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;
556 static GrayQueue remember_major_objects_gray_queue;
558 static SgenRemeberedSet remset;
560 /* The gray queue to use from the main collection thread. */
561 #define WORKERS_DISTRIBUTE_GRAY_QUEUE (&gray_queue)
564 * The gray queue a worker job must use. If we're not parallel or
565 * concurrent, we use the main gray queue.
567 static SgenGrayQueue*
568 sgen_workers_get_job_gray_queue (WorkerData *worker_data)
570 return worker_data ? &worker_data->private_gray_queue : WORKERS_DISTRIBUTE_GRAY_QUEUE;
574 sgen_remember_major_object_for_concurrent_mark (char *obj)
576 if (!major_collector.is_concurrent)
579 g_assert (current_collection_generation == GENERATION_NURSERY || current_collection_generation == -1);
581 if (!concurrent_collection_in_progress)
584 GRAY_OBJECT_ENQUEUE (&remember_major_objects_gray_queue, obj);
590 is_xdomain_ref_allowed (gpointer *ptr, char *obj, MonoDomain *domain)
592 MonoObject *o = (MonoObject*)(obj);
593 MonoObject *ref = (MonoObject*)*(ptr);
594 int offset = (char*)(ptr) - (char*)o;
596 if (o->vtable->klass == mono_defaults.thread_class && offset == G_STRUCT_OFFSET (MonoThread, internal_thread))
598 if (o->vtable->klass == mono_defaults.internal_thread_class && offset == G_STRUCT_OFFSET (MonoInternalThread, current_appcontext))
600 if (mono_class_has_parent_fast (o->vtable->klass, mono_defaults.real_proxy_class) &&
601 offset == G_STRUCT_OFFSET (MonoRealProxy, unwrapped_server))
603 /* Thread.cached_culture_info */
604 if (!strcmp (ref->vtable->klass->name_space, "System.Globalization") &&
605 !strcmp (ref->vtable->klass->name, "CultureInfo") &&
606 !strcmp(o->vtable->klass->name_space, "System") &&
607 !strcmp(o->vtable->klass->name, "Object[]"))
610 * 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
611 * at System.IO.MemoryStream..ctor (byte[]) [0x00017] in /home/schani/Work/novell/trunk/mcs/class/corlib/System.IO/MemoryStream.cs:81
612 * at (wrapper remoting-invoke-with-check) System.IO.MemoryStream..ctor (byte[]) <IL 0x00020, 0xffffffff>
613 * at System.Runtime.Remoting.Messaging.CADMethodCallMessage.GetArguments () [0x0000d] in /home/schani/Work/novell/trunk/mcs/class/corlib/System.Runtime.Remoting.Messaging/CADMessages.cs:327
614 * 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
615 * 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
616 * at (wrapper remoting-invoke-with-check) System.AppDomain.ProcessMessageInDomain (byte[],System.Runtime.Remoting.Messaging.CADMethodCallMessage,byte[]&,System.Runtime.Remoting.Messaging.CADMethodReturnMessage&) <IL 0x0003d, 0xffffffff>
617 * 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
618 * at (wrapper runtime-invoke) object.runtime_invoke_CrossAppDomainSink/ProcessMessageRes_object_object (object,intptr,intptr,intptr) <IL 0x0004c, 0xffffffff>
620 if (!strcmp (ref->vtable->klass->name_space, "System") &&
621 !strcmp (ref->vtable->klass->name, "Byte[]") &&
622 !strcmp (o->vtable->klass->name_space, "System.IO") &&
623 !strcmp (o->vtable->klass->name, "MemoryStream"))
625 /* append_job() in threadpool.c */
626 if (!strcmp (ref->vtable->klass->name_space, "System.Runtime.Remoting.Messaging") &&
627 !strcmp (ref->vtable->klass->name, "AsyncResult") &&
628 !strcmp (o->vtable->klass->name_space, "System") &&
629 !strcmp (o->vtable->klass->name, "Object[]") &&
630 mono_thread_pool_is_queue_array ((MonoArray*) o))
636 check_reference_for_xdomain (gpointer *ptr, char *obj, MonoDomain *domain)
638 MonoObject *o = (MonoObject*)(obj);
639 MonoObject *ref = (MonoObject*)*(ptr);
640 int offset = (char*)(ptr) - (char*)o;
642 MonoClassField *field;
645 if (!ref || ref->vtable->domain == domain)
647 if (is_xdomain_ref_allowed (ptr, obj, domain))
651 for (class = o->vtable->klass; class; class = class->parent) {
654 for (i = 0; i < class->field.count; ++i) {
655 if (class->fields[i].offset == offset) {
656 field = &class->fields[i];
664 if (ref->vtable->klass == mono_defaults.string_class)
665 str = mono_string_to_utf8 ((MonoString*)ref);
668 g_print ("xdomain reference in %p (%s.%s) at offset %d (%s) to %p (%s.%s) (%s) - pointed to by:\n",
669 o, o->vtable->klass->name_space, o->vtable->klass->name,
670 offset, field ? field->name : "",
671 ref, ref->vtable->klass->name_space, ref->vtable->klass->name, str ? str : "");
672 mono_gc_scan_for_specific_ref (o, TRUE);
678 #define HANDLE_PTR(ptr,obj) check_reference_for_xdomain ((ptr), (obj), domain)
681 scan_object_for_xdomain_refs (char *start, mword size, void *data)
683 MonoDomain *domain = ((MonoObject*)start)->vtable->domain;
685 #include "sgen-scan-object.h"
688 static gboolean scan_object_for_specific_ref_precise = TRUE;
691 #define HANDLE_PTR(ptr,obj) do { \
692 if ((MonoObject*)*(ptr) == key) { \
693 g_print ("found ref to %p in object %p (%s) at offset %td\n", \
694 key, (obj), safe_name ((obj)), ((char*)(ptr) - (char*)(obj))); \
699 scan_object_for_specific_ref (char *start, MonoObject *key)
703 if ((forwarded = SGEN_OBJECT_IS_FORWARDED (start)))
706 if (scan_object_for_specific_ref_precise) {
707 #include "sgen-scan-object.h"
709 mword *words = (mword*)start;
710 size_t size = safe_object_get_size ((MonoObject*)start);
712 for (i = 0; i < size / sizeof (mword); ++i) {
713 if (words [i] == (mword)key) {
714 g_print ("found possible ref to %p in object %p (%s) at offset %td\n",
715 key, start, safe_name (start), i * sizeof (mword));
722 sgen_scan_area_with_callback (char *start, char *end, IterateObjectCallbackFunc callback, void *data, gboolean allow_flags)
724 while (start < end) {
728 if (!*(void**)start) {
729 start += sizeof (void*); /* should be ALLOC_ALIGN, really */
734 if (!(obj = SGEN_OBJECT_IS_FORWARDED (start)))
740 size = ALIGN_UP (safe_object_get_size ((MonoObject*)obj));
742 if ((MonoVTable*)SGEN_LOAD_VTABLE (obj) != array_fill_vtable)
743 callback (obj, size, data);
750 scan_object_for_specific_ref_callback (char *obj, size_t size, MonoObject *key)
752 scan_object_for_specific_ref (obj, key);
756 check_root_obj_specific_ref (RootRecord *root, MonoObject *key, MonoObject *obj)
760 g_print ("found ref to %p in root record %p\n", key, root);
763 static MonoObject *check_key = NULL;
764 static RootRecord *check_root = NULL;
767 check_root_obj_specific_ref_from_marker (void **obj)
769 check_root_obj_specific_ref (check_root, check_key, *obj);
773 scan_roots_for_specific_ref (MonoObject *key, int root_type)
779 SGEN_HASH_TABLE_FOREACH (&roots_hash [root_type], start_root, root) {
780 mword desc = root->root_desc;
784 switch (desc & ROOT_DESC_TYPE_MASK) {
785 case ROOT_DESC_BITMAP:
786 desc >>= ROOT_DESC_TYPE_SHIFT;
789 check_root_obj_specific_ref (root, key, *start_root);
794 case ROOT_DESC_COMPLEX: {
795 gsize *bitmap_data = sgen_get_complex_descriptor_bitmap (desc);
796 int bwords = (*bitmap_data) - 1;
797 void **start_run = start_root;
799 while (bwords-- > 0) {
800 gsize bmap = *bitmap_data++;
801 void **objptr = start_run;
804 check_root_obj_specific_ref (root, key, *objptr);
808 start_run += GC_BITS_PER_WORD;
812 case ROOT_DESC_USER: {
813 MonoGCRootMarkFunc marker = sgen_get_user_descriptor_func (desc);
814 marker (start_root, check_root_obj_specific_ref_from_marker);
817 case ROOT_DESC_RUN_LEN:
818 g_assert_not_reached ();
820 g_assert_not_reached ();
822 } SGEN_HASH_TABLE_FOREACH_END;
829 mono_gc_scan_for_specific_ref (MonoObject *key, gboolean precise)
834 scan_object_for_specific_ref_precise = precise;
836 sgen_scan_area_with_callback (nursery_section->data, nursery_section->end_data,
837 (IterateObjectCallbackFunc)scan_object_for_specific_ref_callback, key, TRUE);
839 major_collector.iterate_objects (TRUE, TRUE, (IterateObjectCallbackFunc)scan_object_for_specific_ref_callback, key);
841 sgen_los_iterate_objects ((IterateObjectCallbackFunc)scan_object_for_specific_ref_callback, key);
843 scan_roots_for_specific_ref (key, ROOT_TYPE_NORMAL);
844 scan_roots_for_specific_ref (key, ROOT_TYPE_WBARRIER);
846 SGEN_HASH_TABLE_FOREACH (&roots_hash [ROOT_TYPE_PINNED], ptr, root) {
847 while (ptr < (void**)root->end_root) {
848 check_root_obj_specific_ref (root, *ptr, key);
851 } SGEN_HASH_TABLE_FOREACH_END;
855 need_remove_object_for_domain (char *start, MonoDomain *domain)
857 if (mono_object_domain (start) == domain) {
858 SGEN_LOG (4, "Need to cleanup object %p", start);
859 binary_protocol_cleanup (start, (gpointer)LOAD_VTABLE (start), safe_object_get_size ((MonoObject*)start));
866 process_object_for_domain_clearing (char *start, MonoDomain *domain)
868 GCVTable *vt = (GCVTable*)LOAD_VTABLE (start);
869 if (vt->klass == mono_defaults.internal_thread_class)
870 g_assert (mono_object_domain (start) == mono_get_root_domain ());
871 /* The object could be a proxy for an object in the domain
873 if (mono_class_has_parent_fast (vt->klass, mono_defaults.real_proxy_class)) {
874 MonoObject *server = ((MonoRealProxy*)start)->unwrapped_server;
876 /* The server could already have been zeroed out, so
877 we need to check for that, too. */
878 if (server && (!LOAD_VTABLE (server) || mono_object_domain (server) == domain)) {
879 SGEN_LOG (4, "Cleaning up remote pointer in %p to object %p", start, server);
880 ((MonoRealProxy*)start)->unwrapped_server = NULL;
885 static MonoDomain *check_domain = NULL;
888 check_obj_not_in_domain (void **o)
890 g_assert (((MonoObject*)(*o))->vtable->domain != check_domain);
894 scan_for_registered_roots_in_domain (MonoDomain *domain, int root_type)
898 check_domain = domain;
899 SGEN_HASH_TABLE_FOREACH (&roots_hash [root_type], start_root, root) {
900 mword desc = root->root_desc;
902 /* The MonoDomain struct is allowed to hold
903 references to objects in its own domain. */
904 if (start_root == (void**)domain)
907 switch (desc & ROOT_DESC_TYPE_MASK) {
908 case ROOT_DESC_BITMAP:
909 desc >>= ROOT_DESC_TYPE_SHIFT;
911 if ((desc & 1) && *start_root)
912 check_obj_not_in_domain (*start_root);
917 case ROOT_DESC_COMPLEX: {
918 gsize *bitmap_data = sgen_get_complex_descriptor_bitmap (desc);
919 int bwords = (*bitmap_data) - 1;
920 void **start_run = start_root;
922 while (bwords-- > 0) {
923 gsize bmap = *bitmap_data++;
924 void **objptr = start_run;
926 if ((bmap & 1) && *objptr)
927 check_obj_not_in_domain (*objptr);
931 start_run += GC_BITS_PER_WORD;
935 case ROOT_DESC_USER: {
936 MonoGCRootMarkFunc marker = sgen_get_user_descriptor_func (desc);
937 marker (start_root, check_obj_not_in_domain);
940 case ROOT_DESC_RUN_LEN:
941 g_assert_not_reached ();
943 g_assert_not_reached ();
945 } SGEN_HASH_TABLE_FOREACH_END;
951 check_for_xdomain_refs (void)
955 sgen_scan_area_with_callback (nursery_section->data, nursery_section->end_data,
956 (IterateObjectCallbackFunc)scan_object_for_xdomain_refs, NULL, FALSE);
958 major_collector.iterate_objects (TRUE, TRUE, (IterateObjectCallbackFunc)scan_object_for_xdomain_refs, NULL);
960 for (bigobj = los_object_list; bigobj; bigobj = bigobj->next)
961 scan_object_for_xdomain_refs (bigobj->data, sgen_los_object_size (bigobj), NULL);
965 clear_domain_process_object (char *obj, MonoDomain *domain)
969 process_object_for_domain_clearing (obj, domain);
970 remove = need_remove_object_for_domain (obj, domain);
972 if (remove && ((MonoObject*)obj)->synchronisation) {
973 void **dislink = mono_monitor_get_object_monitor_weak_link ((MonoObject*)obj);
975 sgen_register_disappearing_link (NULL, dislink, FALSE, TRUE);
982 clear_domain_process_minor_object_callback (char *obj, size_t size, MonoDomain *domain)
984 if (clear_domain_process_object (obj, domain))
985 memset (obj, 0, size);
989 clear_domain_process_major_object_callback (char *obj, size_t size, MonoDomain *domain)
991 clear_domain_process_object (obj, domain);
995 clear_domain_free_major_non_pinned_object_callback (char *obj, size_t size, MonoDomain *domain)
997 if (need_remove_object_for_domain (obj, domain))
998 major_collector.free_non_pinned_object (obj, size);
1002 clear_domain_free_major_pinned_object_callback (char *obj, size_t size, MonoDomain *domain)
1004 if (need_remove_object_for_domain (obj, domain))
1005 major_collector.free_pinned_object (obj, size);
1009 * When appdomains are unloaded we can easily remove objects that have finalizers,
1010 * but all the others could still be present in random places on the heap.
1011 * We need a sweep to get rid of them even though it's going to be costly
1013 * The reason we need to remove them is because we access the vtable and class
1014 * structures to know the object size and the reference bitmap: once the domain is
1015 * unloaded the point to random memory.
1018 mono_gc_clear_domain (MonoDomain * domain)
1020 LOSObject *bigobj, *prev;
1025 sgen_process_fin_stage_entries ();
1026 sgen_process_dislink_stage_entries ();
1028 sgen_clear_nursery_fragments ();
1030 if (xdomain_checks && domain != mono_get_root_domain ()) {
1031 scan_for_registered_roots_in_domain (domain, ROOT_TYPE_NORMAL);
1032 scan_for_registered_roots_in_domain (domain, ROOT_TYPE_WBARRIER);
1033 check_for_xdomain_refs ();
1036 /*Ephemerons and dislinks must be processed before LOS since they might end up pointing
1037 to memory returned to the OS.*/
1038 null_ephemerons_for_domain (domain);
1040 for (i = GENERATION_NURSERY; i < GENERATION_MAX; ++i)
1041 sgen_null_links_for_domain (domain, i);
1043 for (i = GENERATION_NURSERY; i < GENERATION_MAX; ++i)
1044 sgen_remove_finalizers_for_domain (domain, i);
1046 sgen_scan_area_with_callback (nursery_section->data, nursery_section->end_data,
1047 (IterateObjectCallbackFunc)clear_domain_process_minor_object_callback, domain, FALSE);
1049 /* We need two passes over major and large objects because
1050 freeing such objects might give their memory back to the OS
1051 (in the case of large objects) or obliterate its vtable
1052 (pinned objects with major-copying or pinned and non-pinned
1053 objects with major-mark&sweep), but we might need to
1054 dereference a pointer from an object to another object if
1055 the first object is a proxy. */
1056 major_collector.iterate_objects (TRUE, TRUE, (IterateObjectCallbackFunc)clear_domain_process_major_object_callback, domain);
1057 for (bigobj = los_object_list; bigobj; bigobj = bigobj->next)
1058 clear_domain_process_object (bigobj->data, domain);
1061 for (bigobj = los_object_list; bigobj;) {
1062 if (need_remove_object_for_domain (bigobj->data, domain)) {
1063 LOSObject *to_free = bigobj;
1065 prev->next = bigobj->next;
1067 los_object_list = bigobj->next;
1068 bigobj = bigobj->next;
1069 SGEN_LOG (4, "Freeing large object %p", bigobj->data);
1070 sgen_los_free_object (to_free);
1074 bigobj = bigobj->next;
1076 major_collector.iterate_objects (TRUE, FALSE, (IterateObjectCallbackFunc)clear_domain_free_major_non_pinned_object_callback, domain);
1077 major_collector.iterate_objects (FALSE, TRUE, (IterateObjectCallbackFunc)clear_domain_free_major_pinned_object_callback, domain);
1079 if (G_UNLIKELY (do_pin_stats)) {
1080 if (domain == mono_get_root_domain ())
1081 sgen_pin_stats_print_class_stats ();
1088 * sgen_add_to_global_remset:
1090 * The global remset contains locations which point into newspace after
1091 * a minor collection. This can happen if the objects they point to are pinned.
1093 * LOCKING: If called from a parallel collector, the global remset
1094 * lock must be held. For serial collectors that is not necessary.
1097 sgen_add_to_global_remset (gpointer ptr)
1099 remset.record_pointer (ptr);
1103 * sgen_drain_gray_stack:
1105 * Scan objects in the gray stack until the stack is empty. This should be called
1106 * frequently after each object is copied, to achieve better locality and cache
1110 sgen_drain_gray_stack (GrayQueue *queue, ScanObjectFunc scan_func, int max_objs)
1114 if (max_objs == -1) {
1116 GRAY_OBJECT_DEQUEUE (queue, obj);
1119 SGEN_LOG (9, "Precise gray object scan %p (%s)", obj, safe_name (obj));
1120 scan_func (obj, queue);
1126 for (i = 0; i != max_objs; ++i) {
1127 GRAY_OBJECT_DEQUEUE (queue, obj);
1130 SGEN_LOG (9, "Precise gray object scan %p (%s)", obj, safe_name (obj));
1131 scan_func (obj, queue);
1133 } while (max_objs < 0);
1139 * Addresses from start to end are already sorted. This function finds
1140 * the object header for each address and pins the object. The
1141 * addresses must be inside the passed section. The (start of the)
1142 * address array is overwritten with the addresses of the actually
1143 * pinned objects. Return the number of pinned objects.
1146 pin_objects_from_addresses (GCMemSection *section, void **start, void **end, void *start_nursery, void *end_nursery, GrayQueue *queue, ScanObjectFunc scan_func)
1151 void *last_obj = NULL;
1152 size_t last_obj_size = 0;
1155 void **definitely_pinned = start;
1157 sgen_nursery_allocator_prepare_for_pinning ();
1159 while (start < end) {
1161 /* the range check should be reduntant */
1162 if (addr != last && addr >= start_nursery && addr < end_nursery) {
1163 SGEN_LOG (5, "Considering pinning addr %p", addr);
1164 /* multiple pointers to the same object */
1165 if (addr >= last_obj && (char*)addr < (char*)last_obj + last_obj_size) {
1169 idx = ((char*)addr - (char*)section->data) / SCAN_START_SIZE;
1170 g_assert (idx < section->num_scan_start);
1171 search_start = (void*)section->scan_starts [idx];
1172 if (!search_start || search_start > addr) {
1175 search_start = section->scan_starts [idx];
1176 if (search_start && search_start <= addr)
1179 if (!search_start || search_start > addr)
1180 search_start = start_nursery;
1182 if (search_start < last_obj)
1183 search_start = (char*)last_obj + last_obj_size;
1184 /* now addr should be in an object a short distance from search_start
1185 * Note that search_start must point to zeroed mem or point to an object.
1189 if (!*(void**)search_start) {
1190 /* Consistency check */
1192 for (frag = nursery_fragments; frag; frag = frag->next) {
1193 if (search_start >= frag->fragment_start && search_start < frag->fragment_end)
1194 g_assert_not_reached ();
1198 search_start = (void*)ALIGN_UP ((mword)search_start + sizeof (gpointer));
1201 last_obj = search_start;
1202 last_obj_size = ALIGN_UP (safe_object_get_size ((MonoObject*)search_start));
1204 if (((MonoObject*)last_obj)->synchronisation == GINT_TO_POINTER (-1)) {
1205 /* Marks the beginning of a nursery fragment, skip */
1207 SGEN_LOG (8, "Pinned try match %p (%s), size %zd", last_obj, safe_name (last_obj), last_obj_size);
1208 if (addr >= search_start && (char*)addr < (char*)last_obj + last_obj_size) {
1209 SGEN_LOG (4, "Pinned object %p, vtable %p (%s), count %d\n", search_start, *(void**)search_start, safe_name (search_start), count);
1210 binary_protocol_pin (search_start, (gpointer)LOAD_VTABLE (search_start), safe_object_get_size (search_start));
1211 if (G_UNLIKELY (MONO_GC_OBJ_PINNED_ENABLED ())) {
1212 int gen = sgen_ptr_in_nursery (search_start) ? GENERATION_NURSERY : GENERATION_OLD;
1213 MonoVTable *vt = (MonoVTable*)LOAD_VTABLE (search_start);
1214 MONO_GC_OBJ_PINNED ((mword)search_start, sgen_safe_object_get_size (search_start), vt->klass->name_space, vt->klass->name, gen);
1217 scan_func (search_start, queue);
1219 pin_object (search_start);
1220 GRAY_OBJECT_ENQUEUE (queue, search_start);
1221 if (G_UNLIKELY (do_pin_stats))
1222 sgen_pin_stats_register_object (search_start, last_obj_size);
1223 definitely_pinned [count] = search_start;
1229 /* skip to the next object */
1230 search_start = (void*)((char*)search_start + last_obj_size);
1231 } while (search_start <= addr);
1232 /* we either pinned the correct object or we ignored the addr because
1233 * it points to unused zeroed memory.
1239 //printf ("effective pinned: %d (at the end: %d)\n", count, (char*)end_nursery - (char*)last);
1240 if (mono_profiler_get_events () & MONO_PROFILE_GC_ROOTS) {
1241 GCRootReport report;
1243 for (idx = 0; idx < count; ++idx)
1244 add_profile_gc_root (&report, definitely_pinned [idx], MONO_PROFILE_GC_ROOT_PINNING | MONO_PROFILE_GC_ROOT_MISC, 0);
1245 notify_gc_roots (&report);
1247 stat_pinned_objects += count;
1252 sgen_pin_objects_in_section (GCMemSection *section, GrayQueue *queue, ScanObjectFunc scan_func)
1254 int num_entries = section->pin_queue_num_entries;
1256 void **start = section->pin_queue_start;
1258 reduced_to = pin_objects_from_addresses (section, start, start + num_entries,
1259 section->data, section->next_data, queue, scan_func);
1260 section->pin_queue_num_entries = reduced_to;
1262 section->pin_queue_start = NULL;
1268 sgen_pin_object (void *object, GrayQueue *queue)
1270 g_assert (!concurrent_collection_in_progress);
1272 if (sgen_collection_is_parallel ()) {
1274 /*object arrives pinned*/
1275 sgen_pin_stage_ptr (object);
1279 SGEN_PIN_OBJECT (object);
1280 sgen_pin_stage_ptr (object);
1282 if (G_UNLIKELY (do_pin_stats))
1283 sgen_pin_stats_register_object (object, safe_object_get_size (object));
1285 GRAY_OBJECT_ENQUEUE (queue, object);
1286 binary_protocol_pin (object, (gpointer)LOAD_VTABLE (object), safe_object_get_size (object));
1287 if (G_UNLIKELY (MONO_GC_OBJ_PINNED_ENABLED ())) {
1288 int gen = sgen_ptr_in_nursery (object) ? GENERATION_NURSERY : GENERATION_OLD;
1289 MonoVTable *vt = (MonoVTable*)LOAD_VTABLE (object);
1290 MONO_GC_OBJ_PINNED ((mword)object, sgen_safe_object_get_size (object), vt->klass->name_space, vt->klass->name, gen);
1295 sgen_parallel_pin_or_update (void **ptr, void *obj, MonoVTable *vt, SgenGrayQueue *queue)
1299 gboolean major_pinned = FALSE;
1301 if (sgen_ptr_in_nursery (obj)) {
1302 if (SGEN_CAS_PTR (obj, (void*)((mword)vt | SGEN_PINNED_BIT), vt) == vt) {
1303 sgen_pin_object (obj, queue);
1307 major_collector.pin_major_object (obj, queue);
1308 major_pinned = TRUE;
1311 vtable_word = *(mword*)obj;
1312 /*someone else forwarded it, update the pointer and bail out*/
1313 if (vtable_word & SGEN_FORWARDED_BIT) {
1314 *ptr = (void*)(vtable_word & ~SGEN_VTABLE_BITS_MASK);
1318 /*someone pinned it, nothing to do.*/
1319 if (vtable_word & SGEN_PINNED_BIT || major_pinned)
1324 /* Sort the addresses in array in increasing order.
1325 * Done using a by-the book heap sort. Which has decent and stable performance, is pretty cache efficient.
1328 sgen_sort_addresses (void **array, int size)
1333 for (i = 1; i < size; ++i) {
1336 int parent = (child - 1) / 2;
1338 if (array [parent] >= array [child])
1341 tmp = array [parent];
1342 array [parent] = array [child];
1343 array [child] = tmp;
1349 for (i = size - 1; i > 0; --i) {
1352 array [i] = array [0];
1358 while (root * 2 + 1 <= end) {
1359 int child = root * 2 + 1;
1361 if (child < end && array [child] < array [child + 1])
1363 if (array [root] >= array [child])
1367 array [root] = array [child];
1368 array [child] = tmp;
1376 * Scan the memory between start and end and queue values which could be pointers
1377 * to the area between start_nursery and end_nursery for later consideration.
1378 * Typically used for thread stacks.
1381 conservatively_pin_objects_from (void **start, void **end, void *start_nursery, void *end_nursery, int pin_type)
1385 #ifdef VALGRIND_MAKE_MEM_DEFINED_IF_ADDRESSABLE
1386 VALGRIND_MAKE_MEM_DEFINED_IF_ADDRESSABLE (start, (char*)end - (char*)start);
1389 while (start < end) {
1390 if (*start >= start_nursery && *start < end_nursery) {
1392 * *start can point to the middle of an object
1393 * note: should we handle pointing at the end of an object?
1394 * pinning in C# code disallows pointing at the end of an object
1395 * but there is some small chance that an optimizing C compiler
1396 * may keep the only reference to an object by pointing
1397 * at the end of it. We ignore this small chance for now.
1398 * Pointers to the end of an object are indistinguishable
1399 * from pointers to the start of the next object in memory
1400 * so if we allow that we'd need to pin two objects...
1401 * We queue the pointer in an array, the
1402 * array will then be sorted and uniqued. This way
1403 * we can coalesce several pinning pointers and it should
1404 * be faster since we'd do a memory scan with increasing
1405 * addresses. Note: we can align the address to the allocation
1406 * alignment, so the unique process is more effective.
1408 mword addr = (mword)*start;
1409 addr &= ~(ALLOC_ALIGN - 1);
1410 if (addr >= (mword)start_nursery && addr < (mword)end_nursery) {
1411 SGEN_LOG (6, "Pinning address %p from %p", (void*)addr, start);
1412 sgen_pin_stage_ptr ((void*)addr);
1415 if (G_UNLIKELY (do_pin_stats)) {
1416 if (ptr_in_nursery ((void*)addr))
1417 sgen_pin_stats_register_address ((char*)addr, pin_type);
1423 SGEN_LOG (7, "found %d potential pinned heap pointers", count);
1427 * The first thing we do in a collection is to identify pinned objects.
1428 * This function considers all the areas of memory that need to be
1429 * conservatively scanned.
1432 pin_from_roots (void *start_nursery, void *end_nursery, GrayQueue *queue)
1436 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);
1437 /* objects pinned from the API are inside these roots */
1438 SGEN_HASH_TABLE_FOREACH (&roots_hash [ROOT_TYPE_PINNED], start_root, root) {
1439 SGEN_LOG (6, "Pinned roots %p-%p", start_root, root->end_root);
1440 conservatively_pin_objects_from (start_root, (void**)root->end_root, start_nursery, end_nursery, PIN_TYPE_OTHER);
1441 } SGEN_HASH_TABLE_FOREACH_END;
1442 /* now deal with the thread stacks
1443 * in the future we should be able to conservatively scan only:
1444 * *) the cpu registers
1445 * *) the unmanaged stack frames
1446 * *) the _last_ managed stack frame
1447 * *) pointers slots in managed frames
1449 scan_thread_data (start_nursery, end_nursery, FALSE, queue);
1453 CopyOrMarkObjectFunc func;
1455 } UserCopyOrMarkData;
1457 static MonoNativeTlsKey user_copy_or_mark_key;
1460 init_user_copy_or_mark_key (void)
1462 mono_native_tls_alloc (&user_copy_or_mark_key, NULL);
1466 set_user_copy_or_mark_data (UserCopyOrMarkData *data)
1468 mono_native_tls_set_value (user_copy_or_mark_key, data);
1472 single_arg_user_copy_or_mark (void **obj)
1474 UserCopyOrMarkData *data = mono_native_tls_get_value (user_copy_or_mark_key);
1476 data->func (obj, data->queue);
1480 * The memory area from start_root to end_root contains pointers to objects.
1481 * Their position is precisely described by @desc (this means that the pointer
1482 * can be either NULL or the pointer to the start of an object).
1483 * This functions copies them to to_space updates them.
1485 * This function is not thread-safe!
1488 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)
1490 switch (desc & ROOT_DESC_TYPE_MASK) {
1491 case ROOT_DESC_BITMAP:
1492 desc >>= ROOT_DESC_TYPE_SHIFT;
1494 if ((desc & 1) && *start_root) {
1495 copy_func (start_root, queue);
1496 SGEN_LOG (9, "Overwrote root at %p with %p", start_root, *start_root);
1497 sgen_drain_gray_stack (queue, scan_func, -1);
1503 case ROOT_DESC_COMPLEX: {
1504 gsize *bitmap_data = sgen_get_complex_descriptor_bitmap (desc);
1505 int bwords = (*bitmap_data) - 1;
1506 void **start_run = start_root;
1508 while (bwords-- > 0) {
1509 gsize bmap = *bitmap_data++;
1510 void **objptr = start_run;
1512 if ((bmap & 1) && *objptr) {
1513 copy_func (objptr, queue);
1514 SGEN_LOG (9, "Overwrote root at %p with %p", objptr, *objptr);
1515 sgen_drain_gray_stack (queue, scan_func, -1);
1520 start_run += GC_BITS_PER_WORD;
1524 case ROOT_DESC_USER: {
1525 UserCopyOrMarkData data = { copy_func, queue };
1526 MonoGCRootMarkFunc marker = sgen_get_user_descriptor_func (desc);
1527 set_user_copy_or_mark_data (&data);
1528 marker (start_root, single_arg_user_copy_or_mark);
1529 set_user_copy_or_mark_data (NULL);
1532 case ROOT_DESC_RUN_LEN:
1533 g_assert_not_reached ();
1535 g_assert_not_reached ();
1540 reset_heap_boundaries (void)
1542 lowest_heap_address = ~(mword)0;
1543 highest_heap_address = 0;
1547 sgen_update_heap_boundaries (mword low, mword high)
1552 old = lowest_heap_address;
1555 } while (SGEN_CAS_PTR ((gpointer*)&lowest_heap_address, (gpointer)low, (gpointer)old) != (gpointer)old);
1558 old = highest_heap_address;
1561 } while (SGEN_CAS_PTR ((gpointer*)&highest_heap_address, (gpointer)high, (gpointer)old) != (gpointer)old);
1565 * Allocate and setup the data structures needed to be able to allocate objects
1566 * in the nursery. The nursery is stored in nursery_section.
1569 alloc_nursery (void)
1571 GCMemSection *section;
1576 if (nursery_section)
1578 SGEN_LOG (2, "Allocating nursery size: %lu", (unsigned long)sgen_nursery_size);
1579 /* later we will alloc a larger area for the nursery but only activate
1580 * what we need. The rest will be used as expansion if we have too many pinned
1581 * objects in the existing nursery.
1583 /* FIXME: handle OOM */
1584 section = sgen_alloc_internal (INTERNAL_MEM_SECTION);
1586 alloc_size = sgen_nursery_size;
1588 /* If there isn't enough space even for the nursery we should simply abort. */
1589 g_assert (sgen_memgov_try_alloc_space (alloc_size, SPACE_NURSERY));
1591 #ifdef SGEN_ALIGN_NURSERY
1592 data = major_collector.alloc_heap (alloc_size, alloc_size, DEFAULT_NURSERY_BITS);
1594 data = major_collector.alloc_heap (alloc_size, 0, DEFAULT_NURSERY_BITS);
1596 sgen_update_heap_boundaries ((mword)data, (mword)(data + sgen_nursery_size));
1597 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 ());
1598 section->data = section->next_data = data;
1599 section->size = alloc_size;
1600 section->end_data = data + sgen_nursery_size;
1601 scan_starts = (alloc_size + SCAN_START_SIZE - 1) / SCAN_START_SIZE;
1602 section->scan_starts = sgen_alloc_internal_dynamic (sizeof (char*) * scan_starts, INTERNAL_MEM_SCAN_STARTS, TRUE);
1603 section->num_scan_start = scan_starts;
1604 section->block.role = MEMORY_ROLE_GEN0;
1605 section->block.next = NULL;
1607 nursery_section = section;
1609 sgen_nursery_allocator_set_nursery_bounds (data, data + sgen_nursery_size);
1613 mono_gc_get_nursery (int *shift_bits, size_t *size)
1615 *size = sgen_nursery_size;
1616 #ifdef SGEN_ALIGN_NURSERY
1617 *shift_bits = DEFAULT_NURSERY_BITS;
1621 return sgen_get_nursery_start ();
1625 mono_gc_set_current_thread_appdomain (MonoDomain *domain)
1627 SgenThreadInfo *info = mono_thread_info_current ();
1629 /* Could be called from sgen_thread_unregister () with a NULL info */
1632 info->stopped_domain = domain;
1637 mono_gc_precise_stack_mark_enabled (void)
1639 return !conservative_stack_mark;
1643 mono_gc_get_logfile (void)
1645 return gc_debug_file;
1649 report_finalizer_roots_list (FinalizeReadyEntry *list)
1651 GCRootReport report;
1652 FinalizeReadyEntry *fin;
1655 for (fin = list; fin; fin = fin->next) {
1658 add_profile_gc_root (&report, fin->object, MONO_PROFILE_GC_ROOT_FINALIZER, 0);
1660 notify_gc_roots (&report);
1664 report_finalizer_roots (void)
1666 report_finalizer_roots_list (fin_ready_list);
1667 report_finalizer_roots_list (critical_fin_list);
1670 static GCRootReport *root_report;
1673 single_arg_report_root (void **obj)
1676 add_profile_gc_root (root_report, *obj, MONO_PROFILE_GC_ROOT_OTHER, 0);
1680 precisely_report_roots_from (GCRootReport *report, void** start_root, void** end_root, mword desc)
1682 switch (desc & ROOT_DESC_TYPE_MASK) {
1683 case ROOT_DESC_BITMAP:
1684 desc >>= ROOT_DESC_TYPE_SHIFT;
1686 if ((desc & 1) && *start_root) {
1687 add_profile_gc_root (report, *start_root, MONO_PROFILE_GC_ROOT_OTHER, 0);
1693 case ROOT_DESC_COMPLEX: {
1694 gsize *bitmap_data = sgen_get_complex_descriptor_bitmap (desc);
1695 int bwords = (*bitmap_data) - 1;
1696 void **start_run = start_root;
1698 while (bwords-- > 0) {
1699 gsize bmap = *bitmap_data++;
1700 void **objptr = start_run;
1702 if ((bmap & 1) && *objptr) {
1703 add_profile_gc_root (report, *objptr, MONO_PROFILE_GC_ROOT_OTHER, 0);
1708 start_run += GC_BITS_PER_WORD;
1712 case ROOT_DESC_USER: {
1713 MonoGCRootMarkFunc marker = sgen_get_user_descriptor_func (desc);
1714 root_report = report;
1715 marker (start_root, single_arg_report_root);
1718 case ROOT_DESC_RUN_LEN:
1719 g_assert_not_reached ();
1721 g_assert_not_reached ();
1726 report_registered_roots_by_type (int root_type)
1728 GCRootReport report;
1732 SGEN_HASH_TABLE_FOREACH (&roots_hash [root_type], start_root, root) {
1733 SGEN_LOG (6, "Precise root scan %p-%p (desc: %p)", start_root, root->end_root, (void*)root->root_desc);
1734 precisely_report_roots_from (&report, start_root, (void**)root->end_root, root->root_desc);
1735 } SGEN_HASH_TABLE_FOREACH_END;
1736 notify_gc_roots (&report);
1740 report_registered_roots (void)
1742 report_registered_roots_by_type (ROOT_TYPE_NORMAL);
1743 report_registered_roots_by_type (ROOT_TYPE_WBARRIER);
1747 scan_finalizer_entries (CopyOrMarkObjectFunc copy_func, FinalizeReadyEntry *list, GrayQueue *queue)
1749 FinalizeReadyEntry *fin;
1751 for (fin = list; fin; fin = fin->next) {
1754 SGEN_LOG (5, "Scan of fin ready object: %p (%s)\n", fin->object, safe_name (fin->object));
1755 copy_func (&fin->object, queue);
1760 generation_name (int generation)
1762 switch (generation) {
1763 case GENERATION_NURSERY: return "nursery";
1764 case GENERATION_OLD: return "old";
1765 default: g_assert_not_reached ();
1770 sgen_generation_name (int generation)
1772 return generation_name (generation);
1775 SgenObjectOperations *
1776 sgen_get_current_object_ops (void){
1777 return ¤t_object_ops;
1782 finish_gray_stack (char *start_addr, char *end_addr, int generation, GrayQueue *queue)
1786 int done_with_ephemerons, ephemeron_rounds = 0;
1787 CopyOrMarkObjectFunc copy_func = current_object_ops.copy_or_mark_object;
1788 ScanObjectFunc scan_func = current_object_ops.scan_object;
1791 * We copied all the reachable objects. Now it's the time to copy
1792 * the objects that were not referenced by the roots, but by the copied objects.
1793 * we built a stack of objects pointed to by gray_start: they are
1794 * additional roots and we may add more items as we go.
1795 * We loop until gray_start == gray_objects which means no more objects have
1796 * been added. Note this is iterative: no recursion is involved.
1797 * We need to walk the LO list as well in search of marked big objects
1798 * (use a flag since this is needed only on major collections). We need to loop
1799 * here as well, so keep a counter of marked LO (increasing it in copy_object).
1800 * To achieve better cache locality and cache usage, we drain the gray stack
1801 * frequently, after each object is copied, and just finish the work here.
1803 sgen_drain_gray_stack (queue, scan_func, -1);
1805 SGEN_LOG (2, "%s generation done", generation_name (generation));
1808 Reset bridge data, we might have lingering data from a previous collection if this is a major
1809 collection trigged by minor overflow.
1811 We must reset the gathered bridges since their original block might be evacuated due to major
1812 fragmentation in the meanwhile and the bridge code should not have to deal with that.
1814 sgen_bridge_reset_data ();
1817 * Walk the ephemeron tables marking all values with reachable keys. This must be completely done
1818 * before processing finalizable objects or non-tracking weak hamdle to avoid finalizing/clearing
1819 * objects that are in fact reachable.
1821 done_with_ephemerons = 0;
1823 done_with_ephemerons = mark_ephemerons_in_range (copy_func, start_addr, end_addr, queue);
1824 sgen_drain_gray_stack (queue, scan_func, -1);
1826 } while (!done_with_ephemerons);
1828 sgen_scan_togglerefs (copy_func, start_addr, end_addr, queue);
1829 if (generation == GENERATION_OLD)
1830 sgen_scan_togglerefs (copy_func, sgen_get_nursery_start (), sgen_get_nursery_end (), queue);
1832 if (sgen_need_bridge_processing ()) {
1833 sgen_collect_bridge_objects (copy_func, start_addr, end_addr, generation, queue);
1834 if (generation == GENERATION_OLD)
1835 sgen_collect_bridge_objects (copy_func, sgen_get_nursery_start (), sgen_get_nursery_end (), GENERATION_NURSERY, queue);
1839 Make sure we drain the gray stack before processing disappearing links and finalizers.
1840 If we don't make sure it is empty we might wrongly see a live object as dead.
1842 sgen_drain_gray_stack (queue, scan_func, -1);
1845 We must clear weak links that don't track resurrection before processing object ready for
1846 finalization so they can be cleared before that.
1848 sgen_null_link_in_range (copy_func, start_addr, end_addr, generation, TRUE, queue);
1849 if (generation == GENERATION_OLD)
1850 sgen_null_link_in_range (copy_func, start_addr, end_addr, GENERATION_NURSERY, TRUE, queue);
1853 /* walk the finalization queue and move also the objects that need to be
1854 * finalized: use the finalized objects as new roots so the objects they depend
1855 * on are also not reclaimed. As with the roots above, only objects in the nursery
1856 * are marked/copied.
1858 sgen_finalize_in_range (copy_func, start_addr, end_addr, generation, queue);
1859 if (generation == GENERATION_OLD)
1860 sgen_finalize_in_range (copy_func, sgen_get_nursery_start (), sgen_get_nursery_end (), GENERATION_NURSERY, queue);
1861 /* drain the new stack that might have been created */
1862 SGEN_LOG (6, "Precise scan of gray area post fin");
1863 sgen_drain_gray_stack (queue, scan_func, -1);
1866 * This must be done again after processing finalizable objects since CWL slots are cleared only after the key is finalized.
1868 done_with_ephemerons = 0;
1870 done_with_ephemerons = mark_ephemerons_in_range (copy_func, start_addr, end_addr, queue);
1871 sgen_drain_gray_stack (queue, scan_func, -1);
1873 } while (!done_with_ephemerons);
1876 * Clear ephemeron pairs with unreachable keys.
1877 * We pass the copy func so we can figure out if an array was promoted or not.
1879 clear_unreachable_ephemerons (copy_func, start_addr, end_addr, queue);
1882 SGEN_LOG (2, "Finalize queue handling scan for %s generation: %d usecs %d ephemeron rounds", generation_name (generation), TV_ELAPSED (atv, btv), ephemeron_rounds);
1885 * handle disappearing links
1886 * Note we do this after checking the finalization queue because if an object
1887 * survives (at least long enough to be finalized) we don't clear the link.
1888 * This also deals with a possible issue with the monitor reclamation: with the Boehm
1889 * GC a finalized object my lose the monitor because it is cleared before the finalizer is
1892 g_assert (sgen_gray_object_queue_is_empty (queue));
1894 sgen_null_link_in_range (copy_func, start_addr, end_addr, generation, FALSE, queue);
1895 if (generation == GENERATION_OLD)
1896 sgen_null_link_in_range (copy_func, start_addr, end_addr, GENERATION_NURSERY, FALSE, queue);
1897 if (sgen_gray_object_queue_is_empty (queue))
1899 sgen_drain_gray_stack (queue, scan_func, -1);
1902 g_assert (sgen_gray_object_queue_is_empty (queue));
1906 sgen_check_section_scan_starts (GCMemSection *section)
1909 for (i = 0; i < section->num_scan_start; ++i) {
1910 if (section->scan_starts [i]) {
1911 guint size = safe_object_get_size ((MonoObject*) section->scan_starts [i]);
1912 g_assert (size >= sizeof (MonoObject) && size <= MAX_SMALL_OBJ_SIZE);
1918 check_scan_starts (void)
1920 if (!do_scan_starts_check)
1922 sgen_check_section_scan_starts (nursery_section);
1923 major_collector.check_scan_starts ();
1927 scan_from_registered_roots (CopyOrMarkObjectFunc copy_func, ScanObjectFunc scan_func, char *addr_start, char *addr_end, int root_type, GrayQueue *queue)
1931 SGEN_HASH_TABLE_FOREACH (&roots_hash [root_type], start_root, root) {
1932 SGEN_LOG (6, "Precise root scan %p-%p (desc: %p)", start_root, root->end_root, (void*)root->root_desc);
1933 precisely_scan_objects_from (copy_func, scan_func, start_root, (void**)root->end_root, addr_start, addr_end, root->root_desc, queue);
1934 } SGEN_HASH_TABLE_FOREACH_END;
1938 sgen_dump_occupied (char *start, char *end, char *section_start)
1940 fprintf (heap_dump_file, "<occupied offset=\"%td\" size=\"%td\"/>\n", start - section_start, end - start);
1944 sgen_dump_section (GCMemSection *section, const char *type)
1946 char *start = section->data;
1947 char *end = section->data + section->size;
1948 char *occ_start = NULL;
1950 char *old_start = NULL; /* just for debugging */
1952 fprintf (heap_dump_file, "<section type=\"%s\" size=\"%lu\">\n", type, (unsigned long)section->size);
1954 while (start < end) {
1958 if (!*(void**)start) {
1960 sgen_dump_occupied (occ_start, start, section->data);
1963 start += sizeof (void*); /* should be ALLOC_ALIGN, really */
1966 g_assert (start < section->next_data);
1971 vt = (GCVTable*)LOAD_VTABLE (start);
1974 size = ALIGN_UP (safe_object_get_size ((MonoObject*) start));
1977 fprintf (heap_dump_file, "<object offset=\"%d\" class=\"%s.%s\" size=\"%d\"/>\n",
1978 start - section->data,
1979 vt->klass->name_space, vt->klass->name,
1987 sgen_dump_occupied (occ_start, start, section->data);
1989 fprintf (heap_dump_file, "</section>\n");
1993 dump_object (MonoObject *obj, gboolean dump_location)
1995 static char class_name [1024];
1997 MonoClass *class = mono_object_class (obj);
2001 * Python's XML parser is too stupid to parse angle brackets
2002 * in strings, so we just ignore them;
2005 while (class->name [i] && j < sizeof (class_name) - 1) {
2006 if (!strchr ("<>\"", class->name [i]))
2007 class_name [j++] = class->name [i];
2010 g_assert (j < sizeof (class_name));
2013 fprintf (heap_dump_file, "<object class=\"%s.%s\" size=\"%d\"",
2014 class->name_space, class_name,
2015 safe_object_get_size (obj));
2016 if (dump_location) {
2017 const char *location;
2018 if (ptr_in_nursery (obj))
2019 location = "nursery";
2020 else if (safe_object_get_size (obj) <= MAX_SMALL_OBJ_SIZE)
2024 fprintf (heap_dump_file, " location=\"%s\"", location);
2026 fprintf (heap_dump_file, "/>\n");
2030 dump_heap (const char *type, int num, const char *reason)
2035 fprintf (heap_dump_file, "<collection type=\"%s\" num=\"%d\"", type, num);
2037 fprintf (heap_dump_file, " reason=\"%s\"", reason);
2038 fprintf (heap_dump_file, ">\n");
2039 fprintf (heap_dump_file, "<other-mem-usage type=\"mempools\" size=\"%ld\"/>\n", mono_mempool_get_bytes_allocated ());
2040 sgen_dump_internal_mem_usage (heap_dump_file);
2041 fprintf (heap_dump_file, "<pinned type=\"stack\" bytes=\"%zu\"/>\n", sgen_pin_stats_get_pinned_byte_count (PIN_TYPE_STACK));
2042 /* fprintf (heap_dump_file, "<pinned type=\"static-data\" bytes=\"%d\"/>\n", pinned_byte_counts [PIN_TYPE_STATIC_DATA]); */
2043 fprintf (heap_dump_file, "<pinned type=\"other\" bytes=\"%zu\"/>\n", sgen_pin_stats_get_pinned_byte_count (PIN_TYPE_OTHER));
2045 fprintf (heap_dump_file, "<pinned-objects>\n");
2046 for (list = sgen_pin_stats_get_object_list (); list; list = list->next)
2047 dump_object (list->obj, TRUE);
2048 fprintf (heap_dump_file, "</pinned-objects>\n");
2050 sgen_dump_section (nursery_section, "nursery");
2052 major_collector.dump_heap (heap_dump_file);
2054 fprintf (heap_dump_file, "<los>\n");
2055 for (bigobj = los_object_list; bigobj; bigobj = bigobj->next)
2056 dump_object ((MonoObject*)bigobj->data, FALSE);
2057 fprintf (heap_dump_file, "</los>\n");
2059 fprintf (heap_dump_file, "</collection>\n");
2063 sgen_register_moved_object (void *obj, void *destination)
2065 g_assert (mono_profiler_events & MONO_PROFILE_GC_MOVES);
2067 /* FIXME: handle this for parallel collector */
2068 g_assert (!sgen_collection_is_parallel ());
2070 if (moved_objects_idx == MOVED_OBJECTS_NUM) {
2071 mono_profiler_gc_moves (moved_objects, moved_objects_idx);
2072 moved_objects_idx = 0;
2074 moved_objects [moved_objects_idx++] = obj;
2075 moved_objects [moved_objects_idx++] = destination;
2081 static gboolean inited = FALSE;
2086 mono_counters_register ("Minor fragment clear", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_minor_pre_collection_fragment_clear);
2087 mono_counters_register ("Minor pinning", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_minor_pinning);
2088 mono_counters_register ("Minor scan remembered set", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_minor_scan_remsets);
2089 mono_counters_register ("Minor scan pinned", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_minor_scan_pinned);
2090 mono_counters_register ("Minor scan registered roots", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_minor_scan_registered_roots);
2091 mono_counters_register ("Minor scan thread data", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_minor_scan_thread_data);
2092 mono_counters_register ("Minor finish gray stack", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_minor_finish_gray_stack);
2093 mono_counters_register ("Minor fragment creation", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_minor_fragment_creation);
2095 mono_counters_register ("Major fragment clear", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_major_pre_collection_fragment_clear);
2096 mono_counters_register ("Major pinning", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_major_pinning);
2097 mono_counters_register ("Major scan pinned", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_major_scan_pinned);
2098 mono_counters_register ("Major scan registered roots", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_major_scan_registered_roots);
2099 mono_counters_register ("Major scan thread data", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_major_scan_thread_data);
2100 mono_counters_register ("Major scan alloc_pinned", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_major_scan_alloc_pinned);
2101 mono_counters_register ("Major scan finalized", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_major_scan_finalized);
2102 mono_counters_register ("Major scan big objects", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_major_scan_big_objects);
2103 mono_counters_register ("Major finish gray stack", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_major_finish_gray_stack);
2104 mono_counters_register ("Major free big objects", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_major_free_bigobjs);
2105 mono_counters_register ("Major LOS sweep", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_major_los_sweep);
2106 mono_counters_register ("Major sweep", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_major_sweep);
2107 mono_counters_register ("Major fragment creation", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_major_fragment_creation);
2109 mono_counters_register ("Number of pinned objects", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_pinned_objects);
2111 #ifdef HEAVY_STATISTICS
2112 mono_counters_register ("WBarrier set field", MONO_COUNTER_GC | MONO_COUNTER_INT, &stat_wbarrier_set_field);
2113 mono_counters_register ("WBarrier set arrayref", MONO_COUNTER_GC | MONO_COUNTER_INT, &stat_wbarrier_set_arrayref);
2114 mono_counters_register ("WBarrier arrayref copy", MONO_COUNTER_GC | MONO_COUNTER_INT, &stat_wbarrier_arrayref_copy);
2115 mono_counters_register ("WBarrier generic store called", MONO_COUNTER_GC | MONO_COUNTER_INT, &stat_wbarrier_generic_store);
2116 mono_counters_register ("WBarrier set root", MONO_COUNTER_GC | MONO_COUNTER_INT, &stat_wbarrier_set_root);
2117 mono_counters_register ("WBarrier value copy", MONO_COUNTER_GC | MONO_COUNTER_INT, &stat_wbarrier_value_copy);
2118 mono_counters_register ("WBarrier object copy", MONO_COUNTER_GC | MONO_COUNTER_INT, &stat_wbarrier_object_copy);
2120 mono_counters_register ("# objects allocated degraded", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_objects_alloced_degraded);
2121 mono_counters_register ("bytes allocated degraded", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_bytes_alloced_degraded);
2123 mono_counters_register ("# copy_object() called (nursery)", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_copy_object_called_nursery);
2124 mono_counters_register ("# objects copied (nursery)", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_objects_copied_nursery);
2125 mono_counters_register ("# copy_object() called (major)", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_copy_object_called_major);
2126 mono_counters_register ("# objects copied (major)", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_objects_copied_major);
2128 mono_counters_register ("# scan_object() called (nursery)", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_scan_object_called_nursery);
2129 mono_counters_register ("# scan_object() called (major)", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_scan_object_called_major);
2131 mono_counters_register ("Slots allocated in vain", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_slots_allocated_in_vain);
2133 mono_counters_register ("# nursery copy_object() failed from space", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_nursery_copy_object_failed_from_space);
2134 mono_counters_register ("# nursery copy_object() failed forwarded", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_nursery_copy_object_failed_forwarded);
2135 mono_counters_register ("# nursery copy_object() failed pinned", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_nursery_copy_object_failed_pinned);
2136 mono_counters_register ("# nursery copy_object() failed to space", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_nursery_copy_object_failed_to_space);
2138 sgen_nursery_allocator_init_heavy_stats ();
2139 sgen_alloc_init_heavy_stats ();
2147 reset_pinned_from_failed_allocation (void)
2149 bytes_pinned_from_failed_allocation = 0;
2153 sgen_set_pinned_from_failed_allocation (mword objsize)
2155 bytes_pinned_from_failed_allocation += objsize;
2159 sgen_collection_is_parallel (void)
2161 switch (current_collection_generation) {
2162 case GENERATION_NURSERY:
2163 return nursery_collection_is_parallel;
2164 case GENERATION_OLD:
2165 return major_collector.is_parallel;
2167 g_error ("Invalid current generation %d", current_collection_generation);
2172 sgen_collection_is_concurrent (void)
2174 switch (current_collection_generation) {
2175 case GENERATION_NURSERY:
2177 case GENERATION_OLD:
2178 return major_collector.is_concurrent;
2180 g_error ("Invalid current generation %d", current_collection_generation);
2185 sgen_concurrent_collection_in_progress (void)
2187 return concurrent_collection_in_progress;
2194 } FinishRememberedSetScanJobData;
2197 job_finish_remembered_set_scan (WorkerData *worker_data, void *job_data_untyped)
2199 FinishRememberedSetScanJobData *job_data = job_data_untyped;
2201 remset.finish_scan_remsets (job_data->heap_start, job_data->heap_end, sgen_workers_get_job_gray_queue (worker_data));
2202 sgen_free_internal_dynamic (job_data, sizeof (FinishRememberedSetScanJobData), INTERNAL_MEM_WORKER_JOB_DATA);
2207 CopyOrMarkObjectFunc copy_or_mark_func;
2208 ScanObjectFunc scan_func;
2212 } ScanFromRegisteredRootsJobData;
2215 job_scan_from_registered_roots (WorkerData *worker_data, void *job_data_untyped)
2217 ScanFromRegisteredRootsJobData *job_data = job_data_untyped;
2219 scan_from_registered_roots (job_data->copy_or_mark_func, job_data->scan_func,
2220 job_data->heap_start, job_data->heap_end,
2221 job_data->root_type,
2222 sgen_workers_get_job_gray_queue (worker_data));
2223 sgen_free_internal_dynamic (job_data, sizeof (ScanFromRegisteredRootsJobData), INTERNAL_MEM_WORKER_JOB_DATA);
2230 } ScanThreadDataJobData;
2233 job_scan_thread_data (WorkerData *worker_data, void *job_data_untyped)
2235 ScanThreadDataJobData *job_data = job_data_untyped;
2237 scan_thread_data (job_data->heap_start, job_data->heap_end, TRUE,
2238 sgen_workers_get_job_gray_queue (worker_data));
2239 sgen_free_internal_dynamic (job_data, sizeof (ScanThreadDataJobData), INTERNAL_MEM_WORKER_JOB_DATA);
2244 FinalizeReadyEntry *list;
2245 } ScanFinalizerEntriesJobData;
2248 job_scan_finalizer_entries (WorkerData *worker_data, void *job_data_untyped)
2250 ScanFinalizerEntriesJobData *job_data = job_data_untyped;
2252 scan_finalizer_entries (current_object_ops.copy_or_mark_object,
2254 sgen_workers_get_job_gray_queue (worker_data));
2255 sgen_free_internal_dynamic (job_data, sizeof (ScanFinalizerEntriesJobData), INTERNAL_MEM_WORKER_JOB_DATA);
2259 job_scan_major_mod_union_cardtable (WorkerData *worker_data, void *job_data_untyped)
2261 g_assert (concurrent_collection_in_progress);
2262 major_collector.scan_card_table (TRUE, sgen_workers_get_job_gray_queue (worker_data));
2266 job_scan_los_mod_union_cardtable (WorkerData *worker_data, void *job_data_untyped)
2268 g_assert (concurrent_collection_in_progress);
2269 sgen_los_scan_card_table (TRUE, sgen_workers_get_job_gray_queue (worker_data));
2273 verify_scan_starts (char *start, char *end)
2277 for (i = 0; i < nursery_section->num_scan_start; ++i) {
2278 char *addr = nursery_section->scan_starts [i];
2279 if (addr > start && addr < end)
2280 SGEN_LOG (1, "NFC-BAD SCAN START [%d] %p for obj [%p %p]", i, addr, start, end);
2285 verify_nursery (void)
2287 char *start, *end, *cur, *hole_start;
2289 if (!do_verify_nursery)
2292 /*This cleans up unused fragments */
2293 sgen_nursery_allocator_prepare_for_pinning ();
2295 hole_start = start = cur = sgen_get_nursery_start ();
2296 end = sgen_get_nursery_end ();
2301 if (!*(void**)cur) {
2302 cur += sizeof (void*);
2306 if (object_is_forwarded (cur))
2307 SGEN_LOG (1, "FORWARDED OBJ %p", cur);
2308 else if (object_is_pinned (cur))
2309 SGEN_LOG (1, "PINNED OBJ %p", cur);
2311 ss = safe_object_get_size ((MonoObject*)cur);
2312 size = ALIGN_UP (safe_object_get_size ((MonoObject*)cur));
2313 verify_scan_starts (cur, cur + size);
2314 if (do_dump_nursery_content) {
2315 if (cur > hole_start)
2316 SGEN_LOG (1, "HOLE [%p %p %d]", hole_start, cur, (int)(cur - hole_start));
2317 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 ());
2325 * Checks that no objects in the nursery are fowarded or pinned. This
2326 * is a precondition to restarting the mutator while doing a
2327 * concurrent collection. Note that we don't clear fragments because
2328 * we depend on that having happened earlier.
2331 check_nursery_is_clean (void)
2333 char *start, *end, *cur;
2335 start = cur = sgen_get_nursery_start ();
2336 end = sgen_get_nursery_end ();
2341 if (!*(void**)cur) {
2342 cur += sizeof (void*);
2346 g_assert (!object_is_forwarded (cur));
2347 g_assert (!object_is_pinned (cur));
2349 ss = safe_object_get_size ((MonoObject*)cur);
2350 size = ALIGN_UP (safe_object_get_size ((MonoObject*)cur));
2351 verify_scan_starts (cur, cur + size);
2358 gray_queue_redirect (SgenGrayQueue *queue)
2360 gboolean wake = FALSE;
2364 GrayQueueSection *section = sgen_gray_object_dequeue_section (queue);
2367 sgen_section_gray_queue_enqueue (queue->alloc_prepare_data, section);
2372 g_assert (concurrent_collection_in_progress);
2373 sgen_workers_wake_up_all ();
2378 init_gray_queue (void)
2380 if (sgen_collection_is_parallel () || sgen_collection_is_concurrent ()) {
2381 sgen_workers_init_distribute_gray_queue ();
2382 sgen_gray_object_queue_init_with_alloc_prepare (&gray_queue, NULL,
2383 gray_queue_redirect, sgen_workers_get_distribute_section_gray_queue ());
2385 sgen_gray_object_queue_init (&gray_queue, NULL);
2388 if (major_collector.is_concurrent) {
2389 sgen_gray_object_queue_init_with_alloc_prepare (&remember_major_objects_gray_queue, NULL,
2390 gray_queue_redirect, sgen_workers_get_distribute_section_gray_queue ());
2392 sgen_gray_object_queue_init_invalid (&remember_major_objects_gray_queue);
2397 * Collect objects in the nursery. Returns whether to trigger a major
2401 collect_nursery (void)
2403 gboolean needs_major;
2404 size_t max_garbage_amount;
2406 FinishRememberedSetScanJobData *frssjd;
2407 ScanFromRegisteredRootsJobData *scrrjd_normal, *scrrjd_wbarrier;
2408 ScanFinalizerEntriesJobData *sfejd_fin_ready, *sfejd_critical_fin;
2409 ScanThreadDataJobData *stdjd;
2410 mword fragment_total;
2411 TV_DECLARE (all_atv);
2412 TV_DECLARE (all_btv);
2416 if (disable_minor_collections)
2419 MONO_GC_BEGIN (GENERATION_NURSERY);
2420 binary_protocol_collection_begin (stat_minor_gcs, GENERATION_NURSERY);
2424 #ifndef DISABLE_PERFCOUNTERS
2425 mono_perfcounters->gc_collections0++;
2428 current_collection_generation = GENERATION_NURSERY;
2429 if (sgen_collection_is_parallel ())
2430 current_object_ops = sgen_minor_collector.parallel_ops;
2432 current_object_ops = sgen_minor_collector.serial_ops;
2434 reset_pinned_from_failed_allocation ();
2436 check_scan_starts ();
2438 sgen_nursery_alloc_prepare_for_minor ();
2442 nursery_next = sgen_nursery_alloc_get_upper_alloc_bound ();
2443 /* FIXME: optimize later to use the higher address where an object can be present */
2444 nursery_next = MAX (nursery_next, sgen_get_nursery_end ());
2446 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 ()));
2447 max_garbage_amount = nursery_next - sgen_get_nursery_start ();
2448 g_assert (nursery_section->size >= max_garbage_amount);
2450 /* world must be stopped already */
2451 TV_GETTIME (all_atv);
2455 time_minor_pre_collection_fragment_clear += TV_ELAPSED (atv, btv);
2457 if (xdomain_checks) {
2458 sgen_clear_nursery_fragments ();
2459 check_for_xdomain_refs ();
2462 nursery_section->next_data = nursery_next;
2464 major_collector.start_nursery_collection ();
2466 sgen_memgov_minor_collection_start ();
2471 gc_stats.minor_gc_count ++;
2473 if (remset.prepare_for_minor_collection)
2474 remset.prepare_for_minor_collection ();
2476 sgen_process_fin_stage_entries ();
2477 sgen_process_dislink_stage_entries ();
2479 /* pin from pinned handles */
2480 sgen_init_pinning ();
2481 mono_profiler_gc_event (MONO_GC_EVENT_MARK_START, 0);
2482 pin_from_roots (sgen_get_nursery_start (), nursery_next, WORKERS_DISTRIBUTE_GRAY_QUEUE);
2483 /* identify pinned objects */
2484 sgen_optimize_pin_queue (0);
2485 sgen_pinning_setup_section (nursery_section);
2486 sgen_pin_objects_in_section (nursery_section, WORKERS_DISTRIBUTE_GRAY_QUEUE, NULL);
2487 sgen_pinning_trim_queue_to_section (nursery_section);
2490 time_minor_pinning += TV_ELAPSED (btv, atv);
2491 SGEN_LOG (2, "Finding pinned pointers: %d in %d usecs", sgen_get_pinned_count (), TV_ELAPSED (btv, atv));
2492 SGEN_LOG (4, "Start scan with %d pinned objects", sgen_get_pinned_count ());
2494 if (whole_heap_check_before_collection) {
2495 sgen_clear_nursery_fragments ();
2496 sgen_check_whole_heap ();
2498 if (consistency_check_at_minor_collection)
2499 sgen_check_consistency ();
2501 sgen_workers_start_all_workers ();
2504 * Perform the sequential part of remembered set scanning.
2505 * This usually involves scanning global information that might later be produced by evacuation.
2507 if (remset.begin_scan_remsets)
2508 remset.begin_scan_remsets (sgen_get_nursery_start (), nursery_next, WORKERS_DISTRIBUTE_GRAY_QUEUE);
2510 sgen_workers_start_marking ();
2512 frssjd = sgen_alloc_internal_dynamic (sizeof (FinishRememberedSetScanJobData), INTERNAL_MEM_WORKER_JOB_DATA, TRUE);
2513 frssjd->heap_start = sgen_get_nursery_start ();
2514 frssjd->heap_end = nursery_next;
2515 sgen_workers_enqueue_job (job_finish_remembered_set_scan, frssjd);
2517 /* we don't have complete write barrier yet, so we scan all the old generation sections */
2519 time_minor_scan_remsets += TV_ELAPSED (atv, btv);
2520 SGEN_LOG (2, "Old generation scan: %d usecs", TV_ELAPSED (atv, btv));
2522 if (!sgen_collection_is_parallel ())
2523 sgen_drain_gray_stack (&gray_queue, current_object_ops.scan_object, -1);
2525 if (mono_profiler_get_events () & MONO_PROFILE_GC_ROOTS)
2526 report_registered_roots ();
2527 if (mono_profiler_get_events () & MONO_PROFILE_GC_ROOTS)
2528 report_finalizer_roots ();
2530 time_minor_scan_pinned += TV_ELAPSED (btv, atv);
2532 /* registered roots, this includes static fields */
2533 scrrjd_normal = sgen_alloc_internal_dynamic (sizeof (ScanFromRegisteredRootsJobData), INTERNAL_MEM_WORKER_JOB_DATA, TRUE);
2534 scrrjd_normal->copy_or_mark_func = current_object_ops.copy_or_mark_object;
2535 scrrjd_normal->scan_func = current_object_ops.scan_object;
2536 scrrjd_normal->heap_start = sgen_get_nursery_start ();
2537 scrrjd_normal->heap_end = nursery_next;
2538 scrrjd_normal->root_type = ROOT_TYPE_NORMAL;
2539 sgen_workers_enqueue_job (job_scan_from_registered_roots, scrrjd_normal);
2541 scrrjd_wbarrier = sgen_alloc_internal_dynamic (sizeof (ScanFromRegisteredRootsJobData), INTERNAL_MEM_WORKER_JOB_DATA, TRUE);
2542 scrrjd_wbarrier->copy_or_mark_func = current_object_ops.copy_or_mark_object;
2543 scrrjd_wbarrier->scan_func = current_object_ops.scan_object;
2544 scrrjd_wbarrier->heap_start = sgen_get_nursery_start ();
2545 scrrjd_wbarrier->heap_end = nursery_next;
2546 scrrjd_wbarrier->root_type = ROOT_TYPE_WBARRIER;
2547 sgen_workers_enqueue_job (job_scan_from_registered_roots, scrrjd_wbarrier);
2550 time_minor_scan_registered_roots += TV_ELAPSED (atv, btv);
2553 stdjd = sgen_alloc_internal_dynamic (sizeof (ScanThreadDataJobData), INTERNAL_MEM_WORKER_JOB_DATA, TRUE);
2554 stdjd->heap_start = sgen_get_nursery_start ();
2555 stdjd->heap_end = nursery_next;
2556 sgen_workers_enqueue_job (job_scan_thread_data, stdjd);
2559 time_minor_scan_thread_data += TV_ELAPSED (btv, atv);
2562 g_assert (!sgen_collection_is_parallel () && !sgen_collection_is_concurrent ());
2564 if (sgen_collection_is_parallel () || sgen_collection_is_concurrent ())
2565 g_assert (sgen_gray_object_queue_is_empty (&gray_queue));
2567 /* Scan the list of objects ready for finalization. If */
2568 sfejd_fin_ready = sgen_alloc_internal_dynamic (sizeof (ScanFinalizerEntriesJobData), INTERNAL_MEM_WORKER_JOB_DATA, TRUE);
2569 sfejd_fin_ready->list = fin_ready_list;
2570 sgen_workers_enqueue_job (job_scan_finalizer_entries, sfejd_fin_ready);
2572 sfejd_critical_fin = sgen_alloc_internal_dynamic (sizeof (ScanFinalizerEntriesJobData), INTERNAL_MEM_WORKER_JOB_DATA, TRUE);
2573 sfejd_critical_fin->list = critical_fin_list;
2574 sgen_workers_enqueue_job (job_scan_finalizer_entries, sfejd_critical_fin);
2576 finish_gray_stack (sgen_get_nursery_start (), nursery_next, GENERATION_NURSERY, &gray_queue);
2578 time_minor_finish_gray_stack += TV_ELAPSED (btv, atv);
2579 mono_profiler_gc_event (MONO_GC_EVENT_MARK_END, 0);
2582 * The (single-threaded) finalization code might have done
2583 * some copying/marking so we can only reset the GC thread's
2584 * worker data here instead of earlier when we joined the
2587 sgen_workers_reset_data ();
2589 if (objects_pinned) {
2590 sgen_optimize_pin_queue (0);
2591 sgen_pinning_setup_section (nursery_section);
2594 /* walk the pin_queue, build up the fragment list of free memory, unmark
2595 * pinned objects as we go, memzero() the empty fragments so they are ready for the
2598 mono_profiler_gc_event (MONO_GC_EVENT_RECLAIM_START, 0);
2599 fragment_total = sgen_build_nursery_fragments (nursery_section, nursery_section->pin_queue_start, nursery_section->pin_queue_num_entries);
2600 if (!fragment_total)
2603 /* Clear TLABs for all threads */
2604 sgen_clear_tlabs ();
2606 mono_profiler_gc_event (MONO_GC_EVENT_RECLAIM_END, 0);
2608 time_minor_fragment_creation += TV_ELAPSED (atv, btv);
2609 SGEN_LOG (2, "Fragment creation: %d usecs, %lu bytes available", TV_ELAPSED (atv, btv), (unsigned long)fragment_total);
2611 if (consistency_check_at_minor_collection)
2612 sgen_check_major_refs ();
2614 major_collector.finish_nursery_collection ();
2616 TV_GETTIME (all_btv);
2617 gc_stats.minor_gc_time_usecs += TV_ELAPSED (all_atv, all_btv);
2620 dump_heap ("minor", stat_minor_gcs - 1, NULL);
2622 /* prepare the pin queue for the next collection */
2623 sgen_finish_pinning ();
2624 if (fin_ready_list || critical_fin_list) {
2625 SGEN_LOG (4, "Finalizer-thread wakeup: ready %d", num_ready_finalizers);
2626 mono_gc_finalize_notify ();
2628 sgen_pin_stats_reset ();
2630 g_assert (sgen_gray_object_queue_is_empty (&gray_queue));
2632 if (remset.finish_minor_collection)
2633 remset.finish_minor_collection ();
2635 check_scan_starts ();
2637 binary_protocol_flush_buffers (FALSE);
2639 sgen_memgov_minor_collection_end ();
2641 /*objects are late pinned because of lack of memory, so a major is a good call*/
2642 needs_major = objects_pinned > 0;
2643 current_collection_generation = -1;
2646 MONO_GC_END (GENERATION_NURSERY);
2647 binary_protocol_collection_end (stat_minor_gcs - 1, GENERATION_NURSERY);
2653 major_copy_or_mark_from_roots (int *old_next_pin_slot, gboolean finish_up_concurrent_mark, gboolean scan_mod_union)
2658 /* FIXME: only use these values for the precise scan
2659 * note that to_space pointers should be excluded anyway...
2661 char *heap_start = NULL;
2662 char *heap_end = (char*)-1;
2663 gboolean profile_roots = mono_profiler_get_events () & MONO_PROFILE_GC_ROOTS;
2664 GCRootReport root_report = { 0 };
2665 ScanFromRegisteredRootsJobData *scrrjd_normal, *scrrjd_wbarrier;
2666 ScanThreadDataJobData *stdjd;
2667 ScanFinalizerEntriesJobData *sfejd_fin_ready, *sfejd_critical_fin;
2669 if (major_collector.is_concurrent) {
2670 /*This cleans up unused fragments */
2671 sgen_nursery_allocator_prepare_for_pinning ();
2673 if (do_concurrent_checks)
2674 check_nursery_is_clean ();
2676 /* The concurrent collector doesn't touch the nursery. */
2677 sgen_nursery_alloc_prepare_for_major ();
2684 /* Pinning depends on this */
2685 sgen_clear_nursery_fragments ();
2687 if (whole_heap_check_before_collection)
2688 sgen_check_whole_heap ();
2691 time_major_pre_collection_fragment_clear += TV_ELAPSED (atv, btv);
2693 if (!sgen_collection_is_concurrent ())
2694 nursery_section->next_data = sgen_get_nursery_end ();
2695 /* we should also coalesce scanning from sections close to each other
2696 * and deal with pointers outside of the sections later.
2700 *major_collector.have_swept = FALSE;
2702 if (xdomain_checks) {
2703 sgen_clear_nursery_fragments ();
2704 check_for_xdomain_refs ();
2707 if (!major_collector.is_concurrent) {
2708 /* Remsets are not useful for a major collection */
2709 remset.prepare_for_major_collection ();
2712 sgen_process_fin_stage_entries ();
2713 sgen_process_dislink_stage_entries ();
2716 sgen_init_pinning ();
2717 SGEN_LOG (6, "Collecting pinned addresses");
2718 pin_from_roots ((void*)lowest_heap_address, (void*)highest_heap_address, WORKERS_DISTRIBUTE_GRAY_QUEUE);
2719 sgen_optimize_pin_queue (0);
2722 * pin_queue now contains all candidate pointers, sorted and
2723 * uniqued. We must do two passes now to figure out which
2724 * objects are pinned.
2726 * The first is to find within the pin_queue the area for each
2727 * section. This requires that the pin_queue be sorted. We
2728 * also process the LOS objects and pinned chunks here.
2730 * The second, destructive, pass is to reduce the section
2731 * areas to pointers to the actually pinned objects.
2733 SGEN_LOG (6, "Pinning from sections");
2734 /* first pass for the sections */
2735 sgen_find_section_pin_queue_start_end (nursery_section);
2736 major_collector.find_pin_queue_start_ends (WORKERS_DISTRIBUTE_GRAY_QUEUE);
2737 /* identify possible pointers to the insize of large objects */
2738 SGEN_LOG (6, "Pinning from large objects");
2739 for (bigobj = los_object_list; bigobj; bigobj = bigobj->next) {
2741 if (sgen_find_optimized_pin_queue_area (bigobj->data, (char*)bigobj->data + sgen_los_object_size (bigobj), &dummy)) {
2742 binary_protocol_pin (bigobj->data, (gpointer)LOAD_VTABLE (bigobj->data), safe_object_get_size (((MonoObject*)(bigobj->data))));
2743 if (G_UNLIKELY (MONO_GC_OBJ_PINNED_ENABLED ())) {
2744 MonoVTable *vt = (MonoVTable*)LOAD_VTABLE (bigobj->data);
2745 MONO_GC_OBJ_PINNED ((mword)bigobj->data, sgen_safe_object_get_size ((MonoObject*)bigobj->data), vt->klass->name_space, vt->klass->name, GENERATION_OLD);
2747 if (sgen_los_object_is_pinned (bigobj->data)) {
2748 g_assert (finish_up_concurrent_mark);
2751 sgen_los_pin_object (bigobj->data);
2752 /* FIXME: only enqueue if object has references */
2753 GRAY_OBJECT_ENQUEUE (WORKERS_DISTRIBUTE_GRAY_QUEUE, bigobj->data);
2754 if (G_UNLIKELY (do_pin_stats))
2755 sgen_pin_stats_register_object ((char*) bigobj->data, safe_object_get_size ((MonoObject*) bigobj->data));
2756 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));
2759 add_profile_gc_root (&root_report, bigobj->data, MONO_PROFILE_GC_ROOT_PINNING | MONO_PROFILE_GC_ROOT_MISC, 0);
2763 notify_gc_roots (&root_report);
2764 /* second pass for the sections */
2765 sgen_pin_objects_in_section (nursery_section, WORKERS_DISTRIBUTE_GRAY_QUEUE,
2766 concurrent_collection_in_progress ? current_object_ops.scan_object : NULL);
2767 major_collector.pin_objects (WORKERS_DISTRIBUTE_GRAY_QUEUE);
2768 if (old_next_pin_slot)
2769 *old_next_pin_slot = sgen_get_pinned_count ();
2772 time_major_pinning += TV_ELAPSED (atv, btv);
2773 SGEN_LOG (2, "Finding pinned pointers: %d in %d usecs", sgen_get_pinned_count (), TV_ELAPSED (atv, btv));
2774 SGEN_LOG (4, "Start scan with %d pinned objects", sgen_get_pinned_count ());
2776 major_collector.init_to_space ();
2778 #ifdef SGEN_DEBUG_INTERNAL_ALLOC
2779 main_gc_thread = mono_native_thread_self ();
2782 sgen_workers_start_all_workers ();
2783 sgen_workers_start_marking ();
2785 if (mono_profiler_get_events () & MONO_PROFILE_GC_ROOTS)
2786 report_registered_roots ();
2788 time_major_scan_pinned += TV_ELAPSED (btv, atv);
2790 /* registered roots, this includes static fields */
2791 scrrjd_normal = sgen_alloc_internal_dynamic (sizeof (ScanFromRegisteredRootsJobData), INTERNAL_MEM_WORKER_JOB_DATA, TRUE);
2792 scrrjd_normal->copy_or_mark_func = current_object_ops.copy_or_mark_object;
2793 scrrjd_normal->scan_func = current_object_ops.scan_object;
2794 scrrjd_normal->heap_start = heap_start;
2795 scrrjd_normal->heap_end = heap_end;
2796 scrrjd_normal->root_type = ROOT_TYPE_NORMAL;
2797 sgen_workers_enqueue_job (job_scan_from_registered_roots, scrrjd_normal);
2799 scrrjd_wbarrier = sgen_alloc_internal_dynamic (sizeof (ScanFromRegisteredRootsJobData), INTERNAL_MEM_WORKER_JOB_DATA, TRUE);
2800 scrrjd_wbarrier->copy_or_mark_func = current_object_ops.copy_or_mark_object;
2801 scrrjd_wbarrier->scan_func = current_object_ops.scan_object;
2802 scrrjd_wbarrier->heap_start = heap_start;
2803 scrrjd_wbarrier->heap_end = heap_end;
2804 scrrjd_wbarrier->root_type = ROOT_TYPE_WBARRIER;
2805 sgen_workers_enqueue_job (job_scan_from_registered_roots, scrrjd_wbarrier);
2808 time_major_scan_registered_roots += TV_ELAPSED (atv, btv);
2811 stdjd = sgen_alloc_internal_dynamic (sizeof (ScanThreadDataJobData), INTERNAL_MEM_WORKER_JOB_DATA, TRUE);
2812 stdjd->heap_start = heap_start;
2813 stdjd->heap_end = heap_end;
2814 sgen_workers_enqueue_job (job_scan_thread_data, stdjd);
2817 time_major_scan_thread_data += TV_ELAPSED (btv, atv);
2820 time_major_scan_alloc_pinned += TV_ELAPSED (atv, btv);
2822 if (mono_profiler_get_events () & MONO_PROFILE_GC_ROOTS)
2823 report_finalizer_roots ();
2825 /* scan the list of objects ready for finalization */
2826 sfejd_fin_ready = sgen_alloc_internal_dynamic (sizeof (ScanFinalizerEntriesJobData), INTERNAL_MEM_WORKER_JOB_DATA, TRUE);
2827 sfejd_fin_ready->list = fin_ready_list;
2828 sgen_workers_enqueue_job (job_scan_finalizer_entries, sfejd_fin_ready);
2830 sfejd_critical_fin = sgen_alloc_internal_dynamic (sizeof (ScanFinalizerEntriesJobData), INTERNAL_MEM_WORKER_JOB_DATA, TRUE);
2831 sfejd_critical_fin->list = critical_fin_list;
2832 sgen_workers_enqueue_job (job_scan_finalizer_entries, sfejd_critical_fin);
2834 if (scan_mod_union) {
2835 g_assert (finish_up_concurrent_mark);
2837 /* Mod union card table */
2838 sgen_workers_enqueue_job (job_scan_major_mod_union_cardtable, NULL);
2839 sgen_workers_enqueue_job (job_scan_los_mod_union_cardtable, NULL);
2843 time_major_scan_finalized += TV_ELAPSED (btv, atv);
2844 SGEN_LOG (2, "Root scan: %d usecs", TV_ELAPSED (btv, atv));
2847 time_major_scan_big_objects += TV_ELAPSED (atv, btv);
2849 if (major_collector.is_concurrent) {
2850 /* prepare the pin queue for the next collection */
2851 sgen_finish_pinning ();
2853 sgen_pin_stats_reset ();
2855 if (do_concurrent_checks)
2856 check_nursery_is_clean ();
2861 major_start_collection (int *old_next_pin_slot)
2863 MONO_GC_BEGIN (GENERATION_OLD);
2864 binary_protocol_collection_begin (stat_major_gcs, GENERATION_OLD);
2866 current_collection_generation = GENERATION_OLD;
2867 #ifndef DISABLE_PERFCOUNTERS
2868 mono_perfcounters->gc_collections1++;
2871 if (major_collector.is_concurrent)
2872 concurrent_collection_in_progress = TRUE;
2874 current_object_ops = major_collector.major_ops;
2876 reset_pinned_from_failed_allocation ();
2878 sgen_memgov_major_collection_start ();
2880 //count_ref_nonref_objs ();
2881 //consistency_check ();
2883 check_scan_starts ();
2886 SGEN_LOG (1, "Start major collection %d", stat_major_gcs);
2888 gc_stats.major_gc_count ++;
2890 if (major_collector.start_major_collection)
2891 major_collector.start_major_collection ();
2893 major_copy_or_mark_from_roots (old_next_pin_slot, FALSE, FALSE);
2897 wait_for_workers_to_finish (void)
2899 g_assert (sgen_gray_object_queue_is_empty (&remember_major_objects_gray_queue));
2901 if (major_collector.is_parallel || major_collector.is_concurrent) {
2902 gray_queue_redirect (&gray_queue);
2903 sgen_workers_join ();
2906 g_assert (sgen_gray_object_queue_is_empty (&gray_queue));
2908 #ifdef SGEN_DEBUG_INTERNAL_ALLOC
2909 main_gc_thread = NULL;
2914 major_finish_collection (const char *reason, int old_next_pin_slot, gboolean scan_mod_union)
2916 LOSObject *bigobj, *prevbo;
2919 char *heap_start = NULL;
2920 char *heap_end = (char*)-1;
2924 wait_for_workers_to_finish ();
2926 current_object_ops = major_collector.major_ops;
2928 if (major_collector.is_concurrent) {
2929 major_copy_or_mark_from_roots (NULL, TRUE, scan_mod_union);
2930 wait_for_workers_to_finish ();
2932 g_assert (sgen_gray_object_queue_is_empty (&gray_queue));
2934 if (do_concurrent_checks)
2935 check_nursery_is_clean ();
2938 g_assert (sgen_section_gray_queue_is_empty (sgen_workers_get_distribute_section_gray_queue ()));
2940 /* all the objects in the heap */
2941 finish_gray_stack (heap_start, heap_end, GENERATION_OLD, &gray_queue);
2943 time_major_finish_gray_stack += TV_ELAPSED (btv, atv);
2946 * The (single-threaded) finalization code might have done
2947 * some copying/marking so we can only reset the GC thread's
2948 * worker data here instead of earlier when we joined the
2951 sgen_workers_reset_data ();
2953 if (objects_pinned) {
2954 g_assert (!major_collector.is_concurrent);
2956 /*This is slow, but we just OOM'd*/
2957 sgen_pin_queue_clear_discarded_entries (nursery_section, old_next_pin_slot);
2958 sgen_optimize_pin_queue (0);
2959 sgen_find_section_pin_queue_start_end (nursery_section);
2963 reset_heap_boundaries ();
2964 sgen_update_heap_boundaries ((mword)sgen_get_nursery_start (), (mword)sgen_get_nursery_end ());
2966 MONO_GC_SWEEP_BEGIN (GENERATION_OLD);
2968 /* sweep the big objects list */
2970 for (bigobj = los_object_list; bigobj;) {
2971 g_assert (!object_is_pinned (bigobj->data));
2972 if (sgen_los_object_is_pinned (bigobj->data)) {
2973 sgen_los_unpin_object (bigobj->data);
2974 sgen_update_heap_boundaries ((mword)bigobj->data, (mword)bigobj->data + sgen_los_object_size (bigobj));
2977 /* not referenced anywhere, so we can free it */
2979 prevbo->next = bigobj->next;
2981 los_object_list = bigobj->next;
2983 bigobj = bigobj->next;
2984 sgen_los_free_object (to_free);
2988 bigobj = bigobj->next;
2992 time_major_free_bigobjs += TV_ELAPSED (atv, btv);
2997 time_major_los_sweep += TV_ELAPSED (btv, atv);
2999 major_collector.sweep ();
3001 MONO_GC_SWEEP_END (GENERATION_OLD);
3004 time_major_sweep += TV_ELAPSED (atv, btv);
3006 if (!major_collector.is_concurrent) {
3007 /* walk the pin_queue, build up the fragment list of free memory, unmark
3008 * pinned objects as we go, memzero() the empty fragments so they are ready for the
3011 if (!sgen_build_nursery_fragments (nursery_section, nursery_section->pin_queue_start, nursery_section->pin_queue_num_entries))
3014 /* prepare the pin queue for the next collection */
3015 sgen_finish_pinning ();
3017 /* Clear TLABs for all threads */
3018 sgen_clear_tlabs ();
3020 sgen_pin_stats_reset ();
3024 time_major_fragment_creation += TV_ELAPSED (btv, atv);
3027 dump_heap ("major", stat_major_gcs - 1, reason);
3029 if (fin_ready_list || critical_fin_list) {
3030 SGEN_LOG (4, "Finalizer-thread wakeup: ready %d", num_ready_finalizers);
3031 mono_gc_finalize_notify ();
3034 g_assert (sgen_gray_object_queue_is_empty (&gray_queue));
3036 sgen_memgov_major_collection_end ();
3037 current_collection_generation = -1;
3039 major_collector.finish_major_collection ();
3041 if (major_collector.is_concurrent)
3042 concurrent_collection_in_progress = FALSE;
3044 check_scan_starts ();
3046 binary_protocol_flush_buffers (FALSE);
3048 //consistency_check ();
3050 MONO_GC_END (GENERATION_OLD);
3051 binary_protocol_collection_end (stat_major_gcs - 1, GENERATION_OLD);
3055 major_do_collection (const char *reason)
3057 TV_DECLARE (all_atv);
3058 TV_DECLARE (all_btv);
3059 int old_next_pin_slot;
3061 /* world must be stopped already */
3062 TV_GETTIME (all_atv);
3064 major_start_collection (&old_next_pin_slot);
3065 major_finish_collection (reason, old_next_pin_slot, FALSE);
3067 TV_GETTIME (all_btv);
3068 gc_stats.major_gc_time_usecs += TV_ELAPSED (all_atv, all_btv);
3070 return bytes_pinned_from_failed_allocation > 0;
3073 static gboolean major_do_collection (const char *reason);
3076 major_start_concurrent_collection (const char *reason)
3078 MONO_GC_CONCURRENT_START_BEGIN (GENERATION_OLD);
3080 // FIXME: store reason and pass it when finishing
3081 major_start_collection (NULL);
3083 gray_queue_redirect (&gray_queue);
3084 sgen_workers_wait_for_jobs ();
3086 MONO_GC_CONCURRENT_START_END (GENERATION_OLD);
3088 current_collection_generation = -1;
3092 major_update_or_finish_concurrent_collection (gboolean force_finish)
3094 MONO_GC_CONCURRENT_UPDATE_FINISH_BEGIN (GENERATION_OLD);
3096 major_collector.update_cardtable_mod_union ();
3097 sgen_los_update_cardtable_mod_union ();
3099 g_assert (sgen_gray_object_queue_is_empty (&gray_queue));
3100 g_assert (sgen_gray_object_queue_is_empty (&remember_major_objects_gray_queue));
3102 if (!force_finish && !sgen_workers_all_done ()) {
3103 MONO_GC_CONCURRENT_UPDATE_END (GENERATION_OLD);
3105 g_print ("workers not done\n");
3110 gray_queue_redirect (&remember_major_objects_gray_queue);
3112 current_collection_generation = GENERATION_OLD;
3113 major_finish_collection ("finishing", -1, TRUE);
3115 MONO_GC_CONCURRENT_FINISH_END (GENERATION_OLD);
3117 current_collection_generation = -1;
3119 if (whole_heap_check_before_collection)
3120 sgen_check_whole_heap ();
3126 * Ensure an allocation request for @size will succeed by freeing enough memory.
3128 * LOCKING: The GC lock MUST be held.
3131 sgen_ensure_free_space (size_t size)
3133 int generation_to_collect = -1;
3134 const char *reason = NULL;
3137 if (size > SGEN_MAX_SMALL_OBJ_SIZE) {
3138 if (sgen_need_major_collection (size)) {
3139 reason = "LOS overflow";
3140 generation_to_collect = GENERATION_OLD;
3143 if (degraded_mode) {
3144 if (sgen_need_major_collection (size)) {
3145 reason = "Degraded mode overflow";
3146 generation_to_collect = GENERATION_OLD;
3148 } else if (sgen_need_major_collection (size)) {
3149 reason = "Minor allowance";
3150 generation_to_collect = GENERATION_OLD;
3152 generation_to_collect = GENERATION_NURSERY;
3153 reason = "Nursery full";
3157 if (generation_to_collect == -1)
3159 sgen_perform_collection (size, generation_to_collect, reason, generation_to_collect == GENERATION_NURSERY);
3163 sgen_perform_collection (size_t requested_size, int generation_to_collect, const char *reason, gboolean wait_to_finish)
3165 TV_DECLARE (gc_end);
3166 GGTimingInfo infos [2];
3167 int overflow_generation_to_collect = -1;
3168 const char *overflow_reason = NULL;
3170 memset (infos, 0, sizeof (infos));
3171 mono_profiler_gc_event (MONO_GC_EVENT_START, generation_to_collect);
3173 infos [0].generation = generation_to_collect;
3174 infos [0].reason = reason;
3175 infos [0].is_overflow = FALSE;
3176 TV_GETTIME (infos [0].total_time);
3177 infos [1].generation = -1;
3179 sgen_stop_world (generation_to_collect);
3181 if (concurrent_collection_in_progress) {
3182 g_print ("finishing concurrent collection\n");
3183 if (major_update_or_finish_concurrent_collection (generation_to_collect == GENERATION_OLD))
3187 //FIXME extract overflow reason
3188 if (generation_to_collect == GENERATION_NURSERY) {
3189 if (collect_nursery ()) {
3190 overflow_generation_to_collect = GENERATION_OLD;
3191 overflow_reason = "Minor overflow";
3193 if (concurrent_collection_in_progress) {
3194 gray_queue_redirect (&remember_major_objects_gray_queue);
3195 sgen_workers_wake_up_all ();
3198 if (major_collector.is_concurrent) {
3199 g_assert (!concurrent_collection_in_progress);
3203 if (major_collector.is_concurrent && !wait_to_finish) {
3204 major_start_concurrent_collection (reason);
3205 // FIXME: set infos[0] properly
3208 if (major_do_collection (reason)) {
3209 overflow_generation_to_collect = GENERATION_NURSERY;
3210 overflow_reason = "Excessive pinning";
3215 TV_GETTIME (gc_end);
3216 infos [0].total_time = SGEN_TV_ELAPSED (infos [0].total_time, gc_end);
3219 if (!major_collector.is_concurrent && overflow_generation_to_collect != -1) {
3220 mono_profiler_gc_event (MONO_GC_EVENT_START, overflow_generation_to_collect);
3221 infos [1].generation = overflow_generation_to_collect;
3222 infos [1].reason = overflow_reason;
3223 infos [1].is_overflow = TRUE;
3224 infos [1].total_time = gc_end;
3226 if (overflow_generation_to_collect == GENERATION_NURSERY)
3229 major_do_collection (overflow_reason);
3231 TV_GETTIME (gc_end);
3232 infos [1].total_time = SGEN_TV_ELAPSED (infos [1].total_time, gc_end);
3234 /* keep events symmetric */
3235 mono_profiler_gc_event (MONO_GC_EVENT_END, overflow_generation_to_collect);
3238 SGEN_LOG (2, "Heap size: %lu, LOS size: %lu", (unsigned long)mono_gc_get_heap_size (), (unsigned long)los_memory_usage);
3240 /* this also sets the proper pointers for the next allocation */
3241 if (generation_to_collect == GENERATION_NURSERY && !sgen_can_alloc_size (requested_size)) {
3242 /* TypeBuilder and MonoMethod are killing mcs with fragmentation */
3243 SGEN_LOG (1, "nursery collection didn't find enough room for %zd alloc (%d pinned)", requested_size, sgen_get_pinned_count ());
3244 sgen_dump_pin_queue ();
3249 g_assert (sgen_gray_object_queue_is_empty (&gray_queue));
3250 g_assert (sgen_gray_object_queue_is_empty (&remember_major_objects_gray_queue));
3252 sgen_restart_world (generation_to_collect, infos);
3254 mono_profiler_gc_event (MONO_GC_EVENT_END, generation_to_collect);
3258 * ######################################################################
3259 * ######## Memory allocation from the OS
3260 * ######################################################################
3261 * This section of code deals with getting memory from the OS and
3262 * allocating memory for GC-internal data structures.
3263 * Internal memory can be handled with a freelist for small objects.
3269 G_GNUC_UNUSED static void
3270 report_internal_mem_usage (void)
3272 printf ("Internal memory usage:\n");
3273 sgen_report_internal_mem_usage ();
3274 printf ("Pinned memory usage:\n");
3275 major_collector.report_pinned_memory_usage ();
3279 * ######################################################################
3280 * ######## Finalization support
3281 * ######################################################################
3285 * If the object has been forwarded it means it's still referenced from a root.
3286 * If it is pinned it's still alive as well.
3287 * A LOS object is only alive if we have pinned it.
3288 * Return TRUE if @obj is ready to be finalized.
3290 static inline gboolean
3291 sgen_is_object_alive (void *object)
3295 if (ptr_in_nursery (object))
3296 return sgen_nursery_is_object_alive (object);
3297 /* Oldgen objects can be pinned and forwarded too */
3298 if (SGEN_OBJECT_IS_PINNED (object) || SGEN_OBJECT_IS_FORWARDED (object))
3302 * FIXME: major_collector.is_object_live() also calculates the
3303 * size. Avoid the double calculation.
3305 objsize = SGEN_ALIGN_UP (sgen_safe_object_get_size ((MonoObject*)object));
3306 if (objsize > SGEN_MAX_SMALL_OBJ_SIZE)
3307 return sgen_los_object_is_pinned (object);
3309 return major_collector.is_object_live (object);
3313 sgen_gc_is_object_ready_for_finalization (void *object)
3315 return !sgen_is_object_alive (object);
3319 has_critical_finalizer (MonoObject *obj)
3323 if (!mono_defaults.critical_finalizer_object)
3326 class = ((MonoVTable*)LOAD_VTABLE (obj))->klass;
3328 return mono_class_has_parent_fast (class, mono_defaults.critical_finalizer_object);
3332 sgen_queue_finalization_entry (MonoObject *obj)
3334 FinalizeReadyEntry *entry = sgen_alloc_internal (INTERNAL_MEM_FINALIZE_READY_ENTRY);
3335 entry->object = obj;
3336 if (has_critical_finalizer (obj)) {
3337 entry->next = critical_fin_list;
3338 critical_fin_list = entry;
3340 entry->next = fin_ready_list;
3341 fin_ready_list = entry;
3346 object_is_reachable (char *object, char *start, char *end)
3348 /*This happens for non nursery objects during minor collections. We just treat all objects as alive.*/
3349 if (object < start || object >= end)
3352 return sgen_is_object_alive (object);
3356 sgen_object_is_live (void *obj)
3358 if (ptr_in_nursery (obj))
3359 return object_is_pinned (obj);
3360 /* FIXME This is semantically wrong! All tenured object are considered alive during a nursery collection. */
3361 if (current_collection_generation == GENERATION_NURSERY)
3363 return major_collector.is_object_live (obj);
3366 /* LOCKING: requires that the GC lock is held */
3368 null_ephemerons_for_domain (MonoDomain *domain)
3370 EphemeronLinkNode *current = ephemeron_list, *prev = NULL;
3373 MonoObject *object = (MonoObject*)current->array;
3375 if (object && !object->vtable) {
3376 EphemeronLinkNode *tmp = current;
3379 prev->next = current->next;
3381 ephemeron_list = current->next;
3383 current = current->next;
3384 sgen_free_internal (tmp, INTERNAL_MEM_EPHEMERON_LINK);
3387 current = current->next;
3392 /* LOCKING: requires that the GC lock is held */
3394 clear_unreachable_ephemerons (CopyOrMarkObjectFunc copy_func, char *start, char *end, GrayQueue *queue)
3396 int was_in_nursery, was_promoted;
3397 EphemeronLinkNode *current = ephemeron_list, *prev = NULL;
3399 Ephemeron *cur, *array_end;
3403 char *object = current->array;
3405 if (!object_is_reachable (object, start, end)) {
3406 EphemeronLinkNode *tmp = current;
3408 SGEN_LOG (5, "Dead Ephemeron array at %p", object);
3411 prev->next = current->next;
3413 ephemeron_list = current->next;
3415 current = current->next;
3416 sgen_free_internal (tmp, INTERNAL_MEM_EPHEMERON_LINK);
3421 was_in_nursery = ptr_in_nursery (object);
3422 copy_func ((void**)&object, queue);
3423 current->array = object;
3425 /*The array was promoted, add global remsets for key/values left behind in nursery.*/
3426 was_promoted = was_in_nursery && !ptr_in_nursery (object);
3428 SGEN_LOG (5, "Clearing unreachable entries for ephemeron array at %p", object);
3430 array = (MonoArray*)object;
3431 cur = mono_array_addr (array, Ephemeron, 0);
3432 array_end = cur + mono_array_length_fast (array);
3433 tombstone = (char*)((MonoVTable*)LOAD_VTABLE (object))->domain->ephemeron_tombstone;
3435 for (; cur < array_end; ++cur) {
3436 char *key = (char*)cur->key;
3438 if (!key || key == tombstone)
3441 SGEN_LOG (5, "[%td] key %p (%s) value %p (%s)", cur - mono_array_addr (array, Ephemeron, 0),
3442 key, object_is_reachable (key, start, end) ? "reachable" : "unreachable",
3443 cur->value, cur->value && object_is_reachable (cur->value, start, end) ? "reachable" : "unreachable");
3445 if (!object_is_reachable (key, start, end)) {
3446 cur->key = tombstone;
3452 if (ptr_in_nursery (key)) {/*key was not promoted*/
3453 SGEN_LOG (5, "\tAdded remset to key %p", key);
3454 sgen_add_to_global_remset (&cur->key);
3456 if (ptr_in_nursery (cur->value)) {/*value was not promoted*/
3457 SGEN_LOG (5, "\tAdded remset to value %p", cur->value);
3458 sgen_add_to_global_remset (&cur->value);
3463 current = current->next;
3467 /* LOCKING: requires that the GC lock is held */
3469 mark_ephemerons_in_range (CopyOrMarkObjectFunc copy_func, char *start, char *end, GrayQueue *queue)
3471 int nothing_marked = 1;
3472 EphemeronLinkNode *current = ephemeron_list;
3474 Ephemeron *cur, *array_end;
3477 for (current = ephemeron_list; current; current = current->next) {
3478 char *object = current->array;
3479 SGEN_LOG (5, "Ephemeron array at %p", object);
3482 For now we process all ephemerons during all collections.
3483 Ideally we should use remset information to partially scan those
3485 We already emit write barriers for Ephemeron fields, it's
3486 just that we don't process them.
3488 /*if (object < start || object >= end)
3491 /*It has to be alive*/
3492 if (!object_is_reachable (object, start, end)) {
3493 SGEN_LOG (5, "\tnot reachable");
3497 copy_func ((void**)&object, queue);
3499 array = (MonoArray*)object;
3500 cur = mono_array_addr (array, Ephemeron, 0);
3501 array_end = cur + mono_array_length_fast (array);
3502 tombstone = (char*)((MonoVTable*)LOAD_VTABLE (object))->domain->ephemeron_tombstone;
3504 for (; cur < array_end; ++cur) {
3505 char *key = cur->key;
3507 if (!key || key == tombstone)
3510 SGEN_LOG (5, "[%td] key %p (%s) value %p (%s)", cur - mono_array_addr (array, Ephemeron, 0),
3511 key, object_is_reachable (key, start, end) ? "reachable" : "unreachable",
3512 cur->value, cur->value && object_is_reachable (cur->value, start, end) ? "reachable" : "unreachable");
3514 if (object_is_reachable (key, start, end)) {
3515 char *value = cur->value;
3517 copy_func ((void**)&cur->key, queue);
3519 if (!object_is_reachable (value, start, end))
3521 copy_func ((void**)&cur->value, queue);
3527 SGEN_LOG (5, "Ephemeron run finished. Is it done %d", nothing_marked);
3528 return nothing_marked;
3532 mono_gc_invoke_finalizers (void)
3534 FinalizeReadyEntry *entry = NULL;
3535 gboolean entry_is_critical = FALSE;
3538 /* FIXME: batch to reduce lock contention */
3539 while (fin_ready_list || critical_fin_list) {
3543 FinalizeReadyEntry **list = entry_is_critical ? &critical_fin_list : &fin_ready_list;
3545 /* We have finalized entry in the last
3546 interation, now we need to remove it from
3549 *list = entry->next;
3551 FinalizeReadyEntry *e = *list;
3552 while (e->next != entry)
3554 e->next = entry->next;
3556 sgen_free_internal (entry, INTERNAL_MEM_FINALIZE_READY_ENTRY);
3560 /* Now look for the first non-null entry. */
3561 for (entry = fin_ready_list; entry && !entry->object; entry = entry->next)
3564 entry_is_critical = FALSE;
3566 entry_is_critical = TRUE;
3567 for (entry = critical_fin_list; entry && !entry->object; entry = entry->next)
3572 g_assert (entry->object);
3573 num_ready_finalizers--;
3574 obj = entry->object;
3575 entry->object = NULL;
3576 SGEN_LOG (7, "Finalizing object %p (%s)", obj, safe_name (obj));
3584 g_assert (entry->object == NULL);
3586 /* the object is on the stack so it is pinned */
3587 /*g_print ("Calling finalizer for object: %p (%s)\n", entry->object, safe_name (entry->object));*/
3588 mono_gc_run_finalize (obj, NULL);
3595 mono_gc_pending_finalizers (void)
3597 return fin_ready_list || critical_fin_list;
3601 * ######################################################################
3602 * ######## registered roots support
3603 * ######################################################################
3607 * We do not coalesce roots.
3610 mono_gc_register_root_inner (char *start, size_t size, void *descr, int root_type)
3612 RootRecord new_root;
3615 for (i = 0; i < ROOT_TYPE_NUM; ++i) {
3616 RootRecord *root = sgen_hash_table_lookup (&roots_hash [i], start);
3617 /* we allow changing the size and the descriptor (for thread statics etc) */
3619 size_t old_size = root->end_root - start;
3620 root->end_root = start + size;
3621 g_assert (((root->root_desc != 0) && (descr != NULL)) ||
3622 ((root->root_desc == 0) && (descr == NULL)));
3623 root->root_desc = (mword)descr;
3625 roots_size -= old_size;
3631 new_root.end_root = start + size;
3632 new_root.root_desc = (mword)descr;
3634 sgen_hash_table_replace (&roots_hash [root_type], start, &new_root, NULL);
3637 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);
3644 mono_gc_register_root (char *start, size_t size, void *descr)
3646 return mono_gc_register_root_inner (start, size, descr, descr ? ROOT_TYPE_NORMAL : ROOT_TYPE_PINNED);
3650 mono_gc_register_root_wbarrier (char *start, size_t size, void *descr)
3652 return mono_gc_register_root_inner (start, size, descr, ROOT_TYPE_WBARRIER);
3656 mono_gc_deregister_root (char* addr)
3662 for (root_type = 0; root_type < ROOT_TYPE_NUM; ++root_type) {
3663 if (sgen_hash_table_remove (&roots_hash [root_type], addr, &root))
3664 roots_size -= (root.end_root - addr);
3670 * ######################################################################
3671 * ######## Thread handling (stop/start code)
3672 * ######################################################################
3675 unsigned int sgen_global_stop_count = 0;
3678 sgen_fill_thread_info_for_suspend (SgenThreadInfo *info)
3680 if (remset.fill_thread_info_for_suspend)
3681 remset.fill_thread_info_for_suspend (info);
3685 sgen_get_current_collection_generation (void)
3687 return current_collection_generation;
3691 mono_gc_set_gc_callbacks (MonoGCCallbacks *callbacks)
3693 gc_callbacks = *callbacks;
3697 mono_gc_get_gc_callbacks ()
3699 return &gc_callbacks;
3702 /* Variables holding start/end nursery so it won't have to be passed at every call */
3703 static void *scan_area_arg_start, *scan_area_arg_end;
3706 mono_gc_conservatively_scan_area (void *start, void *end)
3708 conservatively_pin_objects_from (start, end, scan_area_arg_start, scan_area_arg_end, PIN_TYPE_STACK);
3712 mono_gc_scan_object (void *obj)
3714 UserCopyOrMarkData *data = mono_native_tls_get_value (user_copy_or_mark_key);
3715 current_object_ops.copy_or_mark_object (&obj, data->queue);
3720 * Mark from thread stacks and registers.
3723 scan_thread_data (void *start_nursery, void *end_nursery, gboolean precise, GrayQueue *queue)
3725 SgenThreadInfo *info;
3727 scan_area_arg_start = start_nursery;
3728 scan_area_arg_end = end_nursery;
3730 FOREACH_THREAD (info) {
3732 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);
3735 if (info->gc_disabled) {
3736 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);
3740 if (!info->joined_stw) {
3741 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);
3745 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 ());
3746 if (!info->thread_is_dying) {
3747 if (gc_callbacks.thread_mark_func && !conservative_stack_mark) {
3748 UserCopyOrMarkData data = { NULL, queue };
3749 set_user_copy_or_mark_data (&data);
3750 gc_callbacks.thread_mark_func (info->runtime_data, info->stack_start, info->stack_end, precise);
3751 set_user_copy_or_mark_data (NULL);
3752 } else if (!precise) {
3753 conservatively_pin_objects_from (info->stack_start, info->stack_end, start_nursery, end_nursery, PIN_TYPE_STACK);
3757 if (!info->thread_is_dying && !precise) {
3759 conservatively_pin_objects_from ((void**)&info->ctx, (void**)&info->ctx + ARCH_NUM_REGS,
3760 start_nursery, end_nursery, PIN_TYPE_STACK);
3762 conservatively_pin_objects_from (&info->regs, &info->regs + ARCH_NUM_REGS,
3763 start_nursery, end_nursery, PIN_TYPE_STACK);
3766 } END_FOREACH_THREAD
3770 ptr_on_stack (void *ptr)
3772 gpointer stack_start = &stack_start;
3773 SgenThreadInfo *info = mono_thread_info_current ();
3775 if (ptr >= stack_start && ptr < (gpointer)info->stack_end)
3781 sgen_thread_register (SgenThreadInfo* info, void *addr)
3783 #ifndef HAVE_KW_THREAD
3784 SgenThreadInfo *__thread_info__ = info;
3788 #ifndef HAVE_KW_THREAD
3789 info->tlab_start = info->tlab_next = info->tlab_temp_end = info->tlab_real_end = NULL;
3791 g_assert (!mono_native_tls_get_value (thread_info_key));
3792 mono_native_tls_set_value (thread_info_key, info);
3794 sgen_thread_info = info;
3797 #if !defined(__MACH__)
3798 info->stop_count = -1;
3802 info->joined_stw = FALSE;
3803 info->doing_handshake = FALSE;
3804 info->thread_is_dying = FALSE;
3805 info->stack_start = NULL;
3806 info->store_remset_buffer_addr = &STORE_REMSET_BUFFER;
3807 info->store_remset_buffer_index_addr = &STORE_REMSET_BUFFER_INDEX;
3808 info->stopped_ip = NULL;
3809 info->stopped_domain = NULL;
3811 memset (&info->ctx, 0, sizeof (MonoContext));
3813 memset (&info->regs, 0, sizeof (info->regs));
3816 sgen_init_tlab_info (info);
3818 binary_protocol_thread_register ((gpointer)mono_thread_info_get_tid (info));
3820 #ifdef HAVE_KW_THREAD
3821 store_remset_buffer_index_addr = &store_remset_buffer_index;
3824 /* try to get it with attributes first */
3825 #if defined(HAVE_PTHREAD_GETATTR_NP) && defined(HAVE_PTHREAD_ATTR_GETSTACK)
3829 pthread_attr_t attr;
3830 pthread_getattr_np (pthread_self (), &attr);
3831 pthread_attr_getstack (&attr, &sstart, &size);
3832 info->stack_start_limit = sstart;
3833 info->stack_end = (char*)sstart + size;
3834 pthread_attr_destroy (&attr);
3836 #elif defined(HAVE_PTHREAD_GET_STACKSIZE_NP) && defined(HAVE_PTHREAD_GET_STACKADDR_NP)
3837 info->stack_end = (char*)pthread_get_stackaddr_np (pthread_self ());
3838 info->stack_start_limit = (char*)info->stack_end - pthread_get_stacksize_np (pthread_self ());
3841 /* FIXME: we assume the stack grows down */
3842 gsize stack_bottom = (gsize)addr;
3843 stack_bottom += 4095;
3844 stack_bottom &= ~4095;
3845 info->stack_end = (char*)stack_bottom;
3849 #ifdef HAVE_KW_THREAD
3850 stack_end = info->stack_end;
3853 if (remset.register_thread)
3854 remset.register_thread (info);
3856 SGEN_LOG (3, "registered thread %p (%p) stack end %p", info, (gpointer)mono_thread_info_get_tid (info), info->stack_end);
3858 if (gc_callbacks.thread_attach_func)
3859 info->runtime_data = gc_callbacks.thread_attach_func ();
3866 sgen_wbarrier_cleanup_thread (SgenThreadInfo *p)
3868 if (remset.cleanup_thread)
3869 remset.cleanup_thread (p);
3873 sgen_thread_unregister (SgenThreadInfo *p)
3875 /* If a delegate is passed to native code and invoked on a thread we dont
3876 * know about, the jit will register it with mono_jit_thread_attach, but
3877 * we have no way of knowing when that thread goes away. SGen has a TSD
3878 * so we assume that if the domain is still registered, we can detach
3881 if (mono_domain_get ())
3882 mono_thread_detach (mono_thread_current ());
3884 p->thread_is_dying = TRUE;
3887 There is a race condition between a thread finishing executing and been removed
3888 from the GC thread set.
3889 This happens on posix systems when TLS data is been cleaned-up, libpthread will
3890 set the thread_info slot to NULL before calling the cleanup function. This
3891 opens a window in which the thread is registered but has a NULL TLS.
3893 The suspend signal handler needs TLS data to know where to store thread state
3894 data or otherwise it will simply ignore the thread.
3896 This solution works because the thread doing STW will wait until all threads been
3897 suspended handshake back, so there is no race between the doing_hankshake test
3898 and the suspend_thread call.
3900 This is not required on systems that do synchronous STW as those can deal with
3901 the above race at suspend time.
3903 FIXME: I believe we could avoid this by using mono_thread_info_lookup when
3904 mono_thread_info_current returns NULL. Or fix mono_thread_info_lookup to do so.
3906 #if (defined(__MACH__) && MONO_MACH_ARCH_SUPPORTED) || !defined(HAVE_PTHREAD_KILL)
3909 while (!TRYLOCK_GC) {
3910 if (!sgen_park_current_thread_if_doing_handshake (p))
3916 binary_protocol_thread_unregister ((gpointer)mono_thread_info_get_tid (p));
3917 SGEN_LOG (3, "unregister thread %p (%p)", p, (gpointer)mono_thread_info_get_tid (p));
3919 if (gc_callbacks.thread_detach_func) {
3920 gc_callbacks.thread_detach_func (p->runtime_data);
3921 p->runtime_data = NULL;
3923 sgen_wbarrier_cleanup_thread (p);
3925 mono_threads_unregister_current_thread (p);
3931 sgen_thread_attach (SgenThreadInfo *info)
3934 /*this is odd, can we get attached before the gc is inited?*/
3938 if (gc_callbacks.thread_attach_func && !info->runtime_data)
3939 info->runtime_data = gc_callbacks.thread_attach_func ();
3942 mono_gc_register_thread (void *baseptr)
3944 return mono_thread_info_attach (baseptr) != NULL;
3948 * mono_gc_set_stack_end:
3950 * Set the end of the current threads stack to STACK_END. The stack space between
3951 * STACK_END and the real end of the threads stack will not be scanned during collections.
3954 mono_gc_set_stack_end (void *stack_end)
3956 SgenThreadInfo *info;
3959 info = mono_thread_info_current ();
3961 g_assert (stack_end < info->stack_end);
3962 info->stack_end = stack_end;
3967 #if USE_PTHREAD_INTERCEPT
3971 mono_gc_pthread_create (pthread_t *new_thread, const pthread_attr_t *attr, void *(*start_routine)(void *), void *arg)
3973 return pthread_create (new_thread, attr, start_routine, arg);
3977 mono_gc_pthread_join (pthread_t thread, void **retval)
3979 return pthread_join (thread, retval);
3983 mono_gc_pthread_detach (pthread_t thread)
3985 return pthread_detach (thread);
3989 mono_gc_pthread_exit (void *retval)
3991 pthread_exit (retval);
3994 #endif /* USE_PTHREAD_INTERCEPT */
3997 * ######################################################################
3998 * ######## Write barriers
3999 * ######################################################################
4003 * Note: the write barriers first do the needed GC work and then do the actual store:
4004 * this way the value is visible to the conservative GC scan after the write barrier
4005 * itself. If a GC interrupts the barrier in the middle, value will be kept alive by
4006 * the conservative scan, otherwise by the remembered set scan.
4009 mono_gc_wbarrier_set_field (MonoObject *obj, gpointer field_ptr, MonoObject* value)
4011 HEAVY_STAT (++stat_wbarrier_set_field);
4012 if (ptr_in_nursery (field_ptr)) {
4013 *(void**)field_ptr = value;
4016 SGEN_LOG (8, "Adding remset at %p", field_ptr);
4018 binary_protocol_wbarrier (field_ptr, value, value->vtable);
4020 remset.wbarrier_set_field (obj, field_ptr, value);
4024 mono_gc_wbarrier_set_arrayref (MonoArray *arr, gpointer slot_ptr, MonoObject* value)
4026 HEAVY_STAT (++stat_wbarrier_set_arrayref);
4027 if (ptr_in_nursery (slot_ptr)) {
4028 *(void**)slot_ptr = value;
4031 SGEN_LOG (8, "Adding remset at %p", slot_ptr);
4033 binary_protocol_wbarrier (slot_ptr, value, value->vtable);
4035 remset.wbarrier_set_arrayref (arr, slot_ptr, value);
4039 mono_gc_wbarrier_arrayref_copy (gpointer dest_ptr, gpointer src_ptr, int count)
4041 HEAVY_STAT (++stat_wbarrier_arrayref_copy);
4042 /*This check can be done without taking a lock since dest_ptr array is pinned*/
4043 if (ptr_in_nursery (dest_ptr) || count <= 0) {
4044 mono_gc_memmove (dest_ptr, src_ptr, count * sizeof (gpointer));
4048 #ifdef SGEN_BINARY_PROTOCOL
4051 for (i = 0; i < count; ++i) {
4052 gpointer dest = (gpointer*)dest_ptr + i;
4053 gpointer obj = *((gpointer*)src_ptr + i);
4055 binary_protocol_wbarrier (dest, obj, (gpointer)LOAD_VTABLE (obj));
4060 remset.wbarrier_arrayref_copy (dest_ptr, src_ptr, count);
4063 static char *found_obj;
4066 find_object_for_ptr_callback (char *obj, size_t size, void *user_data)
4068 char *ptr = user_data;
4070 if (ptr >= obj && ptr < obj + size) {
4071 g_assert (!found_obj);
4076 /* for use in the debugger */
4077 char* find_object_for_ptr (char *ptr);
4079 find_object_for_ptr (char *ptr)
4081 if (ptr >= nursery_section->data && ptr < nursery_section->end_data) {
4083 sgen_scan_area_with_callback (nursery_section->data, nursery_section->end_data,
4084 find_object_for_ptr_callback, ptr, TRUE);
4090 sgen_los_iterate_objects (find_object_for_ptr_callback, ptr);
4095 * Very inefficient, but this is debugging code, supposed to
4096 * be called from gdb, so we don't care.
4099 major_collector.iterate_objects (TRUE, TRUE, find_object_for_ptr_callback, ptr);
4104 mono_gc_wbarrier_generic_nostore (gpointer ptr)
4108 HEAVY_STAT (++stat_wbarrier_generic_store);
4110 #ifdef XDOMAIN_CHECKS_IN_WBARRIER
4111 /* FIXME: ptr_in_heap must be called with the GC lock held */
4112 if (xdomain_checks && *(MonoObject**)ptr && ptr_in_heap (ptr)) {
4113 char *start = find_object_for_ptr (ptr);
4114 MonoObject *value = *(MonoObject**)ptr;
4118 MonoObject *obj = (MonoObject*)start;
4119 if (obj->vtable->domain != value->vtable->domain)
4120 g_assert (is_xdomain_ref_allowed (ptr, start, obj->vtable->domain));
4126 obj = *(gpointer*)ptr;
4128 binary_protocol_wbarrier (ptr, obj, (gpointer)LOAD_VTABLE (obj));
4130 if (ptr_in_nursery (ptr) || ptr_on_stack (ptr)) {
4131 SGEN_LOG (8, "Skipping remset at %p", ptr);
4136 * We need to record old->old pointer locations for the
4137 * concurrent collector.
4139 if (!ptr_in_nursery (obj) && !concurrent_collection_in_progress) {
4140 SGEN_LOG (8, "Skipping remset at %p", ptr);
4144 SGEN_LOG (8, "Adding remset at %p", ptr);
4146 remset.wbarrier_generic_nostore (ptr);
4150 mono_gc_wbarrier_generic_store (gpointer ptr, MonoObject* value)
4152 SGEN_LOG (8, "Wbarrier store at %p to %p (%s)", ptr, value, value ? safe_name (value) : "null");
4153 *(void**)ptr = value;
4154 if (ptr_in_nursery (value))
4155 mono_gc_wbarrier_generic_nostore (ptr);
4156 sgen_dummy_use (value);
4159 void mono_gc_wbarrier_value_copy_bitmap (gpointer _dest, gpointer _src, int size, unsigned bitmap)
4161 mword *dest = _dest;
4166 mono_gc_wbarrier_generic_store (dest, (MonoObject*)*src);
4171 size -= SIZEOF_VOID_P;
4176 #ifdef SGEN_BINARY_PROTOCOL
4178 #define HANDLE_PTR(ptr,obj) do { \
4179 gpointer o = *(gpointer*)(ptr); \
4181 gpointer d = ((char*)dest) + ((char*)(ptr) - (char*)(obj)); \
4182 binary_protocol_wbarrier (d, o, (gpointer) LOAD_VTABLE (o)); \
4187 scan_object_for_binary_protocol_copy_wbarrier (gpointer dest, char *start, mword desc)
4189 #define SCAN_OBJECT_NOVTABLE
4190 #include "sgen-scan-object.h"
4195 mono_gc_wbarrier_value_copy (gpointer dest, gpointer src, int count, MonoClass *klass)
4197 HEAVY_STAT (++stat_wbarrier_value_copy);
4198 g_assert (klass->valuetype);
4200 SGEN_LOG (8, "Adding value remset at %p, count %d, descr %p for class %s (%p)", dest, count, klass->gc_descr, klass->name, klass);
4202 if (ptr_in_nursery (dest) || ptr_on_stack (dest) || !SGEN_CLASS_HAS_REFERENCES (klass)) {
4203 size_t element_size = mono_class_value_size (klass, NULL);
4204 size_t size = count * element_size;
4205 mono_gc_memmove (dest, src, size);
4209 #ifdef SGEN_BINARY_PROTOCOL
4211 size_t element_size = mono_class_value_size (klass, NULL);
4213 for (i = 0; i < count; ++i) {
4214 scan_object_for_binary_protocol_copy_wbarrier ((char*)dest + i * element_size,
4215 (char*)src + i * element_size - sizeof (MonoObject),
4216 (mword) klass->gc_descr);
4221 remset.wbarrier_value_copy (dest, src, count, klass);
4225 * mono_gc_wbarrier_object_copy:
4227 * Write barrier to call when obj is the result of a clone or copy of an object.
4230 mono_gc_wbarrier_object_copy (MonoObject* obj, MonoObject *src)
4234 HEAVY_STAT (++stat_wbarrier_object_copy);
4236 if (ptr_in_nursery (obj) || ptr_on_stack (obj)) {
4237 size = mono_object_class (obj)->instance_size;
4238 mono_gc_memmove ((char*)obj + sizeof (MonoObject), (char*)src + sizeof (MonoObject),
4239 size - sizeof (MonoObject));
4243 #ifdef SGEN_BINARY_PROTOCOL
4244 scan_object_for_binary_protocol_copy_wbarrier (obj, (char*)src, (mword) src->vtable->gc_descr);
4247 remset.wbarrier_object_copy (obj, src);
4252 * ######################################################################
4253 * ######## Other mono public interface functions.
4254 * ######################################################################
4257 #define REFS_SIZE 128
4260 MonoGCReferences callback;
4264 MonoObject *refs [REFS_SIZE];
4265 uintptr_t offsets [REFS_SIZE];
4269 #define HANDLE_PTR(ptr,obj) do { \
4271 if (hwi->count == REFS_SIZE) { \
4272 hwi->callback ((MonoObject*)start, mono_object_class (start), hwi->called? 0: size, hwi->count, hwi->refs, hwi->offsets, hwi->data); \
4276 hwi->offsets [hwi->count] = (char*)(ptr)-(char*)start; \
4277 hwi->refs [hwi->count++] = *(ptr); \
4282 collect_references (HeapWalkInfo *hwi, char *start, size_t size)
4284 #include "sgen-scan-object.h"
4288 walk_references (char *start, size_t size, void *data)
4290 HeapWalkInfo *hwi = data;
4293 collect_references (hwi, start, size);
4294 if (hwi->count || !hwi->called)
4295 hwi->callback ((MonoObject*)start, mono_object_class (start), hwi->called? 0: size, hwi->count, hwi->refs, hwi->offsets, hwi->data);
4299 * mono_gc_walk_heap:
4300 * @flags: flags for future use
4301 * @callback: a function pointer called for each object in the heap
4302 * @data: a user data pointer that is passed to callback
4304 * This function can be used to iterate over all the live objects in the heap:
4305 * for each object, @callback is invoked, providing info about the object's
4306 * location in memory, its class, its size and the objects it references.
4307 * For each referenced object it's offset from the object address is
4308 * reported in the offsets array.
4309 * The object references may be buffered, so the callback may be invoked
4310 * multiple times for the same object: in all but the first call, the size
4311 * argument will be zero.
4312 * Note that this function can be only called in the #MONO_GC_EVENT_PRE_START_WORLD
4313 * profiler event handler.
4315 * Returns: a non-zero value if the GC doesn't support heap walking
4318 mono_gc_walk_heap (int flags, MonoGCReferences callback, void *data)
4323 hwi.callback = callback;
4326 sgen_clear_nursery_fragments ();
4327 sgen_scan_area_with_callback (nursery_section->data, nursery_section->end_data, walk_references, &hwi, FALSE);
4329 major_collector.iterate_objects (TRUE, TRUE, walk_references, &hwi);
4330 sgen_los_iterate_objects (walk_references, &hwi);
4336 mono_gc_collect (int generation)
4341 sgen_perform_collection (0, generation, "user request", TRUE);
4346 mono_gc_max_generation (void)
4352 mono_gc_collection_count (int generation)
4354 if (generation == 0)
4355 return stat_minor_gcs;
4356 return stat_major_gcs;
4360 mono_gc_get_used_size (void)
4364 tot = los_memory_usage;
4365 tot += nursery_section->next_data - nursery_section->data;
4366 tot += major_collector.get_used_size ();
4367 /* FIXME: account for pinned objects */
4373 mono_gc_disable (void)
4381 mono_gc_enable (void)
4389 mono_gc_get_los_limit (void)
4391 return MAX_SMALL_OBJ_SIZE;
4395 mono_gc_user_markers_supported (void)
4401 mono_object_is_alive (MonoObject* o)
4407 mono_gc_get_generation (MonoObject *obj)
4409 if (ptr_in_nursery (obj))
4415 mono_gc_enable_events (void)
4420 mono_gc_weak_link_add (void **link_addr, MonoObject *obj, gboolean track)
4422 sgen_register_disappearing_link (obj, link_addr, track, FALSE);
4426 mono_gc_weak_link_remove (void **link_addr)
4428 sgen_register_disappearing_link (NULL, link_addr, FALSE, FALSE);
4432 mono_gc_weak_link_get (void **link_addr)
4435 * We must only load *link_addr once because it might change
4436 * under our feet, and REVEAL_POINTER (NULL) results in an
4437 * invalid reference.
4439 void *ptr = *link_addr;
4444 * During the second bridge processing step the world is
4445 * running again. That step processes all weak links once
4446 * more to null those that refer to dead objects. Before that
4447 * is completed, those links must not be followed, so we
4448 * conservatively wait for bridge processing when any weak
4449 * link is dereferenced.
4451 if (G_UNLIKELY (bridge_processing_in_progress))
4452 mono_gc_wait_for_bridge_processing ();
4454 return (MonoObject*) REVEAL_POINTER (ptr);
4458 mono_gc_ephemeron_array_add (MonoObject *obj)
4460 EphemeronLinkNode *node;
4464 node = sgen_alloc_internal (INTERNAL_MEM_EPHEMERON_LINK);
4469 node->array = (char*)obj;
4470 node->next = ephemeron_list;
4471 ephemeron_list = node;
4473 SGEN_LOG (5, "Registered ephemeron array %p", obj);
4480 mono_gc_invoke_with_gc_lock (MonoGCLockedCallbackFunc func, void *data)
4484 result = func (data);
4485 UNLOCK_INTERRUPTION;
4490 mono_gc_is_gc_thread (void)
4494 result = mono_thread_info_current () != NULL;
4500 is_critical_method (MonoMethod *method)
4502 return mono_runtime_is_critical_method (method) || sgen_is_critical_method (method);
4506 mono_gc_base_init (void)
4508 MonoThreadInfoCallbacks cb;
4511 char *major_collector_opt = NULL;
4512 char *minor_collector_opt = NULL;
4514 glong soft_limit = 0;
4518 gboolean debug_print_allowance = FALSE;
4519 double allowance_ratio = 0, save_target = 0;
4522 result = InterlockedCompareExchange (&gc_initialized, -1, 0);
4525 /* already inited */
4528 /* being inited by another thread */
4532 /* we will init it */
4535 g_assert_not_reached ();
4537 } while (result != 0);
4539 LOCK_INIT (gc_mutex);
4541 pagesize = mono_pagesize ();
4542 gc_debug_file = stderr;
4544 cb.thread_register = sgen_thread_register;
4545 cb.thread_unregister = sgen_thread_unregister;
4546 cb.thread_attach = sgen_thread_attach;
4547 cb.mono_method_is_critical = (gpointer)is_critical_method;
4549 cb.mono_gc_pthread_create = (gpointer)mono_gc_pthread_create;
4552 mono_threads_init (&cb, sizeof (SgenThreadInfo));
4554 LOCK_INIT (sgen_interruption_mutex);
4555 LOCK_INIT (pin_queue_mutex);
4557 init_user_copy_or_mark_key ();
4559 if ((env = getenv ("MONO_GC_PARAMS"))) {
4560 opts = g_strsplit (env, ",", -1);
4561 for (ptr = opts; *ptr; ++ptr) {
4563 if (g_str_has_prefix (opt, "major=")) {
4564 opt = strchr (opt, '=') + 1;
4565 major_collector_opt = g_strdup (opt);
4566 } else if (g_str_has_prefix (opt, "minor=")) {
4567 opt = strchr (opt, '=') + 1;
4568 minor_collector_opt = g_strdup (opt);
4576 sgen_init_internal_allocator ();
4577 sgen_init_nursery_allocator ();
4579 sgen_register_fixed_internal_mem_type (INTERNAL_MEM_SECTION, SGEN_SIZEOF_GC_MEM_SECTION);
4580 sgen_register_fixed_internal_mem_type (INTERNAL_MEM_FINALIZE_READY_ENTRY, sizeof (FinalizeReadyEntry));
4581 sgen_register_fixed_internal_mem_type (INTERNAL_MEM_GRAY_QUEUE, sizeof (GrayQueueSection));
4582 g_assert (sizeof (GenericStoreRememberedSet) == sizeof (gpointer) * STORE_REMSET_BUFFER_SIZE);
4583 sgen_register_fixed_internal_mem_type (INTERNAL_MEM_STORE_REMSET, sizeof (GenericStoreRememberedSet));
4584 sgen_register_fixed_internal_mem_type (INTERNAL_MEM_EPHEMERON_LINK, sizeof (EphemeronLinkNode));
4586 #ifndef HAVE_KW_THREAD
4587 mono_native_tls_alloc (&thread_info_key, NULL);
4591 * This needs to happen before any internal allocations because
4592 * it inits the small id which is required for hazard pointer
4597 mono_thread_info_attach (&dummy);
4599 if (!minor_collector_opt) {
4600 sgen_simple_nursery_init (&sgen_minor_collector);
4602 if (!strcmp (minor_collector_opt, "simple"))
4603 sgen_simple_nursery_init (&sgen_minor_collector);
4604 else if (!strcmp (minor_collector_opt, "split"))
4605 sgen_split_nursery_init (&sgen_minor_collector);
4607 fprintf (stderr, "Unknown minor collector `%s'.\n", minor_collector_opt);
4612 if (!major_collector_opt || !strcmp (major_collector_opt, "marksweep")) {
4613 sgen_marksweep_init (&major_collector);
4614 } else if (!major_collector_opt || !strcmp (major_collector_opt, "marksweep-fixed")) {
4615 sgen_marksweep_fixed_init (&major_collector);
4616 } else if (!major_collector_opt || !strcmp (major_collector_opt, "marksweep-par")) {
4617 sgen_marksweep_par_init (&major_collector);
4618 } else if (!major_collector_opt || !strcmp (major_collector_opt, "marksweep-fixed-par")) {
4619 sgen_marksweep_fixed_par_init (&major_collector);
4620 } else if (!major_collector_opt || !strcmp (major_collector_opt, "marksweep-conc")) {
4621 sgen_marksweep_conc_init (&major_collector);
4622 } else if (!strcmp (major_collector_opt, "copying")) {
4623 sgen_copying_init (&major_collector);
4625 fprintf (stderr, "Unknown major collector `%s'.\n", major_collector_opt);
4629 #ifdef SGEN_HAVE_CARDTABLE
4630 use_cardtable = major_collector.supports_cardtable;
4632 use_cardtable = FALSE;
4635 num_workers = mono_cpu_count ();
4636 g_assert (num_workers > 0);
4637 if (num_workers > 16)
4640 ///* Keep this the default for now */
4641 /* Precise marking is broken on all supported targets. Disable until fixed. */
4642 conservative_stack_mark = TRUE;
4644 sgen_nursery_size = DEFAULT_NURSERY_SIZE;
4647 for (ptr = opts; *ptr; ++ptr) {
4649 if (g_str_has_prefix (opt, "major="))
4651 if (g_str_has_prefix (opt, "minor="))
4653 if (g_str_has_prefix (opt, "wbarrier=")) {
4654 opt = strchr (opt, '=') + 1;
4655 if (strcmp (opt, "remset") == 0) {
4656 if (major_collector.is_concurrent) {
4657 fprintf (stderr, "The concurrent collector does not support the SSB write barrier.\n");
4660 use_cardtable = FALSE;
4661 } else if (strcmp (opt, "cardtable") == 0) {
4662 if (!use_cardtable) {
4663 if (major_collector.supports_cardtable)
4664 fprintf (stderr, "The cardtable write barrier is not supported on this platform.\n");
4666 fprintf (stderr, "The major collector does not support the cardtable write barrier.\n");
4670 fprintf (stderr, "wbarrier must either be `remset' or `cardtable'.");
4675 if (g_str_has_prefix (opt, "max-heap-size=")) {
4676 opt = strchr (opt, '=') + 1;
4677 if (*opt && mono_gc_parse_environment_string_extract_number (opt, &max_heap)) {
4678 if ((max_heap & (mono_pagesize () - 1))) {
4679 fprintf (stderr, "max-heap-size size must be a multiple of %d.\n", mono_pagesize ());
4683 fprintf (stderr, "max-heap-size must be an integer.\n");
4688 if (g_str_has_prefix (opt, "soft-heap-limit=")) {
4689 opt = strchr (opt, '=') + 1;
4690 if (*opt && mono_gc_parse_environment_string_extract_number (opt, &soft_limit)) {
4691 if (soft_limit <= 0) {
4692 fprintf (stderr, "soft-heap-limit must be positive.\n");
4696 fprintf (stderr, "soft-heap-limit must be an integer.\n");
4701 if (g_str_has_prefix (opt, "workers=")) {
4704 if (!major_collector.is_parallel) {
4705 fprintf (stderr, "The workers= option can only be used for parallel collectors.");
4708 opt = strchr (opt, '=') + 1;
4709 val = strtol (opt, &endptr, 10);
4710 if (!*opt || *endptr) {
4711 fprintf (stderr, "Cannot parse the workers= option value.");
4714 if (val <= 0 || val > 16) {
4715 fprintf (stderr, "The number of workers must be in the range 1 to 16.");
4718 num_workers = (int)val;
4721 if (g_str_has_prefix (opt, "stack-mark=")) {
4722 opt = strchr (opt, '=') + 1;
4723 if (!strcmp (opt, "precise")) {
4724 conservative_stack_mark = FALSE;
4725 } else if (!strcmp (opt, "conservative")) {
4726 conservative_stack_mark = TRUE;
4728 fprintf (stderr, "Invalid value '%s' for stack-mark= option, possible values are: 'precise', 'conservative'.\n", opt);
4733 if (g_str_has_prefix (opt, "bridge=")) {
4734 opt = strchr (opt, '=') + 1;
4735 sgen_register_test_bridge_callbacks (g_strdup (opt));
4739 if (g_str_has_prefix (opt, "nursery-size=")) {
4741 opt = strchr (opt, '=') + 1;
4742 if (*opt && mono_gc_parse_environment_string_extract_number (opt, &val)) {
4743 sgen_nursery_size = val;
4744 #ifdef SGEN_ALIGN_NURSERY
4745 if ((val & (val - 1))) {
4746 fprintf (stderr, "The nursery size must be a power of two.\n");
4750 if (val < SGEN_MAX_NURSERY_WASTE) {
4751 fprintf (stderr, "The nursery size must be at least %d bytes.\n", SGEN_MAX_NURSERY_WASTE);
4755 sgen_nursery_bits = 0;
4756 while (1 << (++ sgen_nursery_bits) != sgen_nursery_size)
4760 fprintf (stderr, "nursery-size must be an integer.\n");
4766 if (g_str_has_prefix (opt, "save-target-ratio=")) {
4768 opt = strchr (opt, '=') + 1;
4769 save_target = strtod (opt, &endptr);
4770 if (endptr == opt) {
4771 fprintf (stderr, "save-target-ratio must be a number.");
4774 if (save_target < SGEN_MIN_SAVE_TARGET_RATIO || save_target > SGEN_MAX_SAVE_TARGET_RATIO) {
4775 fprintf (stderr, "save-target-ratio must be between %.2f - %.2f.", SGEN_MIN_SAVE_TARGET_RATIO, SGEN_MAX_SAVE_TARGET_RATIO);
4780 if (g_str_has_prefix (opt, "default-allowance-ratio=")) {
4782 opt = strchr (opt, '=') + 1;
4784 allowance_ratio = strtod (opt, &endptr);
4785 if (endptr == opt) {
4786 fprintf (stderr, "save-target-ratio must be a number.");
4789 if (allowance_ratio < SGEN_MIN_ALLOWANCE_NURSERY_SIZE_RATIO || allowance_ratio > SGEN_MIN_ALLOWANCE_NURSERY_SIZE_RATIO) {
4790 fprintf (stderr, "default-allowance-ratio must be between %.2f - %.2f.", SGEN_MIN_ALLOWANCE_NURSERY_SIZE_RATIO, SGEN_MIN_ALLOWANCE_NURSERY_SIZE_RATIO);
4796 if (major_collector.handle_gc_param && major_collector.handle_gc_param (opt))
4799 if (sgen_minor_collector.handle_gc_param && sgen_minor_collector.handle_gc_param (opt))
4802 fprintf (stderr, "MONO_GC_PARAMS must be a comma-delimited list of one or more of the following:\n");
4803 fprintf (stderr, " max-heap-size=N (where N is an integer, possibly with a k, m or a g suffix)\n");
4804 fprintf (stderr, " soft-heap-limit=n (where N is an integer, possibly with a k, m or a g suffix)\n");
4805 fprintf (stderr, " nursery-size=N (where N is an integer, possibly with a k, m or a g suffix)\n");
4806 fprintf (stderr, " major=COLLECTOR (where COLLECTOR is `marksweep', `marksweep-par', 'marksweep-fixed', 'marksweep-fixed-par' or `copying')\n");
4807 fprintf (stderr, " minor=COLLECTOR (where COLLECTOR is `simple' or `split')\n");
4808 fprintf (stderr, " wbarrier=WBARRIER (where WBARRIER is `remset' or `cardtable')\n");
4809 fprintf (stderr, " stack-mark=MARK-METHOD (where MARK-METHOD is 'precise' or 'conservative')\n");
4810 if (major_collector.print_gc_param_usage)
4811 major_collector.print_gc_param_usage ();
4812 if (sgen_minor_collector.print_gc_param_usage)
4813 sgen_minor_collector.print_gc_param_usage ();
4814 fprintf (stderr, " Experimental options:\n");
4815 fprintf (stderr, " save-target-ratio=R (where R must be between %.2f - %.2f).\n", SGEN_MIN_SAVE_TARGET_RATIO, SGEN_MAX_SAVE_TARGET_RATIO);
4816 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);
4822 if (major_collector.is_parallel)
4823 sgen_workers_init (num_workers);
4824 else if (major_collector.is_concurrent)
4825 sgen_workers_init (1);
4827 if (major_collector_opt)
4828 g_free (major_collector_opt);
4830 if (minor_collector_opt)
4831 g_free (minor_collector_opt);
4835 if ((env = getenv ("MONO_GC_DEBUG"))) {
4836 opts = g_strsplit (env, ",", -1);
4837 for (ptr = opts; ptr && *ptr; ptr ++) {
4839 if (opt [0] >= '0' && opt [0] <= '9') {
4840 gc_debug_level = atoi (opt);
4846 char *rf = g_strdup_printf ("%s.%d", opt, GetCurrentProcessId ());
4848 char *rf = g_strdup_printf ("%s.%d", opt, getpid ());
4850 gc_debug_file = fopen (rf, "wb");
4852 gc_debug_file = stderr;
4855 } else if (!strcmp (opt, "print-allowance")) {
4856 debug_print_allowance = TRUE;
4857 } else if (!strcmp (opt, "print-pinning")) {
4858 do_pin_stats = TRUE;
4859 } else if (!strcmp (opt, "verify-before-allocs")) {
4860 verify_before_allocs = 1;
4861 has_per_allocation_action = TRUE;
4862 } else if (g_str_has_prefix (opt, "verify-before-allocs=")) {
4863 char *arg = strchr (opt, '=') + 1;
4864 verify_before_allocs = atoi (arg);
4865 has_per_allocation_action = TRUE;
4866 } else if (!strcmp (opt, "collect-before-allocs")) {
4867 collect_before_allocs = 1;
4868 has_per_allocation_action = TRUE;
4869 } else if (g_str_has_prefix (opt, "collect-before-allocs=")) {
4870 char *arg = strchr (opt, '=') + 1;
4871 has_per_allocation_action = TRUE;
4872 collect_before_allocs = atoi (arg);
4873 } else if (!strcmp (opt, "verify-before-collections")) {
4874 whole_heap_check_before_collection = TRUE;
4875 } else if (!strcmp (opt, "check-at-minor-collections")) {
4876 consistency_check_at_minor_collection = TRUE;
4877 nursery_clear_policy = CLEAR_AT_GC;
4878 } else if (!strcmp (opt, "xdomain-checks")) {
4879 xdomain_checks = TRUE;
4880 } else if (!strcmp (opt, "clear-at-gc")) {
4881 nursery_clear_policy = CLEAR_AT_GC;
4882 } else if (!strcmp (opt, "clear-nursery-at-gc")) {
4883 nursery_clear_policy = CLEAR_AT_GC;
4884 } else if (!strcmp (opt, "check-scan-starts")) {
4885 do_scan_starts_check = TRUE;
4886 } else if (!strcmp (opt, "verify-nursery-at-minor-gc")) {
4887 do_verify_nursery = TRUE;
4888 } else if (!strcmp (opt, "check-concurrent")) {
4889 if (!major_collector.is_concurrent) {
4890 fprintf (stderr, "Error: check-concurrent only world with concurrent major collectors.\n");
4893 do_concurrent_checks = TRUE;
4894 } else if (!strcmp (opt, "dump-nursery-at-minor-gc")) {
4895 do_dump_nursery_content = TRUE;
4896 } else if (!strcmp (opt, "no-managed-allocator")) {
4897 sgen_set_use_managed_allocator (FALSE);
4898 } else if (!strcmp (opt, "disable-minor")) {
4899 disable_minor_collections = TRUE;
4900 } else if (!strcmp (opt, "disable-major")) {
4901 disable_major_collections = TRUE;
4902 } else if (g_str_has_prefix (opt, "heap-dump=")) {
4903 char *filename = strchr (opt, '=') + 1;
4904 nursery_clear_policy = CLEAR_AT_GC;
4905 heap_dump_file = fopen (filename, "w");
4906 if (heap_dump_file) {
4907 fprintf (heap_dump_file, "<sgen-dump>\n");
4908 do_pin_stats = TRUE;
4910 #ifdef SGEN_BINARY_PROTOCOL
4911 } else if (g_str_has_prefix (opt, "binary-protocol=")) {
4912 char *filename = strchr (opt, '=') + 1;
4913 binary_protocol_init (filename);
4915 fprintf (stderr, "Warning: Cardtable write barriers will not be binary-protocolled.\n");
4918 fprintf (stderr, "Invalid format for the MONO_GC_DEBUG env variable: '%s'\n", env);
4919 fprintf (stderr, "The format is: MONO_GC_DEBUG=[l[:filename]|<option>]+ where l is a debug level 0-9.\n");
4920 fprintf (stderr, "Valid options are:\n");
4921 fprintf (stderr, " collect-before-allocs[=<n>]\n");
4922 fprintf (stderr, " verify-before-allocs[=<n>]\n");
4923 fprintf (stderr, " check-at-minor-collections\n");
4924 fprintf (stderr, " verify-before-collections\n");
4925 fprintf (stderr, " verify-nursery-at-minor-gc\n");
4926 fprintf (stderr, " dump-nursery-at-minor-gc\n");
4927 fprintf (stderr, " disable-minor\n");
4928 fprintf (stderr, " disable-major\n");
4929 fprintf (stderr, " xdomain-checks\n");
4930 fprintf (stderr, " check-concurrent\n");
4931 fprintf (stderr, " clear-at-gc\n");
4932 fprintf (stderr, " clear-nursery-at-gc\n");
4933 fprintf (stderr, " check-scan-starts\n");
4934 fprintf (stderr, " no-managed-allocator\n");
4935 fprintf (stderr, " print-allowance\n");
4936 fprintf (stderr, " print-pinning\n");
4937 fprintf (stderr, " heap-dump=<filename>\n");
4938 #ifdef SGEN_BINARY_PROTOCOL
4939 fprintf (stderr, " binary-protocol=<filename>\n");
4947 if (major_collector.is_parallel) {
4948 if (heap_dump_file) {
4949 fprintf (stderr, "Error: Cannot do heap dump with the parallel collector.\n");
4953 fprintf (stderr, "Error: Cannot gather pinning statistics with the parallel collector.\n");
4958 if (major_collector.post_param_init)
4959 major_collector.post_param_init ();
4961 sgen_memgov_init (max_heap, soft_limit, debug_print_allowance, allowance_ratio, save_target);
4963 memset (&remset, 0, sizeof (remset));
4965 #ifdef SGEN_HAVE_CARDTABLE
4967 sgen_card_table_init (&remset);
4970 sgen_ssb_init (&remset);
4972 if (remset.register_thread)
4973 remset.register_thread (mono_thread_info_current ());
4979 mono_gc_get_gc_name (void)
4984 static MonoMethod *write_barrier_method;
4987 sgen_is_critical_method (MonoMethod *method)
4989 return (method == write_barrier_method || sgen_is_managed_allocator (method));
4993 sgen_has_critical_method (void)
4995 return write_barrier_method || sgen_has_managed_allocator ();
4999 emit_nursery_check (MonoMethodBuilder *mb, int *nursery_check_return_labels)
5001 memset (nursery_check_return_labels, 0, sizeof (int) * 3);
5002 #ifdef SGEN_ALIGN_NURSERY
5003 // if (ptr_in_nursery (ptr)) return;
5005 * Masking out the bits might be faster, but we would have to use 64 bit
5006 * immediates, which might be slower.
5008 mono_mb_emit_ldarg (mb, 0);
5009 mono_mb_emit_icon (mb, DEFAULT_NURSERY_BITS);
5010 mono_mb_emit_byte (mb, CEE_SHR_UN);
5011 mono_mb_emit_icon (mb, (mword)sgen_get_nursery_start () >> DEFAULT_NURSERY_BITS);
5012 nursery_check_return_labels [0] = mono_mb_emit_branch (mb, CEE_BEQ);
5014 if (!major_collector.is_concurrent) {
5015 // if (!ptr_in_nursery (*ptr)) return;
5016 mono_mb_emit_ldarg (mb, 0);
5017 mono_mb_emit_byte (mb, CEE_LDIND_I);
5018 mono_mb_emit_icon (mb, DEFAULT_NURSERY_BITS);
5019 mono_mb_emit_byte (mb, CEE_SHR_UN);
5020 mono_mb_emit_icon (mb, (mword)sgen_get_nursery_start () >> DEFAULT_NURSERY_BITS);
5021 nursery_check_return_labels [1] = mono_mb_emit_branch (mb, CEE_BNE_UN);
5024 int label_continue1, label_continue2;
5025 int dereferenced_var;
5027 // if (ptr < (sgen_get_nursery_start ())) goto continue;
5028 mono_mb_emit_ldarg (mb, 0);
5029 mono_mb_emit_ptr (mb, (gpointer) sgen_get_nursery_start ());
5030 label_continue_1 = mono_mb_emit_branch (mb, CEE_BLT);
5032 // if (ptr >= sgen_get_nursery_end ())) goto continue;
5033 mono_mb_emit_ldarg (mb, 0);
5034 mono_mb_emit_ptr (mb, (gpointer) sgen_get_nursery_end ());
5035 label_continue_2 = mono_mb_emit_branch (mb, CEE_BGE);
5038 nursery_check_return_labels [0] = mono_mb_emit_branch (mb, CEE_BR);
5041 mono_mb_patch_branch (mb, label_continue_1);
5042 mono_mb_patch_branch (mb, label_continue_2);
5044 // Dereference and store in local var
5045 dereferenced_var = mono_mb_add_local (mb, &mono_defaults.int_class->byval_arg);
5046 mono_mb_emit_ldarg (mb, 0);
5047 mono_mb_emit_byte (mb, CEE_LDIND_I);
5048 mono_mb_emit_stloc (mb, dereferenced_var);
5050 if (!major_collector.is_concurrent) {
5051 // if (*ptr < sgen_get_nursery_start ()) return;
5052 mono_mb_emit_ldloc (mb, dereferenced_var);
5053 mono_mb_emit_ptr (mb, (gpointer) sgen_get_nursery_start ());
5054 nursery_check_return_labels [1] = mono_mb_emit_branch (mb, CEE_BLT);
5056 // if (*ptr >= sgen_get_nursery_end ()) return;
5057 mono_mb_emit_ldloc (mb, dereferenced_var);
5058 mono_mb_emit_ptr (mb, (gpointer) sgen_get_nursery_end ());
5059 nursery_check_return_labels [2] = mono_mb_emit_branch (mb, CEE_BGE);
5065 mono_gc_get_write_barrier (void)
5068 MonoMethodBuilder *mb;
5069 MonoMethodSignature *sig;
5070 #ifdef MANAGED_WBARRIER
5071 int i, nursery_check_labels [3];
5072 int label_no_wb_3, label_no_wb_4, label_need_wb, label_slow_path;
5073 int buffer_var, buffer_index_var, dummy_var;
5075 #ifdef HAVE_KW_THREAD
5076 int stack_end_offset = -1, store_remset_buffer_offset = -1;
5077 int store_remset_buffer_index_offset = -1, store_remset_buffer_index_addr_offset = -1;
5079 MONO_THREAD_VAR_OFFSET (stack_end, stack_end_offset);
5080 g_assert (stack_end_offset != -1);
5081 MONO_THREAD_VAR_OFFSET (store_remset_buffer, store_remset_buffer_offset);
5082 g_assert (store_remset_buffer_offset != -1);
5083 MONO_THREAD_VAR_OFFSET (store_remset_buffer_index, store_remset_buffer_index_offset);
5084 g_assert (store_remset_buffer_index_offset != -1);
5085 MONO_THREAD_VAR_OFFSET (store_remset_buffer_index_addr, store_remset_buffer_index_addr_offset);
5086 g_assert (store_remset_buffer_index_addr_offset != -1);
5090 // FIXME: Maybe create a separate version for ctors (the branch would be
5091 // correctly predicted more times)
5092 if (write_barrier_method)
5093 return write_barrier_method;
5095 /* Create the IL version of mono_gc_barrier_generic_store () */
5096 sig = mono_metadata_signature_alloc (mono_defaults.corlib, 1);
5097 sig->ret = &mono_defaults.void_class->byval_arg;
5098 sig->params [0] = &mono_defaults.int_class->byval_arg;
5100 mb = mono_mb_new (mono_defaults.object_class, "wbarrier", MONO_WRAPPER_WRITE_BARRIER);
5102 #ifdef MANAGED_WBARRIER
5103 if (use_cardtable) {
5104 emit_nursery_check (mb, nursery_check_labels);
5106 addr = sgen_cardtable + ((address >> CARD_BITS) & CARD_MASK)
5110 LDC_PTR sgen_cardtable
5112 address >> CARD_BITS
5116 if (SGEN_HAVE_OVERLAPPING_CARDS) {
5117 LDC_PTR card_table_mask
5124 mono_mb_emit_ptr (mb, sgen_cardtable);
5125 mono_mb_emit_ldarg (mb, 0);
5126 mono_mb_emit_icon (mb, CARD_BITS);
5127 mono_mb_emit_byte (mb, CEE_SHR_UN);
5128 #ifdef SGEN_HAVE_OVERLAPPING_CARDS
5129 mono_mb_emit_ptr (mb, (gpointer)CARD_MASK);
5130 mono_mb_emit_byte (mb, CEE_AND);
5132 mono_mb_emit_byte (mb, CEE_ADD);
5133 mono_mb_emit_icon (mb, 1);
5134 mono_mb_emit_byte (mb, CEE_STIND_I1);
5137 for (i = 0; i < 3; ++i) {
5138 if (nursery_check_labels [i])
5139 mono_mb_patch_branch (mb, nursery_check_labels [i]);
5141 mono_mb_emit_byte (mb, CEE_RET);
5142 } else if (mono_runtime_has_tls_get ()) {
5143 emit_nursery_check (mb, nursery_check_labels);
5145 // if (ptr >= stack_end) goto need_wb;
5146 mono_mb_emit_ldarg (mb, 0);
5147 EMIT_TLS_ACCESS (mb, stack_end, stack_end_offset);
5148 label_need_wb = mono_mb_emit_branch (mb, CEE_BGE_UN);
5150 // if (ptr >= stack_start) return;
5151 dummy_var = mono_mb_add_local (mb, &mono_defaults.int_class->byval_arg);
5152 mono_mb_emit_ldarg (mb, 0);
5153 mono_mb_emit_ldloc_addr (mb, dummy_var);
5154 label_no_wb_3 = mono_mb_emit_branch (mb, CEE_BGE_UN);
5157 mono_mb_patch_branch (mb, label_need_wb);
5159 // buffer = STORE_REMSET_BUFFER;
5160 buffer_var = mono_mb_add_local (mb, &mono_defaults.int_class->byval_arg);
5161 EMIT_TLS_ACCESS (mb, store_remset_buffer, store_remset_buffer_offset);
5162 mono_mb_emit_stloc (mb, buffer_var);
5164 // buffer_index = STORE_REMSET_BUFFER_INDEX;
5165 buffer_index_var = mono_mb_add_local (mb, &mono_defaults.int_class->byval_arg);
5166 EMIT_TLS_ACCESS (mb, store_remset_buffer_index, store_remset_buffer_index_offset);
5167 mono_mb_emit_stloc (mb, buffer_index_var);
5169 // if (buffer [buffer_index] == ptr) return;
5170 mono_mb_emit_ldloc (mb, buffer_var);
5171 mono_mb_emit_ldloc (mb, buffer_index_var);
5172 g_assert (sizeof (gpointer) == 4 || sizeof (gpointer) == 8);
5173 mono_mb_emit_icon (mb, sizeof (gpointer) == 4 ? 2 : 3);
5174 mono_mb_emit_byte (mb, CEE_SHL);
5175 mono_mb_emit_byte (mb, CEE_ADD);
5176 mono_mb_emit_byte (mb, CEE_LDIND_I);
5177 mono_mb_emit_ldarg (mb, 0);
5178 label_no_wb_4 = mono_mb_emit_branch (mb, CEE_BEQ);
5181 mono_mb_emit_ldloc (mb, buffer_index_var);
5182 mono_mb_emit_icon (mb, 1);
5183 mono_mb_emit_byte (mb, CEE_ADD);
5184 mono_mb_emit_stloc (mb, buffer_index_var);
5186 // if (buffer_index >= STORE_REMSET_BUFFER_SIZE) goto slow_path;
5187 mono_mb_emit_ldloc (mb, buffer_index_var);
5188 mono_mb_emit_icon (mb, STORE_REMSET_BUFFER_SIZE);
5189 label_slow_path = mono_mb_emit_branch (mb, CEE_BGE);
5191 // buffer [buffer_index] = ptr;
5192 mono_mb_emit_ldloc (mb, buffer_var);
5193 mono_mb_emit_ldloc (mb, buffer_index_var);
5194 g_assert (sizeof (gpointer) == 4 || sizeof (gpointer) == 8);
5195 mono_mb_emit_icon (mb, sizeof (gpointer) == 4 ? 2 : 3);
5196 mono_mb_emit_byte (mb, CEE_SHL);
5197 mono_mb_emit_byte (mb, CEE_ADD);
5198 mono_mb_emit_ldarg (mb, 0);
5199 mono_mb_emit_byte (mb, CEE_STIND_I);
5201 // STORE_REMSET_BUFFER_INDEX = buffer_index;
5202 EMIT_TLS_ACCESS (mb, store_remset_buffer_index_addr, store_remset_buffer_index_addr_offset);
5203 mono_mb_emit_ldloc (mb, buffer_index_var);
5204 mono_mb_emit_byte (mb, CEE_STIND_I);
5207 for (i = 0; i < 3; ++i) {
5208 if (nursery_check_labels [i])
5209 mono_mb_patch_branch (mb, nursery_check_labels [i]);
5211 mono_mb_patch_branch (mb, label_no_wb_3);
5212 mono_mb_patch_branch (mb, label_no_wb_4);
5213 mono_mb_emit_byte (mb, CEE_RET);
5216 mono_mb_patch_branch (mb, label_slow_path);
5218 mono_mb_emit_ldarg (mb, 0);
5219 mono_mb_emit_icall (mb, mono_gc_wbarrier_generic_nostore);
5220 mono_mb_emit_byte (mb, CEE_RET);
5224 mono_mb_emit_ldarg (mb, 0);
5225 mono_mb_emit_icall (mb, mono_gc_wbarrier_generic_nostore);
5226 mono_mb_emit_byte (mb, CEE_RET);
5229 res = mono_mb_create_method (mb, sig, 16);
5232 mono_loader_lock ();
5233 if (write_barrier_method) {
5234 /* Already created */
5235 mono_free_method (res);
5237 /* double-checked locking */
5238 mono_memory_barrier ();
5239 write_barrier_method = res;
5241 mono_loader_unlock ();
5243 return write_barrier_method;
5247 mono_gc_get_description (void)
5249 return g_strdup ("sgen");
5253 mono_gc_set_desktop_mode (void)
5258 mono_gc_is_moving (void)
5264 mono_gc_is_disabled (void)
5270 BOOL APIENTRY mono_gc_dllmain (HMODULE module_handle, DWORD reason, LPVOID reserved)
5277 sgen_get_nursery_clear_policy (void)
5279 return nursery_clear_policy;
5283 sgen_get_array_fill_vtable (void)
5285 if (!array_fill_vtable) {
5286 static MonoClass klass;
5287 static MonoVTable vtable;
5290 MonoDomain *domain = mono_get_root_domain ();
5293 klass.element_class = mono_defaults.byte_class;
5295 klass.instance_size = sizeof (MonoArray);
5296 klass.sizes.element_size = 1;
5297 klass.name = "array_filler_type";
5299 vtable.klass = &klass;
5301 vtable.gc_descr = mono_gc_make_descr_for_array (TRUE, &bmap, 0, 1);
5304 array_fill_vtable = &vtable;
5306 return array_fill_vtable;
5316 sgen_gc_unlock (void)
5322 sgen_major_collector_iterate_live_block_ranges (sgen_cardtable_block_callback callback)
5324 major_collector.iterate_live_block_ranges (callback);
5328 sgen_major_collector_scan_card_table (SgenGrayQueue *queue)
5330 major_collector.scan_card_table (FALSE, queue);
5334 sgen_get_major_collector (void)
5336 return &major_collector;
5339 void mono_gc_set_skip_thread (gboolean skip)
5341 SgenThreadInfo *info = mono_thread_info_current ();
5344 info->gc_disabled = skip;
5349 sgen_get_remset (void)
5355 mono_gc_get_vtable_bits (MonoClass *class)
5357 if (sgen_need_bridge_processing () && sgen_is_bridge_class (class))
5358 return SGEN_GC_BIT_BRIDGE_OBJECT;
5363 mono_gc_register_altstack (gpointer stack, gint32 stack_size, gpointer altstack, gint32 altstack_size)
5370 sgen_check_whole_heap_stw (void)
5372 sgen_stop_world (0);
5373 sgen_clear_nursery_fragments ();
5374 sgen_check_whole_heap ();
5375 sgen_restart_world (0, NULL);
5379 sgen_gc_event_moves (void)
5381 if (moved_objects_idx) {
5382 mono_profiler_gc_moves (moved_objects, moved_objects_idx);
5383 moved_objects_idx = 0;
5387 #endif /* HAVE_SGEN_GC */