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, check whether mark bits are consistent after major collections */
264 static gboolean check_mark_bits_after_major_collection = FALSE;
265 /* If set, do a few checks when the concurrent collector is used */
266 static gboolean do_concurrent_checks = FALSE;
267 /* If set, check that there are no references to the domain left at domain unload */
268 static gboolean xdomain_checks = FALSE;
269 /* If not null, dump the heap after each collection into this file */
270 static FILE *heap_dump_file = NULL;
271 /* If set, mark stacks conservatively, even if precise marking is possible */
272 static gboolean conservative_stack_mark = FALSE;
273 /* If set, do a plausibility check on the scan_starts before and after
275 static gboolean do_scan_starts_check = FALSE;
276 static gboolean nursery_collection_is_parallel = FALSE;
277 static gboolean disable_minor_collections = FALSE;
278 static gboolean disable_major_collections = FALSE;
279 gboolean do_pin_stats = FALSE;
280 static gboolean do_verify_nursery = FALSE;
281 static gboolean do_dump_nursery_content = FALSE;
283 #ifdef HEAVY_STATISTICS
284 long long stat_objects_alloced_degraded = 0;
285 long long stat_bytes_alloced_degraded = 0;
287 long long stat_copy_object_called_nursery = 0;
288 long long stat_objects_copied_nursery = 0;
289 long long stat_copy_object_called_major = 0;
290 long long stat_objects_copied_major = 0;
292 long long stat_scan_object_called_nursery = 0;
293 long long stat_scan_object_called_major = 0;
295 long long stat_slots_allocated_in_vain;
297 long long stat_nursery_copy_object_failed_from_space = 0;
298 long long stat_nursery_copy_object_failed_forwarded = 0;
299 long long stat_nursery_copy_object_failed_pinned = 0;
300 long long stat_nursery_copy_object_failed_to_space = 0;
302 static int stat_wbarrier_set_field = 0;
303 static int stat_wbarrier_set_arrayref = 0;
304 static int stat_wbarrier_arrayref_copy = 0;
305 static int stat_wbarrier_generic_store = 0;
306 static int stat_wbarrier_set_root = 0;
307 static int stat_wbarrier_value_copy = 0;
308 static int stat_wbarrier_object_copy = 0;
311 int stat_minor_gcs = 0;
312 int stat_major_gcs = 0;
314 static long long stat_pinned_objects = 0;
316 static long long time_minor_pre_collection_fragment_clear = 0;
317 static long long time_minor_pinning = 0;
318 static long long time_minor_scan_remsets = 0;
319 static long long time_minor_scan_pinned = 0;
320 static long long time_minor_scan_registered_roots = 0;
321 static long long time_minor_scan_thread_data = 0;
322 static long long time_minor_finish_gray_stack = 0;
323 static long long time_minor_fragment_creation = 0;
325 static long long time_major_pre_collection_fragment_clear = 0;
326 static long long time_major_pinning = 0;
327 static long long time_major_scan_pinned = 0;
328 static long long time_major_scan_registered_roots = 0;
329 static long long time_major_scan_thread_data = 0;
330 static long long time_major_scan_alloc_pinned = 0;
331 static long long time_major_scan_finalized = 0;
332 static long long time_major_scan_big_objects = 0;
333 static long long time_major_finish_gray_stack = 0;
334 static long long time_major_free_bigobjs = 0;
335 static long long time_major_los_sweep = 0;
336 static long long time_major_sweep = 0;
337 static long long time_major_fragment_creation = 0;
339 int gc_debug_level = 0;
344 mono_gc_flush_info (void)
346 fflush (gc_debug_file);
350 #define TV_DECLARE SGEN_TV_DECLARE
351 #define TV_GETTIME SGEN_TV_GETTIME
352 #define TV_ELAPSED SGEN_TV_ELAPSED
353 #define TV_ELAPSED_MS SGEN_TV_ELAPSED_MS
355 #define ALIGN_TO(val,align) ((((guint64)val) + ((align) - 1)) & ~((align) - 1))
357 NurseryClearPolicy nursery_clear_policy = CLEAR_AT_TLAB_CREATION;
359 #define object_is_forwarded SGEN_OBJECT_IS_FORWARDED
360 #define object_is_pinned SGEN_OBJECT_IS_PINNED
361 #define pin_object SGEN_PIN_OBJECT
362 #define unpin_object SGEN_UNPIN_OBJECT
364 #define ptr_in_nursery sgen_ptr_in_nursery
366 #define LOAD_VTABLE SGEN_LOAD_VTABLE
369 safe_name (void* obj)
371 MonoVTable *vt = (MonoVTable*)LOAD_VTABLE (obj);
372 return vt->klass->name;
375 #define safe_object_get_size sgen_safe_object_get_size
378 sgen_safe_name (void* obj)
380 return safe_name (obj);
384 * ######################################################################
385 * ######## Global data.
386 * ######################################################################
388 LOCK_DECLARE (gc_mutex);
389 static int gc_disabled = 0;
391 static gboolean use_cardtable;
393 #define SCAN_START_SIZE SGEN_SCAN_START_SIZE
395 static mword pagesize = 4096;
396 int degraded_mode = 0;
398 static mword bytes_pinned_from_failed_allocation = 0;
400 GCMemSection *nursery_section = NULL;
401 static mword lowest_heap_address = ~(mword)0;
402 static mword highest_heap_address = 0;
404 LOCK_DECLARE (sgen_interruption_mutex);
405 static LOCK_DECLARE (pin_queue_mutex);
407 #define LOCK_PIN_QUEUE mono_mutex_lock (&pin_queue_mutex)
408 #define UNLOCK_PIN_QUEUE mono_mutex_unlock (&pin_queue_mutex)
410 typedef struct _FinalizeReadyEntry FinalizeReadyEntry;
411 struct _FinalizeReadyEntry {
412 FinalizeReadyEntry *next;
416 typedef struct _EphemeronLinkNode EphemeronLinkNode;
418 struct _EphemeronLinkNode {
419 EphemeronLinkNode *next;
428 int current_collection_generation = -1;
429 volatile gboolean concurrent_collection_in_progress = FALSE;
431 /* objects that are ready to be finalized */
432 static FinalizeReadyEntry *fin_ready_list = NULL;
433 static FinalizeReadyEntry *critical_fin_list = NULL;
435 static EphemeronLinkNode *ephemeron_list;
437 /* registered roots: the key to the hash is the root start address */
439 * Different kinds of roots are kept separate to speed up pin_from_roots () for example.
441 SgenHashTable roots_hash [ROOT_TYPE_NUM] = {
442 SGEN_HASH_TABLE_INIT (INTERNAL_MEM_ROOTS_TABLE, INTERNAL_MEM_ROOT_RECORD, sizeof (RootRecord), mono_aligned_addr_hash, NULL),
443 SGEN_HASH_TABLE_INIT (INTERNAL_MEM_ROOTS_TABLE, INTERNAL_MEM_ROOT_RECORD, sizeof (RootRecord), mono_aligned_addr_hash, NULL),
444 SGEN_HASH_TABLE_INIT (INTERNAL_MEM_ROOTS_TABLE, INTERNAL_MEM_ROOT_RECORD, sizeof (RootRecord), mono_aligned_addr_hash, NULL)
446 static mword roots_size = 0; /* amount of memory in the root set */
448 #define GC_ROOT_NUM 32
450 int count; /* must be the first field */
451 void *objects [GC_ROOT_NUM];
452 int root_types [GC_ROOT_NUM];
453 uintptr_t extra_info [GC_ROOT_NUM];
457 notify_gc_roots (GCRootReport *report)
461 mono_profiler_gc_roots (report->count, report->objects, report->root_types, report->extra_info);
466 add_profile_gc_root (GCRootReport *report, void *object, int rtype, uintptr_t extra_info)
468 if (report->count == GC_ROOT_NUM)
469 notify_gc_roots (report);
470 report->objects [report->count] = object;
471 report->root_types [report->count] = rtype;
472 report->extra_info [report->count++] = (uintptr_t)((MonoVTable*)LOAD_VTABLE (object))->klass;
475 MonoNativeTlsKey thread_info_key;
477 #ifdef HAVE_KW_THREAD
478 __thread SgenThreadInfo *sgen_thread_info;
479 __thread gpointer *store_remset_buffer;
480 __thread long store_remset_buffer_index;
481 __thread char *stack_end;
482 __thread long *store_remset_buffer_index_addr;
485 /* The size of a TLAB */
486 /* The bigger the value, the less often we have to go to the slow path to allocate a new
487 * one, but the more space is wasted by threads not allocating much memory.
489 * FIXME: Make this self-tuning for each thread.
491 guint32 tlab_size = (1024 * 4);
493 #define MAX_SMALL_OBJ_SIZE SGEN_MAX_SMALL_OBJ_SIZE
495 /* Functions supplied by the runtime to be called by the GC */
496 static MonoGCCallbacks gc_callbacks;
498 #define ALLOC_ALIGN SGEN_ALLOC_ALIGN
499 #define ALLOC_ALIGN_BITS SGEN_ALLOC_ALIGN_BITS
501 #define ALIGN_UP SGEN_ALIGN_UP
503 #define MOVED_OBJECTS_NUM 64
504 static void *moved_objects [MOVED_OBJECTS_NUM];
505 static int moved_objects_idx = 0;
507 /* Vtable of the objects used to fill out nursery fragments before a collection */
508 static MonoVTable *array_fill_vtable;
510 #ifdef SGEN_DEBUG_INTERNAL_ALLOC
511 MonoNativeThreadId main_gc_thread = NULL;
514 /*Object was pinned during the current collection*/
515 static mword objects_pinned;
518 * ######################################################################
519 * ######## Macros and function declarations.
520 * ######################################################################
524 align_pointer (void *ptr)
526 mword p = (mword)ptr;
527 p += sizeof (gpointer) - 1;
528 p &= ~ (sizeof (gpointer) - 1);
532 typedef SgenGrayQueue GrayQueue;
534 /* forward declarations */
535 static void scan_thread_data (void *start_nursery, void *end_nursery, gboolean precise, GrayQueue *queue);
536 static void scan_from_registered_roots (char *addr_start, char *addr_end, int root_type, ScanCopyContext ctx);
537 static void scan_finalizer_entries (FinalizeReadyEntry *list, ScanCopyContext ctx);
538 static void report_finalizer_roots (void);
539 static void report_registered_roots (void);
541 static void pin_from_roots (void *start_nursery, void *end_nursery, GrayQueue *queue);
542 static int pin_objects_from_addresses (GCMemSection *section, void **start, void **end, void *start_nursery, void *end_nursery, ScanCopyContext ctx);
543 static void finish_gray_stack (char *start_addr, char *end_addr, int generation, GrayQueue *queue);
545 void mono_gc_scan_for_specific_ref (MonoObject *key, gboolean precise);
548 static void init_stats (void);
550 static int mark_ephemerons_in_range (char *start, char *end, ScanCopyContext ctx);
551 static void clear_unreachable_ephemerons (char *start, char *end, ScanCopyContext ctx);
552 static void null_ephemerons_for_domain (MonoDomain *domain);
554 SgenObjectOperations current_object_ops;
555 SgenMajorCollector major_collector;
556 SgenMinorCollector sgen_minor_collector;
557 static GrayQueue gray_queue;
558 static GrayQueue remember_major_objects_gray_queue;
560 static SgenRemeberedSet remset;
562 /* The gray queue to use from the main collection thread. */
563 #define WORKERS_DISTRIBUTE_GRAY_QUEUE (&gray_queue)
566 * The gray queue a worker job must use. If we're not parallel or
567 * concurrent, we use the main gray queue.
569 static SgenGrayQueue*
570 sgen_workers_get_job_gray_queue (WorkerData *worker_data)
572 return worker_data ? &worker_data->private_gray_queue : WORKERS_DISTRIBUTE_GRAY_QUEUE;
575 static gboolean have_non_collection_major_object_remembers = FALSE;
578 sgen_remember_major_object_for_concurrent_mark (char *obj)
580 if (!major_collector.is_concurrent)
583 g_assert (current_collection_generation == GENERATION_NURSERY || current_collection_generation == -1);
585 if (!concurrent_collection_in_progress)
588 GRAY_OBJECT_ENQUEUE (&remember_major_objects_gray_queue, obj);
590 if (current_collection_generation != GENERATION_NURSERY) {
592 * This happens when the mutator allocates large or
593 * pinned objects or when allocating in degraded
596 have_non_collection_major_object_remembers = TRUE;
603 gray_queue_redirect (SgenGrayQueue *queue)
605 gboolean wake = FALSE;
609 GrayQueueSection *section = sgen_gray_object_dequeue_section (queue);
612 sgen_section_gray_queue_enqueue (queue->alloc_prepare_data, section);
617 g_assert (concurrent_collection_in_progress ||
618 (current_collection_generation == GENERATION_OLD && major_collector.is_parallel));
619 if (sgen_workers_have_started ()) {
620 sgen_workers_wake_up_all ();
622 if (concurrent_collection_in_progress)
623 g_assert (current_collection_generation == -1);
629 redirect_major_object_remembers (void)
631 gray_queue_redirect (&remember_major_objects_gray_queue);
632 have_non_collection_major_object_remembers = FALSE;
636 is_xdomain_ref_allowed (gpointer *ptr, char *obj, MonoDomain *domain)
638 MonoObject *o = (MonoObject*)(obj);
639 MonoObject *ref = (MonoObject*)*(ptr);
640 int offset = (char*)(ptr) - (char*)o;
642 if (o->vtable->klass == mono_defaults.thread_class && offset == G_STRUCT_OFFSET (MonoThread, internal_thread))
644 if (o->vtable->klass == mono_defaults.internal_thread_class && offset == G_STRUCT_OFFSET (MonoInternalThread, current_appcontext))
646 if (mono_class_has_parent_fast (o->vtable->klass, mono_defaults.real_proxy_class) &&
647 offset == G_STRUCT_OFFSET (MonoRealProxy, unwrapped_server))
649 /* Thread.cached_culture_info */
650 if (!strcmp (ref->vtable->klass->name_space, "System.Globalization") &&
651 !strcmp (ref->vtable->klass->name, "CultureInfo") &&
652 !strcmp(o->vtable->klass->name_space, "System") &&
653 !strcmp(o->vtable->klass->name, "Object[]"))
656 * 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
657 * at System.IO.MemoryStream..ctor (byte[]) [0x00017] in /home/schani/Work/novell/trunk/mcs/class/corlib/System.IO/MemoryStream.cs:81
658 * at (wrapper remoting-invoke-with-check) System.IO.MemoryStream..ctor (byte[]) <IL 0x00020, 0xffffffff>
659 * at System.Runtime.Remoting.Messaging.CADMethodCallMessage.GetArguments () [0x0000d] in /home/schani/Work/novell/trunk/mcs/class/corlib/System.Runtime.Remoting.Messaging/CADMessages.cs:327
660 * 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
661 * 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
662 * at (wrapper remoting-invoke-with-check) System.AppDomain.ProcessMessageInDomain (byte[],System.Runtime.Remoting.Messaging.CADMethodCallMessage,byte[]&,System.Runtime.Remoting.Messaging.CADMethodReturnMessage&) <IL 0x0003d, 0xffffffff>
663 * 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
664 * at (wrapper runtime-invoke) object.runtime_invoke_CrossAppDomainSink/ProcessMessageRes_object_object (object,intptr,intptr,intptr) <IL 0x0004c, 0xffffffff>
666 if (!strcmp (ref->vtable->klass->name_space, "System") &&
667 !strcmp (ref->vtable->klass->name, "Byte[]") &&
668 !strcmp (o->vtable->klass->name_space, "System.IO") &&
669 !strcmp (o->vtable->klass->name, "MemoryStream"))
671 /* append_job() in threadpool.c */
672 if (!strcmp (ref->vtable->klass->name_space, "System.Runtime.Remoting.Messaging") &&
673 !strcmp (ref->vtable->klass->name, "AsyncResult") &&
674 !strcmp (o->vtable->klass->name_space, "System") &&
675 !strcmp (o->vtable->klass->name, "Object[]") &&
676 mono_thread_pool_is_queue_array ((MonoArray*) o))
682 check_reference_for_xdomain (gpointer *ptr, char *obj, MonoDomain *domain)
684 MonoObject *o = (MonoObject*)(obj);
685 MonoObject *ref = (MonoObject*)*(ptr);
686 int offset = (char*)(ptr) - (char*)o;
688 MonoClassField *field;
691 if (!ref || ref->vtable->domain == domain)
693 if (is_xdomain_ref_allowed (ptr, obj, domain))
697 for (class = o->vtable->klass; class; class = class->parent) {
700 for (i = 0; i < class->field.count; ++i) {
701 if (class->fields[i].offset == offset) {
702 field = &class->fields[i];
710 if (ref->vtable->klass == mono_defaults.string_class)
711 str = mono_string_to_utf8 ((MonoString*)ref);
714 g_print ("xdomain reference in %p (%s.%s) at offset %d (%s) to %p (%s.%s) (%s) - pointed to by:\n",
715 o, o->vtable->klass->name_space, o->vtable->klass->name,
716 offset, field ? field->name : "",
717 ref, ref->vtable->klass->name_space, ref->vtable->klass->name, str ? str : "");
718 mono_gc_scan_for_specific_ref (o, TRUE);
724 #define HANDLE_PTR(ptr,obj) check_reference_for_xdomain ((ptr), (obj), domain)
727 scan_object_for_xdomain_refs (char *start, mword size, void *data)
729 MonoDomain *domain = ((MonoObject*)start)->vtable->domain;
731 #include "sgen-scan-object.h"
734 static gboolean scan_object_for_specific_ref_precise = TRUE;
737 #define HANDLE_PTR(ptr,obj) do { \
738 if ((MonoObject*)*(ptr) == key) { \
739 g_print ("found ref to %p in object %p (%s) at offset %td\n", \
740 key, (obj), safe_name ((obj)), ((char*)(ptr) - (char*)(obj))); \
745 scan_object_for_specific_ref (char *start, MonoObject *key)
749 if ((forwarded = SGEN_OBJECT_IS_FORWARDED (start)))
752 if (scan_object_for_specific_ref_precise) {
753 #include "sgen-scan-object.h"
755 mword *words = (mword*)start;
756 size_t size = safe_object_get_size ((MonoObject*)start);
758 for (i = 0; i < size / sizeof (mword); ++i) {
759 if (words [i] == (mword)key) {
760 g_print ("found possible ref to %p in object %p (%s) at offset %td\n",
761 key, start, safe_name (start), i * sizeof (mword));
768 sgen_scan_area_with_callback (char *start, char *end, IterateObjectCallbackFunc callback, void *data, gboolean allow_flags)
770 while (start < end) {
774 if (!*(void**)start) {
775 start += sizeof (void*); /* should be ALLOC_ALIGN, really */
780 if (!(obj = SGEN_OBJECT_IS_FORWARDED (start)))
786 size = ALIGN_UP (safe_object_get_size ((MonoObject*)obj));
788 if ((MonoVTable*)SGEN_LOAD_VTABLE (obj) != array_fill_vtable)
789 callback (obj, size, data);
796 scan_object_for_specific_ref_callback (char *obj, size_t size, MonoObject *key)
798 scan_object_for_specific_ref (obj, key);
802 check_root_obj_specific_ref (RootRecord *root, MonoObject *key, MonoObject *obj)
806 g_print ("found ref to %p in root record %p\n", key, root);
809 static MonoObject *check_key = NULL;
810 static RootRecord *check_root = NULL;
813 check_root_obj_specific_ref_from_marker (void **obj)
815 check_root_obj_specific_ref (check_root, check_key, *obj);
819 scan_roots_for_specific_ref (MonoObject *key, int root_type)
825 SGEN_HASH_TABLE_FOREACH (&roots_hash [root_type], start_root, root) {
826 mword desc = root->root_desc;
830 switch (desc & ROOT_DESC_TYPE_MASK) {
831 case ROOT_DESC_BITMAP:
832 desc >>= ROOT_DESC_TYPE_SHIFT;
835 check_root_obj_specific_ref (root, key, *start_root);
840 case ROOT_DESC_COMPLEX: {
841 gsize *bitmap_data = sgen_get_complex_descriptor_bitmap (desc);
842 int bwords = (*bitmap_data) - 1;
843 void **start_run = start_root;
845 while (bwords-- > 0) {
846 gsize bmap = *bitmap_data++;
847 void **objptr = start_run;
850 check_root_obj_specific_ref (root, key, *objptr);
854 start_run += GC_BITS_PER_WORD;
858 case ROOT_DESC_USER: {
859 MonoGCRootMarkFunc marker = sgen_get_user_descriptor_func (desc);
860 marker (start_root, check_root_obj_specific_ref_from_marker);
863 case ROOT_DESC_RUN_LEN:
864 g_assert_not_reached ();
866 g_assert_not_reached ();
868 } SGEN_HASH_TABLE_FOREACH_END;
875 mono_gc_scan_for_specific_ref (MonoObject *key, gboolean precise)
880 scan_object_for_specific_ref_precise = precise;
882 sgen_scan_area_with_callback (nursery_section->data, nursery_section->end_data,
883 (IterateObjectCallbackFunc)scan_object_for_specific_ref_callback, key, TRUE);
885 major_collector.iterate_objects (TRUE, TRUE, (IterateObjectCallbackFunc)scan_object_for_specific_ref_callback, key);
887 sgen_los_iterate_objects ((IterateObjectCallbackFunc)scan_object_for_specific_ref_callback, key);
889 scan_roots_for_specific_ref (key, ROOT_TYPE_NORMAL);
890 scan_roots_for_specific_ref (key, ROOT_TYPE_WBARRIER);
892 SGEN_HASH_TABLE_FOREACH (&roots_hash [ROOT_TYPE_PINNED], ptr, root) {
893 while (ptr < (void**)root->end_root) {
894 check_root_obj_specific_ref (root, *ptr, key);
897 } SGEN_HASH_TABLE_FOREACH_END;
901 need_remove_object_for_domain (char *start, MonoDomain *domain)
903 if (mono_object_domain (start) == domain) {
904 SGEN_LOG (4, "Need to cleanup object %p", start);
905 binary_protocol_cleanup (start, (gpointer)LOAD_VTABLE (start), safe_object_get_size ((MonoObject*)start));
912 process_object_for_domain_clearing (char *start, MonoDomain *domain)
914 GCVTable *vt = (GCVTable*)LOAD_VTABLE (start);
915 if (vt->klass == mono_defaults.internal_thread_class)
916 g_assert (mono_object_domain (start) == mono_get_root_domain ());
917 /* The object could be a proxy for an object in the domain
919 if (mono_class_has_parent_fast (vt->klass, mono_defaults.real_proxy_class)) {
920 MonoObject *server = ((MonoRealProxy*)start)->unwrapped_server;
922 /* The server could already have been zeroed out, so
923 we need to check for that, too. */
924 if (server && (!LOAD_VTABLE (server) || mono_object_domain (server) == domain)) {
925 SGEN_LOG (4, "Cleaning up remote pointer in %p to object %p", start, server);
926 ((MonoRealProxy*)start)->unwrapped_server = NULL;
931 static MonoDomain *check_domain = NULL;
934 check_obj_not_in_domain (void **o)
936 g_assert (((MonoObject*)(*o))->vtable->domain != check_domain);
940 scan_for_registered_roots_in_domain (MonoDomain *domain, int root_type)
944 check_domain = domain;
945 SGEN_HASH_TABLE_FOREACH (&roots_hash [root_type], start_root, root) {
946 mword desc = root->root_desc;
948 /* The MonoDomain struct is allowed to hold
949 references to objects in its own domain. */
950 if (start_root == (void**)domain)
953 switch (desc & ROOT_DESC_TYPE_MASK) {
954 case ROOT_DESC_BITMAP:
955 desc >>= ROOT_DESC_TYPE_SHIFT;
957 if ((desc & 1) && *start_root)
958 check_obj_not_in_domain (*start_root);
963 case ROOT_DESC_COMPLEX: {
964 gsize *bitmap_data = sgen_get_complex_descriptor_bitmap (desc);
965 int bwords = (*bitmap_data) - 1;
966 void **start_run = start_root;
968 while (bwords-- > 0) {
969 gsize bmap = *bitmap_data++;
970 void **objptr = start_run;
972 if ((bmap & 1) && *objptr)
973 check_obj_not_in_domain (*objptr);
977 start_run += GC_BITS_PER_WORD;
981 case ROOT_DESC_USER: {
982 MonoGCRootMarkFunc marker = sgen_get_user_descriptor_func (desc);
983 marker (start_root, check_obj_not_in_domain);
986 case ROOT_DESC_RUN_LEN:
987 g_assert_not_reached ();
989 g_assert_not_reached ();
991 } SGEN_HASH_TABLE_FOREACH_END;
997 check_for_xdomain_refs (void)
1001 sgen_scan_area_with_callback (nursery_section->data, nursery_section->end_data,
1002 (IterateObjectCallbackFunc)scan_object_for_xdomain_refs, NULL, FALSE);
1004 major_collector.iterate_objects (TRUE, TRUE, (IterateObjectCallbackFunc)scan_object_for_xdomain_refs, NULL);
1006 for (bigobj = los_object_list; bigobj; bigobj = bigobj->next)
1007 scan_object_for_xdomain_refs (bigobj->data, sgen_los_object_size (bigobj), NULL);
1011 clear_domain_process_object (char *obj, MonoDomain *domain)
1015 process_object_for_domain_clearing (obj, domain);
1016 remove = need_remove_object_for_domain (obj, domain);
1018 if (remove && ((MonoObject*)obj)->synchronisation) {
1019 void **dislink = mono_monitor_get_object_monitor_weak_link ((MonoObject*)obj);
1021 sgen_register_disappearing_link (NULL, dislink, FALSE, TRUE);
1028 clear_domain_process_minor_object_callback (char *obj, size_t size, MonoDomain *domain)
1030 if (clear_domain_process_object (obj, domain))
1031 memset (obj, 0, size);
1035 clear_domain_process_major_object_callback (char *obj, size_t size, MonoDomain *domain)
1037 clear_domain_process_object (obj, domain);
1041 clear_domain_free_major_non_pinned_object_callback (char *obj, size_t size, MonoDomain *domain)
1043 if (need_remove_object_for_domain (obj, domain))
1044 major_collector.free_non_pinned_object (obj, size);
1048 clear_domain_free_major_pinned_object_callback (char *obj, size_t size, MonoDomain *domain)
1050 if (need_remove_object_for_domain (obj, domain))
1051 major_collector.free_pinned_object (obj, size);
1055 * When appdomains are unloaded we can easily remove objects that have finalizers,
1056 * but all the others could still be present in random places on the heap.
1057 * We need a sweep to get rid of them even though it's going to be costly
1059 * The reason we need to remove them is because we access the vtable and class
1060 * structures to know the object size and the reference bitmap: once the domain is
1061 * unloaded the point to random memory.
1064 mono_gc_clear_domain (MonoDomain * domain)
1066 LOSObject *bigobj, *prev;
1071 sgen_process_fin_stage_entries ();
1072 sgen_process_dislink_stage_entries ();
1074 sgen_clear_nursery_fragments ();
1076 if (xdomain_checks && domain != mono_get_root_domain ()) {
1077 scan_for_registered_roots_in_domain (domain, ROOT_TYPE_NORMAL);
1078 scan_for_registered_roots_in_domain (domain, ROOT_TYPE_WBARRIER);
1079 check_for_xdomain_refs ();
1082 /*Ephemerons and dislinks must be processed before LOS since they might end up pointing
1083 to memory returned to the OS.*/
1084 null_ephemerons_for_domain (domain);
1086 for (i = GENERATION_NURSERY; i < GENERATION_MAX; ++i)
1087 sgen_null_links_for_domain (domain, i);
1089 for (i = GENERATION_NURSERY; i < GENERATION_MAX; ++i)
1090 sgen_remove_finalizers_for_domain (domain, i);
1092 sgen_scan_area_with_callback (nursery_section->data, nursery_section->end_data,
1093 (IterateObjectCallbackFunc)clear_domain_process_minor_object_callback, domain, FALSE);
1095 /* We need two passes over major and large objects because
1096 freeing such objects might give their memory back to the OS
1097 (in the case of large objects) or obliterate its vtable
1098 (pinned objects with major-copying or pinned and non-pinned
1099 objects with major-mark&sweep), but we might need to
1100 dereference a pointer from an object to another object if
1101 the first object is a proxy. */
1102 major_collector.iterate_objects (TRUE, TRUE, (IterateObjectCallbackFunc)clear_domain_process_major_object_callback, domain);
1103 for (bigobj = los_object_list; bigobj; bigobj = bigobj->next)
1104 clear_domain_process_object (bigobj->data, domain);
1107 for (bigobj = los_object_list; bigobj;) {
1108 if (need_remove_object_for_domain (bigobj->data, domain)) {
1109 LOSObject *to_free = bigobj;
1111 prev->next = bigobj->next;
1113 los_object_list = bigobj->next;
1114 bigobj = bigobj->next;
1115 SGEN_LOG (4, "Freeing large object %p", bigobj->data);
1116 sgen_los_free_object (to_free);
1120 bigobj = bigobj->next;
1122 major_collector.iterate_objects (TRUE, FALSE, (IterateObjectCallbackFunc)clear_domain_free_major_non_pinned_object_callback, domain);
1123 major_collector.iterate_objects (FALSE, TRUE, (IterateObjectCallbackFunc)clear_domain_free_major_pinned_object_callback, domain);
1125 if (G_UNLIKELY (do_pin_stats)) {
1126 if (domain == mono_get_root_domain ())
1127 sgen_pin_stats_print_class_stats ();
1134 * sgen_add_to_global_remset:
1136 * The global remset contains locations which point into newspace after
1137 * a minor collection. This can happen if the objects they point to are pinned.
1139 * LOCKING: If called from a parallel collector, the global remset
1140 * lock must be held. For serial collectors that is not necessary.
1143 sgen_add_to_global_remset (gpointer ptr, gpointer obj)
1145 remset.record_pointer (ptr);
1147 if (G_UNLIKELY (MONO_GC_GLOBAL_REMSET_ADD_ENABLED ())) {
1148 MonoVTable *vt = (MonoVTable*)LOAD_VTABLE (obj);
1149 MONO_GC_GLOBAL_REMSET_ADD ((mword)ptr, (mword)obj, sgen_safe_object_get_size (obj),
1150 vt->klass->name_space, vt->klass->name);
1155 * sgen_drain_gray_stack:
1157 * Scan objects in the gray stack until the stack is empty. This should be called
1158 * frequently after each object is copied, to achieve better locality and cache
1162 sgen_drain_gray_stack (int max_objs, ScanCopyContext ctx)
1165 ScanObjectFunc scan_func = ctx.scan_func;
1166 GrayQueue *queue = ctx.queue;
1168 if (max_objs == -1) {
1170 GRAY_OBJECT_DEQUEUE (queue, obj);
1173 SGEN_LOG (9, "Precise gray object scan %p (%s)", obj, safe_name (obj));
1174 scan_func (obj, queue);
1180 for (i = 0; i != max_objs; ++i) {
1181 GRAY_OBJECT_DEQUEUE (queue, obj);
1184 SGEN_LOG (9, "Precise gray object scan %p (%s)", obj, safe_name (obj));
1185 scan_func (obj, queue);
1187 } while (max_objs < 0);
1193 * Addresses from start to end are already sorted. This function finds
1194 * the object header for each address and pins the object. The
1195 * addresses must be inside the passed section. The (start of the)
1196 * address array is overwritten with the addresses of the actually
1197 * pinned objects. Return the number of pinned objects.
1200 pin_objects_from_addresses (GCMemSection *section, void **start, void **end, void *start_nursery, void *end_nursery, ScanCopyContext ctx)
1205 void *last_obj = NULL;
1206 size_t last_obj_size = 0;
1209 void **definitely_pinned = start;
1210 ScanObjectFunc scan_func = ctx.scan_func;
1211 SgenGrayQueue *queue = ctx.queue;
1213 sgen_nursery_allocator_prepare_for_pinning ();
1215 while (start < end) {
1217 /* the range check should be reduntant */
1218 if (addr != last && addr >= start_nursery && addr < end_nursery) {
1219 SGEN_LOG (5, "Considering pinning addr %p", addr);
1220 /* multiple pointers to the same object */
1221 if (addr >= last_obj && (char*)addr < (char*)last_obj + last_obj_size) {
1225 idx = ((char*)addr - (char*)section->data) / SCAN_START_SIZE;
1226 g_assert (idx < section->num_scan_start);
1227 search_start = (void*)section->scan_starts [idx];
1228 if (!search_start || search_start > addr) {
1231 search_start = section->scan_starts [idx];
1232 if (search_start && search_start <= addr)
1235 if (!search_start || search_start > addr)
1236 search_start = start_nursery;
1238 if (search_start < last_obj)
1239 search_start = (char*)last_obj + last_obj_size;
1240 /* now addr should be in an object a short distance from search_start
1241 * Note that search_start must point to zeroed mem or point to an object.
1245 if (!*(void**)search_start) {
1246 /* Consistency check */
1248 for (frag = nursery_fragments; frag; frag = frag->next) {
1249 if (search_start >= frag->fragment_start && search_start < frag->fragment_end)
1250 g_assert_not_reached ();
1254 search_start = (void*)ALIGN_UP ((mword)search_start + sizeof (gpointer));
1257 last_obj = search_start;
1258 last_obj_size = ALIGN_UP (safe_object_get_size ((MonoObject*)search_start));
1260 if (((MonoObject*)last_obj)->synchronisation == GINT_TO_POINTER (-1)) {
1261 /* Marks the beginning of a nursery fragment, skip */
1263 SGEN_LOG (8, "Pinned try match %p (%s), size %zd", last_obj, safe_name (last_obj), last_obj_size);
1264 if (addr >= search_start && (char*)addr < (char*)last_obj + last_obj_size) {
1265 SGEN_LOG (4, "Pinned object %p, vtable %p (%s), count %d\n", search_start, *(void**)search_start, safe_name (search_start), count);
1266 binary_protocol_pin (search_start, (gpointer)LOAD_VTABLE (search_start), safe_object_get_size (search_start));
1267 if (G_UNLIKELY (MONO_GC_OBJ_PINNED_ENABLED ())) {
1268 int gen = sgen_ptr_in_nursery (search_start) ? GENERATION_NURSERY : GENERATION_OLD;
1269 MonoVTable *vt = (MonoVTable*)LOAD_VTABLE (search_start);
1270 MONO_GC_OBJ_PINNED ((mword)search_start, sgen_safe_object_get_size (search_start), vt->klass->name_space, vt->klass->name, gen);
1273 scan_func (search_start, queue);
1275 pin_object (search_start);
1276 GRAY_OBJECT_ENQUEUE (queue, search_start);
1277 if (G_UNLIKELY (do_pin_stats))
1278 sgen_pin_stats_register_object (search_start, last_obj_size);
1279 definitely_pinned [count] = search_start;
1285 /* skip to the next object */
1286 search_start = (void*)((char*)search_start + last_obj_size);
1287 } while (search_start <= addr);
1288 /* we either pinned the correct object or we ignored the addr because
1289 * it points to unused zeroed memory.
1295 //printf ("effective pinned: %d (at the end: %d)\n", count, (char*)end_nursery - (char*)last);
1296 if (mono_profiler_get_events () & MONO_PROFILE_GC_ROOTS) {
1297 GCRootReport report;
1299 for (idx = 0; idx < count; ++idx)
1300 add_profile_gc_root (&report, definitely_pinned [idx], MONO_PROFILE_GC_ROOT_PINNING | MONO_PROFILE_GC_ROOT_MISC, 0);
1301 notify_gc_roots (&report);
1303 stat_pinned_objects += count;
1308 sgen_pin_objects_in_section (GCMemSection *section, ScanCopyContext ctx)
1310 int num_entries = section->pin_queue_num_entries;
1312 void **start = section->pin_queue_start;
1314 reduced_to = pin_objects_from_addresses (section, start, start + num_entries,
1315 section->data, section->next_data, ctx);
1316 section->pin_queue_num_entries = reduced_to;
1318 section->pin_queue_start = NULL;
1324 sgen_pin_object (void *object, GrayQueue *queue)
1326 g_assert (!concurrent_collection_in_progress);
1328 if (sgen_collection_is_parallel ()) {
1330 /*object arrives pinned*/
1331 sgen_pin_stage_ptr (object);
1335 SGEN_PIN_OBJECT (object);
1336 sgen_pin_stage_ptr (object);
1338 if (G_UNLIKELY (do_pin_stats))
1339 sgen_pin_stats_register_object (object, safe_object_get_size (object));
1341 GRAY_OBJECT_ENQUEUE (queue, object);
1342 binary_protocol_pin (object, (gpointer)LOAD_VTABLE (object), safe_object_get_size (object));
1343 if (G_UNLIKELY (MONO_GC_OBJ_PINNED_ENABLED ())) {
1344 int gen = sgen_ptr_in_nursery (object) ? GENERATION_NURSERY : GENERATION_OLD;
1345 MonoVTable *vt = (MonoVTable*)LOAD_VTABLE (object);
1346 MONO_GC_OBJ_PINNED ((mword)object, sgen_safe_object_get_size (object), vt->klass->name_space, vt->klass->name, gen);
1351 sgen_parallel_pin_or_update (void **ptr, void *obj, MonoVTable *vt, SgenGrayQueue *queue)
1355 gboolean major_pinned = FALSE;
1357 if (sgen_ptr_in_nursery (obj)) {
1358 if (SGEN_CAS_PTR (obj, (void*)((mword)vt | SGEN_PINNED_BIT), vt) == vt) {
1359 sgen_pin_object (obj, queue);
1363 major_collector.pin_major_object (obj, queue);
1364 major_pinned = TRUE;
1367 vtable_word = *(mword*)obj;
1368 /*someone else forwarded it, update the pointer and bail out*/
1369 if (vtable_word & SGEN_FORWARDED_BIT) {
1370 *ptr = (void*)(vtable_word & ~SGEN_VTABLE_BITS_MASK);
1374 /*someone pinned it, nothing to do.*/
1375 if (vtable_word & SGEN_PINNED_BIT || major_pinned)
1380 /* Sort the addresses in array in increasing order.
1381 * Done using a by-the book heap sort. Which has decent and stable performance, is pretty cache efficient.
1384 sgen_sort_addresses (void **array, int size)
1389 for (i = 1; i < size; ++i) {
1392 int parent = (child - 1) / 2;
1394 if (array [parent] >= array [child])
1397 tmp = array [parent];
1398 array [parent] = array [child];
1399 array [child] = tmp;
1405 for (i = size - 1; i > 0; --i) {
1408 array [i] = array [0];
1414 while (root * 2 + 1 <= end) {
1415 int child = root * 2 + 1;
1417 if (child < end && array [child] < array [child + 1])
1419 if (array [root] >= array [child])
1423 array [root] = array [child];
1424 array [child] = tmp;
1432 * Scan the memory between start and end and queue values which could be pointers
1433 * to the area between start_nursery and end_nursery for later consideration.
1434 * Typically used for thread stacks.
1437 conservatively_pin_objects_from (void **start, void **end, void *start_nursery, void *end_nursery, int pin_type)
1441 #ifdef VALGRIND_MAKE_MEM_DEFINED_IF_ADDRESSABLE
1442 VALGRIND_MAKE_MEM_DEFINED_IF_ADDRESSABLE (start, (char*)end - (char*)start);
1445 while (start < end) {
1446 if (*start >= start_nursery && *start < end_nursery) {
1448 * *start can point to the middle of an object
1449 * note: should we handle pointing at the end of an object?
1450 * pinning in C# code disallows pointing at the end of an object
1451 * but there is some small chance that an optimizing C compiler
1452 * may keep the only reference to an object by pointing
1453 * at the end of it. We ignore this small chance for now.
1454 * Pointers to the end of an object are indistinguishable
1455 * from pointers to the start of the next object in memory
1456 * so if we allow that we'd need to pin two objects...
1457 * We queue the pointer in an array, the
1458 * array will then be sorted and uniqued. This way
1459 * we can coalesce several pinning pointers and it should
1460 * be faster since we'd do a memory scan with increasing
1461 * addresses. Note: we can align the address to the allocation
1462 * alignment, so the unique process is more effective.
1464 mword addr = (mword)*start;
1465 addr &= ~(ALLOC_ALIGN - 1);
1466 if (addr >= (mword)start_nursery && addr < (mword)end_nursery) {
1467 SGEN_LOG (6, "Pinning address %p from %p", (void*)addr, start);
1468 sgen_pin_stage_ptr ((void*)addr);
1471 if (G_UNLIKELY (do_pin_stats)) {
1472 if (ptr_in_nursery ((void*)addr))
1473 sgen_pin_stats_register_address ((char*)addr, pin_type);
1479 SGEN_LOG (7, "found %d potential pinned heap pointers", count);
1483 * The first thing we do in a collection is to identify pinned objects.
1484 * This function considers all the areas of memory that need to be
1485 * conservatively scanned.
1488 pin_from_roots (void *start_nursery, void *end_nursery, GrayQueue *queue)
1492 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);
1493 /* objects pinned from the API are inside these roots */
1494 SGEN_HASH_TABLE_FOREACH (&roots_hash [ROOT_TYPE_PINNED], start_root, root) {
1495 SGEN_LOG (6, "Pinned roots %p-%p", start_root, root->end_root);
1496 conservatively_pin_objects_from (start_root, (void**)root->end_root, start_nursery, end_nursery, PIN_TYPE_OTHER);
1497 } SGEN_HASH_TABLE_FOREACH_END;
1498 /* now deal with the thread stacks
1499 * in the future we should be able to conservatively scan only:
1500 * *) the cpu registers
1501 * *) the unmanaged stack frames
1502 * *) the _last_ managed stack frame
1503 * *) pointers slots in managed frames
1505 scan_thread_data (start_nursery, end_nursery, FALSE, queue);
1509 unpin_objects_from_queue (SgenGrayQueue *queue)
1513 GRAY_OBJECT_DEQUEUE (queue, addr);
1516 SGEN_UNPIN_OBJECT (addr);
1521 CopyOrMarkObjectFunc func;
1523 } UserCopyOrMarkData;
1525 static MonoNativeTlsKey user_copy_or_mark_key;
1528 init_user_copy_or_mark_key (void)
1530 mono_native_tls_alloc (&user_copy_or_mark_key, NULL);
1534 set_user_copy_or_mark_data (UserCopyOrMarkData *data)
1536 mono_native_tls_set_value (user_copy_or_mark_key, data);
1540 single_arg_user_copy_or_mark (void **obj)
1542 UserCopyOrMarkData *data = mono_native_tls_get_value (user_copy_or_mark_key);
1544 data->func (obj, data->queue);
1548 * The memory area from start_root to end_root contains pointers to objects.
1549 * Their position is precisely described by @desc (this means that the pointer
1550 * can be either NULL or the pointer to the start of an object).
1551 * This functions copies them to to_space updates them.
1553 * This function is not thread-safe!
1556 precisely_scan_objects_from (void** start_root, void** end_root, char* n_start, char *n_end, mword desc, ScanCopyContext ctx)
1558 CopyOrMarkObjectFunc copy_func = ctx.copy_func;
1559 SgenGrayQueue *queue = ctx.queue;
1561 switch (desc & ROOT_DESC_TYPE_MASK) {
1562 case ROOT_DESC_BITMAP:
1563 desc >>= ROOT_DESC_TYPE_SHIFT;
1565 if ((desc & 1) && *start_root) {
1566 copy_func (start_root, queue);
1567 SGEN_LOG (9, "Overwrote root at %p with %p", start_root, *start_root);
1568 sgen_drain_gray_stack (-1, ctx);
1574 case ROOT_DESC_COMPLEX: {
1575 gsize *bitmap_data = sgen_get_complex_descriptor_bitmap (desc);
1576 int bwords = (*bitmap_data) - 1;
1577 void **start_run = start_root;
1579 while (bwords-- > 0) {
1580 gsize bmap = *bitmap_data++;
1581 void **objptr = start_run;
1583 if ((bmap & 1) && *objptr) {
1584 copy_func (objptr, queue);
1585 SGEN_LOG (9, "Overwrote root at %p with %p", objptr, *objptr);
1586 sgen_drain_gray_stack (-1, ctx);
1591 start_run += GC_BITS_PER_WORD;
1595 case ROOT_DESC_USER: {
1596 UserCopyOrMarkData data = { copy_func, queue };
1597 MonoGCRootMarkFunc marker = sgen_get_user_descriptor_func (desc);
1598 set_user_copy_or_mark_data (&data);
1599 marker (start_root, single_arg_user_copy_or_mark);
1600 set_user_copy_or_mark_data (NULL);
1603 case ROOT_DESC_RUN_LEN:
1604 g_assert_not_reached ();
1606 g_assert_not_reached ();
1611 reset_heap_boundaries (void)
1613 lowest_heap_address = ~(mword)0;
1614 highest_heap_address = 0;
1618 sgen_update_heap_boundaries (mword low, mword high)
1623 old = lowest_heap_address;
1626 } while (SGEN_CAS_PTR ((gpointer*)&lowest_heap_address, (gpointer)low, (gpointer)old) != (gpointer)old);
1629 old = highest_heap_address;
1632 } while (SGEN_CAS_PTR ((gpointer*)&highest_heap_address, (gpointer)high, (gpointer)old) != (gpointer)old);
1636 * Allocate and setup the data structures needed to be able to allocate objects
1637 * in the nursery. The nursery is stored in nursery_section.
1640 alloc_nursery (void)
1642 GCMemSection *section;
1647 if (nursery_section)
1649 SGEN_LOG (2, "Allocating nursery size: %lu", (unsigned long)sgen_nursery_size);
1650 /* later we will alloc a larger area for the nursery but only activate
1651 * what we need. The rest will be used as expansion if we have too many pinned
1652 * objects in the existing nursery.
1654 /* FIXME: handle OOM */
1655 section = sgen_alloc_internal (INTERNAL_MEM_SECTION);
1657 alloc_size = sgen_nursery_size;
1659 /* If there isn't enough space even for the nursery we should simply abort. */
1660 g_assert (sgen_memgov_try_alloc_space (alloc_size, SPACE_NURSERY));
1662 #ifdef SGEN_ALIGN_NURSERY
1663 data = major_collector.alloc_heap (alloc_size, alloc_size, DEFAULT_NURSERY_BITS);
1665 data = major_collector.alloc_heap (alloc_size, 0, DEFAULT_NURSERY_BITS);
1667 sgen_update_heap_boundaries ((mword)data, (mword)(data + sgen_nursery_size));
1668 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 ());
1669 section->data = section->next_data = data;
1670 section->size = alloc_size;
1671 section->end_data = data + sgen_nursery_size;
1672 scan_starts = (alloc_size + SCAN_START_SIZE - 1) / SCAN_START_SIZE;
1673 section->scan_starts = sgen_alloc_internal_dynamic (sizeof (char*) * scan_starts, INTERNAL_MEM_SCAN_STARTS, TRUE);
1674 section->num_scan_start = scan_starts;
1675 section->block.role = MEMORY_ROLE_GEN0;
1676 section->block.next = NULL;
1678 nursery_section = section;
1680 sgen_nursery_allocator_set_nursery_bounds (data, data + sgen_nursery_size);
1684 mono_gc_get_nursery (int *shift_bits, size_t *size)
1686 *size = sgen_nursery_size;
1687 #ifdef SGEN_ALIGN_NURSERY
1688 *shift_bits = DEFAULT_NURSERY_BITS;
1692 return sgen_get_nursery_start ();
1696 mono_gc_set_current_thread_appdomain (MonoDomain *domain)
1698 SgenThreadInfo *info = mono_thread_info_current ();
1700 /* Could be called from sgen_thread_unregister () with a NULL info */
1703 info->stopped_domain = domain;
1708 mono_gc_precise_stack_mark_enabled (void)
1710 return !conservative_stack_mark;
1714 mono_gc_get_logfile (void)
1716 return gc_debug_file;
1720 report_finalizer_roots_list (FinalizeReadyEntry *list)
1722 GCRootReport report;
1723 FinalizeReadyEntry *fin;
1726 for (fin = list; fin; fin = fin->next) {
1729 add_profile_gc_root (&report, fin->object, MONO_PROFILE_GC_ROOT_FINALIZER, 0);
1731 notify_gc_roots (&report);
1735 report_finalizer_roots (void)
1737 report_finalizer_roots_list (fin_ready_list);
1738 report_finalizer_roots_list (critical_fin_list);
1741 static GCRootReport *root_report;
1744 single_arg_report_root (void **obj)
1747 add_profile_gc_root (root_report, *obj, MONO_PROFILE_GC_ROOT_OTHER, 0);
1751 precisely_report_roots_from (GCRootReport *report, void** start_root, void** end_root, mword desc)
1753 switch (desc & ROOT_DESC_TYPE_MASK) {
1754 case ROOT_DESC_BITMAP:
1755 desc >>= ROOT_DESC_TYPE_SHIFT;
1757 if ((desc & 1) && *start_root) {
1758 add_profile_gc_root (report, *start_root, MONO_PROFILE_GC_ROOT_OTHER, 0);
1764 case ROOT_DESC_COMPLEX: {
1765 gsize *bitmap_data = sgen_get_complex_descriptor_bitmap (desc);
1766 int bwords = (*bitmap_data) - 1;
1767 void **start_run = start_root;
1769 while (bwords-- > 0) {
1770 gsize bmap = *bitmap_data++;
1771 void **objptr = start_run;
1773 if ((bmap & 1) && *objptr) {
1774 add_profile_gc_root (report, *objptr, MONO_PROFILE_GC_ROOT_OTHER, 0);
1779 start_run += GC_BITS_PER_WORD;
1783 case ROOT_DESC_USER: {
1784 MonoGCRootMarkFunc marker = sgen_get_user_descriptor_func (desc);
1785 root_report = report;
1786 marker (start_root, single_arg_report_root);
1789 case ROOT_DESC_RUN_LEN:
1790 g_assert_not_reached ();
1792 g_assert_not_reached ();
1797 report_registered_roots_by_type (int root_type)
1799 GCRootReport report;
1803 SGEN_HASH_TABLE_FOREACH (&roots_hash [root_type], start_root, root) {
1804 SGEN_LOG (6, "Precise root scan %p-%p (desc: %p)", start_root, root->end_root, (void*)root->root_desc);
1805 precisely_report_roots_from (&report, start_root, (void**)root->end_root, root->root_desc);
1806 } SGEN_HASH_TABLE_FOREACH_END;
1807 notify_gc_roots (&report);
1811 report_registered_roots (void)
1813 report_registered_roots_by_type (ROOT_TYPE_NORMAL);
1814 report_registered_roots_by_type (ROOT_TYPE_WBARRIER);
1818 scan_finalizer_entries (FinalizeReadyEntry *list, ScanCopyContext ctx)
1820 CopyOrMarkObjectFunc copy_func = ctx.copy_func;
1821 SgenGrayQueue *queue = ctx.queue;
1822 FinalizeReadyEntry *fin;
1824 for (fin = list; fin; fin = fin->next) {
1827 SGEN_LOG (5, "Scan of fin ready object: %p (%s)\n", fin->object, safe_name (fin->object));
1828 copy_func (&fin->object, queue);
1833 generation_name (int generation)
1835 switch (generation) {
1836 case GENERATION_NURSERY: return "nursery";
1837 case GENERATION_OLD: return "old";
1838 default: g_assert_not_reached ();
1843 sgen_generation_name (int generation)
1845 return generation_name (generation);
1848 SgenObjectOperations *
1849 sgen_get_current_object_ops (void){
1850 return ¤t_object_ops;
1855 finish_gray_stack (char *start_addr, char *end_addr, int generation, GrayQueue *queue)
1859 int done_with_ephemerons, ephemeron_rounds = 0;
1860 CopyOrMarkObjectFunc copy_func = current_object_ops.copy_or_mark_object;
1861 ScanObjectFunc scan_func = current_object_ops.scan_object;
1862 ScanCopyContext ctx = { scan_func, copy_func, queue };
1865 * We copied all the reachable objects. Now it's the time to copy
1866 * the objects that were not referenced by the roots, but by the copied objects.
1867 * we built a stack of objects pointed to by gray_start: they are
1868 * additional roots and we may add more items as we go.
1869 * We loop until gray_start == gray_objects which means no more objects have
1870 * been added. Note this is iterative: no recursion is involved.
1871 * We need to walk the LO list as well in search of marked big objects
1872 * (use a flag since this is needed only on major collections). We need to loop
1873 * here as well, so keep a counter of marked LO (increasing it in copy_object).
1874 * To achieve better cache locality and cache usage, we drain the gray stack
1875 * frequently, after each object is copied, and just finish the work here.
1877 sgen_drain_gray_stack (-1, ctx);
1879 SGEN_LOG (2, "%s generation done", generation_name (generation));
1882 Reset bridge data, we might have lingering data from a previous collection if this is a major
1883 collection trigged by minor overflow.
1885 We must reset the gathered bridges since their original block might be evacuated due to major
1886 fragmentation in the meanwhile and the bridge code should not have to deal with that.
1888 sgen_bridge_reset_data ();
1891 * Walk the ephemeron tables marking all values with reachable keys. This must be completely done
1892 * before processing finalizable objects or non-tracking weak hamdle to avoid finalizing/clearing
1893 * objects that are in fact reachable.
1895 done_with_ephemerons = 0;
1897 done_with_ephemerons = mark_ephemerons_in_range (start_addr, end_addr, ctx);
1898 sgen_drain_gray_stack (-1, ctx);
1900 } while (!done_with_ephemerons);
1902 sgen_scan_togglerefs (start_addr, end_addr, ctx);
1903 if (generation == GENERATION_OLD)
1904 sgen_scan_togglerefs (sgen_get_nursery_start (), sgen_get_nursery_end (), ctx);
1906 if (sgen_need_bridge_processing ()) {
1907 sgen_collect_bridge_objects (start_addr, end_addr, generation, ctx);
1908 if (generation == GENERATION_OLD)
1909 sgen_collect_bridge_objects (sgen_get_nursery_start (), sgen_get_nursery_end (), GENERATION_NURSERY, ctx);
1913 Make sure we drain the gray stack before processing disappearing links and finalizers.
1914 If we don't make sure it is empty we might wrongly see a live object as dead.
1916 sgen_drain_gray_stack (-1, ctx);
1919 We must clear weak links that don't track resurrection before processing object ready for
1920 finalization so they can be cleared before that.
1922 sgen_null_link_in_range (start_addr, end_addr, generation, TRUE, ctx);
1923 if (generation == GENERATION_OLD)
1924 sgen_null_link_in_range (start_addr, end_addr, GENERATION_NURSERY, TRUE, ctx);
1927 /* walk the finalization queue and move also the objects that need to be
1928 * finalized: use the finalized objects as new roots so the objects they depend
1929 * on are also not reclaimed. As with the roots above, only objects in the nursery
1930 * are marked/copied.
1932 sgen_finalize_in_range (start_addr, end_addr, generation, ctx);
1933 if (generation == GENERATION_OLD)
1934 sgen_finalize_in_range (sgen_get_nursery_start (), sgen_get_nursery_end (), GENERATION_NURSERY, ctx);
1935 /* drain the new stack that might have been created */
1936 SGEN_LOG (6, "Precise scan of gray area post fin");
1937 sgen_drain_gray_stack (-1, ctx);
1940 * This must be done again after processing finalizable objects since CWL slots are cleared only after the key is finalized.
1942 done_with_ephemerons = 0;
1944 done_with_ephemerons = mark_ephemerons_in_range (start_addr, end_addr, ctx);
1945 sgen_drain_gray_stack (-1, ctx);
1947 } while (!done_with_ephemerons);
1950 * Clear ephemeron pairs with unreachable keys.
1951 * We pass the copy func so we can figure out if an array was promoted or not.
1953 clear_unreachable_ephemerons (start_addr, end_addr, ctx);
1956 SGEN_LOG (2, "Finalize queue handling scan for %s generation: %d usecs %d ephemeron rounds", generation_name (generation), TV_ELAPSED (atv, btv), ephemeron_rounds);
1959 * handle disappearing links
1960 * Note we do this after checking the finalization queue because if an object
1961 * survives (at least long enough to be finalized) we don't clear the link.
1962 * This also deals with a possible issue with the monitor reclamation: with the Boehm
1963 * GC a finalized object my lose the monitor because it is cleared before the finalizer is
1966 g_assert (sgen_gray_object_queue_is_empty (queue));
1968 sgen_null_link_in_range (start_addr, end_addr, generation, FALSE, ctx);
1969 if (generation == GENERATION_OLD)
1970 sgen_null_link_in_range (start_addr, end_addr, GENERATION_NURSERY, FALSE, ctx);
1971 if (sgen_gray_object_queue_is_empty (queue))
1973 sgen_drain_gray_stack (-1, ctx);
1976 g_assert (sgen_gray_object_queue_is_empty (queue));
1980 sgen_check_section_scan_starts (GCMemSection *section)
1983 for (i = 0; i < section->num_scan_start; ++i) {
1984 if (section->scan_starts [i]) {
1985 guint size = safe_object_get_size ((MonoObject*) section->scan_starts [i]);
1986 g_assert (size >= sizeof (MonoObject) && size <= MAX_SMALL_OBJ_SIZE);
1992 check_scan_starts (void)
1994 if (!do_scan_starts_check)
1996 sgen_check_section_scan_starts (nursery_section);
1997 major_collector.check_scan_starts ();
2001 scan_from_registered_roots (char *addr_start, char *addr_end, int root_type, ScanCopyContext ctx)
2005 SGEN_HASH_TABLE_FOREACH (&roots_hash [root_type], start_root, root) {
2006 SGEN_LOG (6, "Precise root scan %p-%p (desc: %p)", start_root, root->end_root, (void*)root->root_desc);
2007 precisely_scan_objects_from (start_root, (void**)root->end_root, addr_start, addr_end, root->root_desc, ctx);
2008 } SGEN_HASH_TABLE_FOREACH_END;
2012 sgen_dump_occupied (char *start, char *end, char *section_start)
2014 fprintf (heap_dump_file, "<occupied offset=\"%td\" size=\"%td\"/>\n", start - section_start, end - start);
2018 sgen_dump_section (GCMemSection *section, const char *type)
2020 char *start = section->data;
2021 char *end = section->data + section->size;
2022 char *occ_start = NULL;
2024 char *old_start = NULL; /* just for debugging */
2026 fprintf (heap_dump_file, "<section type=\"%s\" size=\"%lu\">\n", type, (unsigned long)section->size);
2028 while (start < end) {
2032 if (!*(void**)start) {
2034 sgen_dump_occupied (occ_start, start, section->data);
2037 start += sizeof (void*); /* should be ALLOC_ALIGN, really */
2040 g_assert (start < section->next_data);
2045 vt = (GCVTable*)LOAD_VTABLE (start);
2048 size = ALIGN_UP (safe_object_get_size ((MonoObject*) start));
2051 fprintf (heap_dump_file, "<object offset=\"%d\" class=\"%s.%s\" size=\"%d\"/>\n",
2052 start - section->data,
2053 vt->klass->name_space, vt->klass->name,
2061 sgen_dump_occupied (occ_start, start, section->data);
2063 fprintf (heap_dump_file, "</section>\n");
2067 dump_object (MonoObject *obj, gboolean dump_location)
2069 static char class_name [1024];
2071 MonoClass *class = mono_object_class (obj);
2075 * Python's XML parser is too stupid to parse angle brackets
2076 * in strings, so we just ignore them;
2079 while (class->name [i] && j < sizeof (class_name) - 1) {
2080 if (!strchr ("<>\"", class->name [i]))
2081 class_name [j++] = class->name [i];
2084 g_assert (j < sizeof (class_name));
2087 fprintf (heap_dump_file, "<object class=\"%s.%s\" size=\"%d\"",
2088 class->name_space, class_name,
2089 safe_object_get_size (obj));
2090 if (dump_location) {
2091 const char *location;
2092 if (ptr_in_nursery (obj))
2093 location = "nursery";
2094 else if (safe_object_get_size (obj) <= MAX_SMALL_OBJ_SIZE)
2098 fprintf (heap_dump_file, " location=\"%s\"", location);
2100 fprintf (heap_dump_file, "/>\n");
2104 dump_heap (const char *type, int num, const char *reason)
2109 fprintf (heap_dump_file, "<collection type=\"%s\" num=\"%d\"", type, num);
2111 fprintf (heap_dump_file, " reason=\"%s\"", reason);
2112 fprintf (heap_dump_file, ">\n");
2113 fprintf (heap_dump_file, "<other-mem-usage type=\"mempools\" size=\"%ld\"/>\n", mono_mempool_get_bytes_allocated ());
2114 sgen_dump_internal_mem_usage (heap_dump_file);
2115 fprintf (heap_dump_file, "<pinned type=\"stack\" bytes=\"%zu\"/>\n", sgen_pin_stats_get_pinned_byte_count (PIN_TYPE_STACK));
2116 /* fprintf (heap_dump_file, "<pinned type=\"static-data\" bytes=\"%d\"/>\n", pinned_byte_counts [PIN_TYPE_STATIC_DATA]); */
2117 fprintf (heap_dump_file, "<pinned type=\"other\" bytes=\"%zu\"/>\n", sgen_pin_stats_get_pinned_byte_count (PIN_TYPE_OTHER));
2119 fprintf (heap_dump_file, "<pinned-objects>\n");
2120 for (list = sgen_pin_stats_get_object_list (); list; list = list->next)
2121 dump_object (list->obj, TRUE);
2122 fprintf (heap_dump_file, "</pinned-objects>\n");
2124 sgen_dump_section (nursery_section, "nursery");
2126 major_collector.dump_heap (heap_dump_file);
2128 fprintf (heap_dump_file, "<los>\n");
2129 for (bigobj = los_object_list; bigobj; bigobj = bigobj->next)
2130 dump_object ((MonoObject*)bigobj->data, FALSE);
2131 fprintf (heap_dump_file, "</los>\n");
2133 fprintf (heap_dump_file, "</collection>\n");
2137 sgen_register_moved_object (void *obj, void *destination)
2139 g_assert (mono_profiler_events & MONO_PROFILE_GC_MOVES);
2141 /* FIXME: handle this for parallel collector */
2142 g_assert (!sgen_collection_is_parallel ());
2144 if (moved_objects_idx == MOVED_OBJECTS_NUM) {
2145 mono_profiler_gc_moves (moved_objects, moved_objects_idx);
2146 moved_objects_idx = 0;
2148 moved_objects [moved_objects_idx++] = obj;
2149 moved_objects [moved_objects_idx++] = destination;
2155 static gboolean inited = FALSE;
2160 mono_counters_register ("Minor fragment clear", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_minor_pre_collection_fragment_clear);
2161 mono_counters_register ("Minor pinning", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_minor_pinning);
2162 mono_counters_register ("Minor scan remembered set", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_minor_scan_remsets);
2163 mono_counters_register ("Minor scan pinned", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_minor_scan_pinned);
2164 mono_counters_register ("Minor scan registered roots", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_minor_scan_registered_roots);
2165 mono_counters_register ("Minor scan thread data", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_minor_scan_thread_data);
2166 mono_counters_register ("Minor finish gray stack", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_minor_finish_gray_stack);
2167 mono_counters_register ("Minor fragment creation", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_minor_fragment_creation);
2169 mono_counters_register ("Major fragment clear", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_major_pre_collection_fragment_clear);
2170 mono_counters_register ("Major pinning", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_major_pinning);
2171 mono_counters_register ("Major scan pinned", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_major_scan_pinned);
2172 mono_counters_register ("Major scan registered roots", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_major_scan_registered_roots);
2173 mono_counters_register ("Major scan thread data", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_major_scan_thread_data);
2174 mono_counters_register ("Major scan alloc_pinned", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_major_scan_alloc_pinned);
2175 mono_counters_register ("Major scan finalized", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_major_scan_finalized);
2176 mono_counters_register ("Major scan big objects", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_major_scan_big_objects);
2177 mono_counters_register ("Major finish gray stack", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_major_finish_gray_stack);
2178 mono_counters_register ("Major free big objects", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_major_free_bigobjs);
2179 mono_counters_register ("Major LOS sweep", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_major_los_sweep);
2180 mono_counters_register ("Major sweep", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_major_sweep);
2181 mono_counters_register ("Major fragment creation", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_major_fragment_creation);
2183 mono_counters_register ("Number of pinned objects", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_pinned_objects);
2185 #ifdef HEAVY_STATISTICS
2186 mono_counters_register ("WBarrier set field", MONO_COUNTER_GC | MONO_COUNTER_INT, &stat_wbarrier_set_field);
2187 mono_counters_register ("WBarrier set arrayref", MONO_COUNTER_GC | MONO_COUNTER_INT, &stat_wbarrier_set_arrayref);
2188 mono_counters_register ("WBarrier arrayref copy", MONO_COUNTER_GC | MONO_COUNTER_INT, &stat_wbarrier_arrayref_copy);
2189 mono_counters_register ("WBarrier generic store called", MONO_COUNTER_GC | MONO_COUNTER_INT, &stat_wbarrier_generic_store);
2190 mono_counters_register ("WBarrier set root", MONO_COUNTER_GC | MONO_COUNTER_INT, &stat_wbarrier_set_root);
2191 mono_counters_register ("WBarrier value copy", MONO_COUNTER_GC | MONO_COUNTER_INT, &stat_wbarrier_value_copy);
2192 mono_counters_register ("WBarrier object copy", MONO_COUNTER_GC | MONO_COUNTER_INT, &stat_wbarrier_object_copy);
2194 mono_counters_register ("# objects allocated degraded", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_objects_alloced_degraded);
2195 mono_counters_register ("bytes allocated degraded", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_bytes_alloced_degraded);
2197 mono_counters_register ("# copy_object() called (nursery)", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_copy_object_called_nursery);
2198 mono_counters_register ("# objects copied (nursery)", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_objects_copied_nursery);
2199 mono_counters_register ("# copy_object() called (major)", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_copy_object_called_major);
2200 mono_counters_register ("# objects copied (major)", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_objects_copied_major);
2202 mono_counters_register ("# scan_object() called (nursery)", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_scan_object_called_nursery);
2203 mono_counters_register ("# scan_object() called (major)", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_scan_object_called_major);
2205 mono_counters_register ("Slots allocated in vain", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_slots_allocated_in_vain);
2207 mono_counters_register ("# nursery copy_object() failed from space", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_nursery_copy_object_failed_from_space);
2208 mono_counters_register ("# nursery copy_object() failed forwarded", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_nursery_copy_object_failed_forwarded);
2209 mono_counters_register ("# nursery copy_object() failed pinned", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_nursery_copy_object_failed_pinned);
2210 mono_counters_register ("# nursery copy_object() failed to space", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_nursery_copy_object_failed_to_space);
2212 sgen_nursery_allocator_init_heavy_stats ();
2213 sgen_alloc_init_heavy_stats ();
2221 reset_pinned_from_failed_allocation (void)
2223 bytes_pinned_from_failed_allocation = 0;
2227 sgen_set_pinned_from_failed_allocation (mword objsize)
2229 bytes_pinned_from_failed_allocation += objsize;
2233 sgen_collection_is_parallel (void)
2235 switch (current_collection_generation) {
2236 case GENERATION_NURSERY:
2237 return nursery_collection_is_parallel;
2238 case GENERATION_OLD:
2239 return major_collector.is_parallel;
2241 g_error ("Invalid current generation %d", current_collection_generation);
2246 sgen_collection_is_concurrent (void)
2248 switch (current_collection_generation) {
2249 case GENERATION_NURSERY:
2251 case GENERATION_OLD:
2252 return major_collector.is_concurrent;
2254 g_error ("Invalid current generation %d", current_collection_generation);
2259 sgen_concurrent_collection_in_progress (void)
2261 return concurrent_collection_in_progress;
2268 } FinishRememberedSetScanJobData;
2271 job_finish_remembered_set_scan (WorkerData *worker_data, void *job_data_untyped)
2273 FinishRememberedSetScanJobData *job_data = job_data_untyped;
2275 remset.finish_scan_remsets (job_data->heap_start, job_data->heap_end, sgen_workers_get_job_gray_queue (worker_data));
2276 sgen_free_internal_dynamic (job_data, sizeof (FinishRememberedSetScanJobData), INTERNAL_MEM_WORKER_JOB_DATA);
2281 CopyOrMarkObjectFunc copy_or_mark_func;
2282 ScanObjectFunc scan_func;
2286 } ScanFromRegisteredRootsJobData;
2289 job_scan_from_registered_roots (WorkerData *worker_data, void *job_data_untyped)
2291 ScanFromRegisteredRootsJobData *job_data = job_data_untyped;
2292 ScanCopyContext ctx = { job_data->scan_func, job_data->copy_or_mark_func,
2293 sgen_workers_get_job_gray_queue (worker_data) };
2295 scan_from_registered_roots (job_data->heap_start, job_data->heap_end, job_data->root_type, ctx);
2296 sgen_free_internal_dynamic (job_data, sizeof (ScanFromRegisteredRootsJobData), INTERNAL_MEM_WORKER_JOB_DATA);
2303 } ScanThreadDataJobData;
2306 job_scan_thread_data (WorkerData *worker_data, void *job_data_untyped)
2308 ScanThreadDataJobData *job_data = job_data_untyped;
2310 scan_thread_data (job_data->heap_start, job_data->heap_end, TRUE,
2311 sgen_workers_get_job_gray_queue (worker_data));
2312 sgen_free_internal_dynamic (job_data, sizeof (ScanThreadDataJobData), INTERNAL_MEM_WORKER_JOB_DATA);
2317 FinalizeReadyEntry *list;
2318 } ScanFinalizerEntriesJobData;
2321 job_scan_finalizer_entries (WorkerData *worker_data, void *job_data_untyped)
2323 ScanFinalizerEntriesJobData *job_data = job_data_untyped;
2324 ScanCopyContext ctx = { NULL, current_object_ops.copy_or_mark_object, sgen_workers_get_job_gray_queue (worker_data) };
2326 scan_finalizer_entries (job_data->list, ctx);
2327 sgen_free_internal_dynamic (job_data, sizeof (ScanFinalizerEntriesJobData), INTERNAL_MEM_WORKER_JOB_DATA);
2331 job_scan_major_mod_union_cardtable (WorkerData *worker_data, void *job_data_untyped)
2333 g_assert (concurrent_collection_in_progress);
2334 major_collector.scan_card_table (TRUE, sgen_workers_get_job_gray_queue (worker_data));
2338 job_scan_los_mod_union_cardtable (WorkerData *worker_data, void *job_data_untyped)
2340 g_assert (concurrent_collection_in_progress);
2341 sgen_los_scan_card_table (TRUE, sgen_workers_get_job_gray_queue (worker_data));
2345 verify_scan_starts (char *start, char *end)
2349 for (i = 0; i < nursery_section->num_scan_start; ++i) {
2350 char *addr = nursery_section->scan_starts [i];
2351 if (addr > start && addr < end)
2352 SGEN_LOG (1, "NFC-BAD SCAN START [%d] %p for obj [%p %p]", i, addr, start, end);
2357 verify_nursery (void)
2359 char *start, *end, *cur, *hole_start;
2361 if (!do_verify_nursery)
2364 /*This cleans up unused fragments */
2365 sgen_nursery_allocator_prepare_for_pinning ();
2367 hole_start = start = cur = sgen_get_nursery_start ();
2368 end = sgen_get_nursery_end ();
2373 if (!*(void**)cur) {
2374 cur += sizeof (void*);
2378 if (object_is_forwarded (cur))
2379 SGEN_LOG (1, "FORWARDED OBJ %p", cur);
2380 else if (object_is_pinned (cur))
2381 SGEN_LOG (1, "PINNED OBJ %p", cur);
2383 ss = safe_object_get_size ((MonoObject*)cur);
2384 size = ALIGN_UP (safe_object_get_size ((MonoObject*)cur));
2385 verify_scan_starts (cur, cur + size);
2386 if (do_dump_nursery_content) {
2387 if (cur > hole_start)
2388 SGEN_LOG (1, "HOLE [%p %p %d]", hole_start, cur, (int)(cur - hole_start));
2389 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 ());
2397 * Checks that no objects in the nursery are fowarded or pinned. This
2398 * is a precondition to restarting the mutator while doing a
2399 * concurrent collection. Note that we don't clear fragments because
2400 * we depend on that having happened earlier.
2403 check_nursery_is_clean (void)
2405 char *start, *end, *cur;
2407 start = cur = sgen_get_nursery_start ();
2408 end = sgen_get_nursery_end ();
2413 if (!*(void**)cur) {
2414 cur += sizeof (void*);
2418 g_assert (!object_is_forwarded (cur));
2419 g_assert (!object_is_pinned (cur));
2421 ss = safe_object_get_size ((MonoObject*)cur);
2422 size = ALIGN_UP (safe_object_get_size ((MonoObject*)cur));
2423 verify_scan_starts (cur, cur + size);
2430 init_gray_queue (void)
2432 if (sgen_collection_is_parallel () || sgen_collection_is_concurrent ()) {
2433 sgen_workers_init_distribute_gray_queue ();
2434 sgen_gray_object_queue_init_with_alloc_prepare (&gray_queue, NULL,
2435 gray_queue_redirect, sgen_workers_get_distribute_section_gray_queue ());
2437 sgen_gray_object_queue_init (&gray_queue, NULL);
2440 if (major_collector.is_concurrent) {
2441 sgen_gray_object_queue_init_with_alloc_prepare (&remember_major_objects_gray_queue, NULL,
2442 gray_queue_redirect, sgen_workers_get_distribute_section_gray_queue ());
2444 sgen_gray_object_queue_init_invalid (&remember_major_objects_gray_queue);
2449 * Collect objects in the nursery. Returns whether to trigger a major
2453 collect_nursery (SgenGrayQueue *unpin_queue)
2455 gboolean needs_major;
2456 size_t max_garbage_amount;
2458 FinishRememberedSetScanJobData *frssjd;
2459 ScanFromRegisteredRootsJobData *scrrjd_normal, *scrrjd_wbarrier;
2460 ScanFinalizerEntriesJobData *sfejd_fin_ready, *sfejd_critical_fin;
2461 ScanThreadDataJobData *stdjd;
2462 mword fragment_total;
2463 ScanCopyContext ctx;
2464 TV_DECLARE (all_atv);
2465 TV_DECLARE (all_btv);
2469 if (disable_minor_collections)
2472 MONO_GC_BEGIN (GENERATION_NURSERY);
2473 binary_protocol_collection_begin (stat_minor_gcs, GENERATION_NURSERY);
2477 #ifndef DISABLE_PERFCOUNTERS
2478 mono_perfcounters->gc_collections0++;
2481 current_collection_generation = GENERATION_NURSERY;
2482 if (sgen_collection_is_parallel ())
2483 current_object_ops = sgen_minor_collector.parallel_ops;
2485 current_object_ops = sgen_minor_collector.serial_ops;
2487 reset_pinned_from_failed_allocation ();
2489 check_scan_starts ();
2491 sgen_nursery_alloc_prepare_for_minor ();
2495 nursery_next = sgen_nursery_alloc_get_upper_alloc_bound ();
2496 /* FIXME: optimize later to use the higher address where an object can be present */
2497 nursery_next = MAX (nursery_next, sgen_get_nursery_end ());
2499 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 ()));
2500 max_garbage_amount = nursery_next - sgen_get_nursery_start ();
2501 g_assert (nursery_section->size >= max_garbage_amount);
2503 /* world must be stopped already */
2504 TV_GETTIME (all_atv);
2508 time_minor_pre_collection_fragment_clear += TV_ELAPSED (atv, btv);
2510 if (xdomain_checks) {
2511 sgen_clear_nursery_fragments ();
2512 check_for_xdomain_refs ();
2515 nursery_section->next_data = nursery_next;
2517 major_collector.start_nursery_collection ();
2519 sgen_memgov_minor_collection_start ();
2524 gc_stats.minor_gc_count ++;
2526 if (remset.prepare_for_minor_collection)
2527 remset.prepare_for_minor_collection ();
2529 MONO_GC_CHECKPOINT_1 (GENERATION_NURSERY);
2531 sgen_process_fin_stage_entries ();
2532 sgen_process_dislink_stage_entries ();
2534 MONO_GC_CHECKPOINT_2 (GENERATION_NURSERY);
2536 /* pin from pinned handles */
2537 sgen_init_pinning ();
2538 mono_profiler_gc_event (MONO_GC_EVENT_MARK_START, 0);
2539 pin_from_roots (sgen_get_nursery_start (), nursery_next, WORKERS_DISTRIBUTE_GRAY_QUEUE);
2540 /* identify pinned objects */
2541 sgen_optimize_pin_queue (0);
2542 sgen_pinning_setup_section (nursery_section);
2543 ctx.scan_func = NULL;
2544 ctx.copy_func = NULL;
2545 ctx.queue = WORKERS_DISTRIBUTE_GRAY_QUEUE;
2546 sgen_pin_objects_in_section (nursery_section, ctx);
2547 sgen_pinning_trim_queue_to_section (nursery_section);
2550 time_minor_pinning += TV_ELAPSED (btv, atv);
2551 SGEN_LOG (2, "Finding pinned pointers: %d in %d usecs", sgen_get_pinned_count (), TV_ELAPSED (btv, atv));
2552 SGEN_LOG (4, "Start scan with %d pinned objects", sgen_get_pinned_count ());
2554 MONO_GC_CHECKPOINT_3 (GENERATION_NURSERY);
2556 if (whole_heap_check_before_collection) {
2557 sgen_clear_nursery_fragments ();
2558 sgen_check_whole_heap ();
2560 if (consistency_check_at_minor_collection)
2561 sgen_check_consistency ();
2563 sgen_workers_start_all_workers ();
2566 * Perform the sequential part of remembered set scanning.
2567 * This usually involves scanning global information that might later be produced by evacuation.
2569 if (remset.begin_scan_remsets)
2570 remset.begin_scan_remsets (sgen_get_nursery_start (), nursery_next, WORKERS_DISTRIBUTE_GRAY_QUEUE);
2572 sgen_workers_start_marking ();
2574 frssjd = sgen_alloc_internal_dynamic (sizeof (FinishRememberedSetScanJobData), INTERNAL_MEM_WORKER_JOB_DATA, TRUE);
2575 frssjd->heap_start = sgen_get_nursery_start ();
2576 frssjd->heap_end = nursery_next;
2577 sgen_workers_enqueue_job (job_finish_remembered_set_scan, frssjd);
2579 /* we don't have complete write barrier yet, so we scan all the old generation sections */
2581 time_minor_scan_remsets += TV_ELAPSED (atv, btv);
2582 SGEN_LOG (2, "Old generation scan: %d usecs", TV_ELAPSED (atv, btv));
2584 MONO_GC_CHECKPOINT_4 (GENERATION_NURSERY);
2586 if (!sgen_collection_is_parallel ()) {
2587 ctx.scan_func = current_object_ops.scan_object;
2588 ctx.copy_func = NULL;
2589 ctx.queue = &gray_queue;
2590 sgen_drain_gray_stack (-1, ctx);
2593 if (mono_profiler_get_events () & MONO_PROFILE_GC_ROOTS)
2594 report_registered_roots ();
2595 if (mono_profiler_get_events () & MONO_PROFILE_GC_ROOTS)
2596 report_finalizer_roots ();
2598 time_minor_scan_pinned += TV_ELAPSED (btv, atv);
2600 MONO_GC_CHECKPOINT_5 (GENERATION_NURSERY);
2602 /* registered roots, this includes static fields */
2603 scrrjd_normal = sgen_alloc_internal_dynamic (sizeof (ScanFromRegisteredRootsJobData), INTERNAL_MEM_WORKER_JOB_DATA, TRUE);
2604 scrrjd_normal->copy_or_mark_func = current_object_ops.copy_or_mark_object;
2605 scrrjd_normal->scan_func = current_object_ops.scan_object;
2606 scrrjd_normal->heap_start = sgen_get_nursery_start ();
2607 scrrjd_normal->heap_end = nursery_next;
2608 scrrjd_normal->root_type = ROOT_TYPE_NORMAL;
2609 sgen_workers_enqueue_job (job_scan_from_registered_roots, scrrjd_normal);
2611 scrrjd_wbarrier = sgen_alloc_internal_dynamic (sizeof (ScanFromRegisteredRootsJobData), INTERNAL_MEM_WORKER_JOB_DATA, TRUE);
2612 scrrjd_wbarrier->copy_or_mark_func = current_object_ops.copy_or_mark_object;
2613 scrrjd_wbarrier->scan_func = current_object_ops.scan_object;
2614 scrrjd_wbarrier->heap_start = sgen_get_nursery_start ();
2615 scrrjd_wbarrier->heap_end = nursery_next;
2616 scrrjd_wbarrier->root_type = ROOT_TYPE_WBARRIER;
2617 sgen_workers_enqueue_job (job_scan_from_registered_roots, scrrjd_wbarrier);
2620 time_minor_scan_registered_roots += TV_ELAPSED (atv, btv);
2622 MONO_GC_CHECKPOINT_6 (GENERATION_NURSERY);
2625 stdjd = sgen_alloc_internal_dynamic (sizeof (ScanThreadDataJobData), INTERNAL_MEM_WORKER_JOB_DATA, TRUE);
2626 stdjd->heap_start = sgen_get_nursery_start ();
2627 stdjd->heap_end = nursery_next;
2628 sgen_workers_enqueue_job (job_scan_thread_data, stdjd);
2631 time_minor_scan_thread_data += TV_ELAPSED (btv, atv);
2634 MONO_GC_CHECKPOINT_7 (GENERATION_NURSERY);
2636 g_assert (!sgen_collection_is_parallel () && !sgen_collection_is_concurrent ());
2638 if (sgen_collection_is_parallel () || sgen_collection_is_concurrent ())
2639 g_assert (sgen_gray_object_queue_is_empty (&gray_queue));
2641 /* Scan the list of objects ready for finalization. If */
2642 sfejd_fin_ready = sgen_alloc_internal_dynamic (sizeof (ScanFinalizerEntriesJobData), INTERNAL_MEM_WORKER_JOB_DATA, TRUE);
2643 sfejd_fin_ready->list = fin_ready_list;
2644 sgen_workers_enqueue_job (job_scan_finalizer_entries, sfejd_fin_ready);
2646 sfejd_critical_fin = sgen_alloc_internal_dynamic (sizeof (ScanFinalizerEntriesJobData), INTERNAL_MEM_WORKER_JOB_DATA, TRUE);
2647 sfejd_critical_fin->list = critical_fin_list;
2648 sgen_workers_enqueue_job (job_scan_finalizer_entries, sfejd_critical_fin);
2650 MONO_GC_CHECKPOINT_8 (GENERATION_NURSERY);
2652 finish_gray_stack (sgen_get_nursery_start (), nursery_next, GENERATION_NURSERY, &gray_queue);
2654 time_minor_finish_gray_stack += TV_ELAPSED (btv, atv);
2655 mono_profiler_gc_event (MONO_GC_EVENT_MARK_END, 0);
2657 MONO_GC_CHECKPOINT_9 (GENERATION_NURSERY);
2660 * The (single-threaded) finalization code might have done
2661 * some copying/marking so we can only reset the GC thread's
2662 * worker data here instead of earlier when we joined the
2665 sgen_workers_reset_data ();
2667 if (objects_pinned) {
2668 sgen_optimize_pin_queue (0);
2669 sgen_pinning_setup_section (nursery_section);
2672 /* walk the pin_queue, build up the fragment list of free memory, unmark
2673 * pinned objects as we go, memzero() the empty fragments so they are ready for the
2676 mono_profiler_gc_event (MONO_GC_EVENT_RECLAIM_START, 0);
2677 fragment_total = sgen_build_nursery_fragments (nursery_section,
2678 nursery_section->pin_queue_start, nursery_section->pin_queue_num_entries,
2680 if (!fragment_total)
2683 /* Clear TLABs for all threads */
2684 sgen_clear_tlabs ();
2686 mono_profiler_gc_event (MONO_GC_EVENT_RECLAIM_END, 0);
2688 time_minor_fragment_creation += TV_ELAPSED (atv, btv);
2689 SGEN_LOG (2, "Fragment creation: %d usecs, %lu bytes available", TV_ELAPSED (atv, btv), (unsigned long)fragment_total);
2691 if (consistency_check_at_minor_collection)
2692 sgen_check_major_refs ();
2694 major_collector.finish_nursery_collection ();
2696 TV_GETTIME (all_btv);
2697 gc_stats.minor_gc_time_usecs += TV_ELAPSED (all_atv, all_btv);
2700 dump_heap ("minor", stat_minor_gcs - 1, NULL);
2702 /* prepare the pin queue for the next collection */
2703 sgen_finish_pinning ();
2704 if (fin_ready_list || critical_fin_list) {
2705 SGEN_LOG (4, "Finalizer-thread wakeup: ready %d", num_ready_finalizers);
2706 mono_gc_finalize_notify ();
2708 sgen_pin_stats_reset ();
2710 g_assert (sgen_gray_object_queue_is_empty (&gray_queue));
2712 if (remset.finish_minor_collection)
2713 remset.finish_minor_collection ();
2715 check_scan_starts ();
2717 binary_protocol_flush_buffers (FALSE);
2719 sgen_memgov_minor_collection_end ();
2721 /*objects are late pinned because of lack of memory, so a major is a good call*/
2722 needs_major = objects_pinned > 0;
2723 current_collection_generation = -1;
2726 MONO_GC_END (GENERATION_NURSERY);
2727 binary_protocol_collection_end (stat_minor_gcs - 1, GENERATION_NURSERY);
2733 major_copy_or_mark_from_roots (int *old_next_pin_slot, gboolean finish_up_concurrent_mark, gboolean scan_mod_union)
2738 /* FIXME: only use these values for the precise scan
2739 * note that to_space pointers should be excluded anyway...
2741 char *heap_start = NULL;
2742 char *heap_end = (char*)-1;
2743 gboolean profile_roots = mono_profiler_get_events () & MONO_PROFILE_GC_ROOTS;
2744 GCRootReport root_report = { 0 };
2745 ScanFromRegisteredRootsJobData *scrrjd_normal, *scrrjd_wbarrier;
2746 ScanThreadDataJobData *stdjd;
2747 ScanFinalizerEntriesJobData *sfejd_fin_ready, *sfejd_critical_fin;
2748 ScanCopyContext ctx;
2750 if (major_collector.is_concurrent) {
2751 /*This cleans up unused fragments */
2752 sgen_nursery_allocator_prepare_for_pinning ();
2754 if (do_concurrent_checks)
2755 check_nursery_is_clean ();
2757 /* The concurrent collector doesn't touch the nursery. */
2758 sgen_nursery_alloc_prepare_for_major ();
2765 /* Pinning depends on this */
2766 sgen_clear_nursery_fragments ();
2768 if (whole_heap_check_before_collection)
2769 sgen_check_whole_heap ();
2772 time_major_pre_collection_fragment_clear += TV_ELAPSED (atv, btv);
2774 if (!sgen_collection_is_concurrent ())
2775 nursery_section->next_data = sgen_get_nursery_end ();
2776 /* we should also coalesce scanning from sections close to each other
2777 * and deal with pointers outside of the sections later.
2781 *major_collector.have_swept = FALSE;
2783 if (xdomain_checks) {
2784 sgen_clear_nursery_fragments ();
2785 check_for_xdomain_refs ();
2788 if (!major_collector.is_concurrent) {
2789 /* Remsets are not useful for a major collection */
2790 remset.prepare_for_major_collection ();
2793 sgen_process_fin_stage_entries ();
2794 sgen_process_dislink_stage_entries ();
2797 sgen_init_pinning ();
2798 SGEN_LOG (6, "Collecting pinned addresses");
2799 pin_from_roots ((void*)lowest_heap_address, (void*)highest_heap_address, WORKERS_DISTRIBUTE_GRAY_QUEUE);
2800 sgen_optimize_pin_queue (0);
2803 * The concurrent collector doesn't move objects, neither on
2804 * the major heap nor in the nursery, so we can mark even
2805 * before pinning has finished. For the non-concurrent
2806 * collector we start the workers after pinning.
2808 if (major_collector.is_concurrent) {
2809 sgen_workers_start_all_workers ();
2810 sgen_workers_start_marking ();
2814 * pin_queue now contains all candidate pointers, sorted and
2815 * uniqued. We must do two passes now to figure out which
2816 * objects are pinned.
2818 * The first is to find within the pin_queue the area for each
2819 * section. This requires that the pin_queue be sorted. We
2820 * also process the LOS objects and pinned chunks here.
2822 * The second, destructive, pass is to reduce the section
2823 * areas to pointers to the actually pinned objects.
2825 SGEN_LOG (6, "Pinning from sections");
2826 /* first pass for the sections */
2827 sgen_find_section_pin_queue_start_end (nursery_section);
2828 major_collector.find_pin_queue_start_ends (WORKERS_DISTRIBUTE_GRAY_QUEUE);
2829 /* identify possible pointers to the insize of large objects */
2830 SGEN_LOG (6, "Pinning from large objects");
2831 for (bigobj = los_object_list; bigobj; bigobj = bigobj->next) {
2833 if (sgen_find_optimized_pin_queue_area (bigobj->data, (char*)bigobj->data + sgen_los_object_size (bigobj), &dummy)) {
2834 binary_protocol_pin (bigobj->data, (gpointer)LOAD_VTABLE (bigobj->data), safe_object_get_size (((MonoObject*)(bigobj->data))));
2835 if (G_UNLIKELY (MONO_GC_OBJ_PINNED_ENABLED ())) {
2836 MonoVTable *vt = (MonoVTable*)LOAD_VTABLE (bigobj->data);
2837 MONO_GC_OBJ_PINNED ((mword)bigobj->data, sgen_safe_object_get_size ((MonoObject*)bigobj->data), vt->klass->name_space, vt->klass->name, GENERATION_OLD);
2839 if (sgen_los_object_is_pinned (bigobj->data)) {
2840 g_assert (finish_up_concurrent_mark);
2843 sgen_los_pin_object (bigobj->data);
2844 /* FIXME: only enqueue if object has references */
2845 GRAY_OBJECT_ENQUEUE (WORKERS_DISTRIBUTE_GRAY_QUEUE, bigobj->data);
2846 if (G_UNLIKELY (do_pin_stats))
2847 sgen_pin_stats_register_object ((char*) bigobj->data, safe_object_get_size ((MonoObject*) bigobj->data));
2848 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));
2851 add_profile_gc_root (&root_report, bigobj->data, MONO_PROFILE_GC_ROOT_PINNING | MONO_PROFILE_GC_ROOT_MISC, 0);
2855 notify_gc_roots (&root_report);
2856 /* second pass for the sections */
2857 ctx.scan_func = concurrent_collection_in_progress ? current_object_ops.scan_object : NULL;
2858 ctx.copy_func = NULL;
2859 ctx.queue = WORKERS_DISTRIBUTE_GRAY_QUEUE;
2860 sgen_pin_objects_in_section (nursery_section, ctx);
2861 major_collector.pin_objects (WORKERS_DISTRIBUTE_GRAY_QUEUE);
2862 if (old_next_pin_slot)
2863 *old_next_pin_slot = sgen_get_pinned_count ();
2866 time_major_pinning += TV_ELAPSED (atv, btv);
2867 SGEN_LOG (2, "Finding pinned pointers: %d in %d usecs", sgen_get_pinned_count (), TV_ELAPSED (atv, btv));
2868 SGEN_LOG (4, "Start scan with %d pinned objects", sgen_get_pinned_count ());
2870 major_collector.init_to_space ();
2872 #ifdef SGEN_DEBUG_INTERNAL_ALLOC
2873 main_gc_thread = mono_native_thread_self ();
2876 if (!major_collector.is_concurrent) {
2877 sgen_workers_start_all_workers ();
2878 sgen_workers_start_marking ();
2881 if (mono_profiler_get_events () & MONO_PROFILE_GC_ROOTS)
2882 report_registered_roots ();
2884 time_major_scan_pinned += TV_ELAPSED (btv, atv);
2886 /* registered roots, this includes static fields */
2887 scrrjd_normal = sgen_alloc_internal_dynamic (sizeof (ScanFromRegisteredRootsJobData), INTERNAL_MEM_WORKER_JOB_DATA, TRUE);
2888 scrrjd_normal->copy_or_mark_func = current_object_ops.copy_or_mark_object;
2889 scrrjd_normal->scan_func = current_object_ops.scan_object;
2890 scrrjd_normal->heap_start = heap_start;
2891 scrrjd_normal->heap_end = heap_end;
2892 scrrjd_normal->root_type = ROOT_TYPE_NORMAL;
2893 sgen_workers_enqueue_job (job_scan_from_registered_roots, scrrjd_normal);
2895 scrrjd_wbarrier = sgen_alloc_internal_dynamic (sizeof (ScanFromRegisteredRootsJobData), INTERNAL_MEM_WORKER_JOB_DATA, TRUE);
2896 scrrjd_wbarrier->copy_or_mark_func = current_object_ops.copy_or_mark_object;
2897 scrrjd_wbarrier->scan_func = current_object_ops.scan_object;
2898 scrrjd_wbarrier->heap_start = heap_start;
2899 scrrjd_wbarrier->heap_end = heap_end;
2900 scrrjd_wbarrier->root_type = ROOT_TYPE_WBARRIER;
2901 sgen_workers_enqueue_job (job_scan_from_registered_roots, scrrjd_wbarrier);
2904 time_major_scan_registered_roots += TV_ELAPSED (atv, btv);
2907 stdjd = sgen_alloc_internal_dynamic (sizeof (ScanThreadDataJobData), INTERNAL_MEM_WORKER_JOB_DATA, TRUE);
2908 stdjd->heap_start = heap_start;
2909 stdjd->heap_end = heap_end;
2910 sgen_workers_enqueue_job (job_scan_thread_data, stdjd);
2913 time_major_scan_thread_data += TV_ELAPSED (btv, atv);
2916 time_major_scan_alloc_pinned += TV_ELAPSED (atv, btv);
2918 if (mono_profiler_get_events () & MONO_PROFILE_GC_ROOTS)
2919 report_finalizer_roots ();
2921 /* scan the list of objects ready for finalization */
2922 sfejd_fin_ready = sgen_alloc_internal_dynamic (sizeof (ScanFinalizerEntriesJobData), INTERNAL_MEM_WORKER_JOB_DATA, TRUE);
2923 sfejd_fin_ready->list = fin_ready_list;
2924 sgen_workers_enqueue_job (job_scan_finalizer_entries, sfejd_fin_ready);
2926 sfejd_critical_fin = sgen_alloc_internal_dynamic (sizeof (ScanFinalizerEntriesJobData), INTERNAL_MEM_WORKER_JOB_DATA, TRUE);
2927 sfejd_critical_fin->list = critical_fin_list;
2928 sgen_workers_enqueue_job (job_scan_finalizer_entries, sfejd_critical_fin);
2930 if (scan_mod_union) {
2931 g_assert (finish_up_concurrent_mark);
2933 /* Mod union card table */
2934 sgen_workers_enqueue_job (job_scan_major_mod_union_cardtable, NULL);
2935 sgen_workers_enqueue_job (job_scan_los_mod_union_cardtable, NULL);
2939 time_major_scan_finalized += TV_ELAPSED (btv, atv);
2940 SGEN_LOG (2, "Root scan: %d usecs", TV_ELAPSED (btv, atv));
2943 time_major_scan_big_objects += TV_ELAPSED (atv, btv);
2945 if (major_collector.is_concurrent) {
2946 /* prepare the pin queue for the next collection */
2947 sgen_finish_pinning ();
2949 sgen_pin_stats_reset ();
2951 if (do_concurrent_checks)
2952 check_nursery_is_clean ();
2957 major_start_collection (int *old_next_pin_slot)
2959 MONO_GC_BEGIN (GENERATION_OLD);
2960 binary_protocol_collection_begin (stat_major_gcs, GENERATION_OLD);
2962 current_collection_generation = GENERATION_OLD;
2963 #ifndef DISABLE_PERFCOUNTERS
2964 mono_perfcounters->gc_collections1++;
2967 g_assert (sgen_section_gray_queue_is_empty (sgen_workers_get_distribute_section_gray_queue ()));
2969 if (major_collector.is_concurrent)
2970 concurrent_collection_in_progress = TRUE;
2972 current_object_ops = major_collector.major_ops;
2974 reset_pinned_from_failed_allocation ();
2976 sgen_memgov_major_collection_start ();
2978 //count_ref_nonref_objs ();
2979 //consistency_check ();
2981 check_scan_starts ();
2984 SGEN_LOG (1, "Start major collection %d", stat_major_gcs);
2986 gc_stats.major_gc_count ++;
2988 if (major_collector.start_major_collection)
2989 major_collector.start_major_collection ();
2991 major_copy_or_mark_from_roots (old_next_pin_slot, FALSE, FALSE);
2995 wait_for_workers_to_finish (void)
2997 g_assert (sgen_gray_object_queue_is_empty (&remember_major_objects_gray_queue));
2999 if (major_collector.is_parallel || major_collector.is_concurrent) {
3000 gray_queue_redirect (&gray_queue);
3001 sgen_workers_join ();
3004 g_assert (sgen_gray_object_queue_is_empty (&gray_queue));
3006 #ifdef SGEN_DEBUG_INTERNAL_ALLOC
3007 main_gc_thread = NULL;
3012 major_finish_collection (const char *reason, int old_next_pin_slot, gboolean scan_mod_union)
3014 LOSObject *bigobj, *prevbo;
3017 char *heap_start = NULL;
3018 char *heap_end = (char*)-1;
3022 if (major_collector.is_concurrent || major_collector.is_parallel)
3023 wait_for_workers_to_finish ();
3025 current_object_ops = major_collector.major_ops;
3027 if (major_collector.is_concurrent) {
3028 major_copy_or_mark_from_roots (NULL, TRUE, scan_mod_union);
3029 wait_for_workers_to_finish ();
3031 g_assert (sgen_gray_object_queue_is_empty (&gray_queue));
3033 if (do_concurrent_checks)
3034 check_nursery_is_clean ();
3038 * The workers have stopped so we need to finish gray queue
3039 * work that might result from finalization in the main GC
3040 * thread. Redirection must therefore be turned off.
3042 sgen_gray_object_queue_disable_alloc_prepare (&gray_queue);
3043 g_assert (sgen_section_gray_queue_is_empty (sgen_workers_get_distribute_section_gray_queue ()));
3045 /* all the objects in the heap */
3046 finish_gray_stack (heap_start, heap_end, GENERATION_OLD, &gray_queue);
3048 time_major_finish_gray_stack += TV_ELAPSED (btv, atv);
3051 * The (single-threaded) finalization code might have done
3052 * some copying/marking so we can only reset the GC thread's
3053 * worker data here instead of earlier when we joined the
3056 sgen_workers_reset_data ();
3058 if (objects_pinned) {
3059 g_assert (!major_collector.is_concurrent);
3061 /*This is slow, but we just OOM'd*/
3062 sgen_pin_queue_clear_discarded_entries (nursery_section, old_next_pin_slot);
3063 sgen_optimize_pin_queue (0);
3064 sgen_find_section_pin_queue_start_end (nursery_section);
3068 reset_heap_boundaries ();
3069 sgen_update_heap_boundaries ((mword)sgen_get_nursery_start (), (mword)sgen_get_nursery_end ());
3071 if (check_mark_bits_after_major_collection)
3072 sgen_check_major_heap_marked ();
3074 MONO_GC_SWEEP_BEGIN (GENERATION_OLD, !major_collector.sweeps_lazily);
3076 /* sweep the big objects list */
3078 for (bigobj = los_object_list; bigobj;) {
3079 g_assert (!object_is_pinned (bigobj->data));
3080 if (sgen_los_object_is_pinned (bigobj->data)) {
3081 sgen_los_unpin_object (bigobj->data);
3082 sgen_update_heap_boundaries ((mword)bigobj->data, (mword)bigobj->data + sgen_los_object_size (bigobj));
3085 /* not referenced anywhere, so we can free it */
3087 prevbo->next = bigobj->next;
3089 los_object_list = bigobj->next;
3091 bigobj = bigobj->next;
3092 sgen_los_free_object (to_free);
3096 bigobj = bigobj->next;
3100 time_major_free_bigobjs += TV_ELAPSED (atv, btv);
3105 time_major_los_sweep += TV_ELAPSED (btv, atv);
3107 major_collector.sweep ();
3109 MONO_GC_SWEEP_END (GENERATION_OLD, !major_collector.sweeps_lazily);
3112 time_major_sweep += TV_ELAPSED (atv, btv);
3114 if (!major_collector.is_concurrent) {
3115 /* walk the pin_queue, build up the fragment list of free memory, unmark
3116 * pinned objects as we go, memzero() the empty fragments so they are ready for the
3119 if (!sgen_build_nursery_fragments (nursery_section, nursery_section->pin_queue_start, nursery_section->pin_queue_num_entries, NULL))
3122 /* prepare the pin queue for the next collection */
3123 sgen_finish_pinning ();
3125 /* Clear TLABs for all threads */
3126 sgen_clear_tlabs ();
3128 sgen_pin_stats_reset ();
3132 time_major_fragment_creation += TV_ELAPSED (btv, atv);
3135 dump_heap ("major", stat_major_gcs - 1, reason);
3137 if (fin_ready_list || critical_fin_list) {
3138 SGEN_LOG (4, "Finalizer-thread wakeup: ready %d", num_ready_finalizers);
3139 mono_gc_finalize_notify ();
3142 g_assert (sgen_gray_object_queue_is_empty (&gray_queue));
3144 sgen_memgov_major_collection_end ();
3145 current_collection_generation = -1;
3147 major_collector.finish_major_collection ();
3149 g_assert (sgen_section_gray_queue_is_empty (sgen_workers_get_distribute_section_gray_queue ()));
3151 if (major_collector.is_concurrent)
3152 concurrent_collection_in_progress = FALSE;
3154 check_scan_starts ();
3156 binary_protocol_flush_buffers (FALSE);
3158 //consistency_check ();
3160 MONO_GC_END (GENERATION_OLD);
3161 binary_protocol_collection_end (stat_major_gcs - 1, GENERATION_OLD);
3165 major_do_collection (const char *reason)
3167 TV_DECLARE (all_atv);
3168 TV_DECLARE (all_btv);
3169 int old_next_pin_slot;
3171 if (major_collector.get_and_reset_num_major_objects_marked) {
3172 long long num_marked = major_collector.get_and_reset_num_major_objects_marked ();
3173 g_assert (!num_marked);
3176 /* world must be stopped already */
3177 TV_GETTIME (all_atv);
3179 major_start_collection (&old_next_pin_slot);
3180 major_finish_collection (reason, old_next_pin_slot, FALSE);
3182 TV_GETTIME (all_btv);
3183 gc_stats.major_gc_time_usecs += TV_ELAPSED (all_atv, all_btv);
3185 /* FIXME: also report this to the user, preferably in gc-end. */
3186 if (major_collector.get_and_reset_num_major_objects_marked)
3187 major_collector.get_and_reset_num_major_objects_marked ();
3189 return bytes_pinned_from_failed_allocation > 0;
3192 static gboolean major_do_collection (const char *reason);
3195 major_start_concurrent_collection (const char *reason)
3197 long long num_objects_marked = major_collector.get_and_reset_num_major_objects_marked ();
3199 g_assert (num_objects_marked == 0);
3201 MONO_GC_CONCURRENT_START_BEGIN (GENERATION_OLD);
3203 // FIXME: store reason and pass it when finishing
3204 major_start_collection (NULL);
3206 gray_queue_redirect (&gray_queue);
3207 sgen_workers_wait_for_jobs ();
3209 num_objects_marked = major_collector.get_and_reset_num_major_objects_marked ();
3210 MONO_GC_CONCURRENT_START_END (GENERATION_OLD, num_objects_marked);
3212 current_collection_generation = -1;
3216 major_update_or_finish_concurrent_collection (gboolean force_finish)
3218 SgenGrayQueue unpin_queue;
3219 memset (&unpin_queue, 0, sizeof (unpin_queue));
3221 MONO_GC_CONCURRENT_UPDATE_FINISH_BEGIN (GENERATION_OLD, major_collector.get_and_reset_num_major_objects_marked ());
3223 g_assert (sgen_gray_object_queue_is_empty (&gray_queue));
3224 if (!have_non_collection_major_object_remembers)
3225 g_assert (sgen_gray_object_queue_is_empty (&remember_major_objects_gray_queue));
3227 major_collector.update_cardtable_mod_union ();
3228 sgen_los_update_cardtable_mod_union ();
3230 if (!force_finish && !sgen_workers_all_done ()) {
3231 MONO_GC_CONCURRENT_UPDATE_END (GENERATION_OLD, major_collector.get_and_reset_num_major_objects_marked ());
3235 collect_nursery (&unpin_queue);
3236 redirect_major_object_remembers ();
3238 current_collection_generation = GENERATION_OLD;
3239 major_finish_collection ("finishing", -1, TRUE);
3241 unpin_objects_from_queue (&unpin_queue);
3242 sgen_gray_object_queue_deinit (&unpin_queue);
3244 MONO_GC_CONCURRENT_FINISH_END (GENERATION_OLD, major_collector.get_and_reset_num_major_objects_marked ());
3246 current_collection_generation = -1;
3248 if (whole_heap_check_before_collection)
3249 sgen_check_whole_heap ();
3255 * Ensure an allocation request for @size will succeed by freeing enough memory.
3257 * LOCKING: The GC lock MUST be held.
3260 sgen_ensure_free_space (size_t size)
3262 int generation_to_collect = -1;
3263 const char *reason = NULL;
3266 if (size > SGEN_MAX_SMALL_OBJ_SIZE) {
3267 if (sgen_need_major_collection (size)) {
3268 reason = "LOS overflow";
3269 generation_to_collect = GENERATION_OLD;
3272 if (degraded_mode) {
3273 if (sgen_need_major_collection (size)) {
3274 reason = "Degraded mode overflow";
3275 generation_to_collect = GENERATION_OLD;
3277 } else if (sgen_need_major_collection (size)) {
3278 reason = "Minor allowance";
3279 generation_to_collect = GENERATION_OLD;
3281 generation_to_collect = GENERATION_NURSERY;
3282 reason = "Nursery full";
3286 if (generation_to_collect == -1)
3288 sgen_perform_collection (size, generation_to_collect, reason, FALSE);
3292 sgen_perform_collection (size_t requested_size, int generation_to_collect, const char *reason, gboolean wait_to_finish)
3294 TV_DECLARE (gc_end);
3295 GGTimingInfo infos [2];
3296 int overflow_generation_to_collect = -1;
3297 int oldest_generation_collected = generation_to_collect;
3298 const char *overflow_reason = NULL;
3300 g_assert (generation_to_collect == GENERATION_NURSERY || generation_to_collect == GENERATION_OLD);
3302 if (have_non_collection_major_object_remembers) {
3303 g_assert (concurrent_collection_in_progress);
3304 redirect_major_object_remembers ();
3307 memset (infos, 0, sizeof (infos));
3308 mono_profiler_gc_event (MONO_GC_EVENT_START, generation_to_collect);
3310 infos [0].generation = generation_to_collect;
3311 infos [0].reason = reason;
3312 infos [0].is_overflow = FALSE;
3313 TV_GETTIME (infos [0].total_time);
3314 infos [1].generation = -1;
3316 sgen_stop_world (generation_to_collect);
3318 if (concurrent_collection_in_progress) {
3319 if (major_update_or_finish_concurrent_collection (wait_to_finish && generation_to_collect == GENERATION_OLD)) {
3320 oldest_generation_collected = GENERATION_OLD;
3323 if (generation_to_collect == GENERATION_OLD)
3327 //FIXME extract overflow reason
3328 if (generation_to_collect == GENERATION_NURSERY) {
3329 if (collect_nursery (NULL)) {
3330 overflow_generation_to_collect = GENERATION_OLD;
3331 overflow_reason = "Minor overflow";
3333 if (concurrent_collection_in_progress) {
3334 redirect_major_object_remembers ();
3335 sgen_workers_wake_up_all ();
3338 SgenGrayQueue unpin_queue;
3339 SgenGrayQueue *unpin_queue_ptr;
3340 memset (&unpin_queue, 0, sizeof (unpin_queue));
3342 if (major_collector.is_concurrent && wait_to_finish)
3343 unpin_queue_ptr = &unpin_queue;
3345 unpin_queue_ptr = NULL;
3347 if (major_collector.is_concurrent) {
3348 g_assert (!concurrent_collection_in_progress);
3349 collect_nursery (unpin_queue_ptr);
3352 if (major_collector.is_concurrent && !wait_to_finish) {
3353 major_start_concurrent_collection (reason);
3354 // FIXME: set infos[0] properly
3357 if (major_do_collection (reason)) {
3358 overflow_generation_to_collect = GENERATION_NURSERY;
3359 overflow_reason = "Excessive pinning";
3363 if (unpin_queue_ptr) {
3364 unpin_objects_from_queue (unpin_queue_ptr);
3365 sgen_gray_object_queue_deinit (unpin_queue_ptr);
3369 TV_GETTIME (gc_end);
3370 infos [0].total_time = SGEN_TV_ELAPSED (infos [0].total_time, gc_end);
3373 if (!major_collector.is_concurrent && overflow_generation_to_collect != -1) {
3374 mono_profiler_gc_event (MONO_GC_EVENT_START, overflow_generation_to_collect);
3375 infos [1].generation = overflow_generation_to_collect;
3376 infos [1].reason = overflow_reason;
3377 infos [1].is_overflow = TRUE;
3378 infos [1].total_time = gc_end;
3380 if (overflow_generation_to_collect == GENERATION_NURSERY)
3381 collect_nursery (NULL);
3383 major_do_collection (overflow_reason);
3385 TV_GETTIME (gc_end);
3386 infos [1].total_time = SGEN_TV_ELAPSED (infos [1].total_time, gc_end);
3388 /* keep events symmetric */
3389 mono_profiler_gc_event (MONO_GC_EVENT_END, overflow_generation_to_collect);
3391 oldest_generation_collected = MAX (oldest_generation_collected, overflow_generation_to_collect);
3394 SGEN_LOG (2, "Heap size: %lu, LOS size: %lu", (unsigned long)mono_gc_get_heap_size (), (unsigned long)los_memory_usage);
3396 /* this also sets the proper pointers for the next allocation */
3397 if (generation_to_collect == GENERATION_NURSERY && !sgen_can_alloc_size (requested_size)) {
3398 /* TypeBuilder and MonoMethod are killing mcs with fragmentation */
3399 SGEN_LOG (1, "nursery collection didn't find enough room for %zd alloc (%d pinned)", requested_size, sgen_get_pinned_count ());
3400 sgen_dump_pin_queue ();
3405 g_assert (sgen_gray_object_queue_is_empty (&gray_queue));
3406 g_assert (sgen_gray_object_queue_is_empty (&remember_major_objects_gray_queue));
3408 sgen_restart_world (oldest_generation_collected, infos);
3410 mono_profiler_gc_event (MONO_GC_EVENT_END, generation_to_collect);
3414 * ######################################################################
3415 * ######## Memory allocation from the OS
3416 * ######################################################################
3417 * This section of code deals with getting memory from the OS and
3418 * allocating memory for GC-internal data structures.
3419 * Internal memory can be handled with a freelist for small objects.
3425 G_GNUC_UNUSED static void
3426 report_internal_mem_usage (void)
3428 printf ("Internal memory usage:\n");
3429 sgen_report_internal_mem_usage ();
3430 printf ("Pinned memory usage:\n");
3431 major_collector.report_pinned_memory_usage ();
3435 * ######################################################################
3436 * ######## Finalization support
3437 * ######################################################################
3441 * If the object has been forwarded it means it's still referenced from a root.
3442 * If it is pinned it's still alive as well.
3443 * A LOS object is only alive if we have pinned it.
3444 * Return TRUE if @obj is ready to be finalized.
3446 static inline gboolean
3447 sgen_is_object_alive (void *object)
3451 if (ptr_in_nursery (object))
3452 return sgen_nursery_is_object_alive (object);
3453 /* Oldgen objects can be pinned and forwarded too */
3454 if (SGEN_OBJECT_IS_PINNED (object) || SGEN_OBJECT_IS_FORWARDED (object))
3458 * FIXME: major_collector.is_object_live() also calculates the
3459 * size. Avoid the double calculation.
3461 objsize = SGEN_ALIGN_UP (sgen_safe_object_get_size ((MonoObject*)object));
3462 if (objsize > SGEN_MAX_SMALL_OBJ_SIZE)
3463 return sgen_los_object_is_pinned (object);
3465 return major_collector.is_object_live (object);
3469 sgen_gc_is_object_ready_for_finalization (void *object)
3471 return !sgen_is_object_alive (object);
3475 has_critical_finalizer (MonoObject *obj)
3479 if (!mono_defaults.critical_finalizer_object)
3482 class = ((MonoVTable*)LOAD_VTABLE (obj))->klass;
3484 return mono_class_has_parent_fast (class, mono_defaults.critical_finalizer_object);
3488 sgen_queue_finalization_entry (MonoObject *obj)
3490 FinalizeReadyEntry *entry = sgen_alloc_internal (INTERNAL_MEM_FINALIZE_READY_ENTRY);
3491 gboolean critical = has_critical_finalizer (obj);
3492 entry->object = obj;
3494 entry->next = critical_fin_list;
3495 critical_fin_list = entry;
3497 entry->next = fin_ready_list;
3498 fin_ready_list = entry;
3501 if (G_UNLIKELY (MONO_GC_FINALIZE_ENQUEUE_ENABLED ())) {
3502 int gen = sgen_ptr_in_nursery (obj) ? GENERATION_NURSERY : GENERATION_OLD;
3503 MonoVTable *vt = (MonoVTable*)LOAD_VTABLE (obj);
3504 MONO_GC_FINALIZE_ENQUEUE ((mword)obj, sgen_safe_object_get_size (obj),
3505 vt->klass->name_space, vt->klass->name, gen, critical);
3510 object_is_reachable (char *object, char *start, char *end)
3512 /*This happens for non nursery objects during minor collections. We just treat all objects as alive.*/
3513 if (object < start || object >= end)
3516 return sgen_is_object_alive (object);
3520 sgen_object_is_live (void *obj)
3522 if (ptr_in_nursery (obj))
3523 return object_is_pinned (obj);
3524 /* FIXME This is semantically wrong! All tenured object are considered alive during a nursery collection. */
3525 if (current_collection_generation == GENERATION_NURSERY)
3527 return major_collector.is_object_live (obj);
3530 /* LOCKING: requires that the GC lock is held */
3532 null_ephemerons_for_domain (MonoDomain *domain)
3534 EphemeronLinkNode *current = ephemeron_list, *prev = NULL;
3537 MonoObject *object = (MonoObject*)current->array;
3539 if (object && !object->vtable) {
3540 EphemeronLinkNode *tmp = current;
3543 prev->next = current->next;
3545 ephemeron_list = current->next;
3547 current = current->next;
3548 sgen_free_internal (tmp, INTERNAL_MEM_EPHEMERON_LINK);
3551 current = current->next;
3556 /* LOCKING: requires that the GC lock is held */
3558 clear_unreachable_ephemerons (char *start, char *end, ScanCopyContext ctx)
3560 CopyOrMarkObjectFunc copy_func = ctx.copy_func;
3561 GrayQueue *queue = ctx.queue;
3562 int was_in_nursery, was_promoted;
3563 EphemeronLinkNode *current = ephemeron_list, *prev = NULL;
3565 Ephemeron *cur, *array_end;
3569 char *object = current->array;
3571 if (!object_is_reachable (object, start, end)) {
3572 EphemeronLinkNode *tmp = current;
3574 SGEN_LOG (5, "Dead Ephemeron array at %p", object);
3577 prev->next = current->next;
3579 ephemeron_list = current->next;
3581 current = current->next;
3582 sgen_free_internal (tmp, INTERNAL_MEM_EPHEMERON_LINK);
3587 was_in_nursery = ptr_in_nursery (object);
3588 copy_func ((void**)&object, queue);
3589 current->array = object;
3591 /*The array was promoted, add global remsets for key/values left behind in nursery.*/
3592 was_promoted = was_in_nursery && !ptr_in_nursery (object);
3594 SGEN_LOG (5, "Clearing unreachable entries for ephemeron array at %p", object);
3596 array = (MonoArray*)object;
3597 cur = mono_array_addr (array, Ephemeron, 0);
3598 array_end = cur + mono_array_length_fast (array);
3599 tombstone = (char*)((MonoVTable*)LOAD_VTABLE (object))->domain->ephemeron_tombstone;
3601 for (; cur < array_end; ++cur) {
3602 char *key = (char*)cur->key;
3604 if (!key || key == tombstone)
3607 SGEN_LOG (5, "[%td] key %p (%s) value %p (%s)", cur - mono_array_addr (array, Ephemeron, 0),
3608 key, object_is_reachable (key, start, end) ? "reachable" : "unreachable",
3609 cur->value, cur->value && object_is_reachable (cur->value, start, end) ? "reachable" : "unreachable");
3611 if (!object_is_reachable (key, start, end)) {
3612 cur->key = tombstone;
3618 gpointer value = cur->value;
3619 if (ptr_in_nursery (key)) {/*key was not promoted*/
3620 SGEN_LOG (5, "\tAdded remset to key %p", key);
3621 sgen_add_to_global_remset (&cur->key, key);
3623 if (ptr_in_nursery (value)) {/*value was not promoted*/
3624 SGEN_LOG (5, "\tAdded remset to value %p", cur->value);
3625 sgen_add_to_global_remset (&cur->value, value);
3630 current = current->next;
3634 /* LOCKING: requires that the GC lock is held */
3636 mark_ephemerons_in_range (char *start, char *end, ScanCopyContext ctx)
3638 CopyOrMarkObjectFunc copy_func = ctx.copy_func;
3639 GrayQueue *queue = ctx.queue;
3640 int nothing_marked = 1;
3641 EphemeronLinkNode *current = ephemeron_list;
3643 Ephemeron *cur, *array_end;
3646 for (current = ephemeron_list; current; current = current->next) {
3647 char *object = current->array;
3648 SGEN_LOG (5, "Ephemeron array at %p", object);
3651 For now we process all ephemerons during all collections.
3652 Ideally we should use remset information to partially scan those
3654 We already emit write barriers for Ephemeron fields, it's
3655 just that we don't process them.
3657 /*if (object < start || object >= end)
3660 /*It has to be alive*/
3661 if (!object_is_reachable (object, start, end)) {
3662 SGEN_LOG (5, "\tnot reachable");
3666 copy_func ((void**)&object, queue);
3668 array = (MonoArray*)object;
3669 cur = mono_array_addr (array, Ephemeron, 0);
3670 array_end = cur + mono_array_length_fast (array);
3671 tombstone = (char*)((MonoVTable*)LOAD_VTABLE (object))->domain->ephemeron_tombstone;
3673 for (; cur < array_end; ++cur) {
3674 char *key = cur->key;
3676 if (!key || key == tombstone)
3679 SGEN_LOG (5, "[%td] key %p (%s) value %p (%s)", cur - mono_array_addr (array, Ephemeron, 0),
3680 key, object_is_reachable (key, start, end) ? "reachable" : "unreachable",
3681 cur->value, cur->value && object_is_reachable (cur->value, start, end) ? "reachable" : "unreachable");
3683 if (object_is_reachable (key, start, end)) {
3684 char *value = cur->value;
3686 copy_func ((void**)&cur->key, queue);
3688 if (!object_is_reachable (value, start, end))
3690 copy_func ((void**)&cur->value, queue);
3696 SGEN_LOG (5, "Ephemeron run finished. Is it done %d", nothing_marked);
3697 return nothing_marked;
3701 mono_gc_invoke_finalizers (void)
3703 FinalizeReadyEntry *entry = NULL;
3704 gboolean entry_is_critical = FALSE;
3707 /* FIXME: batch to reduce lock contention */
3708 while (fin_ready_list || critical_fin_list) {
3712 FinalizeReadyEntry **list = entry_is_critical ? &critical_fin_list : &fin_ready_list;
3714 /* We have finalized entry in the last
3715 interation, now we need to remove it from
3718 *list = entry->next;
3720 FinalizeReadyEntry *e = *list;
3721 while (e->next != entry)
3723 e->next = entry->next;
3725 sgen_free_internal (entry, INTERNAL_MEM_FINALIZE_READY_ENTRY);
3729 /* Now look for the first non-null entry. */
3730 for (entry = fin_ready_list; entry && !entry->object; entry = entry->next)
3733 entry_is_critical = FALSE;
3735 entry_is_critical = TRUE;
3736 for (entry = critical_fin_list; entry && !entry->object; entry = entry->next)
3741 g_assert (entry->object);
3742 num_ready_finalizers--;
3743 obj = entry->object;
3744 entry->object = NULL;
3745 SGEN_LOG (7, "Finalizing object %p (%s)", obj, safe_name (obj));
3753 g_assert (entry->object == NULL);
3755 /* the object is on the stack so it is pinned */
3756 /*g_print ("Calling finalizer for object: %p (%s)\n", entry->object, safe_name (entry->object));*/
3757 mono_gc_run_finalize (obj, NULL);
3764 mono_gc_pending_finalizers (void)
3766 return fin_ready_list || critical_fin_list;
3770 * ######################################################################
3771 * ######## registered roots support
3772 * ######################################################################
3776 * We do not coalesce roots.
3779 mono_gc_register_root_inner (char *start, size_t size, void *descr, int root_type)
3781 RootRecord new_root;
3784 for (i = 0; i < ROOT_TYPE_NUM; ++i) {
3785 RootRecord *root = sgen_hash_table_lookup (&roots_hash [i], start);
3786 /* we allow changing the size and the descriptor (for thread statics etc) */
3788 size_t old_size = root->end_root - start;
3789 root->end_root = start + size;
3790 g_assert (((root->root_desc != 0) && (descr != NULL)) ||
3791 ((root->root_desc == 0) && (descr == NULL)));
3792 root->root_desc = (mword)descr;
3794 roots_size -= old_size;
3800 new_root.end_root = start + size;
3801 new_root.root_desc = (mword)descr;
3803 sgen_hash_table_replace (&roots_hash [root_type], start, &new_root, NULL);
3806 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);
3813 mono_gc_register_root (char *start, size_t size, void *descr)
3815 return mono_gc_register_root_inner (start, size, descr, descr ? ROOT_TYPE_NORMAL : ROOT_TYPE_PINNED);
3819 mono_gc_register_root_wbarrier (char *start, size_t size, void *descr)
3821 return mono_gc_register_root_inner (start, size, descr, ROOT_TYPE_WBARRIER);
3825 mono_gc_deregister_root (char* addr)
3831 for (root_type = 0; root_type < ROOT_TYPE_NUM; ++root_type) {
3832 if (sgen_hash_table_remove (&roots_hash [root_type], addr, &root))
3833 roots_size -= (root.end_root - addr);
3839 * ######################################################################
3840 * ######## Thread handling (stop/start code)
3841 * ######################################################################
3844 unsigned int sgen_global_stop_count = 0;
3847 sgen_fill_thread_info_for_suspend (SgenThreadInfo *info)
3849 if (remset.fill_thread_info_for_suspend)
3850 remset.fill_thread_info_for_suspend (info);
3854 sgen_get_current_collection_generation (void)
3856 return current_collection_generation;
3860 mono_gc_set_gc_callbacks (MonoGCCallbacks *callbacks)
3862 gc_callbacks = *callbacks;
3866 mono_gc_get_gc_callbacks ()
3868 return &gc_callbacks;
3871 /* Variables holding start/end nursery so it won't have to be passed at every call */
3872 static void *scan_area_arg_start, *scan_area_arg_end;
3875 mono_gc_conservatively_scan_area (void *start, void *end)
3877 conservatively_pin_objects_from (start, end, scan_area_arg_start, scan_area_arg_end, PIN_TYPE_STACK);
3881 mono_gc_scan_object (void *obj)
3883 UserCopyOrMarkData *data = mono_native_tls_get_value (user_copy_or_mark_key);
3884 current_object_ops.copy_or_mark_object (&obj, data->queue);
3889 * Mark from thread stacks and registers.
3892 scan_thread_data (void *start_nursery, void *end_nursery, gboolean precise, GrayQueue *queue)
3894 SgenThreadInfo *info;
3896 scan_area_arg_start = start_nursery;
3897 scan_area_arg_end = end_nursery;
3899 FOREACH_THREAD (info) {
3901 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);
3904 if (info->gc_disabled) {
3905 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);
3909 if (!info->joined_stw) {
3910 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);
3914 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 ());
3915 if (!info->thread_is_dying) {
3916 if (gc_callbacks.thread_mark_func && !conservative_stack_mark) {
3917 UserCopyOrMarkData data = { NULL, queue };
3918 set_user_copy_or_mark_data (&data);
3919 gc_callbacks.thread_mark_func (info->runtime_data, info->stack_start, info->stack_end, precise);
3920 set_user_copy_or_mark_data (NULL);
3921 } else if (!precise) {
3922 if (!conservative_stack_mark) {
3923 fprintf (stderr, "Precise stack mark not supported - disabling.\n");
3924 conservative_stack_mark = TRUE;
3926 conservatively_pin_objects_from (info->stack_start, info->stack_end, start_nursery, end_nursery, PIN_TYPE_STACK);
3930 if (!info->thread_is_dying && !precise) {
3932 conservatively_pin_objects_from ((void**)&info->ctx, (void**)&info->ctx + ARCH_NUM_REGS,
3933 start_nursery, end_nursery, PIN_TYPE_STACK);
3935 conservatively_pin_objects_from (&info->regs, &info->regs + ARCH_NUM_REGS,
3936 start_nursery, end_nursery, PIN_TYPE_STACK);
3939 } END_FOREACH_THREAD
3943 ptr_on_stack (void *ptr)
3945 gpointer stack_start = &stack_start;
3946 SgenThreadInfo *info = mono_thread_info_current ();
3948 if (ptr >= stack_start && ptr < (gpointer)info->stack_end)
3954 sgen_thread_register (SgenThreadInfo* info, void *addr)
3956 #ifndef HAVE_KW_THREAD
3957 SgenThreadInfo *__thread_info__ = info;
3961 #ifndef HAVE_KW_THREAD
3962 info->tlab_start = info->tlab_next = info->tlab_temp_end = info->tlab_real_end = NULL;
3964 g_assert (!mono_native_tls_get_value (thread_info_key));
3965 mono_native_tls_set_value (thread_info_key, info);
3967 sgen_thread_info = info;
3970 #if !defined(__MACH__)
3971 info->stop_count = -1;
3975 info->joined_stw = FALSE;
3976 info->doing_handshake = FALSE;
3977 info->thread_is_dying = FALSE;
3978 info->stack_start = NULL;
3979 info->store_remset_buffer_addr = &STORE_REMSET_BUFFER;
3980 info->store_remset_buffer_index_addr = &STORE_REMSET_BUFFER_INDEX;
3981 info->stopped_ip = NULL;
3982 info->stopped_domain = NULL;
3984 memset (&info->ctx, 0, sizeof (MonoContext));
3986 memset (&info->regs, 0, sizeof (info->regs));
3989 sgen_init_tlab_info (info);
3991 binary_protocol_thread_register ((gpointer)mono_thread_info_get_tid (info));
3993 #ifdef HAVE_KW_THREAD
3994 store_remset_buffer_index_addr = &store_remset_buffer_index;
3997 /* try to get it with attributes first */
3998 #if defined(HAVE_PTHREAD_GETATTR_NP) && defined(HAVE_PTHREAD_ATTR_GETSTACK)
4002 pthread_attr_t attr;
4003 pthread_getattr_np (pthread_self (), &attr);
4004 pthread_attr_getstack (&attr, &sstart, &size);
4005 info->stack_start_limit = sstart;
4006 info->stack_end = (char*)sstart + size;
4007 pthread_attr_destroy (&attr);
4009 #elif defined(HAVE_PTHREAD_GET_STACKSIZE_NP) && defined(HAVE_PTHREAD_GET_STACKADDR_NP)
4010 info->stack_end = (char*)pthread_get_stackaddr_np (pthread_self ());
4011 info->stack_start_limit = (char*)info->stack_end - pthread_get_stacksize_np (pthread_self ());
4014 /* FIXME: we assume the stack grows down */
4015 gsize stack_bottom = (gsize)addr;
4016 stack_bottom += 4095;
4017 stack_bottom &= ~4095;
4018 info->stack_end = (char*)stack_bottom;
4022 #ifdef HAVE_KW_THREAD
4023 stack_end = info->stack_end;
4026 if (remset.register_thread)
4027 remset.register_thread (info);
4029 SGEN_LOG (3, "registered thread %p (%p) stack end %p", info, (gpointer)mono_thread_info_get_tid (info), info->stack_end);
4031 if (gc_callbacks.thread_attach_func)
4032 info->runtime_data = gc_callbacks.thread_attach_func ();
4039 sgen_wbarrier_cleanup_thread (SgenThreadInfo *p)
4041 if (remset.cleanup_thread)
4042 remset.cleanup_thread (p);
4046 sgen_thread_unregister (SgenThreadInfo *p)
4048 /* If a delegate is passed to native code and invoked on a thread we dont
4049 * know about, the jit will register it with mono_jit_thread_attach, but
4050 * we have no way of knowing when that thread goes away. SGen has a TSD
4051 * so we assume that if the domain is still registered, we can detach
4054 if (mono_domain_get ())
4055 mono_thread_detach (mono_thread_current ());
4057 p->thread_is_dying = TRUE;
4060 There is a race condition between a thread finishing executing and been removed
4061 from the GC thread set.
4062 This happens on posix systems when TLS data is been cleaned-up, libpthread will
4063 set the thread_info slot to NULL before calling the cleanup function. This
4064 opens a window in which the thread is registered but has a NULL TLS.
4066 The suspend signal handler needs TLS data to know where to store thread state
4067 data or otherwise it will simply ignore the thread.
4069 This solution works because the thread doing STW will wait until all threads been
4070 suspended handshake back, so there is no race between the doing_hankshake test
4071 and the suspend_thread call.
4073 This is not required on systems that do synchronous STW as those can deal with
4074 the above race at suspend time.
4076 FIXME: I believe we could avoid this by using mono_thread_info_lookup when
4077 mono_thread_info_current returns NULL. Or fix mono_thread_info_lookup to do so.
4079 #if (defined(__MACH__) && MONO_MACH_ARCH_SUPPORTED) || !defined(HAVE_PTHREAD_KILL)
4082 while (!TRYLOCK_GC) {
4083 if (!sgen_park_current_thread_if_doing_handshake (p))
4089 binary_protocol_thread_unregister ((gpointer)mono_thread_info_get_tid (p));
4090 SGEN_LOG (3, "unregister thread %p (%p)", p, (gpointer)mono_thread_info_get_tid (p));
4092 if (gc_callbacks.thread_detach_func) {
4093 gc_callbacks.thread_detach_func (p->runtime_data);
4094 p->runtime_data = NULL;
4096 sgen_wbarrier_cleanup_thread (p);
4098 mono_threads_unregister_current_thread (p);
4104 sgen_thread_attach (SgenThreadInfo *info)
4107 /*this is odd, can we get attached before the gc is inited?*/
4111 if (gc_callbacks.thread_attach_func && !info->runtime_data)
4112 info->runtime_data = gc_callbacks.thread_attach_func ();
4115 mono_gc_register_thread (void *baseptr)
4117 return mono_thread_info_attach (baseptr) != NULL;
4121 * mono_gc_set_stack_end:
4123 * Set the end of the current threads stack to STACK_END. The stack space between
4124 * STACK_END and the real end of the threads stack will not be scanned during collections.
4127 mono_gc_set_stack_end (void *stack_end)
4129 SgenThreadInfo *info;
4132 info = mono_thread_info_current ();
4134 g_assert (stack_end < info->stack_end);
4135 info->stack_end = stack_end;
4140 #if USE_PTHREAD_INTERCEPT
4144 mono_gc_pthread_create (pthread_t *new_thread, const pthread_attr_t *attr, void *(*start_routine)(void *), void *arg)
4146 return pthread_create (new_thread, attr, start_routine, arg);
4150 mono_gc_pthread_join (pthread_t thread, void **retval)
4152 return pthread_join (thread, retval);
4156 mono_gc_pthread_detach (pthread_t thread)
4158 return pthread_detach (thread);
4162 mono_gc_pthread_exit (void *retval)
4164 pthread_exit (retval);
4167 #endif /* USE_PTHREAD_INTERCEPT */
4170 * ######################################################################
4171 * ######## Write barriers
4172 * ######################################################################
4176 * Note: the write barriers first do the needed GC work and then do the actual store:
4177 * this way the value is visible to the conservative GC scan after the write barrier
4178 * itself. If a GC interrupts the barrier in the middle, value will be kept alive by
4179 * the conservative scan, otherwise by the remembered set scan.
4182 mono_gc_wbarrier_set_field (MonoObject *obj, gpointer field_ptr, MonoObject* value)
4184 HEAVY_STAT (++stat_wbarrier_set_field);
4185 if (ptr_in_nursery (field_ptr)) {
4186 *(void**)field_ptr = value;
4189 SGEN_LOG (8, "Adding remset at %p", field_ptr);
4191 binary_protocol_wbarrier (field_ptr, value, value->vtable);
4193 remset.wbarrier_set_field (obj, field_ptr, value);
4197 mono_gc_wbarrier_set_arrayref (MonoArray *arr, gpointer slot_ptr, MonoObject* value)
4199 HEAVY_STAT (++stat_wbarrier_set_arrayref);
4200 if (ptr_in_nursery (slot_ptr)) {
4201 *(void**)slot_ptr = value;
4204 SGEN_LOG (8, "Adding remset at %p", slot_ptr);
4206 binary_protocol_wbarrier (slot_ptr, value, value->vtable);
4208 remset.wbarrier_set_arrayref (arr, slot_ptr, value);
4212 mono_gc_wbarrier_arrayref_copy (gpointer dest_ptr, gpointer src_ptr, int count)
4214 HEAVY_STAT (++stat_wbarrier_arrayref_copy);
4215 /*This check can be done without taking a lock since dest_ptr array is pinned*/
4216 if (ptr_in_nursery (dest_ptr) || count <= 0) {
4217 mono_gc_memmove (dest_ptr, src_ptr, count * sizeof (gpointer));
4221 #ifdef SGEN_BINARY_PROTOCOL
4224 for (i = 0; i < count; ++i) {
4225 gpointer dest = (gpointer*)dest_ptr + i;
4226 gpointer obj = *((gpointer*)src_ptr + i);
4228 binary_protocol_wbarrier (dest, obj, (gpointer)LOAD_VTABLE (obj));
4233 remset.wbarrier_arrayref_copy (dest_ptr, src_ptr, count);
4236 static char *found_obj;
4239 find_object_for_ptr_callback (char *obj, size_t size, void *user_data)
4241 char *ptr = user_data;
4243 if (ptr >= obj && ptr < obj + size) {
4244 g_assert (!found_obj);
4249 /* for use in the debugger */
4250 char* find_object_for_ptr (char *ptr);
4252 find_object_for_ptr (char *ptr)
4254 if (ptr >= nursery_section->data && ptr < nursery_section->end_data) {
4256 sgen_scan_area_with_callback (nursery_section->data, nursery_section->end_data,
4257 find_object_for_ptr_callback, ptr, TRUE);
4263 sgen_los_iterate_objects (find_object_for_ptr_callback, ptr);
4268 * Very inefficient, but this is debugging code, supposed to
4269 * be called from gdb, so we don't care.
4272 major_collector.iterate_objects (TRUE, TRUE, find_object_for_ptr_callback, ptr);
4277 mono_gc_wbarrier_generic_nostore (gpointer ptr)
4281 HEAVY_STAT (++stat_wbarrier_generic_store);
4283 #ifdef XDOMAIN_CHECKS_IN_WBARRIER
4284 /* FIXME: ptr_in_heap must be called with the GC lock held */
4285 if (xdomain_checks && *(MonoObject**)ptr && ptr_in_heap (ptr)) {
4286 char *start = find_object_for_ptr (ptr);
4287 MonoObject *value = *(MonoObject**)ptr;
4291 MonoObject *obj = (MonoObject*)start;
4292 if (obj->vtable->domain != value->vtable->domain)
4293 g_assert (is_xdomain_ref_allowed (ptr, start, obj->vtable->domain));
4299 obj = *(gpointer*)ptr;
4301 binary_protocol_wbarrier (ptr, obj, (gpointer)LOAD_VTABLE (obj));
4303 if (ptr_in_nursery (ptr) || ptr_on_stack (ptr)) {
4304 SGEN_LOG (8, "Skipping remset at %p", ptr);
4309 * We need to record old->old pointer locations for the
4310 * concurrent collector.
4312 if (!ptr_in_nursery (obj) && !concurrent_collection_in_progress) {
4313 SGEN_LOG (8, "Skipping remset at %p", ptr);
4317 SGEN_LOG (8, "Adding remset at %p", ptr);
4319 remset.wbarrier_generic_nostore (ptr);
4323 mono_gc_wbarrier_generic_store (gpointer ptr, MonoObject* value)
4325 SGEN_LOG (8, "Wbarrier store at %p to %p (%s)", ptr, value, value ? safe_name (value) : "null");
4326 *(void**)ptr = value;
4327 if (ptr_in_nursery (value))
4328 mono_gc_wbarrier_generic_nostore (ptr);
4329 sgen_dummy_use (value);
4332 void mono_gc_wbarrier_value_copy_bitmap (gpointer _dest, gpointer _src, int size, unsigned bitmap)
4334 mword *dest = _dest;
4339 mono_gc_wbarrier_generic_store (dest, (MonoObject*)*src);
4344 size -= SIZEOF_VOID_P;
4349 #ifdef SGEN_BINARY_PROTOCOL
4351 #define HANDLE_PTR(ptr,obj) do { \
4352 gpointer o = *(gpointer*)(ptr); \
4354 gpointer d = ((char*)dest) + ((char*)(ptr) - (char*)(obj)); \
4355 binary_protocol_wbarrier (d, o, (gpointer) LOAD_VTABLE (o)); \
4360 scan_object_for_binary_protocol_copy_wbarrier (gpointer dest, char *start, mword desc)
4362 #define SCAN_OBJECT_NOVTABLE
4363 #include "sgen-scan-object.h"
4368 mono_gc_wbarrier_value_copy (gpointer dest, gpointer src, int count, MonoClass *klass)
4370 HEAVY_STAT (++stat_wbarrier_value_copy);
4371 g_assert (klass->valuetype);
4373 SGEN_LOG (8, "Adding value remset at %p, count %d, descr %p for class %s (%p)", dest, count, klass->gc_descr, klass->name, klass);
4375 if (ptr_in_nursery (dest) || ptr_on_stack (dest) || !SGEN_CLASS_HAS_REFERENCES (klass)) {
4376 size_t element_size = mono_class_value_size (klass, NULL);
4377 size_t size = count * element_size;
4378 mono_gc_memmove (dest, src, size);
4382 #ifdef SGEN_BINARY_PROTOCOL
4384 size_t element_size = mono_class_value_size (klass, NULL);
4386 for (i = 0; i < count; ++i) {
4387 scan_object_for_binary_protocol_copy_wbarrier ((char*)dest + i * element_size,
4388 (char*)src + i * element_size - sizeof (MonoObject),
4389 (mword) klass->gc_descr);
4394 remset.wbarrier_value_copy (dest, src, count, klass);
4398 * mono_gc_wbarrier_object_copy:
4400 * Write barrier to call when obj is the result of a clone or copy of an object.
4403 mono_gc_wbarrier_object_copy (MonoObject* obj, MonoObject *src)
4407 HEAVY_STAT (++stat_wbarrier_object_copy);
4409 if (ptr_in_nursery (obj) || ptr_on_stack (obj)) {
4410 size = mono_object_class (obj)->instance_size;
4411 mono_gc_memmove ((char*)obj + sizeof (MonoObject), (char*)src + sizeof (MonoObject),
4412 size - sizeof (MonoObject));
4416 #ifdef SGEN_BINARY_PROTOCOL
4417 scan_object_for_binary_protocol_copy_wbarrier (obj, (char*)src, (mword) src->vtable->gc_descr);
4420 remset.wbarrier_object_copy (obj, src);
4425 * ######################################################################
4426 * ######## Other mono public interface functions.
4427 * ######################################################################
4430 #define REFS_SIZE 128
4433 MonoGCReferences callback;
4437 MonoObject *refs [REFS_SIZE];
4438 uintptr_t offsets [REFS_SIZE];
4442 #define HANDLE_PTR(ptr,obj) do { \
4444 if (hwi->count == REFS_SIZE) { \
4445 hwi->callback ((MonoObject*)start, mono_object_class (start), hwi->called? 0: size, hwi->count, hwi->refs, hwi->offsets, hwi->data); \
4449 hwi->offsets [hwi->count] = (char*)(ptr)-(char*)start; \
4450 hwi->refs [hwi->count++] = *(ptr); \
4455 collect_references (HeapWalkInfo *hwi, char *start, size_t size)
4457 #include "sgen-scan-object.h"
4461 walk_references (char *start, size_t size, void *data)
4463 HeapWalkInfo *hwi = data;
4466 collect_references (hwi, start, size);
4467 if (hwi->count || !hwi->called)
4468 hwi->callback ((MonoObject*)start, mono_object_class (start), hwi->called? 0: size, hwi->count, hwi->refs, hwi->offsets, hwi->data);
4472 * mono_gc_walk_heap:
4473 * @flags: flags for future use
4474 * @callback: a function pointer called for each object in the heap
4475 * @data: a user data pointer that is passed to callback
4477 * This function can be used to iterate over all the live objects in the heap:
4478 * for each object, @callback is invoked, providing info about the object's
4479 * location in memory, its class, its size and the objects it references.
4480 * For each referenced object it's offset from the object address is
4481 * reported in the offsets array.
4482 * The object references may be buffered, so the callback may be invoked
4483 * multiple times for the same object: in all but the first call, the size
4484 * argument will be zero.
4485 * Note that this function can be only called in the #MONO_GC_EVENT_PRE_START_WORLD
4486 * profiler event handler.
4488 * Returns: a non-zero value if the GC doesn't support heap walking
4491 mono_gc_walk_heap (int flags, MonoGCReferences callback, void *data)
4496 hwi.callback = callback;
4499 sgen_clear_nursery_fragments ();
4500 sgen_scan_area_with_callback (nursery_section->data, nursery_section->end_data, walk_references, &hwi, FALSE);
4502 major_collector.iterate_objects (TRUE, TRUE, walk_references, &hwi);
4503 sgen_los_iterate_objects (walk_references, &hwi);
4509 mono_gc_collect (int generation)
4514 sgen_perform_collection (0, generation, "user request", TRUE);
4519 mono_gc_max_generation (void)
4525 mono_gc_collection_count (int generation)
4527 if (generation == 0)
4528 return stat_minor_gcs;
4529 return stat_major_gcs;
4533 mono_gc_get_used_size (void)
4537 tot = los_memory_usage;
4538 tot += nursery_section->next_data - nursery_section->data;
4539 tot += major_collector.get_used_size ();
4540 /* FIXME: account for pinned objects */
4546 mono_gc_disable (void)
4554 mono_gc_enable (void)
4562 mono_gc_get_los_limit (void)
4564 return MAX_SMALL_OBJ_SIZE;
4568 mono_gc_user_markers_supported (void)
4574 mono_object_is_alive (MonoObject* o)
4580 mono_gc_get_generation (MonoObject *obj)
4582 if (ptr_in_nursery (obj))
4588 mono_gc_enable_events (void)
4593 mono_gc_weak_link_add (void **link_addr, MonoObject *obj, gboolean track)
4595 sgen_register_disappearing_link (obj, link_addr, track, FALSE);
4599 mono_gc_weak_link_remove (void **link_addr)
4601 sgen_register_disappearing_link (NULL, link_addr, FALSE, FALSE);
4605 mono_gc_weak_link_get (void **link_addr)
4608 * We must only load *link_addr once because it might change
4609 * under our feet, and REVEAL_POINTER (NULL) results in an
4610 * invalid reference.
4612 void *ptr = *link_addr;
4617 * During the second bridge processing step the world is
4618 * running again. That step processes all weak links once
4619 * more to null those that refer to dead objects. Before that
4620 * is completed, those links must not be followed, so we
4621 * conservatively wait for bridge processing when any weak
4622 * link is dereferenced.
4624 if (G_UNLIKELY (bridge_processing_in_progress))
4625 mono_gc_wait_for_bridge_processing ();
4627 return (MonoObject*) REVEAL_POINTER (ptr);
4631 mono_gc_ephemeron_array_add (MonoObject *obj)
4633 EphemeronLinkNode *node;
4637 node = sgen_alloc_internal (INTERNAL_MEM_EPHEMERON_LINK);
4642 node->array = (char*)obj;
4643 node->next = ephemeron_list;
4644 ephemeron_list = node;
4646 SGEN_LOG (5, "Registered ephemeron array %p", obj);
4653 mono_gc_invoke_with_gc_lock (MonoGCLockedCallbackFunc func, void *data)
4657 result = func (data);
4658 UNLOCK_INTERRUPTION;
4663 mono_gc_is_gc_thread (void)
4667 result = mono_thread_info_current () != NULL;
4673 is_critical_method (MonoMethod *method)
4675 return mono_runtime_is_critical_method (method) || sgen_is_critical_method (method);
4679 mono_gc_base_init (void)
4681 MonoThreadInfoCallbacks cb;
4684 char *major_collector_opt = NULL;
4685 char *minor_collector_opt = NULL;
4687 glong soft_limit = 0;
4691 gboolean debug_print_allowance = FALSE;
4692 double allowance_ratio = 0, save_target = 0;
4693 gboolean have_split_nursery = FALSE;
4696 result = InterlockedCompareExchange (&gc_initialized, -1, 0);
4699 /* already inited */
4702 /* being inited by another thread */
4706 /* we will init it */
4709 g_assert_not_reached ();
4711 } while (result != 0);
4713 LOCK_INIT (gc_mutex);
4715 pagesize = mono_pagesize ();
4716 gc_debug_file = stderr;
4718 cb.thread_register = sgen_thread_register;
4719 cb.thread_unregister = sgen_thread_unregister;
4720 cb.thread_attach = sgen_thread_attach;
4721 cb.mono_method_is_critical = (gpointer)is_critical_method;
4723 cb.mono_gc_pthread_create = (gpointer)mono_gc_pthread_create;
4726 mono_threads_init (&cb, sizeof (SgenThreadInfo));
4728 LOCK_INIT (sgen_interruption_mutex);
4729 LOCK_INIT (pin_queue_mutex);
4731 init_user_copy_or_mark_key ();
4733 if ((env = getenv ("MONO_GC_PARAMS"))) {
4734 opts = g_strsplit (env, ",", -1);
4735 for (ptr = opts; *ptr; ++ptr) {
4737 if (g_str_has_prefix (opt, "major=")) {
4738 opt = strchr (opt, '=') + 1;
4739 major_collector_opt = g_strdup (opt);
4740 } else if (g_str_has_prefix (opt, "minor=")) {
4741 opt = strchr (opt, '=') + 1;
4742 minor_collector_opt = g_strdup (opt);
4750 sgen_init_internal_allocator ();
4751 sgen_init_nursery_allocator ();
4753 sgen_register_fixed_internal_mem_type (INTERNAL_MEM_SECTION, SGEN_SIZEOF_GC_MEM_SECTION);
4754 sgen_register_fixed_internal_mem_type (INTERNAL_MEM_FINALIZE_READY_ENTRY, sizeof (FinalizeReadyEntry));
4755 sgen_register_fixed_internal_mem_type (INTERNAL_MEM_GRAY_QUEUE, sizeof (GrayQueueSection));
4756 g_assert (sizeof (GenericStoreRememberedSet) == sizeof (gpointer) * STORE_REMSET_BUFFER_SIZE);
4757 sgen_register_fixed_internal_mem_type (INTERNAL_MEM_STORE_REMSET, sizeof (GenericStoreRememberedSet));
4758 sgen_register_fixed_internal_mem_type (INTERNAL_MEM_EPHEMERON_LINK, sizeof (EphemeronLinkNode));
4760 #ifndef HAVE_KW_THREAD
4761 mono_native_tls_alloc (&thread_info_key, NULL);
4765 * This needs to happen before any internal allocations because
4766 * it inits the small id which is required for hazard pointer
4771 mono_thread_info_attach (&dummy);
4773 if (!minor_collector_opt) {
4774 sgen_simple_nursery_init (&sgen_minor_collector);
4776 if (!strcmp (minor_collector_opt, "simple")) {
4777 sgen_simple_nursery_init (&sgen_minor_collector);
4778 } else if (!strcmp (minor_collector_opt, "split")) {
4779 sgen_split_nursery_init (&sgen_minor_collector);
4780 have_split_nursery = TRUE;
4782 fprintf (stderr, "Unknown minor collector `%s'.\n", minor_collector_opt);
4787 if (!major_collector_opt || !strcmp (major_collector_opt, "marksweep")) {
4788 sgen_marksweep_init (&major_collector);
4789 } else if (!major_collector_opt || !strcmp (major_collector_opt, "marksweep-fixed")) {
4790 sgen_marksweep_fixed_init (&major_collector);
4791 } else if (!major_collector_opt || !strcmp (major_collector_opt, "marksweep-par")) {
4792 sgen_marksweep_par_init (&major_collector);
4793 } else if (!major_collector_opt || !strcmp (major_collector_opt, "marksweep-fixed-par")) {
4794 sgen_marksweep_fixed_par_init (&major_collector);
4795 } else if (!major_collector_opt || !strcmp (major_collector_opt, "marksweep-conc")) {
4796 if (have_split_nursery) {
4797 fprintf (stderr, "Concurrent Mark&Sweep does not yet support the split nursery.\n");
4800 sgen_marksweep_conc_init (&major_collector);
4801 } else if (!strcmp (major_collector_opt, "copying")) {
4802 sgen_copying_init (&major_collector);
4804 fprintf (stderr, "Unknown major collector `%s'.\n", major_collector_opt);
4808 #ifdef SGEN_HAVE_CARDTABLE
4809 use_cardtable = major_collector.supports_cardtable;
4811 use_cardtable = FALSE;
4814 num_workers = mono_cpu_count ();
4815 g_assert (num_workers > 0);
4816 if (num_workers > 16)
4819 ///* Keep this the default for now */
4820 /* Precise marking is broken on all supported targets. Disable until fixed. */
4821 conservative_stack_mark = TRUE;
4823 sgen_nursery_size = DEFAULT_NURSERY_SIZE;
4826 for (ptr = opts; *ptr; ++ptr) {
4828 if (g_str_has_prefix (opt, "major="))
4830 if (g_str_has_prefix (opt, "minor="))
4832 if (g_str_has_prefix (opt, "wbarrier=")) {
4833 opt = strchr (opt, '=') + 1;
4834 if (strcmp (opt, "remset") == 0) {
4835 if (major_collector.is_concurrent) {
4836 fprintf (stderr, "The concurrent collector does not support the SSB write barrier.\n");
4839 use_cardtable = FALSE;
4840 } else if (strcmp (opt, "cardtable") == 0) {
4841 if (!use_cardtable) {
4842 if (major_collector.supports_cardtable)
4843 fprintf (stderr, "The cardtable write barrier is not supported on this platform.\n");
4845 fprintf (stderr, "The major collector does not support the cardtable write barrier.\n");
4849 fprintf (stderr, "wbarrier must either be `remset' or `cardtable'.");
4854 if (g_str_has_prefix (opt, "max-heap-size=")) {
4855 opt = strchr (opt, '=') + 1;
4856 if (*opt && mono_gc_parse_environment_string_extract_number (opt, &max_heap)) {
4857 if ((max_heap & (mono_pagesize () - 1))) {
4858 fprintf (stderr, "max-heap-size size must be a multiple of %d.\n", mono_pagesize ());
4862 fprintf (stderr, "max-heap-size must be an integer.\n");
4867 if (g_str_has_prefix (opt, "soft-heap-limit=")) {
4868 opt = strchr (opt, '=') + 1;
4869 if (*opt && mono_gc_parse_environment_string_extract_number (opt, &soft_limit)) {
4870 if (soft_limit <= 0) {
4871 fprintf (stderr, "soft-heap-limit must be positive.\n");
4875 fprintf (stderr, "soft-heap-limit must be an integer.\n");
4880 if (g_str_has_prefix (opt, "workers=")) {
4883 if (!major_collector.is_parallel) {
4884 fprintf (stderr, "The workers= option can only be used for parallel collectors.");
4887 opt = strchr (opt, '=') + 1;
4888 val = strtol (opt, &endptr, 10);
4889 if (!*opt || *endptr) {
4890 fprintf (stderr, "Cannot parse the workers= option value.");
4893 if (val <= 0 || val > 16) {
4894 fprintf (stderr, "The number of workers must be in the range 1 to 16.");
4897 num_workers = (int)val;
4900 if (g_str_has_prefix (opt, "stack-mark=")) {
4901 opt = strchr (opt, '=') + 1;
4902 if (!strcmp (opt, "precise")) {
4903 conservative_stack_mark = FALSE;
4904 } else if (!strcmp (opt, "conservative")) {
4905 conservative_stack_mark = TRUE;
4907 fprintf (stderr, "Invalid value '%s' for stack-mark= option, possible values are: 'precise', 'conservative'.\n", opt);
4912 if (g_str_has_prefix (opt, "bridge=")) {
4913 opt = strchr (opt, '=') + 1;
4914 sgen_register_test_bridge_callbacks (g_strdup (opt));
4918 if (g_str_has_prefix (opt, "nursery-size=")) {
4920 opt = strchr (opt, '=') + 1;
4921 if (*opt && mono_gc_parse_environment_string_extract_number (opt, &val)) {
4922 sgen_nursery_size = val;
4923 #ifdef SGEN_ALIGN_NURSERY
4924 if ((val & (val - 1))) {
4925 fprintf (stderr, "The nursery size must be a power of two.\n");
4929 if (val < SGEN_MAX_NURSERY_WASTE) {
4930 fprintf (stderr, "The nursery size must be at least %d bytes.\n", SGEN_MAX_NURSERY_WASTE);
4934 sgen_nursery_bits = 0;
4935 while (1 << (++ sgen_nursery_bits) != sgen_nursery_size)
4939 fprintf (stderr, "nursery-size must be an integer.\n");
4945 if (g_str_has_prefix (opt, "save-target-ratio=")) {
4947 opt = strchr (opt, '=') + 1;
4948 save_target = strtod (opt, &endptr);
4949 if (endptr == opt) {
4950 fprintf (stderr, "save-target-ratio must be a number.");
4953 if (save_target < SGEN_MIN_SAVE_TARGET_RATIO || save_target > SGEN_MAX_SAVE_TARGET_RATIO) {
4954 fprintf (stderr, "save-target-ratio must be between %.2f - %.2f.", SGEN_MIN_SAVE_TARGET_RATIO, SGEN_MAX_SAVE_TARGET_RATIO);
4959 if (g_str_has_prefix (opt, "default-allowance-ratio=")) {
4961 opt = strchr (opt, '=') + 1;
4963 allowance_ratio = strtod (opt, &endptr);
4964 if (endptr == opt) {
4965 fprintf (stderr, "save-target-ratio must be a number.");
4968 if (allowance_ratio < SGEN_MIN_ALLOWANCE_NURSERY_SIZE_RATIO || allowance_ratio > SGEN_MIN_ALLOWANCE_NURSERY_SIZE_RATIO) {
4969 fprintf (stderr, "default-allowance-ratio must be between %.2f - %.2f.", SGEN_MIN_ALLOWANCE_NURSERY_SIZE_RATIO, SGEN_MIN_ALLOWANCE_NURSERY_SIZE_RATIO);
4975 if (major_collector.handle_gc_param && major_collector.handle_gc_param (opt))
4978 if (sgen_minor_collector.handle_gc_param && sgen_minor_collector.handle_gc_param (opt))
4981 fprintf (stderr, "MONO_GC_PARAMS must be a comma-delimited list of one or more of the following:\n");
4982 fprintf (stderr, " max-heap-size=N (where N is an integer, possibly with a k, m or a g suffix)\n");
4983 fprintf (stderr, " soft-heap-limit=n (where N is an integer, possibly with a k, m or a g suffix)\n");
4984 fprintf (stderr, " nursery-size=N (where N is an integer, possibly with a k, m or a g suffix)\n");
4985 fprintf (stderr, " major=COLLECTOR (where COLLECTOR is `marksweep', `marksweep-par', 'marksweep-fixed', 'marksweep-fixed-par' or `copying')\n");
4986 fprintf (stderr, " minor=COLLECTOR (where COLLECTOR is `simple' or `split')\n");
4987 fprintf (stderr, " wbarrier=WBARRIER (where WBARRIER is `remset' or `cardtable')\n");
4988 fprintf (stderr, " stack-mark=MARK-METHOD (where MARK-METHOD is 'precise' or 'conservative')\n");
4989 if (major_collector.print_gc_param_usage)
4990 major_collector.print_gc_param_usage ();
4991 if (sgen_minor_collector.print_gc_param_usage)
4992 sgen_minor_collector.print_gc_param_usage ();
4993 fprintf (stderr, " Experimental options:\n");
4994 fprintf (stderr, " save-target-ratio=R (where R must be between %.2f - %.2f).\n", SGEN_MIN_SAVE_TARGET_RATIO, SGEN_MAX_SAVE_TARGET_RATIO);
4995 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);
5001 if (major_collector.is_parallel)
5002 sgen_workers_init (num_workers);
5003 else if (major_collector.is_concurrent)
5004 sgen_workers_init (1);
5006 if (major_collector_opt)
5007 g_free (major_collector_opt);
5009 if (minor_collector_opt)
5010 g_free (minor_collector_opt);
5014 if ((env = getenv ("MONO_GC_DEBUG"))) {
5015 opts = g_strsplit (env, ",", -1);
5016 for (ptr = opts; ptr && *ptr; ptr ++) {
5018 if (opt [0] >= '0' && opt [0] <= '9') {
5019 gc_debug_level = atoi (opt);
5025 char *rf = g_strdup_printf ("%s.%d", opt, GetCurrentProcessId ());
5027 char *rf = g_strdup_printf ("%s.%d", opt, getpid ());
5029 gc_debug_file = fopen (rf, "wb");
5031 gc_debug_file = stderr;
5034 } else if (!strcmp (opt, "print-allowance")) {
5035 debug_print_allowance = TRUE;
5036 } else if (!strcmp (opt, "print-pinning")) {
5037 do_pin_stats = TRUE;
5038 } else if (!strcmp (opt, "verify-before-allocs")) {
5039 verify_before_allocs = 1;
5040 has_per_allocation_action = TRUE;
5041 } else if (g_str_has_prefix (opt, "verify-before-allocs=")) {
5042 char *arg = strchr (opt, '=') + 1;
5043 verify_before_allocs = atoi (arg);
5044 has_per_allocation_action = TRUE;
5045 } else if (!strcmp (opt, "collect-before-allocs")) {
5046 collect_before_allocs = 1;
5047 has_per_allocation_action = TRUE;
5048 } else if (g_str_has_prefix (opt, "collect-before-allocs=")) {
5049 char *arg = strchr (opt, '=') + 1;
5050 has_per_allocation_action = TRUE;
5051 collect_before_allocs = atoi (arg);
5052 } else if (!strcmp (opt, "verify-before-collections")) {
5053 whole_heap_check_before_collection = TRUE;
5054 } else if (!strcmp (opt, "check-at-minor-collections")) {
5055 consistency_check_at_minor_collection = TRUE;
5056 nursery_clear_policy = CLEAR_AT_GC;
5057 } else if (!strcmp (opt, "check-mark-bits")) {
5058 check_mark_bits_after_major_collection = TRUE;
5059 } else if (!strcmp (opt, "xdomain-checks")) {
5060 xdomain_checks = TRUE;
5061 } else if (!strcmp (opt, "clear-at-gc")) {
5062 nursery_clear_policy = CLEAR_AT_GC;
5063 } else if (!strcmp (opt, "clear-nursery-at-gc")) {
5064 nursery_clear_policy = CLEAR_AT_GC;
5065 } else if (!strcmp (opt, "check-scan-starts")) {
5066 do_scan_starts_check = TRUE;
5067 } else if (!strcmp (opt, "verify-nursery-at-minor-gc")) {
5068 do_verify_nursery = TRUE;
5069 } else if (!strcmp (opt, "check-concurrent")) {
5070 if (!major_collector.is_concurrent) {
5071 fprintf (stderr, "Error: check-concurrent only world with concurrent major collectors.\n");
5074 do_concurrent_checks = TRUE;
5075 } else if (!strcmp (opt, "dump-nursery-at-minor-gc")) {
5076 do_dump_nursery_content = TRUE;
5077 } else if (!strcmp (opt, "no-managed-allocator")) {
5078 sgen_set_use_managed_allocator (FALSE);
5079 } else if (!strcmp (opt, "disable-minor")) {
5080 disable_minor_collections = TRUE;
5081 } else if (!strcmp (opt, "disable-major")) {
5082 disable_major_collections = TRUE;
5083 } else if (g_str_has_prefix (opt, "heap-dump=")) {
5084 char *filename = strchr (opt, '=') + 1;
5085 nursery_clear_policy = CLEAR_AT_GC;
5086 heap_dump_file = fopen (filename, "w");
5087 if (heap_dump_file) {
5088 fprintf (heap_dump_file, "<sgen-dump>\n");
5089 do_pin_stats = TRUE;
5091 #ifdef SGEN_BINARY_PROTOCOL
5092 } else if (g_str_has_prefix (opt, "binary-protocol=")) {
5093 char *filename = strchr (opt, '=') + 1;
5094 binary_protocol_init (filename);
5096 fprintf (stderr, "Warning: Cardtable write barriers will not be binary-protocolled.\n");
5099 fprintf (stderr, "Invalid format for the MONO_GC_DEBUG env variable: '%s'\n", env);
5100 fprintf (stderr, "The format is: MONO_GC_DEBUG=[l[:filename]|<option>]+ where l is a debug level 0-9.\n");
5101 fprintf (stderr, "Valid options are:\n");
5102 fprintf (stderr, " collect-before-allocs[=<n>]\n");
5103 fprintf (stderr, " verify-before-allocs[=<n>]\n");
5104 fprintf (stderr, " check-at-minor-collections\n");
5105 fprintf (stderr, " check-mark-bits\n");
5106 fprintf (stderr, " verify-before-collections\n");
5107 fprintf (stderr, " verify-nursery-at-minor-gc\n");
5108 fprintf (stderr, " dump-nursery-at-minor-gc\n");
5109 fprintf (stderr, " disable-minor\n");
5110 fprintf (stderr, " disable-major\n");
5111 fprintf (stderr, " xdomain-checks\n");
5112 fprintf (stderr, " check-concurrent\n");
5113 fprintf (stderr, " clear-at-gc\n");
5114 fprintf (stderr, " clear-nursery-at-gc\n");
5115 fprintf (stderr, " check-scan-starts\n");
5116 fprintf (stderr, " no-managed-allocator\n");
5117 fprintf (stderr, " print-allowance\n");
5118 fprintf (stderr, " print-pinning\n");
5119 fprintf (stderr, " heap-dump=<filename>\n");
5120 #ifdef SGEN_BINARY_PROTOCOL
5121 fprintf (stderr, " binary-protocol=<filename>\n");
5129 if (major_collector.is_parallel) {
5130 if (heap_dump_file) {
5131 fprintf (stderr, "Error: Cannot do heap dump with the parallel collector.\n");
5135 fprintf (stderr, "Error: Cannot gather pinning statistics with the parallel collector.\n");
5140 if (major_collector.post_param_init)
5141 major_collector.post_param_init (&major_collector);
5143 sgen_memgov_init (max_heap, soft_limit, debug_print_allowance, allowance_ratio, save_target);
5145 memset (&remset, 0, sizeof (remset));
5147 #ifdef SGEN_HAVE_CARDTABLE
5149 sgen_card_table_init (&remset);
5152 sgen_ssb_init (&remset);
5154 if (remset.register_thread)
5155 remset.register_thread (mono_thread_info_current ());
5161 mono_gc_get_gc_name (void)
5166 static MonoMethod *write_barrier_method;
5169 sgen_is_critical_method (MonoMethod *method)
5171 return (method == write_barrier_method || sgen_is_managed_allocator (method));
5175 sgen_has_critical_method (void)
5177 return write_barrier_method || sgen_has_managed_allocator ();
5181 emit_nursery_check (MonoMethodBuilder *mb, int *nursery_check_return_labels)
5183 memset (nursery_check_return_labels, 0, sizeof (int) * 3);
5184 #ifdef SGEN_ALIGN_NURSERY
5185 // if (ptr_in_nursery (ptr)) return;
5187 * Masking out the bits might be faster, but we would have to use 64 bit
5188 * immediates, which might be slower.
5190 mono_mb_emit_ldarg (mb, 0);
5191 mono_mb_emit_icon (mb, DEFAULT_NURSERY_BITS);
5192 mono_mb_emit_byte (mb, CEE_SHR_UN);
5193 mono_mb_emit_icon (mb, (mword)sgen_get_nursery_start () >> DEFAULT_NURSERY_BITS);
5194 nursery_check_return_labels [0] = mono_mb_emit_branch (mb, CEE_BEQ);
5196 if (!major_collector.is_concurrent) {
5197 // if (!ptr_in_nursery (*ptr)) return;
5198 mono_mb_emit_ldarg (mb, 0);
5199 mono_mb_emit_byte (mb, CEE_LDIND_I);
5200 mono_mb_emit_icon (mb, DEFAULT_NURSERY_BITS);
5201 mono_mb_emit_byte (mb, CEE_SHR_UN);
5202 mono_mb_emit_icon (mb, (mword)sgen_get_nursery_start () >> DEFAULT_NURSERY_BITS);
5203 nursery_check_return_labels [1] = mono_mb_emit_branch (mb, CEE_BNE_UN);
5206 int label_continue1, label_continue2;
5207 int dereferenced_var;
5209 // if (ptr < (sgen_get_nursery_start ())) goto continue;
5210 mono_mb_emit_ldarg (mb, 0);
5211 mono_mb_emit_ptr (mb, (gpointer) sgen_get_nursery_start ());
5212 label_continue_1 = mono_mb_emit_branch (mb, CEE_BLT);
5214 // if (ptr >= sgen_get_nursery_end ())) goto continue;
5215 mono_mb_emit_ldarg (mb, 0);
5216 mono_mb_emit_ptr (mb, (gpointer) sgen_get_nursery_end ());
5217 label_continue_2 = mono_mb_emit_branch (mb, CEE_BGE);
5220 nursery_check_return_labels [0] = mono_mb_emit_branch (mb, CEE_BR);
5223 mono_mb_patch_branch (mb, label_continue_1);
5224 mono_mb_patch_branch (mb, label_continue_2);
5226 // Dereference and store in local var
5227 dereferenced_var = mono_mb_add_local (mb, &mono_defaults.int_class->byval_arg);
5228 mono_mb_emit_ldarg (mb, 0);
5229 mono_mb_emit_byte (mb, CEE_LDIND_I);
5230 mono_mb_emit_stloc (mb, dereferenced_var);
5232 if (!major_collector.is_concurrent) {
5233 // if (*ptr < sgen_get_nursery_start ()) return;
5234 mono_mb_emit_ldloc (mb, dereferenced_var);
5235 mono_mb_emit_ptr (mb, (gpointer) sgen_get_nursery_start ());
5236 nursery_check_return_labels [1] = mono_mb_emit_branch (mb, CEE_BLT);
5238 // if (*ptr >= sgen_get_nursery_end ()) return;
5239 mono_mb_emit_ldloc (mb, dereferenced_var);
5240 mono_mb_emit_ptr (mb, (gpointer) sgen_get_nursery_end ());
5241 nursery_check_return_labels [2] = mono_mb_emit_branch (mb, CEE_BGE);
5247 mono_gc_get_write_barrier (void)
5250 MonoMethodBuilder *mb;
5251 MonoMethodSignature *sig;
5252 #ifdef MANAGED_WBARRIER
5253 int i, nursery_check_labels [3];
5254 int label_no_wb_3, label_no_wb_4, label_need_wb, label_slow_path;
5255 int buffer_var, buffer_index_var, dummy_var;
5257 #ifdef HAVE_KW_THREAD
5258 int stack_end_offset = -1, store_remset_buffer_offset = -1;
5259 int store_remset_buffer_index_offset = -1, store_remset_buffer_index_addr_offset = -1;
5261 MONO_THREAD_VAR_OFFSET (stack_end, stack_end_offset);
5262 g_assert (stack_end_offset != -1);
5263 MONO_THREAD_VAR_OFFSET (store_remset_buffer, store_remset_buffer_offset);
5264 g_assert (store_remset_buffer_offset != -1);
5265 MONO_THREAD_VAR_OFFSET (store_remset_buffer_index, store_remset_buffer_index_offset);
5266 g_assert (store_remset_buffer_index_offset != -1);
5267 MONO_THREAD_VAR_OFFSET (store_remset_buffer_index_addr, store_remset_buffer_index_addr_offset);
5268 g_assert (store_remset_buffer_index_addr_offset != -1);
5272 // FIXME: Maybe create a separate version for ctors (the branch would be
5273 // correctly predicted more times)
5274 if (write_barrier_method)
5275 return write_barrier_method;
5277 /* Create the IL version of mono_gc_barrier_generic_store () */
5278 sig = mono_metadata_signature_alloc (mono_defaults.corlib, 1);
5279 sig->ret = &mono_defaults.void_class->byval_arg;
5280 sig->params [0] = &mono_defaults.int_class->byval_arg;
5282 mb = mono_mb_new (mono_defaults.object_class, "wbarrier", MONO_WRAPPER_WRITE_BARRIER);
5284 #ifdef MANAGED_WBARRIER
5285 if (use_cardtable) {
5286 emit_nursery_check (mb, nursery_check_labels);
5288 addr = sgen_cardtable + ((address >> CARD_BITS) & CARD_MASK)
5292 LDC_PTR sgen_cardtable
5294 address >> CARD_BITS
5298 if (SGEN_HAVE_OVERLAPPING_CARDS) {
5299 LDC_PTR card_table_mask
5306 mono_mb_emit_ptr (mb, sgen_cardtable);
5307 mono_mb_emit_ldarg (mb, 0);
5308 mono_mb_emit_icon (mb, CARD_BITS);
5309 mono_mb_emit_byte (mb, CEE_SHR_UN);
5310 #ifdef SGEN_HAVE_OVERLAPPING_CARDS
5311 mono_mb_emit_ptr (mb, (gpointer)CARD_MASK);
5312 mono_mb_emit_byte (mb, CEE_AND);
5314 mono_mb_emit_byte (mb, CEE_ADD);
5315 mono_mb_emit_icon (mb, 1);
5316 mono_mb_emit_byte (mb, CEE_STIND_I1);
5319 for (i = 0; i < 3; ++i) {
5320 if (nursery_check_labels [i])
5321 mono_mb_patch_branch (mb, nursery_check_labels [i]);
5323 mono_mb_emit_byte (mb, CEE_RET);
5324 } else if (mono_runtime_has_tls_get ()) {
5325 emit_nursery_check (mb, nursery_check_labels);
5327 // if (ptr >= stack_end) goto need_wb;
5328 mono_mb_emit_ldarg (mb, 0);
5329 EMIT_TLS_ACCESS (mb, stack_end, stack_end_offset);
5330 label_need_wb = mono_mb_emit_branch (mb, CEE_BGE_UN);
5332 // if (ptr >= stack_start) return;
5333 dummy_var = mono_mb_add_local (mb, &mono_defaults.int_class->byval_arg);
5334 mono_mb_emit_ldarg (mb, 0);
5335 mono_mb_emit_ldloc_addr (mb, dummy_var);
5336 label_no_wb_3 = mono_mb_emit_branch (mb, CEE_BGE_UN);
5339 mono_mb_patch_branch (mb, label_need_wb);
5341 // buffer = STORE_REMSET_BUFFER;
5342 buffer_var = mono_mb_add_local (mb, &mono_defaults.int_class->byval_arg);
5343 EMIT_TLS_ACCESS (mb, store_remset_buffer, store_remset_buffer_offset);
5344 mono_mb_emit_stloc (mb, buffer_var);
5346 // buffer_index = STORE_REMSET_BUFFER_INDEX;
5347 buffer_index_var = mono_mb_add_local (mb, &mono_defaults.int_class->byval_arg);
5348 EMIT_TLS_ACCESS (mb, store_remset_buffer_index, store_remset_buffer_index_offset);
5349 mono_mb_emit_stloc (mb, buffer_index_var);
5351 // if (buffer [buffer_index] == ptr) return;
5352 mono_mb_emit_ldloc (mb, buffer_var);
5353 mono_mb_emit_ldloc (mb, buffer_index_var);
5354 g_assert (sizeof (gpointer) == 4 || sizeof (gpointer) == 8);
5355 mono_mb_emit_icon (mb, sizeof (gpointer) == 4 ? 2 : 3);
5356 mono_mb_emit_byte (mb, CEE_SHL);
5357 mono_mb_emit_byte (mb, CEE_ADD);
5358 mono_mb_emit_byte (mb, CEE_LDIND_I);
5359 mono_mb_emit_ldarg (mb, 0);
5360 label_no_wb_4 = mono_mb_emit_branch (mb, CEE_BEQ);
5363 mono_mb_emit_ldloc (mb, buffer_index_var);
5364 mono_mb_emit_icon (mb, 1);
5365 mono_mb_emit_byte (mb, CEE_ADD);
5366 mono_mb_emit_stloc (mb, buffer_index_var);
5368 // if (buffer_index >= STORE_REMSET_BUFFER_SIZE) goto slow_path;
5369 mono_mb_emit_ldloc (mb, buffer_index_var);
5370 mono_mb_emit_icon (mb, STORE_REMSET_BUFFER_SIZE);
5371 label_slow_path = mono_mb_emit_branch (mb, CEE_BGE);
5373 // buffer [buffer_index] = ptr;
5374 mono_mb_emit_ldloc (mb, buffer_var);
5375 mono_mb_emit_ldloc (mb, buffer_index_var);
5376 g_assert (sizeof (gpointer) == 4 || sizeof (gpointer) == 8);
5377 mono_mb_emit_icon (mb, sizeof (gpointer) == 4 ? 2 : 3);
5378 mono_mb_emit_byte (mb, CEE_SHL);
5379 mono_mb_emit_byte (mb, CEE_ADD);
5380 mono_mb_emit_ldarg (mb, 0);
5381 mono_mb_emit_byte (mb, CEE_STIND_I);
5383 // STORE_REMSET_BUFFER_INDEX = buffer_index;
5384 EMIT_TLS_ACCESS (mb, store_remset_buffer_index_addr, store_remset_buffer_index_addr_offset);
5385 mono_mb_emit_ldloc (mb, buffer_index_var);
5386 mono_mb_emit_byte (mb, CEE_STIND_I);
5389 for (i = 0; i < 3; ++i) {
5390 if (nursery_check_labels [i])
5391 mono_mb_patch_branch (mb, nursery_check_labels [i]);
5393 mono_mb_patch_branch (mb, label_no_wb_3);
5394 mono_mb_patch_branch (mb, label_no_wb_4);
5395 mono_mb_emit_byte (mb, CEE_RET);
5398 mono_mb_patch_branch (mb, label_slow_path);
5400 mono_mb_emit_ldarg (mb, 0);
5401 mono_mb_emit_icall (mb, mono_gc_wbarrier_generic_nostore);
5402 mono_mb_emit_byte (mb, CEE_RET);
5406 mono_mb_emit_ldarg (mb, 0);
5407 mono_mb_emit_icall (mb, mono_gc_wbarrier_generic_nostore);
5408 mono_mb_emit_byte (mb, CEE_RET);
5411 res = mono_mb_create_method (mb, sig, 16);
5414 mono_loader_lock ();
5415 if (write_barrier_method) {
5416 /* Already created */
5417 mono_free_method (res);
5419 /* double-checked locking */
5420 mono_memory_barrier ();
5421 write_barrier_method = res;
5423 mono_loader_unlock ();
5425 return write_barrier_method;
5429 mono_gc_get_description (void)
5431 return g_strdup ("sgen");
5435 mono_gc_set_desktop_mode (void)
5440 mono_gc_is_moving (void)
5446 mono_gc_is_disabled (void)
5452 BOOL APIENTRY mono_gc_dllmain (HMODULE module_handle, DWORD reason, LPVOID reserved)
5459 sgen_get_nursery_clear_policy (void)
5461 return nursery_clear_policy;
5465 sgen_get_array_fill_vtable (void)
5467 if (!array_fill_vtable) {
5468 static MonoClass klass;
5469 static MonoVTable vtable;
5472 MonoDomain *domain = mono_get_root_domain ();
5475 klass.element_class = mono_defaults.byte_class;
5477 klass.instance_size = sizeof (MonoArray);
5478 klass.sizes.element_size = 1;
5479 klass.name = "array_filler_type";
5481 vtable.klass = &klass;
5483 vtable.gc_descr = mono_gc_make_descr_for_array (TRUE, &bmap, 0, 1);
5486 array_fill_vtable = &vtable;
5488 return array_fill_vtable;
5498 sgen_gc_unlock (void)
5504 sgen_major_collector_iterate_live_block_ranges (sgen_cardtable_block_callback callback)
5506 major_collector.iterate_live_block_ranges (callback);
5510 sgen_major_collector_scan_card_table (SgenGrayQueue *queue)
5512 major_collector.scan_card_table (FALSE, queue);
5516 sgen_get_major_collector (void)
5518 return &major_collector;
5521 void mono_gc_set_skip_thread (gboolean skip)
5523 SgenThreadInfo *info = mono_thread_info_current ();
5526 info->gc_disabled = skip;
5531 sgen_get_remset (void)
5537 mono_gc_get_vtable_bits (MonoClass *class)
5539 if (sgen_need_bridge_processing () && sgen_is_bridge_class (class))
5540 return SGEN_GC_BIT_BRIDGE_OBJECT;
5545 mono_gc_register_altstack (gpointer stack, gint32 stack_size, gpointer altstack, gint32 altstack_size)
5552 sgen_check_whole_heap_stw (void)
5554 sgen_stop_world (0);
5555 sgen_clear_nursery_fragments ();
5556 sgen_check_whole_heap ();
5557 sgen_restart_world (0, NULL);
5561 sgen_gc_event_moves (void)
5563 if (moved_objects_idx) {
5564 mono_profiler_gc_moves (moved_objects, moved_objects_idx);
5565 moved_objects_idx = 0;
5569 #endif /* HAVE_SGEN_GC */