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 that there are no references to the domain left at domain unload */
264 static gboolean xdomain_checks = FALSE;
265 /* If not null, dump the heap after each collection into this file */
266 static FILE *heap_dump_file = NULL;
267 /* If set, mark stacks conservatively, even if precise marking is possible */
268 static gboolean conservative_stack_mark = FALSE;
269 /* If set, do a plausibility check on the scan_starts before and after
271 static gboolean do_scan_starts_check = FALSE;
272 static gboolean nursery_collection_is_parallel = FALSE;
273 static gboolean disable_minor_collections = FALSE;
274 static gboolean disable_major_collections = FALSE;
275 gboolean do_pin_stats = FALSE;
276 static gboolean do_verify_nursery = FALSE;
277 static gboolean do_dump_nursery_content = FALSE;
279 #ifdef HEAVY_STATISTICS
280 long long stat_objects_alloced_degraded = 0;
281 long long stat_bytes_alloced_degraded = 0;
283 long long stat_copy_object_called_nursery = 0;
284 long long stat_objects_copied_nursery = 0;
285 long long stat_copy_object_called_major = 0;
286 long long stat_objects_copied_major = 0;
288 long long stat_scan_object_called_nursery = 0;
289 long long stat_scan_object_called_major = 0;
291 long long stat_slots_allocated_in_vain;
293 long long stat_nursery_copy_object_failed_from_space = 0;
294 long long stat_nursery_copy_object_failed_forwarded = 0;
295 long long stat_nursery_copy_object_failed_pinned = 0;
296 long long stat_nursery_copy_object_failed_to_space = 0;
298 static int stat_wbarrier_set_field = 0;
299 static int stat_wbarrier_set_arrayref = 0;
300 static int stat_wbarrier_arrayref_copy = 0;
301 static int stat_wbarrier_generic_store = 0;
302 static int stat_wbarrier_set_root = 0;
303 static int stat_wbarrier_value_copy = 0;
304 static int stat_wbarrier_object_copy = 0;
307 int stat_minor_gcs = 0;
308 int stat_major_gcs = 0;
310 static long long stat_pinned_objects = 0;
312 static long long time_minor_pre_collection_fragment_clear = 0;
313 static long long time_minor_pinning = 0;
314 static long long time_minor_scan_remsets = 0;
315 static long long time_minor_scan_pinned = 0;
316 static long long time_minor_scan_registered_roots = 0;
317 static long long time_minor_scan_thread_data = 0;
318 static long long time_minor_finish_gray_stack = 0;
319 static long long time_minor_fragment_creation = 0;
321 static long long time_major_pre_collection_fragment_clear = 0;
322 static long long time_major_pinning = 0;
323 static long long time_major_scan_pinned = 0;
324 static long long time_major_scan_registered_roots = 0;
325 static long long time_major_scan_thread_data = 0;
326 static long long time_major_scan_alloc_pinned = 0;
327 static long long time_major_scan_finalized = 0;
328 static long long time_major_scan_big_objects = 0;
329 static long long time_major_finish_gray_stack = 0;
330 static long long time_major_free_bigobjs = 0;
331 static long long time_major_los_sweep = 0;
332 static long long time_major_sweep = 0;
333 static long long time_major_fragment_creation = 0;
335 int gc_debug_level = 0;
340 mono_gc_flush_info (void)
342 fflush (gc_debug_file);
346 #define TV_DECLARE SGEN_TV_DECLARE
347 #define TV_GETTIME SGEN_TV_GETTIME
348 #define TV_ELAPSED SGEN_TV_ELAPSED
349 #define TV_ELAPSED_MS SGEN_TV_ELAPSED_MS
351 #define ALIGN_TO(val,align) ((((guint64)val) + ((align) - 1)) & ~((align) - 1))
353 NurseryClearPolicy nursery_clear_policy = CLEAR_AT_TLAB_CREATION;
355 #define object_is_forwarded SGEN_OBJECT_IS_FORWARDED
356 #define object_is_pinned SGEN_OBJECT_IS_PINNED
357 #define pin_object SGEN_PIN_OBJECT
358 #define unpin_object SGEN_UNPIN_OBJECT
360 #define ptr_in_nursery sgen_ptr_in_nursery
362 #define LOAD_VTABLE SGEN_LOAD_VTABLE
365 safe_name (void* obj)
367 MonoVTable *vt = (MonoVTable*)LOAD_VTABLE (obj);
368 return vt->klass->name;
371 #define safe_object_get_size sgen_safe_object_get_size
374 sgen_safe_name (void* obj)
376 return safe_name (obj);
380 * ######################################################################
381 * ######## Global data.
382 * ######################################################################
384 LOCK_DECLARE (gc_mutex);
385 static int gc_disabled = 0;
387 static gboolean use_cardtable;
389 #define SCAN_START_SIZE SGEN_SCAN_START_SIZE
391 static mword pagesize = 4096;
392 int degraded_mode = 0;
394 static mword bytes_pinned_from_failed_allocation = 0;
396 GCMemSection *nursery_section = NULL;
397 static mword lowest_heap_address = ~(mword)0;
398 static mword highest_heap_address = 0;
400 LOCK_DECLARE (sgen_interruption_mutex);
401 static LOCK_DECLARE (pin_queue_mutex);
403 #define LOCK_PIN_QUEUE mono_mutex_lock (&pin_queue_mutex)
404 #define UNLOCK_PIN_QUEUE mono_mutex_unlock (&pin_queue_mutex)
406 typedef struct _FinalizeReadyEntry FinalizeReadyEntry;
407 struct _FinalizeReadyEntry {
408 FinalizeReadyEntry *next;
412 typedef struct _EphemeronLinkNode EphemeronLinkNode;
414 struct _EphemeronLinkNode {
415 EphemeronLinkNode *next;
424 int current_collection_generation = -1;
425 volatile gboolean concurrent_collection_in_progress = FALSE;
427 /* objects that are ready to be finalized */
428 static FinalizeReadyEntry *fin_ready_list = NULL;
429 static FinalizeReadyEntry *critical_fin_list = NULL;
431 static EphemeronLinkNode *ephemeron_list;
433 /* registered roots: the key to the hash is the root start address */
435 * Different kinds of roots are kept separate to speed up pin_from_roots () for example.
437 SgenHashTable roots_hash [ROOT_TYPE_NUM] = {
438 SGEN_HASH_TABLE_INIT (INTERNAL_MEM_ROOTS_TABLE, INTERNAL_MEM_ROOT_RECORD, sizeof (RootRecord), mono_aligned_addr_hash, NULL),
439 SGEN_HASH_TABLE_INIT (INTERNAL_MEM_ROOTS_TABLE, INTERNAL_MEM_ROOT_RECORD, sizeof (RootRecord), mono_aligned_addr_hash, NULL),
440 SGEN_HASH_TABLE_INIT (INTERNAL_MEM_ROOTS_TABLE, INTERNAL_MEM_ROOT_RECORD, sizeof (RootRecord), mono_aligned_addr_hash, NULL)
442 static mword roots_size = 0; /* amount of memory in the root set */
444 #define GC_ROOT_NUM 32
446 int count; /* must be the first field */
447 void *objects [GC_ROOT_NUM];
448 int root_types [GC_ROOT_NUM];
449 uintptr_t extra_info [GC_ROOT_NUM];
453 notify_gc_roots (GCRootReport *report)
457 mono_profiler_gc_roots (report->count, report->objects, report->root_types, report->extra_info);
462 add_profile_gc_root (GCRootReport *report, void *object, int rtype, uintptr_t extra_info)
464 if (report->count == GC_ROOT_NUM)
465 notify_gc_roots (report);
466 report->objects [report->count] = object;
467 report->root_types [report->count] = rtype;
468 report->extra_info [report->count++] = (uintptr_t)((MonoVTable*)LOAD_VTABLE (object))->klass;
471 MonoNativeTlsKey thread_info_key;
473 #ifdef HAVE_KW_THREAD
474 __thread SgenThreadInfo *sgen_thread_info;
475 __thread gpointer *store_remset_buffer;
476 __thread long store_remset_buffer_index;
477 __thread char *stack_end;
478 __thread long *store_remset_buffer_index_addr;
481 /* The size of a TLAB */
482 /* The bigger the value, the less often we have to go to the slow path to allocate a new
483 * one, but the more space is wasted by threads not allocating much memory.
485 * FIXME: Make this self-tuning for each thread.
487 guint32 tlab_size = (1024 * 4);
489 #define MAX_SMALL_OBJ_SIZE SGEN_MAX_SMALL_OBJ_SIZE
491 /* Functions supplied by the runtime to be called by the GC */
492 static MonoGCCallbacks gc_callbacks;
494 #define ALLOC_ALIGN SGEN_ALLOC_ALIGN
495 #define ALLOC_ALIGN_BITS SGEN_ALLOC_ALIGN_BITS
497 #define ALIGN_UP SGEN_ALIGN_UP
499 #define MOVED_OBJECTS_NUM 64
500 static void *moved_objects [MOVED_OBJECTS_NUM];
501 static int moved_objects_idx = 0;
503 /* Vtable of the objects used to fill out nursery fragments before a collection */
504 static MonoVTable *array_fill_vtable;
506 #ifdef SGEN_DEBUG_INTERNAL_ALLOC
507 MonoNativeThreadId main_gc_thread = NULL;
510 /*Object was pinned during the current collection*/
511 static mword objects_pinned;
514 * ######################################################################
515 * ######## Macros and function declarations.
516 * ######################################################################
520 align_pointer (void *ptr)
522 mword p = (mword)ptr;
523 p += sizeof (gpointer) - 1;
524 p &= ~ (sizeof (gpointer) - 1);
528 typedef SgenGrayQueue GrayQueue;
530 /* forward declarations */
531 static void scan_thread_data (void *start_nursery, void *end_nursery, gboolean precise, GrayQueue *queue);
532 static void scan_from_registered_roots (CopyOrMarkObjectFunc copy_func, ScanObjectFunc scan_func, char *addr_start, char *addr_end, int root_type, GrayQueue *queue);
533 static void scan_finalizer_entries (CopyOrMarkObjectFunc copy_func, FinalizeReadyEntry *list, GrayQueue *queue);
534 static void report_finalizer_roots (void);
535 static void report_registered_roots (void);
537 static void pin_from_roots (void *start_nursery, void *end_nursery, GrayQueue *queue);
538 static int pin_objects_from_addresses (GCMemSection *section, void **start, void **end, void *start_nursery, void *end_nursery, GrayQueue *queue, gboolean only_enqueue);
539 static void finish_gray_stack (char *start_addr, char *end_addr, int generation, GrayQueue *queue);
541 void mono_gc_scan_for_specific_ref (MonoObject *key, gboolean precise);
544 static void init_stats (void);
546 static int mark_ephemerons_in_range (CopyOrMarkObjectFunc copy_func, char *start, char *end, GrayQueue *queue);
547 static void clear_unreachable_ephemerons (CopyOrMarkObjectFunc copy_func, char *start, char *end, GrayQueue *queue);
548 static void null_ephemerons_for_domain (MonoDomain *domain);
550 SgenObjectOperations current_object_ops;
551 SgenMajorCollector major_collector;
552 SgenMinorCollector sgen_minor_collector;
553 static GrayQueue gray_queue;
555 static SgenRemeberedSet remset;
557 /* The gray queue to use from the main collection thread. */
558 static SgenGrayQueue*
559 sgen_workers_get_main_thread_queue (void)
561 if (sgen_collection_is_parallel () || sgen_collection_is_concurrent ())
562 return sgen_workers_get_distribute_gray_queue ();
566 #define WORKERS_DISTRIBUTE_GRAY_QUEUE (sgen_workers_get_main_thread_queue ())
569 * The gray queue a worker job must use. If we're not parallel or
570 * concurrent, we use the main gray queue.
572 static SgenGrayQueue*
573 sgen_workers_get_job_gray_queue (WorkerData *worker_data)
575 return worker_data ? &worker_data->private_gray_queue : WORKERS_DISTRIBUTE_GRAY_QUEUE;
579 is_xdomain_ref_allowed (gpointer *ptr, char *obj, MonoDomain *domain)
581 MonoObject *o = (MonoObject*)(obj);
582 MonoObject *ref = (MonoObject*)*(ptr);
583 int offset = (char*)(ptr) - (char*)o;
585 if (o->vtable->klass == mono_defaults.thread_class && offset == G_STRUCT_OFFSET (MonoThread, internal_thread))
587 if (o->vtable->klass == mono_defaults.internal_thread_class && offset == G_STRUCT_OFFSET (MonoInternalThread, current_appcontext))
589 if (mono_class_has_parent_fast (o->vtable->klass, mono_defaults.real_proxy_class) &&
590 offset == G_STRUCT_OFFSET (MonoRealProxy, unwrapped_server))
592 /* Thread.cached_culture_info */
593 if (!strcmp (ref->vtable->klass->name_space, "System.Globalization") &&
594 !strcmp (ref->vtable->klass->name, "CultureInfo") &&
595 !strcmp(o->vtable->klass->name_space, "System") &&
596 !strcmp(o->vtable->klass->name, "Object[]"))
599 * 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
600 * at System.IO.MemoryStream..ctor (byte[]) [0x00017] in /home/schani/Work/novell/trunk/mcs/class/corlib/System.IO/MemoryStream.cs:81
601 * at (wrapper remoting-invoke-with-check) System.IO.MemoryStream..ctor (byte[]) <IL 0x00020, 0xffffffff>
602 * at System.Runtime.Remoting.Messaging.CADMethodCallMessage.GetArguments () [0x0000d] in /home/schani/Work/novell/trunk/mcs/class/corlib/System.Runtime.Remoting.Messaging/CADMessages.cs:327
603 * 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
604 * 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
605 * at (wrapper remoting-invoke-with-check) System.AppDomain.ProcessMessageInDomain (byte[],System.Runtime.Remoting.Messaging.CADMethodCallMessage,byte[]&,System.Runtime.Remoting.Messaging.CADMethodReturnMessage&) <IL 0x0003d, 0xffffffff>
606 * 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
607 * at (wrapper runtime-invoke) object.runtime_invoke_CrossAppDomainSink/ProcessMessageRes_object_object (object,intptr,intptr,intptr) <IL 0x0004c, 0xffffffff>
609 if (!strcmp (ref->vtable->klass->name_space, "System") &&
610 !strcmp (ref->vtable->klass->name, "Byte[]") &&
611 !strcmp (o->vtable->klass->name_space, "System.IO") &&
612 !strcmp (o->vtable->klass->name, "MemoryStream"))
614 /* append_job() in threadpool.c */
615 if (!strcmp (ref->vtable->klass->name_space, "System.Runtime.Remoting.Messaging") &&
616 !strcmp (ref->vtable->klass->name, "AsyncResult") &&
617 !strcmp (o->vtable->klass->name_space, "System") &&
618 !strcmp (o->vtable->klass->name, "Object[]") &&
619 mono_thread_pool_is_queue_array ((MonoArray*) o))
625 check_reference_for_xdomain (gpointer *ptr, char *obj, MonoDomain *domain)
627 MonoObject *o = (MonoObject*)(obj);
628 MonoObject *ref = (MonoObject*)*(ptr);
629 int offset = (char*)(ptr) - (char*)o;
631 MonoClassField *field;
634 if (!ref || ref->vtable->domain == domain)
636 if (is_xdomain_ref_allowed (ptr, obj, domain))
640 for (class = o->vtable->klass; class; class = class->parent) {
643 for (i = 0; i < class->field.count; ++i) {
644 if (class->fields[i].offset == offset) {
645 field = &class->fields[i];
653 if (ref->vtable->klass == mono_defaults.string_class)
654 str = mono_string_to_utf8 ((MonoString*)ref);
657 g_print ("xdomain reference in %p (%s.%s) at offset %d (%s) to %p (%s.%s) (%s) - pointed to by:\n",
658 o, o->vtable->klass->name_space, o->vtable->klass->name,
659 offset, field ? field->name : "",
660 ref, ref->vtable->klass->name_space, ref->vtable->klass->name, str ? str : "");
661 mono_gc_scan_for_specific_ref (o, TRUE);
667 #define HANDLE_PTR(ptr,obj) check_reference_for_xdomain ((ptr), (obj), domain)
670 scan_object_for_xdomain_refs (char *start, mword size, void *data)
672 MonoDomain *domain = ((MonoObject*)start)->vtable->domain;
674 #include "sgen-scan-object.h"
677 static gboolean scan_object_for_specific_ref_precise = TRUE;
680 #define HANDLE_PTR(ptr,obj) do { \
681 if ((MonoObject*)*(ptr) == key) { \
682 g_print ("found ref to %p in object %p (%s) at offset %td\n", \
683 key, (obj), safe_name ((obj)), ((char*)(ptr) - (char*)(obj))); \
688 scan_object_for_specific_ref (char *start, MonoObject *key)
692 if ((forwarded = SGEN_OBJECT_IS_FORWARDED (start)))
695 if (scan_object_for_specific_ref_precise) {
696 #include "sgen-scan-object.h"
698 mword *words = (mword*)start;
699 size_t size = safe_object_get_size ((MonoObject*)start);
701 for (i = 0; i < size / sizeof (mword); ++i) {
702 if (words [i] == (mword)key) {
703 g_print ("found possible ref to %p in object %p (%s) at offset %td\n",
704 key, start, safe_name (start), i * sizeof (mword));
711 sgen_scan_area_with_callback (char *start, char *end, IterateObjectCallbackFunc callback, void *data, gboolean allow_flags)
713 while (start < end) {
717 if (!*(void**)start) {
718 start += sizeof (void*); /* should be ALLOC_ALIGN, really */
723 if (!(obj = SGEN_OBJECT_IS_FORWARDED (start)))
729 size = ALIGN_UP (safe_object_get_size ((MonoObject*)obj));
731 if ((MonoVTable*)SGEN_LOAD_VTABLE (obj) != array_fill_vtable)
732 callback (obj, size, data);
739 scan_object_for_specific_ref_callback (char *obj, size_t size, MonoObject *key)
741 scan_object_for_specific_ref (obj, key);
745 check_root_obj_specific_ref (RootRecord *root, MonoObject *key, MonoObject *obj)
749 g_print ("found ref to %p in root record %p\n", key, root);
752 static MonoObject *check_key = NULL;
753 static RootRecord *check_root = NULL;
756 check_root_obj_specific_ref_from_marker (void **obj)
758 check_root_obj_specific_ref (check_root, check_key, *obj);
762 scan_roots_for_specific_ref (MonoObject *key, int root_type)
768 SGEN_HASH_TABLE_FOREACH (&roots_hash [root_type], start_root, root) {
769 mword desc = root->root_desc;
773 switch (desc & ROOT_DESC_TYPE_MASK) {
774 case ROOT_DESC_BITMAP:
775 desc >>= ROOT_DESC_TYPE_SHIFT;
778 check_root_obj_specific_ref (root, key, *start_root);
783 case ROOT_DESC_COMPLEX: {
784 gsize *bitmap_data = sgen_get_complex_descriptor_bitmap (desc);
785 int bwords = (*bitmap_data) - 1;
786 void **start_run = start_root;
788 while (bwords-- > 0) {
789 gsize bmap = *bitmap_data++;
790 void **objptr = start_run;
793 check_root_obj_specific_ref (root, key, *objptr);
797 start_run += GC_BITS_PER_WORD;
801 case ROOT_DESC_USER: {
802 MonoGCRootMarkFunc marker = sgen_get_user_descriptor_func (desc);
803 marker (start_root, check_root_obj_specific_ref_from_marker);
806 case ROOT_DESC_RUN_LEN:
807 g_assert_not_reached ();
809 g_assert_not_reached ();
811 } SGEN_HASH_TABLE_FOREACH_END;
818 mono_gc_scan_for_specific_ref (MonoObject *key, gboolean precise)
823 scan_object_for_specific_ref_precise = precise;
825 sgen_scan_area_with_callback (nursery_section->data, nursery_section->end_data,
826 (IterateObjectCallbackFunc)scan_object_for_specific_ref_callback, key, TRUE);
828 major_collector.iterate_objects (TRUE, TRUE, (IterateObjectCallbackFunc)scan_object_for_specific_ref_callback, key);
830 sgen_los_iterate_objects ((IterateObjectCallbackFunc)scan_object_for_specific_ref_callback, key);
832 scan_roots_for_specific_ref (key, ROOT_TYPE_NORMAL);
833 scan_roots_for_specific_ref (key, ROOT_TYPE_WBARRIER);
835 SGEN_HASH_TABLE_FOREACH (&roots_hash [ROOT_TYPE_PINNED], ptr, root) {
836 while (ptr < (void**)root->end_root) {
837 check_root_obj_specific_ref (root, *ptr, key);
840 } SGEN_HASH_TABLE_FOREACH_END;
844 need_remove_object_for_domain (char *start, MonoDomain *domain)
846 if (mono_object_domain (start) == domain) {
847 SGEN_LOG (4, "Need to cleanup object %p", start);
848 binary_protocol_cleanup (start, (gpointer)LOAD_VTABLE (start), safe_object_get_size ((MonoObject*)start));
855 process_object_for_domain_clearing (char *start, MonoDomain *domain)
857 GCVTable *vt = (GCVTable*)LOAD_VTABLE (start);
858 if (vt->klass == mono_defaults.internal_thread_class)
859 g_assert (mono_object_domain (start) == mono_get_root_domain ());
860 /* The object could be a proxy for an object in the domain
862 if (mono_class_has_parent_fast (vt->klass, mono_defaults.real_proxy_class)) {
863 MonoObject *server = ((MonoRealProxy*)start)->unwrapped_server;
865 /* The server could already have been zeroed out, so
866 we need to check for that, too. */
867 if (server && (!LOAD_VTABLE (server) || mono_object_domain (server) == domain)) {
868 SGEN_LOG (4, "Cleaning up remote pointer in %p to object %p", start, server);
869 ((MonoRealProxy*)start)->unwrapped_server = NULL;
874 static MonoDomain *check_domain = NULL;
877 check_obj_not_in_domain (void **o)
879 g_assert (((MonoObject*)(*o))->vtable->domain != check_domain);
883 scan_for_registered_roots_in_domain (MonoDomain *domain, int root_type)
887 check_domain = domain;
888 SGEN_HASH_TABLE_FOREACH (&roots_hash [root_type], start_root, root) {
889 mword desc = root->root_desc;
891 /* The MonoDomain struct is allowed to hold
892 references to objects in its own domain. */
893 if (start_root == (void**)domain)
896 switch (desc & ROOT_DESC_TYPE_MASK) {
897 case ROOT_DESC_BITMAP:
898 desc >>= ROOT_DESC_TYPE_SHIFT;
900 if ((desc & 1) && *start_root)
901 check_obj_not_in_domain (*start_root);
906 case ROOT_DESC_COMPLEX: {
907 gsize *bitmap_data = sgen_get_complex_descriptor_bitmap (desc);
908 int bwords = (*bitmap_data) - 1;
909 void **start_run = start_root;
911 while (bwords-- > 0) {
912 gsize bmap = *bitmap_data++;
913 void **objptr = start_run;
915 if ((bmap & 1) && *objptr)
916 check_obj_not_in_domain (*objptr);
920 start_run += GC_BITS_PER_WORD;
924 case ROOT_DESC_USER: {
925 MonoGCRootMarkFunc marker = sgen_get_user_descriptor_func (desc);
926 marker (start_root, check_obj_not_in_domain);
929 case ROOT_DESC_RUN_LEN:
930 g_assert_not_reached ();
932 g_assert_not_reached ();
934 } SGEN_HASH_TABLE_FOREACH_END;
940 check_for_xdomain_refs (void)
944 sgen_scan_area_with_callback (nursery_section->data, nursery_section->end_data,
945 (IterateObjectCallbackFunc)scan_object_for_xdomain_refs, NULL, FALSE);
947 major_collector.iterate_objects (TRUE, TRUE, (IterateObjectCallbackFunc)scan_object_for_xdomain_refs, NULL);
949 for (bigobj = los_object_list; bigobj; bigobj = bigobj->next)
950 scan_object_for_xdomain_refs (bigobj->data, sgen_los_object_size (bigobj), NULL);
954 clear_domain_process_object (char *obj, MonoDomain *domain)
958 process_object_for_domain_clearing (obj, domain);
959 remove = need_remove_object_for_domain (obj, domain);
961 if (remove && ((MonoObject*)obj)->synchronisation) {
962 void **dislink = mono_monitor_get_object_monitor_weak_link ((MonoObject*)obj);
964 sgen_register_disappearing_link (NULL, dislink, FALSE, TRUE);
971 clear_domain_process_minor_object_callback (char *obj, size_t size, MonoDomain *domain)
973 if (clear_domain_process_object (obj, domain))
974 memset (obj, 0, size);
978 clear_domain_process_major_object_callback (char *obj, size_t size, MonoDomain *domain)
980 clear_domain_process_object (obj, domain);
984 clear_domain_free_major_non_pinned_object_callback (char *obj, size_t size, MonoDomain *domain)
986 if (need_remove_object_for_domain (obj, domain))
987 major_collector.free_non_pinned_object (obj, size);
991 clear_domain_free_major_pinned_object_callback (char *obj, size_t size, MonoDomain *domain)
993 if (need_remove_object_for_domain (obj, domain))
994 major_collector.free_pinned_object (obj, size);
998 * When appdomains are unloaded we can easily remove objects that have finalizers,
999 * but all the others could still be present in random places on the heap.
1000 * We need a sweep to get rid of them even though it's going to be costly
1002 * The reason we need to remove them is because we access the vtable and class
1003 * structures to know the object size and the reference bitmap: once the domain is
1004 * unloaded the point to random memory.
1007 mono_gc_clear_domain (MonoDomain * domain)
1009 LOSObject *bigobj, *prev;
1014 sgen_process_fin_stage_entries ();
1015 sgen_process_dislink_stage_entries ();
1017 sgen_clear_nursery_fragments ();
1019 if (xdomain_checks && domain != mono_get_root_domain ()) {
1020 scan_for_registered_roots_in_domain (domain, ROOT_TYPE_NORMAL);
1021 scan_for_registered_roots_in_domain (domain, ROOT_TYPE_WBARRIER);
1022 check_for_xdomain_refs ();
1025 /*Ephemerons and dislinks must be processed before LOS since they might end up pointing
1026 to memory returned to the OS.*/
1027 null_ephemerons_for_domain (domain);
1029 for (i = GENERATION_NURSERY; i < GENERATION_MAX; ++i)
1030 sgen_null_links_for_domain (domain, i);
1032 for (i = GENERATION_NURSERY; i < GENERATION_MAX; ++i)
1033 sgen_remove_finalizers_for_domain (domain, i);
1035 sgen_scan_area_with_callback (nursery_section->data, nursery_section->end_data,
1036 (IterateObjectCallbackFunc)clear_domain_process_minor_object_callback, domain, FALSE);
1038 /* We need two passes over major and large objects because
1039 freeing such objects might give their memory back to the OS
1040 (in the case of large objects) or obliterate its vtable
1041 (pinned objects with major-copying or pinned and non-pinned
1042 objects with major-mark&sweep), but we might need to
1043 dereference a pointer from an object to another object if
1044 the first object is a proxy. */
1045 major_collector.iterate_objects (TRUE, TRUE, (IterateObjectCallbackFunc)clear_domain_process_major_object_callback, domain);
1046 for (bigobj = los_object_list; bigobj; bigobj = bigobj->next)
1047 clear_domain_process_object (bigobj->data, domain);
1050 for (bigobj = los_object_list; bigobj;) {
1051 if (need_remove_object_for_domain (bigobj->data, domain)) {
1052 LOSObject *to_free = bigobj;
1054 prev->next = bigobj->next;
1056 los_object_list = bigobj->next;
1057 bigobj = bigobj->next;
1058 SGEN_LOG (4, "Freeing large object %p", bigobj->data);
1059 sgen_los_free_object (to_free);
1063 bigobj = bigobj->next;
1065 major_collector.iterate_objects (TRUE, FALSE, (IterateObjectCallbackFunc)clear_domain_free_major_non_pinned_object_callback, domain);
1066 major_collector.iterate_objects (FALSE, TRUE, (IterateObjectCallbackFunc)clear_domain_free_major_pinned_object_callback, domain);
1068 if (G_UNLIKELY (do_pin_stats)) {
1069 if (domain == mono_get_root_domain ())
1070 sgen_pin_stats_print_class_stats ();
1077 * sgen_add_to_global_remset:
1079 * The global remset contains locations which point into newspace after
1080 * a minor collection. This can happen if the objects they point to are pinned.
1082 * LOCKING: If called from a parallel collector, the global remset
1083 * lock must be held. For serial collectors that is not necessary.
1086 sgen_add_to_global_remset (gpointer ptr)
1088 remset.record_pointer (ptr);
1092 * sgen_drain_gray_stack:
1094 * Scan objects in the gray stack until the stack is empty. This should be called
1095 * frequently after each object is copied, to achieve better locality and cache
1099 sgen_drain_gray_stack (GrayQueue *queue, ScanObjectFunc scan_func, int max_objs)
1103 if (max_objs == -1) {
1105 GRAY_OBJECT_DEQUEUE (queue, obj);
1108 SGEN_LOG (9, "Precise gray object scan %p (%s)", obj, safe_name (obj));
1109 scan_func (obj, queue);
1115 for (i = 0; i != max_objs; ++i) {
1116 GRAY_OBJECT_DEQUEUE (queue, obj);
1119 SGEN_LOG (9, "Precise gray object scan %p (%s)", obj, safe_name (obj));
1120 scan_func (obj, queue);
1122 } while (max_objs < 0);
1128 * Addresses from start to end are already sorted. This function finds
1129 * the object header for each address and pins the object. The
1130 * addresses must be inside the passed section. The (start of the)
1131 * address array is overwritten with the addresses of the actually
1132 * pinned objects. Return the number of pinned objects.
1135 pin_objects_from_addresses (GCMemSection *section, void **start, void **end, void *start_nursery, void *end_nursery, GrayQueue *queue, gboolean only_enqueue)
1140 void *last_obj = NULL;
1141 size_t last_obj_size = 0;
1144 void **definitely_pinned = start;
1146 sgen_nursery_allocator_prepare_for_pinning ();
1148 while (start < end) {
1150 /* the range check should be reduntant */
1151 if (addr != last && addr >= start_nursery && addr < end_nursery) {
1152 SGEN_LOG (5, "Considering pinning addr %p", addr);
1153 /* multiple pointers to the same object */
1154 if (addr >= last_obj && (char*)addr < (char*)last_obj + last_obj_size) {
1158 idx = ((char*)addr - (char*)section->data) / SCAN_START_SIZE;
1159 g_assert (idx < section->num_scan_start);
1160 search_start = (void*)section->scan_starts [idx];
1161 if (!search_start || search_start > addr) {
1164 search_start = section->scan_starts [idx];
1165 if (search_start && search_start <= addr)
1168 if (!search_start || search_start > addr)
1169 search_start = start_nursery;
1171 if (search_start < last_obj)
1172 search_start = (char*)last_obj + last_obj_size;
1173 /* now addr should be in an object a short distance from search_start
1174 * Note that search_start must point to zeroed mem or point to an object.
1178 if (!*(void**)search_start) {
1179 /* Consistency check */
1181 for (frag = nursery_fragments; frag; frag = frag->next) {
1182 if (search_start >= frag->fragment_start && search_start < frag->fragment_end)
1183 g_assert_not_reached ();
1187 search_start = (void*)ALIGN_UP ((mword)search_start + sizeof (gpointer));
1190 last_obj = search_start;
1191 last_obj_size = ALIGN_UP (safe_object_get_size ((MonoObject*)search_start));
1193 if (((MonoObject*)last_obj)->synchronisation == GINT_TO_POINTER (-1)) {
1194 /* Marks the beginning of a nursery fragment, skip */
1196 SGEN_LOG (8, "Pinned try match %p (%s), size %zd", last_obj, safe_name (last_obj), last_obj_size);
1197 if (addr >= search_start && (char*)addr < (char*)last_obj + last_obj_size) {
1198 SGEN_LOG (4, "Pinned object %p, vtable %p (%s), count %d\n", search_start, *(void**)search_start, safe_name (search_start), count);
1199 binary_protocol_pin (search_start, (gpointer)LOAD_VTABLE (search_start), safe_object_get_size (search_start));
1200 if (G_UNLIKELY (MONO_GC_OBJ_PINNED_ENABLED ())) {
1201 int gen = sgen_ptr_in_nursery (search_start) ? GENERATION_NURSERY : GENERATION_OLD;
1202 MonoVTable *vt = (MonoVTable*)LOAD_VTABLE (search_start);
1203 MONO_GC_OBJ_PINNED ((mword)search_start, sgen_safe_object_get_size (search_start), vt->klass->name_space, vt->klass->name, gen);
1206 pin_object (search_start);
1207 GRAY_OBJECT_ENQUEUE (queue, search_start);
1208 if (G_UNLIKELY (do_pin_stats))
1209 sgen_pin_stats_register_object (search_start, last_obj_size);
1210 definitely_pinned [count] = search_start;
1215 /* skip to the next object */
1216 search_start = (void*)((char*)search_start + last_obj_size);
1217 } while (search_start <= addr);
1218 /* we either pinned the correct object or we ignored the addr because
1219 * it points to unused zeroed memory.
1225 //printf ("effective pinned: %d (at the end: %d)\n", count, (char*)end_nursery - (char*)last);
1226 if (mono_profiler_get_events () & MONO_PROFILE_GC_ROOTS) {
1227 GCRootReport report;
1229 for (idx = 0; idx < count; ++idx)
1230 add_profile_gc_root (&report, definitely_pinned [idx], MONO_PROFILE_GC_ROOT_PINNING | MONO_PROFILE_GC_ROOT_MISC, 0);
1231 notify_gc_roots (&report);
1233 stat_pinned_objects += count;
1238 sgen_pin_objects_in_section (GCMemSection *section, GrayQueue *queue, gboolean only_enqueue)
1240 int num_entries = section->pin_queue_num_entries;
1242 void **start = section->pin_queue_start;
1244 reduced_to = pin_objects_from_addresses (section, start, start + num_entries,
1245 section->data, section->next_data, queue, only_enqueue);
1246 section->pin_queue_num_entries = reduced_to;
1248 section->pin_queue_start = NULL;
1254 sgen_pin_object (void *object, GrayQueue *queue)
1256 g_assert (!concurrent_collection_in_progress);
1258 if (sgen_collection_is_parallel ()) {
1260 /*object arrives pinned*/
1261 sgen_pin_stage_ptr (object);
1265 SGEN_PIN_OBJECT (object);
1266 sgen_pin_stage_ptr (object);
1268 if (G_UNLIKELY (do_pin_stats))
1269 sgen_pin_stats_register_object (object, safe_object_get_size (object));
1271 GRAY_OBJECT_ENQUEUE (queue, object);
1272 binary_protocol_pin (object, (gpointer)LOAD_VTABLE (object), safe_object_get_size (object));
1273 if (G_UNLIKELY (MONO_GC_OBJ_PINNED_ENABLED ())) {
1274 int gen = sgen_ptr_in_nursery (object) ? GENERATION_NURSERY : GENERATION_OLD;
1275 MonoVTable *vt = (MonoVTable*)LOAD_VTABLE (object);
1276 MONO_GC_OBJ_PINNED ((mword)object, sgen_safe_object_get_size (object), vt->klass->name_space, vt->klass->name, gen);
1281 sgen_parallel_pin_or_update (void **ptr, void *obj, MonoVTable *vt, SgenGrayQueue *queue)
1285 gboolean major_pinned = FALSE;
1287 if (sgen_ptr_in_nursery (obj)) {
1288 if (SGEN_CAS_PTR (obj, (void*)((mword)vt | SGEN_PINNED_BIT), vt) == vt) {
1289 sgen_pin_object (obj, queue);
1293 major_collector.pin_major_object (obj, queue);
1294 major_pinned = TRUE;
1297 vtable_word = *(mword*)obj;
1298 /*someone else forwarded it, update the pointer and bail out*/
1299 if (vtable_word & SGEN_FORWARDED_BIT) {
1300 *ptr = (void*)(vtable_word & ~SGEN_VTABLE_BITS_MASK);
1304 /*someone pinned it, nothing to do.*/
1305 if (vtable_word & SGEN_PINNED_BIT || major_pinned)
1310 /* Sort the addresses in array in increasing order.
1311 * Done using a by-the book heap sort. Which has decent and stable performance, is pretty cache efficient.
1314 sgen_sort_addresses (void **array, int size)
1319 for (i = 1; i < size; ++i) {
1322 int parent = (child - 1) / 2;
1324 if (array [parent] >= array [child])
1327 tmp = array [parent];
1328 array [parent] = array [child];
1329 array [child] = tmp;
1335 for (i = size - 1; i > 0; --i) {
1338 array [i] = array [0];
1344 while (root * 2 + 1 <= end) {
1345 int child = root * 2 + 1;
1347 if (child < end && array [child] < array [child + 1])
1349 if (array [root] >= array [child])
1353 array [root] = array [child];
1354 array [child] = tmp;
1362 * Scan the memory between start and end and queue values which could be pointers
1363 * to the area between start_nursery and end_nursery for later consideration.
1364 * Typically used for thread stacks.
1367 conservatively_pin_objects_from (void **start, void **end, void *start_nursery, void *end_nursery, int pin_type)
1371 #ifdef VALGRIND_MAKE_MEM_DEFINED_IF_ADDRESSABLE
1372 VALGRIND_MAKE_MEM_DEFINED_IF_ADDRESSABLE (start, (char*)end - (char*)start);
1375 while (start < end) {
1376 if (*start >= start_nursery && *start < end_nursery) {
1378 * *start can point to the middle of an object
1379 * note: should we handle pointing at the end of an object?
1380 * pinning in C# code disallows pointing at the end of an object
1381 * but there is some small chance that an optimizing C compiler
1382 * may keep the only reference to an object by pointing
1383 * at the end of it. We ignore this small chance for now.
1384 * Pointers to the end of an object are indistinguishable
1385 * from pointers to the start of the next object in memory
1386 * so if we allow that we'd need to pin two objects...
1387 * We queue the pointer in an array, the
1388 * array will then be sorted and uniqued. This way
1389 * we can coalesce several pinning pointers and it should
1390 * be faster since we'd do a memory scan with increasing
1391 * addresses. Note: we can align the address to the allocation
1392 * alignment, so the unique process is more effective.
1394 mword addr = (mword)*start;
1395 addr &= ~(ALLOC_ALIGN - 1);
1396 if (addr >= (mword)start_nursery && addr < (mword)end_nursery) {
1397 SGEN_LOG (6, "Pinning address %p from %p", (void*)addr, start);
1398 sgen_pin_stage_ptr ((void*)addr);
1401 if (G_UNLIKELY (do_pin_stats)) {
1402 if (ptr_in_nursery ((void*)addr))
1403 sgen_pin_stats_register_address ((char*)addr, pin_type);
1409 SGEN_LOG (7, "found %d potential pinned heap pointers", count);
1413 * The first thing we do in a collection is to identify pinned objects.
1414 * This function considers all the areas of memory that need to be
1415 * conservatively scanned.
1418 pin_from_roots (void *start_nursery, void *end_nursery, GrayQueue *queue)
1422 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);
1423 /* objects pinned from the API are inside these roots */
1424 SGEN_HASH_TABLE_FOREACH (&roots_hash [ROOT_TYPE_PINNED], start_root, root) {
1425 SGEN_LOG (6, "Pinned roots %p-%p", start_root, root->end_root);
1426 conservatively_pin_objects_from (start_root, (void**)root->end_root, start_nursery, end_nursery, PIN_TYPE_OTHER);
1427 } SGEN_HASH_TABLE_FOREACH_END;
1428 /* now deal with the thread stacks
1429 * in the future we should be able to conservatively scan only:
1430 * *) the cpu registers
1431 * *) the unmanaged stack frames
1432 * *) the _last_ managed stack frame
1433 * *) pointers slots in managed frames
1435 scan_thread_data (start_nursery, end_nursery, FALSE, queue);
1439 CopyOrMarkObjectFunc func;
1441 } UserCopyOrMarkData;
1443 static MonoNativeTlsKey user_copy_or_mark_key;
1446 init_user_copy_or_mark_key (void)
1448 mono_native_tls_alloc (&user_copy_or_mark_key, NULL);
1452 set_user_copy_or_mark_data (UserCopyOrMarkData *data)
1454 mono_native_tls_set_value (user_copy_or_mark_key, data);
1458 single_arg_user_copy_or_mark (void **obj)
1460 UserCopyOrMarkData *data = mono_native_tls_get_value (user_copy_or_mark_key);
1462 data->func (obj, data->queue);
1466 * The memory area from start_root to end_root contains pointers to objects.
1467 * Their position is precisely described by @desc (this means that the pointer
1468 * can be either NULL or the pointer to the start of an object).
1469 * This functions copies them to to_space updates them.
1471 * This function is not thread-safe!
1474 precisely_scan_objects_from (CopyOrMarkObjectFunc copy_func, ScanObjectFunc scan_func, void** start_root, void** end_root, char* n_start, char *n_end, mword desc, GrayQueue *queue)
1476 switch (desc & ROOT_DESC_TYPE_MASK) {
1477 case ROOT_DESC_BITMAP:
1478 desc >>= ROOT_DESC_TYPE_SHIFT;
1480 if ((desc & 1) && *start_root) {
1481 copy_func (start_root, queue);
1482 SGEN_LOG (9, "Overwrote root at %p with %p", start_root, *start_root);
1483 sgen_drain_gray_stack (queue, scan_func, -1);
1489 case ROOT_DESC_COMPLEX: {
1490 gsize *bitmap_data = sgen_get_complex_descriptor_bitmap (desc);
1491 int bwords = (*bitmap_data) - 1;
1492 void **start_run = start_root;
1494 while (bwords-- > 0) {
1495 gsize bmap = *bitmap_data++;
1496 void **objptr = start_run;
1498 if ((bmap & 1) && *objptr) {
1499 copy_func (objptr, queue);
1500 SGEN_LOG (9, "Overwrote root at %p with %p", objptr, *objptr);
1501 sgen_drain_gray_stack (queue, scan_func, -1);
1506 start_run += GC_BITS_PER_WORD;
1510 case ROOT_DESC_USER: {
1511 UserCopyOrMarkData data = { copy_func, queue };
1512 MonoGCRootMarkFunc marker = sgen_get_user_descriptor_func (desc);
1513 set_user_copy_or_mark_data (&data);
1514 marker (start_root, single_arg_user_copy_or_mark);
1515 set_user_copy_or_mark_data (NULL);
1518 case ROOT_DESC_RUN_LEN:
1519 g_assert_not_reached ();
1521 g_assert_not_reached ();
1526 reset_heap_boundaries (void)
1528 lowest_heap_address = ~(mword)0;
1529 highest_heap_address = 0;
1533 sgen_update_heap_boundaries (mword low, mword high)
1538 old = lowest_heap_address;
1541 } while (SGEN_CAS_PTR ((gpointer*)&lowest_heap_address, (gpointer)low, (gpointer)old) != (gpointer)old);
1544 old = highest_heap_address;
1547 } while (SGEN_CAS_PTR ((gpointer*)&highest_heap_address, (gpointer)high, (gpointer)old) != (gpointer)old);
1551 * Allocate and setup the data structures needed to be able to allocate objects
1552 * in the nursery. The nursery is stored in nursery_section.
1555 alloc_nursery (void)
1557 GCMemSection *section;
1562 if (nursery_section)
1564 SGEN_LOG (2, "Allocating nursery size: %lu", (unsigned long)sgen_nursery_size);
1565 /* later we will alloc a larger area for the nursery but only activate
1566 * what we need. The rest will be used as expansion if we have too many pinned
1567 * objects in the existing nursery.
1569 /* FIXME: handle OOM */
1570 section = sgen_alloc_internal (INTERNAL_MEM_SECTION);
1572 alloc_size = sgen_nursery_size;
1574 /* If there isn't enough space even for the nursery we should simply abort. */
1575 g_assert (sgen_memgov_try_alloc_space (alloc_size, SPACE_NURSERY));
1577 #ifdef SGEN_ALIGN_NURSERY
1578 data = major_collector.alloc_heap (alloc_size, alloc_size, DEFAULT_NURSERY_BITS);
1580 data = major_collector.alloc_heap (alloc_size, 0, DEFAULT_NURSERY_BITS);
1582 sgen_update_heap_boundaries ((mword)data, (mword)(data + sgen_nursery_size));
1583 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 ());
1584 section->data = section->next_data = data;
1585 section->size = alloc_size;
1586 section->end_data = data + sgen_nursery_size;
1587 scan_starts = (alloc_size + SCAN_START_SIZE - 1) / SCAN_START_SIZE;
1588 section->scan_starts = sgen_alloc_internal_dynamic (sizeof (char*) * scan_starts, INTERNAL_MEM_SCAN_STARTS, TRUE);
1589 section->num_scan_start = scan_starts;
1590 section->block.role = MEMORY_ROLE_GEN0;
1591 section->block.next = NULL;
1593 nursery_section = section;
1595 sgen_nursery_allocator_set_nursery_bounds (data, data + sgen_nursery_size);
1599 mono_gc_get_nursery (int *shift_bits, size_t *size)
1601 *size = sgen_nursery_size;
1602 #ifdef SGEN_ALIGN_NURSERY
1603 *shift_bits = DEFAULT_NURSERY_BITS;
1607 return sgen_get_nursery_start ();
1611 mono_gc_set_current_thread_appdomain (MonoDomain *domain)
1613 SgenThreadInfo *info = mono_thread_info_current ();
1615 /* Could be called from sgen_thread_unregister () with a NULL info */
1618 info->stopped_domain = domain;
1623 mono_gc_precise_stack_mark_enabled (void)
1625 return !conservative_stack_mark;
1629 mono_gc_get_logfile (void)
1631 return gc_debug_file;
1635 report_finalizer_roots_list (FinalizeReadyEntry *list)
1637 GCRootReport report;
1638 FinalizeReadyEntry *fin;
1641 for (fin = list; fin; fin = fin->next) {
1644 add_profile_gc_root (&report, fin->object, MONO_PROFILE_GC_ROOT_FINALIZER, 0);
1646 notify_gc_roots (&report);
1650 report_finalizer_roots (void)
1652 report_finalizer_roots_list (fin_ready_list);
1653 report_finalizer_roots_list (critical_fin_list);
1656 static GCRootReport *root_report;
1659 single_arg_report_root (void **obj)
1662 add_profile_gc_root (root_report, *obj, MONO_PROFILE_GC_ROOT_OTHER, 0);
1666 precisely_report_roots_from (GCRootReport *report, void** start_root, void** end_root, mword desc)
1668 switch (desc & ROOT_DESC_TYPE_MASK) {
1669 case ROOT_DESC_BITMAP:
1670 desc >>= ROOT_DESC_TYPE_SHIFT;
1672 if ((desc & 1) && *start_root) {
1673 add_profile_gc_root (report, *start_root, MONO_PROFILE_GC_ROOT_OTHER, 0);
1679 case ROOT_DESC_COMPLEX: {
1680 gsize *bitmap_data = sgen_get_complex_descriptor_bitmap (desc);
1681 int bwords = (*bitmap_data) - 1;
1682 void **start_run = start_root;
1684 while (bwords-- > 0) {
1685 gsize bmap = *bitmap_data++;
1686 void **objptr = start_run;
1688 if ((bmap & 1) && *objptr) {
1689 add_profile_gc_root (report, *objptr, MONO_PROFILE_GC_ROOT_OTHER, 0);
1694 start_run += GC_BITS_PER_WORD;
1698 case ROOT_DESC_USER: {
1699 MonoGCRootMarkFunc marker = sgen_get_user_descriptor_func (desc);
1700 root_report = report;
1701 marker (start_root, single_arg_report_root);
1704 case ROOT_DESC_RUN_LEN:
1705 g_assert_not_reached ();
1707 g_assert_not_reached ();
1712 report_registered_roots_by_type (int root_type)
1714 GCRootReport report;
1718 SGEN_HASH_TABLE_FOREACH (&roots_hash [root_type], start_root, root) {
1719 SGEN_LOG (6, "Precise root scan %p-%p (desc: %p)", start_root, root->end_root, (void*)root->root_desc);
1720 precisely_report_roots_from (&report, start_root, (void**)root->end_root, root->root_desc);
1721 } SGEN_HASH_TABLE_FOREACH_END;
1722 notify_gc_roots (&report);
1726 report_registered_roots (void)
1728 report_registered_roots_by_type (ROOT_TYPE_NORMAL);
1729 report_registered_roots_by_type (ROOT_TYPE_WBARRIER);
1733 scan_finalizer_entries (CopyOrMarkObjectFunc copy_func, FinalizeReadyEntry *list, GrayQueue *queue)
1735 FinalizeReadyEntry *fin;
1737 for (fin = list; fin; fin = fin->next) {
1740 SGEN_LOG (5, "Scan of fin ready object: %p (%s)\n", fin->object, safe_name (fin->object));
1741 copy_func (&fin->object, queue);
1746 generation_name (int generation)
1748 switch (generation) {
1749 case GENERATION_NURSERY: return "nursery";
1750 case GENERATION_OLD: return "old";
1751 default: g_assert_not_reached ();
1756 sgen_generation_name (int generation)
1758 return generation_name (generation);
1761 SgenObjectOperations *
1762 sgen_get_current_object_ops (void){
1763 return ¤t_object_ops;
1768 finish_gray_stack (char *start_addr, char *end_addr, int generation, GrayQueue *queue)
1772 int done_with_ephemerons, ephemeron_rounds = 0;
1773 CopyOrMarkObjectFunc copy_func = current_object_ops.copy_or_mark_object;
1774 ScanObjectFunc scan_func = current_object_ops.scan_object;
1777 * We copied all the reachable objects. Now it's the time to copy
1778 * the objects that were not referenced by the roots, but by the copied objects.
1779 * we built a stack of objects pointed to by gray_start: they are
1780 * additional roots and we may add more items as we go.
1781 * We loop until gray_start == gray_objects which means no more objects have
1782 * been added. Note this is iterative: no recursion is involved.
1783 * We need to walk the LO list as well in search of marked big objects
1784 * (use a flag since this is needed only on major collections). We need to loop
1785 * here as well, so keep a counter of marked LO (increasing it in copy_object).
1786 * To achieve better cache locality and cache usage, we drain the gray stack
1787 * frequently, after each object is copied, and just finish the work here.
1789 sgen_drain_gray_stack (queue, scan_func, -1);
1791 SGEN_LOG (2, "%s generation done", generation_name (generation));
1794 Reset bridge data, we might have lingering data from a previous collection if this is a major
1795 collection trigged by minor overflow.
1797 We must reset the gathered bridges since their original block might be evacuated due to major
1798 fragmentation in the meanwhile and the bridge code should not have to deal with that.
1800 sgen_bridge_reset_data ();
1803 * Walk the ephemeron tables marking all values with reachable keys. This must be completely done
1804 * before processing finalizable objects or non-tracking weak hamdle to avoid finalizing/clearing
1805 * objects that are in fact reachable.
1807 done_with_ephemerons = 0;
1809 done_with_ephemerons = mark_ephemerons_in_range (copy_func, start_addr, end_addr, queue);
1810 sgen_drain_gray_stack (queue, scan_func, -1);
1812 } while (!done_with_ephemerons);
1814 sgen_scan_togglerefs (copy_func, start_addr, end_addr, queue);
1815 if (generation == GENERATION_OLD)
1816 sgen_scan_togglerefs (copy_func, sgen_get_nursery_start (), sgen_get_nursery_end (), queue);
1818 if (sgen_need_bridge_processing ()) {
1819 sgen_collect_bridge_objects (copy_func, start_addr, end_addr, generation, queue);
1820 if (generation == GENERATION_OLD)
1821 sgen_collect_bridge_objects (copy_func, sgen_get_nursery_start (), sgen_get_nursery_end (), GENERATION_NURSERY, queue);
1825 Make sure we drain the gray stack before processing disappearing links and finalizers.
1826 If we don't make sure it is empty we might wrongly see a live object as dead.
1828 sgen_drain_gray_stack (queue, scan_func, -1);
1831 We must clear weak links that don't track resurrection before processing object ready for
1832 finalization so they can be cleared before that.
1834 sgen_null_link_in_range (copy_func, start_addr, end_addr, generation, TRUE, queue);
1835 if (generation == GENERATION_OLD)
1836 sgen_null_link_in_range (copy_func, start_addr, end_addr, GENERATION_NURSERY, TRUE, queue);
1839 /* walk the finalization queue and move also the objects that need to be
1840 * finalized: use the finalized objects as new roots so the objects they depend
1841 * on are also not reclaimed. As with the roots above, only objects in the nursery
1842 * are marked/copied.
1844 sgen_finalize_in_range (copy_func, start_addr, end_addr, generation, queue);
1845 if (generation == GENERATION_OLD)
1846 sgen_finalize_in_range (copy_func, sgen_get_nursery_start (), sgen_get_nursery_end (), GENERATION_NURSERY, queue);
1847 /* drain the new stack that might have been created */
1848 SGEN_LOG (6, "Precise scan of gray area post fin");
1849 sgen_drain_gray_stack (queue, scan_func, -1);
1852 * This must be done again after processing finalizable objects since CWL slots are cleared only after the key is finalized.
1854 done_with_ephemerons = 0;
1856 done_with_ephemerons = mark_ephemerons_in_range (copy_func, start_addr, end_addr, queue);
1857 sgen_drain_gray_stack (queue, scan_func, -1);
1859 } while (!done_with_ephemerons);
1862 * Clear ephemeron pairs with unreachable keys.
1863 * We pass the copy func so we can figure out if an array was promoted or not.
1865 clear_unreachable_ephemerons (copy_func, start_addr, end_addr, queue);
1868 SGEN_LOG (2, "Finalize queue handling scan for %s generation: %d usecs %d ephemeron rounds", generation_name (generation), TV_ELAPSED (atv, btv), ephemeron_rounds);
1871 * handle disappearing links
1872 * Note we do this after checking the finalization queue because if an object
1873 * survives (at least long enough to be finalized) we don't clear the link.
1874 * This also deals with a possible issue with the monitor reclamation: with the Boehm
1875 * GC a finalized object my lose the monitor because it is cleared before the finalizer is
1878 g_assert (sgen_gray_object_queue_is_empty (queue));
1880 sgen_null_link_in_range (copy_func, start_addr, end_addr, generation, FALSE, queue);
1881 if (generation == GENERATION_OLD)
1882 sgen_null_link_in_range (copy_func, start_addr, end_addr, GENERATION_NURSERY, FALSE, queue);
1883 if (sgen_gray_object_queue_is_empty (queue))
1885 sgen_drain_gray_stack (queue, scan_func, -1);
1888 g_assert (sgen_gray_object_queue_is_empty (queue));
1892 sgen_check_section_scan_starts (GCMemSection *section)
1895 for (i = 0; i < section->num_scan_start; ++i) {
1896 if (section->scan_starts [i]) {
1897 guint size = safe_object_get_size ((MonoObject*) section->scan_starts [i]);
1898 g_assert (size >= sizeof (MonoObject) && size <= MAX_SMALL_OBJ_SIZE);
1904 check_scan_starts (void)
1906 if (!do_scan_starts_check)
1908 sgen_check_section_scan_starts (nursery_section);
1909 major_collector.check_scan_starts ();
1913 scan_from_registered_roots (CopyOrMarkObjectFunc copy_func, ScanObjectFunc scan_func, char *addr_start, char *addr_end, int root_type, GrayQueue *queue)
1917 SGEN_HASH_TABLE_FOREACH (&roots_hash [root_type], start_root, root) {
1918 SGEN_LOG (6, "Precise root scan %p-%p (desc: %p)", start_root, root->end_root, (void*)root->root_desc);
1919 precisely_scan_objects_from (copy_func, scan_func, start_root, (void**)root->end_root, addr_start, addr_end, root->root_desc, queue);
1920 } SGEN_HASH_TABLE_FOREACH_END;
1924 sgen_dump_occupied (char *start, char *end, char *section_start)
1926 fprintf (heap_dump_file, "<occupied offset=\"%td\" size=\"%td\"/>\n", start - section_start, end - start);
1930 sgen_dump_section (GCMemSection *section, const char *type)
1932 char *start = section->data;
1933 char *end = section->data + section->size;
1934 char *occ_start = NULL;
1936 char *old_start = NULL; /* just for debugging */
1938 fprintf (heap_dump_file, "<section type=\"%s\" size=\"%lu\">\n", type, (unsigned long)section->size);
1940 while (start < end) {
1944 if (!*(void**)start) {
1946 sgen_dump_occupied (occ_start, start, section->data);
1949 start += sizeof (void*); /* should be ALLOC_ALIGN, really */
1952 g_assert (start < section->next_data);
1957 vt = (GCVTable*)LOAD_VTABLE (start);
1960 size = ALIGN_UP (safe_object_get_size ((MonoObject*) start));
1963 fprintf (heap_dump_file, "<object offset=\"%d\" class=\"%s.%s\" size=\"%d\"/>\n",
1964 start - section->data,
1965 vt->klass->name_space, vt->klass->name,
1973 sgen_dump_occupied (occ_start, start, section->data);
1975 fprintf (heap_dump_file, "</section>\n");
1979 dump_object (MonoObject *obj, gboolean dump_location)
1981 static char class_name [1024];
1983 MonoClass *class = mono_object_class (obj);
1987 * Python's XML parser is too stupid to parse angle brackets
1988 * in strings, so we just ignore them;
1991 while (class->name [i] && j < sizeof (class_name) - 1) {
1992 if (!strchr ("<>\"", class->name [i]))
1993 class_name [j++] = class->name [i];
1996 g_assert (j < sizeof (class_name));
1999 fprintf (heap_dump_file, "<object class=\"%s.%s\" size=\"%d\"",
2000 class->name_space, class_name,
2001 safe_object_get_size (obj));
2002 if (dump_location) {
2003 const char *location;
2004 if (ptr_in_nursery (obj))
2005 location = "nursery";
2006 else if (safe_object_get_size (obj) <= MAX_SMALL_OBJ_SIZE)
2010 fprintf (heap_dump_file, " location=\"%s\"", location);
2012 fprintf (heap_dump_file, "/>\n");
2016 dump_heap (const char *type, int num, const char *reason)
2021 fprintf (heap_dump_file, "<collection type=\"%s\" num=\"%d\"", type, num);
2023 fprintf (heap_dump_file, " reason=\"%s\"", reason);
2024 fprintf (heap_dump_file, ">\n");
2025 fprintf (heap_dump_file, "<other-mem-usage type=\"mempools\" size=\"%ld\"/>\n", mono_mempool_get_bytes_allocated ());
2026 sgen_dump_internal_mem_usage (heap_dump_file);
2027 fprintf (heap_dump_file, "<pinned type=\"stack\" bytes=\"%zu\"/>\n", sgen_pin_stats_get_pinned_byte_count (PIN_TYPE_STACK));
2028 /* fprintf (heap_dump_file, "<pinned type=\"static-data\" bytes=\"%d\"/>\n", pinned_byte_counts [PIN_TYPE_STATIC_DATA]); */
2029 fprintf (heap_dump_file, "<pinned type=\"other\" bytes=\"%zu\"/>\n", sgen_pin_stats_get_pinned_byte_count (PIN_TYPE_OTHER));
2031 fprintf (heap_dump_file, "<pinned-objects>\n");
2032 for (list = sgen_pin_stats_get_object_list (); list; list = list->next)
2033 dump_object (list->obj, TRUE);
2034 fprintf (heap_dump_file, "</pinned-objects>\n");
2036 sgen_dump_section (nursery_section, "nursery");
2038 major_collector.dump_heap (heap_dump_file);
2040 fprintf (heap_dump_file, "<los>\n");
2041 for (bigobj = los_object_list; bigobj; bigobj = bigobj->next)
2042 dump_object ((MonoObject*)bigobj->data, FALSE);
2043 fprintf (heap_dump_file, "</los>\n");
2045 fprintf (heap_dump_file, "</collection>\n");
2049 sgen_register_moved_object (void *obj, void *destination)
2051 g_assert (mono_profiler_events & MONO_PROFILE_GC_MOVES);
2053 /* FIXME: handle this for parallel collector */
2054 g_assert (!sgen_collection_is_parallel ());
2056 if (moved_objects_idx == MOVED_OBJECTS_NUM) {
2057 mono_profiler_gc_moves (moved_objects, moved_objects_idx);
2058 moved_objects_idx = 0;
2060 moved_objects [moved_objects_idx++] = obj;
2061 moved_objects [moved_objects_idx++] = destination;
2067 static gboolean inited = FALSE;
2072 mono_counters_register ("Minor fragment clear", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_minor_pre_collection_fragment_clear);
2073 mono_counters_register ("Minor pinning", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_minor_pinning);
2074 mono_counters_register ("Minor scan remembered set", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_minor_scan_remsets);
2075 mono_counters_register ("Minor scan pinned", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_minor_scan_pinned);
2076 mono_counters_register ("Minor scan registered roots", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_minor_scan_registered_roots);
2077 mono_counters_register ("Minor scan thread data", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_minor_scan_thread_data);
2078 mono_counters_register ("Minor finish gray stack", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_minor_finish_gray_stack);
2079 mono_counters_register ("Minor fragment creation", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_minor_fragment_creation);
2081 mono_counters_register ("Major fragment clear", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_major_pre_collection_fragment_clear);
2082 mono_counters_register ("Major pinning", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_major_pinning);
2083 mono_counters_register ("Major scan pinned", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_major_scan_pinned);
2084 mono_counters_register ("Major scan registered roots", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_major_scan_registered_roots);
2085 mono_counters_register ("Major scan thread data", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_major_scan_thread_data);
2086 mono_counters_register ("Major scan alloc_pinned", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_major_scan_alloc_pinned);
2087 mono_counters_register ("Major scan finalized", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_major_scan_finalized);
2088 mono_counters_register ("Major scan big objects", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_major_scan_big_objects);
2089 mono_counters_register ("Major finish gray stack", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_major_finish_gray_stack);
2090 mono_counters_register ("Major free big objects", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_major_free_bigobjs);
2091 mono_counters_register ("Major LOS sweep", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_major_los_sweep);
2092 mono_counters_register ("Major sweep", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_major_sweep);
2093 mono_counters_register ("Major fragment creation", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_major_fragment_creation);
2095 mono_counters_register ("Number of pinned objects", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_pinned_objects);
2097 #ifdef HEAVY_STATISTICS
2098 mono_counters_register ("WBarrier set field", MONO_COUNTER_GC | MONO_COUNTER_INT, &stat_wbarrier_set_field);
2099 mono_counters_register ("WBarrier set arrayref", MONO_COUNTER_GC | MONO_COUNTER_INT, &stat_wbarrier_set_arrayref);
2100 mono_counters_register ("WBarrier arrayref copy", MONO_COUNTER_GC | MONO_COUNTER_INT, &stat_wbarrier_arrayref_copy);
2101 mono_counters_register ("WBarrier generic store called", MONO_COUNTER_GC | MONO_COUNTER_INT, &stat_wbarrier_generic_store);
2102 mono_counters_register ("WBarrier set root", MONO_COUNTER_GC | MONO_COUNTER_INT, &stat_wbarrier_set_root);
2103 mono_counters_register ("WBarrier value copy", MONO_COUNTER_GC | MONO_COUNTER_INT, &stat_wbarrier_value_copy);
2104 mono_counters_register ("WBarrier object copy", MONO_COUNTER_GC | MONO_COUNTER_INT, &stat_wbarrier_object_copy);
2106 mono_counters_register ("# objects allocated degraded", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_objects_alloced_degraded);
2107 mono_counters_register ("bytes allocated degraded", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_bytes_alloced_degraded);
2109 mono_counters_register ("# copy_object() called (nursery)", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_copy_object_called_nursery);
2110 mono_counters_register ("# objects copied (nursery)", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_objects_copied_nursery);
2111 mono_counters_register ("# copy_object() called (major)", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_copy_object_called_major);
2112 mono_counters_register ("# objects copied (major)", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_objects_copied_major);
2114 mono_counters_register ("# scan_object() called (nursery)", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_scan_object_called_nursery);
2115 mono_counters_register ("# scan_object() called (major)", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_scan_object_called_major);
2117 mono_counters_register ("Slots allocated in vain", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_slots_allocated_in_vain);
2119 mono_counters_register ("# nursery copy_object() failed from space", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_nursery_copy_object_failed_from_space);
2120 mono_counters_register ("# nursery copy_object() failed forwarded", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_nursery_copy_object_failed_forwarded);
2121 mono_counters_register ("# nursery copy_object() failed pinned", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_nursery_copy_object_failed_pinned);
2122 mono_counters_register ("# nursery copy_object() failed to space", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_nursery_copy_object_failed_to_space);
2124 sgen_nursery_allocator_init_heavy_stats ();
2125 sgen_alloc_init_heavy_stats ();
2133 reset_pinned_from_failed_allocation (void)
2135 bytes_pinned_from_failed_allocation = 0;
2139 sgen_set_pinned_from_failed_allocation (mword objsize)
2141 bytes_pinned_from_failed_allocation += objsize;
2145 sgen_collection_is_parallel (void)
2147 switch (current_collection_generation) {
2148 case GENERATION_NURSERY:
2149 return nursery_collection_is_parallel;
2150 case GENERATION_OLD:
2151 return major_collector.is_parallel;
2153 g_error ("Invalid current generation %d", current_collection_generation);
2158 sgen_collection_is_concurrent (void)
2160 switch (current_collection_generation) {
2161 case GENERATION_NURSERY:
2163 case GENERATION_OLD:
2164 return major_collector.is_concurrent;
2166 g_error ("Invalid current generation %d", current_collection_generation);
2171 sgen_concurrent_collection_in_progress (void)
2173 return concurrent_collection_in_progress;
2180 } FinishRememberedSetScanJobData;
2183 job_finish_remembered_set_scan (WorkerData *worker_data, void *job_data_untyped)
2185 FinishRememberedSetScanJobData *job_data = job_data_untyped;
2187 remset.finish_scan_remsets (job_data->heap_start, job_data->heap_end, sgen_workers_get_job_gray_queue (worker_data));
2188 sgen_free_internal_dynamic (job_data, sizeof (FinishRememberedSetScanJobData), INTERNAL_MEM_WORKER_JOB_DATA);
2193 CopyOrMarkObjectFunc copy_or_mark_func;
2194 ScanObjectFunc scan_func;
2198 } ScanFromRegisteredRootsJobData;
2201 job_scan_from_registered_roots (WorkerData *worker_data, void *job_data_untyped)
2203 ScanFromRegisteredRootsJobData *job_data = job_data_untyped;
2205 scan_from_registered_roots (job_data->copy_or_mark_func, job_data->scan_func,
2206 job_data->heap_start, job_data->heap_end,
2207 job_data->root_type,
2208 sgen_workers_get_job_gray_queue (worker_data));
2209 sgen_free_internal_dynamic (job_data, sizeof (ScanFromRegisteredRootsJobData), INTERNAL_MEM_WORKER_JOB_DATA);
2216 } ScanThreadDataJobData;
2219 job_scan_thread_data (WorkerData *worker_data, void *job_data_untyped)
2221 ScanThreadDataJobData *job_data = job_data_untyped;
2223 scan_thread_data (job_data->heap_start, job_data->heap_end, TRUE,
2224 sgen_workers_get_job_gray_queue (worker_data));
2225 sgen_free_internal_dynamic (job_data, sizeof (ScanThreadDataJobData), INTERNAL_MEM_WORKER_JOB_DATA);
2230 FinalizeReadyEntry *list;
2231 } ScanFinalizerEntriesJobData;
2234 job_scan_finalizer_entries (WorkerData *worker_data, void *job_data_untyped)
2236 ScanFinalizerEntriesJobData *job_data = job_data_untyped;
2238 scan_finalizer_entries (current_object_ops.copy_or_mark_object,
2240 sgen_workers_get_job_gray_queue (worker_data));
2241 sgen_free_internal_dynamic (job_data, sizeof (ScanFinalizerEntriesJobData), INTERNAL_MEM_WORKER_JOB_DATA);
2245 job_scan_major_mod_union_cardtable (WorkerData *worker_data, void *job_data_untyped)
2247 g_assert (concurrent_collection_in_progress);
2248 major_collector.scan_card_table (TRUE, sgen_workers_get_job_gray_queue (worker_data));
2252 job_scan_los_mod_union_cardtable (WorkerData *worker_data, void *job_data_untyped)
2254 g_assert (concurrent_collection_in_progress);
2255 sgen_los_scan_card_table (TRUE, sgen_workers_get_job_gray_queue (worker_data));
2259 verify_scan_starts (char *start, char *end)
2263 for (i = 0; i < nursery_section->num_scan_start; ++i) {
2264 char *addr = nursery_section->scan_starts [i];
2265 if (addr > start && addr < end)
2266 SGEN_LOG (1, "NFC-BAD SCAN START [%d] %p for obj [%p %p]", i, addr, start, end);
2271 verify_nursery (void)
2273 char *start, *end, *cur, *hole_start;
2275 if (!do_verify_nursery)
2278 /*This cleans up unused fragments */
2279 sgen_nursery_allocator_prepare_for_pinning ();
2281 hole_start = start = cur = sgen_get_nursery_start ();
2282 end = sgen_get_nursery_end ();
2287 if (!*(void**)cur) {
2288 cur += sizeof (void*);
2292 if (object_is_forwarded (cur))
2293 SGEN_LOG (1, "FORWARDED OBJ %p", cur);
2294 else if (object_is_pinned (cur))
2295 SGEN_LOG (1, "PINNED OBJ %p", cur);
2297 ss = safe_object_get_size ((MonoObject*)cur);
2298 size = ALIGN_UP (safe_object_get_size ((MonoObject*)cur));
2299 verify_scan_starts (cur, cur + size);
2300 if (do_dump_nursery_content) {
2301 if (cur > hole_start)
2302 SGEN_LOG (1, "HOLE [%p %p %d]", hole_start, cur, (int)(cur - hole_start));
2303 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 ());
2311 * Checks that no objects in the nursery are fowarded or pinned. This
2312 * is a precondition to restarting the mutator while doing a
2313 * concurrent collection. Note that we don't clear fragments because
2314 * we depend on that having happened earlier.
2317 check_nursery_is_clean (void)
2319 char *start, *end, *cur;
2321 start = cur = sgen_get_nursery_start ();
2322 end = sgen_get_nursery_end ();
2327 if (!*(void**)cur) {
2328 cur += sizeof (void*);
2332 g_assert (!object_is_forwarded (cur));
2333 g_assert (!object_is_pinned (cur));
2335 ss = safe_object_get_size ((MonoObject*)cur);
2336 size = ALIGN_UP (safe_object_get_size ((MonoObject*)cur));
2337 verify_scan_starts (cur, cur + size);
2344 init_gray_queue (void)
2346 if (sgen_collection_is_parallel () || sgen_collection_is_concurrent ()) {
2347 sgen_gray_object_queue_init_invalid (&gray_queue);
2348 sgen_workers_init_distribute_gray_queue ();
2350 sgen_gray_object_queue_init (&gray_queue);
2355 * Collect objects in the nursery. Returns whether to trigger a major
2359 collect_nursery (void)
2361 gboolean needs_major;
2362 size_t max_garbage_amount;
2364 FinishRememberedSetScanJobData *frssjd;
2365 ScanFromRegisteredRootsJobData *scrrjd_normal, *scrrjd_wbarrier;
2366 ScanFinalizerEntriesJobData *sfejd_fin_ready, *sfejd_critical_fin;
2367 ScanThreadDataJobData *stdjd;
2368 mword fragment_total;
2369 TV_DECLARE (all_atv);
2370 TV_DECLARE (all_btv);
2374 if (disable_minor_collections)
2377 MONO_GC_BEGIN (GENERATION_NURSERY);
2381 #ifndef DISABLE_PERFCOUNTERS
2382 mono_perfcounters->gc_collections0++;
2385 current_collection_generation = GENERATION_NURSERY;
2386 if (sgen_collection_is_parallel ())
2387 current_object_ops = sgen_minor_collector.parallel_ops;
2389 current_object_ops = sgen_minor_collector.serial_ops;
2391 reset_pinned_from_failed_allocation ();
2393 binary_protocol_collection (stat_minor_gcs, GENERATION_NURSERY);
2394 check_scan_starts ();
2396 sgen_nursery_alloc_prepare_for_minor ();
2400 nursery_next = sgen_nursery_alloc_get_upper_alloc_bound ();
2401 /* FIXME: optimize later to use the higher address where an object can be present */
2402 nursery_next = MAX (nursery_next, sgen_get_nursery_end ());
2404 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 ()));
2405 max_garbage_amount = nursery_next - sgen_get_nursery_start ();
2406 g_assert (nursery_section->size >= max_garbage_amount);
2408 /* world must be stopped already */
2409 TV_GETTIME (all_atv);
2413 time_minor_pre_collection_fragment_clear += TV_ELAPSED (atv, btv);
2415 if (xdomain_checks) {
2416 sgen_clear_nursery_fragments ();
2417 check_for_xdomain_refs ();
2420 nursery_section->next_data = nursery_next;
2422 major_collector.start_nursery_collection ();
2424 sgen_memgov_minor_collection_start ();
2429 gc_stats.minor_gc_count ++;
2431 if (remset.prepare_for_minor_collection)
2432 remset.prepare_for_minor_collection ();
2434 sgen_process_fin_stage_entries ();
2435 sgen_process_dislink_stage_entries ();
2437 /* pin from pinned handles */
2438 sgen_init_pinning ();
2439 mono_profiler_gc_event (MONO_GC_EVENT_MARK_START, 0);
2440 pin_from_roots (sgen_get_nursery_start (), nursery_next, WORKERS_DISTRIBUTE_GRAY_QUEUE);
2441 /* identify pinned objects */
2442 sgen_optimize_pin_queue (0);
2443 sgen_pinning_setup_section (nursery_section);
2444 sgen_pin_objects_in_section (nursery_section, WORKERS_DISTRIBUTE_GRAY_QUEUE, FALSE);
2445 sgen_pinning_trim_queue_to_section (nursery_section);
2448 time_minor_pinning += TV_ELAPSED (btv, atv);
2449 SGEN_LOG (2, "Finding pinned pointers: %d in %d usecs", sgen_get_pinned_count (), TV_ELAPSED (btv, atv));
2450 SGEN_LOG (4, "Start scan with %d pinned objects", sgen_get_pinned_count ());
2452 if (whole_heap_check_before_collection)
2453 sgen_check_whole_heap ();
2454 if (consistency_check_at_minor_collection)
2455 sgen_check_consistency ();
2457 sgen_workers_start_all_workers ();
2460 * Perform the sequential part of remembered set scanning.
2461 * This usually involves scanning global information that might later be produced by evacuation.
2463 if (remset.begin_scan_remsets)
2464 remset.begin_scan_remsets (sgen_get_nursery_start (), nursery_next, WORKERS_DISTRIBUTE_GRAY_QUEUE);
2466 sgen_workers_start_marking ();
2468 frssjd = sgen_alloc_internal_dynamic (sizeof (FinishRememberedSetScanJobData), INTERNAL_MEM_WORKER_JOB_DATA, TRUE);
2469 frssjd->heap_start = sgen_get_nursery_start ();
2470 frssjd->heap_end = nursery_next;
2471 sgen_workers_enqueue_job (job_finish_remembered_set_scan, frssjd);
2473 /* we don't have complete write barrier yet, so we scan all the old generation sections */
2475 time_minor_scan_remsets += TV_ELAPSED (atv, btv);
2476 SGEN_LOG (2, "Old generation scan: %d usecs", TV_ELAPSED (atv, btv));
2478 if (!sgen_collection_is_parallel ())
2479 sgen_drain_gray_stack (&gray_queue, current_object_ops.scan_object, -1);
2481 if (mono_profiler_get_events () & MONO_PROFILE_GC_ROOTS)
2482 report_registered_roots ();
2483 if (mono_profiler_get_events () & MONO_PROFILE_GC_ROOTS)
2484 report_finalizer_roots ();
2486 time_minor_scan_pinned += TV_ELAPSED (btv, atv);
2488 /* registered roots, this includes static fields */
2489 scrrjd_normal = sgen_alloc_internal_dynamic (sizeof (ScanFromRegisteredRootsJobData), INTERNAL_MEM_WORKER_JOB_DATA, TRUE);
2490 scrrjd_normal->copy_or_mark_func = current_object_ops.copy_or_mark_object;
2491 scrrjd_normal->scan_func = current_object_ops.scan_object;
2492 scrrjd_normal->heap_start = sgen_get_nursery_start ();
2493 scrrjd_normal->heap_end = nursery_next;
2494 scrrjd_normal->root_type = ROOT_TYPE_NORMAL;
2495 sgen_workers_enqueue_job (job_scan_from_registered_roots, scrrjd_normal);
2497 scrrjd_wbarrier = sgen_alloc_internal_dynamic (sizeof (ScanFromRegisteredRootsJobData), INTERNAL_MEM_WORKER_JOB_DATA, TRUE);
2498 scrrjd_wbarrier->copy_or_mark_func = current_object_ops.copy_or_mark_object;
2499 scrrjd_wbarrier->scan_func = current_object_ops.scan_object;
2500 scrrjd_wbarrier->heap_start = sgen_get_nursery_start ();
2501 scrrjd_wbarrier->heap_end = nursery_next;
2502 scrrjd_wbarrier->root_type = ROOT_TYPE_WBARRIER;
2503 sgen_workers_enqueue_job (job_scan_from_registered_roots, scrrjd_wbarrier);
2506 time_minor_scan_registered_roots += TV_ELAPSED (atv, btv);
2509 stdjd = sgen_alloc_internal_dynamic (sizeof (ScanThreadDataJobData), INTERNAL_MEM_WORKER_JOB_DATA, TRUE);
2510 stdjd->heap_start = sgen_get_nursery_start ();
2511 stdjd->heap_end = nursery_next;
2512 sgen_workers_enqueue_job (job_scan_thread_data, stdjd);
2515 time_minor_scan_thread_data += TV_ELAPSED (btv, atv);
2518 if (sgen_collection_is_parallel () || sgen_collection_is_concurrent ()) {
2519 while (!sgen_gray_object_queue_is_empty (WORKERS_DISTRIBUTE_GRAY_QUEUE)) {
2520 sgen_workers_distribute_gray_queue_sections ();
2524 sgen_workers_join ();
2526 if (sgen_collection_is_parallel () || sgen_collection_is_concurrent ())
2527 g_assert (sgen_gray_object_queue_is_empty (&gray_queue));
2529 /* Scan the list of objects ready for finalization. If */
2530 sfejd_fin_ready = sgen_alloc_internal_dynamic (sizeof (ScanFinalizerEntriesJobData), INTERNAL_MEM_WORKER_JOB_DATA, TRUE);
2531 sfejd_fin_ready->list = fin_ready_list;
2532 sgen_workers_enqueue_job (job_scan_finalizer_entries, sfejd_fin_ready);
2534 sfejd_critical_fin = sgen_alloc_internal_dynamic (sizeof (ScanFinalizerEntriesJobData), INTERNAL_MEM_WORKER_JOB_DATA, TRUE);
2535 sfejd_critical_fin->list = critical_fin_list;
2536 sgen_workers_enqueue_job (job_scan_finalizer_entries, sfejd_critical_fin);
2538 finish_gray_stack (sgen_get_nursery_start (), nursery_next, GENERATION_NURSERY, &gray_queue);
2540 time_minor_finish_gray_stack += TV_ELAPSED (btv, atv);
2541 mono_profiler_gc_event (MONO_GC_EVENT_MARK_END, 0);
2544 * The (single-threaded) finalization code might have done
2545 * some copying/marking so we can only reset the GC thread's
2546 * worker data here instead of earlier when we joined the
2549 sgen_workers_reset_data ();
2551 if (objects_pinned) {
2552 sgen_optimize_pin_queue (0);
2553 sgen_pinning_setup_section (nursery_section);
2556 /* walk the pin_queue, build up the fragment list of free memory, unmark
2557 * pinned objects as we go, memzero() the empty fragments so they are ready for the
2560 mono_profiler_gc_event (MONO_GC_EVENT_RECLAIM_START, 0);
2561 fragment_total = sgen_build_nursery_fragments (nursery_section, nursery_section->pin_queue_start, nursery_section->pin_queue_num_entries);
2562 if (!fragment_total)
2565 /* Clear TLABs for all threads */
2566 sgen_clear_tlabs ();
2568 mono_profiler_gc_event (MONO_GC_EVENT_RECLAIM_END, 0);
2570 time_minor_fragment_creation += TV_ELAPSED (atv, btv);
2571 SGEN_LOG (2, "Fragment creation: %d usecs, %lu bytes available", TV_ELAPSED (atv, btv), (unsigned long)fragment_total);
2573 if (consistency_check_at_minor_collection)
2574 sgen_check_major_refs ();
2576 major_collector.finish_nursery_collection ();
2578 TV_GETTIME (all_btv);
2579 gc_stats.minor_gc_time_usecs += TV_ELAPSED (all_atv, all_btv);
2582 dump_heap ("minor", stat_minor_gcs - 1, NULL);
2584 /* prepare the pin queue for the next collection */
2585 sgen_finish_pinning ();
2586 if (fin_ready_list || critical_fin_list) {
2587 SGEN_LOG (4, "Finalizer-thread wakeup: ready %d", num_ready_finalizers);
2588 mono_gc_finalize_notify ();
2590 sgen_pin_stats_reset ();
2592 g_assert (sgen_gray_object_queue_is_empty (&gray_queue));
2594 if (remset.finish_minor_collection)
2595 remset.finish_minor_collection ();
2597 check_scan_starts ();
2599 binary_protocol_flush_buffers (FALSE);
2601 sgen_memgov_minor_collection_end ();
2603 /*objects are late pinned because of lack of memory, so a major is a good call*/
2604 needs_major = objects_pinned > 0;
2605 current_collection_generation = -1;
2608 MONO_GC_END (GENERATION_NURSERY);
2614 major_copy_or_mark_from_roots (int *old_next_pin_slot, gboolean finish_up_concurrent_mark)
2619 /* FIXME: only use these values for the precise scan
2620 * note that to_space pointers should be excluded anyway...
2622 char *heap_start = NULL;
2623 char *heap_end = (char*)-1;
2624 gboolean profile_roots = mono_profiler_get_events () & MONO_PROFILE_GC_ROOTS;
2625 GCRootReport root_report = { 0 };
2626 ScanFromRegisteredRootsJobData *scrrjd_normal, *scrrjd_wbarrier;
2627 ScanThreadDataJobData *stdjd;
2628 ScanFinalizerEntriesJobData *sfejd_fin_ready, *sfejd_critical_fin;
2630 if (major_collector.is_concurrent) {
2631 /*This cleans up unused fragments */
2632 sgen_nursery_allocator_prepare_for_pinning ();
2634 check_nursery_is_clean ();
2636 /* The concurrent collector doesn't touch the nursery. */
2637 sgen_nursery_alloc_prepare_for_major ();
2644 /* Pinning depends on this */
2645 sgen_clear_nursery_fragments ();
2647 if (whole_heap_check_before_collection)
2648 sgen_check_whole_heap ();
2651 time_major_pre_collection_fragment_clear += TV_ELAPSED (atv, btv);
2653 if (!sgen_collection_is_concurrent ())
2654 nursery_section->next_data = sgen_get_nursery_end ();
2655 /* we should also coalesce scanning from sections close to each other
2656 * and deal with pointers outside of the sections later.
2660 *major_collector.have_swept = FALSE;
2662 if (xdomain_checks) {
2663 sgen_clear_nursery_fragments ();
2664 check_for_xdomain_refs ();
2667 if (!finish_up_concurrent_mark) {
2668 /* Remsets are not useful for a major collection */
2669 remset.prepare_for_major_collection ();
2672 sgen_process_fin_stage_entries ();
2673 sgen_process_dislink_stage_entries ();
2676 sgen_init_pinning ();
2677 SGEN_LOG (6, "Collecting pinned addresses");
2678 pin_from_roots ((void*)lowest_heap_address, (void*)highest_heap_address, WORKERS_DISTRIBUTE_GRAY_QUEUE);
2679 sgen_optimize_pin_queue (0);
2682 * pin_queue now contains all candidate pointers, sorted and
2683 * uniqued. We must do two passes now to figure out which
2684 * objects are pinned.
2686 * The first is to find within the pin_queue the area for each
2687 * section. This requires that the pin_queue be sorted. We
2688 * also process the LOS objects and pinned chunks here.
2690 * The second, destructive, pass is to reduce the section
2691 * areas to pointers to the actually pinned objects.
2693 SGEN_LOG (6, "Pinning from sections");
2694 /* first pass for the sections */
2695 sgen_find_section_pin_queue_start_end (nursery_section);
2696 major_collector.find_pin_queue_start_ends (WORKERS_DISTRIBUTE_GRAY_QUEUE);
2697 /* identify possible pointers to the insize of large objects */
2698 SGEN_LOG (6, "Pinning from large objects");
2699 for (bigobj = los_object_list; bigobj; bigobj = bigobj->next) {
2701 if (sgen_find_optimized_pin_queue_area (bigobj->data, (char*)bigobj->data + sgen_los_object_size (bigobj), &dummy)) {
2702 binary_protocol_pin (bigobj->data, (gpointer)LOAD_VTABLE (bigobj->data), safe_object_get_size (((MonoObject*)(bigobj->data))));
2703 if (G_UNLIKELY (MONO_GC_OBJ_PINNED_ENABLED ())) {
2704 MonoVTable *vt = (MonoVTable*)LOAD_VTABLE (bigobj->data);
2705 MONO_GC_OBJ_PINNED ((mword)bigobj->data, sgen_safe_object_get_size ((MonoObject*)bigobj->data), vt->klass->name_space, vt->klass->name, GENERATION_OLD);
2707 if (sgen_los_object_is_pinned (bigobj->data)) {
2708 g_assert (finish_up_concurrent_mark);
2711 sgen_los_pin_object (bigobj->data);
2712 /* FIXME: only enqueue if object has references */
2713 GRAY_OBJECT_ENQUEUE (WORKERS_DISTRIBUTE_GRAY_QUEUE, bigobj->data);
2714 if (G_UNLIKELY (do_pin_stats))
2715 sgen_pin_stats_register_object ((char*) bigobj->data, safe_object_get_size ((MonoObject*) bigobj->data));
2716 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));
2719 add_profile_gc_root (&root_report, bigobj->data, MONO_PROFILE_GC_ROOT_PINNING | MONO_PROFILE_GC_ROOT_MISC, 0);
2723 notify_gc_roots (&root_report);
2724 /* second pass for the sections */
2725 sgen_pin_objects_in_section (nursery_section, WORKERS_DISTRIBUTE_GRAY_QUEUE, concurrent_collection_in_progress);
2726 major_collector.pin_objects (WORKERS_DISTRIBUTE_GRAY_QUEUE);
2727 if (old_next_pin_slot)
2728 *old_next_pin_slot = sgen_get_pinned_count ();
2731 time_major_pinning += TV_ELAPSED (atv, btv);
2732 SGEN_LOG (2, "Finding pinned pointers: %d in %d usecs", sgen_get_pinned_count (), TV_ELAPSED (atv, btv));
2733 SGEN_LOG (4, "Start scan with %d pinned objects", sgen_get_pinned_count ());
2735 major_collector.init_to_space ();
2737 #ifdef SGEN_DEBUG_INTERNAL_ALLOC
2738 main_gc_thread = mono_native_thread_self ();
2741 sgen_workers_start_all_workers ();
2742 sgen_workers_start_marking ();
2744 if (mono_profiler_get_events () & MONO_PROFILE_GC_ROOTS)
2745 report_registered_roots ();
2747 time_major_scan_pinned += TV_ELAPSED (btv, atv);
2749 /* registered roots, this includes static fields */
2750 scrrjd_normal = sgen_alloc_internal_dynamic (sizeof (ScanFromRegisteredRootsJobData), INTERNAL_MEM_WORKER_JOB_DATA, TRUE);
2751 scrrjd_normal->copy_or_mark_func = current_object_ops.copy_or_mark_object;
2752 scrrjd_normal->scan_func = current_object_ops.scan_object;
2753 scrrjd_normal->heap_start = heap_start;
2754 scrrjd_normal->heap_end = heap_end;
2755 scrrjd_normal->root_type = ROOT_TYPE_NORMAL;
2756 sgen_workers_enqueue_job (job_scan_from_registered_roots, scrrjd_normal);
2758 scrrjd_wbarrier = sgen_alloc_internal_dynamic (sizeof (ScanFromRegisteredRootsJobData), INTERNAL_MEM_WORKER_JOB_DATA, TRUE);
2759 scrrjd_wbarrier->copy_or_mark_func = current_object_ops.copy_or_mark_object;
2760 scrrjd_wbarrier->scan_func = current_object_ops.scan_object;
2761 scrrjd_wbarrier->heap_start = heap_start;
2762 scrrjd_wbarrier->heap_end = heap_end;
2763 scrrjd_wbarrier->root_type = ROOT_TYPE_WBARRIER;
2764 sgen_workers_enqueue_job (job_scan_from_registered_roots, scrrjd_wbarrier);
2767 time_major_scan_registered_roots += TV_ELAPSED (atv, btv);
2770 stdjd = sgen_alloc_internal_dynamic (sizeof (ScanThreadDataJobData), INTERNAL_MEM_WORKER_JOB_DATA, TRUE);
2771 stdjd->heap_start = heap_start;
2772 stdjd->heap_end = heap_end;
2773 sgen_workers_enqueue_job (job_scan_thread_data, stdjd);
2776 time_major_scan_thread_data += TV_ELAPSED (btv, atv);
2779 time_major_scan_alloc_pinned += TV_ELAPSED (atv, btv);
2781 if (mono_profiler_get_events () & MONO_PROFILE_GC_ROOTS)
2782 report_finalizer_roots ();
2784 /* scan the list of objects ready for finalization */
2785 sfejd_fin_ready = sgen_alloc_internal_dynamic (sizeof (ScanFinalizerEntriesJobData), INTERNAL_MEM_WORKER_JOB_DATA, TRUE);
2786 sfejd_fin_ready->list = fin_ready_list;
2787 sgen_workers_enqueue_job (job_scan_finalizer_entries, sfejd_fin_ready);
2789 sfejd_critical_fin = sgen_alloc_internal_dynamic (sizeof (ScanFinalizerEntriesJobData), INTERNAL_MEM_WORKER_JOB_DATA, TRUE);
2790 sfejd_critical_fin->list = critical_fin_list;
2791 sgen_workers_enqueue_job (job_scan_finalizer_entries, sfejd_critical_fin);
2793 if (finish_up_concurrent_mark) {
2794 /* Mod union card table */
2795 sgen_workers_enqueue_job (job_scan_major_mod_union_cardtable, NULL);
2796 sgen_workers_enqueue_job (job_scan_los_mod_union_cardtable, NULL);
2800 time_major_scan_finalized += TV_ELAPSED (btv, atv);
2801 SGEN_LOG (2, "Root scan: %d usecs", TV_ELAPSED (btv, atv));
2804 time_major_scan_big_objects += TV_ELAPSED (atv, btv);
2806 if (major_collector.is_concurrent) {
2807 /* prepare the pin queue for the next collection */
2808 sgen_finish_pinning ();
2810 sgen_pin_stats_reset ();
2812 check_nursery_is_clean ();
2817 major_start_collection (int *old_next_pin_slot)
2819 MONO_GC_BEGIN (GENERATION_OLD);
2821 current_collection_generation = GENERATION_OLD;
2822 #ifndef DISABLE_PERFCOUNTERS
2823 mono_perfcounters->gc_collections1++;
2826 if (major_collector.is_concurrent)
2827 concurrent_collection_in_progress = TRUE;
2829 current_object_ops = major_collector.major_ops;
2831 reset_pinned_from_failed_allocation ();
2833 sgen_memgov_major_collection_start ();
2835 //count_ref_nonref_objs ();
2836 //consistency_check ();
2838 binary_protocol_collection (stat_major_gcs, GENERATION_OLD);
2839 check_scan_starts ();
2842 SGEN_LOG (1, "Start major collection %d", stat_major_gcs);
2844 gc_stats.major_gc_count ++;
2846 if (major_collector.start_major_collection)
2847 major_collector.start_major_collection ();
2849 major_copy_or_mark_from_roots (old_next_pin_slot, FALSE);
2853 wait_for_workers_to_finish (void)
2855 if (major_collector.is_parallel || major_collector.is_concurrent) {
2856 while (!sgen_gray_object_queue_is_empty (WORKERS_DISTRIBUTE_GRAY_QUEUE)) {
2857 sgen_workers_distribute_gray_queue_sections ();
2861 sgen_workers_join ();
2863 if (major_collector.is_parallel || major_collector.is_concurrent)
2864 g_assert (sgen_gray_object_queue_is_empty (&gray_queue));
2866 #ifdef SGEN_DEBUG_INTERNAL_ALLOC
2867 main_gc_thread = NULL;
2872 major_finish_collection (const char *reason, int old_next_pin_slot)
2874 LOSObject *bigobj, *prevbo;
2877 char *heap_start = NULL;
2878 char *heap_end = (char*)-1;
2882 wait_for_workers_to_finish ();
2884 current_object_ops = major_collector.major_ops;
2886 if (major_collector.is_concurrent) {
2887 major_collector.update_cardtable_mod_union ();
2888 sgen_los_update_cardtable_mod_union ();
2890 major_copy_or_mark_from_roots (NULL, TRUE);
2891 wait_for_workers_to_finish ();
2893 check_nursery_is_clean ();
2896 /* all the objects in the heap */
2897 finish_gray_stack (heap_start, heap_end, GENERATION_OLD, &gray_queue);
2899 time_major_finish_gray_stack += TV_ELAPSED (btv, atv);
2902 * The (single-threaded) finalization code might have done
2903 * some copying/marking so we can only reset the GC thread's
2904 * worker data here instead of earlier when we joined the
2907 sgen_workers_reset_data ();
2909 if (objects_pinned) {
2910 g_assert (!major_collector.is_concurrent);
2912 /*This is slow, but we just OOM'd*/
2913 sgen_pin_queue_clear_discarded_entries (nursery_section, old_next_pin_slot);
2914 sgen_optimize_pin_queue (0);
2915 sgen_find_section_pin_queue_start_end (nursery_section);
2919 reset_heap_boundaries ();
2920 sgen_update_heap_boundaries ((mword)sgen_get_nursery_start (), (mword)sgen_get_nursery_end ());
2922 /* sweep the big objects list */
2924 for (bigobj = los_object_list; bigobj;) {
2925 g_assert (!object_is_pinned (bigobj->data));
2926 if (sgen_los_object_is_pinned (bigobj->data)) {
2927 sgen_los_unpin_object (bigobj->data);
2928 sgen_update_heap_boundaries ((mword)bigobj->data, (mword)bigobj->data + sgen_los_object_size (bigobj));
2931 /* not referenced anywhere, so we can free it */
2933 prevbo->next = bigobj->next;
2935 los_object_list = bigobj->next;
2937 bigobj = bigobj->next;
2938 sgen_los_free_object (to_free);
2942 bigobj = bigobj->next;
2946 time_major_free_bigobjs += TV_ELAPSED (atv, btv);
2951 time_major_los_sweep += TV_ELAPSED (btv, atv);
2953 major_collector.sweep ();
2956 time_major_sweep += TV_ELAPSED (atv, btv);
2958 if (!major_collector.is_concurrent) {
2959 /* walk the pin_queue, build up the fragment list of free memory, unmark
2960 * pinned objects as we go, memzero() the empty fragments so they are ready for the
2963 if (!sgen_build_nursery_fragments (nursery_section, nursery_section->pin_queue_start, nursery_section->pin_queue_num_entries))
2966 /* prepare the pin queue for the next collection */
2967 sgen_finish_pinning ();
2969 /* Clear TLABs for all threads */
2970 sgen_clear_tlabs ();
2972 sgen_pin_stats_reset ();
2976 time_major_fragment_creation += TV_ELAPSED (btv, atv);
2979 dump_heap ("major", stat_major_gcs - 1, reason);
2981 if (fin_ready_list || critical_fin_list) {
2982 SGEN_LOG (4, "Finalizer-thread wakeup: ready %d", num_ready_finalizers);
2983 mono_gc_finalize_notify ();
2986 g_assert (sgen_gray_object_queue_is_empty (&gray_queue));
2988 sgen_memgov_major_collection_end ();
2989 current_collection_generation = -1;
2991 major_collector.finish_major_collection ();
2993 if (major_collector.is_concurrent)
2994 concurrent_collection_in_progress = FALSE;
2996 check_scan_starts ();
2998 binary_protocol_flush_buffers (FALSE);
3000 //consistency_check ();
3002 MONO_GC_END (GENERATION_OLD);
3006 major_do_collection (const char *reason)
3008 TV_DECLARE (all_atv);
3009 TV_DECLARE (all_btv);
3010 int old_next_pin_slot;
3012 /* world must be stopped already */
3013 TV_GETTIME (all_atv);
3015 major_start_collection (&old_next_pin_slot);
3016 major_finish_collection (reason, old_next_pin_slot);
3018 TV_GETTIME (all_btv);
3019 gc_stats.major_gc_time_usecs += TV_ELAPSED (all_atv, all_btv);
3021 return bytes_pinned_from_failed_allocation > 0;
3024 static gboolean major_do_collection (const char *reason);
3027 major_start_concurrent_collection (const char *reason)
3029 // FIXME: store reason and pass it when finishing
3030 major_start_collection (NULL);
3032 sgen_workers_distribute_gray_queue_sections ();
3033 g_assert (sgen_gray_object_queue_is_empty (WORKERS_DISTRIBUTE_GRAY_QUEUE));
3035 sgen_workers_wait_for_jobs ();
3037 current_collection_generation = -1;
3041 major_finish_concurrent_collection (void)
3043 current_collection_generation = GENERATION_OLD;
3044 major_finish_collection ("finishing", -1);
3045 current_collection_generation = -1;
3049 * Ensure an allocation request for @size will succeed by freeing enough memory.
3051 * LOCKING: The GC lock MUST be held.
3054 sgen_ensure_free_space (size_t size)
3056 int generation_to_collect = -1;
3057 const char *reason = NULL;
3060 if (size > SGEN_MAX_SMALL_OBJ_SIZE) {
3061 if (sgen_need_major_collection (size)) {
3062 reason = "LOS overflow";
3063 generation_to_collect = GENERATION_OLD;
3066 if (degraded_mode) {
3067 if (sgen_need_major_collection (size)) {
3068 reason = "Degraded mode overflow";
3069 generation_to_collect = GENERATION_OLD;
3071 } else if (sgen_need_major_collection (size)) {
3072 reason = "Minor allowance";
3073 generation_to_collect = GENERATION_OLD;
3075 generation_to_collect = GENERATION_NURSERY;
3076 reason = "Nursery full";
3080 if (generation_to_collect == -1)
3082 sgen_perform_collection (size, generation_to_collect, reason, generation_to_collect == GENERATION_NURSERY);
3086 sgen_perform_collection (size_t requested_size, int generation_to_collect, const char *reason, gboolean wait_to_finish)
3088 TV_DECLARE (gc_end);
3089 GGTimingInfo infos [2];
3090 int overflow_generation_to_collect = -1;
3091 const char *overflow_reason = NULL;
3093 memset (infos, 0, sizeof (infos));
3094 mono_profiler_gc_event (MONO_GC_EVENT_START, generation_to_collect);
3096 infos [0].generation = generation_to_collect;
3097 infos [0].reason = reason;
3098 infos [0].is_overflow = FALSE;
3099 TV_GETTIME (infos [0].total_time);
3100 infos [1].generation = -1;
3102 sgen_stop_world (generation_to_collect);
3104 if (concurrent_collection_in_progress) {
3105 g_assert (generation_to_collect == GENERATION_NURSERY);
3106 major_finish_concurrent_collection ();
3109 //FIXME extract overflow reason
3110 if (generation_to_collect == GENERATION_NURSERY) {
3111 if (collect_nursery ()) {
3112 overflow_generation_to_collect = GENERATION_OLD;
3113 overflow_reason = "Minor overflow";
3116 if (major_collector.is_concurrent)
3119 if (major_collector.is_concurrent && !wait_to_finish) {
3120 major_start_concurrent_collection (reason);
3121 // FIXME: set infos[0] properly
3124 if (major_do_collection (reason)) {
3125 overflow_generation_to_collect = GENERATION_NURSERY;
3126 overflow_reason = "Excessive pinning";
3131 TV_GETTIME (gc_end);
3132 infos [0].total_time = SGEN_TV_ELAPSED (infos [0].total_time, gc_end);
3135 if (!major_collector.is_concurrent && overflow_generation_to_collect != -1) {
3136 mono_profiler_gc_event (MONO_GC_EVENT_START, overflow_generation_to_collect);
3137 infos [1].generation = overflow_generation_to_collect;
3138 infos [1].reason = overflow_reason;
3139 infos [1].is_overflow = TRUE;
3140 infos [1].total_time = gc_end;
3142 if (overflow_generation_to_collect == GENERATION_NURSERY)
3145 major_do_collection (overflow_reason);
3147 TV_GETTIME (gc_end);
3148 infos [1].total_time = SGEN_TV_ELAPSED (infos [1].total_time, gc_end);
3150 /* keep events symmetric */
3151 mono_profiler_gc_event (MONO_GC_EVENT_END, overflow_generation_to_collect);
3154 SGEN_LOG (2, "Heap size: %lu, LOS size: %lu", (unsigned long)mono_gc_get_heap_size (), (unsigned long)los_memory_usage);
3156 /* this also sets the proper pointers for the next allocation */
3157 if (generation_to_collect == GENERATION_NURSERY && !sgen_can_alloc_size (requested_size)) {
3158 /* TypeBuilder and MonoMethod are killing mcs with fragmentation */
3159 SGEN_LOG (1, "nursery collection didn't find enough room for %zd alloc (%d pinned)", requested_size, sgen_get_pinned_count ());
3160 sgen_dump_pin_queue ();
3165 sgen_restart_world (generation_to_collect, infos);
3167 mono_profiler_gc_event (MONO_GC_EVENT_END, generation_to_collect);
3171 * ######################################################################
3172 * ######## Memory allocation from the OS
3173 * ######################################################################
3174 * This section of code deals with getting memory from the OS and
3175 * allocating memory for GC-internal data structures.
3176 * Internal memory can be handled with a freelist for small objects.
3182 G_GNUC_UNUSED static void
3183 report_internal_mem_usage (void)
3185 printf ("Internal memory usage:\n");
3186 sgen_report_internal_mem_usage ();
3187 printf ("Pinned memory usage:\n");
3188 major_collector.report_pinned_memory_usage ();
3192 * ######################################################################
3193 * ######## Finalization support
3194 * ######################################################################
3198 * If the object has been forwarded it means it's still referenced from a root.
3199 * If it is pinned it's still alive as well.
3200 * A LOS object is only alive if we have pinned it.
3201 * Return TRUE if @obj is ready to be finalized.
3203 static inline gboolean
3204 sgen_is_object_alive (void *object)
3208 if (ptr_in_nursery (object))
3209 return sgen_nursery_is_object_alive (object);
3210 /* Oldgen objects can be pinned and forwarded too */
3211 if (SGEN_OBJECT_IS_PINNED (object) || SGEN_OBJECT_IS_FORWARDED (object))
3215 * FIXME: major_collector.is_object_live() also calculates the
3216 * size. Avoid the double calculation.
3218 objsize = SGEN_ALIGN_UP (sgen_safe_object_get_size ((MonoObject*)object));
3219 if (objsize > SGEN_MAX_SMALL_OBJ_SIZE)
3220 return sgen_los_object_is_pinned (object);
3222 return major_collector.is_object_live (object);
3226 sgen_gc_is_object_ready_for_finalization (void *object)
3228 return !sgen_is_object_alive (object);
3232 has_critical_finalizer (MonoObject *obj)
3236 if (!mono_defaults.critical_finalizer_object)
3239 class = ((MonoVTable*)LOAD_VTABLE (obj))->klass;
3241 return mono_class_has_parent_fast (class, mono_defaults.critical_finalizer_object);
3245 sgen_queue_finalization_entry (MonoObject *obj)
3247 FinalizeReadyEntry *entry = sgen_alloc_internal (INTERNAL_MEM_FINALIZE_READY_ENTRY);
3248 entry->object = obj;
3249 if (has_critical_finalizer (obj)) {
3250 entry->next = critical_fin_list;
3251 critical_fin_list = entry;
3253 entry->next = fin_ready_list;
3254 fin_ready_list = entry;
3259 object_is_reachable (char *object, char *start, char *end)
3261 /*This happens for non nursery objects during minor collections. We just treat all objects as alive.*/
3262 if (object < start || object >= end)
3265 return sgen_is_object_alive (object);
3269 sgen_object_is_live (void *obj)
3271 if (ptr_in_nursery (obj))
3272 return object_is_pinned (obj);
3273 /* FIXME This is semantically wrong! All tenured object are considered alive during a nursery collection. */
3274 if (current_collection_generation == GENERATION_NURSERY)
3276 return major_collector.is_object_live (obj);
3279 /* LOCKING: requires that the GC lock is held */
3281 null_ephemerons_for_domain (MonoDomain *domain)
3283 EphemeronLinkNode *current = ephemeron_list, *prev = NULL;
3286 MonoObject *object = (MonoObject*)current->array;
3288 if (object && !object->vtable) {
3289 EphemeronLinkNode *tmp = current;
3292 prev->next = current->next;
3294 ephemeron_list = current->next;
3296 current = current->next;
3297 sgen_free_internal (tmp, INTERNAL_MEM_EPHEMERON_LINK);
3300 current = current->next;
3305 /* LOCKING: requires that the GC lock is held */
3307 clear_unreachable_ephemerons (CopyOrMarkObjectFunc copy_func, char *start, char *end, GrayQueue *queue)
3309 int was_in_nursery, was_promoted;
3310 EphemeronLinkNode *current = ephemeron_list, *prev = NULL;
3312 Ephemeron *cur, *array_end;
3316 char *object = current->array;
3318 if (!object_is_reachable (object, start, end)) {
3319 EphemeronLinkNode *tmp = current;
3321 SGEN_LOG (5, "Dead Ephemeron array at %p", object);
3324 prev->next = current->next;
3326 ephemeron_list = current->next;
3328 current = current->next;
3329 sgen_free_internal (tmp, INTERNAL_MEM_EPHEMERON_LINK);
3334 was_in_nursery = ptr_in_nursery (object);
3335 copy_func ((void**)&object, queue);
3336 current->array = object;
3338 /*The array was promoted, add global remsets for key/values left behind in nursery.*/
3339 was_promoted = was_in_nursery && !ptr_in_nursery (object);
3341 SGEN_LOG (5, "Clearing unreachable entries for ephemeron array at %p", object);
3343 array = (MonoArray*)object;
3344 cur = mono_array_addr (array, Ephemeron, 0);
3345 array_end = cur + mono_array_length_fast (array);
3346 tombstone = (char*)((MonoVTable*)LOAD_VTABLE (object))->domain->ephemeron_tombstone;
3348 for (; cur < array_end; ++cur) {
3349 char *key = (char*)cur->key;
3351 if (!key || key == tombstone)
3354 SGEN_LOG (5, "[%td] key %p (%s) value %p (%s)", cur - mono_array_addr (array, Ephemeron, 0),
3355 key, object_is_reachable (key, start, end) ? "reachable" : "unreachable",
3356 cur->value, cur->value && object_is_reachable (cur->value, start, end) ? "reachable" : "unreachable");
3358 if (!object_is_reachable (key, start, end)) {
3359 cur->key = tombstone;
3365 if (ptr_in_nursery (key)) {/*key was not promoted*/
3366 SGEN_LOG (5, "\tAdded remset to key %p", key);
3367 sgen_add_to_global_remset (&cur->key);
3369 if (ptr_in_nursery (cur->value)) {/*value was not promoted*/
3370 SGEN_LOG (5, "\tAdded remset to value %p", cur->value);
3371 sgen_add_to_global_remset (&cur->value);
3376 current = current->next;
3380 /* LOCKING: requires that the GC lock is held */
3382 mark_ephemerons_in_range (CopyOrMarkObjectFunc copy_func, char *start, char *end, GrayQueue *queue)
3384 int nothing_marked = 1;
3385 EphemeronLinkNode *current = ephemeron_list;
3387 Ephemeron *cur, *array_end;
3390 for (current = ephemeron_list; current; current = current->next) {
3391 char *object = current->array;
3392 SGEN_LOG (5, "Ephemeron array at %p", object);
3395 For now we process all ephemerons during all collections.
3396 Ideally we should use remset information to partially scan those
3398 We already emit write barriers for Ephemeron fields, it's
3399 just that we don't process them.
3401 /*if (object < start || object >= end)
3404 /*It has to be alive*/
3405 if (!object_is_reachable (object, start, end)) {
3406 SGEN_LOG (5, "\tnot reachable");
3410 copy_func ((void**)&object, queue);
3412 array = (MonoArray*)object;
3413 cur = mono_array_addr (array, Ephemeron, 0);
3414 array_end = cur + mono_array_length_fast (array);
3415 tombstone = (char*)((MonoVTable*)LOAD_VTABLE (object))->domain->ephemeron_tombstone;
3417 for (; cur < array_end; ++cur) {
3418 char *key = cur->key;
3420 if (!key || key == tombstone)
3423 SGEN_LOG (5, "[%td] key %p (%s) value %p (%s)", cur - mono_array_addr (array, Ephemeron, 0),
3424 key, object_is_reachable (key, start, end) ? "reachable" : "unreachable",
3425 cur->value, cur->value && object_is_reachable (cur->value, start, end) ? "reachable" : "unreachable");
3427 if (object_is_reachable (key, start, end)) {
3428 char *value = cur->value;
3430 copy_func ((void**)&cur->key, queue);
3432 if (!object_is_reachable (value, start, end))
3434 copy_func ((void**)&cur->value, queue);
3440 SGEN_LOG (5, "Ephemeron run finished. Is it done %d", nothing_marked);
3441 return nothing_marked;
3445 mono_gc_invoke_finalizers (void)
3447 FinalizeReadyEntry *entry = NULL;
3448 gboolean entry_is_critical = FALSE;
3451 /* FIXME: batch to reduce lock contention */
3452 while (fin_ready_list || critical_fin_list) {
3456 FinalizeReadyEntry **list = entry_is_critical ? &critical_fin_list : &fin_ready_list;
3458 /* We have finalized entry in the last
3459 interation, now we need to remove it from
3462 *list = entry->next;
3464 FinalizeReadyEntry *e = *list;
3465 while (e->next != entry)
3467 e->next = entry->next;
3469 sgen_free_internal (entry, INTERNAL_MEM_FINALIZE_READY_ENTRY);
3473 /* Now look for the first non-null entry. */
3474 for (entry = fin_ready_list; entry && !entry->object; entry = entry->next)
3477 entry_is_critical = FALSE;
3479 entry_is_critical = TRUE;
3480 for (entry = critical_fin_list; entry && !entry->object; entry = entry->next)
3485 g_assert (entry->object);
3486 num_ready_finalizers--;
3487 obj = entry->object;
3488 entry->object = NULL;
3489 SGEN_LOG (7, "Finalizing object %p (%s)", obj, safe_name (obj));
3497 g_assert (entry->object == NULL);
3499 /* the object is on the stack so it is pinned */
3500 /*g_print ("Calling finalizer for object: %p (%s)\n", entry->object, safe_name (entry->object));*/
3501 mono_gc_run_finalize (obj, NULL);
3508 mono_gc_pending_finalizers (void)
3510 return fin_ready_list || critical_fin_list;
3514 * ######################################################################
3515 * ######## registered roots support
3516 * ######################################################################
3520 * We do not coalesce roots.
3523 mono_gc_register_root_inner (char *start, size_t size, void *descr, int root_type)
3525 RootRecord new_root;
3528 for (i = 0; i < ROOT_TYPE_NUM; ++i) {
3529 RootRecord *root = sgen_hash_table_lookup (&roots_hash [i], start);
3530 /* we allow changing the size and the descriptor (for thread statics etc) */
3532 size_t old_size = root->end_root - start;
3533 root->end_root = start + size;
3534 g_assert (((root->root_desc != 0) && (descr != NULL)) ||
3535 ((root->root_desc == 0) && (descr == NULL)));
3536 root->root_desc = (mword)descr;
3538 roots_size -= old_size;
3544 new_root.end_root = start + size;
3545 new_root.root_desc = (mword)descr;
3547 sgen_hash_table_replace (&roots_hash [root_type], start, &new_root, NULL);
3550 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);
3557 mono_gc_register_root (char *start, size_t size, void *descr)
3559 return mono_gc_register_root_inner (start, size, descr, descr ? ROOT_TYPE_NORMAL : ROOT_TYPE_PINNED);
3563 mono_gc_register_root_wbarrier (char *start, size_t size, void *descr)
3565 return mono_gc_register_root_inner (start, size, descr, ROOT_TYPE_WBARRIER);
3569 mono_gc_deregister_root (char* addr)
3575 for (root_type = 0; root_type < ROOT_TYPE_NUM; ++root_type) {
3576 if (sgen_hash_table_remove (&roots_hash [root_type], addr, &root))
3577 roots_size -= (root.end_root - addr);
3583 * ######################################################################
3584 * ######## Thread handling (stop/start code)
3585 * ######################################################################
3588 unsigned int sgen_global_stop_count = 0;
3591 sgen_fill_thread_info_for_suspend (SgenThreadInfo *info)
3593 if (remset.fill_thread_info_for_suspend)
3594 remset.fill_thread_info_for_suspend (info);
3598 sgen_get_current_collection_generation (void)
3600 return current_collection_generation;
3604 mono_gc_set_gc_callbacks (MonoGCCallbacks *callbacks)
3606 gc_callbacks = *callbacks;
3610 mono_gc_get_gc_callbacks ()
3612 return &gc_callbacks;
3615 /* Variables holding start/end nursery so it won't have to be passed at every call */
3616 static void *scan_area_arg_start, *scan_area_arg_end;
3619 mono_gc_conservatively_scan_area (void *start, void *end)
3621 conservatively_pin_objects_from (start, end, scan_area_arg_start, scan_area_arg_end, PIN_TYPE_STACK);
3625 mono_gc_scan_object (void *obj)
3627 UserCopyOrMarkData *data = mono_native_tls_get_value (user_copy_or_mark_key);
3628 current_object_ops.copy_or_mark_object (&obj, data->queue);
3633 * Mark from thread stacks and registers.
3636 scan_thread_data (void *start_nursery, void *end_nursery, gboolean precise, GrayQueue *queue)
3638 SgenThreadInfo *info;
3640 scan_area_arg_start = start_nursery;
3641 scan_area_arg_end = end_nursery;
3643 FOREACH_THREAD (info) {
3645 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);
3648 if (info->gc_disabled) {
3649 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);
3653 if (!info->joined_stw) {
3654 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);
3658 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 ());
3659 if (!info->thread_is_dying) {
3660 if (gc_callbacks.thread_mark_func && !conservative_stack_mark) {
3661 UserCopyOrMarkData data = { NULL, queue };
3662 set_user_copy_or_mark_data (&data);
3663 gc_callbacks.thread_mark_func (info->runtime_data, info->stack_start, info->stack_end, precise);
3664 set_user_copy_or_mark_data (NULL);
3665 } else if (!precise) {
3666 conservatively_pin_objects_from (info->stack_start, info->stack_end, start_nursery, end_nursery, PIN_TYPE_STACK);
3670 if (!info->thread_is_dying && !precise) {
3672 conservatively_pin_objects_from ((void**)&info->ctx, (void**)&info->ctx + ARCH_NUM_REGS,
3673 start_nursery, end_nursery, PIN_TYPE_STACK);
3675 conservatively_pin_objects_from (&info->regs, &info->regs + ARCH_NUM_REGS,
3676 start_nursery, end_nursery, PIN_TYPE_STACK);
3679 } END_FOREACH_THREAD
3683 ptr_on_stack (void *ptr)
3685 gpointer stack_start = &stack_start;
3686 SgenThreadInfo *info = mono_thread_info_current ();
3688 if (ptr >= stack_start && ptr < (gpointer)info->stack_end)
3694 sgen_thread_register (SgenThreadInfo* info, void *addr)
3696 #ifndef HAVE_KW_THREAD
3697 SgenThreadInfo *__thread_info__ = info;
3701 #ifndef HAVE_KW_THREAD
3702 info->tlab_start = info->tlab_next = info->tlab_temp_end = info->tlab_real_end = NULL;
3704 g_assert (!mono_native_tls_get_value (thread_info_key));
3705 mono_native_tls_set_value (thread_info_key, info);
3707 sgen_thread_info = info;
3710 #if !defined(__MACH__)
3711 info->stop_count = -1;
3715 info->joined_stw = FALSE;
3716 info->doing_handshake = FALSE;
3717 info->thread_is_dying = FALSE;
3718 info->stack_start = NULL;
3719 info->store_remset_buffer_addr = &STORE_REMSET_BUFFER;
3720 info->store_remset_buffer_index_addr = &STORE_REMSET_BUFFER_INDEX;
3721 info->stopped_ip = NULL;
3722 info->stopped_domain = NULL;
3724 memset (&info->ctx, 0, sizeof (MonoContext));
3726 memset (&info->regs, 0, sizeof (info->regs));
3729 sgen_init_tlab_info (info);
3731 binary_protocol_thread_register ((gpointer)mono_thread_info_get_tid (info));
3733 #ifdef HAVE_KW_THREAD
3734 store_remset_buffer_index_addr = &store_remset_buffer_index;
3737 /* try to get it with attributes first */
3738 #if defined(HAVE_PTHREAD_GETATTR_NP) && defined(HAVE_PTHREAD_ATTR_GETSTACK)
3742 pthread_attr_t attr;
3743 pthread_getattr_np (pthread_self (), &attr);
3744 pthread_attr_getstack (&attr, &sstart, &size);
3745 info->stack_start_limit = sstart;
3746 info->stack_end = (char*)sstart + size;
3747 pthread_attr_destroy (&attr);
3749 #elif defined(HAVE_PTHREAD_GET_STACKSIZE_NP) && defined(HAVE_PTHREAD_GET_STACKADDR_NP)
3750 info->stack_end = (char*)pthread_get_stackaddr_np (pthread_self ());
3751 info->stack_start_limit = (char*)info->stack_end - pthread_get_stacksize_np (pthread_self ());
3754 /* FIXME: we assume the stack grows down */
3755 gsize stack_bottom = (gsize)addr;
3756 stack_bottom += 4095;
3757 stack_bottom &= ~4095;
3758 info->stack_end = (char*)stack_bottom;
3762 #ifdef HAVE_KW_THREAD
3763 stack_end = info->stack_end;
3766 if (remset.register_thread)
3767 remset.register_thread (info);
3769 SGEN_LOG (3, "registered thread %p (%p) stack end %p", info, (gpointer)mono_thread_info_get_tid (info), info->stack_end);
3771 if (gc_callbacks.thread_attach_func)
3772 info->runtime_data = gc_callbacks.thread_attach_func ();
3779 sgen_wbarrier_cleanup_thread (SgenThreadInfo *p)
3781 if (remset.cleanup_thread)
3782 remset.cleanup_thread (p);
3786 sgen_thread_unregister (SgenThreadInfo *p)
3788 /* If a delegate is passed to native code and invoked on a thread we dont
3789 * know about, the jit will register it with mono_jit_thread_attach, but
3790 * we have no way of knowing when that thread goes away. SGen has a TSD
3791 * so we assume that if the domain is still registered, we can detach
3794 if (mono_domain_get ())
3795 mono_thread_detach (mono_thread_current ());
3797 p->thread_is_dying = TRUE;
3800 There is a race condition between a thread finishing executing and been removed
3801 from the GC thread set.
3802 This happens on posix systems when TLS data is been cleaned-up, libpthread will
3803 set the thread_info slot to NULL before calling the cleanup function. This
3804 opens a window in which the thread is registered but has a NULL TLS.
3806 The suspend signal handler needs TLS data to know where to store thread state
3807 data or otherwise it will simply ignore the thread.
3809 This solution works because the thread doing STW will wait until all threads been
3810 suspended handshake back, so there is no race between the doing_hankshake test
3811 and the suspend_thread call.
3813 This is not required on systems that do synchronous STW as those can deal with
3814 the above race at suspend time.
3816 FIXME: I believe we could avoid this by using mono_thread_info_lookup when
3817 mono_thread_info_current returns NULL. Or fix mono_thread_info_lookup to do so.
3819 #if (defined(__MACH__) && MONO_MACH_ARCH_SUPPORTED) || !defined(HAVE_PTHREAD_KILL)
3822 while (!TRYLOCK_GC) {
3823 if (!sgen_park_current_thread_if_doing_handshake (p))
3829 binary_protocol_thread_unregister ((gpointer)mono_thread_info_get_tid (p));
3830 SGEN_LOG (3, "unregister thread %p (%p)", p, (gpointer)mono_thread_info_get_tid (p));
3832 if (gc_callbacks.thread_detach_func) {
3833 gc_callbacks.thread_detach_func (p->runtime_data);
3834 p->runtime_data = NULL;
3836 sgen_wbarrier_cleanup_thread (p);
3838 mono_threads_unregister_current_thread (p);
3844 sgen_thread_attach (SgenThreadInfo *info)
3847 /*this is odd, can we get attached before the gc is inited?*/
3851 if (gc_callbacks.thread_attach_func && !info->runtime_data)
3852 info->runtime_data = gc_callbacks.thread_attach_func ();
3855 mono_gc_register_thread (void *baseptr)
3857 return mono_thread_info_attach (baseptr) != NULL;
3861 * mono_gc_set_stack_end:
3863 * Set the end of the current threads stack to STACK_END. The stack space between
3864 * STACK_END and the real end of the threads stack will not be scanned during collections.
3867 mono_gc_set_stack_end (void *stack_end)
3869 SgenThreadInfo *info;
3872 info = mono_thread_info_current ();
3874 g_assert (stack_end < info->stack_end);
3875 info->stack_end = stack_end;
3880 #if USE_PTHREAD_INTERCEPT
3884 mono_gc_pthread_create (pthread_t *new_thread, const pthread_attr_t *attr, void *(*start_routine)(void *), void *arg)
3886 return pthread_create (new_thread, attr, start_routine, arg);
3890 mono_gc_pthread_join (pthread_t thread, void **retval)
3892 return pthread_join (thread, retval);
3896 mono_gc_pthread_detach (pthread_t thread)
3898 return pthread_detach (thread);
3902 mono_gc_pthread_exit (void *retval)
3904 pthread_exit (retval);
3907 #endif /* USE_PTHREAD_INTERCEPT */
3910 * ######################################################################
3911 * ######## Write barriers
3912 * ######################################################################
3916 * Note: the write barriers first do the needed GC work and then do the actual store:
3917 * this way the value is visible to the conservative GC scan after the write barrier
3918 * itself. If a GC interrupts the barrier in the middle, value will be kept alive by
3919 * the conservative scan, otherwise by the remembered set scan.
3922 mono_gc_wbarrier_set_field (MonoObject *obj, gpointer field_ptr, MonoObject* value)
3924 HEAVY_STAT (++stat_wbarrier_set_field);
3925 if (ptr_in_nursery (field_ptr)) {
3926 *(void**)field_ptr = value;
3929 SGEN_LOG (8, "Adding remset at %p", field_ptr);
3931 binary_protocol_wbarrier (field_ptr, value, value->vtable);
3933 remset.wbarrier_set_field (obj, field_ptr, value);
3937 mono_gc_wbarrier_set_arrayref (MonoArray *arr, gpointer slot_ptr, MonoObject* value)
3939 HEAVY_STAT (++stat_wbarrier_set_arrayref);
3940 if (ptr_in_nursery (slot_ptr)) {
3941 *(void**)slot_ptr = value;
3944 SGEN_LOG (8, "Adding remset at %p", slot_ptr);
3946 binary_protocol_wbarrier (slot_ptr, value, value->vtable);
3948 remset.wbarrier_set_arrayref (arr, slot_ptr, value);
3952 mono_gc_wbarrier_arrayref_copy (gpointer dest_ptr, gpointer src_ptr, int count)
3954 HEAVY_STAT (++stat_wbarrier_arrayref_copy);
3955 /*This check can be done without taking a lock since dest_ptr array is pinned*/
3956 if (ptr_in_nursery (dest_ptr) || count <= 0) {
3957 mono_gc_memmove (dest_ptr, src_ptr, count * sizeof (gpointer));
3961 #ifdef SGEN_BINARY_PROTOCOL
3964 for (i = 0; i < count; ++i) {
3965 gpointer dest = (gpointer*)dest_ptr + i;
3966 gpointer obj = *((gpointer*)src_ptr + i);
3968 binary_protocol_wbarrier (dest, obj, (gpointer)LOAD_VTABLE (obj));
3973 remset.wbarrier_arrayref_copy (dest_ptr, src_ptr, count);
3976 static char *found_obj;
3979 find_object_for_ptr_callback (char *obj, size_t size, void *user_data)
3981 char *ptr = user_data;
3983 if (ptr >= obj && ptr < obj + size) {
3984 g_assert (!found_obj);
3989 /* for use in the debugger */
3990 char* find_object_for_ptr (char *ptr);
3992 find_object_for_ptr (char *ptr)
3994 if (ptr >= nursery_section->data && ptr < nursery_section->end_data) {
3996 sgen_scan_area_with_callback (nursery_section->data, nursery_section->end_data,
3997 find_object_for_ptr_callback, ptr, TRUE);
4003 sgen_los_iterate_objects (find_object_for_ptr_callback, ptr);
4008 * Very inefficient, but this is debugging code, supposed to
4009 * be called from gdb, so we don't care.
4012 major_collector.iterate_objects (TRUE, TRUE, find_object_for_ptr_callback, ptr);
4017 mono_gc_wbarrier_generic_nostore (gpointer ptr)
4021 HEAVY_STAT (++stat_wbarrier_generic_store);
4023 #ifdef XDOMAIN_CHECKS_IN_WBARRIER
4024 /* FIXME: ptr_in_heap must be called with the GC lock held */
4025 if (xdomain_checks && *(MonoObject**)ptr && ptr_in_heap (ptr)) {
4026 char *start = find_object_for_ptr (ptr);
4027 MonoObject *value = *(MonoObject**)ptr;
4031 MonoObject *obj = (MonoObject*)start;
4032 if (obj->vtable->domain != value->vtable->domain)
4033 g_assert (is_xdomain_ref_allowed (ptr, start, obj->vtable->domain));
4039 obj = *(gpointer*)ptr;
4041 binary_protocol_wbarrier (ptr, obj, (gpointer)LOAD_VTABLE (obj));
4043 if (ptr_in_nursery (ptr) || ptr_on_stack (ptr)) {
4044 SGEN_LOG (8, "Skipping remset at %p", ptr);
4049 * We need to record old->old pointer locations for the
4050 * concurrent collector.
4052 if (!ptr_in_nursery (obj) && !concurrent_collection_in_progress) {
4053 SGEN_LOG (8, "Skipping remset at %p", ptr);
4057 SGEN_LOG (8, "Adding remset at %p", ptr);
4059 remset.wbarrier_generic_nostore (ptr);
4063 mono_gc_wbarrier_generic_store (gpointer ptr, MonoObject* value)
4065 SGEN_LOG (8, "Wbarrier store at %p to %p (%s)", ptr, value, value ? safe_name (value) : "null");
4066 *(void**)ptr = value;
4067 if (ptr_in_nursery (value))
4068 mono_gc_wbarrier_generic_nostore (ptr);
4069 sgen_dummy_use (value);
4072 void mono_gc_wbarrier_value_copy_bitmap (gpointer _dest, gpointer _src, int size, unsigned bitmap)
4074 mword *dest = _dest;
4079 mono_gc_wbarrier_generic_store (dest, (MonoObject*)*src);
4084 size -= SIZEOF_VOID_P;
4089 #ifdef SGEN_BINARY_PROTOCOL
4091 #define HANDLE_PTR(ptr,obj) do { \
4092 gpointer o = *(gpointer*)(ptr); \
4094 gpointer d = ((char*)dest) + ((char*)(ptr) - (char*)(obj)); \
4095 binary_protocol_wbarrier (d, o, (gpointer) LOAD_VTABLE (o)); \
4100 scan_object_for_binary_protocol_copy_wbarrier (gpointer dest, char *start, mword desc)
4102 #define SCAN_OBJECT_NOVTABLE
4103 #include "sgen-scan-object.h"
4108 mono_gc_wbarrier_value_copy (gpointer dest, gpointer src, int count, MonoClass *klass)
4110 HEAVY_STAT (++stat_wbarrier_value_copy);
4111 g_assert (klass->valuetype);
4113 SGEN_LOG (8, "Adding value remset at %p, count %d, descr %p for class %s (%p)", dest, count, klass->gc_descr, klass->name, klass);
4115 if (ptr_in_nursery (dest) || ptr_on_stack (dest) || !SGEN_CLASS_HAS_REFERENCES (klass)) {
4116 size_t element_size = mono_class_value_size (klass, NULL);
4117 size_t size = count * element_size;
4118 mono_gc_memmove (dest, src, size);
4122 #ifdef SGEN_BINARY_PROTOCOL
4124 size_t element_size = mono_class_value_size (klass, NULL);
4126 for (i = 0; i < count; ++i) {
4127 scan_object_for_binary_protocol_copy_wbarrier ((char*)dest + i * element_size,
4128 (char*)src + i * element_size - sizeof (MonoObject),
4129 (mword) klass->gc_descr);
4134 remset.wbarrier_value_copy (dest, src, count, klass);
4138 * mono_gc_wbarrier_object_copy:
4140 * Write barrier to call when obj is the result of a clone or copy of an object.
4143 mono_gc_wbarrier_object_copy (MonoObject* obj, MonoObject *src)
4147 HEAVY_STAT (++stat_wbarrier_object_copy);
4149 if (ptr_in_nursery (obj) || ptr_on_stack (obj)) {
4150 size = mono_object_class (obj)->instance_size;
4151 mono_gc_memmove ((char*)obj + sizeof (MonoObject), (char*)src + sizeof (MonoObject),
4152 size - sizeof (MonoObject));
4156 #ifdef SGEN_BINARY_PROTOCOL
4157 scan_object_for_binary_protocol_copy_wbarrier (obj, (char*)src, (mword) src->vtable->gc_descr);
4160 remset.wbarrier_object_copy (obj, src);
4165 * ######################################################################
4166 * ######## Other mono public interface functions.
4167 * ######################################################################
4170 #define REFS_SIZE 128
4173 MonoGCReferences callback;
4177 MonoObject *refs [REFS_SIZE];
4178 uintptr_t offsets [REFS_SIZE];
4182 #define HANDLE_PTR(ptr,obj) do { \
4184 if (hwi->count == REFS_SIZE) { \
4185 hwi->callback ((MonoObject*)start, mono_object_class (start), hwi->called? 0: size, hwi->count, hwi->refs, hwi->offsets, hwi->data); \
4189 hwi->offsets [hwi->count] = (char*)(ptr)-(char*)start; \
4190 hwi->refs [hwi->count++] = *(ptr); \
4195 collect_references (HeapWalkInfo *hwi, char *start, size_t size)
4197 #include "sgen-scan-object.h"
4201 walk_references (char *start, size_t size, void *data)
4203 HeapWalkInfo *hwi = data;
4206 collect_references (hwi, start, size);
4207 if (hwi->count || !hwi->called)
4208 hwi->callback ((MonoObject*)start, mono_object_class (start), hwi->called? 0: size, hwi->count, hwi->refs, hwi->offsets, hwi->data);
4212 * mono_gc_walk_heap:
4213 * @flags: flags for future use
4214 * @callback: a function pointer called for each object in the heap
4215 * @data: a user data pointer that is passed to callback
4217 * This function can be used to iterate over all the live objects in the heap:
4218 * for each object, @callback is invoked, providing info about the object's
4219 * location in memory, its class, its size and the objects it references.
4220 * For each referenced object it's offset from the object address is
4221 * reported in the offsets array.
4222 * The object references may be buffered, so the callback may be invoked
4223 * multiple times for the same object: in all but the first call, the size
4224 * argument will be zero.
4225 * Note that this function can be only called in the #MONO_GC_EVENT_PRE_START_WORLD
4226 * profiler event handler.
4228 * Returns: a non-zero value if the GC doesn't support heap walking
4231 mono_gc_walk_heap (int flags, MonoGCReferences callback, void *data)
4236 hwi.callback = callback;
4239 sgen_clear_nursery_fragments ();
4240 sgen_scan_area_with_callback (nursery_section->data, nursery_section->end_data, walk_references, &hwi, FALSE);
4242 major_collector.iterate_objects (TRUE, TRUE, walk_references, &hwi);
4243 sgen_los_iterate_objects (walk_references, &hwi);
4249 mono_gc_collect (int generation)
4254 sgen_perform_collection (0, generation, "user request", TRUE);
4259 mono_gc_max_generation (void)
4265 mono_gc_collection_count (int generation)
4267 if (generation == 0)
4268 return stat_minor_gcs;
4269 return stat_major_gcs;
4273 mono_gc_get_used_size (void)
4277 tot = los_memory_usage;
4278 tot += nursery_section->next_data - nursery_section->data;
4279 tot += major_collector.get_used_size ();
4280 /* FIXME: account for pinned objects */
4286 mono_gc_disable (void)
4294 mono_gc_enable (void)
4302 mono_gc_get_los_limit (void)
4304 return MAX_SMALL_OBJ_SIZE;
4308 mono_gc_user_markers_supported (void)
4314 mono_object_is_alive (MonoObject* o)
4320 mono_gc_get_generation (MonoObject *obj)
4322 if (ptr_in_nursery (obj))
4328 mono_gc_enable_events (void)
4333 mono_gc_weak_link_add (void **link_addr, MonoObject *obj, gboolean track)
4335 sgen_register_disappearing_link (obj, link_addr, track, FALSE);
4339 mono_gc_weak_link_remove (void **link_addr)
4341 sgen_register_disappearing_link (NULL, link_addr, FALSE, FALSE);
4345 mono_gc_weak_link_get (void **link_addr)
4348 * We must only load *link_addr once because it might change
4349 * under our feet, and REVEAL_POINTER (NULL) results in an
4350 * invalid reference.
4352 void *ptr = *link_addr;
4357 * During the second bridge processing step the world is
4358 * running again. That step processes all weak links once
4359 * more to null those that refer to dead objects. Before that
4360 * is completed, those links must not be followed, so we
4361 * conservatively wait for bridge processing when any weak
4362 * link is dereferenced.
4364 if (G_UNLIKELY (bridge_processing_in_progress))
4365 mono_gc_wait_for_bridge_processing ();
4367 return (MonoObject*) REVEAL_POINTER (ptr);
4371 mono_gc_ephemeron_array_add (MonoObject *obj)
4373 EphemeronLinkNode *node;
4377 node = sgen_alloc_internal (INTERNAL_MEM_EPHEMERON_LINK);
4382 node->array = (char*)obj;
4383 node->next = ephemeron_list;
4384 ephemeron_list = node;
4386 SGEN_LOG (5, "Registered ephemeron array %p", obj);
4393 mono_gc_invoke_with_gc_lock (MonoGCLockedCallbackFunc func, void *data)
4397 result = func (data);
4398 UNLOCK_INTERRUPTION;
4403 mono_gc_is_gc_thread (void)
4407 result = mono_thread_info_current () != NULL;
4413 is_critical_method (MonoMethod *method)
4415 return mono_runtime_is_critical_method (method) || sgen_is_critical_method (method);
4419 mono_gc_base_init (void)
4421 MonoThreadInfoCallbacks cb;
4424 char *major_collector_opt = NULL;
4425 char *minor_collector_opt = NULL;
4427 glong soft_limit = 0;
4431 gboolean debug_print_allowance = FALSE;
4432 double allowance_ratio = 0, save_target = 0;
4435 result = InterlockedCompareExchange (&gc_initialized, -1, 0);
4438 /* already inited */
4441 /* being inited by another thread */
4445 /* we will init it */
4448 g_assert_not_reached ();
4450 } while (result != 0);
4452 LOCK_INIT (gc_mutex);
4454 pagesize = mono_pagesize ();
4455 gc_debug_file = stderr;
4457 cb.thread_register = sgen_thread_register;
4458 cb.thread_unregister = sgen_thread_unregister;
4459 cb.thread_attach = sgen_thread_attach;
4460 cb.mono_method_is_critical = (gpointer)is_critical_method;
4462 cb.mono_gc_pthread_create = (gpointer)mono_gc_pthread_create;
4465 mono_threads_init (&cb, sizeof (SgenThreadInfo));
4467 LOCK_INIT (sgen_interruption_mutex);
4468 LOCK_INIT (pin_queue_mutex);
4470 init_user_copy_or_mark_key ();
4472 if ((env = getenv ("MONO_GC_PARAMS"))) {
4473 opts = g_strsplit (env, ",", -1);
4474 for (ptr = opts; *ptr; ++ptr) {
4476 if (g_str_has_prefix (opt, "major=")) {
4477 opt = strchr (opt, '=') + 1;
4478 major_collector_opt = g_strdup (opt);
4479 } else if (g_str_has_prefix (opt, "minor=")) {
4480 opt = strchr (opt, '=') + 1;
4481 minor_collector_opt = g_strdup (opt);
4489 sgen_init_internal_allocator ();
4490 sgen_init_nursery_allocator ();
4492 sgen_register_fixed_internal_mem_type (INTERNAL_MEM_SECTION, SGEN_SIZEOF_GC_MEM_SECTION);
4493 sgen_register_fixed_internal_mem_type (INTERNAL_MEM_FINALIZE_READY_ENTRY, sizeof (FinalizeReadyEntry));
4494 sgen_register_fixed_internal_mem_type (INTERNAL_MEM_GRAY_QUEUE, sizeof (GrayQueueSection));
4495 g_assert (sizeof (GenericStoreRememberedSet) == sizeof (gpointer) * STORE_REMSET_BUFFER_SIZE);
4496 sgen_register_fixed_internal_mem_type (INTERNAL_MEM_STORE_REMSET, sizeof (GenericStoreRememberedSet));
4497 sgen_register_fixed_internal_mem_type (INTERNAL_MEM_EPHEMERON_LINK, sizeof (EphemeronLinkNode));
4499 #ifndef HAVE_KW_THREAD
4500 mono_native_tls_alloc (&thread_info_key, NULL);
4504 * This needs to happen before any internal allocations because
4505 * it inits the small id which is required for hazard pointer
4510 mono_thread_info_attach (&dummy);
4512 if (!minor_collector_opt) {
4513 sgen_simple_nursery_init (&sgen_minor_collector);
4515 if (!strcmp (minor_collector_opt, "simple"))
4516 sgen_simple_nursery_init (&sgen_minor_collector);
4517 else if (!strcmp (minor_collector_opt, "split"))
4518 sgen_split_nursery_init (&sgen_minor_collector);
4520 fprintf (stderr, "Unknown minor collector `%s'.\n", minor_collector_opt);
4525 if (!major_collector_opt || !strcmp (major_collector_opt, "marksweep")) {
4526 sgen_marksweep_init (&major_collector);
4527 } else if (!major_collector_opt || !strcmp (major_collector_opt, "marksweep-fixed")) {
4528 sgen_marksweep_fixed_init (&major_collector);
4529 } else if (!major_collector_opt || !strcmp (major_collector_opt, "marksweep-par")) {
4530 sgen_marksweep_par_init (&major_collector);
4531 } else if (!major_collector_opt || !strcmp (major_collector_opt, "marksweep-fixed-par")) {
4532 sgen_marksweep_fixed_par_init (&major_collector);
4533 } else if (!major_collector_opt || !strcmp (major_collector_opt, "marksweep-conc")) {
4534 sgen_marksweep_conc_init (&major_collector);
4535 } else if (!strcmp (major_collector_opt, "copying")) {
4536 sgen_copying_init (&major_collector);
4538 fprintf (stderr, "Unknown major collector `%s'.\n", major_collector_opt);
4542 #ifdef SGEN_HAVE_CARDTABLE
4543 use_cardtable = major_collector.supports_cardtable;
4545 use_cardtable = FALSE;
4548 num_workers = mono_cpu_count ();
4549 g_assert (num_workers > 0);
4550 if (num_workers > 16)
4553 ///* Keep this the default for now */
4554 /* Precise marking is broken on all supported targets. Disable until fixed. */
4555 conservative_stack_mark = TRUE;
4557 sgen_nursery_size = DEFAULT_NURSERY_SIZE;
4560 for (ptr = opts; *ptr; ++ptr) {
4562 if (g_str_has_prefix (opt, "major="))
4564 if (g_str_has_prefix (opt, "minor="))
4566 if (g_str_has_prefix (opt, "wbarrier=")) {
4567 opt = strchr (opt, '=') + 1;
4568 if (strcmp (opt, "remset") == 0) {
4569 if (major_collector.is_concurrent) {
4570 fprintf (stderr, "The concurrent collector does not support the SSB write barrier.\n");
4573 use_cardtable = FALSE;
4574 } else if (strcmp (opt, "cardtable") == 0) {
4575 if (!use_cardtable) {
4576 if (major_collector.supports_cardtable)
4577 fprintf (stderr, "The cardtable write barrier is not supported on this platform.\n");
4579 fprintf (stderr, "The major collector does not support the cardtable write barrier.\n");
4583 fprintf (stderr, "wbarrier must either be `remset' or `cardtable'.");
4588 if (g_str_has_prefix (opt, "max-heap-size=")) {
4589 opt = strchr (opt, '=') + 1;
4590 if (*opt && mono_gc_parse_environment_string_extract_number (opt, &max_heap)) {
4591 if ((max_heap & (mono_pagesize () - 1))) {
4592 fprintf (stderr, "max-heap-size size must be a multiple of %d.\n", mono_pagesize ());
4596 fprintf (stderr, "max-heap-size must be an integer.\n");
4601 if (g_str_has_prefix (opt, "soft-heap-limit=")) {
4602 opt = strchr (opt, '=') + 1;
4603 if (*opt && mono_gc_parse_environment_string_extract_number (opt, &soft_limit)) {
4604 if (soft_limit <= 0) {
4605 fprintf (stderr, "soft-heap-limit must be positive.\n");
4609 fprintf (stderr, "soft-heap-limit must be an integer.\n");
4614 if (g_str_has_prefix (opt, "workers=")) {
4617 if (!major_collector.is_parallel) {
4618 fprintf (stderr, "The workers= option can only be used for parallel collectors.");
4621 opt = strchr (opt, '=') + 1;
4622 val = strtol (opt, &endptr, 10);
4623 if (!*opt || *endptr) {
4624 fprintf (stderr, "Cannot parse the workers= option value.");
4627 if (val <= 0 || val > 16) {
4628 fprintf (stderr, "The number of workers must be in the range 1 to 16.");
4631 num_workers = (int)val;
4634 if (g_str_has_prefix (opt, "stack-mark=")) {
4635 opt = strchr (opt, '=') + 1;
4636 if (!strcmp (opt, "precise")) {
4637 conservative_stack_mark = FALSE;
4638 } else if (!strcmp (opt, "conservative")) {
4639 conservative_stack_mark = TRUE;
4641 fprintf (stderr, "Invalid value '%s' for stack-mark= option, possible values are: 'precise', 'conservative'.\n", opt);
4646 if (g_str_has_prefix (opt, "bridge=")) {
4647 opt = strchr (opt, '=') + 1;
4648 sgen_register_test_bridge_callbacks (g_strdup (opt));
4652 if (g_str_has_prefix (opt, "nursery-size=")) {
4654 opt = strchr (opt, '=') + 1;
4655 if (*opt && mono_gc_parse_environment_string_extract_number (opt, &val)) {
4656 sgen_nursery_size = val;
4657 #ifdef SGEN_ALIGN_NURSERY
4658 if ((val & (val - 1))) {
4659 fprintf (stderr, "The nursery size must be a power of two.\n");
4663 if (val < SGEN_MAX_NURSERY_WASTE) {
4664 fprintf (stderr, "The nursery size must be at least %d bytes.\n", SGEN_MAX_NURSERY_WASTE);
4668 sgen_nursery_bits = 0;
4669 while (1 << (++ sgen_nursery_bits) != sgen_nursery_size)
4673 fprintf (stderr, "nursery-size must be an integer.\n");
4679 if (g_str_has_prefix (opt, "save-target-ratio=")) {
4681 opt = strchr (opt, '=') + 1;
4682 save_target = strtod (opt, &endptr);
4683 if (endptr == opt) {
4684 fprintf (stderr, "save-target-ratio must be a number.");
4687 if (save_target < SGEN_MIN_SAVE_TARGET_RATIO || save_target > SGEN_MAX_SAVE_TARGET_RATIO) {
4688 fprintf (stderr, "save-target-ratio must be between %.2f - %.2f.", SGEN_MIN_SAVE_TARGET_RATIO, SGEN_MAX_SAVE_TARGET_RATIO);
4693 if (g_str_has_prefix (opt, "default-allowance-ratio=")) {
4695 opt = strchr (opt, '=') + 1;
4697 allowance_ratio = strtod (opt, &endptr);
4698 if (endptr == opt) {
4699 fprintf (stderr, "save-target-ratio must be a number.");
4702 if (allowance_ratio < SGEN_MIN_ALLOWANCE_NURSERY_SIZE_RATIO || allowance_ratio > SGEN_MIN_ALLOWANCE_NURSERY_SIZE_RATIO) {
4703 fprintf (stderr, "default-allowance-ratio must be between %.2f - %.2f.", SGEN_MIN_ALLOWANCE_NURSERY_SIZE_RATIO, SGEN_MIN_ALLOWANCE_NURSERY_SIZE_RATIO);
4709 if (major_collector.handle_gc_param && major_collector.handle_gc_param (opt))
4712 if (sgen_minor_collector.handle_gc_param && sgen_minor_collector.handle_gc_param (opt))
4715 fprintf (stderr, "MONO_GC_PARAMS must be a comma-delimited list of one or more of the following:\n");
4716 fprintf (stderr, " max-heap-size=N (where N is an integer, possibly with a k, m or a g suffix)\n");
4717 fprintf (stderr, " soft-heap-limit=n (where N is an integer, possibly with a k, m or a g suffix)\n");
4718 fprintf (stderr, " nursery-size=N (where N is an integer, possibly with a k, m or a g suffix)\n");
4719 fprintf (stderr, " major=COLLECTOR (where COLLECTOR is `marksweep', `marksweep-par', 'marksweep-fixed', 'marksweep-fixed-par' or `copying')\n");
4720 fprintf (stderr, " minor=COLLECTOR (where COLLECTOR is `simple' or `split')\n");
4721 fprintf (stderr, " wbarrier=WBARRIER (where WBARRIER is `remset' or `cardtable')\n");
4722 fprintf (stderr, " stack-mark=MARK-METHOD (where MARK-METHOD is 'precise' or 'conservative')\n");
4723 if (major_collector.print_gc_param_usage)
4724 major_collector.print_gc_param_usage ();
4725 if (sgen_minor_collector.print_gc_param_usage)
4726 sgen_minor_collector.print_gc_param_usage ();
4727 fprintf (stderr, " Experimental options:\n");
4728 fprintf (stderr, " save-target-ratio=R (where R must be between %.2f - %.2f).\n", SGEN_MIN_SAVE_TARGET_RATIO, SGEN_MAX_SAVE_TARGET_RATIO);
4729 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);
4735 if (major_collector.is_parallel)
4736 sgen_workers_init (num_workers);
4737 else if (major_collector.is_concurrent)
4738 sgen_workers_init (1);
4740 if (major_collector_opt)
4741 g_free (major_collector_opt);
4743 if (minor_collector_opt)
4744 g_free (minor_collector_opt);
4748 if ((env = getenv ("MONO_GC_DEBUG"))) {
4749 opts = g_strsplit (env, ",", -1);
4750 for (ptr = opts; ptr && *ptr; ptr ++) {
4752 if (opt [0] >= '0' && opt [0] <= '9') {
4753 gc_debug_level = atoi (opt);
4759 char *rf = g_strdup_printf ("%s.%d", opt, GetCurrentProcessId ());
4761 char *rf = g_strdup_printf ("%s.%d", opt, getpid ());
4763 gc_debug_file = fopen (rf, "wb");
4765 gc_debug_file = stderr;
4768 } else if (!strcmp (opt, "print-allowance")) {
4769 debug_print_allowance = TRUE;
4770 } else if (!strcmp (opt, "print-pinning")) {
4771 do_pin_stats = TRUE;
4772 } else if (!strcmp (opt, "verify-before-allocs")) {
4773 verify_before_allocs = 1;
4774 has_per_allocation_action = TRUE;
4775 } else if (g_str_has_prefix (opt, "verify-before-allocs=")) {
4776 char *arg = strchr (opt, '=') + 1;
4777 verify_before_allocs = atoi (arg);
4778 has_per_allocation_action = TRUE;
4779 } else if (!strcmp (opt, "collect-before-allocs")) {
4780 collect_before_allocs = 1;
4781 has_per_allocation_action = TRUE;
4782 } else if (g_str_has_prefix (opt, "collect-before-allocs=")) {
4783 char *arg = strchr (opt, '=') + 1;
4784 has_per_allocation_action = TRUE;
4785 collect_before_allocs = atoi (arg);
4786 } else if (!strcmp (opt, "verify-before-collections")) {
4787 whole_heap_check_before_collection = TRUE;
4788 } else if (!strcmp (opt, "check-at-minor-collections")) {
4789 consistency_check_at_minor_collection = TRUE;
4790 nursery_clear_policy = CLEAR_AT_GC;
4791 } else if (!strcmp (opt, "xdomain-checks")) {
4792 xdomain_checks = TRUE;
4793 } else if (!strcmp (opt, "clear-at-gc")) {
4794 nursery_clear_policy = CLEAR_AT_GC;
4795 } else if (!strcmp (opt, "clear-nursery-at-gc")) {
4796 nursery_clear_policy = CLEAR_AT_GC;
4797 } else if (!strcmp (opt, "check-scan-starts")) {
4798 do_scan_starts_check = TRUE;
4799 } else if (!strcmp (opt, "verify-nursery-at-minor-gc")) {
4800 do_verify_nursery = TRUE;
4801 } else if (!strcmp (opt, "dump-nursery-at-minor-gc")) {
4802 do_dump_nursery_content = TRUE;
4803 } else if (!strcmp (opt, "no-managed-allocator")) {
4804 sgen_set_use_managed_allocator (FALSE);
4805 } else if (!strcmp (opt, "disable-minor")) {
4806 disable_minor_collections = TRUE;
4807 } else if (!strcmp (opt, "disable-major")) {
4808 disable_major_collections = TRUE;
4809 } else if (g_str_has_prefix (opt, "heap-dump=")) {
4810 char *filename = strchr (opt, '=') + 1;
4811 nursery_clear_policy = CLEAR_AT_GC;
4812 heap_dump_file = fopen (filename, "w");
4813 if (heap_dump_file) {
4814 fprintf (heap_dump_file, "<sgen-dump>\n");
4815 do_pin_stats = TRUE;
4817 #ifdef SGEN_BINARY_PROTOCOL
4818 } else if (g_str_has_prefix (opt, "binary-protocol=")) {
4819 char *filename = strchr (opt, '=') + 1;
4820 binary_protocol_init (filename);
4822 fprintf (stderr, "Warning: Cardtable write barriers will not be binary-protocolled.\n");
4825 fprintf (stderr, "Invalid format for the MONO_GC_DEBUG env variable: '%s'\n", env);
4826 fprintf (stderr, "The format is: MONO_GC_DEBUG=[l[:filename]|<option>]+ where l is a debug level 0-9.\n");
4827 fprintf (stderr, "Valid options are:\n");
4828 fprintf (stderr, " collect-before-allocs[=<n>]\n");
4829 fprintf (stderr, " verify-before-allocs[=<n>]\n");
4830 fprintf (stderr, " check-at-minor-collections\n");
4831 fprintf (stderr, " verify-before-collections\n");
4832 fprintf (stderr, " verify-nursery-at-minor-gc\n");
4833 fprintf (stderr, " dump-nursery-at-minor-gc\n");
4834 fprintf (stderr, " disable-minor\n");
4835 fprintf (stderr, " disable-major\n");
4836 fprintf (stderr, " xdomain-checks\n");
4837 fprintf (stderr, " clear-at-gc\n");
4838 fprintf (stderr, " clear-nursery-at-gc\n");
4839 fprintf (stderr, " check-scan-starts\n");
4840 fprintf (stderr, " no-managed-allocator\n");
4841 fprintf (stderr, " print-allowance\n");
4842 fprintf (stderr, " print-pinning\n");
4843 fprintf (stderr, " heap-dump=<filename>\n");
4844 #ifdef SGEN_BINARY_PROTOCOL
4845 fprintf (stderr, " binary-protocol=<filename>\n");
4853 if (major_collector.is_parallel) {
4854 if (heap_dump_file) {
4855 fprintf (stderr, "Error: Cannot do heap dump with the parallel collector.\n");
4859 fprintf (stderr, "Error: Cannot gather pinning statistics with the parallel collector.\n");
4864 if (major_collector.post_param_init)
4865 major_collector.post_param_init ();
4867 sgen_memgov_init (max_heap, soft_limit, debug_print_allowance, allowance_ratio, save_target);
4869 memset (&remset, 0, sizeof (remset));
4871 #ifdef SGEN_HAVE_CARDTABLE
4873 sgen_card_table_init (&remset);
4876 sgen_ssb_init (&remset);
4878 if (remset.register_thread)
4879 remset.register_thread (mono_thread_info_current ());
4885 mono_gc_get_gc_name (void)
4890 static MonoMethod *write_barrier_method;
4893 sgen_is_critical_method (MonoMethod *method)
4895 return (method == write_barrier_method || sgen_is_managed_allocator (method));
4899 sgen_has_critical_method (void)
4901 return write_barrier_method || sgen_has_managed_allocator ();
4905 emit_nursery_check (MonoMethodBuilder *mb, int *nursery_check_return_labels)
4907 memset (nursery_check_return_labels, 0, sizeof (int) * 3);
4908 #ifdef SGEN_ALIGN_NURSERY
4909 // if (ptr_in_nursery (ptr)) return;
4911 * Masking out the bits might be faster, but we would have to use 64 bit
4912 * immediates, which might be slower.
4914 mono_mb_emit_ldarg (mb, 0);
4915 mono_mb_emit_icon (mb, DEFAULT_NURSERY_BITS);
4916 mono_mb_emit_byte (mb, CEE_SHR_UN);
4917 mono_mb_emit_icon (mb, (mword)sgen_get_nursery_start () >> DEFAULT_NURSERY_BITS);
4918 nursery_check_return_labels [0] = mono_mb_emit_branch (mb, CEE_BEQ);
4920 if (!major_collector.is_concurrent) {
4921 // if (!ptr_in_nursery (*ptr)) return;
4922 mono_mb_emit_ldarg (mb, 0);
4923 mono_mb_emit_byte (mb, CEE_LDIND_I);
4924 mono_mb_emit_icon (mb, DEFAULT_NURSERY_BITS);
4925 mono_mb_emit_byte (mb, CEE_SHR_UN);
4926 mono_mb_emit_icon (mb, (mword)sgen_get_nursery_start () >> DEFAULT_NURSERY_BITS);
4927 nursery_check_return_labels [1] = mono_mb_emit_branch (mb, CEE_BNE_UN);
4930 int label_continue1, label_continue2;
4931 int dereferenced_var;
4933 // if (ptr < (sgen_get_nursery_start ())) goto continue;
4934 mono_mb_emit_ldarg (mb, 0);
4935 mono_mb_emit_ptr (mb, (gpointer) sgen_get_nursery_start ());
4936 label_continue_1 = mono_mb_emit_branch (mb, CEE_BLT);
4938 // if (ptr >= sgen_get_nursery_end ())) goto continue;
4939 mono_mb_emit_ldarg (mb, 0);
4940 mono_mb_emit_ptr (mb, (gpointer) sgen_get_nursery_end ());
4941 label_continue_2 = mono_mb_emit_branch (mb, CEE_BGE);
4944 nursery_check_return_labels [0] = mono_mb_emit_branch (mb, CEE_BR);
4947 mono_mb_patch_branch (mb, label_continue_1);
4948 mono_mb_patch_branch (mb, label_continue_2);
4950 // Dereference and store in local var
4951 dereferenced_var = mono_mb_add_local (mb, &mono_defaults.int_class->byval_arg);
4952 mono_mb_emit_ldarg (mb, 0);
4953 mono_mb_emit_byte (mb, CEE_LDIND_I);
4954 mono_mb_emit_stloc (mb, dereferenced_var);
4956 if (!major_collector.is_concurrent) {
4957 // if (*ptr < sgen_get_nursery_start ()) return;
4958 mono_mb_emit_ldloc (mb, dereferenced_var);
4959 mono_mb_emit_ptr (mb, (gpointer) sgen_get_nursery_start ());
4960 nursery_check_return_labels [1] = mono_mb_emit_branch (mb, CEE_BLT);
4962 // if (*ptr >= sgen_get_nursery_end ()) return;
4963 mono_mb_emit_ldloc (mb, dereferenced_var);
4964 mono_mb_emit_ptr (mb, (gpointer) sgen_get_nursery_end ());
4965 nursery_check_return_labels [2] = mono_mb_emit_branch (mb, CEE_BGE);
4971 mono_gc_get_write_barrier (void)
4974 MonoMethodBuilder *mb;
4975 MonoMethodSignature *sig;
4976 #ifdef MANAGED_WBARRIER
4977 int i, nursery_check_labels [3];
4978 int label_no_wb_3, label_no_wb_4, label_need_wb, label_slow_path;
4979 int buffer_var, buffer_index_var, dummy_var;
4981 #ifdef HAVE_KW_THREAD
4982 int stack_end_offset = -1, store_remset_buffer_offset = -1;
4983 int store_remset_buffer_index_offset = -1, store_remset_buffer_index_addr_offset = -1;
4985 MONO_THREAD_VAR_OFFSET (stack_end, stack_end_offset);
4986 g_assert (stack_end_offset != -1);
4987 MONO_THREAD_VAR_OFFSET (store_remset_buffer, store_remset_buffer_offset);
4988 g_assert (store_remset_buffer_offset != -1);
4989 MONO_THREAD_VAR_OFFSET (store_remset_buffer_index, store_remset_buffer_index_offset);
4990 g_assert (store_remset_buffer_index_offset != -1);
4991 MONO_THREAD_VAR_OFFSET (store_remset_buffer_index_addr, store_remset_buffer_index_addr_offset);
4992 g_assert (store_remset_buffer_index_addr_offset != -1);
4996 // FIXME: Maybe create a separate version for ctors (the branch would be
4997 // correctly predicted more times)
4998 if (write_barrier_method)
4999 return write_barrier_method;
5001 /* Create the IL version of mono_gc_barrier_generic_store () */
5002 sig = mono_metadata_signature_alloc (mono_defaults.corlib, 1);
5003 sig->ret = &mono_defaults.void_class->byval_arg;
5004 sig->params [0] = &mono_defaults.int_class->byval_arg;
5006 mb = mono_mb_new (mono_defaults.object_class, "wbarrier", MONO_WRAPPER_WRITE_BARRIER);
5008 #ifdef MANAGED_WBARRIER
5009 if (use_cardtable) {
5010 emit_nursery_check (mb, nursery_check_labels);
5012 addr = sgen_cardtable + ((address >> CARD_BITS) & CARD_MASK)
5016 LDC_PTR sgen_cardtable
5018 address >> CARD_BITS
5022 if (SGEN_HAVE_OVERLAPPING_CARDS) {
5023 LDC_PTR card_table_mask
5030 mono_mb_emit_ptr (mb, sgen_cardtable);
5031 mono_mb_emit_ldarg (mb, 0);
5032 mono_mb_emit_icon (mb, CARD_BITS);
5033 mono_mb_emit_byte (mb, CEE_SHR_UN);
5034 #ifdef SGEN_HAVE_OVERLAPPING_CARDS
5035 mono_mb_emit_ptr (mb, (gpointer)CARD_MASK);
5036 mono_mb_emit_byte (mb, CEE_AND);
5038 mono_mb_emit_byte (mb, CEE_ADD);
5039 mono_mb_emit_icon (mb, 1);
5040 mono_mb_emit_byte (mb, CEE_STIND_I1);
5043 for (i = 0; i < 3; ++i) {
5044 if (nursery_check_labels [i])
5045 mono_mb_patch_branch (mb, nursery_check_labels [i]);
5047 mono_mb_emit_byte (mb, CEE_RET);
5048 } else if (mono_runtime_has_tls_get ()) {
5049 emit_nursery_check (mb, nursery_check_labels);
5051 // if (ptr >= stack_end) goto need_wb;
5052 mono_mb_emit_ldarg (mb, 0);
5053 EMIT_TLS_ACCESS (mb, stack_end, stack_end_offset);
5054 label_need_wb = mono_mb_emit_branch (mb, CEE_BGE_UN);
5056 // if (ptr >= stack_start) return;
5057 dummy_var = mono_mb_add_local (mb, &mono_defaults.int_class->byval_arg);
5058 mono_mb_emit_ldarg (mb, 0);
5059 mono_mb_emit_ldloc_addr (mb, dummy_var);
5060 label_no_wb_3 = mono_mb_emit_branch (mb, CEE_BGE_UN);
5063 mono_mb_patch_branch (mb, label_need_wb);
5065 // buffer = STORE_REMSET_BUFFER;
5066 buffer_var = mono_mb_add_local (mb, &mono_defaults.int_class->byval_arg);
5067 EMIT_TLS_ACCESS (mb, store_remset_buffer, store_remset_buffer_offset);
5068 mono_mb_emit_stloc (mb, buffer_var);
5070 // buffer_index = STORE_REMSET_BUFFER_INDEX;
5071 buffer_index_var = mono_mb_add_local (mb, &mono_defaults.int_class->byval_arg);
5072 EMIT_TLS_ACCESS (mb, store_remset_buffer_index, store_remset_buffer_index_offset);
5073 mono_mb_emit_stloc (mb, buffer_index_var);
5075 // if (buffer [buffer_index] == ptr) return;
5076 mono_mb_emit_ldloc (mb, buffer_var);
5077 mono_mb_emit_ldloc (mb, buffer_index_var);
5078 g_assert (sizeof (gpointer) == 4 || sizeof (gpointer) == 8);
5079 mono_mb_emit_icon (mb, sizeof (gpointer) == 4 ? 2 : 3);
5080 mono_mb_emit_byte (mb, CEE_SHL);
5081 mono_mb_emit_byte (mb, CEE_ADD);
5082 mono_mb_emit_byte (mb, CEE_LDIND_I);
5083 mono_mb_emit_ldarg (mb, 0);
5084 label_no_wb_4 = mono_mb_emit_branch (mb, CEE_BEQ);
5087 mono_mb_emit_ldloc (mb, buffer_index_var);
5088 mono_mb_emit_icon (mb, 1);
5089 mono_mb_emit_byte (mb, CEE_ADD);
5090 mono_mb_emit_stloc (mb, buffer_index_var);
5092 // if (buffer_index >= STORE_REMSET_BUFFER_SIZE) goto slow_path;
5093 mono_mb_emit_ldloc (mb, buffer_index_var);
5094 mono_mb_emit_icon (mb, STORE_REMSET_BUFFER_SIZE);
5095 label_slow_path = mono_mb_emit_branch (mb, CEE_BGE);
5097 // buffer [buffer_index] = ptr;
5098 mono_mb_emit_ldloc (mb, buffer_var);
5099 mono_mb_emit_ldloc (mb, buffer_index_var);
5100 g_assert (sizeof (gpointer) == 4 || sizeof (gpointer) == 8);
5101 mono_mb_emit_icon (mb, sizeof (gpointer) == 4 ? 2 : 3);
5102 mono_mb_emit_byte (mb, CEE_SHL);
5103 mono_mb_emit_byte (mb, CEE_ADD);
5104 mono_mb_emit_ldarg (mb, 0);
5105 mono_mb_emit_byte (mb, CEE_STIND_I);
5107 // STORE_REMSET_BUFFER_INDEX = buffer_index;
5108 EMIT_TLS_ACCESS (mb, store_remset_buffer_index_addr, store_remset_buffer_index_addr_offset);
5109 mono_mb_emit_ldloc (mb, buffer_index_var);
5110 mono_mb_emit_byte (mb, CEE_STIND_I);
5113 for (i = 0; i < 3; ++i) {
5114 if (nursery_check_labels [i])
5115 mono_mb_patch_branch (mb, nursery_check_labels [i]);
5117 mono_mb_patch_branch (mb, label_no_wb_3);
5118 mono_mb_patch_branch (mb, label_no_wb_4);
5119 mono_mb_emit_byte (mb, CEE_RET);
5122 mono_mb_patch_branch (mb, label_slow_path);
5124 mono_mb_emit_ldarg (mb, 0);
5125 mono_mb_emit_icall (mb, mono_gc_wbarrier_generic_nostore);
5126 mono_mb_emit_byte (mb, CEE_RET);
5130 mono_mb_emit_ldarg (mb, 0);
5131 mono_mb_emit_icall (mb, mono_gc_wbarrier_generic_nostore);
5132 mono_mb_emit_byte (mb, CEE_RET);
5135 res = mono_mb_create_method (mb, sig, 16);
5138 mono_loader_lock ();
5139 if (write_barrier_method) {
5140 /* Already created */
5141 mono_free_method (res);
5143 /* double-checked locking */
5144 mono_memory_barrier ();
5145 write_barrier_method = res;
5147 mono_loader_unlock ();
5149 return write_barrier_method;
5153 mono_gc_get_description (void)
5155 return g_strdup ("sgen");
5159 mono_gc_set_desktop_mode (void)
5164 mono_gc_is_moving (void)
5170 mono_gc_is_disabled (void)
5176 BOOL APIENTRY mono_gc_dllmain (HMODULE module_handle, DWORD reason, LPVOID reserved)
5183 sgen_get_nursery_clear_policy (void)
5185 return nursery_clear_policy;
5189 sgen_get_array_fill_vtable (void)
5191 if (!array_fill_vtable) {
5192 static MonoClass klass;
5193 static MonoVTable vtable;
5196 MonoDomain *domain = mono_get_root_domain ();
5199 klass.element_class = mono_defaults.byte_class;
5201 klass.instance_size = sizeof (MonoArray);
5202 klass.sizes.element_size = 1;
5203 klass.name = "array_filler_type";
5205 vtable.klass = &klass;
5207 vtable.gc_descr = mono_gc_make_descr_for_array (TRUE, &bmap, 0, 1);
5210 array_fill_vtable = &vtable;
5212 return array_fill_vtable;
5222 sgen_gc_unlock (void)
5228 sgen_major_collector_iterate_live_block_ranges (sgen_cardtable_block_callback callback)
5230 major_collector.iterate_live_block_ranges (callback);
5234 sgen_major_collector_scan_card_table (SgenGrayQueue *queue)
5236 major_collector.scan_card_table (FALSE, queue);
5240 sgen_get_major_collector (void)
5242 return &major_collector;
5245 void mono_gc_set_skip_thread (gboolean skip)
5247 SgenThreadInfo *info = mono_thread_info_current ();
5250 info->gc_disabled = skip;
5255 sgen_get_remset (void)
5261 mono_gc_get_vtable_bits (MonoClass *class)
5263 if (sgen_need_bridge_processing () && sgen_is_bridge_class (class))
5264 return SGEN_GC_BIT_BRIDGE_OBJECT;
5269 mono_gc_register_altstack (gpointer stack, gint32 stack_size, gpointer altstack, gint32 altstack_size)
5276 sgen_check_whole_heap_stw (void)
5278 sgen_stop_world (0);
5279 sgen_clear_nursery_fragments ();
5280 sgen_check_whole_heap ();
5281 sgen_restart_world (0, NULL);
5285 sgen_gc_event_moves (void)
5287 if (moved_objects_idx) {
5288 mono_profiler_gc_moves (moved_objects, moved_objects_idx);
5289 moved_objects_idx = 0;
5293 #endif /* HAVE_SGEN_GC */