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.
16 * Copyright 2001-2003 Ximian, Inc
17 * Copyright 2003-2010 Novell, Inc.
18 * Copyright 2011 Xamarin, Inc.
19 * Copyright (C) 2012 Xamarin Inc
21 * This library is free software; you can redistribute it and/or
22 * modify it under the terms of the GNU Library General Public
23 * License 2.0 as published by the Free Software Foundation;
25 * This library is distributed in the hope that it will be useful,
26 * but WITHOUT ANY WARRANTY; without even the implied warranty of
27 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
28 * Library General Public License for more details.
30 * You should have received a copy of the GNU Library General Public
31 * License 2.0 along with this library; if not, write to the Free
32 * Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
34 * Important: allocation provides always zeroed memory, having to do
35 * a memset after allocation is deadly for performance.
36 * Memory usage at startup is currently as follows:
38 * 64 KB internal space
40 * We should provide a small memory config with half the sizes
42 * We currently try to make as few mono assumptions as possible:
43 * 1) 2-word header with no GC pointers in it (first vtable, second to store the
45 * 2) gc descriptor is the second word in the vtable (first word in the class)
46 * 3) 8 byte alignment is the minimum and enough (not true for special structures (SIMD), FIXME)
47 * 4) there is a function to get an object's size and the number of
48 * elements in an array.
49 * 5) we know the special way bounds are allocated for complex arrays
50 * 6) we know about proxies and how to treat them when domains are unloaded
52 * Always try to keep stack usage to a minimum: no recursive behaviour
53 * and no large stack allocs.
55 * General description.
56 * Objects are initially allocated in a nursery using a fast bump-pointer technique.
57 * When the nursery is full we start a nursery collection: this is performed with a
59 * When the old generation is full we start a copying GC of the old generation as well:
60 * this will be changed to mark&sweep with copying when fragmentation becomes to severe
61 * in the future. Maybe we'll even do both during the same collection like IMMIX.
63 * The things that complicate this description are:
64 * *) pinned objects: we can't move them so we need to keep track of them
65 * *) no precise info of the thread stacks and registers: we need to be able to
66 * quickly find the objects that may be referenced conservatively and pin them
67 * (this makes the first issues more important)
68 * *) large objects are too expensive to be dealt with using copying GC: we handle them
69 * with mark/sweep during major collections
70 * *) some objects need to not move even if they are small (interned strings, Type handles):
71 * we use mark/sweep for them, too: they are not allocated in the nursery, but inside
72 * PinnedChunks regions
78 *) we could have a function pointer in MonoClass to implement
79 customized write barriers for value types
81 *) investigate the stuff needed to advance a thread to a GC-safe
82 point (single-stepping, read from unmapped memory etc) and implement it.
83 This would enable us to inline allocations and write barriers, for example,
84 or at least parts of them, like the write barrier checks.
85 We may need this also for handling precise info on stacks, even simple things
86 as having uninitialized data on the stack and having to wait for the prolog
87 to zero it. Not an issue for the last frame that we scan conservatively.
88 We could always not trust the value in the slots anyway.
90 *) modify the jit to save info about references in stack locations:
91 this can be done just for locals as a start, so that at least
92 part of the stack is handled precisely.
94 *) test/fix endianess issues
96 *) Implement a card table as the write barrier instead of remembered
97 sets? Card tables are not easy to implement with our current
98 memory layout. We have several different kinds of major heap
99 objects: Small objects in regular blocks, small objects in pinned
100 chunks and LOS objects. If we just have a pointer we have no way
101 to tell which kind of object it points into, therefore we cannot
102 know where its card table is. The least we have to do to make
103 this happen is to get rid of write barriers for indirect stores.
106 *) Get rid of write barriers for indirect stores. We can do this by
107 telling the GC to wbarrier-register an object once we do an ldloca
108 or ldelema on it, and to unregister it once it's not used anymore
109 (it can only travel downwards on the stack). The problem with
110 unregistering is that it needs to happen eventually no matter
111 what, even if exceptions are thrown, the thread aborts, etc.
112 Rodrigo suggested that we could do only the registering part and
113 let the collector find out (pessimistically) when it's safe to
114 unregister, namely when the stack pointer of the thread that
115 registered the object is higher than it was when the registering
116 happened. This might make for a good first implementation to get
117 some data on performance.
119 *) Some sort of blacklist support? Blacklists is a concept from the
120 Boehm GC: if during a conservative scan we find pointers to an
121 area which we might use as heap, we mark that area as unusable, so
122 pointer retention by random pinning pointers is reduced.
124 *) experiment with max small object size (very small right now - 2kb,
125 because it's tied to the max freelist size)
127 *) add an option to mmap the whole heap in one chunk: it makes for many
128 simplifications in the checks (put the nursery at the top and just use a single
129 check for inclusion/exclusion): the issue this has is that on 32 bit systems it's
130 not flexible (too much of the address space may be used by default or we can't
131 increase the heap as needed) and we'd need a race-free mechanism to return memory
132 back to the system (mprotect(PROT_NONE) will still keep the memory allocated if it
133 was written to, munmap is needed, but the following mmap may not find the same segment
136 *) memzero the major fragments after restarting the world and optionally a smaller
139 *) investigate having fragment zeroing threads
141 *) separate locks for finalization and other minor stuff to reduce
144 *) try a different copying order to improve memory locality
146 *) a thread abort after a store but before the write barrier will
147 prevent the write barrier from executing
149 *) specialized dynamically generated markers/copiers
151 *) Dynamically adjust TLAB size to the number of threads. If we have
152 too many threads that do allocation, we might need smaller TLABs,
153 and we might get better performance with larger TLABs if we only
154 have a handful of threads. We could sum up the space left in all
155 assigned TLABs and if that's more than some percentage of the
156 nursery size, reduce the TLAB size.
158 *) Explore placing unreachable objects on unused nursery memory.
159 Instead of memset'ng a region to zero, place an int[] covering it.
160 A good place to start is add_nursery_frag. The tricky thing here is
161 placing those objects atomically outside of a collection.
163 *) Allocation should use asymmetric Dekker synchronization:
164 http://blogs.oracle.com/dave/resource/Asymmetric-Dekker-Synchronization.txt
165 This should help weak consistency archs.
172 #define _XOPEN_SOURCE
173 #define _DARWIN_C_SOURCE
179 #ifdef HAVE_PTHREAD_H
182 #ifdef HAVE_SEMAPHORE_H
183 #include <semaphore.h>
191 #include "metadata/sgen-gc.h"
192 #include "metadata/metadata-internals.h"
193 #include "metadata/class-internals.h"
194 #include "metadata/gc-internal.h"
195 #include "metadata/object-internals.h"
196 #include "metadata/threads.h"
197 #include "metadata/sgen-cardtable.h"
198 #include "metadata/sgen-ssb.h"
199 #include "metadata/sgen-protocol.h"
200 #include "metadata/sgen-archdep.h"
201 #include "metadata/sgen-bridge.h"
202 #include "metadata/sgen-memory-governor.h"
203 #include "metadata/sgen-hash-table.h"
204 #include "metadata/mono-gc.h"
205 #include "metadata/method-builder.h"
206 #include "metadata/profiler-private.h"
207 #include "metadata/monitor.h"
208 #include "metadata/threadpool-internals.h"
209 #include "metadata/mempool-internals.h"
210 #include "metadata/marshal.h"
211 #include "metadata/runtime.h"
212 #include "metadata/sgen-cardtable.h"
213 #include "metadata/sgen-pinning.h"
214 #include "metadata/sgen-workers.h"
215 #include "utils/mono-mmap.h"
216 #include "utils/mono-time.h"
217 #include "utils/mono-semaphore.h"
218 #include "utils/mono-counters.h"
219 #include "utils/mono-proclib.h"
220 #include "utils/mono-memory-model.h"
221 #include "utils/mono-logger-internal.h"
222 #include "utils/dtrace.h"
224 #include <mono/utils/mono-logger-internal.h>
225 #include <mono/utils/memcheck.h>
227 #if defined(__MACH__)
228 #include "utils/mach-support.h"
231 #define OPDEF(a,b,c,d,e,f,g,h,i,j) \
235 #include "mono/cil/opcode.def"
241 #undef pthread_create
243 #undef pthread_detach
246 * ######################################################################
247 * ######## Types and constants used by the GC.
248 * ######################################################################
251 /* 0 means not initialized, 1 is initialized, -1 means in progress */
252 static int gc_initialized = 0;
253 /* If set, check if we need to do something every X allocations */
254 gboolean has_per_allocation_action;
255 /* If set, do a heap check every X allocation */
256 guint32 verify_before_allocs = 0;
257 /* If set, do a minor collection before every X allocation */
258 guint32 collect_before_allocs = 0;
259 /* If set, do a whole heap check before each collection */
260 static gboolean whole_heap_check_before_collection = FALSE;
261 /* If set, do a heap consistency check before each minor collection */
262 static gboolean consistency_check_at_minor_collection = FALSE;
263 /* If set, do a few checks when the concurrent collector is used */
264 static gboolean do_concurrent_checks = FALSE;
265 /* If set, check that there are no references to the domain left at domain unload */
266 static gboolean xdomain_checks = FALSE;
267 /* If not null, dump the heap after each collection into this file */
268 static FILE *heap_dump_file = NULL;
269 /* If set, mark stacks conservatively, even if precise marking is possible */
270 static gboolean conservative_stack_mark = FALSE;
271 /* If set, do a plausibility check on the scan_starts before and after
273 static gboolean do_scan_starts_check = FALSE;
274 static gboolean nursery_collection_is_parallel = FALSE;
275 static gboolean disable_minor_collections = FALSE;
276 static gboolean disable_major_collections = FALSE;
277 gboolean do_pin_stats = FALSE;
278 static gboolean do_verify_nursery = FALSE;
279 static gboolean do_dump_nursery_content = FALSE;
281 #ifdef HEAVY_STATISTICS
282 long long stat_objects_alloced_degraded = 0;
283 long long stat_bytes_alloced_degraded = 0;
285 long long stat_copy_object_called_nursery = 0;
286 long long stat_objects_copied_nursery = 0;
287 long long stat_copy_object_called_major = 0;
288 long long stat_objects_copied_major = 0;
290 long long stat_scan_object_called_nursery = 0;
291 long long stat_scan_object_called_major = 0;
293 long long stat_slots_allocated_in_vain;
295 long long stat_nursery_copy_object_failed_from_space = 0;
296 long long stat_nursery_copy_object_failed_forwarded = 0;
297 long long stat_nursery_copy_object_failed_pinned = 0;
298 long long stat_nursery_copy_object_failed_to_space = 0;
300 static int stat_wbarrier_set_field = 0;
301 static int stat_wbarrier_set_arrayref = 0;
302 static int stat_wbarrier_arrayref_copy = 0;
303 static int stat_wbarrier_generic_store = 0;
304 static int stat_wbarrier_set_root = 0;
305 static int stat_wbarrier_value_copy = 0;
306 static int stat_wbarrier_object_copy = 0;
309 int stat_minor_gcs = 0;
310 int stat_major_gcs = 0;
312 static long long stat_pinned_objects = 0;
314 static long long time_minor_pre_collection_fragment_clear = 0;
315 static long long time_minor_pinning = 0;
316 static long long time_minor_scan_remsets = 0;
317 static long long time_minor_scan_pinned = 0;
318 static long long time_minor_scan_registered_roots = 0;
319 static long long time_minor_scan_thread_data = 0;
320 static long long time_minor_finish_gray_stack = 0;
321 static long long time_minor_fragment_creation = 0;
323 static long long time_major_pre_collection_fragment_clear = 0;
324 static long long time_major_pinning = 0;
325 static long long time_major_scan_pinned = 0;
326 static long long time_major_scan_registered_roots = 0;
327 static long long time_major_scan_thread_data = 0;
328 static long long time_major_scan_alloc_pinned = 0;
329 static long long time_major_scan_finalized = 0;
330 static long long time_major_scan_big_objects = 0;
331 static long long time_major_finish_gray_stack = 0;
332 static long long time_major_free_bigobjs = 0;
333 static long long time_major_los_sweep = 0;
334 static long long time_major_sweep = 0;
335 static long long time_major_fragment_creation = 0;
337 int gc_debug_level = 0;
342 mono_gc_flush_info (void)
344 fflush (gc_debug_file);
348 #define TV_DECLARE SGEN_TV_DECLARE
349 #define TV_GETTIME SGEN_TV_GETTIME
350 #define TV_ELAPSED SGEN_TV_ELAPSED
351 #define TV_ELAPSED_MS SGEN_TV_ELAPSED_MS
353 #define ALIGN_TO(val,align) ((((guint64)val) + ((align) - 1)) & ~((align) - 1))
355 NurseryClearPolicy nursery_clear_policy = CLEAR_AT_TLAB_CREATION;
357 #define object_is_forwarded SGEN_OBJECT_IS_FORWARDED
358 #define object_is_pinned SGEN_OBJECT_IS_PINNED
359 #define pin_object SGEN_PIN_OBJECT
360 #define unpin_object SGEN_UNPIN_OBJECT
362 #define ptr_in_nursery sgen_ptr_in_nursery
364 #define LOAD_VTABLE SGEN_LOAD_VTABLE
367 safe_name (void* obj)
369 MonoVTable *vt = (MonoVTable*)LOAD_VTABLE (obj);
370 return vt->klass->name;
373 #define safe_object_get_size sgen_safe_object_get_size
376 sgen_safe_name (void* obj)
378 return safe_name (obj);
382 * ######################################################################
383 * ######## Global data.
384 * ######################################################################
386 LOCK_DECLARE (gc_mutex);
387 static int gc_disabled = 0;
389 static gboolean use_cardtable;
391 #define SCAN_START_SIZE SGEN_SCAN_START_SIZE
393 static mword pagesize = 4096;
394 int degraded_mode = 0;
396 static mword bytes_pinned_from_failed_allocation = 0;
398 GCMemSection *nursery_section = NULL;
399 static mword lowest_heap_address = ~(mword)0;
400 static mword highest_heap_address = 0;
402 LOCK_DECLARE (sgen_interruption_mutex);
403 static LOCK_DECLARE (pin_queue_mutex);
405 #define LOCK_PIN_QUEUE mono_mutex_lock (&pin_queue_mutex)
406 #define UNLOCK_PIN_QUEUE mono_mutex_unlock (&pin_queue_mutex)
408 typedef struct _FinalizeReadyEntry FinalizeReadyEntry;
409 struct _FinalizeReadyEntry {
410 FinalizeReadyEntry *next;
414 typedef struct _EphemeronLinkNode EphemeronLinkNode;
416 struct _EphemeronLinkNode {
417 EphemeronLinkNode *next;
426 int current_collection_generation = -1;
427 volatile gboolean concurrent_collection_in_progress = FALSE;
429 /* objects that are ready to be finalized */
430 static FinalizeReadyEntry *fin_ready_list = NULL;
431 static FinalizeReadyEntry *critical_fin_list = NULL;
433 static EphemeronLinkNode *ephemeron_list;
435 /* registered roots: the key to the hash is the root start address */
437 * Different kinds of roots are kept separate to speed up pin_from_roots () for example.
439 SgenHashTable roots_hash [ROOT_TYPE_NUM] = {
440 SGEN_HASH_TABLE_INIT (INTERNAL_MEM_ROOTS_TABLE, INTERNAL_MEM_ROOT_RECORD, sizeof (RootRecord), mono_aligned_addr_hash, NULL),
441 SGEN_HASH_TABLE_INIT (INTERNAL_MEM_ROOTS_TABLE, INTERNAL_MEM_ROOT_RECORD, sizeof (RootRecord), mono_aligned_addr_hash, NULL),
442 SGEN_HASH_TABLE_INIT (INTERNAL_MEM_ROOTS_TABLE, INTERNAL_MEM_ROOT_RECORD, sizeof (RootRecord), mono_aligned_addr_hash, NULL)
444 static mword roots_size = 0; /* amount of memory in the root set */
446 #define GC_ROOT_NUM 32
448 int count; /* must be the first field */
449 void *objects [GC_ROOT_NUM];
450 int root_types [GC_ROOT_NUM];
451 uintptr_t extra_info [GC_ROOT_NUM];
455 notify_gc_roots (GCRootReport *report)
459 mono_profiler_gc_roots (report->count, report->objects, report->root_types, report->extra_info);
464 add_profile_gc_root (GCRootReport *report, void *object, int rtype, uintptr_t extra_info)
466 if (report->count == GC_ROOT_NUM)
467 notify_gc_roots (report);
468 report->objects [report->count] = object;
469 report->root_types [report->count] = rtype;
470 report->extra_info [report->count++] = (uintptr_t)((MonoVTable*)LOAD_VTABLE (object))->klass;
473 MonoNativeTlsKey thread_info_key;
475 #ifdef HAVE_KW_THREAD
476 __thread SgenThreadInfo *sgen_thread_info;
477 __thread gpointer *store_remset_buffer;
478 __thread long store_remset_buffer_index;
479 __thread char *stack_end;
480 __thread long *store_remset_buffer_index_addr;
483 /* The size of a TLAB */
484 /* The bigger the value, the less often we have to go to the slow path to allocate a new
485 * one, but the more space is wasted by threads not allocating much memory.
487 * FIXME: Make this self-tuning for each thread.
489 guint32 tlab_size = (1024 * 4);
491 #define MAX_SMALL_OBJ_SIZE SGEN_MAX_SMALL_OBJ_SIZE
493 /* Functions supplied by the runtime to be called by the GC */
494 static MonoGCCallbacks gc_callbacks;
496 #define ALLOC_ALIGN SGEN_ALLOC_ALIGN
497 #define ALLOC_ALIGN_BITS SGEN_ALLOC_ALIGN_BITS
499 #define ALIGN_UP SGEN_ALIGN_UP
501 #define MOVED_OBJECTS_NUM 64
502 static void *moved_objects [MOVED_OBJECTS_NUM];
503 static int moved_objects_idx = 0;
505 /* Vtable of the objects used to fill out nursery fragments before a collection */
506 static MonoVTable *array_fill_vtable;
508 #ifdef SGEN_DEBUG_INTERNAL_ALLOC
509 MonoNativeThreadId main_gc_thread = NULL;
512 /*Object was pinned during the current collection*/
513 static mword objects_pinned;
516 * ######################################################################
517 * ######## Macros and function declarations.
518 * ######################################################################
522 align_pointer (void *ptr)
524 mword p = (mword)ptr;
525 p += sizeof (gpointer) - 1;
526 p &= ~ (sizeof (gpointer) - 1);
530 typedef SgenGrayQueue GrayQueue;
532 /* forward declarations */
533 static void scan_thread_data (void *start_nursery, void *end_nursery, gboolean precise, GrayQueue *queue);
534 static void scan_from_registered_roots (char *addr_start, char *addr_end, int root_type, ScanCopyContext ctx);
535 static void scan_finalizer_entries (FinalizeReadyEntry *list, ScanCopyContext ctx);
536 static void report_finalizer_roots (void);
537 static void report_registered_roots (void);
539 static void pin_from_roots (void *start_nursery, void *end_nursery, GrayQueue *queue);
540 static int pin_objects_from_addresses (GCMemSection *section, void **start, void **end, void *start_nursery, void *end_nursery, ScanCopyContext ctx);
541 static void finish_gray_stack (char *start_addr, char *end_addr, int generation, GrayQueue *queue);
543 void mono_gc_scan_for_specific_ref (MonoObject *key, gboolean precise);
546 static void init_stats (void);
548 static int mark_ephemerons_in_range (char *start, char *end, ScanCopyContext ctx);
549 static void clear_unreachable_ephemerons (char *start, char *end, ScanCopyContext ctx);
550 static void null_ephemerons_for_domain (MonoDomain *domain);
552 SgenObjectOperations current_object_ops;
553 SgenMajorCollector major_collector;
554 SgenMinorCollector sgen_minor_collector;
555 static GrayQueue gray_queue;
556 static GrayQueue remember_major_objects_gray_queue;
558 static SgenRemeberedSet remset;
560 /* The gray queue to use from the main collection thread. */
561 #define WORKERS_DISTRIBUTE_GRAY_QUEUE (&gray_queue)
564 * The gray queue a worker job must use. If we're not parallel or
565 * concurrent, we use the main gray queue.
567 static SgenGrayQueue*
568 sgen_workers_get_job_gray_queue (WorkerData *worker_data)
570 return worker_data ? &worker_data->private_gray_queue : WORKERS_DISTRIBUTE_GRAY_QUEUE;
573 static gboolean have_non_collection_major_object_remembers = FALSE;
576 sgen_remember_major_object_for_concurrent_mark (char *obj)
578 if (!major_collector.is_concurrent)
581 g_assert (current_collection_generation == GENERATION_NURSERY || current_collection_generation == -1);
583 if (!concurrent_collection_in_progress)
586 GRAY_OBJECT_ENQUEUE (&remember_major_objects_gray_queue, obj);
588 if (current_collection_generation != GENERATION_NURSERY) {
590 * This happens when the mutator allocates large or
591 * pinned objects or when allocating in degraded
594 have_non_collection_major_object_remembers = TRUE;
601 gray_queue_redirect (SgenGrayQueue *queue)
603 gboolean wake = FALSE;
607 GrayQueueSection *section = sgen_gray_object_dequeue_section (queue);
610 sgen_section_gray_queue_enqueue (queue->alloc_prepare_data, section);
615 g_assert (concurrent_collection_in_progress ||
616 (current_collection_generation == GENERATION_OLD && major_collector.is_parallel));
617 if (sgen_workers_have_started ()) {
618 sgen_workers_wake_up_all ();
620 if (concurrent_collection_in_progress)
621 g_assert (current_collection_generation == -1);
627 redirect_major_object_remembers (void)
629 gray_queue_redirect (&remember_major_objects_gray_queue);
630 have_non_collection_major_object_remembers = FALSE;
634 is_xdomain_ref_allowed (gpointer *ptr, char *obj, MonoDomain *domain)
636 MonoObject *o = (MonoObject*)(obj);
637 MonoObject *ref = (MonoObject*)*(ptr);
638 int offset = (char*)(ptr) - (char*)o;
640 if (o->vtable->klass == mono_defaults.thread_class && offset == G_STRUCT_OFFSET (MonoThread, internal_thread))
642 if (o->vtable->klass == mono_defaults.internal_thread_class && offset == G_STRUCT_OFFSET (MonoInternalThread, current_appcontext))
644 if (mono_class_has_parent_fast (o->vtable->klass, mono_defaults.real_proxy_class) &&
645 offset == G_STRUCT_OFFSET (MonoRealProxy, unwrapped_server))
647 /* Thread.cached_culture_info */
648 if (!strcmp (ref->vtable->klass->name_space, "System.Globalization") &&
649 !strcmp (ref->vtable->klass->name, "CultureInfo") &&
650 !strcmp(o->vtable->klass->name_space, "System") &&
651 !strcmp(o->vtable->klass->name, "Object[]"))
654 * 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
655 * at System.IO.MemoryStream..ctor (byte[]) [0x00017] in /home/schani/Work/novell/trunk/mcs/class/corlib/System.IO/MemoryStream.cs:81
656 * at (wrapper remoting-invoke-with-check) System.IO.MemoryStream..ctor (byte[]) <IL 0x00020, 0xffffffff>
657 * at System.Runtime.Remoting.Messaging.CADMethodCallMessage.GetArguments () [0x0000d] in /home/schani/Work/novell/trunk/mcs/class/corlib/System.Runtime.Remoting.Messaging/CADMessages.cs:327
658 * 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
659 * 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
660 * at (wrapper remoting-invoke-with-check) System.AppDomain.ProcessMessageInDomain (byte[],System.Runtime.Remoting.Messaging.CADMethodCallMessage,byte[]&,System.Runtime.Remoting.Messaging.CADMethodReturnMessage&) <IL 0x0003d, 0xffffffff>
661 * 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
662 * at (wrapper runtime-invoke) object.runtime_invoke_CrossAppDomainSink/ProcessMessageRes_object_object (object,intptr,intptr,intptr) <IL 0x0004c, 0xffffffff>
664 if (!strcmp (ref->vtable->klass->name_space, "System") &&
665 !strcmp (ref->vtable->klass->name, "Byte[]") &&
666 !strcmp (o->vtable->klass->name_space, "System.IO") &&
667 !strcmp (o->vtable->klass->name, "MemoryStream"))
669 /* append_job() in threadpool.c */
670 if (!strcmp (ref->vtable->klass->name_space, "System.Runtime.Remoting.Messaging") &&
671 !strcmp (ref->vtable->klass->name, "AsyncResult") &&
672 !strcmp (o->vtable->klass->name_space, "System") &&
673 !strcmp (o->vtable->klass->name, "Object[]") &&
674 mono_thread_pool_is_queue_array ((MonoArray*) o))
680 check_reference_for_xdomain (gpointer *ptr, char *obj, MonoDomain *domain)
682 MonoObject *o = (MonoObject*)(obj);
683 MonoObject *ref = (MonoObject*)*(ptr);
684 int offset = (char*)(ptr) - (char*)o;
686 MonoClassField *field;
689 if (!ref || ref->vtable->domain == domain)
691 if (is_xdomain_ref_allowed (ptr, obj, domain))
695 for (class = o->vtable->klass; class; class = class->parent) {
698 for (i = 0; i < class->field.count; ++i) {
699 if (class->fields[i].offset == offset) {
700 field = &class->fields[i];
708 if (ref->vtable->klass == mono_defaults.string_class)
709 str = mono_string_to_utf8 ((MonoString*)ref);
712 g_print ("xdomain reference in %p (%s.%s) at offset %d (%s) to %p (%s.%s) (%s) - pointed to by:\n",
713 o, o->vtable->klass->name_space, o->vtable->klass->name,
714 offset, field ? field->name : "",
715 ref, ref->vtable->klass->name_space, ref->vtable->klass->name, str ? str : "");
716 mono_gc_scan_for_specific_ref (o, TRUE);
722 #define HANDLE_PTR(ptr,obj) check_reference_for_xdomain ((ptr), (obj), domain)
725 scan_object_for_xdomain_refs (char *start, mword size, void *data)
727 MonoDomain *domain = ((MonoObject*)start)->vtable->domain;
729 #include "sgen-scan-object.h"
732 static gboolean scan_object_for_specific_ref_precise = TRUE;
735 #define HANDLE_PTR(ptr,obj) do { \
736 if ((MonoObject*)*(ptr) == key) { \
737 g_print ("found ref to %p in object %p (%s) at offset %td\n", \
738 key, (obj), safe_name ((obj)), ((char*)(ptr) - (char*)(obj))); \
743 scan_object_for_specific_ref (char *start, MonoObject *key)
747 if ((forwarded = SGEN_OBJECT_IS_FORWARDED (start)))
750 if (scan_object_for_specific_ref_precise) {
751 #include "sgen-scan-object.h"
753 mword *words = (mword*)start;
754 size_t size = safe_object_get_size ((MonoObject*)start);
756 for (i = 0; i < size / sizeof (mword); ++i) {
757 if (words [i] == (mword)key) {
758 g_print ("found possible ref to %p in object %p (%s) at offset %td\n",
759 key, start, safe_name (start), i * sizeof (mword));
766 sgen_scan_area_with_callback (char *start, char *end, IterateObjectCallbackFunc callback, void *data, gboolean allow_flags)
768 while (start < end) {
772 if (!*(void**)start) {
773 start += sizeof (void*); /* should be ALLOC_ALIGN, really */
778 if (!(obj = SGEN_OBJECT_IS_FORWARDED (start)))
784 size = ALIGN_UP (safe_object_get_size ((MonoObject*)obj));
786 if ((MonoVTable*)SGEN_LOAD_VTABLE (obj) != array_fill_vtable)
787 callback (obj, size, data);
794 scan_object_for_specific_ref_callback (char *obj, size_t size, MonoObject *key)
796 scan_object_for_specific_ref (obj, key);
800 check_root_obj_specific_ref (RootRecord *root, MonoObject *key, MonoObject *obj)
804 g_print ("found ref to %p in root record %p\n", key, root);
807 static MonoObject *check_key = NULL;
808 static RootRecord *check_root = NULL;
811 check_root_obj_specific_ref_from_marker (void **obj)
813 check_root_obj_specific_ref (check_root, check_key, *obj);
817 scan_roots_for_specific_ref (MonoObject *key, int root_type)
823 SGEN_HASH_TABLE_FOREACH (&roots_hash [root_type], start_root, root) {
824 mword desc = root->root_desc;
828 switch (desc & ROOT_DESC_TYPE_MASK) {
829 case ROOT_DESC_BITMAP:
830 desc >>= ROOT_DESC_TYPE_SHIFT;
833 check_root_obj_specific_ref (root, key, *start_root);
838 case ROOT_DESC_COMPLEX: {
839 gsize *bitmap_data = sgen_get_complex_descriptor_bitmap (desc);
840 int bwords = (*bitmap_data) - 1;
841 void **start_run = start_root;
843 while (bwords-- > 0) {
844 gsize bmap = *bitmap_data++;
845 void **objptr = start_run;
848 check_root_obj_specific_ref (root, key, *objptr);
852 start_run += GC_BITS_PER_WORD;
856 case ROOT_DESC_USER: {
857 MonoGCRootMarkFunc marker = sgen_get_user_descriptor_func (desc);
858 marker (start_root, check_root_obj_specific_ref_from_marker);
861 case ROOT_DESC_RUN_LEN:
862 g_assert_not_reached ();
864 g_assert_not_reached ();
866 } SGEN_HASH_TABLE_FOREACH_END;
873 mono_gc_scan_for_specific_ref (MonoObject *key, gboolean precise)
878 scan_object_for_specific_ref_precise = precise;
880 sgen_scan_area_with_callback (nursery_section->data, nursery_section->end_data,
881 (IterateObjectCallbackFunc)scan_object_for_specific_ref_callback, key, TRUE);
883 major_collector.iterate_objects (TRUE, TRUE, (IterateObjectCallbackFunc)scan_object_for_specific_ref_callback, key);
885 sgen_los_iterate_objects ((IterateObjectCallbackFunc)scan_object_for_specific_ref_callback, key);
887 scan_roots_for_specific_ref (key, ROOT_TYPE_NORMAL);
888 scan_roots_for_specific_ref (key, ROOT_TYPE_WBARRIER);
890 SGEN_HASH_TABLE_FOREACH (&roots_hash [ROOT_TYPE_PINNED], ptr, root) {
891 while (ptr < (void**)root->end_root) {
892 check_root_obj_specific_ref (root, *ptr, key);
895 } SGEN_HASH_TABLE_FOREACH_END;
899 need_remove_object_for_domain (char *start, MonoDomain *domain)
901 if (mono_object_domain (start) == domain) {
902 SGEN_LOG (4, "Need to cleanup object %p", start);
903 binary_protocol_cleanup (start, (gpointer)LOAD_VTABLE (start), safe_object_get_size ((MonoObject*)start));
910 process_object_for_domain_clearing (char *start, MonoDomain *domain)
912 GCVTable *vt = (GCVTable*)LOAD_VTABLE (start);
913 if (vt->klass == mono_defaults.internal_thread_class)
914 g_assert (mono_object_domain (start) == mono_get_root_domain ());
915 /* The object could be a proxy for an object in the domain
917 if (mono_class_has_parent_fast (vt->klass, mono_defaults.real_proxy_class)) {
918 MonoObject *server = ((MonoRealProxy*)start)->unwrapped_server;
920 /* The server could already have been zeroed out, so
921 we need to check for that, too. */
922 if (server && (!LOAD_VTABLE (server) || mono_object_domain (server) == domain)) {
923 SGEN_LOG (4, "Cleaning up remote pointer in %p to object %p", start, server);
924 ((MonoRealProxy*)start)->unwrapped_server = NULL;
929 static MonoDomain *check_domain = NULL;
932 check_obj_not_in_domain (void **o)
934 g_assert (((MonoObject*)(*o))->vtable->domain != check_domain);
938 scan_for_registered_roots_in_domain (MonoDomain *domain, int root_type)
942 check_domain = domain;
943 SGEN_HASH_TABLE_FOREACH (&roots_hash [root_type], start_root, root) {
944 mword desc = root->root_desc;
946 /* The MonoDomain struct is allowed to hold
947 references to objects in its own domain. */
948 if (start_root == (void**)domain)
951 switch (desc & ROOT_DESC_TYPE_MASK) {
952 case ROOT_DESC_BITMAP:
953 desc >>= ROOT_DESC_TYPE_SHIFT;
955 if ((desc & 1) && *start_root)
956 check_obj_not_in_domain (*start_root);
961 case ROOT_DESC_COMPLEX: {
962 gsize *bitmap_data = sgen_get_complex_descriptor_bitmap (desc);
963 int bwords = (*bitmap_data) - 1;
964 void **start_run = start_root;
966 while (bwords-- > 0) {
967 gsize bmap = *bitmap_data++;
968 void **objptr = start_run;
970 if ((bmap & 1) && *objptr)
971 check_obj_not_in_domain (*objptr);
975 start_run += GC_BITS_PER_WORD;
979 case ROOT_DESC_USER: {
980 MonoGCRootMarkFunc marker = sgen_get_user_descriptor_func (desc);
981 marker (start_root, check_obj_not_in_domain);
984 case ROOT_DESC_RUN_LEN:
985 g_assert_not_reached ();
987 g_assert_not_reached ();
989 } SGEN_HASH_TABLE_FOREACH_END;
995 check_for_xdomain_refs (void)
999 sgen_scan_area_with_callback (nursery_section->data, nursery_section->end_data,
1000 (IterateObjectCallbackFunc)scan_object_for_xdomain_refs, NULL, FALSE);
1002 major_collector.iterate_objects (TRUE, TRUE, (IterateObjectCallbackFunc)scan_object_for_xdomain_refs, NULL);
1004 for (bigobj = los_object_list; bigobj; bigobj = bigobj->next)
1005 scan_object_for_xdomain_refs (bigobj->data, sgen_los_object_size (bigobj), NULL);
1009 clear_domain_process_object (char *obj, MonoDomain *domain)
1013 process_object_for_domain_clearing (obj, domain);
1014 remove = need_remove_object_for_domain (obj, domain);
1016 if (remove && ((MonoObject*)obj)->synchronisation) {
1017 void **dislink = mono_monitor_get_object_monitor_weak_link ((MonoObject*)obj);
1019 sgen_register_disappearing_link (NULL, dislink, FALSE, TRUE);
1026 clear_domain_process_minor_object_callback (char *obj, size_t size, MonoDomain *domain)
1028 if (clear_domain_process_object (obj, domain))
1029 memset (obj, 0, size);
1033 clear_domain_process_major_object_callback (char *obj, size_t size, MonoDomain *domain)
1035 clear_domain_process_object (obj, domain);
1039 clear_domain_free_major_non_pinned_object_callback (char *obj, size_t size, MonoDomain *domain)
1041 if (need_remove_object_for_domain (obj, domain))
1042 major_collector.free_non_pinned_object (obj, size);
1046 clear_domain_free_major_pinned_object_callback (char *obj, size_t size, MonoDomain *domain)
1048 if (need_remove_object_for_domain (obj, domain))
1049 major_collector.free_pinned_object (obj, size);
1053 * When appdomains are unloaded we can easily remove objects that have finalizers,
1054 * but all the others could still be present in random places on the heap.
1055 * We need a sweep to get rid of them even though it's going to be costly
1057 * The reason we need to remove them is because we access the vtable and class
1058 * structures to know the object size and the reference bitmap: once the domain is
1059 * unloaded the point to random memory.
1062 mono_gc_clear_domain (MonoDomain * domain)
1064 LOSObject *bigobj, *prev;
1069 sgen_process_fin_stage_entries ();
1070 sgen_process_dislink_stage_entries ();
1072 sgen_clear_nursery_fragments ();
1074 if (xdomain_checks && domain != mono_get_root_domain ()) {
1075 scan_for_registered_roots_in_domain (domain, ROOT_TYPE_NORMAL);
1076 scan_for_registered_roots_in_domain (domain, ROOT_TYPE_WBARRIER);
1077 check_for_xdomain_refs ();
1080 /*Ephemerons and dislinks must be processed before LOS since they might end up pointing
1081 to memory returned to the OS.*/
1082 null_ephemerons_for_domain (domain);
1084 for (i = GENERATION_NURSERY; i < GENERATION_MAX; ++i)
1085 sgen_null_links_for_domain (domain, i);
1087 for (i = GENERATION_NURSERY; i < GENERATION_MAX; ++i)
1088 sgen_remove_finalizers_for_domain (domain, i);
1090 sgen_scan_area_with_callback (nursery_section->data, nursery_section->end_data,
1091 (IterateObjectCallbackFunc)clear_domain_process_minor_object_callback, domain, FALSE);
1093 /* We need two passes over major and large objects because
1094 freeing such objects might give their memory back to the OS
1095 (in the case of large objects) or obliterate its vtable
1096 (pinned objects with major-copying or pinned and non-pinned
1097 objects with major-mark&sweep), but we might need to
1098 dereference a pointer from an object to another object if
1099 the first object is a proxy. */
1100 major_collector.iterate_objects (TRUE, TRUE, (IterateObjectCallbackFunc)clear_domain_process_major_object_callback, domain);
1101 for (bigobj = los_object_list; bigobj; bigobj = bigobj->next)
1102 clear_domain_process_object (bigobj->data, domain);
1105 for (bigobj = los_object_list; bigobj;) {
1106 if (need_remove_object_for_domain (bigobj->data, domain)) {
1107 LOSObject *to_free = bigobj;
1109 prev->next = bigobj->next;
1111 los_object_list = bigobj->next;
1112 bigobj = bigobj->next;
1113 SGEN_LOG (4, "Freeing large object %p", bigobj->data);
1114 sgen_los_free_object (to_free);
1118 bigobj = bigobj->next;
1120 major_collector.iterate_objects (TRUE, FALSE, (IterateObjectCallbackFunc)clear_domain_free_major_non_pinned_object_callback, domain);
1121 major_collector.iterate_objects (FALSE, TRUE, (IterateObjectCallbackFunc)clear_domain_free_major_pinned_object_callback, domain);
1123 if (G_UNLIKELY (do_pin_stats)) {
1124 if (domain == mono_get_root_domain ())
1125 sgen_pin_stats_print_class_stats ();
1132 * sgen_add_to_global_remset:
1134 * The global remset contains locations which point into newspace after
1135 * a minor collection. This can happen if the objects they point to are pinned.
1137 * LOCKING: If called from a parallel collector, the global remset
1138 * lock must be held. For serial collectors that is not necessary.
1141 sgen_add_to_global_remset (gpointer ptr)
1143 remset.record_pointer (ptr);
1145 if (G_UNLIKELY (MONO_GC_GLOBAL_REMSET_ADD_ENABLED ())) {
1146 void *obj = *(void**)ptr;
1147 MonoVTable *vt = (MonoVTable*)LOAD_VTABLE (obj);
1148 MONO_GC_GLOBAL_REMSET_ADD ((mword)ptr, (mword)obj, sgen_safe_object_get_size (obj),
1149 vt->klass->name_space, vt->klass->name);
1154 * sgen_drain_gray_stack:
1156 * Scan objects in the gray stack until the stack is empty. This should be called
1157 * frequently after each object is copied, to achieve better locality and cache
1161 sgen_drain_gray_stack (int max_objs, ScanCopyContext ctx)
1164 ScanObjectFunc scan_func = ctx.scan_func;
1165 GrayQueue *queue = ctx.queue;
1167 if (max_objs == -1) {
1169 GRAY_OBJECT_DEQUEUE (queue, obj);
1172 SGEN_LOG (9, "Precise gray object scan %p (%s)", obj, safe_name (obj));
1173 scan_func (obj, queue);
1179 for (i = 0; i != max_objs; ++i) {
1180 GRAY_OBJECT_DEQUEUE (queue, obj);
1183 SGEN_LOG (9, "Precise gray object scan %p (%s)", obj, safe_name (obj));
1184 scan_func (obj, queue);
1186 } while (max_objs < 0);
1192 * Addresses from start to end are already sorted. This function finds
1193 * the object header for each address and pins the object. The
1194 * addresses must be inside the passed section. The (start of the)
1195 * address array is overwritten with the addresses of the actually
1196 * pinned objects. Return the number of pinned objects.
1199 pin_objects_from_addresses (GCMemSection *section, void **start, void **end, void *start_nursery, void *end_nursery, ScanCopyContext ctx)
1204 void *last_obj = NULL;
1205 size_t last_obj_size = 0;
1208 void **definitely_pinned = start;
1209 ScanObjectFunc scan_func = ctx.scan_func;
1210 SgenGrayQueue *queue = ctx.queue;
1212 sgen_nursery_allocator_prepare_for_pinning ();
1214 while (start < end) {
1216 /* the range check should be reduntant */
1217 if (addr != last && addr >= start_nursery && addr < end_nursery) {
1218 SGEN_LOG (5, "Considering pinning addr %p", addr);
1219 /* multiple pointers to the same object */
1220 if (addr >= last_obj && (char*)addr < (char*)last_obj + last_obj_size) {
1224 idx = ((char*)addr - (char*)section->data) / SCAN_START_SIZE;
1225 g_assert (idx < section->num_scan_start);
1226 search_start = (void*)section->scan_starts [idx];
1227 if (!search_start || search_start > addr) {
1230 search_start = section->scan_starts [idx];
1231 if (search_start && search_start <= addr)
1234 if (!search_start || search_start > addr)
1235 search_start = start_nursery;
1237 if (search_start < last_obj)
1238 search_start = (char*)last_obj + last_obj_size;
1239 /* now addr should be in an object a short distance from search_start
1240 * Note that search_start must point to zeroed mem or point to an object.
1244 if (!*(void**)search_start) {
1245 /* Consistency check */
1247 for (frag = nursery_fragments; frag; frag = frag->next) {
1248 if (search_start >= frag->fragment_start && search_start < frag->fragment_end)
1249 g_assert_not_reached ();
1253 search_start = (void*)ALIGN_UP ((mword)search_start + sizeof (gpointer));
1256 last_obj = search_start;
1257 last_obj_size = ALIGN_UP (safe_object_get_size ((MonoObject*)search_start));
1259 if (((MonoObject*)last_obj)->synchronisation == GINT_TO_POINTER (-1)) {
1260 /* Marks the beginning of a nursery fragment, skip */
1262 SGEN_LOG (8, "Pinned try match %p (%s), size %zd", last_obj, safe_name (last_obj), last_obj_size);
1263 if (addr >= search_start && (char*)addr < (char*)last_obj + last_obj_size) {
1264 SGEN_LOG (4, "Pinned object %p, vtable %p (%s), count %d\n", search_start, *(void**)search_start, safe_name (search_start), count);
1265 binary_protocol_pin (search_start, (gpointer)LOAD_VTABLE (search_start), safe_object_get_size (search_start));
1266 if (G_UNLIKELY (MONO_GC_OBJ_PINNED_ENABLED ())) {
1267 int gen = sgen_ptr_in_nursery (search_start) ? GENERATION_NURSERY : GENERATION_OLD;
1268 MonoVTable *vt = (MonoVTable*)LOAD_VTABLE (search_start);
1269 MONO_GC_OBJ_PINNED ((mword)search_start, sgen_safe_object_get_size (search_start), vt->klass->name_space, vt->klass->name, gen);
1272 scan_func (search_start, queue);
1274 pin_object (search_start);
1275 GRAY_OBJECT_ENQUEUE (queue, search_start);
1276 if (G_UNLIKELY (do_pin_stats))
1277 sgen_pin_stats_register_object (search_start, last_obj_size);
1278 definitely_pinned [count] = search_start;
1284 /* skip to the next object */
1285 search_start = (void*)((char*)search_start + last_obj_size);
1286 } while (search_start <= addr);
1287 /* we either pinned the correct object or we ignored the addr because
1288 * it points to unused zeroed memory.
1294 //printf ("effective pinned: %d (at the end: %d)\n", count, (char*)end_nursery - (char*)last);
1295 if (mono_profiler_get_events () & MONO_PROFILE_GC_ROOTS) {
1296 GCRootReport report;
1298 for (idx = 0; idx < count; ++idx)
1299 add_profile_gc_root (&report, definitely_pinned [idx], MONO_PROFILE_GC_ROOT_PINNING | MONO_PROFILE_GC_ROOT_MISC, 0);
1300 notify_gc_roots (&report);
1302 stat_pinned_objects += count;
1307 sgen_pin_objects_in_section (GCMemSection *section, ScanCopyContext ctx)
1309 int num_entries = section->pin_queue_num_entries;
1311 void **start = section->pin_queue_start;
1313 reduced_to = pin_objects_from_addresses (section, start, start + num_entries,
1314 section->data, section->next_data, ctx);
1315 section->pin_queue_num_entries = reduced_to;
1317 section->pin_queue_start = NULL;
1323 sgen_pin_object (void *object, GrayQueue *queue)
1325 g_assert (!concurrent_collection_in_progress);
1327 if (sgen_collection_is_parallel ()) {
1329 /*object arrives pinned*/
1330 sgen_pin_stage_ptr (object);
1334 SGEN_PIN_OBJECT (object);
1335 sgen_pin_stage_ptr (object);
1337 if (G_UNLIKELY (do_pin_stats))
1338 sgen_pin_stats_register_object (object, safe_object_get_size (object));
1340 GRAY_OBJECT_ENQUEUE (queue, object);
1341 binary_protocol_pin (object, (gpointer)LOAD_VTABLE (object), safe_object_get_size (object));
1342 if (G_UNLIKELY (MONO_GC_OBJ_PINNED_ENABLED ())) {
1343 int gen = sgen_ptr_in_nursery (object) ? GENERATION_NURSERY : GENERATION_OLD;
1344 MonoVTable *vt = (MonoVTable*)LOAD_VTABLE (object);
1345 MONO_GC_OBJ_PINNED ((mword)object, sgen_safe_object_get_size (object), vt->klass->name_space, vt->klass->name, gen);
1350 sgen_parallel_pin_or_update (void **ptr, void *obj, MonoVTable *vt, SgenGrayQueue *queue)
1354 gboolean major_pinned = FALSE;
1356 if (sgen_ptr_in_nursery (obj)) {
1357 if (SGEN_CAS_PTR (obj, (void*)((mword)vt | SGEN_PINNED_BIT), vt) == vt) {
1358 sgen_pin_object (obj, queue);
1362 major_collector.pin_major_object (obj, queue);
1363 major_pinned = TRUE;
1366 vtable_word = *(mword*)obj;
1367 /*someone else forwarded it, update the pointer and bail out*/
1368 if (vtable_word & SGEN_FORWARDED_BIT) {
1369 *ptr = (void*)(vtable_word & ~SGEN_VTABLE_BITS_MASK);
1373 /*someone pinned it, nothing to do.*/
1374 if (vtable_word & SGEN_PINNED_BIT || major_pinned)
1379 /* Sort the addresses in array in increasing order.
1380 * Done using a by-the book heap sort. Which has decent and stable performance, is pretty cache efficient.
1383 sgen_sort_addresses (void **array, int size)
1388 for (i = 1; i < size; ++i) {
1391 int parent = (child - 1) / 2;
1393 if (array [parent] >= array [child])
1396 tmp = array [parent];
1397 array [parent] = array [child];
1398 array [child] = tmp;
1404 for (i = size - 1; i > 0; --i) {
1407 array [i] = array [0];
1413 while (root * 2 + 1 <= end) {
1414 int child = root * 2 + 1;
1416 if (child < end && array [child] < array [child + 1])
1418 if (array [root] >= array [child])
1422 array [root] = array [child];
1423 array [child] = tmp;
1431 * Scan the memory between start and end and queue values which could be pointers
1432 * to the area between start_nursery and end_nursery for later consideration.
1433 * Typically used for thread stacks.
1436 conservatively_pin_objects_from (void **start, void **end, void *start_nursery, void *end_nursery, int pin_type)
1440 #ifdef VALGRIND_MAKE_MEM_DEFINED_IF_ADDRESSABLE
1441 VALGRIND_MAKE_MEM_DEFINED_IF_ADDRESSABLE (start, (char*)end - (char*)start);
1444 while (start < end) {
1445 if (*start >= start_nursery && *start < end_nursery) {
1447 * *start can point to the middle of an object
1448 * note: should we handle pointing at the end of an object?
1449 * pinning in C# code disallows pointing at the end of an object
1450 * but there is some small chance that an optimizing C compiler
1451 * may keep the only reference to an object by pointing
1452 * at the end of it. We ignore this small chance for now.
1453 * Pointers to the end of an object are indistinguishable
1454 * from pointers to the start of the next object in memory
1455 * so if we allow that we'd need to pin two objects...
1456 * We queue the pointer in an array, the
1457 * array will then be sorted and uniqued. This way
1458 * we can coalesce several pinning pointers and it should
1459 * be faster since we'd do a memory scan with increasing
1460 * addresses. Note: we can align the address to the allocation
1461 * alignment, so the unique process is more effective.
1463 mword addr = (mword)*start;
1464 addr &= ~(ALLOC_ALIGN - 1);
1465 if (addr >= (mword)start_nursery && addr < (mword)end_nursery) {
1466 SGEN_LOG (6, "Pinning address %p from %p", (void*)addr, start);
1467 sgen_pin_stage_ptr ((void*)addr);
1470 if (G_UNLIKELY (do_pin_stats)) {
1471 if (ptr_in_nursery ((void*)addr))
1472 sgen_pin_stats_register_address ((char*)addr, pin_type);
1478 SGEN_LOG (7, "found %d potential pinned heap pointers", count);
1482 * The first thing we do in a collection is to identify pinned objects.
1483 * This function considers all the areas of memory that need to be
1484 * conservatively scanned.
1487 pin_from_roots (void *start_nursery, void *end_nursery, GrayQueue *queue)
1491 SGEN_LOG (2, "Scanning pinned roots (%d bytes, %d/%d entries)", (int)roots_size, roots_hash [ROOT_TYPE_NORMAL].num_entries, roots_hash [ROOT_TYPE_PINNED].num_entries);
1492 /* objects pinned from the API are inside these roots */
1493 SGEN_HASH_TABLE_FOREACH (&roots_hash [ROOT_TYPE_PINNED], start_root, root) {
1494 SGEN_LOG (6, "Pinned roots %p-%p", start_root, root->end_root);
1495 conservatively_pin_objects_from (start_root, (void**)root->end_root, start_nursery, end_nursery, PIN_TYPE_OTHER);
1496 } SGEN_HASH_TABLE_FOREACH_END;
1497 /* now deal with the thread stacks
1498 * in the future we should be able to conservatively scan only:
1499 * *) the cpu registers
1500 * *) the unmanaged stack frames
1501 * *) the _last_ managed stack frame
1502 * *) pointers slots in managed frames
1504 scan_thread_data (start_nursery, end_nursery, FALSE, queue);
1508 unpin_objects_from_queue (SgenGrayQueue *queue)
1512 GRAY_OBJECT_DEQUEUE (queue, addr);
1515 SGEN_UNPIN_OBJECT (addr);
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 (void** start_root, void** end_root, char* n_start, char *n_end, mword desc, ScanCopyContext ctx)
1557 CopyOrMarkObjectFunc copy_func = ctx.copy_func;
1558 SgenGrayQueue *queue = ctx.queue;
1560 switch (desc & ROOT_DESC_TYPE_MASK) {
1561 case ROOT_DESC_BITMAP:
1562 desc >>= ROOT_DESC_TYPE_SHIFT;
1564 if ((desc & 1) && *start_root) {
1565 copy_func (start_root, queue);
1566 SGEN_LOG (9, "Overwrote root at %p with %p", start_root, *start_root);
1567 sgen_drain_gray_stack (-1, ctx);
1573 case ROOT_DESC_COMPLEX: {
1574 gsize *bitmap_data = sgen_get_complex_descriptor_bitmap (desc);
1575 int bwords = (*bitmap_data) - 1;
1576 void **start_run = start_root;
1578 while (bwords-- > 0) {
1579 gsize bmap = *bitmap_data++;
1580 void **objptr = start_run;
1582 if ((bmap & 1) && *objptr) {
1583 copy_func (objptr, queue);
1584 SGEN_LOG (9, "Overwrote root at %p with %p", objptr, *objptr);
1585 sgen_drain_gray_stack (-1, ctx);
1590 start_run += GC_BITS_PER_WORD;
1594 case ROOT_DESC_USER: {
1595 UserCopyOrMarkData data = { copy_func, queue };
1596 MonoGCRootMarkFunc marker = sgen_get_user_descriptor_func (desc);
1597 set_user_copy_or_mark_data (&data);
1598 marker (start_root, single_arg_user_copy_or_mark);
1599 set_user_copy_or_mark_data (NULL);
1602 case ROOT_DESC_RUN_LEN:
1603 g_assert_not_reached ();
1605 g_assert_not_reached ();
1610 reset_heap_boundaries (void)
1612 lowest_heap_address = ~(mword)0;
1613 highest_heap_address = 0;
1617 sgen_update_heap_boundaries (mword low, mword high)
1622 old = lowest_heap_address;
1625 } while (SGEN_CAS_PTR ((gpointer*)&lowest_heap_address, (gpointer)low, (gpointer)old) != (gpointer)old);
1628 old = highest_heap_address;
1631 } while (SGEN_CAS_PTR ((gpointer*)&highest_heap_address, (gpointer)high, (gpointer)old) != (gpointer)old);
1635 * Allocate and setup the data structures needed to be able to allocate objects
1636 * in the nursery. The nursery is stored in nursery_section.
1639 alloc_nursery (void)
1641 GCMemSection *section;
1646 if (nursery_section)
1648 SGEN_LOG (2, "Allocating nursery size: %lu", (unsigned long)sgen_nursery_size);
1649 /* later we will alloc a larger area for the nursery but only activate
1650 * what we need. The rest will be used as expansion if we have too many pinned
1651 * objects in the existing nursery.
1653 /* FIXME: handle OOM */
1654 section = sgen_alloc_internal (INTERNAL_MEM_SECTION);
1656 alloc_size = sgen_nursery_size;
1658 /* If there isn't enough space even for the nursery we should simply abort. */
1659 g_assert (sgen_memgov_try_alloc_space (alloc_size, SPACE_NURSERY));
1661 #ifdef SGEN_ALIGN_NURSERY
1662 data = major_collector.alloc_heap (alloc_size, alloc_size, DEFAULT_NURSERY_BITS);
1664 data = major_collector.alloc_heap (alloc_size, 0, DEFAULT_NURSERY_BITS);
1666 sgen_update_heap_boundaries ((mword)data, (mword)(data + sgen_nursery_size));
1667 SGEN_LOG (4, "Expanding nursery size (%p-%p): %lu, total: %lu", data, data + alloc_size, (unsigned long)sgen_nursery_size, (unsigned long)mono_gc_get_heap_size ());
1668 section->data = section->next_data = data;
1669 section->size = alloc_size;
1670 section->end_data = data + sgen_nursery_size;
1671 scan_starts = (alloc_size + SCAN_START_SIZE - 1) / SCAN_START_SIZE;
1672 section->scan_starts = sgen_alloc_internal_dynamic (sizeof (char*) * scan_starts, INTERNAL_MEM_SCAN_STARTS, TRUE);
1673 section->num_scan_start = scan_starts;
1674 section->block.role = MEMORY_ROLE_GEN0;
1675 section->block.next = NULL;
1677 nursery_section = section;
1679 sgen_nursery_allocator_set_nursery_bounds (data, data + sgen_nursery_size);
1683 mono_gc_get_nursery (int *shift_bits, size_t *size)
1685 *size = sgen_nursery_size;
1686 #ifdef SGEN_ALIGN_NURSERY
1687 *shift_bits = DEFAULT_NURSERY_BITS;
1691 return sgen_get_nursery_start ();
1695 mono_gc_set_current_thread_appdomain (MonoDomain *domain)
1697 SgenThreadInfo *info = mono_thread_info_current ();
1699 /* Could be called from sgen_thread_unregister () with a NULL info */
1702 info->stopped_domain = domain;
1707 mono_gc_precise_stack_mark_enabled (void)
1709 return !conservative_stack_mark;
1713 mono_gc_get_logfile (void)
1715 return gc_debug_file;
1719 report_finalizer_roots_list (FinalizeReadyEntry *list)
1721 GCRootReport report;
1722 FinalizeReadyEntry *fin;
1725 for (fin = list; fin; fin = fin->next) {
1728 add_profile_gc_root (&report, fin->object, MONO_PROFILE_GC_ROOT_FINALIZER, 0);
1730 notify_gc_roots (&report);
1734 report_finalizer_roots (void)
1736 report_finalizer_roots_list (fin_ready_list);
1737 report_finalizer_roots_list (critical_fin_list);
1740 static GCRootReport *root_report;
1743 single_arg_report_root (void **obj)
1746 add_profile_gc_root (root_report, *obj, MONO_PROFILE_GC_ROOT_OTHER, 0);
1750 precisely_report_roots_from (GCRootReport *report, void** start_root, void** end_root, mword desc)
1752 switch (desc & ROOT_DESC_TYPE_MASK) {
1753 case ROOT_DESC_BITMAP:
1754 desc >>= ROOT_DESC_TYPE_SHIFT;
1756 if ((desc & 1) && *start_root) {
1757 add_profile_gc_root (report, *start_root, MONO_PROFILE_GC_ROOT_OTHER, 0);
1763 case ROOT_DESC_COMPLEX: {
1764 gsize *bitmap_data = sgen_get_complex_descriptor_bitmap (desc);
1765 int bwords = (*bitmap_data) - 1;
1766 void **start_run = start_root;
1768 while (bwords-- > 0) {
1769 gsize bmap = *bitmap_data++;
1770 void **objptr = start_run;
1772 if ((bmap & 1) && *objptr) {
1773 add_profile_gc_root (report, *objptr, MONO_PROFILE_GC_ROOT_OTHER, 0);
1778 start_run += GC_BITS_PER_WORD;
1782 case ROOT_DESC_USER: {
1783 MonoGCRootMarkFunc marker = sgen_get_user_descriptor_func (desc);
1784 root_report = report;
1785 marker (start_root, single_arg_report_root);
1788 case ROOT_DESC_RUN_LEN:
1789 g_assert_not_reached ();
1791 g_assert_not_reached ();
1796 report_registered_roots_by_type (int root_type)
1798 GCRootReport report;
1802 SGEN_HASH_TABLE_FOREACH (&roots_hash [root_type], start_root, root) {
1803 SGEN_LOG (6, "Precise root scan %p-%p (desc: %p)", start_root, root->end_root, (void*)root->root_desc);
1804 precisely_report_roots_from (&report, start_root, (void**)root->end_root, root->root_desc);
1805 } SGEN_HASH_TABLE_FOREACH_END;
1806 notify_gc_roots (&report);
1810 report_registered_roots (void)
1812 report_registered_roots_by_type (ROOT_TYPE_NORMAL);
1813 report_registered_roots_by_type (ROOT_TYPE_WBARRIER);
1817 scan_finalizer_entries (FinalizeReadyEntry *list, ScanCopyContext ctx)
1819 CopyOrMarkObjectFunc copy_func = ctx.copy_func;
1820 SgenGrayQueue *queue = ctx.queue;
1821 FinalizeReadyEntry *fin;
1823 for (fin = list; fin; fin = fin->next) {
1826 SGEN_LOG (5, "Scan of fin ready object: %p (%s)\n", fin->object, safe_name (fin->object));
1827 copy_func (&fin->object, queue);
1832 generation_name (int generation)
1834 switch (generation) {
1835 case GENERATION_NURSERY: return "nursery";
1836 case GENERATION_OLD: return "old";
1837 default: g_assert_not_reached ();
1842 sgen_generation_name (int generation)
1844 return generation_name (generation);
1847 SgenObjectOperations *
1848 sgen_get_current_object_ops (void){
1849 return ¤t_object_ops;
1854 finish_gray_stack (char *start_addr, char *end_addr, int generation, GrayQueue *queue)
1858 int done_with_ephemerons, ephemeron_rounds = 0;
1859 CopyOrMarkObjectFunc copy_func = current_object_ops.copy_or_mark_object;
1860 ScanObjectFunc scan_func = current_object_ops.scan_object;
1861 ScanCopyContext ctx = { scan_func, copy_func, queue };
1864 * We copied all the reachable objects. Now it's the time to copy
1865 * the objects that were not referenced by the roots, but by the copied objects.
1866 * we built a stack of objects pointed to by gray_start: they are
1867 * additional roots and we may add more items as we go.
1868 * We loop until gray_start == gray_objects which means no more objects have
1869 * been added. Note this is iterative: no recursion is involved.
1870 * We need to walk the LO list as well in search of marked big objects
1871 * (use a flag since this is needed only on major collections). We need to loop
1872 * here as well, so keep a counter of marked LO (increasing it in copy_object).
1873 * To achieve better cache locality and cache usage, we drain the gray stack
1874 * frequently, after each object is copied, and just finish the work here.
1876 sgen_drain_gray_stack (-1, ctx);
1878 SGEN_LOG (2, "%s generation done", generation_name (generation));
1881 Reset bridge data, we might have lingering data from a previous collection if this is a major
1882 collection trigged by minor overflow.
1884 We must reset the gathered bridges since their original block might be evacuated due to major
1885 fragmentation in the meanwhile and the bridge code should not have to deal with that.
1887 sgen_bridge_reset_data ();
1890 * Walk the ephemeron tables marking all values with reachable keys. This must be completely done
1891 * before processing finalizable objects or non-tracking weak hamdle to avoid finalizing/clearing
1892 * objects that are in fact reachable.
1894 done_with_ephemerons = 0;
1896 done_with_ephemerons = mark_ephemerons_in_range (start_addr, end_addr, ctx);
1897 sgen_drain_gray_stack (-1, ctx);
1899 } while (!done_with_ephemerons);
1901 sgen_scan_togglerefs (start_addr, end_addr, ctx);
1902 if (generation == GENERATION_OLD)
1903 sgen_scan_togglerefs (sgen_get_nursery_start (), sgen_get_nursery_end (), ctx);
1905 if (sgen_need_bridge_processing ()) {
1906 sgen_collect_bridge_objects (start_addr, end_addr, generation, ctx);
1907 if (generation == GENERATION_OLD)
1908 sgen_collect_bridge_objects (sgen_get_nursery_start (), sgen_get_nursery_end (), GENERATION_NURSERY, ctx);
1912 Make sure we drain the gray stack before processing disappearing links and finalizers.
1913 If we don't make sure it is empty we might wrongly see a live object as dead.
1915 sgen_drain_gray_stack (-1, ctx);
1918 We must clear weak links that don't track resurrection before processing object ready for
1919 finalization so they can be cleared before that.
1921 sgen_null_link_in_range (start_addr, end_addr, generation, TRUE, ctx);
1922 if (generation == GENERATION_OLD)
1923 sgen_null_link_in_range (start_addr, end_addr, GENERATION_NURSERY, TRUE, ctx);
1926 /* walk the finalization queue and move also the objects that need to be
1927 * finalized: use the finalized objects as new roots so the objects they depend
1928 * on are also not reclaimed. As with the roots above, only objects in the nursery
1929 * are marked/copied.
1931 sgen_finalize_in_range (start_addr, end_addr, generation, ctx);
1932 if (generation == GENERATION_OLD)
1933 sgen_finalize_in_range (sgen_get_nursery_start (), sgen_get_nursery_end (), GENERATION_NURSERY, ctx);
1934 /* drain the new stack that might have been created */
1935 SGEN_LOG (6, "Precise scan of gray area post fin");
1936 sgen_drain_gray_stack (-1, ctx);
1939 * This must be done again after processing finalizable objects since CWL slots are cleared only after the key is finalized.
1941 done_with_ephemerons = 0;
1943 done_with_ephemerons = mark_ephemerons_in_range (start_addr, end_addr, ctx);
1944 sgen_drain_gray_stack (-1, ctx);
1946 } while (!done_with_ephemerons);
1949 * Clear ephemeron pairs with unreachable keys.
1950 * We pass the copy func so we can figure out if an array was promoted or not.
1952 clear_unreachable_ephemerons (start_addr, end_addr, ctx);
1955 SGEN_LOG (2, "Finalize queue handling scan for %s generation: %d usecs %d ephemeron rounds", generation_name (generation), TV_ELAPSED (atv, btv), ephemeron_rounds);
1958 * handle disappearing links
1959 * Note we do this after checking the finalization queue because if an object
1960 * survives (at least long enough to be finalized) we don't clear the link.
1961 * This also deals with a possible issue with the monitor reclamation: with the Boehm
1962 * GC a finalized object my lose the monitor because it is cleared before the finalizer is
1965 g_assert (sgen_gray_object_queue_is_empty (queue));
1967 sgen_null_link_in_range (start_addr, end_addr, generation, FALSE, ctx);
1968 if (generation == GENERATION_OLD)
1969 sgen_null_link_in_range (start_addr, end_addr, GENERATION_NURSERY, FALSE, ctx);
1970 if (sgen_gray_object_queue_is_empty (queue))
1972 sgen_drain_gray_stack (-1, ctx);
1975 g_assert (sgen_gray_object_queue_is_empty (queue));
1979 sgen_check_section_scan_starts (GCMemSection *section)
1982 for (i = 0; i < section->num_scan_start; ++i) {
1983 if (section->scan_starts [i]) {
1984 guint size = safe_object_get_size ((MonoObject*) section->scan_starts [i]);
1985 g_assert (size >= sizeof (MonoObject) && size <= MAX_SMALL_OBJ_SIZE);
1991 check_scan_starts (void)
1993 if (!do_scan_starts_check)
1995 sgen_check_section_scan_starts (nursery_section);
1996 major_collector.check_scan_starts ();
2000 scan_from_registered_roots (char *addr_start, char *addr_end, int root_type, ScanCopyContext ctx)
2004 SGEN_HASH_TABLE_FOREACH (&roots_hash [root_type], start_root, root) {
2005 SGEN_LOG (6, "Precise root scan %p-%p (desc: %p)", start_root, root->end_root, (void*)root->root_desc);
2006 precisely_scan_objects_from (start_root, (void**)root->end_root, addr_start, addr_end, root->root_desc, ctx);
2007 } SGEN_HASH_TABLE_FOREACH_END;
2011 sgen_dump_occupied (char *start, char *end, char *section_start)
2013 fprintf (heap_dump_file, "<occupied offset=\"%td\" size=\"%td\"/>\n", start - section_start, end - start);
2017 sgen_dump_section (GCMemSection *section, const char *type)
2019 char *start = section->data;
2020 char *end = section->data + section->size;
2021 char *occ_start = NULL;
2023 char *old_start = NULL; /* just for debugging */
2025 fprintf (heap_dump_file, "<section type=\"%s\" size=\"%lu\">\n", type, (unsigned long)section->size);
2027 while (start < end) {
2031 if (!*(void**)start) {
2033 sgen_dump_occupied (occ_start, start, section->data);
2036 start += sizeof (void*); /* should be ALLOC_ALIGN, really */
2039 g_assert (start < section->next_data);
2044 vt = (GCVTable*)LOAD_VTABLE (start);
2047 size = ALIGN_UP (safe_object_get_size ((MonoObject*) start));
2050 fprintf (heap_dump_file, "<object offset=\"%d\" class=\"%s.%s\" size=\"%d\"/>\n",
2051 start - section->data,
2052 vt->klass->name_space, vt->klass->name,
2060 sgen_dump_occupied (occ_start, start, section->data);
2062 fprintf (heap_dump_file, "</section>\n");
2066 dump_object (MonoObject *obj, gboolean dump_location)
2068 static char class_name [1024];
2070 MonoClass *class = mono_object_class (obj);
2074 * Python's XML parser is too stupid to parse angle brackets
2075 * in strings, so we just ignore them;
2078 while (class->name [i] && j < sizeof (class_name) - 1) {
2079 if (!strchr ("<>\"", class->name [i]))
2080 class_name [j++] = class->name [i];
2083 g_assert (j < sizeof (class_name));
2086 fprintf (heap_dump_file, "<object class=\"%s.%s\" size=\"%d\"",
2087 class->name_space, class_name,
2088 safe_object_get_size (obj));
2089 if (dump_location) {
2090 const char *location;
2091 if (ptr_in_nursery (obj))
2092 location = "nursery";
2093 else if (safe_object_get_size (obj) <= MAX_SMALL_OBJ_SIZE)
2097 fprintf (heap_dump_file, " location=\"%s\"", location);
2099 fprintf (heap_dump_file, "/>\n");
2103 dump_heap (const char *type, int num, const char *reason)
2108 fprintf (heap_dump_file, "<collection type=\"%s\" num=\"%d\"", type, num);
2110 fprintf (heap_dump_file, " reason=\"%s\"", reason);
2111 fprintf (heap_dump_file, ">\n");
2112 fprintf (heap_dump_file, "<other-mem-usage type=\"mempools\" size=\"%ld\"/>\n", mono_mempool_get_bytes_allocated ());
2113 sgen_dump_internal_mem_usage (heap_dump_file);
2114 fprintf (heap_dump_file, "<pinned type=\"stack\" bytes=\"%zu\"/>\n", sgen_pin_stats_get_pinned_byte_count (PIN_TYPE_STACK));
2115 /* fprintf (heap_dump_file, "<pinned type=\"static-data\" bytes=\"%d\"/>\n", pinned_byte_counts [PIN_TYPE_STATIC_DATA]); */
2116 fprintf (heap_dump_file, "<pinned type=\"other\" bytes=\"%zu\"/>\n", sgen_pin_stats_get_pinned_byte_count (PIN_TYPE_OTHER));
2118 fprintf (heap_dump_file, "<pinned-objects>\n");
2119 for (list = sgen_pin_stats_get_object_list (); list; list = list->next)
2120 dump_object (list->obj, TRUE);
2121 fprintf (heap_dump_file, "</pinned-objects>\n");
2123 sgen_dump_section (nursery_section, "nursery");
2125 major_collector.dump_heap (heap_dump_file);
2127 fprintf (heap_dump_file, "<los>\n");
2128 for (bigobj = los_object_list; bigobj; bigobj = bigobj->next)
2129 dump_object ((MonoObject*)bigobj->data, FALSE);
2130 fprintf (heap_dump_file, "</los>\n");
2132 fprintf (heap_dump_file, "</collection>\n");
2136 sgen_register_moved_object (void *obj, void *destination)
2138 g_assert (mono_profiler_events & MONO_PROFILE_GC_MOVES);
2140 /* FIXME: handle this for parallel collector */
2141 g_assert (!sgen_collection_is_parallel ());
2143 if (moved_objects_idx == MOVED_OBJECTS_NUM) {
2144 mono_profiler_gc_moves (moved_objects, moved_objects_idx);
2145 moved_objects_idx = 0;
2147 moved_objects [moved_objects_idx++] = obj;
2148 moved_objects [moved_objects_idx++] = destination;
2154 static gboolean inited = FALSE;
2159 mono_counters_register ("Minor fragment clear", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_minor_pre_collection_fragment_clear);
2160 mono_counters_register ("Minor pinning", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_minor_pinning);
2161 mono_counters_register ("Minor scan remembered set", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_minor_scan_remsets);
2162 mono_counters_register ("Minor scan pinned", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_minor_scan_pinned);
2163 mono_counters_register ("Minor scan registered roots", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_minor_scan_registered_roots);
2164 mono_counters_register ("Minor scan thread data", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_minor_scan_thread_data);
2165 mono_counters_register ("Minor finish gray stack", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_minor_finish_gray_stack);
2166 mono_counters_register ("Minor fragment creation", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_minor_fragment_creation);
2168 mono_counters_register ("Major fragment clear", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_major_pre_collection_fragment_clear);
2169 mono_counters_register ("Major pinning", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_major_pinning);
2170 mono_counters_register ("Major scan pinned", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_major_scan_pinned);
2171 mono_counters_register ("Major scan registered roots", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_major_scan_registered_roots);
2172 mono_counters_register ("Major scan thread data", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_major_scan_thread_data);
2173 mono_counters_register ("Major scan alloc_pinned", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_major_scan_alloc_pinned);
2174 mono_counters_register ("Major scan finalized", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_major_scan_finalized);
2175 mono_counters_register ("Major scan big objects", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_major_scan_big_objects);
2176 mono_counters_register ("Major finish gray stack", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_major_finish_gray_stack);
2177 mono_counters_register ("Major free big objects", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_major_free_bigobjs);
2178 mono_counters_register ("Major LOS sweep", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_major_los_sweep);
2179 mono_counters_register ("Major sweep", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_major_sweep);
2180 mono_counters_register ("Major fragment creation", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_major_fragment_creation);
2182 mono_counters_register ("Number of pinned objects", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_pinned_objects);
2184 #ifdef HEAVY_STATISTICS
2185 mono_counters_register ("WBarrier set field", MONO_COUNTER_GC | MONO_COUNTER_INT, &stat_wbarrier_set_field);
2186 mono_counters_register ("WBarrier set arrayref", MONO_COUNTER_GC | MONO_COUNTER_INT, &stat_wbarrier_set_arrayref);
2187 mono_counters_register ("WBarrier arrayref copy", MONO_COUNTER_GC | MONO_COUNTER_INT, &stat_wbarrier_arrayref_copy);
2188 mono_counters_register ("WBarrier generic store called", MONO_COUNTER_GC | MONO_COUNTER_INT, &stat_wbarrier_generic_store);
2189 mono_counters_register ("WBarrier set root", MONO_COUNTER_GC | MONO_COUNTER_INT, &stat_wbarrier_set_root);
2190 mono_counters_register ("WBarrier value copy", MONO_COUNTER_GC | MONO_COUNTER_INT, &stat_wbarrier_value_copy);
2191 mono_counters_register ("WBarrier object copy", MONO_COUNTER_GC | MONO_COUNTER_INT, &stat_wbarrier_object_copy);
2193 mono_counters_register ("# objects allocated degraded", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_objects_alloced_degraded);
2194 mono_counters_register ("bytes allocated degraded", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_bytes_alloced_degraded);
2196 mono_counters_register ("# copy_object() called (nursery)", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_copy_object_called_nursery);
2197 mono_counters_register ("# objects copied (nursery)", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_objects_copied_nursery);
2198 mono_counters_register ("# copy_object() called (major)", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_copy_object_called_major);
2199 mono_counters_register ("# objects copied (major)", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_objects_copied_major);
2201 mono_counters_register ("# scan_object() called (nursery)", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_scan_object_called_nursery);
2202 mono_counters_register ("# scan_object() called (major)", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_scan_object_called_major);
2204 mono_counters_register ("Slots allocated in vain", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_slots_allocated_in_vain);
2206 mono_counters_register ("# nursery copy_object() failed from space", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_nursery_copy_object_failed_from_space);
2207 mono_counters_register ("# nursery copy_object() failed forwarded", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_nursery_copy_object_failed_forwarded);
2208 mono_counters_register ("# nursery copy_object() failed pinned", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_nursery_copy_object_failed_pinned);
2209 mono_counters_register ("# nursery copy_object() failed to space", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_nursery_copy_object_failed_to_space);
2211 sgen_nursery_allocator_init_heavy_stats ();
2212 sgen_alloc_init_heavy_stats ();
2220 reset_pinned_from_failed_allocation (void)
2222 bytes_pinned_from_failed_allocation = 0;
2226 sgen_set_pinned_from_failed_allocation (mword objsize)
2228 bytes_pinned_from_failed_allocation += objsize;
2232 sgen_collection_is_parallel (void)
2234 switch (current_collection_generation) {
2235 case GENERATION_NURSERY:
2236 return nursery_collection_is_parallel;
2237 case GENERATION_OLD:
2238 return major_collector.is_parallel;
2240 g_error ("Invalid current generation %d", current_collection_generation);
2245 sgen_collection_is_concurrent (void)
2247 switch (current_collection_generation) {
2248 case GENERATION_NURSERY:
2250 case GENERATION_OLD:
2251 return major_collector.is_concurrent;
2253 g_error ("Invalid current generation %d", current_collection_generation);
2258 sgen_concurrent_collection_in_progress (void)
2260 return concurrent_collection_in_progress;
2267 } FinishRememberedSetScanJobData;
2270 job_finish_remembered_set_scan (WorkerData *worker_data, void *job_data_untyped)
2272 FinishRememberedSetScanJobData *job_data = job_data_untyped;
2274 remset.finish_scan_remsets (job_data->heap_start, job_data->heap_end, sgen_workers_get_job_gray_queue (worker_data));
2275 sgen_free_internal_dynamic (job_data, sizeof (FinishRememberedSetScanJobData), INTERNAL_MEM_WORKER_JOB_DATA);
2280 CopyOrMarkObjectFunc copy_or_mark_func;
2281 ScanObjectFunc scan_func;
2285 } ScanFromRegisteredRootsJobData;
2288 job_scan_from_registered_roots (WorkerData *worker_data, void *job_data_untyped)
2290 ScanFromRegisteredRootsJobData *job_data = job_data_untyped;
2291 ScanCopyContext ctx = { job_data->scan_func, job_data->copy_or_mark_func,
2292 sgen_workers_get_job_gray_queue (worker_data) };
2294 scan_from_registered_roots (job_data->heap_start, job_data->heap_end, job_data->root_type, ctx);
2295 sgen_free_internal_dynamic (job_data, sizeof (ScanFromRegisteredRootsJobData), INTERNAL_MEM_WORKER_JOB_DATA);
2302 } ScanThreadDataJobData;
2305 job_scan_thread_data (WorkerData *worker_data, void *job_data_untyped)
2307 ScanThreadDataJobData *job_data = job_data_untyped;
2309 scan_thread_data (job_data->heap_start, job_data->heap_end, TRUE,
2310 sgen_workers_get_job_gray_queue (worker_data));
2311 sgen_free_internal_dynamic (job_data, sizeof (ScanThreadDataJobData), INTERNAL_MEM_WORKER_JOB_DATA);
2316 FinalizeReadyEntry *list;
2317 } ScanFinalizerEntriesJobData;
2320 job_scan_finalizer_entries (WorkerData *worker_data, void *job_data_untyped)
2322 ScanFinalizerEntriesJobData *job_data = job_data_untyped;
2323 ScanCopyContext ctx = { NULL, current_object_ops.copy_or_mark_object, sgen_workers_get_job_gray_queue (worker_data) };
2325 scan_finalizer_entries (job_data->list, ctx);
2326 sgen_free_internal_dynamic (job_data, sizeof (ScanFinalizerEntriesJobData), INTERNAL_MEM_WORKER_JOB_DATA);
2330 job_scan_major_mod_union_cardtable (WorkerData *worker_data, void *job_data_untyped)
2332 g_assert (concurrent_collection_in_progress);
2333 major_collector.scan_card_table (TRUE, sgen_workers_get_job_gray_queue (worker_data));
2337 job_scan_los_mod_union_cardtable (WorkerData *worker_data, void *job_data_untyped)
2339 g_assert (concurrent_collection_in_progress);
2340 sgen_los_scan_card_table (TRUE, sgen_workers_get_job_gray_queue (worker_data));
2344 verify_scan_starts (char *start, char *end)
2348 for (i = 0; i < nursery_section->num_scan_start; ++i) {
2349 char *addr = nursery_section->scan_starts [i];
2350 if (addr > start && addr < end)
2351 SGEN_LOG (1, "NFC-BAD SCAN START [%d] %p for obj [%p %p]", i, addr, start, end);
2356 verify_nursery (void)
2358 char *start, *end, *cur, *hole_start;
2360 if (!do_verify_nursery)
2363 /*This cleans up unused fragments */
2364 sgen_nursery_allocator_prepare_for_pinning ();
2366 hole_start = start = cur = sgen_get_nursery_start ();
2367 end = sgen_get_nursery_end ();
2372 if (!*(void**)cur) {
2373 cur += sizeof (void*);
2377 if (object_is_forwarded (cur))
2378 SGEN_LOG (1, "FORWARDED OBJ %p", cur);
2379 else if (object_is_pinned (cur))
2380 SGEN_LOG (1, "PINNED OBJ %p", cur);
2382 ss = safe_object_get_size ((MonoObject*)cur);
2383 size = ALIGN_UP (safe_object_get_size ((MonoObject*)cur));
2384 verify_scan_starts (cur, cur + size);
2385 if (do_dump_nursery_content) {
2386 if (cur > hole_start)
2387 SGEN_LOG (1, "HOLE [%p %p %d]", hole_start, cur, (int)(cur - hole_start));
2388 SGEN_LOG (1, "OBJ [%p %p %d %d %s %d]", cur, cur + size, (int)size, (int)ss, sgen_safe_name ((MonoObject*)cur), (gpointer)LOAD_VTABLE (cur) == sgen_get_array_fill_vtable ());
2396 * Checks that no objects in the nursery are fowarded or pinned. This
2397 * is a precondition to restarting the mutator while doing a
2398 * concurrent collection. Note that we don't clear fragments because
2399 * we depend on that having happened earlier.
2402 check_nursery_is_clean (void)
2404 char *start, *end, *cur;
2406 start = cur = sgen_get_nursery_start ();
2407 end = sgen_get_nursery_end ();
2412 if (!*(void**)cur) {
2413 cur += sizeof (void*);
2417 g_assert (!object_is_forwarded (cur));
2418 g_assert (!object_is_pinned (cur));
2420 ss = safe_object_get_size ((MonoObject*)cur);
2421 size = ALIGN_UP (safe_object_get_size ((MonoObject*)cur));
2422 verify_scan_starts (cur, cur + size);
2429 init_gray_queue (void)
2431 if (sgen_collection_is_parallel () || sgen_collection_is_concurrent ()) {
2432 sgen_workers_init_distribute_gray_queue ();
2433 sgen_gray_object_queue_init_with_alloc_prepare (&gray_queue, NULL,
2434 gray_queue_redirect, sgen_workers_get_distribute_section_gray_queue ());
2436 sgen_gray_object_queue_init (&gray_queue, NULL);
2439 if (major_collector.is_concurrent) {
2440 sgen_gray_object_queue_init_with_alloc_prepare (&remember_major_objects_gray_queue, NULL,
2441 gray_queue_redirect, sgen_workers_get_distribute_section_gray_queue ());
2443 sgen_gray_object_queue_init_invalid (&remember_major_objects_gray_queue);
2448 * Collect objects in the nursery. Returns whether to trigger a major
2452 collect_nursery (SgenGrayQueue *unpin_queue)
2454 gboolean needs_major;
2455 size_t max_garbage_amount;
2457 FinishRememberedSetScanJobData *frssjd;
2458 ScanFromRegisteredRootsJobData *scrrjd_normal, *scrrjd_wbarrier;
2459 ScanFinalizerEntriesJobData *sfejd_fin_ready, *sfejd_critical_fin;
2460 ScanThreadDataJobData *stdjd;
2461 mword fragment_total;
2462 ScanCopyContext ctx;
2463 TV_DECLARE (all_atv);
2464 TV_DECLARE (all_btv);
2468 if (disable_minor_collections)
2471 MONO_GC_BEGIN (GENERATION_NURSERY);
2472 binary_protocol_collection_begin (stat_minor_gcs, GENERATION_NURSERY);
2476 #ifndef DISABLE_PERFCOUNTERS
2477 mono_perfcounters->gc_collections0++;
2480 current_collection_generation = GENERATION_NURSERY;
2481 if (sgen_collection_is_parallel ())
2482 current_object_ops = sgen_minor_collector.parallel_ops;
2484 current_object_ops = sgen_minor_collector.serial_ops;
2486 reset_pinned_from_failed_allocation ();
2488 check_scan_starts ();
2490 sgen_nursery_alloc_prepare_for_minor ();
2494 nursery_next = sgen_nursery_alloc_get_upper_alloc_bound ();
2495 /* FIXME: optimize later to use the higher address where an object can be present */
2496 nursery_next = MAX (nursery_next, sgen_get_nursery_end ());
2498 SGEN_LOG (1, "Start nursery collection %d %p-%p, size: %d", stat_minor_gcs, sgen_get_nursery_start (), nursery_next, (int)(nursery_next - sgen_get_nursery_start ()));
2499 max_garbage_amount = nursery_next - sgen_get_nursery_start ();
2500 g_assert (nursery_section->size >= max_garbage_amount);
2502 /* world must be stopped already */
2503 TV_GETTIME (all_atv);
2507 time_minor_pre_collection_fragment_clear += TV_ELAPSED (atv, btv);
2509 if (xdomain_checks) {
2510 sgen_clear_nursery_fragments ();
2511 check_for_xdomain_refs ();
2514 nursery_section->next_data = nursery_next;
2516 major_collector.start_nursery_collection ();
2518 sgen_memgov_minor_collection_start ();
2523 gc_stats.minor_gc_count ++;
2525 if (remset.prepare_for_minor_collection)
2526 remset.prepare_for_minor_collection ();
2528 MONO_GC_CHECKPOINT_1 (GENERATION_NURSERY);
2530 sgen_process_fin_stage_entries ();
2531 sgen_process_dislink_stage_entries ();
2533 MONO_GC_CHECKPOINT_2 (GENERATION_NURSERY);
2535 /* pin from pinned handles */
2536 sgen_init_pinning ();
2537 mono_profiler_gc_event (MONO_GC_EVENT_MARK_START, 0);
2538 pin_from_roots (sgen_get_nursery_start (), nursery_next, WORKERS_DISTRIBUTE_GRAY_QUEUE);
2539 /* identify pinned objects */
2540 sgen_optimize_pin_queue (0);
2541 sgen_pinning_setup_section (nursery_section);
2542 ctx.scan_func = NULL;
2543 ctx.copy_func = NULL;
2544 ctx.queue = WORKERS_DISTRIBUTE_GRAY_QUEUE;
2545 sgen_pin_objects_in_section (nursery_section, ctx);
2546 sgen_pinning_trim_queue_to_section (nursery_section);
2549 time_minor_pinning += TV_ELAPSED (btv, atv);
2550 SGEN_LOG (2, "Finding pinned pointers: %d in %d usecs", sgen_get_pinned_count (), TV_ELAPSED (btv, atv));
2551 SGEN_LOG (4, "Start scan with %d pinned objects", sgen_get_pinned_count ());
2553 MONO_GC_CHECKPOINT_3 (GENERATION_NURSERY);
2555 if (whole_heap_check_before_collection) {
2556 sgen_clear_nursery_fragments ();
2557 sgen_check_whole_heap ();
2559 if (consistency_check_at_minor_collection)
2560 sgen_check_consistency ();
2562 sgen_workers_start_all_workers ();
2565 * Perform the sequential part of remembered set scanning.
2566 * This usually involves scanning global information that might later be produced by evacuation.
2568 if (remset.begin_scan_remsets)
2569 remset.begin_scan_remsets (sgen_get_nursery_start (), nursery_next, WORKERS_DISTRIBUTE_GRAY_QUEUE);
2571 sgen_workers_start_marking ();
2573 frssjd = sgen_alloc_internal_dynamic (sizeof (FinishRememberedSetScanJobData), INTERNAL_MEM_WORKER_JOB_DATA, TRUE);
2574 frssjd->heap_start = sgen_get_nursery_start ();
2575 frssjd->heap_end = nursery_next;
2576 sgen_workers_enqueue_job (job_finish_remembered_set_scan, frssjd);
2578 /* we don't have complete write barrier yet, so we scan all the old generation sections */
2580 time_minor_scan_remsets += TV_ELAPSED (atv, btv);
2581 SGEN_LOG (2, "Old generation scan: %d usecs", TV_ELAPSED (atv, btv));
2583 MONO_GC_CHECKPOINT_4 (GENERATION_NURSERY);
2585 if (!sgen_collection_is_parallel ()) {
2586 ctx.scan_func = current_object_ops.scan_object;
2587 ctx.copy_func = NULL;
2588 ctx.queue = &gray_queue;
2589 sgen_drain_gray_stack (-1, ctx);
2592 if (mono_profiler_get_events () & MONO_PROFILE_GC_ROOTS)
2593 report_registered_roots ();
2594 if (mono_profiler_get_events () & MONO_PROFILE_GC_ROOTS)
2595 report_finalizer_roots ();
2597 time_minor_scan_pinned += TV_ELAPSED (btv, atv);
2599 MONO_GC_CHECKPOINT_5 (GENERATION_NURSERY);
2601 /* registered roots, this includes static fields */
2602 scrrjd_normal = sgen_alloc_internal_dynamic (sizeof (ScanFromRegisteredRootsJobData), INTERNAL_MEM_WORKER_JOB_DATA, TRUE);
2603 scrrjd_normal->copy_or_mark_func = current_object_ops.copy_or_mark_object;
2604 scrrjd_normal->scan_func = current_object_ops.scan_object;
2605 scrrjd_normal->heap_start = sgen_get_nursery_start ();
2606 scrrjd_normal->heap_end = nursery_next;
2607 scrrjd_normal->root_type = ROOT_TYPE_NORMAL;
2608 sgen_workers_enqueue_job (job_scan_from_registered_roots, scrrjd_normal);
2610 scrrjd_wbarrier = sgen_alloc_internal_dynamic (sizeof (ScanFromRegisteredRootsJobData), INTERNAL_MEM_WORKER_JOB_DATA, TRUE);
2611 scrrjd_wbarrier->copy_or_mark_func = current_object_ops.copy_or_mark_object;
2612 scrrjd_wbarrier->scan_func = current_object_ops.scan_object;
2613 scrrjd_wbarrier->heap_start = sgen_get_nursery_start ();
2614 scrrjd_wbarrier->heap_end = nursery_next;
2615 scrrjd_wbarrier->root_type = ROOT_TYPE_WBARRIER;
2616 sgen_workers_enqueue_job (job_scan_from_registered_roots, scrrjd_wbarrier);
2619 time_minor_scan_registered_roots += TV_ELAPSED (atv, btv);
2621 MONO_GC_CHECKPOINT_6 (GENERATION_NURSERY);
2624 stdjd = sgen_alloc_internal_dynamic (sizeof (ScanThreadDataJobData), INTERNAL_MEM_WORKER_JOB_DATA, TRUE);
2625 stdjd->heap_start = sgen_get_nursery_start ();
2626 stdjd->heap_end = nursery_next;
2627 sgen_workers_enqueue_job (job_scan_thread_data, stdjd);
2630 time_minor_scan_thread_data += TV_ELAPSED (btv, atv);
2633 MONO_GC_CHECKPOINT_7 (GENERATION_NURSERY);
2635 g_assert (!sgen_collection_is_parallel () && !sgen_collection_is_concurrent ());
2637 if (sgen_collection_is_parallel () || sgen_collection_is_concurrent ())
2638 g_assert (sgen_gray_object_queue_is_empty (&gray_queue));
2640 /* Scan the list of objects ready for finalization. If */
2641 sfejd_fin_ready = sgen_alloc_internal_dynamic (sizeof (ScanFinalizerEntriesJobData), INTERNAL_MEM_WORKER_JOB_DATA, TRUE);
2642 sfejd_fin_ready->list = fin_ready_list;
2643 sgen_workers_enqueue_job (job_scan_finalizer_entries, sfejd_fin_ready);
2645 sfejd_critical_fin = sgen_alloc_internal_dynamic (sizeof (ScanFinalizerEntriesJobData), INTERNAL_MEM_WORKER_JOB_DATA, TRUE);
2646 sfejd_critical_fin->list = critical_fin_list;
2647 sgen_workers_enqueue_job (job_scan_finalizer_entries, sfejd_critical_fin);
2649 MONO_GC_CHECKPOINT_8 (GENERATION_NURSERY);
2651 finish_gray_stack (sgen_get_nursery_start (), nursery_next, GENERATION_NURSERY, &gray_queue);
2653 time_minor_finish_gray_stack += TV_ELAPSED (btv, atv);
2654 mono_profiler_gc_event (MONO_GC_EVENT_MARK_END, 0);
2656 MONO_GC_CHECKPOINT_9 (GENERATION_NURSERY);
2659 * The (single-threaded) finalization code might have done
2660 * some copying/marking so we can only reset the GC thread's
2661 * worker data here instead of earlier when we joined the
2664 sgen_workers_reset_data ();
2666 if (objects_pinned) {
2667 sgen_optimize_pin_queue (0);
2668 sgen_pinning_setup_section (nursery_section);
2671 /* walk the pin_queue, build up the fragment list of free memory, unmark
2672 * pinned objects as we go, memzero() the empty fragments so they are ready for the
2675 mono_profiler_gc_event (MONO_GC_EVENT_RECLAIM_START, 0);
2676 fragment_total = sgen_build_nursery_fragments (nursery_section,
2677 nursery_section->pin_queue_start, nursery_section->pin_queue_num_entries,
2679 if (!fragment_total)
2682 /* Clear TLABs for all threads */
2683 sgen_clear_tlabs ();
2685 mono_profiler_gc_event (MONO_GC_EVENT_RECLAIM_END, 0);
2687 time_minor_fragment_creation += TV_ELAPSED (atv, btv);
2688 SGEN_LOG (2, "Fragment creation: %d usecs, %lu bytes available", TV_ELAPSED (atv, btv), (unsigned long)fragment_total);
2690 if (consistency_check_at_minor_collection)
2691 sgen_check_major_refs ();
2693 major_collector.finish_nursery_collection ();
2695 TV_GETTIME (all_btv);
2696 gc_stats.minor_gc_time_usecs += TV_ELAPSED (all_atv, all_btv);
2699 dump_heap ("minor", stat_minor_gcs - 1, NULL);
2701 /* prepare the pin queue for the next collection */
2702 sgen_finish_pinning ();
2703 if (fin_ready_list || critical_fin_list) {
2704 SGEN_LOG (4, "Finalizer-thread wakeup: ready %d", num_ready_finalizers);
2705 mono_gc_finalize_notify ();
2707 sgen_pin_stats_reset ();
2709 g_assert (sgen_gray_object_queue_is_empty (&gray_queue));
2711 if (remset.finish_minor_collection)
2712 remset.finish_minor_collection ();
2714 check_scan_starts ();
2716 binary_protocol_flush_buffers (FALSE);
2718 sgen_memgov_minor_collection_end ();
2720 /*objects are late pinned because of lack of memory, so a major is a good call*/
2721 needs_major = objects_pinned > 0;
2722 current_collection_generation = -1;
2725 MONO_GC_END (GENERATION_NURSERY);
2726 binary_protocol_collection_end (stat_minor_gcs - 1, GENERATION_NURSERY);
2732 major_copy_or_mark_from_roots (int *old_next_pin_slot, gboolean finish_up_concurrent_mark, gboolean scan_mod_union)
2737 /* FIXME: only use these values for the precise scan
2738 * note that to_space pointers should be excluded anyway...
2740 char *heap_start = NULL;
2741 char *heap_end = (char*)-1;
2742 gboolean profile_roots = mono_profiler_get_events () & MONO_PROFILE_GC_ROOTS;
2743 GCRootReport root_report = { 0 };
2744 ScanFromRegisteredRootsJobData *scrrjd_normal, *scrrjd_wbarrier;
2745 ScanThreadDataJobData *stdjd;
2746 ScanFinalizerEntriesJobData *sfejd_fin_ready, *sfejd_critical_fin;
2747 ScanCopyContext ctx;
2749 if (major_collector.is_concurrent) {
2750 /*This cleans up unused fragments */
2751 sgen_nursery_allocator_prepare_for_pinning ();
2753 if (do_concurrent_checks)
2754 check_nursery_is_clean ();
2756 /* The concurrent collector doesn't touch the nursery. */
2757 sgen_nursery_alloc_prepare_for_major ();
2764 /* Pinning depends on this */
2765 sgen_clear_nursery_fragments ();
2767 if (whole_heap_check_before_collection)
2768 sgen_check_whole_heap ();
2771 time_major_pre_collection_fragment_clear += TV_ELAPSED (atv, btv);
2773 if (!sgen_collection_is_concurrent ())
2774 nursery_section->next_data = sgen_get_nursery_end ();
2775 /* we should also coalesce scanning from sections close to each other
2776 * and deal with pointers outside of the sections later.
2780 *major_collector.have_swept = FALSE;
2782 if (xdomain_checks) {
2783 sgen_clear_nursery_fragments ();
2784 check_for_xdomain_refs ();
2787 if (!major_collector.is_concurrent) {
2788 /* Remsets are not useful for a major collection */
2789 remset.prepare_for_major_collection ();
2792 sgen_process_fin_stage_entries ();
2793 sgen_process_dislink_stage_entries ();
2796 sgen_init_pinning ();
2797 SGEN_LOG (6, "Collecting pinned addresses");
2798 pin_from_roots ((void*)lowest_heap_address, (void*)highest_heap_address, WORKERS_DISTRIBUTE_GRAY_QUEUE);
2799 sgen_optimize_pin_queue (0);
2802 * The concurrent collector doesn't move objects, neither on
2803 * the major heap nor in the nursery, so we can mark even
2804 * before pinning has finished. For the non-concurrent
2805 * collector we start the workers after pinning.
2807 if (major_collector.is_concurrent) {
2808 sgen_workers_start_all_workers ();
2809 sgen_workers_start_marking ();
2813 * pin_queue now contains all candidate pointers, sorted and
2814 * uniqued. We must do two passes now to figure out which
2815 * objects are pinned.
2817 * The first is to find within the pin_queue the area for each
2818 * section. This requires that the pin_queue be sorted. We
2819 * also process the LOS objects and pinned chunks here.
2821 * The second, destructive, pass is to reduce the section
2822 * areas to pointers to the actually pinned objects.
2824 SGEN_LOG (6, "Pinning from sections");
2825 /* first pass for the sections */
2826 sgen_find_section_pin_queue_start_end (nursery_section);
2827 major_collector.find_pin_queue_start_ends (WORKERS_DISTRIBUTE_GRAY_QUEUE);
2828 /* identify possible pointers to the insize of large objects */
2829 SGEN_LOG (6, "Pinning from large objects");
2830 for (bigobj = los_object_list; bigobj; bigobj = bigobj->next) {
2832 if (sgen_find_optimized_pin_queue_area (bigobj->data, (char*)bigobj->data + sgen_los_object_size (bigobj), &dummy)) {
2833 binary_protocol_pin (bigobj->data, (gpointer)LOAD_VTABLE (bigobj->data), safe_object_get_size (((MonoObject*)(bigobj->data))));
2834 if (G_UNLIKELY (MONO_GC_OBJ_PINNED_ENABLED ())) {
2835 MonoVTable *vt = (MonoVTable*)LOAD_VTABLE (bigobj->data);
2836 MONO_GC_OBJ_PINNED ((mword)bigobj->data, sgen_safe_object_get_size ((MonoObject*)bigobj->data), vt->klass->name_space, vt->klass->name, GENERATION_OLD);
2838 if (sgen_los_object_is_pinned (bigobj->data)) {
2839 g_assert (finish_up_concurrent_mark);
2842 sgen_los_pin_object (bigobj->data);
2843 /* FIXME: only enqueue if object has references */
2844 GRAY_OBJECT_ENQUEUE (WORKERS_DISTRIBUTE_GRAY_QUEUE, bigobj->data);
2845 if (G_UNLIKELY (do_pin_stats))
2846 sgen_pin_stats_register_object ((char*) bigobj->data, safe_object_get_size ((MonoObject*) bigobj->data));
2847 SGEN_LOG (6, "Marked large object %p (%s) size: %lu from roots", bigobj->data, safe_name (bigobj->data), (unsigned long)sgen_los_object_size (bigobj));
2850 add_profile_gc_root (&root_report, bigobj->data, MONO_PROFILE_GC_ROOT_PINNING | MONO_PROFILE_GC_ROOT_MISC, 0);
2854 notify_gc_roots (&root_report);
2855 /* second pass for the sections */
2856 ctx.scan_func = concurrent_collection_in_progress ? current_object_ops.scan_object : NULL;
2857 ctx.copy_func = NULL;
2858 ctx.queue = WORKERS_DISTRIBUTE_GRAY_QUEUE;
2859 sgen_pin_objects_in_section (nursery_section, ctx);
2860 major_collector.pin_objects (WORKERS_DISTRIBUTE_GRAY_QUEUE);
2861 if (old_next_pin_slot)
2862 *old_next_pin_slot = sgen_get_pinned_count ();
2865 time_major_pinning += TV_ELAPSED (atv, btv);
2866 SGEN_LOG (2, "Finding pinned pointers: %d in %d usecs", sgen_get_pinned_count (), TV_ELAPSED (atv, btv));
2867 SGEN_LOG (4, "Start scan with %d pinned objects", sgen_get_pinned_count ());
2869 major_collector.init_to_space ();
2871 #ifdef SGEN_DEBUG_INTERNAL_ALLOC
2872 main_gc_thread = mono_native_thread_self ();
2875 if (!major_collector.is_concurrent) {
2876 sgen_workers_start_all_workers ();
2877 sgen_workers_start_marking ();
2880 if (mono_profiler_get_events () & MONO_PROFILE_GC_ROOTS)
2881 report_registered_roots ();
2883 time_major_scan_pinned += TV_ELAPSED (btv, atv);
2885 /* registered roots, this includes static fields */
2886 scrrjd_normal = sgen_alloc_internal_dynamic (sizeof (ScanFromRegisteredRootsJobData), INTERNAL_MEM_WORKER_JOB_DATA, TRUE);
2887 scrrjd_normal->copy_or_mark_func = current_object_ops.copy_or_mark_object;
2888 scrrjd_normal->scan_func = current_object_ops.scan_object;
2889 scrrjd_normal->heap_start = heap_start;
2890 scrrjd_normal->heap_end = heap_end;
2891 scrrjd_normal->root_type = ROOT_TYPE_NORMAL;
2892 sgen_workers_enqueue_job (job_scan_from_registered_roots, scrrjd_normal);
2894 scrrjd_wbarrier = sgen_alloc_internal_dynamic (sizeof (ScanFromRegisteredRootsJobData), INTERNAL_MEM_WORKER_JOB_DATA, TRUE);
2895 scrrjd_wbarrier->copy_or_mark_func = current_object_ops.copy_or_mark_object;
2896 scrrjd_wbarrier->scan_func = current_object_ops.scan_object;
2897 scrrjd_wbarrier->heap_start = heap_start;
2898 scrrjd_wbarrier->heap_end = heap_end;
2899 scrrjd_wbarrier->root_type = ROOT_TYPE_WBARRIER;
2900 sgen_workers_enqueue_job (job_scan_from_registered_roots, scrrjd_wbarrier);
2903 time_major_scan_registered_roots += TV_ELAPSED (atv, btv);
2906 stdjd = sgen_alloc_internal_dynamic (sizeof (ScanThreadDataJobData), INTERNAL_MEM_WORKER_JOB_DATA, TRUE);
2907 stdjd->heap_start = heap_start;
2908 stdjd->heap_end = heap_end;
2909 sgen_workers_enqueue_job (job_scan_thread_data, stdjd);
2912 time_major_scan_thread_data += TV_ELAPSED (btv, atv);
2915 time_major_scan_alloc_pinned += TV_ELAPSED (atv, btv);
2917 if (mono_profiler_get_events () & MONO_PROFILE_GC_ROOTS)
2918 report_finalizer_roots ();
2920 /* scan the list of objects ready for finalization */
2921 sfejd_fin_ready = sgen_alloc_internal_dynamic (sizeof (ScanFinalizerEntriesJobData), INTERNAL_MEM_WORKER_JOB_DATA, TRUE);
2922 sfejd_fin_ready->list = fin_ready_list;
2923 sgen_workers_enqueue_job (job_scan_finalizer_entries, sfejd_fin_ready);
2925 sfejd_critical_fin = sgen_alloc_internal_dynamic (sizeof (ScanFinalizerEntriesJobData), INTERNAL_MEM_WORKER_JOB_DATA, TRUE);
2926 sfejd_critical_fin->list = critical_fin_list;
2927 sgen_workers_enqueue_job (job_scan_finalizer_entries, sfejd_critical_fin);
2929 if (scan_mod_union) {
2930 g_assert (finish_up_concurrent_mark);
2932 /* Mod union card table */
2933 sgen_workers_enqueue_job (job_scan_major_mod_union_cardtable, NULL);
2934 sgen_workers_enqueue_job (job_scan_los_mod_union_cardtable, NULL);
2938 time_major_scan_finalized += TV_ELAPSED (btv, atv);
2939 SGEN_LOG (2, "Root scan: %d usecs", TV_ELAPSED (btv, atv));
2942 time_major_scan_big_objects += TV_ELAPSED (atv, btv);
2944 if (major_collector.is_concurrent) {
2945 /* prepare the pin queue for the next collection */
2946 sgen_finish_pinning ();
2948 sgen_pin_stats_reset ();
2950 if (do_concurrent_checks)
2951 check_nursery_is_clean ();
2956 major_start_collection (int *old_next_pin_slot)
2958 MONO_GC_BEGIN (GENERATION_OLD);
2959 binary_protocol_collection_begin (stat_major_gcs, GENERATION_OLD);
2961 current_collection_generation = GENERATION_OLD;
2962 #ifndef DISABLE_PERFCOUNTERS
2963 mono_perfcounters->gc_collections1++;
2966 g_assert (sgen_section_gray_queue_is_empty (sgen_workers_get_distribute_section_gray_queue ()));
2968 if (major_collector.is_concurrent)
2969 concurrent_collection_in_progress = TRUE;
2971 current_object_ops = major_collector.major_ops;
2973 reset_pinned_from_failed_allocation ();
2975 sgen_memgov_major_collection_start ();
2977 //count_ref_nonref_objs ();
2978 //consistency_check ();
2980 check_scan_starts ();
2983 SGEN_LOG (1, "Start major collection %d", stat_major_gcs);
2985 gc_stats.major_gc_count ++;
2987 if (major_collector.start_major_collection)
2988 major_collector.start_major_collection ();
2990 major_copy_or_mark_from_roots (old_next_pin_slot, FALSE, FALSE);
2994 wait_for_workers_to_finish (void)
2996 g_assert (sgen_gray_object_queue_is_empty (&remember_major_objects_gray_queue));
2998 if (major_collector.is_parallel || major_collector.is_concurrent) {
2999 gray_queue_redirect (&gray_queue);
3000 sgen_workers_join ();
3003 g_assert (sgen_gray_object_queue_is_empty (&gray_queue));
3005 #ifdef SGEN_DEBUG_INTERNAL_ALLOC
3006 main_gc_thread = NULL;
3011 major_finish_collection (const char *reason, int old_next_pin_slot, gboolean scan_mod_union)
3013 LOSObject *bigobj, *prevbo;
3016 char *heap_start = NULL;
3017 char *heap_end = (char*)-1;
3021 if (major_collector.is_concurrent || major_collector.is_parallel)
3022 wait_for_workers_to_finish ();
3024 current_object_ops = major_collector.major_ops;
3026 if (major_collector.is_concurrent) {
3027 major_copy_or_mark_from_roots (NULL, TRUE, scan_mod_union);
3028 wait_for_workers_to_finish ();
3030 g_assert (sgen_gray_object_queue_is_empty (&gray_queue));
3032 if (do_concurrent_checks)
3033 check_nursery_is_clean ();
3037 * The workers have stopped so we need to finish gray queue
3038 * work that might result from finalization in the main GC
3039 * thread. Redirection must therefore be turned off.
3041 sgen_gray_object_queue_disable_alloc_prepare (&gray_queue);
3042 g_assert (sgen_section_gray_queue_is_empty (sgen_workers_get_distribute_section_gray_queue ()));
3044 /* all the objects in the heap */
3045 finish_gray_stack (heap_start, heap_end, GENERATION_OLD, &gray_queue);
3047 time_major_finish_gray_stack += TV_ELAPSED (btv, atv);
3050 * The (single-threaded) finalization code might have done
3051 * some copying/marking so we can only reset the GC thread's
3052 * worker data here instead of earlier when we joined the
3055 sgen_workers_reset_data ();
3057 if (objects_pinned) {
3058 g_assert (!major_collector.is_concurrent);
3060 /*This is slow, but we just OOM'd*/
3061 sgen_pin_queue_clear_discarded_entries (nursery_section, old_next_pin_slot);
3062 sgen_optimize_pin_queue (0);
3063 sgen_find_section_pin_queue_start_end (nursery_section);
3067 reset_heap_boundaries ();
3068 sgen_update_heap_boundaries ((mword)sgen_get_nursery_start (), (mword)sgen_get_nursery_end ());
3070 MONO_GC_SWEEP_BEGIN (GENERATION_OLD, !major_collector.sweeps_lazily);
3072 /* sweep the big objects list */
3074 for (bigobj = los_object_list; bigobj;) {
3075 g_assert (!object_is_pinned (bigobj->data));
3076 if (sgen_los_object_is_pinned (bigobj->data)) {
3077 sgen_los_unpin_object (bigobj->data);
3078 sgen_update_heap_boundaries ((mword)bigobj->data, (mword)bigobj->data + sgen_los_object_size (bigobj));
3081 /* not referenced anywhere, so we can free it */
3083 prevbo->next = bigobj->next;
3085 los_object_list = bigobj->next;
3087 bigobj = bigobj->next;
3088 sgen_los_free_object (to_free);
3092 bigobj = bigobj->next;
3096 time_major_free_bigobjs += TV_ELAPSED (atv, btv);
3101 time_major_los_sweep += TV_ELAPSED (btv, atv);
3103 major_collector.sweep ();
3105 MONO_GC_SWEEP_END (GENERATION_OLD, !major_collector.sweeps_lazily);
3108 time_major_sweep += TV_ELAPSED (atv, btv);
3110 if (!major_collector.is_concurrent) {
3111 /* walk the pin_queue, build up the fragment list of free memory, unmark
3112 * pinned objects as we go, memzero() the empty fragments so they are ready for the
3115 if (!sgen_build_nursery_fragments (nursery_section, nursery_section->pin_queue_start, nursery_section->pin_queue_num_entries, NULL))
3118 /* prepare the pin queue for the next collection */
3119 sgen_finish_pinning ();
3121 /* Clear TLABs for all threads */
3122 sgen_clear_tlabs ();
3124 sgen_pin_stats_reset ();
3128 time_major_fragment_creation += TV_ELAPSED (btv, atv);
3131 dump_heap ("major", stat_major_gcs - 1, reason);
3133 if (fin_ready_list || critical_fin_list) {
3134 SGEN_LOG (4, "Finalizer-thread wakeup: ready %d", num_ready_finalizers);
3135 mono_gc_finalize_notify ();
3138 g_assert (sgen_gray_object_queue_is_empty (&gray_queue));
3140 sgen_memgov_major_collection_end ();
3141 current_collection_generation = -1;
3143 major_collector.finish_major_collection ();
3145 g_assert (sgen_section_gray_queue_is_empty (sgen_workers_get_distribute_section_gray_queue ()));
3147 if (major_collector.is_concurrent)
3148 concurrent_collection_in_progress = FALSE;
3150 check_scan_starts ();
3152 binary_protocol_flush_buffers (FALSE);
3154 //consistency_check ();
3156 MONO_GC_END (GENERATION_OLD);
3157 binary_protocol_collection_end (stat_major_gcs - 1, GENERATION_OLD);
3161 major_do_collection (const char *reason)
3163 TV_DECLARE (all_atv);
3164 TV_DECLARE (all_btv);
3165 int old_next_pin_slot;
3167 if (major_collector.get_and_reset_num_major_objects_marked) {
3168 long long num_marked = major_collector.get_and_reset_num_major_objects_marked ();
3169 g_assert (!num_marked);
3172 /* world must be stopped already */
3173 TV_GETTIME (all_atv);
3175 major_start_collection (&old_next_pin_slot);
3176 major_finish_collection (reason, old_next_pin_slot, FALSE);
3178 TV_GETTIME (all_btv);
3179 gc_stats.major_gc_time_usecs += TV_ELAPSED (all_atv, all_btv);
3181 /* FIXME: also report this to the user, preferably in gc-end. */
3182 if (major_collector.get_and_reset_num_major_objects_marked)
3183 major_collector.get_and_reset_num_major_objects_marked ();
3185 return bytes_pinned_from_failed_allocation > 0;
3188 static gboolean major_do_collection (const char *reason);
3191 major_start_concurrent_collection (const char *reason)
3193 long long num_objects_marked = major_collector.get_and_reset_num_major_objects_marked ();
3195 g_assert (num_objects_marked == 0);
3197 MONO_GC_CONCURRENT_START_BEGIN (GENERATION_OLD);
3199 // FIXME: store reason and pass it when finishing
3200 major_start_collection (NULL);
3202 gray_queue_redirect (&gray_queue);
3203 sgen_workers_wait_for_jobs ();
3205 num_objects_marked = major_collector.get_and_reset_num_major_objects_marked ();
3206 MONO_GC_CONCURRENT_START_END (GENERATION_OLD, num_objects_marked);
3208 current_collection_generation = -1;
3212 major_update_or_finish_concurrent_collection (gboolean force_finish)
3214 SgenGrayQueue unpin_queue;
3215 memset (&unpin_queue, 0, sizeof (unpin_queue));
3217 MONO_GC_CONCURRENT_UPDATE_FINISH_BEGIN (GENERATION_OLD, major_collector.get_and_reset_num_major_objects_marked ());
3219 g_assert (sgen_gray_object_queue_is_empty (&gray_queue));
3220 if (!have_non_collection_major_object_remembers)
3221 g_assert (sgen_gray_object_queue_is_empty (&remember_major_objects_gray_queue));
3223 major_collector.update_cardtable_mod_union ();
3224 sgen_los_update_cardtable_mod_union ();
3226 if (!force_finish && !sgen_workers_all_done ()) {
3227 MONO_GC_CONCURRENT_UPDATE_END (GENERATION_OLD, major_collector.get_and_reset_num_major_objects_marked ());
3231 collect_nursery (&unpin_queue);
3232 redirect_major_object_remembers ();
3234 current_collection_generation = GENERATION_OLD;
3235 major_finish_collection ("finishing", -1, TRUE);
3237 unpin_objects_from_queue (&unpin_queue);
3238 sgen_gray_object_queue_deinit (&unpin_queue);
3240 MONO_GC_CONCURRENT_FINISH_END (GENERATION_OLD, major_collector.get_and_reset_num_major_objects_marked ());
3242 current_collection_generation = -1;
3244 if (whole_heap_check_before_collection)
3245 sgen_check_whole_heap ();
3251 * Ensure an allocation request for @size will succeed by freeing enough memory.
3253 * LOCKING: The GC lock MUST be held.
3256 sgen_ensure_free_space (size_t size)
3258 int generation_to_collect = -1;
3259 const char *reason = NULL;
3262 if (size > SGEN_MAX_SMALL_OBJ_SIZE) {
3263 if (sgen_need_major_collection (size)) {
3264 reason = "LOS overflow";
3265 generation_to_collect = GENERATION_OLD;
3268 if (degraded_mode) {
3269 if (sgen_need_major_collection (size)) {
3270 reason = "Degraded mode overflow";
3271 generation_to_collect = GENERATION_OLD;
3273 } else if (sgen_need_major_collection (size)) {
3274 reason = "Minor allowance";
3275 generation_to_collect = GENERATION_OLD;
3277 generation_to_collect = GENERATION_NURSERY;
3278 reason = "Nursery full";
3282 if (generation_to_collect == -1)
3284 sgen_perform_collection (size, generation_to_collect, reason, generation_to_collect == GENERATION_NURSERY);
3288 sgen_perform_collection (size_t requested_size, int generation_to_collect, const char *reason, gboolean wait_to_finish)
3290 TV_DECLARE (gc_end);
3291 GGTimingInfo infos [2];
3292 int overflow_generation_to_collect = -1;
3293 int oldest_generation_collected = generation_to_collect;
3294 const char *overflow_reason = NULL;
3296 g_assert (generation_to_collect == GENERATION_NURSERY || generation_to_collect == GENERATION_OLD);
3298 if (have_non_collection_major_object_remembers) {
3299 g_assert (concurrent_collection_in_progress);
3300 redirect_major_object_remembers ();
3303 memset (infos, 0, sizeof (infos));
3304 mono_profiler_gc_event (MONO_GC_EVENT_START, generation_to_collect);
3306 infos [0].generation = generation_to_collect;
3307 infos [0].reason = reason;
3308 infos [0].is_overflow = FALSE;
3309 TV_GETTIME (infos [0].total_time);
3310 infos [1].generation = -1;
3312 sgen_stop_world (generation_to_collect);
3314 if (concurrent_collection_in_progress) {
3315 if (major_update_or_finish_concurrent_collection (generation_to_collect == GENERATION_OLD)) {
3316 oldest_generation_collected = GENERATION_OLD;
3321 //FIXME extract overflow reason
3322 if (generation_to_collect == GENERATION_NURSERY) {
3323 if (collect_nursery (NULL)) {
3324 overflow_generation_to_collect = GENERATION_OLD;
3325 overflow_reason = "Minor overflow";
3327 if (concurrent_collection_in_progress) {
3328 redirect_major_object_remembers ();
3329 sgen_workers_wake_up_all ();
3332 SgenGrayQueue unpin_queue;
3333 SgenGrayQueue *unpin_queue_ptr;
3334 memset (&unpin_queue, 0, sizeof (unpin_queue));
3336 if (major_collector.is_concurrent && wait_to_finish)
3337 unpin_queue_ptr = &unpin_queue;
3339 unpin_queue_ptr = NULL;
3341 if (major_collector.is_concurrent) {
3342 g_assert (!concurrent_collection_in_progress);
3343 collect_nursery (unpin_queue_ptr);
3346 if (major_collector.is_concurrent && !wait_to_finish) {
3347 major_start_concurrent_collection (reason);
3348 // FIXME: set infos[0] properly
3351 if (major_do_collection (reason)) {
3352 overflow_generation_to_collect = GENERATION_NURSERY;
3353 overflow_reason = "Excessive pinning";
3357 if (unpin_queue_ptr) {
3358 unpin_objects_from_queue (unpin_queue_ptr);
3359 sgen_gray_object_queue_deinit (unpin_queue_ptr);
3363 TV_GETTIME (gc_end);
3364 infos [0].total_time = SGEN_TV_ELAPSED (infos [0].total_time, gc_end);
3367 if (!major_collector.is_concurrent && overflow_generation_to_collect != -1) {
3368 mono_profiler_gc_event (MONO_GC_EVENT_START, overflow_generation_to_collect);
3369 infos [1].generation = overflow_generation_to_collect;
3370 infos [1].reason = overflow_reason;
3371 infos [1].is_overflow = TRUE;
3372 infos [1].total_time = gc_end;
3374 if (overflow_generation_to_collect == GENERATION_NURSERY)
3375 collect_nursery (NULL);
3377 major_do_collection (overflow_reason);
3379 TV_GETTIME (gc_end);
3380 infos [1].total_time = SGEN_TV_ELAPSED (infos [1].total_time, gc_end);
3382 /* keep events symmetric */
3383 mono_profiler_gc_event (MONO_GC_EVENT_END, overflow_generation_to_collect);
3385 oldest_generation_collected = MAX (oldest_generation_collected, overflow_generation_to_collect);
3388 SGEN_LOG (2, "Heap size: %lu, LOS size: %lu", (unsigned long)mono_gc_get_heap_size (), (unsigned long)los_memory_usage);
3390 /* this also sets the proper pointers for the next allocation */
3391 if (generation_to_collect == GENERATION_NURSERY && !sgen_can_alloc_size (requested_size)) {
3392 /* TypeBuilder and MonoMethod are killing mcs with fragmentation */
3393 SGEN_LOG (1, "nursery collection didn't find enough room for %zd alloc (%d pinned)", requested_size, sgen_get_pinned_count ());
3394 sgen_dump_pin_queue ();
3399 g_assert (sgen_gray_object_queue_is_empty (&gray_queue));
3400 g_assert (sgen_gray_object_queue_is_empty (&remember_major_objects_gray_queue));
3402 sgen_restart_world (oldest_generation_collected, infos);
3404 mono_profiler_gc_event (MONO_GC_EVENT_END, generation_to_collect);
3408 * ######################################################################
3409 * ######## Memory allocation from the OS
3410 * ######################################################################
3411 * This section of code deals with getting memory from the OS and
3412 * allocating memory for GC-internal data structures.
3413 * Internal memory can be handled with a freelist for small objects.
3419 G_GNUC_UNUSED static void
3420 report_internal_mem_usage (void)
3422 printf ("Internal memory usage:\n");
3423 sgen_report_internal_mem_usage ();
3424 printf ("Pinned memory usage:\n");
3425 major_collector.report_pinned_memory_usage ();
3429 * ######################################################################
3430 * ######## Finalization support
3431 * ######################################################################
3435 * If the object has been forwarded it means it's still referenced from a root.
3436 * If it is pinned it's still alive as well.
3437 * A LOS object is only alive if we have pinned it.
3438 * Return TRUE if @obj is ready to be finalized.
3440 static inline gboolean
3441 sgen_is_object_alive (void *object)
3445 if (ptr_in_nursery (object))
3446 return sgen_nursery_is_object_alive (object);
3447 /* Oldgen objects can be pinned and forwarded too */
3448 if (SGEN_OBJECT_IS_PINNED (object) || SGEN_OBJECT_IS_FORWARDED (object))
3452 * FIXME: major_collector.is_object_live() also calculates the
3453 * size. Avoid the double calculation.
3455 objsize = SGEN_ALIGN_UP (sgen_safe_object_get_size ((MonoObject*)object));
3456 if (objsize > SGEN_MAX_SMALL_OBJ_SIZE)
3457 return sgen_los_object_is_pinned (object);
3459 return major_collector.is_object_live (object);
3463 sgen_gc_is_object_ready_for_finalization (void *object)
3465 return !sgen_is_object_alive (object);
3469 has_critical_finalizer (MonoObject *obj)
3473 if (!mono_defaults.critical_finalizer_object)
3476 class = ((MonoVTable*)LOAD_VTABLE (obj))->klass;
3478 return mono_class_has_parent_fast (class, mono_defaults.critical_finalizer_object);
3482 sgen_queue_finalization_entry (MonoObject *obj)
3484 FinalizeReadyEntry *entry = sgen_alloc_internal (INTERNAL_MEM_FINALIZE_READY_ENTRY);
3485 gboolean critical = has_critical_finalizer (obj);
3486 entry->object = obj;
3488 entry->next = critical_fin_list;
3489 critical_fin_list = entry;
3491 entry->next = fin_ready_list;
3492 fin_ready_list = entry;
3495 if (G_UNLIKELY (MONO_GC_FINALIZE_ENQUEUE_ENABLED ())) {
3496 int gen = sgen_ptr_in_nursery (obj) ? GENERATION_NURSERY : GENERATION_OLD;
3497 MonoVTable *vt = (MonoVTable*)LOAD_VTABLE (obj);
3498 MONO_GC_FINALIZE_ENQUEUE ((mword)obj, sgen_safe_object_get_size (obj),
3499 vt->klass->name_space, vt->klass->name, gen, critical);
3504 object_is_reachable (char *object, char *start, char *end)
3506 /*This happens for non nursery objects during minor collections. We just treat all objects as alive.*/
3507 if (object < start || object >= end)
3510 return sgen_is_object_alive (object);
3514 sgen_object_is_live (void *obj)
3516 if (ptr_in_nursery (obj))
3517 return object_is_pinned (obj);
3518 /* FIXME This is semantically wrong! All tenured object are considered alive during a nursery collection. */
3519 if (current_collection_generation == GENERATION_NURSERY)
3521 return major_collector.is_object_live (obj);
3524 /* LOCKING: requires that the GC lock is held */
3526 null_ephemerons_for_domain (MonoDomain *domain)
3528 EphemeronLinkNode *current = ephemeron_list, *prev = NULL;
3531 MonoObject *object = (MonoObject*)current->array;
3533 if (object && !object->vtable) {
3534 EphemeronLinkNode *tmp = current;
3537 prev->next = current->next;
3539 ephemeron_list = current->next;
3541 current = current->next;
3542 sgen_free_internal (tmp, INTERNAL_MEM_EPHEMERON_LINK);
3545 current = current->next;
3550 /* LOCKING: requires that the GC lock is held */
3552 clear_unreachable_ephemerons (char *start, char *end, ScanCopyContext ctx)
3554 CopyOrMarkObjectFunc copy_func = ctx.copy_func;
3555 GrayQueue *queue = ctx.queue;
3556 int was_in_nursery, was_promoted;
3557 EphemeronLinkNode *current = ephemeron_list, *prev = NULL;
3559 Ephemeron *cur, *array_end;
3563 char *object = current->array;
3565 if (!object_is_reachable (object, start, end)) {
3566 EphemeronLinkNode *tmp = current;
3568 SGEN_LOG (5, "Dead Ephemeron array at %p", object);
3571 prev->next = current->next;
3573 ephemeron_list = current->next;
3575 current = current->next;
3576 sgen_free_internal (tmp, INTERNAL_MEM_EPHEMERON_LINK);
3581 was_in_nursery = ptr_in_nursery (object);
3582 copy_func ((void**)&object, queue);
3583 current->array = object;
3585 /*The array was promoted, add global remsets for key/values left behind in nursery.*/
3586 was_promoted = was_in_nursery && !ptr_in_nursery (object);
3588 SGEN_LOG (5, "Clearing unreachable entries for ephemeron array at %p", object);
3590 array = (MonoArray*)object;
3591 cur = mono_array_addr (array, Ephemeron, 0);
3592 array_end = cur + mono_array_length_fast (array);
3593 tombstone = (char*)((MonoVTable*)LOAD_VTABLE (object))->domain->ephemeron_tombstone;
3595 for (; cur < array_end; ++cur) {
3596 char *key = (char*)cur->key;
3598 if (!key || key == tombstone)
3601 SGEN_LOG (5, "[%td] key %p (%s) value %p (%s)", cur - mono_array_addr (array, Ephemeron, 0),
3602 key, object_is_reachable (key, start, end) ? "reachable" : "unreachable",
3603 cur->value, cur->value && object_is_reachable (cur->value, start, end) ? "reachable" : "unreachable");
3605 if (!object_is_reachable (key, start, end)) {
3606 cur->key = tombstone;
3612 if (ptr_in_nursery (key)) {/*key was not promoted*/
3613 SGEN_LOG (5, "\tAdded remset to key %p", key);
3614 sgen_add_to_global_remset (&cur->key);
3616 if (ptr_in_nursery (cur->value)) {/*value was not promoted*/
3617 SGEN_LOG (5, "\tAdded remset to value %p", cur->value);
3618 sgen_add_to_global_remset (&cur->value);
3623 current = current->next;
3627 /* LOCKING: requires that the GC lock is held */
3629 mark_ephemerons_in_range (char *start, char *end, ScanCopyContext ctx)
3631 CopyOrMarkObjectFunc copy_func = ctx.copy_func;
3632 GrayQueue *queue = ctx.queue;
3633 int nothing_marked = 1;
3634 EphemeronLinkNode *current = ephemeron_list;
3636 Ephemeron *cur, *array_end;
3639 for (current = ephemeron_list; current; current = current->next) {
3640 char *object = current->array;
3641 SGEN_LOG (5, "Ephemeron array at %p", object);
3644 For now we process all ephemerons during all collections.
3645 Ideally we should use remset information to partially scan those
3647 We already emit write barriers for Ephemeron fields, it's
3648 just that we don't process them.
3650 /*if (object < start || object >= end)
3653 /*It has to be alive*/
3654 if (!object_is_reachable (object, start, end)) {
3655 SGEN_LOG (5, "\tnot reachable");
3659 copy_func ((void**)&object, queue);
3661 array = (MonoArray*)object;
3662 cur = mono_array_addr (array, Ephemeron, 0);
3663 array_end = cur + mono_array_length_fast (array);
3664 tombstone = (char*)((MonoVTable*)LOAD_VTABLE (object))->domain->ephemeron_tombstone;
3666 for (; cur < array_end; ++cur) {
3667 char *key = cur->key;
3669 if (!key || key == tombstone)
3672 SGEN_LOG (5, "[%td] key %p (%s) value %p (%s)", cur - mono_array_addr (array, Ephemeron, 0),
3673 key, object_is_reachable (key, start, end) ? "reachable" : "unreachable",
3674 cur->value, cur->value && object_is_reachable (cur->value, start, end) ? "reachable" : "unreachable");
3676 if (object_is_reachable (key, start, end)) {
3677 char *value = cur->value;
3679 copy_func ((void**)&cur->key, queue);
3681 if (!object_is_reachable (value, start, end))
3683 copy_func ((void**)&cur->value, queue);
3689 SGEN_LOG (5, "Ephemeron run finished. Is it done %d", nothing_marked);
3690 return nothing_marked;
3694 mono_gc_invoke_finalizers (void)
3696 FinalizeReadyEntry *entry = NULL;
3697 gboolean entry_is_critical = FALSE;
3700 /* FIXME: batch to reduce lock contention */
3701 while (fin_ready_list || critical_fin_list) {
3705 FinalizeReadyEntry **list = entry_is_critical ? &critical_fin_list : &fin_ready_list;
3707 /* We have finalized entry in the last
3708 interation, now we need to remove it from
3711 *list = entry->next;
3713 FinalizeReadyEntry *e = *list;
3714 while (e->next != entry)
3716 e->next = entry->next;
3718 sgen_free_internal (entry, INTERNAL_MEM_FINALIZE_READY_ENTRY);
3722 /* Now look for the first non-null entry. */
3723 for (entry = fin_ready_list; entry && !entry->object; entry = entry->next)
3726 entry_is_critical = FALSE;
3728 entry_is_critical = TRUE;
3729 for (entry = critical_fin_list; entry && !entry->object; entry = entry->next)
3734 g_assert (entry->object);
3735 num_ready_finalizers--;
3736 obj = entry->object;
3737 entry->object = NULL;
3738 SGEN_LOG (7, "Finalizing object %p (%s)", obj, safe_name (obj));
3746 g_assert (entry->object == NULL);
3748 /* the object is on the stack so it is pinned */
3749 /*g_print ("Calling finalizer for object: %p (%s)\n", entry->object, safe_name (entry->object));*/
3750 mono_gc_run_finalize (obj, NULL);
3757 mono_gc_pending_finalizers (void)
3759 return fin_ready_list || critical_fin_list;
3763 * ######################################################################
3764 * ######## registered roots support
3765 * ######################################################################
3769 * We do not coalesce roots.
3772 mono_gc_register_root_inner (char *start, size_t size, void *descr, int root_type)
3774 RootRecord new_root;
3777 for (i = 0; i < ROOT_TYPE_NUM; ++i) {
3778 RootRecord *root = sgen_hash_table_lookup (&roots_hash [i], start);
3779 /* we allow changing the size and the descriptor (for thread statics etc) */
3781 size_t old_size = root->end_root - start;
3782 root->end_root = start + size;
3783 g_assert (((root->root_desc != 0) && (descr != NULL)) ||
3784 ((root->root_desc == 0) && (descr == NULL)));
3785 root->root_desc = (mword)descr;
3787 roots_size -= old_size;
3793 new_root.end_root = start + size;
3794 new_root.root_desc = (mword)descr;
3796 sgen_hash_table_replace (&roots_hash [root_type], start, &new_root, NULL);
3799 SGEN_LOG (3, "Added root for range: %p-%p, descr: %p (%d/%d bytes)", start, new_root.end_root, descr, (int)size, (int)roots_size);
3806 mono_gc_register_root (char *start, size_t size, void *descr)
3808 return mono_gc_register_root_inner (start, size, descr, descr ? ROOT_TYPE_NORMAL : ROOT_TYPE_PINNED);
3812 mono_gc_register_root_wbarrier (char *start, size_t size, void *descr)
3814 return mono_gc_register_root_inner (start, size, descr, ROOT_TYPE_WBARRIER);
3818 mono_gc_deregister_root (char* addr)
3824 for (root_type = 0; root_type < ROOT_TYPE_NUM; ++root_type) {
3825 if (sgen_hash_table_remove (&roots_hash [root_type], addr, &root))
3826 roots_size -= (root.end_root - addr);
3832 * ######################################################################
3833 * ######## Thread handling (stop/start code)
3834 * ######################################################################
3837 unsigned int sgen_global_stop_count = 0;
3840 sgen_fill_thread_info_for_suspend (SgenThreadInfo *info)
3842 if (remset.fill_thread_info_for_suspend)
3843 remset.fill_thread_info_for_suspend (info);
3847 sgen_get_current_collection_generation (void)
3849 return current_collection_generation;
3853 mono_gc_set_gc_callbacks (MonoGCCallbacks *callbacks)
3855 gc_callbacks = *callbacks;
3859 mono_gc_get_gc_callbacks ()
3861 return &gc_callbacks;
3864 /* Variables holding start/end nursery so it won't have to be passed at every call */
3865 static void *scan_area_arg_start, *scan_area_arg_end;
3868 mono_gc_conservatively_scan_area (void *start, void *end)
3870 conservatively_pin_objects_from (start, end, scan_area_arg_start, scan_area_arg_end, PIN_TYPE_STACK);
3874 mono_gc_scan_object (void *obj)
3876 UserCopyOrMarkData *data = mono_native_tls_get_value (user_copy_or_mark_key);
3877 current_object_ops.copy_or_mark_object (&obj, data->queue);
3882 * Mark from thread stacks and registers.
3885 scan_thread_data (void *start_nursery, void *end_nursery, gboolean precise, GrayQueue *queue)
3887 SgenThreadInfo *info;
3889 scan_area_arg_start = start_nursery;
3890 scan_area_arg_end = end_nursery;
3892 FOREACH_THREAD (info) {
3894 SGEN_LOG (3, "Skipping dead thread %p, range: %p-%p, size: %td", info, info->stack_start, info->stack_end, (char*)info->stack_end - (char*)info->stack_start);
3897 if (info->gc_disabled) {
3898 SGEN_LOG (3, "GC disabled for thread %p, range: %p-%p, size: %td", info, info->stack_start, info->stack_end, (char*)info->stack_end - (char*)info->stack_start);
3902 if (!info->joined_stw) {
3903 SGEN_LOG (3, "Skipping thread not seen in STW %p, range: %p-%p, size: %td", info, info->stack_start, info->stack_end, (char*)info->stack_end - (char*)info->stack_start);
3907 SGEN_LOG (3, "Scanning thread %p, range: %p-%p, size: %td, pinned=%d", info, info->stack_start, info->stack_end, (char*)info->stack_end - (char*)info->stack_start, sgen_get_pinned_count ());
3908 if (!info->thread_is_dying) {
3909 if (gc_callbacks.thread_mark_func && !conservative_stack_mark) {
3910 UserCopyOrMarkData data = { NULL, queue };
3911 set_user_copy_or_mark_data (&data);
3912 gc_callbacks.thread_mark_func (info->runtime_data, info->stack_start, info->stack_end, precise);
3913 set_user_copy_or_mark_data (NULL);
3914 } else if (!precise) {
3915 if (!conservative_stack_mark) {
3916 fprintf (stderr, "Precise stack mark not supported - disabling.\n");
3917 conservative_stack_mark = TRUE;
3919 conservatively_pin_objects_from (info->stack_start, info->stack_end, start_nursery, end_nursery, PIN_TYPE_STACK);
3923 if (!info->thread_is_dying && !precise) {
3925 conservatively_pin_objects_from ((void**)&info->ctx, (void**)&info->ctx + ARCH_NUM_REGS,
3926 start_nursery, end_nursery, PIN_TYPE_STACK);
3928 conservatively_pin_objects_from (&info->regs, &info->regs + ARCH_NUM_REGS,
3929 start_nursery, end_nursery, PIN_TYPE_STACK);
3932 } END_FOREACH_THREAD
3936 ptr_on_stack (void *ptr)
3938 gpointer stack_start = &stack_start;
3939 SgenThreadInfo *info = mono_thread_info_current ();
3941 if (ptr >= stack_start && ptr < (gpointer)info->stack_end)
3947 sgen_thread_register (SgenThreadInfo* info, void *addr)
3949 #ifndef HAVE_KW_THREAD
3950 SgenThreadInfo *__thread_info__ = info;
3954 #ifndef HAVE_KW_THREAD
3955 info->tlab_start = info->tlab_next = info->tlab_temp_end = info->tlab_real_end = NULL;
3957 g_assert (!mono_native_tls_get_value (thread_info_key));
3958 mono_native_tls_set_value (thread_info_key, info);
3960 sgen_thread_info = info;
3963 #if !defined(__MACH__)
3964 info->stop_count = -1;
3968 info->joined_stw = FALSE;
3969 info->doing_handshake = FALSE;
3970 info->thread_is_dying = FALSE;
3971 info->stack_start = NULL;
3972 info->store_remset_buffer_addr = &STORE_REMSET_BUFFER;
3973 info->store_remset_buffer_index_addr = &STORE_REMSET_BUFFER_INDEX;
3974 info->stopped_ip = NULL;
3975 info->stopped_domain = NULL;
3977 memset (&info->ctx, 0, sizeof (MonoContext));
3979 memset (&info->regs, 0, sizeof (info->regs));
3982 sgen_init_tlab_info (info);
3984 binary_protocol_thread_register ((gpointer)mono_thread_info_get_tid (info));
3986 #ifdef HAVE_KW_THREAD
3987 store_remset_buffer_index_addr = &store_remset_buffer_index;
3990 /* try to get it with attributes first */
3991 #if defined(HAVE_PTHREAD_GETATTR_NP) && defined(HAVE_PTHREAD_ATTR_GETSTACK)
3995 pthread_attr_t attr;
3996 pthread_getattr_np (pthread_self (), &attr);
3997 pthread_attr_getstack (&attr, &sstart, &size);
3998 info->stack_start_limit = sstart;
3999 info->stack_end = (char*)sstart + size;
4000 pthread_attr_destroy (&attr);
4002 #elif defined(HAVE_PTHREAD_GET_STACKSIZE_NP) && defined(HAVE_PTHREAD_GET_STACKADDR_NP)
4003 info->stack_end = (char*)pthread_get_stackaddr_np (pthread_self ());
4004 info->stack_start_limit = (char*)info->stack_end - pthread_get_stacksize_np (pthread_self ());
4007 /* FIXME: we assume the stack grows down */
4008 gsize stack_bottom = (gsize)addr;
4009 stack_bottom += 4095;
4010 stack_bottom &= ~4095;
4011 info->stack_end = (char*)stack_bottom;
4015 #ifdef HAVE_KW_THREAD
4016 stack_end = info->stack_end;
4019 if (remset.register_thread)
4020 remset.register_thread (info);
4022 SGEN_LOG (3, "registered thread %p (%p) stack end %p", info, (gpointer)mono_thread_info_get_tid (info), info->stack_end);
4024 if (gc_callbacks.thread_attach_func)
4025 info->runtime_data = gc_callbacks.thread_attach_func ();
4032 sgen_wbarrier_cleanup_thread (SgenThreadInfo *p)
4034 if (remset.cleanup_thread)
4035 remset.cleanup_thread (p);
4039 sgen_thread_unregister (SgenThreadInfo *p)
4041 /* If a delegate is passed to native code and invoked on a thread we dont
4042 * know about, the jit will register it with mono_jit_thread_attach, but
4043 * we have no way of knowing when that thread goes away. SGen has a TSD
4044 * so we assume that if the domain is still registered, we can detach
4047 if (mono_domain_get ())
4048 mono_thread_detach (mono_thread_current ());
4050 p->thread_is_dying = TRUE;
4053 There is a race condition between a thread finishing executing and been removed
4054 from the GC thread set.
4055 This happens on posix systems when TLS data is been cleaned-up, libpthread will
4056 set the thread_info slot to NULL before calling the cleanup function. This
4057 opens a window in which the thread is registered but has a NULL TLS.
4059 The suspend signal handler needs TLS data to know where to store thread state
4060 data or otherwise it will simply ignore the thread.
4062 This solution works because the thread doing STW will wait until all threads been
4063 suspended handshake back, so there is no race between the doing_hankshake test
4064 and the suspend_thread call.
4066 This is not required on systems that do synchronous STW as those can deal with
4067 the above race at suspend time.
4069 FIXME: I believe we could avoid this by using mono_thread_info_lookup when
4070 mono_thread_info_current returns NULL. Or fix mono_thread_info_lookup to do so.
4072 #if (defined(__MACH__) && MONO_MACH_ARCH_SUPPORTED) || !defined(HAVE_PTHREAD_KILL)
4075 while (!TRYLOCK_GC) {
4076 if (!sgen_park_current_thread_if_doing_handshake (p))
4082 binary_protocol_thread_unregister ((gpointer)mono_thread_info_get_tid (p));
4083 SGEN_LOG (3, "unregister thread %p (%p)", p, (gpointer)mono_thread_info_get_tid (p));
4085 if (gc_callbacks.thread_detach_func) {
4086 gc_callbacks.thread_detach_func (p->runtime_data);
4087 p->runtime_data = NULL;
4089 sgen_wbarrier_cleanup_thread (p);
4091 mono_threads_unregister_current_thread (p);
4097 sgen_thread_attach (SgenThreadInfo *info)
4100 /*this is odd, can we get attached before the gc is inited?*/
4104 if (gc_callbacks.thread_attach_func && !info->runtime_data)
4105 info->runtime_data = gc_callbacks.thread_attach_func ();
4108 mono_gc_register_thread (void *baseptr)
4110 return mono_thread_info_attach (baseptr) != NULL;
4114 * mono_gc_set_stack_end:
4116 * Set the end of the current threads stack to STACK_END. The stack space between
4117 * STACK_END and the real end of the threads stack will not be scanned during collections.
4120 mono_gc_set_stack_end (void *stack_end)
4122 SgenThreadInfo *info;
4125 info = mono_thread_info_current ();
4127 g_assert (stack_end < info->stack_end);
4128 info->stack_end = stack_end;
4133 #if USE_PTHREAD_INTERCEPT
4137 mono_gc_pthread_create (pthread_t *new_thread, const pthread_attr_t *attr, void *(*start_routine)(void *), void *arg)
4139 return pthread_create (new_thread, attr, start_routine, arg);
4143 mono_gc_pthread_join (pthread_t thread, void **retval)
4145 return pthread_join (thread, retval);
4149 mono_gc_pthread_detach (pthread_t thread)
4151 return pthread_detach (thread);
4155 mono_gc_pthread_exit (void *retval)
4157 pthread_exit (retval);
4160 #endif /* USE_PTHREAD_INTERCEPT */
4163 * ######################################################################
4164 * ######## Write barriers
4165 * ######################################################################
4169 * Note: the write barriers first do the needed GC work and then do the actual store:
4170 * this way the value is visible to the conservative GC scan after the write barrier
4171 * itself. If a GC interrupts the barrier in the middle, value will be kept alive by
4172 * the conservative scan, otherwise by the remembered set scan.
4175 mono_gc_wbarrier_set_field (MonoObject *obj, gpointer field_ptr, MonoObject* value)
4177 HEAVY_STAT (++stat_wbarrier_set_field);
4178 if (ptr_in_nursery (field_ptr)) {
4179 *(void**)field_ptr = value;
4182 SGEN_LOG (8, "Adding remset at %p", field_ptr);
4184 binary_protocol_wbarrier (field_ptr, value, value->vtable);
4186 remset.wbarrier_set_field (obj, field_ptr, value);
4190 mono_gc_wbarrier_set_arrayref (MonoArray *arr, gpointer slot_ptr, MonoObject* value)
4192 HEAVY_STAT (++stat_wbarrier_set_arrayref);
4193 if (ptr_in_nursery (slot_ptr)) {
4194 *(void**)slot_ptr = value;
4197 SGEN_LOG (8, "Adding remset at %p", slot_ptr);
4199 binary_protocol_wbarrier (slot_ptr, value, value->vtable);
4201 remset.wbarrier_set_arrayref (arr, slot_ptr, value);
4205 mono_gc_wbarrier_arrayref_copy (gpointer dest_ptr, gpointer src_ptr, int count)
4207 HEAVY_STAT (++stat_wbarrier_arrayref_copy);
4208 /*This check can be done without taking a lock since dest_ptr array is pinned*/
4209 if (ptr_in_nursery (dest_ptr) || count <= 0) {
4210 mono_gc_memmove (dest_ptr, src_ptr, count * sizeof (gpointer));
4214 #ifdef SGEN_BINARY_PROTOCOL
4217 for (i = 0; i < count; ++i) {
4218 gpointer dest = (gpointer*)dest_ptr + i;
4219 gpointer obj = *((gpointer*)src_ptr + i);
4221 binary_protocol_wbarrier (dest, obj, (gpointer)LOAD_VTABLE (obj));
4226 remset.wbarrier_arrayref_copy (dest_ptr, src_ptr, count);
4229 static char *found_obj;
4232 find_object_for_ptr_callback (char *obj, size_t size, void *user_data)
4234 char *ptr = user_data;
4236 if (ptr >= obj && ptr < obj + size) {
4237 g_assert (!found_obj);
4242 /* for use in the debugger */
4243 char* find_object_for_ptr (char *ptr);
4245 find_object_for_ptr (char *ptr)
4247 if (ptr >= nursery_section->data && ptr < nursery_section->end_data) {
4249 sgen_scan_area_with_callback (nursery_section->data, nursery_section->end_data,
4250 find_object_for_ptr_callback, ptr, TRUE);
4256 sgen_los_iterate_objects (find_object_for_ptr_callback, ptr);
4261 * Very inefficient, but this is debugging code, supposed to
4262 * be called from gdb, so we don't care.
4265 major_collector.iterate_objects (TRUE, TRUE, find_object_for_ptr_callback, ptr);
4270 mono_gc_wbarrier_generic_nostore (gpointer ptr)
4274 HEAVY_STAT (++stat_wbarrier_generic_store);
4276 #ifdef XDOMAIN_CHECKS_IN_WBARRIER
4277 /* FIXME: ptr_in_heap must be called with the GC lock held */
4278 if (xdomain_checks && *(MonoObject**)ptr && ptr_in_heap (ptr)) {
4279 char *start = find_object_for_ptr (ptr);
4280 MonoObject *value = *(MonoObject**)ptr;
4284 MonoObject *obj = (MonoObject*)start;
4285 if (obj->vtable->domain != value->vtable->domain)
4286 g_assert (is_xdomain_ref_allowed (ptr, start, obj->vtable->domain));
4292 obj = *(gpointer*)ptr;
4294 binary_protocol_wbarrier (ptr, obj, (gpointer)LOAD_VTABLE (obj));
4296 if (ptr_in_nursery (ptr) || ptr_on_stack (ptr)) {
4297 SGEN_LOG (8, "Skipping remset at %p", ptr);
4302 * We need to record old->old pointer locations for the
4303 * concurrent collector.
4305 if (!ptr_in_nursery (obj) && !concurrent_collection_in_progress) {
4306 SGEN_LOG (8, "Skipping remset at %p", ptr);
4310 SGEN_LOG (8, "Adding remset at %p", ptr);
4312 remset.wbarrier_generic_nostore (ptr);
4316 mono_gc_wbarrier_generic_store (gpointer ptr, MonoObject* value)
4318 SGEN_LOG (8, "Wbarrier store at %p to %p (%s)", ptr, value, value ? safe_name (value) : "null");
4319 *(void**)ptr = value;
4320 if (ptr_in_nursery (value))
4321 mono_gc_wbarrier_generic_nostore (ptr);
4322 sgen_dummy_use (value);
4325 void mono_gc_wbarrier_value_copy_bitmap (gpointer _dest, gpointer _src, int size, unsigned bitmap)
4327 mword *dest = _dest;
4332 mono_gc_wbarrier_generic_store (dest, (MonoObject*)*src);
4337 size -= SIZEOF_VOID_P;
4342 #ifdef SGEN_BINARY_PROTOCOL
4344 #define HANDLE_PTR(ptr,obj) do { \
4345 gpointer o = *(gpointer*)(ptr); \
4347 gpointer d = ((char*)dest) + ((char*)(ptr) - (char*)(obj)); \
4348 binary_protocol_wbarrier (d, o, (gpointer) LOAD_VTABLE (o)); \
4353 scan_object_for_binary_protocol_copy_wbarrier (gpointer dest, char *start, mword desc)
4355 #define SCAN_OBJECT_NOVTABLE
4356 #include "sgen-scan-object.h"
4361 mono_gc_wbarrier_value_copy (gpointer dest, gpointer src, int count, MonoClass *klass)
4363 HEAVY_STAT (++stat_wbarrier_value_copy);
4364 g_assert (klass->valuetype);
4366 SGEN_LOG (8, "Adding value remset at %p, count %d, descr %p for class %s (%p)", dest, count, klass->gc_descr, klass->name, klass);
4368 if (ptr_in_nursery (dest) || ptr_on_stack (dest) || !SGEN_CLASS_HAS_REFERENCES (klass)) {
4369 size_t element_size = mono_class_value_size (klass, NULL);
4370 size_t size = count * element_size;
4371 mono_gc_memmove (dest, src, size);
4375 #ifdef SGEN_BINARY_PROTOCOL
4377 size_t element_size = mono_class_value_size (klass, NULL);
4379 for (i = 0; i < count; ++i) {
4380 scan_object_for_binary_protocol_copy_wbarrier ((char*)dest + i * element_size,
4381 (char*)src + i * element_size - sizeof (MonoObject),
4382 (mword) klass->gc_descr);
4387 remset.wbarrier_value_copy (dest, src, count, klass);
4391 * mono_gc_wbarrier_object_copy:
4393 * Write barrier to call when obj is the result of a clone or copy of an object.
4396 mono_gc_wbarrier_object_copy (MonoObject* obj, MonoObject *src)
4400 HEAVY_STAT (++stat_wbarrier_object_copy);
4402 if (ptr_in_nursery (obj) || ptr_on_stack (obj)) {
4403 size = mono_object_class (obj)->instance_size;
4404 mono_gc_memmove ((char*)obj + sizeof (MonoObject), (char*)src + sizeof (MonoObject),
4405 size - sizeof (MonoObject));
4409 #ifdef SGEN_BINARY_PROTOCOL
4410 scan_object_for_binary_protocol_copy_wbarrier (obj, (char*)src, (mword) src->vtable->gc_descr);
4413 remset.wbarrier_object_copy (obj, src);
4418 * ######################################################################
4419 * ######## Other mono public interface functions.
4420 * ######################################################################
4423 #define REFS_SIZE 128
4426 MonoGCReferences callback;
4430 MonoObject *refs [REFS_SIZE];
4431 uintptr_t offsets [REFS_SIZE];
4435 #define HANDLE_PTR(ptr,obj) do { \
4437 if (hwi->count == REFS_SIZE) { \
4438 hwi->callback ((MonoObject*)start, mono_object_class (start), hwi->called? 0: size, hwi->count, hwi->refs, hwi->offsets, hwi->data); \
4442 hwi->offsets [hwi->count] = (char*)(ptr)-(char*)start; \
4443 hwi->refs [hwi->count++] = *(ptr); \
4448 collect_references (HeapWalkInfo *hwi, char *start, size_t size)
4450 #include "sgen-scan-object.h"
4454 walk_references (char *start, size_t size, void *data)
4456 HeapWalkInfo *hwi = data;
4459 collect_references (hwi, start, size);
4460 if (hwi->count || !hwi->called)
4461 hwi->callback ((MonoObject*)start, mono_object_class (start), hwi->called? 0: size, hwi->count, hwi->refs, hwi->offsets, hwi->data);
4465 * mono_gc_walk_heap:
4466 * @flags: flags for future use
4467 * @callback: a function pointer called for each object in the heap
4468 * @data: a user data pointer that is passed to callback
4470 * This function can be used to iterate over all the live objects in the heap:
4471 * for each object, @callback is invoked, providing info about the object's
4472 * location in memory, its class, its size and the objects it references.
4473 * For each referenced object it's offset from the object address is
4474 * reported in the offsets array.
4475 * The object references may be buffered, so the callback may be invoked
4476 * multiple times for the same object: in all but the first call, the size
4477 * argument will be zero.
4478 * Note that this function can be only called in the #MONO_GC_EVENT_PRE_START_WORLD
4479 * profiler event handler.
4481 * Returns: a non-zero value if the GC doesn't support heap walking
4484 mono_gc_walk_heap (int flags, MonoGCReferences callback, void *data)
4489 hwi.callback = callback;
4492 sgen_clear_nursery_fragments ();
4493 sgen_scan_area_with_callback (nursery_section->data, nursery_section->end_data, walk_references, &hwi, FALSE);
4495 major_collector.iterate_objects (TRUE, TRUE, walk_references, &hwi);
4496 sgen_los_iterate_objects (walk_references, &hwi);
4502 mono_gc_collect (int generation)
4507 sgen_perform_collection (0, generation, "user request", TRUE);
4512 mono_gc_max_generation (void)
4518 mono_gc_collection_count (int generation)
4520 if (generation == 0)
4521 return stat_minor_gcs;
4522 return stat_major_gcs;
4526 mono_gc_get_used_size (void)
4530 tot = los_memory_usage;
4531 tot += nursery_section->next_data - nursery_section->data;
4532 tot += major_collector.get_used_size ();
4533 /* FIXME: account for pinned objects */
4539 mono_gc_disable (void)
4547 mono_gc_enable (void)
4555 mono_gc_get_los_limit (void)
4557 return MAX_SMALL_OBJ_SIZE;
4561 mono_gc_user_markers_supported (void)
4567 mono_object_is_alive (MonoObject* o)
4573 mono_gc_get_generation (MonoObject *obj)
4575 if (ptr_in_nursery (obj))
4581 mono_gc_enable_events (void)
4586 mono_gc_weak_link_add (void **link_addr, MonoObject *obj, gboolean track)
4588 sgen_register_disappearing_link (obj, link_addr, track, FALSE);
4592 mono_gc_weak_link_remove (void **link_addr)
4594 sgen_register_disappearing_link (NULL, link_addr, FALSE, FALSE);
4598 mono_gc_weak_link_get (void **link_addr)
4601 * We must only load *link_addr once because it might change
4602 * under our feet, and REVEAL_POINTER (NULL) results in an
4603 * invalid reference.
4605 void *ptr = *link_addr;
4610 * During the second bridge processing step the world is
4611 * running again. That step processes all weak links once
4612 * more to null those that refer to dead objects. Before that
4613 * is completed, those links must not be followed, so we
4614 * conservatively wait for bridge processing when any weak
4615 * link is dereferenced.
4617 if (G_UNLIKELY (bridge_processing_in_progress))
4618 mono_gc_wait_for_bridge_processing ();
4620 return (MonoObject*) REVEAL_POINTER (ptr);
4624 mono_gc_ephemeron_array_add (MonoObject *obj)
4626 EphemeronLinkNode *node;
4630 node = sgen_alloc_internal (INTERNAL_MEM_EPHEMERON_LINK);
4635 node->array = (char*)obj;
4636 node->next = ephemeron_list;
4637 ephemeron_list = node;
4639 SGEN_LOG (5, "Registered ephemeron array %p", obj);
4646 mono_gc_invoke_with_gc_lock (MonoGCLockedCallbackFunc func, void *data)
4650 result = func (data);
4651 UNLOCK_INTERRUPTION;
4656 mono_gc_is_gc_thread (void)
4660 result = mono_thread_info_current () != NULL;
4666 is_critical_method (MonoMethod *method)
4668 return mono_runtime_is_critical_method (method) || sgen_is_critical_method (method);
4672 mono_gc_base_init (void)
4674 MonoThreadInfoCallbacks cb;
4677 char *major_collector_opt = NULL;
4678 char *minor_collector_opt = NULL;
4680 glong soft_limit = 0;
4684 gboolean debug_print_allowance = FALSE;
4685 double allowance_ratio = 0, save_target = 0;
4686 gboolean have_split_nursery = FALSE;
4689 result = InterlockedCompareExchange (&gc_initialized, -1, 0);
4692 /* already inited */
4695 /* being inited by another thread */
4699 /* we will init it */
4702 g_assert_not_reached ();
4704 } while (result != 0);
4706 LOCK_INIT (gc_mutex);
4708 pagesize = mono_pagesize ();
4709 gc_debug_file = stderr;
4711 cb.thread_register = sgen_thread_register;
4712 cb.thread_unregister = sgen_thread_unregister;
4713 cb.thread_attach = sgen_thread_attach;
4714 cb.mono_method_is_critical = (gpointer)is_critical_method;
4716 cb.mono_gc_pthread_create = (gpointer)mono_gc_pthread_create;
4719 mono_threads_init (&cb, sizeof (SgenThreadInfo));
4721 LOCK_INIT (sgen_interruption_mutex);
4722 LOCK_INIT (pin_queue_mutex);
4724 init_user_copy_or_mark_key ();
4726 if ((env = getenv ("MONO_GC_PARAMS"))) {
4727 opts = g_strsplit (env, ",", -1);
4728 for (ptr = opts; *ptr; ++ptr) {
4730 if (g_str_has_prefix (opt, "major=")) {
4731 opt = strchr (opt, '=') + 1;
4732 major_collector_opt = g_strdup (opt);
4733 } else if (g_str_has_prefix (opt, "minor=")) {
4734 opt = strchr (opt, '=') + 1;
4735 minor_collector_opt = g_strdup (opt);
4743 sgen_init_internal_allocator ();
4744 sgen_init_nursery_allocator ();
4746 sgen_register_fixed_internal_mem_type (INTERNAL_MEM_SECTION, SGEN_SIZEOF_GC_MEM_SECTION);
4747 sgen_register_fixed_internal_mem_type (INTERNAL_MEM_FINALIZE_READY_ENTRY, sizeof (FinalizeReadyEntry));
4748 sgen_register_fixed_internal_mem_type (INTERNAL_MEM_GRAY_QUEUE, sizeof (GrayQueueSection));
4749 g_assert (sizeof (GenericStoreRememberedSet) == sizeof (gpointer) * STORE_REMSET_BUFFER_SIZE);
4750 sgen_register_fixed_internal_mem_type (INTERNAL_MEM_STORE_REMSET, sizeof (GenericStoreRememberedSet));
4751 sgen_register_fixed_internal_mem_type (INTERNAL_MEM_EPHEMERON_LINK, sizeof (EphemeronLinkNode));
4753 #ifndef HAVE_KW_THREAD
4754 mono_native_tls_alloc (&thread_info_key, NULL);
4758 * This needs to happen before any internal allocations because
4759 * it inits the small id which is required for hazard pointer
4764 mono_thread_info_attach (&dummy);
4766 if (!minor_collector_opt) {
4767 sgen_simple_nursery_init (&sgen_minor_collector);
4769 if (!strcmp (minor_collector_opt, "simple")) {
4770 sgen_simple_nursery_init (&sgen_minor_collector);
4771 } else if (!strcmp (minor_collector_opt, "split")) {
4772 sgen_split_nursery_init (&sgen_minor_collector);
4773 have_split_nursery = TRUE;
4775 fprintf (stderr, "Unknown minor collector `%s'.\n", minor_collector_opt);
4780 if (!major_collector_opt || !strcmp (major_collector_opt, "marksweep")) {
4781 sgen_marksweep_init (&major_collector);
4782 } else if (!major_collector_opt || !strcmp (major_collector_opt, "marksweep-fixed")) {
4783 sgen_marksweep_fixed_init (&major_collector);
4784 } else if (!major_collector_opt || !strcmp (major_collector_opt, "marksweep-par")) {
4785 sgen_marksweep_par_init (&major_collector);
4786 } else if (!major_collector_opt || !strcmp (major_collector_opt, "marksweep-fixed-par")) {
4787 sgen_marksweep_fixed_par_init (&major_collector);
4788 } else if (!major_collector_opt || !strcmp (major_collector_opt, "marksweep-conc")) {
4789 if (have_split_nursery) {
4790 fprintf (stderr, "Concurrent Mark&Sweep does not yet support the split nursery.\n");
4793 sgen_marksweep_conc_init (&major_collector);
4794 } else if (!strcmp (major_collector_opt, "copying")) {
4795 sgen_copying_init (&major_collector);
4797 fprintf (stderr, "Unknown major collector `%s'.\n", major_collector_opt);
4801 #ifdef SGEN_HAVE_CARDTABLE
4802 use_cardtable = major_collector.supports_cardtable;
4804 use_cardtable = FALSE;
4807 num_workers = mono_cpu_count ();
4808 g_assert (num_workers > 0);
4809 if (num_workers > 16)
4812 ///* Keep this the default for now */
4813 /* Precise marking is broken on all supported targets. Disable until fixed. */
4814 conservative_stack_mark = TRUE;
4816 sgen_nursery_size = DEFAULT_NURSERY_SIZE;
4819 for (ptr = opts; *ptr; ++ptr) {
4821 if (g_str_has_prefix (opt, "major="))
4823 if (g_str_has_prefix (opt, "minor="))
4825 if (g_str_has_prefix (opt, "wbarrier=")) {
4826 opt = strchr (opt, '=') + 1;
4827 if (strcmp (opt, "remset") == 0) {
4828 if (major_collector.is_concurrent) {
4829 fprintf (stderr, "The concurrent collector does not support the SSB write barrier.\n");
4832 use_cardtable = FALSE;
4833 } else if (strcmp (opt, "cardtable") == 0) {
4834 if (!use_cardtable) {
4835 if (major_collector.supports_cardtable)
4836 fprintf (stderr, "The cardtable write barrier is not supported on this platform.\n");
4838 fprintf (stderr, "The major collector does not support the cardtable write barrier.\n");
4842 fprintf (stderr, "wbarrier must either be `remset' or `cardtable'.");
4847 if (g_str_has_prefix (opt, "max-heap-size=")) {
4848 opt = strchr (opt, '=') + 1;
4849 if (*opt && mono_gc_parse_environment_string_extract_number (opt, &max_heap)) {
4850 if ((max_heap & (mono_pagesize () - 1))) {
4851 fprintf (stderr, "max-heap-size size must be a multiple of %d.\n", mono_pagesize ());
4855 fprintf (stderr, "max-heap-size must be an integer.\n");
4860 if (g_str_has_prefix (opt, "soft-heap-limit=")) {
4861 opt = strchr (opt, '=') + 1;
4862 if (*opt && mono_gc_parse_environment_string_extract_number (opt, &soft_limit)) {
4863 if (soft_limit <= 0) {
4864 fprintf (stderr, "soft-heap-limit must be positive.\n");
4868 fprintf (stderr, "soft-heap-limit must be an integer.\n");
4873 if (g_str_has_prefix (opt, "workers=")) {
4876 if (!major_collector.is_parallel) {
4877 fprintf (stderr, "The workers= option can only be used for parallel collectors.");
4880 opt = strchr (opt, '=') + 1;
4881 val = strtol (opt, &endptr, 10);
4882 if (!*opt || *endptr) {
4883 fprintf (stderr, "Cannot parse the workers= option value.");
4886 if (val <= 0 || val > 16) {
4887 fprintf (stderr, "The number of workers must be in the range 1 to 16.");
4890 num_workers = (int)val;
4893 if (g_str_has_prefix (opt, "stack-mark=")) {
4894 opt = strchr (opt, '=') + 1;
4895 if (!strcmp (opt, "precise")) {
4896 conservative_stack_mark = FALSE;
4897 } else if (!strcmp (opt, "conservative")) {
4898 conservative_stack_mark = TRUE;
4900 fprintf (stderr, "Invalid value '%s' for stack-mark= option, possible values are: 'precise', 'conservative'.\n", opt);
4905 if (g_str_has_prefix (opt, "bridge=")) {
4906 opt = strchr (opt, '=') + 1;
4907 sgen_register_test_bridge_callbacks (g_strdup (opt));
4911 if (g_str_has_prefix (opt, "nursery-size=")) {
4913 opt = strchr (opt, '=') + 1;
4914 if (*opt && mono_gc_parse_environment_string_extract_number (opt, &val)) {
4915 sgen_nursery_size = val;
4916 #ifdef SGEN_ALIGN_NURSERY
4917 if ((val & (val - 1))) {
4918 fprintf (stderr, "The nursery size must be a power of two.\n");
4922 if (val < SGEN_MAX_NURSERY_WASTE) {
4923 fprintf (stderr, "The nursery size must be at least %d bytes.\n", SGEN_MAX_NURSERY_WASTE);
4927 sgen_nursery_bits = 0;
4928 while (1 << (++ sgen_nursery_bits) != sgen_nursery_size)
4932 fprintf (stderr, "nursery-size must be an integer.\n");
4938 if (g_str_has_prefix (opt, "save-target-ratio=")) {
4940 opt = strchr (opt, '=') + 1;
4941 save_target = strtod (opt, &endptr);
4942 if (endptr == opt) {
4943 fprintf (stderr, "save-target-ratio must be a number.");
4946 if (save_target < SGEN_MIN_SAVE_TARGET_RATIO || save_target > SGEN_MAX_SAVE_TARGET_RATIO) {
4947 fprintf (stderr, "save-target-ratio must be between %.2f - %.2f.", SGEN_MIN_SAVE_TARGET_RATIO, SGEN_MAX_SAVE_TARGET_RATIO);
4952 if (g_str_has_prefix (opt, "default-allowance-ratio=")) {
4954 opt = strchr (opt, '=') + 1;
4956 allowance_ratio = strtod (opt, &endptr);
4957 if (endptr == opt) {
4958 fprintf (stderr, "save-target-ratio must be a number.");
4961 if (allowance_ratio < SGEN_MIN_ALLOWANCE_NURSERY_SIZE_RATIO || allowance_ratio > SGEN_MIN_ALLOWANCE_NURSERY_SIZE_RATIO) {
4962 fprintf (stderr, "default-allowance-ratio must be between %.2f - %.2f.", SGEN_MIN_ALLOWANCE_NURSERY_SIZE_RATIO, SGEN_MIN_ALLOWANCE_NURSERY_SIZE_RATIO);
4968 if (major_collector.handle_gc_param && major_collector.handle_gc_param (opt))
4971 if (sgen_minor_collector.handle_gc_param && sgen_minor_collector.handle_gc_param (opt))
4974 fprintf (stderr, "MONO_GC_PARAMS must be a comma-delimited list of one or more of the following:\n");
4975 fprintf (stderr, " max-heap-size=N (where N is an integer, possibly with a k, m or a g suffix)\n");
4976 fprintf (stderr, " soft-heap-limit=n (where N is an integer, possibly with a k, m or a g suffix)\n");
4977 fprintf (stderr, " nursery-size=N (where N is an integer, possibly with a k, m or a g suffix)\n");
4978 fprintf (stderr, " major=COLLECTOR (where COLLECTOR is `marksweep', `marksweep-par', 'marksweep-fixed', 'marksweep-fixed-par' or `copying')\n");
4979 fprintf (stderr, " minor=COLLECTOR (where COLLECTOR is `simple' or `split')\n");
4980 fprintf (stderr, " wbarrier=WBARRIER (where WBARRIER is `remset' or `cardtable')\n");
4981 fprintf (stderr, " stack-mark=MARK-METHOD (where MARK-METHOD is 'precise' or 'conservative')\n");
4982 if (major_collector.print_gc_param_usage)
4983 major_collector.print_gc_param_usage ();
4984 if (sgen_minor_collector.print_gc_param_usage)
4985 sgen_minor_collector.print_gc_param_usage ();
4986 fprintf (stderr, " Experimental options:\n");
4987 fprintf (stderr, " save-target-ratio=R (where R must be between %.2f - %.2f).\n", SGEN_MIN_SAVE_TARGET_RATIO, SGEN_MAX_SAVE_TARGET_RATIO);
4988 fprintf (stderr, " default-allowance-ratio=R (where R must be between %.2f - %.2f).\n", SGEN_MIN_ALLOWANCE_NURSERY_SIZE_RATIO, SGEN_MAX_ALLOWANCE_NURSERY_SIZE_RATIO);
4994 if (major_collector.is_parallel)
4995 sgen_workers_init (num_workers);
4996 else if (major_collector.is_concurrent)
4997 sgen_workers_init (1);
4999 if (major_collector_opt)
5000 g_free (major_collector_opt);
5002 if (minor_collector_opt)
5003 g_free (minor_collector_opt);
5007 if ((env = getenv ("MONO_GC_DEBUG"))) {
5008 opts = g_strsplit (env, ",", -1);
5009 for (ptr = opts; ptr && *ptr; ptr ++) {
5011 if (opt [0] >= '0' && opt [0] <= '9') {
5012 gc_debug_level = atoi (opt);
5018 char *rf = g_strdup_printf ("%s.%d", opt, GetCurrentProcessId ());
5020 char *rf = g_strdup_printf ("%s.%d", opt, getpid ());
5022 gc_debug_file = fopen (rf, "wb");
5024 gc_debug_file = stderr;
5027 } else if (!strcmp (opt, "print-allowance")) {
5028 debug_print_allowance = TRUE;
5029 } else if (!strcmp (opt, "print-pinning")) {
5030 do_pin_stats = TRUE;
5031 } else if (!strcmp (opt, "verify-before-allocs")) {
5032 verify_before_allocs = 1;
5033 has_per_allocation_action = TRUE;
5034 } else if (g_str_has_prefix (opt, "verify-before-allocs=")) {
5035 char *arg = strchr (opt, '=') + 1;
5036 verify_before_allocs = atoi (arg);
5037 has_per_allocation_action = TRUE;
5038 } else if (!strcmp (opt, "collect-before-allocs")) {
5039 collect_before_allocs = 1;
5040 has_per_allocation_action = TRUE;
5041 } else if (g_str_has_prefix (opt, "collect-before-allocs=")) {
5042 char *arg = strchr (opt, '=') + 1;
5043 has_per_allocation_action = TRUE;
5044 collect_before_allocs = atoi (arg);
5045 } else if (!strcmp (opt, "verify-before-collections")) {
5046 whole_heap_check_before_collection = TRUE;
5047 } else if (!strcmp (opt, "check-at-minor-collections")) {
5048 consistency_check_at_minor_collection = TRUE;
5049 nursery_clear_policy = CLEAR_AT_GC;
5050 } else if (!strcmp (opt, "xdomain-checks")) {
5051 xdomain_checks = TRUE;
5052 } else if (!strcmp (opt, "clear-at-gc")) {
5053 nursery_clear_policy = CLEAR_AT_GC;
5054 } else if (!strcmp (opt, "clear-nursery-at-gc")) {
5055 nursery_clear_policy = CLEAR_AT_GC;
5056 } else if (!strcmp (opt, "check-scan-starts")) {
5057 do_scan_starts_check = TRUE;
5058 } else if (!strcmp (opt, "verify-nursery-at-minor-gc")) {
5059 do_verify_nursery = TRUE;
5060 } else if (!strcmp (opt, "check-concurrent")) {
5061 if (!major_collector.is_concurrent) {
5062 fprintf (stderr, "Error: check-concurrent only world with concurrent major collectors.\n");
5065 do_concurrent_checks = TRUE;
5066 } else if (!strcmp (opt, "dump-nursery-at-minor-gc")) {
5067 do_dump_nursery_content = TRUE;
5068 } else if (!strcmp (opt, "no-managed-allocator")) {
5069 sgen_set_use_managed_allocator (FALSE);
5070 } else if (!strcmp (opt, "disable-minor")) {
5071 disable_minor_collections = TRUE;
5072 } else if (!strcmp (opt, "disable-major")) {
5073 disable_major_collections = TRUE;
5074 } else if (g_str_has_prefix (opt, "heap-dump=")) {
5075 char *filename = strchr (opt, '=') + 1;
5076 nursery_clear_policy = CLEAR_AT_GC;
5077 heap_dump_file = fopen (filename, "w");
5078 if (heap_dump_file) {
5079 fprintf (heap_dump_file, "<sgen-dump>\n");
5080 do_pin_stats = TRUE;
5082 #ifdef SGEN_BINARY_PROTOCOL
5083 } else if (g_str_has_prefix (opt, "binary-protocol=")) {
5084 char *filename = strchr (opt, '=') + 1;
5085 binary_protocol_init (filename);
5087 fprintf (stderr, "Warning: Cardtable write barriers will not be binary-protocolled.\n");
5090 fprintf (stderr, "Invalid format for the MONO_GC_DEBUG env variable: '%s'\n", env);
5091 fprintf (stderr, "The format is: MONO_GC_DEBUG=[l[:filename]|<option>]+ where l is a debug level 0-9.\n");
5092 fprintf (stderr, "Valid options are:\n");
5093 fprintf (stderr, " collect-before-allocs[=<n>]\n");
5094 fprintf (stderr, " verify-before-allocs[=<n>]\n");
5095 fprintf (stderr, " check-at-minor-collections\n");
5096 fprintf (stderr, " verify-before-collections\n");
5097 fprintf (stderr, " verify-nursery-at-minor-gc\n");
5098 fprintf (stderr, " dump-nursery-at-minor-gc\n");
5099 fprintf (stderr, " disable-minor\n");
5100 fprintf (stderr, " disable-major\n");
5101 fprintf (stderr, " xdomain-checks\n");
5102 fprintf (stderr, " check-concurrent\n");
5103 fprintf (stderr, " clear-at-gc\n");
5104 fprintf (stderr, " clear-nursery-at-gc\n");
5105 fprintf (stderr, " check-scan-starts\n");
5106 fprintf (stderr, " no-managed-allocator\n");
5107 fprintf (stderr, " print-allowance\n");
5108 fprintf (stderr, " print-pinning\n");
5109 fprintf (stderr, " heap-dump=<filename>\n");
5110 #ifdef SGEN_BINARY_PROTOCOL
5111 fprintf (stderr, " binary-protocol=<filename>\n");
5119 if (major_collector.is_parallel) {
5120 if (heap_dump_file) {
5121 fprintf (stderr, "Error: Cannot do heap dump with the parallel collector.\n");
5125 fprintf (stderr, "Error: Cannot gather pinning statistics with the parallel collector.\n");
5130 if (major_collector.post_param_init)
5131 major_collector.post_param_init (&major_collector);
5133 sgen_memgov_init (max_heap, soft_limit, debug_print_allowance, allowance_ratio, save_target);
5135 memset (&remset, 0, sizeof (remset));
5137 #ifdef SGEN_HAVE_CARDTABLE
5139 sgen_card_table_init (&remset);
5142 sgen_ssb_init (&remset);
5144 if (remset.register_thread)
5145 remset.register_thread (mono_thread_info_current ());
5151 mono_gc_get_gc_name (void)
5156 static MonoMethod *write_barrier_method;
5159 sgen_is_critical_method (MonoMethod *method)
5161 return (method == write_barrier_method || sgen_is_managed_allocator (method));
5165 sgen_has_critical_method (void)
5167 return write_barrier_method || sgen_has_managed_allocator ();
5171 emit_nursery_check (MonoMethodBuilder *mb, int *nursery_check_return_labels)
5173 memset (nursery_check_return_labels, 0, sizeof (int) * 3);
5174 #ifdef SGEN_ALIGN_NURSERY
5175 // if (ptr_in_nursery (ptr)) return;
5177 * Masking out the bits might be faster, but we would have to use 64 bit
5178 * immediates, which might be slower.
5180 mono_mb_emit_ldarg (mb, 0);
5181 mono_mb_emit_icon (mb, DEFAULT_NURSERY_BITS);
5182 mono_mb_emit_byte (mb, CEE_SHR_UN);
5183 mono_mb_emit_icon (mb, (mword)sgen_get_nursery_start () >> DEFAULT_NURSERY_BITS);
5184 nursery_check_return_labels [0] = mono_mb_emit_branch (mb, CEE_BEQ);
5186 if (!major_collector.is_concurrent) {
5187 // if (!ptr_in_nursery (*ptr)) return;
5188 mono_mb_emit_ldarg (mb, 0);
5189 mono_mb_emit_byte (mb, CEE_LDIND_I);
5190 mono_mb_emit_icon (mb, DEFAULT_NURSERY_BITS);
5191 mono_mb_emit_byte (mb, CEE_SHR_UN);
5192 mono_mb_emit_icon (mb, (mword)sgen_get_nursery_start () >> DEFAULT_NURSERY_BITS);
5193 nursery_check_return_labels [1] = mono_mb_emit_branch (mb, CEE_BNE_UN);
5196 int label_continue1, label_continue2;
5197 int dereferenced_var;
5199 // if (ptr < (sgen_get_nursery_start ())) goto continue;
5200 mono_mb_emit_ldarg (mb, 0);
5201 mono_mb_emit_ptr (mb, (gpointer) sgen_get_nursery_start ());
5202 label_continue_1 = mono_mb_emit_branch (mb, CEE_BLT);
5204 // if (ptr >= sgen_get_nursery_end ())) goto continue;
5205 mono_mb_emit_ldarg (mb, 0);
5206 mono_mb_emit_ptr (mb, (gpointer) sgen_get_nursery_end ());
5207 label_continue_2 = mono_mb_emit_branch (mb, CEE_BGE);
5210 nursery_check_return_labels [0] = mono_mb_emit_branch (mb, CEE_BR);
5213 mono_mb_patch_branch (mb, label_continue_1);
5214 mono_mb_patch_branch (mb, label_continue_2);
5216 // Dereference and store in local var
5217 dereferenced_var = mono_mb_add_local (mb, &mono_defaults.int_class->byval_arg);
5218 mono_mb_emit_ldarg (mb, 0);
5219 mono_mb_emit_byte (mb, CEE_LDIND_I);
5220 mono_mb_emit_stloc (mb, dereferenced_var);
5222 if (!major_collector.is_concurrent) {
5223 // if (*ptr < sgen_get_nursery_start ()) return;
5224 mono_mb_emit_ldloc (mb, dereferenced_var);
5225 mono_mb_emit_ptr (mb, (gpointer) sgen_get_nursery_start ());
5226 nursery_check_return_labels [1] = mono_mb_emit_branch (mb, CEE_BLT);
5228 // if (*ptr >= sgen_get_nursery_end ()) return;
5229 mono_mb_emit_ldloc (mb, dereferenced_var);
5230 mono_mb_emit_ptr (mb, (gpointer) sgen_get_nursery_end ());
5231 nursery_check_return_labels [2] = mono_mb_emit_branch (mb, CEE_BGE);
5237 mono_gc_get_write_barrier (void)
5240 MonoMethodBuilder *mb;
5241 MonoMethodSignature *sig;
5242 #ifdef MANAGED_WBARRIER
5243 int i, nursery_check_labels [3];
5244 int label_no_wb_3, label_no_wb_4, label_need_wb, label_slow_path;
5245 int buffer_var, buffer_index_var, dummy_var;
5247 #ifdef HAVE_KW_THREAD
5248 int stack_end_offset = -1, store_remset_buffer_offset = -1;
5249 int store_remset_buffer_index_offset = -1, store_remset_buffer_index_addr_offset = -1;
5251 MONO_THREAD_VAR_OFFSET (stack_end, stack_end_offset);
5252 g_assert (stack_end_offset != -1);
5253 MONO_THREAD_VAR_OFFSET (store_remset_buffer, store_remset_buffer_offset);
5254 g_assert (store_remset_buffer_offset != -1);
5255 MONO_THREAD_VAR_OFFSET (store_remset_buffer_index, store_remset_buffer_index_offset);
5256 g_assert (store_remset_buffer_index_offset != -1);
5257 MONO_THREAD_VAR_OFFSET (store_remset_buffer_index_addr, store_remset_buffer_index_addr_offset);
5258 g_assert (store_remset_buffer_index_addr_offset != -1);
5262 // FIXME: Maybe create a separate version for ctors (the branch would be
5263 // correctly predicted more times)
5264 if (write_barrier_method)
5265 return write_barrier_method;
5267 /* Create the IL version of mono_gc_barrier_generic_store () */
5268 sig = mono_metadata_signature_alloc (mono_defaults.corlib, 1);
5269 sig->ret = &mono_defaults.void_class->byval_arg;
5270 sig->params [0] = &mono_defaults.int_class->byval_arg;
5272 mb = mono_mb_new (mono_defaults.object_class, "wbarrier", MONO_WRAPPER_WRITE_BARRIER);
5274 #ifdef MANAGED_WBARRIER
5275 if (use_cardtable) {
5276 emit_nursery_check (mb, nursery_check_labels);
5278 addr = sgen_cardtable + ((address >> CARD_BITS) & CARD_MASK)
5282 LDC_PTR sgen_cardtable
5284 address >> CARD_BITS
5288 if (SGEN_HAVE_OVERLAPPING_CARDS) {
5289 LDC_PTR card_table_mask
5296 mono_mb_emit_ptr (mb, sgen_cardtable);
5297 mono_mb_emit_ldarg (mb, 0);
5298 mono_mb_emit_icon (mb, CARD_BITS);
5299 mono_mb_emit_byte (mb, CEE_SHR_UN);
5300 #ifdef SGEN_HAVE_OVERLAPPING_CARDS
5301 mono_mb_emit_ptr (mb, (gpointer)CARD_MASK);
5302 mono_mb_emit_byte (mb, CEE_AND);
5304 mono_mb_emit_byte (mb, CEE_ADD);
5305 mono_mb_emit_icon (mb, 1);
5306 mono_mb_emit_byte (mb, CEE_STIND_I1);
5309 for (i = 0; i < 3; ++i) {
5310 if (nursery_check_labels [i])
5311 mono_mb_patch_branch (mb, nursery_check_labels [i]);
5313 mono_mb_emit_byte (mb, CEE_RET);
5314 } else if (mono_runtime_has_tls_get ()) {
5315 emit_nursery_check (mb, nursery_check_labels);
5317 // if (ptr >= stack_end) goto need_wb;
5318 mono_mb_emit_ldarg (mb, 0);
5319 EMIT_TLS_ACCESS (mb, stack_end, stack_end_offset);
5320 label_need_wb = mono_mb_emit_branch (mb, CEE_BGE_UN);
5322 // if (ptr >= stack_start) return;
5323 dummy_var = mono_mb_add_local (mb, &mono_defaults.int_class->byval_arg);
5324 mono_mb_emit_ldarg (mb, 0);
5325 mono_mb_emit_ldloc_addr (mb, dummy_var);
5326 label_no_wb_3 = mono_mb_emit_branch (mb, CEE_BGE_UN);
5329 mono_mb_patch_branch (mb, label_need_wb);
5331 // buffer = STORE_REMSET_BUFFER;
5332 buffer_var = mono_mb_add_local (mb, &mono_defaults.int_class->byval_arg);
5333 EMIT_TLS_ACCESS (mb, store_remset_buffer, store_remset_buffer_offset);
5334 mono_mb_emit_stloc (mb, buffer_var);
5336 // buffer_index = STORE_REMSET_BUFFER_INDEX;
5337 buffer_index_var = mono_mb_add_local (mb, &mono_defaults.int_class->byval_arg);
5338 EMIT_TLS_ACCESS (mb, store_remset_buffer_index, store_remset_buffer_index_offset);
5339 mono_mb_emit_stloc (mb, buffer_index_var);
5341 // if (buffer [buffer_index] == ptr) return;
5342 mono_mb_emit_ldloc (mb, buffer_var);
5343 mono_mb_emit_ldloc (mb, buffer_index_var);
5344 g_assert (sizeof (gpointer) == 4 || sizeof (gpointer) == 8);
5345 mono_mb_emit_icon (mb, sizeof (gpointer) == 4 ? 2 : 3);
5346 mono_mb_emit_byte (mb, CEE_SHL);
5347 mono_mb_emit_byte (mb, CEE_ADD);
5348 mono_mb_emit_byte (mb, CEE_LDIND_I);
5349 mono_mb_emit_ldarg (mb, 0);
5350 label_no_wb_4 = mono_mb_emit_branch (mb, CEE_BEQ);
5353 mono_mb_emit_ldloc (mb, buffer_index_var);
5354 mono_mb_emit_icon (mb, 1);
5355 mono_mb_emit_byte (mb, CEE_ADD);
5356 mono_mb_emit_stloc (mb, buffer_index_var);
5358 // if (buffer_index >= STORE_REMSET_BUFFER_SIZE) goto slow_path;
5359 mono_mb_emit_ldloc (mb, buffer_index_var);
5360 mono_mb_emit_icon (mb, STORE_REMSET_BUFFER_SIZE);
5361 label_slow_path = mono_mb_emit_branch (mb, CEE_BGE);
5363 // buffer [buffer_index] = ptr;
5364 mono_mb_emit_ldloc (mb, buffer_var);
5365 mono_mb_emit_ldloc (mb, buffer_index_var);
5366 g_assert (sizeof (gpointer) == 4 || sizeof (gpointer) == 8);
5367 mono_mb_emit_icon (mb, sizeof (gpointer) == 4 ? 2 : 3);
5368 mono_mb_emit_byte (mb, CEE_SHL);
5369 mono_mb_emit_byte (mb, CEE_ADD);
5370 mono_mb_emit_ldarg (mb, 0);
5371 mono_mb_emit_byte (mb, CEE_STIND_I);
5373 // STORE_REMSET_BUFFER_INDEX = buffer_index;
5374 EMIT_TLS_ACCESS (mb, store_remset_buffer_index_addr, store_remset_buffer_index_addr_offset);
5375 mono_mb_emit_ldloc (mb, buffer_index_var);
5376 mono_mb_emit_byte (mb, CEE_STIND_I);
5379 for (i = 0; i < 3; ++i) {
5380 if (nursery_check_labels [i])
5381 mono_mb_patch_branch (mb, nursery_check_labels [i]);
5383 mono_mb_patch_branch (mb, label_no_wb_3);
5384 mono_mb_patch_branch (mb, label_no_wb_4);
5385 mono_mb_emit_byte (mb, CEE_RET);
5388 mono_mb_patch_branch (mb, label_slow_path);
5390 mono_mb_emit_ldarg (mb, 0);
5391 mono_mb_emit_icall (mb, mono_gc_wbarrier_generic_nostore);
5392 mono_mb_emit_byte (mb, CEE_RET);
5396 mono_mb_emit_ldarg (mb, 0);
5397 mono_mb_emit_icall (mb, mono_gc_wbarrier_generic_nostore);
5398 mono_mb_emit_byte (mb, CEE_RET);
5401 res = mono_mb_create_method (mb, sig, 16);
5404 mono_loader_lock ();
5405 if (write_barrier_method) {
5406 /* Already created */
5407 mono_free_method (res);
5409 /* double-checked locking */
5410 mono_memory_barrier ();
5411 write_barrier_method = res;
5413 mono_loader_unlock ();
5415 return write_barrier_method;
5419 mono_gc_get_description (void)
5421 return g_strdup ("sgen");
5425 mono_gc_set_desktop_mode (void)
5430 mono_gc_is_moving (void)
5436 mono_gc_is_disabled (void)
5442 BOOL APIENTRY mono_gc_dllmain (HMODULE module_handle, DWORD reason, LPVOID reserved)
5449 sgen_get_nursery_clear_policy (void)
5451 return nursery_clear_policy;
5455 sgen_get_array_fill_vtable (void)
5457 if (!array_fill_vtable) {
5458 static MonoClass klass;
5459 static MonoVTable vtable;
5462 MonoDomain *domain = mono_get_root_domain ();
5465 klass.element_class = mono_defaults.byte_class;
5467 klass.instance_size = sizeof (MonoArray);
5468 klass.sizes.element_size = 1;
5469 klass.name = "array_filler_type";
5471 vtable.klass = &klass;
5473 vtable.gc_descr = mono_gc_make_descr_for_array (TRUE, &bmap, 0, 1);
5476 array_fill_vtable = &vtable;
5478 return array_fill_vtable;
5488 sgen_gc_unlock (void)
5494 sgen_major_collector_iterate_live_block_ranges (sgen_cardtable_block_callback callback)
5496 major_collector.iterate_live_block_ranges (callback);
5500 sgen_major_collector_scan_card_table (SgenGrayQueue *queue)
5502 major_collector.scan_card_table (FALSE, queue);
5506 sgen_get_major_collector (void)
5508 return &major_collector;
5511 void mono_gc_set_skip_thread (gboolean skip)
5513 SgenThreadInfo *info = mono_thread_info_current ();
5516 info->gc_disabled = skip;
5521 sgen_get_remset (void)
5527 mono_gc_get_vtable_bits (MonoClass *class)
5529 if (sgen_need_bridge_processing () && sgen_is_bridge_class (class))
5530 return SGEN_GC_BIT_BRIDGE_OBJECT;
5535 mono_gc_register_altstack (gpointer stack, gint32 stack_size, gpointer altstack, gint32 altstack_size)
5542 sgen_check_whole_heap_stw (void)
5544 sgen_stop_world (0);
5545 sgen_clear_nursery_fragments ();
5546 sgen_check_whole_heap ();
5547 sgen_restart_world (0, NULL);
5551 sgen_gc_event_moves (void)
5553 if (moved_objects_idx) {
5554 mono_profiler_gc_moves (moved_objects, moved_objects_idx);
5555 moved_objects_idx = 0;
5559 #endif /* HAVE_SGEN_GC */