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, gpointer obj)
1143 remset.record_pointer (ptr);
1145 if (G_UNLIKELY (MONO_GC_GLOBAL_REMSET_ADD_ENABLED ())) {
1146 MonoVTable *vt = (MonoVTable*)LOAD_VTABLE (obj);
1147 MONO_GC_GLOBAL_REMSET_ADD ((mword)ptr, (mword)obj, sgen_safe_object_get_size (obj),
1148 vt->klass->name_space, vt->klass->name);
1153 * sgen_drain_gray_stack:
1155 * Scan objects in the gray stack until the stack is empty. This should be called
1156 * frequently after each object is copied, to achieve better locality and cache
1160 sgen_drain_gray_stack (int max_objs, ScanCopyContext ctx)
1163 ScanObjectFunc scan_func = ctx.scan_func;
1164 GrayQueue *queue = ctx.queue;
1166 if (max_objs == -1) {
1168 GRAY_OBJECT_DEQUEUE (queue, obj);
1171 SGEN_LOG (9, "Precise gray object scan %p (%s)", obj, safe_name (obj));
1172 scan_func (obj, queue);
1178 for (i = 0; i != max_objs; ++i) {
1179 GRAY_OBJECT_DEQUEUE (queue, obj);
1182 SGEN_LOG (9, "Precise gray object scan %p (%s)", obj, safe_name (obj));
1183 scan_func (obj, queue);
1185 } while (max_objs < 0);
1191 * Addresses from start to end are already sorted. This function finds
1192 * the object header for each address and pins the object. The
1193 * addresses must be inside the passed section. The (start of the)
1194 * address array is overwritten with the addresses of the actually
1195 * pinned objects. Return the number of pinned objects.
1198 pin_objects_from_addresses (GCMemSection *section, void **start, void **end, void *start_nursery, void *end_nursery, ScanCopyContext ctx)
1203 void *last_obj = NULL;
1204 size_t last_obj_size = 0;
1207 void **definitely_pinned = start;
1208 ScanObjectFunc scan_func = ctx.scan_func;
1209 SgenGrayQueue *queue = ctx.queue;
1211 sgen_nursery_allocator_prepare_for_pinning ();
1213 while (start < end) {
1215 /* the range check should be reduntant */
1216 if (addr != last && addr >= start_nursery && addr < end_nursery) {
1217 SGEN_LOG (5, "Considering pinning addr %p", addr);
1218 /* multiple pointers to the same object */
1219 if (addr >= last_obj && (char*)addr < (char*)last_obj + last_obj_size) {
1223 idx = ((char*)addr - (char*)section->data) / SCAN_START_SIZE;
1224 g_assert (idx < section->num_scan_start);
1225 search_start = (void*)section->scan_starts [idx];
1226 if (!search_start || search_start > addr) {
1229 search_start = section->scan_starts [idx];
1230 if (search_start && search_start <= addr)
1233 if (!search_start || search_start > addr)
1234 search_start = start_nursery;
1236 if (search_start < last_obj)
1237 search_start = (char*)last_obj + last_obj_size;
1238 /* now addr should be in an object a short distance from search_start
1239 * Note that search_start must point to zeroed mem or point to an object.
1243 if (!*(void**)search_start) {
1244 /* Consistency check */
1246 for (frag = nursery_fragments; frag; frag = frag->next) {
1247 if (search_start >= frag->fragment_start && search_start < frag->fragment_end)
1248 g_assert_not_reached ();
1252 search_start = (void*)ALIGN_UP ((mword)search_start + sizeof (gpointer));
1255 last_obj = search_start;
1256 last_obj_size = ALIGN_UP (safe_object_get_size ((MonoObject*)search_start));
1258 if (((MonoObject*)last_obj)->synchronisation == GINT_TO_POINTER (-1)) {
1259 /* Marks the beginning of a nursery fragment, skip */
1261 SGEN_LOG (8, "Pinned try match %p (%s), size %zd", last_obj, safe_name (last_obj), last_obj_size);
1262 if (addr >= search_start && (char*)addr < (char*)last_obj + last_obj_size) {
1263 SGEN_LOG (4, "Pinned object %p, vtable %p (%s), count %d\n", search_start, *(void**)search_start, safe_name (search_start), count);
1264 binary_protocol_pin (search_start, (gpointer)LOAD_VTABLE (search_start), safe_object_get_size (search_start));
1265 if (G_UNLIKELY (MONO_GC_OBJ_PINNED_ENABLED ())) {
1266 int gen = sgen_ptr_in_nursery (search_start) ? GENERATION_NURSERY : GENERATION_OLD;
1267 MonoVTable *vt = (MonoVTable*)LOAD_VTABLE (search_start);
1268 MONO_GC_OBJ_PINNED ((mword)search_start, sgen_safe_object_get_size (search_start), vt->klass->name_space, vt->klass->name, gen);
1271 scan_func (search_start, queue);
1273 pin_object (search_start);
1274 GRAY_OBJECT_ENQUEUE (queue, search_start);
1275 if (G_UNLIKELY (do_pin_stats))
1276 sgen_pin_stats_register_object (search_start, last_obj_size);
1277 definitely_pinned [count] = search_start;
1283 /* skip to the next object */
1284 search_start = (void*)((char*)search_start + last_obj_size);
1285 } while (search_start <= addr);
1286 /* we either pinned the correct object or we ignored the addr because
1287 * it points to unused zeroed memory.
1293 //printf ("effective pinned: %d (at the end: %d)\n", count, (char*)end_nursery - (char*)last);
1294 if (mono_profiler_get_events () & MONO_PROFILE_GC_ROOTS) {
1295 GCRootReport report;
1297 for (idx = 0; idx < count; ++idx)
1298 add_profile_gc_root (&report, definitely_pinned [idx], MONO_PROFILE_GC_ROOT_PINNING | MONO_PROFILE_GC_ROOT_MISC, 0);
1299 notify_gc_roots (&report);
1301 stat_pinned_objects += count;
1306 sgen_pin_objects_in_section (GCMemSection *section, ScanCopyContext ctx)
1308 int num_entries = section->pin_queue_num_entries;
1310 void **start = section->pin_queue_start;
1312 reduced_to = pin_objects_from_addresses (section, start, start + num_entries,
1313 section->data, section->next_data, ctx);
1314 section->pin_queue_num_entries = reduced_to;
1316 section->pin_queue_start = NULL;
1322 sgen_pin_object (void *object, GrayQueue *queue)
1324 g_assert (!concurrent_collection_in_progress);
1326 if (sgen_collection_is_parallel ()) {
1328 /*object arrives pinned*/
1329 sgen_pin_stage_ptr (object);
1333 SGEN_PIN_OBJECT (object);
1334 sgen_pin_stage_ptr (object);
1336 if (G_UNLIKELY (do_pin_stats))
1337 sgen_pin_stats_register_object (object, safe_object_get_size (object));
1339 GRAY_OBJECT_ENQUEUE (queue, object);
1340 binary_protocol_pin (object, (gpointer)LOAD_VTABLE (object), safe_object_get_size (object));
1341 if (G_UNLIKELY (MONO_GC_OBJ_PINNED_ENABLED ())) {
1342 int gen = sgen_ptr_in_nursery (object) ? GENERATION_NURSERY : GENERATION_OLD;
1343 MonoVTable *vt = (MonoVTable*)LOAD_VTABLE (object);
1344 MONO_GC_OBJ_PINNED ((mword)object, sgen_safe_object_get_size (object), vt->klass->name_space, vt->klass->name, gen);
1349 sgen_parallel_pin_or_update (void **ptr, void *obj, MonoVTable *vt, SgenGrayQueue *queue)
1353 gboolean major_pinned = FALSE;
1355 if (sgen_ptr_in_nursery (obj)) {
1356 if (SGEN_CAS_PTR (obj, (void*)((mword)vt | SGEN_PINNED_BIT), vt) == vt) {
1357 sgen_pin_object (obj, queue);
1361 major_collector.pin_major_object (obj, queue);
1362 major_pinned = TRUE;
1365 vtable_word = *(mword*)obj;
1366 /*someone else forwarded it, update the pointer and bail out*/
1367 if (vtable_word & SGEN_FORWARDED_BIT) {
1368 *ptr = (void*)(vtable_word & ~SGEN_VTABLE_BITS_MASK);
1372 /*someone pinned it, nothing to do.*/
1373 if (vtable_word & SGEN_PINNED_BIT || major_pinned)
1378 /* Sort the addresses in array in increasing order.
1379 * Done using a by-the book heap sort. Which has decent and stable performance, is pretty cache efficient.
1382 sgen_sort_addresses (void **array, int size)
1387 for (i = 1; i < size; ++i) {
1390 int parent = (child - 1) / 2;
1392 if (array [parent] >= array [child])
1395 tmp = array [parent];
1396 array [parent] = array [child];
1397 array [child] = tmp;
1403 for (i = size - 1; i > 0; --i) {
1406 array [i] = array [0];
1412 while (root * 2 + 1 <= end) {
1413 int child = root * 2 + 1;
1415 if (child < end && array [child] < array [child + 1])
1417 if (array [root] >= array [child])
1421 array [root] = array [child];
1422 array [child] = tmp;
1430 * Scan the memory between start and end and queue values which could be pointers
1431 * to the area between start_nursery and end_nursery for later consideration.
1432 * Typically used for thread stacks.
1435 conservatively_pin_objects_from (void **start, void **end, void *start_nursery, void *end_nursery, int pin_type)
1439 #ifdef VALGRIND_MAKE_MEM_DEFINED_IF_ADDRESSABLE
1440 VALGRIND_MAKE_MEM_DEFINED_IF_ADDRESSABLE (start, (char*)end - (char*)start);
1443 while (start < end) {
1444 if (*start >= start_nursery && *start < end_nursery) {
1446 * *start can point to the middle of an object
1447 * note: should we handle pointing at the end of an object?
1448 * pinning in C# code disallows pointing at the end of an object
1449 * but there is some small chance that an optimizing C compiler
1450 * may keep the only reference to an object by pointing
1451 * at the end of it. We ignore this small chance for now.
1452 * Pointers to the end of an object are indistinguishable
1453 * from pointers to the start of the next object in memory
1454 * so if we allow that we'd need to pin two objects...
1455 * We queue the pointer in an array, the
1456 * array will then be sorted and uniqued. This way
1457 * we can coalesce several pinning pointers and it should
1458 * be faster since we'd do a memory scan with increasing
1459 * addresses. Note: we can align the address to the allocation
1460 * alignment, so the unique process is more effective.
1462 mword addr = (mword)*start;
1463 addr &= ~(ALLOC_ALIGN - 1);
1464 if (addr >= (mword)start_nursery && addr < (mword)end_nursery) {
1465 SGEN_LOG (6, "Pinning address %p from %p", (void*)addr, start);
1466 sgen_pin_stage_ptr ((void*)addr);
1469 if (G_UNLIKELY (do_pin_stats)) {
1470 if (ptr_in_nursery ((void*)addr))
1471 sgen_pin_stats_register_address ((char*)addr, pin_type);
1477 SGEN_LOG (7, "found %d potential pinned heap pointers", count);
1481 * The first thing we do in a collection is to identify pinned objects.
1482 * This function considers all the areas of memory that need to be
1483 * conservatively scanned.
1486 pin_from_roots (void *start_nursery, void *end_nursery, GrayQueue *queue)
1490 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);
1491 /* objects pinned from the API are inside these roots */
1492 SGEN_HASH_TABLE_FOREACH (&roots_hash [ROOT_TYPE_PINNED], start_root, root) {
1493 SGEN_LOG (6, "Pinned roots %p-%p", start_root, root->end_root);
1494 conservatively_pin_objects_from (start_root, (void**)root->end_root, start_nursery, end_nursery, PIN_TYPE_OTHER);
1495 } SGEN_HASH_TABLE_FOREACH_END;
1496 /* now deal with the thread stacks
1497 * in the future we should be able to conservatively scan only:
1498 * *) the cpu registers
1499 * *) the unmanaged stack frames
1500 * *) the _last_ managed stack frame
1501 * *) pointers slots in managed frames
1503 scan_thread_data (start_nursery, end_nursery, FALSE, queue);
1507 unpin_objects_from_queue (SgenGrayQueue *queue)
1511 GRAY_OBJECT_DEQUEUE (queue, addr);
1514 SGEN_UNPIN_OBJECT (addr);
1519 CopyOrMarkObjectFunc func;
1521 } UserCopyOrMarkData;
1523 static MonoNativeTlsKey user_copy_or_mark_key;
1526 init_user_copy_or_mark_key (void)
1528 mono_native_tls_alloc (&user_copy_or_mark_key, NULL);
1532 set_user_copy_or_mark_data (UserCopyOrMarkData *data)
1534 mono_native_tls_set_value (user_copy_or_mark_key, data);
1538 single_arg_user_copy_or_mark (void **obj)
1540 UserCopyOrMarkData *data = mono_native_tls_get_value (user_copy_or_mark_key);
1542 data->func (obj, data->queue);
1546 * The memory area from start_root to end_root contains pointers to objects.
1547 * Their position is precisely described by @desc (this means that the pointer
1548 * can be either NULL or the pointer to the start of an object).
1549 * This functions copies them to to_space updates them.
1551 * This function is not thread-safe!
1554 precisely_scan_objects_from (void** start_root, void** end_root, char* n_start, char *n_end, mword desc, ScanCopyContext ctx)
1556 CopyOrMarkObjectFunc copy_func = ctx.copy_func;
1557 SgenGrayQueue *queue = ctx.queue;
1559 switch (desc & ROOT_DESC_TYPE_MASK) {
1560 case ROOT_DESC_BITMAP:
1561 desc >>= ROOT_DESC_TYPE_SHIFT;
1563 if ((desc & 1) && *start_root) {
1564 copy_func (start_root, queue);
1565 SGEN_LOG (9, "Overwrote root at %p with %p", start_root, *start_root);
1566 sgen_drain_gray_stack (-1, ctx);
1572 case ROOT_DESC_COMPLEX: {
1573 gsize *bitmap_data = sgen_get_complex_descriptor_bitmap (desc);
1574 int bwords = (*bitmap_data) - 1;
1575 void **start_run = start_root;
1577 while (bwords-- > 0) {
1578 gsize bmap = *bitmap_data++;
1579 void **objptr = start_run;
1581 if ((bmap & 1) && *objptr) {
1582 copy_func (objptr, queue);
1583 SGEN_LOG (9, "Overwrote root at %p with %p", objptr, *objptr);
1584 sgen_drain_gray_stack (-1, ctx);
1589 start_run += GC_BITS_PER_WORD;
1593 case ROOT_DESC_USER: {
1594 UserCopyOrMarkData data = { copy_func, queue };
1595 MonoGCRootMarkFunc marker = sgen_get_user_descriptor_func (desc);
1596 set_user_copy_or_mark_data (&data);
1597 marker (start_root, single_arg_user_copy_or_mark);
1598 set_user_copy_or_mark_data (NULL);
1601 case ROOT_DESC_RUN_LEN:
1602 g_assert_not_reached ();
1604 g_assert_not_reached ();
1609 reset_heap_boundaries (void)
1611 lowest_heap_address = ~(mword)0;
1612 highest_heap_address = 0;
1616 sgen_update_heap_boundaries (mword low, mword high)
1621 old = lowest_heap_address;
1624 } while (SGEN_CAS_PTR ((gpointer*)&lowest_heap_address, (gpointer)low, (gpointer)old) != (gpointer)old);
1627 old = highest_heap_address;
1630 } while (SGEN_CAS_PTR ((gpointer*)&highest_heap_address, (gpointer)high, (gpointer)old) != (gpointer)old);
1634 * Allocate and setup the data structures needed to be able to allocate objects
1635 * in the nursery. The nursery is stored in nursery_section.
1638 alloc_nursery (void)
1640 GCMemSection *section;
1645 if (nursery_section)
1647 SGEN_LOG (2, "Allocating nursery size: %lu", (unsigned long)sgen_nursery_size);
1648 /* later we will alloc a larger area for the nursery but only activate
1649 * what we need. The rest will be used as expansion if we have too many pinned
1650 * objects in the existing nursery.
1652 /* FIXME: handle OOM */
1653 section = sgen_alloc_internal (INTERNAL_MEM_SECTION);
1655 alloc_size = sgen_nursery_size;
1657 /* If there isn't enough space even for the nursery we should simply abort. */
1658 g_assert (sgen_memgov_try_alloc_space (alloc_size, SPACE_NURSERY));
1660 #ifdef SGEN_ALIGN_NURSERY
1661 data = major_collector.alloc_heap (alloc_size, alloc_size, DEFAULT_NURSERY_BITS);
1663 data = major_collector.alloc_heap (alloc_size, 0, DEFAULT_NURSERY_BITS);
1665 sgen_update_heap_boundaries ((mword)data, (mword)(data + sgen_nursery_size));
1666 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 ());
1667 section->data = section->next_data = data;
1668 section->size = alloc_size;
1669 section->end_data = data + sgen_nursery_size;
1670 scan_starts = (alloc_size + SCAN_START_SIZE - 1) / SCAN_START_SIZE;
1671 section->scan_starts = sgen_alloc_internal_dynamic (sizeof (char*) * scan_starts, INTERNAL_MEM_SCAN_STARTS, TRUE);
1672 section->num_scan_start = scan_starts;
1673 section->block.role = MEMORY_ROLE_GEN0;
1674 section->block.next = NULL;
1676 nursery_section = section;
1678 sgen_nursery_allocator_set_nursery_bounds (data, data + sgen_nursery_size);
1682 mono_gc_get_nursery (int *shift_bits, size_t *size)
1684 *size = sgen_nursery_size;
1685 #ifdef SGEN_ALIGN_NURSERY
1686 *shift_bits = DEFAULT_NURSERY_BITS;
1690 return sgen_get_nursery_start ();
1694 mono_gc_set_current_thread_appdomain (MonoDomain *domain)
1696 SgenThreadInfo *info = mono_thread_info_current ();
1698 /* Could be called from sgen_thread_unregister () with a NULL info */
1701 info->stopped_domain = domain;
1706 mono_gc_precise_stack_mark_enabled (void)
1708 return !conservative_stack_mark;
1712 mono_gc_get_logfile (void)
1714 return gc_debug_file;
1718 report_finalizer_roots_list (FinalizeReadyEntry *list)
1720 GCRootReport report;
1721 FinalizeReadyEntry *fin;
1724 for (fin = list; fin; fin = fin->next) {
1727 add_profile_gc_root (&report, fin->object, MONO_PROFILE_GC_ROOT_FINALIZER, 0);
1729 notify_gc_roots (&report);
1733 report_finalizer_roots (void)
1735 report_finalizer_roots_list (fin_ready_list);
1736 report_finalizer_roots_list (critical_fin_list);
1739 static GCRootReport *root_report;
1742 single_arg_report_root (void **obj)
1745 add_profile_gc_root (root_report, *obj, MONO_PROFILE_GC_ROOT_OTHER, 0);
1749 precisely_report_roots_from (GCRootReport *report, void** start_root, void** end_root, mword desc)
1751 switch (desc & ROOT_DESC_TYPE_MASK) {
1752 case ROOT_DESC_BITMAP:
1753 desc >>= ROOT_DESC_TYPE_SHIFT;
1755 if ((desc & 1) && *start_root) {
1756 add_profile_gc_root (report, *start_root, MONO_PROFILE_GC_ROOT_OTHER, 0);
1762 case ROOT_DESC_COMPLEX: {
1763 gsize *bitmap_data = sgen_get_complex_descriptor_bitmap (desc);
1764 int bwords = (*bitmap_data) - 1;
1765 void **start_run = start_root;
1767 while (bwords-- > 0) {
1768 gsize bmap = *bitmap_data++;
1769 void **objptr = start_run;
1771 if ((bmap & 1) && *objptr) {
1772 add_profile_gc_root (report, *objptr, MONO_PROFILE_GC_ROOT_OTHER, 0);
1777 start_run += GC_BITS_PER_WORD;
1781 case ROOT_DESC_USER: {
1782 MonoGCRootMarkFunc marker = sgen_get_user_descriptor_func (desc);
1783 root_report = report;
1784 marker (start_root, single_arg_report_root);
1787 case ROOT_DESC_RUN_LEN:
1788 g_assert_not_reached ();
1790 g_assert_not_reached ();
1795 report_registered_roots_by_type (int root_type)
1797 GCRootReport report;
1801 SGEN_HASH_TABLE_FOREACH (&roots_hash [root_type], start_root, root) {
1802 SGEN_LOG (6, "Precise root scan %p-%p (desc: %p)", start_root, root->end_root, (void*)root->root_desc);
1803 precisely_report_roots_from (&report, start_root, (void**)root->end_root, root->root_desc);
1804 } SGEN_HASH_TABLE_FOREACH_END;
1805 notify_gc_roots (&report);
1809 report_registered_roots (void)
1811 report_registered_roots_by_type (ROOT_TYPE_NORMAL);
1812 report_registered_roots_by_type (ROOT_TYPE_WBARRIER);
1816 scan_finalizer_entries (FinalizeReadyEntry *list, ScanCopyContext ctx)
1818 CopyOrMarkObjectFunc copy_func = ctx.copy_func;
1819 SgenGrayQueue *queue = ctx.queue;
1820 FinalizeReadyEntry *fin;
1822 for (fin = list; fin; fin = fin->next) {
1825 SGEN_LOG (5, "Scan of fin ready object: %p (%s)\n", fin->object, safe_name (fin->object));
1826 copy_func (&fin->object, queue);
1831 generation_name (int generation)
1833 switch (generation) {
1834 case GENERATION_NURSERY: return "nursery";
1835 case GENERATION_OLD: return "old";
1836 default: g_assert_not_reached ();
1841 sgen_generation_name (int generation)
1843 return generation_name (generation);
1846 SgenObjectOperations *
1847 sgen_get_current_object_ops (void){
1848 return ¤t_object_ops;
1853 finish_gray_stack (char *start_addr, char *end_addr, int generation, GrayQueue *queue)
1857 int done_with_ephemerons, ephemeron_rounds = 0;
1858 CopyOrMarkObjectFunc copy_func = current_object_ops.copy_or_mark_object;
1859 ScanObjectFunc scan_func = current_object_ops.scan_object;
1860 ScanCopyContext ctx = { scan_func, copy_func, queue };
1863 * We copied all the reachable objects. Now it's the time to copy
1864 * the objects that were not referenced by the roots, but by the copied objects.
1865 * we built a stack of objects pointed to by gray_start: they are
1866 * additional roots and we may add more items as we go.
1867 * We loop until gray_start == gray_objects which means no more objects have
1868 * been added. Note this is iterative: no recursion is involved.
1869 * We need to walk the LO list as well in search of marked big objects
1870 * (use a flag since this is needed only on major collections). We need to loop
1871 * here as well, so keep a counter of marked LO (increasing it in copy_object).
1872 * To achieve better cache locality and cache usage, we drain the gray stack
1873 * frequently, after each object is copied, and just finish the work here.
1875 sgen_drain_gray_stack (-1, ctx);
1877 SGEN_LOG (2, "%s generation done", generation_name (generation));
1880 Reset bridge data, we might have lingering data from a previous collection if this is a major
1881 collection trigged by minor overflow.
1883 We must reset the gathered bridges since their original block might be evacuated due to major
1884 fragmentation in the meanwhile and the bridge code should not have to deal with that.
1886 sgen_bridge_reset_data ();
1889 * Walk the ephemeron tables marking all values with reachable keys. This must be completely done
1890 * before processing finalizable objects or non-tracking weak hamdle to avoid finalizing/clearing
1891 * objects that are in fact reachable.
1893 done_with_ephemerons = 0;
1895 done_with_ephemerons = mark_ephemerons_in_range (start_addr, end_addr, ctx);
1896 sgen_drain_gray_stack (-1, ctx);
1898 } while (!done_with_ephemerons);
1900 sgen_scan_togglerefs (start_addr, end_addr, ctx);
1901 if (generation == GENERATION_OLD)
1902 sgen_scan_togglerefs (sgen_get_nursery_start (), sgen_get_nursery_end (), ctx);
1904 if (sgen_need_bridge_processing ()) {
1905 sgen_collect_bridge_objects (start_addr, end_addr, generation, ctx);
1906 if (generation == GENERATION_OLD)
1907 sgen_collect_bridge_objects (sgen_get_nursery_start (), sgen_get_nursery_end (), GENERATION_NURSERY, ctx);
1911 Make sure we drain the gray stack before processing disappearing links and finalizers.
1912 If we don't make sure it is empty we might wrongly see a live object as dead.
1914 sgen_drain_gray_stack (-1, ctx);
1917 We must clear weak links that don't track resurrection before processing object ready for
1918 finalization so they can be cleared before that.
1920 sgen_null_link_in_range (start_addr, end_addr, generation, TRUE, ctx);
1921 if (generation == GENERATION_OLD)
1922 sgen_null_link_in_range (start_addr, end_addr, GENERATION_NURSERY, TRUE, ctx);
1925 /* walk the finalization queue and move also the objects that need to be
1926 * finalized: use the finalized objects as new roots so the objects they depend
1927 * on are also not reclaimed. As with the roots above, only objects in the nursery
1928 * are marked/copied.
1930 sgen_finalize_in_range (start_addr, end_addr, generation, ctx);
1931 if (generation == GENERATION_OLD)
1932 sgen_finalize_in_range (sgen_get_nursery_start (), sgen_get_nursery_end (), GENERATION_NURSERY, ctx);
1933 /* drain the new stack that might have been created */
1934 SGEN_LOG (6, "Precise scan of gray area post fin");
1935 sgen_drain_gray_stack (-1, ctx);
1938 * This must be done again after processing finalizable objects since CWL slots are cleared only after the key is finalized.
1940 done_with_ephemerons = 0;
1942 done_with_ephemerons = mark_ephemerons_in_range (start_addr, end_addr, ctx);
1943 sgen_drain_gray_stack (-1, ctx);
1945 } while (!done_with_ephemerons);
1948 * Clear ephemeron pairs with unreachable keys.
1949 * We pass the copy func so we can figure out if an array was promoted or not.
1951 clear_unreachable_ephemerons (start_addr, end_addr, ctx);
1954 SGEN_LOG (2, "Finalize queue handling scan for %s generation: %d usecs %d ephemeron rounds", generation_name (generation), TV_ELAPSED (atv, btv), ephemeron_rounds);
1957 * handle disappearing links
1958 * Note we do this after checking the finalization queue because if an object
1959 * survives (at least long enough to be finalized) we don't clear the link.
1960 * This also deals with a possible issue with the monitor reclamation: with the Boehm
1961 * GC a finalized object my lose the monitor because it is cleared before the finalizer is
1964 g_assert (sgen_gray_object_queue_is_empty (queue));
1966 sgen_null_link_in_range (start_addr, end_addr, generation, FALSE, ctx);
1967 if (generation == GENERATION_OLD)
1968 sgen_null_link_in_range (start_addr, end_addr, GENERATION_NURSERY, FALSE, ctx);
1969 if (sgen_gray_object_queue_is_empty (queue))
1971 sgen_drain_gray_stack (-1, ctx);
1974 g_assert (sgen_gray_object_queue_is_empty (queue));
1978 sgen_check_section_scan_starts (GCMemSection *section)
1981 for (i = 0; i < section->num_scan_start; ++i) {
1982 if (section->scan_starts [i]) {
1983 guint size = safe_object_get_size ((MonoObject*) section->scan_starts [i]);
1984 g_assert (size >= sizeof (MonoObject) && size <= MAX_SMALL_OBJ_SIZE);
1990 check_scan_starts (void)
1992 if (!do_scan_starts_check)
1994 sgen_check_section_scan_starts (nursery_section);
1995 major_collector.check_scan_starts ();
1999 scan_from_registered_roots (char *addr_start, char *addr_end, int root_type, ScanCopyContext ctx)
2003 SGEN_HASH_TABLE_FOREACH (&roots_hash [root_type], start_root, root) {
2004 SGEN_LOG (6, "Precise root scan %p-%p (desc: %p)", start_root, root->end_root, (void*)root->root_desc);
2005 precisely_scan_objects_from (start_root, (void**)root->end_root, addr_start, addr_end, root->root_desc, ctx);
2006 } SGEN_HASH_TABLE_FOREACH_END;
2010 sgen_dump_occupied (char *start, char *end, char *section_start)
2012 fprintf (heap_dump_file, "<occupied offset=\"%td\" size=\"%td\"/>\n", start - section_start, end - start);
2016 sgen_dump_section (GCMemSection *section, const char *type)
2018 char *start = section->data;
2019 char *end = section->data + section->size;
2020 char *occ_start = NULL;
2022 char *old_start = NULL; /* just for debugging */
2024 fprintf (heap_dump_file, "<section type=\"%s\" size=\"%lu\">\n", type, (unsigned long)section->size);
2026 while (start < end) {
2030 if (!*(void**)start) {
2032 sgen_dump_occupied (occ_start, start, section->data);
2035 start += sizeof (void*); /* should be ALLOC_ALIGN, really */
2038 g_assert (start < section->next_data);
2043 vt = (GCVTable*)LOAD_VTABLE (start);
2046 size = ALIGN_UP (safe_object_get_size ((MonoObject*) start));
2049 fprintf (heap_dump_file, "<object offset=\"%d\" class=\"%s.%s\" size=\"%d\"/>\n",
2050 start - section->data,
2051 vt->klass->name_space, vt->klass->name,
2059 sgen_dump_occupied (occ_start, start, section->data);
2061 fprintf (heap_dump_file, "</section>\n");
2065 dump_object (MonoObject *obj, gboolean dump_location)
2067 static char class_name [1024];
2069 MonoClass *class = mono_object_class (obj);
2073 * Python's XML parser is too stupid to parse angle brackets
2074 * in strings, so we just ignore them;
2077 while (class->name [i] && j < sizeof (class_name) - 1) {
2078 if (!strchr ("<>\"", class->name [i]))
2079 class_name [j++] = class->name [i];
2082 g_assert (j < sizeof (class_name));
2085 fprintf (heap_dump_file, "<object class=\"%s.%s\" size=\"%d\"",
2086 class->name_space, class_name,
2087 safe_object_get_size (obj));
2088 if (dump_location) {
2089 const char *location;
2090 if (ptr_in_nursery (obj))
2091 location = "nursery";
2092 else if (safe_object_get_size (obj) <= MAX_SMALL_OBJ_SIZE)
2096 fprintf (heap_dump_file, " location=\"%s\"", location);
2098 fprintf (heap_dump_file, "/>\n");
2102 dump_heap (const char *type, int num, const char *reason)
2107 fprintf (heap_dump_file, "<collection type=\"%s\" num=\"%d\"", type, num);
2109 fprintf (heap_dump_file, " reason=\"%s\"", reason);
2110 fprintf (heap_dump_file, ">\n");
2111 fprintf (heap_dump_file, "<other-mem-usage type=\"mempools\" size=\"%ld\"/>\n", mono_mempool_get_bytes_allocated ());
2112 sgen_dump_internal_mem_usage (heap_dump_file);
2113 fprintf (heap_dump_file, "<pinned type=\"stack\" bytes=\"%zu\"/>\n", sgen_pin_stats_get_pinned_byte_count (PIN_TYPE_STACK));
2114 /* fprintf (heap_dump_file, "<pinned type=\"static-data\" bytes=\"%d\"/>\n", pinned_byte_counts [PIN_TYPE_STATIC_DATA]); */
2115 fprintf (heap_dump_file, "<pinned type=\"other\" bytes=\"%zu\"/>\n", sgen_pin_stats_get_pinned_byte_count (PIN_TYPE_OTHER));
2117 fprintf (heap_dump_file, "<pinned-objects>\n");
2118 for (list = sgen_pin_stats_get_object_list (); list; list = list->next)
2119 dump_object (list->obj, TRUE);
2120 fprintf (heap_dump_file, "</pinned-objects>\n");
2122 sgen_dump_section (nursery_section, "nursery");
2124 major_collector.dump_heap (heap_dump_file);
2126 fprintf (heap_dump_file, "<los>\n");
2127 for (bigobj = los_object_list; bigobj; bigobj = bigobj->next)
2128 dump_object ((MonoObject*)bigobj->data, FALSE);
2129 fprintf (heap_dump_file, "</los>\n");
2131 fprintf (heap_dump_file, "</collection>\n");
2135 sgen_register_moved_object (void *obj, void *destination)
2137 g_assert (mono_profiler_events & MONO_PROFILE_GC_MOVES);
2139 /* FIXME: handle this for parallel collector */
2140 g_assert (!sgen_collection_is_parallel ());
2142 if (moved_objects_idx == MOVED_OBJECTS_NUM) {
2143 mono_profiler_gc_moves (moved_objects, moved_objects_idx);
2144 moved_objects_idx = 0;
2146 moved_objects [moved_objects_idx++] = obj;
2147 moved_objects [moved_objects_idx++] = destination;
2153 static gboolean inited = FALSE;
2158 mono_counters_register ("Minor fragment clear", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_minor_pre_collection_fragment_clear);
2159 mono_counters_register ("Minor pinning", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_minor_pinning);
2160 mono_counters_register ("Minor scan remembered set", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_minor_scan_remsets);
2161 mono_counters_register ("Minor scan pinned", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_minor_scan_pinned);
2162 mono_counters_register ("Minor scan registered roots", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_minor_scan_registered_roots);
2163 mono_counters_register ("Minor scan thread data", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_minor_scan_thread_data);
2164 mono_counters_register ("Minor finish gray stack", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_minor_finish_gray_stack);
2165 mono_counters_register ("Minor fragment creation", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_minor_fragment_creation);
2167 mono_counters_register ("Major fragment clear", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_major_pre_collection_fragment_clear);
2168 mono_counters_register ("Major pinning", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_major_pinning);
2169 mono_counters_register ("Major scan pinned", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_major_scan_pinned);
2170 mono_counters_register ("Major scan registered roots", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_major_scan_registered_roots);
2171 mono_counters_register ("Major scan thread data", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_major_scan_thread_data);
2172 mono_counters_register ("Major scan alloc_pinned", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_major_scan_alloc_pinned);
2173 mono_counters_register ("Major scan finalized", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_major_scan_finalized);
2174 mono_counters_register ("Major scan big objects", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_major_scan_big_objects);
2175 mono_counters_register ("Major finish gray stack", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_major_finish_gray_stack);
2176 mono_counters_register ("Major free big objects", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_major_free_bigobjs);
2177 mono_counters_register ("Major LOS sweep", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_major_los_sweep);
2178 mono_counters_register ("Major sweep", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_major_sweep);
2179 mono_counters_register ("Major fragment creation", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_major_fragment_creation);
2181 mono_counters_register ("Number of pinned objects", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_pinned_objects);
2183 #ifdef HEAVY_STATISTICS
2184 mono_counters_register ("WBarrier set field", MONO_COUNTER_GC | MONO_COUNTER_INT, &stat_wbarrier_set_field);
2185 mono_counters_register ("WBarrier set arrayref", MONO_COUNTER_GC | MONO_COUNTER_INT, &stat_wbarrier_set_arrayref);
2186 mono_counters_register ("WBarrier arrayref copy", MONO_COUNTER_GC | MONO_COUNTER_INT, &stat_wbarrier_arrayref_copy);
2187 mono_counters_register ("WBarrier generic store called", MONO_COUNTER_GC | MONO_COUNTER_INT, &stat_wbarrier_generic_store);
2188 mono_counters_register ("WBarrier set root", MONO_COUNTER_GC | MONO_COUNTER_INT, &stat_wbarrier_set_root);
2189 mono_counters_register ("WBarrier value copy", MONO_COUNTER_GC | MONO_COUNTER_INT, &stat_wbarrier_value_copy);
2190 mono_counters_register ("WBarrier object copy", MONO_COUNTER_GC | MONO_COUNTER_INT, &stat_wbarrier_object_copy);
2192 mono_counters_register ("# objects allocated degraded", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_objects_alloced_degraded);
2193 mono_counters_register ("bytes allocated degraded", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_bytes_alloced_degraded);
2195 mono_counters_register ("# copy_object() called (nursery)", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_copy_object_called_nursery);
2196 mono_counters_register ("# objects copied (nursery)", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_objects_copied_nursery);
2197 mono_counters_register ("# copy_object() called (major)", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_copy_object_called_major);
2198 mono_counters_register ("# objects copied (major)", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_objects_copied_major);
2200 mono_counters_register ("# scan_object() called (nursery)", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_scan_object_called_nursery);
2201 mono_counters_register ("# scan_object() called (major)", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_scan_object_called_major);
2203 mono_counters_register ("Slots allocated in vain", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_slots_allocated_in_vain);
2205 mono_counters_register ("# nursery copy_object() failed from space", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_nursery_copy_object_failed_from_space);
2206 mono_counters_register ("# nursery copy_object() failed forwarded", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_nursery_copy_object_failed_forwarded);
2207 mono_counters_register ("# nursery copy_object() failed pinned", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_nursery_copy_object_failed_pinned);
2208 mono_counters_register ("# nursery copy_object() failed to space", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_nursery_copy_object_failed_to_space);
2210 sgen_nursery_allocator_init_heavy_stats ();
2211 sgen_alloc_init_heavy_stats ();
2219 reset_pinned_from_failed_allocation (void)
2221 bytes_pinned_from_failed_allocation = 0;
2225 sgen_set_pinned_from_failed_allocation (mword objsize)
2227 bytes_pinned_from_failed_allocation += objsize;
2231 sgen_collection_is_parallel (void)
2233 switch (current_collection_generation) {
2234 case GENERATION_NURSERY:
2235 return nursery_collection_is_parallel;
2236 case GENERATION_OLD:
2237 return major_collector.is_parallel;
2239 g_error ("Invalid current generation %d", current_collection_generation);
2244 sgen_collection_is_concurrent (void)
2246 switch (current_collection_generation) {
2247 case GENERATION_NURSERY:
2249 case GENERATION_OLD:
2250 return major_collector.is_concurrent;
2252 g_error ("Invalid current generation %d", current_collection_generation);
2257 sgen_concurrent_collection_in_progress (void)
2259 return concurrent_collection_in_progress;
2266 } FinishRememberedSetScanJobData;
2269 job_finish_remembered_set_scan (WorkerData *worker_data, void *job_data_untyped)
2271 FinishRememberedSetScanJobData *job_data = job_data_untyped;
2273 remset.finish_scan_remsets (job_data->heap_start, job_data->heap_end, sgen_workers_get_job_gray_queue (worker_data));
2274 sgen_free_internal_dynamic (job_data, sizeof (FinishRememberedSetScanJobData), INTERNAL_MEM_WORKER_JOB_DATA);
2279 CopyOrMarkObjectFunc copy_or_mark_func;
2280 ScanObjectFunc scan_func;
2284 } ScanFromRegisteredRootsJobData;
2287 job_scan_from_registered_roots (WorkerData *worker_data, void *job_data_untyped)
2289 ScanFromRegisteredRootsJobData *job_data = job_data_untyped;
2290 ScanCopyContext ctx = { job_data->scan_func, job_data->copy_or_mark_func,
2291 sgen_workers_get_job_gray_queue (worker_data) };
2293 scan_from_registered_roots (job_data->heap_start, job_data->heap_end, job_data->root_type, ctx);
2294 sgen_free_internal_dynamic (job_data, sizeof (ScanFromRegisteredRootsJobData), INTERNAL_MEM_WORKER_JOB_DATA);
2301 } ScanThreadDataJobData;
2304 job_scan_thread_data (WorkerData *worker_data, void *job_data_untyped)
2306 ScanThreadDataJobData *job_data = job_data_untyped;
2308 scan_thread_data (job_data->heap_start, job_data->heap_end, TRUE,
2309 sgen_workers_get_job_gray_queue (worker_data));
2310 sgen_free_internal_dynamic (job_data, sizeof (ScanThreadDataJobData), INTERNAL_MEM_WORKER_JOB_DATA);
2315 FinalizeReadyEntry *list;
2316 } ScanFinalizerEntriesJobData;
2319 job_scan_finalizer_entries (WorkerData *worker_data, void *job_data_untyped)
2321 ScanFinalizerEntriesJobData *job_data = job_data_untyped;
2322 ScanCopyContext ctx = { NULL, current_object_ops.copy_or_mark_object, sgen_workers_get_job_gray_queue (worker_data) };
2324 scan_finalizer_entries (job_data->list, ctx);
2325 sgen_free_internal_dynamic (job_data, sizeof (ScanFinalizerEntriesJobData), INTERNAL_MEM_WORKER_JOB_DATA);
2329 job_scan_major_mod_union_cardtable (WorkerData *worker_data, void *job_data_untyped)
2331 g_assert (concurrent_collection_in_progress);
2332 major_collector.scan_card_table (TRUE, sgen_workers_get_job_gray_queue (worker_data));
2336 job_scan_los_mod_union_cardtable (WorkerData *worker_data, void *job_data_untyped)
2338 g_assert (concurrent_collection_in_progress);
2339 sgen_los_scan_card_table (TRUE, sgen_workers_get_job_gray_queue (worker_data));
2343 verify_scan_starts (char *start, char *end)
2347 for (i = 0; i < nursery_section->num_scan_start; ++i) {
2348 char *addr = nursery_section->scan_starts [i];
2349 if (addr > start && addr < end)
2350 SGEN_LOG (1, "NFC-BAD SCAN START [%d] %p for obj [%p %p]", i, addr, start, end);
2355 verify_nursery (void)
2357 char *start, *end, *cur, *hole_start;
2359 if (!do_verify_nursery)
2362 /*This cleans up unused fragments */
2363 sgen_nursery_allocator_prepare_for_pinning ();
2365 hole_start = start = cur = sgen_get_nursery_start ();
2366 end = sgen_get_nursery_end ();
2371 if (!*(void**)cur) {
2372 cur += sizeof (void*);
2376 if (object_is_forwarded (cur))
2377 SGEN_LOG (1, "FORWARDED OBJ %p", cur);
2378 else if (object_is_pinned (cur))
2379 SGEN_LOG (1, "PINNED OBJ %p", cur);
2381 ss = safe_object_get_size ((MonoObject*)cur);
2382 size = ALIGN_UP (safe_object_get_size ((MonoObject*)cur));
2383 verify_scan_starts (cur, cur + size);
2384 if (do_dump_nursery_content) {
2385 if (cur > hole_start)
2386 SGEN_LOG (1, "HOLE [%p %p %d]", hole_start, cur, (int)(cur - hole_start));
2387 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 ());
2395 * Checks that no objects in the nursery are fowarded or pinned. This
2396 * is a precondition to restarting the mutator while doing a
2397 * concurrent collection. Note that we don't clear fragments because
2398 * we depend on that having happened earlier.
2401 check_nursery_is_clean (void)
2403 char *start, *end, *cur;
2405 start = cur = sgen_get_nursery_start ();
2406 end = sgen_get_nursery_end ();
2411 if (!*(void**)cur) {
2412 cur += sizeof (void*);
2416 g_assert (!object_is_forwarded (cur));
2417 g_assert (!object_is_pinned (cur));
2419 ss = safe_object_get_size ((MonoObject*)cur);
2420 size = ALIGN_UP (safe_object_get_size ((MonoObject*)cur));
2421 verify_scan_starts (cur, cur + size);
2428 init_gray_queue (void)
2430 if (sgen_collection_is_parallel () || sgen_collection_is_concurrent ()) {
2431 sgen_workers_init_distribute_gray_queue ();
2432 sgen_gray_object_queue_init_with_alloc_prepare (&gray_queue, NULL,
2433 gray_queue_redirect, sgen_workers_get_distribute_section_gray_queue ());
2435 sgen_gray_object_queue_init (&gray_queue, NULL);
2438 if (major_collector.is_concurrent) {
2439 sgen_gray_object_queue_init_with_alloc_prepare (&remember_major_objects_gray_queue, NULL,
2440 gray_queue_redirect, sgen_workers_get_distribute_section_gray_queue ());
2442 sgen_gray_object_queue_init_invalid (&remember_major_objects_gray_queue);
2447 * Collect objects in the nursery. Returns whether to trigger a major
2451 collect_nursery (SgenGrayQueue *unpin_queue)
2453 gboolean needs_major;
2454 size_t max_garbage_amount;
2456 FinishRememberedSetScanJobData *frssjd;
2457 ScanFromRegisteredRootsJobData *scrrjd_normal, *scrrjd_wbarrier;
2458 ScanFinalizerEntriesJobData *sfejd_fin_ready, *sfejd_critical_fin;
2459 ScanThreadDataJobData *stdjd;
2460 mword fragment_total;
2461 ScanCopyContext ctx;
2462 TV_DECLARE (all_atv);
2463 TV_DECLARE (all_btv);
2467 if (disable_minor_collections)
2470 MONO_GC_BEGIN (GENERATION_NURSERY);
2471 binary_protocol_collection_begin (stat_minor_gcs, GENERATION_NURSERY);
2475 #ifndef DISABLE_PERFCOUNTERS
2476 mono_perfcounters->gc_collections0++;
2479 current_collection_generation = GENERATION_NURSERY;
2480 if (sgen_collection_is_parallel ())
2481 current_object_ops = sgen_minor_collector.parallel_ops;
2483 current_object_ops = sgen_minor_collector.serial_ops;
2485 reset_pinned_from_failed_allocation ();
2487 check_scan_starts ();
2489 sgen_nursery_alloc_prepare_for_minor ();
2493 nursery_next = sgen_nursery_alloc_get_upper_alloc_bound ();
2494 /* FIXME: optimize later to use the higher address where an object can be present */
2495 nursery_next = MAX (nursery_next, sgen_get_nursery_end ());
2497 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 ()));
2498 max_garbage_amount = nursery_next - sgen_get_nursery_start ();
2499 g_assert (nursery_section->size >= max_garbage_amount);
2501 /* world must be stopped already */
2502 TV_GETTIME (all_atv);
2506 time_minor_pre_collection_fragment_clear += TV_ELAPSED (atv, btv);
2508 if (xdomain_checks) {
2509 sgen_clear_nursery_fragments ();
2510 check_for_xdomain_refs ();
2513 nursery_section->next_data = nursery_next;
2515 major_collector.start_nursery_collection ();
2517 sgen_memgov_minor_collection_start ();
2522 gc_stats.minor_gc_count ++;
2524 if (remset.prepare_for_minor_collection)
2525 remset.prepare_for_minor_collection ();
2527 MONO_GC_CHECKPOINT_1 (GENERATION_NURSERY);
2529 sgen_process_fin_stage_entries ();
2530 sgen_process_dislink_stage_entries ();
2532 MONO_GC_CHECKPOINT_2 (GENERATION_NURSERY);
2534 /* pin from pinned handles */
2535 sgen_init_pinning ();
2536 mono_profiler_gc_event (MONO_GC_EVENT_MARK_START, 0);
2537 pin_from_roots (sgen_get_nursery_start (), nursery_next, WORKERS_DISTRIBUTE_GRAY_QUEUE);
2538 /* identify pinned objects */
2539 sgen_optimize_pin_queue (0);
2540 sgen_pinning_setup_section (nursery_section);
2541 ctx.scan_func = NULL;
2542 ctx.copy_func = NULL;
2543 ctx.queue = WORKERS_DISTRIBUTE_GRAY_QUEUE;
2544 sgen_pin_objects_in_section (nursery_section, ctx);
2545 sgen_pinning_trim_queue_to_section (nursery_section);
2548 time_minor_pinning += TV_ELAPSED (btv, atv);
2549 SGEN_LOG (2, "Finding pinned pointers: %d in %d usecs", sgen_get_pinned_count (), TV_ELAPSED (btv, atv));
2550 SGEN_LOG (4, "Start scan with %d pinned objects", sgen_get_pinned_count ());
2552 MONO_GC_CHECKPOINT_3 (GENERATION_NURSERY);
2554 if (whole_heap_check_before_collection) {
2555 sgen_clear_nursery_fragments ();
2556 sgen_check_whole_heap ();
2558 if (consistency_check_at_minor_collection)
2559 sgen_check_consistency ();
2561 sgen_workers_start_all_workers ();
2564 * Perform the sequential part of remembered set scanning.
2565 * This usually involves scanning global information that might later be produced by evacuation.
2567 if (remset.begin_scan_remsets)
2568 remset.begin_scan_remsets (sgen_get_nursery_start (), nursery_next, WORKERS_DISTRIBUTE_GRAY_QUEUE);
2570 sgen_workers_start_marking ();
2572 frssjd = sgen_alloc_internal_dynamic (sizeof (FinishRememberedSetScanJobData), INTERNAL_MEM_WORKER_JOB_DATA, TRUE);
2573 frssjd->heap_start = sgen_get_nursery_start ();
2574 frssjd->heap_end = nursery_next;
2575 sgen_workers_enqueue_job (job_finish_remembered_set_scan, frssjd);
2577 /* we don't have complete write barrier yet, so we scan all the old generation sections */
2579 time_minor_scan_remsets += TV_ELAPSED (atv, btv);
2580 SGEN_LOG (2, "Old generation scan: %d usecs", TV_ELAPSED (atv, btv));
2582 MONO_GC_CHECKPOINT_4 (GENERATION_NURSERY);
2584 if (!sgen_collection_is_parallel ()) {
2585 ctx.scan_func = current_object_ops.scan_object;
2586 ctx.copy_func = NULL;
2587 ctx.queue = &gray_queue;
2588 sgen_drain_gray_stack (-1, ctx);
2591 if (mono_profiler_get_events () & MONO_PROFILE_GC_ROOTS)
2592 report_registered_roots ();
2593 if (mono_profiler_get_events () & MONO_PROFILE_GC_ROOTS)
2594 report_finalizer_roots ();
2596 time_minor_scan_pinned += TV_ELAPSED (btv, atv);
2598 MONO_GC_CHECKPOINT_5 (GENERATION_NURSERY);
2600 /* registered roots, this includes static fields */
2601 scrrjd_normal = sgen_alloc_internal_dynamic (sizeof (ScanFromRegisteredRootsJobData), INTERNAL_MEM_WORKER_JOB_DATA, TRUE);
2602 scrrjd_normal->copy_or_mark_func = current_object_ops.copy_or_mark_object;
2603 scrrjd_normal->scan_func = current_object_ops.scan_object;
2604 scrrjd_normal->heap_start = sgen_get_nursery_start ();
2605 scrrjd_normal->heap_end = nursery_next;
2606 scrrjd_normal->root_type = ROOT_TYPE_NORMAL;
2607 sgen_workers_enqueue_job (job_scan_from_registered_roots, scrrjd_normal);
2609 scrrjd_wbarrier = sgen_alloc_internal_dynamic (sizeof (ScanFromRegisteredRootsJobData), INTERNAL_MEM_WORKER_JOB_DATA, TRUE);
2610 scrrjd_wbarrier->copy_or_mark_func = current_object_ops.copy_or_mark_object;
2611 scrrjd_wbarrier->scan_func = current_object_ops.scan_object;
2612 scrrjd_wbarrier->heap_start = sgen_get_nursery_start ();
2613 scrrjd_wbarrier->heap_end = nursery_next;
2614 scrrjd_wbarrier->root_type = ROOT_TYPE_WBARRIER;
2615 sgen_workers_enqueue_job (job_scan_from_registered_roots, scrrjd_wbarrier);
2618 time_minor_scan_registered_roots += TV_ELAPSED (atv, btv);
2620 MONO_GC_CHECKPOINT_6 (GENERATION_NURSERY);
2623 stdjd = sgen_alloc_internal_dynamic (sizeof (ScanThreadDataJobData), INTERNAL_MEM_WORKER_JOB_DATA, TRUE);
2624 stdjd->heap_start = sgen_get_nursery_start ();
2625 stdjd->heap_end = nursery_next;
2626 sgen_workers_enqueue_job (job_scan_thread_data, stdjd);
2629 time_minor_scan_thread_data += TV_ELAPSED (btv, atv);
2632 MONO_GC_CHECKPOINT_7 (GENERATION_NURSERY);
2634 g_assert (!sgen_collection_is_parallel () && !sgen_collection_is_concurrent ());
2636 if (sgen_collection_is_parallel () || sgen_collection_is_concurrent ())
2637 g_assert (sgen_gray_object_queue_is_empty (&gray_queue));
2639 /* Scan the list of objects ready for finalization. If */
2640 sfejd_fin_ready = sgen_alloc_internal_dynamic (sizeof (ScanFinalizerEntriesJobData), INTERNAL_MEM_WORKER_JOB_DATA, TRUE);
2641 sfejd_fin_ready->list = fin_ready_list;
2642 sgen_workers_enqueue_job (job_scan_finalizer_entries, sfejd_fin_ready);
2644 sfejd_critical_fin = sgen_alloc_internal_dynamic (sizeof (ScanFinalizerEntriesJobData), INTERNAL_MEM_WORKER_JOB_DATA, TRUE);
2645 sfejd_critical_fin->list = critical_fin_list;
2646 sgen_workers_enqueue_job (job_scan_finalizer_entries, sfejd_critical_fin);
2648 MONO_GC_CHECKPOINT_8 (GENERATION_NURSERY);
2650 finish_gray_stack (sgen_get_nursery_start (), nursery_next, GENERATION_NURSERY, &gray_queue);
2652 time_minor_finish_gray_stack += TV_ELAPSED (btv, atv);
2653 mono_profiler_gc_event (MONO_GC_EVENT_MARK_END, 0);
2655 MONO_GC_CHECKPOINT_9 (GENERATION_NURSERY);
2658 * The (single-threaded) finalization code might have done
2659 * some copying/marking so we can only reset the GC thread's
2660 * worker data here instead of earlier when we joined the
2663 sgen_workers_reset_data ();
2665 if (objects_pinned) {
2666 sgen_optimize_pin_queue (0);
2667 sgen_pinning_setup_section (nursery_section);
2670 /* walk the pin_queue, build up the fragment list of free memory, unmark
2671 * pinned objects as we go, memzero() the empty fragments so they are ready for the
2674 mono_profiler_gc_event (MONO_GC_EVENT_RECLAIM_START, 0);
2675 fragment_total = sgen_build_nursery_fragments (nursery_section,
2676 nursery_section->pin_queue_start, nursery_section->pin_queue_num_entries,
2678 if (!fragment_total)
2681 /* Clear TLABs for all threads */
2682 sgen_clear_tlabs ();
2684 mono_profiler_gc_event (MONO_GC_EVENT_RECLAIM_END, 0);
2686 time_minor_fragment_creation += TV_ELAPSED (atv, btv);
2687 SGEN_LOG (2, "Fragment creation: %d usecs, %lu bytes available", TV_ELAPSED (atv, btv), (unsigned long)fragment_total);
2689 if (consistency_check_at_minor_collection)
2690 sgen_check_major_refs ();
2692 major_collector.finish_nursery_collection ();
2694 TV_GETTIME (all_btv);
2695 gc_stats.minor_gc_time_usecs += TV_ELAPSED (all_atv, all_btv);
2698 dump_heap ("minor", stat_minor_gcs - 1, NULL);
2700 /* prepare the pin queue for the next collection */
2701 sgen_finish_pinning ();
2702 if (fin_ready_list || critical_fin_list) {
2703 SGEN_LOG (4, "Finalizer-thread wakeup: ready %d", num_ready_finalizers);
2704 mono_gc_finalize_notify ();
2706 sgen_pin_stats_reset ();
2708 g_assert (sgen_gray_object_queue_is_empty (&gray_queue));
2710 if (remset.finish_minor_collection)
2711 remset.finish_minor_collection ();
2713 check_scan_starts ();
2715 binary_protocol_flush_buffers (FALSE);
2717 sgen_memgov_minor_collection_end ();
2719 /*objects are late pinned because of lack of memory, so a major is a good call*/
2720 needs_major = objects_pinned > 0;
2721 current_collection_generation = -1;
2724 MONO_GC_END (GENERATION_NURSERY);
2725 binary_protocol_collection_end (stat_minor_gcs - 1, GENERATION_NURSERY);
2731 major_copy_or_mark_from_roots (int *old_next_pin_slot, gboolean finish_up_concurrent_mark, gboolean scan_mod_union)
2736 /* FIXME: only use these values for the precise scan
2737 * note that to_space pointers should be excluded anyway...
2739 char *heap_start = NULL;
2740 char *heap_end = (char*)-1;
2741 gboolean profile_roots = mono_profiler_get_events () & MONO_PROFILE_GC_ROOTS;
2742 GCRootReport root_report = { 0 };
2743 ScanFromRegisteredRootsJobData *scrrjd_normal, *scrrjd_wbarrier;
2744 ScanThreadDataJobData *stdjd;
2745 ScanFinalizerEntriesJobData *sfejd_fin_ready, *sfejd_critical_fin;
2746 ScanCopyContext ctx;
2748 if (major_collector.is_concurrent) {
2749 /*This cleans up unused fragments */
2750 sgen_nursery_allocator_prepare_for_pinning ();
2752 if (do_concurrent_checks)
2753 check_nursery_is_clean ();
2755 /* The concurrent collector doesn't touch the nursery. */
2756 sgen_nursery_alloc_prepare_for_major ();
2763 /* Pinning depends on this */
2764 sgen_clear_nursery_fragments ();
2766 if (whole_heap_check_before_collection)
2767 sgen_check_whole_heap ();
2770 time_major_pre_collection_fragment_clear += TV_ELAPSED (atv, btv);
2772 if (!sgen_collection_is_concurrent ())
2773 nursery_section->next_data = sgen_get_nursery_end ();
2774 /* we should also coalesce scanning from sections close to each other
2775 * and deal with pointers outside of the sections later.
2779 *major_collector.have_swept = FALSE;
2781 if (xdomain_checks) {
2782 sgen_clear_nursery_fragments ();
2783 check_for_xdomain_refs ();
2786 if (!major_collector.is_concurrent) {
2787 /* Remsets are not useful for a major collection */
2788 remset.prepare_for_major_collection ();
2791 sgen_process_fin_stage_entries ();
2792 sgen_process_dislink_stage_entries ();
2795 sgen_init_pinning ();
2796 SGEN_LOG (6, "Collecting pinned addresses");
2797 pin_from_roots ((void*)lowest_heap_address, (void*)highest_heap_address, WORKERS_DISTRIBUTE_GRAY_QUEUE);
2798 sgen_optimize_pin_queue (0);
2801 * The concurrent collector doesn't move objects, neither on
2802 * the major heap nor in the nursery, so we can mark even
2803 * before pinning has finished. For the non-concurrent
2804 * collector we start the workers after pinning.
2806 if (major_collector.is_concurrent) {
2807 sgen_workers_start_all_workers ();
2808 sgen_workers_start_marking ();
2812 * pin_queue now contains all candidate pointers, sorted and
2813 * uniqued. We must do two passes now to figure out which
2814 * objects are pinned.
2816 * The first is to find within the pin_queue the area for each
2817 * section. This requires that the pin_queue be sorted. We
2818 * also process the LOS objects and pinned chunks here.
2820 * The second, destructive, pass is to reduce the section
2821 * areas to pointers to the actually pinned objects.
2823 SGEN_LOG (6, "Pinning from sections");
2824 /* first pass for the sections */
2825 sgen_find_section_pin_queue_start_end (nursery_section);
2826 major_collector.find_pin_queue_start_ends (WORKERS_DISTRIBUTE_GRAY_QUEUE);
2827 /* identify possible pointers to the insize of large objects */
2828 SGEN_LOG (6, "Pinning from large objects");
2829 for (bigobj = los_object_list; bigobj; bigobj = bigobj->next) {
2831 if (sgen_find_optimized_pin_queue_area (bigobj->data, (char*)bigobj->data + sgen_los_object_size (bigobj), &dummy)) {
2832 binary_protocol_pin (bigobj->data, (gpointer)LOAD_VTABLE (bigobj->data), safe_object_get_size (((MonoObject*)(bigobj->data))));
2833 if (G_UNLIKELY (MONO_GC_OBJ_PINNED_ENABLED ())) {
2834 MonoVTable *vt = (MonoVTable*)LOAD_VTABLE (bigobj->data);
2835 MONO_GC_OBJ_PINNED ((mword)bigobj->data, sgen_safe_object_get_size ((MonoObject*)bigobj->data), vt->klass->name_space, vt->klass->name, GENERATION_OLD);
2837 if (sgen_los_object_is_pinned (bigobj->data)) {
2838 g_assert (finish_up_concurrent_mark);
2841 sgen_los_pin_object (bigobj->data);
2842 /* FIXME: only enqueue if object has references */
2843 GRAY_OBJECT_ENQUEUE (WORKERS_DISTRIBUTE_GRAY_QUEUE, bigobj->data);
2844 if (G_UNLIKELY (do_pin_stats))
2845 sgen_pin_stats_register_object ((char*) bigobj->data, safe_object_get_size ((MonoObject*) bigobj->data));
2846 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));
2849 add_profile_gc_root (&root_report, bigobj->data, MONO_PROFILE_GC_ROOT_PINNING | MONO_PROFILE_GC_ROOT_MISC, 0);
2853 notify_gc_roots (&root_report);
2854 /* second pass for the sections */
2855 ctx.scan_func = concurrent_collection_in_progress ? current_object_ops.scan_object : NULL;
2856 ctx.copy_func = NULL;
2857 ctx.queue = WORKERS_DISTRIBUTE_GRAY_QUEUE;
2858 sgen_pin_objects_in_section (nursery_section, ctx);
2859 major_collector.pin_objects (WORKERS_DISTRIBUTE_GRAY_QUEUE);
2860 if (old_next_pin_slot)
2861 *old_next_pin_slot = sgen_get_pinned_count ();
2864 time_major_pinning += TV_ELAPSED (atv, btv);
2865 SGEN_LOG (2, "Finding pinned pointers: %d in %d usecs", sgen_get_pinned_count (), TV_ELAPSED (atv, btv));
2866 SGEN_LOG (4, "Start scan with %d pinned objects", sgen_get_pinned_count ());
2868 major_collector.init_to_space ();
2870 #ifdef SGEN_DEBUG_INTERNAL_ALLOC
2871 main_gc_thread = mono_native_thread_self ();
2874 if (!major_collector.is_concurrent) {
2875 sgen_workers_start_all_workers ();
2876 sgen_workers_start_marking ();
2879 if (mono_profiler_get_events () & MONO_PROFILE_GC_ROOTS)
2880 report_registered_roots ();
2882 time_major_scan_pinned += TV_ELAPSED (btv, atv);
2884 /* registered roots, this includes static fields */
2885 scrrjd_normal = sgen_alloc_internal_dynamic (sizeof (ScanFromRegisteredRootsJobData), INTERNAL_MEM_WORKER_JOB_DATA, TRUE);
2886 scrrjd_normal->copy_or_mark_func = current_object_ops.copy_or_mark_object;
2887 scrrjd_normal->scan_func = current_object_ops.scan_object;
2888 scrrjd_normal->heap_start = heap_start;
2889 scrrjd_normal->heap_end = heap_end;
2890 scrrjd_normal->root_type = ROOT_TYPE_NORMAL;
2891 sgen_workers_enqueue_job (job_scan_from_registered_roots, scrrjd_normal);
2893 scrrjd_wbarrier = sgen_alloc_internal_dynamic (sizeof (ScanFromRegisteredRootsJobData), INTERNAL_MEM_WORKER_JOB_DATA, TRUE);
2894 scrrjd_wbarrier->copy_or_mark_func = current_object_ops.copy_or_mark_object;
2895 scrrjd_wbarrier->scan_func = current_object_ops.scan_object;
2896 scrrjd_wbarrier->heap_start = heap_start;
2897 scrrjd_wbarrier->heap_end = heap_end;
2898 scrrjd_wbarrier->root_type = ROOT_TYPE_WBARRIER;
2899 sgen_workers_enqueue_job (job_scan_from_registered_roots, scrrjd_wbarrier);
2902 time_major_scan_registered_roots += TV_ELAPSED (atv, btv);
2905 stdjd = sgen_alloc_internal_dynamic (sizeof (ScanThreadDataJobData), INTERNAL_MEM_WORKER_JOB_DATA, TRUE);
2906 stdjd->heap_start = heap_start;
2907 stdjd->heap_end = heap_end;
2908 sgen_workers_enqueue_job (job_scan_thread_data, stdjd);
2911 time_major_scan_thread_data += TV_ELAPSED (btv, atv);
2914 time_major_scan_alloc_pinned += TV_ELAPSED (atv, btv);
2916 if (mono_profiler_get_events () & MONO_PROFILE_GC_ROOTS)
2917 report_finalizer_roots ();
2919 /* scan the list of objects ready for finalization */
2920 sfejd_fin_ready = sgen_alloc_internal_dynamic (sizeof (ScanFinalizerEntriesJobData), INTERNAL_MEM_WORKER_JOB_DATA, TRUE);
2921 sfejd_fin_ready->list = fin_ready_list;
2922 sgen_workers_enqueue_job (job_scan_finalizer_entries, sfejd_fin_ready);
2924 sfejd_critical_fin = sgen_alloc_internal_dynamic (sizeof (ScanFinalizerEntriesJobData), INTERNAL_MEM_WORKER_JOB_DATA, TRUE);
2925 sfejd_critical_fin->list = critical_fin_list;
2926 sgen_workers_enqueue_job (job_scan_finalizer_entries, sfejd_critical_fin);
2928 if (scan_mod_union) {
2929 g_assert (finish_up_concurrent_mark);
2931 /* Mod union card table */
2932 sgen_workers_enqueue_job (job_scan_major_mod_union_cardtable, NULL);
2933 sgen_workers_enqueue_job (job_scan_los_mod_union_cardtable, NULL);
2937 time_major_scan_finalized += TV_ELAPSED (btv, atv);
2938 SGEN_LOG (2, "Root scan: %d usecs", TV_ELAPSED (btv, atv));
2941 time_major_scan_big_objects += TV_ELAPSED (atv, btv);
2943 if (major_collector.is_concurrent) {
2944 /* prepare the pin queue for the next collection */
2945 sgen_finish_pinning ();
2947 sgen_pin_stats_reset ();
2949 if (do_concurrent_checks)
2950 check_nursery_is_clean ();
2955 major_start_collection (int *old_next_pin_slot)
2957 MONO_GC_BEGIN (GENERATION_OLD);
2958 binary_protocol_collection_begin (stat_major_gcs, GENERATION_OLD);
2960 current_collection_generation = GENERATION_OLD;
2961 #ifndef DISABLE_PERFCOUNTERS
2962 mono_perfcounters->gc_collections1++;
2965 g_assert (sgen_section_gray_queue_is_empty (sgen_workers_get_distribute_section_gray_queue ()));
2967 if (major_collector.is_concurrent)
2968 concurrent_collection_in_progress = TRUE;
2970 current_object_ops = major_collector.major_ops;
2972 reset_pinned_from_failed_allocation ();
2974 sgen_memgov_major_collection_start ();
2976 //count_ref_nonref_objs ();
2977 //consistency_check ();
2979 check_scan_starts ();
2982 SGEN_LOG (1, "Start major collection %d", stat_major_gcs);
2984 gc_stats.major_gc_count ++;
2986 if (major_collector.start_major_collection)
2987 major_collector.start_major_collection ();
2989 major_copy_or_mark_from_roots (old_next_pin_slot, FALSE, FALSE);
2993 wait_for_workers_to_finish (void)
2995 g_assert (sgen_gray_object_queue_is_empty (&remember_major_objects_gray_queue));
2997 if (major_collector.is_parallel || major_collector.is_concurrent) {
2998 gray_queue_redirect (&gray_queue);
2999 sgen_workers_join ();
3002 g_assert (sgen_gray_object_queue_is_empty (&gray_queue));
3004 #ifdef SGEN_DEBUG_INTERNAL_ALLOC
3005 main_gc_thread = NULL;
3010 major_finish_collection (const char *reason, int old_next_pin_slot, gboolean scan_mod_union)
3012 LOSObject *bigobj, *prevbo;
3015 char *heap_start = NULL;
3016 char *heap_end = (char*)-1;
3020 if (major_collector.is_concurrent || major_collector.is_parallel)
3021 wait_for_workers_to_finish ();
3023 current_object_ops = major_collector.major_ops;
3025 if (major_collector.is_concurrent) {
3026 major_copy_or_mark_from_roots (NULL, TRUE, scan_mod_union);
3027 wait_for_workers_to_finish ();
3029 g_assert (sgen_gray_object_queue_is_empty (&gray_queue));
3031 if (do_concurrent_checks)
3032 check_nursery_is_clean ();
3036 * The workers have stopped so we need to finish gray queue
3037 * work that might result from finalization in the main GC
3038 * thread. Redirection must therefore be turned off.
3040 sgen_gray_object_queue_disable_alloc_prepare (&gray_queue);
3041 g_assert (sgen_section_gray_queue_is_empty (sgen_workers_get_distribute_section_gray_queue ()));
3043 /* all the objects in the heap */
3044 finish_gray_stack (heap_start, heap_end, GENERATION_OLD, &gray_queue);
3046 time_major_finish_gray_stack += TV_ELAPSED (btv, atv);
3049 * The (single-threaded) finalization code might have done
3050 * some copying/marking so we can only reset the GC thread's
3051 * worker data here instead of earlier when we joined the
3054 sgen_workers_reset_data ();
3056 if (objects_pinned) {
3057 g_assert (!major_collector.is_concurrent);
3059 /*This is slow, but we just OOM'd*/
3060 sgen_pin_queue_clear_discarded_entries (nursery_section, old_next_pin_slot);
3061 sgen_optimize_pin_queue (0);
3062 sgen_find_section_pin_queue_start_end (nursery_section);
3066 reset_heap_boundaries ();
3067 sgen_update_heap_boundaries ((mword)sgen_get_nursery_start (), (mword)sgen_get_nursery_end ());
3069 MONO_GC_SWEEP_BEGIN (GENERATION_OLD, !major_collector.sweeps_lazily);
3071 /* sweep the big objects list */
3073 for (bigobj = los_object_list; bigobj;) {
3074 g_assert (!object_is_pinned (bigobj->data));
3075 if (sgen_los_object_is_pinned (bigobj->data)) {
3076 sgen_los_unpin_object (bigobj->data);
3077 sgen_update_heap_boundaries ((mword)bigobj->data, (mword)bigobj->data + sgen_los_object_size (bigobj));
3080 /* not referenced anywhere, so we can free it */
3082 prevbo->next = bigobj->next;
3084 los_object_list = bigobj->next;
3086 bigobj = bigobj->next;
3087 sgen_los_free_object (to_free);
3091 bigobj = bigobj->next;
3095 time_major_free_bigobjs += TV_ELAPSED (atv, btv);
3100 time_major_los_sweep += TV_ELAPSED (btv, atv);
3102 major_collector.sweep ();
3104 MONO_GC_SWEEP_END (GENERATION_OLD, !major_collector.sweeps_lazily);
3107 time_major_sweep += TV_ELAPSED (atv, btv);
3109 if (!major_collector.is_concurrent) {
3110 /* walk the pin_queue, build up the fragment list of free memory, unmark
3111 * pinned objects as we go, memzero() the empty fragments so they are ready for the
3114 if (!sgen_build_nursery_fragments (nursery_section, nursery_section->pin_queue_start, nursery_section->pin_queue_num_entries, NULL))
3117 /* prepare the pin queue for the next collection */
3118 sgen_finish_pinning ();
3120 /* Clear TLABs for all threads */
3121 sgen_clear_tlabs ();
3123 sgen_pin_stats_reset ();
3127 time_major_fragment_creation += TV_ELAPSED (btv, atv);
3130 dump_heap ("major", stat_major_gcs - 1, reason);
3132 if (fin_ready_list || critical_fin_list) {
3133 SGEN_LOG (4, "Finalizer-thread wakeup: ready %d", num_ready_finalizers);
3134 mono_gc_finalize_notify ();
3137 g_assert (sgen_gray_object_queue_is_empty (&gray_queue));
3139 sgen_memgov_major_collection_end ();
3140 current_collection_generation = -1;
3142 major_collector.finish_major_collection ();
3144 g_assert (sgen_section_gray_queue_is_empty (sgen_workers_get_distribute_section_gray_queue ()));
3146 if (major_collector.is_concurrent)
3147 concurrent_collection_in_progress = FALSE;
3149 check_scan_starts ();
3151 binary_protocol_flush_buffers (FALSE);
3153 //consistency_check ();
3155 MONO_GC_END (GENERATION_OLD);
3156 binary_protocol_collection_end (stat_major_gcs - 1, GENERATION_OLD);
3160 major_do_collection (const char *reason)
3162 TV_DECLARE (all_atv);
3163 TV_DECLARE (all_btv);
3164 int old_next_pin_slot;
3166 if (major_collector.get_and_reset_num_major_objects_marked) {
3167 long long num_marked = major_collector.get_and_reset_num_major_objects_marked ();
3168 g_assert (!num_marked);
3171 /* world must be stopped already */
3172 TV_GETTIME (all_atv);
3174 major_start_collection (&old_next_pin_slot);
3175 major_finish_collection (reason, old_next_pin_slot, FALSE);
3177 TV_GETTIME (all_btv);
3178 gc_stats.major_gc_time_usecs += TV_ELAPSED (all_atv, all_btv);
3180 /* FIXME: also report this to the user, preferably in gc-end. */
3181 if (major_collector.get_and_reset_num_major_objects_marked)
3182 major_collector.get_and_reset_num_major_objects_marked ();
3184 return bytes_pinned_from_failed_allocation > 0;
3187 static gboolean major_do_collection (const char *reason);
3190 major_start_concurrent_collection (const char *reason)
3192 long long num_objects_marked = major_collector.get_and_reset_num_major_objects_marked ();
3194 g_assert (num_objects_marked == 0);
3196 MONO_GC_CONCURRENT_START_BEGIN (GENERATION_OLD);
3198 // FIXME: store reason and pass it when finishing
3199 major_start_collection (NULL);
3201 gray_queue_redirect (&gray_queue);
3202 sgen_workers_wait_for_jobs ();
3204 num_objects_marked = major_collector.get_and_reset_num_major_objects_marked ();
3205 MONO_GC_CONCURRENT_START_END (GENERATION_OLD, num_objects_marked);
3207 current_collection_generation = -1;
3211 major_update_or_finish_concurrent_collection (gboolean force_finish)
3213 SgenGrayQueue unpin_queue;
3214 memset (&unpin_queue, 0, sizeof (unpin_queue));
3216 MONO_GC_CONCURRENT_UPDATE_FINISH_BEGIN (GENERATION_OLD, major_collector.get_and_reset_num_major_objects_marked ());
3218 g_assert (sgen_gray_object_queue_is_empty (&gray_queue));
3219 if (!have_non_collection_major_object_remembers)
3220 g_assert (sgen_gray_object_queue_is_empty (&remember_major_objects_gray_queue));
3222 major_collector.update_cardtable_mod_union ();
3223 sgen_los_update_cardtable_mod_union ();
3225 if (!force_finish && !sgen_workers_all_done ()) {
3226 MONO_GC_CONCURRENT_UPDATE_END (GENERATION_OLD, major_collector.get_and_reset_num_major_objects_marked ());
3230 collect_nursery (&unpin_queue);
3231 redirect_major_object_remembers ();
3233 current_collection_generation = GENERATION_OLD;
3234 major_finish_collection ("finishing", -1, TRUE);
3236 unpin_objects_from_queue (&unpin_queue);
3237 sgen_gray_object_queue_deinit (&unpin_queue);
3239 MONO_GC_CONCURRENT_FINISH_END (GENERATION_OLD, major_collector.get_and_reset_num_major_objects_marked ());
3241 current_collection_generation = -1;
3243 if (whole_heap_check_before_collection)
3244 sgen_check_whole_heap ();
3250 * Ensure an allocation request for @size will succeed by freeing enough memory.
3252 * LOCKING: The GC lock MUST be held.
3255 sgen_ensure_free_space (size_t size)
3257 int generation_to_collect = -1;
3258 const char *reason = NULL;
3261 if (size > SGEN_MAX_SMALL_OBJ_SIZE) {
3262 if (sgen_need_major_collection (size)) {
3263 reason = "LOS overflow";
3264 generation_to_collect = GENERATION_OLD;
3267 if (degraded_mode) {
3268 if (sgen_need_major_collection (size)) {
3269 reason = "Degraded mode overflow";
3270 generation_to_collect = GENERATION_OLD;
3272 } else if (sgen_need_major_collection (size)) {
3273 reason = "Minor allowance";
3274 generation_to_collect = GENERATION_OLD;
3276 generation_to_collect = GENERATION_NURSERY;
3277 reason = "Nursery full";
3281 if (generation_to_collect == -1)
3283 sgen_perform_collection (size, generation_to_collect, reason, FALSE);
3287 sgen_perform_collection (size_t requested_size, int generation_to_collect, const char *reason, gboolean wait_to_finish)
3289 TV_DECLARE (gc_end);
3290 GGTimingInfo infos [2];
3291 int overflow_generation_to_collect = -1;
3292 int oldest_generation_collected = generation_to_collect;
3293 const char *overflow_reason = NULL;
3295 g_assert (generation_to_collect == GENERATION_NURSERY || generation_to_collect == GENERATION_OLD);
3297 if (have_non_collection_major_object_remembers) {
3298 g_assert (concurrent_collection_in_progress);
3299 redirect_major_object_remembers ();
3302 memset (infos, 0, sizeof (infos));
3303 mono_profiler_gc_event (MONO_GC_EVENT_START, generation_to_collect);
3305 infos [0].generation = generation_to_collect;
3306 infos [0].reason = reason;
3307 infos [0].is_overflow = FALSE;
3308 TV_GETTIME (infos [0].total_time);
3309 infos [1].generation = -1;
3311 sgen_stop_world (generation_to_collect);
3313 if (concurrent_collection_in_progress) {
3314 if (major_update_or_finish_concurrent_collection (wait_to_finish && generation_to_collect == GENERATION_OLD)) {
3315 oldest_generation_collected = GENERATION_OLD;
3318 if (generation_to_collect == GENERATION_OLD)
3322 //FIXME extract overflow reason
3323 if (generation_to_collect == GENERATION_NURSERY) {
3324 if (collect_nursery (NULL)) {
3325 overflow_generation_to_collect = GENERATION_OLD;
3326 overflow_reason = "Minor overflow";
3328 if (concurrent_collection_in_progress) {
3329 redirect_major_object_remembers ();
3330 sgen_workers_wake_up_all ();
3333 SgenGrayQueue unpin_queue;
3334 SgenGrayQueue *unpin_queue_ptr;
3335 memset (&unpin_queue, 0, sizeof (unpin_queue));
3337 if (major_collector.is_concurrent && wait_to_finish)
3338 unpin_queue_ptr = &unpin_queue;
3340 unpin_queue_ptr = NULL;
3342 if (major_collector.is_concurrent) {
3343 g_assert (!concurrent_collection_in_progress);
3344 collect_nursery (unpin_queue_ptr);
3347 if (major_collector.is_concurrent && !wait_to_finish) {
3348 major_start_concurrent_collection (reason);
3349 // FIXME: set infos[0] properly
3352 if (major_do_collection (reason)) {
3353 overflow_generation_to_collect = GENERATION_NURSERY;
3354 overflow_reason = "Excessive pinning";
3358 if (unpin_queue_ptr) {
3359 unpin_objects_from_queue (unpin_queue_ptr);
3360 sgen_gray_object_queue_deinit (unpin_queue_ptr);
3364 TV_GETTIME (gc_end);
3365 infos [0].total_time = SGEN_TV_ELAPSED (infos [0].total_time, gc_end);
3368 if (!major_collector.is_concurrent && overflow_generation_to_collect != -1) {
3369 mono_profiler_gc_event (MONO_GC_EVENT_START, overflow_generation_to_collect);
3370 infos [1].generation = overflow_generation_to_collect;
3371 infos [1].reason = overflow_reason;
3372 infos [1].is_overflow = TRUE;
3373 infos [1].total_time = gc_end;
3375 if (overflow_generation_to_collect == GENERATION_NURSERY)
3376 collect_nursery (NULL);
3378 major_do_collection (overflow_reason);
3380 TV_GETTIME (gc_end);
3381 infos [1].total_time = SGEN_TV_ELAPSED (infos [1].total_time, gc_end);
3383 /* keep events symmetric */
3384 mono_profiler_gc_event (MONO_GC_EVENT_END, overflow_generation_to_collect);
3386 oldest_generation_collected = MAX (oldest_generation_collected, overflow_generation_to_collect);
3389 SGEN_LOG (2, "Heap size: %lu, LOS size: %lu", (unsigned long)mono_gc_get_heap_size (), (unsigned long)los_memory_usage);
3391 /* this also sets the proper pointers for the next allocation */
3392 if (generation_to_collect == GENERATION_NURSERY && !sgen_can_alloc_size (requested_size)) {
3393 /* TypeBuilder and MonoMethod are killing mcs with fragmentation */
3394 SGEN_LOG (1, "nursery collection didn't find enough room for %zd alloc (%d pinned)", requested_size, sgen_get_pinned_count ());
3395 sgen_dump_pin_queue ();
3400 g_assert (sgen_gray_object_queue_is_empty (&gray_queue));
3401 g_assert (sgen_gray_object_queue_is_empty (&remember_major_objects_gray_queue));
3403 sgen_restart_world (oldest_generation_collected, infos);
3405 mono_profiler_gc_event (MONO_GC_EVENT_END, generation_to_collect);
3409 * ######################################################################
3410 * ######## Memory allocation from the OS
3411 * ######################################################################
3412 * This section of code deals with getting memory from the OS and
3413 * allocating memory for GC-internal data structures.
3414 * Internal memory can be handled with a freelist for small objects.
3420 G_GNUC_UNUSED static void
3421 report_internal_mem_usage (void)
3423 printf ("Internal memory usage:\n");
3424 sgen_report_internal_mem_usage ();
3425 printf ("Pinned memory usage:\n");
3426 major_collector.report_pinned_memory_usage ();
3430 * ######################################################################
3431 * ######## Finalization support
3432 * ######################################################################
3436 * If the object has been forwarded it means it's still referenced from a root.
3437 * If it is pinned it's still alive as well.
3438 * A LOS object is only alive if we have pinned it.
3439 * Return TRUE if @obj is ready to be finalized.
3441 static inline gboolean
3442 sgen_is_object_alive (void *object)
3446 if (ptr_in_nursery (object))
3447 return sgen_nursery_is_object_alive (object);
3448 /* Oldgen objects can be pinned and forwarded too */
3449 if (SGEN_OBJECT_IS_PINNED (object) || SGEN_OBJECT_IS_FORWARDED (object))
3453 * FIXME: major_collector.is_object_live() also calculates the
3454 * size. Avoid the double calculation.
3456 objsize = SGEN_ALIGN_UP (sgen_safe_object_get_size ((MonoObject*)object));
3457 if (objsize > SGEN_MAX_SMALL_OBJ_SIZE)
3458 return sgen_los_object_is_pinned (object);
3460 return major_collector.is_object_live (object);
3464 sgen_gc_is_object_ready_for_finalization (void *object)
3466 return !sgen_is_object_alive (object);
3470 has_critical_finalizer (MonoObject *obj)
3474 if (!mono_defaults.critical_finalizer_object)
3477 class = ((MonoVTable*)LOAD_VTABLE (obj))->klass;
3479 return mono_class_has_parent_fast (class, mono_defaults.critical_finalizer_object);
3483 sgen_queue_finalization_entry (MonoObject *obj)
3485 FinalizeReadyEntry *entry = sgen_alloc_internal (INTERNAL_MEM_FINALIZE_READY_ENTRY);
3486 gboolean critical = has_critical_finalizer (obj);
3487 entry->object = obj;
3489 entry->next = critical_fin_list;
3490 critical_fin_list = entry;
3492 entry->next = fin_ready_list;
3493 fin_ready_list = entry;
3496 if (G_UNLIKELY (MONO_GC_FINALIZE_ENQUEUE_ENABLED ())) {
3497 int gen = sgen_ptr_in_nursery (obj) ? GENERATION_NURSERY : GENERATION_OLD;
3498 MonoVTable *vt = (MonoVTable*)LOAD_VTABLE (obj);
3499 MONO_GC_FINALIZE_ENQUEUE ((mword)obj, sgen_safe_object_get_size (obj),
3500 vt->klass->name_space, vt->klass->name, gen, critical);
3505 object_is_reachable (char *object, char *start, char *end)
3507 /*This happens for non nursery objects during minor collections. We just treat all objects as alive.*/
3508 if (object < start || object >= end)
3511 return sgen_is_object_alive (object);
3515 sgen_object_is_live (void *obj)
3517 if (ptr_in_nursery (obj))
3518 return object_is_pinned (obj);
3519 /* FIXME This is semantically wrong! All tenured object are considered alive during a nursery collection. */
3520 if (current_collection_generation == GENERATION_NURSERY)
3522 return major_collector.is_object_live (obj);
3525 /* LOCKING: requires that the GC lock is held */
3527 null_ephemerons_for_domain (MonoDomain *domain)
3529 EphemeronLinkNode *current = ephemeron_list, *prev = NULL;
3532 MonoObject *object = (MonoObject*)current->array;
3534 if (object && !object->vtable) {
3535 EphemeronLinkNode *tmp = current;
3538 prev->next = current->next;
3540 ephemeron_list = current->next;
3542 current = current->next;
3543 sgen_free_internal (tmp, INTERNAL_MEM_EPHEMERON_LINK);
3546 current = current->next;
3551 /* LOCKING: requires that the GC lock is held */
3553 clear_unreachable_ephemerons (char *start, char *end, ScanCopyContext ctx)
3555 CopyOrMarkObjectFunc copy_func = ctx.copy_func;
3556 GrayQueue *queue = ctx.queue;
3557 int was_in_nursery, was_promoted;
3558 EphemeronLinkNode *current = ephemeron_list, *prev = NULL;
3560 Ephemeron *cur, *array_end;
3564 char *object = current->array;
3566 if (!object_is_reachable (object, start, end)) {
3567 EphemeronLinkNode *tmp = current;
3569 SGEN_LOG (5, "Dead Ephemeron array at %p", object);
3572 prev->next = current->next;
3574 ephemeron_list = current->next;
3576 current = current->next;
3577 sgen_free_internal (tmp, INTERNAL_MEM_EPHEMERON_LINK);
3582 was_in_nursery = ptr_in_nursery (object);
3583 copy_func ((void**)&object, queue);
3584 current->array = object;
3586 /*The array was promoted, add global remsets for key/values left behind in nursery.*/
3587 was_promoted = was_in_nursery && !ptr_in_nursery (object);
3589 SGEN_LOG (5, "Clearing unreachable entries for ephemeron array at %p", object);
3591 array = (MonoArray*)object;
3592 cur = mono_array_addr (array, Ephemeron, 0);
3593 array_end = cur + mono_array_length_fast (array);
3594 tombstone = (char*)((MonoVTable*)LOAD_VTABLE (object))->domain->ephemeron_tombstone;
3596 for (; cur < array_end; ++cur) {
3597 char *key = (char*)cur->key;
3599 if (!key || key == tombstone)
3602 SGEN_LOG (5, "[%td] key %p (%s) value %p (%s)", cur - mono_array_addr (array, Ephemeron, 0),
3603 key, object_is_reachable (key, start, end) ? "reachable" : "unreachable",
3604 cur->value, cur->value && object_is_reachable (cur->value, start, end) ? "reachable" : "unreachable");
3606 if (!object_is_reachable (key, start, end)) {
3607 cur->key = tombstone;
3613 gpointer value = cur->value;
3614 if (ptr_in_nursery (key)) {/*key was not promoted*/
3615 SGEN_LOG (5, "\tAdded remset to key %p", key);
3616 sgen_add_to_global_remset (&cur->key, key);
3618 if (ptr_in_nursery (value)) {/*value was not promoted*/
3619 SGEN_LOG (5, "\tAdded remset to value %p", cur->value);
3620 sgen_add_to_global_remset (&cur->value, value);
3625 current = current->next;
3629 /* LOCKING: requires that the GC lock is held */
3631 mark_ephemerons_in_range (char *start, char *end, ScanCopyContext ctx)
3633 CopyOrMarkObjectFunc copy_func = ctx.copy_func;
3634 GrayQueue *queue = ctx.queue;
3635 int nothing_marked = 1;
3636 EphemeronLinkNode *current = ephemeron_list;
3638 Ephemeron *cur, *array_end;
3641 for (current = ephemeron_list; current; current = current->next) {
3642 char *object = current->array;
3643 SGEN_LOG (5, "Ephemeron array at %p", object);
3646 For now we process all ephemerons during all collections.
3647 Ideally we should use remset information to partially scan those
3649 We already emit write barriers for Ephemeron fields, it's
3650 just that we don't process them.
3652 /*if (object < start || object >= end)
3655 /*It has to be alive*/
3656 if (!object_is_reachable (object, start, end)) {
3657 SGEN_LOG (5, "\tnot reachable");
3661 copy_func ((void**)&object, queue);
3663 array = (MonoArray*)object;
3664 cur = mono_array_addr (array, Ephemeron, 0);
3665 array_end = cur + mono_array_length_fast (array);
3666 tombstone = (char*)((MonoVTable*)LOAD_VTABLE (object))->domain->ephemeron_tombstone;
3668 for (; cur < array_end; ++cur) {
3669 char *key = cur->key;
3671 if (!key || key == tombstone)
3674 SGEN_LOG (5, "[%td] key %p (%s) value %p (%s)", cur - mono_array_addr (array, Ephemeron, 0),
3675 key, object_is_reachable (key, start, end) ? "reachable" : "unreachable",
3676 cur->value, cur->value && object_is_reachable (cur->value, start, end) ? "reachable" : "unreachable");
3678 if (object_is_reachable (key, start, end)) {
3679 char *value = cur->value;
3681 copy_func ((void**)&cur->key, queue);
3683 if (!object_is_reachable (value, start, end))
3685 copy_func ((void**)&cur->value, queue);
3691 SGEN_LOG (5, "Ephemeron run finished. Is it done %d", nothing_marked);
3692 return nothing_marked;
3696 mono_gc_invoke_finalizers (void)
3698 FinalizeReadyEntry *entry = NULL;
3699 gboolean entry_is_critical = FALSE;
3702 /* FIXME: batch to reduce lock contention */
3703 while (fin_ready_list || critical_fin_list) {
3707 FinalizeReadyEntry **list = entry_is_critical ? &critical_fin_list : &fin_ready_list;
3709 /* We have finalized entry in the last
3710 interation, now we need to remove it from
3713 *list = entry->next;
3715 FinalizeReadyEntry *e = *list;
3716 while (e->next != entry)
3718 e->next = entry->next;
3720 sgen_free_internal (entry, INTERNAL_MEM_FINALIZE_READY_ENTRY);
3724 /* Now look for the first non-null entry. */
3725 for (entry = fin_ready_list; entry && !entry->object; entry = entry->next)
3728 entry_is_critical = FALSE;
3730 entry_is_critical = TRUE;
3731 for (entry = critical_fin_list; entry && !entry->object; entry = entry->next)
3736 g_assert (entry->object);
3737 num_ready_finalizers--;
3738 obj = entry->object;
3739 entry->object = NULL;
3740 SGEN_LOG (7, "Finalizing object %p (%s)", obj, safe_name (obj));
3748 g_assert (entry->object == NULL);
3750 /* the object is on the stack so it is pinned */
3751 /*g_print ("Calling finalizer for object: %p (%s)\n", entry->object, safe_name (entry->object));*/
3752 mono_gc_run_finalize (obj, NULL);
3759 mono_gc_pending_finalizers (void)
3761 return fin_ready_list || critical_fin_list;
3765 * ######################################################################
3766 * ######## registered roots support
3767 * ######################################################################
3771 * We do not coalesce roots.
3774 mono_gc_register_root_inner (char *start, size_t size, void *descr, int root_type)
3776 RootRecord new_root;
3779 for (i = 0; i < ROOT_TYPE_NUM; ++i) {
3780 RootRecord *root = sgen_hash_table_lookup (&roots_hash [i], start);
3781 /* we allow changing the size and the descriptor (for thread statics etc) */
3783 size_t old_size = root->end_root - start;
3784 root->end_root = start + size;
3785 g_assert (((root->root_desc != 0) && (descr != NULL)) ||
3786 ((root->root_desc == 0) && (descr == NULL)));
3787 root->root_desc = (mword)descr;
3789 roots_size -= old_size;
3795 new_root.end_root = start + size;
3796 new_root.root_desc = (mword)descr;
3798 sgen_hash_table_replace (&roots_hash [root_type], start, &new_root, NULL);
3801 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);
3808 mono_gc_register_root (char *start, size_t size, void *descr)
3810 return mono_gc_register_root_inner (start, size, descr, descr ? ROOT_TYPE_NORMAL : ROOT_TYPE_PINNED);
3814 mono_gc_register_root_wbarrier (char *start, size_t size, void *descr)
3816 return mono_gc_register_root_inner (start, size, descr, ROOT_TYPE_WBARRIER);
3820 mono_gc_deregister_root (char* addr)
3826 for (root_type = 0; root_type < ROOT_TYPE_NUM; ++root_type) {
3827 if (sgen_hash_table_remove (&roots_hash [root_type], addr, &root))
3828 roots_size -= (root.end_root - addr);
3834 * ######################################################################
3835 * ######## Thread handling (stop/start code)
3836 * ######################################################################
3839 unsigned int sgen_global_stop_count = 0;
3842 sgen_fill_thread_info_for_suspend (SgenThreadInfo *info)
3844 if (remset.fill_thread_info_for_suspend)
3845 remset.fill_thread_info_for_suspend (info);
3849 sgen_get_current_collection_generation (void)
3851 return current_collection_generation;
3855 mono_gc_set_gc_callbacks (MonoGCCallbacks *callbacks)
3857 gc_callbacks = *callbacks;
3861 mono_gc_get_gc_callbacks ()
3863 return &gc_callbacks;
3866 /* Variables holding start/end nursery so it won't have to be passed at every call */
3867 static void *scan_area_arg_start, *scan_area_arg_end;
3870 mono_gc_conservatively_scan_area (void *start, void *end)
3872 conservatively_pin_objects_from (start, end, scan_area_arg_start, scan_area_arg_end, PIN_TYPE_STACK);
3876 mono_gc_scan_object (void *obj)
3878 UserCopyOrMarkData *data = mono_native_tls_get_value (user_copy_or_mark_key);
3879 current_object_ops.copy_or_mark_object (&obj, data->queue);
3884 * Mark from thread stacks and registers.
3887 scan_thread_data (void *start_nursery, void *end_nursery, gboolean precise, GrayQueue *queue)
3889 SgenThreadInfo *info;
3891 scan_area_arg_start = start_nursery;
3892 scan_area_arg_end = end_nursery;
3894 FOREACH_THREAD (info) {
3896 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);
3899 if (info->gc_disabled) {
3900 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);
3904 if (!info->joined_stw) {
3905 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);
3909 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 ());
3910 if (!info->thread_is_dying) {
3911 if (gc_callbacks.thread_mark_func && !conservative_stack_mark) {
3912 UserCopyOrMarkData data = { NULL, queue };
3913 set_user_copy_or_mark_data (&data);
3914 gc_callbacks.thread_mark_func (info->runtime_data, info->stack_start, info->stack_end, precise);
3915 set_user_copy_or_mark_data (NULL);
3916 } else if (!precise) {
3917 if (!conservative_stack_mark) {
3918 fprintf (stderr, "Precise stack mark not supported - disabling.\n");
3919 conservative_stack_mark = TRUE;
3921 conservatively_pin_objects_from (info->stack_start, info->stack_end, start_nursery, end_nursery, PIN_TYPE_STACK);
3925 if (!info->thread_is_dying && !precise) {
3927 conservatively_pin_objects_from ((void**)&info->ctx, (void**)&info->ctx + ARCH_NUM_REGS,
3928 start_nursery, end_nursery, PIN_TYPE_STACK);
3930 conservatively_pin_objects_from (&info->regs, &info->regs + ARCH_NUM_REGS,
3931 start_nursery, end_nursery, PIN_TYPE_STACK);
3934 } END_FOREACH_THREAD
3938 ptr_on_stack (void *ptr)
3940 gpointer stack_start = &stack_start;
3941 SgenThreadInfo *info = mono_thread_info_current ();
3943 if (ptr >= stack_start && ptr < (gpointer)info->stack_end)
3949 sgen_thread_register (SgenThreadInfo* info, void *addr)
3951 #ifndef HAVE_KW_THREAD
3952 SgenThreadInfo *__thread_info__ = info;
3956 #ifndef HAVE_KW_THREAD
3957 info->tlab_start = info->tlab_next = info->tlab_temp_end = info->tlab_real_end = NULL;
3959 g_assert (!mono_native_tls_get_value (thread_info_key));
3960 mono_native_tls_set_value (thread_info_key, info);
3962 sgen_thread_info = info;
3965 #if !defined(__MACH__)
3966 info->stop_count = -1;
3970 info->joined_stw = FALSE;
3971 info->doing_handshake = FALSE;
3972 info->thread_is_dying = FALSE;
3973 info->stack_start = NULL;
3974 info->store_remset_buffer_addr = &STORE_REMSET_BUFFER;
3975 info->store_remset_buffer_index_addr = &STORE_REMSET_BUFFER_INDEX;
3976 info->stopped_ip = NULL;
3977 info->stopped_domain = NULL;
3979 memset (&info->ctx, 0, sizeof (MonoContext));
3981 memset (&info->regs, 0, sizeof (info->regs));
3984 sgen_init_tlab_info (info);
3986 binary_protocol_thread_register ((gpointer)mono_thread_info_get_tid (info));
3988 #ifdef HAVE_KW_THREAD
3989 store_remset_buffer_index_addr = &store_remset_buffer_index;
3992 /* try to get it with attributes first */
3993 #if defined(HAVE_PTHREAD_GETATTR_NP) && defined(HAVE_PTHREAD_ATTR_GETSTACK)
3997 pthread_attr_t attr;
3998 pthread_getattr_np (pthread_self (), &attr);
3999 pthread_attr_getstack (&attr, &sstart, &size);
4000 info->stack_start_limit = sstart;
4001 info->stack_end = (char*)sstart + size;
4002 pthread_attr_destroy (&attr);
4004 #elif defined(HAVE_PTHREAD_GET_STACKSIZE_NP) && defined(HAVE_PTHREAD_GET_STACKADDR_NP)
4005 info->stack_end = (char*)pthread_get_stackaddr_np (pthread_self ());
4006 info->stack_start_limit = (char*)info->stack_end - pthread_get_stacksize_np (pthread_self ());
4009 /* FIXME: we assume the stack grows down */
4010 gsize stack_bottom = (gsize)addr;
4011 stack_bottom += 4095;
4012 stack_bottom &= ~4095;
4013 info->stack_end = (char*)stack_bottom;
4017 #ifdef HAVE_KW_THREAD
4018 stack_end = info->stack_end;
4021 if (remset.register_thread)
4022 remset.register_thread (info);
4024 SGEN_LOG (3, "registered thread %p (%p) stack end %p", info, (gpointer)mono_thread_info_get_tid (info), info->stack_end);
4026 if (gc_callbacks.thread_attach_func)
4027 info->runtime_data = gc_callbacks.thread_attach_func ();
4034 sgen_wbarrier_cleanup_thread (SgenThreadInfo *p)
4036 if (remset.cleanup_thread)
4037 remset.cleanup_thread (p);
4041 sgen_thread_unregister (SgenThreadInfo *p)
4043 /* If a delegate is passed to native code and invoked on a thread we dont
4044 * know about, the jit will register it with mono_jit_thread_attach, but
4045 * we have no way of knowing when that thread goes away. SGen has a TSD
4046 * so we assume that if the domain is still registered, we can detach
4049 if (mono_domain_get ())
4050 mono_thread_detach (mono_thread_current ());
4052 p->thread_is_dying = TRUE;
4055 There is a race condition between a thread finishing executing and been removed
4056 from the GC thread set.
4057 This happens on posix systems when TLS data is been cleaned-up, libpthread will
4058 set the thread_info slot to NULL before calling the cleanup function. This
4059 opens a window in which the thread is registered but has a NULL TLS.
4061 The suspend signal handler needs TLS data to know where to store thread state
4062 data or otherwise it will simply ignore the thread.
4064 This solution works because the thread doing STW will wait until all threads been
4065 suspended handshake back, so there is no race between the doing_hankshake test
4066 and the suspend_thread call.
4068 This is not required on systems that do synchronous STW as those can deal with
4069 the above race at suspend time.
4071 FIXME: I believe we could avoid this by using mono_thread_info_lookup when
4072 mono_thread_info_current returns NULL. Or fix mono_thread_info_lookup to do so.
4074 #if (defined(__MACH__) && MONO_MACH_ARCH_SUPPORTED) || !defined(HAVE_PTHREAD_KILL)
4077 while (!TRYLOCK_GC) {
4078 if (!sgen_park_current_thread_if_doing_handshake (p))
4084 binary_protocol_thread_unregister ((gpointer)mono_thread_info_get_tid (p));
4085 SGEN_LOG (3, "unregister thread %p (%p)", p, (gpointer)mono_thread_info_get_tid (p));
4087 if (gc_callbacks.thread_detach_func) {
4088 gc_callbacks.thread_detach_func (p->runtime_data);
4089 p->runtime_data = NULL;
4091 sgen_wbarrier_cleanup_thread (p);
4093 mono_threads_unregister_current_thread (p);
4099 sgen_thread_attach (SgenThreadInfo *info)
4102 /*this is odd, can we get attached before the gc is inited?*/
4106 if (gc_callbacks.thread_attach_func && !info->runtime_data)
4107 info->runtime_data = gc_callbacks.thread_attach_func ();
4110 mono_gc_register_thread (void *baseptr)
4112 return mono_thread_info_attach (baseptr) != NULL;
4116 * mono_gc_set_stack_end:
4118 * Set the end of the current threads stack to STACK_END. The stack space between
4119 * STACK_END and the real end of the threads stack will not be scanned during collections.
4122 mono_gc_set_stack_end (void *stack_end)
4124 SgenThreadInfo *info;
4127 info = mono_thread_info_current ();
4129 g_assert (stack_end < info->stack_end);
4130 info->stack_end = stack_end;
4135 #if USE_PTHREAD_INTERCEPT
4139 mono_gc_pthread_create (pthread_t *new_thread, const pthread_attr_t *attr, void *(*start_routine)(void *), void *arg)
4141 return pthread_create (new_thread, attr, start_routine, arg);
4145 mono_gc_pthread_join (pthread_t thread, void **retval)
4147 return pthread_join (thread, retval);
4151 mono_gc_pthread_detach (pthread_t thread)
4153 return pthread_detach (thread);
4157 mono_gc_pthread_exit (void *retval)
4159 pthread_exit (retval);
4162 #endif /* USE_PTHREAD_INTERCEPT */
4165 * ######################################################################
4166 * ######## Write barriers
4167 * ######################################################################
4171 * Note: the write barriers first do the needed GC work and then do the actual store:
4172 * this way the value is visible to the conservative GC scan after the write barrier
4173 * itself. If a GC interrupts the barrier in the middle, value will be kept alive by
4174 * the conservative scan, otherwise by the remembered set scan.
4177 mono_gc_wbarrier_set_field (MonoObject *obj, gpointer field_ptr, MonoObject* value)
4179 HEAVY_STAT (++stat_wbarrier_set_field);
4180 if (ptr_in_nursery (field_ptr)) {
4181 *(void**)field_ptr = value;
4184 SGEN_LOG (8, "Adding remset at %p", field_ptr);
4186 binary_protocol_wbarrier (field_ptr, value, value->vtable);
4188 remset.wbarrier_set_field (obj, field_ptr, value);
4192 mono_gc_wbarrier_set_arrayref (MonoArray *arr, gpointer slot_ptr, MonoObject* value)
4194 HEAVY_STAT (++stat_wbarrier_set_arrayref);
4195 if (ptr_in_nursery (slot_ptr)) {
4196 *(void**)slot_ptr = value;
4199 SGEN_LOG (8, "Adding remset at %p", slot_ptr);
4201 binary_protocol_wbarrier (slot_ptr, value, value->vtable);
4203 remset.wbarrier_set_arrayref (arr, slot_ptr, value);
4207 mono_gc_wbarrier_arrayref_copy (gpointer dest_ptr, gpointer src_ptr, int count)
4209 HEAVY_STAT (++stat_wbarrier_arrayref_copy);
4210 /*This check can be done without taking a lock since dest_ptr array is pinned*/
4211 if (ptr_in_nursery (dest_ptr) || count <= 0) {
4212 mono_gc_memmove (dest_ptr, src_ptr, count * sizeof (gpointer));
4216 #ifdef SGEN_BINARY_PROTOCOL
4219 for (i = 0; i < count; ++i) {
4220 gpointer dest = (gpointer*)dest_ptr + i;
4221 gpointer obj = *((gpointer*)src_ptr + i);
4223 binary_protocol_wbarrier (dest, obj, (gpointer)LOAD_VTABLE (obj));
4228 remset.wbarrier_arrayref_copy (dest_ptr, src_ptr, count);
4231 static char *found_obj;
4234 find_object_for_ptr_callback (char *obj, size_t size, void *user_data)
4236 char *ptr = user_data;
4238 if (ptr >= obj && ptr < obj + size) {
4239 g_assert (!found_obj);
4244 /* for use in the debugger */
4245 char* find_object_for_ptr (char *ptr);
4247 find_object_for_ptr (char *ptr)
4249 if (ptr >= nursery_section->data && ptr < nursery_section->end_data) {
4251 sgen_scan_area_with_callback (nursery_section->data, nursery_section->end_data,
4252 find_object_for_ptr_callback, ptr, TRUE);
4258 sgen_los_iterate_objects (find_object_for_ptr_callback, ptr);
4263 * Very inefficient, but this is debugging code, supposed to
4264 * be called from gdb, so we don't care.
4267 major_collector.iterate_objects (TRUE, TRUE, find_object_for_ptr_callback, ptr);
4272 mono_gc_wbarrier_generic_nostore (gpointer ptr)
4276 HEAVY_STAT (++stat_wbarrier_generic_store);
4278 #ifdef XDOMAIN_CHECKS_IN_WBARRIER
4279 /* FIXME: ptr_in_heap must be called with the GC lock held */
4280 if (xdomain_checks && *(MonoObject**)ptr && ptr_in_heap (ptr)) {
4281 char *start = find_object_for_ptr (ptr);
4282 MonoObject *value = *(MonoObject**)ptr;
4286 MonoObject *obj = (MonoObject*)start;
4287 if (obj->vtable->domain != value->vtable->domain)
4288 g_assert (is_xdomain_ref_allowed (ptr, start, obj->vtable->domain));
4294 obj = *(gpointer*)ptr;
4296 binary_protocol_wbarrier (ptr, obj, (gpointer)LOAD_VTABLE (obj));
4298 if (ptr_in_nursery (ptr) || ptr_on_stack (ptr)) {
4299 SGEN_LOG (8, "Skipping remset at %p", ptr);
4304 * We need to record old->old pointer locations for the
4305 * concurrent collector.
4307 if (!ptr_in_nursery (obj) && !concurrent_collection_in_progress) {
4308 SGEN_LOG (8, "Skipping remset at %p", ptr);
4312 SGEN_LOG (8, "Adding remset at %p", ptr);
4314 remset.wbarrier_generic_nostore (ptr);
4318 mono_gc_wbarrier_generic_store (gpointer ptr, MonoObject* value)
4320 SGEN_LOG (8, "Wbarrier store at %p to %p (%s)", ptr, value, value ? safe_name (value) : "null");
4321 *(void**)ptr = value;
4322 if (ptr_in_nursery (value))
4323 mono_gc_wbarrier_generic_nostore (ptr);
4324 sgen_dummy_use (value);
4327 void mono_gc_wbarrier_value_copy_bitmap (gpointer _dest, gpointer _src, int size, unsigned bitmap)
4329 mword *dest = _dest;
4334 mono_gc_wbarrier_generic_store (dest, (MonoObject*)*src);
4339 size -= SIZEOF_VOID_P;
4344 #ifdef SGEN_BINARY_PROTOCOL
4346 #define HANDLE_PTR(ptr,obj) do { \
4347 gpointer o = *(gpointer*)(ptr); \
4349 gpointer d = ((char*)dest) + ((char*)(ptr) - (char*)(obj)); \
4350 binary_protocol_wbarrier (d, o, (gpointer) LOAD_VTABLE (o)); \
4355 scan_object_for_binary_protocol_copy_wbarrier (gpointer dest, char *start, mword desc)
4357 #define SCAN_OBJECT_NOVTABLE
4358 #include "sgen-scan-object.h"
4363 mono_gc_wbarrier_value_copy (gpointer dest, gpointer src, int count, MonoClass *klass)
4365 HEAVY_STAT (++stat_wbarrier_value_copy);
4366 g_assert (klass->valuetype);
4368 SGEN_LOG (8, "Adding value remset at %p, count %d, descr %p for class %s (%p)", dest, count, klass->gc_descr, klass->name, klass);
4370 if (ptr_in_nursery (dest) || ptr_on_stack (dest) || !SGEN_CLASS_HAS_REFERENCES (klass)) {
4371 size_t element_size = mono_class_value_size (klass, NULL);
4372 size_t size = count * element_size;
4373 mono_gc_memmove (dest, src, size);
4377 #ifdef SGEN_BINARY_PROTOCOL
4379 size_t element_size = mono_class_value_size (klass, NULL);
4381 for (i = 0; i < count; ++i) {
4382 scan_object_for_binary_protocol_copy_wbarrier ((char*)dest + i * element_size,
4383 (char*)src + i * element_size - sizeof (MonoObject),
4384 (mword) klass->gc_descr);
4389 remset.wbarrier_value_copy (dest, src, count, klass);
4393 * mono_gc_wbarrier_object_copy:
4395 * Write barrier to call when obj is the result of a clone or copy of an object.
4398 mono_gc_wbarrier_object_copy (MonoObject* obj, MonoObject *src)
4402 HEAVY_STAT (++stat_wbarrier_object_copy);
4404 if (ptr_in_nursery (obj) || ptr_on_stack (obj)) {
4405 size = mono_object_class (obj)->instance_size;
4406 mono_gc_memmove ((char*)obj + sizeof (MonoObject), (char*)src + sizeof (MonoObject),
4407 size - sizeof (MonoObject));
4411 #ifdef SGEN_BINARY_PROTOCOL
4412 scan_object_for_binary_protocol_copy_wbarrier (obj, (char*)src, (mword) src->vtable->gc_descr);
4415 remset.wbarrier_object_copy (obj, src);
4420 * ######################################################################
4421 * ######## Other mono public interface functions.
4422 * ######################################################################
4425 #define REFS_SIZE 128
4428 MonoGCReferences callback;
4432 MonoObject *refs [REFS_SIZE];
4433 uintptr_t offsets [REFS_SIZE];
4437 #define HANDLE_PTR(ptr,obj) do { \
4439 if (hwi->count == REFS_SIZE) { \
4440 hwi->callback ((MonoObject*)start, mono_object_class (start), hwi->called? 0: size, hwi->count, hwi->refs, hwi->offsets, hwi->data); \
4444 hwi->offsets [hwi->count] = (char*)(ptr)-(char*)start; \
4445 hwi->refs [hwi->count++] = *(ptr); \
4450 collect_references (HeapWalkInfo *hwi, char *start, size_t size)
4452 #include "sgen-scan-object.h"
4456 walk_references (char *start, size_t size, void *data)
4458 HeapWalkInfo *hwi = data;
4461 collect_references (hwi, start, size);
4462 if (hwi->count || !hwi->called)
4463 hwi->callback ((MonoObject*)start, mono_object_class (start), hwi->called? 0: size, hwi->count, hwi->refs, hwi->offsets, hwi->data);
4467 * mono_gc_walk_heap:
4468 * @flags: flags for future use
4469 * @callback: a function pointer called for each object in the heap
4470 * @data: a user data pointer that is passed to callback
4472 * This function can be used to iterate over all the live objects in the heap:
4473 * for each object, @callback is invoked, providing info about the object's
4474 * location in memory, its class, its size and the objects it references.
4475 * For each referenced object it's offset from the object address is
4476 * reported in the offsets array.
4477 * The object references may be buffered, so the callback may be invoked
4478 * multiple times for the same object: in all but the first call, the size
4479 * argument will be zero.
4480 * Note that this function can be only called in the #MONO_GC_EVENT_PRE_START_WORLD
4481 * profiler event handler.
4483 * Returns: a non-zero value if the GC doesn't support heap walking
4486 mono_gc_walk_heap (int flags, MonoGCReferences callback, void *data)
4491 hwi.callback = callback;
4494 sgen_clear_nursery_fragments ();
4495 sgen_scan_area_with_callback (nursery_section->data, nursery_section->end_data, walk_references, &hwi, FALSE);
4497 major_collector.iterate_objects (TRUE, TRUE, walk_references, &hwi);
4498 sgen_los_iterate_objects (walk_references, &hwi);
4504 mono_gc_collect (int generation)
4509 sgen_perform_collection (0, generation, "user request", TRUE);
4514 mono_gc_max_generation (void)
4520 mono_gc_collection_count (int generation)
4522 if (generation == 0)
4523 return stat_minor_gcs;
4524 return stat_major_gcs;
4528 mono_gc_get_used_size (void)
4532 tot = los_memory_usage;
4533 tot += nursery_section->next_data - nursery_section->data;
4534 tot += major_collector.get_used_size ();
4535 /* FIXME: account for pinned objects */
4541 mono_gc_disable (void)
4549 mono_gc_enable (void)
4557 mono_gc_get_los_limit (void)
4559 return MAX_SMALL_OBJ_SIZE;
4563 mono_gc_user_markers_supported (void)
4569 mono_object_is_alive (MonoObject* o)
4575 mono_gc_get_generation (MonoObject *obj)
4577 if (ptr_in_nursery (obj))
4583 mono_gc_enable_events (void)
4588 mono_gc_weak_link_add (void **link_addr, MonoObject *obj, gboolean track)
4590 sgen_register_disappearing_link (obj, link_addr, track, FALSE);
4594 mono_gc_weak_link_remove (void **link_addr)
4596 sgen_register_disappearing_link (NULL, link_addr, FALSE, FALSE);
4600 mono_gc_weak_link_get (void **link_addr)
4603 * We must only load *link_addr once because it might change
4604 * under our feet, and REVEAL_POINTER (NULL) results in an
4605 * invalid reference.
4607 void *ptr = *link_addr;
4612 * During the second bridge processing step the world is
4613 * running again. That step processes all weak links once
4614 * more to null those that refer to dead objects. Before that
4615 * is completed, those links must not be followed, so we
4616 * conservatively wait for bridge processing when any weak
4617 * link is dereferenced.
4619 if (G_UNLIKELY (bridge_processing_in_progress))
4620 mono_gc_wait_for_bridge_processing ();
4622 return (MonoObject*) REVEAL_POINTER (ptr);
4626 mono_gc_ephemeron_array_add (MonoObject *obj)
4628 EphemeronLinkNode *node;
4632 node = sgen_alloc_internal (INTERNAL_MEM_EPHEMERON_LINK);
4637 node->array = (char*)obj;
4638 node->next = ephemeron_list;
4639 ephemeron_list = node;
4641 SGEN_LOG (5, "Registered ephemeron array %p", obj);
4648 mono_gc_invoke_with_gc_lock (MonoGCLockedCallbackFunc func, void *data)
4652 result = func (data);
4653 UNLOCK_INTERRUPTION;
4658 mono_gc_is_gc_thread (void)
4662 result = mono_thread_info_current () != NULL;
4668 is_critical_method (MonoMethod *method)
4670 return mono_runtime_is_critical_method (method) || sgen_is_critical_method (method);
4674 mono_gc_base_init (void)
4676 MonoThreadInfoCallbacks cb;
4679 char *major_collector_opt = NULL;
4680 char *minor_collector_opt = NULL;
4682 glong soft_limit = 0;
4686 gboolean debug_print_allowance = FALSE;
4687 double allowance_ratio = 0, save_target = 0;
4688 gboolean have_split_nursery = FALSE;
4691 result = InterlockedCompareExchange (&gc_initialized, -1, 0);
4694 /* already inited */
4697 /* being inited by another thread */
4701 /* we will init it */
4704 g_assert_not_reached ();
4706 } while (result != 0);
4708 LOCK_INIT (gc_mutex);
4710 pagesize = mono_pagesize ();
4711 gc_debug_file = stderr;
4713 cb.thread_register = sgen_thread_register;
4714 cb.thread_unregister = sgen_thread_unregister;
4715 cb.thread_attach = sgen_thread_attach;
4716 cb.mono_method_is_critical = (gpointer)is_critical_method;
4718 cb.mono_gc_pthread_create = (gpointer)mono_gc_pthread_create;
4721 mono_threads_init (&cb, sizeof (SgenThreadInfo));
4723 LOCK_INIT (sgen_interruption_mutex);
4724 LOCK_INIT (pin_queue_mutex);
4726 init_user_copy_or_mark_key ();
4728 if ((env = getenv ("MONO_GC_PARAMS"))) {
4729 opts = g_strsplit (env, ",", -1);
4730 for (ptr = opts; *ptr; ++ptr) {
4732 if (g_str_has_prefix (opt, "major=")) {
4733 opt = strchr (opt, '=') + 1;
4734 major_collector_opt = g_strdup (opt);
4735 } else if (g_str_has_prefix (opt, "minor=")) {
4736 opt = strchr (opt, '=') + 1;
4737 minor_collector_opt = g_strdup (opt);
4745 sgen_init_internal_allocator ();
4746 sgen_init_nursery_allocator ();
4748 sgen_register_fixed_internal_mem_type (INTERNAL_MEM_SECTION, SGEN_SIZEOF_GC_MEM_SECTION);
4749 sgen_register_fixed_internal_mem_type (INTERNAL_MEM_FINALIZE_READY_ENTRY, sizeof (FinalizeReadyEntry));
4750 sgen_register_fixed_internal_mem_type (INTERNAL_MEM_GRAY_QUEUE, sizeof (GrayQueueSection));
4751 g_assert (sizeof (GenericStoreRememberedSet) == sizeof (gpointer) * STORE_REMSET_BUFFER_SIZE);
4752 sgen_register_fixed_internal_mem_type (INTERNAL_MEM_STORE_REMSET, sizeof (GenericStoreRememberedSet));
4753 sgen_register_fixed_internal_mem_type (INTERNAL_MEM_EPHEMERON_LINK, sizeof (EphemeronLinkNode));
4755 #ifndef HAVE_KW_THREAD
4756 mono_native_tls_alloc (&thread_info_key, NULL);
4760 * This needs to happen before any internal allocations because
4761 * it inits the small id which is required for hazard pointer
4766 mono_thread_info_attach (&dummy);
4768 if (!minor_collector_opt) {
4769 sgen_simple_nursery_init (&sgen_minor_collector);
4771 if (!strcmp (minor_collector_opt, "simple")) {
4772 sgen_simple_nursery_init (&sgen_minor_collector);
4773 } else if (!strcmp (minor_collector_opt, "split")) {
4774 sgen_split_nursery_init (&sgen_minor_collector);
4775 have_split_nursery = TRUE;
4777 fprintf (stderr, "Unknown minor collector `%s'.\n", minor_collector_opt);
4782 if (!major_collector_opt || !strcmp (major_collector_opt, "marksweep")) {
4783 sgen_marksweep_init (&major_collector);
4784 } else if (!major_collector_opt || !strcmp (major_collector_opt, "marksweep-fixed")) {
4785 sgen_marksweep_fixed_init (&major_collector);
4786 } else if (!major_collector_opt || !strcmp (major_collector_opt, "marksweep-par")) {
4787 sgen_marksweep_par_init (&major_collector);
4788 } else if (!major_collector_opt || !strcmp (major_collector_opt, "marksweep-fixed-par")) {
4789 sgen_marksweep_fixed_par_init (&major_collector);
4790 } else if (!major_collector_opt || !strcmp (major_collector_opt, "marksweep-conc")) {
4791 if (have_split_nursery) {
4792 fprintf (stderr, "Concurrent Mark&Sweep does not yet support the split nursery.\n");
4795 sgen_marksweep_conc_init (&major_collector);
4796 } else if (!strcmp (major_collector_opt, "copying")) {
4797 sgen_copying_init (&major_collector);
4799 fprintf (stderr, "Unknown major collector `%s'.\n", major_collector_opt);
4803 #ifdef SGEN_HAVE_CARDTABLE
4804 use_cardtable = major_collector.supports_cardtable;
4806 use_cardtable = FALSE;
4809 num_workers = mono_cpu_count ();
4810 g_assert (num_workers > 0);
4811 if (num_workers > 16)
4814 ///* Keep this the default for now */
4815 /* Precise marking is broken on all supported targets. Disable until fixed. */
4816 conservative_stack_mark = TRUE;
4818 sgen_nursery_size = DEFAULT_NURSERY_SIZE;
4821 for (ptr = opts; *ptr; ++ptr) {
4823 if (g_str_has_prefix (opt, "major="))
4825 if (g_str_has_prefix (opt, "minor="))
4827 if (g_str_has_prefix (opt, "wbarrier=")) {
4828 opt = strchr (opt, '=') + 1;
4829 if (strcmp (opt, "remset") == 0) {
4830 if (major_collector.is_concurrent) {
4831 fprintf (stderr, "The concurrent collector does not support the SSB write barrier.\n");
4834 use_cardtable = FALSE;
4835 } else if (strcmp (opt, "cardtable") == 0) {
4836 if (!use_cardtable) {
4837 if (major_collector.supports_cardtable)
4838 fprintf (stderr, "The cardtable write barrier is not supported on this platform.\n");
4840 fprintf (stderr, "The major collector does not support the cardtable write barrier.\n");
4844 fprintf (stderr, "wbarrier must either be `remset' or `cardtable'.");
4849 if (g_str_has_prefix (opt, "max-heap-size=")) {
4850 opt = strchr (opt, '=') + 1;
4851 if (*opt && mono_gc_parse_environment_string_extract_number (opt, &max_heap)) {
4852 if ((max_heap & (mono_pagesize () - 1))) {
4853 fprintf (stderr, "max-heap-size size must be a multiple of %d.\n", mono_pagesize ());
4857 fprintf (stderr, "max-heap-size must be an integer.\n");
4862 if (g_str_has_prefix (opt, "soft-heap-limit=")) {
4863 opt = strchr (opt, '=') + 1;
4864 if (*opt && mono_gc_parse_environment_string_extract_number (opt, &soft_limit)) {
4865 if (soft_limit <= 0) {
4866 fprintf (stderr, "soft-heap-limit must be positive.\n");
4870 fprintf (stderr, "soft-heap-limit must be an integer.\n");
4875 if (g_str_has_prefix (opt, "workers=")) {
4878 if (!major_collector.is_parallel) {
4879 fprintf (stderr, "The workers= option can only be used for parallel collectors.");
4882 opt = strchr (opt, '=') + 1;
4883 val = strtol (opt, &endptr, 10);
4884 if (!*opt || *endptr) {
4885 fprintf (stderr, "Cannot parse the workers= option value.");
4888 if (val <= 0 || val > 16) {
4889 fprintf (stderr, "The number of workers must be in the range 1 to 16.");
4892 num_workers = (int)val;
4895 if (g_str_has_prefix (opt, "stack-mark=")) {
4896 opt = strchr (opt, '=') + 1;
4897 if (!strcmp (opt, "precise")) {
4898 conservative_stack_mark = FALSE;
4899 } else if (!strcmp (opt, "conservative")) {
4900 conservative_stack_mark = TRUE;
4902 fprintf (stderr, "Invalid value '%s' for stack-mark= option, possible values are: 'precise', 'conservative'.\n", opt);
4907 if (g_str_has_prefix (opt, "bridge=")) {
4908 opt = strchr (opt, '=') + 1;
4909 sgen_register_test_bridge_callbacks (g_strdup (opt));
4913 if (g_str_has_prefix (opt, "nursery-size=")) {
4915 opt = strchr (opt, '=') + 1;
4916 if (*opt && mono_gc_parse_environment_string_extract_number (opt, &val)) {
4917 sgen_nursery_size = val;
4918 #ifdef SGEN_ALIGN_NURSERY
4919 if ((val & (val - 1))) {
4920 fprintf (stderr, "The nursery size must be a power of two.\n");
4924 if (val < SGEN_MAX_NURSERY_WASTE) {
4925 fprintf (stderr, "The nursery size must be at least %d bytes.\n", SGEN_MAX_NURSERY_WASTE);
4929 sgen_nursery_bits = 0;
4930 while (1 << (++ sgen_nursery_bits) != sgen_nursery_size)
4934 fprintf (stderr, "nursery-size must be an integer.\n");
4940 if (g_str_has_prefix (opt, "save-target-ratio=")) {
4942 opt = strchr (opt, '=') + 1;
4943 save_target = strtod (opt, &endptr);
4944 if (endptr == opt) {
4945 fprintf (stderr, "save-target-ratio must be a number.");
4948 if (save_target < SGEN_MIN_SAVE_TARGET_RATIO || save_target > SGEN_MAX_SAVE_TARGET_RATIO) {
4949 fprintf (stderr, "save-target-ratio must be between %.2f - %.2f.", SGEN_MIN_SAVE_TARGET_RATIO, SGEN_MAX_SAVE_TARGET_RATIO);
4954 if (g_str_has_prefix (opt, "default-allowance-ratio=")) {
4956 opt = strchr (opt, '=') + 1;
4958 allowance_ratio = strtod (opt, &endptr);
4959 if (endptr == opt) {
4960 fprintf (stderr, "save-target-ratio must be a number.");
4963 if (allowance_ratio < SGEN_MIN_ALLOWANCE_NURSERY_SIZE_RATIO || allowance_ratio > SGEN_MIN_ALLOWANCE_NURSERY_SIZE_RATIO) {
4964 fprintf (stderr, "default-allowance-ratio must be between %.2f - %.2f.", SGEN_MIN_ALLOWANCE_NURSERY_SIZE_RATIO, SGEN_MIN_ALLOWANCE_NURSERY_SIZE_RATIO);
4970 if (major_collector.handle_gc_param && major_collector.handle_gc_param (opt))
4973 if (sgen_minor_collector.handle_gc_param && sgen_minor_collector.handle_gc_param (opt))
4976 fprintf (stderr, "MONO_GC_PARAMS must be a comma-delimited list of one or more of the following:\n");
4977 fprintf (stderr, " max-heap-size=N (where N is an integer, possibly with a k, m or a g suffix)\n");
4978 fprintf (stderr, " soft-heap-limit=n (where N is an integer, possibly with a k, m or a g suffix)\n");
4979 fprintf (stderr, " nursery-size=N (where N is an integer, possibly with a k, m or a g suffix)\n");
4980 fprintf (stderr, " major=COLLECTOR (where COLLECTOR is `marksweep', `marksweep-par', 'marksweep-fixed', 'marksweep-fixed-par' or `copying')\n");
4981 fprintf (stderr, " minor=COLLECTOR (where COLLECTOR is `simple' or `split')\n");
4982 fprintf (stderr, " wbarrier=WBARRIER (where WBARRIER is `remset' or `cardtable')\n");
4983 fprintf (stderr, " stack-mark=MARK-METHOD (where MARK-METHOD is 'precise' or 'conservative')\n");
4984 if (major_collector.print_gc_param_usage)
4985 major_collector.print_gc_param_usage ();
4986 if (sgen_minor_collector.print_gc_param_usage)
4987 sgen_minor_collector.print_gc_param_usage ();
4988 fprintf (stderr, " Experimental options:\n");
4989 fprintf (stderr, " save-target-ratio=R (where R must be between %.2f - %.2f).\n", SGEN_MIN_SAVE_TARGET_RATIO, SGEN_MAX_SAVE_TARGET_RATIO);
4990 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);
4996 if (major_collector.is_parallel)
4997 sgen_workers_init (num_workers);
4998 else if (major_collector.is_concurrent)
4999 sgen_workers_init (1);
5001 if (major_collector_opt)
5002 g_free (major_collector_opt);
5004 if (minor_collector_opt)
5005 g_free (minor_collector_opt);
5009 if ((env = getenv ("MONO_GC_DEBUG"))) {
5010 opts = g_strsplit (env, ",", -1);
5011 for (ptr = opts; ptr && *ptr; ptr ++) {
5013 if (opt [0] >= '0' && opt [0] <= '9') {
5014 gc_debug_level = atoi (opt);
5020 char *rf = g_strdup_printf ("%s.%d", opt, GetCurrentProcessId ());
5022 char *rf = g_strdup_printf ("%s.%d", opt, getpid ());
5024 gc_debug_file = fopen (rf, "wb");
5026 gc_debug_file = stderr;
5029 } else if (!strcmp (opt, "print-allowance")) {
5030 debug_print_allowance = TRUE;
5031 } else if (!strcmp (opt, "print-pinning")) {
5032 do_pin_stats = TRUE;
5033 } else if (!strcmp (opt, "verify-before-allocs")) {
5034 verify_before_allocs = 1;
5035 has_per_allocation_action = TRUE;
5036 } else if (g_str_has_prefix (opt, "verify-before-allocs=")) {
5037 char *arg = strchr (opt, '=') + 1;
5038 verify_before_allocs = atoi (arg);
5039 has_per_allocation_action = TRUE;
5040 } else if (!strcmp (opt, "collect-before-allocs")) {
5041 collect_before_allocs = 1;
5042 has_per_allocation_action = TRUE;
5043 } else if (g_str_has_prefix (opt, "collect-before-allocs=")) {
5044 char *arg = strchr (opt, '=') + 1;
5045 has_per_allocation_action = TRUE;
5046 collect_before_allocs = atoi (arg);
5047 } else if (!strcmp (opt, "verify-before-collections")) {
5048 whole_heap_check_before_collection = TRUE;
5049 } else if (!strcmp (opt, "check-at-minor-collections")) {
5050 consistency_check_at_minor_collection = TRUE;
5051 nursery_clear_policy = CLEAR_AT_GC;
5052 } else if (!strcmp (opt, "xdomain-checks")) {
5053 xdomain_checks = TRUE;
5054 } else if (!strcmp (opt, "clear-at-gc")) {
5055 nursery_clear_policy = CLEAR_AT_GC;
5056 } else if (!strcmp (opt, "clear-nursery-at-gc")) {
5057 nursery_clear_policy = CLEAR_AT_GC;
5058 } else if (!strcmp (opt, "check-scan-starts")) {
5059 do_scan_starts_check = TRUE;
5060 } else if (!strcmp (opt, "verify-nursery-at-minor-gc")) {
5061 do_verify_nursery = TRUE;
5062 } else if (!strcmp (opt, "check-concurrent")) {
5063 if (!major_collector.is_concurrent) {
5064 fprintf (stderr, "Error: check-concurrent only world with concurrent major collectors.\n");
5067 do_concurrent_checks = TRUE;
5068 } else if (!strcmp (opt, "dump-nursery-at-minor-gc")) {
5069 do_dump_nursery_content = TRUE;
5070 } else if (!strcmp (opt, "no-managed-allocator")) {
5071 sgen_set_use_managed_allocator (FALSE);
5072 } else if (!strcmp (opt, "disable-minor")) {
5073 disable_minor_collections = TRUE;
5074 } else if (!strcmp (opt, "disable-major")) {
5075 disable_major_collections = TRUE;
5076 } else if (g_str_has_prefix (opt, "heap-dump=")) {
5077 char *filename = strchr (opt, '=') + 1;
5078 nursery_clear_policy = CLEAR_AT_GC;
5079 heap_dump_file = fopen (filename, "w");
5080 if (heap_dump_file) {
5081 fprintf (heap_dump_file, "<sgen-dump>\n");
5082 do_pin_stats = TRUE;
5084 #ifdef SGEN_BINARY_PROTOCOL
5085 } else if (g_str_has_prefix (opt, "binary-protocol=")) {
5086 char *filename = strchr (opt, '=') + 1;
5087 binary_protocol_init (filename);
5089 fprintf (stderr, "Warning: Cardtable write barriers will not be binary-protocolled.\n");
5092 fprintf (stderr, "Invalid format for the MONO_GC_DEBUG env variable: '%s'\n", env);
5093 fprintf (stderr, "The format is: MONO_GC_DEBUG=[l[:filename]|<option>]+ where l is a debug level 0-9.\n");
5094 fprintf (stderr, "Valid options are:\n");
5095 fprintf (stderr, " collect-before-allocs[=<n>]\n");
5096 fprintf (stderr, " verify-before-allocs[=<n>]\n");
5097 fprintf (stderr, " check-at-minor-collections\n");
5098 fprintf (stderr, " verify-before-collections\n");
5099 fprintf (stderr, " verify-nursery-at-minor-gc\n");
5100 fprintf (stderr, " dump-nursery-at-minor-gc\n");
5101 fprintf (stderr, " disable-minor\n");
5102 fprintf (stderr, " disable-major\n");
5103 fprintf (stderr, " xdomain-checks\n");
5104 fprintf (stderr, " check-concurrent\n");
5105 fprintf (stderr, " clear-at-gc\n");
5106 fprintf (stderr, " clear-nursery-at-gc\n");
5107 fprintf (stderr, " check-scan-starts\n");
5108 fprintf (stderr, " no-managed-allocator\n");
5109 fprintf (stderr, " print-allowance\n");
5110 fprintf (stderr, " print-pinning\n");
5111 fprintf (stderr, " heap-dump=<filename>\n");
5112 #ifdef SGEN_BINARY_PROTOCOL
5113 fprintf (stderr, " binary-protocol=<filename>\n");
5121 if (major_collector.is_parallel) {
5122 if (heap_dump_file) {
5123 fprintf (stderr, "Error: Cannot do heap dump with the parallel collector.\n");
5127 fprintf (stderr, "Error: Cannot gather pinning statistics with the parallel collector.\n");
5132 if (major_collector.post_param_init)
5133 major_collector.post_param_init (&major_collector);
5135 sgen_memgov_init (max_heap, soft_limit, debug_print_allowance, allowance_ratio, save_target);
5137 memset (&remset, 0, sizeof (remset));
5139 #ifdef SGEN_HAVE_CARDTABLE
5141 sgen_card_table_init (&remset);
5144 sgen_ssb_init (&remset);
5146 if (remset.register_thread)
5147 remset.register_thread (mono_thread_info_current ());
5153 mono_gc_get_gc_name (void)
5158 static MonoMethod *write_barrier_method;
5161 sgen_is_critical_method (MonoMethod *method)
5163 return (method == write_barrier_method || sgen_is_managed_allocator (method));
5167 sgen_has_critical_method (void)
5169 return write_barrier_method || sgen_has_managed_allocator ();
5173 emit_nursery_check (MonoMethodBuilder *mb, int *nursery_check_return_labels)
5175 memset (nursery_check_return_labels, 0, sizeof (int) * 3);
5176 #ifdef SGEN_ALIGN_NURSERY
5177 // if (ptr_in_nursery (ptr)) return;
5179 * Masking out the bits might be faster, but we would have to use 64 bit
5180 * immediates, which might be slower.
5182 mono_mb_emit_ldarg (mb, 0);
5183 mono_mb_emit_icon (mb, DEFAULT_NURSERY_BITS);
5184 mono_mb_emit_byte (mb, CEE_SHR_UN);
5185 mono_mb_emit_icon (mb, (mword)sgen_get_nursery_start () >> DEFAULT_NURSERY_BITS);
5186 nursery_check_return_labels [0] = mono_mb_emit_branch (mb, CEE_BEQ);
5188 if (!major_collector.is_concurrent) {
5189 // if (!ptr_in_nursery (*ptr)) return;
5190 mono_mb_emit_ldarg (mb, 0);
5191 mono_mb_emit_byte (mb, CEE_LDIND_I);
5192 mono_mb_emit_icon (mb, DEFAULT_NURSERY_BITS);
5193 mono_mb_emit_byte (mb, CEE_SHR_UN);
5194 mono_mb_emit_icon (mb, (mword)sgen_get_nursery_start () >> DEFAULT_NURSERY_BITS);
5195 nursery_check_return_labels [1] = mono_mb_emit_branch (mb, CEE_BNE_UN);
5198 int label_continue1, label_continue2;
5199 int dereferenced_var;
5201 // if (ptr < (sgen_get_nursery_start ())) goto continue;
5202 mono_mb_emit_ldarg (mb, 0);
5203 mono_mb_emit_ptr (mb, (gpointer) sgen_get_nursery_start ());
5204 label_continue_1 = mono_mb_emit_branch (mb, CEE_BLT);
5206 // if (ptr >= sgen_get_nursery_end ())) goto continue;
5207 mono_mb_emit_ldarg (mb, 0);
5208 mono_mb_emit_ptr (mb, (gpointer) sgen_get_nursery_end ());
5209 label_continue_2 = mono_mb_emit_branch (mb, CEE_BGE);
5212 nursery_check_return_labels [0] = mono_mb_emit_branch (mb, CEE_BR);
5215 mono_mb_patch_branch (mb, label_continue_1);
5216 mono_mb_patch_branch (mb, label_continue_2);
5218 // Dereference and store in local var
5219 dereferenced_var = mono_mb_add_local (mb, &mono_defaults.int_class->byval_arg);
5220 mono_mb_emit_ldarg (mb, 0);
5221 mono_mb_emit_byte (mb, CEE_LDIND_I);
5222 mono_mb_emit_stloc (mb, dereferenced_var);
5224 if (!major_collector.is_concurrent) {
5225 // if (*ptr < sgen_get_nursery_start ()) return;
5226 mono_mb_emit_ldloc (mb, dereferenced_var);
5227 mono_mb_emit_ptr (mb, (gpointer) sgen_get_nursery_start ());
5228 nursery_check_return_labels [1] = mono_mb_emit_branch (mb, CEE_BLT);
5230 // if (*ptr >= sgen_get_nursery_end ()) return;
5231 mono_mb_emit_ldloc (mb, dereferenced_var);
5232 mono_mb_emit_ptr (mb, (gpointer) sgen_get_nursery_end ());
5233 nursery_check_return_labels [2] = mono_mb_emit_branch (mb, CEE_BGE);
5239 mono_gc_get_write_barrier (void)
5242 MonoMethodBuilder *mb;
5243 MonoMethodSignature *sig;
5244 #ifdef MANAGED_WBARRIER
5245 int i, nursery_check_labels [3];
5246 int label_no_wb_3, label_no_wb_4, label_need_wb, label_slow_path;
5247 int buffer_var, buffer_index_var, dummy_var;
5249 #ifdef HAVE_KW_THREAD
5250 int stack_end_offset = -1, store_remset_buffer_offset = -1;
5251 int store_remset_buffer_index_offset = -1, store_remset_buffer_index_addr_offset = -1;
5253 MONO_THREAD_VAR_OFFSET (stack_end, stack_end_offset);
5254 g_assert (stack_end_offset != -1);
5255 MONO_THREAD_VAR_OFFSET (store_remset_buffer, store_remset_buffer_offset);
5256 g_assert (store_remset_buffer_offset != -1);
5257 MONO_THREAD_VAR_OFFSET (store_remset_buffer_index, store_remset_buffer_index_offset);
5258 g_assert (store_remset_buffer_index_offset != -1);
5259 MONO_THREAD_VAR_OFFSET (store_remset_buffer_index_addr, store_remset_buffer_index_addr_offset);
5260 g_assert (store_remset_buffer_index_addr_offset != -1);
5264 // FIXME: Maybe create a separate version for ctors (the branch would be
5265 // correctly predicted more times)
5266 if (write_barrier_method)
5267 return write_barrier_method;
5269 /* Create the IL version of mono_gc_barrier_generic_store () */
5270 sig = mono_metadata_signature_alloc (mono_defaults.corlib, 1);
5271 sig->ret = &mono_defaults.void_class->byval_arg;
5272 sig->params [0] = &mono_defaults.int_class->byval_arg;
5274 mb = mono_mb_new (mono_defaults.object_class, "wbarrier", MONO_WRAPPER_WRITE_BARRIER);
5276 #ifdef MANAGED_WBARRIER
5277 if (use_cardtable) {
5278 emit_nursery_check (mb, nursery_check_labels);
5280 addr = sgen_cardtable + ((address >> CARD_BITS) & CARD_MASK)
5284 LDC_PTR sgen_cardtable
5286 address >> CARD_BITS
5290 if (SGEN_HAVE_OVERLAPPING_CARDS) {
5291 LDC_PTR card_table_mask
5298 mono_mb_emit_ptr (mb, sgen_cardtable);
5299 mono_mb_emit_ldarg (mb, 0);
5300 mono_mb_emit_icon (mb, CARD_BITS);
5301 mono_mb_emit_byte (mb, CEE_SHR_UN);
5302 #ifdef SGEN_HAVE_OVERLAPPING_CARDS
5303 mono_mb_emit_ptr (mb, (gpointer)CARD_MASK);
5304 mono_mb_emit_byte (mb, CEE_AND);
5306 mono_mb_emit_byte (mb, CEE_ADD);
5307 mono_mb_emit_icon (mb, 1);
5308 mono_mb_emit_byte (mb, CEE_STIND_I1);
5311 for (i = 0; i < 3; ++i) {
5312 if (nursery_check_labels [i])
5313 mono_mb_patch_branch (mb, nursery_check_labels [i]);
5315 mono_mb_emit_byte (mb, CEE_RET);
5316 } else if (mono_runtime_has_tls_get ()) {
5317 emit_nursery_check (mb, nursery_check_labels);
5319 // if (ptr >= stack_end) goto need_wb;
5320 mono_mb_emit_ldarg (mb, 0);
5321 EMIT_TLS_ACCESS (mb, stack_end, stack_end_offset);
5322 label_need_wb = mono_mb_emit_branch (mb, CEE_BGE_UN);
5324 // if (ptr >= stack_start) return;
5325 dummy_var = mono_mb_add_local (mb, &mono_defaults.int_class->byval_arg);
5326 mono_mb_emit_ldarg (mb, 0);
5327 mono_mb_emit_ldloc_addr (mb, dummy_var);
5328 label_no_wb_3 = mono_mb_emit_branch (mb, CEE_BGE_UN);
5331 mono_mb_patch_branch (mb, label_need_wb);
5333 // buffer = STORE_REMSET_BUFFER;
5334 buffer_var = mono_mb_add_local (mb, &mono_defaults.int_class->byval_arg);
5335 EMIT_TLS_ACCESS (mb, store_remset_buffer, store_remset_buffer_offset);
5336 mono_mb_emit_stloc (mb, buffer_var);
5338 // buffer_index = STORE_REMSET_BUFFER_INDEX;
5339 buffer_index_var = mono_mb_add_local (mb, &mono_defaults.int_class->byval_arg);
5340 EMIT_TLS_ACCESS (mb, store_remset_buffer_index, store_remset_buffer_index_offset);
5341 mono_mb_emit_stloc (mb, buffer_index_var);
5343 // if (buffer [buffer_index] == ptr) return;
5344 mono_mb_emit_ldloc (mb, buffer_var);
5345 mono_mb_emit_ldloc (mb, buffer_index_var);
5346 g_assert (sizeof (gpointer) == 4 || sizeof (gpointer) == 8);
5347 mono_mb_emit_icon (mb, sizeof (gpointer) == 4 ? 2 : 3);
5348 mono_mb_emit_byte (mb, CEE_SHL);
5349 mono_mb_emit_byte (mb, CEE_ADD);
5350 mono_mb_emit_byte (mb, CEE_LDIND_I);
5351 mono_mb_emit_ldarg (mb, 0);
5352 label_no_wb_4 = mono_mb_emit_branch (mb, CEE_BEQ);
5355 mono_mb_emit_ldloc (mb, buffer_index_var);
5356 mono_mb_emit_icon (mb, 1);
5357 mono_mb_emit_byte (mb, CEE_ADD);
5358 mono_mb_emit_stloc (mb, buffer_index_var);
5360 // if (buffer_index >= STORE_REMSET_BUFFER_SIZE) goto slow_path;
5361 mono_mb_emit_ldloc (mb, buffer_index_var);
5362 mono_mb_emit_icon (mb, STORE_REMSET_BUFFER_SIZE);
5363 label_slow_path = mono_mb_emit_branch (mb, CEE_BGE);
5365 // buffer [buffer_index] = ptr;
5366 mono_mb_emit_ldloc (mb, buffer_var);
5367 mono_mb_emit_ldloc (mb, buffer_index_var);
5368 g_assert (sizeof (gpointer) == 4 || sizeof (gpointer) == 8);
5369 mono_mb_emit_icon (mb, sizeof (gpointer) == 4 ? 2 : 3);
5370 mono_mb_emit_byte (mb, CEE_SHL);
5371 mono_mb_emit_byte (mb, CEE_ADD);
5372 mono_mb_emit_ldarg (mb, 0);
5373 mono_mb_emit_byte (mb, CEE_STIND_I);
5375 // STORE_REMSET_BUFFER_INDEX = buffer_index;
5376 EMIT_TLS_ACCESS (mb, store_remset_buffer_index_addr, store_remset_buffer_index_addr_offset);
5377 mono_mb_emit_ldloc (mb, buffer_index_var);
5378 mono_mb_emit_byte (mb, CEE_STIND_I);
5381 for (i = 0; i < 3; ++i) {
5382 if (nursery_check_labels [i])
5383 mono_mb_patch_branch (mb, nursery_check_labels [i]);
5385 mono_mb_patch_branch (mb, label_no_wb_3);
5386 mono_mb_patch_branch (mb, label_no_wb_4);
5387 mono_mb_emit_byte (mb, CEE_RET);
5390 mono_mb_patch_branch (mb, label_slow_path);
5392 mono_mb_emit_ldarg (mb, 0);
5393 mono_mb_emit_icall (mb, mono_gc_wbarrier_generic_nostore);
5394 mono_mb_emit_byte (mb, CEE_RET);
5398 mono_mb_emit_ldarg (mb, 0);
5399 mono_mb_emit_icall (mb, mono_gc_wbarrier_generic_nostore);
5400 mono_mb_emit_byte (mb, CEE_RET);
5403 res = mono_mb_create_method (mb, sig, 16);
5406 mono_loader_lock ();
5407 if (write_barrier_method) {
5408 /* Already created */
5409 mono_free_method (res);
5411 /* double-checked locking */
5412 mono_memory_barrier ();
5413 write_barrier_method = res;
5415 mono_loader_unlock ();
5417 return write_barrier_method;
5421 mono_gc_get_description (void)
5423 return g_strdup ("sgen");
5427 mono_gc_set_desktop_mode (void)
5432 mono_gc_is_moving (void)
5438 mono_gc_is_disabled (void)
5444 BOOL APIENTRY mono_gc_dllmain (HMODULE module_handle, DWORD reason, LPVOID reserved)
5451 sgen_get_nursery_clear_policy (void)
5453 return nursery_clear_policy;
5457 sgen_get_array_fill_vtable (void)
5459 if (!array_fill_vtable) {
5460 static MonoClass klass;
5461 static MonoVTable vtable;
5464 MonoDomain *domain = mono_get_root_domain ();
5467 klass.element_class = mono_defaults.byte_class;
5469 klass.instance_size = sizeof (MonoArray);
5470 klass.sizes.element_size = 1;
5471 klass.name = "array_filler_type";
5473 vtable.klass = &klass;
5475 vtable.gc_descr = mono_gc_make_descr_for_array (TRUE, &bmap, 0, 1);
5478 array_fill_vtable = &vtable;
5480 return array_fill_vtable;
5490 sgen_gc_unlock (void)
5496 sgen_major_collector_iterate_live_block_ranges (sgen_cardtable_block_callback callback)
5498 major_collector.iterate_live_block_ranges (callback);
5502 sgen_major_collector_scan_card_table (SgenGrayQueue *queue)
5504 major_collector.scan_card_table (FALSE, queue);
5508 sgen_get_major_collector (void)
5510 return &major_collector;
5513 void mono_gc_set_skip_thread (gboolean skip)
5515 SgenThreadInfo *info = mono_thread_info_current ();
5518 info->gc_disabled = skip;
5523 sgen_get_remset (void)
5529 mono_gc_get_vtable_bits (MonoClass *class)
5531 if (sgen_need_bridge_processing () && sgen_is_bridge_class (class))
5532 return SGEN_GC_BIT_BRIDGE_OBJECT;
5537 mono_gc_register_altstack (gpointer stack, gint32 stack_size, gpointer altstack, gint32 altstack_size)
5544 sgen_check_whole_heap_stw (void)
5546 sgen_stop_world (0);
5547 sgen_clear_nursery_fragments ();
5548 sgen_check_whole_heap ();
5549 sgen_restart_world (0, NULL);
5553 sgen_gc_event_moves (void)
5555 if (moved_objects_idx) {
5556 mono_profiler_gc_moves (moved_objects, moved_objects_idx);
5557 moved_objects_idx = 0;
5561 #endif /* HAVE_SGEN_GC */