2 * sgen-gc.c: Simple generational GC.
5 * Paolo Molaro (lupus@ximian.com)
6 * Rodrigo Kumpera (kumpera@gmail.com)
8 * Copyright 2005-2011 Novell, Inc (http://www.novell.com)
9 * Copyright 2011 Xamarin Inc (http://www.xamarin.com)
11 * Thread start/stop adapted from Boehm's GC:
12 * Copyright (c) 1994 by Xerox Corporation. All rights reserved.
13 * Copyright (c) 1996 by Silicon Graphics. All rights reserved.
14 * Copyright (c) 1998 by Fergus Henderson. All rights reserved.
15 * Copyright (c) 2000-2004 by Hewlett-Packard Company. All rights reserved.
17 * THIS MATERIAL IS PROVIDED AS IS, WITH ABSOLUTELY NO WARRANTY EXPRESSED
18 * OR IMPLIED. ANY USE IS AT YOUR OWN RISK.
20 * Permission is hereby granted to use or copy this program
21 * for any purpose, provided the above notices are retained on all copies.
22 * Permission to modify the code and to distribute modified code is granted,
23 * provided the above notices are retained, and a notice that the code was
24 * modified is included with the above copyright notice.
27 * Copyright 2001-2003 Ximian, Inc
28 * Copyright 2003-2010 Novell, Inc.
29 * Copyright 2011 Xamarin, Inc.
31 * Permission is hereby granted, free of charge, to any person obtaining
32 * a copy of this software and associated documentation files (the
33 * "Software"), to deal in the Software without restriction, including
34 * without limitation the rights to use, copy, modify, merge, publish,
35 * distribute, sublicense, and/or sell copies of the Software, and to
36 * permit persons to whom the Software is furnished to do so, subject to
37 * the following conditions:
39 * The above copyright notice and this permission notice shall be
40 * included in all copies or substantial portions of the Software.
42 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
43 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
44 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
45 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
46 * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
47 * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
48 * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
51 * Important: allocation provides always zeroed memory, having to do
52 * a memset after allocation is deadly for performance.
53 * Memory usage at startup is currently as follows:
55 * 64 KB internal space
57 * We should provide a small memory config with half the sizes
59 * We currently try to make as few mono assumptions as possible:
60 * 1) 2-word header with no GC pointers in it (first vtable, second to store the
62 * 2) gc descriptor is the second word in the vtable (first word in the class)
63 * 3) 8 byte alignment is the minimum and enough (not true for special structures (SIMD), FIXME)
64 * 4) there is a function to get an object's size and the number of
65 * elements in an array.
66 * 5) we know the special way bounds are allocated for complex arrays
67 * 6) we know about proxies and how to treat them when domains are unloaded
69 * Always try to keep stack usage to a minimum: no recursive behaviour
70 * and no large stack allocs.
72 * General description.
73 * Objects are initially allocated in a nursery using a fast bump-pointer technique.
74 * When the nursery is full we start a nursery collection: this is performed with a
76 * When the old generation is full we start a copying GC of the old generation as well:
77 * this will be changed to mark&sweep with copying when fragmentation becomes to severe
78 * in the future. Maybe we'll even do both during the same collection like IMMIX.
80 * The things that complicate this description are:
81 * *) pinned objects: we can't move them so we need to keep track of them
82 * *) no precise info of the thread stacks and registers: we need to be able to
83 * quickly find the objects that may be referenced conservatively and pin them
84 * (this makes the first issues more important)
85 * *) large objects are too expensive to be dealt with using copying GC: we handle them
86 * with mark/sweep during major collections
87 * *) some objects need to not move even if they are small (interned strings, Type handles):
88 * we use mark/sweep for them, too: they are not allocated in the nursery, but inside
89 * PinnedChunks regions
95 *) we could have a function pointer in MonoClass to implement
96 customized write barriers for value types
98 *) investigate the stuff needed to advance a thread to a GC-safe
99 point (single-stepping, read from unmapped memory etc) and implement it.
100 This would enable us to inline allocations and write barriers, for example,
101 or at least parts of them, like the write barrier checks.
102 We may need this also for handling precise info on stacks, even simple things
103 as having uninitialized data on the stack and having to wait for the prolog
104 to zero it. Not an issue for the last frame that we scan conservatively.
105 We could always not trust the value in the slots anyway.
107 *) modify the jit to save info about references in stack locations:
108 this can be done just for locals as a start, so that at least
109 part of the stack is handled precisely.
111 *) test/fix endianess issues
113 *) Implement a card table as the write barrier instead of remembered
114 sets? Card tables are not easy to implement with our current
115 memory layout. We have several different kinds of major heap
116 objects: Small objects in regular blocks, small objects in pinned
117 chunks and LOS objects. If we just have a pointer we have no way
118 to tell which kind of object it points into, therefore we cannot
119 know where its card table is. The least we have to do to make
120 this happen is to get rid of write barriers for indirect stores.
123 *) Get rid of write barriers for indirect stores. We can do this by
124 telling the GC to wbarrier-register an object once we do an ldloca
125 or ldelema on it, and to unregister it once it's not used anymore
126 (it can only travel downwards on the stack). The problem with
127 unregistering is that it needs to happen eventually no matter
128 what, even if exceptions are thrown, the thread aborts, etc.
129 Rodrigo suggested that we could do only the registering part and
130 let the collector find out (pessimistically) when it's safe to
131 unregister, namely when the stack pointer of the thread that
132 registered the object is higher than it was when the registering
133 happened. This might make for a good first implementation to get
134 some data on performance.
136 *) Some sort of blacklist support? Blacklists is a concept from the
137 Boehm GC: if during a conservative scan we find pointers to an
138 area which we might use as heap, we mark that area as unusable, so
139 pointer retention by random pinning pointers is reduced.
141 *) experiment with max small object size (very small right now - 2kb,
142 because it's tied to the max freelist size)
144 *) add an option to mmap the whole heap in one chunk: it makes for many
145 simplifications in the checks (put the nursery at the top and just use a single
146 check for inclusion/exclusion): the issue this has is that on 32 bit systems it's
147 not flexible (too much of the address space may be used by default or we can't
148 increase the heap as needed) and we'd need a race-free mechanism to return memory
149 back to the system (mprotect(PROT_NONE) will still keep the memory allocated if it
150 was written to, munmap is needed, but the following mmap may not find the same segment
153 *) memzero the major fragments after restarting the world and optionally a smaller
156 *) investigate having fragment zeroing threads
158 *) separate locks for finalization and other minor stuff to reduce
161 *) try a different copying order to improve memory locality
163 *) a thread abort after a store but before the write barrier will
164 prevent the write barrier from executing
166 *) specialized dynamically generated markers/copiers
168 *) Dynamically adjust TLAB size to the number of threads. If we have
169 too many threads that do allocation, we might need smaller TLABs,
170 and we might get better performance with larger TLABs if we only
171 have a handful of threads. We could sum up the space left in all
172 assigned TLABs and if that's more than some percentage of the
173 nursery size, reduce the TLAB size.
175 *) Explore placing unreachable objects on unused nursery memory.
176 Instead of memset'ng a region to zero, place an int[] covering it.
177 A good place to start is add_nursery_frag. The tricky thing here is
178 placing those objects atomically outside of a collection.
180 *) Allocation should use asymmetric Dekker synchronization:
181 http://blogs.oracle.com/dave/resource/Asymmetric-Dekker-Synchronization.txt
182 This should help weak consistency archs.
190 #ifdef HAVE_PTHREAD_H
193 #ifdef HAVE_SEMAPHORE_H
194 #include <semaphore.h>
205 #define _XOPEN_SOURCE
208 #include "metadata/sgen-gc.h"
209 #include "metadata/metadata-internals.h"
210 #include "metadata/class-internals.h"
211 #include "metadata/gc-internal.h"
212 #include "metadata/object-internals.h"
213 #include "metadata/threads.h"
214 #include "metadata/sgen-cardtable.h"
215 #include "metadata/sgen-ssb.h"
216 #include "metadata/sgen-protocol.h"
217 #include "metadata/sgen-archdep.h"
218 #include "metadata/sgen-bridge.h"
219 #include "metadata/mono-gc.h"
220 #include "metadata/method-builder.h"
221 #include "metadata/profiler-private.h"
222 #include "metadata/monitor.h"
223 #include "metadata/threadpool-internals.h"
224 #include "metadata/mempool-internals.h"
225 #include "metadata/marshal.h"
226 #include "metadata/runtime.h"
227 #include "metadata/sgen-cardtable.h"
228 #include "metadata/sgen-pinning.h"
229 #include "metadata/sgen-workers.h"
230 #include "utils/mono-mmap.h"
231 #include "utils/mono-time.h"
232 #include "utils/mono-semaphore.h"
233 #include "utils/mono-counters.h"
234 #include "utils/mono-proclib.h"
235 #include "utils/mono-memory-model.h"
236 #include "utils/mono-logger-internal.h"
238 #include <mono/utils/mono-logger-internal.h>
239 #include <mono/utils/memcheck.h>
241 #if defined(__MACH__)
242 #include "utils/mach-support.h"
245 #define OPDEF(a,b,c,d,e,f,g,h,i,j) \
249 #include "mono/cil/opcode.def"
255 #undef pthread_create
257 #undef pthread_detach
260 * ######################################################################
261 * ######## Types and constants used by the GC.
262 * ######################################################################
265 /* 0 means not initialized, 1 is initialized, -1 means in progress */
266 static gint32 gc_initialized = 0;
267 /* If set, do a minor collection before every X allocation */
268 guint32 collect_before_allocs = 0;
269 /* If set, do a heap consistency check before each minor collection */
270 static gboolean consistency_check_at_minor_collection = FALSE;
271 /* If set, check that there are no references to the domain left at domain unload */
272 static gboolean xdomain_checks = FALSE;
273 /* If not null, dump the heap after each collection into this file */
274 static FILE *heap_dump_file = NULL;
275 /* If set, mark stacks conservatively, even if precise marking is possible */
276 static gboolean conservative_stack_mark = FALSE;
277 /* If set, do a plausibility check on the scan_starts before and after
279 static gboolean do_scan_starts_check = FALSE;
280 static gboolean nursery_collection_is_parallel = FALSE;
281 static gboolean disable_minor_collections = FALSE;
282 static gboolean disable_major_collections = FALSE;
283 gboolean do_pin_stats = FALSE;
284 static gboolean do_verify_nursery = FALSE;
285 static gboolean do_dump_nursery_content = FALSE;
287 #ifdef HEAVY_STATISTICS
288 long long stat_objects_alloced_degraded = 0;
289 long long stat_bytes_alloced_degraded = 0;
291 long long stat_copy_object_called_nursery = 0;
292 long long stat_objects_copied_nursery = 0;
293 long long stat_copy_object_called_major = 0;
294 long long stat_objects_copied_major = 0;
296 long long stat_scan_object_called_nursery = 0;
297 long long stat_scan_object_called_major = 0;
299 long long stat_nursery_copy_object_failed_from_space = 0;
300 long long stat_nursery_copy_object_failed_forwarded = 0;
301 long long stat_nursery_copy_object_failed_pinned = 0;
303 static int stat_wbarrier_set_field = 0;
304 static int stat_wbarrier_set_arrayref = 0;
305 static int stat_wbarrier_arrayref_copy = 0;
306 static int stat_wbarrier_generic_store = 0;
307 static int stat_wbarrier_set_root = 0;
308 static int stat_wbarrier_value_copy = 0;
309 static int stat_wbarrier_object_copy = 0;
312 int stat_minor_gcs = 0;
313 int stat_major_gcs = 0;
315 static long long stat_pinned_objects = 0;
317 static long long time_minor_pre_collection_fragment_clear = 0;
318 static long long time_minor_pinning = 0;
319 static long long time_minor_scan_remsets = 0;
320 static long long time_minor_scan_pinned = 0;
321 static long long time_minor_scan_registered_roots = 0;
322 static long long time_minor_scan_thread_data = 0;
323 static long long time_minor_finish_gray_stack = 0;
324 static long long time_minor_fragment_creation = 0;
326 static long long time_major_pre_collection_fragment_clear = 0;
327 static long long time_major_pinning = 0;
328 static long long time_major_scan_pinned = 0;
329 static long long time_major_scan_registered_roots = 0;
330 static long long time_major_scan_thread_data = 0;
331 static long long time_major_scan_alloc_pinned = 0;
332 static long long time_major_scan_finalized = 0;
333 static long long time_major_scan_big_objects = 0;
334 static long long time_major_finish_gray_stack = 0;
335 static long long time_major_free_bigobjs = 0;
336 static long long time_major_los_sweep = 0;
337 static long long time_major_sweep = 0;
338 static long long time_major_fragment_creation = 0;
340 int gc_debug_level = 0;
342 static gboolean debug_print_allowance = FALSE;
346 mono_gc_flush_info (void)
348 fflush (gc_debug_file);
352 #define TV_DECLARE SGEN_TV_DECLARE
353 #define TV_GETTIME SGEN_TV_GETTIME
354 #define TV_ELAPSED SGEN_TV_ELAPSED
355 #define TV_ELAPSED_MS SGEN_TV_ELAPSED_MS
357 #define ALIGN_TO(val,align) ((((guint64)val) + ((align) - 1)) & ~((align) - 1))
359 NurseryClearPolicy nursery_clear_policy = CLEAR_AT_TLAB_CREATION;
361 /* the runtime can register areas of memory as roots: we keep two lists of roots,
362 * a pinned root set for conservatively scanned roots and a normal one for
363 * precisely scanned roots (currently implemented as a single list).
365 typedef struct _RootRecord RootRecord;
371 #define object_is_forwarded SGEN_OBJECT_IS_FORWARDED
372 #define object_is_pinned SGEN_OBJECT_IS_PINNED
373 #define pin_object SGEN_PIN_OBJECT
374 #define unpin_object SGEN_UNPIN_OBJECT
376 #define ptr_in_nursery mono_sgen_ptr_in_nursery
378 #define LOAD_VTABLE SGEN_LOAD_VTABLE
381 safe_name (void* obj)
383 MonoVTable *vt = (MonoVTable*)LOAD_VTABLE (obj);
384 return vt->klass->name;
387 #define safe_object_get_size mono_sgen_safe_object_get_size
390 mono_sgen_safe_name (void* obj)
392 return safe_name (obj);
396 * ######################################################################
397 * ######## Global data.
398 * ######################################################################
400 LOCK_DECLARE (gc_mutex);
401 static int gc_disabled = 0;
403 static gboolean use_cardtable;
405 #define MIN_MINOR_COLLECTION_ALLOWANCE (DEFAULT_NURSERY_SIZE * 4)
407 #define SCAN_START_SIZE SGEN_SCAN_START_SIZE
409 static mword pagesize = 4096;
410 static mword nursery_size;
411 int degraded_mode = 0;
413 static mword bytes_pinned_from_failed_allocation = 0;
415 static mword total_alloc = 0;
416 /* use this to tune when to do a major/minor collection */
417 static mword memory_pressure = 0;
418 static mword minor_collection_allowance;
419 static int minor_collection_sections_alloced = 0;
422 /* GC Logging stats */
423 static int last_major_num_sections = 0;
424 static int last_los_memory_usage = 0;
425 static gboolean major_collection_happened = FALSE;
427 GCMemSection *nursery_section = NULL;
428 static mword lowest_heap_address = ~(mword)0;
429 static mword highest_heap_address = 0;
431 static LOCK_DECLARE (interruption_mutex);
432 static LOCK_DECLARE (pin_queue_mutex);
434 #define LOCK_PIN_QUEUE mono_mutex_lock (&pin_queue_mutex)
435 #define UNLOCK_PIN_QUEUE mono_mutex_unlock (&pin_queue_mutex)
437 typedef struct _FinalizeReadyEntry FinalizeReadyEntry;
438 struct _FinalizeReadyEntry {
439 FinalizeReadyEntry *next;
443 typedef struct _EphemeronLinkNode EphemeronLinkNode;
445 struct _EphemeronLinkNode {
446 EphemeronLinkNode *next;
455 int current_collection_generation = -1;
458 * The link pointer is hidden by negating each bit. We use the lowest
459 * bit of the link (before negation) to store whether it needs
460 * resurrection tracking.
462 #define HIDE_POINTER(p,t) ((gpointer)(~((gulong)(p)|((t)?1:0))))
463 #define REVEAL_POINTER(p) ((gpointer)((~(gulong)(p))&~3L))
465 /* objects that are ready to be finalized */
466 static FinalizeReadyEntry *fin_ready_list = NULL;
467 static FinalizeReadyEntry *critical_fin_list = NULL;
469 static EphemeronLinkNode *ephemeron_list;
471 static int num_ready_finalizers = 0;
472 static int no_finalize = 0;
475 ROOT_TYPE_NORMAL = 0, /* "normal" roots */
476 ROOT_TYPE_PINNED = 1, /* roots without a GC descriptor */
477 ROOT_TYPE_WBARRIER = 2, /* roots with a write barrier */
481 /* registered roots: the key to the hash is the root start address */
483 * Different kinds of roots are kept separate to speed up pin_from_roots () for example.
485 static SgenHashTable roots_hash [ROOT_TYPE_NUM] = {
486 SGEN_HASH_TABLE_INIT (INTERNAL_MEM_ROOTS_TABLE, INTERNAL_MEM_ROOT_RECORD, sizeof (RootRecord), mono_aligned_addr_hash, NULL),
487 SGEN_HASH_TABLE_INIT (INTERNAL_MEM_ROOTS_TABLE, INTERNAL_MEM_ROOT_RECORD, sizeof (RootRecord), mono_aligned_addr_hash, NULL),
488 SGEN_HASH_TABLE_INIT (INTERNAL_MEM_ROOTS_TABLE, INTERNAL_MEM_ROOT_RECORD, sizeof (RootRecord), mono_aligned_addr_hash, NULL)
490 static mword roots_size = 0; /* amount of memory in the root set */
492 #define GC_ROOT_NUM 32
495 void *objects [GC_ROOT_NUM];
496 int root_types [GC_ROOT_NUM];
497 uintptr_t extra_info [GC_ROOT_NUM];
501 notify_gc_roots (GCRootReport *report)
505 mono_profiler_gc_roots (report->count, report->objects, report->root_types, report->extra_info);
510 add_profile_gc_root (GCRootReport *report, void *object, int rtype, uintptr_t extra_info)
512 if (report->count == GC_ROOT_NUM)
513 notify_gc_roots (report);
514 report->objects [report->count] = object;
515 report->root_types [report->count] = rtype;
516 report->extra_info [report->count++] = (uintptr_t)((MonoVTable*)LOAD_VTABLE (object))->klass;
519 MonoNativeTlsKey thread_info_key;
521 #ifdef HAVE_KW_THREAD
522 __thread SgenThreadInfo *thread_info;
523 __thread gpointer *store_remset_buffer;
524 __thread long store_remset_buffer_index;
525 __thread char *stack_end;
526 __thread long *store_remset_buffer_index_addr;
529 /* The size of a TLAB */
530 /* The bigger the value, the less often we have to go to the slow path to allocate a new
531 * one, but the more space is wasted by threads not allocating much memory.
533 * FIXME: Make this self-tuning for each thread.
535 guint32 tlab_size = (1024 * 4);
537 #define MAX_SMALL_OBJ_SIZE SGEN_MAX_SMALL_OBJ_SIZE
539 /* Functions supplied by the runtime to be called by the GC */
540 static MonoGCCallbacks gc_callbacks;
542 #define ALLOC_ALIGN SGEN_ALLOC_ALIGN
543 #define ALLOC_ALIGN_BITS SGEN_ALLOC_ALIGN_BITS
545 #define ALIGN_UP SGEN_ALIGN_UP
547 #define MOVED_OBJECTS_NUM 64
548 static void *moved_objects [MOVED_OBJECTS_NUM];
549 static int moved_objects_idx = 0;
551 /* Vtable of the objects used to fill out nursery fragments before a collection */
552 static MonoVTable *array_fill_vtable;
554 #ifdef SGEN_DEBUG_INTERNAL_ALLOC
555 MonoNativeThreadId main_gc_thread = NULL;
559 * ######################################################################
560 * ######## Heap size accounting
561 * ######################################################################
564 static mword max_heap_size = ((mword)0)- ((mword)1);
565 static mword soft_heap_limit = ((mword)0) - ((mword)1);
566 static mword allocated_heap;
568 /*Object was pinned during the current collection*/
569 static mword objects_pinned;
572 mono_sgen_release_space (mword size, int space)
574 allocated_heap -= size;
578 available_free_space (void)
580 return max_heap_size - MIN (allocated_heap, max_heap_size);
584 mono_sgen_try_alloc_space (mword size, int space)
586 if (available_free_space () < size)
589 allocated_heap += size;
590 mono_runtime_resource_check_limit (MONO_RESOURCE_GC_HEAP, allocated_heap);
595 init_heap_size_limits (glong max_heap, glong soft_limit)
598 soft_heap_limit = soft_limit;
603 if (max_heap < soft_limit) {
604 fprintf (stderr, "max-heap-size must be at least as large as soft-heap-limit.\n");
608 if (max_heap < nursery_size * 4) {
609 fprintf (stderr, "max-heap-size must be at least 4 times larger than nursery size.\n");
612 max_heap_size = max_heap - nursery_size;
616 * ######################################################################
617 * ######## Macros and function declarations.
618 * ######################################################################
622 align_pointer (void *ptr)
624 mword p = (mword)ptr;
625 p += sizeof (gpointer) - 1;
626 p &= ~ (sizeof (gpointer) - 1);
630 typedef SgenGrayQueue GrayQueue;
632 /* forward declarations */
633 static int stop_world (int generation);
634 static int restart_world (int generation);
635 static void scan_thread_data (void *start_nursery, void *end_nursery, gboolean precise, GrayQueue *queue);
636 static void scan_from_registered_roots (CopyOrMarkObjectFunc copy_func, char *addr_start, char *addr_end, int root_type, GrayQueue *queue);
637 static void scan_finalizer_entries (CopyOrMarkObjectFunc copy_func, FinalizeReadyEntry *list, GrayQueue *queue);
638 static void report_finalizer_roots (void);
639 static void report_registered_roots (void);
640 static void find_pinning_ref_from_thread (char *obj, size_t size);
641 static void update_current_thread_stack (void *start);
642 static void collect_bridge_objects (CopyOrMarkObjectFunc copy_func, char *start, char *end, int generation, GrayQueue *queue);
643 static void finalize_in_range (CopyOrMarkObjectFunc copy_func, char *start, char *end, int generation, GrayQueue *queue);
644 static void process_fin_stage_entries (void);
645 static void null_link_in_range (CopyOrMarkObjectFunc copy_func, char *start, char *end, int generation, gboolean before_finalization, GrayQueue *queue);
646 static void null_links_for_domain (MonoDomain *domain, int generation);
647 static void process_dislink_stage_entries (void);
649 static void pin_from_roots (void *start_nursery, void *end_nursery, GrayQueue *queue);
650 static int pin_objects_from_addresses (GCMemSection *section, void **start, void **end, void *start_nursery, void *end_nursery, GrayQueue *queue);
651 static void finish_gray_stack (char *start_addr, char *end_addr, int generation, GrayQueue *queue);
652 static gboolean need_major_collection (mword space_needed);
653 static void major_collection (const char *reason);
655 static void mono_gc_register_disappearing_link (MonoObject *obj, void **link, gboolean track, gboolean in_gc);
656 static gboolean mono_gc_is_critical_method (MonoMethod *method);
658 void mono_gc_scan_for_specific_ref (MonoObject *key, gboolean precise);
660 static void init_stats (void);
662 static int mark_ephemerons_in_range (CopyOrMarkObjectFunc copy_func, char *start, char *end, GrayQueue *queue);
663 static void clear_unreachable_ephemerons (CopyOrMarkObjectFunc copy_func, char *start, char *end, GrayQueue *queue);
664 static void null_ephemerons_for_domain (MonoDomain *domain);
666 SgenMajorCollector major_collector;
667 static GrayQueue gray_queue;
669 static SgenRemeberedSet remset;
672 #define WORKERS_DISTRIBUTE_GRAY_QUEUE (mono_sgen_collection_is_parallel () ? mono_sgen_workers_get_distribute_gray_queue () : &gray_queue)
674 static SgenGrayQueue*
675 mono_sgen_workers_get_job_gray_queue (WorkerData *worker_data)
677 return worker_data ? &worker_data->private_gray_queue : WORKERS_DISTRIBUTE_GRAY_QUEUE;
681 is_xdomain_ref_allowed (gpointer *ptr, char *obj, MonoDomain *domain)
683 MonoObject *o = (MonoObject*)(obj);
684 MonoObject *ref = (MonoObject*)*(ptr);
685 int offset = (char*)(ptr) - (char*)o;
687 if (o->vtable->klass == mono_defaults.thread_class && offset == G_STRUCT_OFFSET (MonoThread, internal_thread))
689 if (o->vtable->klass == mono_defaults.internal_thread_class && offset == G_STRUCT_OFFSET (MonoInternalThread, current_appcontext))
691 if (mono_class_has_parent_fast (o->vtable->klass, mono_defaults.real_proxy_class) &&
692 offset == G_STRUCT_OFFSET (MonoRealProxy, unwrapped_server))
694 /* Thread.cached_culture_info */
695 if (!strcmp (ref->vtable->klass->name_space, "System.Globalization") &&
696 !strcmp (ref->vtable->klass->name, "CultureInfo") &&
697 !strcmp(o->vtable->klass->name_space, "System") &&
698 !strcmp(o->vtable->klass->name, "Object[]"))
701 * 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
702 * at System.IO.MemoryStream..ctor (byte[]) [0x00017] in /home/schani/Work/novell/trunk/mcs/class/corlib/System.IO/MemoryStream.cs:81
703 * at (wrapper remoting-invoke-with-check) System.IO.MemoryStream..ctor (byte[]) <IL 0x00020, 0xffffffff>
704 * at System.Runtime.Remoting.Messaging.CADMethodCallMessage.GetArguments () [0x0000d] in /home/schani/Work/novell/trunk/mcs/class/corlib/System.Runtime.Remoting.Messaging/CADMessages.cs:327
705 * 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
706 * 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
707 * at (wrapper remoting-invoke-with-check) System.AppDomain.ProcessMessageInDomain (byte[],System.Runtime.Remoting.Messaging.CADMethodCallMessage,byte[]&,System.Runtime.Remoting.Messaging.CADMethodReturnMessage&) <IL 0x0003d, 0xffffffff>
708 * 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
709 * at (wrapper runtime-invoke) object.runtime_invoke_CrossAppDomainSink/ProcessMessageRes_object_object (object,intptr,intptr,intptr) <IL 0x0004c, 0xffffffff>
711 if (!strcmp (ref->vtable->klass->name_space, "System") &&
712 !strcmp (ref->vtable->klass->name, "Byte[]") &&
713 !strcmp (o->vtable->klass->name_space, "System.IO") &&
714 !strcmp (o->vtable->klass->name, "MemoryStream"))
716 /* append_job() in threadpool.c */
717 if (!strcmp (ref->vtable->klass->name_space, "System.Runtime.Remoting.Messaging") &&
718 !strcmp (ref->vtable->klass->name, "AsyncResult") &&
719 !strcmp (o->vtable->klass->name_space, "System") &&
720 !strcmp (o->vtable->klass->name, "Object[]") &&
721 mono_thread_pool_is_queue_array ((MonoArray*) o))
727 check_reference_for_xdomain (gpointer *ptr, char *obj, MonoDomain *domain)
729 MonoObject *o = (MonoObject*)(obj);
730 MonoObject *ref = (MonoObject*)*(ptr);
731 int offset = (char*)(ptr) - (char*)o;
733 MonoClassField *field;
736 if (!ref || ref->vtable->domain == domain)
738 if (is_xdomain_ref_allowed (ptr, obj, domain))
742 for (class = o->vtable->klass; class; class = class->parent) {
745 for (i = 0; i < class->field.count; ++i) {
746 if (class->fields[i].offset == offset) {
747 field = &class->fields[i];
755 if (ref->vtable->klass == mono_defaults.string_class)
756 str = mono_string_to_utf8 ((MonoString*)ref);
759 g_print ("xdomain reference in %p (%s.%s) at offset %d (%s) to %p (%s.%s) (%s) - pointed to by:\n",
760 o, o->vtable->klass->name_space, o->vtable->klass->name,
761 offset, field ? field->name : "",
762 ref, ref->vtable->klass->name_space, ref->vtable->klass->name, str ? str : "");
763 mono_gc_scan_for_specific_ref (o, TRUE);
769 #define HANDLE_PTR(ptr,obj) check_reference_for_xdomain ((ptr), (obj), domain)
772 scan_object_for_xdomain_refs (char *start, mword size, void *data)
774 MonoDomain *domain = ((MonoObject*)start)->vtable->domain;
776 #include "sgen-scan-object.h"
779 static gboolean scan_object_for_specific_ref_precise = TRUE;
782 #define HANDLE_PTR(ptr,obj) do { \
783 if ((MonoObject*)*(ptr) == key) { \
784 g_print ("found ref to %p in object %p (%s) at offset %td\n", \
785 key, (obj), safe_name ((obj)), ((char*)(ptr) - (char*)(obj))); \
790 scan_object_for_specific_ref (char *start, MonoObject *key)
794 if ((forwarded = SGEN_OBJECT_IS_FORWARDED (start)))
797 if (scan_object_for_specific_ref_precise) {
798 #include "sgen-scan-object.h"
800 mword *words = (mword*)start;
801 size_t size = safe_object_get_size ((MonoObject*)start);
803 for (i = 0; i < size / sizeof (mword); ++i) {
804 if (words [i] == (mword)key) {
805 g_print ("found possible ref to %p in object %p (%s) at offset %td\n",
806 key, start, safe_name (start), i * sizeof (mword));
813 mono_sgen_scan_area_with_callback (char *start, char *end, IterateObjectCallbackFunc callback, void *data, gboolean allow_flags)
815 while (start < end) {
819 if (!*(void**)start) {
820 start += sizeof (void*); /* should be ALLOC_ALIGN, really */
825 if (!(obj = SGEN_OBJECT_IS_FORWARDED (start)))
831 size = ALIGN_UP (safe_object_get_size ((MonoObject*)obj));
833 if ((MonoVTable*)SGEN_LOAD_VTABLE (obj) != array_fill_vtable)
834 callback (obj, size, data);
841 scan_object_for_specific_ref_callback (char *obj, size_t size, MonoObject *key)
843 scan_object_for_specific_ref (obj, key);
847 check_root_obj_specific_ref (RootRecord *root, MonoObject *key, MonoObject *obj)
851 g_print ("found ref to %p in root record %p\n", key, root);
854 static MonoObject *check_key = NULL;
855 static RootRecord *check_root = NULL;
858 check_root_obj_specific_ref_from_marker (void **obj)
860 check_root_obj_specific_ref (check_root, check_key, *obj);
864 scan_roots_for_specific_ref (MonoObject *key, int root_type)
870 SGEN_HASH_TABLE_FOREACH (&roots_hash [root_type], start_root, root) {
871 mword desc = root->root_desc;
875 switch (desc & ROOT_DESC_TYPE_MASK) {
876 case ROOT_DESC_BITMAP:
877 desc >>= ROOT_DESC_TYPE_SHIFT;
880 check_root_obj_specific_ref (root, key, *start_root);
885 case ROOT_DESC_COMPLEX: {
886 gsize *bitmap_data = mono_sgen_get_complex_descriptor_bitmap (desc);
887 int bwords = (*bitmap_data) - 1;
888 void **start_run = start_root;
890 while (bwords-- > 0) {
891 gsize bmap = *bitmap_data++;
892 void **objptr = start_run;
895 check_root_obj_specific_ref (root, key, *objptr);
899 start_run += GC_BITS_PER_WORD;
903 case ROOT_DESC_USER: {
904 MonoGCRootMarkFunc marker = mono_sgen_get_user_descriptor_func (desc);
905 marker (start_root, check_root_obj_specific_ref_from_marker);
908 case ROOT_DESC_RUN_LEN:
909 g_assert_not_reached ();
911 g_assert_not_reached ();
913 } SGEN_HASH_TABLE_FOREACH_END;
920 mono_gc_scan_for_specific_ref (MonoObject *key, gboolean precise)
925 scan_object_for_specific_ref_precise = precise;
927 mono_sgen_scan_area_with_callback (nursery_section->data, nursery_section->end_data,
928 (IterateObjectCallbackFunc)scan_object_for_specific_ref_callback, key, TRUE);
930 major_collector.iterate_objects (TRUE, TRUE, (IterateObjectCallbackFunc)scan_object_for_specific_ref_callback, key);
932 mono_sgen_los_iterate_objects ((IterateObjectCallbackFunc)scan_object_for_specific_ref_callback, key);
934 scan_roots_for_specific_ref (key, ROOT_TYPE_NORMAL);
935 scan_roots_for_specific_ref (key, ROOT_TYPE_WBARRIER);
937 SGEN_HASH_TABLE_FOREACH (&roots_hash [ROOT_TYPE_PINNED], ptr, root) {
938 while (ptr < (void**)root->end_root) {
939 check_root_obj_specific_ref (root, *ptr, key);
942 } SGEN_HASH_TABLE_FOREACH_END;
946 need_remove_object_for_domain (char *start, MonoDomain *domain)
948 if (mono_object_domain (start) == domain) {
949 DEBUG (4, fprintf (gc_debug_file, "Need to cleanup object %p\n", start));
950 binary_protocol_cleanup (start, (gpointer)LOAD_VTABLE (start), safe_object_get_size ((MonoObject*)start));
957 process_object_for_domain_clearing (char *start, MonoDomain *domain)
959 GCVTable *vt = (GCVTable*)LOAD_VTABLE (start);
960 if (vt->klass == mono_defaults.internal_thread_class)
961 g_assert (mono_object_domain (start) == mono_get_root_domain ());
962 /* The object could be a proxy for an object in the domain
964 if (mono_class_has_parent_fast (vt->klass, mono_defaults.real_proxy_class)) {
965 MonoObject *server = ((MonoRealProxy*)start)->unwrapped_server;
967 /* The server could already have been zeroed out, so
968 we need to check for that, too. */
969 if (server && (!LOAD_VTABLE (server) || mono_object_domain (server) == domain)) {
970 DEBUG (4, fprintf (gc_debug_file, "Cleaning up remote pointer in %p to object %p\n",
972 ((MonoRealProxy*)start)->unwrapped_server = NULL;
977 static MonoDomain *check_domain = NULL;
980 check_obj_not_in_domain (void **o)
982 g_assert (((MonoObject*)(*o))->vtable->domain != check_domain);
986 scan_for_registered_roots_in_domain (MonoDomain *domain, int root_type)
990 check_domain = domain;
991 SGEN_HASH_TABLE_FOREACH (&roots_hash [root_type], start_root, root) {
992 mword desc = root->root_desc;
994 /* The MonoDomain struct is allowed to hold
995 references to objects in its own domain. */
996 if (start_root == (void**)domain)
999 switch (desc & ROOT_DESC_TYPE_MASK) {
1000 case ROOT_DESC_BITMAP:
1001 desc >>= ROOT_DESC_TYPE_SHIFT;
1003 if ((desc & 1) && *start_root)
1004 check_obj_not_in_domain (*start_root);
1009 case ROOT_DESC_COMPLEX: {
1010 gsize *bitmap_data = mono_sgen_get_complex_descriptor_bitmap (desc);
1011 int bwords = (*bitmap_data) - 1;
1012 void **start_run = start_root;
1014 while (bwords-- > 0) {
1015 gsize bmap = *bitmap_data++;
1016 void **objptr = start_run;
1018 if ((bmap & 1) && *objptr)
1019 check_obj_not_in_domain (*objptr);
1023 start_run += GC_BITS_PER_WORD;
1027 case ROOT_DESC_USER: {
1028 MonoGCRootMarkFunc marker = mono_sgen_get_user_descriptor_func (desc);
1029 marker (start_root, check_obj_not_in_domain);
1032 case ROOT_DESC_RUN_LEN:
1033 g_assert_not_reached ();
1035 g_assert_not_reached ();
1037 } SGEN_HASH_TABLE_FOREACH_END;
1039 check_domain = NULL;
1043 check_for_xdomain_refs (void)
1047 mono_sgen_scan_area_with_callback (nursery_section->data, nursery_section->end_data,
1048 (IterateObjectCallbackFunc)scan_object_for_xdomain_refs, NULL, FALSE);
1050 major_collector.iterate_objects (TRUE, TRUE, (IterateObjectCallbackFunc)scan_object_for_xdomain_refs, NULL);
1052 for (bigobj = los_object_list; bigobj; bigobj = bigobj->next)
1053 scan_object_for_xdomain_refs (bigobj->data, bigobj->size, NULL);
1057 clear_domain_process_object (char *obj, MonoDomain *domain)
1061 process_object_for_domain_clearing (obj, domain);
1062 remove = need_remove_object_for_domain (obj, domain);
1064 if (remove && ((MonoObject*)obj)->synchronisation) {
1065 void **dislink = mono_monitor_get_object_monitor_weak_link ((MonoObject*)obj);
1067 mono_gc_register_disappearing_link (NULL, dislink, FALSE, TRUE);
1074 clear_domain_process_minor_object_callback (char *obj, size_t size, MonoDomain *domain)
1076 if (clear_domain_process_object (obj, domain))
1077 memset (obj, 0, size);
1081 clear_domain_process_major_object_callback (char *obj, size_t size, MonoDomain *domain)
1083 clear_domain_process_object (obj, domain);
1087 clear_domain_free_major_non_pinned_object_callback (char *obj, size_t size, MonoDomain *domain)
1089 if (need_remove_object_for_domain (obj, domain))
1090 major_collector.free_non_pinned_object (obj, size);
1094 clear_domain_free_major_pinned_object_callback (char *obj, size_t size, MonoDomain *domain)
1096 if (need_remove_object_for_domain (obj, domain))
1097 major_collector.free_pinned_object (obj, size);
1101 * When appdomains are unloaded we can easily remove objects that have finalizers,
1102 * but all the others could still be present in random places on the heap.
1103 * We need a sweep to get rid of them even though it's going to be costly
1105 * The reason we need to remove them is because we access the vtable and class
1106 * structures to know the object size and the reference bitmap: once the domain is
1107 * unloaded the point to random memory.
1110 mono_gc_clear_domain (MonoDomain * domain)
1112 LOSObject *bigobj, *prev;
1117 process_fin_stage_entries ();
1118 process_dislink_stage_entries ();
1120 mono_sgen_clear_nursery_fragments ();
1122 if (xdomain_checks && domain != mono_get_root_domain ()) {
1123 scan_for_registered_roots_in_domain (domain, ROOT_TYPE_NORMAL);
1124 scan_for_registered_roots_in_domain (domain, ROOT_TYPE_WBARRIER);
1125 check_for_xdomain_refs ();
1128 mono_sgen_scan_area_with_callback (nursery_section->data, nursery_section->end_data,
1129 (IterateObjectCallbackFunc)clear_domain_process_minor_object_callback, domain, FALSE);
1131 /*Ephemerons and dislinks must be processed before LOS since they might end up pointing
1132 to memory returned to the OS.*/
1133 null_ephemerons_for_domain (domain);
1135 for (i = GENERATION_NURSERY; i < GENERATION_MAX; ++i)
1136 null_links_for_domain (domain, i);
1138 /* We need two passes over major and large objects because
1139 freeing such objects might give their memory back to the OS
1140 (in the case of large objects) or obliterate its vtable
1141 (pinned objects with major-copying or pinned and non-pinned
1142 objects with major-mark&sweep), but we might need to
1143 dereference a pointer from an object to another object if
1144 the first object is a proxy. */
1145 major_collector.iterate_objects (TRUE, TRUE, (IterateObjectCallbackFunc)clear_domain_process_major_object_callback, domain);
1146 for (bigobj = los_object_list; bigobj; bigobj = bigobj->next)
1147 clear_domain_process_object (bigobj->data, domain);
1150 for (bigobj = los_object_list; bigobj;) {
1151 if (need_remove_object_for_domain (bigobj->data, domain)) {
1152 LOSObject *to_free = bigobj;
1154 prev->next = bigobj->next;
1156 los_object_list = bigobj->next;
1157 bigobj = bigobj->next;
1158 DEBUG (4, fprintf (gc_debug_file, "Freeing large object %p\n",
1160 mono_sgen_los_free_object (to_free);
1164 bigobj = bigobj->next;
1166 major_collector.iterate_objects (TRUE, FALSE, (IterateObjectCallbackFunc)clear_domain_free_major_non_pinned_object_callback, domain);
1167 major_collector.iterate_objects (FALSE, TRUE, (IterateObjectCallbackFunc)clear_domain_free_major_pinned_object_callback, domain);
1169 if (G_UNLIKELY (do_pin_stats)) {
1170 if (domain == mono_get_root_domain ())
1171 mono_sgen_pin_stats_print_class_stats ();
1178 * mono_sgen_add_to_global_remset:
1180 * The global remset contains locations which point into newspace after
1181 * a minor collection. This can happen if the objects they point to are pinned.
1183 * LOCKING: If called from a parallel collector, the global remset
1184 * lock must be held. For serial collectors that is not necessary.
1187 mono_sgen_add_to_global_remset (gpointer ptr)
1189 remset.record_pointer (ptr);
1193 * mono_sgen_drain_gray_stack:
1195 * Scan objects in the gray stack until the stack is empty. This should be called
1196 * frequently after each object is copied, to achieve better locality and cache
1200 mono_sgen_drain_gray_stack (GrayQueue *queue, int max_objs)
1204 if (current_collection_generation == GENERATION_NURSERY) {
1205 ScanObjectFunc scan_func = mono_sgen_get_minor_scan_object ();
1208 GRAY_OBJECT_DEQUEUE (queue, obj);
1211 DEBUG (9, fprintf (gc_debug_file, "Precise gray object scan %p (%s)\n", obj, safe_name (obj)));
1212 scan_func (obj, queue);
1217 if (mono_sgen_collection_is_parallel () && mono_sgen_workers_is_distributed_queue (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 major_collector.major_scan_object (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 mono_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 mono_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 mono_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 mono_sgen_pin_object (void *object, GrayQueue *queue)
1356 if (mono_sgen_collection_is_parallel ()) {
1358 /*object arrives pinned*/
1359 mono_sgen_pin_stage_ptr (object);
1363 SGEN_PIN_OBJECT (object);
1364 mono_sgen_pin_stage_ptr (object);
1366 if (G_UNLIKELY (do_pin_stats))
1367 mono_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));
1373 /* Sort the addresses in array in increasing order.
1374 * Done using a by-the book heap sort. Which has decent and stable performance, is pretty cache efficient.
1377 mono_sgen_sort_addresses (void **array, int size)
1382 for (i = 1; i < size; ++i) {
1385 int parent = (child - 1) / 2;
1387 if (array [parent] >= array [child])
1390 tmp = array [parent];
1391 array [parent] = array [child];
1392 array [child] = tmp;
1398 for (i = size - 1; i > 0; --i) {
1401 array [i] = array [0];
1407 while (root * 2 + 1 <= end) {
1408 int child = root * 2 + 1;
1410 if (child < end && array [child] < array [child + 1])
1412 if (array [root] >= array [child])
1416 array [root] = array [child];
1417 array [child] = tmp;
1425 * Scan the memory between start and end and queue values which could be pointers
1426 * to the area between start_nursery and end_nursery for later consideration.
1427 * Typically used for thread stacks.
1430 conservatively_pin_objects_from (void **start, void **end, void *start_nursery, void *end_nursery, int pin_type)
1433 while (start < end) {
1434 if (*start >= start_nursery && *start < end_nursery) {
1436 * *start can point to the middle of an object
1437 * note: should we handle pointing at the end of an object?
1438 * pinning in C# code disallows pointing at the end of an object
1439 * but there is some small chance that an optimizing C compiler
1440 * may keep the only reference to an object by pointing
1441 * at the end of it. We ignore this small chance for now.
1442 * Pointers to the end of an object are indistinguishable
1443 * from pointers to the start of the next object in memory
1444 * so if we allow that we'd need to pin two objects...
1445 * We queue the pointer in an array, the
1446 * array will then be sorted and uniqued. This way
1447 * we can coalesce several pinning pointers and it should
1448 * be faster since we'd do a memory scan with increasing
1449 * addresses. Note: we can align the address to the allocation
1450 * alignment, so the unique process is more effective.
1452 mword addr = (mword)*start;
1453 addr &= ~(ALLOC_ALIGN - 1);
1454 if (addr >= (mword)start_nursery && addr < (mword)end_nursery)
1455 mono_sgen_pin_stage_ptr ((void*)addr);
1456 if (G_UNLIKELY (do_pin_stats)) {
1457 if (ptr_in_nursery ((void*)addr))
1458 mono_sgen_pin_stats_register_address ((char*)addr, pin_type);
1460 DEBUG (6, if (count) fprintf (gc_debug_file, "Pinning address %p from %p\n", (void*)addr, start));
1465 DEBUG (7, if (count) fprintf (gc_debug_file, "found %d potential pinned heap pointers\n", count));
1469 * Debugging function: find in the conservative roots where @obj is being pinned.
1471 static G_GNUC_UNUSED void
1472 find_pinning_reference (char *obj, size_t size)
1476 char *endobj = obj + size;
1478 SGEN_HASH_TABLE_FOREACH (&roots_hash [ROOT_TYPE_NORMAL], start, root) {
1479 /* if desc is non-null it has precise info */
1480 if (!root->root_desc) {
1481 while (start < (char**)root->end_root) {
1482 if (*start >= obj && *start < endobj) {
1483 DEBUG (0, fprintf (gc_debug_file, "Object %p referenced in pinned roots %p-%p\n", obj, start, root->end_root));
1488 } SGEN_HASH_TABLE_FOREACH_END;
1490 find_pinning_ref_from_thread (obj, size);
1494 * The first thing we do in a collection is to identify pinned objects.
1495 * This function considers all the areas of memory that need to be
1496 * conservatively scanned.
1499 pin_from_roots (void *start_nursery, void *end_nursery, GrayQueue *queue)
1503 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));
1504 /* objects pinned from the API are inside these roots */
1505 SGEN_HASH_TABLE_FOREACH (&roots_hash [ROOT_TYPE_PINNED], start_root, root) {
1506 DEBUG (6, fprintf (gc_debug_file, "Pinned roots %p-%p\n", start_root, root->end_root));
1507 conservatively_pin_objects_from (start_root, (void**)root->end_root, start_nursery, end_nursery, PIN_TYPE_OTHER);
1508 } SGEN_HASH_TABLE_FOREACH_END;
1509 /* now deal with the thread stacks
1510 * in the future we should be able to conservatively scan only:
1511 * *) the cpu registers
1512 * *) the unmanaged stack frames
1513 * *) the _last_ managed stack frame
1514 * *) pointers slots in managed frames
1516 scan_thread_data (start_nursery, end_nursery, FALSE, queue);
1520 CopyOrMarkObjectFunc func;
1522 } UserCopyOrMarkData;
1524 static MonoNativeTlsKey user_copy_or_mark_key;
1527 init_user_copy_or_mark_key (void)
1529 mono_native_tls_alloc (&user_copy_or_mark_key, NULL);
1533 set_user_copy_or_mark_data (UserCopyOrMarkData *data)
1535 mono_native_tls_set_value (user_copy_or_mark_key, data);
1539 single_arg_user_copy_or_mark (void **obj)
1541 UserCopyOrMarkData *data = mono_native_tls_get_value (user_copy_or_mark_key);
1543 data->func (obj, data->queue);
1547 * The memory area from start_root to end_root contains pointers to objects.
1548 * Their position is precisely described by @desc (this means that the pointer
1549 * can be either NULL or the pointer to the start of an object).
1550 * This functions copies them to to_space updates them.
1552 * This function is not thread-safe!
1555 precisely_scan_objects_from (CopyOrMarkObjectFunc copy_func, void** start_root, void** end_root, char* n_start, char *n_end, mword desc, GrayQueue *queue)
1557 switch (desc & ROOT_DESC_TYPE_MASK) {
1558 case ROOT_DESC_BITMAP:
1559 desc >>= ROOT_DESC_TYPE_SHIFT;
1561 if ((desc & 1) && *start_root) {
1562 copy_func (start_root, queue);
1563 DEBUG (9, fprintf (gc_debug_file, "Overwrote root at %p with %p\n", start_root, *start_root));
1564 mono_sgen_drain_gray_stack (queue, -1);
1570 case ROOT_DESC_COMPLEX: {
1571 gsize *bitmap_data = mono_sgen_get_complex_descriptor_bitmap (desc);
1572 int bwords = (*bitmap_data) - 1;
1573 void **start_run = start_root;
1575 while (bwords-- > 0) {
1576 gsize bmap = *bitmap_data++;
1577 void **objptr = start_run;
1579 if ((bmap & 1) && *objptr) {
1580 copy_func (objptr, queue);
1581 DEBUG (9, fprintf (gc_debug_file, "Overwrote root at %p with %p\n", objptr, *objptr));
1582 mono_sgen_drain_gray_stack (queue, -1);
1587 start_run += GC_BITS_PER_WORD;
1591 case ROOT_DESC_USER: {
1592 UserCopyOrMarkData data = { copy_func, queue };
1593 MonoGCRootMarkFunc marker = mono_sgen_get_user_descriptor_func (desc);
1594 set_user_copy_or_mark_data (&data);
1595 marker (start_root, single_arg_user_copy_or_mark);
1596 set_user_copy_or_mark_data (NULL);
1599 case ROOT_DESC_RUN_LEN:
1600 g_assert_not_reached ();
1602 g_assert_not_reached ();
1607 reset_heap_boundaries (void)
1609 lowest_heap_address = ~(mword)0;
1610 highest_heap_address = 0;
1614 mono_sgen_update_heap_boundaries (mword low, mword high)
1619 old = lowest_heap_address;
1622 } while (SGEN_CAS_PTR ((gpointer*)&lowest_heap_address, (gpointer)low, (gpointer)old) != (gpointer)old);
1625 old = highest_heap_address;
1628 } while (SGEN_CAS_PTR ((gpointer*)&highest_heap_address, (gpointer)high, (gpointer)old) != (gpointer)old);
1631 static unsigned long
1632 prot_flags_for_activate (int activate)
1634 unsigned long prot_flags = activate? MONO_MMAP_READ|MONO_MMAP_WRITE: MONO_MMAP_NONE;
1635 return prot_flags | MONO_MMAP_PRIVATE | MONO_MMAP_ANON;
1639 * Allocate a big chunk of memory from the OS (usually 64KB to several megabytes).
1640 * This must not require any lock.
1643 mono_sgen_alloc_os_memory (size_t size, int activate)
1645 void *ptr = mono_valloc (0, size, prot_flags_for_activate (activate));
1648 total_alloc += size;
1653 /* size must be a power of 2 */
1655 mono_sgen_alloc_os_memory_aligned (mword size, mword alignment, gboolean activate)
1657 void *ptr = mono_valloc_aligned (size, alignment, prot_flags_for_activate (activate));
1660 total_alloc += size;
1666 * Free the memory returned by mono_sgen_alloc_os_memory (), returning it to the OS.
1669 mono_sgen_free_os_memory (void *addr, size_t size)
1671 mono_vfree (addr, size);
1673 total_alloc -= size;
1677 * Allocate and setup the data structures needed to be able to allocate objects
1678 * in the nursery. The nursery is stored in nursery_section.
1681 alloc_nursery (void)
1683 GCMemSection *section;
1688 if (nursery_section)
1690 DEBUG (2, fprintf (gc_debug_file, "Allocating nursery size: %lu\n", (unsigned long)nursery_size));
1691 /* later we will alloc a larger area for the nursery but only activate
1692 * what we need. The rest will be used as expansion if we have too many pinned
1693 * objects in the existing nursery.
1695 /* FIXME: handle OOM */
1696 section = mono_sgen_alloc_internal (INTERNAL_MEM_SECTION);
1698 g_assert (nursery_size == DEFAULT_NURSERY_SIZE);
1699 alloc_size = nursery_size;
1700 #ifdef SGEN_ALIGN_NURSERY
1701 data = major_collector.alloc_heap (alloc_size, alloc_size, DEFAULT_NURSERY_BITS);
1703 data = major_collector.alloc_heap (alloc_size, 0, DEFAULT_NURSERY_BITS);
1705 mono_sgen_update_heap_boundaries ((mword)data, (mword)(data + nursery_size));
1706 DEBUG (4, fprintf (gc_debug_file, "Expanding nursery size (%p-%p): %lu, total: %lu\n", data, data + alloc_size, (unsigned long)nursery_size, (unsigned long)total_alloc));
1707 section->data = section->next_data = data;
1708 section->size = alloc_size;
1709 section->end_data = data + nursery_size;
1710 scan_starts = (alloc_size + SCAN_START_SIZE - 1) / SCAN_START_SIZE;
1711 section->scan_starts = mono_sgen_alloc_internal_dynamic (sizeof (char*) * scan_starts, INTERNAL_MEM_SCAN_STARTS);
1712 section->num_scan_start = scan_starts;
1713 section->block.role = MEMORY_ROLE_GEN0;
1714 section->block.next = NULL;
1716 nursery_section = section;
1718 mono_sgen_nursery_allocator_set_nursery_bounds (data, data + nursery_size);
1722 mono_gc_get_nursery (int *shift_bits, size_t *size)
1724 *size = nursery_size;
1725 #ifdef SGEN_ALIGN_NURSERY
1726 *shift_bits = DEFAULT_NURSERY_BITS;
1730 return mono_sgen_get_nursery_start ();
1734 mono_gc_set_current_thread_appdomain (MonoDomain *domain)
1736 SgenThreadInfo *info = mono_thread_info_current ();
1738 /* Could be called from sgen_thread_unregister () with a NULL info */
1741 info->stopped_domain = domain;
1746 mono_gc_precise_stack_mark_enabled (void)
1748 return !conservative_stack_mark;
1752 mono_gc_get_logfile (void)
1754 return mono_sgen_get_logfile ();
1758 report_finalizer_roots_list (FinalizeReadyEntry *list)
1760 GCRootReport report;
1761 FinalizeReadyEntry *fin;
1764 for (fin = list; fin; fin = fin->next) {
1767 add_profile_gc_root (&report, fin->object, MONO_PROFILE_GC_ROOT_FINALIZER, 0);
1769 notify_gc_roots (&report);
1773 report_finalizer_roots (void)
1775 report_finalizer_roots_list (fin_ready_list);
1776 report_finalizer_roots_list (critical_fin_list);
1779 static GCRootReport *root_report;
1782 single_arg_report_root (void **obj)
1785 add_profile_gc_root (root_report, *obj, MONO_PROFILE_GC_ROOT_OTHER, 0);
1789 precisely_report_roots_from (GCRootReport *report, void** start_root, void** end_root, mword desc)
1791 switch (desc & ROOT_DESC_TYPE_MASK) {
1792 case ROOT_DESC_BITMAP:
1793 desc >>= ROOT_DESC_TYPE_SHIFT;
1795 if ((desc & 1) && *start_root) {
1796 add_profile_gc_root (report, *start_root, MONO_PROFILE_GC_ROOT_OTHER, 0);
1802 case ROOT_DESC_COMPLEX: {
1803 gsize *bitmap_data = mono_sgen_get_complex_descriptor_bitmap (desc);
1804 int bwords = (*bitmap_data) - 1;
1805 void **start_run = start_root;
1807 while (bwords-- > 0) {
1808 gsize bmap = *bitmap_data++;
1809 void **objptr = start_run;
1811 if ((bmap & 1) && *objptr) {
1812 add_profile_gc_root (report, *objptr, MONO_PROFILE_GC_ROOT_OTHER, 0);
1817 start_run += GC_BITS_PER_WORD;
1821 case ROOT_DESC_USER: {
1822 MonoGCRootMarkFunc marker = mono_sgen_get_user_descriptor_func (desc);
1823 root_report = report;
1824 marker (start_root, single_arg_report_root);
1827 case ROOT_DESC_RUN_LEN:
1828 g_assert_not_reached ();
1830 g_assert_not_reached ();
1835 report_registered_roots_by_type (int root_type)
1837 GCRootReport report;
1841 SGEN_HASH_TABLE_FOREACH (&roots_hash [root_type], start_root, root) {
1842 DEBUG (6, fprintf (gc_debug_file, "Precise root scan %p-%p (desc: %p)\n", start_root, root->end_root, (void*)root->root_desc));
1843 precisely_report_roots_from (&report, start_root, (void**)root->end_root, root->root_desc);
1844 } SGEN_HASH_TABLE_FOREACH_END;
1845 notify_gc_roots (&report);
1849 report_registered_roots (void)
1851 report_registered_roots_by_type (ROOT_TYPE_NORMAL);
1852 report_registered_roots_by_type (ROOT_TYPE_WBARRIER);
1856 scan_finalizer_entries (CopyOrMarkObjectFunc copy_func, FinalizeReadyEntry *list, GrayQueue *queue)
1858 FinalizeReadyEntry *fin;
1860 for (fin = list; fin; fin = fin->next) {
1863 DEBUG (5, fprintf (gc_debug_file, "Scan of fin ready object: %p (%s)\n", fin->object, safe_name (fin->object)));
1864 copy_func (&fin->object, queue);
1869 generation_name (int generation)
1871 switch (generation) {
1872 case GENERATION_NURSERY: return "nursery";
1873 case GENERATION_OLD: return "old";
1874 default: g_assert_not_reached ();
1880 stw_bridge_process (void)
1882 mono_sgen_bridge_processing_stw_step ();
1886 bridge_process (void)
1888 mono_sgen_bridge_processing_finish ();
1891 CopyOrMarkObjectFunc
1892 mono_sgen_get_copy_object (void)
1894 if (current_collection_generation == GENERATION_NURSERY) {
1895 if (mono_sgen_collection_is_parallel ())
1896 return major_collector.copy_object;
1898 return major_collector.nopar_copy_object;
1900 return major_collector.copy_or_mark_object;
1905 mono_sgen_get_minor_scan_object (void)
1907 g_assert (current_collection_generation == GENERATION_NURSERY);
1909 if (mono_sgen_collection_is_parallel ())
1910 return major_collector.minor_scan_object;
1912 return major_collector.nopar_minor_scan_object;
1916 mono_sgen_get_minor_scan_vtype (void)
1918 g_assert (current_collection_generation == GENERATION_NURSERY);
1920 if (mono_sgen_collection_is_parallel ())
1921 return major_collector.minor_scan_vtype;
1923 return major_collector.nopar_minor_scan_vtype;
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 = mono_sgen_get_copy_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 mono_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 mono_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 mono_sgen_drain_gray_stack (queue, -1);
1970 } while (!done_with_ephemerons);
1972 mono_sgen_scan_togglerefs (copy_func, start_addr, end_addr, queue);
1973 if (generation == GENERATION_OLD)
1974 mono_sgen_scan_togglerefs (copy_func, mono_sgen_get_nursery_start (), mono_sgen_get_nursery_end (), queue);
1976 if (mono_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, mono_sgen_get_nursery_start (), mono_sgen_get_nursery_end (), GENERATION_NURSERY, queue);
1980 mono_sgen_drain_gray_stack (queue, -1);
1984 We must clear weak links that don't track resurrection before processing object ready for
1985 finalization so they can be cleared before that.
1987 null_link_in_range (copy_func, start_addr, end_addr, generation, TRUE, queue);
1988 if (generation == GENERATION_OLD)
1989 null_link_in_range (copy_func, start_addr, end_addr, GENERATION_NURSERY, TRUE, queue);
1992 /* walk the finalization queue and move also the objects that need to be
1993 * finalized: use the finalized objects as new roots so the objects they depend
1994 * on are also not reclaimed. As with the roots above, only objects in the nursery
1995 * are marked/copied.
1997 finalize_in_range (copy_func, start_addr, end_addr, generation, queue);
1998 if (generation == GENERATION_OLD)
1999 finalize_in_range (copy_func, mono_sgen_get_nursery_start (), mono_sgen_get_nursery_end (), GENERATION_NURSERY, queue);
2000 /* drain the new stack that might have been created */
2001 DEBUG (6, fprintf (gc_debug_file, "Precise scan of gray area post fin\n"));
2002 mono_sgen_drain_gray_stack (queue, -1);
2005 * This must be done again after processing finalizable objects since CWL slots are cleared only after the key is finalized.
2007 done_with_ephemerons = 0;
2009 done_with_ephemerons = mark_ephemerons_in_range (copy_func, start_addr, end_addr, queue);
2010 mono_sgen_drain_gray_stack (queue, -1);
2012 } while (!done_with_ephemerons);
2015 * Clear ephemeron pairs with unreachable keys.
2016 * We pass the copy func so we can figure out if an array was promoted or not.
2018 clear_unreachable_ephemerons (copy_func, start_addr, end_addr, queue);
2021 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));
2024 * handle disappearing links
2025 * Note we do this after checking the finalization queue because if an object
2026 * survives (at least long enough to be finalized) we don't clear the link.
2027 * This also deals with a possible issue with the monitor reclamation: with the Boehm
2028 * GC a finalized object my lose the monitor because it is cleared before the finalizer is
2031 g_assert (mono_sgen_gray_object_queue_is_empty (queue));
2033 null_link_in_range (copy_func, start_addr, end_addr, generation, FALSE, queue);
2034 if (generation == GENERATION_OLD)
2035 null_link_in_range (copy_func, start_addr, end_addr, GENERATION_NURSERY, FALSE, queue);
2036 if (mono_sgen_gray_object_queue_is_empty (queue))
2038 mono_sgen_drain_gray_stack (queue, -1);
2041 g_assert (mono_sgen_gray_object_queue_is_empty (queue));
2045 mono_sgen_check_section_scan_starts (GCMemSection *section)
2048 for (i = 0; i < section->num_scan_start; ++i) {
2049 if (section->scan_starts [i]) {
2050 guint size = safe_object_get_size ((MonoObject*) section->scan_starts [i]);
2051 g_assert (size >= sizeof (MonoObject) && size <= MAX_SMALL_OBJ_SIZE);
2057 check_scan_starts (void)
2059 if (!do_scan_starts_check)
2061 mono_sgen_check_section_scan_starts (nursery_section);
2062 major_collector.check_scan_starts ();
2066 scan_from_registered_roots (CopyOrMarkObjectFunc copy_func, char *addr_start, char *addr_end, int root_type, GrayQueue *queue)
2070 SGEN_HASH_TABLE_FOREACH (&roots_hash [root_type], start_root, root) {
2071 DEBUG (6, fprintf (gc_debug_file, "Precise root scan %p-%p (desc: %p)\n", start_root, root->end_root, (void*)root->root_desc));
2072 precisely_scan_objects_from (copy_func, start_root, (void**)root->end_root, addr_start, addr_end, root->root_desc, queue);
2073 } SGEN_HASH_TABLE_FOREACH_END;
2077 mono_sgen_dump_occupied (char *start, char *end, char *section_start)
2079 fprintf (heap_dump_file, "<occupied offset=\"%td\" size=\"%td\"/>\n", start - section_start, end - start);
2083 mono_sgen_dump_section (GCMemSection *section, const char *type)
2085 char *start = section->data;
2086 char *end = section->data + section->size;
2087 char *occ_start = NULL;
2089 char *old_start = NULL; /* just for debugging */
2091 fprintf (heap_dump_file, "<section type=\"%s\" size=\"%lu\">\n", type, (unsigned long)section->size);
2093 while (start < end) {
2097 if (!*(void**)start) {
2099 mono_sgen_dump_occupied (occ_start, start, section->data);
2102 start += sizeof (void*); /* should be ALLOC_ALIGN, really */
2105 g_assert (start < section->next_data);
2110 vt = (GCVTable*)LOAD_VTABLE (start);
2113 size = ALIGN_UP (safe_object_get_size ((MonoObject*) start));
2116 fprintf (heap_dump_file, "<object offset=\"%d\" class=\"%s.%s\" size=\"%d\"/>\n",
2117 start - section->data,
2118 vt->klass->name_space, vt->klass->name,
2126 mono_sgen_dump_occupied (occ_start, start, section->data);
2128 fprintf (heap_dump_file, "</section>\n");
2132 dump_object (MonoObject *obj, gboolean dump_location)
2134 static char class_name [1024];
2136 MonoClass *class = mono_object_class (obj);
2140 * Python's XML parser is too stupid to parse angle brackets
2141 * in strings, so we just ignore them;
2144 while (class->name [i] && j < sizeof (class_name) - 1) {
2145 if (!strchr ("<>\"", class->name [i]))
2146 class_name [j++] = class->name [i];
2149 g_assert (j < sizeof (class_name));
2152 fprintf (heap_dump_file, "<object class=\"%s.%s\" size=\"%d\"",
2153 class->name_space, class_name,
2154 safe_object_get_size (obj));
2155 if (dump_location) {
2156 const char *location;
2157 if (ptr_in_nursery (obj))
2158 location = "nursery";
2159 else if (safe_object_get_size (obj) <= MAX_SMALL_OBJ_SIZE)
2163 fprintf (heap_dump_file, " location=\"%s\"", location);
2165 fprintf (heap_dump_file, "/>\n");
2169 dump_heap (const char *type, int num, const char *reason)
2174 fprintf (heap_dump_file, "<collection type=\"%s\" num=\"%d\"", type, num);
2176 fprintf (heap_dump_file, " reason=\"%s\"", reason);
2177 fprintf (heap_dump_file, ">\n");
2178 fprintf (heap_dump_file, "<other-mem-usage type=\"mempools\" size=\"%ld\"/>\n", mono_mempool_get_bytes_allocated ());
2179 mono_sgen_dump_internal_mem_usage (heap_dump_file);
2180 fprintf (heap_dump_file, "<pinned type=\"stack\" bytes=\"%zu\"/>\n", mono_sgen_pin_stats_get_pinned_byte_count (PIN_TYPE_STACK));
2181 /* fprintf (heap_dump_file, "<pinned type=\"static-data\" bytes=\"%d\"/>\n", pinned_byte_counts [PIN_TYPE_STATIC_DATA]); */
2182 fprintf (heap_dump_file, "<pinned type=\"other\" bytes=\"%zu\"/>\n", mono_sgen_pin_stats_get_pinned_byte_count (PIN_TYPE_OTHER));
2184 fprintf (heap_dump_file, "<pinned-objects>\n");
2185 for (list = mono_sgen_pin_stats_get_object_list (); list; list = list->next)
2186 dump_object (list->obj, TRUE);
2187 fprintf (heap_dump_file, "</pinned-objects>\n");
2189 mono_sgen_dump_section (nursery_section, "nursery");
2191 major_collector.dump_heap (heap_dump_file);
2193 fprintf (heap_dump_file, "<los>\n");
2194 for (bigobj = los_object_list; bigobj; bigobj = bigobj->next)
2195 dump_object ((MonoObject*)bigobj->data, FALSE);
2196 fprintf (heap_dump_file, "</los>\n");
2198 fprintf (heap_dump_file, "</collection>\n");
2202 mono_sgen_register_moved_object (void *obj, void *destination)
2204 g_assert (mono_profiler_events & MONO_PROFILE_GC_MOVES);
2206 /* FIXME: handle this for parallel collector */
2207 g_assert (!mono_sgen_collection_is_parallel ());
2209 if (moved_objects_idx == MOVED_OBJECTS_NUM) {
2210 mono_profiler_gc_moves (moved_objects, moved_objects_idx);
2211 moved_objects_idx = 0;
2213 moved_objects [moved_objects_idx++] = obj;
2214 moved_objects [moved_objects_idx++] = destination;
2220 static gboolean inited = FALSE;
2225 mono_counters_register ("Minor fragment clear", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_minor_pre_collection_fragment_clear);
2226 mono_counters_register ("Minor pinning", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_minor_pinning);
2227 mono_counters_register ("Minor scan remembered set", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_minor_scan_remsets);
2228 mono_counters_register ("Minor scan pinned", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_minor_scan_pinned);
2229 mono_counters_register ("Minor scan registered roots", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_minor_scan_registered_roots);
2230 mono_counters_register ("Minor scan thread data", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_minor_scan_thread_data);
2231 mono_counters_register ("Minor finish gray stack", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_minor_finish_gray_stack);
2232 mono_counters_register ("Minor fragment creation", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_minor_fragment_creation);
2234 mono_counters_register ("Major fragment clear", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_major_pre_collection_fragment_clear);
2235 mono_counters_register ("Major pinning", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_major_pinning);
2236 mono_counters_register ("Major scan pinned", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_major_scan_pinned);
2237 mono_counters_register ("Major scan registered roots", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_major_scan_registered_roots);
2238 mono_counters_register ("Major scan thread data", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_major_scan_thread_data);
2239 mono_counters_register ("Major scan alloc_pinned", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_major_scan_alloc_pinned);
2240 mono_counters_register ("Major scan finalized", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_major_scan_finalized);
2241 mono_counters_register ("Major scan big objects", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_major_scan_big_objects);
2242 mono_counters_register ("Major finish gray stack", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_major_finish_gray_stack);
2243 mono_counters_register ("Major free big objects", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_major_free_bigobjs);
2244 mono_counters_register ("Major LOS sweep", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_major_los_sweep);
2245 mono_counters_register ("Major sweep", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_major_sweep);
2246 mono_counters_register ("Major fragment creation", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_major_fragment_creation);
2248 mono_counters_register ("Number of pinned objects", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_pinned_objects);
2250 #ifdef HEAVY_STATISTICS
2251 mono_counters_register ("WBarrier set field", MONO_COUNTER_GC | MONO_COUNTER_INT, &stat_wbarrier_set_field);
2252 mono_counters_register ("WBarrier set arrayref", MONO_COUNTER_GC | MONO_COUNTER_INT, &stat_wbarrier_set_arrayref);
2253 mono_counters_register ("WBarrier arrayref copy", MONO_COUNTER_GC | MONO_COUNTER_INT, &stat_wbarrier_arrayref_copy);
2254 mono_counters_register ("WBarrier generic store called", MONO_COUNTER_GC | MONO_COUNTER_INT, &stat_wbarrier_generic_store);
2255 mono_counters_register ("WBarrier set root", MONO_COUNTER_GC | MONO_COUNTER_INT, &stat_wbarrier_set_root);
2256 mono_counters_register ("WBarrier value copy", MONO_COUNTER_GC | MONO_COUNTER_INT, &stat_wbarrier_value_copy);
2257 mono_counters_register ("WBarrier object copy", MONO_COUNTER_GC | MONO_COUNTER_INT, &stat_wbarrier_object_copy);
2259 mono_counters_register ("# objects allocated degraded", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_objects_alloced_degraded);
2260 mono_counters_register ("bytes allocated degraded", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_bytes_alloced_degraded);
2262 mono_counters_register ("# copy_object() called (nursery)", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_copy_object_called_nursery);
2263 mono_counters_register ("# objects copied (nursery)", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_objects_copied_nursery);
2264 mono_counters_register ("# copy_object() called (major)", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_copy_object_called_major);
2265 mono_counters_register ("# objects copied (major)", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_objects_copied_major);
2267 mono_counters_register ("# scan_object() called (nursery)", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_scan_object_called_nursery);
2268 mono_counters_register ("# scan_object() called (major)", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_scan_object_called_major);
2270 mono_counters_register ("# nursery copy_object() failed from space", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_nursery_copy_object_failed_from_space);
2271 mono_counters_register ("# nursery copy_object() failed forwarded", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_nursery_copy_object_failed_forwarded);
2272 mono_counters_register ("# nursery copy_object() failed pinned", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_nursery_copy_object_failed_pinned);
2274 mono_sgen_nursery_allocator_init_heavy_stats ();
2275 mono_sgen_alloc_init_heavy_stats ();
2281 static gboolean need_calculate_minor_collection_allowance;
2283 static int last_collection_old_num_major_sections;
2284 static mword last_collection_los_memory_usage = 0;
2285 static mword last_collection_old_los_memory_usage;
2286 static mword last_collection_los_memory_alloced;
2289 reset_minor_collection_allowance (void)
2291 need_calculate_minor_collection_allowance = TRUE;
2295 try_calculate_minor_collection_allowance (gboolean overwrite)
2297 int num_major_sections, num_major_sections_saved, save_target, allowance_target;
2298 mword los_memory_saved, new_major, new_heap_size;
2301 g_assert (need_calculate_minor_collection_allowance);
2303 if (!need_calculate_minor_collection_allowance)
2306 if (!*major_collector.have_swept) {
2308 minor_collection_allowance = MIN_MINOR_COLLECTION_ALLOWANCE;
2312 num_major_sections = major_collector.get_num_major_sections ();
2314 num_major_sections_saved = MAX (last_collection_old_num_major_sections - num_major_sections, 0);
2315 los_memory_saved = MAX (last_collection_old_los_memory_usage - last_collection_los_memory_usage, 1);
2317 new_major = num_major_sections * major_collector.section_size;
2318 new_heap_size = new_major + last_collection_los_memory_usage;
2321 * FIXME: Why is save_target half the major memory plus half the
2322 * LOS memory saved? Shouldn't it be half the major memory
2323 * saved plus half the LOS memory saved? Or half the whole heap
2326 save_target = (new_major + los_memory_saved) / 2;
2329 * We aim to allow the allocation of as many sections as is
2330 * necessary to reclaim save_target sections in the next
2331 * collection. We assume the collection pattern won't change.
2332 * In the last cycle, we had num_major_sections_saved for
2333 * minor_collection_sections_alloced. Assuming things won't
2334 * change, this must be the same ratio as save_target for
2335 * allowance_target, i.e.
2337 * num_major_sections_saved save_target
2338 * --------------------------------- == ----------------
2339 * minor_collection_sections_alloced allowance_target
2343 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));
2345 minor_collection_allowance = MAX (MIN (allowance_target, num_major_sections * major_collector.section_size + los_memory_usage), MIN_MINOR_COLLECTION_ALLOWANCE);
2347 if (new_heap_size + minor_collection_allowance > soft_heap_limit) {
2348 if (new_heap_size > soft_heap_limit)
2349 minor_collection_allowance = MIN_MINOR_COLLECTION_ALLOWANCE;
2351 minor_collection_allowance = MAX (soft_heap_limit - new_heap_size, MIN_MINOR_COLLECTION_ALLOWANCE);
2354 if (debug_print_allowance) {
2355 mword old_major = last_collection_old_num_major_sections * major_collector.section_size;
2357 fprintf (gc_debug_file, "Before collection: %ld bytes (%ld major, %ld LOS)\n",
2358 old_major + last_collection_old_los_memory_usage, old_major, last_collection_old_los_memory_usage);
2359 fprintf (gc_debug_file, "After collection: %ld bytes (%ld major, %ld LOS)\n",
2360 new_heap_size, new_major, last_collection_los_memory_usage);
2361 fprintf (gc_debug_file, "Allowance: %ld bytes\n", minor_collection_allowance);
2364 if (major_collector.have_computed_minor_collection_allowance)
2365 major_collector.have_computed_minor_collection_allowance ();
2367 need_calculate_minor_collection_allowance = FALSE;
2371 need_major_collection (mword space_needed)
2373 mword los_alloced = los_memory_usage - MIN (last_collection_los_memory_usage, los_memory_usage);
2374 return (space_needed > available_free_space ()) ||
2375 minor_collection_sections_alloced * major_collector.section_size + los_alloced > minor_collection_allowance;
2379 mono_sgen_need_major_collection (mword space_needed)
2381 return need_major_collection (space_needed);
2385 reset_pinned_from_failed_allocation (void)
2387 bytes_pinned_from_failed_allocation = 0;
2391 mono_sgen_set_pinned_from_failed_allocation (mword objsize)
2393 bytes_pinned_from_failed_allocation += objsize;
2397 mono_sgen_collection_is_parallel (void)
2399 switch (current_collection_generation) {
2400 case GENERATION_NURSERY:
2401 return nursery_collection_is_parallel;
2402 case GENERATION_OLD:
2403 return major_collector.is_parallel;
2405 g_assert_not_reached ();
2410 mono_sgen_nursery_collection_is_parallel (void)
2412 return nursery_collection_is_parallel;
2419 } FinishRememberedSetScanJobData;
2422 job_finish_remembered_set_scan (WorkerData *worker_data, void *job_data_untyped)
2424 FinishRememberedSetScanJobData *job_data = job_data_untyped;
2426 remset.finish_scan_remsets (job_data->heap_start, job_data->heap_end, mono_sgen_workers_get_job_gray_queue (worker_data));
2431 CopyOrMarkObjectFunc func;
2435 } ScanFromRegisteredRootsJobData;
2438 job_scan_from_registered_roots (WorkerData *worker_data, void *job_data_untyped)
2440 ScanFromRegisteredRootsJobData *job_data = job_data_untyped;
2442 scan_from_registered_roots (job_data->func,
2443 job_data->heap_start, job_data->heap_end,
2444 job_data->root_type,
2445 mono_sgen_workers_get_job_gray_queue (worker_data));
2452 } ScanThreadDataJobData;
2455 job_scan_thread_data (WorkerData *worker_data, void *job_data_untyped)
2457 ScanThreadDataJobData *job_data = job_data_untyped;
2459 scan_thread_data (job_data->heap_start, job_data->heap_end, TRUE,
2460 mono_sgen_workers_get_job_gray_queue (worker_data));
2465 FinalizeReadyEntry *list;
2466 } ScanFinalizerEntriesJobData;
2469 job_scan_finalizer_entries (WorkerData *worker_data, void *job_data_untyped)
2471 ScanFinalizerEntriesJobData *job_data = job_data_untyped;
2473 scan_finalizer_entries (mono_sgen_get_copy_object (),
2475 mono_sgen_workers_get_job_gray_queue (worker_data));
2479 verify_scan_starts (char *start, char *end)
2483 for (i = 0; i < nursery_section->num_scan_start; ++i) {
2484 char *addr = nursery_section->scan_starts [i];
2485 if (addr > start && addr < end)
2486 fprintf (gc_debug_file, "NFC-BAD SCAN START [%d] %p for obj [%p %p]\n", i, addr, start, end);
2491 verify_nursery (void)
2493 char *start, *end, *cur, *hole_start;
2495 if (!do_verify_nursery)
2498 /*This cleans up unused fragments */
2499 mono_sgen_nursery_allocator_prepare_for_pinning ();
2501 hole_start = start = cur = mono_sgen_get_nursery_start ();
2502 end = mono_sgen_get_nursery_end ();
2507 if (!*(void**)cur) {
2508 cur += sizeof (void*);
2512 if (object_is_forwarded (cur))
2513 fprintf (gc_debug_file, "FORWARDED OBJ %p\n", cur);
2514 else if (object_is_pinned (cur))
2515 fprintf (gc_debug_file, "PINNED OBJ %p\n", cur);
2517 ss = safe_object_get_size ((MonoObject*)cur);
2518 size = ALIGN_UP (safe_object_get_size ((MonoObject*)cur));
2519 verify_scan_starts (cur, cur + size);
2520 if (do_dump_nursery_content) {
2521 if (cur > hole_start)
2522 fprintf (gc_debug_file, "HOLE [%p %p %d]\n", hole_start, cur, (int)(cur - hole_start));
2523 fprintf (gc_debug_file, "OBJ [%p %p %d %d %s %d]\n", cur, cur + size, (int)size, (int)ss, mono_sgen_safe_name ((MonoObject*)cur), (gpointer)LOAD_VTABLE (cur) == mono_sgen_get_array_fill_vtable ());
2528 fflush (gc_debug_file);
2532 * Collect objects in the nursery. Returns whether to trigger a major
2536 collect_nursery (size_t requested_size)
2538 gboolean needs_major;
2539 size_t max_garbage_amount;
2541 FinishRememberedSetScanJobData frssjd;
2542 ScanFromRegisteredRootsJobData scrrjd_normal, scrrjd_wbarrier;
2543 ScanFinalizerEntriesJobData sfejd_fin_ready, sfejd_critical_fin;
2544 ScanThreadDataJobData stdjd;
2545 mword fragment_total;
2546 TV_DECLARE (all_atv);
2547 TV_DECLARE (all_btv);
2551 if (disable_minor_collections)
2556 mono_perfcounters->gc_collections0++;
2558 current_collection_generation = GENERATION_NURSERY;
2560 reset_pinned_from_failed_allocation ();
2562 binary_protocol_collection (GENERATION_NURSERY);
2563 check_scan_starts ();
2567 nursery_next = mono_sgen_nursery_alloc_get_upper_alloc_bound ();
2568 /* FIXME: optimize later to use the higher address where an object can be present */
2569 nursery_next = MAX (nursery_next, mono_sgen_get_nursery_end ());
2571 DEBUG (1, fprintf (gc_debug_file, "Start nursery collection %d %p-%p, size: %d\n", stat_minor_gcs, mono_sgen_get_nursery_start (), nursery_next, (int)(nursery_next - mono_sgen_get_nursery_start ())));
2572 max_garbage_amount = nursery_next - mono_sgen_get_nursery_start ();
2573 g_assert (nursery_section->size >= max_garbage_amount);
2575 /* world must be stopped already */
2576 TV_GETTIME (all_atv);
2580 time_minor_pre_collection_fragment_clear += TV_ELAPSED (atv, btv);
2583 check_for_xdomain_refs ();
2585 nursery_section->next_data = nursery_next;
2587 major_collector.start_nursery_collection ();
2589 try_calculate_minor_collection_allowance (FALSE);
2591 mono_sgen_gray_object_queue_init (&gray_queue);
2592 mono_sgen_workers_init_distribute_gray_queue ();
2595 mono_stats.minor_gc_count ++;
2597 if (remset.prepare_for_minor_collection)
2598 remset.prepare_for_minor_collection ();
2600 process_fin_stage_entries ();
2601 process_dislink_stage_entries ();
2603 /* pin from pinned handles */
2604 mono_sgen_init_pinning ();
2605 mono_profiler_gc_event (MONO_GC_EVENT_MARK_START, 0);
2606 pin_from_roots (mono_sgen_get_nursery_start (), nursery_next, WORKERS_DISTRIBUTE_GRAY_QUEUE);
2607 /* identify pinned objects */
2608 mono_sgen_optimize_pin_queue (0);
2609 mono_sgen_pinning_setup_section (nursery_section);
2610 mono_sgen_pin_objects_in_section (nursery_section, WORKERS_DISTRIBUTE_GRAY_QUEUE);
2611 mono_sgen_pinning_trim_queue_to_section (nursery_section);
2614 time_minor_pinning += TV_ELAPSED (btv, atv);
2615 DEBUG (2, fprintf (gc_debug_file, "Finding pinned pointers: %d in %d usecs\n", mono_sgen_get_pinned_count (), TV_ELAPSED (btv, atv)));
2616 DEBUG (4, fprintf (gc_debug_file, "Start scan with %d pinned objects\n", mono_sgen_get_pinned_count ()));
2618 if (consistency_check_at_minor_collection)
2619 mono_sgen_check_consistency ();
2621 mono_sgen_workers_start_all_workers ();
2624 * Perform the sequential part of remembered set scanning.
2625 * This usually involves scanning global information that might later be produced by evacuation.
2627 if (remset.begin_scan_remsets)
2628 remset.begin_scan_remsets (mono_sgen_get_nursery_start (), nursery_next, WORKERS_DISTRIBUTE_GRAY_QUEUE);
2630 mono_sgen_workers_start_marking ();
2632 frssjd.heap_start = mono_sgen_get_nursery_start ();
2633 frssjd.heap_end = nursery_next;
2634 mono_sgen_workers_enqueue_job (job_finish_remembered_set_scan, &frssjd);
2636 /* we don't have complete write barrier yet, so we scan all the old generation sections */
2638 time_minor_scan_remsets += TV_ELAPSED (atv, btv);
2639 DEBUG (2, fprintf (gc_debug_file, "Old generation scan: %d usecs\n", TV_ELAPSED (atv, btv)));
2641 if (!mono_sgen_collection_is_parallel ())
2642 mono_sgen_drain_gray_stack (&gray_queue, -1);
2644 if (mono_profiler_get_events () & MONO_PROFILE_GC_ROOTS)
2645 report_registered_roots ();
2646 if (mono_profiler_get_events () & MONO_PROFILE_GC_ROOTS)
2647 report_finalizer_roots ();
2649 time_minor_scan_pinned += TV_ELAPSED (btv, atv);
2651 /* registered roots, this includes static fields */
2652 scrrjd_normal.func = mono_sgen_collection_is_parallel () ? major_collector.copy_object : major_collector.nopar_copy_object;
2653 scrrjd_normal.heap_start = mono_sgen_get_nursery_start ();
2654 scrrjd_normal.heap_end = nursery_next;
2655 scrrjd_normal.root_type = ROOT_TYPE_NORMAL;
2656 mono_sgen_workers_enqueue_job (job_scan_from_registered_roots, &scrrjd_normal);
2658 scrrjd_wbarrier.func = mono_sgen_collection_is_parallel () ? major_collector.copy_object : major_collector.nopar_copy_object;
2659 scrrjd_wbarrier.heap_start = mono_sgen_get_nursery_start ();
2660 scrrjd_wbarrier.heap_end = nursery_next;
2661 scrrjd_wbarrier.root_type = ROOT_TYPE_WBARRIER;
2662 mono_sgen_workers_enqueue_job (job_scan_from_registered_roots, &scrrjd_wbarrier);
2665 time_minor_scan_registered_roots += TV_ELAPSED (atv, btv);
2668 stdjd.heap_start = mono_sgen_get_nursery_start ();
2669 stdjd.heap_end = nursery_next;
2670 mono_sgen_workers_enqueue_job (job_scan_thread_data, &stdjd);
2673 time_minor_scan_thread_data += TV_ELAPSED (btv, atv);
2676 if (mono_sgen_collection_is_parallel ()) {
2677 while (!mono_sgen_gray_object_queue_is_empty (WORKERS_DISTRIBUTE_GRAY_QUEUE)) {
2678 mono_sgen_workers_distribute_gray_queue_sections ();
2682 mono_sgen_workers_join ();
2684 if (mono_sgen_collection_is_parallel ())
2685 g_assert (mono_sgen_gray_object_queue_is_empty (&gray_queue));
2687 /* Scan the list of objects ready for finalization. If */
2688 sfejd_fin_ready.list = fin_ready_list;
2689 mono_sgen_workers_enqueue_job (job_scan_finalizer_entries, &sfejd_fin_ready);
2691 sfejd_critical_fin.list = critical_fin_list;
2692 mono_sgen_workers_enqueue_job (job_scan_finalizer_entries, &sfejd_critical_fin);
2694 finish_gray_stack (mono_sgen_get_nursery_start (), nursery_next, GENERATION_NURSERY, &gray_queue);
2696 time_minor_finish_gray_stack += TV_ELAPSED (btv, atv);
2697 mono_profiler_gc_event (MONO_GC_EVENT_MARK_END, 0);
2700 * The (single-threaded) finalization code might have done
2701 * some copying/marking so we can only reset the GC thread's
2702 * worker data here instead of earlier when we joined the
2705 mono_sgen_workers_reset_data ();
2707 if (objects_pinned) {
2708 mono_sgen_optimize_pin_queue (0);
2709 mono_sgen_pinning_setup_section (nursery_section);
2712 /* walk the pin_queue, build up the fragment list of free memory, unmark
2713 * pinned objects as we go, memzero() the empty fragments so they are ready for the
2716 mono_profiler_gc_event (MONO_GC_EVENT_RECLAIM_START, 0);
2717 fragment_total = mono_sgen_build_nursery_fragments (nursery_section, nursery_section->pin_queue_start, nursery_section->pin_queue_num_entries);
2718 if (!fragment_total)
2721 /* Clear TLABs for all threads */
2722 mono_sgen_clear_tlabs ();
2724 mono_profiler_gc_event (MONO_GC_EVENT_RECLAIM_END, 0);
2726 time_minor_fragment_creation += TV_ELAPSED (atv, btv);
2727 DEBUG (2, fprintf (gc_debug_file, "Fragment creation: %d usecs, %lu bytes available\n", TV_ELAPSED (atv, btv), (unsigned long)fragment_total));
2729 if (consistency_check_at_minor_collection)
2730 mono_sgen_check_major_refs ();
2732 major_collector.finish_nursery_collection ();
2734 TV_GETTIME (all_btv);
2735 mono_stats.minor_gc_time_usecs += TV_ELAPSED (all_atv, all_btv);
2738 dump_heap ("minor", stat_minor_gcs - 1, NULL);
2740 /* prepare the pin queue for the next collection */
2741 mono_sgen_finish_pinning ();
2742 if (fin_ready_list || critical_fin_list) {
2743 DEBUG (4, fprintf (gc_debug_file, "Finalizer-thread wakeup: ready %d\n", num_ready_finalizers));
2744 mono_gc_finalize_notify ();
2746 mono_sgen_pin_stats_reset ();
2748 g_assert (mono_sgen_gray_object_queue_is_empty (&gray_queue));
2750 if (remset.finish_minor_collection)
2751 remset.finish_minor_collection ();
2753 check_scan_starts ();
2755 binary_protocol_flush_buffers (FALSE);
2757 /*objects are late pinned because of lack of memory, so a major is a good call*/
2758 needs_major = need_major_collection (0) || objects_pinned;
2759 current_collection_generation = -1;
2766 mono_sgen_collect_nursery_no_lock (size_t requested_size)
2768 gint64 gc_start_time;
2770 mono_profiler_gc_event (MONO_GC_EVENT_START, 0);
2771 gc_start_time = mono_100ns_ticks ();
2774 collect_nursery (requested_size);
2777 mono_trace_message (MONO_TRACE_GC, "minor gc took %d usecs", (mono_100ns_ticks () - gc_start_time) / 10);
2778 mono_profiler_gc_event (MONO_GC_EVENT_END, 0);
2782 major_do_collection (const char *reason)
2784 LOSObject *bigobj, *prevbo;
2785 TV_DECLARE (all_atv);
2786 TV_DECLARE (all_btv);
2789 /* FIXME: only use these values for the precise scan
2790 * note that to_space pointers should be excluded anyway...
2792 char *heap_start = NULL;
2793 char *heap_end = (char*)-1;
2794 int old_next_pin_slot;
2795 ScanFromRegisteredRootsJobData scrrjd_normal, scrrjd_wbarrier;
2796 ScanThreadDataJobData stdjd;
2797 ScanFinalizerEntriesJobData sfejd_fin_ready, sfejd_critical_fin;
2799 mono_perfcounters->gc_collections1++;
2801 reset_pinned_from_failed_allocation ();
2803 last_collection_old_num_major_sections = major_collector.get_num_major_sections ();
2806 * A domain could have been freed, resulting in
2807 * los_memory_usage being less than last_collection_los_memory_usage.
2809 last_collection_los_memory_alloced = los_memory_usage - MIN (last_collection_los_memory_usage, los_memory_usage);
2810 last_collection_old_los_memory_usage = los_memory_usage;
2813 //count_ref_nonref_objs ();
2814 //consistency_check ();
2816 binary_protocol_collection (GENERATION_OLD);
2817 check_scan_starts ();
2818 mono_sgen_gray_object_queue_init (&gray_queue);
2819 mono_sgen_workers_init_distribute_gray_queue ();
2822 DEBUG (1, fprintf (gc_debug_file, "Start major collection %d\n", stat_major_gcs));
2824 mono_stats.major_gc_count ++;
2826 /* world must be stopped already */
2827 TV_GETTIME (all_atv);
2830 /* Pinning depends on this */
2831 mono_sgen_clear_nursery_fragments ();
2834 time_major_pre_collection_fragment_clear += TV_ELAPSED (atv, btv);
2836 nursery_section->next_data = mono_sgen_get_nursery_end ();
2837 /* we should also coalesce scanning from sections close to each other
2838 * and deal with pointers outside of the sections later.
2841 if (major_collector.start_major_collection)
2842 major_collector.start_major_collection ();
2844 *major_collector.have_swept = FALSE;
2845 reset_minor_collection_allowance ();
2848 check_for_xdomain_refs ();
2850 /* Remsets are not useful for a major collection */
2851 remset.prepare_for_major_collection ();
2853 process_fin_stage_entries ();
2854 process_dislink_stage_entries ();
2857 mono_sgen_init_pinning ();
2858 DEBUG (6, fprintf (gc_debug_file, "Collecting pinned addresses\n"));
2859 pin_from_roots ((void*)lowest_heap_address, (void*)highest_heap_address, WORKERS_DISTRIBUTE_GRAY_QUEUE);
2860 mono_sgen_optimize_pin_queue (0);
2863 * pin_queue now contains all candidate pointers, sorted and
2864 * uniqued. We must do two passes now to figure out which
2865 * objects are pinned.
2867 * The first is to find within the pin_queue the area for each
2868 * section. This requires that the pin_queue be sorted. We
2869 * also process the LOS objects and pinned chunks here.
2871 * The second, destructive, pass is to reduce the section
2872 * areas to pointers to the actually pinned objects.
2874 DEBUG (6, fprintf (gc_debug_file, "Pinning from sections\n"));
2875 /* first pass for the sections */
2876 mono_sgen_find_section_pin_queue_start_end (nursery_section);
2877 major_collector.find_pin_queue_start_ends (WORKERS_DISTRIBUTE_GRAY_QUEUE);
2878 /* identify possible pointers to the insize of large objects */
2879 DEBUG (6, fprintf (gc_debug_file, "Pinning from large objects\n"));
2880 for (bigobj = los_object_list; bigobj; bigobj = bigobj->next) {
2882 gboolean profile_roots = mono_profiler_get_events () & MONO_PROFILE_GC_ROOTS;
2883 GCRootReport report;
2885 if (mono_sgen_find_optimized_pin_queue_area (bigobj->data, (char*)bigobj->data + bigobj->size, &dummy)) {
2886 binary_protocol_pin (bigobj->data, (gpointer)LOAD_VTABLE (bigobj->data), safe_object_get_size (bigobj->data));
2887 pin_object (bigobj->data);
2888 /* FIXME: only enqueue if object has references */
2889 GRAY_OBJECT_ENQUEUE (WORKERS_DISTRIBUTE_GRAY_QUEUE, bigobj->data);
2890 if (G_UNLIKELY (do_pin_stats))
2891 mono_sgen_pin_stats_register_object ((char*) bigobj->data, safe_object_get_size ((MonoObject*) bigobj->data));
2892 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));
2895 add_profile_gc_root (&report, bigobj->data, MONO_PROFILE_GC_ROOT_PINNING | MONO_PROFILE_GC_ROOT_MISC, 0);
2898 notify_gc_roots (&report);
2900 /* second pass for the sections */
2901 mono_sgen_pin_objects_in_section (nursery_section, WORKERS_DISTRIBUTE_GRAY_QUEUE);
2902 major_collector.pin_objects (WORKERS_DISTRIBUTE_GRAY_QUEUE);
2903 old_next_pin_slot = mono_sgen_get_pinned_count ();
2906 time_major_pinning += TV_ELAPSED (atv, btv);
2907 DEBUG (2, fprintf (gc_debug_file, "Finding pinned pointers: %d in %d usecs\n", mono_sgen_get_pinned_count (), TV_ELAPSED (atv, btv)));
2908 DEBUG (4, fprintf (gc_debug_file, "Start scan with %d pinned objects\n", mono_sgen_get_pinned_count ()));
2910 major_collector.init_to_space ();
2912 #ifdef SGEN_DEBUG_INTERNAL_ALLOC
2913 main_gc_thread = mono_native_thread_self ();
2916 mono_sgen_workers_start_all_workers ();
2917 mono_sgen_workers_start_marking ();
2919 if (mono_profiler_get_events () & MONO_PROFILE_GC_ROOTS)
2920 report_registered_roots ();
2922 time_major_scan_pinned += TV_ELAPSED (btv, atv);
2924 /* registered roots, this includes static fields */
2925 scrrjd_normal.func = major_collector.copy_or_mark_object;
2926 scrrjd_normal.heap_start = heap_start;
2927 scrrjd_normal.heap_end = heap_end;
2928 scrrjd_normal.root_type = ROOT_TYPE_NORMAL;
2929 mono_sgen_workers_enqueue_job (job_scan_from_registered_roots, &scrrjd_normal);
2931 scrrjd_wbarrier.func = major_collector.copy_or_mark_object;
2932 scrrjd_wbarrier.heap_start = heap_start;
2933 scrrjd_wbarrier.heap_end = heap_end;
2934 scrrjd_wbarrier.root_type = ROOT_TYPE_WBARRIER;
2935 mono_sgen_workers_enqueue_job (job_scan_from_registered_roots, &scrrjd_wbarrier);
2938 time_major_scan_registered_roots += TV_ELAPSED (atv, btv);
2941 stdjd.heap_start = heap_start;
2942 stdjd.heap_end = heap_end;
2943 mono_sgen_workers_enqueue_job (job_scan_thread_data, &stdjd);
2946 time_major_scan_thread_data += TV_ELAPSED (btv, atv);
2949 time_major_scan_alloc_pinned += TV_ELAPSED (atv, btv);
2951 if (mono_profiler_get_events () & MONO_PROFILE_GC_ROOTS)
2952 report_finalizer_roots ();
2954 /* scan the list of objects ready for finalization */
2955 sfejd_fin_ready.list = fin_ready_list;
2956 mono_sgen_workers_enqueue_job (job_scan_finalizer_entries, &sfejd_fin_ready);
2958 sfejd_critical_fin.list = critical_fin_list;
2959 mono_sgen_workers_enqueue_job (job_scan_finalizer_entries, &sfejd_critical_fin);
2962 time_major_scan_finalized += TV_ELAPSED (btv, atv);
2963 DEBUG (2, fprintf (gc_debug_file, "Root scan: %d usecs\n", TV_ELAPSED (btv, atv)));
2966 time_major_scan_big_objects += TV_ELAPSED (atv, btv);
2968 if (major_collector.is_parallel) {
2969 while (!mono_sgen_gray_object_queue_is_empty (WORKERS_DISTRIBUTE_GRAY_QUEUE)) {
2970 mono_sgen_workers_distribute_gray_queue_sections ();
2974 mono_sgen_workers_join ();
2976 #ifdef SGEN_DEBUG_INTERNAL_ALLOC
2977 main_gc_thread = NULL;
2980 if (major_collector.is_parallel)
2981 g_assert (mono_sgen_gray_object_queue_is_empty (&gray_queue));
2983 /* all the objects in the heap */
2984 finish_gray_stack (heap_start, heap_end, GENERATION_OLD, &gray_queue);
2986 time_major_finish_gray_stack += TV_ELAPSED (btv, atv);
2989 * The (single-threaded) finalization code might have done
2990 * some copying/marking so we can only reset the GC thread's
2991 * worker data here instead of earlier when we joined the
2994 mono_sgen_workers_reset_data ();
2996 if (objects_pinned) {
2997 /*This is slow, but we just OOM'd*/
2998 mono_sgen_pin_queue_clear_discarded_entries (nursery_section, old_next_pin_slot);
2999 mono_sgen_optimize_pin_queue (0);
3000 mono_sgen_find_section_pin_queue_start_end (nursery_section);
3004 reset_heap_boundaries ();
3005 mono_sgen_update_heap_boundaries ((mword)mono_sgen_get_nursery_start (), (mword)mono_sgen_get_nursery_end ());
3007 /* sweep the big objects list */
3009 for (bigobj = los_object_list; bigobj;) {
3010 if (object_is_pinned (bigobj->data)) {
3011 unpin_object (bigobj->data);
3012 mono_sgen_update_heap_boundaries ((mword)bigobj->data, (mword)bigobj->data + bigobj->size);
3015 /* not referenced anywhere, so we can free it */
3017 prevbo->next = bigobj->next;
3019 los_object_list = bigobj->next;
3021 bigobj = bigobj->next;
3022 mono_sgen_los_free_object (to_free);
3026 bigobj = bigobj->next;
3030 time_major_free_bigobjs += TV_ELAPSED (atv, btv);
3032 mono_sgen_los_sweep ();
3035 time_major_los_sweep += TV_ELAPSED (btv, atv);
3037 major_collector.sweep ();
3040 time_major_sweep += TV_ELAPSED (atv, btv);
3042 /* walk the pin_queue, build up the fragment list of free memory, unmark
3043 * pinned objects as we go, memzero() the empty fragments so they are ready for the
3046 if (!mono_sgen_build_nursery_fragments (nursery_section, nursery_section->pin_queue_start, nursery_section->pin_queue_num_entries))
3049 /* Clear TLABs for all threads */
3050 mono_sgen_clear_tlabs ();
3053 time_major_fragment_creation += TV_ELAPSED (btv, atv);
3055 TV_GETTIME (all_btv);
3056 mono_stats.major_gc_time_usecs += TV_ELAPSED (all_atv, all_btv);
3059 dump_heap ("major", stat_major_gcs - 1, reason);
3061 /* prepare the pin queue for the next collection */
3062 mono_sgen_finish_pinning ();
3064 if (fin_ready_list || critical_fin_list) {
3065 DEBUG (4, fprintf (gc_debug_file, "Finalizer-thread wakeup: ready %d\n", num_ready_finalizers));
3066 mono_gc_finalize_notify ();
3068 mono_sgen_pin_stats_reset ();
3070 g_assert (mono_sgen_gray_object_queue_is_empty (&gray_queue));
3072 try_calculate_minor_collection_allowance (TRUE);
3074 minor_collection_sections_alloced = 0;
3075 last_collection_los_memory_usage = los_memory_usage;
3077 major_collector.finish_major_collection ();
3079 check_scan_starts ();
3081 binary_protocol_flush_buffers (FALSE);
3083 //consistency_check ();
3085 return bytes_pinned_from_failed_allocation > 0;
3089 major_collection (const char *reason)
3091 gboolean need_minor_collection;
3093 if (disable_major_collections) {
3094 collect_nursery (0);
3098 major_collection_happened = TRUE;
3099 current_collection_generation = GENERATION_OLD;
3100 need_minor_collection = major_do_collection (reason);
3101 current_collection_generation = -1;
3103 if (need_minor_collection)
3104 collect_nursery (0);
3108 sgen_collect_major_no_lock (const char *reason)
3110 gint64 gc_start_time;
3112 mono_profiler_gc_event (MONO_GC_EVENT_START, 1);
3113 gc_start_time = mono_100ns_ticks ();
3115 major_collection (reason);
3117 mono_trace_message (MONO_TRACE_GC, "major gc took %d usecs", (mono_100ns_ticks () - gc_start_time) / 10);
3118 mono_profiler_gc_event (MONO_GC_EVENT_END, 1);
3122 * When deciding if it's better to collect or to expand, keep track
3123 * of how much garbage was reclaimed with the last collection: if it's too
3125 * This is called when we could not allocate a small object.
3127 static void __attribute__((noinline))
3128 minor_collect_or_expand_inner (size_t size)
3130 int do_minor_collection = 1;
3132 g_assert (nursery_section);
3133 if (do_minor_collection) {
3134 gint64 total_gc_time, major_gc_time = 0;
3136 mono_profiler_gc_event (MONO_GC_EVENT_START, 0);
3137 total_gc_time = mono_100ns_ticks ();
3140 if (collect_nursery (size)) {
3141 mono_profiler_gc_event (MONO_GC_EVENT_START, 1);
3142 major_gc_time = mono_100ns_ticks ();
3144 major_collection ("minor overflow");
3146 /* keep events symmetric */
3147 major_gc_time = mono_100ns_ticks () - major_gc_time;
3148 mono_profiler_gc_event (MONO_GC_EVENT_END, 1);
3150 DEBUG (2, fprintf (gc_debug_file, "Heap size: %lu, LOS size: %lu\n", (unsigned long)total_alloc, (unsigned long)los_memory_usage));
3153 total_gc_time = mono_100ns_ticks () - total_gc_time;
3155 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);
3157 mono_trace_message (MONO_TRACE_GC, "minor gc took %d usecs", total_gc_time / 10);
3159 /* this also sets the proper pointers for the next allocation */
3160 if (!mono_sgen_can_alloc_size (size)) {
3161 /* TypeBuilder and MonoMethod are killing mcs with fragmentation */
3162 DEBUG (1, fprintf (gc_debug_file, "nursery collection didn't find enough room for %zd alloc (%d pinned)\n", size, mono_sgen_get_pinned_count ()));
3163 mono_sgen_dump_pin_queue ();
3166 mono_profiler_gc_event (MONO_GC_EVENT_END, 0);
3168 //report_internal_mem_usage ();
3172 mono_sgen_minor_collect_or_expand_inner (size_t size)
3174 minor_collect_or_expand_inner (size);
3178 * ######################################################################
3179 * ######## Memory allocation from the OS
3180 * ######################################################################
3181 * This section of code deals with getting memory from the OS and
3182 * allocating memory for GC-internal data structures.
3183 * Internal memory can be handled with a freelist for small objects.
3189 G_GNUC_UNUSED static void
3190 report_internal_mem_usage (void)
3192 printf ("Internal memory usage:\n");
3193 mono_sgen_report_internal_mem_usage ();
3194 printf ("Pinned memory usage:\n");
3195 major_collector.report_pinned_memory_usage ();
3199 * ######################################################################
3200 * ######## Finalization support
3201 * ######################################################################
3205 * If the object has been forwarded it means it's still referenced from a root.
3206 * If it is pinned it's still alive as well.
3207 * A LOS object is only alive if we have pinned it.
3208 * Return TRUE if @obj is ready to be finalized.
3210 static inline gboolean
3211 mono_sgen_is_object_alive (void *object)
3213 if (SGEN_OBJECT_IS_PINNED (object) || SGEN_OBJECT_IS_FORWARDED (object))
3215 return major_collector.is_object_live (object);
3219 mono_sgen_gc_is_object_ready_for_finalization (void *object)
3221 return !mono_sgen_is_object_alive (object);
3225 has_critical_finalizer (MonoObject *obj)
3229 if (!mono_defaults.critical_finalizer_object)
3232 class = ((MonoVTable*)LOAD_VTABLE (obj))->klass;
3234 return mono_class_has_parent_fast (class, mono_defaults.critical_finalizer_object);
3238 queue_finalization_entry (MonoObject *obj) {
3239 FinalizeReadyEntry *entry = mono_sgen_alloc_internal (INTERNAL_MEM_FINALIZE_READY_ENTRY);
3240 entry->object = obj;
3241 if (has_critical_finalizer (obj)) {
3242 entry->next = critical_fin_list;
3243 critical_fin_list = entry;
3245 entry->next = fin_ready_list;
3246 fin_ready_list = entry;
3251 object_is_reachable (char *object, char *start, char *end)
3253 /*This happens for non nursery objects during minor collections. We just treat all objects as alive.*/
3254 if (object < start || object >= end)
3257 return mono_sgen_is_object_alive (object);
3260 #include "sgen-fin-weak-hash.c"
3263 mono_sgen_object_is_live (void *obj)
3265 if (ptr_in_nursery (obj))
3266 return object_is_pinned (obj);
3267 /* FIXME This is semantically wrong! All tenured object are considered alive during a nursery collection. */
3268 if (current_collection_generation == GENERATION_NURSERY)
3270 return major_collector.is_object_live (obj);
3273 /* LOCKING: requires that the GC lock is held */
3275 null_ephemerons_for_domain (MonoDomain *domain)
3277 EphemeronLinkNode *current = ephemeron_list, *prev = NULL;
3280 MonoObject *object = (MonoObject*)current->array;
3282 if (object && !object->vtable) {
3283 EphemeronLinkNode *tmp = current;
3286 prev->next = current->next;
3288 ephemeron_list = current->next;
3290 current = current->next;
3291 mono_sgen_free_internal (tmp, INTERNAL_MEM_EPHEMERON_LINK);
3294 current = current->next;
3299 /* LOCKING: requires that the GC lock is held */
3301 clear_unreachable_ephemerons (CopyOrMarkObjectFunc copy_func, char *start, char *end, GrayQueue *queue)
3303 int was_in_nursery, was_promoted;
3304 EphemeronLinkNode *current = ephemeron_list, *prev = NULL;
3306 Ephemeron *cur, *array_end;
3310 char *object = current->array;
3312 if (!object_is_reachable (object, start, end)) {
3313 EphemeronLinkNode *tmp = current;
3315 DEBUG (5, fprintf (gc_debug_file, "Dead Ephemeron array at %p\n", object));
3318 prev->next = current->next;
3320 ephemeron_list = current->next;
3322 current = current->next;
3323 mono_sgen_free_internal (tmp, INTERNAL_MEM_EPHEMERON_LINK);
3328 was_in_nursery = ptr_in_nursery (object);
3329 copy_func ((void**)&object, queue);
3330 current->array = object;
3332 /*The array was promoted, add global remsets for key/values left behind in nursery.*/
3333 was_promoted = was_in_nursery && !ptr_in_nursery (object);
3335 DEBUG (5, fprintf (gc_debug_file, "Clearing unreachable entries for ephemeron array at %p\n", object));
3337 array = (MonoArray*)object;
3338 cur = mono_array_addr (array, Ephemeron, 0);
3339 array_end = cur + mono_array_length_fast (array);
3340 tombstone = (char*)((MonoVTable*)LOAD_VTABLE (object))->domain->ephemeron_tombstone;
3342 for (; cur < array_end; ++cur) {
3343 char *key = (char*)cur->key;
3345 if (!key || key == tombstone)
3348 DEBUG (5, fprintf (gc_debug_file, "[%td] key %p (%s) value %p (%s)\n", cur - mono_array_addr (array, Ephemeron, 0),
3349 key, object_is_reachable (key, start, end) ? "reachable" : "unreachable",
3350 cur->value, cur->value && object_is_reachable (cur->value, start, end) ? "reachable" : "unreachable"));
3352 if (!object_is_reachable (key, start, end)) {
3353 cur->key = tombstone;
3359 if (ptr_in_nursery (key)) {/*key was not promoted*/
3360 DEBUG (5, fprintf (gc_debug_file, "\tAdded remset to key %p\n", key));
3361 mono_sgen_add_to_global_remset (&cur->key);
3363 if (ptr_in_nursery (cur->value)) {/*value was not promoted*/
3364 DEBUG (5, fprintf (gc_debug_file, "\tAdded remset to value %p\n", cur->value));
3365 mono_sgen_add_to_global_remset (&cur->value);
3370 current = current->next;
3374 /* LOCKING: requires that the GC lock is held */
3376 mark_ephemerons_in_range (CopyOrMarkObjectFunc copy_func, char *start, char *end, GrayQueue *queue)
3378 int nothing_marked = 1;
3379 EphemeronLinkNode *current = ephemeron_list;
3381 Ephemeron *cur, *array_end;
3384 for (current = ephemeron_list; current; current = current->next) {
3385 char *object = current->array;
3386 DEBUG (5, fprintf (gc_debug_file, "Ephemeron array at %p\n", object));
3389 For now we process all ephemerons during all collections.
3390 Ideally we should use remset information to partially scan those
3392 We already emit write barriers for Ephemeron fields, it's
3393 just that we don't process them.
3395 /*if (object < start || object >= end)
3398 /*It has to be alive*/
3399 if (!object_is_reachable (object, start, end)) {
3400 DEBUG (5, fprintf (gc_debug_file, "\tnot reachable\n"));
3404 copy_func ((void**)&object, queue);
3406 array = (MonoArray*)object;
3407 cur = mono_array_addr (array, Ephemeron, 0);
3408 array_end = cur + mono_array_length_fast (array);
3409 tombstone = (char*)((MonoVTable*)LOAD_VTABLE (object))->domain->ephemeron_tombstone;
3411 for (; cur < array_end; ++cur) {
3412 char *key = cur->key;
3414 if (!key || key == tombstone)
3417 DEBUG (5, fprintf (gc_debug_file, "[%td] key %p (%s) value %p (%s)\n", cur - mono_array_addr (array, Ephemeron, 0),
3418 key, object_is_reachable (key, start, end) ? "reachable" : "unreachable",
3419 cur->value, cur->value && object_is_reachable (cur->value, start, end) ? "reachable" : "unreachable"));
3421 if (object_is_reachable (key, start, end)) {
3422 char *value = cur->value;
3424 copy_func ((void**)&cur->key, queue);
3426 if (!object_is_reachable (value, start, end))
3428 copy_func ((void**)&cur->value, queue);
3434 DEBUG (5, fprintf (gc_debug_file, "Ephemeron run finished. Is it done %d\n", nothing_marked));
3435 return nothing_marked;
3439 mono_gc_invoke_finalizers (void)
3441 FinalizeReadyEntry *entry = NULL;
3442 gboolean entry_is_critical = FALSE;
3445 /* FIXME: batch to reduce lock contention */
3446 while (fin_ready_list || critical_fin_list) {
3450 FinalizeReadyEntry **list = entry_is_critical ? &critical_fin_list : &fin_ready_list;
3452 /* We have finalized entry in the last
3453 interation, now we need to remove it from
3456 *list = entry->next;
3458 FinalizeReadyEntry *e = *list;
3459 while (e->next != entry)
3461 e->next = entry->next;
3463 mono_sgen_free_internal (entry, INTERNAL_MEM_FINALIZE_READY_ENTRY);
3467 /* Now look for the first non-null entry. */
3468 for (entry = fin_ready_list; entry && !entry->object; entry = entry->next)
3471 entry_is_critical = FALSE;
3473 entry_is_critical = TRUE;
3474 for (entry = critical_fin_list; entry && !entry->object; entry = entry->next)
3479 g_assert (entry->object);
3480 num_ready_finalizers--;
3481 obj = entry->object;
3482 entry->object = NULL;
3483 DEBUG (7, fprintf (gc_debug_file, "Finalizing object %p (%s)\n", obj, safe_name (obj)));
3491 g_assert (entry->object == NULL);
3493 /* the object is on the stack so it is pinned */
3494 /*g_print ("Calling finalizer for object: %p (%s)\n", entry->object, safe_name (entry->object));*/
3495 mono_gc_run_finalize (obj, NULL);
3502 mono_gc_pending_finalizers (void)
3504 return fin_ready_list || critical_fin_list;
3507 /* Negative value to remove */
3509 mono_gc_add_memory_pressure (gint64 value)
3511 /* FIXME: Use interlocked functions */
3513 memory_pressure += value;
3518 mono_sgen_register_major_sections_alloced (int num_sections)
3520 minor_collection_sections_alloced += num_sections;
3524 mono_sgen_get_minor_collection_allowance (void)
3526 return minor_collection_allowance;
3530 * ######################################################################
3531 * ######## registered roots support
3532 * ######################################################################
3536 * We do not coalesce roots.
3539 mono_gc_register_root_inner (char *start, size_t size, void *descr, int root_type)
3541 RootRecord new_root;
3544 for (i = 0; i < ROOT_TYPE_NUM; ++i) {
3545 RootRecord *root = mono_sgen_hash_table_lookup (&roots_hash [i], start);
3546 /* we allow changing the size and the descriptor (for thread statics etc) */
3548 size_t old_size = root->end_root - start;
3549 root->end_root = start + size;
3550 g_assert (((root->root_desc != 0) && (descr != NULL)) ||
3551 ((root->root_desc == 0) && (descr == NULL)));
3552 root->root_desc = (mword)descr;
3554 roots_size -= old_size;
3560 new_root.end_root = start + size;
3561 new_root.root_desc = (mword)descr;
3563 mono_sgen_hash_table_replace (&roots_hash [root_type], start, &new_root);
3566 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));
3573 mono_gc_register_root (char *start, size_t size, void *descr)
3575 return mono_gc_register_root_inner (start, size, descr, descr ? ROOT_TYPE_NORMAL : ROOT_TYPE_PINNED);
3579 mono_gc_register_root_wbarrier (char *start, size_t size, void *descr)
3581 return mono_gc_register_root_inner (start, size, descr, ROOT_TYPE_WBARRIER);
3585 mono_gc_deregister_root (char* addr)
3591 for (root_type = 0; root_type < ROOT_TYPE_NUM; ++root_type) {
3592 if (mono_sgen_hash_table_remove (&roots_hash [root_type], addr, &root))
3593 roots_size -= (root.end_root - addr);
3599 * ######################################################################
3600 * ######## Thread handling (stop/start code)
3601 * ######################################################################
3604 unsigned int mono_sgen_global_stop_count = 0;
3607 static MonoContext cur_thread_ctx = {0};
3609 static mword cur_thread_regs [ARCH_NUM_REGS] = {0};
3613 update_current_thread_stack (void *start)
3615 int stack_guard = 0;
3616 #ifndef USE_MONO_CTX
3617 void *ptr = cur_thread_regs;
3619 SgenThreadInfo *info = mono_thread_info_current ();
3621 info->stack_start = align_pointer (&stack_guard);
3622 g_assert (info->stack_start >= info->stack_start_limit && info->stack_start < info->stack_end);
3624 MONO_CONTEXT_GET_CURRENT (cur_thread_ctx);
3625 info->monoctx = &cur_thread_ctx;
3627 ARCH_STORE_REGS (ptr);
3628 info->stopped_regs = ptr;
3630 if (gc_callbacks.thread_suspend_func)
3631 gc_callbacks.thread_suspend_func (info->runtime_data, NULL);
3635 mono_sgen_fill_thread_info_for_suspend (SgenThreadInfo *info)
3637 if (remset.fill_thread_info_for_suspend)
3638 remset.fill_thread_info_for_suspend (info);
3642 is_ip_in_managed_allocator (MonoDomain *domain, gpointer ip);
3645 restart_threads_until_none_in_managed_allocator (void)
3647 SgenThreadInfo *info;
3648 int num_threads_died = 0;
3649 int sleep_duration = -1;
3652 int restart_count = 0, restarted_count = 0;
3653 /* restart all threads that stopped in the
3655 FOREACH_THREAD_SAFE (info) {
3657 if (info->skip || info->gc_disabled)
3659 if (!info->thread_is_dying && (!info->stack_start || info->in_critical_region ||
3660 is_ip_in_managed_allocator (info->stopped_domain, info->stopped_ip))) {
3661 binary_protocol_thread_restart ((gpointer)mono_thread_info_get_tid (info));
3662 result = mono_sgen_resume_thread (info);
3669 /* we set the stopped_ip to
3670 NULL for threads which
3671 we're not restarting so
3672 that we can easily identify
3674 info->stopped_ip = NULL;
3675 info->stopped_domain = NULL;
3677 } END_FOREACH_THREAD_SAFE
3678 /* if no threads were restarted, we're done */
3679 if (restart_count == 0)
3682 /* wait for the threads to signal their restart */
3683 mono_sgen_wait_for_suspend_ack (restart_count);
3685 if (sleep_duration < 0) {
3693 g_usleep (sleep_duration);
3694 sleep_duration += 10;
3697 /* stop them again */
3698 FOREACH_THREAD (info) {
3700 if (info->skip || info->stopped_ip == NULL)
3702 result = mono_sgen_suspend_thread (info);
3709 } END_FOREACH_THREAD
3710 /* some threads might have died */
3711 num_threads_died += restart_count - restarted_count;
3712 /* wait for the threads to signal their suspension
3714 mono_sgen_wait_for_suspend_ack (restart_count);
3717 return num_threads_died;
3721 acquire_gc_locks (void)
3724 mono_thread_info_suspend_lock ();
3728 release_gc_locks (void)
3730 mono_thread_info_suspend_unlock ();
3731 UNLOCK_INTERRUPTION;
3734 static TV_DECLARE (stop_world_time);
3735 static unsigned long max_pause_usec = 0;
3737 /* LOCKING: assumes the GC lock is held */
3739 stop_world (int generation)
3743 /*XXX this is the right stop, thought might not be the nicest place to put it*/
3744 mono_sgen_process_togglerefs ();
3746 mono_profiler_gc_event (MONO_GC_EVENT_PRE_STOP_WORLD, generation);
3747 acquire_gc_locks ();
3749 update_current_thread_stack (&count);
3751 mono_sgen_global_stop_count++;
3752 DEBUG (3, fprintf (gc_debug_file, "stopping world n %d from %p %p\n", mono_sgen_global_stop_count, mono_thread_info_current (), (gpointer)mono_native_thread_id_get ()));
3753 TV_GETTIME (stop_world_time);
3754 count = mono_sgen_thread_handshake (TRUE);
3755 count -= restart_threads_until_none_in_managed_allocator ();
3756 g_assert (count >= 0);
3757 DEBUG (3, fprintf (gc_debug_file, "world stopped %d thread(s)\n", count));
3758 mono_profiler_gc_event (MONO_GC_EVENT_POST_STOP_WORLD, generation);
3760 last_major_num_sections = major_collector.get_num_major_sections ();
3761 last_los_memory_usage = los_memory_usage;
3762 major_collection_happened = FALSE;
3766 /* LOCKING: assumes the GC lock is held */
3768 restart_world (int generation)
3770 int count, num_major_sections;
3771 SgenThreadInfo *info;
3772 TV_DECLARE (end_sw);
3773 TV_DECLARE (end_bridge);
3774 unsigned long usec, bridge_usec;
3776 /* notify the profiler of the leftovers */
3777 if (G_UNLIKELY (mono_profiler_events & MONO_PROFILE_GC_MOVES)) {
3778 if (moved_objects_idx) {
3779 mono_profiler_gc_moves (moved_objects, moved_objects_idx);
3780 moved_objects_idx = 0;
3783 mono_profiler_gc_event (MONO_GC_EVENT_PRE_START_WORLD, generation);
3784 FOREACH_THREAD (info) {
3785 info->stack_start = NULL;
3787 info->monoctx = NULL;
3789 info->stopped_regs = NULL;
3791 } END_FOREACH_THREAD
3793 stw_bridge_process ();
3794 release_gc_locks ();
3796 count = mono_sgen_thread_handshake (FALSE);
3797 TV_GETTIME (end_sw);
3798 usec = TV_ELAPSED (stop_world_time, end_sw);
3799 max_pause_usec = MAX (usec, max_pause_usec);
3800 DEBUG (2, fprintf (gc_debug_file, "restarted %d thread(s) (pause time: %d usec, max: %d)\n", count, (int)usec, (int)max_pause_usec));
3801 mono_profiler_gc_event (MONO_GC_EVENT_POST_START_WORLD, generation);
3805 TV_GETTIME (end_bridge);
3806 bridge_usec = TV_ELAPSED (end_sw, end_bridge);
3808 num_major_sections = major_collector.get_num_major_sections ();
3809 if (major_collection_happened)
3810 mono_trace (G_LOG_LEVEL_INFO, MONO_TRACE_GC, "GC_MAJOR: %s pause %.2fms, bridge %.2fms major %dK/%dK los %dK/%dK",
3811 generation ? "" : "(minor overflow)",
3812 (int)usec / 1000.0f, (int)bridge_usec / 1000.0f,
3813 major_collector.section_size * num_major_sections / 1024,
3814 major_collector.section_size * last_major_num_sections / 1024,
3815 los_memory_usage / 1024,
3816 last_los_memory_usage / 1024);
3818 mono_trace (G_LOG_LEVEL_INFO, MONO_TRACE_GC, "GC_MINOR: pause %.2fms, bridge %.2fms promoted %dK major %dK los %dK",
3819 (int)usec / 1000.0f, (int)bridge_usec / 1000.0f,
3820 (num_major_sections - last_major_num_sections) * major_collector.section_size / 1024,
3821 major_collector.section_size * num_major_sections / 1024,
3822 los_memory_usage / 1024);
3828 mono_sgen_get_current_collection_generation (void)
3830 return current_collection_generation;
3834 mono_gc_set_gc_callbacks (MonoGCCallbacks *callbacks)
3836 gc_callbacks = *callbacks;
3840 mono_gc_get_gc_callbacks ()
3842 return &gc_callbacks;
3845 /* Variables holding start/end nursery so it won't have to be passed at every call */
3846 static void *scan_area_arg_start, *scan_area_arg_end;
3849 mono_gc_conservatively_scan_area (void *start, void *end)
3851 conservatively_pin_objects_from (start, end, scan_area_arg_start, scan_area_arg_end, PIN_TYPE_STACK);
3855 mono_gc_scan_object (void *obj)
3857 UserCopyOrMarkData *data = mono_native_tls_get_value (user_copy_or_mark_key);
3859 if (current_collection_generation == GENERATION_NURSERY) {
3860 if (mono_sgen_collection_is_parallel ())
3861 major_collector.copy_object (&obj, data->queue);
3863 major_collector.nopar_copy_object (&obj, data->queue);
3865 major_collector.copy_or_mark_object (&obj, data->queue);
3871 * Mark from thread stacks and registers.
3874 scan_thread_data (void *start_nursery, void *end_nursery, gboolean precise, GrayQueue *queue)
3876 SgenThreadInfo *info;
3878 scan_area_arg_start = start_nursery;
3879 scan_area_arg_end = end_nursery;
3881 FOREACH_THREAD (info) {
3883 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));
3886 if (info->gc_disabled) {
3887 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));
3890 DEBUG (3, fprintf (gc_debug_file, "Scanning thread %p, range: %p-%p, size: %ld, pinned=%d\n", info, info->stack_start, info->stack_end, (char*)info->stack_end - (char*)info->stack_start, mono_sgen_get_pinned_count ()));
3891 if (!info->thread_is_dying) {
3892 if (gc_callbacks.thread_mark_func && !conservative_stack_mark) {
3893 UserCopyOrMarkData data = { NULL, queue };
3894 set_user_copy_or_mark_data (&data);
3895 gc_callbacks.thread_mark_func (info->runtime_data, info->stack_start, info->stack_end, precise);
3896 set_user_copy_or_mark_data (NULL);
3897 } else if (!precise) {
3898 conservatively_pin_objects_from (info->stack_start, info->stack_end, start_nursery, end_nursery, PIN_TYPE_STACK);
3903 if (!info->thread_is_dying && !precise)
3904 conservatively_pin_objects_from ((void**)info->monoctx, (void**)info->monoctx + ARCH_NUM_REGS,
3905 start_nursery, end_nursery, PIN_TYPE_STACK);
3907 if (!info->thread_is_dying && !precise)
3908 conservatively_pin_objects_from (info->stopped_regs, info->stopped_regs + ARCH_NUM_REGS,
3909 start_nursery, end_nursery, PIN_TYPE_STACK);
3911 } END_FOREACH_THREAD
3915 find_pinning_ref_from_thread (char *obj, size_t size)
3918 SgenThreadInfo *info;
3919 char *endobj = obj + size;
3921 FOREACH_THREAD (info) {
3922 char **start = (char**)info->stack_start;
3925 while (start < (char**)info->stack_end) {
3926 if (*start >= obj && *start < endobj) {
3927 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));
3932 for (j = 0; j < ARCH_NUM_REGS; ++j) {
3934 mword w = ((mword*)info->monoctx) [j];
3936 mword w = (mword)info->stopped_regs [j];
3939 if (w >= (mword)obj && w < (mword)obj + size)
3940 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)));
3941 } END_FOREACH_THREAD
3946 ptr_on_stack (void *ptr)
3948 gpointer stack_start = &stack_start;
3949 SgenThreadInfo *info = mono_thread_info_current ();
3951 if (ptr >= stack_start && ptr < (gpointer)info->stack_end)
3957 sgen_thread_register (SgenThreadInfo* info, void *addr)
3959 #ifndef HAVE_KW_THREAD
3960 SgenThreadInfo *__thread_info__ = info;
3964 #ifndef HAVE_KW_THREAD
3965 info->tlab_start = info->tlab_next = info->tlab_temp_end = info->tlab_real_end = NULL;
3967 g_assert (!mono_native_tls_get_value (thread_info_key));
3968 mono_native_tls_set_value (thread_info_key, info);
3973 #if !defined(__MACH__)
3974 info->stop_count = -1;
3978 info->doing_handshake = FALSE;
3979 info->thread_is_dying = FALSE;
3980 info->stack_start = NULL;
3981 info->store_remset_buffer_addr = &STORE_REMSET_BUFFER;
3982 info->store_remset_buffer_index_addr = &STORE_REMSET_BUFFER_INDEX;
3983 info->stopped_ip = NULL;
3984 info->stopped_domain = NULL;
3986 info->monoctx = NULL;
3988 info->stopped_regs = NULL;
3991 mono_sgen_init_tlab_info (info);
3993 binary_protocol_thread_register ((gpointer)mono_thread_info_get_tid (info));
3995 #ifdef HAVE_KW_THREAD
3996 store_remset_buffer_index_addr = &store_remset_buffer_index;
3999 #if defined(__MACH__)
4000 info->mach_port = mach_thread_self ();
4003 /* try to get it with attributes first */
4004 #if defined(HAVE_PTHREAD_GETATTR_NP) && defined(HAVE_PTHREAD_ATTR_GETSTACK)
4008 pthread_attr_t attr;
4009 pthread_getattr_np (pthread_self (), &attr);
4010 pthread_attr_getstack (&attr, &sstart, &size);
4011 info->stack_start_limit = sstart;
4012 info->stack_end = (char*)sstart + size;
4013 pthread_attr_destroy (&attr);
4015 #elif defined(HAVE_PTHREAD_GET_STACKSIZE_NP) && defined(HAVE_PTHREAD_GET_STACKADDR_NP)
4016 info->stack_end = (char*)pthread_get_stackaddr_np (pthread_self ());
4017 info->stack_start_limit = (char*)info->stack_end - pthread_get_stacksize_np (pthread_self ());
4020 /* FIXME: we assume the stack grows down */
4021 gsize stack_bottom = (gsize)addr;
4022 stack_bottom += 4095;
4023 stack_bottom &= ~4095;
4024 info->stack_end = (char*)stack_bottom;
4028 #ifdef HAVE_KW_THREAD
4029 stack_end = info->stack_end;
4032 if (remset.register_thread)
4033 remset.register_thread (info);
4035 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));
4037 if (gc_callbacks.thread_attach_func)
4038 info->runtime_data = gc_callbacks.thread_attach_func ();
4045 mono_sgen_wbarrier_cleanup_thread (SgenThreadInfo *p)
4047 if (remset.cleanup_thread)
4048 remset.cleanup_thread (p);
4052 sgen_thread_unregister (SgenThreadInfo *p)
4054 /* If a delegate is passed to native code and invoked on a thread we dont
4055 * know about, the jit will register it with mono_jit_thread_attach, but
4056 * we have no way of knowing when that thread goes away. SGen has a TSD
4057 * so we assume that if the domain is still registered, we can detach
4060 if (mono_domain_get ())
4061 mono_thread_detach (mono_thread_current ());
4063 p->thread_is_dying = TRUE;
4066 There is a race condition between a thread finishing executing and been removed
4067 from the GC thread set.
4068 This happens on posix systems when TLS data is been cleaned-up, libpthread will
4069 set the thread_info slot to NULL before calling the cleanup function. This
4070 opens a window in which the thread is registered but has a NULL TLS.
4072 The suspend signal handler needs TLS data to know where to store thread state
4073 data or otherwise it will simply ignore the thread.
4075 This solution works because the thread doing STW will wait until all threads been
4076 suspended handshake back, so there is no race between the doing_hankshake test
4077 and the suspend_thread call.
4079 This is not required on systems that do synchronous STW as those can deal with
4080 the above race at suspend time.
4082 FIXME: I believe we could avoid this by using mono_thread_info_lookup when
4083 mono_thread_info_current returns NULL. Or fix mono_thread_info_lookup to do so.
4085 #if (defined(__MACH__) && MONO_MACH_ARCH_SUPPORTED) || !defined(HAVE_PTHREAD_KILL)
4088 while (!TRYLOCK_GC) {
4089 if (!mono_sgen_park_current_thread_if_doing_handshake (p))
4094 binary_protocol_thread_unregister ((gpointer)mono_thread_info_get_tid (p));
4095 DEBUG (3, fprintf (gc_debug_file, "unregister thread %p (%p)\n", p, (gpointer)mono_thread_info_get_tid (p)));
4097 #if defined(__MACH__)
4098 mach_port_deallocate (current_task (), p->mach_port);
4101 if (gc_callbacks.thread_detach_func) {
4102 gc_callbacks.thread_detach_func (p->runtime_data);
4103 p->runtime_data = NULL;
4105 mono_sgen_wbarrier_cleanup_thread (p);
4107 mono_threads_unregister_current_thread (p);
4113 sgen_thread_attach (SgenThreadInfo *info)
4116 /*this is odd, can we get attached before the gc is inited?*/
4120 if (gc_callbacks.thread_attach_func && !info->runtime_data)
4121 info->runtime_data = gc_callbacks.thread_attach_func ();
4124 mono_gc_register_thread (void *baseptr)
4126 return mono_thread_info_attach (baseptr) != NULL;
4130 * mono_gc_set_stack_end:
4132 * Set the end of the current threads stack to STACK_END. The stack space between
4133 * STACK_END and the real end of the threads stack will not be scanned during collections.
4136 mono_gc_set_stack_end (void *stack_end)
4138 SgenThreadInfo *info;
4141 info = mono_thread_info_current ();
4143 g_assert (stack_end < info->stack_end);
4144 info->stack_end = stack_end;
4149 #if USE_PTHREAD_INTERCEPT
4153 mono_gc_pthread_create (pthread_t *new_thread, const pthread_attr_t *attr, void *(*start_routine)(void *), void *arg)
4155 return pthread_create (new_thread, attr, start_routine, arg);
4159 mono_gc_pthread_join (pthread_t thread, void **retval)
4161 return pthread_join (thread, retval);
4165 mono_gc_pthread_detach (pthread_t thread)
4167 return pthread_detach (thread);
4171 mono_gc_pthread_exit (void *retval)
4173 pthread_exit (retval);
4176 #endif /* USE_PTHREAD_INTERCEPT */
4179 * ######################################################################
4180 * ######## Write barriers
4181 * ######################################################################
4185 * Note: the write barriers first do the needed GC work and then do the actual store:
4186 * this way the value is visible to the conservative GC scan after the write barrier
4187 * itself. If a GC interrupts the barrier in the middle, value will be kept alive by
4188 * the conservative scan, otherwise by the remembered set scan.
4191 mono_gc_wbarrier_set_field (MonoObject *obj, gpointer field_ptr, MonoObject* value)
4193 HEAVY_STAT (++stat_wbarrier_set_field);
4194 if (ptr_in_nursery (field_ptr)) {
4195 *(void**)field_ptr = value;
4198 DEBUG (8, fprintf (gc_debug_file, "Adding remset at %p\n", field_ptr));
4200 binary_protocol_wbarrier (field_ptr, value, value->vtable);
4202 remset.wbarrier_set_field (obj, field_ptr, value);
4206 mono_gc_wbarrier_set_arrayref (MonoArray *arr, gpointer slot_ptr, MonoObject* value)
4208 HEAVY_STAT (++stat_wbarrier_set_arrayref);
4209 if (ptr_in_nursery (slot_ptr)) {
4210 *(void**)slot_ptr = value;
4213 DEBUG (8, fprintf (gc_debug_file, "Adding remset at %p\n", slot_ptr));
4215 binary_protocol_wbarrier (slot_ptr, value, value->vtable);
4217 remset.wbarrier_set_arrayref (arr, slot_ptr, value);
4221 mono_gc_wbarrier_arrayref_copy (gpointer dest_ptr, gpointer src_ptr, int count)
4223 HEAVY_STAT (++stat_wbarrier_arrayref_copy);
4224 /*This check can be done without taking a lock since dest_ptr array is pinned*/
4225 if (ptr_in_nursery (dest_ptr) || count <= 0) {
4226 mono_gc_memmove (dest_ptr, src_ptr, count * sizeof (gpointer));
4230 #ifdef SGEN_BINARY_PROTOCOL
4233 for (i = 0; i < count; ++i) {
4234 gpointer dest = (gpointer*)dest_ptr + i;
4235 gpointer obj = *((gpointer*)src_ptr + i);
4237 binary_protocol_wbarrier (dest, obj, (gpointer)LOAD_VTABLE (obj));
4242 remset.wbarrier_arrayref_copy (dest_ptr, src_ptr, count);
4245 static char *found_obj;
4248 find_object_for_ptr_callback (char *obj, size_t size, void *user_data)
4250 char *ptr = user_data;
4252 if (ptr >= obj && ptr < obj + size) {
4253 g_assert (!found_obj);
4258 /* for use in the debugger */
4259 char* find_object_for_ptr (char *ptr);
4261 find_object_for_ptr (char *ptr)
4263 if (ptr >= nursery_section->data && ptr < nursery_section->end_data) {
4265 mono_sgen_scan_area_with_callback (nursery_section->data, nursery_section->end_data,
4266 find_object_for_ptr_callback, ptr, TRUE);
4272 mono_sgen_los_iterate_objects (find_object_for_ptr_callback, ptr);
4277 * Very inefficient, but this is debugging code, supposed to
4278 * be called from gdb, so we don't care.
4281 major_collector.iterate_objects (TRUE, TRUE, find_object_for_ptr_callback, ptr);
4286 mono_gc_wbarrier_generic_nostore (gpointer ptr)
4288 HEAVY_STAT (++stat_wbarrier_generic_store);
4290 #ifdef XDOMAIN_CHECKS_IN_WBARRIER
4291 /* FIXME: ptr_in_heap must be called with the GC lock held */
4292 if (xdomain_checks && *(MonoObject**)ptr && ptr_in_heap (ptr)) {
4293 char *start = find_object_for_ptr (ptr);
4294 MonoObject *value = *(MonoObject**)ptr;
4298 MonoObject *obj = (MonoObject*)start;
4299 if (obj->vtable->domain != value->vtable->domain)
4300 g_assert (is_xdomain_ref_allowed (ptr, start, obj->vtable->domain));
4306 if (*(gpointer*)ptr)
4307 binary_protocol_wbarrier (ptr, *(gpointer*)ptr, (gpointer)LOAD_VTABLE (*(gpointer*)ptr));
4309 if (ptr_in_nursery (ptr) || ptr_on_stack (ptr) || !ptr_in_nursery (*(gpointer*)ptr)) {
4310 DEBUG (8, fprintf (gc_debug_file, "Skipping remset at %p\n", ptr));
4314 DEBUG (8, fprintf (gc_debug_file, "Adding remset at %p\n", ptr));
4316 remset.wbarrier_generic_nostore (ptr);
4320 mono_gc_wbarrier_generic_store (gpointer ptr, MonoObject* value)
4322 DEBUG (8, fprintf (gc_debug_file, "Wbarrier store at %p to %p (%s)\n", ptr, value, value ? safe_name (value) : "null"));
4323 *(void**)ptr = value;
4324 if (ptr_in_nursery (value))
4325 mono_gc_wbarrier_generic_nostore (ptr);
4326 mono_sgen_dummy_use (value);
4329 void mono_gc_wbarrier_value_copy_bitmap (gpointer _dest, gpointer _src, int size, unsigned bitmap)
4331 mword *dest = _dest;
4336 mono_gc_wbarrier_generic_store (dest, (MonoObject*)*src);
4341 size -= SIZEOF_VOID_P;
4346 #ifdef SGEN_BINARY_PROTOCOL
4348 #define HANDLE_PTR(ptr,obj) do { \
4349 gpointer o = *(gpointer*)(ptr); \
4351 gpointer d = ((char*)dest) + ((char*)(ptr) - (char*)(obj)); \
4352 binary_protocol_wbarrier (d, o, (gpointer) LOAD_VTABLE (o)); \
4357 scan_object_for_binary_protocol_copy_wbarrier (gpointer dest, char *start, mword desc)
4359 #define SCAN_OBJECT_NOVTABLE
4360 #include "sgen-scan-object.h"
4365 mono_gc_wbarrier_value_copy (gpointer dest, gpointer src, int count, MonoClass *klass)
4367 HEAVY_STAT (++stat_wbarrier_value_copy);
4368 g_assert (klass->valuetype);
4370 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));
4372 if (ptr_in_nursery (dest) || ptr_on_stack (dest) || !SGEN_CLASS_HAS_REFERENCES (klass)) {
4373 size_t element_size = mono_class_value_size (klass, NULL);
4374 size_t size = count * element_size;
4375 mono_gc_memmove (dest, src, size);
4379 #ifdef SGEN_BINARY_PROTOCOL
4382 for (i = 0; i < count; ++i) {
4383 scan_object_for_binary_protocol_copy_wbarrier ((char*)dest + i * element_size,
4384 (char*)src + i * element_size - sizeof (MonoObject),
4385 (mword) klass->gc_descr);
4390 remset.wbarrier_value_copy (dest, src, count, klass);
4394 * mono_gc_wbarrier_object_copy:
4396 * Write barrier to call when obj is the result of a clone or copy of an object.
4399 mono_gc_wbarrier_object_copy (MonoObject* obj, MonoObject *src)
4403 HEAVY_STAT (++stat_wbarrier_object_copy);
4405 if (ptr_in_nursery (obj) || ptr_on_stack (obj)) {
4406 size = mono_object_class (obj)->instance_size;
4407 mono_gc_memmove ((char*)obj + sizeof (MonoObject), (char*)src + sizeof (MonoObject),
4408 size - sizeof (MonoObject));
4412 #ifdef SGEN_BINARY_PROTOCOL
4413 scan_object_for_binary_protocol_copy_wbarrier (obj, (char*)src, (mword) src->vtable->gc_descr);
4416 remset.wbarrier_object_copy (obj, src);
4420 * ######################################################################
4421 * ######## Other mono public interface functions.
4422 * ######################################################################
4425 #define REFS_SIZE 128
4428 MonoGCReferences callback;
4432 MonoObject *refs [REFS_SIZE];
4433 uintptr_t offsets [REFS_SIZE];
4437 #define HANDLE_PTR(ptr,obj) do { \
4439 if (hwi->count == REFS_SIZE) { \
4440 hwi->callback ((MonoObject*)start, mono_object_class (start), hwi->called? 0: size, hwi->count, hwi->refs, hwi->offsets, hwi->data); \
4444 hwi->offsets [hwi->count] = (char*)(ptr)-(char*)start; \
4445 hwi->refs [hwi->count++] = *(ptr); \
4450 collect_references (HeapWalkInfo *hwi, char *start, size_t size)
4452 #include "sgen-scan-object.h"
4456 walk_references (char *start, size_t size, void *data)
4458 HeapWalkInfo *hwi = data;
4461 collect_references (hwi, start, size);
4462 if (hwi->count || !hwi->called)
4463 hwi->callback ((MonoObject*)start, mono_object_class (start), hwi->called? 0: size, hwi->count, hwi->refs, hwi->offsets, hwi->data);
4467 * mono_gc_walk_heap:
4468 * @flags: flags for future use
4469 * @callback: a function pointer called for each object in the heap
4470 * @data: a user data pointer that is passed to callback
4472 * This function can be used to iterate over all the live objects in the heap:
4473 * for each object, @callback is invoked, providing info about the object's
4474 * location in memory, its class, its size and the objects it references.
4475 * For each referenced object it's offset from the object address is
4476 * reported in the offsets array.
4477 * The object references may be buffered, so the callback may be invoked
4478 * multiple times for the same object: in all but the first call, the size
4479 * argument will be zero.
4480 * Note that this function can be only called in the #MONO_GC_EVENT_PRE_START_WORLD
4481 * profiler event handler.
4483 * Returns: a non-zero value if the GC doesn't support heap walking
4486 mono_gc_walk_heap (int flags, MonoGCReferences callback, void *data)
4491 hwi.callback = callback;
4494 mono_sgen_clear_nursery_fragments ();
4495 mono_sgen_scan_area_with_callback (nursery_section->data, nursery_section->end_data, walk_references, &hwi, FALSE);
4497 major_collector.iterate_objects (TRUE, TRUE, walk_references, &hwi);
4498 mono_sgen_los_iterate_objects (walk_references, &hwi);
4504 mono_gc_collect (int generation)
4509 mono_profiler_gc_event (MONO_GC_EVENT_START, generation);
4510 stop_world (generation);
4511 if (generation == 0) {
4512 collect_nursery (0);
4514 major_collection ("user request");
4516 restart_world (generation);
4517 mono_profiler_gc_event (MONO_GC_EVENT_END, generation);
4522 mono_gc_max_generation (void)
4528 mono_gc_collection_count (int generation)
4530 if (generation == 0)
4531 return stat_minor_gcs;
4532 return stat_major_gcs;
4536 mono_gc_get_used_size (void)
4540 tot = los_memory_usage;
4541 tot += nursery_section->next_data - nursery_section->data;
4542 tot += major_collector.get_used_size ();
4543 /* FIXME: account for pinned objects */
4549 mono_gc_get_heap_size (void)
4555 mono_gc_disable (void)
4563 mono_gc_enable (void)
4571 mono_gc_get_los_limit (void)
4573 return MAX_SMALL_OBJ_SIZE;
4577 mono_object_is_alive (MonoObject* o)
4583 mono_gc_get_generation (MonoObject *obj)
4585 if (ptr_in_nursery (obj))
4591 mono_gc_enable_events (void)
4596 mono_gc_weak_link_add (void **link_addr, MonoObject *obj, gboolean track)
4598 mono_gc_register_disappearing_link (obj, link_addr, track, FALSE);
4602 mono_gc_weak_link_remove (void **link_addr)
4604 mono_gc_register_disappearing_link (NULL, link_addr, FALSE, FALSE);
4608 mono_gc_weak_link_get (void **link_addr)
4612 return (MonoObject*) REVEAL_POINTER (*link_addr);
4616 mono_gc_ephemeron_array_add (MonoObject *obj)
4618 EphemeronLinkNode *node;
4622 node = mono_sgen_alloc_internal (INTERNAL_MEM_EPHEMERON_LINK);
4627 node->array = (char*)obj;
4628 node->next = ephemeron_list;
4629 ephemeron_list = node;
4631 DEBUG (5, fprintf (gc_debug_file, "Registered ephemeron array %p\n", obj));
4638 mono_gc_invoke_with_gc_lock (MonoGCLockedCallbackFunc func, void *data)
4642 result = func (data);
4643 UNLOCK_INTERRUPTION;
4648 mono_gc_is_gc_thread (void)
4652 result = mono_thread_info_current () != NULL;
4658 is_critical_method (MonoMethod *method)
4660 return mono_runtime_is_critical_method (method) || mono_gc_is_critical_method (method);
4664 mono_gc_base_init (void)
4666 MonoThreadInfoCallbacks cb;
4669 char *major_collector_opt = NULL;
4671 glong soft_limit = 0;
4677 result = InterlockedCompareExchange (&gc_initialized, -1, 0);
4680 /* already inited */
4683 /* being inited by another thread */
4687 /* we will init it */
4690 g_assert_not_reached ();
4692 } while (result != 0);
4694 LOCK_INIT (gc_mutex);
4696 pagesize = mono_pagesize ();
4697 gc_debug_file = stderr;
4699 cb.thread_register = sgen_thread_register;
4700 cb.thread_unregister = sgen_thread_unregister;
4701 cb.thread_attach = sgen_thread_attach;
4702 cb.mono_method_is_critical = (gpointer)is_critical_method;
4704 cb.mono_gc_pthread_create = (gpointer)mono_gc_pthread_create;
4707 mono_threads_init (&cb, sizeof (SgenThreadInfo));
4709 LOCK_INIT (interruption_mutex);
4710 LOCK_INIT (pin_queue_mutex);
4712 init_user_copy_or_mark_key ();
4714 if ((env = getenv ("MONO_GC_PARAMS"))) {
4715 opts = g_strsplit (env, ",", -1);
4716 for (ptr = opts; *ptr; ++ptr) {
4718 if (g_str_has_prefix (opt, "major=")) {
4719 opt = strchr (opt, '=') + 1;
4720 major_collector_opt = g_strdup (opt);
4728 mono_sgen_init_internal_allocator ();
4729 mono_sgen_init_nursery_allocator ();
4731 mono_sgen_register_fixed_internal_mem_type (INTERNAL_MEM_SECTION, SGEN_SIZEOF_GC_MEM_SECTION);
4732 mono_sgen_register_fixed_internal_mem_type (INTERNAL_MEM_FINALIZE_READY_ENTRY, sizeof (FinalizeReadyEntry));
4733 mono_sgen_register_fixed_internal_mem_type (INTERNAL_MEM_GRAY_QUEUE, sizeof (GrayQueueSection));
4734 g_assert (sizeof (GenericStoreRememberedSet) == sizeof (gpointer) * STORE_REMSET_BUFFER_SIZE);
4735 mono_sgen_register_fixed_internal_mem_type (INTERNAL_MEM_STORE_REMSET, sizeof (GenericStoreRememberedSet));
4736 mono_sgen_register_fixed_internal_mem_type (INTERNAL_MEM_EPHEMERON_LINK, sizeof (EphemeronLinkNode));
4738 #ifndef HAVE_KW_THREAD
4739 mono_native_tls_alloc (&thread_info_key, NULL);
4743 * This needs to happen before any internal allocations because
4744 * it inits the small id which is required for hazard pointer
4747 mono_sgen_os_init ();
4749 mono_thread_info_attach (&dummy);
4751 if (!major_collector_opt || !strcmp (major_collector_opt, "marksweep")) {
4752 mono_sgen_marksweep_init (&major_collector);
4753 } else if (!major_collector_opt || !strcmp (major_collector_opt, "marksweep-fixed")) {
4754 mono_sgen_marksweep_fixed_init (&major_collector);
4755 } else if (!major_collector_opt || !strcmp (major_collector_opt, "marksweep-par")) {
4756 mono_sgen_marksweep_par_init (&major_collector);
4757 } else if (!major_collector_opt || !strcmp (major_collector_opt, "marksweep-fixed-par")) {
4758 mono_sgen_marksweep_fixed_par_init (&major_collector);
4759 } else if (!strcmp (major_collector_opt, "copying")) {
4760 mono_sgen_copying_init (&major_collector);
4762 fprintf (stderr, "Unknown major collector `%s'.\n", major_collector_opt);
4766 #ifdef SGEN_HAVE_CARDTABLE
4767 use_cardtable = major_collector.supports_cardtable;
4769 use_cardtable = FALSE;
4772 num_workers = mono_cpu_count ();
4773 g_assert (num_workers > 0);
4774 if (num_workers > 16)
4777 ///* Keep this the default for now */
4779 conservative_stack_mark = TRUE;
4783 for (ptr = opts; *ptr; ++ptr) {
4785 if (g_str_has_prefix (opt, "major="))
4787 if (g_str_has_prefix (opt, "wbarrier=")) {
4788 opt = strchr (opt, '=') + 1;
4789 if (strcmp (opt, "remset") == 0) {
4790 use_cardtable = FALSE;
4791 } else if (strcmp (opt, "cardtable") == 0) {
4792 if (!use_cardtable) {
4793 if (major_collector.supports_cardtable)
4794 fprintf (stderr, "The cardtable write barrier is not supported on this platform.\n");
4796 fprintf (stderr, "The major collector does not support the cardtable write barrier.\n");
4802 if (g_str_has_prefix (opt, "max-heap-size=")) {
4803 opt = strchr (opt, '=') + 1;
4804 if (*opt && mono_gc_parse_environment_string_extract_number (opt, &max_heap)) {
4805 if ((max_heap & (mono_pagesize () - 1))) {
4806 fprintf (stderr, "max-heap-size size must be a multiple of %d.\n", mono_pagesize ());
4810 fprintf (stderr, "max-heap-size must be an integer.\n");
4815 if (g_str_has_prefix (opt, "soft-heap-limit=")) {
4816 opt = strchr (opt, '=') + 1;
4817 if (*opt && mono_gc_parse_environment_string_extract_number (opt, &soft_limit)) {
4818 if (soft_limit <= 0) {
4819 fprintf (stderr, "soft-heap-limit must be positive.\n");
4823 fprintf (stderr, "soft-heap-limit must be an integer.\n");
4828 if (g_str_has_prefix (opt, "workers=")) {
4831 if (!major_collector.is_parallel) {
4832 fprintf (stderr, "The workers= option can only be used for parallel collectors.");
4835 opt = strchr (opt, '=') + 1;
4836 val = strtol (opt, &endptr, 10);
4837 if (!*opt || *endptr) {
4838 fprintf (stderr, "Cannot parse the workers= option value.");
4841 if (val <= 0 || val > 16) {
4842 fprintf (stderr, "The number of workers must be in the range 1 to 16.");
4845 num_workers = (int)val;
4848 if (g_str_has_prefix (opt, "stack-mark=")) {
4849 opt = strchr (opt, '=') + 1;
4850 if (!strcmp (opt, "precise")) {
4851 conservative_stack_mark = FALSE;
4852 } else if (!strcmp (opt, "conservative")) {
4853 conservative_stack_mark = TRUE;
4855 fprintf (stderr, "Invalid value '%s' for stack-mark= option, possible values are: 'precise', 'conservative'.\n", opt);
4860 if (g_str_has_prefix (opt, "bridge=")) {
4861 opt = strchr (opt, '=') + 1;
4862 mono_sgen_register_test_bridge_callbacks (g_strdup (opt));
4866 if (g_str_has_prefix (opt, "nursery-size=")) {
4868 opt = strchr (opt, '=') + 1;
4869 if (*opt && mono_gc_parse_environment_string_extract_number (opt, &val)) {
4870 mono_sgen_nursery_size = val;
4871 #ifdef SGEN_ALIGN_NURSERY
4872 if ((val & (val - 1))) {
4873 fprintf (stderr, "The nursery size must be a power of two.\n");
4877 if (val < SGEN_MAX_NURSERY_WASTE) {
4878 fprintf (stderr, "The nursery size must be at least %d bytes.\n", SGEN_MAX_NURSERY_WASTE);
4882 mono_sgen_nursery_bits = 0;
4883 while (1 << (++ mono_sgen_nursery_bits) != mono_sgen_nursery_size)
4887 fprintf (stderr, "nursery-size must be an integer.\n");
4893 if (!(major_collector.handle_gc_param && major_collector.handle_gc_param (opt))) {
4894 fprintf (stderr, "MONO_GC_PARAMS must be a comma-delimited list of one or more of the following:\n");
4895 fprintf (stderr, " max-heap-size=N (where N is an integer, possibly with a k, m or a g suffix)\n");
4896 fprintf (stderr, " soft-heap-limit=n (where N is an integer, possibly with a k, m or a g suffix)\n");
4897 fprintf (stderr, " nursery-size=N (where N is an integer, possibly with a k, m or a g suffix)\n");
4898 fprintf (stderr, " major=COLLECTOR (where COLLECTOR is `marksweep', `marksweep-par' or `copying')\n");
4899 fprintf (stderr, " wbarrier=WBARRIER (where WBARRIER is `remset' or `cardtable')\n");
4900 fprintf (stderr, " stack-mark=MARK-METHOD (where MARK-METHOD is 'precise' or 'conservative')\n");
4901 if (major_collector.print_gc_param_usage)
4902 major_collector.print_gc_param_usage ();
4909 if (major_collector.is_parallel)
4910 mono_sgen_workers_init (num_workers);
4912 if (major_collector_opt)
4913 g_free (major_collector_opt);
4915 nursery_size = DEFAULT_NURSERY_SIZE;
4916 minor_collection_allowance = MIN_MINOR_COLLECTION_ALLOWANCE;
4917 init_heap_size_limits (max_heap, soft_limit);
4921 if ((env = getenv ("MONO_GC_DEBUG"))) {
4922 opts = g_strsplit (env, ",", -1);
4923 for (ptr = opts; ptr && *ptr; ptr ++) {
4925 if (opt [0] >= '0' && opt [0] <= '9') {
4926 gc_debug_level = atoi (opt);
4931 char *rf = g_strdup_printf ("%s.%d", opt, getpid ());
4932 gc_debug_file = fopen (rf, "wb");
4934 gc_debug_file = stderr;
4937 } else if (!strcmp (opt, "print-allowance")) {
4938 debug_print_allowance = TRUE;
4939 } else if (!strcmp (opt, "print-pinning")) {
4940 do_pin_stats = TRUE;
4941 } else if (!strcmp (opt, "collect-before-allocs")) {
4942 collect_before_allocs = 1;
4943 } else if (g_str_has_prefix (opt, "collect-before-allocs=")) {
4944 char *arg = strchr (opt, '=') + 1;
4945 collect_before_allocs = atoi (arg);
4946 } else if (!strcmp (opt, "check-at-minor-collections")) {
4947 consistency_check_at_minor_collection = TRUE;
4948 nursery_clear_policy = CLEAR_AT_GC;
4949 } else if (!strcmp (opt, "xdomain-checks")) {
4950 xdomain_checks = TRUE;
4951 } else if (!strcmp (opt, "clear-at-gc")) {
4952 nursery_clear_policy = CLEAR_AT_GC;
4953 } else if (!strcmp (opt, "clear-nursery-at-gc")) {
4954 nursery_clear_policy = CLEAR_AT_GC;
4955 } else if (!strcmp (opt, "check-scan-starts")) {
4956 do_scan_starts_check = TRUE;
4957 } else if (!strcmp (opt, "verify-nursery-at-minor-gc")) {
4958 do_verify_nursery = TRUE;
4959 } else if (!strcmp (opt, "dump-nursery-at-minor-gc")) {
4960 do_dump_nursery_content = TRUE;
4961 } else if (!strcmp (opt, "disable-minor")) {
4962 disable_minor_collections = TRUE;
4963 } else if (!strcmp (opt, "disable-major")) {
4964 disable_major_collections = TRUE;
4965 } else if (g_str_has_prefix (opt, "heap-dump=")) {
4966 char *filename = strchr (opt, '=') + 1;
4967 nursery_clear_policy = CLEAR_AT_GC;
4968 heap_dump_file = fopen (filename, "w");
4969 if (heap_dump_file) {
4970 fprintf (heap_dump_file, "<sgen-dump>\n");
4971 do_pin_stats = TRUE;
4973 #ifdef SGEN_BINARY_PROTOCOL
4974 } else if (g_str_has_prefix (opt, "binary-protocol=")) {
4975 char *filename = strchr (opt, '=') + 1;
4976 binary_protocol_init (filename);
4978 fprintf (stderr, "Warning: Cardtable write barriers will not be binary-protocolled.\n");
4981 fprintf (stderr, "Invalid format for the MONO_GC_DEBUG env variable: '%s'\n", env);
4982 fprintf (stderr, "The format is: MONO_GC_DEBUG=[l[:filename]|<option>]+ where l is a debug level 0-9.\n");
4983 fprintf (stderr, "Valid options are:\n");
4984 fprintf (stderr, " collect-before-allocs[=<n>]\n");
4985 fprintf (stderr, " check-at-minor-collections\n");
4986 fprintf (stderr, " disable-minor\n");
4987 fprintf (stderr, " disable-major\n");
4988 fprintf (stderr, " xdomain-checks\n");
4989 fprintf (stderr, " clear-at-gc\n");
4990 fprintf (stderr, " print-allowance\n");
4991 fprintf (stderr, " print-pinning\n");
4998 if (major_collector.is_parallel) {
4999 if (heap_dump_file) {
5000 fprintf (stderr, "Error: Cannot do heap dump with the parallel collector.\n");
5004 fprintf (stderr, "Error: Cannot gather pinning statistics with the parallel collector.\n");
5009 if (major_collector.post_param_init)
5010 major_collector.post_param_init ();
5012 memset (&remset, 0, sizeof (remset));
5014 #ifdef SGEN_HAVE_CARDTABLE
5016 sgen_card_table_init (&remset);
5019 mono_sgen_ssb_init (&remset);
5021 if (remset.register_thread)
5022 remset.register_thread (mono_thread_info_current ());
5028 mono_gc_get_gc_name (void)
5033 static MonoMethod *write_barrier_method;
5036 mono_gc_is_critical_method (MonoMethod *method)
5038 return (method == write_barrier_method || mono_sgen_is_managed_allocator (method));
5042 is_ip_in_managed_allocator (MonoDomain *domain, gpointer ip)
5046 if (!mono_thread_internal_current ())
5047 /* Happens during thread attach */
5052 ji = mono_jit_info_table_find (domain, ip);
5056 return mono_gc_is_critical_method (ji->method);
5060 emit_nursery_check (MonoMethodBuilder *mb, int *nursery_check_return_labels)
5062 memset (nursery_check_return_labels, 0, sizeof (int) * 3);
5063 #ifdef SGEN_ALIGN_NURSERY
5064 // if (ptr_in_nursery (ptr)) return;
5066 * Masking out the bits might be faster, but we would have to use 64 bit
5067 * immediates, which might be slower.
5069 mono_mb_emit_ldarg (mb, 0);
5070 mono_mb_emit_icon (mb, DEFAULT_NURSERY_BITS);
5071 mono_mb_emit_byte (mb, CEE_SHR_UN);
5072 mono_mb_emit_icon (mb, (mword)mono_sgen_get_nursery_start () >> DEFAULT_NURSERY_BITS);
5073 nursery_check_return_labels [0] = mono_mb_emit_branch (mb, CEE_BEQ);
5075 // if (!ptr_in_nursery (*ptr)) return;
5076 mono_mb_emit_ldarg (mb, 0);
5077 mono_mb_emit_byte (mb, CEE_LDIND_I);
5078 mono_mb_emit_icon (mb, DEFAULT_NURSERY_BITS);
5079 mono_mb_emit_byte (mb, CEE_SHR_UN);
5080 mono_mb_emit_icon (mb, (mword)mono_sgen_get_nursery_start () >> DEFAULT_NURSERY_BITS);
5081 nursery_check_return_labels [1] = mono_mb_emit_branch (mb, CEE_BNE_UN);
5083 int label_continue1, label_continue2;
5084 int dereferenced_var;
5086 // if (ptr < (mono_sgen_get_nursery_start ())) goto continue;
5087 mono_mb_emit_ldarg (mb, 0);
5088 mono_mb_emit_ptr (mb, (gpointer) mono_sgen_get_nursery_start ());
5089 label_continue_1 = mono_mb_emit_branch (mb, CEE_BLT);
5091 // if (ptr >= mono_sgen_get_nursery_end ())) goto continue;
5092 mono_mb_emit_ldarg (mb, 0);
5093 mono_mb_emit_ptr (mb, (gpointer) mono_sgen_get_nursery_end ());
5094 label_continue_2 = mono_mb_emit_branch (mb, CEE_BGE);
5097 nursery_check_return_labels [0] = mono_mb_emit_branch (mb, CEE_BR);
5100 mono_mb_patch_branch (mb, label_continue_1);
5101 mono_mb_patch_branch (mb, label_continue_2);
5103 // Dereference and store in local var
5104 dereferenced_var = mono_mb_add_local (mb, &mono_defaults.int_class->byval_arg);
5105 mono_mb_emit_ldarg (mb, 0);
5106 mono_mb_emit_byte (mb, CEE_LDIND_I);
5107 mono_mb_emit_stloc (mb, dereferenced_var);
5109 // if (*ptr < mono_sgen_get_nursery_start ()) return;
5110 mono_mb_emit_ldloc (mb, dereferenced_var);
5111 mono_mb_emit_ptr (mb, (gpointer) mono_sgen_get_nursery_start ());
5112 nursery_check_return_labels [1] = mono_mb_emit_branch (mb, CEE_BLT);
5114 // if (*ptr >= mono_sgen_get_nursery_end ()) return;
5115 mono_mb_emit_ldloc (mb, dereferenced_var);
5116 mono_mb_emit_ptr (mb, (gpointer) mono_sgen_get_nursery_end ());
5117 nursery_check_return_labels [2] = mono_mb_emit_branch (mb, CEE_BGE);
5122 mono_gc_get_write_barrier (void)
5125 MonoMethodBuilder *mb;
5126 MonoMethodSignature *sig;
5127 #ifdef MANAGED_WBARRIER
5128 int i, nursery_check_labels [3];
5129 int label_no_wb_3, label_no_wb_4, label_need_wb, label_slow_path;
5130 int buffer_var, buffer_index_var, dummy_var;
5132 #ifdef HAVE_KW_THREAD
5133 int stack_end_offset = -1, store_remset_buffer_offset = -1;
5134 int store_remset_buffer_index_offset = -1, store_remset_buffer_index_addr_offset = -1;
5136 MONO_THREAD_VAR_OFFSET (stack_end, stack_end_offset);
5137 g_assert (stack_end_offset != -1);
5138 MONO_THREAD_VAR_OFFSET (store_remset_buffer, store_remset_buffer_offset);
5139 g_assert (store_remset_buffer_offset != -1);
5140 MONO_THREAD_VAR_OFFSET (store_remset_buffer_index, store_remset_buffer_index_offset);
5141 g_assert (store_remset_buffer_index_offset != -1);
5142 MONO_THREAD_VAR_OFFSET (store_remset_buffer_index_addr, store_remset_buffer_index_addr_offset);
5143 g_assert (store_remset_buffer_index_addr_offset != -1);
5147 // FIXME: Maybe create a separate version for ctors (the branch would be
5148 // correctly predicted more times)
5149 if (write_barrier_method)
5150 return write_barrier_method;
5152 /* Create the IL version of mono_gc_barrier_generic_store () */
5153 sig = mono_metadata_signature_alloc (mono_defaults.corlib, 1);
5154 sig->ret = &mono_defaults.void_class->byval_arg;
5155 sig->params [0] = &mono_defaults.int_class->byval_arg;
5157 mb = mono_mb_new (mono_defaults.object_class, "wbarrier", MONO_WRAPPER_WRITE_BARRIER);
5159 #ifdef MANAGED_WBARRIER
5160 if (use_cardtable) {
5161 emit_nursery_check (mb, nursery_check_labels);
5163 addr = sgen_cardtable + ((address >> CARD_BITS) & CARD_MASK)
5167 LDC_PTR sgen_cardtable
5169 address >> CARD_BITS
5173 if (SGEN_HAVE_OVERLAPPING_CARDS) {
5174 LDC_PTR card_table_mask
5181 mono_mb_emit_ptr (mb, sgen_cardtable);
5182 mono_mb_emit_ldarg (mb, 0);
5183 mono_mb_emit_icon (mb, CARD_BITS);
5184 mono_mb_emit_byte (mb, CEE_SHR_UN);
5185 #ifdef SGEN_HAVE_OVERLAPPING_CARDS
5186 mono_mb_emit_ptr (mb, (gpointer)CARD_MASK);
5187 mono_mb_emit_byte (mb, CEE_AND);
5189 mono_mb_emit_byte (mb, CEE_ADD);
5190 mono_mb_emit_icon (mb, 1);
5191 mono_mb_emit_byte (mb, CEE_STIND_I1);
5194 for (i = 0; i < 3; ++i) {
5195 if (nursery_check_labels [i])
5196 mono_mb_patch_branch (mb, nursery_check_labels [i]);
5198 mono_mb_emit_byte (mb, CEE_RET);
5199 } else if (mono_runtime_has_tls_get ()) {
5200 emit_nursery_check (mb, nursery_check_labels);
5202 // if (ptr >= stack_end) goto need_wb;
5203 mono_mb_emit_ldarg (mb, 0);
5204 EMIT_TLS_ACCESS (mb, stack_end, stack_end_offset);
5205 label_need_wb = mono_mb_emit_branch (mb, CEE_BGE_UN);
5207 // if (ptr >= stack_start) return;
5208 dummy_var = mono_mb_add_local (mb, &mono_defaults.int_class->byval_arg);
5209 mono_mb_emit_ldarg (mb, 0);
5210 mono_mb_emit_ldloc_addr (mb, dummy_var);
5211 label_no_wb_3 = mono_mb_emit_branch (mb, CEE_BGE_UN);
5214 mono_mb_patch_branch (mb, label_need_wb);
5216 // buffer = STORE_REMSET_BUFFER;
5217 buffer_var = mono_mb_add_local (mb, &mono_defaults.int_class->byval_arg);
5218 EMIT_TLS_ACCESS (mb, store_remset_buffer, store_remset_buffer_offset);
5219 mono_mb_emit_stloc (mb, buffer_var);
5221 // buffer_index = STORE_REMSET_BUFFER_INDEX;
5222 buffer_index_var = mono_mb_add_local (mb, &mono_defaults.int_class->byval_arg);
5223 EMIT_TLS_ACCESS (mb, store_remset_buffer_index, store_remset_buffer_index_offset);
5224 mono_mb_emit_stloc (mb, buffer_index_var);
5226 // if (buffer [buffer_index] == ptr) return;
5227 mono_mb_emit_ldloc (mb, buffer_var);
5228 mono_mb_emit_ldloc (mb, buffer_index_var);
5229 g_assert (sizeof (gpointer) == 4 || sizeof (gpointer) == 8);
5230 mono_mb_emit_icon (mb, sizeof (gpointer) == 4 ? 2 : 3);
5231 mono_mb_emit_byte (mb, CEE_SHL);
5232 mono_mb_emit_byte (mb, CEE_ADD);
5233 mono_mb_emit_byte (mb, CEE_LDIND_I);
5234 mono_mb_emit_ldarg (mb, 0);
5235 label_no_wb_4 = mono_mb_emit_branch (mb, CEE_BEQ);
5238 mono_mb_emit_ldloc (mb, buffer_index_var);
5239 mono_mb_emit_icon (mb, 1);
5240 mono_mb_emit_byte (mb, CEE_ADD);
5241 mono_mb_emit_stloc (mb, buffer_index_var);
5243 // if (buffer_index >= STORE_REMSET_BUFFER_SIZE) goto slow_path;
5244 mono_mb_emit_ldloc (mb, buffer_index_var);
5245 mono_mb_emit_icon (mb, STORE_REMSET_BUFFER_SIZE);
5246 label_slow_path = mono_mb_emit_branch (mb, CEE_BGE);
5248 // buffer [buffer_index] = ptr;
5249 mono_mb_emit_ldloc (mb, buffer_var);
5250 mono_mb_emit_ldloc (mb, buffer_index_var);
5251 g_assert (sizeof (gpointer) == 4 || sizeof (gpointer) == 8);
5252 mono_mb_emit_icon (mb, sizeof (gpointer) == 4 ? 2 : 3);
5253 mono_mb_emit_byte (mb, CEE_SHL);
5254 mono_mb_emit_byte (mb, CEE_ADD);
5255 mono_mb_emit_ldarg (mb, 0);
5256 mono_mb_emit_byte (mb, CEE_STIND_I);
5258 // STORE_REMSET_BUFFER_INDEX = buffer_index;
5259 EMIT_TLS_ACCESS (mb, store_remset_buffer_index_addr, store_remset_buffer_index_addr_offset);
5260 mono_mb_emit_ldloc (mb, buffer_index_var);
5261 mono_mb_emit_byte (mb, CEE_STIND_I);
5264 for (i = 0; i < 3; ++i) {
5265 if (nursery_check_labels [i])
5266 mono_mb_patch_branch (mb, nursery_check_labels [i]);
5268 mono_mb_patch_branch (mb, label_no_wb_3);
5269 mono_mb_patch_branch (mb, label_no_wb_4);
5270 mono_mb_emit_byte (mb, CEE_RET);
5273 mono_mb_patch_branch (mb, label_slow_path);
5275 mono_mb_emit_ldarg (mb, 0);
5276 mono_mb_emit_icall (mb, mono_gc_wbarrier_generic_nostore);
5277 mono_mb_emit_byte (mb, CEE_RET);
5281 mono_mb_emit_ldarg (mb, 0);
5282 mono_mb_emit_icall (mb, mono_gc_wbarrier_generic_nostore);
5283 mono_mb_emit_byte (mb, CEE_RET);
5286 res = mono_mb_create_method (mb, sig, 16);
5289 mono_loader_lock ();
5290 if (write_barrier_method) {
5291 /* Already created */
5292 mono_free_method (res);
5294 /* double-checked locking */
5295 mono_memory_barrier ();
5296 write_barrier_method = res;
5298 mono_loader_unlock ();
5300 return write_barrier_method;
5304 mono_gc_get_description (void)
5306 return g_strdup ("sgen");
5310 mono_gc_set_desktop_mode (void)
5315 mono_gc_is_moving (void)
5321 mono_gc_is_disabled (void)
5327 mono_sgen_debug_printf (int level, const char *format, ...)
5331 if (level > gc_debug_level)
5334 va_start (ap, format);
5335 vfprintf (gc_debug_file, format, ap);
5340 mono_sgen_get_logfile (void)
5342 return gc_debug_file;
5346 BOOL APIENTRY mono_gc_dllmain (HMODULE module_handle, DWORD reason, LPVOID reserved)
5353 mono_sgen_get_nursery_clear_policy (void)
5355 return nursery_clear_policy;
5359 mono_sgen_get_array_fill_vtable (void)
5361 if (!array_fill_vtable) {
5362 static MonoClass klass;
5363 static MonoVTable vtable;
5366 MonoDomain *domain = mono_get_root_domain ();
5369 klass.element_class = mono_defaults.byte_class;
5371 klass.instance_size = sizeof (MonoArray);
5372 klass.sizes.element_size = 1;
5373 klass.name = "array_filler_type";
5375 vtable.klass = &klass;
5377 vtable.gc_descr = mono_gc_make_descr_for_array (TRUE, &bmap, 0, 1);
5380 array_fill_vtable = &vtable;
5382 return array_fill_vtable;
5386 mono_sgen_gc_lock (void)
5392 mono_sgen_gc_unlock (void)
5398 sgen_major_collector_iterate_live_block_ranges (sgen_cardtable_block_callback callback)
5400 major_collector.iterate_live_block_ranges (callback);
5404 sgen_major_collector_scan_card_table (SgenGrayQueue *queue)
5406 major_collector.scan_card_table (queue);
5410 mono_sgen_get_major_collector (void)
5412 return &major_collector;
5415 void mono_gc_set_skip_thread (gboolean skip)
5417 SgenThreadInfo *info = mono_thread_info_current ();
5420 info->gc_disabled = skip;
5425 mono_sgen_get_remset (void)
5431 mono_gc_get_vtable_bits (MonoClass *class)
5433 if (mono_sgen_need_bridge_processing () && mono_sgen_is_bridge_class (class))
5434 return SGEN_GC_BIT_BRIDGE_OBJECT;
5438 #endif /* HAVE_SGEN_GC */