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.
189 #define _XOPEN_SOURCE
190 #define _DARWIN_C_SOURCE
196 #ifdef HAVE_PTHREAD_H
199 #ifdef HAVE_SEMAPHORE_H
200 #include <semaphore.h>
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_slots_allocated_in_vain;
301 long long stat_nursery_copy_object_failed_from_space = 0;
302 long long stat_nursery_copy_object_failed_forwarded = 0;
303 long long stat_nursery_copy_object_failed_pinned = 0;
304 long long stat_nursery_copy_object_failed_to_space = 0;
306 static int stat_wbarrier_set_field = 0;
307 static int stat_wbarrier_set_arrayref = 0;
308 static int stat_wbarrier_arrayref_copy = 0;
309 static int stat_wbarrier_generic_store = 0;
310 static int stat_wbarrier_set_root = 0;
311 static int stat_wbarrier_value_copy = 0;
312 static int stat_wbarrier_object_copy = 0;
315 int stat_minor_gcs = 0;
316 int stat_major_gcs = 0;
318 static long long stat_pinned_objects = 0;
320 static long long time_minor_pre_collection_fragment_clear = 0;
321 static long long time_minor_pinning = 0;
322 static long long time_minor_scan_remsets = 0;
323 static long long time_minor_scan_pinned = 0;
324 static long long time_minor_scan_registered_roots = 0;
325 static long long time_minor_scan_thread_data = 0;
326 static long long time_minor_finish_gray_stack = 0;
327 static long long time_minor_fragment_creation = 0;
329 static long long time_major_pre_collection_fragment_clear = 0;
330 static long long time_major_pinning = 0;
331 static long long time_major_scan_pinned = 0;
332 static long long time_major_scan_registered_roots = 0;
333 static long long time_major_scan_thread_data = 0;
334 static long long time_major_scan_alloc_pinned = 0;
335 static long long time_major_scan_finalized = 0;
336 static long long time_major_scan_big_objects = 0;
337 static long long time_major_finish_gray_stack = 0;
338 static long long time_major_free_bigobjs = 0;
339 static long long time_major_los_sweep = 0;
340 static long long time_major_sweep = 0;
341 static long long time_major_fragment_creation = 0;
343 int gc_debug_level = 0;
345 static gboolean debug_print_allowance = FALSE;
349 mono_gc_flush_info (void)
351 fflush (gc_debug_file);
355 #define TV_DECLARE SGEN_TV_DECLARE
356 #define TV_GETTIME SGEN_TV_GETTIME
357 #define TV_ELAPSED SGEN_TV_ELAPSED
358 #define TV_ELAPSED_MS SGEN_TV_ELAPSED_MS
360 #define ALIGN_TO(val,align) ((((guint64)val) + ((align) - 1)) & ~((align) - 1))
362 NurseryClearPolicy nursery_clear_policy = CLEAR_AT_TLAB_CREATION;
364 /* the runtime can register areas of memory as roots: we keep two lists of roots,
365 * a pinned root set for conservatively scanned roots and a normal one for
366 * precisely scanned roots (currently implemented as a single list).
368 typedef struct _RootRecord RootRecord;
374 #define object_is_forwarded SGEN_OBJECT_IS_FORWARDED
375 #define object_is_pinned SGEN_OBJECT_IS_PINNED
376 #define pin_object SGEN_PIN_OBJECT
377 #define unpin_object SGEN_UNPIN_OBJECT
379 #define ptr_in_nursery sgen_ptr_in_nursery
381 #define LOAD_VTABLE SGEN_LOAD_VTABLE
384 safe_name (void* obj)
386 MonoVTable *vt = (MonoVTable*)LOAD_VTABLE (obj);
387 return vt->klass->name;
390 #define safe_object_get_size sgen_safe_object_get_size
393 sgen_safe_name (void* obj)
395 return safe_name (obj);
399 * ######################################################################
400 * ######## Global data.
401 * ######################################################################
403 LOCK_DECLARE (gc_mutex);
404 static int gc_disabled = 0;
406 static gboolean use_cardtable;
408 #define MIN_MINOR_COLLECTION_ALLOWANCE (DEFAULT_NURSERY_SIZE * 4)
410 #define SCAN_START_SIZE SGEN_SCAN_START_SIZE
412 static mword pagesize = 4096;
413 int degraded_mode = 0;
415 static mword bytes_pinned_from_failed_allocation = 0;
417 static mword total_alloc = 0;
418 /* use this to tune when to do a major/minor collection */
419 static mword memory_pressure = 0;
420 static mword minor_collection_allowance;
421 static int minor_collection_sections_alloced = 0;
424 /* GC Logging stats */
425 static int last_major_num_sections = 0;
426 static int last_los_memory_usage = 0;
427 static gboolean major_collection_happened = FALSE;
429 GCMemSection *nursery_section = NULL;
430 static mword lowest_heap_address = ~(mword)0;
431 static mword highest_heap_address = 0;
433 static LOCK_DECLARE (interruption_mutex);
434 static LOCK_DECLARE (pin_queue_mutex);
436 #define LOCK_PIN_QUEUE mono_mutex_lock (&pin_queue_mutex)
437 #define UNLOCK_PIN_QUEUE mono_mutex_unlock (&pin_queue_mutex)
439 typedef struct _FinalizeReadyEntry FinalizeReadyEntry;
440 struct _FinalizeReadyEntry {
441 FinalizeReadyEntry *next;
445 typedef struct _EphemeronLinkNode EphemeronLinkNode;
447 struct _EphemeronLinkNode {
448 EphemeronLinkNode *next;
457 int current_collection_generation = -1;
460 * The link pointer is hidden by negating each bit. We use the lowest
461 * bit of the link (before negation) to store whether it needs
462 * resurrection tracking.
464 #define HIDE_POINTER(p,t) ((gpointer)(~((gulong)(p)|((t)?1:0))))
465 #define REVEAL_POINTER(p) ((gpointer)((~(gulong)(p))&~3L))
467 /* objects that are ready to be finalized */
468 static FinalizeReadyEntry *fin_ready_list = NULL;
469 static FinalizeReadyEntry *critical_fin_list = NULL;
471 static EphemeronLinkNode *ephemeron_list;
473 static int num_ready_finalizers = 0;
474 static int no_finalize = 0;
477 ROOT_TYPE_NORMAL = 0, /* "normal" roots */
478 ROOT_TYPE_PINNED = 1, /* roots without a GC descriptor */
479 ROOT_TYPE_WBARRIER = 2, /* roots with a write barrier */
483 /* registered roots: the key to the hash is the root start address */
485 * Different kinds of roots are kept separate to speed up pin_from_roots () for example.
487 static SgenHashTable roots_hash [ROOT_TYPE_NUM] = {
488 SGEN_HASH_TABLE_INIT (INTERNAL_MEM_ROOTS_TABLE, INTERNAL_MEM_ROOT_RECORD, sizeof (RootRecord), mono_aligned_addr_hash, NULL),
489 SGEN_HASH_TABLE_INIT (INTERNAL_MEM_ROOTS_TABLE, INTERNAL_MEM_ROOT_RECORD, sizeof (RootRecord), mono_aligned_addr_hash, NULL),
490 SGEN_HASH_TABLE_INIT (INTERNAL_MEM_ROOTS_TABLE, INTERNAL_MEM_ROOT_RECORD, sizeof (RootRecord), mono_aligned_addr_hash, NULL)
492 static mword roots_size = 0; /* amount of memory in the root set */
494 #define GC_ROOT_NUM 32
497 void *objects [GC_ROOT_NUM];
498 int root_types [GC_ROOT_NUM];
499 uintptr_t extra_info [GC_ROOT_NUM];
503 notify_gc_roots (GCRootReport *report)
507 mono_profiler_gc_roots (report->count, report->objects, report->root_types, report->extra_info);
512 add_profile_gc_root (GCRootReport *report, void *object, int rtype, uintptr_t extra_info)
514 if (report->count == GC_ROOT_NUM)
515 notify_gc_roots (report);
516 report->objects [report->count] = object;
517 report->root_types [report->count] = rtype;
518 report->extra_info [report->count++] = (uintptr_t)((MonoVTable*)LOAD_VTABLE (object))->klass;
521 MonoNativeTlsKey thread_info_key;
523 #ifdef HAVE_KW_THREAD
524 __thread SgenThreadInfo *thread_info;
525 __thread gpointer *store_remset_buffer;
526 __thread long store_remset_buffer_index;
527 __thread char *stack_end;
528 __thread long *store_remset_buffer_index_addr;
531 /* The size of a TLAB */
532 /* The bigger the value, the less often we have to go to the slow path to allocate a new
533 * one, but the more space is wasted by threads not allocating much memory.
535 * FIXME: Make this self-tuning for each thread.
537 guint32 tlab_size = (1024 * 4);
539 #define MAX_SMALL_OBJ_SIZE SGEN_MAX_SMALL_OBJ_SIZE
541 /* Functions supplied by the runtime to be called by the GC */
542 static MonoGCCallbacks gc_callbacks;
544 #define ALLOC_ALIGN SGEN_ALLOC_ALIGN
545 #define ALLOC_ALIGN_BITS SGEN_ALLOC_ALIGN_BITS
547 #define ALIGN_UP SGEN_ALIGN_UP
549 #define MOVED_OBJECTS_NUM 64
550 static void *moved_objects [MOVED_OBJECTS_NUM];
551 static int moved_objects_idx = 0;
553 /* Vtable of the objects used to fill out nursery fragments before a collection */
554 static MonoVTable *array_fill_vtable;
556 #ifdef SGEN_DEBUG_INTERNAL_ALLOC
557 MonoNativeThreadId main_gc_thread = NULL;
561 * ######################################################################
562 * ######## Heap size accounting
563 * ######################################################################
566 static mword max_heap_size = ((mword)0)- ((mword)1);
567 static mword soft_heap_limit = ((mword)0) - ((mword)1);
568 static mword allocated_heap;
570 /*Object was pinned during the current collection*/
571 static mword objects_pinned;
574 sgen_release_space (mword size, int space)
576 allocated_heap -= size;
580 available_free_space (void)
582 return max_heap_size - MIN (allocated_heap, max_heap_size);
586 sgen_try_alloc_space (mword size, int space)
588 if (available_free_space () < size)
591 allocated_heap += size;
592 mono_runtime_resource_check_limit (MONO_RESOURCE_GC_HEAP, allocated_heap);
597 init_heap_size_limits (glong max_heap, glong soft_limit)
600 soft_heap_limit = soft_limit;
605 if (max_heap < soft_limit) {
606 fprintf (stderr, "max-heap-size must be at least as large as soft-heap-limit.\n");
610 if (max_heap < sgen_nursery_size * 4) {
611 fprintf (stderr, "max-heap-size must be at least 4 times larger than nursery size.\n");
614 max_heap_size = max_heap - sgen_nursery_size;
618 * ######################################################################
619 * ######## Macros and function declarations.
620 * ######################################################################
624 align_pointer (void *ptr)
626 mword p = (mword)ptr;
627 p += sizeof (gpointer) - 1;
628 p &= ~ (sizeof (gpointer) - 1);
632 typedef SgenGrayQueue GrayQueue;
634 /* forward declarations */
635 static int stop_world (int generation);
636 static int restart_world (int generation);
637 static void scan_thread_data (void *start_nursery, void *end_nursery, gboolean precise, GrayQueue *queue);
638 static void scan_from_registered_roots (CopyOrMarkObjectFunc copy_func, char *addr_start, char *addr_end, int root_type, GrayQueue *queue);
639 static void scan_finalizer_entries (CopyOrMarkObjectFunc copy_func, FinalizeReadyEntry *list, GrayQueue *queue);
640 static void report_finalizer_roots (void);
641 static void report_registered_roots (void);
642 static void find_pinning_ref_from_thread (char *obj, size_t size);
643 static void update_current_thread_stack (void *start);
644 static void collect_bridge_objects (CopyOrMarkObjectFunc copy_func, char *start, char *end, int generation, GrayQueue *queue);
645 static void finalize_in_range (CopyOrMarkObjectFunc copy_func, char *start, char *end, int generation, GrayQueue *queue);
646 static void process_fin_stage_entries (void);
647 static void null_link_in_range (CopyOrMarkObjectFunc copy_func, char *start, char *end, int generation, gboolean before_finalization, GrayQueue *queue);
648 static void null_links_for_domain (MonoDomain *domain, int generation);
649 static void process_dislink_stage_entries (void);
651 static void pin_from_roots (void *start_nursery, void *end_nursery, GrayQueue *queue);
652 static int pin_objects_from_addresses (GCMemSection *section, void **start, void **end, void *start_nursery, void *end_nursery, GrayQueue *queue);
653 static void finish_gray_stack (char *start_addr, char *end_addr, int generation, GrayQueue *queue);
654 static gboolean need_major_collection (mword space_needed);
655 static void major_collection (const char *reason);
657 static void mono_gc_register_disappearing_link (MonoObject *obj, void **link, gboolean track, gboolean in_gc);
658 static gboolean mono_gc_is_critical_method (MonoMethod *method);
660 void mono_gc_scan_for_specific_ref (MonoObject *key, gboolean precise);
662 static void init_stats (void);
664 static int mark_ephemerons_in_range (CopyOrMarkObjectFunc copy_func, char *start, char *end, GrayQueue *queue);
665 static void clear_unreachable_ephemerons (CopyOrMarkObjectFunc copy_func, char *start, char *end, GrayQueue *queue);
666 static void null_ephemerons_for_domain (MonoDomain *domain);
668 SgenObjectOperations current_object_ops;
669 SgenMajorCollector major_collector;
670 SgenMinorCollector sgen_minor_collector;
671 static GrayQueue gray_queue;
673 static SgenRemeberedSet remset;
676 #define WORKERS_DISTRIBUTE_GRAY_QUEUE (sgen_collection_is_parallel () ? sgen_workers_get_distribute_gray_queue () : &gray_queue)
678 static SgenGrayQueue*
679 sgen_workers_get_job_gray_queue (WorkerData *worker_data)
681 return worker_data ? &worker_data->private_gray_queue : WORKERS_DISTRIBUTE_GRAY_QUEUE;
685 is_xdomain_ref_allowed (gpointer *ptr, char *obj, MonoDomain *domain)
687 MonoObject *o = (MonoObject*)(obj);
688 MonoObject *ref = (MonoObject*)*(ptr);
689 int offset = (char*)(ptr) - (char*)o;
691 if (o->vtable->klass == mono_defaults.thread_class && offset == G_STRUCT_OFFSET (MonoThread, internal_thread))
693 if (o->vtable->klass == mono_defaults.internal_thread_class && offset == G_STRUCT_OFFSET (MonoInternalThread, current_appcontext))
695 if (mono_class_has_parent_fast (o->vtable->klass, mono_defaults.real_proxy_class) &&
696 offset == G_STRUCT_OFFSET (MonoRealProxy, unwrapped_server))
698 /* Thread.cached_culture_info */
699 if (!strcmp (ref->vtable->klass->name_space, "System.Globalization") &&
700 !strcmp (ref->vtable->klass->name, "CultureInfo") &&
701 !strcmp(o->vtable->klass->name_space, "System") &&
702 !strcmp(o->vtable->klass->name, "Object[]"))
705 * 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
706 * at System.IO.MemoryStream..ctor (byte[]) [0x00017] in /home/schani/Work/novell/trunk/mcs/class/corlib/System.IO/MemoryStream.cs:81
707 * at (wrapper remoting-invoke-with-check) System.IO.MemoryStream..ctor (byte[]) <IL 0x00020, 0xffffffff>
708 * at System.Runtime.Remoting.Messaging.CADMethodCallMessage.GetArguments () [0x0000d] in /home/schani/Work/novell/trunk/mcs/class/corlib/System.Runtime.Remoting.Messaging/CADMessages.cs:327
709 * 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
710 * 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
711 * at (wrapper remoting-invoke-with-check) System.AppDomain.ProcessMessageInDomain (byte[],System.Runtime.Remoting.Messaging.CADMethodCallMessage,byte[]&,System.Runtime.Remoting.Messaging.CADMethodReturnMessage&) <IL 0x0003d, 0xffffffff>
712 * 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
713 * at (wrapper runtime-invoke) object.runtime_invoke_CrossAppDomainSink/ProcessMessageRes_object_object (object,intptr,intptr,intptr) <IL 0x0004c, 0xffffffff>
715 if (!strcmp (ref->vtable->klass->name_space, "System") &&
716 !strcmp (ref->vtable->klass->name, "Byte[]") &&
717 !strcmp (o->vtable->klass->name_space, "System.IO") &&
718 !strcmp (o->vtable->klass->name, "MemoryStream"))
720 /* append_job() in threadpool.c */
721 if (!strcmp (ref->vtable->klass->name_space, "System.Runtime.Remoting.Messaging") &&
722 !strcmp (ref->vtable->klass->name, "AsyncResult") &&
723 !strcmp (o->vtable->klass->name_space, "System") &&
724 !strcmp (o->vtable->klass->name, "Object[]") &&
725 mono_thread_pool_is_queue_array ((MonoArray*) o))
731 check_reference_for_xdomain (gpointer *ptr, char *obj, MonoDomain *domain)
733 MonoObject *o = (MonoObject*)(obj);
734 MonoObject *ref = (MonoObject*)*(ptr);
735 int offset = (char*)(ptr) - (char*)o;
737 MonoClassField *field;
740 if (!ref || ref->vtable->domain == domain)
742 if (is_xdomain_ref_allowed (ptr, obj, domain))
746 for (class = o->vtable->klass; class; class = class->parent) {
749 for (i = 0; i < class->field.count; ++i) {
750 if (class->fields[i].offset == offset) {
751 field = &class->fields[i];
759 if (ref->vtable->klass == mono_defaults.string_class)
760 str = mono_string_to_utf8 ((MonoString*)ref);
763 g_print ("xdomain reference in %p (%s.%s) at offset %d (%s) to %p (%s.%s) (%s) - pointed to by:\n",
764 o, o->vtable->klass->name_space, o->vtable->klass->name,
765 offset, field ? field->name : "",
766 ref, ref->vtable->klass->name_space, ref->vtable->klass->name, str ? str : "");
767 mono_gc_scan_for_specific_ref (o, TRUE);
773 #define HANDLE_PTR(ptr,obj) check_reference_for_xdomain ((ptr), (obj), domain)
776 scan_object_for_xdomain_refs (char *start, mword size, void *data)
778 MonoDomain *domain = ((MonoObject*)start)->vtable->domain;
780 #include "sgen-scan-object.h"
783 static gboolean scan_object_for_specific_ref_precise = TRUE;
786 #define HANDLE_PTR(ptr,obj) do { \
787 if ((MonoObject*)*(ptr) == key) { \
788 g_print ("found ref to %p in object %p (%s) at offset %td\n", \
789 key, (obj), safe_name ((obj)), ((char*)(ptr) - (char*)(obj))); \
794 scan_object_for_specific_ref (char *start, MonoObject *key)
798 if ((forwarded = SGEN_OBJECT_IS_FORWARDED (start)))
801 if (scan_object_for_specific_ref_precise) {
802 #include "sgen-scan-object.h"
804 mword *words = (mword*)start;
805 size_t size = safe_object_get_size ((MonoObject*)start);
807 for (i = 0; i < size / sizeof (mword); ++i) {
808 if (words [i] == (mword)key) {
809 g_print ("found possible ref to %p in object %p (%s) at offset %td\n",
810 key, start, safe_name (start), i * sizeof (mword));
817 sgen_scan_area_with_callback (char *start, char *end, IterateObjectCallbackFunc callback, void *data, gboolean allow_flags)
819 while (start < end) {
823 if (!*(void**)start) {
824 start += sizeof (void*); /* should be ALLOC_ALIGN, really */
829 if (!(obj = SGEN_OBJECT_IS_FORWARDED (start)))
835 size = ALIGN_UP (safe_object_get_size ((MonoObject*)obj));
837 if ((MonoVTable*)SGEN_LOAD_VTABLE (obj) != array_fill_vtable)
838 callback (obj, size, data);
845 scan_object_for_specific_ref_callback (char *obj, size_t size, MonoObject *key)
847 scan_object_for_specific_ref (obj, key);
851 check_root_obj_specific_ref (RootRecord *root, MonoObject *key, MonoObject *obj)
855 g_print ("found ref to %p in root record %p\n", key, root);
858 static MonoObject *check_key = NULL;
859 static RootRecord *check_root = NULL;
862 check_root_obj_specific_ref_from_marker (void **obj)
864 check_root_obj_specific_ref (check_root, check_key, *obj);
868 scan_roots_for_specific_ref (MonoObject *key, int root_type)
874 SGEN_HASH_TABLE_FOREACH (&roots_hash [root_type], start_root, root) {
875 mword desc = root->root_desc;
879 switch (desc & ROOT_DESC_TYPE_MASK) {
880 case ROOT_DESC_BITMAP:
881 desc >>= ROOT_DESC_TYPE_SHIFT;
884 check_root_obj_specific_ref (root, key, *start_root);
889 case ROOT_DESC_COMPLEX: {
890 gsize *bitmap_data = sgen_get_complex_descriptor_bitmap (desc);
891 int bwords = (*bitmap_data) - 1;
892 void **start_run = start_root;
894 while (bwords-- > 0) {
895 gsize bmap = *bitmap_data++;
896 void **objptr = start_run;
899 check_root_obj_specific_ref (root, key, *objptr);
903 start_run += GC_BITS_PER_WORD;
907 case ROOT_DESC_USER: {
908 MonoGCRootMarkFunc marker = sgen_get_user_descriptor_func (desc);
909 marker (start_root, check_root_obj_specific_ref_from_marker);
912 case ROOT_DESC_RUN_LEN:
913 g_assert_not_reached ();
915 g_assert_not_reached ();
917 } SGEN_HASH_TABLE_FOREACH_END;
924 mono_gc_scan_for_specific_ref (MonoObject *key, gboolean precise)
929 scan_object_for_specific_ref_precise = precise;
931 sgen_scan_area_with_callback (nursery_section->data, nursery_section->end_data,
932 (IterateObjectCallbackFunc)scan_object_for_specific_ref_callback, key, TRUE);
934 major_collector.iterate_objects (TRUE, TRUE, (IterateObjectCallbackFunc)scan_object_for_specific_ref_callback, key);
936 sgen_los_iterate_objects ((IterateObjectCallbackFunc)scan_object_for_specific_ref_callback, key);
938 scan_roots_for_specific_ref (key, ROOT_TYPE_NORMAL);
939 scan_roots_for_specific_ref (key, ROOT_TYPE_WBARRIER);
941 SGEN_HASH_TABLE_FOREACH (&roots_hash [ROOT_TYPE_PINNED], ptr, root) {
942 while (ptr < (void**)root->end_root) {
943 check_root_obj_specific_ref (root, *ptr, key);
946 } SGEN_HASH_TABLE_FOREACH_END;
950 need_remove_object_for_domain (char *start, MonoDomain *domain)
952 if (mono_object_domain (start) == domain) {
953 DEBUG (4, fprintf (gc_debug_file, "Need to cleanup object %p\n", start));
954 binary_protocol_cleanup (start, (gpointer)LOAD_VTABLE (start), safe_object_get_size ((MonoObject*)start));
961 process_object_for_domain_clearing (char *start, MonoDomain *domain)
963 GCVTable *vt = (GCVTable*)LOAD_VTABLE (start);
964 if (vt->klass == mono_defaults.internal_thread_class)
965 g_assert (mono_object_domain (start) == mono_get_root_domain ());
966 /* The object could be a proxy for an object in the domain
968 if (mono_class_has_parent_fast (vt->klass, mono_defaults.real_proxy_class)) {
969 MonoObject *server = ((MonoRealProxy*)start)->unwrapped_server;
971 /* The server could already have been zeroed out, so
972 we need to check for that, too. */
973 if (server && (!LOAD_VTABLE (server) || mono_object_domain (server) == domain)) {
974 DEBUG (4, fprintf (gc_debug_file, "Cleaning up remote pointer in %p to object %p\n",
976 ((MonoRealProxy*)start)->unwrapped_server = NULL;
981 static MonoDomain *check_domain = NULL;
984 check_obj_not_in_domain (void **o)
986 g_assert (((MonoObject*)(*o))->vtable->domain != check_domain);
990 scan_for_registered_roots_in_domain (MonoDomain *domain, int root_type)
994 check_domain = domain;
995 SGEN_HASH_TABLE_FOREACH (&roots_hash [root_type], start_root, root) {
996 mword desc = root->root_desc;
998 /* The MonoDomain struct is allowed to hold
999 references to objects in its own domain. */
1000 if (start_root == (void**)domain)
1003 switch (desc & ROOT_DESC_TYPE_MASK) {
1004 case ROOT_DESC_BITMAP:
1005 desc >>= ROOT_DESC_TYPE_SHIFT;
1007 if ((desc & 1) && *start_root)
1008 check_obj_not_in_domain (*start_root);
1013 case ROOT_DESC_COMPLEX: {
1014 gsize *bitmap_data = sgen_get_complex_descriptor_bitmap (desc);
1015 int bwords = (*bitmap_data) - 1;
1016 void **start_run = start_root;
1018 while (bwords-- > 0) {
1019 gsize bmap = *bitmap_data++;
1020 void **objptr = start_run;
1022 if ((bmap & 1) && *objptr)
1023 check_obj_not_in_domain (*objptr);
1027 start_run += GC_BITS_PER_WORD;
1031 case ROOT_DESC_USER: {
1032 MonoGCRootMarkFunc marker = sgen_get_user_descriptor_func (desc);
1033 marker (start_root, check_obj_not_in_domain);
1036 case ROOT_DESC_RUN_LEN:
1037 g_assert_not_reached ();
1039 g_assert_not_reached ();
1041 } SGEN_HASH_TABLE_FOREACH_END;
1043 check_domain = NULL;
1047 check_for_xdomain_refs (void)
1051 sgen_scan_area_with_callback (nursery_section->data, nursery_section->end_data,
1052 (IterateObjectCallbackFunc)scan_object_for_xdomain_refs, NULL, FALSE);
1054 major_collector.iterate_objects (TRUE, TRUE, (IterateObjectCallbackFunc)scan_object_for_xdomain_refs, NULL);
1056 for (bigobj = los_object_list; bigobj; bigobj = bigobj->next)
1057 scan_object_for_xdomain_refs (bigobj->data, bigobj->size, NULL);
1061 clear_domain_process_object (char *obj, MonoDomain *domain)
1065 process_object_for_domain_clearing (obj, domain);
1066 remove = need_remove_object_for_domain (obj, domain);
1068 if (remove && ((MonoObject*)obj)->synchronisation) {
1069 void **dislink = mono_monitor_get_object_monitor_weak_link ((MonoObject*)obj);
1071 mono_gc_register_disappearing_link (NULL, dislink, FALSE, TRUE);
1078 clear_domain_process_minor_object_callback (char *obj, size_t size, MonoDomain *domain)
1080 if (clear_domain_process_object (obj, domain))
1081 memset (obj, 0, size);
1085 clear_domain_process_major_object_callback (char *obj, size_t size, MonoDomain *domain)
1087 clear_domain_process_object (obj, domain);
1091 clear_domain_free_major_non_pinned_object_callback (char *obj, size_t size, MonoDomain *domain)
1093 if (need_remove_object_for_domain (obj, domain))
1094 major_collector.free_non_pinned_object (obj, size);
1098 clear_domain_free_major_pinned_object_callback (char *obj, size_t size, MonoDomain *domain)
1100 if (need_remove_object_for_domain (obj, domain))
1101 major_collector.free_pinned_object (obj, size);
1105 * When appdomains are unloaded we can easily remove objects that have finalizers,
1106 * but all the others could still be present in random places on the heap.
1107 * We need a sweep to get rid of them even though it's going to be costly
1109 * The reason we need to remove them is because we access the vtable and class
1110 * structures to know the object size and the reference bitmap: once the domain is
1111 * unloaded the point to random memory.
1114 mono_gc_clear_domain (MonoDomain * domain)
1116 LOSObject *bigobj, *prev;
1121 process_fin_stage_entries ();
1122 process_dislink_stage_entries ();
1124 sgen_clear_nursery_fragments ();
1126 if (xdomain_checks && domain != mono_get_root_domain ()) {
1127 scan_for_registered_roots_in_domain (domain, ROOT_TYPE_NORMAL);
1128 scan_for_registered_roots_in_domain (domain, ROOT_TYPE_WBARRIER);
1129 check_for_xdomain_refs ();
1132 sgen_scan_area_with_callback (nursery_section->data, nursery_section->end_data,
1133 (IterateObjectCallbackFunc)clear_domain_process_minor_object_callback, domain, FALSE);
1135 /*Ephemerons and dislinks must be processed before LOS since they might end up pointing
1136 to memory returned to the OS.*/
1137 null_ephemerons_for_domain (domain);
1139 for (i = GENERATION_NURSERY; i < GENERATION_MAX; ++i)
1140 null_links_for_domain (domain, i);
1142 /* We need two passes over major and large objects because
1143 freeing such objects might give their memory back to the OS
1144 (in the case of large objects) or obliterate its vtable
1145 (pinned objects with major-copying or pinned and non-pinned
1146 objects with major-mark&sweep), but we might need to
1147 dereference a pointer from an object to another object if
1148 the first object is a proxy. */
1149 major_collector.iterate_objects (TRUE, TRUE, (IterateObjectCallbackFunc)clear_domain_process_major_object_callback, domain);
1150 for (bigobj = los_object_list; bigobj; bigobj = bigobj->next)
1151 clear_domain_process_object (bigobj->data, domain);
1154 for (bigobj = los_object_list; bigobj;) {
1155 if (need_remove_object_for_domain (bigobj->data, domain)) {
1156 LOSObject *to_free = bigobj;
1158 prev->next = bigobj->next;
1160 los_object_list = bigobj->next;
1161 bigobj = bigobj->next;
1162 DEBUG (4, fprintf (gc_debug_file, "Freeing large object %p\n",
1164 sgen_los_free_object (to_free);
1168 bigobj = bigobj->next;
1170 major_collector.iterate_objects (TRUE, FALSE, (IterateObjectCallbackFunc)clear_domain_free_major_non_pinned_object_callback, domain);
1171 major_collector.iterate_objects (FALSE, TRUE, (IterateObjectCallbackFunc)clear_domain_free_major_pinned_object_callback, domain);
1173 if (G_UNLIKELY (do_pin_stats)) {
1174 if (domain == mono_get_root_domain ())
1175 sgen_pin_stats_print_class_stats ();
1182 * sgen_add_to_global_remset:
1184 * The global remset contains locations which point into newspace after
1185 * a minor collection. This can happen if the objects they point to are pinned.
1187 * LOCKING: If called from a parallel collector, the global remset
1188 * lock must be held. For serial collectors that is not necessary.
1191 sgen_add_to_global_remset (gpointer ptr)
1193 remset.record_pointer (ptr);
1197 * sgen_drain_gray_stack:
1199 * Scan objects in the gray stack until the stack is empty. This should be called
1200 * frequently after each object is copied, to achieve better locality and cache
1204 sgen_drain_gray_stack (GrayQueue *queue, int max_objs)
1207 ScanObjectFunc scan_func = current_object_ops.scan_object;
1209 if (max_objs == -1) {
1211 GRAY_OBJECT_DEQUEUE (queue, obj);
1214 DEBUG (9, fprintf (gc_debug_file, "Precise gray object scan %p (%s)\n", obj, safe_name (obj)));
1215 scan_func (obj, queue);
1221 for (i = 0; i != max_objs; ++i) {
1222 GRAY_OBJECT_DEQUEUE (queue, obj);
1225 DEBUG (9, fprintf (gc_debug_file, "Precise gray object scan %p (%s)\n", obj, safe_name (obj)));
1226 scan_func (obj, queue);
1228 } while (max_objs < 0);
1234 * Addresses from start to end are already sorted. This function finds
1235 * the object header for each address and pins the object. The
1236 * addresses must be inside the passed section. The (start of the)
1237 * address array is overwritten with the addresses of the actually
1238 * pinned objects. Return the number of pinned objects.
1241 pin_objects_from_addresses (GCMemSection *section, void **start, void **end, void *start_nursery, void *end_nursery, GrayQueue *queue)
1246 void *last_obj = NULL;
1247 size_t last_obj_size = 0;
1250 void **definitely_pinned = start;
1252 sgen_nursery_allocator_prepare_for_pinning ();
1254 while (start < end) {
1256 /* the range check should be reduntant */
1257 if (addr != last && addr >= start_nursery && addr < end_nursery) {
1258 DEBUG (5, fprintf (gc_debug_file, "Considering pinning addr %p\n", addr));
1259 /* multiple pointers to the same object */
1260 if (addr >= last_obj && (char*)addr < (char*)last_obj + last_obj_size) {
1264 idx = ((char*)addr - (char*)section->data) / SCAN_START_SIZE;
1265 g_assert (idx < section->num_scan_start);
1266 search_start = (void*)section->scan_starts [idx];
1267 if (!search_start || search_start > addr) {
1270 search_start = section->scan_starts [idx];
1271 if (search_start && search_start <= addr)
1274 if (!search_start || search_start > addr)
1275 search_start = start_nursery;
1277 if (search_start < last_obj)
1278 search_start = (char*)last_obj + last_obj_size;
1279 /* now addr should be in an object a short distance from search_start
1280 * Note that search_start must point to zeroed mem or point to an object.
1284 if (!*(void**)search_start) {
1285 /* Consistency check */
1287 for (frag = nursery_fragments; frag; frag = frag->next) {
1288 if (search_start >= frag->fragment_start && search_start < frag->fragment_end)
1289 g_assert_not_reached ();
1293 search_start = (void*)ALIGN_UP ((mword)search_start + sizeof (gpointer));
1296 last_obj = search_start;
1297 last_obj_size = ALIGN_UP (safe_object_get_size ((MonoObject*)search_start));
1299 if (((MonoObject*)last_obj)->synchronisation == GINT_TO_POINTER (-1)) {
1300 /* Marks the beginning of a nursery fragment, skip */
1302 DEBUG (8, fprintf (gc_debug_file, "Pinned try match %p (%s), size %zd\n", last_obj, safe_name (last_obj), last_obj_size));
1303 if (addr >= search_start && (char*)addr < (char*)last_obj + last_obj_size) {
1304 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));
1305 binary_protocol_pin (search_start, (gpointer)LOAD_VTABLE (search_start), safe_object_get_size (search_start));
1306 pin_object (search_start);
1307 GRAY_OBJECT_ENQUEUE (queue, search_start);
1308 if (G_UNLIKELY (do_pin_stats))
1309 sgen_pin_stats_register_object (search_start, last_obj_size);
1310 definitely_pinned [count] = search_start;
1315 /* skip to the next object */
1316 search_start = (void*)((char*)search_start + last_obj_size);
1317 } while (search_start <= addr);
1318 /* we either pinned the correct object or we ignored the addr because
1319 * it points to unused zeroed memory.
1325 //printf ("effective pinned: %d (at the end: %d)\n", count, (char*)end_nursery - (char*)last);
1326 if (mono_profiler_get_events () & MONO_PROFILE_GC_ROOTS) {
1327 GCRootReport report;
1329 for (idx = 0; idx < count; ++idx)
1330 add_profile_gc_root (&report, definitely_pinned [idx], MONO_PROFILE_GC_ROOT_PINNING | MONO_PROFILE_GC_ROOT_MISC, 0);
1331 notify_gc_roots (&report);
1333 stat_pinned_objects += count;
1338 sgen_pin_objects_in_section (GCMemSection *section, GrayQueue *queue)
1340 int num_entries = section->pin_queue_num_entries;
1342 void **start = section->pin_queue_start;
1344 reduced_to = pin_objects_from_addresses (section, start, start + num_entries,
1345 section->data, section->next_data, queue);
1346 section->pin_queue_num_entries = reduced_to;
1348 section->pin_queue_start = NULL;
1354 sgen_pin_object (void *object, GrayQueue *queue)
1356 if (sgen_collection_is_parallel ()) {
1358 /*object arrives pinned*/
1359 sgen_pin_stage_ptr (object);
1363 SGEN_PIN_OBJECT (object);
1364 sgen_pin_stage_ptr (object);
1366 if (G_UNLIKELY (do_pin_stats))
1367 sgen_pin_stats_register_object (object, safe_object_get_size (object));
1369 GRAY_OBJECT_ENQUEUE (queue, object);
1370 binary_protocol_pin (object, (gpointer)LOAD_VTABLE (object), safe_object_get_size (object));
1374 sgen_parallel_pin_or_update (void **ptr, void *obj, MonoVTable *vt, SgenGrayQueue *queue)
1378 gboolean major_pinned = FALSE;
1380 if (sgen_ptr_in_nursery (obj)) {
1381 if (SGEN_CAS_PTR (obj, (void*)((mword)vt | SGEN_PINNED_BIT), vt) == vt) {
1382 sgen_pin_object (obj, queue);
1386 major_collector.pin_major_object (obj, queue);
1387 major_pinned = TRUE;
1390 vtable_word = *(mword*)obj;
1391 /*someone else forwarded it, update the pointer and bail out*/
1392 if (vtable_word & SGEN_FORWARDED_BIT) {
1393 *ptr = (void*)(vtable_word & ~SGEN_VTABLE_BITS_MASK);
1397 /*someone pinned it, nothing to do.*/
1398 if (vtable_word & SGEN_PINNED_BIT || major_pinned)
1403 /* Sort the addresses in array in increasing order.
1404 * Done using a by-the book heap sort. Which has decent and stable performance, is pretty cache efficient.
1407 sgen_sort_addresses (void **array, int size)
1412 for (i = 1; i < size; ++i) {
1415 int parent = (child - 1) / 2;
1417 if (array [parent] >= array [child])
1420 tmp = array [parent];
1421 array [parent] = array [child];
1422 array [child] = tmp;
1428 for (i = size - 1; i > 0; --i) {
1431 array [i] = array [0];
1437 while (root * 2 + 1 <= end) {
1438 int child = root * 2 + 1;
1440 if (child < end && array [child] < array [child + 1])
1442 if (array [root] >= array [child])
1446 array [root] = array [child];
1447 array [child] = tmp;
1455 * Scan the memory between start and end and queue values which could be pointers
1456 * to the area between start_nursery and end_nursery for later consideration.
1457 * Typically used for thread stacks.
1460 conservatively_pin_objects_from (void **start, void **end, void *start_nursery, void *end_nursery, int pin_type)
1463 while (start < end) {
1464 if (*start >= start_nursery && *start < end_nursery) {
1466 * *start can point to the middle of an object
1467 * note: should we handle pointing at the end of an object?
1468 * pinning in C# code disallows pointing at the end of an object
1469 * but there is some small chance that an optimizing C compiler
1470 * may keep the only reference to an object by pointing
1471 * at the end of it. We ignore this small chance for now.
1472 * Pointers to the end of an object are indistinguishable
1473 * from pointers to the start of the next object in memory
1474 * so if we allow that we'd need to pin two objects...
1475 * We queue the pointer in an array, the
1476 * array will then be sorted and uniqued. This way
1477 * we can coalesce several pinning pointers and it should
1478 * be faster since we'd do a memory scan with increasing
1479 * addresses. Note: we can align the address to the allocation
1480 * alignment, so the unique process is more effective.
1482 mword addr = (mword)*start;
1483 addr &= ~(ALLOC_ALIGN - 1);
1484 if (addr >= (mword)start_nursery && addr < (mword)end_nursery)
1485 sgen_pin_stage_ptr ((void*)addr);
1486 if (G_UNLIKELY (do_pin_stats)) {
1487 if (ptr_in_nursery ((void*)addr))
1488 sgen_pin_stats_register_address ((char*)addr, pin_type);
1490 DEBUG (6, if (count) fprintf (gc_debug_file, "Pinning address %p from %p\n", (void*)addr, start));
1495 DEBUG (7, if (count) fprintf (gc_debug_file, "found %d potential pinned heap pointers\n", count));
1499 * Debugging function: find in the conservative roots where @obj is being pinned.
1501 static G_GNUC_UNUSED void
1502 find_pinning_reference (char *obj, size_t size)
1506 char *endobj = obj + size;
1508 SGEN_HASH_TABLE_FOREACH (&roots_hash [ROOT_TYPE_NORMAL], start, root) {
1509 /* if desc is non-null it has precise info */
1510 if (!root->root_desc) {
1511 while (start < (char**)root->end_root) {
1512 if (*start >= obj && *start < endobj) {
1513 DEBUG (0, fprintf (gc_debug_file, "Object %p referenced in pinned roots %p-%p\n", obj, start, root->end_root));
1518 } SGEN_HASH_TABLE_FOREACH_END;
1520 find_pinning_ref_from_thread (obj, size);
1524 * The first thing we do in a collection is to identify pinned objects.
1525 * This function considers all the areas of memory that need to be
1526 * conservatively scanned.
1529 pin_from_roots (void *start_nursery, void *end_nursery, GrayQueue *queue)
1533 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));
1534 /* objects pinned from the API are inside these roots */
1535 SGEN_HASH_TABLE_FOREACH (&roots_hash [ROOT_TYPE_PINNED], start_root, root) {
1536 DEBUG (6, fprintf (gc_debug_file, "Pinned roots %p-%p\n", start_root, root->end_root));
1537 conservatively_pin_objects_from (start_root, (void**)root->end_root, start_nursery, end_nursery, PIN_TYPE_OTHER);
1538 } SGEN_HASH_TABLE_FOREACH_END;
1539 /* now deal with the thread stacks
1540 * in the future we should be able to conservatively scan only:
1541 * *) the cpu registers
1542 * *) the unmanaged stack frames
1543 * *) the _last_ managed stack frame
1544 * *) pointers slots in managed frames
1546 scan_thread_data (start_nursery, end_nursery, FALSE, queue);
1550 CopyOrMarkObjectFunc func;
1552 } UserCopyOrMarkData;
1554 static MonoNativeTlsKey user_copy_or_mark_key;
1557 init_user_copy_or_mark_key (void)
1559 mono_native_tls_alloc (&user_copy_or_mark_key, NULL);
1563 set_user_copy_or_mark_data (UserCopyOrMarkData *data)
1565 mono_native_tls_set_value (user_copy_or_mark_key, data);
1569 single_arg_user_copy_or_mark (void **obj)
1571 UserCopyOrMarkData *data = mono_native_tls_get_value (user_copy_or_mark_key);
1573 data->func (obj, data->queue);
1577 * The memory area from start_root to end_root contains pointers to objects.
1578 * Their position is precisely described by @desc (this means that the pointer
1579 * can be either NULL or the pointer to the start of an object).
1580 * This functions copies them to to_space updates them.
1582 * This function is not thread-safe!
1585 precisely_scan_objects_from (CopyOrMarkObjectFunc copy_func, void** start_root, void** end_root, char* n_start, char *n_end, mword desc, GrayQueue *queue)
1587 switch (desc & ROOT_DESC_TYPE_MASK) {
1588 case ROOT_DESC_BITMAP:
1589 desc >>= ROOT_DESC_TYPE_SHIFT;
1591 if ((desc & 1) && *start_root) {
1592 copy_func (start_root, queue);
1593 DEBUG (9, fprintf (gc_debug_file, "Overwrote root at %p with %p\n", start_root, *start_root));
1594 sgen_drain_gray_stack (queue, -1);
1600 case ROOT_DESC_COMPLEX: {
1601 gsize *bitmap_data = sgen_get_complex_descriptor_bitmap (desc);
1602 int bwords = (*bitmap_data) - 1;
1603 void **start_run = start_root;
1605 while (bwords-- > 0) {
1606 gsize bmap = *bitmap_data++;
1607 void **objptr = start_run;
1609 if ((bmap & 1) && *objptr) {
1610 copy_func (objptr, queue);
1611 DEBUG (9, fprintf (gc_debug_file, "Overwrote root at %p with %p\n", objptr, *objptr));
1612 sgen_drain_gray_stack (queue, -1);
1617 start_run += GC_BITS_PER_WORD;
1621 case ROOT_DESC_USER: {
1622 UserCopyOrMarkData data = { copy_func, queue };
1623 MonoGCRootMarkFunc marker = sgen_get_user_descriptor_func (desc);
1624 set_user_copy_or_mark_data (&data);
1625 marker (start_root, single_arg_user_copy_or_mark);
1626 set_user_copy_or_mark_data (NULL);
1629 case ROOT_DESC_RUN_LEN:
1630 g_assert_not_reached ();
1632 g_assert_not_reached ();
1637 reset_heap_boundaries (void)
1639 lowest_heap_address = ~(mword)0;
1640 highest_heap_address = 0;
1644 sgen_update_heap_boundaries (mword low, mword high)
1649 old = lowest_heap_address;
1652 } while (SGEN_CAS_PTR ((gpointer*)&lowest_heap_address, (gpointer)low, (gpointer)old) != (gpointer)old);
1655 old = highest_heap_address;
1658 } while (SGEN_CAS_PTR ((gpointer*)&highest_heap_address, (gpointer)high, (gpointer)old) != (gpointer)old);
1661 static unsigned long
1662 prot_flags_for_activate (int activate)
1664 unsigned long prot_flags = activate? MONO_MMAP_READ|MONO_MMAP_WRITE: MONO_MMAP_NONE;
1665 return prot_flags | MONO_MMAP_PRIVATE | MONO_MMAP_ANON;
1669 * Allocate a big chunk of memory from the OS (usually 64KB to several megabytes).
1670 * This must not require any lock.
1673 sgen_alloc_os_memory (size_t size, int activate)
1675 void *ptr = mono_valloc (0, size, prot_flags_for_activate (activate));
1678 total_alloc += size;
1683 /* size must be a power of 2 */
1685 sgen_alloc_os_memory_aligned (mword size, mword alignment, gboolean activate)
1687 void *ptr = mono_valloc_aligned (size, alignment, prot_flags_for_activate (activate));
1690 total_alloc += size;
1696 * Free the memory returned by sgen_alloc_os_memory (), returning it to the OS.
1699 sgen_free_os_memory (void *addr, size_t size)
1701 mono_vfree (addr, size);
1703 total_alloc -= size;
1707 * Allocate and setup the data structures needed to be able to allocate objects
1708 * in the nursery. The nursery is stored in nursery_section.
1711 alloc_nursery (void)
1713 GCMemSection *section;
1718 if (nursery_section)
1720 DEBUG (2, fprintf (gc_debug_file, "Allocating nursery size: %lu\n", (unsigned long)sgen_nursery_size));
1721 /* later we will alloc a larger area for the nursery but only activate
1722 * what we need. The rest will be used as expansion if we have too many pinned
1723 * objects in the existing nursery.
1725 /* FIXME: handle OOM */
1726 section = sgen_alloc_internal (INTERNAL_MEM_SECTION);
1728 alloc_size = sgen_nursery_size;
1729 #ifdef SGEN_ALIGN_NURSERY
1730 data = major_collector.alloc_heap (alloc_size, alloc_size, DEFAULT_NURSERY_BITS);
1732 data = major_collector.alloc_heap (alloc_size, 0, DEFAULT_NURSERY_BITS);
1734 sgen_update_heap_boundaries ((mword)data, (mword)(data + sgen_nursery_size));
1735 DEBUG (4, fprintf (gc_debug_file, "Expanding nursery size (%p-%p): %lu, total: %lu\n", data, data + alloc_size, (unsigned long)sgen_nursery_size, (unsigned long)total_alloc));
1736 section->data = section->next_data = data;
1737 section->size = alloc_size;
1738 section->end_data = data + sgen_nursery_size;
1739 scan_starts = (alloc_size + SCAN_START_SIZE - 1) / SCAN_START_SIZE;
1740 section->scan_starts = sgen_alloc_internal_dynamic (sizeof (char*) * scan_starts, INTERNAL_MEM_SCAN_STARTS);
1741 section->num_scan_start = scan_starts;
1742 section->block.role = MEMORY_ROLE_GEN0;
1743 section->block.next = NULL;
1745 nursery_section = section;
1747 sgen_nursery_allocator_set_nursery_bounds (data, data + sgen_nursery_size);
1751 mono_gc_get_nursery (int *shift_bits, size_t *size)
1753 *size = sgen_nursery_size;
1754 #ifdef SGEN_ALIGN_NURSERY
1755 *shift_bits = DEFAULT_NURSERY_BITS;
1759 return sgen_get_nursery_start ();
1763 mono_gc_set_current_thread_appdomain (MonoDomain *domain)
1765 SgenThreadInfo *info = mono_thread_info_current ();
1767 /* Could be called from sgen_thread_unregister () with a NULL info */
1770 info->stopped_domain = domain;
1775 mono_gc_precise_stack_mark_enabled (void)
1777 return !conservative_stack_mark;
1781 mono_gc_get_logfile (void)
1783 return sgen_get_logfile ();
1787 report_finalizer_roots_list (FinalizeReadyEntry *list)
1789 GCRootReport report;
1790 FinalizeReadyEntry *fin;
1793 for (fin = list; fin; fin = fin->next) {
1796 add_profile_gc_root (&report, fin->object, MONO_PROFILE_GC_ROOT_FINALIZER, 0);
1798 notify_gc_roots (&report);
1802 report_finalizer_roots (void)
1804 report_finalizer_roots_list (fin_ready_list);
1805 report_finalizer_roots_list (critical_fin_list);
1808 static GCRootReport *root_report;
1811 single_arg_report_root (void **obj)
1814 add_profile_gc_root (root_report, *obj, MONO_PROFILE_GC_ROOT_OTHER, 0);
1818 precisely_report_roots_from (GCRootReport *report, void** start_root, void** end_root, mword desc)
1820 switch (desc & ROOT_DESC_TYPE_MASK) {
1821 case ROOT_DESC_BITMAP:
1822 desc >>= ROOT_DESC_TYPE_SHIFT;
1824 if ((desc & 1) && *start_root) {
1825 add_profile_gc_root (report, *start_root, MONO_PROFILE_GC_ROOT_OTHER, 0);
1831 case ROOT_DESC_COMPLEX: {
1832 gsize *bitmap_data = sgen_get_complex_descriptor_bitmap (desc);
1833 int bwords = (*bitmap_data) - 1;
1834 void **start_run = start_root;
1836 while (bwords-- > 0) {
1837 gsize bmap = *bitmap_data++;
1838 void **objptr = start_run;
1840 if ((bmap & 1) && *objptr) {
1841 add_profile_gc_root (report, *objptr, MONO_PROFILE_GC_ROOT_OTHER, 0);
1846 start_run += GC_BITS_PER_WORD;
1850 case ROOT_DESC_USER: {
1851 MonoGCRootMarkFunc marker = sgen_get_user_descriptor_func (desc);
1852 root_report = report;
1853 marker (start_root, single_arg_report_root);
1856 case ROOT_DESC_RUN_LEN:
1857 g_assert_not_reached ();
1859 g_assert_not_reached ();
1864 report_registered_roots_by_type (int root_type)
1866 GCRootReport report;
1870 SGEN_HASH_TABLE_FOREACH (&roots_hash [root_type], start_root, root) {
1871 DEBUG (6, fprintf (gc_debug_file, "Precise root scan %p-%p (desc: %p)\n", start_root, root->end_root, (void*)root->root_desc));
1872 precisely_report_roots_from (&report, start_root, (void**)root->end_root, root->root_desc);
1873 } SGEN_HASH_TABLE_FOREACH_END;
1874 notify_gc_roots (&report);
1878 report_registered_roots (void)
1880 report_registered_roots_by_type (ROOT_TYPE_NORMAL);
1881 report_registered_roots_by_type (ROOT_TYPE_WBARRIER);
1885 scan_finalizer_entries (CopyOrMarkObjectFunc copy_func, FinalizeReadyEntry *list, GrayQueue *queue)
1887 FinalizeReadyEntry *fin;
1889 for (fin = list; fin; fin = fin->next) {
1892 DEBUG (5, fprintf (gc_debug_file, "Scan of fin ready object: %p (%s)\n", fin->object, safe_name (fin->object)));
1893 copy_func (&fin->object, queue);
1898 generation_name (int generation)
1900 switch (generation) {
1901 case GENERATION_NURSERY: return "nursery";
1902 case GENERATION_OLD: return "old";
1903 default: g_assert_not_reached ();
1909 stw_bridge_process (void)
1911 sgen_bridge_processing_stw_step ();
1915 bridge_process (void)
1917 sgen_bridge_processing_finish ();
1920 SgenObjectOperations *
1921 sgen_get_current_object_ops (void){
1922 return ¤t_object_ops;
1927 finish_gray_stack (char *start_addr, char *end_addr, int generation, GrayQueue *queue)
1931 int done_with_ephemerons, ephemeron_rounds = 0;
1932 CopyOrMarkObjectFunc copy_func = current_object_ops.copy_or_mark_object;
1935 * We copied all the reachable objects. Now it's the time to copy
1936 * the objects that were not referenced by the roots, but by the copied objects.
1937 * we built a stack of objects pointed to by gray_start: they are
1938 * additional roots and we may add more items as we go.
1939 * We loop until gray_start == gray_objects which means no more objects have
1940 * been added. Note this is iterative: no recursion is involved.
1941 * We need to walk the LO list as well in search of marked big objects
1942 * (use a flag since this is needed only on major collections). We need to loop
1943 * here as well, so keep a counter of marked LO (increasing it in copy_object).
1944 * To achieve better cache locality and cache usage, we drain the gray stack
1945 * frequently, after each object is copied, and just finish the work here.
1947 sgen_drain_gray_stack (queue, -1);
1949 DEBUG (2, fprintf (gc_debug_file, "%s generation done\n", generation_name (generation)));
1952 Reset bridge data, we might have lingering data from a previous collection if this is a major
1953 collection trigged by minor overflow.
1955 We must reset the gathered bridges since their original block might be evacuated due to major
1956 fragmentation in the meanwhile and the bridge code should not have to deal with that.
1958 sgen_bridge_reset_data ();
1961 * Walk the ephemeron tables marking all values with reachable keys. This must be completely done
1962 * before processing finalizable objects or non-tracking weak hamdle to avoid finalizing/clearing
1963 * objects that are in fact reachable.
1965 done_with_ephemerons = 0;
1967 done_with_ephemerons = mark_ephemerons_in_range (copy_func, start_addr, end_addr, queue);
1968 sgen_drain_gray_stack (queue, -1);
1970 } while (!done_with_ephemerons);
1972 sgen_scan_togglerefs (copy_func, start_addr, end_addr, queue);
1973 if (generation == GENERATION_OLD)
1974 sgen_scan_togglerefs (copy_func, sgen_get_nursery_start (), sgen_get_nursery_end (), queue);
1976 if (sgen_need_bridge_processing ()) {
1977 collect_bridge_objects (copy_func, start_addr, end_addr, generation, queue);
1978 if (generation == GENERATION_OLD)
1979 collect_bridge_objects (copy_func, sgen_get_nursery_start (), sgen_get_nursery_end (), GENERATION_NURSERY, queue);
1983 Make sure we drain the gray stack before processing disappearing links and finalizers.
1984 If we don't make sure it is empty we might wrongly see a live object as dead.
1986 sgen_drain_gray_stack (queue, -1);
1989 We must clear weak links that don't track resurrection before processing object ready for
1990 finalization so they can be cleared before that.
1992 null_link_in_range (copy_func, start_addr, end_addr, generation, TRUE, queue);
1993 if (generation == GENERATION_OLD)
1994 null_link_in_range (copy_func, start_addr, end_addr, GENERATION_NURSERY, TRUE, queue);
1997 /* walk the finalization queue and move also the objects that need to be
1998 * finalized: use the finalized objects as new roots so the objects they depend
1999 * on are also not reclaimed. As with the roots above, only objects in the nursery
2000 * are marked/copied.
2002 finalize_in_range (copy_func, start_addr, end_addr, generation, queue);
2003 if (generation == GENERATION_OLD)
2004 finalize_in_range (copy_func, sgen_get_nursery_start (), sgen_get_nursery_end (), GENERATION_NURSERY, queue);
2005 /* drain the new stack that might have been created */
2006 DEBUG (6, fprintf (gc_debug_file, "Precise scan of gray area post fin\n"));
2007 sgen_drain_gray_stack (queue, -1);
2010 * This must be done again after processing finalizable objects since CWL slots are cleared only after the key is finalized.
2012 done_with_ephemerons = 0;
2014 done_with_ephemerons = mark_ephemerons_in_range (copy_func, start_addr, end_addr, queue);
2015 sgen_drain_gray_stack (queue, -1);
2017 } while (!done_with_ephemerons);
2020 * Clear ephemeron pairs with unreachable keys.
2021 * We pass the copy func so we can figure out if an array was promoted or not.
2023 clear_unreachable_ephemerons (copy_func, start_addr, end_addr, queue);
2026 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));
2029 * handle disappearing links
2030 * Note we do this after checking the finalization queue because if an object
2031 * survives (at least long enough to be finalized) we don't clear the link.
2032 * This also deals with a possible issue with the monitor reclamation: with the Boehm
2033 * GC a finalized object my lose the monitor because it is cleared before the finalizer is
2036 g_assert (sgen_gray_object_queue_is_empty (queue));
2038 null_link_in_range (copy_func, start_addr, end_addr, generation, FALSE, queue);
2039 if (generation == GENERATION_OLD)
2040 null_link_in_range (copy_func, start_addr, end_addr, GENERATION_NURSERY, FALSE, queue);
2041 if (sgen_gray_object_queue_is_empty (queue))
2043 sgen_drain_gray_stack (queue, -1);
2046 g_assert (sgen_gray_object_queue_is_empty (queue));
2050 sgen_check_section_scan_starts (GCMemSection *section)
2053 for (i = 0; i < section->num_scan_start; ++i) {
2054 if (section->scan_starts [i]) {
2055 guint size = safe_object_get_size ((MonoObject*) section->scan_starts [i]);
2056 g_assert (size >= sizeof (MonoObject) && size <= MAX_SMALL_OBJ_SIZE);
2062 check_scan_starts (void)
2064 if (!do_scan_starts_check)
2066 sgen_check_section_scan_starts (nursery_section);
2067 major_collector.check_scan_starts ();
2071 scan_from_registered_roots (CopyOrMarkObjectFunc copy_func, char *addr_start, char *addr_end, int root_type, GrayQueue *queue)
2075 SGEN_HASH_TABLE_FOREACH (&roots_hash [root_type], start_root, root) {
2076 DEBUG (6, fprintf (gc_debug_file, "Precise root scan %p-%p (desc: %p)\n", start_root, root->end_root, (void*)root->root_desc));
2077 precisely_scan_objects_from (copy_func, start_root, (void**)root->end_root, addr_start, addr_end, root->root_desc, queue);
2078 } SGEN_HASH_TABLE_FOREACH_END;
2082 sgen_dump_occupied (char *start, char *end, char *section_start)
2084 fprintf (heap_dump_file, "<occupied offset=\"%td\" size=\"%td\"/>\n", start - section_start, end - start);
2088 sgen_dump_section (GCMemSection *section, const char *type)
2090 char *start = section->data;
2091 char *end = section->data + section->size;
2092 char *occ_start = NULL;
2094 char *old_start = NULL; /* just for debugging */
2096 fprintf (heap_dump_file, "<section type=\"%s\" size=\"%lu\">\n", type, (unsigned long)section->size);
2098 while (start < end) {
2102 if (!*(void**)start) {
2104 sgen_dump_occupied (occ_start, start, section->data);
2107 start += sizeof (void*); /* should be ALLOC_ALIGN, really */
2110 g_assert (start < section->next_data);
2115 vt = (GCVTable*)LOAD_VTABLE (start);
2118 size = ALIGN_UP (safe_object_get_size ((MonoObject*) start));
2121 fprintf (heap_dump_file, "<object offset=\"%d\" class=\"%s.%s\" size=\"%d\"/>\n",
2122 start - section->data,
2123 vt->klass->name_space, vt->klass->name,
2131 sgen_dump_occupied (occ_start, start, section->data);
2133 fprintf (heap_dump_file, "</section>\n");
2137 dump_object (MonoObject *obj, gboolean dump_location)
2139 static char class_name [1024];
2141 MonoClass *class = mono_object_class (obj);
2145 * Python's XML parser is too stupid to parse angle brackets
2146 * in strings, so we just ignore them;
2149 while (class->name [i] && j < sizeof (class_name) - 1) {
2150 if (!strchr ("<>\"", class->name [i]))
2151 class_name [j++] = class->name [i];
2154 g_assert (j < sizeof (class_name));
2157 fprintf (heap_dump_file, "<object class=\"%s.%s\" size=\"%d\"",
2158 class->name_space, class_name,
2159 safe_object_get_size (obj));
2160 if (dump_location) {
2161 const char *location;
2162 if (ptr_in_nursery (obj))
2163 location = "nursery";
2164 else if (safe_object_get_size (obj) <= MAX_SMALL_OBJ_SIZE)
2168 fprintf (heap_dump_file, " location=\"%s\"", location);
2170 fprintf (heap_dump_file, "/>\n");
2174 dump_heap (const char *type, int num, const char *reason)
2179 fprintf (heap_dump_file, "<collection type=\"%s\" num=\"%d\"", type, num);
2181 fprintf (heap_dump_file, " reason=\"%s\"", reason);
2182 fprintf (heap_dump_file, ">\n");
2183 fprintf (heap_dump_file, "<other-mem-usage type=\"mempools\" size=\"%ld\"/>\n", mono_mempool_get_bytes_allocated ());
2184 sgen_dump_internal_mem_usage (heap_dump_file);
2185 fprintf (heap_dump_file, "<pinned type=\"stack\" bytes=\"%zu\"/>\n", sgen_pin_stats_get_pinned_byte_count (PIN_TYPE_STACK));
2186 /* fprintf (heap_dump_file, "<pinned type=\"static-data\" bytes=\"%d\"/>\n", pinned_byte_counts [PIN_TYPE_STATIC_DATA]); */
2187 fprintf (heap_dump_file, "<pinned type=\"other\" bytes=\"%zu\"/>\n", sgen_pin_stats_get_pinned_byte_count (PIN_TYPE_OTHER));
2189 fprintf (heap_dump_file, "<pinned-objects>\n");
2190 for (list = sgen_pin_stats_get_object_list (); list; list = list->next)
2191 dump_object (list->obj, TRUE);
2192 fprintf (heap_dump_file, "</pinned-objects>\n");
2194 sgen_dump_section (nursery_section, "nursery");
2196 major_collector.dump_heap (heap_dump_file);
2198 fprintf (heap_dump_file, "<los>\n");
2199 for (bigobj = los_object_list; bigobj; bigobj = bigobj->next)
2200 dump_object ((MonoObject*)bigobj->data, FALSE);
2201 fprintf (heap_dump_file, "</los>\n");
2203 fprintf (heap_dump_file, "</collection>\n");
2207 sgen_register_moved_object (void *obj, void *destination)
2209 g_assert (mono_profiler_events & MONO_PROFILE_GC_MOVES);
2211 /* FIXME: handle this for parallel collector */
2212 g_assert (!sgen_collection_is_parallel ());
2214 if (moved_objects_idx == MOVED_OBJECTS_NUM) {
2215 mono_profiler_gc_moves (moved_objects, moved_objects_idx);
2216 moved_objects_idx = 0;
2218 moved_objects [moved_objects_idx++] = obj;
2219 moved_objects [moved_objects_idx++] = destination;
2225 static gboolean inited = FALSE;
2230 mono_counters_register ("Minor fragment clear", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_minor_pre_collection_fragment_clear);
2231 mono_counters_register ("Minor pinning", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_minor_pinning);
2232 mono_counters_register ("Minor scan remembered set", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_minor_scan_remsets);
2233 mono_counters_register ("Minor scan pinned", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_minor_scan_pinned);
2234 mono_counters_register ("Minor scan registered roots", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_minor_scan_registered_roots);
2235 mono_counters_register ("Minor scan thread data", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_minor_scan_thread_data);
2236 mono_counters_register ("Minor finish gray stack", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_minor_finish_gray_stack);
2237 mono_counters_register ("Minor fragment creation", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_minor_fragment_creation);
2239 mono_counters_register ("Major fragment clear", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_major_pre_collection_fragment_clear);
2240 mono_counters_register ("Major pinning", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_major_pinning);
2241 mono_counters_register ("Major scan pinned", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_major_scan_pinned);
2242 mono_counters_register ("Major scan registered roots", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_major_scan_registered_roots);
2243 mono_counters_register ("Major scan thread data", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_major_scan_thread_data);
2244 mono_counters_register ("Major scan alloc_pinned", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_major_scan_alloc_pinned);
2245 mono_counters_register ("Major scan finalized", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_major_scan_finalized);
2246 mono_counters_register ("Major scan big objects", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_major_scan_big_objects);
2247 mono_counters_register ("Major finish gray stack", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_major_finish_gray_stack);
2248 mono_counters_register ("Major free big objects", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_major_free_bigobjs);
2249 mono_counters_register ("Major LOS sweep", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_major_los_sweep);
2250 mono_counters_register ("Major sweep", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_major_sweep);
2251 mono_counters_register ("Major fragment creation", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_major_fragment_creation);
2253 mono_counters_register ("Number of pinned objects", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_pinned_objects);
2255 #ifdef HEAVY_STATISTICS
2256 mono_counters_register ("WBarrier set field", MONO_COUNTER_GC | MONO_COUNTER_INT, &stat_wbarrier_set_field);
2257 mono_counters_register ("WBarrier set arrayref", MONO_COUNTER_GC | MONO_COUNTER_INT, &stat_wbarrier_set_arrayref);
2258 mono_counters_register ("WBarrier arrayref copy", MONO_COUNTER_GC | MONO_COUNTER_INT, &stat_wbarrier_arrayref_copy);
2259 mono_counters_register ("WBarrier generic store called", MONO_COUNTER_GC | MONO_COUNTER_INT, &stat_wbarrier_generic_store);
2260 mono_counters_register ("WBarrier set root", MONO_COUNTER_GC | MONO_COUNTER_INT, &stat_wbarrier_set_root);
2261 mono_counters_register ("WBarrier value copy", MONO_COUNTER_GC | MONO_COUNTER_INT, &stat_wbarrier_value_copy);
2262 mono_counters_register ("WBarrier object copy", MONO_COUNTER_GC | MONO_COUNTER_INT, &stat_wbarrier_object_copy);
2264 mono_counters_register ("# objects allocated degraded", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_objects_alloced_degraded);
2265 mono_counters_register ("bytes allocated degraded", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_bytes_alloced_degraded);
2267 mono_counters_register ("# copy_object() called (nursery)", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_copy_object_called_nursery);
2268 mono_counters_register ("# objects copied (nursery)", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_objects_copied_nursery);
2269 mono_counters_register ("# copy_object() called (major)", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_copy_object_called_major);
2270 mono_counters_register ("# objects copied (major)", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_objects_copied_major);
2272 mono_counters_register ("# scan_object() called (nursery)", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_scan_object_called_nursery);
2273 mono_counters_register ("# scan_object() called (major)", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_scan_object_called_major);
2275 mono_counters_register ("Slots allocated in vain", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_slots_allocated_in_vain);
2277 mono_counters_register ("# nursery copy_object() failed from space", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_nursery_copy_object_failed_from_space);
2278 mono_counters_register ("# nursery copy_object() failed forwarded", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_nursery_copy_object_failed_forwarded);
2279 mono_counters_register ("# nursery copy_object() failed pinned", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_nursery_copy_object_failed_pinned);
2280 mono_counters_register ("# nursery copy_object() failed to space", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_nursery_copy_object_failed_to_space);
2282 sgen_nursery_allocator_init_heavy_stats ();
2283 sgen_alloc_init_heavy_stats ();
2289 static gboolean need_calculate_minor_collection_allowance;
2291 static int last_collection_old_num_major_sections;
2292 static mword last_collection_los_memory_usage = 0;
2293 static mword last_collection_old_los_memory_usage;
2294 static mword last_collection_los_memory_alloced;
2297 reset_minor_collection_allowance (void)
2299 need_calculate_minor_collection_allowance = TRUE;
2303 try_calculate_minor_collection_allowance (gboolean overwrite)
2305 int num_major_sections, num_major_sections_saved, save_target, allowance_target;
2306 mword los_memory_saved, new_major, new_heap_size;
2309 g_assert (need_calculate_minor_collection_allowance);
2311 if (!need_calculate_minor_collection_allowance)
2314 if (!*major_collector.have_swept) {
2316 minor_collection_allowance = MIN_MINOR_COLLECTION_ALLOWANCE;
2320 num_major_sections = major_collector.get_num_major_sections ();
2322 num_major_sections_saved = MAX (last_collection_old_num_major_sections - num_major_sections, 0);
2323 los_memory_saved = MAX (last_collection_old_los_memory_usage - last_collection_los_memory_usage, 1);
2325 new_major = num_major_sections * major_collector.section_size;
2326 new_heap_size = new_major + last_collection_los_memory_usage;
2329 * FIXME: Why is save_target half the major memory plus half the
2330 * LOS memory saved? Shouldn't it be half the major memory
2331 * saved plus half the LOS memory saved? Or half the whole heap
2334 save_target = (new_major + los_memory_saved) / 2;
2337 * We aim to allow the allocation of as many sections as is
2338 * necessary to reclaim save_target sections in the next
2339 * collection. We assume the collection pattern won't change.
2340 * In the last cycle, we had num_major_sections_saved for
2341 * minor_collection_sections_alloced. Assuming things won't
2342 * change, this must be the same ratio as save_target for
2343 * allowance_target, i.e.
2345 * num_major_sections_saved save_target
2346 * --------------------------------- == ----------------
2347 * minor_collection_sections_alloced allowance_target
2351 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));
2353 minor_collection_allowance = MAX (MIN (allowance_target, num_major_sections * major_collector.section_size + los_memory_usage), MIN_MINOR_COLLECTION_ALLOWANCE);
2355 if (new_heap_size + minor_collection_allowance > soft_heap_limit) {
2356 if (new_heap_size > soft_heap_limit)
2357 minor_collection_allowance = MIN_MINOR_COLLECTION_ALLOWANCE;
2359 minor_collection_allowance = MAX (soft_heap_limit - new_heap_size, MIN_MINOR_COLLECTION_ALLOWANCE);
2362 if (debug_print_allowance) {
2363 mword old_major = last_collection_old_num_major_sections * major_collector.section_size;
2365 fprintf (gc_debug_file, "Before collection: %td bytes (%td major, %td LOS)\n",
2366 old_major + last_collection_old_los_memory_usage, old_major, last_collection_old_los_memory_usage);
2367 fprintf (gc_debug_file, "After collection: %td bytes (%td major, %td LOS)\n",
2368 new_heap_size, new_major, last_collection_los_memory_usage);
2369 fprintf (gc_debug_file, "Allowance: %td bytes\n", minor_collection_allowance);
2372 if (major_collector.have_computed_minor_collection_allowance)
2373 major_collector.have_computed_minor_collection_allowance ();
2375 need_calculate_minor_collection_allowance = FALSE;
2379 need_major_collection (mword space_needed)
2381 mword los_alloced = los_memory_usage - MIN (last_collection_los_memory_usage, los_memory_usage);
2382 return (space_needed > available_free_space ()) ||
2383 minor_collection_sections_alloced * major_collector.section_size + los_alloced > minor_collection_allowance;
2387 sgen_need_major_collection (mword space_needed)
2389 return need_major_collection (space_needed);
2393 reset_pinned_from_failed_allocation (void)
2395 bytes_pinned_from_failed_allocation = 0;
2399 sgen_set_pinned_from_failed_allocation (mword objsize)
2401 bytes_pinned_from_failed_allocation += objsize;
2405 sgen_collection_is_parallel (void)
2407 switch (current_collection_generation) {
2408 case GENERATION_NURSERY:
2409 return nursery_collection_is_parallel;
2410 case GENERATION_OLD:
2411 return major_collector.is_parallel;
2413 g_assert_not_reached ();
2421 } FinishRememberedSetScanJobData;
2424 job_finish_remembered_set_scan (WorkerData *worker_data, void *job_data_untyped)
2426 FinishRememberedSetScanJobData *job_data = job_data_untyped;
2428 remset.finish_scan_remsets (job_data->heap_start, job_data->heap_end, sgen_workers_get_job_gray_queue (worker_data));
2433 CopyOrMarkObjectFunc func;
2437 } ScanFromRegisteredRootsJobData;
2440 job_scan_from_registered_roots (WorkerData *worker_data, void *job_data_untyped)
2442 ScanFromRegisteredRootsJobData *job_data = job_data_untyped;
2444 scan_from_registered_roots (job_data->func,
2445 job_data->heap_start, job_data->heap_end,
2446 job_data->root_type,
2447 sgen_workers_get_job_gray_queue (worker_data));
2454 } ScanThreadDataJobData;
2457 job_scan_thread_data (WorkerData *worker_data, void *job_data_untyped)
2459 ScanThreadDataJobData *job_data = job_data_untyped;
2461 scan_thread_data (job_data->heap_start, job_data->heap_end, TRUE,
2462 sgen_workers_get_job_gray_queue (worker_data));
2467 FinalizeReadyEntry *list;
2468 } ScanFinalizerEntriesJobData;
2471 job_scan_finalizer_entries (WorkerData *worker_data, void *job_data_untyped)
2473 ScanFinalizerEntriesJobData *job_data = job_data_untyped;
2475 scan_finalizer_entries (current_object_ops.copy_or_mark_object,
2477 sgen_workers_get_job_gray_queue (worker_data));
2481 verify_scan_starts (char *start, char *end)
2485 for (i = 0; i < nursery_section->num_scan_start; ++i) {
2486 char *addr = nursery_section->scan_starts [i];
2487 if (addr > start && addr < end)
2488 fprintf (gc_debug_file, "NFC-BAD SCAN START [%d] %p for obj [%p %p]\n", i, addr, start, end);
2493 verify_nursery (void)
2495 char *start, *end, *cur, *hole_start;
2497 if (!do_verify_nursery)
2500 /*This cleans up unused fragments */
2501 sgen_nursery_allocator_prepare_for_pinning ();
2503 hole_start = start = cur = sgen_get_nursery_start ();
2504 end = sgen_get_nursery_end ();
2509 if (!*(void**)cur) {
2510 cur += sizeof (void*);
2514 if (object_is_forwarded (cur))
2515 fprintf (gc_debug_file, "FORWARDED OBJ %p\n", cur);
2516 else if (object_is_pinned (cur))
2517 fprintf (gc_debug_file, "PINNED OBJ %p\n", cur);
2519 ss = safe_object_get_size ((MonoObject*)cur);
2520 size = ALIGN_UP (safe_object_get_size ((MonoObject*)cur));
2521 verify_scan_starts (cur, cur + size);
2522 if (do_dump_nursery_content) {
2523 if (cur > hole_start)
2524 fprintf (gc_debug_file, "HOLE [%p %p %d]\n", hole_start, cur, (int)(cur - hole_start));
2525 fprintf (gc_debug_file, "OBJ [%p %p %d %d %s %d]\n", cur, cur + size, (int)size, (int)ss, sgen_safe_name ((MonoObject*)cur), (gpointer)LOAD_VTABLE (cur) == sgen_get_array_fill_vtable ());
2530 fflush (gc_debug_file);
2534 * Collect objects in the nursery. Returns whether to trigger a major
2538 collect_nursery (size_t requested_size)
2540 gboolean needs_major;
2541 size_t max_garbage_amount;
2543 FinishRememberedSetScanJobData frssjd;
2544 ScanFromRegisteredRootsJobData scrrjd_normal, scrrjd_wbarrier;
2545 ScanFinalizerEntriesJobData sfejd_fin_ready, sfejd_critical_fin;
2546 ScanThreadDataJobData stdjd;
2547 mword fragment_total;
2548 TV_DECLARE (all_atv);
2549 TV_DECLARE (all_btv);
2553 if (disable_minor_collections)
2558 mono_perfcounters->gc_collections0++;
2560 current_collection_generation = GENERATION_NURSERY;
2561 if (sgen_collection_is_parallel ())
2562 current_object_ops = sgen_minor_collector.parallel_ops;
2564 current_object_ops = sgen_minor_collector.serial_ops;
2566 reset_pinned_from_failed_allocation ();
2568 binary_protocol_collection (GENERATION_NURSERY);
2569 check_scan_starts ();
2571 sgen_nursery_alloc_prepare_for_minor ();
2575 nursery_next = sgen_nursery_alloc_get_upper_alloc_bound ();
2576 /* FIXME: optimize later to use the higher address where an object can be present */
2577 nursery_next = MAX (nursery_next, sgen_get_nursery_end ());
2579 DEBUG (1, fprintf (gc_debug_file, "Start nursery collection %d %p-%p, size: %d\n", stat_minor_gcs, sgen_get_nursery_start (), nursery_next, (int)(nursery_next - sgen_get_nursery_start ())));
2580 max_garbage_amount = nursery_next - sgen_get_nursery_start ();
2581 g_assert (nursery_section->size >= max_garbage_amount);
2583 /* world must be stopped already */
2584 TV_GETTIME (all_atv);
2588 time_minor_pre_collection_fragment_clear += TV_ELAPSED (atv, btv);
2591 check_for_xdomain_refs ();
2593 nursery_section->next_data = nursery_next;
2595 major_collector.start_nursery_collection ();
2597 try_calculate_minor_collection_allowance (FALSE);
2599 sgen_gray_object_queue_init (&gray_queue);
2600 sgen_workers_init_distribute_gray_queue ();
2603 mono_stats.minor_gc_count ++;
2605 if (remset.prepare_for_minor_collection)
2606 remset.prepare_for_minor_collection ();
2608 process_fin_stage_entries ();
2609 process_dislink_stage_entries ();
2611 /* pin from pinned handles */
2612 sgen_init_pinning ();
2613 mono_profiler_gc_event (MONO_GC_EVENT_MARK_START, 0);
2614 pin_from_roots (sgen_get_nursery_start (), nursery_next, WORKERS_DISTRIBUTE_GRAY_QUEUE);
2615 /* identify pinned objects */
2616 sgen_optimize_pin_queue (0);
2617 sgen_pinning_setup_section (nursery_section);
2618 sgen_pin_objects_in_section (nursery_section, WORKERS_DISTRIBUTE_GRAY_QUEUE);
2619 sgen_pinning_trim_queue_to_section (nursery_section);
2622 time_minor_pinning += TV_ELAPSED (btv, atv);
2623 DEBUG (2, fprintf (gc_debug_file, "Finding pinned pointers: %d in %d usecs\n", sgen_get_pinned_count (), TV_ELAPSED (btv, atv)));
2624 DEBUG (4, fprintf (gc_debug_file, "Start scan with %d pinned objects\n", sgen_get_pinned_count ()));
2626 if (consistency_check_at_minor_collection)
2627 sgen_check_consistency ();
2629 sgen_workers_start_all_workers ();
2632 * Perform the sequential part of remembered set scanning.
2633 * This usually involves scanning global information that might later be produced by evacuation.
2635 if (remset.begin_scan_remsets)
2636 remset.begin_scan_remsets (sgen_get_nursery_start (), nursery_next, WORKERS_DISTRIBUTE_GRAY_QUEUE);
2638 sgen_workers_start_marking ();
2640 frssjd.heap_start = sgen_get_nursery_start ();
2641 frssjd.heap_end = nursery_next;
2642 sgen_workers_enqueue_job (job_finish_remembered_set_scan, &frssjd);
2644 /* we don't have complete write barrier yet, so we scan all the old generation sections */
2646 time_minor_scan_remsets += TV_ELAPSED (atv, btv);
2647 DEBUG (2, fprintf (gc_debug_file, "Old generation scan: %d usecs\n", TV_ELAPSED (atv, btv)));
2649 if (!sgen_collection_is_parallel ())
2650 sgen_drain_gray_stack (&gray_queue, -1);
2652 if (mono_profiler_get_events () & MONO_PROFILE_GC_ROOTS)
2653 report_registered_roots ();
2654 if (mono_profiler_get_events () & MONO_PROFILE_GC_ROOTS)
2655 report_finalizer_roots ();
2657 time_minor_scan_pinned += TV_ELAPSED (btv, atv);
2659 /* registered roots, this includes static fields */
2660 scrrjd_normal.func = current_object_ops.copy_or_mark_object;
2661 scrrjd_normal.heap_start = sgen_get_nursery_start ();
2662 scrrjd_normal.heap_end = nursery_next;
2663 scrrjd_normal.root_type = ROOT_TYPE_NORMAL;
2664 sgen_workers_enqueue_job (job_scan_from_registered_roots, &scrrjd_normal);
2666 scrrjd_wbarrier.func = current_object_ops.copy_or_mark_object;
2667 scrrjd_wbarrier.heap_start = sgen_get_nursery_start ();
2668 scrrjd_wbarrier.heap_end = nursery_next;
2669 scrrjd_wbarrier.root_type = ROOT_TYPE_WBARRIER;
2670 sgen_workers_enqueue_job (job_scan_from_registered_roots, &scrrjd_wbarrier);
2673 time_minor_scan_registered_roots += TV_ELAPSED (atv, btv);
2676 stdjd.heap_start = sgen_get_nursery_start ();
2677 stdjd.heap_end = nursery_next;
2678 sgen_workers_enqueue_job (job_scan_thread_data, &stdjd);
2681 time_minor_scan_thread_data += TV_ELAPSED (btv, atv);
2684 if (sgen_collection_is_parallel ()) {
2685 while (!sgen_gray_object_queue_is_empty (WORKERS_DISTRIBUTE_GRAY_QUEUE)) {
2686 sgen_workers_distribute_gray_queue_sections ();
2690 sgen_workers_join ();
2692 if (sgen_collection_is_parallel ())
2693 g_assert (sgen_gray_object_queue_is_empty (&gray_queue));
2695 /* Scan the list of objects ready for finalization. If */
2696 sfejd_fin_ready.list = fin_ready_list;
2697 sgen_workers_enqueue_job (job_scan_finalizer_entries, &sfejd_fin_ready);
2699 sfejd_critical_fin.list = critical_fin_list;
2700 sgen_workers_enqueue_job (job_scan_finalizer_entries, &sfejd_critical_fin);
2702 finish_gray_stack (sgen_get_nursery_start (), nursery_next, GENERATION_NURSERY, &gray_queue);
2704 time_minor_finish_gray_stack += TV_ELAPSED (btv, atv);
2705 mono_profiler_gc_event (MONO_GC_EVENT_MARK_END, 0);
2708 * The (single-threaded) finalization code might have done
2709 * some copying/marking so we can only reset the GC thread's
2710 * worker data here instead of earlier when we joined the
2713 sgen_workers_reset_data ();
2715 if (objects_pinned) {
2716 sgen_optimize_pin_queue (0);
2717 sgen_pinning_setup_section (nursery_section);
2720 /* walk the pin_queue, build up the fragment list of free memory, unmark
2721 * pinned objects as we go, memzero() the empty fragments so they are ready for the
2724 mono_profiler_gc_event (MONO_GC_EVENT_RECLAIM_START, 0);
2725 fragment_total = sgen_build_nursery_fragments (nursery_section, nursery_section->pin_queue_start, nursery_section->pin_queue_num_entries);
2726 if (!fragment_total)
2729 /* Clear TLABs for all threads */
2730 sgen_clear_tlabs ();
2732 mono_profiler_gc_event (MONO_GC_EVENT_RECLAIM_END, 0);
2734 time_minor_fragment_creation += TV_ELAPSED (atv, btv);
2735 DEBUG (2, fprintf (gc_debug_file, "Fragment creation: %d usecs, %lu bytes available\n", TV_ELAPSED (atv, btv), (unsigned long)fragment_total));
2737 if (consistency_check_at_minor_collection)
2738 sgen_check_major_refs ();
2740 major_collector.finish_nursery_collection ();
2742 TV_GETTIME (all_btv);
2743 mono_stats.minor_gc_time_usecs += TV_ELAPSED (all_atv, all_btv);
2746 dump_heap ("minor", stat_minor_gcs - 1, NULL);
2748 /* prepare the pin queue for the next collection */
2749 sgen_finish_pinning ();
2750 if (fin_ready_list || critical_fin_list) {
2751 DEBUG (4, fprintf (gc_debug_file, "Finalizer-thread wakeup: ready %d\n", num_ready_finalizers));
2752 mono_gc_finalize_notify ();
2754 sgen_pin_stats_reset ();
2756 g_assert (sgen_gray_object_queue_is_empty (&gray_queue));
2758 if (remset.finish_minor_collection)
2759 remset.finish_minor_collection ();
2761 check_scan_starts ();
2763 binary_protocol_flush_buffers (FALSE);
2765 /*objects are late pinned because of lack of memory, so a major is a good call*/
2766 needs_major = need_major_collection (0) || objects_pinned;
2767 current_collection_generation = -1;
2774 sgen_collect_nursery_no_lock (size_t requested_size)
2776 gint64 gc_start_time;
2778 mono_profiler_gc_event (MONO_GC_EVENT_START, 0);
2779 gc_start_time = mono_100ns_ticks ();
2782 collect_nursery (requested_size);
2785 mono_trace_message (MONO_TRACE_GC, "minor gc took %d usecs", (mono_100ns_ticks () - gc_start_time) / 10);
2786 mono_profiler_gc_event (MONO_GC_EVENT_END, 0);
2790 major_do_collection (const char *reason)
2792 LOSObject *bigobj, *prevbo;
2793 TV_DECLARE (all_atv);
2794 TV_DECLARE (all_btv);
2797 /* FIXME: only use these values for the precise scan
2798 * note that to_space pointers should be excluded anyway...
2800 char *heap_start = NULL;
2801 char *heap_end = (char*)-1;
2802 int old_next_pin_slot;
2803 ScanFromRegisteredRootsJobData scrrjd_normal, scrrjd_wbarrier;
2804 ScanThreadDataJobData stdjd;
2805 ScanFinalizerEntriesJobData sfejd_fin_ready, sfejd_critical_fin;
2807 mono_perfcounters->gc_collections1++;
2809 current_object_ops = major_collector.major_ops;
2811 reset_pinned_from_failed_allocation ();
2813 last_collection_old_num_major_sections = major_collector.get_num_major_sections ();
2816 * A domain could have been freed, resulting in
2817 * los_memory_usage being less than last_collection_los_memory_usage.
2819 last_collection_los_memory_alloced = los_memory_usage - MIN (last_collection_los_memory_usage, los_memory_usage);
2820 last_collection_old_los_memory_usage = los_memory_usage;
2823 //count_ref_nonref_objs ();
2824 //consistency_check ();
2826 binary_protocol_collection (GENERATION_OLD);
2827 check_scan_starts ();
2829 sgen_gray_object_queue_init (&gray_queue);
2830 sgen_workers_init_distribute_gray_queue ();
2831 sgen_nursery_alloc_prepare_for_major (reason);
2834 DEBUG (1, fprintf (gc_debug_file, "Start major collection %d\n", stat_major_gcs));
2836 mono_stats.major_gc_count ++;
2838 /* world must be stopped already */
2839 TV_GETTIME (all_atv);
2842 /* Pinning depends on this */
2843 sgen_clear_nursery_fragments ();
2846 time_major_pre_collection_fragment_clear += TV_ELAPSED (atv, btv);
2848 nursery_section->next_data = sgen_get_nursery_end ();
2849 /* we should also coalesce scanning from sections close to each other
2850 * and deal with pointers outside of the sections later.
2853 if (major_collector.start_major_collection)
2854 major_collector.start_major_collection ();
2856 *major_collector.have_swept = FALSE;
2857 reset_minor_collection_allowance ();
2860 check_for_xdomain_refs ();
2862 /* Remsets are not useful for a major collection */
2863 remset.prepare_for_major_collection ();
2865 process_fin_stage_entries ();
2866 process_dislink_stage_entries ();
2869 sgen_init_pinning ();
2870 DEBUG (6, fprintf (gc_debug_file, "Collecting pinned addresses\n"));
2871 pin_from_roots ((void*)lowest_heap_address, (void*)highest_heap_address, WORKERS_DISTRIBUTE_GRAY_QUEUE);
2872 sgen_optimize_pin_queue (0);
2875 * pin_queue now contains all candidate pointers, sorted and
2876 * uniqued. We must do two passes now to figure out which
2877 * objects are pinned.
2879 * The first is to find within the pin_queue the area for each
2880 * section. This requires that the pin_queue be sorted. We
2881 * also process the LOS objects and pinned chunks here.
2883 * The second, destructive, pass is to reduce the section
2884 * areas to pointers to the actually pinned objects.
2886 DEBUG (6, fprintf (gc_debug_file, "Pinning from sections\n"));
2887 /* first pass for the sections */
2888 sgen_find_section_pin_queue_start_end (nursery_section);
2889 major_collector.find_pin_queue_start_ends (WORKERS_DISTRIBUTE_GRAY_QUEUE);
2890 /* identify possible pointers to the insize of large objects */
2891 DEBUG (6, fprintf (gc_debug_file, "Pinning from large objects\n"));
2892 for (bigobj = los_object_list; bigobj; bigobj = bigobj->next) {
2894 gboolean profile_roots = mono_profiler_get_events () & MONO_PROFILE_GC_ROOTS;
2895 GCRootReport report;
2897 if (sgen_find_optimized_pin_queue_area (bigobj->data, (char*)bigobj->data + bigobj->size, &dummy)) {
2898 binary_protocol_pin (bigobj->data, (gpointer)LOAD_VTABLE (bigobj->data), safe_object_get_size (bigobj->data));
2899 pin_object (bigobj->data);
2900 /* FIXME: only enqueue if object has references */
2901 GRAY_OBJECT_ENQUEUE (WORKERS_DISTRIBUTE_GRAY_QUEUE, bigobj->data);
2902 if (G_UNLIKELY (do_pin_stats))
2903 sgen_pin_stats_register_object ((char*) bigobj->data, safe_object_get_size ((MonoObject*) bigobj->data));
2904 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));
2907 add_profile_gc_root (&report, bigobj->data, MONO_PROFILE_GC_ROOT_PINNING | MONO_PROFILE_GC_ROOT_MISC, 0);
2910 notify_gc_roots (&report);
2912 /* second pass for the sections */
2913 sgen_pin_objects_in_section (nursery_section, WORKERS_DISTRIBUTE_GRAY_QUEUE);
2914 major_collector.pin_objects (WORKERS_DISTRIBUTE_GRAY_QUEUE);
2915 old_next_pin_slot = sgen_get_pinned_count ();
2918 time_major_pinning += TV_ELAPSED (atv, btv);
2919 DEBUG (2, fprintf (gc_debug_file, "Finding pinned pointers: %d in %d usecs\n", sgen_get_pinned_count (), TV_ELAPSED (atv, btv)));
2920 DEBUG (4, fprintf (gc_debug_file, "Start scan with %d pinned objects\n", sgen_get_pinned_count ()));
2922 major_collector.init_to_space ();
2924 #ifdef SGEN_DEBUG_INTERNAL_ALLOC
2925 main_gc_thread = mono_native_thread_self ();
2928 sgen_workers_start_all_workers ();
2929 sgen_workers_start_marking ();
2931 if (mono_profiler_get_events () & MONO_PROFILE_GC_ROOTS)
2932 report_registered_roots ();
2934 time_major_scan_pinned += TV_ELAPSED (btv, atv);
2936 /* registered roots, this includes static fields */
2937 scrrjd_normal.func = current_object_ops.copy_or_mark_object;
2938 scrrjd_normal.heap_start = heap_start;
2939 scrrjd_normal.heap_end = heap_end;
2940 scrrjd_normal.root_type = ROOT_TYPE_NORMAL;
2941 sgen_workers_enqueue_job (job_scan_from_registered_roots, &scrrjd_normal);
2943 scrrjd_wbarrier.func = current_object_ops.copy_or_mark_object;
2944 scrrjd_wbarrier.heap_start = heap_start;
2945 scrrjd_wbarrier.heap_end = heap_end;
2946 scrrjd_wbarrier.root_type = ROOT_TYPE_WBARRIER;
2947 sgen_workers_enqueue_job (job_scan_from_registered_roots, &scrrjd_wbarrier);
2950 time_major_scan_registered_roots += TV_ELAPSED (atv, btv);
2953 stdjd.heap_start = heap_start;
2954 stdjd.heap_end = heap_end;
2955 sgen_workers_enqueue_job (job_scan_thread_data, &stdjd);
2958 time_major_scan_thread_data += TV_ELAPSED (btv, atv);
2961 time_major_scan_alloc_pinned += TV_ELAPSED (atv, btv);
2963 if (mono_profiler_get_events () & MONO_PROFILE_GC_ROOTS)
2964 report_finalizer_roots ();
2966 /* scan the list of objects ready for finalization */
2967 sfejd_fin_ready.list = fin_ready_list;
2968 sgen_workers_enqueue_job (job_scan_finalizer_entries, &sfejd_fin_ready);
2970 sfejd_critical_fin.list = critical_fin_list;
2971 sgen_workers_enqueue_job (job_scan_finalizer_entries, &sfejd_critical_fin);
2974 time_major_scan_finalized += TV_ELAPSED (btv, atv);
2975 DEBUG (2, fprintf (gc_debug_file, "Root scan: %d usecs\n", TV_ELAPSED (btv, atv)));
2978 time_major_scan_big_objects += TV_ELAPSED (atv, btv);
2980 if (major_collector.is_parallel) {
2981 while (!sgen_gray_object_queue_is_empty (WORKERS_DISTRIBUTE_GRAY_QUEUE)) {
2982 sgen_workers_distribute_gray_queue_sections ();
2986 sgen_workers_join ();
2988 #ifdef SGEN_DEBUG_INTERNAL_ALLOC
2989 main_gc_thread = NULL;
2992 if (major_collector.is_parallel)
2993 g_assert (sgen_gray_object_queue_is_empty (&gray_queue));
2995 /* all the objects in the heap */
2996 finish_gray_stack (heap_start, heap_end, GENERATION_OLD, &gray_queue);
2998 time_major_finish_gray_stack += TV_ELAPSED (btv, atv);
3001 * The (single-threaded) finalization code might have done
3002 * some copying/marking so we can only reset the GC thread's
3003 * worker data here instead of earlier when we joined the
3006 sgen_workers_reset_data ();
3008 if (objects_pinned) {
3009 /*This is slow, but we just OOM'd*/
3010 sgen_pin_queue_clear_discarded_entries (nursery_section, old_next_pin_slot);
3011 sgen_optimize_pin_queue (0);
3012 sgen_find_section_pin_queue_start_end (nursery_section);
3016 reset_heap_boundaries ();
3017 sgen_update_heap_boundaries ((mword)sgen_get_nursery_start (), (mword)sgen_get_nursery_end ());
3019 /* sweep the big objects list */
3021 for (bigobj = los_object_list; bigobj;) {
3022 if (object_is_pinned (bigobj->data)) {
3023 unpin_object (bigobj->data);
3024 sgen_update_heap_boundaries ((mword)bigobj->data, (mword)bigobj->data + bigobj->size);
3027 /* not referenced anywhere, so we can free it */
3029 prevbo->next = bigobj->next;
3031 los_object_list = bigobj->next;
3033 bigobj = bigobj->next;
3034 sgen_los_free_object (to_free);
3038 bigobj = bigobj->next;
3042 time_major_free_bigobjs += TV_ELAPSED (atv, btv);
3047 time_major_los_sweep += TV_ELAPSED (btv, atv);
3049 major_collector.sweep ();
3052 time_major_sweep += TV_ELAPSED (atv, btv);
3054 /* walk the pin_queue, build up the fragment list of free memory, unmark
3055 * pinned objects as we go, memzero() the empty fragments so they are ready for the
3058 if (!sgen_build_nursery_fragments (nursery_section, nursery_section->pin_queue_start, nursery_section->pin_queue_num_entries))
3061 /* Clear TLABs for all threads */
3062 sgen_clear_tlabs ();
3065 time_major_fragment_creation += TV_ELAPSED (btv, atv);
3067 TV_GETTIME (all_btv);
3068 mono_stats.major_gc_time_usecs += TV_ELAPSED (all_atv, all_btv);
3071 dump_heap ("major", stat_major_gcs - 1, reason);
3073 /* prepare the pin queue for the next collection */
3074 sgen_finish_pinning ();
3076 if (fin_ready_list || critical_fin_list) {
3077 DEBUG (4, fprintf (gc_debug_file, "Finalizer-thread wakeup: ready %d\n", num_ready_finalizers));
3078 mono_gc_finalize_notify ();
3080 sgen_pin_stats_reset ();
3082 g_assert (sgen_gray_object_queue_is_empty (&gray_queue));
3084 try_calculate_minor_collection_allowance (TRUE);
3086 minor_collection_sections_alloced = 0;
3087 last_collection_los_memory_usage = los_memory_usage;
3089 major_collector.finish_major_collection ();
3091 check_scan_starts ();
3093 binary_protocol_flush_buffers (FALSE);
3095 //consistency_check ();
3097 return bytes_pinned_from_failed_allocation > 0;
3101 major_collection (const char *reason)
3103 gboolean need_minor_collection;
3105 if (disable_major_collections) {
3106 collect_nursery (0);
3110 major_collection_happened = TRUE;
3111 current_collection_generation = GENERATION_OLD;
3112 need_minor_collection = major_do_collection (reason);
3113 current_collection_generation = -1;
3115 if (need_minor_collection)
3116 collect_nursery (0);
3120 sgen_collect_major_no_lock (const char *reason)
3122 gint64 gc_start_time;
3124 mono_profiler_gc_event (MONO_GC_EVENT_START, 1);
3125 gc_start_time = mono_100ns_ticks ();
3127 major_collection (reason);
3129 mono_trace_message (MONO_TRACE_GC, "major gc took %d usecs", (mono_100ns_ticks () - gc_start_time) / 10);
3130 mono_profiler_gc_event (MONO_GC_EVENT_END, 1);
3134 * When deciding if it's better to collect or to expand, keep track
3135 * of how much garbage was reclaimed with the last collection: if it's too
3137 * This is called when we could not allocate a small object.
3139 static void __attribute__((noinline))
3140 minor_collect_or_expand_inner (size_t size)
3142 int do_minor_collection = 1;
3144 g_assert (nursery_section);
3145 if (do_minor_collection) {
3146 gint64 total_gc_time, major_gc_time = 0;
3148 mono_profiler_gc_event (MONO_GC_EVENT_START, 0);
3149 total_gc_time = mono_100ns_ticks ();
3152 if (collect_nursery (size)) {
3153 mono_profiler_gc_event (MONO_GC_EVENT_START, 1);
3154 major_gc_time = mono_100ns_ticks ();
3156 major_collection ("minor overflow");
3158 /* keep events symmetric */
3159 major_gc_time = mono_100ns_ticks () - major_gc_time;
3160 mono_profiler_gc_event (MONO_GC_EVENT_END, 1);
3162 DEBUG (2, fprintf (gc_debug_file, "Heap size: %lu, LOS size: %lu\n", (unsigned long)total_alloc, (unsigned long)los_memory_usage));
3165 total_gc_time = mono_100ns_ticks () - total_gc_time;
3167 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);
3169 mono_trace_message (MONO_TRACE_GC, "minor gc took %d usecs", total_gc_time / 10);
3171 /* this also sets the proper pointers for the next allocation */
3172 if (!sgen_can_alloc_size (size)) {
3173 /* TypeBuilder and MonoMethod are killing mcs with fragmentation */
3174 DEBUG (1, fprintf (gc_debug_file, "nursery collection didn't find enough room for %zd alloc (%d pinned)\n", size, sgen_get_pinned_count ()));
3175 sgen_dump_pin_queue ();
3178 mono_profiler_gc_event (MONO_GC_EVENT_END, 0);
3180 //report_internal_mem_usage ();
3184 sgen_minor_collect_or_expand_inner (size_t size)
3186 minor_collect_or_expand_inner (size);
3190 * ######################################################################
3191 * ######## Memory allocation from the OS
3192 * ######################################################################
3193 * This section of code deals with getting memory from the OS and
3194 * allocating memory for GC-internal data structures.
3195 * Internal memory can be handled with a freelist for small objects.
3201 G_GNUC_UNUSED static void
3202 report_internal_mem_usage (void)
3204 printf ("Internal memory usage:\n");
3205 sgen_report_internal_mem_usage ();
3206 printf ("Pinned memory usage:\n");
3207 major_collector.report_pinned_memory_usage ();
3211 * ######################################################################
3212 * ######## Finalization support
3213 * ######################################################################
3217 * If the object has been forwarded it means it's still referenced from a root.
3218 * If it is pinned it's still alive as well.
3219 * A LOS object is only alive if we have pinned it.
3220 * Return TRUE if @obj is ready to be finalized.
3222 static inline gboolean
3223 sgen_is_object_alive (void *object)
3225 if (ptr_in_nursery (object))
3226 return sgen_nursery_is_object_alive (object);
3227 /* Oldgen objects can be pinned and forwarded too */
3228 if (SGEN_OBJECT_IS_PINNED (object) || SGEN_OBJECT_IS_FORWARDED (object))
3230 return major_collector.is_object_live (object);
3234 sgen_gc_is_object_ready_for_finalization (void *object)
3236 return !sgen_is_object_alive (object);
3240 has_critical_finalizer (MonoObject *obj)
3244 if (!mono_defaults.critical_finalizer_object)
3247 class = ((MonoVTable*)LOAD_VTABLE (obj))->klass;
3249 return mono_class_has_parent_fast (class, mono_defaults.critical_finalizer_object);
3253 queue_finalization_entry (MonoObject *obj) {
3254 FinalizeReadyEntry *entry = sgen_alloc_internal (INTERNAL_MEM_FINALIZE_READY_ENTRY);
3255 entry->object = obj;
3256 if (has_critical_finalizer (obj)) {
3257 entry->next = critical_fin_list;
3258 critical_fin_list = entry;
3260 entry->next = fin_ready_list;
3261 fin_ready_list = entry;
3266 object_is_reachable (char *object, char *start, char *end)
3268 /*This happens for non nursery objects during minor collections. We just treat all objects as alive.*/
3269 if (object < start || object >= end)
3272 return sgen_is_object_alive (object);
3275 #include "sgen-fin-weak-hash.c"
3278 sgen_object_is_live (void *obj)
3280 if (ptr_in_nursery (obj))
3281 return object_is_pinned (obj);
3282 /* FIXME This is semantically wrong! All tenured object are considered alive during a nursery collection. */
3283 if (current_collection_generation == GENERATION_NURSERY)
3285 return major_collector.is_object_live (obj);
3288 /* LOCKING: requires that the GC lock is held */
3290 null_ephemerons_for_domain (MonoDomain *domain)
3292 EphemeronLinkNode *current = ephemeron_list, *prev = NULL;
3295 MonoObject *object = (MonoObject*)current->array;
3297 if (object && !object->vtable) {
3298 EphemeronLinkNode *tmp = current;
3301 prev->next = current->next;
3303 ephemeron_list = current->next;
3305 current = current->next;
3306 sgen_free_internal (tmp, INTERNAL_MEM_EPHEMERON_LINK);
3309 current = current->next;
3314 /* LOCKING: requires that the GC lock is held */
3316 clear_unreachable_ephemerons (CopyOrMarkObjectFunc copy_func, char *start, char *end, GrayQueue *queue)
3318 int was_in_nursery, was_promoted;
3319 EphemeronLinkNode *current = ephemeron_list, *prev = NULL;
3321 Ephemeron *cur, *array_end;
3325 char *object = current->array;
3327 if (!object_is_reachable (object, start, end)) {
3328 EphemeronLinkNode *tmp = current;
3330 DEBUG (5, fprintf (gc_debug_file, "Dead Ephemeron array at %p\n", object));
3333 prev->next = current->next;
3335 ephemeron_list = current->next;
3337 current = current->next;
3338 sgen_free_internal (tmp, INTERNAL_MEM_EPHEMERON_LINK);
3343 was_in_nursery = ptr_in_nursery (object);
3344 copy_func ((void**)&object, queue);
3345 current->array = object;
3347 /*The array was promoted, add global remsets for key/values left behind in nursery.*/
3348 was_promoted = was_in_nursery && !ptr_in_nursery (object);
3350 DEBUG (5, fprintf (gc_debug_file, "Clearing unreachable entries for ephemeron array at %p\n", object));
3352 array = (MonoArray*)object;
3353 cur = mono_array_addr (array, Ephemeron, 0);
3354 array_end = cur + mono_array_length_fast (array);
3355 tombstone = (char*)((MonoVTable*)LOAD_VTABLE (object))->domain->ephemeron_tombstone;
3357 for (; cur < array_end; ++cur) {
3358 char *key = (char*)cur->key;
3360 if (!key || key == tombstone)
3363 DEBUG (5, fprintf (gc_debug_file, "[%td] key %p (%s) value %p (%s)\n", cur - mono_array_addr (array, Ephemeron, 0),
3364 key, object_is_reachable (key, start, end) ? "reachable" : "unreachable",
3365 cur->value, cur->value && object_is_reachable (cur->value, start, end) ? "reachable" : "unreachable"));
3367 if (!object_is_reachable (key, start, end)) {
3368 cur->key = tombstone;
3374 if (ptr_in_nursery (key)) {/*key was not promoted*/
3375 DEBUG (5, fprintf (gc_debug_file, "\tAdded remset to key %p\n", key));
3376 sgen_add_to_global_remset (&cur->key);
3378 if (ptr_in_nursery (cur->value)) {/*value was not promoted*/
3379 DEBUG (5, fprintf (gc_debug_file, "\tAdded remset to value %p\n", cur->value));
3380 sgen_add_to_global_remset (&cur->value);
3385 current = current->next;
3389 /* LOCKING: requires that the GC lock is held */
3391 mark_ephemerons_in_range (CopyOrMarkObjectFunc copy_func, char *start, char *end, GrayQueue *queue)
3393 int nothing_marked = 1;
3394 EphemeronLinkNode *current = ephemeron_list;
3396 Ephemeron *cur, *array_end;
3399 for (current = ephemeron_list; current; current = current->next) {
3400 char *object = current->array;
3401 DEBUG (5, fprintf (gc_debug_file, "Ephemeron array at %p\n", object));
3404 For now we process all ephemerons during all collections.
3405 Ideally we should use remset information to partially scan those
3407 We already emit write barriers for Ephemeron fields, it's
3408 just that we don't process them.
3410 /*if (object < start || object >= end)
3413 /*It has to be alive*/
3414 if (!object_is_reachable (object, start, end)) {
3415 DEBUG (5, fprintf (gc_debug_file, "\tnot reachable\n"));
3419 copy_func ((void**)&object, queue);
3421 array = (MonoArray*)object;
3422 cur = mono_array_addr (array, Ephemeron, 0);
3423 array_end = cur + mono_array_length_fast (array);
3424 tombstone = (char*)((MonoVTable*)LOAD_VTABLE (object))->domain->ephemeron_tombstone;
3426 for (; cur < array_end; ++cur) {
3427 char *key = cur->key;
3429 if (!key || key == tombstone)
3432 DEBUG (5, fprintf (gc_debug_file, "[%td] key %p (%s) value %p (%s)\n", cur - mono_array_addr (array, Ephemeron, 0),
3433 key, object_is_reachable (key, start, end) ? "reachable" : "unreachable",
3434 cur->value, cur->value && object_is_reachable (cur->value, start, end) ? "reachable" : "unreachable"));
3436 if (object_is_reachable (key, start, end)) {
3437 char *value = cur->value;
3439 copy_func ((void**)&cur->key, queue);
3441 if (!object_is_reachable (value, start, end))
3443 copy_func ((void**)&cur->value, queue);
3449 DEBUG (5, fprintf (gc_debug_file, "Ephemeron run finished. Is it done %d\n", nothing_marked));
3450 return nothing_marked;
3454 mono_gc_invoke_finalizers (void)
3456 FinalizeReadyEntry *entry = NULL;
3457 gboolean entry_is_critical = FALSE;
3460 /* FIXME: batch to reduce lock contention */
3461 while (fin_ready_list || critical_fin_list) {
3465 FinalizeReadyEntry **list = entry_is_critical ? &critical_fin_list : &fin_ready_list;
3467 /* We have finalized entry in the last
3468 interation, now we need to remove it from
3471 *list = entry->next;
3473 FinalizeReadyEntry *e = *list;
3474 while (e->next != entry)
3476 e->next = entry->next;
3478 sgen_free_internal (entry, INTERNAL_MEM_FINALIZE_READY_ENTRY);
3482 /* Now look for the first non-null entry. */
3483 for (entry = fin_ready_list; entry && !entry->object; entry = entry->next)
3486 entry_is_critical = FALSE;
3488 entry_is_critical = TRUE;
3489 for (entry = critical_fin_list; entry && !entry->object; entry = entry->next)
3494 g_assert (entry->object);
3495 num_ready_finalizers--;
3496 obj = entry->object;
3497 entry->object = NULL;
3498 DEBUG (7, fprintf (gc_debug_file, "Finalizing object %p (%s)\n", obj, safe_name (obj)));
3506 g_assert (entry->object == NULL);
3508 /* the object is on the stack so it is pinned */
3509 /*g_print ("Calling finalizer for object: %p (%s)\n", entry->object, safe_name (entry->object));*/
3510 mono_gc_run_finalize (obj, NULL);
3517 mono_gc_pending_finalizers (void)
3519 return fin_ready_list || critical_fin_list;
3522 /* Negative value to remove */
3524 mono_gc_add_memory_pressure (gint64 value)
3526 /* FIXME: Use interlocked functions */
3528 memory_pressure += value;
3533 sgen_register_major_sections_alloced (int num_sections)
3535 minor_collection_sections_alloced += num_sections;
3539 sgen_get_minor_collection_allowance (void)
3541 return minor_collection_allowance;
3545 * ######################################################################
3546 * ######## registered roots support
3547 * ######################################################################
3551 * We do not coalesce roots.
3554 mono_gc_register_root_inner (char *start, size_t size, void *descr, int root_type)
3556 RootRecord new_root;
3559 for (i = 0; i < ROOT_TYPE_NUM; ++i) {
3560 RootRecord *root = sgen_hash_table_lookup (&roots_hash [i], start);
3561 /* we allow changing the size and the descriptor (for thread statics etc) */
3563 size_t old_size = root->end_root - start;
3564 root->end_root = start + size;
3565 g_assert (((root->root_desc != 0) && (descr != NULL)) ||
3566 ((root->root_desc == 0) && (descr == NULL)));
3567 root->root_desc = (mword)descr;
3569 roots_size -= old_size;
3575 new_root.end_root = start + size;
3576 new_root.root_desc = (mword)descr;
3578 sgen_hash_table_replace (&roots_hash [root_type], start, &new_root);
3581 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));
3588 mono_gc_register_root (char *start, size_t size, void *descr)
3590 return mono_gc_register_root_inner (start, size, descr, descr ? ROOT_TYPE_NORMAL : ROOT_TYPE_PINNED);
3594 mono_gc_register_root_wbarrier (char *start, size_t size, void *descr)
3596 return mono_gc_register_root_inner (start, size, descr, ROOT_TYPE_WBARRIER);
3600 mono_gc_deregister_root (char* addr)
3606 for (root_type = 0; root_type < ROOT_TYPE_NUM; ++root_type) {
3607 if (sgen_hash_table_remove (&roots_hash [root_type], addr, &root))
3608 roots_size -= (root.end_root - addr);
3614 * ######################################################################
3615 * ######## Thread handling (stop/start code)
3616 * ######################################################################
3619 unsigned int sgen_global_stop_count = 0;
3622 static MonoContext cur_thread_ctx = {0};
3624 static mword cur_thread_regs [ARCH_NUM_REGS] = {0};
3628 update_current_thread_stack (void *start)
3630 int stack_guard = 0;
3631 #ifndef USE_MONO_CTX
3632 void *ptr = cur_thread_regs;
3634 SgenThreadInfo *info = mono_thread_info_current ();
3636 info->stack_start = align_pointer (&stack_guard);
3637 g_assert (info->stack_start >= info->stack_start_limit && info->stack_start < info->stack_end);
3639 MONO_CONTEXT_GET_CURRENT (cur_thread_ctx);
3640 info->monoctx = &cur_thread_ctx;
3642 ARCH_STORE_REGS (ptr);
3643 info->stopped_regs = ptr;
3645 if (gc_callbacks.thread_suspend_func)
3646 gc_callbacks.thread_suspend_func (info->runtime_data, NULL);
3650 sgen_fill_thread_info_for_suspend (SgenThreadInfo *info)
3652 if (remset.fill_thread_info_for_suspend)
3653 remset.fill_thread_info_for_suspend (info);
3657 is_ip_in_managed_allocator (MonoDomain *domain, gpointer ip);
3660 restart_threads_until_none_in_managed_allocator (void)
3662 SgenThreadInfo *info;
3663 int num_threads_died = 0;
3664 int sleep_duration = -1;
3667 int restart_count = 0, restarted_count = 0;
3668 /* restart all threads that stopped in the
3670 FOREACH_THREAD_SAFE (info) {
3672 if (info->skip || info->gc_disabled)
3674 if (!info->thread_is_dying && (!info->stack_start || info->in_critical_region ||
3675 is_ip_in_managed_allocator (info->stopped_domain, info->stopped_ip))) {
3676 binary_protocol_thread_restart ((gpointer)mono_thread_info_get_tid (info));
3677 result = sgen_resume_thread (info);
3684 /* we set the stopped_ip to
3685 NULL for threads which
3686 we're not restarting so
3687 that we can easily identify
3689 info->stopped_ip = NULL;
3690 info->stopped_domain = NULL;
3692 } END_FOREACH_THREAD_SAFE
3693 /* if no threads were restarted, we're done */
3694 if (restart_count == 0)
3697 /* wait for the threads to signal their restart */
3698 sgen_wait_for_suspend_ack (restart_count);
3700 if (sleep_duration < 0) {
3708 g_usleep (sleep_duration);
3709 sleep_duration += 10;
3712 /* stop them again */
3713 FOREACH_THREAD (info) {
3715 if (info->skip || info->stopped_ip == NULL)
3717 result = sgen_suspend_thread (info);
3724 } END_FOREACH_THREAD
3725 /* some threads might have died */
3726 num_threads_died += restart_count - restarted_count;
3727 /* wait for the threads to signal their suspension
3729 sgen_wait_for_suspend_ack (restart_count);
3732 return num_threads_died;
3736 acquire_gc_locks (void)
3739 mono_thread_info_suspend_lock ();
3743 release_gc_locks (void)
3745 mono_thread_info_suspend_unlock ();
3746 UNLOCK_INTERRUPTION;
3749 static TV_DECLARE (stop_world_time);
3750 static unsigned long max_pause_usec = 0;
3752 /* LOCKING: assumes the GC lock is held */
3754 stop_world (int generation)
3758 /*XXX this is the right stop, thought might not be the nicest place to put it*/
3759 sgen_process_togglerefs ();
3761 mono_profiler_gc_event (MONO_GC_EVENT_PRE_STOP_WORLD, generation);
3762 acquire_gc_locks ();
3764 update_current_thread_stack (&count);
3766 sgen_global_stop_count++;
3767 DEBUG (3, fprintf (gc_debug_file, "stopping world n %d from %p %p\n", sgen_global_stop_count, mono_thread_info_current (), (gpointer)mono_native_thread_id_get ()));
3768 TV_GETTIME (stop_world_time);
3769 count = sgen_thread_handshake (TRUE);
3770 count -= restart_threads_until_none_in_managed_allocator ();
3771 g_assert (count >= 0);
3772 DEBUG (3, fprintf (gc_debug_file, "world stopped %d thread(s)\n", count));
3773 mono_profiler_gc_event (MONO_GC_EVENT_POST_STOP_WORLD, generation);
3775 last_major_num_sections = major_collector.get_num_major_sections ();
3776 last_los_memory_usage = los_memory_usage;
3777 major_collection_happened = FALSE;
3781 /* LOCKING: assumes the GC lock is held */
3783 restart_world (int generation)
3785 int count, num_major_sections;
3786 SgenThreadInfo *info;
3787 TV_DECLARE (end_sw);
3788 TV_DECLARE (end_bridge);
3789 unsigned long usec, bridge_usec;
3791 /* notify the profiler of the leftovers */
3792 if (G_UNLIKELY (mono_profiler_events & MONO_PROFILE_GC_MOVES)) {
3793 if (moved_objects_idx) {
3794 mono_profiler_gc_moves (moved_objects, moved_objects_idx);
3795 moved_objects_idx = 0;
3798 mono_profiler_gc_event (MONO_GC_EVENT_PRE_START_WORLD, generation);
3799 FOREACH_THREAD (info) {
3800 info->stack_start = NULL;
3802 info->monoctx = NULL;
3804 info->stopped_regs = NULL;
3806 } END_FOREACH_THREAD
3808 stw_bridge_process ();
3809 release_gc_locks ();
3811 count = sgen_thread_handshake (FALSE);
3812 TV_GETTIME (end_sw);
3813 usec = TV_ELAPSED (stop_world_time, end_sw);
3814 max_pause_usec = MAX (usec, max_pause_usec);
3815 DEBUG (2, fprintf (gc_debug_file, "restarted %d thread(s) (pause time: %d usec, max: %d)\n", count, (int)usec, (int)max_pause_usec));
3816 mono_profiler_gc_event (MONO_GC_EVENT_POST_START_WORLD, generation);
3820 TV_GETTIME (end_bridge);
3821 bridge_usec = TV_ELAPSED (end_sw, end_bridge);
3823 num_major_sections = major_collector.get_num_major_sections ();
3824 if (major_collection_happened)
3825 mono_trace (G_LOG_LEVEL_INFO, MONO_TRACE_GC, "GC_MAJOR: %s pause %.2fms, bridge %.2fms major %dK/%dK los %dK/%dK",
3826 generation ? "" : "(minor overflow)",
3827 (int)usec / 1000.0f, (int)bridge_usec / 1000.0f,
3828 major_collector.section_size * num_major_sections / 1024,
3829 major_collector.section_size * last_major_num_sections / 1024,
3830 los_memory_usage / 1024,
3831 last_los_memory_usage / 1024);
3833 mono_trace (G_LOG_LEVEL_INFO, MONO_TRACE_GC, "GC_MINOR: pause %.2fms, bridge %.2fms promoted %dK major %dK los %dK",
3834 (int)usec / 1000.0f, (int)bridge_usec / 1000.0f,
3835 (num_major_sections - last_major_num_sections) * major_collector.section_size / 1024,
3836 major_collector.section_size * num_major_sections / 1024,
3837 los_memory_usage / 1024);
3843 sgen_get_current_collection_generation (void)
3845 return current_collection_generation;
3849 mono_gc_set_gc_callbacks (MonoGCCallbacks *callbacks)
3851 gc_callbacks = *callbacks;
3855 mono_gc_get_gc_callbacks ()
3857 return &gc_callbacks;
3860 /* Variables holding start/end nursery so it won't have to be passed at every call */
3861 static void *scan_area_arg_start, *scan_area_arg_end;
3864 mono_gc_conservatively_scan_area (void *start, void *end)
3866 conservatively_pin_objects_from (start, end, scan_area_arg_start, scan_area_arg_end, PIN_TYPE_STACK);
3870 mono_gc_scan_object (void *obj)
3872 UserCopyOrMarkData *data = mono_native_tls_get_value (user_copy_or_mark_key);
3873 current_object_ops.copy_or_mark_object (&obj, data->queue);
3878 * Mark from thread stacks and registers.
3881 scan_thread_data (void *start_nursery, void *end_nursery, gboolean precise, GrayQueue *queue)
3883 SgenThreadInfo *info;
3885 scan_area_arg_start = start_nursery;
3886 scan_area_arg_end = end_nursery;
3888 FOREACH_THREAD (info) {
3890 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));
3893 if (info->gc_disabled) {
3894 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));
3897 DEBUG (3, fprintf (gc_debug_file, "Scanning thread %p, range: %p-%p, size: %td, pinned=%d\n", info, info->stack_start, info->stack_end, (char*)info->stack_end - (char*)info->stack_start, sgen_get_pinned_count ()));
3898 if (!info->thread_is_dying) {
3899 if (gc_callbacks.thread_mark_func && !conservative_stack_mark) {
3900 UserCopyOrMarkData data = { NULL, queue };
3901 set_user_copy_or_mark_data (&data);
3902 gc_callbacks.thread_mark_func (info->runtime_data, info->stack_start, info->stack_end, precise);
3903 set_user_copy_or_mark_data (NULL);
3904 } else if (!precise) {
3905 conservatively_pin_objects_from (info->stack_start, info->stack_end, start_nursery, end_nursery, PIN_TYPE_STACK);
3910 if (!info->thread_is_dying && !precise)
3911 conservatively_pin_objects_from ((void**)info->monoctx, (void**)info->monoctx + ARCH_NUM_REGS,
3912 start_nursery, end_nursery, PIN_TYPE_STACK);
3914 if (!info->thread_is_dying && !precise)
3915 conservatively_pin_objects_from (info->stopped_regs, info->stopped_regs + ARCH_NUM_REGS,
3916 start_nursery, end_nursery, PIN_TYPE_STACK);
3918 } END_FOREACH_THREAD
3922 find_pinning_ref_from_thread (char *obj, size_t size)
3925 SgenThreadInfo *info;
3926 char *endobj = obj + size;
3928 FOREACH_THREAD (info) {
3929 char **start = (char**)info->stack_start;
3932 while (start < (char**)info->stack_end) {
3933 if (*start >= obj && *start < endobj) {
3934 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));
3939 for (j = 0; j < ARCH_NUM_REGS; ++j) {
3941 mword w = ((mword*)info->monoctx) [j];
3943 mword w = (mword)info->stopped_regs [j];
3946 if (w >= (mword)obj && w < (mword)obj + size)
3947 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)));
3948 } END_FOREACH_THREAD
3953 ptr_on_stack (void *ptr)
3955 gpointer stack_start = &stack_start;
3956 SgenThreadInfo *info = mono_thread_info_current ();
3958 if (ptr >= stack_start && ptr < (gpointer)info->stack_end)
3964 sgen_thread_register (SgenThreadInfo* info, void *addr)
3966 #ifndef HAVE_KW_THREAD
3967 SgenThreadInfo *__thread_info__ = info;
3971 #ifndef HAVE_KW_THREAD
3972 info->tlab_start = info->tlab_next = info->tlab_temp_end = info->tlab_real_end = NULL;
3974 g_assert (!mono_native_tls_get_value (thread_info_key));
3975 mono_native_tls_set_value (thread_info_key, info);
3980 #if !defined(__MACH__)
3981 info->stop_count = -1;
3985 info->doing_handshake = FALSE;
3986 info->thread_is_dying = FALSE;
3987 info->stack_start = NULL;
3988 info->store_remset_buffer_addr = &STORE_REMSET_BUFFER;
3989 info->store_remset_buffer_index_addr = &STORE_REMSET_BUFFER_INDEX;
3990 info->stopped_ip = NULL;
3991 info->stopped_domain = NULL;
3993 info->monoctx = NULL;
3995 info->stopped_regs = NULL;
3998 sgen_init_tlab_info (info);
4000 binary_protocol_thread_register ((gpointer)mono_thread_info_get_tid (info));
4002 #ifdef HAVE_KW_THREAD
4003 store_remset_buffer_index_addr = &store_remset_buffer_index;
4006 #if defined(__MACH__)
4007 info->mach_port = mach_thread_self ();
4010 /* try to get it with attributes first */
4011 #if defined(HAVE_PTHREAD_GETATTR_NP) && defined(HAVE_PTHREAD_ATTR_GETSTACK)
4015 pthread_attr_t attr;
4016 pthread_getattr_np (pthread_self (), &attr);
4017 pthread_attr_getstack (&attr, &sstart, &size);
4018 info->stack_start_limit = sstart;
4019 info->stack_end = (char*)sstart + size;
4020 pthread_attr_destroy (&attr);
4022 #elif defined(HAVE_PTHREAD_GET_STACKSIZE_NP) && defined(HAVE_PTHREAD_GET_STACKADDR_NP)
4023 info->stack_end = (char*)pthread_get_stackaddr_np (pthread_self ());
4024 info->stack_start_limit = (char*)info->stack_end - pthread_get_stacksize_np (pthread_self ());
4027 /* FIXME: we assume the stack grows down */
4028 gsize stack_bottom = (gsize)addr;
4029 stack_bottom += 4095;
4030 stack_bottom &= ~4095;
4031 info->stack_end = (char*)stack_bottom;
4035 #ifdef HAVE_KW_THREAD
4036 stack_end = info->stack_end;
4039 if (remset.register_thread)
4040 remset.register_thread (info);
4042 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));
4044 if (gc_callbacks.thread_attach_func)
4045 info->runtime_data = gc_callbacks.thread_attach_func ();
4052 sgen_wbarrier_cleanup_thread (SgenThreadInfo *p)
4054 if (remset.cleanup_thread)
4055 remset.cleanup_thread (p);
4059 sgen_thread_unregister (SgenThreadInfo *p)
4061 /* If a delegate is passed to native code and invoked on a thread we dont
4062 * know about, the jit will register it with mono_jit_thread_attach, but
4063 * we have no way of knowing when that thread goes away. SGen has a TSD
4064 * so we assume that if the domain is still registered, we can detach
4067 if (mono_domain_get ())
4068 mono_thread_detach (mono_thread_current ());
4070 p->thread_is_dying = TRUE;
4073 There is a race condition between a thread finishing executing and been removed
4074 from the GC thread set.
4075 This happens on posix systems when TLS data is been cleaned-up, libpthread will
4076 set the thread_info slot to NULL before calling the cleanup function. This
4077 opens a window in which the thread is registered but has a NULL TLS.
4079 The suspend signal handler needs TLS data to know where to store thread state
4080 data or otherwise it will simply ignore the thread.
4082 This solution works because the thread doing STW will wait until all threads been
4083 suspended handshake back, so there is no race between the doing_hankshake test
4084 and the suspend_thread call.
4086 This is not required on systems that do synchronous STW as those can deal with
4087 the above race at suspend time.
4089 FIXME: I believe we could avoid this by using mono_thread_info_lookup when
4090 mono_thread_info_current returns NULL. Or fix mono_thread_info_lookup to do so.
4092 #if (defined(__MACH__) && MONO_MACH_ARCH_SUPPORTED) || !defined(HAVE_PTHREAD_KILL)
4095 while (!TRYLOCK_GC) {
4096 if (!sgen_park_current_thread_if_doing_handshake (p))
4101 binary_protocol_thread_unregister ((gpointer)mono_thread_info_get_tid (p));
4102 DEBUG (3, fprintf (gc_debug_file, "unregister thread %p (%p)\n", p, (gpointer)mono_thread_info_get_tid (p)));
4104 #if defined(__MACH__)
4105 mach_port_deallocate (current_task (), p->mach_port);
4108 if (gc_callbacks.thread_detach_func) {
4109 gc_callbacks.thread_detach_func (p->runtime_data);
4110 p->runtime_data = NULL;
4112 sgen_wbarrier_cleanup_thread (p);
4114 mono_threads_unregister_current_thread (p);
4120 sgen_thread_attach (SgenThreadInfo *info)
4123 /*this is odd, can we get attached before the gc is inited?*/
4127 if (gc_callbacks.thread_attach_func && !info->runtime_data)
4128 info->runtime_data = gc_callbacks.thread_attach_func ();
4131 mono_gc_register_thread (void *baseptr)
4133 return mono_thread_info_attach (baseptr) != NULL;
4137 * mono_gc_set_stack_end:
4139 * Set the end of the current threads stack to STACK_END. The stack space between
4140 * STACK_END and the real end of the threads stack will not be scanned during collections.
4143 mono_gc_set_stack_end (void *stack_end)
4145 SgenThreadInfo *info;
4148 info = mono_thread_info_current ();
4150 g_assert (stack_end < info->stack_end);
4151 info->stack_end = stack_end;
4156 #if USE_PTHREAD_INTERCEPT
4160 mono_gc_pthread_create (pthread_t *new_thread, const pthread_attr_t *attr, void *(*start_routine)(void *), void *arg)
4162 return pthread_create (new_thread, attr, start_routine, arg);
4166 mono_gc_pthread_join (pthread_t thread, void **retval)
4168 return pthread_join (thread, retval);
4172 mono_gc_pthread_detach (pthread_t thread)
4174 return pthread_detach (thread);
4178 mono_gc_pthread_exit (void *retval)
4180 pthread_exit (retval);
4183 #endif /* USE_PTHREAD_INTERCEPT */
4186 * ######################################################################
4187 * ######## Write barriers
4188 * ######################################################################
4192 * Note: the write barriers first do the needed GC work and then do the actual store:
4193 * this way the value is visible to the conservative GC scan after the write barrier
4194 * itself. If a GC interrupts the barrier in the middle, value will be kept alive by
4195 * the conservative scan, otherwise by the remembered set scan.
4198 mono_gc_wbarrier_set_field (MonoObject *obj, gpointer field_ptr, MonoObject* value)
4200 HEAVY_STAT (++stat_wbarrier_set_field);
4201 if (ptr_in_nursery (field_ptr)) {
4202 *(void**)field_ptr = value;
4205 DEBUG (8, fprintf (gc_debug_file, "Adding remset at %p\n", field_ptr));
4207 binary_protocol_wbarrier (field_ptr, value, value->vtable);
4209 remset.wbarrier_set_field (obj, field_ptr, value);
4213 mono_gc_wbarrier_set_arrayref (MonoArray *arr, gpointer slot_ptr, MonoObject* value)
4215 HEAVY_STAT (++stat_wbarrier_set_arrayref);
4216 if (ptr_in_nursery (slot_ptr)) {
4217 *(void**)slot_ptr = value;
4220 DEBUG (8, fprintf (gc_debug_file, "Adding remset at %p\n", slot_ptr));
4222 binary_protocol_wbarrier (slot_ptr, value, value->vtable);
4224 remset.wbarrier_set_arrayref (arr, slot_ptr, value);
4228 mono_gc_wbarrier_arrayref_copy (gpointer dest_ptr, gpointer src_ptr, int count)
4230 HEAVY_STAT (++stat_wbarrier_arrayref_copy);
4231 /*This check can be done without taking a lock since dest_ptr array is pinned*/
4232 if (ptr_in_nursery (dest_ptr) || count <= 0) {
4233 mono_gc_memmove (dest_ptr, src_ptr, count * sizeof (gpointer));
4237 #ifdef SGEN_BINARY_PROTOCOL
4240 for (i = 0; i < count; ++i) {
4241 gpointer dest = (gpointer*)dest_ptr + i;
4242 gpointer obj = *((gpointer*)src_ptr + i);
4244 binary_protocol_wbarrier (dest, obj, (gpointer)LOAD_VTABLE (obj));
4249 remset.wbarrier_arrayref_copy (dest_ptr, src_ptr, count);
4252 static char *found_obj;
4255 find_object_for_ptr_callback (char *obj, size_t size, void *user_data)
4257 char *ptr = user_data;
4259 if (ptr >= obj && ptr < obj + size) {
4260 g_assert (!found_obj);
4265 /* for use in the debugger */
4266 char* find_object_for_ptr (char *ptr);
4268 find_object_for_ptr (char *ptr)
4270 if (ptr >= nursery_section->data && ptr < nursery_section->end_data) {
4272 sgen_scan_area_with_callback (nursery_section->data, nursery_section->end_data,
4273 find_object_for_ptr_callback, ptr, TRUE);
4279 sgen_los_iterate_objects (find_object_for_ptr_callback, ptr);
4284 * Very inefficient, but this is debugging code, supposed to
4285 * be called from gdb, so we don't care.
4288 major_collector.iterate_objects (TRUE, TRUE, find_object_for_ptr_callback, ptr);
4293 mono_gc_wbarrier_generic_nostore (gpointer ptr)
4295 HEAVY_STAT (++stat_wbarrier_generic_store);
4297 #ifdef XDOMAIN_CHECKS_IN_WBARRIER
4298 /* FIXME: ptr_in_heap must be called with the GC lock held */
4299 if (xdomain_checks && *(MonoObject**)ptr && ptr_in_heap (ptr)) {
4300 char *start = find_object_for_ptr (ptr);
4301 MonoObject *value = *(MonoObject**)ptr;
4305 MonoObject *obj = (MonoObject*)start;
4306 if (obj->vtable->domain != value->vtable->domain)
4307 g_assert (is_xdomain_ref_allowed (ptr, start, obj->vtable->domain));
4313 if (*(gpointer*)ptr)
4314 binary_protocol_wbarrier (ptr, *(gpointer*)ptr, (gpointer)LOAD_VTABLE (*(gpointer*)ptr));
4316 if (ptr_in_nursery (ptr) || ptr_on_stack (ptr) || !ptr_in_nursery (*(gpointer*)ptr)) {
4317 DEBUG (8, fprintf (gc_debug_file, "Skipping remset at %p\n", ptr));
4321 DEBUG (8, fprintf (gc_debug_file, "Adding remset at %p\n", ptr));
4323 remset.wbarrier_generic_nostore (ptr);
4327 mono_gc_wbarrier_generic_store (gpointer ptr, MonoObject* value)
4329 DEBUG (8, fprintf (gc_debug_file, "Wbarrier store at %p to %p (%s)\n", ptr, value, value ? safe_name (value) : "null"));
4330 *(void**)ptr = value;
4331 if (ptr_in_nursery (value))
4332 mono_gc_wbarrier_generic_nostore (ptr);
4333 sgen_dummy_use (value);
4336 void mono_gc_wbarrier_value_copy_bitmap (gpointer _dest, gpointer _src, int size, unsigned bitmap)
4338 mword *dest = _dest;
4343 mono_gc_wbarrier_generic_store (dest, (MonoObject*)*src);
4348 size -= SIZEOF_VOID_P;
4353 #ifdef SGEN_BINARY_PROTOCOL
4355 #define HANDLE_PTR(ptr,obj) do { \
4356 gpointer o = *(gpointer*)(ptr); \
4358 gpointer d = ((char*)dest) + ((char*)(ptr) - (char*)(obj)); \
4359 binary_protocol_wbarrier (d, o, (gpointer) LOAD_VTABLE (o)); \
4364 scan_object_for_binary_protocol_copy_wbarrier (gpointer dest, char *start, mword desc)
4366 #define SCAN_OBJECT_NOVTABLE
4367 #include "sgen-scan-object.h"
4372 mono_gc_wbarrier_value_copy (gpointer dest, gpointer src, int count, MonoClass *klass)
4374 HEAVY_STAT (++stat_wbarrier_value_copy);
4375 g_assert (klass->valuetype);
4377 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));
4379 if (ptr_in_nursery (dest) || ptr_on_stack (dest) || !SGEN_CLASS_HAS_REFERENCES (klass)) {
4380 size_t element_size = mono_class_value_size (klass, NULL);
4381 size_t size = count * element_size;
4382 mono_gc_memmove (dest, src, size);
4386 #ifdef SGEN_BINARY_PROTOCOL
4389 for (i = 0; i < count; ++i) {
4390 scan_object_for_binary_protocol_copy_wbarrier ((char*)dest + i * element_size,
4391 (char*)src + i * element_size - sizeof (MonoObject),
4392 (mword) klass->gc_descr);
4397 remset.wbarrier_value_copy (dest, src, count, klass);
4401 * mono_gc_wbarrier_object_copy:
4403 * Write barrier to call when obj is the result of a clone or copy of an object.
4406 mono_gc_wbarrier_object_copy (MonoObject* obj, MonoObject *src)
4410 HEAVY_STAT (++stat_wbarrier_object_copy);
4412 if (ptr_in_nursery (obj) || ptr_on_stack (obj)) {
4413 size = mono_object_class (obj)->instance_size;
4414 mono_gc_memmove ((char*)obj + sizeof (MonoObject), (char*)src + sizeof (MonoObject),
4415 size - sizeof (MonoObject));
4419 #ifdef SGEN_BINARY_PROTOCOL
4420 scan_object_for_binary_protocol_copy_wbarrier (obj, (char*)src, (mword) src->vtable->gc_descr);
4423 remset.wbarrier_object_copy (obj, src);
4427 * ######################################################################
4428 * ######## Other mono public interface functions.
4429 * ######################################################################
4432 #define REFS_SIZE 128
4435 MonoGCReferences callback;
4439 MonoObject *refs [REFS_SIZE];
4440 uintptr_t offsets [REFS_SIZE];
4444 #define HANDLE_PTR(ptr,obj) do { \
4446 if (hwi->count == REFS_SIZE) { \
4447 hwi->callback ((MonoObject*)start, mono_object_class (start), hwi->called? 0: size, hwi->count, hwi->refs, hwi->offsets, hwi->data); \
4451 hwi->offsets [hwi->count] = (char*)(ptr)-(char*)start; \
4452 hwi->refs [hwi->count++] = *(ptr); \
4457 collect_references (HeapWalkInfo *hwi, char *start, size_t size)
4459 #include "sgen-scan-object.h"
4463 walk_references (char *start, size_t size, void *data)
4465 HeapWalkInfo *hwi = data;
4468 collect_references (hwi, start, size);
4469 if (hwi->count || !hwi->called)
4470 hwi->callback ((MonoObject*)start, mono_object_class (start), hwi->called? 0: size, hwi->count, hwi->refs, hwi->offsets, hwi->data);
4474 * mono_gc_walk_heap:
4475 * @flags: flags for future use
4476 * @callback: a function pointer called for each object in the heap
4477 * @data: a user data pointer that is passed to callback
4479 * This function can be used to iterate over all the live objects in the heap:
4480 * for each object, @callback is invoked, providing info about the object's
4481 * location in memory, its class, its size and the objects it references.
4482 * For each referenced object it's offset from the object address is
4483 * reported in the offsets array.
4484 * The object references may be buffered, so the callback may be invoked
4485 * multiple times for the same object: in all but the first call, the size
4486 * argument will be zero.
4487 * Note that this function can be only called in the #MONO_GC_EVENT_PRE_START_WORLD
4488 * profiler event handler.
4490 * Returns: a non-zero value if the GC doesn't support heap walking
4493 mono_gc_walk_heap (int flags, MonoGCReferences callback, void *data)
4498 hwi.callback = callback;
4501 sgen_clear_nursery_fragments ();
4502 sgen_scan_area_with_callback (nursery_section->data, nursery_section->end_data, walk_references, &hwi, FALSE);
4504 major_collector.iterate_objects (TRUE, TRUE, walk_references, &hwi);
4505 sgen_los_iterate_objects (walk_references, &hwi);
4511 mono_gc_collect (int generation)
4516 mono_profiler_gc_event (MONO_GC_EVENT_START, generation);
4517 stop_world (generation);
4518 if (generation == 0) {
4519 collect_nursery (0);
4521 major_collection ("user request");
4523 restart_world (generation);
4524 mono_profiler_gc_event (MONO_GC_EVENT_END, generation);
4529 mono_gc_max_generation (void)
4535 mono_gc_collection_count (int generation)
4537 if (generation == 0)
4538 return stat_minor_gcs;
4539 return stat_major_gcs;
4543 mono_gc_get_used_size (void)
4547 tot = los_memory_usage;
4548 tot += nursery_section->next_data - nursery_section->data;
4549 tot += major_collector.get_used_size ();
4550 /* FIXME: account for pinned objects */
4556 mono_gc_get_heap_size (void)
4562 mono_gc_disable (void)
4570 mono_gc_enable (void)
4578 mono_gc_get_los_limit (void)
4580 return MAX_SMALL_OBJ_SIZE;
4584 mono_object_is_alive (MonoObject* o)
4590 mono_gc_get_generation (MonoObject *obj)
4592 if (ptr_in_nursery (obj))
4598 mono_gc_enable_events (void)
4603 mono_gc_weak_link_add (void **link_addr, MonoObject *obj, gboolean track)
4605 mono_gc_register_disappearing_link (obj, link_addr, track, FALSE);
4609 mono_gc_weak_link_remove (void **link_addr)
4611 mono_gc_register_disappearing_link (NULL, link_addr, FALSE, FALSE);
4615 mono_gc_weak_link_get (void **link_addr)
4619 return (MonoObject*) REVEAL_POINTER (*link_addr);
4623 mono_gc_ephemeron_array_add (MonoObject *obj)
4625 EphemeronLinkNode *node;
4629 node = sgen_alloc_internal (INTERNAL_MEM_EPHEMERON_LINK);
4634 node->array = (char*)obj;
4635 node->next = ephemeron_list;
4636 ephemeron_list = node;
4638 DEBUG (5, fprintf (gc_debug_file, "Registered ephemeron array %p\n", obj));
4645 mono_gc_invoke_with_gc_lock (MonoGCLockedCallbackFunc func, void *data)
4649 result = func (data);
4650 UNLOCK_INTERRUPTION;
4655 mono_gc_is_gc_thread (void)
4659 result = mono_thread_info_current () != NULL;
4665 is_critical_method (MonoMethod *method)
4667 return mono_runtime_is_critical_method (method) || mono_gc_is_critical_method (method);
4671 mono_gc_base_init (void)
4673 MonoThreadInfoCallbacks cb;
4676 char *major_collector_opt = NULL;
4677 char *minor_collector_opt = NULL;
4679 glong soft_limit = 0;
4685 result = InterlockedCompareExchange (&gc_initialized, -1, 0);
4688 /* already inited */
4691 /* being inited by another thread */
4695 /* we will init it */
4698 g_assert_not_reached ();
4700 } while (result != 0);
4702 LOCK_INIT (gc_mutex);
4704 pagesize = mono_pagesize ();
4705 gc_debug_file = stderr;
4707 cb.thread_register = sgen_thread_register;
4708 cb.thread_unregister = sgen_thread_unregister;
4709 cb.thread_attach = sgen_thread_attach;
4710 cb.mono_method_is_critical = (gpointer)is_critical_method;
4712 cb.mono_gc_pthread_create = (gpointer)mono_gc_pthread_create;
4715 mono_threads_init (&cb, sizeof (SgenThreadInfo));
4717 LOCK_INIT (interruption_mutex);
4718 LOCK_INIT (pin_queue_mutex);
4720 init_user_copy_or_mark_key ();
4722 if ((env = getenv ("MONO_GC_PARAMS"))) {
4723 opts = g_strsplit (env, ",", -1);
4724 for (ptr = opts; *ptr; ++ptr) {
4726 if (g_str_has_prefix (opt, "major=")) {
4727 opt = strchr (opt, '=') + 1;
4728 major_collector_opt = g_strdup (opt);
4729 } else if (g_str_has_prefix (opt, "minor=")) {
4730 opt = strchr (opt, '=') + 1;
4731 minor_collector_opt = g_strdup (opt);
4739 sgen_init_internal_allocator ();
4740 sgen_init_nursery_allocator ();
4742 sgen_register_fixed_internal_mem_type (INTERNAL_MEM_SECTION, SGEN_SIZEOF_GC_MEM_SECTION);
4743 sgen_register_fixed_internal_mem_type (INTERNAL_MEM_FINALIZE_READY_ENTRY, sizeof (FinalizeReadyEntry));
4744 sgen_register_fixed_internal_mem_type (INTERNAL_MEM_GRAY_QUEUE, sizeof (GrayQueueSection));
4745 g_assert (sizeof (GenericStoreRememberedSet) == sizeof (gpointer) * STORE_REMSET_BUFFER_SIZE);
4746 sgen_register_fixed_internal_mem_type (INTERNAL_MEM_STORE_REMSET, sizeof (GenericStoreRememberedSet));
4747 sgen_register_fixed_internal_mem_type (INTERNAL_MEM_EPHEMERON_LINK, sizeof (EphemeronLinkNode));
4749 #ifndef HAVE_KW_THREAD
4750 mono_native_tls_alloc (&thread_info_key, NULL);
4754 * This needs to happen before any internal allocations because
4755 * it inits the small id which is required for hazard pointer
4760 mono_thread_info_attach (&dummy);
4762 if (!minor_collector_opt) {
4763 sgen_simple_nursery_init (&sgen_minor_collector);
4765 if (!strcmp (minor_collector_opt, "simple"))
4766 sgen_simple_nursery_init (&sgen_minor_collector);
4767 else if (!strcmp (minor_collector_opt, "split"))
4768 sgen_split_nursery_init (&sgen_minor_collector);
4770 fprintf (stderr, "Unknown minor collector `%s'.\n", minor_collector_opt);
4776 if (!major_collector_opt || !strcmp (major_collector_opt, "marksweep")) {
4777 sgen_marksweep_init (&major_collector);
4778 } else if (!major_collector_opt || !strcmp (major_collector_opt, "marksweep-fixed")) {
4779 sgen_marksweep_fixed_init (&major_collector);
4780 } else if (!major_collector_opt || !strcmp (major_collector_opt, "marksweep-par")) {
4781 sgen_marksweep_par_init (&major_collector);
4782 } else if (!major_collector_opt || !strcmp (major_collector_opt, "marksweep-fixed-par")) {
4783 sgen_marksweep_fixed_par_init (&major_collector);
4784 } else if (!strcmp (major_collector_opt, "copying")) {
4785 sgen_copying_init (&major_collector);
4787 fprintf (stderr, "Unknown major collector `%s'.\n", major_collector_opt);
4791 #ifdef SGEN_HAVE_CARDTABLE
4792 use_cardtable = major_collector.supports_cardtable;
4794 use_cardtable = FALSE;
4797 num_workers = mono_cpu_count ();
4798 g_assert (num_workers > 0);
4799 if (num_workers > 16)
4802 ///* Keep this the default for now */
4804 conservative_stack_mark = TRUE;
4807 sgen_nursery_size = DEFAULT_NURSERY_SIZE;
4808 minor_collection_allowance = MIN_MINOR_COLLECTION_ALLOWANCE;
4811 for (ptr = opts; *ptr; ++ptr) {
4813 if (g_str_has_prefix (opt, "major="))
4815 if (g_str_has_prefix (opt, "minor="))
4817 if (g_str_has_prefix (opt, "wbarrier=")) {
4818 opt = strchr (opt, '=') + 1;
4819 if (strcmp (opt, "remset") == 0) {
4820 use_cardtable = FALSE;
4821 } else if (strcmp (opt, "cardtable") == 0) {
4822 if (!use_cardtable) {
4823 if (major_collector.supports_cardtable)
4824 fprintf (stderr, "The cardtable write barrier is not supported on this platform.\n");
4826 fprintf (stderr, "The major collector does not support the cardtable write barrier.\n");
4832 if (g_str_has_prefix (opt, "max-heap-size=")) {
4833 opt = strchr (opt, '=') + 1;
4834 if (*opt && mono_gc_parse_environment_string_extract_number (opt, &max_heap)) {
4835 if ((max_heap & (mono_pagesize () - 1))) {
4836 fprintf (stderr, "max-heap-size size must be a multiple of %d.\n", mono_pagesize ());
4840 fprintf (stderr, "max-heap-size must be an integer.\n");
4845 if (g_str_has_prefix (opt, "soft-heap-limit=")) {
4846 opt = strchr (opt, '=') + 1;
4847 if (*opt && mono_gc_parse_environment_string_extract_number (opt, &soft_limit)) {
4848 if (soft_limit <= 0) {
4849 fprintf (stderr, "soft-heap-limit must be positive.\n");
4853 fprintf (stderr, "soft-heap-limit must be an integer.\n");
4858 if (g_str_has_prefix (opt, "workers=")) {
4861 if (!major_collector.is_parallel) {
4862 fprintf (stderr, "The workers= option can only be used for parallel collectors.");
4865 opt = strchr (opt, '=') + 1;
4866 val = strtol (opt, &endptr, 10);
4867 if (!*opt || *endptr) {
4868 fprintf (stderr, "Cannot parse the workers= option value.");
4871 if (val <= 0 || val > 16) {
4872 fprintf (stderr, "The number of workers must be in the range 1 to 16.");
4875 num_workers = (int)val;
4878 if (g_str_has_prefix (opt, "stack-mark=")) {
4879 opt = strchr (opt, '=') + 1;
4880 if (!strcmp (opt, "precise")) {
4881 conservative_stack_mark = FALSE;
4882 } else if (!strcmp (opt, "conservative")) {
4883 conservative_stack_mark = TRUE;
4885 fprintf (stderr, "Invalid value '%s' for stack-mark= option, possible values are: 'precise', 'conservative'.\n", opt);
4890 if (g_str_has_prefix (opt, "bridge=")) {
4891 opt = strchr (opt, '=') + 1;
4892 sgen_register_test_bridge_callbacks (g_strdup (opt));
4896 if (g_str_has_prefix (opt, "nursery-size=")) {
4898 opt = strchr (opt, '=') + 1;
4899 if (*opt && mono_gc_parse_environment_string_extract_number (opt, &val)) {
4900 sgen_nursery_size = val;
4901 #ifdef SGEN_ALIGN_NURSERY
4902 if ((val & (val - 1))) {
4903 fprintf (stderr, "The nursery size must be a power of two.\n");
4907 if (val < SGEN_MAX_NURSERY_WASTE) {
4908 fprintf (stderr, "The nursery size must be at least %d bytes.\n", SGEN_MAX_NURSERY_WASTE);
4912 sgen_nursery_bits = 0;
4913 while (1 << (++ sgen_nursery_bits) != sgen_nursery_size)
4917 fprintf (stderr, "nursery-size must be an integer.\n");
4923 if (major_collector.handle_gc_param && major_collector.handle_gc_param (opt))
4926 if (sgen_minor_collector.handle_gc_param && sgen_minor_collector.handle_gc_param (opt))
4929 fprintf (stderr, "MONO_GC_PARAMS must be a comma-delimited list of one or more of the following:\n");
4930 fprintf (stderr, " max-heap-size=N (where N is an integer, possibly with a k, m or a g suffix)\n");
4931 fprintf (stderr, " soft-heap-limit=n (where N is an integer, possibly with a k, m or a g suffix)\n");
4932 fprintf (stderr, " nursery-size=N (where N is an integer, possibly with a k, m or a g suffix)\n");
4933 fprintf (stderr, " major=COLLECTOR (where COLLECTOR is `marksweep', `marksweep-par' or `copying')\n");
4934 fprintf (stderr, " minor=COLLECTOR (where COLLECTOR is `simple' or `split')\n");
4935 fprintf (stderr, " wbarrier=WBARRIER (where WBARRIER is `remset' or `cardtable')\n");
4936 fprintf (stderr, " stack-mark=MARK-METHOD (where MARK-METHOD is 'precise' or 'conservative')\n");
4937 if (major_collector.print_gc_param_usage)
4938 major_collector.print_gc_param_usage ();
4939 if (sgen_minor_collector.print_gc_param_usage)
4940 sgen_minor_collector.print_gc_param_usage ();
4946 if (major_collector.is_parallel)
4947 sgen_workers_init (num_workers);
4949 if (major_collector_opt)
4950 g_free (major_collector_opt);
4952 init_heap_size_limits (max_heap, soft_limit);
4956 if ((env = getenv ("MONO_GC_DEBUG"))) {
4957 opts = g_strsplit (env, ",", -1);
4958 for (ptr = opts; ptr && *ptr; ptr ++) {
4960 if (opt [0] >= '0' && opt [0] <= '9') {
4961 gc_debug_level = atoi (opt);
4966 char *rf = g_strdup_printf ("%s.%d", opt, getpid ());
4967 gc_debug_file = fopen (rf, "wb");
4969 gc_debug_file = stderr;
4972 } else if (!strcmp (opt, "print-allowance")) {
4973 debug_print_allowance = TRUE;
4974 } else if (!strcmp (opt, "print-pinning")) {
4975 do_pin_stats = TRUE;
4976 } else if (!strcmp (opt, "collect-before-allocs")) {
4977 collect_before_allocs = 1;
4978 } else if (g_str_has_prefix (opt, "collect-before-allocs=")) {
4979 char *arg = strchr (opt, '=') + 1;
4980 collect_before_allocs = atoi (arg);
4981 } else if (!strcmp (opt, "check-at-minor-collections")) {
4982 consistency_check_at_minor_collection = TRUE;
4983 nursery_clear_policy = CLEAR_AT_GC;
4984 } else if (!strcmp (opt, "xdomain-checks")) {
4985 xdomain_checks = TRUE;
4986 } else if (!strcmp (opt, "clear-at-gc")) {
4987 nursery_clear_policy = CLEAR_AT_GC;
4988 } else if (!strcmp (opt, "clear-nursery-at-gc")) {
4989 nursery_clear_policy = CLEAR_AT_GC;
4990 } else if (!strcmp (opt, "check-scan-starts")) {
4991 do_scan_starts_check = TRUE;
4992 } else if (!strcmp (opt, "verify-nursery-at-minor-gc")) {
4993 do_verify_nursery = TRUE;
4994 } else if (!strcmp (opt, "dump-nursery-at-minor-gc")) {
4995 do_dump_nursery_content = TRUE;
4996 } else if (!strcmp (opt, "disable-minor")) {
4997 disable_minor_collections = TRUE;
4998 } else if (!strcmp (opt, "disable-major")) {
4999 disable_major_collections = TRUE;
5000 } else if (g_str_has_prefix (opt, "heap-dump=")) {
5001 char *filename = strchr (opt, '=') + 1;
5002 nursery_clear_policy = CLEAR_AT_GC;
5003 heap_dump_file = fopen (filename, "w");
5004 if (heap_dump_file) {
5005 fprintf (heap_dump_file, "<sgen-dump>\n");
5006 do_pin_stats = TRUE;
5008 #ifdef SGEN_BINARY_PROTOCOL
5009 } else if (g_str_has_prefix (opt, "binary-protocol=")) {
5010 char *filename = strchr (opt, '=') + 1;
5011 binary_protocol_init (filename);
5013 fprintf (stderr, "Warning: Cardtable write barriers will not be binary-protocolled.\n");
5016 fprintf (stderr, "Invalid format for the MONO_GC_DEBUG env variable: '%s'\n", env);
5017 fprintf (stderr, "The format is: MONO_GC_DEBUG=[l[:filename]|<option>]+ where l is a debug level 0-9.\n");
5018 fprintf (stderr, "Valid options are:\n");
5019 fprintf (stderr, " collect-before-allocs[=<n>]\n");
5020 fprintf (stderr, " check-at-minor-collections\n");
5021 fprintf (stderr, " disable-minor\n");
5022 fprintf (stderr, " disable-major\n");
5023 fprintf (stderr, " xdomain-checks\n");
5024 fprintf (stderr, " clear-at-gc\n");
5025 fprintf (stderr, " print-allowance\n");
5026 fprintf (stderr, " print-pinning\n");
5033 if (major_collector.is_parallel) {
5034 if (heap_dump_file) {
5035 fprintf (stderr, "Error: Cannot do heap dump with the parallel collector.\n");
5039 fprintf (stderr, "Error: Cannot gather pinning statistics with the parallel collector.\n");
5044 if (major_collector.post_param_init)
5045 major_collector.post_param_init ();
5047 memset (&remset, 0, sizeof (remset));
5049 #ifdef SGEN_HAVE_CARDTABLE
5051 sgen_card_table_init (&remset);
5054 sgen_ssb_init (&remset);
5056 if (remset.register_thread)
5057 remset.register_thread (mono_thread_info_current ());
5063 mono_gc_get_gc_name (void)
5068 static MonoMethod *write_barrier_method;
5071 mono_gc_is_critical_method (MonoMethod *method)
5073 return (method == write_barrier_method || sgen_is_managed_allocator (method));
5077 is_ip_in_managed_allocator (MonoDomain *domain, gpointer ip)
5081 if (!mono_thread_internal_current ())
5082 /* Happens during thread attach */
5087 ji = mono_jit_info_table_find (domain, ip);
5091 return mono_gc_is_critical_method (ji->method);
5095 emit_nursery_check (MonoMethodBuilder *mb, int *nursery_check_return_labels)
5097 memset (nursery_check_return_labels, 0, sizeof (int) * 3);
5098 #ifdef SGEN_ALIGN_NURSERY
5099 // if (ptr_in_nursery (ptr)) return;
5101 * Masking out the bits might be faster, but we would have to use 64 bit
5102 * immediates, which might be slower.
5104 mono_mb_emit_ldarg (mb, 0);
5105 mono_mb_emit_icon (mb, DEFAULT_NURSERY_BITS);
5106 mono_mb_emit_byte (mb, CEE_SHR_UN);
5107 mono_mb_emit_icon (mb, (mword)sgen_get_nursery_start () >> DEFAULT_NURSERY_BITS);
5108 nursery_check_return_labels [0] = mono_mb_emit_branch (mb, CEE_BEQ);
5110 // if (!ptr_in_nursery (*ptr)) return;
5111 mono_mb_emit_ldarg (mb, 0);
5112 mono_mb_emit_byte (mb, CEE_LDIND_I);
5113 mono_mb_emit_icon (mb, DEFAULT_NURSERY_BITS);
5114 mono_mb_emit_byte (mb, CEE_SHR_UN);
5115 mono_mb_emit_icon (mb, (mword)sgen_get_nursery_start () >> DEFAULT_NURSERY_BITS);
5116 nursery_check_return_labels [1] = mono_mb_emit_branch (mb, CEE_BNE_UN);
5118 int label_continue1, label_continue2;
5119 int dereferenced_var;
5121 // if (ptr < (sgen_get_nursery_start ())) goto continue;
5122 mono_mb_emit_ldarg (mb, 0);
5123 mono_mb_emit_ptr (mb, (gpointer) sgen_get_nursery_start ());
5124 label_continue_1 = mono_mb_emit_branch (mb, CEE_BLT);
5126 // if (ptr >= sgen_get_nursery_end ())) goto continue;
5127 mono_mb_emit_ldarg (mb, 0);
5128 mono_mb_emit_ptr (mb, (gpointer) sgen_get_nursery_end ());
5129 label_continue_2 = mono_mb_emit_branch (mb, CEE_BGE);
5132 nursery_check_return_labels [0] = mono_mb_emit_branch (mb, CEE_BR);
5135 mono_mb_patch_branch (mb, label_continue_1);
5136 mono_mb_patch_branch (mb, label_continue_2);
5138 // Dereference and store in local var
5139 dereferenced_var = mono_mb_add_local (mb, &mono_defaults.int_class->byval_arg);
5140 mono_mb_emit_ldarg (mb, 0);
5141 mono_mb_emit_byte (mb, CEE_LDIND_I);
5142 mono_mb_emit_stloc (mb, dereferenced_var);
5144 // if (*ptr < sgen_get_nursery_start ()) return;
5145 mono_mb_emit_ldloc (mb, dereferenced_var);
5146 mono_mb_emit_ptr (mb, (gpointer) sgen_get_nursery_start ());
5147 nursery_check_return_labels [1] = mono_mb_emit_branch (mb, CEE_BLT);
5149 // if (*ptr >= sgen_get_nursery_end ()) return;
5150 mono_mb_emit_ldloc (mb, dereferenced_var);
5151 mono_mb_emit_ptr (mb, (gpointer) sgen_get_nursery_end ());
5152 nursery_check_return_labels [2] = mono_mb_emit_branch (mb, CEE_BGE);
5157 mono_gc_get_write_barrier (void)
5160 MonoMethodBuilder *mb;
5161 MonoMethodSignature *sig;
5162 #ifdef MANAGED_WBARRIER
5163 int i, nursery_check_labels [3];
5164 int label_no_wb_3, label_no_wb_4, label_need_wb, label_slow_path;
5165 int buffer_var, buffer_index_var, dummy_var;
5167 #ifdef HAVE_KW_THREAD
5168 int stack_end_offset = -1, store_remset_buffer_offset = -1;
5169 int store_remset_buffer_index_offset = -1, store_remset_buffer_index_addr_offset = -1;
5171 MONO_THREAD_VAR_OFFSET (stack_end, stack_end_offset);
5172 g_assert (stack_end_offset != -1);
5173 MONO_THREAD_VAR_OFFSET (store_remset_buffer, store_remset_buffer_offset);
5174 g_assert (store_remset_buffer_offset != -1);
5175 MONO_THREAD_VAR_OFFSET (store_remset_buffer_index, store_remset_buffer_index_offset);
5176 g_assert (store_remset_buffer_index_offset != -1);
5177 MONO_THREAD_VAR_OFFSET (store_remset_buffer_index_addr, store_remset_buffer_index_addr_offset);
5178 g_assert (store_remset_buffer_index_addr_offset != -1);
5182 // FIXME: Maybe create a separate version for ctors (the branch would be
5183 // correctly predicted more times)
5184 if (write_barrier_method)
5185 return write_barrier_method;
5187 /* Create the IL version of mono_gc_barrier_generic_store () */
5188 sig = mono_metadata_signature_alloc (mono_defaults.corlib, 1);
5189 sig->ret = &mono_defaults.void_class->byval_arg;
5190 sig->params [0] = &mono_defaults.int_class->byval_arg;
5192 mb = mono_mb_new (mono_defaults.object_class, "wbarrier", MONO_WRAPPER_WRITE_BARRIER);
5194 #ifdef MANAGED_WBARRIER
5195 if (use_cardtable) {
5196 emit_nursery_check (mb, nursery_check_labels);
5198 addr = sgen_cardtable + ((address >> CARD_BITS) & CARD_MASK)
5202 LDC_PTR sgen_cardtable
5204 address >> CARD_BITS
5208 if (SGEN_HAVE_OVERLAPPING_CARDS) {
5209 LDC_PTR card_table_mask
5216 mono_mb_emit_ptr (mb, sgen_cardtable);
5217 mono_mb_emit_ldarg (mb, 0);
5218 mono_mb_emit_icon (mb, CARD_BITS);
5219 mono_mb_emit_byte (mb, CEE_SHR_UN);
5220 #ifdef SGEN_HAVE_OVERLAPPING_CARDS
5221 mono_mb_emit_ptr (mb, (gpointer)CARD_MASK);
5222 mono_mb_emit_byte (mb, CEE_AND);
5224 mono_mb_emit_byte (mb, CEE_ADD);
5225 mono_mb_emit_icon (mb, 1);
5226 mono_mb_emit_byte (mb, CEE_STIND_I1);
5229 for (i = 0; i < 3; ++i) {
5230 if (nursery_check_labels [i])
5231 mono_mb_patch_branch (mb, nursery_check_labels [i]);
5233 mono_mb_emit_byte (mb, CEE_RET);
5234 } else if (mono_runtime_has_tls_get ()) {
5235 emit_nursery_check (mb, nursery_check_labels);
5237 // if (ptr >= stack_end) goto need_wb;
5238 mono_mb_emit_ldarg (mb, 0);
5239 EMIT_TLS_ACCESS (mb, stack_end, stack_end_offset);
5240 label_need_wb = mono_mb_emit_branch (mb, CEE_BGE_UN);
5242 // if (ptr >= stack_start) return;
5243 dummy_var = mono_mb_add_local (mb, &mono_defaults.int_class->byval_arg);
5244 mono_mb_emit_ldarg (mb, 0);
5245 mono_mb_emit_ldloc_addr (mb, dummy_var);
5246 label_no_wb_3 = mono_mb_emit_branch (mb, CEE_BGE_UN);
5249 mono_mb_patch_branch (mb, label_need_wb);
5251 // buffer = STORE_REMSET_BUFFER;
5252 buffer_var = mono_mb_add_local (mb, &mono_defaults.int_class->byval_arg);
5253 EMIT_TLS_ACCESS (mb, store_remset_buffer, store_remset_buffer_offset);
5254 mono_mb_emit_stloc (mb, buffer_var);
5256 // buffer_index = STORE_REMSET_BUFFER_INDEX;
5257 buffer_index_var = mono_mb_add_local (mb, &mono_defaults.int_class->byval_arg);
5258 EMIT_TLS_ACCESS (mb, store_remset_buffer_index, store_remset_buffer_index_offset);
5259 mono_mb_emit_stloc (mb, buffer_index_var);
5261 // if (buffer [buffer_index] == ptr) return;
5262 mono_mb_emit_ldloc (mb, buffer_var);
5263 mono_mb_emit_ldloc (mb, buffer_index_var);
5264 g_assert (sizeof (gpointer) == 4 || sizeof (gpointer) == 8);
5265 mono_mb_emit_icon (mb, sizeof (gpointer) == 4 ? 2 : 3);
5266 mono_mb_emit_byte (mb, CEE_SHL);
5267 mono_mb_emit_byte (mb, CEE_ADD);
5268 mono_mb_emit_byte (mb, CEE_LDIND_I);
5269 mono_mb_emit_ldarg (mb, 0);
5270 label_no_wb_4 = mono_mb_emit_branch (mb, CEE_BEQ);
5273 mono_mb_emit_ldloc (mb, buffer_index_var);
5274 mono_mb_emit_icon (mb, 1);
5275 mono_mb_emit_byte (mb, CEE_ADD);
5276 mono_mb_emit_stloc (mb, buffer_index_var);
5278 // if (buffer_index >= STORE_REMSET_BUFFER_SIZE) goto slow_path;
5279 mono_mb_emit_ldloc (mb, buffer_index_var);
5280 mono_mb_emit_icon (mb, STORE_REMSET_BUFFER_SIZE);
5281 label_slow_path = mono_mb_emit_branch (mb, CEE_BGE);
5283 // buffer [buffer_index] = ptr;
5284 mono_mb_emit_ldloc (mb, buffer_var);
5285 mono_mb_emit_ldloc (mb, buffer_index_var);
5286 g_assert (sizeof (gpointer) == 4 || sizeof (gpointer) == 8);
5287 mono_mb_emit_icon (mb, sizeof (gpointer) == 4 ? 2 : 3);
5288 mono_mb_emit_byte (mb, CEE_SHL);
5289 mono_mb_emit_byte (mb, CEE_ADD);
5290 mono_mb_emit_ldarg (mb, 0);
5291 mono_mb_emit_byte (mb, CEE_STIND_I);
5293 // STORE_REMSET_BUFFER_INDEX = buffer_index;
5294 EMIT_TLS_ACCESS (mb, store_remset_buffer_index_addr, store_remset_buffer_index_addr_offset);
5295 mono_mb_emit_ldloc (mb, buffer_index_var);
5296 mono_mb_emit_byte (mb, CEE_STIND_I);
5299 for (i = 0; i < 3; ++i) {
5300 if (nursery_check_labels [i])
5301 mono_mb_patch_branch (mb, nursery_check_labels [i]);
5303 mono_mb_patch_branch (mb, label_no_wb_3);
5304 mono_mb_patch_branch (mb, label_no_wb_4);
5305 mono_mb_emit_byte (mb, CEE_RET);
5308 mono_mb_patch_branch (mb, label_slow_path);
5310 mono_mb_emit_ldarg (mb, 0);
5311 mono_mb_emit_icall (mb, mono_gc_wbarrier_generic_nostore);
5312 mono_mb_emit_byte (mb, CEE_RET);
5316 mono_mb_emit_ldarg (mb, 0);
5317 mono_mb_emit_icall (mb, mono_gc_wbarrier_generic_nostore);
5318 mono_mb_emit_byte (mb, CEE_RET);
5321 res = mono_mb_create_method (mb, sig, 16);
5324 mono_loader_lock ();
5325 if (write_barrier_method) {
5326 /* Already created */
5327 mono_free_method (res);
5329 /* double-checked locking */
5330 mono_memory_barrier ();
5331 write_barrier_method = res;
5333 mono_loader_unlock ();
5335 return write_barrier_method;
5339 mono_gc_get_description (void)
5341 return g_strdup ("sgen");
5345 mono_gc_set_desktop_mode (void)
5350 mono_gc_is_moving (void)
5356 mono_gc_is_disabled (void)
5362 sgen_debug_printf (int level, const char *format, ...)
5366 if (level > gc_debug_level)
5369 va_start (ap, format);
5370 vfprintf (gc_debug_file, format, ap);
5375 sgen_get_logfile (void)
5377 return gc_debug_file;
5381 BOOL APIENTRY mono_gc_dllmain (HMODULE module_handle, DWORD reason, LPVOID reserved)
5388 sgen_get_nursery_clear_policy (void)
5390 return nursery_clear_policy;
5394 sgen_get_array_fill_vtable (void)
5396 if (!array_fill_vtable) {
5397 static MonoClass klass;
5398 static MonoVTable vtable;
5401 MonoDomain *domain = mono_get_root_domain ();
5404 klass.element_class = mono_defaults.byte_class;
5406 klass.instance_size = sizeof (MonoArray);
5407 klass.sizes.element_size = 1;
5408 klass.name = "array_filler_type";
5410 vtable.klass = &klass;
5412 vtable.gc_descr = mono_gc_make_descr_for_array (TRUE, &bmap, 0, 1);
5415 array_fill_vtable = &vtable;
5417 return array_fill_vtable;
5427 sgen_gc_unlock (void)
5433 sgen_major_collector_iterate_live_block_ranges (sgen_cardtable_block_callback callback)
5435 major_collector.iterate_live_block_ranges (callback);
5439 sgen_major_collector_scan_card_table (SgenGrayQueue *queue)
5441 major_collector.scan_card_table (queue);
5445 sgen_get_major_collector (void)
5447 return &major_collector;
5450 void mono_gc_set_skip_thread (gboolean skip)
5452 SgenThreadInfo *info = mono_thread_info_current ();
5455 info->gc_disabled = skip;
5460 sgen_get_remset (void)
5466 mono_gc_get_vtable_bits (MonoClass *class)
5468 if (sgen_need_bridge_processing () && sgen_is_bridge_class (class))
5469 return SGEN_GC_BIT_BRIDGE_OBJECT;
5473 #endif /* HAVE_SGEN_GC */