 #include "sgen-fin-weak-hash.c"
3314 mono_sgen_object_is_live (void *obj)
3316 if (ptr_in_nursery (obj))
3317 return object_is_pinned (obj);
3318 if (current_collection_generation == GENERATION_NURSERY)
3320 return major_collector.is_object_live (obj);
3323 /* LOCKING: requires that the GC lock is held */
3325 null_ephemerons_for_domain (MonoDomain *domain)
3327 EphemeronLinkNode *current = ephemeron_list, *prev = NULL;
3330 MonoObject *object = (MonoObject*)current->array;
3332 if (object && !object->vtable) {
3333 EphemeronLinkNode *tmp = current;
3336 prev->next = current->next;
3338 ephemeron_list = current->next;
3340 current = current->next;
3341 mono_sgen_free_internal (tmp, INTERNAL_MEM_EPHEMERON_LINK);
3344 current = current->next;
3349 /* LOCKING: requires that the GC lock is held */
3351 clear_unreachable_ephemerons (CopyOrMarkObjectFunc copy_func, char *start, char *end, GrayQueue *queue)
3353 int was_in_nursery, was_promoted;
3354 EphemeronLinkNode *current = ephemeron_list, *prev = NULL;
3356 Ephemeron *cur, *array_end;
3360 char *object = current->array;
3362 if (!object_is_reachable (object, start, end)) {
3363 EphemeronLinkNode *tmp = current;
3365 DEBUG (5, fprintf (gc_debug_file, "Dead Ephemeron array at %p\n", object));
3368 prev->next = current->next;
3370 ephemeron_list = current->next;
3372 current = current->next;
3373 mono_sgen_free_internal (tmp, INTERNAL_MEM_EPHEMERON_LINK);
3378 was_in_nursery = ptr_in_nursery (object);
3379 copy_func ((void**)&object, queue);
3380 current->array = object;
3382 /*The array was promoted, add global remsets for key/values left behind in nursery.*/
3383 was_promoted = was_in_nursery && !ptr_in_nursery (object);
3385 DEBUG (5, fprintf (gc_debug_file, "Clearing unreachable entries for ephemeron array at %p\n", object));
3387 array = (MonoArray*)object;
3388 cur = mono_array_addr (array, Ephemeron, 0);
3389 array_end = cur + mono_array_length_fast (array);
3390 tombstone = (char*)((MonoVTable*)LOAD_VTABLE (object))->domain->ephemeron_tombstone;
3392 for (; cur < array_end; ++cur) {
3393 char *key = (char*)cur->key;
3395 if (!key || key == tombstone)
3398 DEBUG (5, fprintf (gc_debug_file, "[%td] key %p (%s) value %p (%s)\n", cur - mono_array_addr (array, Ephemeron, 0),
3399 key, object_is_reachable (key, start, end) ? "reachable" : "unreachable",
3400 cur->value, cur->value && object_is_reachable (cur->value, start, end) ? "reachable" : "unreachable"));
3402 if (!object_is_reachable (key, start, end)) {
3403 cur->key = tombstone;
3409 if (ptr_in_nursery (key)) {/*key was not promoted*/
3410 DEBUG (5, fprintf (gc_debug_file, "\tAdded remset to key %p\n", key));
3411 mono_sgen_add_to_global_remset (&cur->key);
3413 if (ptr_in_nursery (cur->value)) {/*value was not promoted*/
3414 DEBUG (5, fprintf (gc_debug_file, "\tAdded remset to value %p\n", cur->value));
3415 mono_sgen_add_to_global_remset (&cur->value);
3420 current = current->next;
3424 /* LOCKING: requires that the GC lock is held */
3426 mark_ephemerons_in_range (CopyOrMarkObjectFunc copy_func, char *start, char *end, GrayQueue *queue)
3428 int nothing_marked = 1;
3429 EphemeronLinkNode *current = ephemeron_list;
3431 Ephemeron *cur, *array_end;
3434 for (current = ephemeron_list; current; current = current->next) {
3435 char *object = current->array;
3436 DEBUG (5, fprintf (gc_debug_file, "Ephemeron array at %p\n", object));
3439 For now we process all ephemerons during all collections.
3440 Ideally we should use remset information to partially scan those
3442 We already emit write barriers for Ephemeron fields, it's
3443 just that we don't process them.
3445 /*if (object < start || object >= end)
3448 /*It has to be alive*/
3449 if (!object_is_reachable (object, start, end)) {
3450 DEBUG (5, fprintf (gc_debug_file, "\tnot reachable\n"));
3454 copy_func ((void**)&object, queue);
3456 array = (MonoArray*)object;
3457 cur = mono_array_addr (array, Ephemeron, 0);
3458 array_end = cur + mono_array_length_fast (array);
3459 tombstone = (char*)((MonoVTable*)LOAD_VTABLE (object))->domain->ephemeron_tombstone;
3461 for (; cur < array_end; ++cur) {
3462 char *key = cur->key;
3464 if (!key || key == tombstone)
3467 DEBUG (5, fprintf (gc_debug_file, "[%td] key %p (%s) value %p (%s)\n", cur - mono_array_addr (array, Ephemeron, 0),
3468 key, object_is_reachable (key, start, end) ? "reachable" : "unreachable",
3469 cur->value, cur->value && object_is_reachable (cur->value, start, end) ? "reachable" : "unreachable"));
3471 if (object_is_reachable (key, start, end)) {
3472 char *value = cur->value;
3474 copy_func ((void**)&cur->key, queue);
3476 if (!object_is_reachable (value, start, end))
3478 copy_func ((void**)&cur->value, queue);
3484 DEBUG (5, fprintf (gc_debug_file, "Ephemeron run finished. Is it done %d\n", nothing_marked));
3485 return nothing_marked;
3489 mono_gc_invoke_finalizers (void)
3491 FinalizeReadyEntry *entry = NULL;
3492 gboolean entry_is_critical = FALSE;
3495 /* FIXME: batch to reduce lock contention */
3496 while (fin_ready_list || critical_fin_list) {
3500 FinalizeReadyEntry **list = entry_is_critical ? &critical_fin_list : &fin_ready_list;
3502 /* We have finalized entry in the last
3503 interation, now we need to remove it from
3506 *list = entry->next;
3508 FinalizeReadyEntry *e = *list;
3509 while (e->next != entry)
3511 e->next = entry->next;
3513 mono_sgen_free_internal (entry, INTERNAL_MEM_FINALIZE_READY_ENTRY);
3517 /* Now look for the first non-null entry. */
3518 for (entry = fin_ready_list; entry && !entry->object; entry = entry->next)
3521 entry_is_critical = FALSE;
3523 entry_is_critical = TRUE;
3524 for (entry = critical_fin_list; entry && !entry->object; entry = entry->next)
3529 g_assert (entry->object);
3530 num_ready_finalizers--;
3531 obj = entry->object;
3532 entry->object = NULL;
3533 DEBUG (7, fprintf (gc_debug_file, "Finalizing object %p (%s)\n", obj, safe_name (obj)));
3541 g_assert (entry->object == NULL);
3543 /* the object is on the stack so it is pinned */
3544 /*g_print ("Calling finalizer for object: %p (%s)\n", entry->object, safe_name (entry->object));*/
3545 mono_gc_run_finalize (obj, NULL);
3552 mono_gc_pending_finalizers (void)
3554 return fin_ready_list || critical_fin_list;
3557 /* Negative value to remove */
3559 mono_gc_add_memory_pressure (gint64 value)
3561 /* FIXME: Use interlocked functions */
3563 memory_pressure += value;
3568 mono_sgen_register_major_sections_alloced (int num_sections)
3570 minor_collection_sections_alloced += num_sections;
3574 mono_sgen_get_minor_collection_allowance (void)
3576 return minor_collection_allowance;
3580 * ######################################################################
3581 * ######## registered roots support
3582 * ######################################################################
3586 * We do not coalesce roots.
3589 mono_gc_register_root_inner (char *start, size_t size, void *descr, int root_type)
3591 RootRecord new_root;
3594 for (i = 0; i < ROOT_TYPE_NUM; ++i) {
3595 RootRecord *root = mono_sgen_hash_table_lookup (&roots_hash [i], start);
3596 /* we allow changing the size and the descriptor (for thread statics etc) */
3598 size_t old_size = root->end_root - start;
3599 root->end_root = start + size;
3600 g_assert (((root->root_desc != 0) && (descr != NULL)) ||
3601 ((root->root_desc == 0) && (descr == NULL)));
3602 root->root_desc = (mword)descr;
3604 roots_size -= old_size;
3610 new_root.end_root = start + size;
3611 new_root.root_desc = (mword)descr;
3613 mono_sgen_hash_table_replace (&roots_hash [root_type], start, &new_root);
3616 DEBUG (3, fprintf (gc_debug_file, "Added root for range: %p-%p, descr: %p (%d/%d bytes)\n", start, new_root.end_root, descr, (int)size, (int)roots_size));
3623 mono_gc_register_root (char *start, size_t size, void *descr)
3625 return mono_gc_register_root_inner (start, size, descr, descr ? ROOT_TYPE_NORMAL : ROOT_TYPE_PINNED);
3629 mono_gc_register_root_wbarrier (char *start, size_t size, void *descr)
3631 return mono_gc_register_root_inner (start, size, descr, ROOT_TYPE_WBARRIER);
3635 mono_gc_deregister_root (char* addr)
3641 for (root_type = 0; root_type < ROOT_TYPE_NUM; ++root_type) {
3642 if (mono_sgen_hash_table_remove (&roots_hash [root_type], addr, &root))
3643 roots_size -= (root.end_root - addr);
3649 * ######################################################################
3650 * ######## Thread handling (stop/start code)
3651 * ######################################################################
3654 unsigned int mono_sgen_global_stop_count = 0;
3657 static MonoContext cur_thread_ctx = {0};
3659 static mword cur_thread_regs [ARCH_NUM_REGS] = {0};
3663 update_current_thread_stack (void *start)
3665 int stack_guard = 0;
3666 #ifndef USE_MONO_CTX
3667 void *ptr = cur_thread_regs;
3669 SgenThreadInfo *info = mono_thread_info_current ();
3671 info->stack_start = align_pointer (&stack_guard);
3672 g_assert (info->stack_start >= info->stack_start_limit && info->stack_start < info->stack_end);
3674 MONO_CONTEXT_GET_CURRENT (cur_thread_ctx);
3675 info->monoctx = &cur_thread_ctx;
3677 ARCH_STORE_REGS (ptr);
3678 info->stopped_regs = ptr;
3680 if (gc_callbacks.thread_suspend_func)
3681 gc_callbacks.thread_suspend_func (info->runtime_data, NULL);
3685 mono_sgen_fill_thread_info_for_suspend (SgenThreadInfo *info)
3687 #ifdef HAVE_KW_THREAD
3688 /* update the remset info in the thread data structure */
3689 info->remset = remembered_set;
3694 is_ip_in_managed_allocator (MonoDomain *domain, gpointer ip);
3697 restart_threads_until_none_in_managed_allocator (void)
3699 SgenThreadInfo *info;
3700 int num_threads_died = 0;
3701 int sleep_duration = -1;
3704 int restart_count = 0, restarted_count = 0;
3705 /* restart all threads that stopped in the
3707 FOREACH_THREAD_SAFE (info) {
3709 if (info->skip || info->gc_disabled)
3711 if (!info->thread_is_dying && (!info->stack_start || info->in_critical_region ||
3712 is_ip_in_managed_allocator (info->stopped_domain, info->stopped_ip))) {
3713 binary_protocol_thread_restart ((gpointer)mono_thread_info_get_tid (info));
3714 result = mono_sgen_resume_thread (info);
3721 /* we set the stopped_ip to
3722 NULL for threads which
3723 we're not restarting so
3724 that we can easily identify
3726 info->stopped_ip = NULL;
3727 info->stopped_domain = NULL;
3729 } END_FOREACH_THREAD_SAFE
3730 /* if no threads were restarted, we're done */
3731 if (restart_count == 0)
3734 /* wait for the threads to signal their restart */
3735 mono_sgen_wait_for_suspend_ack (restart_count);
3737 if (sleep_duration < 0) {
3745 g_usleep (sleep_duration);
3746 sleep_duration += 10;
3749 /* stop them again */
3750 FOREACH_THREAD (info) {
3752 if (info->skip || info->stopped_ip == NULL)
3754 result = mono_sgen_suspend_thread (info);
3761 } END_FOREACH_THREAD
3762 /* some threads might have died */
3763 num_threads_died += restart_count - restarted_count;
3764 /* wait for the threads to signal their suspension
3766 mono_sgen_wait_for_suspend_ack (restart_count);
3769 return num_threads_died;
3773 acquire_gc_locks (void)
3776 mono_thread_info_suspend_lock ();
3780 release_gc_locks (void)
3782 mono_thread_info_suspend_unlock ();
3783 UNLOCK_INTERRUPTION;
3786 static TV_DECLARE (stop_world_time);
3787 static unsigned long max_pause_usec = 0;
3789 /* LOCKING: assumes the GC lock is held */
3791 stop_world (int generation)
3795 /*XXX this is the right stop, thought might not be the nicest place to put it*/
3796 mono_sgen_process_togglerefs ();
3798 mono_profiler_gc_event (MONO_GC_EVENT_PRE_STOP_WORLD, generation);
3799 acquire_gc_locks ();
3801 update_current_thread_stack (&count);
3803 mono_sgen_global_stop_count++;
3804 DEBUG (3, fprintf (gc_debug_file, "stopping world n %d from %p %p\n", mono_sgen_global_stop_count, mono_thread_info_current (), (gpointer)mono_native_thread_id_get ()));
3805 TV_GETTIME (stop_world_time);
3806 count = mono_sgen_thread_handshake (TRUE);
3807 count -= restart_threads_until_none_in_managed_allocator ();
3808 g_assert (count >= 0);
3809 DEBUG (3, fprintf (gc_debug_file, "world stopped %d thread(s)\n", count));
3810 mono_profiler_gc_event (MONO_GC_EVENT_POST_STOP_WORLD, generation);
3812 last_major_num_sections = major_collector.get_num_major_sections ();
3813 last_los_memory_usage = los_memory_usage;
3814 major_collection_happened = FALSE;
3818 /* LOCKING: assumes the GC lock is held */
3820 restart_world (int generation)
3822 int count, num_major_sections;
3823 SgenThreadInfo *info;
3824 TV_DECLARE (end_sw);
3825 TV_DECLARE (end_bridge);
3826 unsigned long usec, bridge_usec;
3828 /* notify the profiler of the leftovers */
3829 if (G_UNLIKELY (mono_profiler_events & MONO_PROFILE_GC_MOVES)) {
3830 if (moved_objects_idx) {
3831 mono_profiler_gc_moves (moved_objects, moved_objects_idx);
3832 moved_objects_idx = 0;
3835 mono_profiler_gc_event (MONO_GC_EVENT_PRE_START_WORLD, generation);
3836 FOREACH_THREAD (info) {
3837 info->stack_start = NULL;
3839 info->monoctx = NULL;
3841 info->stopped_regs = NULL;
3843 } END_FOREACH_THREAD
3845 stw_bridge_process ();
3846 release_gc_locks ();
3848 count = mono_sgen_thread_handshake (FALSE);
3849 TV_GETTIME (end_sw);
3850 usec = TV_ELAPSED (stop_world_time, end_sw);
3851 max_pause_usec = MAX (usec, max_pause_usec);
3852 DEBUG (2, fprintf (gc_debug_file, "restarted %d thread(s) (pause time: %d usec, max: %d)\n", count, (int)usec, (int)max_pause_usec));
3853 mono_profiler_gc_event (MONO_GC_EVENT_POST_START_WORLD, generation);
3857 TV_GETTIME (end_bridge);
3858 bridge_usec = TV_ELAPSED (end_sw, end_bridge);
3860 num_major_sections = major_collector.get_num_major_sections ();
3861 if (major_collection_happened)
3862 mono_trace (G_LOG_LEVEL_INFO, MONO_TRACE_GC, "GC_MAJOR: %s pause %.2fms, bridge %.2fms major %dK/%dK los %dK/%dK",
3863 generation ? "" : "(minor overflow)",
3864 (int)usec / 1000.0f, (int)bridge_usec / 1000.0f,
3865 major_collector.section_size * num_major_sections / 1024,
3866 major_collector.section_size * last_major_num_sections / 1024,
3867 los_memory_usage / 1024,
3868 last_los_memory_usage / 1024);
3870 mono_trace (G_LOG_LEVEL_INFO, MONO_TRACE_GC, "GC_MINOR: pause %.2fms, bridge %.2fms promoted %dK major %dK los %dK",
3871 (int)usec / 1000.0f, (int)bridge_usec / 1000.0f,
3872 (num_major_sections - last_major_num_sections) * major_collector.section_size / 1024,
3873 major_collector.section_size * num_major_sections / 1024,
3874 los_memory_usage / 1024);
3880 mono_sgen_get_current_collection_generation (void)
3882 return current_collection_generation;
3886 mono_gc_set_gc_callbacks (MonoGCCallbacks *callbacks)
3888 gc_callbacks = *callbacks;
3892 mono_gc_get_gc_callbacks ()
3894 return &gc_callbacks;
3897 /* Variables holding start/end nursery so it won't have to be passed at every call */
3898 static void *scan_area_arg_start, *scan_area_arg_end;
3901 mono_gc_conservatively_scan_area (void *start, void *end)
3903 conservatively_pin_objects_from (start, end, scan_area_arg_start, scan_area_arg_end, PIN_TYPE_STACK);
3907 mono_gc_scan_object (void *obj)
3909 UserCopyOrMarkData *data = mono_native_tls_get_value (user_copy_or_mark_key);
3911 if (current_collection_generation == GENERATION_NURSERY) {
3912 if (mono_sgen_collection_is_parallel ())
3913 major_collector.copy_object (&obj, data->queue);
3915 major_collector.nopar_copy_object (&obj, data->queue);
3917 major_collector.copy_or_mark_object (&obj, data->queue);
3923 * Mark from thread stacks and registers.
3926 scan_thread_data (void *start_nursery, void *end_nursery, gboolean precise, GrayQueue *queue)
3928 SgenThreadInfo *info;
3930 scan_area_arg_start = start_nursery;
3931 scan_area_arg_end = end_nursery;
3933 FOREACH_THREAD (info) {
3935 DEBUG (3, fprintf (gc_debug_file, "Skipping dead thread %p, range: %p-%p, size: %td\n", info, info->stack_start, info->stack_end, (char*)info->stack_end - (char*)info->stack_start));
3938 if (info->gc_disabled) {
3939 DEBUG (3, fprintf (gc_debug_file, "GC disabled for thread %p, range: %p-%p, size: %td\n", info, info->stack_start, info->stack_end, (char*)info->stack_end - (char*)info->stack_start));
3942 DEBUG (3, fprintf (gc_debug_file, "Scanning thread %p, range: %p-%p, size: %ld, pinned=%d\n", info, info->stack_start, info->stack_end, (char*)info->stack_end - (char*)info->stack_start, mono_sgen_get_pinned_count ()));
3943 if (!info->thread_is_dying) {
3944 if (gc_callbacks.thread_mark_func && !conservative_stack_mark) {
3945 UserCopyOrMarkData data = { NULL, queue };
3946 set_user_copy_or_mark_data (&data);
3947 gc_callbacks.thread_mark_func (info->runtime_data, info->stack_start, info->stack_end, precise);
3948 set_user_copy_or_mark_data (NULL);
3949 } else if (!precise) {
3950 conservatively_pin_objects_from (info->stack_start, info->stack_end, start_nursery, end_nursery, PIN_TYPE_STACK);
3955 if (!info->thread_is_dying && !precise)
3956 conservatively_pin_objects_from ((void**)info->monoctx, (void**)info->monoctx + ARCH_NUM_REGS,
3957 start_nursery, end_nursery, PIN_TYPE_STACK);
3959 if (!info->thread_is_dying && !precise)
3960 conservatively_pin_objects_from (info->stopped_regs, info->stopped_regs + ARCH_NUM_REGS,
3961 start_nursery, end_nursery, PIN_TYPE_STACK);
3963 } END_FOREACH_THREAD
3967 find_pinning_ref_from_thread (char *obj, size_t size)
3970 SgenThreadInfo *info;
3971 char *endobj = obj + size;
3973 FOREACH_THREAD (info) {
3974 char **start = (char**)info->stack_start;
3977 while (start < (char**)info->stack_end) {
3978 if (*start >= obj && *start < endobj) {
3979 DEBUG (0, fprintf (gc_debug_file, "Object %p referenced in thread %p (id %p) at %p, stack: %p-%p\n", obj, info, (gpointer)mono_thread_info_get_tid (info), start, info->stack_start, info->stack_end));
3984 for (j = 0; j < ARCH_NUM_REGS; ++j) {
3986 mword w = ((mword*)info->monoctx) [j];
3988 mword w = (mword)info->stopped_regs [j];
3991 if (w >= (mword)obj && w < (mword)obj + size)
3992 DEBUG (0, fprintf (gc_debug_file, "Object %p referenced in saved reg %d of thread %p (id %p)\n", obj, j, info, (gpointer)mono_thread_info_get_tid (info)));
3993 } END_FOREACH_THREAD
3998 ptr_on_stack (void *ptr)
4000 gpointer stack_start = &stack_start;
4001 SgenThreadInfo *info = mono_thread_info_current ();
4003 if (ptr >= stack_start && ptr < (gpointer)info->stack_end)
4009 sgen_thread_register (SgenThreadInfo* info, void *addr)
4011 #ifndef HAVE_KW_THREAD
4012 SgenThreadInfo *__thread_info__ = info;
4016 #ifndef HAVE_KW_THREAD
4017 info->tlab_start = info->tlab_next = info->tlab_temp_end = info->tlab_real_end = NULL;
4019 g_assert (!mono_native_tls_get_value (thread_info_key));
4020 mono_native_tls_set_value (thread_info_key, info);
4025 #if !defined(__MACH__)
4026 info->stop_count = -1;
4030 info->doing_handshake = FALSE;
4031 info->thread_is_dying = FALSE;
4032 info->stack_start = NULL;
4033 info->store_remset_buffer_addr = &STORE_REMSET_BUFFER;
4034 info->store_remset_buffer_index_addr = &STORE_REMSET_BUFFER_INDEX;
4035 info->stopped_ip = NULL;
4036 info->stopped_domain = NULL;
4038 info->monoctx = NULL;
4040 info->stopped_regs = NULL;
4043 mono_sgen_init_tlab_info (info);
4045 binary_protocol_thread_register ((gpointer)mono_thread_info_get_tid (info));
4047 #ifdef HAVE_KW_THREAD
4048 store_remset_buffer_index_addr = &store_remset_buffer_index;
4051 #if defined(__MACH__)
4052 info->mach_port = mach_thread_self ();
4055 /* try to get it with attributes first */
4056 #if defined(HAVE_PTHREAD_GETATTR_NP) && defined(HAVE_PTHREAD_ATTR_GETSTACK)
4060 pthread_attr_t attr;
4061 pthread_getattr_np (pthread_self (), &attr);
4062 pthread_attr_getstack (&attr, &sstart, &size);
4063 info->stack_start_limit = sstart;
4064 info->stack_end = (char*)sstart + size;
4065 pthread_attr_destroy (&attr);
4067 #elif defined(HAVE_PTHREAD_GET_STACKSIZE_NP) && defined(HAVE_PTHREAD_GET_STACKADDR_NP)
4068 info->stack_end = (char*)pthread_get_stackaddr_np (pthread_self ());
4069 info->stack_start_limit = (char*)info->stack_end - pthread_get_stacksize_np (pthread_self ());
4072 /* FIXME: we assume the stack grows down */
4073 gsize stack_bottom = (gsize)addr;
4074 stack_bottom += 4095;
4075 stack_bottom &= ~4095;
4076 info->stack_end = (char*)stack_bottom;
4080 #ifdef HAVE_KW_THREAD
4081 stack_end = info->stack_end;
4084 if (remset.register_thread)
4085 remset.register_thread (info);
4087 DEBUG (3, fprintf (gc_debug_file, "registered thread %p (%p) stack end %p\n", info, (gpointer)mono_thread_info_get_tid (info), info->stack_end));
4089 if (gc_callbacks.thread_attach_func)
4090 info->runtime_data = gc_callbacks.thread_attach_func ();
4097 mono_sgen_wbarrier_cleanup_thread (SgenThreadInfo *p)
4099 if (remset.cleanup_thread)
4100 remset.cleanup_thread (p);
4104 sgen_thread_unregister (SgenThreadInfo *p)
4106 /* If a delegate is passed to native code and invoked on a thread we dont
4107 * know about, the jit will register it with mono_jit_thread_attach, but
4108 * we have no way of knowing when that thread goes away. SGen has a TSD
4109 * so we assume that if the domain is still registered, we can detach
4112 if (mono_domain_get ())
4113 mono_thread_detach (mono_thread_current ());
4115 p->thread_is_dying = TRUE;
4118 There is a race condition between a thread finishing executing and been removed
4119 from the GC thread set.
4120 This happens on posix systems when TLS data is been cleaned-up, libpthread will
4121 set the thread_info slot to NULL before calling the cleanup function. This
4122 opens a window in which the thread is registered but has a NULL TLS.
4124 The suspend signal handler needs TLS data to know where to store thread state
4125 data or otherwise it will simply ignore the thread.
4127 This solution works because the thread doing STW will wait until all threads been
4128 suspended handshake back, so there is no race between the doing_hankshake test
4129 and the suspend_thread call.
4131 This is not required on systems that do synchronous STW as those can deal with
4132 the above race at suspend time.
4134 FIXME: I believe we could avoid this by using mono_thread_info_lookup when
4135 mono_thread_info_current returns NULL. Or fix mono_thread_info_lookup to do so.
4137 #if (defined(__MACH__) && MONO_MACH_ARCH_SUPPORTED) || !defined(HAVE_PTHREAD_KILL)
4140 while (!TRYLOCK_GC) {
4141 if (!mono_sgen_park_current_thread_if_doing_handshake (p))
4146 binary_protocol_thread_unregister ((gpointer)mono_thread_info_get_tid (p));
4147 DEBUG (3, fprintf (gc_debug_file, "unregister thread %p (%p)\n", p, (gpointer)mono_thread_info_get_tid (p)));
4149 #if defined(__MACH__)
4150 mach_port_deallocate (current_task (), p->mach_port);
4153 if (gc_callbacks.thread_detach_func) {
4154 gc_callbacks.thread_detach_func (p->runtime_data);
4155 p->runtime_data = NULL;
4157 mono_sgen_wbarrier_cleanup_thread (p);
4159 mono_threads_unregister_current_thread (p);
4165 sgen_thread_attach (SgenThreadInfo *info)
4168 /*this is odd, can we get attached before the gc is inited?*/
4172 if (gc_callbacks.thread_attach_func && !info->runtime_data)
4173 info->runtime_data = gc_callbacks.thread_attach_func ();
4176 mono_gc_register_thread (void *baseptr)
4178 return mono_thread_info_attach (baseptr) != NULL;
4182 * mono_gc_set_stack_end:
4184 * Set the end of the current threads stack to STACK_END. The stack space between
4185 * STACK_END and the real end of the threads stack will not be scanned during collections.
4188 mono_gc_set_stack_end (void *stack_end)
4190 SgenThreadInfo *info;
4193 info = mono_thread_info_current ();
4195 g_assert (stack_end < info->stack_end);
4196 info->stack_end = stack_end;
4201 #if USE_PTHREAD_INTERCEPT
4205 mono_gc_pthread_create (pthread_t *new_thread, const pthread_attr_t *attr, void *(*start_routine)(void *), void *arg)
4207 return pthread_create (new_thread, attr, start_routine, arg);
4211 mono_gc_pthread_join (pthread_t thread, void **retval)
4213 return pthread_join (thread, retval);
4217 mono_gc_pthread_detach (pthread_t thread)
4219 return pthread_detach (thread);
4223 mono_gc_pthread_exit (void *retval)
4225 pthread_exit (retval);
4228 #endif /* USE_PTHREAD_INTERCEPT */
4231 * ######################################################################
4232 * ######## Write barriers
4233 * ######################################################################
4237 * Note: the write barriers first do the needed GC work and then do the actual store:
4238 * this way the value is visible to the conservative GC scan after the write barrier
4239 * itself. If a GC interrupts the barrier in the middle, value will be kept alive by
4240 * the conservative scan, otherwise by the remembered set scan.
4243 mono_gc_wbarrier_set_field (MonoObject *obj, gpointer field_ptr, MonoObject* value)
4245 HEAVY_STAT (++stat_wbarrier_set_field);
4246 if (ptr_in_nursery (field_ptr)) {
4247 *(void**)field_ptr = value;
4250 DEBUG (8, fprintf (gc_debug_file, "Adding remset at %p\n", field_ptr));
4252 binary_protocol_wbarrier (field_ptr, value, value->vtable);
4254 remset.wbarrier_set_field (obj, field_ptr, value);
4258 mono_gc_wbarrier_set_arrayref (MonoArray *arr, gpointer slot_ptr, MonoObject* value)
4260 HEAVY_STAT (++stat_wbarrier_set_arrayref);
4261 if (ptr_in_nursery (slot_ptr)) {
4262 *(void**)slot_ptr = value;
4265 DEBUG (8, fprintf (gc_debug_file, "Adding remset at %p\n", slot_ptr));
4267 binary_protocol_wbarrier (slot_ptr, value, value->vtable);
4269 remset.wbarrier_set_arrayref (arr, slot_ptr, value);
4273 mono_gc_wbarrier_arrayref_copy (gpointer dest_ptr, gpointer src_ptr, int count)
4275 HEAVY_STAT (++stat_wbarrier_arrayref_copy);
4276 /*This check can be done without taking a lock since dest_ptr array is pinned*/
4277 if (ptr_in_nursery (dest_ptr) || count <= 0) {
4278 mono_gc_memmove (dest_ptr, src_ptr, count * sizeof (gpointer));
4282 #ifdef SGEN_BINARY_PROTOCOL
4285 for (i = 0; i < count; ++i) {
4286 gpointer dest = (gpointer*)dest_ptr + i;
4287 gpointer obj = *((gpointer*)src_ptr + i);
4289 binary_protocol_wbarrier (dest, obj, (gpointer)LOAD_VTABLE (obj));
4294 remset.wbarrier_arrayref_copy (dest_ptr, src_ptr, count);
4297 static char *found_obj;
4300 find_object_for_ptr_callback (char *obj, size_t size, void *user_data)
4302 char *ptr = user_data;
4304 if (ptr >= obj && ptr < obj + size) {
4305 g_assert (!found_obj);
4310 /* for use in the debugger */
4311 char* find_object_for_ptr (char *ptr);
4313 find_object_for_ptr (char *ptr)
4315 if (ptr >= nursery_section->data && ptr < nursery_section->end_data) {
4317 mono_sgen_scan_area_with_callback (nursery_section->data, nursery_section->end_data,
4318 find_object_for_ptr_callback, ptr, TRUE);
4324 mono_sgen_los_iterate_objects (find_object_for_ptr_callback, ptr);
4329 * Very inefficient, but this is debugging code, supposed to
4330 * be called from gdb, so we don't care.
4333 major_collector.iterate_objects (TRUE, TRUE, find_object_for_ptr_callback, ptr);
4338 mono_gc_wbarrier_generic_nostore (gpointer ptr)
4340 HEAVY_STAT (++stat_wbarrier_generic_store);
4342 #ifdef XDOMAIN_CHECKS_IN_WBARRIER
4343 /* FIXME: ptr_in_heap must be called with the GC lock held */
4344 if (xdomain_checks && *(MonoObject**)ptr && ptr_in_heap (ptr)) {
4345 char *start = find_object_for_ptr (ptr);
4346 MonoObject *value = *(MonoObject**)ptr;
4350 MonoObject *obj = (MonoObject*)start;
4351 if (obj->vtable->domain != value->vtable->domain)
4352 g_assert (is_xdomain_ref_allowed (ptr, start, obj->vtable->domain));
4358 if (*(gpointer*)ptr)
4359 binary_protocol_wbarrier (ptr, *(gpointer*)ptr, (gpointer)LOAD_VTABLE (*(gpointer*)ptr));
4361 if (ptr_in_nursery (ptr) || ptr_on_stack (ptr) || !ptr_in_nursery (*(gpointer*)ptr)) {
4362 DEBUG (8, fprintf (gc_debug_file, "Skipping remset at %p\n", ptr));
4366 DEBUG (8, fprintf (gc_debug_file, "Adding remset at %p\n", ptr));
4368 remset.wbarrier_generic_nostore (ptr);
4372 mono_gc_wbarrier_generic_store (gpointer ptr, MonoObject* value)
4374 DEBUG (8, fprintf (gc_debug_file, "Wbarrier store at %p to %p (%s)\n", ptr, value, value ? safe_name (value) : "null"));
4375 *(void**)ptr = value;
4376 if (ptr_in_nursery (value))
4377 mono_gc_wbarrier_generic_nostore (ptr);
4378 mono_sgen_dummy_use (value);
4381 void mono_gc_wbarrier_value_copy_bitmap (gpointer _dest, gpointer _src, int size, unsigned bitmap)
4383 mword *dest = _dest;
4388 mono_gc_wbarrier_generic_store (dest, (MonoObject*)*src);
4393 size -= SIZEOF_VOID_P;
4398 #ifdef SGEN_BINARY_PROTOCOL
4400 #define HANDLE_PTR(ptr,obj) do { \
4401 gpointer o = *(gpointer*)(ptr); \
4403 gpointer d = ((char*)dest) + ((char*)(ptr) - (char*)(obj)); \
4404 binary_protocol_wbarrier (d, o, (gpointer) LOAD_VTABLE (o)); \
4409 scan_object_for_binary_protocol_copy_wbarrier (gpointer dest, char *start, mword desc)
4411 #define SCAN_OBJECT_NOVTABLE
4412 #include "sgen-scan-object.h"
4417 mono_gc_wbarrier_value_copy (gpointer dest, gpointer src, int count, MonoClass *klass)
4419 HEAVY_STAT (++stat_wbarrier_value_copy);
4420 g_assert (klass->valuetype);
4422 DEBUG (8, fprintf (gc_debug_file, "Adding value remset at %p, count %d, descr %p for class %s (%p)\n", dest, count, klass->gc_descr, klass->name, klass));
4424 if (ptr_in_nursery (dest) || ptr_on_stack (dest) || !SGEN_CLASS_HAS_REFERENCES (klass)) {
4425 size_t element_size = mono_class_value_size (klass, NULL);
4426 size_t size = count * element_size;
4427 mono_gc_memmove (dest, src, size);
4431 #ifdef SGEN_BINARY_PROTOCOL
4434 for (i = 0; i < count; ++i) {
4435 scan_object_for_binary_protocol_copy_wbarrier ((char*)dest + i * element_size,
4436 (char*)src + i * element_size - sizeof (MonoObject),
4437 (mword) klass->gc_descr);
4442 remset.wbarrier_value_copy (dest, src, count, klass);
4446 * mono_gc_wbarrier_object_copy:
4448 * Write barrier to call when obj is the result of a clone or copy of an object.
4451 mono_gc_wbarrier_object_copy (MonoObject* obj, MonoObject *src)
4455 HEAVY_STAT (++stat_wbarrier_object_copy);
4457 if (ptr_in_nursery (obj) || ptr_on_stack (obj)) {
4458 size = mono_object_class (obj)->instance_size;
4459 mono_gc_memmove ((char*)obj + sizeof (MonoObject), (char*)src + sizeof (MonoObject),
4460 size - sizeof (MonoObject));
4464 #ifdef SGEN_BINARY_PROTOCOL
4465 scan_object_for_binary_protocol_copy_wbarrier (obj, (char*)src, (mword) src->vtable->gc_descr);
4468 remset.wbarrier_object_copy (obj, src);
4472 * ######################################################################
4473 * ######## Other mono public interface functions.
4474 * ######################################################################
4477 #define REFS_SIZE 128
4480 MonoGCReferences callback;
4484 MonoObject *refs [REFS_SIZE];
4485 uintptr_t offsets [REFS_SIZE];
4489 #define HANDLE_PTR(ptr,obj) do { \
4491 if (hwi->count == REFS_SIZE) { \
4492 hwi->callback ((MonoObject*)start, mono_object_class (start), hwi->called? 0: size, hwi->count, hwi->refs, hwi->offsets, hwi->data); \
4496 hwi->offsets [hwi->count] = (char*)(ptr)-(char*)start; \
4497 hwi->refs [hwi->count++] = *(ptr); \
4502 collect_references (HeapWalkInfo *hwi, char *start, size_t size)
4504 #include "sgen-scan-object.h"
4508 walk_references (char *start, size_t size, void *data)
4510 HeapWalkInfo *hwi = data;
4513 collect_references (hwi, start, size);
4514 if (hwi->count || !hwi->called)
4515 hwi->callback ((MonoObject*)start, mono_object_class (start), hwi->called? 0: size, hwi->count, hwi->refs, hwi->offsets, hwi->data);
4519 * mono_gc_walk_heap:
4520 * @flags: flags for future use
4521 * @callback: a function pointer called for each object in the heap
4522 * @data: a user data pointer that is passed to callback
4524 * This function can be used to iterate over all the live objects in the heap:
4525 * for each object, @callback is invoked, providing info about the object's
4526 * location in memory, its class, its size and the objects it references.
4527 * For each referenced object it's offset from the object address is
4528 * reported in the offsets array.
4529 * The object references may be buffered, so the callback may be invoked
4530 * multiple times for the same object: in all but the first call, the size
4531 * argument will be zero.
4532 * Note that this function can be only called in the #MONO_GC_EVENT_PRE_START_WORLD
4533 * profiler event handler.
4535 * Returns: a non-zero value if the GC doesn't support heap walking
4538 mono_gc_walk_heap (int flags, MonoGCReferences callback, void *data)
4543 hwi.callback = callback;
4546 mono_sgen_clear_nursery_fragments ();
4547 mono_sgen_scan_area_with_callback (nursery_section->data, nursery_section->end_data, walk_references, &hwi, FALSE);
4549 major_collector.iterate_objects (TRUE, TRUE, walk_references, &hwi);
4550 mono_sgen_los_iterate_objects (walk_references, &hwi);
4556 mono_gc_collect (int generation)
4561 mono_profiler_gc_event (MONO_GC_EVENT_START, generation);
4562 stop_world (generation);
4563 if (generation == 0) {
4564 collect_nursery (0);
4566 major_collection ("user request");
4568 restart_world (generation);
4569 mono_profiler_gc_event (MONO_GC_EVENT_END, generation);
4574 mono_gc_max_generation (void)
4580 mono_gc_collection_count (int generation)
4582 if (generation == 0)
4583 return stat_minor_gcs;
4584 return stat_major_gcs;
4588 mono_gc_get_used_size (void)
4592 tot = los_memory_usage;
4593 tot += nursery_section->next_data - nursery_section->data;
4594 tot += major_collector.get_used_size ();
4595 /* FIXME: account for pinned objects */
4601 mono_gc_get_heap_size (void)
4607 mono_gc_disable (void)
4615 mono_gc_enable (void)
4623 mono_gc_get_los_limit (void)
4625 return MAX_SMALL_OBJ_SIZE;
4629 mono_object_is_alive (MonoObject* o)
4635 mono_gc_get_generation (MonoObject *obj)
4637 if (ptr_in_nursery (obj))
4643 mono_gc_enable_events (void)
4648 mono_gc_weak_link_add (void **link_addr, MonoObject *obj, gboolean track)
4650 mono_gc_register_disappearing_link (obj, link_addr, track, FALSE);
4654 mono_gc_weak_link_remove (void **link_addr)
4656 mono_gc_register_disappearing_link (NULL, link_addr, FALSE, FALSE);
4660 mono_gc_weak_link_get (void **link_addr)
4664 return (MonoObject*) REVEAL_POINTER (*link_addr);
4668 mono_gc_ephemeron_array_add (MonoObject *obj)
4670 EphemeronLinkNode *node;
4674 node = mono_sgen_alloc_internal (INTERNAL_MEM_EPHEMERON_LINK);
4679 node->array = (char*)obj;
4680 node->next = ephemeron_list;
4681 ephemeron_list = node;
4683 DEBUG (5, fprintf (gc_debug_file, "Registered ephemeron array %p\n", obj));
4690 mono_gc_invoke_with_gc_lock (MonoGCLockedCallbackFunc func, void *data)
4694 result = func (data);
4695 UNLOCK_INTERRUPTION;
4700 mono_gc_is_gc_thread (void)
4704 result = mono_thread_info_current () != NULL;
4710 is_critical_method (MonoMethod *method)
4712 return mono_runtime_is_critical_method (method) || mono_gc_is_critical_method (method);
4716 mono_gc_base_init (void)
4718 MonoThreadInfoCallbacks cb;
4721 char *major_collector_opt = NULL;
4723 glong soft_limit = 0;
4729 result = InterlockedCompareExchange (&gc_initialized, -1, 0);
4732 /* already inited */
4735 /* being inited by another thread */
4739 /* we will init it */
4742 g_assert_not_reached ();
4744 } while (result != 0);
4746 LOCK_INIT (gc_mutex);
4748 pagesize = mono_pagesize ();
4749 gc_debug_file = stderr;
4751 cb.thread_register = sgen_thread_register;
4752 cb.thread_unregister = sgen_thread_unregister;
4753 cb.thread_attach = sgen_thread_attach;
4754 cb.mono_method_is_critical = (gpointer)is_critical_method;
4756 cb.mono_gc_pthread_create = (gpointer)mono_gc_pthread_create;
4759 mono_threads_init (&cb, sizeof (SgenThreadInfo));
4761 LOCK_INIT (interruption_mutex);
4762 LOCK_INIT (pin_queue_mutex);
4764 init_user_copy_or_mark_key ();
4766 if ((env = getenv ("MONO_GC_PARAMS"))) {
4767 opts = g_strsplit (env, ",", -1);
4768 for (ptr = opts; *ptr; ++ptr) {
4770 if (g_str_has_prefix (opt, "major=")) {
4771 opt = strchr (opt, '=') + 1;
4772 major_collector_opt = g_strdup (opt);
4780 mono_sgen_init_internal_allocator ();
4781 mono_sgen_init_nursery_allocator ();
4783 mono_sgen_register_fixed_internal_mem_type (INTERNAL_MEM_SECTION, SGEN_SIZEOF_GC_MEM_SECTION);
4784 mono_sgen_register_fixed_internal_mem_type (INTERNAL_MEM_FINALIZE_READY_ENTRY, sizeof (FinalizeReadyEntry));
4785 mono_sgen_register_fixed_internal_mem_type (INTERNAL_MEM_GRAY_QUEUE, sizeof (GrayQueueSection));
4786 g_assert (sizeof (GenericStoreRememberedSet) == sizeof (gpointer) * STORE_REMSET_BUFFER_SIZE);
4787 mono_sgen_register_fixed_internal_mem_type (INTERNAL_MEM_STORE_REMSET, sizeof (GenericStoreRememberedSet));
4788 mono_sgen_register_fixed_internal_mem_type (INTERNAL_MEM_EPHEMERON_LINK, sizeof (EphemeronLinkNode));
4790 #ifndef HAVE_KW_THREAD
4791 mono_native_tls_alloc (&thread_info_key, NULL);
4795 * This needs to happen before any internal allocations because
4796 * it inits the small id which is required for hazard pointer
4799 mono_sgen_os_init ();
4801 mono_thread_info_attach (&dummy);
4803 if (!major_collector_opt || !strcmp (major_collector_opt, "marksweep")) {
4804 mono_sgen_marksweep_init (&major_collector);
4805 } else if (!major_collector_opt || !strcmp (major_collector_opt, "marksweep-fixed")) {
4806 mono_sgen_marksweep_fixed_init (&major_collector);
4807 } else if (!major_collector_opt || !strcmp (major_collector_opt, "marksweep-par")) {
4808 mono_sgen_marksweep_par_init (&major_collector);
4809 } else if (!major_collector_opt || !strcmp (major_collector_opt, "marksweep-fixed-par")) {
4810 mono_sgen_marksweep_fixed_par_init (&major_collector);
4811 } else if (!strcmp (major_collector_opt, "copying")) {
4812 mono_sgen_copying_init (&major_collector);
4814 fprintf (stderr, "Unknown major collector `%s'.\n", major_collector_opt);
4818 #ifdef SGEN_HAVE_CARDTABLE
4819 use_cardtable = major_collector.supports_cardtable;
4821 use_cardtable = FALSE;
4824 num_workers = mono_cpu_count ();
4825 g_assert (num_workers > 0);
4826 if (num_workers > 16)
4829 ///* Keep this the default for now */
4830 //conservative_stack_mark = TRUE;
4833 for (ptr = opts; *ptr; ++ptr) {
4835 if (g_str_has_prefix (opt, "major="))
4837 if (g_str_has_prefix (opt, "wbarrier=")) {
4838 opt = strchr (opt, '=') + 1;
4839 if (strcmp (opt, "remset") == 0) {
4840 use_cardtable = FALSE;
4841 } else if (strcmp (opt, "cardtable") == 0) {
4842 if (!use_cardtable) {
4843 if (major_collector.supports_cardtable)
4844 fprintf (stderr, "The cardtable write barrier is not supported on this platform.\n");
4846 fprintf (stderr, "The major collector does not support the cardtable write barrier.\n");
4852 if (g_str_has_prefix (opt, "max-heap-size=")) {
4853 opt = strchr (opt, '=') + 1;
4854 if (*opt && mono_gc_parse_environment_string_extract_number (opt, &max_heap)) {
4855 if ((max_heap & (mono_pagesize () - 1))) {
4856 fprintf (stderr, "max-heap-size size must be a multiple of %d.\n", mono_pagesize ());
4860 fprintf (stderr, "max-heap-size must be an integer.\n");
4865 if (g_str_has_prefix (opt, "soft-heap-limit=")) {
4866 opt = strchr (opt, '=') + 1;
4867 if (*opt && mono_gc_parse_environment_string_extract_number (opt, &soft_limit)) {
4868 if (soft_limit <= 0) {
4869 fprintf (stderr, "soft-heap-limit must be positive.\n");
4873 fprintf (stderr, "soft-heap-limit must be an integer.\n");
4878 if (g_str_has_prefix (opt, "workers=")) {
4881 if (!major_collector.is_parallel) {
4882 fprintf (stderr, "The workers= option can only be used for parallel collectors.");
4885 opt = strchr (opt, '=') + 1;
4886 val = strtol (opt, &endptr, 10);
4887 if (!*opt || *endptr) {
4888 fprintf (stderr, "Cannot parse the workers= option value.");
4891 if (val <= 0 || val > 16) {
4892 fprintf (stderr, "The number of workers must be in the range 1 to 16.");
4895 num_workers = (int)val;
4898 if (g_str_has_prefix (opt, "stack-mark=")) {
4899 opt = strchr (opt, '=') + 1;
4900 if (!strcmp (opt, "precise")) {
4901 conservative_stack_mark = FALSE;
4902 } else if (!strcmp (opt, "conservative")) {
4903 conservative_stack_mark = TRUE;
4905 fprintf (stderr, "Invalid value '%s' for stack-mark= option, possible values are: 'precise', 'conservative'.\n", opt);
4910 if (g_str_has_prefix (opt, "bridge=")) {
4911 opt = strchr (opt, '=') + 1;
4912 mono_sgen_register_test_bridge_callbacks (g_strdup (opt));
4916 if (g_str_has_prefix (opt, "nursery-size=")) {
4918 opt = strchr (opt, '=') + 1;
4919 if (*opt && mono_gc_parse_environment_string_extract_number (opt, &val)) {
4920 default_nursery_size = val;
4921 #ifdef SGEN_ALIGN_NURSERY
4922 if ((val & (val - 1))) {
4923 fprintf (stderr, "The nursery size must be a power of two.\n");
4927 if (val < SGEN_MAX_NURSERY_WASTE) {
4928 fprintf (stderr, "The nursery size must be at least %d bytes.\n", SGEN_MAX_NURSERY_WASTE);
4932 default_nursery_bits = 0;
4933 while (1 << (++ default_nursery_bits) != default_nursery_size)
4937 fprintf (stderr, "nursery-size must be an integer.\n");
4943 if (!(major_collector.handle_gc_param && major_collector.handle_gc_param (opt))) {
4944 fprintf (stderr, "MONO_GC_PARAMS must be a comma-delimited list of one or more of the following:\n");
4945 fprintf (stderr, " max-heap-size=N (where N is an integer, possibly with a k, m or a g suffix)\n");
4946 fprintf (stderr, " soft-heap-limit=n (where N is an integer, possibly with a k, m or a g suffix)\n");
4947 fprintf (stderr, " nursery-size=N (where N is an integer, possibly with a k, m or a g suffix)\n");
4948 fprintf (stderr, " major=COLLECTOR (where COLLECTOR is `marksweep', `marksweep-par' or `copying')\n");
4949 fprintf (stderr, " wbarrier=WBARRIER (where WBARRIER is `remset' or `cardtable')\n");
4950 fprintf (stderr, " stack-mark=MARK-METHOD (where MARK-METHOD is 'precise' or 'conservative')\n");
4951 if (major_collector.print_gc_param_usage)
4952 major_collector.print_gc_param_usage ();
4959 if (major_collector.is_parallel)
4960 mono_sgen_workers_init (num_workers);
4962 if (major_collector_opt)
4963 g_free (major_collector_opt);
4965 nursery_size = DEFAULT_NURSERY_SIZE;
4966 minor_collection_allowance = MIN_MINOR_COLLECTION_ALLOWANCE;
4967 init_heap_size_limits (max_heap, soft_limit);
4971 if ((env = getenv ("MONO_GC_DEBUG"))) {
4972 opts = g_strsplit (env, ",", -1);
4973 for (ptr = opts; ptr && *ptr; ptr ++) {
4975 if (opt [0] >= '0' && opt [0] <= '9') {
4976 gc_debug_level = atoi (opt);
4981 char *rf = g_strdup_printf ("%s.%d", opt, getpid ());
4982 gc_debug_file = fopen (rf, "wb");
4984 gc_debug_file = stderr;
4987 } else if (!strcmp (opt, "print-allowance")) {
4988 debug_print_allowance = TRUE;
4989 } else if (!strcmp (opt, "print-pinning")) {
4990 do_pin_stats = TRUE;
4991 } else if (!strcmp (opt, "collect-before-allocs")) {
4992 collect_before_allocs = 1;
4993 } else if (g_str_has_prefix (opt, "collect-before-allocs=")) {
4994 char *arg = strchr (opt, '=') + 1;
4995 collect_before_allocs = atoi (arg);
4996 } else if (!strcmp (opt, "check-at-minor-collections")) {
4997 consistency_check_at_minor_collection = TRUE;
4998 nursery_clear_policy = CLEAR_AT_GC;
4999 } else if (!strcmp (opt, "xdomain-checks")) {
5000 xdomain_checks = TRUE;
5001 } else if (!strcmp (opt, "clear-at-gc")) {
5002 nursery_clear_policy = CLEAR_AT_GC;
5003 } else if (!strcmp (opt, "clear-nursery-at-gc")) {
5004 nursery_clear_policy = CLEAR_AT_GC;
5005 } else if (!strcmp (opt, "check-scan-starts")) {
5006 do_scan_starts_check = TRUE;
5007 } else if (!strcmp (opt, "verify-nursery-at-minor-gc")) {
5008 do_verify_nursery = TRUE;
5009 } else if (!strcmp (opt, "dump-nursery-at-minor-gc")) {
5010 do_dump_nursery_content = TRUE;
5011 } else if (!strcmp (opt, "disable-minor")) {
5012 disable_minor_collections = TRUE;
5013 } else if (!strcmp (opt, "disable-major")) {
5014 disable_major_collections = TRUE;
5015 } else if (g_str_has_prefix (opt, "heap-dump=")) {
5016 char *filename = strchr (opt, '=') + 1;
5017 nursery_clear_policy = CLEAR_AT_GC;
5018 heap_dump_file = fopen (filename, "w");
5019 if (heap_dump_file) {
5020 fprintf (heap_dump_file, "<sgen-dump>\n");
5021 do_pin_stats = TRUE;
5023 #ifdef SGEN_BINARY_PROTOCOL
5024 } else if (g_str_has_prefix (opt, "binary-protocol=")) {
5025 char *filename = strchr (opt, '=') + 1;
5026 binary_protocol_init (filename);
5028 fprintf (stderr, "Warning: Cardtable write barriers will not be binary-protocolled.\n");
5031 fprintf (stderr, "Invalid format for the MONO_GC_DEBUG env variable: '%s'\n", env);
5032 fprintf (stderr, "The format is: MONO_GC_DEBUG=[l[:filename]|<option>]+ where l is a debug level 0-9.\n");
5033 fprintf (stderr, "Valid options are:\n");
5034 fprintf (stderr, " collect-before-allocs[=<n>]\n");
5035 fprintf (stderr, " check-at-minor-collections\n");
5036 fprintf (stderr, " disable-minor\n");
5037 fprintf (stderr, " disable-major\n");
5038 fprintf (stderr, " xdomain-checks\n");
5039 fprintf (stderr, " clear-at-gc\n");
5040 fprintf (stderr, " print-allowance\n");
5041 fprintf (stderr, " print-pinning\n");
5048 if (major_collector.is_parallel) {
5049 if (heap_dump_file) {
5050 fprintf (stderr, "Error: Cannot do heap dump with the parallel collector.\n");
5054 fprintf (stderr, "Error: Cannot gather pinning statistics with the parallel collector.\n");
5059 if (major_collector.post_param_init)
5060 major_collector.post_param_init ();
5062 memset (&remset, 0, sizeof (remset));
5064 #ifdef SGEN_HAVE_CARDTABLE
5066 sgen_card_table_init (&remset);
5069 mono_sgen_ssb_init (&remset);
5071 if (remset.register_thread)
5072 remset.register_thread (mono_thread_info_current ());
5078 mono_gc_get_gc_name (void)
5083 static MonoMethod *write_barrier_method;
5086 mono_gc_is_critical_method (MonoMethod *method)
5088 return (method == write_barrier_method || mono_sgen_is_managed_allocator (method));
5092 is_ip_in_managed_allocator (MonoDomain *domain, gpointer ip)
5096 if (!mono_thread_internal_current ())
5097 /* Happens during thread attach */
5102 ji = mono_jit_info_table_find (domain, ip);
5106 return mono_gc_is_critical_method (ji->method);
5110 emit_nursery_check (MonoMethodBuilder *mb, int *nursery_check_return_labels)
5112 memset (nursery_check_return_labels, 0, sizeof (int) * 3);
5113 #ifdef SGEN_ALIGN_NURSERY
5114 // if (ptr_in_nursery (ptr)) return;
5116 * Masking out the bits might be faster, but we would have to use 64 bit
5117 * immediates, which might be slower.
5119 mono_mb_emit_ldarg (mb, 0);
5120 mono_mb_emit_icon (mb, DEFAULT_NURSERY_BITS);
5121 mono_mb_emit_byte (mb, CEE_SHR_UN);
5122 mono_mb_emit_icon (mb, (mword)nursery_start >> DEFAULT_NURSERY_BITS);
5123 nursery_check_return_labels [0] = mono_mb_emit_branch (mb, CEE_BEQ);
5125 // if (!ptr_in_nursery (*ptr)) return;
5126 mono_mb_emit_ldarg (mb, 0);
5127 mono_mb_emit_byte (mb, CEE_LDIND_I);
5128 mono_mb_emit_icon (mb, DEFAULT_NURSERY_BITS);
5129 mono_mb_emit_byte (mb, CEE_SHR_UN);
5130 mono_mb_emit_icon (mb, (mword)nursery_start >> DEFAULT_NURSERY_BITS);
5131 nursery_check_return_labels [1] = mono_mb_emit_branch (mb, CEE_BNE_UN);
5133 int label_continue1, label_continue2;
5134 int dereferenced_var;
5136 // if (ptr < (nursery_start)) goto continue;
5137 mono_mb_emit_ldarg (mb, 0);
5138 mono_mb_emit_ptr (mb, (gpointer) nursery_start);
5139 label_continue_1 = mono_mb_emit_branch (mb, CEE_BLT);
5141 // if (ptr >= nursery_end)) goto continue;
5142 mono_mb_emit_ldarg (mb, 0);
5143 mono_mb_emit_ptr (mb, (gpointer) nursery_end);
5144 label_continue_2 = mono_mb_emit_branch (mb, CEE_BGE);
5147 nursery_check_return_labels [0] = mono_mb_emit_branch (mb, CEE_BR);
5150 mono_mb_patch_branch (mb, label_continue_1);
5151 mono_mb_patch_branch (mb, label_continue_2);
5153 // Dereference and store in local var
5154 dereferenced_var = mono_mb_add_local (mb, &mono_defaults.int_class->byval_arg);
5155 mono_mb_emit_ldarg (mb, 0);
5156 mono_mb_emit_byte (mb, CEE_LDIND_I);
5157 mono_mb_emit_stloc (mb, dereferenced_var);
5159 // if (*ptr < nursery_start) return;
5160 mono_mb_emit_ldloc (mb, dereferenced_var);
5161 mono_mb_emit_ptr (mb, (gpointer) nursery_start);
5162 nursery_check_return_labels [1] = mono_mb_emit_branch (mb, CEE_BLT);
5164 // if (*ptr >= nursery_end) return;
5165 mono_mb_emit_ldloc (mb, dereferenced_var);
5166 mono_mb_emit_ptr (mb, (gpointer) nursery_end);
5167 nursery_check_return_labels [2] = mono_mb_emit_branch (mb, CEE_BGE);
5172 mono_gc_get_write_barrier (void)
5175 MonoMethodBuilder *mb;
5176 MonoMethodSignature *sig;
5177 #ifdef MANAGED_WBARRIER
5178 int i, nursery_check_labels [3];
5179 int label_no_wb_3, label_no_wb_4, label_need_wb, label_slow_path;
5180 int buffer_var, buffer_index_var, dummy_var;
5182 #ifdef HAVE_KW_THREAD
5183 int stack_end_offset = -1, store_remset_buffer_offset = -1;
5184 int store_remset_buffer_index_offset = -1, store_remset_buffer_index_addr_offset = -1;
5186 MONO_THREAD_VAR_OFFSET (stack_end, stack_end_offset);
5187 g_assert (stack_end_offset != -1);
5188 MONO_THREAD_VAR_OFFSET (store_remset_buffer, store_remset_buffer_offset);
5189 g_assert (store_remset_buffer_offset != -1);
5190 MONO_THREAD_VAR_OFFSET (store_remset_buffer_index, store_remset_buffer_index_offset);
5191 g_assert (store_remset_buffer_index_offset != -1);
5192 MONO_THREAD_VAR_OFFSET (store_remset_buffer_index_addr, store_remset_buffer_index_addr_offset);
5193 g_assert (store_remset_buffer_index_addr_offset != -1);
5197 // FIXME: Maybe create a separate version for ctors (the branch would be
5198 // correctly predicted more times)
5199 if (write_barrier_method)
5200 return write_barrier_method;
5202 /* Create the IL version of mono_gc_barrier_generic_store () */
5203 sig = mono_metadata_signature_alloc (mono_defaults.corlib, 1);
5204 sig->ret = &mono_defaults.void_class->byval_arg;
5205 sig->params [0] = &mono_defaults.int_class->byval_arg;
5207 mb = mono_mb_new (mono_defaults.object_class, "wbarrier", MONO_WRAPPER_WRITE_BARRIER);
5209 #ifdef MANAGED_WBARRIER
5210 if (use_cardtable) {
5211 emit_nursery_check (mb, nursery_check_labels);
5213 addr = sgen_cardtable + ((address >> CARD_BITS) & CARD_MASK)
5217 LDC_PTR sgen_cardtable
5219 address >> CARD_BITS
5223 if (SGEN_HAVE_OVERLAPPING_CARDS) {
5224 LDC_PTR card_table_mask
5231 mono_mb_emit_ptr (mb, sgen_cardtable);
5232 mono_mb_emit_ldarg (mb, 0);
5233 mono_mb_emit_icon (mb, CARD_BITS);
5234 mono_mb_emit_byte (mb, CEE_SHR_UN);
5235 #ifdef SGEN_HAVE_OVERLAPPING_CARDS
5236 mono_mb_emit_ptr (mb, (gpointer)CARD_MASK);
5237 mono_mb_emit_byte (mb, CEE_AND);
5239 mono_mb_emit_byte (mb, CEE_ADD);
5240 mono_mb_emit_icon (mb, 1);
5241 mono_mb_emit_byte (mb, CEE_STIND_I1);
5244 for (i = 0; i < 3; ++i) {
5245 if (nursery_check_labels [i])
5246 mono_mb_patch_branch (mb, nursery_check_labels [i]);
5248 mono_mb_emit_byte (mb, CEE_RET);
5249 } else if (mono_runtime_has_tls_get ()) {
5250 emit_nursery_check (mb, nursery_check_labels);
5252 // if (ptr >= stack_end) goto need_wb;
5253 mono_mb_emit_ldarg (mb, 0);
5254 EMIT_TLS_ACCESS (mb, stack_end, stack_end_offset);
5255 label_need_wb = mono_mb_emit_branch (mb, CEE_BGE_UN);
5257 // if (ptr >= stack_start) return;
5258 dummy_var = mono_mb_add_local (mb, &mono_defaults.int_class->byval_arg);
5259 mono_mb_emit_ldarg (mb, 0);
5260 mono_mb_emit_ldloc_addr (mb, dummy_var);
5261 label_no_wb_3 = mono_mb_emit_branch (mb, CEE_BGE_UN);
5264 mono_mb_patch_branch (mb, label_need_wb);
5266 // buffer = STORE_REMSET_BUFFER;
5267 buffer_var = mono_mb_add_local (mb, &mono_defaults.int_class->byval_arg);
5268 EMIT_TLS_ACCESS (mb, store_remset_buffer, store_remset_buffer_offset);
5269 mono_mb_emit_stloc (mb, buffer_var);
5271 // buffer_index = STORE_REMSET_BUFFER_INDEX;
5272 buffer_index_var = mono_mb_add_local (mb, &mono_defaults.int_class->byval_arg);
5273 EMIT_TLS_ACCESS (mb, store_remset_buffer_index, store_remset_buffer_index_offset);
5274 mono_mb_emit_stloc (mb, buffer_index_var);
5276 // if (buffer [buffer_index] == ptr) return;
5277 mono_mb_emit_ldloc (mb, buffer_var);
5278 mono_mb_emit_ldloc (mb, buffer_index_var);
5279 g_assert (sizeof (gpointer) == 4 || sizeof (gpointer) == 8);
5280 mono_mb_emit_icon (mb, sizeof (gpointer) == 4 ? 2 : 3);
5281 mono_mb_emit_byte (mb, CEE_SHL);
5282 mono_mb_emit_byte (mb, CEE_ADD);
5283 mono_mb_emit_byte (mb, CEE_LDIND_I);
5284 mono_mb_emit_ldarg (mb, 0);
5285 label_no_wb_4 = mono_mb_emit_branch (mb, CEE_BEQ);
5288 mono_mb_emit_ldloc (mb, buffer_index_var);
5289 mono_mb_emit_icon (mb, 1);
5290 mono_mb_emit_byte (mb, CEE_ADD);
5291 mono_mb_emit_stloc (mb, buffer_index_var);
5293 // if (buffer_index >= STORE_REMSET_BUFFER_SIZE) goto slow_path;
5294 mono_mb_emit_ldloc (mb, buffer_index_var);
5295 mono_mb_emit_icon (mb, STORE_REMSET_BUFFER_SIZE);
5296 label_slow_path = mono_mb_emit_branch (mb, CEE_BGE);
5298 // buffer [buffer_index] = ptr;
5299 mono_mb_emit_ldloc (mb, buffer_var);
5300 mono_mb_emit_ldloc (mb, buffer_index_var);
5301 g_assert (sizeof (gpointer) == 4 || sizeof (gpointer) == 8);
5302 mono_mb_emit_icon (mb, sizeof (gpointer) == 4 ? 2 : 3);
5303 mono_mb_emit_byte (mb, CEE_SHL);
5304 mono_mb_emit_byte (mb, CEE_ADD);
5305 mono_mb_emit_ldarg (mb, 0);
5306 mono_mb_emit_byte (mb, CEE_STIND_I);
5308 // STORE_REMSET_BUFFER_INDEX = buffer_index;
5309 EMIT_TLS_ACCESS (mb, store_remset_buffer_index_addr, store_remset_buffer_index_addr_offset);
5310 mono_mb_emit_ldloc (mb, buffer_index_var);
5311 mono_mb_emit_byte (mb, CEE_STIND_I);
5314 for (i = 0; i < 3; ++i) {
5315 if (nursery_check_labels [i])
5316 mono_mb_patch_branch (mb, nursery_check_labels [i]);
5318 mono_mb_patch_branch (mb, label_no_wb_3);
5319 mono_mb_patch_branch (mb, label_no_wb_4);
5320 mono_mb_emit_byte (mb, CEE_RET);
5323 mono_mb_patch_branch (mb, label_slow_path);
5325 mono_mb_emit_ldarg (mb, 0);
5326 mono_mb_emit_icall (mb, mono_gc_wbarrier_generic_nostore);
5327 mono_mb_emit_byte (mb, CEE_RET);
5331 mono_mb_emit_ldarg (mb, 0);
5332 mono_mb_emit_icall (mb, mono_gc_wbarrier_generic_nostore);
5333 mono_mb_emit_byte (mb, CEE_RET);
5336 res = mono_mb_create_method (mb, sig, 16);
5339 mono_loader_lock ();
5340 if (write_barrier_method) {
5341 /* Already created */
5342 mono_free_method (res);
5344 /* double-checked locking */
5345 mono_memory_barrier ();
5346 write_barrier_method = res;
5348 mono_loader_unlock ();
5350 return write_barrier_method;
5354 mono_gc_get_description (void)
5356 return g_strdup ("sgen");
5360 mono_gc_set_desktop_mode (void)
5365 mono_gc_is_moving (void)
5371 mono_gc_is_disabled (void)
5377 mono_sgen_debug_printf (int level, const char *format, ...)
5381 if (level > gc_debug_level)
5384 va_start (ap, format);
5385 vfprintf (gc_debug_file, format, ap);
5390 mono_sgen_get_logfile (void)
5392 return gc_debug_file;
5396 BOOL APIENTRY mono_gc_dllmain (HMODULE module_handle, DWORD reason, LPVOID reserved)
5403 mono_sgen_get_nursery_clear_policy (void)
5405 return nursery_clear_policy;
5409 mono_sgen_get_array_fill_vtable (void)
5411 if (!array_fill_vtable) {
5412 static MonoClass klass;
5413 static MonoVTable vtable;
5416 MonoDomain *domain = mono_get_root_domain ();
5419 klass.element_class = mono_defaults.byte_class;
5421 klass.instance_size = sizeof (MonoArray);
5422 klass.sizes.element_size = 1;
5423 klass.name = "array_filler_type";
5425 vtable.klass = &klass;
5427 vtable.gc_descr = mono_gc_make_descr_for_array (TRUE, &bmap, 0, 1);
5430 array_fill_vtable = &vtable;
5432 return array_fill_vtable;
5436 mono_sgen_gc_lock (void)
5442 mono_sgen_gc_unlock (void)
5448 sgen_major_collector_iterate_live_block_ranges (sgen_cardtable_block_callback callback)
5450 major_collector.iterate_live_block_ranges (callback);
5454 sgen_major_collector_scan_card_table (SgenGrayQueue *queue)
5456 major_collector.scan_card_table (queue);
5460 mono_sgen_ptr_in_nursery (void *p)
5462 return SGEN_PTR_IN_NURSERY ((p), DEFAULT_NURSERY_BITS, nursery_start, nursery_end);
5466 mono_sgen_get_major_collector (void)
5468 return &major_collector;
5471 void mono_gc_set_skip_thread (gboolean skip)
5473 SgenThreadInfo *info = mono_thread_info_current ();
5476 info->gc_disabled = skip;
5481 mono_sgen_get_remset (void)
5487 mono_gc_get_vtable_bits (MonoClass *class)
5489 if (mono_sgen_need_bridge_processing () && mono_sgen_is_bridge_class (class))
5490 return SGEN_GC_BIT_BRIDGE_OBJECT;
5494 #endif /* HAVE_SGEN_GC */