2 * sgen-gc.c: Simple generational GC.
5 * Paolo Molaro (lupus@ximian.com)
6 * Rodrigo Kumpera (kumpera@gmail.com)
8 * Copyright 2005-2011 Novell, Inc (http://www.novell.com)
9 * Copyright 2011 Xamarin Inc (http://www.xamarin.com)
11 * Thread start/stop adapted from Boehm's GC:
12 * Copyright (c) 1994 by Xerox Corporation. All rights reserved.
13 * Copyright (c) 1996 by Silicon Graphics. All rights reserved.
14 * Copyright (c) 1998 by Fergus Henderson. All rights reserved.
15 * Copyright (c) 2000-2004 by Hewlett-Packard Company. All rights reserved.
16 * Copyright 2001-2003 Ximian, Inc
17 * Copyright 2003-2010 Novell, Inc.
18 * Copyright 2011 Xamarin, Inc.
19 * Copyright (C) 2012 Xamarin Inc
21 * This library is free software; you can redistribute it and/or
22 * modify it under the terms of the GNU Library General Public
23 * License 2.0 as published by the Free Software Foundation;
25 * This library is distributed in the hope that it will be useful,
26 * but WITHOUT ANY WARRANTY; without even the implied warranty of
27 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
28 * Library General Public License for more details.
30 * You should have received a copy of the GNU Library General Public
31 * License 2.0 along with this library; if not, write to the Free
32 * Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
34 * Important: allocation provides always zeroed memory, having to do
35 * a memset after allocation is deadly for performance.
36 * Memory usage at startup is currently as follows:
38 * 64 KB internal space
40 * We should provide a small memory config with half the sizes
42 * We currently try to make as few mono assumptions as possible:
43 * 1) 2-word header with no GC pointers in it (first vtable, second to store the
45 * 2) gc descriptor is the second word in the vtable (first word in the class)
46 * 3) 8 byte alignment is the minimum and enough (not true for special structures (SIMD), FIXME)
47 * 4) there is a function to get an object's size and the number of
48 * elements in an array.
49 * 5) we know the special way bounds are allocated for complex arrays
50 * 6) we know about proxies and how to treat them when domains are unloaded
52 * Always try to keep stack usage to a minimum: no recursive behaviour
53 * and no large stack allocs.
55 * General description.
56 * Objects are initially allocated in a nursery using a fast bump-pointer technique.
57 * When the nursery is full we start a nursery collection: this is performed with a
59 * When the old generation is full we start a copying GC of the old generation as well:
60 * this will be changed to mark&sweep with copying when fragmentation becomes to severe
61 * in the future. Maybe we'll even do both during the same collection like IMMIX.
63 * The things that complicate this description are:
64 * *) pinned objects: we can't move them so we need to keep track of them
65 * *) no precise info of the thread stacks and registers: we need to be able to
66 * quickly find the objects that may be referenced conservatively and pin them
67 * (this makes the first issues more important)
68 * *) large objects are too expensive to be dealt with using copying GC: we handle them
69 * with mark/sweep during major collections
70 * *) some objects need to not move even if they are small (interned strings, Type handles):
71 * we use mark/sweep for them, too: they are not allocated in the nursery, but inside
72 * PinnedChunks regions
78 *) we could have a function pointer in MonoClass to implement
79 customized write barriers for value types
81 *) investigate the stuff needed to advance a thread to a GC-safe
82 point (single-stepping, read from unmapped memory etc) and implement it.
83 This would enable us to inline allocations and write barriers, for example,
84 or at least parts of them, like the write barrier checks.
85 We may need this also for handling precise info on stacks, even simple things
86 as having uninitialized data on the stack and having to wait for the prolog
87 to zero it. Not an issue for the last frame that we scan conservatively.
88 We could always not trust the value in the slots anyway.
90 *) modify the jit to save info about references in stack locations:
91 this can be done just for locals as a start, so that at least
92 part of the stack is handled precisely.
94 *) test/fix endianess issues
96 *) Implement a card table as the write barrier instead of remembered
97 sets? Card tables are not easy to implement with our current
98 memory layout. We have several different kinds of major heap
99 objects: Small objects in regular blocks, small objects in pinned
100 chunks and LOS objects. If we just have a pointer we have no way
101 to tell which kind of object it points into, therefore we cannot
102 know where its card table is. The least we have to do to make
103 this happen is to get rid of write barriers for indirect stores.
106 *) Get rid of write barriers for indirect stores. We can do this by
107 telling the GC to wbarrier-register an object once we do an ldloca
108 or ldelema on it, and to unregister it once it's not used anymore
109 (it can only travel downwards on the stack). The problem with
110 unregistering is that it needs to happen eventually no matter
111 what, even if exceptions are thrown, the thread aborts, etc.
112 Rodrigo suggested that we could do only the registering part and
113 let the collector find out (pessimistically) when it's safe to
114 unregister, namely when the stack pointer of the thread that
115 registered the object is higher than it was when the registering
116 happened. This might make for a good first implementation to get
117 some data on performance.
119 *) Some sort of blacklist support? Blacklists is a concept from the
120 Boehm GC: if during a conservative scan we find pointers to an
121 area which we might use as heap, we mark that area as unusable, so
122 pointer retention by random pinning pointers is reduced.
124 *) experiment with max small object size (very small right now - 2kb,
125 because it's tied to the max freelist size)
127 *) add an option to mmap the whole heap in one chunk: it makes for many
128 simplifications in the checks (put the nursery at the top and just use a single
129 check for inclusion/exclusion): the issue this has is that on 32 bit systems it's
130 not flexible (too much of the address space may be used by default or we can't
131 increase the heap as needed) and we'd need a race-free mechanism to return memory
132 back to the system (mprotect(PROT_NONE) will still keep the memory allocated if it
133 was written to, munmap is needed, but the following mmap may not find the same segment
136 *) memzero the major fragments after restarting the world and optionally a smaller
139 *) investigate having fragment zeroing threads
141 *) separate locks for finalization and other minor stuff to reduce
144 *) try a different copying order to improve memory locality
146 *) a thread abort after a store but before the write barrier will
147 prevent the write barrier from executing
149 *) specialized dynamically generated markers/copiers
151 *) Dynamically adjust TLAB size to the number of threads. If we have
152 too many threads that do allocation, we might need smaller TLABs,
153 and we might get better performance with larger TLABs if we only
154 have a handful of threads. We could sum up the space left in all
155 assigned TLABs and if that's more than some percentage of the
156 nursery size, reduce the TLAB size.
158 *) Explore placing unreachable objects on unused nursery memory.
159 Instead of memset'ng a region to zero, place an int[] covering it.
160 A good place to start is add_nursery_frag. The tricky thing here is
161 placing those objects atomically outside of a collection.
163 *) Allocation should use asymmetric Dekker synchronization:
164 http://blogs.oracle.com/dave/resource/Asymmetric-Dekker-Synchronization.txt
165 This should help weak consistency archs.
172 #define _XOPEN_SOURCE
173 #define _DARWIN_C_SOURCE
179 #ifdef HAVE_PTHREAD_H
182 #ifdef HAVE_SEMAPHORE_H
183 #include <semaphore.h>
191 #include "metadata/sgen-gc.h"
192 #include "metadata/metadata-internals.h"
193 #include "metadata/class-internals.h"
194 #include "metadata/gc-internal.h"
195 #include "metadata/object-internals.h"
196 #include "metadata/threads.h"
197 #include "metadata/sgen-cardtable.h"
198 #include "metadata/sgen-ssb.h"
199 #include "metadata/sgen-protocol.h"
200 #include "metadata/sgen-archdep.h"
201 #include "metadata/sgen-bridge.h"
202 #include "metadata/sgen-memory-governor.h"
203 #include "metadata/sgen-hash-table.h"
204 #include "metadata/mono-gc.h"
205 #include "metadata/method-builder.h"
206 #include "metadata/profiler-private.h"
207 #include "metadata/monitor.h"
208 #include "metadata/threadpool-internals.h"
209 #include "metadata/mempool-internals.h"
210 #include "metadata/marshal.h"
211 #include "metadata/runtime.h"
212 #include "metadata/sgen-cardtable.h"
213 #include "metadata/sgen-pinning.h"
214 #include "metadata/sgen-workers.h"
215 #include "utils/mono-mmap.h"
216 #include "utils/mono-time.h"
217 #include "utils/mono-semaphore.h"
218 #include "utils/mono-counters.h"
219 #include "utils/mono-proclib.h"
220 #include "utils/mono-memory-model.h"
221 #include "utils/mono-logger-internal.h"
222 #include "utils/dtrace.h"
224 #include <mono/utils/mono-logger-internal.h>
225 #include <mono/utils/memcheck.h>
227 #if defined(__MACH__)
228 #include "utils/mach-support.h"
231 #define OPDEF(a,b,c,d,e,f,g,h,i,j) \
235 #include "mono/cil/opcode.def"
241 #undef pthread_create
243 #undef pthread_detach
246 * ######################################################################
247 * ######## Types and constants used by the GC.
248 * ######################################################################
251 /* 0 means not initialized, 1 is initialized, -1 means in progress */
252 static int gc_initialized = 0;
253 /* If set, check if we need to do something every X allocations */
254 gboolean has_per_allocation_action;
255 /* If set, do a heap check every X allocation */
256 guint32 verify_before_allocs = 0;
257 /* If set, do a minor collection before every X allocation */
258 guint32 collect_before_allocs = 0;
259 /* If set, do a whole heap check before each collection */
260 static gboolean whole_heap_check_before_collection = FALSE;
261 /* If set, do a heap consistency check before each minor collection */
262 static gboolean consistency_check_at_minor_collection = FALSE;
263 /* If set, do a few checks when the concurrent collector is used */
264 static gboolean do_concurrent_checks = FALSE;
265 /* If set, check that there are no references to the domain left at domain unload */
266 static gboolean xdomain_checks = FALSE;
267 /* If not null, dump the heap after each collection into this file */
268 static FILE *heap_dump_file = NULL;
269 /* If set, mark stacks conservatively, even if precise marking is possible */
270 static gboolean conservative_stack_mark = FALSE;
271 /* If set, do a plausibility check on the scan_starts before and after
273 static gboolean do_scan_starts_check = FALSE;
274 static gboolean nursery_collection_is_parallel = FALSE;
275 static gboolean disable_minor_collections = FALSE;
276 static gboolean disable_major_collections = FALSE;
277 gboolean do_pin_stats = FALSE;
278 static gboolean do_verify_nursery = FALSE;
279 static gboolean do_dump_nursery_content = FALSE;
281 #ifdef HEAVY_STATISTICS
282 long long stat_objects_alloced_degraded = 0;
283 long long stat_bytes_alloced_degraded = 0;
285 long long stat_copy_object_called_nursery = 0;
286 long long stat_objects_copied_nursery = 0;
287 long long stat_copy_object_called_major = 0;
288 long long stat_objects_copied_major = 0;
290 long long stat_scan_object_called_nursery = 0;
291 long long stat_scan_object_called_major = 0;
293 long long stat_slots_allocated_in_vain;
295 long long stat_nursery_copy_object_failed_from_space = 0;
296 long long stat_nursery_copy_object_failed_forwarded = 0;
297 long long stat_nursery_copy_object_failed_pinned = 0;
298 long long stat_nursery_copy_object_failed_to_space = 0;
300 static int stat_wbarrier_set_field = 0;
301 static int stat_wbarrier_set_arrayref = 0;
302 static int stat_wbarrier_arrayref_copy = 0;
303 static int stat_wbarrier_generic_store = 0;
304 static int stat_wbarrier_set_root = 0;
305 static int stat_wbarrier_value_copy = 0;
306 static int stat_wbarrier_object_copy = 0;
309 int stat_minor_gcs = 0;
310 int stat_major_gcs = 0;
312 static long long stat_pinned_objects = 0;
314 static long long time_minor_pre_collection_fragment_clear = 0;
315 static long long time_minor_pinning = 0;
316 static long long time_minor_scan_remsets = 0;
317 static long long time_minor_scan_pinned = 0;
318 static long long time_minor_scan_registered_roots = 0;
319 static long long time_minor_scan_thread_data = 0;
320 static long long time_minor_finish_gray_stack = 0;
321 static long long time_minor_fragment_creation = 0;
323 static long long time_major_pre_collection_fragment_clear = 0;
324 static long long time_major_pinning = 0;
325 static long long time_major_scan_pinned = 0;
326 static long long time_major_scan_registered_roots = 0;
327 static long long time_major_scan_thread_data = 0;
328 static long long time_major_scan_alloc_pinned = 0;
329 static long long time_major_scan_finalized = 0;
330 static long long time_major_scan_big_objects = 0;
331 static long long time_major_finish_gray_stack = 0;
332 static long long time_major_free_bigobjs = 0;
333 static long long time_major_los_sweep = 0;
334 static long long time_major_sweep = 0;
335 static long long time_major_fragment_creation = 0;
337 int gc_debug_level = 0;
342 mono_gc_flush_info (void)
344 fflush (gc_debug_file);
348 #define TV_DECLARE SGEN_TV_DECLARE
349 #define TV_GETTIME SGEN_TV_GETTIME
350 #define TV_ELAPSED SGEN_TV_ELAPSED
351 #define TV_ELAPSED_MS SGEN_TV_ELAPSED_MS
353 #define ALIGN_TO(val,align) ((((guint64)val) + ((align) - 1)) & ~((align) - 1))
355 NurseryClearPolicy nursery_clear_policy = CLEAR_AT_TLAB_CREATION;
357 #define object_is_forwarded SGEN_OBJECT_IS_FORWARDED
358 #define object_is_pinned SGEN_OBJECT_IS_PINNED
359 #define pin_object SGEN_PIN_OBJECT
360 #define unpin_object SGEN_UNPIN_OBJECT
362 #define ptr_in_nursery sgen_ptr_in_nursery
364 #define LOAD_VTABLE SGEN_LOAD_VTABLE
367 safe_name (void* obj)
369 MonoVTable *vt = (MonoVTable*)LOAD_VTABLE (obj);
370 return vt->klass->name;
373 #define safe_object_get_size sgen_safe_object_get_size
376 sgen_safe_name (void* obj)
378 return safe_name (obj);
382 * ######################################################################
383 * ######## Global data.
384 * ######################################################################
386 LOCK_DECLARE (gc_mutex);
387 static int gc_disabled = 0;
389 static gboolean use_cardtable;
391 #define SCAN_START_SIZE SGEN_SCAN_START_SIZE
393 static mword pagesize = 4096;
394 int degraded_mode = 0;
396 static mword bytes_pinned_from_failed_allocation = 0;
398 GCMemSection *nursery_section = NULL;
399 static mword lowest_heap_address = ~(mword)0;
400 static mword highest_heap_address = 0;
402 LOCK_DECLARE (sgen_interruption_mutex);
403 static LOCK_DECLARE (pin_queue_mutex);
405 #define LOCK_PIN_QUEUE mono_mutex_lock (&pin_queue_mutex)
406 #define UNLOCK_PIN_QUEUE mono_mutex_unlock (&pin_queue_mutex)
408 typedef struct _FinalizeReadyEntry FinalizeReadyEntry;
409 struct _FinalizeReadyEntry {
410 FinalizeReadyEntry *next;
414 typedef struct _EphemeronLinkNode EphemeronLinkNode;
416 struct _EphemeronLinkNode {
417 EphemeronLinkNode *next;
426 int current_collection_generation = -1;
427 volatile gboolean concurrent_collection_in_progress = FALSE;
429 /* objects that are ready to be finalized */
430 static FinalizeReadyEntry *fin_ready_list = NULL;
431 static FinalizeReadyEntry *critical_fin_list = NULL;
433 static EphemeronLinkNode *ephemeron_list;
435 /* registered roots: the key to the hash is the root start address */
437 * Different kinds of roots are kept separate to speed up pin_from_roots () for example.
439 SgenHashTable roots_hash [ROOT_TYPE_NUM] = {
440 SGEN_HASH_TABLE_INIT (INTERNAL_MEM_ROOTS_TABLE, INTERNAL_MEM_ROOT_RECORD, sizeof (RootRecord), mono_aligned_addr_hash, NULL),
441 SGEN_HASH_TABLE_INIT (INTERNAL_MEM_ROOTS_TABLE, INTERNAL_MEM_ROOT_RECORD, sizeof (RootRecord), mono_aligned_addr_hash, NULL),
442 SGEN_HASH_TABLE_INIT (INTERNAL_MEM_ROOTS_TABLE, INTERNAL_MEM_ROOT_RECORD, sizeof (RootRecord), mono_aligned_addr_hash, NULL)
444 static mword roots_size = 0; /* amount of memory in the root set */
446 #define GC_ROOT_NUM 32
448 int count; /* must be the first field */
449 void *objects [GC_ROOT_NUM];
450 int root_types [GC_ROOT_NUM];
451 uintptr_t extra_info [GC_ROOT_NUM];
455 notify_gc_roots (GCRootReport *report)
459 mono_profiler_gc_roots (report->count, report->objects, report->root_types, report->extra_info);
464 add_profile_gc_root (GCRootReport *report, void *object, int rtype, uintptr_t extra_info)
466 if (report->count == GC_ROOT_NUM)
467 notify_gc_roots (report);
468 report->objects [report->count] = object;
469 report->root_types [report->count] = rtype;
470 report->extra_info [report->count++] = (uintptr_t)((MonoVTable*)LOAD_VTABLE (object))->klass;
473 MonoNativeTlsKey thread_info_key;
475 #ifdef HAVE_KW_THREAD
476 __thread SgenThreadInfo *sgen_thread_info;
477 __thread gpointer *store_remset_buffer;
478 __thread long store_remset_buffer_index;
479 __thread char *stack_end;
480 __thread long *store_remset_buffer_index_addr;
483 /* The size of a TLAB */
484 /* The bigger the value, the less often we have to go to the slow path to allocate a new
485 * one, but the more space is wasted by threads not allocating much memory.
487 * FIXME: Make this self-tuning for each thread.
489 guint32 tlab_size = (1024 * 4);
491 #define MAX_SMALL_OBJ_SIZE SGEN_MAX_SMALL_OBJ_SIZE
493 /* Functions supplied by the runtime to be called by the GC */
494 static MonoGCCallbacks gc_callbacks;
496 #define ALLOC_ALIGN SGEN_ALLOC_ALIGN
497 #define ALLOC_ALIGN_BITS SGEN_ALLOC_ALIGN_BITS
499 #define ALIGN_UP SGEN_ALIGN_UP
501 #define MOVED_OBJECTS_NUM 64
502 static void *moved_objects [MOVED_OBJECTS_NUM];
503 static int moved_objects_idx = 0;
505 /* Vtable of the objects used to fill out nursery fragments before a collection */
506 static MonoVTable *array_fill_vtable;
508 #ifdef SGEN_DEBUG_INTERNAL_ALLOC
509 MonoNativeThreadId main_gc_thread = NULL;
512 /*Object was pinned during the current collection*/
513 static mword objects_pinned;
516 * ######################################################################
517 * ######## Macros and function declarations.
518 * ######################################################################
522 align_pointer (void *ptr)
524 mword p = (mword)ptr;
525 p += sizeof (gpointer) - 1;
526 p &= ~ (sizeof (gpointer) - 1);
530 typedef SgenGrayQueue GrayQueue;
532 /* forward declarations */
533 static void scan_thread_data (void *start_nursery, void *end_nursery, gboolean precise, GrayQueue *queue);
534 static void scan_from_registered_roots (CopyOrMarkObjectFunc copy_func, ScanObjectFunc scan_func, char *addr_start, char *addr_end, int root_type, GrayQueue *queue);
535 static void scan_finalizer_entries (CopyOrMarkObjectFunc copy_func, FinalizeReadyEntry *list, GrayQueue *queue);
536 static void report_finalizer_roots (void);
537 static void report_registered_roots (void);
539 static void pin_from_roots (void *start_nursery, void *end_nursery, GrayQueue *queue);
540 static int pin_objects_from_addresses (GCMemSection *section, void **start, void **end, void *start_nursery, void *end_nursery, GrayQueue *queue, ScanObjectFunc scan_func);
541 static void finish_gray_stack (char *start_addr, char *end_addr, int generation, GrayQueue *queue);
543 void mono_gc_scan_for_specific_ref (MonoObject *key, gboolean precise);
546 static void init_stats (void);
548 static int mark_ephemerons_in_range (CopyOrMarkObjectFunc copy_func, char *start, char *end, GrayQueue *queue);
549 static void clear_unreachable_ephemerons (CopyOrMarkObjectFunc copy_func, char *start, char *end, GrayQueue *queue);
550 static void null_ephemerons_for_domain (MonoDomain *domain);
552 SgenObjectOperations current_object_ops;
553 SgenMajorCollector major_collector;
554 SgenMinorCollector sgen_minor_collector;
555 static GrayQueue gray_queue;
557 static SgenRemeberedSet remset;
559 /* The gray queue to use from the main collection thread. */
560 static SgenGrayQueue*
561 sgen_workers_get_main_thread_queue (void)
563 if (sgen_collection_is_parallel () || sgen_collection_is_concurrent ())
564 return sgen_workers_get_distribute_gray_queue ();
568 #define WORKERS_DISTRIBUTE_GRAY_QUEUE (sgen_workers_get_main_thread_queue ())
571 * The gray queue a worker job must use. If we're not parallel or
572 * concurrent, we use the main gray queue.
574 static SgenGrayQueue*
575 sgen_workers_get_job_gray_queue (WorkerData *worker_data)
577 return worker_data ? &worker_data->private_gray_queue : WORKERS_DISTRIBUTE_GRAY_QUEUE;
580 static LOCK_DECLARE (workers_distribute_gray_queue_mutex);
583 sgen_remember_major_object_for_concurrent_mark (char *obj)
585 gboolean need_lock = current_collection_generation != GENERATION_NURSERY;
587 if (!major_collector.is_concurrent)
590 g_assert (current_collection_generation == GENERATION_NURSERY || current_collection_generation == -1);
592 if (!concurrent_collection_in_progress)
596 mono_mutex_lock (&workers_distribute_gray_queue_mutex);
598 sgen_gray_object_enqueue (sgen_workers_get_distribute_gray_queue (), obj);
601 mono_mutex_unlock (&workers_distribute_gray_queue_mutex);
607 is_xdomain_ref_allowed (gpointer *ptr, char *obj, MonoDomain *domain)
609 MonoObject *o = (MonoObject*)(obj);
610 MonoObject *ref = (MonoObject*)*(ptr);
611 int offset = (char*)(ptr) - (char*)o;
613 if (o->vtable->klass == mono_defaults.thread_class && offset == G_STRUCT_OFFSET (MonoThread, internal_thread))
615 if (o->vtable->klass == mono_defaults.internal_thread_class && offset == G_STRUCT_OFFSET (MonoInternalThread, current_appcontext))
617 if (mono_class_has_parent_fast (o->vtable->klass, mono_defaults.real_proxy_class) &&
618 offset == G_STRUCT_OFFSET (MonoRealProxy, unwrapped_server))
620 /* Thread.cached_culture_info */
621 if (!strcmp (ref->vtable->klass->name_space, "System.Globalization") &&
622 !strcmp (ref->vtable->klass->name, "CultureInfo") &&
623 !strcmp(o->vtable->klass->name_space, "System") &&
624 !strcmp(o->vtable->klass->name, "Object[]"))
627 * 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
628 * at System.IO.MemoryStream..ctor (byte[]) [0x00017] in /home/schani/Work/novell/trunk/mcs/class/corlib/System.IO/MemoryStream.cs:81
629 * at (wrapper remoting-invoke-with-check) System.IO.MemoryStream..ctor (byte[]) <IL 0x00020, 0xffffffff>
630 * at System.Runtime.Remoting.Messaging.CADMethodCallMessage.GetArguments () [0x0000d] in /home/schani/Work/novell/trunk/mcs/class/corlib/System.Runtime.Remoting.Messaging/CADMessages.cs:327
631 * 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
632 * 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
633 * at (wrapper remoting-invoke-with-check) System.AppDomain.ProcessMessageInDomain (byte[],System.Runtime.Remoting.Messaging.CADMethodCallMessage,byte[]&,System.Runtime.Remoting.Messaging.CADMethodReturnMessage&) <IL 0x0003d, 0xffffffff>
634 * 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
635 * at (wrapper runtime-invoke) object.runtime_invoke_CrossAppDomainSink/ProcessMessageRes_object_object (object,intptr,intptr,intptr) <IL 0x0004c, 0xffffffff>
637 if (!strcmp (ref->vtable->klass->name_space, "System") &&
638 !strcmp (ref->vtable->klass->name, "Byte[]") &&
639 !strcmp (o->vtable->klass->name_space, "System.IO") &&
640 !strcmp (o->vtable->klass->name, "MemoryStream"))
642 /* append_job() in threadpool.c */
643 if (!strcmp (ref->vtable->klass->name_space, "System.Runtime.Remoting.Messaging") &&
644 !strcmp (ref->vtable->klass->name, "AsyncResult") &&
645 !strcmp (o->vtable->klass->name_space, "System") &&
646 !strcmp (o->vtable->klass->name, "Object[]") &&
647 mono_thread_pool_is_queue_array ((MonoArray*) o))
653 check_reference_for_xdomain (gpointer *ptr, char *obj, MonoDomain *domain)
655 MonoObject *o = (MonoObject*)(obj);
656 MonoObject *ref = (MonoObject*)*(ptr);
657 int offset = (char*)(ptr) - (char*)o;
659 MonoClassField *field;
662 if (!ref || ref->vtable->domain == domain)
664 if (is_xdomain_ref_allowed (ptr, obj, domain))
668 for (class = o->vtable->klass; class; class = class->parent) {
671 for (i = 0; i < class->field.count; ++i) {
672 if (class->fields[i].offset == offset) {
673 field = &class->fields[i];
681 if (ref->vtable->klass == mono_defaults.string_class)
682 str = mono_string_to_utf8 ((MonoString*)ref);
685 g_print ("xdomain reference in %p (%s.%s) at offset %d (%s) to %p (%s.%s) (%s) - pointed to by:\n",
686 o, o->vtable->klass->name_space, o->vtable->klass->name,
687 offset, field ? field->name : "",
688 ref, ref->vtable->klass->name_space, ref->vtable->klass->name, str ? str : "");
689 mono_gc_scan_for_specific_ref (o, TRUE);
695 #define HANDLE_PTR(ptr,obj) check_reference_for_xdomain ((ptr), (obj), domain)
698 scan_object_for_xdomain_refs (char *start, mword size, void *data)
700 MonoDomain *domain = ((MonoObject*)start)->vtable->domain;
702 #include "sgen-scan-object.h"
705 static gboolean scan_object_for_specific_ref_precise = TRUE;
708 #define HANDLE_PTR(ptr,obj) do { \
709 if ((MonoObject*)*(ptr) == key) { \
710 g_print ("found ref to %p in object %p (%s) at offset %td\n", \
711 key, (obj), safe_name ((obj)), ((char*)(ptr) - (char*)(obj))); \
716 scan_object_for_specific_ref (char *start, MonoObject *key)
720 if ((forwarded = SGEN_OBJECT_IS_FORWARDED (start)))
723 if (scan_object_for_specific_ref_precise) {
724 #include "sgen-scan-object.h"
726 mword *words = (mword*)start;
727 size_t size = safe_object_get_size ((MonoObject*)start);
729 for (i = 0; i < size / sizeof (mword); ++i) {
730 if (words [i] == (mword)key) {
731 g_print ("found possible ref to %p in object %p (%s) at offset %td\n",
732 key, start, safe_name (start), i * sizeof (mword));
739 sgen_scan_area_with_callback (char *start, char *end, IterateObjectCallbackFunc callback, void *data, gboolean allow_flags)
741 while (start < end) {
745 if (!*(void**)start) {
746 start += sizeof (void*); /* should be ALLOC_ALIGN, really */
751 if (!(obj = SGEN_OBJECT_IS_FORWARDED (start)))
757 size = ALIGN_UP (safe_object_get_size ((MonoObject*)obj));
759 if ((MonoVTable*)SGEN_LOAD_VTABLE (obj) != array_fill_vtable)
760 callback (obj, size, data);
767 scan_object_for_specific_ref_callback (char *obj, size_t size, MonoObject *key)
769 scan_object_for_specific_ref (obj, key);
773 check_root_obj_specific_ref (RootRecord *root, MonoObject *key, MonoObject *obj)
777 g_print ("found ref to %p in root record %p\n", key, root);
780 static MonoObject *check_key = NULL;
781 static RootRecord *check_root = NULL;
784 check_root_obj_specific_ref_from_marker (void **obj)
786 check_root_obj_specific_ref (check_root, check_key, *obj);
790 scan_roots_for_specific_ref (MonoObject *key, int root_type)
796 SGEN_HASH_TABLE_FOREACH (&roots_hash [root_type], start_root, root) {
797 mword desc = root->root_desc;
801 switch (desc & ROOT_DESC_TYPE_MASK) {
802 case ROOT_DESC_BITMAP:
803 desc >>= ROOT_DESC_TYPE_SHIFT;
806 check_root_obj_specific_ref (root, key, *start_root);
811 case ROOT_DESC_COMPLEX: {
812 gsize *bitmap_data = sgen_get_complex_descriptor_bitmap (desc);
813 int bwords = (*bitmap_data) - 1;
814 void **start_run = start_root;
816 while (bwords-- > 0) {
817 gsize bmap = *bitmap_data++;
818 void **objptr = start_run;
821 check_root_obj_specific_ref (root, key, *objptr);
825 start_run += GC_BITS_PER_WORD;
829 case ROOT_DESC_USER: {
830 MonoGCRootMarkFunc marker = sgen_get_user_descriptor_func (desc);
831 marker (start_root, check_root_obj_specific_ref_from_marker);
834 case ROOT_DESC_RUN_LEN:
835 g_assert_not_reached ();
837 g_assert_not_reached ();
839 } SGEN_HASH_TABLE_FOREACH_END;
846 mono_gc_scan_for_specific_ref (MonoObject *key, gboolean precise)
851 scan_object_for_specific_ref_precise = precise;
853 sgen_scan_area_with_callback (nursery_section->data, nursery_section->end_data,
854 (IterateObjectCallbackFunc)scan_object_for_specific_ref_callback, key, TRUE);
856 major_collector.iterate_objects (TRUE, TRUE, (IterateObjectCallbackFunc)scan_object_for_specific_ref_callback, key);
858 sgen_los_iterate_objects ((IterateObjectCallbackFunc)scan_object_for_specific_ref_callback, key);
860 scan_roots_for_specific_ref (key, ROOT_TYPE_NORMAL);
861 scan_roots_for_specific_ref (key, ROOT_TYPE_WBARRIER);
863 SGEN_HASH_TABLE_FOREACH (&roots_hash [ROOT_TYPE_PINNED], ptr, root) {
864 while (ptr < (void**)root->end_root) {
865 check_root_obj_specific_ref (root, *ptr, key);
868 } SGEN_HASH_TABLE_FOREACH_END;
872 need_remove_object_for_domain (char *start, MonoDomain *domain)
874 if (mono_object_domain (start) == domain) {
875 SGEN_LOG (4, "Need to cleanup object %p", start);
876 binary_protocol_cleanup (start, (gpointer)LOAD_VTABLE (start), safe_object_get_size ((MonoObject*)start));
883 process_object_for_domain_clearing (char *start, MonoDomain *domain)
885 GCVTable *vt = (GCVTable*)LOAD_VTABLE (start);
886 if (vt->klass == mono_defaults.internal_thread_class)
887 g_assert (mono_object_domain (start) == mono_get_root_domain ());
888 /* The object could be a proxy for an object in the domain
890 if (mono_class_has_parent_fast (vt->klass, mono_defaults.real_proxy_class)) {
891 MonoObject *server = ((MonoRealProxy*)start)->unwrapped_server;
893 /* The server could already have been zeroed out, so
894 we need to check for that, too. */
895 if (server && (!LOAD_VTABLE (server) || mono_object_domain (server) == domain)) {
896 SGEN_LOG (4, "Cleaning up remote pointer in %p to object %p", start, server);
897 ((MonoRealProxy*)start)->unwrapped_server = NULL;
902 static MonoDomain *check_domain = NULL;
905 check_obj_not_in_domain (void **o)
907 g_assert (((MonoObject*)(*o))->vtable->domain != check_domain);
911 scan_for_registered_roots_in_domain (MonoDomain *domain, int root_type)
915 check_domain = domain;
916 SGEN_HASH_TABLE_FOREACH (&roots_hash [root_type], start_root, root) {
917 mword desc = root->root_desc;
919 /* The MonoDomain struct is allowed to hold
920 references to objects in its own domain. */
921 if (start_root == (void**)domain)
924 switch (desc & ROOT_DESC_TYPE_MASK) {
925 case ROOT_DESC_BITMAP:
926 desc >>= ROOT_DESC_TYPE_SHIFT;
928 if ((desc & 1) && *start_root)
929 check_obj_not_in_domain (*start_root);
934 case ROOT_DESC_COMPLEX: {
935 gsize *bitmap_data = sgen_get_complex_descriptor_bitmap (desc);
936 int bwords = (*bitmap_data) - 1;
937 void **start_run = start_root;
939 while (bwords-- > 0) {
940 gsize bmap = *bitmap_data++;
941 void **objptr = start_run;
943 if ((bmap & 1) && *objptr)
944 check_obj_not_in_domain (*objptr);
948 start_run += GC_BITS_PER_WORD;
952 case ROOT_DESC_USER: {
953 MonoGCRootMarkFunc marker = sgen_get_user_descriptor_func (desc);
954 marker (start_root, check_obj_not_in_domain);
957 case ROOT_DESC_RUN_LEN:
958 g_assert_not_reached ();
960 g_assert_not_reached ();
962 } SGEN_HASH_TABLE_FOREACH_END;
968 check_for_xdomain_refs (void)
972 sgen_scan_area_with_callback (nursery_section->data, nursery_section->end_data,
973 (IterateObjectCallbackFunc)scan_object_for_xdomain_refs, NULL, FALSE);
975 major_collector.iterate_objects (TRUE, TRUE, (IterateObjectCallbackFunc)scan_object_for_xdomain_refs, NULL);
977 for (bigobj = los_object_list; bigobj; bigobj = bigobj->next)
978 scan_object_for_xdomain_refs (bigobj->data, sgen_los_object_size (bigobj), NULL);
982 clear_domain_process_object (char *obj, MonoDomain *domain)
986 process_object_for_domain_clearing (obj, domain);
987 remove = need_remove_object_for_domain (obj, domain);
989 if (remove && ((MonoObject*)obj)->synchronisation) {
990 void **dislink = mono_monitor_get_object_monitor_weak_link ((MonoObject*)obj);
992 sgen_register_disappearing_link (NULL, dislink, FALSE, TRUE);
999 clear_domain_process_minor_object_callback (char *obj, size_t size, MonoDomain *domain)
1001 if (clear_domain_process_object (obj, domain))
1002 memset (obj, 0, size);
1006 clear_domain_process_major_object_callback (char *obj, size_t size, MonoDomain *domain)
1008 clear_domain_process_object (obj, domain);
1012 clear_domain_free_major_non_pinned_object_callback (char *obj, size_t size, MonoDomain *domain)
1014 if (need_remove_object_for_domain (obj, domain))
1015 major_collector.free_non_pinned_object (obj, size);
1019 clear_domain_free_major_pinned_object_callback (char *obj, size_t size, MonoDomain *domain)
1021 if (need_remove_object_for_domain (obj, domain))
1022 major_collector.free_pinned_object (obj, size);
1026 * When appdomains are unloaded we can easily remove objects that have finalizers,
1027 * but all the others could still be present in random places on the heap.
1028 * We need a sweep to get rid of them even though it's going to be costly
1030 * The reason we need to remove them is because we access the vtable and class
1031 * structures to know the object size and the reference bitmap: once the domain is
1032 * unloaded the point to random memory.
1035 mono_gc_clear_domain (MonoDomain * domain)
1037 LOSObject *bigobj, *prev;
1042 sgen_process_fin_stage_entries ();
1043 sgen_process_dislink_stage_entries ();
1045 sgen_clear_nursery_fragments ();
1047 if (xdomain_checks && domain != mono_get_root_domain ()) {
1048 scan_for_registered_roots_in_domain (domain, ROOT_TYPE_NORMAL);
1049 scan_for_registered_roots_in_domain (domain, ROOT_TYPE_WBARRIER);
1050 check_for_xdomain_refs ();
1053 /*Ephemerons and dislinks must be processed before LOS since they might end up pointing
1054 to memory returned to the OS.*/
1055 null_ephemerons_for_domain (domain);
1057 for (i = GENERATION_NURSERY; i < GENERATION_MAX; ++i)
1058 sgen_null_links_for_domain (domain, i);
1060 for (i = GENERATION_NURSERY; i < GENERATION_MAX; ++i)
1061 sgen_remove_finalizers_for_domain (domain, i);
1063 sgen_scan_area_with_callback (nursery_section->data, nursery_section->end_data,
1064 (IterateObjectCallbackFunc)clear_domain_process_minor_object_callback, domain, FALSE);
1066 /* We need two passes over major and large objects because
1067 freeing such objects might give their memory back to the OS
1068 (in the case of large objects) or obliterate its vtable
1069 (pinned objects with major-copying or pinned and non-pinned
1070 objects with major-mark&sweep), but we might need to
1071 dereference a pointer from an object to another object if
1072 the first object is a proxy. */
1073 major_collector.iterate_objects (TRUE, TRUE, (IterateObjectCallbackFunc)clear_domain_process_major_object_callback, domain);
1074 for (bigobj = los_object_list; bigobj; bigobj = bigobj->next)
1075 clear_domain_process_object (bigobj->data, domain);
1078 for (bigobj = los_object_list; bigobj;) {
1079 if (need_remove_object_for_domain (bigobj->data, domain)) {
1080 LOSObject *to_free = bigobj;
1082 prev->next = bigobj->next;
1084 los_object_list = bigobj->next;
1085 bigobj = bigobj->next;
1086 SGEN_LOG (4, "Freeing large object %p", bigobj->data);
1087 sgen_los_free_object (to_free);
1091 bigobj = bigobj->next;
1093 major_collector.iterate_objects (TRUE, FALSE, (IterateObjectCallbackFunc)clear_domain_free_major_non_pinned_object_callback, domain);
1094 major_collector.iterate_objects (FALSE, TRUE, (IterateObjectCallbackFunc)clear_domain_free_major_pinned_object_callback, domain);
1096 if (G_UNLIKELY (do_pin_stats)) {
1097 if (domain == mono_get_root_domain ())
1098 sgen_pin_stats_print_class_stats ();
1105 * sgen_add_to_global_remset:
1107 * The global remset contains locations which point into newspace after
1108 * a minor collection. This can happen if the objects they point to are pinned.
1110 * LOCKING: If called from a parallel collector, the global remset
1111 * lock must be held. For serial collectors that is not necessary.
1114 sgen_add_to_global_remset (gpointer ptr)
1116 remset.record_pointer (ptr);
1120 * sgen_drain_gray_stack:
1122 * Scan objects in the gray stack until the stack is empty. This should be called
1123 * frequently after each object is copied, to achieve better locality and cache
1127 sgen_drain_gray_stack (GrayQueue *queue, ScanObjectFunc scan_func, int max_objs)
1131 if (max_objs == -1) {
1133 GRAY_OBJECT_DEQUEUE (queue, obj);
1136 SGEN_LOG (9, "Precise gray object scan %p (%s)", obj, safe_name (obj));
1137 scan_func (obj, queue);
1143 for (i = 0; i != max_objs; ++i) {
1144 GRAY_OBJECT_DEQUEUE (queue, obj);
1147 SGEN_LOG (9, "Precise gray object scan %p (%s)", obj, safe_name (obj));
1148 scan_func (obj, queue);
1150 } while (max_objs < 0);
1156 * Addresses from start to end are already sorted. This function finds
1157 * the object header for each address and pins the object. The
1158 * addresses must be inside the passed section. The (start of the)
1159 * address array is overwritten with the addresses of the actually
1160 * pinned objects. Return the number of pinned objects.
1163 pin_objects_from_addresses (GCMemSection *section, void **start, void **end, void *start_nursery, void *end_nursery, GrayQueue *queue, ScanObjectFunc scan_func)
1168 void *last_obj = NULL;
1169 size_t last_obj_size = 0;
1172 void **definitely_pinned = start;
1174 sgen_nursery_allocator_prepare_for_pinning ();
1176 while (start < end) {
1178 /* the range check should be reduntant */
1179 if (addr != last && addr >= start_nursery && addr < end_nursery) {
1180 SGEN_LOG (5, "Considering pinning addr %p", addr);
1181 /* multiple pointers to the same object */
1182 if (addr >= last_obj && (char*)addr < (char*)last_obj + last_obj_size) {
1186 idx = ((char*)addr - (char*)section->data) / SCAN_START_SIZE;
1187 g_assert (idx < section->num_scan_start);
1188 search_start = (void*)section->scan_starts [idx];
1189 if (!search_start || search_start > addr) {
1192 search_start = section->scan_starts [idx];
1193 if (search_start && search_start <= addr)
1196 if (!search_start || search_start > addr)
1197 search_start = start_nursery;
1199 if (search_start < last_obj)
1200 search_start = (char*)last_obj + last_obj_size;
1201 /* now addr should be in an object a short distance from search_start
1202 * Note that search_start must point to zeroed mem or point to an object.
1206 if (!*(void**)search_start) {
1207 /* Consistency check */
1209 for (frag = nursery_fragments; frag; frag = frag->next) {
1210 if (search_start >= frag->fragment_start && search_start < frag->fragment_end)
1211 g_assert_not_reached ();
1215 search_start = (void*)ALIGN_UP ((mword)search_start + sizeof (gpointer));
1218 last_obj = search_start;
1219 last_obj_size = ALIGN_UP (safe_object_get_size ((MonoObject*)search_start));
1221 if (((MonoObject*)last_obj)->synchronisation == GINT_TO_POINTER (-1)) {
1222 /* Marks the beginning of a nursery fragment, skip */
1224 SGEN_LOG (8, "Pinned try match %p (%s), size %zd", last_obj, safe_name (last_obj), last_obj_size);
1225 if (addr >= search_start && (char*)addr < (char*)last_obj + last_obj_size) {
1226 SGEN_LOG (4, "Pinned object %p, vtable %p (%s), count %d\n", search_start, *(void**)search_start, safe_name (search_start), count);
1227 binary_protocol_pin (search_start, (gpointer)LOAD_VTABLE (search_start), safe_object_get_size (search_start));
1228 if (G_UNLIKELY (MONO_GC_OBJ_PINNED_ENABLED ())) {
1229 int gen = sgen_ptr_in_nursery (search_start) ? GENERATION_NURSERY : GENERATION_OLD;
1230 MonoVTable *vt = (MonoVTable*)LOAD_VTABLE (search_start);
1231 MONO_GC_OBJ_PINNED ((mword)search_start, sgen_safe_object_get_size (search_start), vt->klass->name_space, vt->klass->name, gen);
1234 scan_func (search_start, queue);
1236 pin_object (search_start);
1237 GRAY_OBJECT_ENQUEUE (queue, search_start);
1238 if (G_UNLIKELY (do_pin_stats))
1239 sgen_pin_stats_register_object (search_start, last_obj_size);
1240 definitely_pinned [count] = search_start;
1246 /* skip to the next object */
1247 search_start = (void*)((char*)search_start + last_obj_size);
1248 } while (search_start <= addr);
1249 /* we either pinned the correct object or we ignored the addr because
1250 * it points to unused zeroed memory.
1256 //printf ("effective pinned: %d (at the end: %d)\n", count, (char*)end_nursery - (char*)last);
1257 if (mono_profiler_get_events () & MONO_PROFILE_GC_ROOTS) {
1258 GCRootReport report;
1260 for (idx = 0; idx < count; ++idx)
1261 add_profile_gc_root (&report, definitely_pinned [idx], MONO_PROFILE_GC_ROOT_PINNING | MONO_PROFILE_GC_ROOT_MISC, 0);
1262 notify_gc_roots (&report);
1264 stat_pinned_objects += count;
1269 sgen_pin_objects_in_section (GCMemSection *section, GrayQueue *queue, ScanObjectFunc scan_func)
1271 int num_entries = section->pin_queue_num_entries;
1273 void **start = section->pin_queue_start;
1275 reduced_to = pin_objects_from_addresses (section, start, start + num_entries,
1276 section->data, section->next_data, queue, scan_func);
1277 section->pin_queue_num_entries = reduced_to;
1279 section->pin_queue_start = NULL;
1285 sgen_pin_object (void *object, GrayQueue *queue)
1287 g_assert (!concurrent_collection_in_progress);
1289 if (sgen_collection_is_parallel ()) {
1291 /*object arrives pinned*/
1292 sgen_pin_stage_ptr (object);
1296 SGEN_PIN_OBJECT (object);
1297 sgen_pin_stage_ptr (object);
1299 if (G_UNLIKELY (do_pin_stats))
1300 sgen_pin_stats_register_object (object, safe_object_get_size (object));
1302 GRAY_OBJECT_ENQUEUE (queue, object);
1303 binary_protocol_pin (object, (gpointer)LOAD_VTABLE (object), safe_object_get_size (object));
1304 if (G_UNLIKELY (MONO_GC_OBJ_PINNED_ENABLED ())) {
1305 int gen = sgen_ptr_in_nursery (object) ? GENERATION_NURSERY : GENERATION_OLD;
1306 MonoVTable *vt = (MonoVTable*)LOAD_VTABLE (object);
1307 MONO_GC_OBJ_PINNED ((mword)object, sgen_safe_object_get_size (object), vt->klass->name_space, vt->klass->name, gen);
1312 sgen_parallel_pin_or_update (void **ptr, void *obj, MonoVTable *vt, SgenGrayQueue *queue)
1316 gboolean major_pinned = FALSE;
1318 if (sgen_ptr_in_nursery (obj)) {
1319 if (SGEN_CAS_PTR (obj, (void*)((mword)vt | SGEN_PINNED_BIT), vt) == vt) {
1320 sgen_pin_object (obj, queue);
1324 major_collector.pin_major_object (obj, queue);
1325 major_pinned = TRUE;
1328 vtable_word = *(mword*)obj;
1329 /*someone else forwarded it, update the pointer and bail out*/
1330 if (vtable_word & SGEN_FORWARDED_BIT) {
1331 *ptr = (void*)(vtable_word & ~SGEN_VTABLE_BITS_MASK);
1335 /*someone pinned it, nothing to do.*/
1336 if (vtable_word & SGEN_PINNED_BIT || major_pinned)
1341 /* Sort the addresses in array in increasing order.
1342 * Done using a by-the book heap sort. Which has decent and stable performance, is pretty cache efficient.
1345 sgen_sort_addresses (void **array, int size)
1350 for (i = 1; i < size; ++i) {
1353 int parent = (child - 1) / 2;
1355 if (array [parent] >= array [child])
1358 tmp = array [parent];
1359 array [parent] = array [child];
1360 array [child] = tmp;
1366 for (i = size - 1; i > 0; --i) {
1369 array [i] = array [0];
1375 while (root * 2 + 1 <= end) {
1376 int child = root * 2 + 1;
1378 if (child < end && array [child] < array [child + 1])
1380 if (array [root] >= array [child])
1384 array [root] = array [child];
1385 array [child] = tmp;
1393 * Scan the memory between start and end and queue values which could be pointers
1394 * to the area between start_nursery and end_nursery for later consideration.
1395 * Typically used for thread stacks.
1398 conservatively_pin_objects_from (void **start, void **end, void *start_nursery, void *end_nursery, int pin_type)
1402 #ifdef VALGRIND_MAKE_MEM_DEFINED_IF_ADDRESSABLE
1403 VALGRIND_MAKE_MEM_DEFINED_IF_ADDRESSABLE (start, (char*)end - (char*)start);
1406 while (start < end) {
1407 if (*start >= start_nursery && *start < end_nursery) {
1409 * *start can point to the middle of an object
1410 * note: should we handle pointing at the end of an object?
1411 * pinning in C# code disallows pointing at the end of an object
1412 * but there is some small chance that an optimizing C compiler
1413 * may keep the only reference to an object by pointing
1414 * at the end of it. We ignore this small chance for now.
1415 * Pointers to the end of an object are indistinguishable
1416 * from pointers to the start of the next object in memory
1417 * so if we allow that we'd need to pin two objects...
1418 * We queue the pointer in an array, the
1419 * array will then be sorted and uniqued. This way
1420 * we can coalesce several pinning pointers and it should
1421 * be faster since we'd do a memory scan with increasing
1422 * addresses. Note: we can align the address to the allocation
1423 * alignment, so the unique process is more effective.
1425 mword addr = (mword)*start;
1426 addr &= ~(ALLOC_ALIGN - 1);
1427 if (addr >= (mword)start_nursery && addr < (mword)end_nursery) {
1428 SGEN_LOG (6, "Pinning address %p from %p", (void*)addr, start);
1429 sgen_pin_stage_ptr ((void*)addr);
1432 if (G_UNLIKELY (do_pin_stats)) {
1433 if (ptr_in_nursery ((void*)addr))
1434 sgen_pin_stats_register_address ((char*)addr, pin_type);
1440 SGEN_LOG (7, "found %d potential pinned heap pointers", count);
1444 * The first thing we do in a collection is to identify pinned objects.
1445 * This function considers all the areas of memory that need to be
1446 * conservatively scanned.
1449 pin_from_roots (void *start_nursery, void *end_nursery, GrayQueue *queue)
1453 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);
1454 /* objects pinned from the API are inside these roots */
1455 SGEN_HASH_TABLE_FOREACH (&roots_hash [ROOT_TYPE_PINNED], start_root, root) {
1456 SGEN_LOG (6, "Pinned roots %p-%p", start_root, root->end_root);
1457 conservatively_pin_objects_from (start_root, (void**)root->end_root, start_nursery, end_nursery, PIN_TYPE_OTHER);
1458 } SGEN_HASH_TABLE_FOREACH_END;
1459 /* now deal with the thread stacks
1460 * in the future we should be able to conservatively scan only:
1461 * *) the cpu registers
1462 * *) the unmanaged stack frames
1463 * *) the _last_ managed stack frame
1464 * *) pointers slots in managed frames
1466 scan_thread_data (start_nursery, end_nursery, FALSE, queue);
1470 CopyOrMarkObjectFunc func;
1472 } UserCopyOrMarkData;
1474 static MonoNativeTlsKey user_copy_or_mark_key;
1477 init_user_copy_or_mark_key (void)
1479 mono_native_tls_alloc (&user_copy_or_mark_key, NULL);
1483 set_user_copy_or_mark_data (UserCopyOrMarkData *data)
1485 mono_native_tls_set_value (user_copy_or_mark_key, data);
1489 single_arg_user_copy_or_mark (void **obj)
1491 UserCopyOrMarkData *data = mono_native_tls_get_value (user_copy_or_mark_key);
1493 data->func (obj, data->queue);
1497 * The memory area from start_root to end_root contains pointers to objects.
1498 * Their position is precisely described by @desc (this means that the pointer
1499 * can be either NULL or the pointer to the start of an object).
1500 * This functions copies them to to_space updates them.
1502 * This function is not thread-safe!
1505 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)
1507 switch (desc & ROOT_DESC_TYPE_MASK) {
1508 case ROOT_DESC_BITMAP:
1509 desc >>= ROOT_DESC_TYPE_SHIFT;
1511 if ((desc & 1) && *start_root) {
1512 copy_func (start_root, queue);
1513 SGEN_LOG (9, "Overwrote root at %p with %p", start_root, *start_root);
1514 sgen_drain_gray_stack (queue, scan_func, -1);
1520 case ROOT_DESC_COMPLEX: {
1521 gsize *bitmap_data = sgen_get_complex_descriptor_bitmap (desc);
1522 int bwords = (*bitmap_data) - 1;
1523 void **start_run = start_root;
1525 while (bwords-- > 0) {
1526 gsize bmap = *bitmap_data++;
1527 void **objptr = start_run;
1529 if ((bmap & 1) && *objptr) {
1530 copy_func (objptr, queue);
1531 SGEN_LOG (9, "Overwrote root at %p with %p", objptr, *objptr);
1532 sgen_drain_gray_stack (queue, scan_func, -1);
1537 start_run += GC_BITS_PER_WORD;
1541 case ROOT_DESC_USER: {
1542 UserCopyOrMarkData data = { copy_func, queue };
1543 MonoGCRootMarkFunc marker = sgen_get_user_descriptor_func (desc);
1544 set_user_copy_or_mark_data (&data);
1545 marker (start_root, single_arg_user_copy_or_mark);
1546 set_user_copy_or_mark_data (NULL);
1549 case ROOT_DESC_RUN_LEN:
1550 g_assert_not_reached ();
1552 g_assert_not_reached ();
1557 reset_heap_boundaries (void)
1559 lowest_heap_address = ~(mword)0;
1560 highest_heap_address = 0;
1564 sgen_update_heap_boundaries (mword low, mword high)
1569 old = lowest_heap_address;
1572 } while (SGEN_CAS_PTR ((gpointer*)&lowest_heap_address, (gpointer)low, (gpointer)old) != (gpointer)old);
1575 old = highest_heap_address;
1578 } while (SGEN_CAS_PTR ((gpointer*)&highest_heap_address, (gpointer)high, (gpointer)old) != (gpointer)old);
1582 * Allocate and setup the data structures needed to be able to allocate objects
1583 * in the nursery. The nursery is stored in nursery_section.
1586 alloc_nursery (void)
1588 GCMemSection *section;
1593 if (nursery_section)
1595 SGEN_LOG (2, "Allocating nursery size: %lu", (unsigned long)sgen_nursery_size);
1596 /* later we will alloc a larger area for the nursery but only activate
1597 * what we need. The rest will be used as expansion if we have too many pinned
1598 * objects in the existing nursery.
1600 /* FIXME: handle OOM */
1601 section = sgen_alloc_internal (INTERNAL_MEM_SECTION);
1603 alloc_size = sgen_nursery_size;
1605 /* If there isn't enough space even for the nursery we should simply abort. */
1606 g_assert (sgen_memgov_try_alloc_space (alloc_size, SPACE_NURSERY));
1608 #ifdef SGEN_ALIGN_NURSERY
1609 data = major_collector.alloc_heap (alloc_size, alloc_size, DEFAULT_NURSERY_BITS);
1611 data = major_collector.alloc_heap (alloc_size, 0, DEFAULT_NURSERY_BITS);
1613 sgen_update_heap_boundaries ((mword)data, (mword)(data + sgen_nursery_size));
1614 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 ());
1615 section->data = section->next_data = data;
1616 section->size = alloc_size;
1617 section->end_data = data + sgen_nursery_size;
1618 scan_starts = (alloc_size + SCAN_START_SIZE - 1) / SCAN_START_SIZE;
1619 section->scan_starts = sgen_alloc_internal_dynamic (sizeof (char*) * scan_starts, INTERNAL_MEM_SCAN_STARTS, TRUE);
1620 section->num_scan_start = scan_starts;
1621 section->block.role = MEMORY_ROLE_GEN0;
1622 section->block.next = NULL;
1624 nursery_section = section;
1626 sgen_nursery_allocator_set_nursery_bounds (data, data + sgen_nursery_size);
1630 mono_gc_get_nursery (int *shift_bits, size_t *size)
1632 *size = sgen_nursery_size;
1633 #ifdef SGEN_ALIGN_NURSERY
1634 *shift_bits = DEFAULT_NURSERY_BITS;
1638 return sgen_get_nursery_start ();
1642 mono_gc_set_current_thread_appdomain (MonoDomain *domain)
1644 SgenThreadInfo *info = mono_thread_info_current ();
1646 /* Could be called from sgen_thread_unregister () with a NULL info */
1649 info->stopped_domain = domain;
1654 mono_gc_precise_stack_mark_enabled (void)
1656 return !conservative_stack_mark;
1660 mono_gc_get_logfile (void)
1662 return gc_debug_file;
1666 report_finalizer_roots_list (FinalizeReadyEntry *list)
1668 GCRootReport report;
1669 FinalizeReadyEntry *fin;
1672 for (fin = list; fin; fin = fin->next) {
1675 add_profile_gc_root (&report, fin->object, MONO_PROFILE_GC_ROOT_FINALIZER, 0);
1677 notify_gc_roots (&report);
1681 report_finalizer_roots (void)
1683 report_finalizer_roots_list (fin_ready_list);
1684 report_finalizer_roots_list (critical_fin_list);
1687 static GCRootReport *root_report;
1690 single_arg_report_root (void **obj)
1693 add_profile_gc_root (root_report, *obj, MONO_PROFILE_GC_ROOT_OTHER, 0);
1697 precisely_report_roots_from (GCRootReport *report, void** start_root, void** end_root, mword desc)
1699 switch (desc & ROOT_DESC_TYPE_MASK) {
1700 case ROOT_DESC_BITMAP:
1701 desc >>= ROOT_DESC_TYPE_SHIFT;
1703 if ((desc & 1) && *start_root) {
1704 add_profile_gc_root (report, *start_root, MONO_PROFILE_GC_ROOT_OTHER, 0);
1710 case ROOT_DESC_COMPLEX: {
1711 gsize *bitmap_data = sgen_get_complex_descriptor_bitmap (desc);
1712 int bwords = (*bitmap_data) - 1;
1713 void **start_run = start_root;
1715 while (bwords-- > 0) {
1716 gsize bmap = *bitmap_data++;
1717 void **objptr = start_run;
1719 if ((bmap & 1) && *objptr) {
1720 add_profile_gc_root (report, *objptr, MONO_PROFILE_GC_ROOT_OTHER, 0);
1725 start_run += GC_BITS_PER_WORD;
1729 case ROOT_DESC_USER: {
1730 MonoGCRootMarkFunc marker = sgen_get_user_descriptor_func (desc);
1731 root_report = report;
1732 marker (start_root, single_arg_report_root);
1735 case ROOT_DESC_RUN_LEN:
1736 g_assert_not_reached ();
1738 g_assert_not_reached ();
1743 report_registered_roots_by_type (int root_type)
1745 GCRootReport report;
1749 SGEN_HASH_TABLE_FOREACH (&roots_hash [root_type], start_root, root) {
1750 SGEN_LOG (6, "Precise root scan %p-%p (desc: %p)", start_root, root->end_root, (void*)root->root_desc);
1751 precisely_report_roots_from (&report, start_root, (void**)root->end_root, root->root_desc);
1752 } SGEN_HASH_TABLE_FOREACH_END;
1753 notify_gc_roots (&report);
1757 report_registered_roots (void)
1759 report_registered_roots_by_type (ROOT_TYPE_NORMAL);
1760 report_registered_roots_by_type (ROOT_TYPE_WBARRIER);
1764 scan_finalizer_entries (CopyOrMarkObjectFunc copy_func, FinalizeReadyEntry *list, GrayQueue *queue)
1766 FinalizeReadyEntry *fin;
1768 for (fin = list; fin; fin = fin->next) {
1771 SGEN_LOG (5, "Scan of fin ready object: %p (%s)\n", fin->object, safe_name (fin->object));
1772 copy_func (&fin->object, queue);
1777 generation_name (int generation)
1779 switch (generation) {
1780 case GENERATION_NURSERY: return "nursery";
1781 case GENERATION_OLD: return "old";
1782 default: g_assert_not_reached ();
1787 sgen_generation_name (int generation)
1789 return generation_name (generation);
1792 SgenObjectOperations *
1793 sgen_get_current_object_ops (void){
1794 return ¤t_object_ops;
1799 finish_gray_stack (char *start_addr, char *end_addr, int generation, GrayQueue *queue)
1803 int done_with_ephemerons, ephemeron_rounds = 0;
1804 CopyOrMarkObjectFunc copy_func = current_object_ops.copy_or_mark_object;
1805 ScanObjectFunc scan_func = current_object_ops.scan_object;
1808 * We copied all the reachable objects. Now it's the time to copy
1809 * the objects that were not referenced by the roots, but by the copied objects.
1810 * we built a stack of objects pointed to by gray_start: they are
1811 * additional roots and we may add more items as we go.
1812 * We loop until gray_start == gray_objects which means no more objects have
1813 * been added. Note this is iterative: no recursion is involved.
1814 * We need to walk the LO list as well in search of marked big objects
1815 * (use a flag since this is needed only on major collections). We need to loop
1816 * here as well, so keep a counter of marked LO (increasing it in copy_object).
1817 * To achieve better cache locality and cache usage, we drain the gray stack
1818 * frequently, after each object is copied, and just finish the work here.
1820 sgen_drain_gray_stack (queue, scan_func, -1);
1822 SGEN_LOG (2, "%s generation done", generation_name (generation));
1825 Reset bridge data, we might have lingering data from a previous collection if this is a major
1826 collection trigged by minor overflow.
1828 We must reset the gathered bridges since their original block might be evacuated due to major
1829 fragmentation in the meanwhile and the bridge code should not have to deal with that.
1831 sgen_bridge_reset_data ();
1834 * Walk the ephemeron tables marking all values with reachable keys. This must be completely done
1835 * before processing finalizable objects or non-tracking weak hamdle to avoid finalizing/clearing
1836 * objects that are in fact reachable.
1838 done_with_ephemerons = 0;
1840 done_with_ephemerons = mark_ephemerons_in_range (copy_func, start_addr, end_addr, queue);
1841 sgen_drain_gray_stack (queue, scan_func, -1);
1843 } while (!done_with_ephemerons);
1845 sgen_scan_togglerefs (copy_func, start_addr, end_addr, queue);
1846 if (generation == GENERATION_OLD)
1847 sgen_scan_togglerefs (copy_func, sgen_get_nursery_start (), sgen_get_nursery_end (), queue);
1849 if (sgen_need_bridge_processing ()) {
1850 sgen_collect_bridge_objects (copy_func, start_addr, end_addr, generation, queue);
1851 if (generation == GENERATION_OLD)
1852 sgen_collect_bridge_objects (copy_func, sgen_get_nursery_start (), sgen_get_nursery_end (), GENERATION_NURSERY, queue);
1856 Make sure we drain the gray stack before processing disappearing links and finalizers.
1857 If we don't make sure it is empty we might wrongly see a live object as dead.
1859 sgen_drain_gray_stack (queue, scan_func, -1);
1862 We must clear weak links that don't track resurrection before processing object ready for
1863 finalization so they can be cleared before that.
1865 sgen_null_link_in_range (copy_func, start_addr, end_addr, generation, TRUE, queue);
1866 if (generation == GENERATION_OLD)
1867 sgen_null_link_in_range (copy_func, start_addr, end_addr, GENERATION_NURSERY, TRUE, queue);
1870 /* walk the finalization queue and move also the objects that need to be
1871 * finalized: use the finalized objects as new roots so the objects they depend
1872 * on are also not reclaimed. As with the roots above, only objects in the nursery
1873 * are marked/copied.
1875 sgen_finalize_in_range (copy_func, start_addr, end_addr, generation, queue);
1876 if (generation == GENERATION_OLD)
1877 sgen_finalize_in_range (copy_func, sgen_get_nursery_start (), sgen_get_nursery_end (), GENERATION_NURSERY, queue);
1878 /* drain the new stack that might have been created */
1879 SGEN_LOG (6, "Precise scan of gray area post fin");
1880 sgen_drain_gray_stack (queue, scan_func, -1);
1883 * This must be done again after processing finalizable objects since CWL slots are cleared only after the key is finalized.
1885 done_with_ephemerons = 0;
1887 done_with_ephemerons = mark_ephemerons_in_range (copy_func, start_addr, end_addr, queue);
1888 sgen_drain_gray_stack (queue, scan_func, -1);
1890 } while (!done_with_ephemerons);
1893 * Clear ephemeron pairs with unreachable keys.
1894 * We pass the copy func so we can figure out if an array was promoted or not.
1896 clear_unreachable_ephemerons (copy_func, start_addr, end_addr, queue);
1899 SGEN_LOG (2, "Finalize queue handling scan for %s generation: %d usecs %d ephemeron rounds", generation_name (generation), TV_ELAPSED (atv, btv), ephemeron_rounds);
1902 * handle disappearing links
1903 * Note we do this after checking the finalization queue because if an object
1904 * survives (at least long enough to be finalized) we don't clear the link.
1905 * This also deals with a possible issue with the monitor reclamation: with the Boehm
1906 * GC a finalized object my lose the monitor because it is cleared before the finalizer is
1909 g_assert (sgen_gray_object_queue_is_empty (queue));
1911 sgen_null_link_in_range (copy_func, start_addr, end_addr, generation, FALSE, queue);
1912 if (generation == GENERATION_OLD)
1913 sgen_null_link_in_range (copy_func, start_addr, end_addr, GENERATION_NURSERY, FALSE, queue);
1914 if (sgen_gray_object_queue_is_empty (queue))
1916 sgen_drain_gray_stack (queue, scan_func, -1);
1919 g_assert (sgen_gray_object_queue_is_empty (queue));
1923 sgen_check_section_scan_starts (GCMemSection *section)
1926 for (i = 0; i < section->num_scan_start; ++i) {
1927 if (section->scan_starts [i]) {
1928 guint size = safe_object_get_size ((MonoObject*) section->scan_starts [i]);
1929 g_assert (size >= sizeof (MonoObject) && size <= MAX_SMALL_OBJ_SIZE);
1935 check_scan_starts (void)
1937 if (!do_scan_starts_check)
1939 sgen_check_section_scan_starts (nursery_section);
1940 major_collector.check_scan_starts ();
1944 scan_from_registered_roots (CopyOrMarkObjectFunc copy_func, ScanObjectFunc scan_func, char *addr_start, char *addr_end, int root_type, GrayQueue *queue)
1948 SGEN_HASH_TABLE_FOREACH (&roots_hash [root_type], start_root, root) {
1949 SGEN_LOG (6, "Precise root scan %p-%p (desc: %p)", start_root, root->end_root, (void*)root->root_desc);
1950 precisely_scan_objects_from (copy_func, scan_func, start_root, (void**)root->end_root, addr_start, addr_end, root->root_desc, queue);
1951 } SGEN_HASH_TABLE_FOREACH_END;
1955 sgen_dump_occupied (char *start, char *end, char *section_start)
1957 fprintf (heap_dump_file, "<occupied offset=\"%td\" size=\"%td\"/>\n", start - section_start, end - start);
1961 sgen_dump_section (GCMemSection *section, const char *type)
1963 char *start = section->data;
1964 char *end = section->data + section->size;
1965 char *occ_start = NULL;
1967 char *old_start = NULL; /* just for debugging */
1969 fprintf (heap_dump_file, "<section type=\"%s\" size=\"%lu\">\n", type, (unsigned long)section->size);
1971 while (start < end) {
1975 if (!*(void**)start) {
1977 sgen_dump_occupied (occ_start, start, section->data);
1980 start += sizeof (void*); /* should be ALLOC_ALIGN, really */
1983 g_assert (start < section->next_data);
1988 vt = (GCVTable*)LOAD_VTABLE (start);
1991 size = ALIGN_UP (safe_object_get_size ((MonoObject*) start));
1994 fprintf (heap_dump_file, "<object offset=\"%d\" class=\"%s.%s\" size=\"%d\"/>\n",
1995 start - section->data,
1996 vt->klass->name_space, vt->klass->name,
2004 sgen_dump_occupied (occ_start, start, section->data);
2006 fprintf (heap_dump_file, "</section>\n");
2010 dump_object (MonoObject *obj, gboolean dump_location)
2012 static char class_name [1024];
2014 MonoClass *class = mono_object_class (obj);
2018 * Python's XML parser is too stupid to parse angle brackets
2019 * in strings, so we just ignore them;
2022 while (class->name [i] && j < sizeof (class_name) - 1) {
2023 if (!strchr ("<>\"", class->name [i]))
2024 class_name [j++] = class->name [i];
2027 g_assert (j < sizeof (class_name));
2030 fprintf (heap_dump_file, "<object class=\"%s.%s\" size=\"%d\"",
2031 class->name_space, class_name,
2032 safe_object_get_size (obj));
2033 if (dump_location) {
2034 const char *location;
2035 if (ptr_in_nursery (obj))
2036 location = "nursery";
2037 else if (safe_object_get_size (obj) <= MAX_SMALL_OBJ_SIZE)
2041 fprintf (heap_dump_file, " location=\"%s\"", location);
2043 fprintf (heap_dump_file, "/>\n");
2047 dump_heap (const char *type, int num, const char *reason)
2052 fprintf (heap_dump_file, "<collection type=\"%s\" num=\"%d\"", type, num);
2054 fprintf (heap_dump_file, " reason=\"%s\"", reason);
2055 fprintf (heap_dump_file, ">\n");
2056 fprintf (heap_dump_file, "<other-mem-usage type=\"mempools\" size=\"%ld\"/>\n", mono_mempool_get_bytes_allocated ());
2057 sgen_dump_internal_mem_usage (heap_dump_file);
2058 fprintf (heap_dump_file, "<pinned type=\"stack\" bytes=\"%zu\"/>\n", sgen_pin_stats_get_pinned_byte_count (PIN_TYPE_STACK));
2059 /* fprintf (heap_dump_file, "<pinned type=\"static-data\" bytes=\"%d\"/>\n", pinned_byte_counts [PIN_TYPE_STATIC_DATA]); */
2060 fprintf (heap_dump_file, "<pinned type=\"other\" bytes=\"%zu\"/>\n", sgen_pin_stats_get_pinned_byte_count (PIN_TYPE_OTHER));
2062 fprintf (heap_dump_file, "<pinned-objects>\n");
2063 for (list = sgen_pin_stats_get_object_list (); list; list = list->next)
2064 dump_object (list->obj, TRUE);
2065 fprintf (heap_dump_file, "</pinned-objects>\n");
2067 sgen_dump_section (nursery_section, "nursery");
2069 major_collector.dump_heap (heap_dump_file);
2071 fprintf (heap_dump_file, "<los>\n");
2072 for (bigobj = los_object_list; bigobj; bigobj = bigobj->next)
2073 dump_object ((MonoObject*)bigobj->data, FALSE);
2074 fprintf (heap_dump_file, "</los>\n");
2076 fprintf (heap_dump_file, "</collection>\n");
2080 sgen_register_moved_object (void *obj, void *destination)
2082 g_assert (mono_profiler_events & MONO_PROFILE_GC_MOVES);
2084 /* FIXME: handle this for parallel collector */
2085 g_assert (!sgen_collection_is_parallel ());
2087 if (moved_objects_idx == MOVED_OBJECTS_NUM) {
2088 mono_profiler_gc_moves (moved_objects, moved_objects_idx);
2089 moved_objects_idx = 0;
2091 moved_objects [moved_objects_idx++] = obj;
2092 moved_objects [moved_objects_idx++] = destination;
2098 static gboolean inited = FALSE;
2103 mono_counters_register ("Minor fragment clear", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_minor_pre_collection_fragment_clear);
2104 mono_counters_register ("Minor pinning", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_minor_pinning);
2105 mono_counters_register ("Minor scan remembered set", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_minor_scan_remsets);
2106 mono_counters_register ("Minor scan pinned", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_minor_scan_pinned);
2107 mono_counters_register ("Minor scan registered roots", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_minor_scan_registered_roots);
2108 mono_counters_register ("Minor scan thread data", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_minor_scan_thread_data);
2109 mono_counters_register ("Minor finish gray stack", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_minor_finish_gray_stack);
2110 mono_counters_register ("Minor fragment creation", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_minor_fragment_creation);
2112 mono_counters_register ("Major fragment clear", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_major_pre_collection_fragment_clear);
2113 mono_counters_register ("Major pinning", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_major_pinning);
2114 mono_counters_register ("Major scan pinned", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_major_scan_pinned);
2115 mono_counters_register ("Major scan registered roots", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_major_scan_registered_roots);
2116 mono_counters_register ("Major scan thread data", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_major_scan_thread_data);
2117 mono_counters_register ("Major scan alloc_pinned", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_major_scan_alloc_pinned);
2118 mono_counters_register ("Major scan finalized", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_major_scan_finalized);
2119 mono_counters_register ("Major scan big objects", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_major_scan_big_objects);
2120 mono_counters_register ("Major finish gray stack", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_major_finish_gray_stack);
2121 mono_counters_register ("Major free big objects", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_major_free_bigobjs);
2122 mono_counters_register ("Major LOS sweep", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_major_los_sweep);
2123 mono_counters_register ("Major sweep", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_major_sweep);
2124 mono_counters_register ("Major fragment creation", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_major_fragment_creation);
2126 mono_counters_register ("Number of pinned objects", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_pinned_objects);
2128 #ifdef HEAVY_STATISTICS
2129 mono_counters_register ("WBarrier set field", MONO_COUNTER_GC | MONO_COUNTER_INT, &stat_wbarrier_set_field);
2130 mono_counters_register ("WBarrier set arrayref", MONO_COUNTER_GC | MONO_COUNTER_INT, &stat_wbarrier_set_arrayref);
2131 mono_counters_register ("WBarrier arrayref copy", MONO_COUNTER_GC | MONO_COUNTER_INT, &stat_wbarrier_arrayref_copy);
2132 mono_counters_register ("WBarrier generic store called", MONO_COUNTER_GC | MONO_COUNTER_INT, &stat_wbarrier_generic_store);
2133 mono_counters_register ("WBarrier set root", MONO_COUNTER_GC | MONO_COUNTER_INT, &stat_wbarrier_set_root);
2134 mono_counters_register ("WBarrier value copy", MONO_COUNTER_GC | MONO_COUNTER_INT, &stat_wbarrier_value_copy);
2135 mono_counters_register ("WBarrier object copy", MONO_COUNTER_GC | MONO_COUNTER_INT, &stat_wbarrier_object_copy);
2137 mono_counters_register ("# objects allocated degraded", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_objects_alloced_degraded);
2138 mono_counters_register ("bytes allocated degraded", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_bytes_alloced_degraded);
2140 mono_counters_register ("# copy_object() called (nursery)", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_copy_object_called_nursery);
2141 mono_counters_register ("# objects copied (nursery)", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_objects_copied_nursery);
2142 mono_counters_register ("# copy_object() called (major)", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_copy_object_called_major);
2143 mono_counters_register ("# objects copied (major)", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_objects_copied_major);
2145 mono_counters_register ("# scan_object() called (nursery)", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_scan_object_called_nursery);
2146 mono_counters_register ("# scan_object() called (major)", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_scan_object_called_major);
2148 mono_counters_register ("Slots allocated in vain", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_slots_allocated_in_vain);
2150 mono_counters_register ("# nursery copy_object() failed from space", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_nursery_copy_object_failed_from_space);
2151 mono_counters_register ("# nursery copy_object() failed forwarded", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_nursery_copy_object_failed_forwarded);
2152 mono_counters_register ("# nursery copy_object() failed pinned", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_nursery_copy_object_failed_pinned);
2153 mono_counters_register ("# nursery copy_object() failed to space", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_nursery_copy_object_failed_to_space);
2155 sgen_nursery_allocator_init_heavy_stats ();
2156 sgen_alloc_init_heavy_stats ();
2164 reset_pinned_from_failed_allocation (void)
2166 bytes_pinned_from_failed_allocation = 0;
2170 sgen_set_pinned_from_failed_allocation (mword objsize)
2172 bytes_pinned_from_failed_allocation += objsize;
2176 sgen_collection_is_parallel (void)
2178 switch (current_collection_generation) {
2179 case GENERATION_NURSERY:
2180 return nursery_collection_is_parallel;
2181 case GENERATION_OLD:
2182 return major_collector.is_parallel;
2184 g_error ("Invalid current generation %d", current_collection_generation);
2189 sgen_collection_is_concurrent (void)
2191 switch (current_collection_generation) {
2192 case GENERATION_NURSERY:
2194 case GENERATION_OLD:
2195 return major_collector.is_concurrent;
2197 g_error ("Invalid current generation %d", current_collection_generation);
2202 sgen_concurrent_collection_in_progress (void)
2204 return concurrent_collection_in_progress;
2211 } FinishRememberedSetScanJobData;
2214 job_finish_remembered_set_scan (WorkerData *worker_data, void *job_data_untyped)
2216 FinishRememberedSetScanJobData *job_data = job_data_untyped;
2218 remset.finish_scan_remsets (job_data->heap_start, job_data->heap_end, sgen_workers_get_job_gray_queue (worker_data));
2219 sgen_free_internal_dynamic (job_data, sizeof (FinishRememberedSetScanJobData), INTERNAL_MEM_WORKER_JOB_DATA);
2224 CopyOrMarkObjectFunc copy_or_mark_func;
2225 ScanObjectFunc scan_func;
2229 } ScanFromRegisteredRootsJobData;
2232 job_scan_from_registered_roots (WorkerData *worker_data, void *job_data_untyped)
2234 ScanFromRegisteredRootsJobData *job_data = job_data_untyped;
2236 scan_from_registered_roots (job_data->copy_or_mark_func, job_data->scan_func,
2237 job_data->heap_start, job_data->heap_end,
2238 job_data->root_type,
2239 sgen_workers_get_job_gray_queue (worker_data));
2240 sgen_free_internal_dynamic (job_data, sizeof (ScanFromRegisteredRootsJobData), INTERNAL_MEM_WORKER_JOB_DATA);
2247 } ScanThreadDataJobData;
2250 job_scan_thread_data (WorkerData *worker_data, void *job_data_untyped)
2252 ScanThreadDataJobData *job_data = job_data_untyped;
2254 scan_thread_data (job_data->heap_start, job_data->heap_end, TRUE,
2255 sgen_workers_get_job_gray_queue (worker_data));
2256 sgen_free_internal_dynamic (job_data, sizeof (ScanThreadDataJobData), INTERNAL_MEM_WORKER_JOB_DATA);
2261 FinalizeReadyEntry *list;
2262 } ScanFinalizerEntriesJobData;
2265 job_scan_finalizer_entries (WorkerData *worker_data, void *job_data_untyped)
2267 ScanFinalizerEntriesJobData *job_data = job_data_untyped;
2269 scan_finalizer_entries (current_object_ops.copy_or_mark_object,
2271 sgen_workers_get_job_gray_queue (worker_data));
2272 sgen_free_internal_dynamic (job_data, sizeof (ScanFinalizerEntriesJobData), INTERNAL_MEM_WORKER_JOB_DATA);
2276 job_scan_major_mod_union_cardtable (WorkerData *worker_data, void *job_data_untyped)
2278 g_assert (concurrent_collection_in_progress);
2279 major_collector.scan_card_table (TRUE, sgen_workers_get_job_gray_queue (worker_data));
2283 job_scan_los_mod_union_cardtable (WorkerData *worker_data, void *job_data_untyped)
2285 g_assert (concurrent_collection_in_progress);
2286 sgen_los_scan_card_table (TRUE, sgen_workers_get_job_gray_queue (worker_data));
2290 verify_scan_starts (char *start, char *end)
2294 for (i = 0; i < nursery_section->num_scan_start; ++i) {
2295 char *addr = nursery_section->scan_starts [i];
2296 if (addr > start && addr < end)
2297 SGEN_LOG (1, "NFC-BAD SCAN START [%d] %p for obj [%p %p]", i, addr, start, end);
2302 verify_nursery (void)
2304 char *start, *end, *cur, *hole_start;
2306 if (!do_verify_nursery)
2309 /*This cleans up unused fragments */
2310 sgen_nursery_allocator_prepare_for_pinning ();
2312 hole_start = start = cur = sgen_get_nursery_start ();
2313 end = sgen_get_nursery_end ();
2318 if (!*(void**)cur) {
2319 cur += sizeof (void*);
2323 if (object_is_forwarded (cur))
2324 SGEN_LOG (1, "FORWARDED OBJ %p", cur);
2325 else if (object_is_pinned (cur))
2326 SGEN_LOG (1, "PINNED OBJ %p", cur);
2328 ss = safe_object_get_size ((MonoObject*)cur);
2329 size = ALIGN_UP (safe_object_get_size ((MonoObject*)cur));
2330 verify_scan_starts (cur, cur + size);
2331 if (do_dump_nursery_content) {
2332 if (cur > hole_start)
2333 SGEN_LOG (1, "HOLE [%p %p %d]", hole_start, cur, (int)(cur - hole_start));
2334 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 ());
2342 * Checks that no objects in the nursery are fowarded or pinned. This
2343 * is a precondition to restarting the mutator while doing a
2344 * concurrent collection. Note that we don't clear fragments because
2345 * we depend on that having happened earlier.
2348 check_nursery_is_clean (void)
2350 char *start, *end, *cur;
2352 start = cur = sgen_get_nursery_start ();
2353 end = sgen_get_nursery_end ();
2358 if (!*(void**)cur) {
2359 cur += sizeof (void*);
2363 g_assert (!object_is_forwarded (cur));
2364 g_assert (!object_is_pinned (cur));
2366 ss = safe_object_get_size ((MonoObject*)cur);
2367 size = ALIGN_UP (safe_object_get_size ((MonoObject*)cur));
2368 verify_scan_starts (cur, cur + size);
2375 init_gray_queue (void)
2377 if (sgen_collection_is_parallel () || sgen_collection_is_concurrent ()) {
2378 sgen_gray_object_queue_init_invalid (&gray_queue);
2379 sgen_workers_init_distribute_gray_queue ();
2381 sgen_gray_object_queue_init (&gray_queue, NULL, FALSE);
2386 * Collect objects in the nursery. Returns whether to trigger a major
2390 collect_nursery (void)
2392 gboolean needs_major;
2393 size_t max_garbage_amount;
2395 FinishRememberedSetScanJobData *frssjd;
2396 ScanFromRegisteredRootsJobData *scrrjd_normal, *scrrjd_wbarrier;
2397 ScanFinalizerEntriesJobData *sfejd_fin_ready, *sfejd_critical_fin;
2398 ScanThreadDataJobData *stdjd;
2399 mword fragment_total;
2400 TV_DECLARE (all_atv);
2401 TV_DECLARE (all_btv);
2405 if (disable_minor_collections)
2408 MONO_GC_BEGIN (GENERATION_NURSERY);
2409 binary_protocol_collection_begin (stat_minor_gcs, GENERATION_NURSERY);
2413 #ifndef DISABLE_PERFCOUNTERS
2414 mono_perfcounters->gc_collections0++;
2417 current_collection_generation = GENERATION_NURSERY;
2418 if (sgen_collection_is_parallel ())
2419 current_object_ops = sgen_minor_collector.parallel_ops;
2421 current_object_ops = sgen_minor_collector.serial_ops;
2423 reset_pinned_from_failed_allocation ();
2425 check_scan_starts ();
2427 sgen_nursery_alloc_prepare_for_minor ();
2431 nursery_next = sgen_nursery_alloc_get_upper_alloc_bound ();
2432 /* FIXME: optimize later to use the higher address where an object can be present */
2433 nursery_next = MAX (nursery_next, sgen_get_nursery_end ());
2435 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 ()));
2436 max_garbage_amount = nursery_next - sgen_get_nursery_start ();
2437 g_assert (nursery_section->size >= max_garbage_amount);
2439 /* world must be stopped already */
2440 TV_GETTIME (all_atv);
2444 time_minor_pre_collection_fragment_clear += TV_ELAPSED (atv, btv);
2446 if (xdomain_checks) {
2447 sgen_clear_nursery_fragments ();
2448 check_for_xdomain_refs ();
2451 nursery_section->next_data = nursery_next;
2453 major_collector.start_nursery_collection ();
2455 sgen_memgov_minor_collection_start ();
2460 gc_stats.minor_gc_count ++;
2462 if (remset.prepare_for_minor_collection)
2463 remset.prepare_for_minor_collection ();
2465 sgen_process_fin_stage_entries ();
2466 sgen_process_dislink_stage_entries ();
2468 /* pin from pinned handles */
2469 sgen_init_pinning ();
2470 mono_profiler_gc_event (MONO_GC_EVENT_MARK_START, 0);
2471 pin_from_roots (sgen_get_nursery_start (), nursery_next, WORKERS_DISTRIBUTE_GRAY_QUEUE);
2472 /* identify pinned objects */
2473 sgen_optimize_pin_queue (0);
2474 sgen_pinning_setup_section (nursery_section);
2475 sgen_pin_objects_in_section (nursery_section, WORKERS_DISTRIBUTE_GRAY_QUEUE, NULL);
2476 sgen_pinning_trim_queue_to_section (nursery_section);
2479 time_minor_pinning += TV_ELAPSED (btv, atv);
2480 SGEN_LOG (2, "Finding pinned pointers: %d in %d usecs", sgen_get_pinned_count (), TV_ELAPSED (btv, atv));
2481 SGEN_LOG (4, "Start scan with %d pinned objects", sgen_get_pinned_count ());
2483 if (whole_heap_check_before_collection) {
2484 sgen_clear_nursery_fragments ();
2485 sgen_check_whole_heap ();
2487 if (consistency_check_at_minor_collection)
2488 sgen_check_consistency ();
2490 sgen_workers_start_all_workers ();
2493 * Perform the sequential part of remembered set scanning.
2494 * This usually involves scanning global information that might later be produced by evacuation.
2496 if (remset.begin_scan_remsets)
2497 remset.begin_scan_remsets (sgen_get_nursery_start (), nursery_next, WORKERS_DISTRIBUTE_GRAY_QUEUE);
2499 sgen_workers_start_marking ();
2501 frssjd = sgen_alloc_internal_dynamic (sizeof (FinishRememberedSetScanJobData), INTERNAL_MEM_WORKER_JOB_DATA, TRUE);
2502 frssjd->heap_start = sgen_get_nursery_start ();
2503 frssjd->heap_end = nursery_next;
2504 sgen_workers_enqueue_job (job_finish_remembered_set_scan, frssjd);
2506 /* we don't have complete write barrier yet, so we scan all the old generation sections */
2508 time_minor_scan_remsets += TV_ELAPSED (atv, btv);
2509 SGEN_LOG (2, "Old generation scan: %d usecs", TV_ELAPSED (atv, btv));
2511 if (!sgen_collection_is_parallel ())
2512 sgen_drain_gray_stack (&gray_queue, current_object_ops.scan_object, -1);
2514 if (mono_profiler_get_events () & MONO_PROFILE_GC_ROOTS)
2515 report_registered_roots ();
2516 if (mono_profiler_get_events () & MONO_PROFILE_GC_ROOTS)
2517 report_finalizer_roots ();
2519 time_minor_scan_pinned += TV_ELAPSED (btv, atv);
2521 /* registered roots, this includes static fields */
2522 scrrjd_normal = sgen_alloc_internal_dynamic (sizeof (ScanFromRegisteredRootsJobData), INTERNAL_MEM_WORKER_JOB_DATA, TRUE);
2523 scrrjd_normal->copy_or_mark_func = current_object_ops.copy_or_mark_object;
2524 scrrjd_normal->scan_func = current_object_ops.scan_object;
2525 scrrjd_normal->heap_start = sgen_get_nursery_start ();
2526 scrrjd_normal->heap_end = nursery_next;
2527 scrrjd_normal->root_type = ROOT_TYPE_NORMAL;
2528 sgen_workers_enqueue_job (job_scan_from_registered_roots, scrrjd_normal);
2530 scrrjd_wbarrier = sgen_alloc_internal_dynamic (sizeof (ScanFromRegisteredRootsJobData), INTERNAL_MEM_WORKER_JOB_DATA, TRUE);
2531 scrrjd_wbarrier->copy_or_mark_func = current_object_ops.copy_or_mark_object;
2532 scrrjd_wbarrier->scan_func = current_object_ops.scan_object;
2533 scrrjd_wbarrier->heap_start = sgen_get_nursery_start ();
2534 scrrjd_wbarrier->heap_end = nursery_next;
2535 scrrjd_wbarrier->root_type = ROOT_TYPE_WBARRIER;
2536 sgen_workers_enqueue_job (job_scan_from_registered_roots, scrrjd_wbarrier);
2539 time_minor_scan_registered_roots += TV_ELAPSED (atv, btv);
2542 stdjd = sgen_alloc_internal_dynamic (sizeof (ScanThreadDataJobData), INTERNAL_MEM_WORKER_JOB_DATA, TRUE);
2543 stdjd->heap_start = sgen_get_nursery_start ();
2544 stdjd->heap_end = nursery_next;
2545 sgen_workers_enqueue_job (job_scan_thread_data, stdjd);
2548 time_minor_scan_thread_data += TV_ELAPSED (btv, atv);
2551 if (sgen_collection_is_parallel () || sgen_collection_is_concurrent ()) {
2552 while (!sgen_gray_object_queue_is_empty (WORKERS_DISTRIBUTE_GRAY_QUEUE)) {
2553 sgen_workers_distribute_gray_queue_sections ();
2557 sgen_workers_join ();
2559 if (sgen_collection_is_parallel () || sgen_collection_is_concurrent ())
2560 g_assert (sgen_gray_object_queue_is_empty (&gray_queue));
2562 /* Scan the list of objects ready for finalization. If */
2563 sfejd_fin_ready = sgen_alloc_internal_dynamic (sizeof (ScanFinalizerEntriesJobData), INTERNAL_MEM_WORKER_JOB_DATA, TRUE);
2564 sfejd_fin_ready->list = fin_ready_list;
2565 sgen_workers_enqueue_job (job_scan_finalizer_entries, sfejd_fin_ready);
2567 sfejd_critical_fin = sgen_alloc_internal_dynamic (sizeof (ScanFinalizerEntriesJobData), INTERNAL_MEM_WORKER_JOB_DATA, TRUE);
2568 sfejd_critical_fin->list = critical_fin_list;
2569 sgen_workers_enqueue_job (job_scan_finalizer_entries, sfejd_critical_fin);
2571 finish_gray_stack (sgen_get_nursery_start (), nursery_next, GENERATION_NURSERY, &gray_queue);
2573 time_minor_finish_gray_stack += TV_ELAPSED (btv, atv);
2574 mono_profiler_gc_event (MONO_GC_EVENT_MARK_END, 0);
2577 * The (single-threaded) finalization code might have done
2578 * some copying/marking so we can only reset the GC thread's
2579 * worker data here instead of earlier when we joined the
2582 sgen_workers_reset_data ();
2584 if (objects_pinned) {
2585 sgen_optimize_pin_queue (0);
2586 sgen_pinning_setup_section (nursery_section);
2589 /* walk the pin_queue, build up the fragment list of free memory, unmark
2590 * pinned objects as we go, memzero() the empty fragments so they are ready for the
2593 mono_profiler_gc_event (MONO_GC_EVENT_RECLAIM_START, 0);
2594 fragment_total = sgen_build_nursery_fragments (nursery_section, nursery_section->pin_queue_start, nursery_section->pin_queue_num_entries);
2595 if (!fragment_total)
2598 /* Clear TLABs for all threads */
2599 sgen_clear_tlabs ();
2601 mono_profiler_gc_event (MONO_GC_EVENT_RECLAIM_END, 0);
2603 time_minor_fragment_creation += TV_ELAPSED (atv, btv);
2604 SGEN_LOG (2, "Fragment creation: %d usecs, %lu bytes available", TV_ELAPSED (atv, btv), (unsigned long)fragment_total);
2606 if (consistency_check_at_minor_collection)
2607 sgen_check_major_refs ();
2609 major_collector.finish_nursery_collection ();
2611 TV_GETTIME (all_btv);
2612 gc_stats.minor_gc_time_usecs += TV_ELAPSED (all_atv, all_btv);
2615 dump_heap ("minor", stat_minor_gcs - 1, NULL);
2617 /* prepare the pin queue for the next collection */
2618 sgen_finish_pinning ();
2619 if (fin_ready_list || critical_fin_list) {
2620 SGEN_LOG (4, "Finalizer-thread wakeup: ready %d", num_ready_finalizers);
2621 mono_gc_finalize_notify ();
2623 sgen_pin_stats_reset ();
2625 g_assert (sgen_gray_object_queue_is_empty (&gray_queue));
2627 if (remset.finish_minor_collection)
2628 remset.finish_minor_collection ();
2630 check_scan_starts ();
2632 binary_protocol_flush_buffers (FALSE);
2634 sgen_memgov_minor_collection_end ();
2636 /*objects are late pinned because of lack of memory, so a major is a good call*/
2637 needs_major = objects_pinned > 0;
2638 current_collection_generation = -1;
2641 MONO_GC_END (GENERATION_NURSERY);
2642 binary_protocol_collection_end (stat_minor_gcs - 1, GENERATION_NURSERY);
2648 major_copy_or_mark_from_roots (int *old_next_pin_slot, gboolean finish_up_concurrent_mark, gboolean scan_mod_union)
2653 /* FIXME: only use these values for the precise scan
2654 * note that to_space pointers should be excluded anyway...
2656 char *heap_start = NULL;
2657 char *heap_end = (char*)-1;
2658 gboolean profile_roots = mono_profiler_get_events () & MONO_PROFILE_GC_ROOTS;
2659 GCRootReport root_report = { 0 };
2660 ScanFromRegisteredRootsJobData *scrrjd_normal, *scrrjd_wbarrier;
2661 ScanThreadDataJobData *stdjd;
2662 ScanFinalizerEntriesJobData *sfejd_fin_ready, *sfejd_critical_fin;
2664 if (major_collector.is_concurrent) {
2665 /*This cleans up unused fragments */
2666 sgen_nursery_allocator_prepare_for_pinning ();
2668 if (do_concurrent_checks)
2669 check_nursery_is_clean ();
2671 /* The concurrent collector doesn't touch the nursery. */
2672 sgen_nursery_alloc_prepare_for_major ();
2679 /* Pinning depends on this */
2680 sgen_clear_nursery_fragments ();
2682 if (whole_heap_check_before_collection)
2683 sgen_check_whole_heap ();
2686 time_major_pre_collection_fragment_clear += TV_ELAPSED (atv, btv);
2688 if (!sgen_collection_is_concurrent ())
2689 nursery_section->next_data = sgen_get_nursery_end ();
2690 /* we should also coalesce scanning from sections close to each other
2691 * and deal with pointers outside of the sections later.
2695 *major_collector.have_swept = FALSE;
2697 if (xdomain_checks) {
2698 sgen_clear_nursery_fragments ();
2699 check_for_xdomain_refs ();
2702 if (!major_collector.is_concurrent) {
2703 /* Remsets are not useful for a major collection */
2704 remset.prepare_for_major_collection ();
2707 sgen_process_fin_stage_entries ();
2708 sgen_process_dislink_stage_entries ();
2711 sgen_init_pinning ();
2712 SGEN_LOG (6, "Collecting pinned addresses");
2713 pin_from_roots ((void*)lowest_heap_address, (void*)highest_heap_address, WORKERS_DISTRIBUTE_GRAY_QUEUE);
2714 sgen_optimize_pin_queue (0);
2717 * pin_queue now contains all candidate pointers, sorted and
2718 * uniqued. We must do two passes now to figure out which
2719 * objects are pinned.
2721 * The first is to find within the pin_queue the area for each
2722 * section. This requires that the pin_queue be sorted. We
2723 * also process the LOS objects and pinned chunks here.
2725 * The second, destructive, pass is to reduce the section
2726 * areas to pointers to the actually pinned objects.
2728 SGEN_LOG (6, "Pinning from sections");
2729 /* first pass for the sections */
2730 sgen_find_section_pin_queue_start_end (nursery_section);
2731 major_collector.find_pin_queue_start_ends (WORKERS_DISTRIBUTE_GRAY_QUEUE);
2732 /* identify possible pointers to the insize of large objects */
2733 SGEN_LOG (6, "Pinning from large objects");
2734 for (bigobj = los_object_list; bigobj; bigobj = bigobj->next) {
2736 if (sgen_find_optimized_pin_queue_area (bigobj->data, (char*)bigobj->data + sgen_los_object_size (bigobj), &dummy)) {
2737 binary_protocol_pin (bigobj->data, (gpointer)LOAD_VTABLE (bigobj->data), safe_object_get_size (((MonoObject*)(bigobj->data))));
2738 if (G_UNLIKELY (MONO_GC_OBJ_PINNED_ENABLED ())) {
2739 MonoVTable *vt = (MonoVTable*)LOAD_VTABLE (bigobj->data);
2740 MONO_GC_OBJ_PINNED ((mword)bigobj->data, sgen_safe_object_get_size ((MonoObject*)bigobj->data), vt->klass->name_space, vt->klass->name, GENERATION_OLD);
2742 if (sgen_los_object_is_pinned (bigobj->data)) {
2743 g_assert (finish_up_concurrent_mark);
2746 sgen_los_pin_object (bigobj->data);
2747 /* FIXME: only enqueue if object has references */
2748 GRAY_OBJECT_ENQUEUE (WORKERS_DISTRIBUTE_GRAY_QUEUE, bigobj->data);
2749 if (G_UNLIKELY (do_pin_stats))
2750 sgen_pin_stats_register_object ((char*) bigobj->data, safe_object_get_size ((MonoObject*) bigobj->data));
2751 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));
2754 add_profile_gc_root (&root_report, bigobj->data, MONO_PROFILE_GC_ROOT_PINNING | MONO_PROFILE_GC_ROOT_MISC, 0);
2758 notify_gc_roots (&root_report);
2759 /* second pass for the sections */
2760 sgen_pin_objects_in_section (nursery_section, WORKERS_DISTRIBUTE_GRAY_QUEUE,
2761 concurrent_collection_in_progress ? current_object_ops.scan_object : NULL);
2762 major_collector.pin_objects (WORKERS_DISTRIBUTE_GRAY_QUEUE);
2763 if (old_next_pin_slot)
2764 *old_next_pin_slot = sgen_get_pinned_count ();
2767 time_major_pinning += TV_ELAPSED (atv, btv);
2768 SGEN_LOG (2, "Finding pinned pointers: %d in %d usecs", sgen_get_pinned_count (), TV_ELAPSED (atv, btv));
2769 SGEN_LOG (4, "Start scan with %d pinned objects", sgen_get_pinned_count ());
2771 major_collector.init_to_space ();
2773 #ifdef SGEN_DEBUG_INTERNAL_ALLOC
2774 main_gc_thread = mono_native_thread_self ();
2777 sgen_workers_start_all_workers ();
2778 sgen_workers_start_marking ();
2780 if (mono_profiler_get_events () & MONO_PROFILE_GC_ROOTS)
2781 report_registered_roots ();
2783 time_major_scan_pinned += TV_ELAPSED (btv, atv);
2785 /* registered roots, this includes static fields */
2786 scrrjd_normal = sgen_alloc_internal_dynamic (sizeof (ScanFromRegisteredRootsJobData), INTERNAL_MEM_WORKER_JOB_DATA, TRUE);
2787 scrrjd_normal->copy_or_mark_func = current_object_ops.copy_or_mark_object;
2788 scrrjd_normal->scan_func = current_object_ops.scan_object;
2789 scrrjd_normal->heap_start = heap_start;
2790 scrrjd_normal->heap_end = heap_end;
2791 scrrjd_normal->root_type = ROOT_TYPE_NORMAL;
2792 sgen_workers_enqueue_job (job_scan_from_registered_roots, scrrjd_normal);
2794 scrrjd_wbarrier = sgen_alloc_internal_dynamic (sizeof (ScanFromRegisteredRootsJobData), INTERNAL_MEM_WORKER_JOB_DATA, TRUE);
2795 scrrjd_wbarrier->copy_or_mark_func = current_object_ops.copy_or_mark_object;
2796 scrrjd_wbarrier->scan_func = current_object_ops.scan_object;
2797 scrrjd_wbarrier->heap_start = heap_start;
2798 scrrjd_wbarrier->heap_end = heap_end;
2799 scrrjd_wbarrier->root_type = ROOT_TYPE_WBARRIER;
2800 sgen_workers_enqueue_job (job_scan_from_registered_roots, scrrjd_wbarrier);
2803 time_major_scan_registered_roots += TV_ELAPSED (atv, btv);
2806 stdjd = sgen_alloc_internal_dynamic (sizeof (ScanThreadDataJobData), INTERNAL_MEM_WORKER_JOB_DATA, TRUE);
2807 stdjd->heap_start = heap_start;
2808 stdjd->heap_end = heap_end;
2809 sgen_workers_enqueue_job (job_scan_thread_data, stdjd);
2812 time_major_scan_thread_data += TV_ELAPSED (btv, atv);
2815 time_major_scan_alloc_pinned += TV_ELAPSED (atv, btv);
2817 if (mono_profiler_get_events () & MONO_PROFILE_GC_ROOTS)
2818 report_finalizer_roots ();
2820 /* scan the list of objects ready for finalization */
2821 sfejd_fin_ready = sgen_alloc_internal_dynamic (sizeof (ScanFinalizerEntriesJobData), INTERNAL_MEM_WORKER_JOB_DATA, TRUE);
2822 sfejd_fin_ready->list = fin_ready_list;
2823 sgen_workers_enqueue_job (job_scan_finalizer_entries, sfejd_fin_ready);
2825 sfejd_critical_fin = sgen_alloc_internal_dynamic (sizeof (ScanFinalizerEntriesJobData), INTERNAL_MEM_WORKER_JOB_DATA, TRUE);
2826 sfejd_critical_fin->list = critical_fin_list;
2827 sgen_workers_enqueue_job (job_scan_finalizer_entries, sfejd_critical_fin);
2829 if (scan_mod_union) {
2830 g_assert (finish_up_concurrent_mark);
2832 /* Mod union card table */
2833 sgen_workers_enqueue_job (job_scan_major_mod_union_cardtable, NULL);
2834 sgen_workers_enqueue_job (job_scan_los_mod_union_cardtable, NULL);
2838 time_major_scan_finalized += TV_ELAPSED (btv, atv);
2839 SGEN_LOG (2, "Root scan: %d usecs", TV_ELAPSED (btv, atv));
2842 time_major_scan_big_objects += TV_ELAPSED (atv, btv);
2844 if (major_collector.is_concurrent) {
2845 /* prepare the pin queue for the next collection */
2846 sgen_finish_pinning ();
2848 sgen_pin_stats_reset ();
2850 if (do_concurrent_checks)
2851 check_nursery_is_clean ();
2856 major_start_collection (int *old_next_pin_slot)
2858 MONO_GC_BEGIN (GENERATION_OLD);
2859 binary_protocol_collection_begin (stat_major_gcs, GENERATION_OLD);
2861 current_collection_generation = GENERATION_OLD;
2862 #ifndef DISABLE_PERFCOUNTERS
2863 mono_perfcounters->gc_collections1++;
2866 if (major_collector.is_concurrent)
2867 concurrent_collection_in_progress = TRUE;
2869 current_object_ops = major_collector.major_ops;
2871 reset_pinned_from_failed_allocation ();
2873 sgen_memgov_major_collection_start ();
2875 //count_ref_nonref_objs ();
2876 //consistency_check ();
2878 check_scan_starts ();
2881 SGEN_LOG (1, "Start major collection %d", stat_major_gcs);
2883 gc_stats.major_gc_count ++;
2885 if (major_collector.start_major_collection)
2886 major_collector.start_major_collection ();
2888 major_copy_or_mark_from_roots (old_next_pin_slot, FALSE, FALSE);
2892 wait_for_workers_to_finish (void)
2894 if (major_collector.is_parallel || major_collector.is_concurrent) {
2895 while (!sgen_gray_object_queue_is_empty (WORKERS_DISTRIBUTE_GRAY_QUEUE)) {
2896 sgen_workers_distribute_gray_queue_sections ();
2900 sgen_workers_join ();
2902 if (major_collector.is_parallel || major_collector.is_concurrent)
2903 g_assert (sgen_gray_object_queue_is_empty (&gray_queue));
2905 #ifdef SGEN_DEBUG_INTERNAL_ALLOC
2906 main_gc_thread = NULL;
2911 major_finish_collection (const char *reason, int old_next_pin_slot, gboolean scan_mod_union)
2913 LOSObject *bigobj, *prevbo;
2916 char *heap_start = NULL;
2917 char *heap_end = (char*)-1;
2921 wait_for_workers_to_finish ();
2923 current_object_ops = major_collector.major_ops;
2925 if (major_collector.is_concurrent) {
2926 major_copy_or_mark_from_roots (NULL, TRUE, scan_mod_union);
2927 wait_for_workers_to_finish ();
2929 if (do_concurrent_checks)
2930 check_nursery_is_clean ();
2933 /* all the objects in the heap */
2934 finish_gray_stack (heap_start, heap_end, GENERATION_OLD, &gray_queue);
2936 time_major_finish_gray_stack += TV_ELAPSED (btv, atv);
2939 * The (single-threaded) finalization code might have done
2940 * some copying/marking so we can only reset the GC thread's
2941 * worker data here instead of earlier when we joined the
2944 sgen_workers_reset_data ();
2946 if (objects_pinned) {
2947 g_assert (!major_collector.is_concurrent);
2949 /*This is slow, but we just OOM'd*/
2950 sgen_pin_queue_clear_discarded_entries (nursery_section, old_next_pin_slot);
2951 sgen_optimize_pin_queue (0);
2952 sgen_find_section_pin_queue_start_end (nursery_section);
2956 reset_heap_boundaries ();
2957 sgen_update_heap_boundaries ((mword)sgen_get_nursery_start (), (mword)sgen_get_nursery_end ());
2959 MONO_GC_SWEEP_BEGIN (GENERATION_OLD);
2961 /* sweep the big objects list */
2963 for (bigobj = los_object_list; bigobj;) {
2964 g_assert (!object_is_pinned (bigobj->data));
2965 if (sgen_los_object_is_pinned (bigobj->data)) {
2966 sgen_los_unpin_object (bigobj->data);
2967 sgen_update_heap_boundaries ((mword)bigobj->data, (mword)bigobj->data + sgen_los_object_size (bigobj));
2970 /* not referenced anywhere, so we can free it */
2972 prevbo->next = bigobj->next;
2974 los_object_list = bigobj->next;
2976 bigobj = bigobj->next;
2977 sgen_los_free_object (to_free);
2981 bigobj = bigobj->next;
2985 time_major_free_bigobjs += TV_ELAPSED (atv, btv);
2990 time_major_los_sweep += TV_ELAPSED (btv, atv);
2992 major_collector.sweep ();
2994 MONO_GC_SWEEP_END (GENERATION_OLD);
2997 time_major_sweep += TV_ELAPSED (atv, btv);
2999 if (!major_collector.is_concurrent) {
3000 /* walk the pin_queue, build up the fragment list of free memory, unmark
3001 * pinned objects as we go, memzero() the empty fragments so they are ready for the
3004 if (!sgen_build_nursery_fragments (nursery_section, nursery_section->pin_queue_start, nursery_section->pin_queue_num_entries))
3007 /* prepare the pin queue for the next collection */
3008 sgen_finish_pinning ();
3010 /* Clear TLABs for all threads */
3011 sgen_clear_tlabs ();
3013 sgen_pin_stats_reset ();
3017 time_major_fragment_creation += TV_ELAPSED (btv, atv);
3020 dump_heap ("major", stat_major_gcs - 1, reason);
3022 if (fin_ready_list || critical_fin_list) {
3023 SGEN_LOG (4, "Finalizer-thread wakeup: ready %d", num_ready_finalizers);
3024 mono_gc_finalize_notify ();
3027 g_assert (sgen_gray_object_queue_is_empty (&gray_queue));
3029 sgen_memgov_major_collection_end ();
3030 current_collection_generation = -1;
3032 major_collector.finish_major_collection ();
3034 if (major_collector.is_concurrent)
3035 concurrent_collection_in_progress = FALSE;
3037 check_scan_starts ();
3039 binary_protocol_flush_buffers (FALSE);
3041 //consistency_check ();
3043 MONO_GC_END (GENERATION_OLD);
3044 binary_protocol_collection_end (stat_major_gcs - 1, GENERATION_OLD);
3048 major_do_collection (const char *reason)
3050 TV_DECLARE (all_atv);
3051 TV_DECLARE (all_btv);
3052 int old_next_pin_slot;
3054 /* world must be stopped already */
3055 TV_GETTIME (all_atv);
3057 major_start_collection (&old_next_pin_slot);
3058 major_finish_collection (reason, old_next_pin_slot, FALSE);
3060 TV_GETTIME (all_btv);
3061 gc_stats.major_gc_time_usecs += TV_ELAPSED (all_atv, all_btv);
3063 return bytes_pinned_from_failed_allocation > 0;
3066 static gboolean major_do_collection (const char *reason);
3069 major_start_concurrent_collection (const char *reason)
3071 MONO_GC_CONCURRENT_START_BEGIN (GENERATION_OLD);
3073 // FIXME: store reason and pass it when finishing
3074 major_start_collection (NULL);
3076 sgen_workers_distribute_gray_queue_sections ();
3077 g_assert (sgen_gray_object_queue_is_empty (sgen_workers_get_distribute_gray_queue ()));
3079 sgen_workers_wait_for_jobs ();
3081 MONO_GC_CONCURRENT_START_END (GENERATION_OLD);
3083 current_collection_generation = -1;
3087 major_update_or_finish_concurrent_collection (void)
3089 MONO_GC_CONCURRENT_UPDATE_FINISH_BEGIN (GENERATION_OLD);
3091 major_collector.update_cardtable_mod_union ();
3092 sgen_los_update_cardtable_mod_union ();
3094 if (!sgen_workers_all_done ()) {
3095 MONO_GC_CONCURRENT_UPDATE_END (GENERATION_OLD);
3097 g_print ("workers not done\n");
3103 current_collection_generation = GENERATION_OLD;
3104 major_finish_collection ("finishing", -1, TRUE);
3106 MONO_GC_CONCURRENT_FINISH_END (GENERATION_OLD);
3108 current_collection_generation = -1;
3110 if (whole_heap_check_before_collection)
3111 sgen_check_whole_heap ();
3117 * Ensure an allocation request for @size will succeed by freeing enough memory.
3119 * LOCKING: The GC lock MUST be held.
3122 sgen_ensure_free_space (size_t size)
3124 int generation_to_collect = -1;
3125 const char *reason = NULL;
3128 if (size > SGEN_MAX_SMALL_OBJ_SIZE) {
3129 if (sgen_need_major_collection (size)) {
3130 reason = "LOS overflow";
3131 generation_to_collect = GENERATION_OLD;
3134 if (degraded_mode) {
3135 if (sgen_need_major_collection (size)) {
3136 reason = "Degraded mode overflow";
3137 generation_to_collect = GENERATION_OLD;
3139 } else if (sgen_need_major_collection (size)) {
3140 reason = "Minor allowance";
3141 generation_to_collect = GENERATION_OLD;
3143 generation_to_collect = GENERATION_NURSERY;
3144 reason = "Nursery full";
3148 if (generation_to_collect == -1)
3150 sgen_perform_collection (size, generation_to_collect, reason, generation_to_collect == GENERATION_NURSERY);
3154 sgen_perform_collection (size_t requested_size, int generation_to_collect, const char *reason, gboolean wait_to_finish)
3156 TV_DECLARE (gc_end);
3157 GGTimingInfo infos [2];
3158 int overflow_generation_to_collect = -1;
3159 const char *overflow_reason = NULL;
3161 memset (infos, 0, sizeof (infos));
3162 mono_profiler_gc_event (MONO_GC_EVENT_START, generation_to_collect);
3164 infos [0].generation = generation_to_collect;
3165 infos [0].reason = reason;
3166 infos [0].is_overflow = FALSE;
3167 TV_GETTIME (infos [0].total_time);
3168 infos [1].generation = -1;
3170 sgen_stop_world (generation_to_collect);
3172 if (concurrent_collection_in_progress) {
3173 g_assert (generation_to_collect == GENERATION_NURSERY);
3174 g_print ("finishing concurrent collection\n");
3175 if (major_update_or_finish_concurrent_collection ())
3179 //FIXME extract overflow reason
3180 if (generation_to_collect == GENERATION_NURSERY) {
3181 if (collect_nursery ()) {
3182 overflow_generation_to_collect = GENERATION_OLD;
3183 overflow_reason = "Minor overflow";
3185 if (concurrent_collection_in_progress)
3186 sgen_workers_wake_up_all ();
3188 if (major_collector.is_concurrent)
3191 if (major_collector.is_concurrent && !wait_to_finish) {
3192 major_start_concurrent_collection (reason);
3193 // FIXME: set infos[0] properly
3196 if (major_do_collection (reason)) {
3197 overflow_generation_to_collect = GENERATION_NURSERY;
3198 overflow_reason = "Excessive pinning";
3203 TV_GETTIME (gc_end);
3204 infos [0].total_time = SGEN_TV_ELAPSED (infos [0].total_time, gc_end);
3207 if (!major_collector.is_concurrent && overflow_generation_to_collect != -1) {
3208 mono_profiler_gc_event (MONO_GC_EVENT_START, overflow_generation_to_collect);
3209 infos [1].generation = overflow_generation_to_collect;
3210 infos [1].reason = overflow_reason;
3211 infos [1].is_overflow = TRUE;
3212 infos [1].total_time = gc_end;
3214 if (overflow_generation_to_collect == GENERATION_NURSERY)
3217 major_do_collection (overflow_reason);
3219 TV_GETTIME (gc_end);
3220 infos [1].total_time = SGEN_TV_ELAPSED (infos [1].total_time, gc_end);
3222 /* keep events symmetric */
3223 mono_profiler_gc_event (MONO_GC_EVENT_END, overflow_generation_to_collect);
3226 SGEN_LOG (2, "Heap size: %lu, LOS size: %lu", (unsigned long)mono_gc_get_heap_size (), (unsigned long)los_memory_usage);
3228 /* this also sets the proper pointers for the next allocation */
3229 if (generation_to_collect == GENERATION_NURSERY && !sgen_can_alloc_size (requested_size)) {
3230 /* TypeBuilder and MonoMethod are killing mcs with fragmentation */
3231 SGEN_LOG (1, "nursery collection didn't find enough room for %zd alloc (%d pinned)", requested_size, sgen_get_pinned_count ());
3232 sgen_dump_pin_queue ();
3237 sgen_restart_world (generation_to_collect, infos);
3239 mono_profiler_gc_event (MONO_GC_EVENT_END, generation_to_collect);
3243 * ######################################################################
3244 * ######## Memory allocation from the OS
3245 * ######################################################################
3246 * This section of code deals with getting memory from the OS and
3247 * allocating memory for GC-internal data structures.
3248 * Internal memory can be handled with a freelist for small objects.
3254 G_GNUC_UNUSED static void
3255 report_internal_mem_usage (void)
3257 printf ("Internal memory usage:\n");
3258 sgen_report_internal_mem_usage ();
3259 printf ("Pinned memory usage:\n");
3260 major_collector.report_pinned_memory_usage ();
3264 * ######################################################################
3265 * ######## Finalization support
3266 * ######################################################################
3270 * If the object has been forwarded it means it's still referenced from a root.
3271 * If it is pinned it's still alive as well.
3272 * A LOS object is only alive if we have pinned it.
3273 * Return TRUE if @obj is ready to be finalized.
3275 static inline gboolean
3276 sgen_is_object_alive (void *object)
3280 if (ptr_in_nursery (object))
3281 return sgen_nursery_is_object_alive (object);
3282 /* Oldgen objects can be pinned and forwarded too */
3283 if (SGEN_OBJECT_IS_PINNED (object) || SGEN_OBJECT_IS_FORWARDED (object))
3287 * FIXME: major_collector.is_object_live() also calculates the
3288 * size. Avoid the double calculation.
3290 objsize = SGEN_ALIGN_UP (sgen_safe_object_get_size ((MonoObject*)object));
3291 if (objsize > SGEN_MAX_SMALL_OBJ_SIZE)
3292 return sgen_los_object_is_pinned (object);
3294 return major_collector.is_object_live (object);
3298 sgen_gc_is_object_ready_for_finalization (void *object)
3300 return !sgen_is_object_alive (object);
3304 has_critical_finalizer (MonoObject *obj)
3308 if (!mono_defaults.critical_finalizer_object)
3311 class = ((MonoVTable*)LOAD_VTABLE (obj))->klass;
3313 return mono_class_has_parent_fast (class, mono_defaults.critical_finalizer_object);
3317 sgen_queue_finalization_entry (MonoObject *obj)
3319 FinalizeReadyEntry *entry = sgen_alloc_internal (INTERNAL_MEM_FINALIZE_READY_ENTRY);
3320 entry->object = obj;
3321 if (has_critical_finalizer (obj)) {
3322 entry->next = critical_fin_list;
3323 critical_fin_list = entry;
3325 entry->next = fin_ready_list;
3326 fin_ready_list = entry;
3331 object_is_reachable (char *object, char *start, char *end)
3333 /*This happens for non nursery objects during minor collections. We just treat all objects as alive.*/
3334 if (object < start || object >= end)
3337 return sgen_is_object_alive (object);
3341 sgen_object_is_live (void *obj)
3343 if (ptr_in_nursery (obj))
3344 return object_is_pinned (obj);
3345 /* FIXME This is semantically wrong! All tenured object are considered alive during a nursery collection. */
3346 if (current_collection_generation == GENERATION_NURSERY)
3348 return major_collector.is_object_live (obj);
3351 /* LOCKING: requires that the GC lock is held */
3353 null_ephemerons_for_domain (MonoDomain *domain)
3355 EphemeronLinkNode *current = ephemeron_list, *prev = NULL;
3358 MonoObject *object = (MonoObject*)current->array;
3360 if (object && !object->vtable) {
3361 EphemeronLinkNode *tmp = current;
3364 prev->next = current->next;
3366 ephemeron_list = current->next;
3368 current = current->next;
3369 sgen_free_internal (tmp, INTERNAL_MEM_EPHEMERON_LINK);
3372 current = current->next;
3377 /* LOCKING: requires that the GC lock is held */
3379 clear_unreachable_ephemerons (CopyOrMarkObjectFunc copy_func, char *start, char *end, GrayQueue *queue)
3381 int was_in_nursery, was_promoted;
3382 EphemeronLinkNode *current = ephemeron_list, *prev = NULL;
3384 Ephemeron *cur, *array_end;
3388 char *object = current->array;
3390 if (!object_is_reachable (object, start, end)) {
3391 EphemeronLinkNode *tmp = current;
3393 SGEN_LOG (5, "Dead Ephemeron array at %p", object);
3396 prev->next = current->next;
3398 ephemeron_list = current->next;
3400 current = current->next;
3401 sgen_free_internal (tmp, INTERNAL_MEM_EPHEMERON_LINK);
3406 was_in_nursery = ptr_in_nursery (object);
3407 copy_func ((void**)&object, queue);
3408 current->array = object;
3410 /*The array was promoted, add global remsets for key/values left behind in nursery.*/
3411 was_promoted = was_in_nursery && !ptr_in_nursery (object);
3413 SGEN_LOG (5, "Clearing unreachable entries for ephemeron array at %p", object);
3415 array = (MonoArray*)object;
3416 cur = mono_array_addr (array, Ephemeron, 0);
3417 array_end = cur + mono_array_length_fast (array);
3418 tombstone = (char*)((MonoVTable*)LOAD_VTABLE (object))->domain->ephemeron_tombstone;
3420 for (; cur < array_end; ++cur) {
3421 char *key = (char*)cur->key;
3423 if (!key || key == tombstone)
3426 SGEN_LOG (5, "[%td] key %p (%s) value %p (%s)", cur - mono_array_addr (array, Ephemeron, 0),
3427 key, object_is_reachable (key, start, end) ? "reachable" : "unreachable",
3428 cur->value, cur->value && object_is_reachable (cur->value, start, end) ? "reachable" : "unreachable");
3430 if (!object_is_reachable (key, start, end)) {
3431 cur->key = tombstone;
3437 if (ptr_in_nursery (key)) {/*key was not promoted*/
3438 SGEN_LOG (5, "\tAdded remset to key %p", key);
3439 sgen_add_to_global_remset (&cur->key);
3441 if (ptr_in_nursery (cur->value)) {/*value was not promoted*/
3442 SGEN_LOG (5, "\tAdded remset to value %p", cur->value);
3443 sgen_add_to_global_remset (&cur->value);
3448 current = current->next;
3452 /* LOCKING: requires that the GC lock is held */
3454 mark_ephemerons_in_range (CopyOrMarkObjectFunc copy_func, char *start, char *end, GrayQueue *queue)
3456 int nothing_marked = 1;
3457 EphemeronLinkNode *current = ephemeron_list;
3459 Ephemeron *cur, *array_end;
3462 for (current = ephemeron_list; current; current = current->next) {
3463 char *object = current->array;
3464 SGEN_LOG (5, "Ephemeron array at %p", object);
3467 For now we process all ephemerons during all collections.
3468 Ideally we should use remset information to partially scan those
3470 We already emit write barriers for Ephemeron fields, it's
3471 just that we don't process them.
3473 /*if (object < start || object >= end)
3476 /*It has to be alive*/
3477 if (!object_is_reachable (object, start, end)) {
3478 SGEN_LOG (5, "\tnot reachable");
3482 copy_func ((void**)&object, queue);
3484 array = (MonoArray*)object;
3485 cur = mono_array_addr (array, Ephemeron, 0);
3486 array_end = cur + mono_array_length_fast (array);
3487 tombstone = (char*)((MonoVTable*)LOAD_VTABLE (object))->domain->ephemeron_tombstone;
3489 for (; cur < array_end; ++cur) {
3490 char *key = cur->key;
3492 if (!key || key == tombstone)
3495 SGEN_LOG (5, "[%td] key %p (%s) value %p (%s)", cur - mono_array_addr (array, Ephemeron, 0),
3496 key, object_is_reachable (key, start, end) ? "reachable" : "unreachable",
3497 cur->value, cur->value && object_is_reachable (cur->value, start, end) ? "reachable" : "unreachable");
3499 if (object_is_reachable (key, start, end)) {
3500 char *value = cur->value;
3502 copy_func ((void**)&cur->key, queue);
3504 if (!object_is_reachable (value, start, end))
3506 copy_func ((void**)&cur->value, queue);
3512 SGEN_LOG (5, "Ephemeron run finished. Is it done %d", nothing_marked);
3513 return nothing_marked;
3517 mono_gc_invoke_finalizers (void)
3519 FinalizeReadyEntry *entry = NULL;
3520 gboolean entry_is_critical = FALSE;
3523 /* FIXME: batch to reduce lock contention */
3524 while (fin_ready_list || critical_fin_list) {
3528 FinalizeReadyEntry **list = entry_is_critical ? &critical_fin_list : &fin_ready_list;
3530 /* We have finalized entry in the last
3531 interation, now we need to remove it from
3534 *list = entry->next;
3536 FinalizeReadyEntry *e = *list;
3537 while (e->next != entry)
3539 e->next = entry->next;
3541 sgen_free_internal (entry, INTERNAL_MEM_FINALIZE_READY_ENTRY);
3545 /* Now look for the first non-null entry. */
3546 for (entry = fin_ready_list; entry && !entry->object; entry = entry->next)
3549 entry_is_critical = FALSE;
3551 entry_is_critical = TRUE;
3552 for (entry = critical_fin_list; entry && !entry->object; entry = entry->next)
3557 g_assert (entry->object);
3558 num_ready_finalizers--;
3559 obj = entry->object;
3560 entry->object = NULL;
3561 SGEN_LOG (7, "Finalizing object %p (%s)", obj, safe_name (obj));
3569 g_assert (entry->object == NULL);
3571 /* the object is on the stack so it is pinned */
3572 /*g_print ("Calling finalizer for object: %p (%s)\n", entry->object, safe_name (entry->object));*/
3573 mono_gc_run_finalize (obj, NULL);
3580 mono_gc_pending_finalizers (void)
3582 return fin_ready_list || critical_fin_list;
3586 * ######################################################################
3587 * ######## registered roots support
3588 * ######################################################################
3592 * We do not coalesce roots.
3595 mono_gc_register_root_inner (char *start, size_t size, void *descr, int root_type)
3597 RootRecord new_root;
3600 for (i = 0; i < ROOT_TYPE_NUM; ++i) {
3601 RootRecord *root = sgen_hash_table_lookup (&roots_hash [i], start);
3602 /* we allow changing the size and the descriptor (for thread statics etc) */
3604 size_t old_size = root->end_root - start;
3605 root->end_root = start + size;
3606 g_assert (((root->root_desc != 0) && (descr != NULL)) ||
3607 ((root->root_desc == 0) && (descr == NULL)));
3608 root->root_desc = (mword)descr;
3610 roots_size -= old_size;
3616 new_root.end_root = start + size;
3617 new_root.root_desc = (mword)descr;
3619 sgen_hash_table_replace (&roots_hash [root_type], start, &new_root, NULL);
3622 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);
3629 mono_gc_register_root (char *start, size_t size, void *descr)
3631 return mono_gc_register_root_inner (start, size, descr, descr ? ROOT_TYPE_NORMAL : ROOT_TYPE_PINNED);
3635 mono_gc_register_root_wbarrier (char *start, size_t size, void *descr)
3637 return mono_gc_register_root_inner (start, size, descr, ROOT_TYPE_WBARRIER);
3641 mono_gc_deregister_root (char* addr)
3647 for (root_type = 0; root_type < ROOT_TYPE_NUM; ++root_type) {
3648 if (sgen_hash_table_remove (&roots_hash [root_type], addr, &root))
3649 roots_size -= (root.end_root - addr);
3655 * ######################################################################
3656 * ######## Thread handling (stop/start code)
3657 * ######################################################################
3660 unsigned int sgen_global_stop_count = 0;
3663 sgen_fill_thread_info_for_suspend (SgenThreadInfo *info)
3665 if (remset.fill_thread_info_for_suspend)
3666 remset.fill_thread_info_for_suspend (info);
3670 sgen_get_current_collection_generation (void)
3672 return current_collection_generation;
3676 mono_gc_set_gc_callbacks (MonoGCCallbacks *callbacks)
3678 gc_callbacks = *callbacks;
3682 mono_gc_get_gc_callbacks ()
3684 return &gc_callbacks;
3687 /* Variables holding start/end nursery so it won't have to be passed at every call */
3688 static void *scan_area_arg_start, *scan_area_arg_end;
3691 mono_gc_conservatively_scan_area (void *start, void *end)
3693 conservatively_pin_objects_from (start, end, scan_area_arg_start, scan_area_arg_end, PIN_TYPE_STACK);
3697 mono_gc_scan_object (void *obj)
3699 UserCopyOrMarkData *data = mono_native_tls_get_value (user_copy_or_mark_key);
3700 current_object_ops.copy_or_mark_object (&obj, data->queue);
3705 * Mark from thread stacks and registers.
3708 scan_thread_data (void *start_nursery, void *end_nursery, gboolean precise, GrayQueue *queue)
3710 SgenThreadInfo *info;
3712 scan_area_arg_start = start_nursery;
3713 scan_area_arg_end = end_nursery;
3715 FOREACH_THREAD (info) {
3717 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);
3720 if (info->gc_disabled) {
3721 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);
3725 if (!info->joined_stw) {
3726 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);
3730 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 ());
3731 if (!info->thread_is_dying) {
3732 if (gc_callbacks.thread_mark_func && !conservative_stack_mark) {
3733 UserCopyOrMarkData data = { NULL, queue };
3734 set_user_copy_or_mark_data (&data);
3735 gc_callbacks.thread_mark_func (info->runtime_data, info->stack_start, info->stack_end, precise);
3736 set_user_copy_or_mark_data (NULL);
3737 } else if (!precise) {
3738 conservatively_pin_objects_from (info->stack_start, info->stack_end, start_nursery, end_nursery, PIN_TYPE_STACK);
3742 if (!info->thread_is_dying && !precise) {
3744 conservatively_pin_objects_from ((void**)&info->ctx, (void**)&info->ctx + ARCH_NUM_REGS,
3745 start_nursery, end_nursery, PIN_TYPE_STACK);
3747 conservatively_pin_objects_from (&info->regs, &info->regs + ARCH_NUM_REGS,
3748 start_nursery, end_nursery, PIN_TYPE_STACK);
3751 } END_FOREACH_THREAD
3755 ptr_on_stack (void *ptr)
3757 gpointer stack_start = &stack_start;
3758 SgenThreadInfo *info = mono_thread_info_current ();
3760 if (ptr >= stack_start && ptr < (gpointer)info->stack_end)
3766 sgen_thread_register (SgenThreadInfo* info, void *addr)
3768 #ifndef HAVE_KW_THREAD
3769 SgenThreadInfo *__thread_info__ = info;
3773 #ifndef HAVE_KW_THREAD
3774 info->tlab_start = info->tlab_next = info->tlab_temp_end = info->tlab_real_end = NULL;
3776 g_assert (!mono_native_tls_get_value (thread_info_key));
3777 mono_native_tls_set_value (thread_info_key, info);
3779 sgen_thread_info = info;
3782 #if !defined(__MACH__)
3783 info->stop_count = -1;
3787 info->joined_stw = FALSE;
3788 info->doing_handshake = FALSE;
3789 info->thread_is_dying = FALSE;
3790 info->stack_start = NULL;
3791 info->store_remset_buffer_addr = &STORE_REMSET_BUFFER;
3792 info->store_remset_buffer_index_addr = &STORE_REMSET_BUFFER_INDEX;
3793 info->stopped_ip = NULL;
3794 info->stopped_domain = NULL;
3796 memset (&info->ctx, 0, sizeof (MonoContext));
3798 memset (&info->regs, 0, sizeof (info->regs));
3801 sgen_init_tlab_info (info);
3803 binary_protocol_thread_register ((gpointer)mono_thread_info_get_tid (info));
3805 #ifdef HAVE_KW_THREAD
3806 store_remset_buffer_index_addr = &store_remset_buffer_index;
3809 /* try to get it with attributes first */
3810 #if defined(HAVE_PTHREAD_GETATTR_NP) && defined(HAVE_PTHREAD_ATTR_GETSTACK)
3814 pthread_attr_t attr;
3815 pthread_getattr_np (pthread_self (), &attr);
3816 pthread_attr_getstack (&attr, &sstart, &size);
3817 info->stack_start_limit = sstart;
3818 info->stack_end = (char*)sstart + size;
3819 pthread_attr_destroy (&attr);
3821 #elif defined(HAVE_PTHREAD_GET_STACKSIZE_NP) && defined(HAVE_PTHREAD_GET_STACKADDR_NP)
3822 info->stack_end = (char*)pthread_get_stackaddr_np (pthread_self ());
3823 info->stack_start_limit = (char*)info->stack_end - pthread_get_stacksize_np (pthread_self ());
3826 /* FIXME: we assume the stack grows down */
3827 gsize stack_bottom = (gsize)addr;
3828 stack_bottom += 4095;
3829 stack_bottom &= ~4095;
3830 info->stack_end = (char*)stack_bottom;
3834 #ifdef HAVE_KW_THREAD
3835 stack_end = info->stack_end;
3838 if (remset.register_thread)
3839 remset.register_thread (info);
3841 SGEN_LOG (3, "registered thread %p (%p) stack end %p", info, (gpointer)mono_thread_info_get_tid (info), info->stack_end);
3843 if (gc_callbacks.thread_attach_func)
3844 info->runtime_data = gc_callbacks.thread_attach_func ();
3851 sgen_wbarrier_cleanup_thread (SgenThreadInfo *p)
3853 if (remset.cleanup_thread)
3854 remset.cleanup_thread (p);
3858 sgen_thread_unregister (SgenThreadInfo *p)
3860 /* If a delegate is passed to native code and invoked on a thread we dont
3861 * know about, the jit will register it with mono_jit_thread_attach, but
3862 * we have no way of knowing when that thread goes away. SGen has a TSD
3863 * so we assume that if the domain is still registered, we can detach
3866 if (mono_domain_get ())
3867 mono_thread_detach (mono_thread_current ());
3869 p->thread_is_dying = TRUE;
3872 There is a race condition between a thread finishing executing and been removed
3873 from the GC thread set.
3874 This happens on posix systems when TLS data is been cleaned-up, libpthread will
3875 set the thread_info slot to NULL before calling the cleanup function. This
3876 opens a window in which the thread is registered but has a NULL TLS.
3878 The suspend signal handler needs TLS data to know where to store thread state
3879 data or otherwise it will simply ignore the thread.
3881 This solution works because the thread doing STW will wait until all threads been
3882 suspended handshake back, so there is no race between the doing_hankshake test
3883 and the suspend_thread call.
3885 This is not required on systems that do synchronous STW as those can deal with
3886 the above race at suspend time.
3888 FIXME: I believe we could avoid this by using mono_thread_info_lookup when
3889 mono_thread_info_current returns NULL. Or fix mono_thread_info_lookup to do so.
3891 #if (defined(__MACH__) && MONO_MACH_ARCH_SUPPORTED) || !defined(HAVE_PTHREAD_KILL)
3894 while (!TRYLOCK_GC) {
3895 if (!sgen_park_current_thread_if_doing_handshake (p))
3901 binary_protocol_thread_unregister ((gpointer)mono_thread_info_get_tid (p));
3902 SGEN_LOG (3, "unregister thread %p (%p)", p, (gpointer)mono_thread_info_get_tid (p));
3904 if (gc_callbacks.thread_detach_func) {
3905 gc_callbacks.thread_detach_func (p->runtime_data);
3906 p->runtime_data = NULL;
3908 sgen_wbarrier_cleanup_thread (p);
3910 mono_threads_unregister_current_thread (p);
3916 sgen_thread_attach (SgenThreadInfo *info)
3919 /*this is odd, can we get attached before the gc is inited?*/
3923 if (gc_callbacks.thread_attach_func && !info->runtime_data)
3924 info->runtime_data = gc_callbacks.thread_attach_func ();
3927 mono_gc_register_thread (void *baseptr)
3929 return mono_thread_info_attach (baseptr) != NULL;
3933 * mono_gc_set_stack_end:
3935 * Set the end of the current threads stack to STACK_END. The stack space between
3936 * STACK_END and the real end of the threads stack will not be scanned during collections.
3939 mono_gc_set_stack_end (void *stack_end)
3941 SgenThreadInfo *info;
3944 info = mono_thread_info_current ();
3946 g_assert (stack_end < info->stack_end);
3947 info->stack_end = stack_end;
3952 #if USE_PTHREAD_INTERCEPT
3956 mono_gc_pthread_create (pthread_t *new_thread, const pthread_attr_t *attr, void *(*start_routine)(void *), void *arg)
3958 return pthread_create (new_thread, attr, start_routine, arg);
3962 mono_gc_pthread_join (pthread_t thread, void **retval)
3964 return pthread_join (thread, retval);
3968 mono_gc_pthread_detach (pthread_t thread)
3970 return pthread_detach (thread);
3974 mono_gc_pthread_exit (void *retval)
3976 pthread_exit (retval);
3979 #endif /* USE_PTHREAD_INTERCEPT */
3982 * ######################################################################
3983 * ######## Write barriers
3984 * ######################################################################
3988 * Note: the write barriers first do the needed GC work and then do the actual store:
3989 * this way the value is visible to the conservative GC scan after the write barrier
3990 * itself. If a GC interrupts the barrier in the middle, value will be kept alive by
3991 * the conservative scan, otherwise by the remembered set scan.
3994 mono_gc_wbarrier_set_field (MonoObject *obj, gpointer field_ptr, MonoObject* value)
3996 HEAVY_STAT (++stat_wbarrier_set_field);
3997 if (ptr_in_nursery (field_ptr)) {
3998 *(void**)field_ptr = value;
4001 SGEN_LOG (8, "Adding remset at %p", field_ptr);
4003 binary_protocol_wbarrier (field_ptr, value, value->vtable);
4005 remset.wbarrier_set_field (obj, field_ptr, value);
4009 mono_gc_wbarrier_set_arrayref (MonoArray *arr, gpointer slot_ptr, MonoObject* value)
4011 HEAVY_STAT (++stat_wbarrier_set_arrayref);
4012 if (ptr_in_nursery (slot_ptr)) {
4013 *(void**)slot_ptr = value;
4016 SGEN_LOG (8, "Adding remset at %p", slot_ptr);
4018 binary_protocol_wbarrier (slot_ptr, value, value->vtable);
4020 remset.wbarrier_set_arrayref (arr, slot_ptr, value);
4024 mono_gc_wbarrier_arrayref_copy (gpointer dest_ptr, gpointer src_ptr, int count)
4026 HEAVY_STAT (++stat_wbarrier_arrayref_copy);
4027 /*This check can be done without taking a lock since dest_ptr array is pinned*/
4028 if (ptr_in_nursery (dest_ptr) || count <= 0) {
4029 mono_gc_memmove (dest_ptr, src_ptr, count * sizeof (gpointer));
4033 #ifdef SGEN_BINARY_PROTOCOL
4036 for (i = 0; i < count; ++i) {
4037 gpointer dest = (gpointer*)dest_ptr + i;
4038 gpointer obj = *((gpointer*)src_ptr + i);
4040 binary_protocol_wbarrier (dest, obj, (gpointer)LOAD_VTABLE (obj));
4045 remset.wbarrier_arrayref_copy (dest_ptr, src_ptr, count);
4048 static char *found_obj;
4051 find_object_for_ptr_callback (char *obj, size_t size, void *user_data)
4053 char *ptr = user_data;
4055 if (ptr >= obj && ptr < obj + size) {
4056 g_assert (!found_obj);
4061 /* for use in the debugger */
4062 char* find_object_for_ptr (char *ptr);
4064 find_object_for_ptr (char *ptr)
4066 if (ptr >= nursery_section->data && ptr < nursery_section->end_data) {
4068 sgen_scan_area_with_callback (nursery_section->data, nursery_section->end_data,
4069 find_object_for_ptr_callback, ptr, TRUE);
4075 sgen_los_iterate_objects (find_object_for_ptr_callback, ptr);
4080 * Very inefficient, but this is debugging code, supposed to
4081 * be called from gdb, so we don't care.
4084 major_collector.iterate_objects (TRUE, TRUE, find_object_for_ptr_callback, ptr);
4089 mono_gc_wbarrier_generic_nostore (gpointer ptr)
4093 HEAVY_STAT (++stat_wbarrier_generic_store);
4095 #ifdef XDOMAIN_CHECKS_IN_WBARRIER
4096 /* FIXME: ptr_in_heap must be called with the GC lock held */
4097 if (xdomain_checks && *(MonoObject**)ptr && ptr_in_heap (ptr)) {
4098 char *start = find_object_for_ptr (ptr);
4099 MonoObject *value = *(MonoObject**)ptr;
4103 MonoObject *obj = (MonoObject*)start;
4104 if (obj->vtable->domain != value->vtable->domain)
4105 g_assert (is_xdomain_ref_allowed (ptr, start, obj->vtable->domain));
4111 obj = *(gpointer*)ptr;
4113 binary_protocol_wbarrier (ptr, obj, (gpointer)LOAD_VTABLE (obj));
4115 if (ptr_in_nursery (ptr) || ptr_on_stack (ptr)) {
4116 SGEN_LOG (8, "Skipping remset at %p", ptr);
4121 * We need to record old->old pointer locations for the
4122 * concurrent collector.
4124 if (!ptr_in_nursery (obj) && !concurrent_collection_in_progress) {
4125 SGEN_LOG (8, "Skipping remset at %p", ptr);
4129 SGEN_LOG (8, "Adding remset at %p", ptr);
4131 remset.wbarrier_generic_nostore (ptr);
4135 mono_gc_wbarrier_generic_store (gpointer ptr, MonoObject* value)
4137 SGEN_LOG (8, "Wbarrier store at %p to %p (%s)", ptr, value, value ? safe_name (value) : "null");
4138 *(void**)ptr = value;
4139 if (ptr_in_nursery (value))
4140 mono_gc_wbarrier_generic_nostore (ptr);
4141 sgen_dummy_use (value);
4144 void mono_gc_wbarrier_value_copy_bitmap (gpointer _dest, gpointer _src, int size, unsigned bitmap)
4146 mword *dest = _dest;
4151 mono_gc_wbarrier_generic_store (dest, (MonoObject*)*src);
4156 size -= SIZEOF_VOID_P;
4161 #ifdef SGEN_BINARY_PROTOCOL
4163 #define HANDLE_PTR(ptr,obj) do { \
4164 gpointer o = *(gpointer*)(ptr); \
4166 gpointer d = ((char*)dest) + ((char*)(ptr) - (char*)(obj)); \
4167 binary_protocol_wbarrier (d, o, (gpointer) LOAD_VTABLE (o)); \
4172 scan_object_for_binary_protocol_copy_wbarrier (gpointer dest, char *start, mword desc)
4174 #define SCAN_OBJECT_NOVTABLE
4175 #include "sgen-scan-object.h"
4180 mono_gc_wbarrier_value_copy (gpointer dest, gpointer src, int count, MonoClass *klass)
4182 HEAVY_STAT (++stat_wbarrier_value_copy);
4183 g_assert (klass->valuetype);
4185 SGEN_LOG (8, "Adding value remset at %p, count %d, descr %p for class %s (%p)", dest, count, klass->gc_descr, klass->name, klass);
4187 if (ptr_in_nursery (dest) || ptr_on_stack (dest) || !SGEN_CLASS_HAS_REFERENCES (klass)) {
4188 size_t element_size = mono_class_value_size (klass, NULL);
4189 size_t size = count * element_size;
4190 mono_gc_memmove (dest, src, size);
4194 #ifdef SGEN_BINARY_PROTOCOL
4196 size_t element_size = mono_class_value_size (klass, NULL);
4198 for (i = 0; i < count; ++i) {
4199 scan_object_for_binary_protocol_copy_wbarrier ((char*)dest + i * element_size,
4200 (char*)src + i * element_size - sizeof (MonoObject),
4201 (mword) klass->gc_descr);
4206 remset.wbarrier_value_copy (dest, src, count, klass);
4210 * mono_gc_wbarrier_object_copy:
4212 * Write barrier to call when obj is the result of a clone or copy of an object.
4215 mono_gc_wbarrier_object_copy (MonoObject* obj, MonoObject *src)
4219 HEAVY_STAT (++stat_wbarrier_object_copy);
4221 if (ptr_in_nursery (obj) || ptr_on_stack (obj)) {
4222 size = mono_object_class (obj)->instance_size;
4223 mono_gc_memmove ((char*)obj + sizeof (MonoObject), (char*)src + sizeof (MonoObject),
4224 size - sizeof (MonoObject));
4228 #ifdef SGEN_BINARY_PROTOCOL
4229 scan_object_for_binary_protocol_copy_wbarrier (obj, (char*)src, (mword) src->vtable->gc_descr);
4232 remset.wbarrier_object_copy (obj, src);
4237 * ######################################################################
4238 * ######## Other mono public interface functions.
4239 * ######################################################################
4242 #define REFS_SIZE 128
4245 MonoGCReferences callback;
4249 MonoObject *refs [REFS_SIZE];
4250 uintptr_t offsets [REFS_SIZE];
4254 #define HANDLE_PTR(ptr,obj) do { \
4256 if (hwi->count == REFS_SIZE) { \
4257 hwi->callback ((MonoObject*)start, mono_object_class (start), hwi->called? 0: size, hwi->count, hwi->refs, hwi->offsets, hwi->data); \
4261 hwi->offsets [hwi->count] = (char*)(ptr)-(char*)start; \
4262 hwi->refs [hwi->count++] = *(ptr); \
4267 collect_references (HeapWalkInfo *hwi, char *start, size_t size)
4269 #include "sgen-scan-object.h"
4273 walk_references (char *start, size_t size, void *data)
4275 HeapWalkInfo *hwi = data;
4278 collect_references (hwi, start, size);
4279 if (hwi->count || !hwi->called)
4280 hwi->callback ((MonoObject*)start, mono_object_class (start), hwi->called? 0: size, hwi->count, hwi->refs, hwi->offsets, hwi->data);
4284 * mono_gc_walk_heap:
4285 * @flags: flags for future use
4286 * @callback: a function pointer called for each object in the heap
4287 * @data: a user data pointer that is passed to callback
4289 * This function can be used to iterate over all the live objects in the heap:
4290 * for each object, @callback is invoked, providing info about the object's
4291 * location in memory, its class, its size and the objects it references.
4292 * For each referenced object it's offset from the object address is
4293 * reported in the offsets array.
4294 * The object references may be buffered, so the callback may be invoked
4295 * multiple times for the same object: in all but the first call, the size
4296 * argument will be zero.
4297 * Note that this function can be only called in the #MONO_GC_EVENT_PRE_START_WORLD
4298 * profiler event handler.
4300 * Returns: a non-zero value if the GC doesn't support heap walking
4303 mono_gc_walk_heap (int flags, MonoGCReferences callback, void *data)
4308 hwi.callback = callback;
4311 sgen_clear_nursery_fragments ();
4312 sgen_scan_area_with_callback (nursery_section->data, nursery_section->end_data, walk_references, &hwi, FALSE);
4314 major_collector.iterate_objects (TRUE, TRUE, walk_references, &hwi);
4315 sgen_los_iterate_objects (walk_references, &hwi);
4321 mono_gc_collect (int generation)
4326 sgen_perform_collection (0, generation, "user request", TRUE);
4331 mono_gc_max_generation (void)
4337 mono_gc_collection_count (int generation)
4339 if (generation == 0)
4340 return stat_minor_gcs;
4341 return stat_major_gcs;
4345 mono_gc_get_used_size (void)
4349 tot = los_memory_usage;
4350 tot += nursery_section->next_data - nursery_section->data;
4351 tot += major_collector.get_used_size ();
4352 /* FIXME: account for pinned objects */
4358 mono_gc_disable (void)
4366 mono_gc_enable (void)
4374 mono_gc_get_los_limit (void)
4376 return MAX_SMALL_OBJ_SIZE;
4380 mono_gc_user_markers_supported (void)
4386 mono_object_is_alive (MonoObject* o)
4392 mono_gc_get_generation (MonoObject *obj)
4394 if (ptr_in_nursery (obj))
4400 mono_gc_enable_events (void)
4405 mono_gc_weak_link_add (void **link_addr, MonoObject *obj, gboolean track)
4407 sgen_register_disappearing_link (obj, link_addr, track, FALSE);
4411 mono_gc_weak_link_remove (void **link_addr)
4413 sgen_register_disappearing_link (NULL, link_addr, FALSE, FALSE);
4417 mono_gc_weak_link_get (void **link_addr)
4420 * We must only load *link_addr once because it might change
4421 * under our feet, and REVEAL_POINTER (NULL) results in an
4422 * invalid reference.
4424 void *ptr = *link_addr;
4429 * During the second bridge processing step the world is
4430 * running again. That step processes all weak links once
4431 * more to null those that refer to dead objects. Before that
4432 * is completed, those links must not be followed, so we
4433 * conservatively wait for bridge processing when any weak
4434 * link is dereferenced.
4436 if (G_UNLIKELY (bridge_processing_in_progress))
4437 mono_gc_wait_for_bridge_processing ();
4439 return (MonoObject*) REVEAL_POINTER (ptr);
4443 mono_gc_ephemeron_array_add (MonoObject *obj)
4445 EphemeronLinkNode *node;
4449 node = sgen_alloc_internal (INTERNAL_MEM_EPHEMERON_LINK);
4454 node->array = (char*)obj;
4455 node->next = ephemeron_list;
4456 ephemeron_list = node;
4458 SGEN_LOG (5, "Registered ephemeron array %p", obj);
4465 mono_gc_invoke_with_gc_lock (MonoGCLockedCallbackFunc func, void *data)
4469 result = func (data);
4470 UNLOCK_INTERRUPTION;
4475 mono_gc_is_gc_thread (void)
4479 result = mono_thread_info_current () != NULL;
4485 is_critical_method (MonoMethod *method)
4487 return mono_runtime_is_critical_method (method) || sgen_is_critical_method (method);
4491 mono_gc_base_init (void)
4493 MonoThreadInfoCallbacks cb;
4496 char *major_collector_opt = NULL;
4497 char *minor_collector_opt = NULL;
4499 glong soft_limit = 0;
4503 gboolean debug_print_allowance = FALSE;
4504 double allowance_ratio = 0, save_target = 0;
4507 result = InterlockedCompareExchange (&gc_initialized, -1, 0);
4510 /* already inited */
4513 /* being inited by another thread */
4517 /* we will init it */
4520 g_assert_not_reached ();
4522 } while (result != 0);
4524 LOCK_INIT (gc_mutex);
4526 pagesize = mono_pagesize ();
4527 gc_debug_file = stderr;
4529 cb.thread_register = sgen_thread_register;
4530 cb.thread_unregister = sgen_thread_unregister;
4531 cb.thread_attach = sgen_thread_attach;
4532 cb.mono_method_is_critical = (gpointer)is_critical_method;
4534 cb.mono_gc_pthread_create = (gpointer)mono_gc_pthread_create;
4537 mono_threads_init (&cb, sizeof (SgenThreadInfo));
4539 LOCK_INIT (sgen_interruption_mutex);
4540 LOCK_INIT (pin_queue_mutex);
4542 init_user_copy_or_mark_key ();
4544 if ((env = getenv ("MONO_GC_PARAMS"))) {
4545 opts = g_strsplit (env, ",", -1);
4546 for (ptr = opts; *ptr; ++ptr) {
4548 if (g_str_has_prefix (opt, "major=")) {
4549 opt = strchr (opt, '=') + 1;
4550 major_collector_opt = g_strdup (opt);
4551 } else if (g_str_has_prefix (opt, "minor=")) {
4552 opt = strchr (opt, '=') + 1;
4553 minor_collector_opt = g_strdup (opt);
4561 sgen_init_internal_allocator ();
4562 sgen_init_nursery_allocator ();
4564 sgen_register_fixed_internal_mem_type (INTERNAL_MEM_SECTION, SGEN_SIZEOF_GC_MEM_SECTION);
4565 sgen_register_fixed_internal_mem_type (INTERNAL_MEM_FINALIZE_READY_ENTRY, sizeof (FinalizeReadyEntry));
4566 sgen_register_fixed_internal_mem_type (INTERNAL_MEM_GRAY_QUEUE, sizeof (GrayQueueSection));
4567 g_assert (sizeof (GenericStoreRememberedSet) == sizeof (gpointer) * STORE_REMSET_BUFFER_SIZE);
4568 sgen_register_fixed_internal_mem_type (INTERNAL_MEM_STORE_REMSET, sizeof (GenericStoreRememberedSet));
4569 sgen_register_fixed_internal_mem_type (INTERNAL_MEM_EPHEMERON_LINK, sizeof (EphemeronLinkNode));
4571 #ifndef HAVE_KW_THREAD
4572 mono_native_tls_alloc (&thread_info_key, NULL);
4576 * This needs to happen before any internal allocations because
4577 * it inits the small id which is required for hazard pointer
4582 mono_thread_info_attach (&dummy);
4584 if (!minor_collector_opt) {
4585 sgen_simple_nursery_init (&sgen_minor_collector);
4587 if (!strcmp (minor_collector_opt, "simple"))
4588 sgen_simple_nursery_init (&sgen_minor_collector);
4589 else if (!strcmp (minor_collector_opt, "split"))
4590 sgen_split_nursery_init (&sgen_minor_collector);
4592 fprintf (stderr, "Unknown minor collector `%s'.\n", minor_collector_opt);
4597 if (!major_collector_opt || !strcmp (major_collector_opt, "marksweep")) {
4598 sgen_marksweep_init (&major_collector);
4599 } else if (!major_collector_opt || !strcmp (major_collector_opt, "marksweep-fixed")) {
4600 sgen_marksweep_fixed_init (&major_collector);
4601 } else if (!major_collector_opt || !strcmp (major_collector_opt, "marksweep-par")) {
4602 sgen_marksweep_par_init (&major_collector);
4603 } else if (!major_collector_opt || !strcmp (major_collector_opt, "marksweep-fixed-par")) {
4604 sgen_marksweep_fixed_par_init (&major_collector);
4605 } else if (!major_collector_opt || !strcmp (major_collector_opt, "marksweep-conc")) {
4606 sgen_marksweep_conc_init (&major_collector);
4607 } else if (!strcmp (major_collector_opt, "copying")) {
4608 sgen_copying_init (&major_collector);
4610 fprintf (stderr, "Unknown major collector `%s'.\n", major_collector_opt);
4614 #ifdef SGEN_HAVE_CARDTABLE
4615 use_cardtable = major_collector.supports_cardtable;
4617 use_cardtable = FALSE;
4620 num_workers = mono_cpu_count ();
4621 g_assert (num_workers > 0);
4622 if (num_workers > 16)
4625 ///* Keep this the default for now */
4626 /* Precise marking is broken on all supported targets. Disable until fixed. */
4627 conservative_stack_mark = TRUE;
4629 sgen_nursery_size = DEFAULT_NURSERY_SIZE;
4632 for (ptr = opts; *ptr; ++ptr) {
4634 if (g_str_has_prefix (opt, "major="))
4636 if (g_str_has_prefix (opt, "minor="))
4638 if (g_str_has_prefix (opt, "wbarrier=")) {
4639 opt = strchr (opt, '=') + 1;
4640 if (strcmp (opt, "remset") == 0) {
4641 if (major_collector.is_concurrent) {
4642 fprintf (stderr, "The concurrent collector does not support the SSB write barrier.\n");
4645 use_cardtable = FALSE;
4646 } else if (strcmp (opt, "cardtable") == 0) {
4647 if (!use_cardtable) {
4648 if (major_collector.supports_cardtable)
4649 fprintf (stderr, "The cardtable write barrier is not supported on this platform.\n");
4651 fprintf (stderr, "The major collector does not support the cardtable write barrier.\n");
4655 fprintf (stderr, "wbarrier must either be `remset' or `cardtable'.");
4660 if (g_str_has_prefix (opt, "max-heap-size=")) {
4661 opt = strchr (opt, '=') + 1;
4662 if (*opt && mono_gc_parse_environment_string_extract_number (opt, &max_heap)) {
4663 if ((max_heap & (mono_pagesize () - 1))) {
4664 fprintf (stderr, "max-heap-size size must be a multiple of %d.\n", mono_pagesize ());
4668 fprintf (stderr, "max-heap-size must be an integer.\n");
4673 if (g_str_has_prefix (opt, "soft-heap-limit=")) {
4674 opt = strchr (opt, '=') + 1;
4675 if (*opt && mono_gc_parse_environment_string_extract_number (opt, &soft_limit)) {
4676 if (soft_limit <= 0) {
4677 fprintf (stderr, "soft-heap-limit must be positive.\n");
4681 fprintf (stderr, "soft-heap-limit must be an integer.\n");
4686 if (g_str_has_prefix (opt, "workers=")) {
4689 if (!major_collector.is_parallel) {
4690 fprintf (stderr, "The workers= option can only be used for parallel collectors.");
4693 opt = strchr (opt, '=') + 1;
4694 val = strtol (opt, &endptr, 10);
4695 if (!*opt || *endptr) {
4696 fprintf (stderr, "Cannot parse the workers= option value.");
4699 if (val <= 0 || val > 16) {
4700 fprintf (stderr, "The number of workers must be in the range 1 to 16.");
4703 num_workers = (int)val;
4706 if (g_str_has_prefix (opt, "stack-mark=")) {
4707 opt = strchr (opt, '=') + 1;
4708 if (!strcmp (opt, "precise")) {
4709 conservative_stack_mark = FALSE;
4710 } else if (!strcmp (opt, "conservative")) {
4711 conservative_stack_mark = TRUE;
4713 fprintf (stderr, "Invalid value '%s' for stack-mark= option, possible values are: 'precise', 'conservative'.\n", opt);
4718 if (g_str_has_prefix (opt, "bridge=")) {
4719 opt = strchr (opt, '=') + 1;
4720 sgen_register_test_bridge_callbacks (g_strdup (opt));
4724 if (g_str_has_prefix (opt, "nursery-size=")) {
4726 opt = strchr (opt, '=') + 1;
4727 if (*opt && mono_gc_parse_environment_string_extract_number (opt, &val)) {
4728 sgen_nursery_size = val;
4729 #ifdef SGEN_ALIGN_NURSERY
4730 if ((val & (val - 1))) {
4731 fprintf (stderr, "The nursery size must be a power of two.\n");
4735 if (val < SGEN_MAX_NURSERY_WASTE) {
4736 fprintf (stderr, "The nursery size must be at least %d bytes.\n", SGEN_MAX_NURSERY_WASTE);
4740 sgen_nursery_bits = 0;
4741 while (1 << (++ sgen_nursery_bits) != sgen_nursery_size)
4745 fprintf (stderr, "nursery-size must be an integer.\n");
4751 if (g_str_has_prefix (opt, "save-target-ratio=")) {
4753 opt = strchr (opt, '=') + 1;
4754 save_target = strtod (opt, &endptr);
4755 if (endptr == opt) {
4756 fprintf (stderr, "save-target-ratio must be a number.");
4759 if (save_target < SGEN_MIN_SAVE_TARGET_RATIO || save_target > SGEN_MAX_SAVE_TARGET_RATIO) {
4760 fprintf (stderr, "save-target-ratio must be between %.2f - %.2f.", SGEN_MIN_SAVE_TARGET_RATIO, SGEN_MAX_SAVE_TARGET_RATIO);
4765 if (g_str_has_prefix (opt, "default-allowance-ratio=")) {
4767 opt = strchr (opt, '=') + 1;
4769 allowance_ratio = strtod (opt, &endptr);
4770 if (endptr == opt) {
4771 fprintf (stderr, "save-target-ratio must be a number.");
4774 if (allowance_ratio < SGEN_MIN_ALLOWANCE_NURSERY_SIZE_RATIO || allowance_ratio > SGEN_MIN_ALLOWANCE_NURSERY_SIZE_RATIO) {
4775 fprintf (stderr, "default-allowance-ratio must be between %.2f - %.2f.", SGEN_MIN_ALLOWANCE_NURSERY_SIZE_RATIO, SGEN_MIN_ALLOWANCE_NURSERY_SIZE_RATIO);
4781 if (major_collector.handle_gc_param && major_collector.handle_gc_param (opt))
4784 if (sgen_minor_collector.handle_gc_param && sgen_minor_collector.handle_gc_param (opt))
4787 fprintf (stderr, "MONO_GC_PARAMS must be a comma-delimited list of one or more of the following:\n");
4788 fprintf (stderr, " max-heap-size=N (where N is an integer, possibly with a k, m or a g suffix)\n");
4789 fprintf (stderr, " soft-heap-limit=n (where N is an integer, possibly with a k, m or a g suffix)\n");
4790 fprintf (stderr, " nursery-size=N (where N is an integer, possibly with a k, m or a g suffix)\n");
4791 fprintf (stderr, " major=COLLECTOR (where COLLECTOR is `marksweep', `marksweep-par', 'marksweep-fixed', 'marksweep-fixed-par' or `copying')\n");
4792 fprintf (stderr, " minor=COLLECTOR (where COLLECTOR is `simple' or `split')\n");
4793 fprintf (stderr, " wbarrier=WBARRIER (where WBARRIER is `remset' or `cardtable')\n");
4794 fprintf (stderr, " stack-mark=MARK-METHOD (where MARK-METHOD is 'precise' or 'conservative')\n");
4795 if (major_collector.print_gc_param_usage)
4796 major_collector.print_gc_param_usage ();
4797 if (sgen_minor_collector.print_gc_param_usage)
4798 sgen_minor_collector.print_gc_param_usage ();
4799 fprintf (stderr, " Experimental options:\n");
4800 fprintf (stderr, " save-target-ratio=R (where R must be between %.2f - %.2f).\n", SGEN_MIN_SAVE_TARGET_RATIO, SGEN_MAX_SAVE_TARGET_RATIO);
4801 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);
4807 if (major_collector.is_parallel)
4808 sgen_workers_init (num_workers);
4809 else if (major_collector.is_concurrent)
4810 sgen_workers_init (1);
4812 if (major_collector_opt)
4813 g_free (major_collector_opt);
4815 if (minor_collector_opt)
4816 g_free (minor_collector_opt);
4818 if (major_collector.is_concurrent)
4819 LOCK_INIT (workers_distribute_gray_queue_mutex);
4823 if ((env = getenv ("MONO_GC_DEBUG"))) {
4824 opts = g_strsplit (env, ",", -1);
4825 for (ptr = opts; ptr && *ptr; ptr ++) {
4827 if (opt [0] >= '0' && opt [0] <= '9') {
4828 gc_debug_level = atoi (opt);
4834 char *rf = g_strdup_printf ("%s.%d", opt, GetCurrentProcessId ());
4836 char *rf = g_strdup_printf ("%s.%d", opt, getpid ());
4838 gc_debug_file = fopen (rf, "wb");
4840 gc_debug_file = stderr;
4843 } else if (!strcmp (opt, "print-allowance")) {
4844 debug_print_allowance = TRUE;
4845 } else if (!strcmp (opt, "print-pinning")) {
4846 do_pin_stats = TRUE;
4847 } else if (!strcmp (opt, "verify-before-allocs")) {
4848 verify_before_allocs = 1;
4849 has_per_allocation_action = TRUE;
4850 } else if (g_str_has_prefix (opt, "verify-before-allocs=")) {
4851 char *arg = strchr (opt, '=') + 1;
4852 verify_before_allocs = atoi (arg);
4853 has_per_allocation_action = TRUE;
4854 } else if (!strcmp (opt, "collect-before-allocs")) {
4855 collect_before_allocs = 1;
4856 has_per_allocation_action = TRUE;
4857 } else if (g_str_has_prefix (opt, "collect-before-allocs=")) {
4858 char *arg = strchr (opt, '=') + 1;
4859 has_per_allocation_action = TRUE;
4860 collect_before_allocs = atoi (arg);
4861 } else if (!strcmp (opt, "verify-before-collections")) {
4862 whole_heap_check_before_collection = TRUE;
4863 } else if (!strcmp (opt, "check-at-minor-collections")) {
4864 consistency_check_at_minor_collection = TRUE;
4865 nursery_clear_policy = CLEAR_AT_GC;
4866 } else if (!strcmp (opt, "xdomain-checks")) {
4867 xdomain_checks = TRUE;
4868 } else if (!strcmp (opt, "clear-at-gc")) {
4869 nursery_clear_policy = CLEAR_AT_GC;
4870 } else if (!strcmp (opt, "clear-nursery-at-gc")) {
4871 nursery_clear_policy = CLEAR_AT_GC;
4872 } else if (!strcmp (opt, "check-scan-starts")) {
4873 do_scan_starts_check = TRUE;
4874 } else if (!strcmp (opt, "verify-nursery-at-minor-gc")) {
4875 do_verify_nursery = TRUE;
4876 } else if (!strcmp (opt, "check-concurrent")) {
4877 if (!major_collector.is_concurrent) {
4878 fprintf (stderr, "Error: check-concurrent only world with concurrent major collectors.\n");
4881 do_concurrent_checks = TRUE;
4882 } else if (!strcmp (opt, "dump-nursery-at-minor-gc")) {
4883 do_dump_nursery_content = TRUE;
4884 } else if (!strcmp (opt, "no-managed-allocator")) {
4885 sgen_set_use_managed_allocator (FALSE);
4886 } else if (!strcmp (opt, "disable-minor")) {
4887 disable_minor_collections = TRUE;
4888 } else if (!strcmp (opt, "disable-major")) {
4889 disable_major_collections = TRUE;
4890 } else if (g_str_has_prefix (opt, "heap-dump=")) {
4891 char *filename = strchr (opt, '=') + 1;
4892 nursery_clear_policy = CLEAR_AT_GC;
4893 heap_dump_file = fopen (filename, "w");
4894 if (heap_dump_file) {
4895 fprintf (heap_dump_file, "<sgen-dump>\n");
4896 do_pin_stats = TRUE;
4898 #ifdef SGEN_BINARY_PROTOCOL
4899 } else if (g_str_has_prefix (opt, "binary-protocol=")) {
4900 char *filename = strchr (opt, '=') + 1;
4901 binary_protocol_init (filename);
4903 fprintf (stderr, "Warning: Cardtable write barriers will not be binary-protocolled.\n");
4906 fprintf (stderr, "Invalid format for the MONO_GC_DEBUG env variable: '%s'\n", env);
4907 fprintf (stderr, "The format is: MONO_GC_DEBUG=[l[:filename]|<option>]+ where l is a debug level 0-9.\n");
4908 fprintf (stderr, "Valid options are:\n");
4909 fprintf (stderr, " collect-before-allocs[=<n>]\n");
4910 fprintf (stderr, " verify-before-allocs[=<n>]\n");
4911 fprintf (stderr, " check-at-minor-collections\n");
4912 fprintf (stderr, " verify-before-collections\n");
4913 fprintf (stderr, " verify-nursery-at-minor-gc\n");
4914 fprintf (stderr, " dump-nursery-at-minor-gc\n");
4915 fprintf (stderr, " disable-minor\n");
4916 fprintf (stderr, " disable-major\n");
4917 fprintf (stderr, " xdomain-checks\n");
4918 fprintf (stderr, " check-concurrent\n");
4919 fprintf (stderr, " clear-at-gc\n");
4920 fprintf (stderr, " clear-nursery-at-gc\n");
4921 fprintf (stderr, " check-scan-starts\n");
4922 fprintf (stderr, " no-managed-allocator\n");
4923 fprintf (stderr, " print-allowance\n");
4924 fprintf (stderr, " print-pinning\n");
4925 fprintf (stderr, " heap-dump=<filename>\n");
4926 #ifdef SGEN_BINARY_PROTOCOL
4927 fprintf (stderr, " binary-protocol=<filename>\n");
4935 if (major_collector.is_parallel) {
4936 if (heap_dump_file) {
4937 fprintf (stderr, "Error: Cannot do heap dump with the parallel collector.\n");
4941 fprintf (stderr, "Error: Cannot gather pinning statistics with the parallel collector.\n");
4946 if (major_collector.post_param_init)
4947 major_collector.post_param_init ();
4949 sgen_memgov_init (max_heap, soft_limit, debug_print_allowance, allowance_ratio, save_target);
4951 memset (&remset, 0, sizeof (remset));
4953 #ifdef SGEN_HAVE_CARDTABLE
4955 sgen_card_table_init (&remset);
4958 sgen_ssb_init (&remset);
4960 if (remset.register_thread)
4961 remset.register_thread (mono_thread_info_current ());
4967 mono_gc_get_gc_name (void)
4972 static MonoMethod *write_barrier_method;
4975 sgen_is_critical_method (MonoMethod *method)
4977 return (method == write_barrier_method || sgen_is_managed_allocator (method));
4981 sgen_has_critical_method (void)
4983 return write_barrier_method || sgen_has_managed_allocator ();
4987 emit_nursery_check (MonoMethodBuilder *mb, int *nursery_check_return_labels)
4989 memset (nursery_check_return_labels, 0, sizeof (int) * 3);
4990 #ifdef SGEN_ALIGN_NURSERY
4991 // if (ptr_in_nursery (ptr)) return;
4993 * Masking out the bits might be faster, but we would have to use 64 bit
4994 * immediates, which might be slower.
4996 mono_mb_emit_ldarg (mb, 0);
4997 mono_mb_emit_icon (mb, DEFAULT_NURSERY_BITS);
4998 mono_mb_emit_byte (mb, CEE_SHR_UN);
4999 mono_mb_emit_icon (mb, (mword)sgen_get_nursery_start () >> DEFAULT_NURSERY_BITS);
5000 nursery_check_return_labels [0] = mono_mb_emit_branch (mb, CEE_BEQ);
5002 if (!major_collector.is_concurrent) {
5003 // if (!ptr_in_nursery (*ptr)) return;
5004 mono_mb_emit_ldarg (mb, 0);
5005 mono_mb_emit_byte (mb, CEE_LDIND_I);
5006 mono_mb_emit_icon (mb, DEFAULT_NURSERY_BITS);
5007 mono_mb_emit_byte (mb, CEE_SHR_UN);
5008 mono_mb_emit_icon (mb, (mword)sgen_get_nursery_start () >> DEFAULT_NURSERY_BITS);
5009 nursery_check_return_labels [1] = mono_mb_emit_branch (mb, CEE_BNE_UN);
5012 int label_continue1, label_continue2;
5013 int dereferenced_var;
5015 // if (ptr < (sgen_get_nursery_start ())) goto continue;
5016 mono_mb_emit_ldarg (mb, 0);
5017 mono_mb_emit_ptr (mb, (gpointer) sgen_get_nursery_start ());
5018 label_continue_1 = mono_mb_emit_branch (mb, CEE_BLT);
5020 // if (ptr >= sgen_get_nursery_end ())) goto continue;
5021 mono_mb_emit_ldarg (mb, 0);
5022 mono_mb_emit_ptr (mb, (gpointer) sgen_get_nursery_end ());
5023 label_continue_2 = mono_mb_emit_branch (mb, CEE_BGE);
5026 nursery_check_return_labels [0] = mono_mb_emit_branch (mb, CEE_BR);
5029 mono_mb_patch_branch (mb, label_continue_1);
5030 mono_mb_patch_branch (mb, label_continue_2);
5032 // Dereference and store in local var
5033 dereferenced_var = mono_mb_add_local (mb, &mono_defaults.int_class->byval_arg);
5034 mono_mb_emit_ldarg (mb, 0);
5035 mono_mb_emit_byte (mb, CEE_LDIND_I);
5036 mono_mb_emit_stloc (mb, dereferenced_var);
5038 if (!major_collector.is_concurrent) {
5039 // if (*ptr < sgen_get_nursery_start ()) return;
5040 mono_mb_emit_ldloc (mb, dereferenced_var);
5041 mono_mb_emit_ptr (mb, (gpointer) sgen_get_nursery_start ());
5042 nursery_check_return_labels [1] = mono_mb_emit_branch (mb, CEE_BLT);
5044 // if (*ptr >= sgen_get_nursery_end ()) return;
5045 mono_mb_emit_ldloc (mb, dereferenced_var);
5046 mono_mb_emit_ptr (mb, (gpointer) sgen_get_nursery_end ());
5047 nursery_check_return_labels [2] = mono_mb_emit_branch (mb, CEE_BGE);
5053 mono_gc_get_write_barrier (void)
5056 MonoMethodBuilder *mb;
5057 MonoMethodSignature *sig;
5058 #ifdef MANAGED_WBARRIER
5059 int i, nursery_check_labels [3];
5060 int label_no_wb_3, label_no_wb_4, label_need_wb, label_slow_path;
5061 int buffer_var, buffer_index_var, dummy_var;
5063 #ifdef HAVE_KW_THREAD
5064 int stack_end_offset = -1, store_remset_buffer_offset = -1;
5065 int store_remset_buffer_index_offset = -1, store_remset_buffer_index_addr_offset = -1;
5067 MONO_THREAD_VAR_OFFSET (stack_end, stack_end_offset);
5068 g_assert (stack_end_offset != -1);
5069 MONO_THREAD_VAR_OFFSET (store_remset_buffer, store_remset_buffer_offset);
5070 g_assert (store_remset_buffer_offset != -1);
5071 MONO_THREAD_VAR_OFFSET (store_remset_buffer_index, store_remset_buffer_index_offset);
5072 g_assert (store_remset_buffer_index_offset != -1);
5073 MONO_THREAD_VAR_OFFSET (store_remset_buffer_index_addr, store_remset_buffer_index_addr_offset);
5074 g_assert (store_remset_buffer_index_addr_offset != -1);
5078 // FIXME: Maybe create a separate version for ctors (the branch would be
5079 // correctly predicted more times)
5080 if (write_barrier_method)
5081 return write_barrier_method;
5083 /* Create the IL version of mono_gc_barrier_generic_store () */
5084 sig = mono_metadata_signature_alloc (mono_defaults.corlib, 1);
5085 sig->ret = &mono_defaults.void_class->byval_arg;
5086 sig->params [0] = &mono_defaults.int_class->byval_arg;
5088 mb = mono_mb_new (mono_defaults.object_class, "wbarrier", MONO_WRAPPER_WRITE_BARRIER);
5090 #ifdef MANAGED_WBARRIER
5091 if (use_cardtable) {
5092 emit_nursery_check (mb, nursery_check_labels);
5094 addr = sgen_cardtable + ((address >> CARD_BITS) & CARD_MASK)
5098 LDC_PTR sgen_cardtable
5100 address >> CARD_BITS
5104 if (SGEN_HAVE_OVERLAPPING_CARDS) {
5105 LDC_PTR card_table_mask
5112 mono_mb_emit_ptr (mb, sgen_cardtable);
5113 mono_mb_emit_ldarg (mb, 0);
5114 mono_mb_emit_icon (mb, CARD_BITS);
5115 mono_mb_emit_byte (mb, CEE_SHR_UN);
5116 #ifdef SGEN_HAVE_OVERLAPPING_CARDS
5117 mono_mb_emit_ptr (mb, (gpointer)CARD_MASK);
5118 mono_mb_emit_byte (mb, CEE_AND);
5120 mono_mb_emit_byte (mb, CEE_ADD);
5121 mono_mb_emit_icon (mb, 1);
5122 mono_mb_emit_byte (mb, CEE_STIND_I1);
5125 for (i = 0; i < 3; ++i) {
5126 if (nursery_check_labels [i])
5127 mono_mb_patch_branch (mb, nursery_check_labels [i]);
5129 mono_mb_emit_byte (mb, CEE_RET);
5130 } else if (mono_runtime_has_tls_get ()) {
5131 emit_nursery_check (mb, nursery_check_labels);
5133 // if (ptr >= stack_end) goto need_wb;
5134 mono_mb_emit_ldarg (mb, 0);
5135 EMIT_TLS_ACCESS (mb, stack_end, stack_end_offset);
5136 label_need_wb = mono_mb_emit_branch (mb, CEE_BGE_UN);
5138 // if (ptr >= stack_start) return;
5139 dummy_var = mono_mb_add_local (mb, &mono_defaults.int_class->byval_arg);
5140 mono_mb_emit_ldarg (mb, 0);
5141 mono_mb_emit_ldloc_addr (mb, dummy_var);
5142 label_no_wb_3 = mono_mb_emit_branch (mb, CEE_BGE_UN);
5145 mono_mb_patch_branch (mb, label_need_wb);
5147 // buffer = STORE_REMSET_BUFFER;
5148 buffer_var = mono_mb_add_local (mb, &mono_defaults.int_class->byval_arg);
5149 EMIT_TLS_ACCESS (mb, store_remset_buffer, store_remset_buffer_offset);
5150 mono_mb_emit_stloc (mb, buffer_var);
5152 // buffer_index = STORE_REMSET_BUFFER_INDEX;
5153 buffer_index_var = mono_mb_add_local (mb, &mono_defaults.int_class->byval_arg);
5154 EMIT_TLS_ACCESS (mb, store_remset_buffer_index, store_remset_buffer_index_offset);
5155 mono_mb_emit_stloc (mb, buffer_index_var);
5157 // if (buffer [buffer_index] == ptr) return;
5158 mono_mb_emit_ldloc (mb, buffer_var);
5159 mono_mb_emit_ldloc (mb, buffer_index_var);
5160 g_assert (sizeof (gpointer) == 4 || sizeof (gpointer) == 8);
5161 mono_mb_emit_icon (mb, sizeof (gpointer) == 4 ? 2 : 3);
5162 mono_mb_emit_byte (mb, CEE_SHL);
5163 mono_mb_emit_byte (mb, CEE_ADD);
5164 mono_mb_emit_byte (mb, CEE_LDIND_I);
5165 mono_mb_emit_ldarg (mb, 0);
5166 label_no_wb_4 = mono_mb_emit_branch (mb, CEE_BEQ);
5169 mono_mb_emit_ldloc (mb, buffer_index_var);
5170 mono_mb_emit_icon (mb, 1);
5171 mono_mb_emit_byte (mb, CEE_ADD);
5172 mono_mb_emit_stloc (mb, buffer_index_var);
5174 // if (buffer_index >= STORE_REMSET_BUFFER_SIZE) goto slow_path;
5175 mono_mb_emit_ldloc (mb, buffer_index_var);
5176 mono_mb_emit_icon (mb, STORE_REMSET_BUFFER_SIZE);
5177 label_slow_path = mono_mb_emit_branch (mb, CEE_BGE);
5179 // buffer [buffer_index] = ptr;
5180 mono_mb_emit_ldloc (mb, buffer_var);
5181 mono_mb_emit_ldloc (mb, buffer_index_var);
5182 g_assert (sizeof (gpointer) == 4 || sizeof (gpointer) == 8);
5183 mono_mb_emit_icon (mb, sizeof (gpointer) == 4 ? 2 : 3);
5184 mono_mb_emit_byte (mb, CEE_SHL);
5185 mono_mb_emit_byte (mb, CEE_ADD);
5186 mono_mb_emit_ldarg (mb, 0);
5187 mono_mb_emit_byte (mb, CEE_STIND_I);
5189 // STORE_REMSET_BUFFER_INDEX = buffer_index;
5190 EMIT_TLS_ACCESS (mb, store_remset_buffer_index_addr, store_remset_buffer_index_addr_offset);
5191 mono_mb_emit_ldloc (mb, buffer_index_var);
5192 mono_mb_emit_byte (mb, CEE_STIND_I);
5195 for (i = 0; i < 3; ++i) {
5196 if (nursery_check_labels [i])
5197 mono_mb_patch_branch (mb, nursery_check_labels [i]);
5199 mono_mb_patch_branch (mb, label_no_wb_3);
5200 mono_mb_patch_branch (mb, label_no_wb_4);
5201 mono_mb_emit_byte (mb, CEE_RET);
5204 mono_mb_patch_branch (mb, label_slow_path);
5206 mono_mb_emit_ldarg (mb, 0);
5207 mono_mb_emit_icall (mb, mono_gc_wbarrier_generic_nostore);
5208 mono_mb_emit_byte (mb, CEE_RET);
5212 mono_mb_emit_ldarg (mb, 0);
5213 mono_mb_emit_icall (mb, mono_gc_wbarrier_generic_nostore);
5214 mono_mb_emit_byte (mb, CEE_RET);
5217 res = mono_mb_create_method (mb, sig, 16);
5220 mono_loader_lock ();
5221 if (write_barrier_method) {
5222 /* Already created */
5223 mono_free_method (res);
5225 /* double-checked locking */
5226 mono_memory_barrier ();
5227 write_barrier_method = res;
5229 mono_loader_unlock ();
5231 return write_barrier_method;
5235 mono_gc_get_description (void)
5237 return g_strdup ("sgen");
5241 mono_gc_set_desktop_mode (void)
5246 mono_gc_is_moving (void)
5252 mono_gc_is_disabled (void)
5258 BOOL APIENTRY mono_gc_dllmain (HMODULE module_handle, DWORD reason, LPVOID reserved)
5265 sgen_get_nursery_clear_policy (void)
5267 return nursery_clear_policy;
5271 sgen_get_array_fill_vtable (void)
5273 if (!array_fill_vtable) {
5274 static MonoClass klass;
5275 static MonoVTable vtable;
5278 MonoDomain *domain = mono_get_root_domain ();
5281 klass.element_class = mono_defaults.byte_class;
5283 klass.instance_size = sizeof (MonoArray);
5284 klass.sizes.element_size = 1;
5285 klass.name = "array_filler_type";
5287 vtable.klass = &klass;
5289 vtable.gc_descr = mono_gc_make_descr_for_array (TRUE, &bmap, 0, 1);
5292 array_fill_vtable = &vtable;
5294 return array_fill_vtable;
5304 sgen_gc_unlock (void)
5310 sgen_major_collector_iterate_live_block_ranges (sgen_cardtable_block_callback callback)
5312 major_collector.iterate_live_block_ranges (callback);
5316 sgen_major_collector_scan_card_table (SgenGrayQueue *queue)
5318 major_collector.scan_card_table (FALSE, queue);
5322 sgen_get_major_collector (void)
5324 return &major_collector;
5327 void mono_gc_set_skip_thread (gboolean skip)
5329 SgenThreadInfo *info = mono_thread_info_current ();
5332 info->gc_disabled = skip;
5337 sgen_get_remset (void)
5343 mono_gc_get_vtable_bits (MonoClass *class)
5345 if (sgen_need_bridge_processing () && sgen_is_bridge_class (class))
5346 return SGEN_GC_BIT_BRIDGE_OBJECT;
5351 mono_gc_register_altstack (gpointer stack, gint32 stack_size, gpointer altstack, gint32 altstack_size)
5358 sgen_check_whole_heap_stw (void)
5360 sgen_stop_world (0);
5361 sgen_clear_nursery_fragments ();
5362 sgen_check_whole_heap ();
5363 sgen_restart_world (0, NULL);
5367 sgen_gc_event_moves (void)
5369 if (moved_objects_idx) {
5370 mono_profiler_gc_moves (moved_objects, moved_objects_idx);
5371 moved_objects_idx = 0;
5375 #endif /* HAVE_SGEN_GC */