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_PTHREAD_NP_H
183 #include <pthread_np.h>
185 #ifdef HAVE_SEMAPHORE_H
186 #include <semaphore.h>
194 #include "metadata/sgen-gc.h"
195 #include "metadata/metadata-internals.h"
196 #include "metadata/class-internals.h"
197 #include "metadata/gc-internal.h"
198 #include "metadata/object-internals.h"
199 #include "metadata/threads.h"
200 #include "metadata/sgen-cardtable.h"
201 #include "metadata/sgen-protocol.h"
202 #include "metadata/sgen-archdep.h"
203 #include "metadata/sgen-bridge.h"
204 #include "metadata/sgen-memory-governor.h"
205 #include "metadata/sgen-hash-table.h"
206 #include "metadata/mono-gc.h"
207 #include "metadata/method-builder.h"
208 #include "metadata/profiler-private.h"
209 #include "metadata/monitor.h"
210 #include "metadata/threadpool-internals.h"
211 #include "metadata/mempool-internals.h"
212 #include "metadata/marshal.h"
213 #include "metadata/runtime.h"
214 #include "metadata/sgen-cardtable.h"
215 #include "metadata/sgen-pinning.h"
216 #include "metadata/sgen-workers.h"
217 #include "metadata/sgen-layout-stats.h"
218 #include "utils/mono-mmap.h"
219 #include "utils/mono-time.h"
220 #include "utils/mono-semaphore.h"
221 #include "utils/mono-counters.h"
222 #include "utils/mono-proclib.h"
223 #include "utils/mono-memory-model.h"
224 #include "utils/mono-logger-internal.h"
225 #include "utils/dtrace.h"
227 #include <mono/utils/mono-logger-internal.h>
228 #include <mono/utils/memcheck.h>
230 #if defined(__MACH__)
231 #include "utils/mach-support.h"
234 #define OPDEF(a,b,c,d,e,f,g,h,i,j) \
238 #include "mono/cil/opcode.def"
244 #undef pthread_create
246 #undef pthread_detach
249 * ######################################################################
250 * ######## Types and constants used by the GC.
251 * ######################################################################
254 /* 0 means not initialized, 1 is initialized, -1 means in progress */
255 static int gc_initialized = 0;
256 /* If set, check if we need to do something every X allocations */
257 gboolean has_per_allocation_action;
258 /* If set, do a heap check every X allocation */
259 guint32 verify_before_allocs = 0;
260 /* If set, do a minor collection before every X allocation */
261 guint32 collect_before_allocs = 0;
262 /* If set, do a whole heap check before each collection */
263 static gboolean whole_heap_check_before_collection = FALSE;
264 /* If set, do a heap consistency check before each minor collection */
265 static gboolean consistency_check_at_minor_collection = FALSE;
266 /* If set, do a mod union consistency check before each finishing collection pause */
267 static gboolean mod_union_consistency_check = FALSE;
268 /* If set, check whether mark bits are consistent after major collections */
269 static gboolean check_mark_bits_after_major_collection = FALSE;
270 /* If set, check that all nursery objects are pinned/not pinned, depending on context */
271 static gboolean check_nursery_objects_pinned = FALSE;
272 /* If set, do a few checks when the concurrent collector is used */
273 static gboolean do_concurrent_checks = FALSE;
274 /* If set, check that there are no references to the domain left at domain unload */
275 static gboolean xdomain_checks = FALSE;
276 /* If not null, dump the heap after each collection into this file */
277 static FILE *heap_dump_file = NULL;
278 /* If set, mark stacks conservatively, even if precise marking is possible */
279 static gboolean conservative_stack_mark = FALSE;
280 /* If set, do a plausibility check on the scan_starts before and after
282 static gboolean do_scan_starts_check = FALSE;
284 * If the major collector is concurrent and this is FALSE, we will
285 * never initiate a synchronous major collection, unless requested via
288 static gboolean allow_synchronous_major = TRUE;
289 static gboolean nursery_collection_is_parallel = FALSE;
290 static gboolean disable_minor_collections = FALSE;
291 static gboolean disable_major_collections = FALSE;
292 gboolean do_pin_stats = FALSE;
293 static gboolean do_verify_nursery = FALSE;
294 static gboolean do_dump_nursery_content = FALSE;
296 #ifdef HEAVY_STATISTICS
297 long long stat_objects_alloced_degraded = 0;
298 long long stat_bytes_alloced_degraded = 0;
300 long long stat_copy_object_called_nursery = 0;
301 long long stat_objects_copied_nursery = 0;
302 long long stat_copy_object_called_major = 0;
303 long long stat_objects_copied_major = 0;
305 long long stat_scan_object_called_nursery = 0;
306 long long stat_scan_object_called_major = 0;
308 long long stat_slots_allocated_in_vain;
310 long long stat_nursery_copy_object_failed_from_space = 0;
311 long long stat_nursery_copy_object_failed_forwarded = 0;
312 long long stat_nursery_copy_object_failed_pinned = 0;
313 long long stat_nursery_copy_object_failed_to_space = 0;
315 static int stat_wbarrier_add_to_global_remset = 0;
316 static int stat_wbarrier_set_field = 0;
317 static int stat_wbarrier_set_arrayref = 0;
318 static int stat_wbarrier_arrayref_copy = 0;
319 static int stat_wbarrier_generic_store = 0;
320 static int stat_wbarrier_set_root = 0;
321 static int stat_wbarrier_value_copy = 0;
322 static int stat_wbarrier_object_copy = 0;
325 int stat_minor_gcs = 0;
326 int stat_major_gcs = 0;
328 static long long stat_pinned_objects = 0;
330 static long long time_minor_pre_collection_fragment_clear = 0;
331 static long long time_minor_pinning = 0;
332 static long long time_minor_scan_remsets = 0;
333 static long long time_minor_scan_pinned = 0;
334 static long long time_minor_scan_registered_roots = 0;
335 static long long time_minor_scan_thread_data = 0;
336 static long long time_minor_finish_gray_stack = 0;
337 static long long time_minor_fragment_creation = 0;
339 static long long time_major_pre_collection_fragment_clear = 0;
340 static long long time_major_pinning = 0;
341 static long long time_major_scan_pinned = 0;
342 static long long time_major_scan_registered_roots = 0;
343 static long long time_major_scan_thread_data = 0;
344 static long long time_major_scan_alloc_pinned = 0;
345 static long long time_major_scan_finalized = 0;
346 static long long time_major_scan_big_objects = 0;
347 static long long time_major_finish_gray_stack = 0;
348 static long long time_major_free_bigobjs = 0;
349 static long long time_major_los_sweep = 0;
350 static long long time_major_sweep = 0;
351 static long long time_major_fragment_creation = 0;
353 int gc_debug_level = 0;
358 mono_gc_flush_info (void)
360 fflush (gc_debug_file);
364 #define TV_DECLARE SGEN_TV_DECLARE
365 #define TV_GETTIME SGEN_TV_GETTIME
366 #define TV_ELAPSED SGEN_TV_ELAPSED
367 #define TV_ELAPSED_MS SGEN_TV_ELAPSED_MS
369 #define ALIGN_TO(val,align) ((((guint64)val) + ((align) - 1)) & ~((align) - 1))
371 NurseryClearPolicy nursery_clear_policy = CLEAR_AT_TLAB_CREATION;
373 #define object_is_forwarded SGEN_OBJECT_IS_FORWARDED
374 #define object_is_pinned SGEN_OBJECT_IS_PINNED
375 #define pin_object SGEN_PIN_OBJECT
376 #define unpin_object SGEN_UNPIN_OBJECT
378 #define ptr_in_nursery sgen_ptr_in_nursery
380 #define LOAD_VTABLE SGEN_LOAD_VTABLE
383 safe_name (void* obj)
385 MonoVTable *vt = (MonoVTable*)LOAD_VTABLE (obj);
386 return vt->klass->name;
389 #define safe_object_get_size sgen_safe_object_get_size
392 sgen_safe_name (void* obj)
394 return safe_name (obj);
398 * ######################################################################
399 * ######## Global data.
400 * ######################################################################
402 LOCK_DECLARE (gc_mutex);
404 #define SCAN_START_SIZE SGEN_SCAN_START_SIZE
406 static mword pagesize = 4096;
407 int degraded_mode = 0;
409 static mword bytes_pinned_from_failed_allocation = 0;
411 GCMemSection *nursery_section = NULL;
412 static mword lowest_heap_address = ~(mword)0;
413 static mword highest_heap_address = 0;
415 LOCK_DECLARE (sgen_interruption_mutex);
416 static LOCK_DECLARE (pin_queue_mutex);
418 #define LOCK_PIN_QUEUE mono_mutex_lock (&pin_queue_mutex)
419 #define UNLOCK_PIN_QUEUE mono_mutex_unlock (&pin_queue_mutex)
421 typedef struct _FinalizeReadyEntry FinalizeReadyEntry;
422 struct _FinalizeReadyEntry {
423 FinalizeReadyEntry *next;
427 typedef struct _EphemeronLinkNode EphemeronLinkNode;
429 struct _EphemeronLinkNode {
430 EphemeronLinkNode *next;
439 int current_collection_generation = -1;
440 volatile gboolean concurrent_collection_in_progress = FALSE;
442 /* objects that are ready to be finalized */
443 static FinalizeReadyEntry *fin_ready_list = NULL;
444 static FinalizeReadyEntry *critical_fin_list = NULL;
446 static EphemeronLinkNode *ephemeron_list;
448 /* registered roots: the key to the hash is the root start address */
450 * Different kinds of roots are kept separate to speed up pin_from_roots () for example.
452 SgenHashTable roots_hash [ROOT_TYPE_NUM] = {
453 SGEN_HASH_TABLE_INIT (INTERNAL_MEM_ROOTS_TABLE, INTERNAL_MEM_ROOT_RECORD, sizeof (RootRecord), mono_aligned_addr_hash, NULL),
454 SGEN_HASH_TABLE_INIT (INTERNAL_MEM_ROOTS_TABLE, INTERNAL_MEM_ROOT_RECORD, sizeof (RootRecord), mono_aligned_addr_hash, NULL),
455 SGEN_HASH_TABLE_INIT (INTERNAL_MEM_ROOTS_TABLE, INTERNAL_MEM_ROOT_RECORD, sizeof (RootRecord), mono_aligned_addr_hash, NULL)
457 static mword roots_size = 0; /* amount of memory in the root set */
459 #define GC_ROOT_NUM 32
461 int count; /* must be the first field */
462 void *objects [GC_ROOT_NUM];
463 int root_types [GC_ROOT_NUM];
464 uintptr_t extra_info [GC_ROOT_NUM];
468 notify_gc_roots (GCRootReport *report)
472 mono_profiler_gc_roots (report->count, report->objects, report->root_types, report->extra_info);
477 add_profile_gc_root (GCRootReport *report, void *object, int rtype, uintptr_t extra_info)
479 if (report->count == GC_ROOT_NUM)
480 notify_gc_roots (report);
481 report->objects [report->count] = object;
482 report->root_types [report->count] = rtype;
483 report->extra_info [report->count++] = (uintptr_t)((MonoVTable*)LOAD_VTABLE (object))->klass;
486 MonoNativeTlsKey thread_info_key;
488 #ifdef HAVE_KW_THREAD
489 __thread SgenThreadInfo *sgen_thread_info;
490 __thread char *stack_end;
493 /* The size of a TLAB */
494 /* The bigger the value, the less often we have to go to the slow path to allocate a new
495 * one, but the more space is wasted by threads not allocating much memory.
497 * FIXME: Make this self-tuning for each thread.
499 guint32 tlab_size = (1024 * 4);
501 #define MAX_SMALL_OBJ_SIZE SGEN_MAX_SMALL_OBJ_SIZE
503 /* Functions supplied by the runtime to be called by the GC */
504 static MonoGCCallbacks gc_callbacks;
506 #define ALLOC_ALIGN SGEN_ALLOC_ALIGN
507 #define ALLOC_ALIGN_BITS SGEN_ALLOC_ALIGN_BITS
509 #define ALIGN_UP SGEN_ALIGN_UP
511 #define MOVED_OBJECTS_NUM 64
512 static void *moved_objects [MOVED_OBJECTS_NUM];
513 static int moved_objects_idx = 0;
515 /* Vtable of the objects used to fill out nursery fragments before a collection */
516 static MonoVTable *array_fill_vtable;
518 #ifdef SGEN_DEBUG_INTERNAL_ALLOC
519 MonoNativeThreadId main_gc_thread = NULL;
522 /*Object was pinned during the current collection*/
523 static mword objects_pinned;
526 * ######################################################################
527 * ######## Macros and function declarations.
528 * ######################################################################
532 align_pointer (void *ptr)
534 mword p = (mword)ptr;
535 p += sizeof (gpointer) - 1;
536 p &= ~ (sizeof (gpointer) - 1);
540 typedef SgenGrayQueue GrayQueue;
542 /* forward declarations */
543 static void scan_thread_data (void *start_nursery, void *end_nursery, gboolean precise, GrayQueue *queue);
544 static void scan_from_registered_roots (char *addr_start, char *addr_end, int root_type, ScanCopyContext ctx);
545 static void scan_finalizer_entries (FinalizeReadyEntry *list, ScanCopyContext ctx);
546 static void report_finalizer_roots (void);
547 static void report_registered_roots (void);
549 static void pin_from_roots (void *start_nursery, void *end_nursery, GrayQueue *queue);
550 static int pin_objects_from_addresses (GCMemSection *section, void **start, void **end, void *start_nursery, void *end_nursery, ScanCopyContext ctx);
551 static void finish_gray_stack (int generation, GrayQueue *queue);
553 void mono_gc_scan_for_specific_ref (MonoObject *key, gboolean precise);
556 static void init_stats (void);
558 static int mark_ephemerons_in_range (ScanCopyContext ctx);
559 static void clear_unreachable_ephemerons (ScanCopyContext ctx);
560 static void null_ephemerons_for_domain (MonoDomain *domain);
562 static gboolean major_update_or_finish_concurrent_collection (gboolean force_finish);
564 SgenObjectOperations current_object_ops;
565 SgenMajorCollector major_collector;
566 SgenMinorCollector sgen_minor_collector;
567 static GrayQueue gray_queue;
569 static SgenRemeberedSet remset;
571 /* The gray queue to use from the main collection thread. */
572 #define WORKERS_DISTRIBUTE_GRAY_QUEUE (&gray_queue)
575 * The gray queue a worker job must use. If we're not parallel or
576 * concurrent, we use the main gray queue.
578 static SgenGrayQueue*
579 sgen_workers_get_job_gray_queue (WorkerData *worker_data)
581 return worker_data ? &worker_data->private_gray_queue : WORKERS_DISTRIBUTE_GRAY_QUEUE;
585 gray_queue_redirect (SgenGrayQueue *queue)
587 gboolean wake = FALSE;
591 GrayQueueSection *section = sgen_gray_object_dequeue_section (queue);
594 sgen_section_gray_queue_enqueue (queue->alloc_prepare_data, section);
599 g_assert (concurrent_collection_in_progress ||
600 (current_collection_generation == GENERATION_OLD && major_collector.is_parallel));
601 if (sgen_workers_have_started ()) {
602 sgen_workers_wake_up_all ();
604 if (concurrent_collection_in_progress)
605 g_assert (current_collection_generation == -1);
611 is_xdomain_ref_allowed (gpointer *ptr, char *obj, MonoDomain *domain)
613 MonoObject *o = (MonoObject*)(obj);
614 MonoObject *ref = (MonoObject*)*(ptr);
615 int offset = (char*)(ptr) - (char*)o;
617 if (o->vtable->klass == mono_defaults.thread_class && offset == G_STRUCT_OFFSET (MonoThread, internal_thread))
619 if (o->vtable->klass == mono_defaults.internal_thread_class && offset == G_STRUCT_OFFSET (MonoInternalThread, current_appcontext))
622 #ifndef DISABLE_REMOTING
623 if (mono_class_has_parent_fast (o->vtable->klass, mono_defaults.real_proxy_class) &&
624 offset == G_STRUCT_OFFSET (MonoRealProxy, unwrapped_server))
627 /* Thread.cached_culture_info */
628 if (!strcmp (ref->vtable->klass->name_space, "System.Globalization") &&
629 !strcmp (ref->vtable->klass->name, "CultureInfo") &&
630 !strcmp(o->vtable->klass->name_space, "System") &&
631 !strcmp(o->vtable->klass->name, "Object[]"))
634 * 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
635 * at System.IO.MemoryStream..ctor (byte[]) [0x00017] in /home/schani/Work/novell/trunk/mcs/class/corlib/System.IO/MemoryStream.cs:81
636 * at (wrapper remoting-invoke-with-check) System.IO.MemoryStream..ctor (byte[]) <IL 0x00020, 0xffffffff>
637 * at System.Runtime.Remoting.Messaging.CADMethodCallMessage.GetArguments () [0x0000d] in /home/schani/Work/novell/trunk/mcs/class/corlib/System.Runtime.Remoting.Messaging/CADMessages.cs:327
638 * 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
639 * 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
640 * at (wrapper remoting-invoke-with-check) System.AppDomain.ProcessMessageInDomain (byte[],System.Runtime.Remoting.Messaging.CADMethodCallMessage,byte[]&,System.Runtime.Remoting.Messaging.CADMethodReturnMessage&) <IL 0x0003d, 0xffffffff>
641 * 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
642 * at (wrapper runtime-invoke) object.runtime_invoke_CrossAppDomainSink/ProcessMessageRes_object_object (object,intptr,intptr,intptr) <IL 0x0004c, 0xffffffff>
644 if (!strcmp (ref->vtable->klass->name_space, "System") &&
645 !strcmp (ref->vtable->klass->name, "Byte[]") &&
646 !strcmp (o->vtable->klass->name_space, "System.IO") &&
647 !strcmp (o->vtable->klass->name, "MemoryStream"))
649 /* append_job() in threadpool.c */
650 if (!strcmp (ref->vtable->klass->name_space, "System.Runtime.Remoting.Messaging") &&
651 !strcmp (ref->vtable->klass->name, "AsyncResult") &&
652 !strcmp (o->vtable->klass->name_space, "System") &&
653 !strcmp (o->vtable->klass->name, "Object[]") &&
654 mono_thread_pool_is_queue_array ((MonoArray*) o))
660 check_reference_for_xdomain (gpointer *ptr, char *obj, MonoDomain *domain)
662 MonoObject *o = (MonoObject*)(obj);
663 MonoObject *ref = (MonoObject*)*(ptr);
664 int offset = (char*)(ptr) - (char*)o;
666 MonoClassField *field;
669 if (!ref || ref->vtable->domain == domain)
671 if (is_xdomain_ref_allowed (ptr, obj, domain))
675 for (class = o->vtable->klass; class; class = class->parent) {
678 for (i = 0; i < class->field.count; ++i) {
679 if (class->fields[i].offset == offset) {
680 field = &class->fields[i];
688 if (ref->vtable->klass == mono_defaults.string_class)
689 str = mono_string_to_utf8 ((MonoString*)ref);
692 g_print ("xdomain reference in %p (%s.%s) at offset %d (%s) to %p (%s.%s) (%s) - pointed to by:\n",
693 o, o->vtable->klass->name_space, o->vtable->klass->name,
694 offset, field ? field->name : "",
695 ref, ref->vtable->klass->name_space, ref->vtable->klass->name, str ? str : "");
696 mono_gc_scan_for_specific_ref (o, TRUE);
702 #define HANDLE_PTR(ptr,obj) check_reference_for_xdomain ((ptr), (obj), domain)
705 scan_object_for_xdomain_refs (char *start, mword size, void *data)
707 MonoDomain *domain = ((MonoObject*)start)->vtable->domain;
709 #include "sgen-scan-object.h"
712 static gboolean scan_object_for_specific_ref_precise = TRUE;
715 #define HANDLE_PTR(ptr,obj) do { \
716 if ((MonoObject*)*(ptr) == key) { \
717 g_print ("found ref to %p in object %p (%s) at offset %td\n", \
718 key, (obj), safe_name ((obj)), ((char*)(ptr) - (char*)(obj))); \
723 scan_object_for_specific_ref (char *start, MonoObject *key)
727 if ((forwarded = SGEN_OBJECT_IS_FORWARDED (start)))
730 if (scan_object_for_specific_ref_precise) {
731 #include "sgen-scan-object.h"
733 mword *words = (mword*)start;
734 size_t size = safe_object_get_size ((MonoObject*)start);
736 for (i = 0; i < size / sizeof (mword); ++i) {
737 if (words [i] == (mword)key) {
738 g_print ("found possible ref to %p in object %p (%s) at offset %td\n",
739 key, start, safe_name (start), i * sizeof (mword));
746 sgen_scan_area_with_callback (char *start, char *end, IterateObjectCallbackFunc callback, void *data, gboolean allow_flags)
748 while (start < end) {
752 if (!*(void**)start) {
753 start += sizeof (void*); /* should be ALLOC_ALIGN, really */
758 if (!(obj = SGEN_OBJECT_IS_FORWARDED (start)))
764 size = ALIGN_UP (safe_object_get_size ((MonoObject*)obj));
766 if ((MonoVTable*)SGEN_LOAD_VTABLE (obj) != array_fill_vtable)
767 callback (obj, size, data);
774 scan_object_for_specific_ref_callback (char *obj, size_t size, MonoObject *key)
776 scan_object_for_specific_ref (obj, key);
780 check_root_obj_specific_ref (RootRecord *root, MonoObject *key, MonoObject *obj)
784 g_print ("found ref to %p in root record %p\n", key, root);
787 static MonoObject *check_key = NULL;
788 static RootRecord *check_root = NULL;
791 check_root_obj_specific_ref_from_marker (void **obj)
793 check_root_obj_specific_ref (check_root, check_key, *obj);
797 scan_roots_for_specific_ref (MonoObject *key, int root_type)
803 SGEN_HASH_TABLE_FOREACH (&roots_hash [root_type], start_root, root) {
804 mword desc = root->root_desc;
808 switch (desc & ROOT_DESC_TYPE_MASK) {
809 case ROOT_DESC_BITMAP:
810 desc >>= ROOT_DESC_TYPE_SHIFT;
813 check_root_obj_specific_ref (root, key, *start_root);
818 case ROOT_DESC_COMPLEX: {
819 gsize *bitmap_data = sgen_get_complex_descriptor_bitmap (desc);
820 int bwords = (*bitmap_data) - 1;
821 void **start_run = start_root;
823 while (bwords-- > 0) {
824 gsize bmap = *bitmap_data++;
825 void **objptr = start_run;
828 check_root_obj_specific_ref (root, key, *objptr);
832 start_run += GC_BITS_PER_WORD;
836 case ROOT_DESC_USER: {
837 MonoGCRootMarkFunc marker = sgen_get_user_descriptor_func (desc);
838 marker (start_root, check_root_obj_specific_ref_from_marker);
841 case ROOT_DESC_RUN_LEN:
842 g_assert_not_reached ();
844 g_assert_not_reached ();
846 } SGEN_HASH_TABLE_FOREACH_END;
853 mono_gc_scan_for_specific_ref (MonoObject *key, gboolean precise)
858 scan_object_for_specific_ref_precise = precise;
860 sgen_scan_area_with_callback (nursery_section->data, nursery_section->end_data,
861 (IterateObjectCallbackFunc)scan_object_for_specific_ref_callback, key, TRUE);
863 major_collector.iterate_objects (TRUE, TRUE, (IterateObjectCallbackFunc)scan_object_for_specific_ref_callback, key);
865 sgen_los_iterate_objects ((IterateObjectCallbackFunc)scan_object_for_specific_ref_callback, key);
867 scan_roots_for_specific_ref (key, ROOT_TYPE_NORMAL);
868 scan_roots_for_specific_ref (key, ROOT_TYPE_WBARRIER);
870 SGEN_HASH_TABLE_FOREACH (&roots_hash [ROOT_TYPE_PINNED], ptr, root) {
871 while (ptr < (void**)root->end_root) {
872 check_root_obj_specific_ref (root, *ptr, key);
875 } SGEN_HASH_TABLE_FOREACH_END;
879 need_remove_object_for_domain (char *start, MonoDomain *domain)
881 if (mono_object_domain (start) == domain) {
882 SGEN_LOG (4, "Need to cleanup object %p", start);
883 binary_protocol_cleanup (start, (gpointer)LOAD_VTABLE (start), safe_object_get_size ((MonoObject*)start));
890 process_object_for_domain_clearing (char *start, MonoDomain *domain)
892 GCVTable *vt = (GCVTable*)LOAD_VTABLE (start);
893 if (vt->klass == mono_defaults.internal_thread_class)
894 g_assert (mono_object_domain (start) == mono_get_root_domain ());
895 /* The object could be a proxy for an object in the domain
897 #ifndef DISABLE_REMOTING
898 if (mono_class_has_parent_fast (vt->klass, mono_defaults.real_proxy_class)) {
899 MonoObject *server = ((MonoRealProxy*)start)->unwrapped_server;
901 /* The server could already have been zeroed out, so
902 we need to check for that, too. */
903 if (server && (!LOAD_VTABLE (server) || mono_object_domain (server) == domain)) {
904 SGEN_LOG (4, "Cleaning up remote pointer in %p to object %p", start, server);
905 ((MonoRealProxy*)start)->unwrapped_server = NULL;
911 static MonoDomain *check_domain = NULL;
914 check_obj_not_in_domain (void **o)
916 g_assert (((MonoObject*)(*o))->vtable->domain != check_domain);
920 scan_for_registered_roots_in_domain (MonoDomain *domain, int root_type)
924 check_domain = domain;
925 SGEN_HASH_TABLE_FOREACH (&roots_hash [root_type], start_root, root) {
926 mword desc = root->root_desc;
928 /* The MonoDomain struct is allowed to hold
929 references to objects in its own domain. */
930 if (start_root == (void**)domain)
933 switch (desc & ROOT_DESC_TYPE_MASK) {
934 case ROOT_DESC_BITMAP:
935 desc >>= ROOT_DESC_TYPE_SHIFT;
937 if ((desc & 1) && *start_root)
938 check_obj_not_in_domain (*start_root);
943 case ROOT_DESC_COMPLEX: {
944 gsize *bitmap_data = sgen_get_complex_descriptor_bitmap (desc);
945 int bwords = (*bitmap_data) - 1;
946 void **start_run = start_root;
948 while (bwords-- > 0) {
949 gsize bmap = *bitmap_data++;
950 void **objptr = start_run;
952 if ((bmap & 1) && *objptr)
953 check_obj_not_in_domain (*objptr);
957 start_run += GC_BITS_PER_WORD;
961 case ROOT_DESC_USER: {
962 MonoGCRootMarkFunc marker = sgen_get_user_descriptor_func (desc);
963 marker (start_root, check_obj_not_in_domain);
966 case ROOT_DESC_RUN_LEN:
967 g_assert_not_reached ();
969 g_assert_not_reached ();
971 } SGEN_HASH_TABLE_FOREACH_END;
977 check_for_xdomain_refs (void)
981 sgen_scan_area_with_callback (nursery_section->data, nursery_section->end_data,
982 (IterateObjectCallbackFunc)scan_object_for_xdomain_refs, NULL, FALSE);
984 major_collector.iterate_objects (TRUE, TRUE, (IterateObjectCallbackFunc)scan_object_for_xdomain_refs, NULL);
986 for (bigobj = los_object_list; bigobj; bigobj = bigobj->next)
987 scan_object_for_xdomain_refs (bigobj->data, sgen_los_object_size (bigobj), NULL);
991 clear_domain_process_object (char *obj, MonoDomain *domain)
995 process_object_for_domain_clearing (obj, domain);
996 remove = need_remove_object_for_domain (obj, domain);
998 if (remove && ((MonoObject*)obj)->synchronisation) {
999 void **dislink = mono_monitor_get_object_monitor_weak_link ((MonoObject*)obj);
1001 sgen_register_disappearing_link (NULL, dislink, FALSE, TRUE);
1008 clear_domain_process_minor_object_callback (char *obj, size_t size, MonoDomain *domain)
1010 if (clear_domain_process_object (obj, domain))
1011 memset (obj, 0, size);
1015 clear_domain_process_major_object_callback (char *obj, size_t size, MonoDomain *domain)
1017 clear_domain_process_object (obj, domain);
1021 clear_domain_free_major_non_pinned_object_callback (char *obj, size_t size, MonoDomain *domain)
1023 if (need_remove_object_for_domain (obj, domain))
1024 major_collector.free_non_pinned_object (obj, size);
1028 clear_domain_free_major_pinned_object_callback (char *obj, size_t size, MonoDomain *domain)
1030 if (need_remove_object_for_domain (obj, domain))
1031 major_collector.free_pinned_object (obj, size);
1035 * When appdomains are unloaded we can easily remove objects that have finalizers,
1036 * but all the others could still be present in random places on the heap.
1037 * We need a sweep to get rid of them even though it's going to be costly
1039 * The reason we need to remove them is because we access the vtable and class
1040 * structures to know the object size and the reference bitmap: once the domain is
1041 * unloaded the point to random memory.
1044 mono_gc_clear_domain (MonoDomain * domain)
1046 LOSObject *bigobj, *prev;
1051 sgen_stop_world (0);
1053 if (concurrent_collection_in_progress)
1054 sgen_perform_collection (0, GENERATION_OLD, "clear domain", TRUE);
1055 g_assert (!concurrent_collection_in_progress);
1057 sgen_process_fin_stage_entries ();
1058 sgen_process_dislink_stage_entries ();
1060 sgen_clear_nursery_fragments ();
1062 if (xdomain_checks && domain != mono_get_root_domain ()) {
1063 scan_for_registered_roots_in_domain (domain, ROOT_TYPE_NORMAL);
1064 scan_for_registered_roots_in_domain (domain, ROOT_TYPE_WBARRIER);
1065 check_for_xdomain_refs ();
1068 /*Ephemerons and dislinks must be processed before LOS since they might end up pointing
1069 to memory returned to the OS.*/
1070 null_ephemerons_for_domain (domain);
1072 for (i = GENERATION_NURSERY; i < GENERATION_MAX; ++i)
1073 sgen_null_links_for_domain (domain, i);
1075 for (i = GENERATION_NURSERY; i < GENERATION_MAX; ++i)
1076 sgen_remove_finalizers_for_domain (domain, i);
1078 sgen_scan_area_with_callback (nursery_section->data, nursery_section->end_data,
1079 (IterateObjectCallbackFunc)clear_domain_process_minor_object_callback, domain, FALSE);
1081 /* We need two passes over major and large objects because
1082 freeing such objects might give their memory back to the OS
1083 (in the case of large objects) or obliterate its vtable
1084 (pinned objects with major-copying or pinned and non-pinned
1085 objects with major-mark&sweep), but we might need to
1086 dereference a pointer from an object to another object if
1087 the first object is a proxy. */
1088 major_collector.iterate_objects (TRUE, TRUE, (IterateObjectCallbackFunc)clear_domain_process_major_object_callback, domain);
1089 for (bigobj = los_object_list; bigobj; bigobj = bigobj->next)
1090 clear_domain_process_object (bigobj->data, domain);
1093 for (bigobj = los_object_list; bigobj;) {
1094 if (need_remove_object_for_domain (bigobj->data, domain)) {
1095 LOSObject *to_free = bigobj;
1097 prev->next = bigobj->next;
1099 los_object_list = bigobj->next;
1100 bigobj = bigobj->next;
1101 SGEN_LOG (4, "Freeing large object %p", bigobj->data);
1102 sgen_los_free_object (to_free);
1106 bigobj = bigobj->next;
1108 major_collector.iterate_objects (TRUE, FALSE, (IterateObjectCallbackFunc)clear_domain_free_major_non_pinned_object_callback, domain);
1109 major_collector.iterate_objects (FALSE, TRUE, (IterateObjectCallbackFunc)clear_domain_free_major_pinned_object_callback, domain);
1111 if (domain == mono_get_root_domain ()) {
1112 if (G_UNLIKELY (do_pin_stats))
1113 sgen_pin_stats_print_class_stats ();
1114 sgen_object_layout_dump (stdout);
1117 sgen_restart_world (0, NULL);
1123 * sgen_add_to_global_remset:
1125 * The global remset contains locations which point into newspace after
1126 * a minor collection. This can happen if the objects they point to are pinned.
1128 * LOCKING: If called from a parallel collector, the global remset
1129 * lock must be held. For serial collectors that is not necessary.
1132 sgen_add_to_global_remset (gpointer ptr, gpointer obj)
1134 SGEN_ASSERT (5, sgen_ptr_in_nursery (obj), "Target pointer of global remset must be in the nursery");
1136 HEAVY_STAT (++stat_wbarrier_add_to_global_remset);
1138 if (!major_collector.is_concurrent) {
1139 SGEN_ASSERT (5, current_collection_generation != -1, "Global remsets can only be added during collections");
1141 if (current_collection_generation == -1)
1142 SGEN_ASSERT (5, sgen_concurrent_collection_in_progress (), "Global remsets outside of collection pauses can only be added by the concurrent collector");
1145 if (!object_is_pinned (obj))
1146 SGEN_ASSERT (5, sgen_minor_collector.is_split || sgen_concurrent_collection_in_progress (), "Non-pinned objects can only remain in nursery if it is a split nursery");
1147 else if (sgen_cement_lookup_or_register (obj))
1150 remset.record_pointer (ptr);
1152 if (G_UNLIKELY (do_pin_stats))
1153 sgen_pin_stats_register_global_remset (obj);
1155 SGEN_LOG (8, "Adding global remset for %p", ptr);
1156 binary_protocol_global_remset (ptr, obj, (gpointer)SGEN_LOAD_VTABLE (obj));
1159 #ifdef ENABLE_DTRACE
1160 if (G_UNLIKELY (MONO_GC_GLOBAL_REMSET_ADD_ENABLED ())) {
1161 MonoVTable *vt = (MonoVTable*)LOAD_VTABLE (obj);
1162 MONO_GC_GLOBAL_REMSET_ADD ((mword)ptr, (mword)obj, sgen_safe_object_get_size (obj),
1163 vt->klass->name_space, vt->klass->name);
1169 * sgen_drain_gray_stack:
1171 * Scan objects in the gray stack until the stack is empty. This should be called
1172 * frequently after each object is copied, to achieve better locality and cache
1176 sgen_drain_gray_stack (int max_objs, ScanCopyContext ctx)
1179 ScanObjectFunc scan_func = ctx.scan_func;
1180 GrayQueue *queue = ctx.queue;
1182 if (max_objs == -1) {
1184 GRAY_OBJECT_DEQUEUE (queue, obj);
1187 SGEN_LOG (9, "Precise gray object scan %p (%s)", obj, safe_name (obj));
1188 scan_func (obj, queue);
1194 for (i = 0; i != max_objs; ++i) {
1195 GRAY_OBJECT_DEQUEUE (queue, obj);
1198 SGEN_LOG (9, "Precise gray object scan %p (%s)", obj, safe_name (obj));
1199 scan_func (obj, queue);
1201 } while (max_objs < 0);
1207 * Addresses from start to end are already sorted. This function finds
1208 * the object header for each address and pins the object. The
1209 * addresses must be inside the passed section. The (start of the)
1210 * address array is overwritten with the addresses of the actually
1211 * pinned objects. Return the number of pinned objects.
1214 pin_objects_from_addresses (GCMemSection *section, void **start, void **end, void *start_nursery, void *end_nursery, ScanCopyContext ctx)
1219 void *last_obj = NULL;
1220 size_t last_obj_size = 0;
1223 void **definitely_pinned = start;
1224 ScanObjectFunc scan_func = ctx.scan_func;
1225 SgenGrayQueue *queue = ctx.queue;
1227 sgen_nursery_allocator_prepare_for_pinning ();
1229 while (start < end) {
1231 /* the range check should be reduntant */
1232 if (addr != last && addr >= start_nursery && addr < end_nursery) {
1233 SGEN_LOG (5, "Considering pinning addr %p", addr);
1234 /* multiple pointers to the same object */
1235 if (addr >= last_obj && (char*)addr < (char*)last_obj + last_obj_size) {
1239 idx = ((char*)addr - (char*)section->data) / SCAN_START_SIZE;
1240 g_assert (idx < section->num_scan_start);
1241 search_start = (void*)section->scan_starts [idx];
1242 if (!search_start || search_start > addr) {
1245 search_start = section->scan_starts [idx];
1246 if (search_start && search_start <= addr)
1249 if (!search_start || search_start > addr)
1250 search_start = start_nursery;
1252 if (search_start < last_obj)
1253 search_start = (char*)last_obj + last_obj_size;
1254 /* now addr should be in an object a short distance from search_start
1255 * Note that search_start must point to zeroed mem or point to an object.
1259 if (!*(void**)search_start) {
1260 /* Consistency check */
1262 for (frag = nursery_fragments; frag; frag = frag->next) {
1263 if (search_start >= frag->fragment_start && search_start < frag->fragment_end)
1264 g_assert_not_reached ();
1268 search_start = (void*)ALIGN_UP ((mword)search_start + sizeof (gpointer));
1271 last_obj = search_start;
1272 last_obj_size = ALIGN_UP (safe_object_get_size ((MonoObject*)search_start));
1274 if (((MonoObject*)last_obj)->synchronisation == GINT_TO_POINTER (-1)) {
1275 /* Marks the beginning of a nursery fragment, skip */
1277 SGEN_LOG (8, "Pinned try match %p (%s), size %zd", last_obj, safe_name (last_obj), last_obj_size);
1278 if (addr >= search_start && (char*)addr < (char*)last_obj + last_obj_size) {
1280 scan_func (search_start, queue);
1282 SGEN_LOG (4, "Pinned object %p, vtable %p (%s), count %d\n",
1283 search_start, *(void**)search_start, safe_name (search_start), count);
1284 binary_protocol_pin (search_start,
1285 (gpointer)LOAD_VTABLE (search_start),
1286 safe_object_get_size (search_start));
1288 #ifdef ENABLE_DTRACE
1289 if (G_UNLIKELY (MONO_GC_OBJ_PINNED_ENABLED ())) {
1290 int gen = sgen_ptr_in_nursery (search_start) ? GENERATION_NURSERY : GENERATION_OLD;
1291 MonoVTable *vt = (MonoVTable*)LOAD_VTABLE (search_start);
1292 MONO_GC_OBJ_PINNED ((mword)search_start,
1293 sgen_safe_object_get_size (search_start),
1294 vt->klass->name_space, vt->klass->name, gen);
1298 pin_object (search_start);
1299 GRAY_OBJECT_ENQUEUE (queue, search_start);
1300 if (G_UNLIKELY (do_pin_stats))
1301 sgen_pin_stats_register_object (search_start, last_obj_size);
1302 definitely_pinned [count] = search_start;
1308 /* skip to the next object */
1309 search_start = (void*)((char*)search_start + last_obj_size);
1310 } while (search_start <= addr);
1311 /* we either pinned the correct object or we ignored the addr because
1312 * it points to unused zeroed memory.
1318 //printf ("effective pinned: %d (at the end: %d)\n", count, (char*)end_nursery - (char*)last);
1319 if (mono_profiler_get_events () & MONO_PROFILE_GC_ROOTS) {
1320 GCRootReport report;
1322 for (idx = 0; idx < count; ++idx)
1323 add_profile_gc_root (&report, definitely_pinned [idx], MONO_PROFILE_GC_ROOT_PINNING | MONO_PROFILE_GC_ROOT_MISC, 0);
1324 notify_gc_roots (&report);
1326 stat_pinned_objects += count;
1331 sgen_pin_objects_in_section (GCMemSection *section, ScanCopyContext ctx)
1333 int num_entries = section->pin_queue_num_entries;
1335 void **start = section->pin_queue_start;
1337 reduced_to = pin_objects_from_addresses (section, start, start + num_entries,
1338 section->data, section->next_data, ctx);
1339 section->pin_queue_num_entries = reduced_to;
1341 section->pin_queue_start = NULL;
1347 sgen_pin_object (void *object, GrayQueue *queue)
1349 g_assert (!concurrent_collection_in_progress);
1351 if (sgen_collection_is_parallel ()) {
1353 /*object arrives pinned*/
1354 sgen_pin_stage_ptr (object);
1358 SGEN_PIN_OBJECT (object);
1359 sgen_pin_stage_ptr (object);
1361 if (G_UNLIKELY (do_pin_stats))
1362 sgen_pin_stats_register_object (object, safe_object_get_size (object));
1364 GRAY_OBJECT_ENQUEUE (queue, object);
1365 binary_protocol_pin (object, (gpointer)LOAD_VTABLE (object), safe_object_get_size (object));
1367 #ifdef ENABLE_DTRACE
1368 if (G_UNLIKELY (MONO_GC_OBJ_PINNED_ENABLED ())) {
1369 int gen = sgen_ptr_in_nursery (object) ? GENERATION_NURSERY : GENERATION_OLD;
1370 MonoVTable *vt = (MonoVTable*)LOAD_VTABLE (object);
1371 MONO_GC_OBJ_PINNED ((mword)object, sgen_safe_object_get_size (object), vt->klass->name_space, vt->klass->name, gen);
1377 sgen_parallel_pin_or_update (void **ptr, void *obj, MonoVTable *vt, SgenGrayQueue *queue)
1381 gboolean major_pinned = FALSE;
1383 if (sgen_ptr_in_nursery (obj)) {
1384 if (SGEN_CAS_PTR (obj, (void*)((mword)vt | SGEN_PINNED_BIT), vt) == vt) {
1385 sgen_pin_object (obj, queue);
1389 major_collector.pin_major_object (obj, queue);
1390 major_pinned = TRUE;
1393 vtable_word = *(mword*)obj;
1394 /*someone else forwarded it, update the pointer and bail out*/
1395 if (vtable_word & SGEN_FORWARDED_BIT) {
1396 *ptr = (void*)(vtable_word & ~SGEN_VTABLE_BITS_MASK);
1400 /*someone pinned it, nothing to do.*/
1401 if (vtable_word & SGEN_PINNED_BIT || major_pinned)
1406 /* Sort the addresses in array in increasing order.
1407 * Done using a by-the book heap sort. Which has decent and stable performance, is pretty cache efficient.
1410 sgen_sort_addresses (void **array, int size)
1415 for (i = 1; i < size; ++i) {
1418 int parent = (child - 1) / 2;
1420 if (array [parent] >= array [child])
1423 tmp = array [parent];
1424 array [parent] = array [child];
1425 array [child] = tmp;
1431 for (i = size - 1; i > 0; --i) {
1434 array [i] = array [0];
1440 while (root * 2 + 1 <= end) {
1441 int child = root * 2 + 1;
1443 if (child < end && array [child] < array [child + 1])
1445 if (array [root] >= array [child])
1449 array [root] = array [child];
1450 array [child] = tmp;
1458 * Scan the memory between start and end and queue values which could be pointers
1459 * to the area between start_nursery and end_nursery for later consideration.
1460 * Typically used for thread stacks.
1463 conservatively_pin_objects_from (void **start, void **end, void *start_nursery, void *end_nursery, int pin_type)
1467 #ifdef VALGRIND_MAKE_MEM_DEFINED_IF_ADDRESSABLE
1468 VALGRIND_MAKE_MEM_DEFINED_IF_ADDRESSABLE (start, (char*)end - (char*)start);
1471 while (start < end) {
1472 if (*start >= start_nursery && *start < end_nursery) {
1474 * *start can point to the middle of an object
1475 * note: should we handle pointing at the end of an object?
1476 * pinning in C# code disallows pointing at the end of an object
1477 * but there is some small chance that an optimizing C compiler
1478 * may keep the only reference to an object by pointing
1479 * at the end of it. We ignore this small chance for now.
1480 * Pointers to the end of an object are indistinguishable
1481 * from pointers to the start of the next object in memory
1482 * so if we allow that we'd need to pin two objects...
1483 * We queue the pointer in an array, the
1484 * array will then be sorted and uniqued. This way
1485 * we can coalesce several pinning pointers and it should
1486 * be faster since we'd do a memory scan with increasing
1487 * addresses. Note: we can align the address to the allocation
1488 * alignment, so the unique process is more effective.
1490 mword addr = (mword)*start;
1491 addr &= ~(ALLOC_ALIGN - 1);
1492 if (addr >= (mword)start_nursery && addr < (mword)end_nursery) {
1493 SGEN_LOG (6, "Pinning address %p from %p", (void*)addr, start);
1494 sgen_pin_stage_ptr ((void*)addr);
1497 if (G_UNLIKELY (do_pin_stats)) {
1498 if (ptr_in_nursery ((void*)addr))
1499 sgen_pin_stats_register_address ((char*)addr, pin_type);
1505 SGEN_LOG (7, "found %d potential pinned heap pointers", count);
1509 * The first thing we do in a collection is to identify pinned objects.
1510 * This function considers all the areas of memory that need to be
1511 * conservatively scanned.
1514 pin_from_roots (void *start_nursery, void *end_nursery, GrayQueue *queue)
1518 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);
1519 /* objects pinned from the API are inside these roots */
1520 SGEN_HASH_TABLE_FOREACH (&roots_hash [ROOT_TYPE_PINNED], start_root, root) {
1521 SGEN_LOG (6, "Pinned roots %p-%p", start_root, root->end_root);
1522 conservatively_pin_objects_from (start_root, (void**)root->end_root, start_nursery, end_nursery, PIN_TYPE_OTHER);
1523 } SGEN_HASH_TABLE_FOREACH_END;
1524 /* now deal with the thread stacks
1525 * in the future we should be able to conservatively scan only:
1526 * *) the cpu registers
1527 * *) the unmanaged stack frames
1528 * *) the _last_ managed stack frame
1529 * *) pointers slots in managed frames
1531 scan_thread_data (start_nursery, end_nursery, FALSE, queue);
1535 unpin_objects_from_queue (SgenGrayQueue *queue)
1539 GRAY_OBJECT_DEQUEUE (queue, addr);
1542 g_assert (SGEN_OBJECT_IS_PINNED (addr));
1543 SGEN_UNPIN_OBJECT (addr);
1548 CopyOrMarkObjectFunc func;
1550 } UserCopyOrMarkData;
1552 static MonoNativeTlsKey user_copy_or_mark_key;
1555 init_user_copy_or_mark_key (void)
1557 mono_native_tls_alloc (&user_copy_or_mark_key, NULL);
1561 set_user_copy_or_mark_data (UserCopyOrMarkData *data)
1563 mono_native_tls_set_value (user_copy_or_mark_key, data);
1567 single_arg_user_copy_or_mark (void **obj)
1569 UserCopyOrMarkData *data = mono_native_tls_get_value (user_copy_or_mark_key);
1571 data->func (obj, data->queue);
1575 * The memory area from start_root to end_root contains pointers to objects.
1576 * Their position is precisely described by @desc (this means that the pointer
1577 * can be either NULL or the pointer to the start of an object).
1578 * This functions copies them to to_space updates them.
1580 * This function is not thread-safe!
1583 precisely_scan_objects_from (void** start_root, void** end_root, char* n_start, char *n_end, mword desc, ScanCopyContext ctx)
1585 CopyOrMarkObjectFunc copy_func = ctx.copy_func;
1586 SgenGrayQueue *queue = ctx.queue;
1588 switch (desc & ROOT_DESC_TYPE_MASK) {
1589 case ROOT_DESC_BITMAP:
1590 desc >>= ROOT_DESC_TYPE_SHIFT;
1592 if ((desc & 1) && *start_root) {
1593 copy_func (start_root, queue);
1594 SGEN_LOG (9, "Overwrote root at %p with %p", start_root, *start_root);
1595 sgen_drain_gray_stack (-1, ctx);
1601 case ROOT_DESC_COMPLEX: {
1602 gsize *bitmap_data = sgen_get_complex_descriptor_bitmap (desc);
1603 int bwords = (*bitmap_data) - 1;
1604 void **start_run = start_root;
1606 while (bwords-- > 0) {
1607 gsize bmap = *bitmap_data++;
1608 void **objptr = start_run;
1610 if ((bmap & 1) && *objptr) {
1611 copy_func (objptr, queue);
1612 SGEN_LOG (9, "Overwrote root at %p with %p", objptr, *objptr);
1613 sgen_drain_gray_stack (-1, ctx);
1618 start_run += GC_BITS_PER_WORD;
1622 case ROOT_DESC_USER: {
1623 UserCopyOrMarkData data = { copy_func, queue };
1624 MonoGCRootMarkFunc marker = sgen_get_user_descriptor_func (desc);
1625 set_user_copy_or_mark_data (&data);
1626 marker (start_root, single_arg_user_copy_or_mark);
1627 set_user_copy_or_mark_data (NULL);
1630 case ROOT_DESC_RUN_LEN:
1631 g_assert_not_reached ();
1633 g_assert_not_reached ();
1638 reset_heap_boundaries (void)
1640 lowest_heap_address = ~(mword)0;
1641 highest_heap_address = 0;
1645 sgen_update_heap_boundaries (mword low, mword high)
1650 old = lowest_heap_address;
1653 } while (SGEN_CAS_PTR ((gpointer*)&lowest_heap_address, (gpointer)low, (gpointer)old) != (gpointer)old);
1656 old = highest_heap_address;
1659 } while (SGEN_CAS_PTR ((gpointer*)&highest_heap_address, (gpointer)high, (gpointer)old) != (gpointer)old);
1663 * Allocate and setup the data structures needed to be able to allocate objects
1664 * in the nursery. The nursery is stored in nursery_section.
1667 alloc_nursery (void)
1669 GCMemSection *section;
1674 if (nursery_section)
1676 SGEN_LOG (2, "Allocating nursery size: %lu", (unsigned long)sgen_nursery_size);
1677 /* later we will alloc a larger area for the nursery but only activate
1678 * what we need. The rest will be used as expansion if we have too many pinned
1679 * objects in the existing nursery.
1681 /* FIXME: handle OOM */
1682 section = sgen_alloc_internal (INTERNAL_MEM_SECTION);
1684 alloc_size = sgen_nursery_size;
1686 /* If there isn't enough space even for the nursery we should simply abort. */
1687 g_assert (sgen_memgov_try_alloc_space (alloc_size, SPACE_NURSERY));
1689 #ifdef SGEN_ALIGN_NURSERY
1690 data = major_collector.alloc_heap (alloc_size, alloc_size, DEFAULT_NURSERY_BITS);
1692 data = major_collector.alloc_heap (alloc_size, 0, DEFAULT_NURSERY_BITS);
1694 sgen_update_heap_boundaries ((mword)data, (mword)(data + sgen_nursery_size));
1695 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 ());
1696 section->data = section->next_data = data;
1697 section->size = alloc_size;
1698 section->end_data = data + sgen_nursery_size;
1699 scan_starts = (alloc_size + SCAN_START_SIZE - 1) / SCAN_START_SIZE;
1700 section->scan_starts = sgen_alloc_internal_dynamic (sizeof (char*) * scan_starts, INTERNAL_MEM_SCAN_STARTS, TRUE);
1701 section->num_scan_start = scan_starts;
1703 nursery_section = section;
1705 sgen_nursery_allocator_set_nursery_bounds (data, data + sgen_nursery_size);
1709 mono_gc_get_nursery (int *shift_bits, size_t *size)
1711 *size = sgen_nursery_size;
1712 #ifdef SGEN_ALIGN_NURSERY
1713 *shift_bits = DEFAULT_NURSERY_BITS;
1717 return sgen_get_nursery_start ();
1721 mono_gc_set_current_thread_appdomain (MonoDomain *domain)
1723 SgenThreadInfo *info = mono_thread_info_current ();
1725 /* Could be called from sgen_thread_unregister () with a NULL info */
1728 info->stopped_domain = domain;
1733 mono_gc_precise_stack_mark_enabled (void)
1735 return !conservative_stack_mark;
1739 mono_gc_get_logfile (void)
1741 return gc_debug_file;
1745 report_finalizer_roots_list (FinalizeReadyEntry *list)
1747 GCRootReport report;
1748 FinalizeReadyEntry *fin;
1751 for (fin = list; fin; fin = fin->next) {
1754 add_profile_gc_root (&report, fin->object, MONO_PROFILE_GC_ROOT_FINALIZER, 0);
1756 notify_gc_roots (&report);
1760 report_finalizer_roots (void)
1762 report_finalizer_roots_list (fin_ready_list);
1763 report_finalizer_roots_list (critical_fin_list);
1766 static GCRootReport *root_report;
1769 single_arg_report_root (void **obj)
1772 add_profile_gc_root (root_report, *obj, MONO_PROFILE_GC_ROOT_OTHER, 0);
1776 precisely_report_roots_from (GCRootReport *report, void** start_root, void** end_root, mword desc)
1778 switch (desc & ROOT_DESC_TYPE_MASK) {
1779 case ROOT_DESC_BITMAP:
1780 desc >>= ROOT_DESC_TYPE_SHIFT;
1782 if ((desc & 1) && *start_root) {
1783 add_profile_gc_root (report, *start_root, MONO_PROFILE_GC_ROOT_OTHER, 0);
1789 case ROOT_DESC_COMPLEX: {
1790 gsize *bitmap_data = sgen_get_complex_descriptor_bitmap (desc);
1791 int bwords = (*bitmap_data) - 1;
1792 void **start_run = start_root;
1794 while (bwords-- > 0) {
1795 gsize bmap = *bitmap_data++;
1796 void **objptr = start_run;
1798 if ((bmap & 1) && *objptr) {
1799 add_profile_gc_root (report, *objptr, MONO_PROFILE_GC_ROOT_OTHER, 0);
1804 start_run += GC_BITS_PER_WORD;
1808 case ROOT_DESC_USER: {
1809 MonoGCRootMarkFunc marker = sgen_get_user_descriptor_func (desc);
1810 root_report = report;
1811 marker (start_root, single_arg_report_root);
1814 case ROOT_DESC_RUN_LEN:
1815 g_assert_not_reached ();
1817 g_assert_not_reached ();
1822 report_registered_roots_by_type (int root_type)
1824 GCRootReport report;
1828 SGEN_HASH_TABLE_FOREACH (&roots_hash [root_type], start_root, root) {
1829 SGEN_LOG (6, "Precise root scan %p-%p (desc: %p)", start_root, root->end_root, (void*)root->root_desc);
1830 precisely_report_roots_from (&report, start_root, (void**)root->end_root, root->root_desc);
1831 } SGEN_HASH_TABLE_FOREACH_END;
1832 notify_gc_roots (&report);
1836 report_registered_roots (void)
1838 report_registered_roots_by_type (ROOT_TYPE_NORMAL);
1839 report_registered_roots_by_type (ROOT_TYPE_WBARRIER);
1843 scan_finalizer_entries (FinalizeReadyEntry *list, ScanCopyContext ctx)
1845 CopyOrMarkObjectFunc copy_func = ctx.copy_func;
1846 SgenGrayQueue *queue = ctx.queue;
1847 FinalizeReadyEntry *fin;
1849 for (fin = list; fin; fin = fin->next) {
1852 SGEN_LOG (5, "Scan of fin ready object: %p (%s)\n", fin->object, safe_name (fin->object));
1853 copy_func (&fin->object, queue);
1858 generation_name (int generation)
1860 switch (generation) {
1861 case GENERATION_NURSERY: return "nursery";
1862 case GENERATION_OLD: return "old";
1863 default: g_assert_not_reached ();
1868 sgen_generation_name (int generation)
1870 return generation_name (generation);
1873 SgenObjectOperations *
1874 sgen_get_current_object_ops (void){
1875 return ¤t_object_ops;
1880 finish_gray_stack (int generation, GrayQueue *queue)
1884 int done_with_ephemerons, ephemeron_rounds = 0;
1885 CopyOrMarkObjectFunc copy_func = current_object_ops.copy_or_mark_object;
1886 ScanObjectFunc scan_func = current_object_ops.scan_object;
1887 ScanCopyContext ctx = { scan_func, copy_func, queue };
1888 char *start_addr = generation == GENERATION_NURSERY ? sgen_get_nursery_start () : NULL;
1889 char *end_addr = generation == GENERATION_NURSERY ? sgen_get_nursery_end () : (char*)-1;
1892 * We copied all the reachable objects. Now it's the time to copy
1893 * the objects that were not referenced by the roots, but by the copied objects.
1894 * we built a stack of objects pointed to by gray_start: they are
1895 * additional roots and we may add more items as we go.
1896 * We loop until gray_start == gray_objects which means no more objects have
1897 * been added. Note this is iterative: no recursion is involved.
1898 * We need to walk the LO list as well in search of marked big objects
1899 * (use a flag since this is needed only on major collections). We need to loop
1900 * here as well, so keep a counter of marked LO (increasing it in copy_object).
1901 * To achieve better cache locality and cache usage, we drain the gray stack
1902 * frequently, after each object is copied, and just finish the work here.
1904 sgen_drain_gray_stack (-1, ctx);
1906 SGEN_LOG (2, "%s generation done", generation_name (generation));
1909 Reset bridge data, we might have lingering data from a previous collection if this is a major
1910 collection trigged by minor overflow.
1912 We must reset the gathered bridges since their original block might be evacuated due to major
1913 fragmentation in the meanwhile and the bridge code should not have to deal with that.
1915 sgen_bridge_reset_data ();
1918 * Walk the ephemeron tables marking all values with reachable keys. This must be completely done
1919 * before processing finalizable objects and non-tracking weak links to avoid finalizing/clearing
1920 * objects that are in fact reachable.
1922 done_with_ephemerons = 0;
1924 done_with_ephemerons = mark_ephemerons_in_range (ctx);
1925 sgen_drain_gray_stack (-1, ctx);
1927 } while (!done_with_ephemerons);
1929 sgen_scan_togglerefs (start_addr, end_addr, ctx);
1931 if (sgen_need_bridge_processing ()) {
1932 sgen_collect_bridge_objects (generation, ctx);
1933 if (generation == GENERATION_OLD)
1934 sgen_collect_bridge_objects (GENERATION_NURSERY, ctx);
1938 Make sure we drain the gray stack before processing disappearing links and finalizers.
1939 If we don't make sure it is empty we might wrongly see a live object as dead.
1941 sgen_drain_gray_stack (-1, ctx);
1944 We must clear weak links that don't track resurrection before processing object ready for
1945 finalization so they can be cleared before that.
1947 sgen_null_link_in_range (generation, TRUE, ctx);
1948 if (generation == GENERATION_OLD)
1949 sgen_null_link_in_range (GENERATION_NURSERY, TRUE, ctx);
1952 /* walk the finalization queue and move also the objects that need to be
1953 * finalized: use the finalized objects as new roots so the objects they depend
1954 * on are also not reclaimed. As with the roots above, only objects in the nursery
1955 * are marked/copied.
1957 sgen_finalize_in_range (generation, ctx);
1958 if (generation == GENERATION_OLD)
1959 sgen_finalize_in_range (GENERATION_NURSERY, ctx);
1960 /* drain the new stack that might have been created */
1961 SGEN_LOG (6, "Precise scan of gray area post fin");
1962 sgen_drain_gray_stack (-1, ctx);
1965 * This must be done again after processing finalizable objects since CWL slots are cleared only after the key is finalized.
1967 done_with_ephemerons = 0;
1969 done_with_ephemerons = mark_ephemerons_in_range (ctx);
1970 sgen_drain_gray_stack (-1, ctx);
1972 } while (!done_with_ephemerons);
1975 * Clear ephemeron pairs with unreachable keys.
1976 * We pass the copy func so we can figure out if an array was promoted or not.
1978 clear_unreachable_ephemerons (ctx);
1981 SGEN_LOG (2, "Finalize queue handling scan for %s generation: %d usecs %d ephemeron rounds", generation_name (generation), TV_ELAPSED (atv, btv), ephemeron_rounds);
1984 * handle disappearing links
1985 * Note we do this after checking the finalization queue because if an object
1986 * survives (at least long enough to be finalized) we don't clear the link.
1987 * This also deals with a possible issue with the monitor reclamation: with the Boehm
1988 * GC a finalized object my lose the monitor because it is cleared before the finalizer is
1991 g_assert (sgen_gray_object_queue_is_empty (queue));
1993 sgen_null_link_in_range (generation, FALSE, ctx);
1994 if (generation == GENERATION_OLD)
1995 sgen_null_link_in_range (GENERATION_NURSERY, FALSE, ctx);
1996 if (sgen_gray_object_queue_is_empty (queue))
1998 sgen_drain_gray_stack (-1, ctx);
2001 g_assert (sgen_gray_object_queue_is_empty (queue));
2005 sgen_check_section_scan_starts (GCMemSection *section)
2008 for (i = 0; i < section->num_scan_start; ++i) {
2009 if (section->scan_starts [i]) {
2010 guint size = safe_object_get_size ((MonoObject*) section->scan_starts [i]);
2011 g_assert (size >= sizeof (MonoObject) && size <= MAX_SMALL_OBJ_SIZE);
2017 check_scan_starts (void)
2019 if (!do_scan_starts_check)
2021 sgen_check_section_scan_starts (nursery_section);
2022 major_collector.check_scan_starts ();
2026 scan_from_registered_roots (char *addr_start, char *addr_end, int root_type, ScanCopyContext ctx)
2030 SGEN_HASH_TABLE_FOREACH (&roots_hash [root_type], start_root, root) {
2031 SGEN_LOG (6, "Precise root scan %p-%p (desc: %p)", start_root, root->end_root, (void*)root->root_desc);
2032 precisely_scan_objects_from (start_root, (void**)root->end_root, addr_start, addr_end, root->root_desc, ctx);
2033 } SGEN_HASH_TABLE_FOREACH_END;
2037 sgen_dump_occupied (char *start, char *end, char *section_start)
2039 fprintf (heap_dump_file, "<occupied offset=\"%td\" size=\"%td\"/>\n", start - section_start, end - start);
2043 sgen_dump_section (GCMemSection *section, const char *type)
2045 char *start = section->data;
2046 char *end = section->data + section->size;
2047 char *occ_start = NULL;
2049 char *old_start = NULL; /* just for debugging */
2051 fprintf (heap_dump_file, "<section type=\"%s\" size=\"%lu\">\n", type, (unsigned long)section->size);
2053 while (start < end) {
2057 if (!*(void**)start) {
2059 sgen_dump_occupied (occ_start, start, section->data);
2062 start += sizeof (void*); /* should be ALLOC_ALIGN, really */
2065 g_assert (start < section->next_data);
2070 vt = (GCVTable*)LOAD_VTABLE (start);
2073 size = ALIGN_UP (safe_object_get_size ((MonoObject*) start));
2076 fprintf (heap_dump_file, "<object offset=\"%d\" class=\"%s.%s\" size=\"%d\"/>\n",
2077 start - section->data,
2078 vt->klass->name_space, vt->klass->name,
2086 sgen_dump_occupied (occ_start, start, section->data);
2088 fprintf (heap_dump_file, "</section>\n");
2092 dump_object (MonoObject *obj, gboolean dump_location)
2094 static char class_name [1024];
2096 MonoClass *class = mono_object_class (obj);
2100 * Python's XML parser is too stupid to parse angle brackets
2101 * in strings, so we just ignore them;
2104 while (class->name [i] && j < sizeof (class_name) - 1) {
2105 if (!strchr ("<>\"", class->name [i]))
2106 class_name [j++] = class->name [i];
2109 g_assert (j < sizeof (class_name));
2112 fprintf (heap_dump_file, "<object class=\"%s.%s\" size=\"%d\"",
2113 class->name_space, class_name,
2114 safe_object_get_size (obj));
2115 if (dump_location) {
2116 const char *location;
2117 if (ptr_in_nursery (obj))
2118 location = "nursery";
2119 else if (safe_object_get_size (obj) <= MAX_SMALL_OBJ_SIZE)
2123 fprintf (heap_dump_file, " location=\"%s\"", location);
2125 fprintf (heap_dump_file, "/>\n");
2129 dump_heap (const char *type, int num, const char *reason)
2134 fprintf (heap_dump_file, "<collection type=\"%s\" num=\"%d\"", type, num);
2136 fprintf (heap_dump_file, " reason=\"%s\"", reason);
2137 fprintf (heap_dump_file, ">\n");
2138 fprintf (heap_dump_file, "<other-mem-usage type=\"mempools\" size=\"%ld\"/>\n", mono_mempool_get_bytes_allocated ());
2139 sgen_dump_internal_mem_usage (heap_dump_file);
2140 fprintf (heap_dump_file, "<pinned type=\"stack\" bytes=\"%zu\"/>\n", sgen_pin_stats_get_pinned_byte_count (PIN_TYPE_STACK));
2141 /* fprintf (heap_dump_file, "<pinned type=\"static-data\" bytes=\"%d\"/>\n", pinned_byte_counts [PIN_TYPE_STATIC_DATA]); */
2142 fprintf (heap_dump_file, "<pinned type=\"other\" bytes=\"%zu\"/>\n", sgen_pin_stats_get_pinned_byte_count (PIN_TYPE_OTHER));
2144 fprintf (heap_dump_file, "<pinned-objects>\n");
2145 for (list = sgen_pin_stats_get_object_list (); list; list = list->next)
2146 dump_object (list->obj, TRUE);
2147 fprintf (heap_dump_file, "</pinned-objects>\n");
2149 sgen_dump_section (nursery_section, "nursery");
2151 major_collector.dump_heap (heap_dump_file);
2153 fprintf (heap_dump_file, "<los>\n");
2154 for (bigobj = los_object_list; bigobj; bigobj = bigobj->next)
2155 dump_object ((MonoObject*)bigobj->data, FALSE);
2156 fprintf (heap_dump_file, "</los>\n");
2158 fprintf (heap_dump_file, "</collection>\n");
2162 sgen_register_moved_object (void *obj, void *destination)
2164 g_assert (mono_profiler_events & MONO_PROFILE_GC_MOVES);
2166 /* FIXME: handle this for parallel collector */
2167 g_assert (!sgen_collection_is_parallel ());
2169 if (moved_objects_idx == MOVED_OBJECTS_NUM) {
2170 mono_profiler_gc_moves (moved_objects, moved_objects_idx);
2171 moved_objects_idx = 0;
2173 moved_objects [moved_objects_idx++] = obj;
2174 moved_objects [moved_objects_idx++] = destination;
2180 static gboolean inited = FALSE;
2185 mono_counters_register ("Minor fragment clear", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_minor_pre_collection_fragment_clear);
2186 mono_counters_register ("Minor pinning", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_minor_pinning);
2187 mono_counters_register ("Minor scan remembered set", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_minor_scan_remsets);
2188 mono_counters_register ("Minor scan pinned", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_minor_scan_pinned);
2189 mono_counters_register ("Minor scan registered roots", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_minor_scan_registered_roots);
2190 mono_counters_register ("Minor scan thread data", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_minor_scan_thread_data);
2191 mono_counters_register ("Minor finish gray stack", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_minor_finish_gray_stack);
2192 mono_counters_register ("Minor fragment creation", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_minor_fragment_creation);
2194 mono_counters_register ("Major fragment clear", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_major_pre_collection_fragment_clear);
2195 mono_counters_register ("Major pinning", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_major_pinning);
2196 mono_counters_register ("Major scan pinned", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_major_scan_pinned);
2197 mono_counters_register ("Major scan registered roots", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_major_scan_registered_roots);
2198 mono_counters_register ("Major scan thread data", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_major_scan_thread_data);
2199 mono_counters_register ("Major scan alloc_pinned", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_major_scan_alloc_pinned);
2200 mono_counters_register ("Major scan finalized", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_major_scan_finalized);
2201 mono_counters_register ("Major scan big objects", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_major_scan_big_objects);
2202 mono_counters_register ("Major finish gray stack", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_major_finish_gray_stack);
2203 mono_counters_register ("Major free big objects", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_major_free_bigobjs);
2204 mono_counters_register ("Major LOS sweep", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_major_los_sweep);
2205 mono_counters_register ("Major sweep", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_major_sweep);
2206 mono_counters_register ("Major fragment creation", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_major_fragment_creation);
2208 mono_counters_register ("Number of pinned objects", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_pinned_objects);
2210 #ifdef HEAVY_STATISTICS
2211 mono_counters_register ("WBarrier remember pointer", MONO_COUNTER_GC | MONO_COUNTER_INT, &stat_wbarrier_add_to_global_remset);
2212 mono_counters_register ("WBarrier set field", MONO_COUNTER_GC | MONO_COUNTER_INT, &stat_wbarrier_set_field);
2213 mono_counters_register ("WBarrier set arrayref", MONO_COUNTER_GC | MONO_COUNTER_INT, &stat_wbarrier_set_arrayref);
2214 mono_counters_register ("WBarrier arrayref copy", MONO_COUNTER_GC | MONO_COUNTER_INT, &stat_wbarrier_arrayref_copy);
2215 mono_counters_register ("WBarrier generic store called", MONO_COUNTER_GC | MONO_COUNTER_INT, &stat_wbarrier_generic_store);
2216 mono_counters_register ("WBarrier set root", MONO_COUNTER_GC | MONO_COUNTER_INT, &stat_wbarrier_set_root);
2217 mono_counters_register ("WBarrier value copy", MONO_COUNTER_GC | MONO_COUNTER_INT, &stat_wbarrier_value_copy);
2218 mono_counters_register ("WBarrier object copy", MONO_COUNTER_GC | MONO_COUNTER_INT, &stat_wbarrier_object_copy);
2220 mono_counters_register ("# objects allocated degraded", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_objects_alloced_degraded);
2221 mono_counters_register ("bytes allocated degraded", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_bytes_alloced_degraded);
2223 mono_counters_register ("# copy_object() called (nursery)", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_copy_object_called_nursery);
2224 mono_counters_register ("# objects copied (nursery)", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_objects_copied_nursery);
2225 mono_counters_register ("# copy_object() called (major)", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_copy_object_called_major);
2226 mono_counters_register ("# objects copied (major)", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_objects_copied_major);
2228 mono_counters_register ("# scan_object() called (nursery)", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_scan_object_called_nursery);
2229 mono_counters_register ("# scan_object() called (major)", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_scan_object_called_major);
2231 mono_counters_register ("Slots allocated in vain", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_slots_allocated_in_vain);
2233 mono_counters_register ("# nursery copy_object() failed from space", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_nursery_copy_object_failed_from_space);
2234 mono_counters_register ("# nursery copy_object() failed forwarded", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_nursery_copy_object_failed_forwarded);
2235 mono_counters_register ("# nursery copy_object() failed pinned", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_nursery_copy_object_failed_pinned);
2236 mono_counters_register ("# nursery copy_object() failed to space", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_nursery_copy_object_failed_to_space);
2238 sgen_nursery_allocator_init_heavy_stats ();
2239 sgen_alloc_init_heavy_stats ();
2247 reset_pinned_from_failed_allocation (void)
2249 bytes_pinned_from_failed_allocation = 0;
2253 sgen_set_pinned_from_failed_allocation (mword objsize)
2255 bytes_pinned_from_failed_allocation += objsize;
2259 sgen_collection_is_parallel (void)
2261 switch (current_collection_generation) {
2262 case GENERATION_NURSERY:
2263 return nursery_collection_is_parallel;
2264 case GENERATION_OLD:
2265 return major_collector.is_parallel;
2267 g_error ("Invalid current generation %d", current_collection_generation);
2272 sgen_collection_is_concurrent (void)
2274 switch (current_collection_generation) {
2275 case GENERATION_NURSERY:
2277 case GENERATION_OLD:
2278 return concurrent_collection_in_progress;
2280 g_error ("Invalid current generation %d", current_collection_generation);
2285 sgen_concurrent_collection_in_progress (void)
2287 return concurrent_collection_in_progress;
2294 } FinishRememberedSetScanJobData;
2297 job_finish_remembered_set_scan (WorkerData *worker_data, void *job_data_untyped)
2299 FinishRememberedSetScanJobData *job_data = job_data_untyped;
2301 remset.finish_scan_remsets (job_data->heap_start, job_data->heap_end, sgen_workers_get_job_gray_queue (worker_data));
2302 sgen_free_internal_dynamic (job_data, sizeof (FinishRememberedSetScanJobData), INTERNAL_MEM_WORKER_JOB_DATA);
2307 CopyOrMarkObjectFunc copy_or_mark_func;
2308 ScanObjectFunc scan_func;
2312 } ScanFromRegisteredRootsJobData;
2315 job_scan_from_registered_roots (WorkerData *worker_data, void *job_data_untyped)
2317 ScanFromRegisteredRootsJobData *job_data = job_data_untyped;
2318 ScanCopyContext ctx = { job_data->scan_func, job_data->copy_or_mark_func,
2319 sgen_workers_get_job_gray_queue (worker_data) };
2321 scan_from_registered_roots (job_data->heap_start, job_data->heap_end, job_data->root_type, ctx);
2322 sgen_free_internal_dynamic (job_data, sizeof (ScanFromRegisteredRootsJobData), INTERNAL_MEM_WORKER_JOB_DATA);
2329 } ScanThreadDataJobData;
2332 job_scan_thread_data (WorkerData *worker_data, void *job_data_untyped)
2334 ScanThreadDataJobData *job_data = job_data_untyped;
2336 scan_thread_data (job_data->heap_start, job_data->heap_end, TRUE,
2337 sgen_workers_get_job_gray_queue (worker_data));
2338 sgen_free_internal_dynamic (job_data, sizeof (ScanThreadDataJobData), INTERNAL_MEM_WORKER_JOB_DATA);
2343 FinalizeReadyEntry *list;
2344 } ScanFinalizerEntriesJobData;
2347 job_scan_finalizer_entries (WorkerData *worker_data, void *job_data_untyped)
2349 ScanFinalizerEntriesJobData *job_data = job_data_untyped;
2350 ScanCopyContext ctx = { NULL, current_object_ops.copy_or_mark_object, sgen_workers_get_job_gray_queue (worker_data) };
2352 scan_finalizer_entries (job_data->list, ctx);
2353 sgen_free_internal_dynamic (job_data, sizeof (ScanFinalizerEntriesJobData), INTERNAL_MEM_WORKER_JOB_DATA);
2357 job_scan_major_mod_union_cardtable (WorkerData *worker_data, void *job_data_untyped)
2359 g_assert (concurrent_collection_in_progress);
2360 major_collector.scan_card_table (TRUE, sgen_workers_get_job_gray_queue (worker_data));
2364 job_scan_los_mod_union_cardtable (WorkerData *worker_data, void *job_data_untyped)
2366 g_assert (concurrent_collection_in_progress);
2367 sgen_los_scan_card_table (TRUE, sgen_workers_get_job_gray_queue (worker_data));
2371 verify_scan_starts (char *start, char *end)
2375 for (i = 0; i < nursery_section->num_scan_start; ++i) {
2376 char *addr = nursery_section->scan_starts [i];
2377 if (addr > start && addr < end)
2378 SGEN_LOG (1, "NFC-BAD SCAN START [%d] %p for obj [%p %p]", i, addr, start, end);
2383 verify_nursery (void)
2385 char *start, *end, *cur, *hole_start;
2387 if (!do_verify_nursery)
2390 /*This cleans up unused fragments */
2391 sgen_nursery_allocator_prepare_for_pinning ();
2393 hole_start = start = cur = sgen_get_nursery_start ();
2394 end = sgen_get_nursery_end ();
2399 if (!*(void**)cur) {
2400 cur += sizeof (void*);
2404 if (object_is_forwarded (cur))
2405 SGEN_LOG (1, "FORWARDED OBJ %p", cur);
2406 else if (object_is_pinned (cur))
2407 SGEN_LOG (1, "PINNED OBJ %p", cur);
2409 ss = safe_object_get_size ((MonoObject*)cur);
2410 size = ALIGN_UP (safe_object_get_size ((MonoObject*)cur));
2411 verify_scan_starts (cur, cur + size);
2412 if (do_dump_nursery_content) {
2413 if (cur > hole_start)
2414 SGEN_LOG (1, "HOLE [%p %p %d]", hole_start, cur, (int)(cur - hole_start));
2415 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 ());
2423 * Checks that no objects in the nursery are fowarded or pinned. This
2424 * is a precondition to restarting the mutator while doing a
2425 * concurrent collection. Note that we don't clear fragments because
2426 * we depend on that having happened earlier.
2429 check_nursery_is_clean (void)
2431 char *start, *end, *cur;
2433 start = cur = sgen_get_nursery_start ();
2434 end = sgen_get_nursery_end ();
2439 if (!*(void**)cur) {
2440 cur += sizeof (void*);
2444 g_assert (!object_is_forwarded (cur));
2445 g_assert (!object_is_pinned (cur));
2447 ss = safe_object_get_size ((MonoObject*)cur);
2448 size = ALIGN_UP (safe_object_get_size ((MonoObject*)cur));
2449 verify_scan_starts (cur, cur + size);
2456 init_gray_queue (void)
2458 if (sgen_collection_is_parallel () || sgen_collection_is_concurrent ()) {
2459 sgen_workers_init_distribute_gray_queue ();
2460 sgen_gray_object_queue_init_with_alloc_prepare (&gray_queue, NULL,
2461 gray_queue_redirect, sgen_workers_get_distribute_section_gray_queue ());
2463 sgen_gray_object_queue_init (&gray_queue, NULL);
2468 pin_stage_object_callback (char *obj, size_t size, void *data)
2470 sgen_pin_stage_ptr (obj);
2471 /* FIXME: do pin stats if enabled */
2475 * Collect objects in the nursery. Returns whether to trigger a major
2479 collect_nursery (SgenGrayQueue *unpin_queue, gboolean finish_up_concurrent_mark)
2481 gboolean needs_major;
2482 size_t max_garbage_amount;
2484 FinishRememberedSetScanJobData *frssjd;
2485 ScanFromRegisteredRootsJobData *scrrjd_normal, *scrrjd_wbarrier;
2486 ScanFinalizerEntriesJobData *sfejd_fin_ready, *sfejd_critical_fin;
2487 ScanThreadDataJobData *stdjd;
2488 mword fragment_total;
2489 ScanCopyContext ctx;
2490 TV_DECLARE (all_atv);
2491 TV_DECLARE (all_btv);
2495 if (disable_minor_collections)
2498 MONO_GC_BEGIN (GENERATION_NURSERY);
2499 binary_protocol_collection_begin (stat_minor_gcs, GENERATION_NURSERY);
2503 #ifndef DISABLE_PERFCOUNTERS
2504 mono_perfcounters->gc_collections0++;
2507 current_collection_generation = GENERATION_NURSERY;
2508 if (sgen_collection_is_parallel ())
2509 current_object_ops = sgen_minor_collector.parallel_ops;
2511 current_object_ops = sgen_minor_collector.serial_ops;
2513 reset_pinned_from_failed_allocation ();
2515 check_scan_starts ();
2517 sgen_nursery_alloc_prepare_for_minor ();
2521 nursery_next = sgen_nursery_alloc_get_upper_alloc_bound ();
2522 /* FIXME: optimize later to use the higher address where an object can be present */
2523 nursery_next = MAX (nursery_next, sgen_get_nursery_end ());
2525 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 ()));
2526 max_garbage_amount = nursery_next - sgen_get_nursery_start ();
2527 g_assert (nursery_section->size >= max_garbage_amount);
2529 /* world must be stopped already */
2530 TV_GETTIME (all_atv);
2534 time_minor_pre_collection_fragment_clear += TV_ELAPSED (atv, btv);
2536 if (xdomain_checks) {
2537 sgen_clear_nursery_fragments ();
2538 check_for_xdomain_refs ();
2541 nursery_section->next_data = nursery_next;
2543 major_collector.start_nursery_collection ();
2545 sgen_memgov_minor_collection_start ();
2550 gc_stats.minor_gc_count ++;
2552 MONO_GC_CHECKPOINT_1 (GENERATION_NURSERY);
2554 sgen_process_fin_stage_entries ();
2555 sgen_process_dislink_stage_entries ();
2557 MONO_GC_CHECKPOINT_2 (GENERATION_NURSERY);
2559 /* pin from pinned handles */
2560 sgen_init_pinning ();
2561 mono_profiler_gc_event (MONO_GC_EVENT_MARK_START, 0);
2562 pin_from_roots (sgen_get_nursery_start (), nursery_next, WORKERS_DISTRIBUTE_GRAY_QUEUE);
2563 /* pin cemented objects */
2564 sgen_cement_iterate (pin_stage_object_callback, NULL);
2565 /* identify pinned objects */
2566 sgen_optimize_pin_queue (0);
2567 sgen_pinning_setup_section (nursery_section);
2568 ctx.scan_func = NULL;
2569 ctx.copy_func = NULL;
2570 ctx.queue = WORKERS_DISTRIBUTE_GRAY_QUEUE;
2571 sgen_pin_objects_in_section (nursery_section, ctx);
2572 sgen_pinning_trim_queue_to_section (nursery_section);
2575 time_minor_pinning += TV_ELAPSED (btv, atv);
2576 SGEN_LOG (2, "Finding pinned pointers: %d in %d usecs", sgen_get_pinned_count (), TV_ELAPSED (btv, atv));
2577 SGEN_LOG (4, "Start scan with %d pinned objects", sgen_get_pinned_count ());
2579 MONO_GC_CHECKPOINT_3 (GENERATION_NURSERY);
2581 if (whole_heap_check_before_collection) {
2582 sgen_clear_nursery_fragments ();
2583 sgen_check_whole_heap (finish_up_concurrent_mark);
2585 if (consistency_check_at_minor_collection)
2586 sgen_check_consistency ();
2588 sgen_workers_start_all_workers ();
2589 sgen_workers_start_marking ();
2591 frssjd = sgen_alloc_internal_dynamic (sizeof (FinishRememberedSetScanJobData), INTERNAL_MEM_WORKER_JOB_DATA, TRUE);
2592 frssjd->heap_start = sgen_get_nursery_start ();
2593 frssjd->heap_end = nursery_next;
2594 sgen_workers_enqueue_job (job_finish_remembered_set_scan, frssjd);
2596 /* we don't have complete write barrier yet, so we scan all the old generation sections */
2598 time_minor_scan_remsets += TV_ELAPSED (atv, btv);
2599 SGEN_LOG (2, "Old generation scan: %d usecs", TV_ELAPSED (atv, btv));
2601 MONO_GC_CHECKPOINT_4 (GENERATION_NURSERY);
2603 if (!sgen_collection_is_parallel ()) {
2604 ctx.scan_func = current_object_ops.scan_object;
2605 ctx.copy_func = NULL;
2606 ctx.queue = &gray_queue;
2607 sgen_drain_gray_stack (-1, ctx);
2610 if (mono_profiler_get_events () & MONO_PROFILE_GC_ROOTS)
2611 report_registered_roots ();
2612 if (mono_profiler_get_events () & MONO_PROFILE_GC_ROOTS)
2613 report_finalizer_roots ();
2615 time_minor_scan_pinned += TV_ELAPSED (btv, atv);
2617 MONO_GC_CHECKPOINT_5 (GENERATION_NURSERY);
2619 /* registered roots, this includes static fields */
2620 scrrjd_normal = sgen_alloc_internal_dynamic (sizeof (ScanFromRegisteredRootsJobData), INTERNAL_MEM_WORKER_JOB_DATA, TRUE);
2621 scrrjd_normal->copy_or_mark_func = current_object_ops.copy_or_mark_object;
2622 scrrjd_normal->scan_func = current_object_ops.scan_object;
2623 scrrjd_normal->heap_start = sgen_get_nursery_start ();
2624 scrrjd_normal->heap_end = nursery_next;
2625 scrrjd_normal->root_type = ROOT_TYPE_NORMAL;
2626 sgen_workers_enqueue_job (job_scan_from_registered_roots, scrrjd_normal);
2628 scrrjd_wbarrier = sgen_alloc_internal_dynamic (sizeof (ScanFromRegisteredRootsJobData), INTERNAL_MEM_WORKER_JOB_DATA, TRUE);
2629 scrrjd_wbarrier->copy_or_mark_func = current_object_ops.copy_or_mark_object;
2630 scrrjd_wbarrier->scan_func = current_object_ops.scan_object;
2631 scrrjd_wbarrier->heap_start = sgen_get_nursery_start ();
2632 scrrjd_wbarrier->heap_end = nursery_next;
2633 scrrjd_wbarrier->root_type = ROOT_TYPE_WBARRIER;
2634 sgen_workers_enqueue_job (job_scan_from_registered_roots, scrrjd_wbarrier);
2637 time_minor_scan_registered_roots += TV_ELAPSED (atv, btv);
2639 MONO_GC_CHECKPOINT_6 (GENERATION_NURSERY);
2642 stdjd = sgen_alloc_internal_dynamic (sizeof (ScanThreadDataJobData), INTERNAL_MEM_WORKER_JOB_DATA, TRUE);
2643 stdjd->heap_start = sgen_get_nursery_start ();
2644 stdjd->heap_end = nursery_next;
2645 sgen_workers_enqueue_job (job_scan_thread_data, stdjd);
2648 time_minor_scan_thread_data += TV_ELAPSED (btv, atv);
2651 MONO_GC_CHECKPOINT_7 (GENERATION_NURSERY);
2653 g_assert (!sgen_collection_is_parallel () && !sgen_collection_is_concurrent ());
2655 if (sgen_collection_is_parallel () || sgen_collection_is_concurrent ())
2656 g_assert (sgen_gray_object_queue_is_empty (&gray_queue));
2658 /* Scan the list of objects ready for finalization. If */
2659 sfejd_fin_ready = sgen_alloc_internal_dynamic (sizeof (ScanFinalizerEntriesJobData), INTERNAL_MEM_WORKER_JOB_DATA, TRUE);
2660 sfejd_fin_ready->list = fin_ready_list;
2661 sgen_workers_enqueue_job (job_scan_finalizer_entries, sfejd_fin_ready);
2663 sfejd_critical_fin = sgen_alloc_internal_dynamic (sizeof (ScanFinalizerEntriesJobData), INTERNAL_MEM_WORKER_JOB_DATA, TRUE);
2664 sfejd_critical_fin->list = critical_fin_list;
2665 sgen_workers_enqueue_job (job_scan_finalizer_entries, sfejd_critical_fin);
2667 MONO_GC_CHECKPOINT_8 (GENERATION_NURSERY);
2669 finish_gray_stack (GENERATION_NURSERY, &gray_queue);
2671 time_minor_finish_gray_stack += TV_ELAPSED (btv, atv);
2672 mono_profiler_gc_event (MONO_GC_EVENT_MARK_END, 0);
2674 MONO_GC_CHECKPOINT_9 (GENERATION_NURSERY);
2677 * The (single-threaded) finalization code might have done
2678 * some copying/marking so we can only reset the GC thread's
2679 * worker data here instead of earlier when we joined the
2682 sgen_workers_reset_data ();
2684 if (objects_pinned) {
2685 sgen_optimize_pin_queue (0);
2686 sgen_pinning_setup_section (nursery_section);
2689 /* walk the pin_queue, build up the fragment list of free memory, unmark
2690 * pinned objects as we go, memzero() the empty fragments so they are ready for the
2693 mono_profiler_gc_event (MONO_GC_EVENT_RECLAIM_START, 0);
2694 fragment_total = sgen_build_nursery_fragments (nursery_section,
2695 nursery_section->pin_queue_start, nursery_section->pin_queue_num_entries,
2697 if (!fragment_total)
2700 /* Clear TLABs for all threads */
2701 sgen_clear_tlabs ();
2703 mono_profiler_gc_event (MONO_GC_EVENT_RECLAIM_END, 0);
2705 time_minor_fragment_creation += TV_ELAPSED (atv, btv);
2706 SGEN_LOG (2, "Fragment creation: %d usecs, %lu bytes available", TV_ELAPSED (atv, btv), (unsigned long)fragment_total);
2708 if (consistency_check_at_minor_collection)
2709 sgen_check_major_refs ();
2711 major_collector.finish_nursery_collection ();
2713 TV_GETTIME (all_btv);
2714 gc_stats.minor_gc_time_usecs += TV_ELAPSED (all_atv, all_btv);
2717 dump_heap ("minor", stat_minor_gcs - 1, NULL);
2719 /* prepare the pin queue for the next collection */
2720 sgen_finish_pinning ();
2721 if (fin_ready_list || critical_fin_list) {
2722 SGEN_LOG (4, "Finalizer-thread wakeup: ready %d", num_ready_finalizers);
2723 mono_gc_finalize_notify ();
2725 sgen_pin_stats_reset ();
2726 /* clear cemented hash */
2727 sgen_cement_clear_below_threshold ();
2729 g_assert (sgen_gray_object_queue_is_empty (&gray_queue));
2731 remset.finish_minor_collection ();
2733 check_scan_starts ();
2735 binary_protocol_flush_buffers (FALSE);
2737 sgen_memgov_minor_collection_end ();
2739 /*objects are late pinned because of lack of memory, so a major is a good call*/
2740 needs_major = objects_pinned > 0;
2741 current_collection_generation = -1;
2744 MONO_GC_END (GENERATION_NURSERY);
2745 binary_protocol_collection_end (stat_minor_gcs - 1, GENERATION_NURSERY);
2747 if (check_nursery_objects_pinned && !sgen_minor_collector.is_split)
2748 sgen_check_nursery_objects_pinned (unpin_queue != NULL);
2754 scan_nursery_objects_callback (char *obj, size_t size, ScanCopyContext *ctx)
2756 ctx->scan_func (obj, ctx->queue);
2760 scan_nursery_objects (ScanCopyContext ctx)
2762 sgen_scan_area_with_callback (nursery_section->data, nursery_section->end_data,
2763 (IterateObjectCallbackFunc)scan_nursery_objects_callback, (void*)&ctx, FALSE);
2767 major_copy_or_mark_from_roots (int *old_next_pin_slot, gboolean finish_up_concurrent_mark, gboolean scan_mod_union)
2772 /* FIXME: only use these values for the precise scan
2773 * note that to_space pointers should be excluded anyway...
2775 char *heap_start = NULL;
2776 char *heap_end = (char*)-1;
2777 gboolean profile_roots = mono_profiler_get_events () & MONO_PROFILE_GC_ROOTS;
2778 GCRootReport root_report = { 0 };
2779 ScanFromRegisteredRootsJobData *scrrjd_normal, *scrrjd_wbarrier;
2780 ScanThreadDataJobData *stdjd;
2781 ScanFinalizerEntriesJobData *sfejd_fin_ready, *sfejd_critical_fin;
2782 ScanCopyContext ctx;
2784 if (concurrent_collection_in_progress) {
2785 /*This cleans up unused fragments */
2786 sgen_nursery_allocator_prepare_for_pinning ();
2788 if (do_concurrent_checks)
2789 check_nursery_is_clean ();
2791 /* The concurrent collector doesn't touch the nursery. */
2792 sgen_nursery_alloc_prepare_for_major ();
2799 /* Pinning depends on this */
2800 sgen_clear_nursery_fragments ();
2802 if (whole_heap_check_before_collection)
2803 sgen_check_whole_heap (finish_up_concurrent_mark);
2806 time_major_pre_collection_fragment_clear += TV_ELAPSED (atv, btv);
2808 if (!sgen_collection_is_concurrent ())
2809 nursery_section->next_data = sgen_get_nursery_end ();
2810 /* we should also coalesce scanning from sections close to each other
2811 * and deal with pointers outside of the sections later.
2815 *major_collector.have_swept = FALSE;
2817 if (xdomain_checks) {
2818 sgen_clear_nursery_fragments ();
2819 check_for_xdomain_refs ();
2822 if (!concurrent_collection_in_progress) {
2823 /* Remsets are not useful for a major collection */
2824 remset.prepare_for_major_collection ();
2827 sgen_process_fin_stage_entries ();
2828 sgen_process_dislink_stage_entries ();
2831 sgen_init_pinning ();
2832 SGEN_LOG (6, "Collecting pinned addresses");
2833 pin_from_roots ((void*)lowest_heap_address, (void*)highest_heap_address, WORKERS_DISTRIBUTE_GRAY_QUEUE);
2835 if (!concurrent_collection_in_progress || finish_up_concurrent_mark) {
2836 if (major_collector.is_concurrent) {
2838 * The concurrent major collector cannot evict
2839 * yet, so we need to pin cemented objects to
2840 * not break some asserts.
2842 * FIXME: We could evict now!
2844 sgen_cement_iterate (pin_stage_object_callback, NULL);
2847 if (!concurrent_collection_in_progress)
2848 sgen_cement_reset ();
2851 sgen_optimize_pin_queue (0);
2854 * The concurrent collector doesn't move objects, neither on
2855 * the major heap nor in the nursery, so we can mark even
2856 * before pinning has finished. For the non-concurrent
2857 * collector we start the workers after pinning.
2859 if (concurrent_collection_in_progress) {
2860 sgen_workers_start_all_workers ();
2861 sgen_workers_start_marking ();
2865 * pin_queue now contains all candidate pointers, sorted and
2866 * uniqued. We must do two passes now to figure out which
2867 * objects are pinned.
2869 * The first is to find within the pin_queue the area for each
2870 * section. This requires that the pin_queue be sorted. We
2871 * also process the LOS objects and pinned chunks here.
2873 * The second, destructive, pass is to reduce the section
2874 * areas to pointers to the actually pinned objects.
2876 SGEN_LOG (6, "Pinning from sections");
2877 /* first pass for the sections */
2878 sgen_find_section_pin_queue_start_end (nursery_section);
2879 major_collector.find_pin_queue_start_ends (WORKERS_DISTRIBUTE_GRAY_QUEUE);
2880 /* identify possible pointers to the insize of large objects */
2881 SGEN_LOG (6, "Pinning from large objects");
2882 for (bigobj = los_object_list; bigobj; bigobj = bigobj->next) {
2884 if (sgen_find_optimized_pin_queue_area (bigobj->data, (char*)bigobj->data + sgen_los_object_size (bigobj), &dummy)) {
2885 binary_protocol_pin (bigobj->data, (gpointer)LOAD_VTABLE (bigobj->data), safe_object_get_size (((MonoObject*)(bigobj->data))));
2887 #ifdef ENABLE_DTRACE
2888 if (G_UNLIKELY (MONO_GC_OBJ_PINNED_ENABLED ())) {
2889 MonoVTable *vt = (MonoVTable*)LOAD_VTABLE (bigobj->data);
2890 MONO_GC_OBJ_PINNED ((mword)bigobj->data, sgen_safe_object_get_size ((MonoObject*)bigobj->data), vt->klass->name_space, vt->klass->name, GENERATION_OLD);
2894 if (sgen_los_object_is_pinned (bigobj->data)) {
2895 g_assert (finish_up_concurrent_mark);
2898 sgen_los_pin_object (bigobj->data);
2899 /* FIXME: only enqueue if object has references */
2900 GRAY_OBJECT_ENQUEUE (WORKERS_DISTRIBUTE_GRAY_QUEUE, bigobj->data);
2901 if (G_UNLIKELY (do_pin_stats))
2902 sgen_pin_stats_register_object ((char*) bigobj->data, safe_object_get_size ((MonoObject*) bigobj->data));
2903 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));
2906 add_profile_gc_root (&root_report, bigobj->data, MONO_PROFILE_GC_ROOT_PINNING | MONO_PROFILE_GC_ROOT_MISC, 0);
2910 notify_gc_roots (&root_report);
2911 /* second pass for the sections */
2912 ctx.scan_func = concurrent_collection_in_progress ? current_object_ops.scan_object : NULL;
2913 ctx.copy_func = NULL;
2914 ctx.queue = WORKERS_DISTRIBUTE_GRAY_QUEUE;
2917 * Concurrent mark never follows references into the nursery.
2918 * In the start and finish pauses we must scan live nursery
2919 * objects, though. We could simply scan all nursery objects,
2920 * but that would be conservative. The easiest way is to do a
2921 * nursery collection, which copies all live nursery objects
2922 * (except pinned ones, with the simple nursery) to the major
2923 * heap. Scanning the mod union table later will then scan
2924 * those promoted objects, provided they're reachable. Pinned
2925 * objects in the nursery - which we can trivially find in the
2926 * pinning queue - are treated as roots in the mark pauses.
2928 * The split nursery complicates the latter part because
2929 * non-pinned objects can survive in the nursery. That's why
2930 * we need to do a full front-to-back scan of the nursery,
2931 * marking all objects.
2933 * Non-concurrent mark evacuates from the nursery, so it's
2934 * sufficient to just scan pinned nursery objects.
2936 if (concurrent_collection_in_progress && sgen_minor_collector.is_split) {
2937 scan_nursery_objects (ctx);
2939 sgen_pin_objects_in_section (nursery_section, ctx);
2940 if (check_nursery_objects_pinned && !sgen_minor_collector.is_split)
2941 sgen_check_nursery_objects_pinned (!concurrent_collection_in_progress || finish_up_concurrent_mark);
2944 major_collector.pin_objects (WORKERS_DISTRIBUTE_GRAY_QUEUE);
2945 if (old_next_pin_slot)
2946 *old_next_pin_slot = sgen_get_pinned_count ();
2949 time_major_pinning += TV_ELAPSED (atv, btv);
2950 SGEN_LOG (2, "Finding pinned pointers: %d in %d usecs", sgen_get_pinned_count (), TV_ELAPSED (atv, btv));
2951 SGEN_LOG (4, "Start scan with %d pinned objects", sgen_get_pinned_count ());
2953 major_collector.init_to_space ();
2955 #ifdef SGEN_DEBUG_INTERNAL_ALLOC
2956 main_gc_thread = mono_native_thread_self ();
2959 if (!concurrent_collection_in_progress && major_collector.is_parallel) {
2960 sgen_workers_start_all_workers ();
2961 sgen_workers_start_marking ();
2964 if (mono_profiler_get_events () & MONO_PROFILE_GC_ROOTS)
2965 report_registered_roots ();
2967 time_major_scan_pinned += TV_ELAPSED (btv, atv);
2969 /* registered roots, this includes static fields */
2970 scrrjd_normal = sgen_alloc_internal_dynamic (sizeof (ScanFromRegisteredRootsJobData), INTERNAL_MEM_WORKER_JOB_DATA, TRUE);
2971 scrrjd_normal->copy_or_mark_func = current_object_ops.copy_or_mark_object;
2972 scrrjd_normal->scan_func = current_object_ops.scan_object;
2973 scrrjd_normal->heap_start = heap_start;
2974 scrrjd_normal->heap_end = heap_end;
2975 scrrjd_normal->root_type = ROOT_TYPE_NORMAL;
2976 sgen_workers_enqueue_job (job_scan_from_registered_roots, scrrjd_normal);
2978 scrrjd_wbarrier = sgen_alloc_internal_dynamic (sizeof (ScanFromRegisteredRootsJobData), INTERNAL_MEM_WORKER_JOB_DATA, TRUE);
2979 scrrjd_wbarrier->copy_or_mark_func = current_object_ops.copy_or_mark_object;
2980 scrrjd_wbarrier->scan_func = current_object_ops.scan_object;
2981 scrrjd_wbarrier->heap_start = heap_start;
2982 scrrjd_wbarrier->heap_end = heap_end;
2983 scrrjd_wbarrier->root_type = ROOT_TYPE_WBARRIER;
2984 sgen_workers_enqueue_job (job_scan_from_registered_roots, scrrjd_wbarrier);
2987 time_major_scan_registered_roots += TV_ELAPSED (atv, btv);
2990 stdjd = sgen_alloc_internal_dynamic (sizeof (ScanThreadDataJobData), INTERNAL_MEM_WORKER_JOB_DATA, TRUE);
2991 stdjd->heap_start = heap_start;
2992 stdjd->heap_end = heap_end;
2993 sgen_workers_enqueue_job (job_scan_thread_data, stdjd);
2996 time_major_scan_thread_data += TV_ELAPSED (btv, atv);
2999 time_major_scan_alloc_pinned += TV_ELAPSED (atv, btv);
3001 if (mono_profiler_get_events () & MONO_PROFILE_GC_ROOTS)
3002 report_finalizer_roots ();
3004 /* scan the list of objects ready for finalization */
3005 sfejd_fin_ready = sgen_alloc_internal_dynamic (sizeof (ScanFinalizerEntriesJobData), INTERNAL_MEM_WORKER_JOB_DATA, TRUE);
3006 sfejd_fin_ready->list = fin_ready_list;
3007 sgen_workers_enqueue_job (job_scan_finalizer_entries, sfejd_fin_ready);
3009 sfejd_critical_fin = sgen_alloc_internal_dynamic (sizeof (ScanFinalizerEntriesJobData), INTERNAL_MEM_WORKER_JOB_DATA, TRUE);
3010 sfejd_critical_fin->list = critical_fin_list;
3011 sgen_workers_enqueue_job (job_scan_finalizer_entries, sfejd_critical_fin);
3013 if (scan_mod_union) {
3014 g_assert (finish_up_concurrent_mark);
3016 /* Mod union card table */
3017 sgen_workers_enqueue_job (job_scan_major_mod_union_cardtable, NULL);
3018 sgen_workers_enqueue_job (job_scan_los_mod_union_cardtable, NULL);
3022 time_major_scan_finalized += TV_ELAPSED (btv, atv);
3023 SGEN_LOG (2, "Root scan: %d usecs", TV_ELAPSED (btv, atv));
3026 time_major_scan_big_objects += TV_ELAPSED (atv, btv);
3028 if (concurrent_collection_in_progress) {
3029 /* prepare the pin queue for the next collection */
3030 sgen_finish_pinning ();
3032 sgen_pin_stats_reset ();
3034 if (do_concurrent_checks)
3035 check_nursery_is_clean ();
3040 major_start_collection (gboolean concurrent, int *old_next_pin_slot)
3042 MONO_GC_BEGIN (GENERATION_OLD);
3043 binary_protocol_collection_begin (stat_major_gcs, GENERATION_OLD);
3045 current_collection_generation = GENERATION_OLD;
3046 #ifndef DISABLE_PERFCOUNTERS
3047 mono_perfcounters->gc_collections1++;
3050 g_assert (sgen_section_gray_queue_is_empty (sgen_workers_get_distribute_section_gray_queue ()));
3053 g_assert (major_collector.is_concurrent);
3054 concurrent_collection_in_progress = TRUE;
3056 sgen_cement_concurrent_start ();
3058 current_object_ops = major_collector.major_concurrent_ops;
3060 current_object_ops = major_collector.major_ops;
3063 reset_pinned_from_failed_allocation ();
3065 sgen_memgov_major_collection_start ();
3067 //count_ref_nonref_objs ();
3068 //consistency_check ();
3070 check_scan_starts ();
3073 SGEN_LOG (1, "Start major collection %d", stat_major_gcs);
3075 gc_stats.major_gc_count ++;
3077 if (major_collector.start_major_collection)
3078 major_collector.start_major_collection ();
3080 major_copy_or_mark_from_roots (old_next_pin_slot, FALSE, FALSE);
3084 wait_for_workers_to_finish (void)
3086 if (concurrent_collection_in_progress || major_collector.is_parallel) {
3087 gray_queue_redirect (&gray_queue);
3088 sgen_workers_join ();
3091 g_assert (sgen_gray_object_queue_is_empty (&gray_queue));
3093 #ifdef SGEN_DEBUG_INTERNAL_ALLOC
3094 main_gc_thread = NULL;
3099 major_finish_collection (const char *reason, int old_next_pin_slot, gboolean scan_mod_union)
3101 LOSObject *bigobj, *prevbo;
3107 if (concurrent_collection_in_progress || major_collector.is_parallel)
3108 wait_for_workers_to_finish ();
3110 if (concurrent_collection_in_progress) {
3111 current_object_ops = major_collector.major_concurrent_ops;
3113 major_copy_or_mark_from_roots (NULL, TRUE, scan_mod_union);
3114 wait_for_workers_to_finish ();
3116 g_assert (sgen_gray_object_queue_is_empty (&gray_queue));
3118 if (do_concurrent_checks)
3119 check_nursery_is_clean ();
3121 current_object_ops = major_collector.major_ops;
3125 * The workers have stopped so we need to finish gray queue
3126 * work that might result from finalization in the main GC
3127 * thread. Redirection must therefore be turned off.
3129 sgen_gray_object_queue_disable_alloc_prepare (&gray_queue);
3130 g_assert (sgen_section_gray_queue_is_empty (sgen_workers_get_distribute_section_gray_queue ()));
3132 /* all the objects in the heap */
3133 finish_gray_stack (GENERATION_OLD, &gray_queue);
3135 time_major_finish_gray_stack += TV_ELAPSED (btv, atv);
3138 * The (single-threaded) finalization code might have done
3139 * some copying/marking so we can only reset the GC thread's
3140 * worker data here instead of earlier when we joined the
3143 sgen_workers_reset_data ();
3145 if (objects_pinned) {
3146 g_assert (!concurrent_collection_in_progress);
3148 /*This is slow, but we just OOM'd*/
3149 sgen_pin_queue_clear_discarded_entries (nursery_section, old_next_pin_slot);
3150 sgen_optimize_pin_queue (0);
3151 sgen_find_section_pin_queue_start_end (nursery_section);
3155 reset_heap_boundaries ();
3156 sgen_update_heap_boundaries ((mword)sgen_get_nursery_start (), (mword)sgen_get_nursery_end ());
3158 if (check_mark_bits_after_major_collection)
3159 sgen_check_major_heap_marked ();
3161 MONO_GC_SWEEP_BEGIN (GENERATION_OLD, !major_collector.sweeps_lazily);
3163 /* sweep the big objects list */
3165 for (bigobj = los_object_list; bigobj;) {
3166 g_assert (!object_is_pinned (bigobj->data));
3167 if (sgen_los_object_is_pinned (bigobj->data)) {
3168 sgen_los_unpin_object (bigobj->data);
3169 sgen_update_heap_boundaries ((mword)bigobj->data, (mword)bigobj->data + sgen_los_object_size (bigobj));
3172 /* not referenced anywhere, so we can free it */
3174 prevbo->next = bigobj->next;
3176 los_object_list = bigobj->next;
3178 bigobj = bigobj->next;
3179 sgen_los_free_object (to_free);
3183 bigobj = bigobj->next;
3187 time_major_free_bigobjs += TV_ELAPSED (atv, btv);
3192 time_major_los_sweep += TV_ELAPSED (btv, atv);
3194 major_collector.sweep ();
3196 MONO_GC_SWEEP_END (GENERATION_OLD, !major_collector.sweeps_lazily);
3199 time_major_sweep += TV_ELAPSED (atv, btv);
3201 if (!concurrent_collection_in_progress) {
3202 /* walk the pin_queue, build up the fragment list of free memory, unmark
3203 * pinned objects as we go, memzero() the empty fragments so they are ready for the
3206 if (!sgen_build_nursery_fragments (nursery_section, nursery_section->pin_queue_start, nursery_section->pin_queue_num_entries, NULL))
3209 /* prepare the pin queue for the next collection */
3210 sgen_finish_pinning ();
3212 /* Clear TLABs for all threads */
3213 sgen_clear_tlabs ();
3215 sgen_pin_stats_reset ();
3218 if (concurrent_collection_in_progress)
3219 sgen_cement_concurrent_finish ();
3220 sgen_cement_clear_below_threshold ();
3223 time_major_fragment_creation += TV_ELAPSED (btv, atv);
3226 dump_heap ("major", stat_major_gcs - 1, reason);
3228 if (fin_ready_list || critical_fin_list) {
3229 SGEN_LOG (4, "Finalizer-thread wakeup: ready %d", num_ready_finalizers);
3230 mono_gc_finalize_notify ();
3233 g_assert (sgen_gray_object_queue_is_empty (&gray_queue));
3235 sgen_memgov_major_collection_end ();
3236 current_collection_generation = -1;
3238 major_collector.finish_major_collection ();
3240 g_assert (sgen_section_gray_queue_is_empty (sgen_workers_get_distribute_section_gray_queue ()));
3242 if (concurrent_collection_in_progress)
3243 concurrent_collection_in_progress = FALSE;
3245 check_scan_starts ();
3247 binary_protocol_flush_buffers (FALSE);
3249 //consistency_check ();
3251 MONO_GC_END (GENERATION_OLD);
3252 binary_protocol_collection_end (stat_major_gcs - 1, GENERATION_OLD);
3256 major_do_collection (const char *reason)
3258 TV_DECLARE (all_atv);
3259 TV_DECLARE (all_btv);
3260 int old_next_pin_slot;
3262 if (major_collector.get_and_reset_num_major_objects_marked) {
3263 long long num_marked = major_collector.get_and_reset_num_major_objects_marked ();
3264 g_assert (!num_marked);
3267 /* world must be stopped already */
3268 TV_GETTIME (all_atv);
3270 major_start_collection (FALSE, &old_next_pin_slot);
3271 major_finish_collection (reason, old_next_pin_slot, FALSE);
3273 TV_GETTIME (all_btv);
3274 gc_stats.major_gc_time_usecs += TV_ELAPSED (all_atv, all_btv);
3276 /* FIXME: also report this to the user, preferably in gc-end. */
3277 if (major_collector.get_and_reset_num_major_objects_marked)
3278 major_collector.get_and_reset_num_major_objects_marked ();
3280 return bytes_pinned_from_failed_allocation > 0;
3283 static gboolean major_do_collection (const char *reason);
3286 major_start_concurrent_collection (const char *reason)
3288 long long num_objects_marked = major_collector.get_and_reset_num_major_objects_marked ();
3290 g_assert (num_objects_marked == 0);
3292 MONO_GC_CONCURRENT_START_BEGIN (GENERATION_OLD);
3294 // FIXME: store reason and pass it when finishing
3295 major_start_collection (TRUE, NULL);
3297 gray_queue_redirect (&gray_queue);
3298 sgen_workers_wait_for_jobs ();
3300 num_objects_marked = major_collector.get_and_reset_num_major_objects_marked ();
3301 MONO_GC_CONCURRENT_START_END (GENERATION_OLD, num_objects_marked);
3303 current_collection_generation = -1;
3307 major_update_or_finish_concurrent_collection (gboolean force_finish)
3309 SgenGrayQueue unpin_queue;
3310 memset (&unpin_queue, 0, sizeof (unpin_queue));
3312 MONO_GC_CONCURRENT_UPDATE_FINISH_BEGIN (GENERATION_OLD, major_collector.get_and_reset_num_major_objects_marked ());
3314 g_assert (sgen_gray_object_queue_is_empty (&gray_queue));
3316 major_collector.update_cardtable_mod_union ();
3317 sgen_los_update_cardtable_mod_union ();
3319 if (!force_finish && !sgen_workers_all_done ()) {
3320 MONO_GC_CONCURRENT_UPDATE_END (GENERATION_OLD, major_collector.get_and_reset_num_major_objects_marked ());
3324 if (mod_union_consistency_check)
3325 sgen_check_mod_union_consistency ();
3327 collect_nursery (&unpin_queue, TRUE);
3329 current_collection_generation = GENERATION_OLD;
3330 major_finish_collection ("finishing", -1, TRUE);
3332 if (whole_heap_check_before_collection)
3333 sgen_check_whole_heap (FALSE);
3335 unpin_objects_from_queue (&unpin_queue);
3336 sgen_gray_object_queue_deinit (&unpin_queue);
3338 MONO_GC_CONCURRENT_FINISH_END (GENERATION_OLD, major_collector.get_and_reset_num_major_objects_marked ());
3340 current_collection_generation = -1;
3346 * Ensure an allocation request for @size will succeed by freeing enough memory.
3348 * LOCKING: The GC lock MUST be held.
3351 sgen_ensure_free_space (size_t size)
3353 int generation_to_collect = -1;
3354 const char *reason = NULL;
3357 if (size > SGEN_MAX_SMALL_OBJ_SIZE) {
3358 if (sgen_need_major_collection (size)) {
3359 reason = "LOS overflow";
3360 generation_to_collect = GENERATION_OLD;
3363 if (degraded_mode) {
3364 if (sgen_need_major_collection (size)) {
3365 reason = "Degraded mode overflow";
3366 generation_to_collect = GENERATION_OLD;
3368 } else if (sgen_need_major_collection (size)) {
3369 reason = "Minor allowance";
3370 generation_to_collect = GENERATION_OLD;
3372 generation_to_collect = GENERATION_NURSERY;
3373 reason = "Nursery full";
3377 if (generation_to_collect == -1) {
3378 if (concurrent_collection_in_progress && sgen_workers_all_done ()) {
3379 generation_to_collect = GENERATION_OLD;
3380 reason = "Finish concurrent collection";
3384 if (generation_to_collect == -1)
3386 sgen_perform_collection (size, generation_to_collect, reason, FALSE);
3390 * LOCKING: Assumes the GC lock is held.
3393 sgen_perform_collection (size_t requested_size, int generation_to_collect, const char *reason, gboolean wait_to_finish)
3395 TV_DECLARE (gc_end);
3396 GGTimingInfo infos [2];
3397 int overflow_generation_to_collect = -1;
3398 int oldest_generation_collected = generation_to_collect;
3399 const char *overflow_reason = NULL;
3401 MONO_GC_REQUESTED (generation_to_collect, requested_size, wait_to_finish ? 1 : 0);
3403 binary_protocol_collection_force (generation_to_collect);
3405 g_assert (generation_to_collect == GENERATION_NURSERY || generation_to_collect == GENERATION_OLD);
3407 memset (infos, 0, sizeof (infos));
3408 mono_profiler_gc_event (MONO_GC_EVENT_START, generation_to_collect);
3410 infos [0].generation = generation_to_collect;
3411 infos [0].reason = reason;
3412 infos [0].is_overflow = FALSE;
3413 TV_GETTIME (infos [0].total_time);
3414 infos [1].generation = -1;
3416 sgen_stop_world (generation_to_collect);
3418 if (concurrent_collection_in_progress) {
3419 if (major_update_or_finish_concurrent_collection (wait_to_finish && generation_to_collect == GENERATION_OLD)) {
3420 oldest_generation_collected = GENERATION_OLD;
3423 if (generation_to_collect == GENERATION_OLD)
3426 if (generation_to_collect == GENERATION_OLD &&
3427 allow_synchronous_major &&
3428 major_collector.want_synchronous_collection &&
3429 *major_collector.want_synchronous_collection) {
3430 wait_to_finish = TRUE;
3434 //FIXME extract overflow reason
3435 if (generation_to_collect == GENERATION_NURSERY) {
3436 if (collect_nursery (NULL, FALSE)) {
3437 overflow_generation_to_collect = GENERATION_OLD;
3438 overflow_reason = "Minor overflow";
3441 if (major_collector.is_concurrent) {
3442 g_assert (!concurrent_collection_in_progress);
3443 if (!wait_to_finish)
3444 collect_nursery (NULL, FALSE);
3447 if (major_collector.is_concurrent && !wait_to_finish) {
3448 major_start_concurrent_collection (reason);
3449 // FIXME: set infos[0] properly
3452 if (major_do_collection (reason)) {
3453 overflow_generation_to_collect = GENERATION_NURSERY;
3454 overflow_reason = "Excessive pinning";
3459 TV_GETTIME (gc_end);
3460 infos [0].total_time = SGEN_TV_ELAPSED (infos [0].total_time, gc_end);
3463 if (!major_collector.is_concurrent && overflow_generation_to_collect != -1) {
3464 mono_profiler_gc_event (MONO_GC_EVENT_START, overflow_generation_to_collect);
3465 infos [1].generation = overflow_generation_to_collect;
3466 infos [1].reason = overflow_reason;
3467 infos [1].is_overflow = TRUE;
3468 infos [1].total_time = gc_end;
3470 if (overflow_generation_to_collect == GENERATION_NURSERY)
3471 collect_nursery (NULL, FALSE);
3473 major_do_collection (overflow_reason);
3475 TV_GETTIME (gc_end);
3476 infos [1].total_time = SGEN_TV_ELAPSED (infos [1].total_time, gc_end);
3478 /* keep events symmetric */
3479 mono_profiler_gc_event (MONO_GC_EVENT_END, overflow_generation_to_collect);
3481 oldest_generation_collected = MAX (oldest_generation_collected, overflow_generation_to_collect);
3484 SGEN_LOG (2, "Heap size: %lu, LOS size: %lu", (unsigned long)mono_gc_get_heap_size (), (unsigned long)los_memory_usage);
3486 /* this also sets the proper pointers for the next allocation */
3487 if (generation_to_collect == GENERATION_NURSERY && !sgen_can_alloc_size (requested_size)) {
3488 /* TypeBuilder and MonoMethod are killing mcs with fragmentation */
3489 SGEN_LOG (1, "nursery collection didn't find enough room for %zd alloc (%d pinned)", requested_size, sgen_get_pinned_count ());
3490 sgen_dump_pin_queue ();
3495 g_assert (sgen_gray_object_queue_is_empty (&gray_queue));
3497 sgen_restart_world (oldest_generation_collected, infos);
3499 mono_profiler_gc_event (MONO_GC_EVENT_END, generation_to_collect);
3503 * ######################################################################
3504 * ######## Memory allocation from the OS
3505 * ######################################################################
3506 * This section of code deals with getting memory from the OS and
3507 * allocating memory for GC-internal data structures.
3508 * Internal memory can be handled with a freelist for small objects.
3514 G_GNUC_UNUSED static void
3515 report_internal_mem_usage (void)
3517 printf ("Internal memory usage:\n");
3518 sgen_report_internal_mem_usage ();
3519 printf ("Pinned memory usage:\n");
3520 major_collector.report_pinned_memory_usage ();
3524 * ######################################################################
3525 * ######## Finalization support
3526 * ######################################################################
3529 static inline gboolean
3530 sgen_major_is_object_alive (void *object)
3534 /* Oldgen objects can be pinned and forwarded too */
3535 if (SGEN_OBJECT_IS_PINNED (object) || SGEN_OBJECT_IS_FORWARDED (object))
3539 * FIXME: major_collector.is_object_live() also calculates the
3540 * size. Avoid the double calculation.
3542 objsize = SGEN_ALIGN_UP (sgen_safe_object_get_size ((MonoObject*)object));
3543 if (objsize > SGEN_MAX_SMALL_OBJ_SIZE)
3544 return sgen_los_object_is_pinned (object);
3546 return major_collector.is_object_live (object);
3550 * If the object has been forwarded it means it's still referenced from a root.
3551 * If it is pinned it's still alive as well.
3552 * A LOS object is only alive if we have pinned it.
3553 * Return TRUE if @obj is ready to be finalized.
3555 static inline gboolean
3556 sgen_is_object_alive (void *object)
3558 if (ptr_in_nursery (object))
3559 return sgen_nursery_is_object_alive (object);
3561 return sgen_major_is_object_alive (object);
3565 * This function returns true if @object is either alive or it belongs to the old gen
3566 * and we're currently doing a minor collection.
3569 sgen_is_object_alive_for_current_gen (char *object)
3571 if (ptr_in_nursery (object))
3572 return sgen_nursery_is_object_alive (object);
3574 if (current_collection_generation == GENERATION_NURSERY)
3577 return sgen_major_is_object_alive (object);
3581 * This function returns true if @object is either alive and belongs to the
3582 * current collection - major collections are full heap, so old gen objects
3583 * are never alive during a minor collection.
3586 sgen_is_object_alive_and_on_current_collection (char *object)
3588 if (ptr_in_nursery (object))
3589 return sgen_nursery_is_object_alive (object);
3591 if (current_collection_generation == GENERATION_NURSERY)
3594 return sgen_major_is_object_alive (object);
3599 sgen_gc_is_object_ready_for_finalization (void *object)
3601 return !sgen_is_object_alive (object);
3605 has_critical_finalizer (MonoObject *obj)
3609 if (!mono_defaults.critical_finalizer_object)
3612 class = ((MonoVTable*)LOAD_VTABLE (obj))->klass;
3614 return mono_class_has_parent_fast (class, mono_defaults.critical_finalizer_object);
3618 sgen_queue_finalization_entry (MonoObject *obj)
3620 FinalizeReadyEntry *entry = sgen_alloc_internal (INTERNAL_MEM_FINALIZE_READY_ENTRY);
3621 gboolean critical = has_critical_finalizer (obj);
3622 entry->object = obj;
3624 entry->next = critical_fin_list;
3625 critical_fin_list = entry;
3627 entry->next = fin_ready_list;
3628 fin_ready_list = entry;
3631 #ifdef ENABLE_DTRACE
3632 if (G_UNLIKELY (MONO_GC_FINALIZE_ENQUEUE_ENABLED ())) {
3633 int gen = sgen_ptr_in_nursery (obj) ? GENERATION_NURSERY : GENERATION_OLD;
3634 MonoVTable *vt = (MonoVTable*)LOAD_VTABLE (obj);
3635 MONO_GC_FINALIZE_ENQUEUE ((mword)obj, sgen_safe_object_get_size (obj),
3636 vt->klass->name_space, vt->klass->name, gen, critical);
3642 sgen_object_is_live (void *obj)
3644 return sgen_is_object_alive_and_on_current_collection (obj);
3647 /* LOCKING: requires that the GC lock is held */
3649 null_ephemerons_for_domain (MonoDomain *domain)
3651 EphemeronLinkNode *current = ephemeron_list, *prev = NULL;
3654 MonoObject *object = (MonoObject*)current->array;
3656 if (object && !object->vtable) {
3657 EphemeronLinkNode *tmp = current;
3660 prev->next = current->next;
3662 ephemeron_list = current->next;
3664 current = current->next;
3665 sgen_free_internal (tmp, INTERNAL_MEM_EPHEMERON_LINK);
3668 current = current->next;
3673 /* LOCKING: requires that the GC lock is held */
3675 clear_unreachable_ephemerons (ScanCopyContext ctx)
3677 CopyOrMarkObjectFunc copy_func = ctx.copy_func;
3678 GrayQueue *queue = ctx.queue;
3679 EphemeronLinkNode *current = ephemeron_list, *prev = NULL;
3681 Ephemeron *cur, *array_end;
3685 char *object = current->array;
3687 if (!sgen_is_object_alive_for_current_gen (object)) {
3688 EphemeronLinkNode *tmp = current;
3690 SGEN_LOG (5, "Dead Ephemeron array at %p", object);
3693 prev->next = current->next;
3695 ephemeron_list = current->next;
3697 current = current->next;
3698 sgen_free_internal (tmp, INTERNAL_MEM_EPHEMERON_LINK);
3703 copy_func ((void**)&object, queue);
3704 current->array = object;
3706 SGEN_LOG (5, "Clearing unreachable entries for ephemeron array at %p", object);
3708 array = (MonoArray*)object;
3709 cur = mono_array_addr (array, Ephemeron, 0);
3710 array_end = cur + mono_array_length_fast (array);
3711 tombstone = (char*)((MonoVTable*)LOAD_VTABLE (object))->domain->ephemeron_tombstone;
3713 for (; cur < array_end; ++cur) {
3714 char *key = (char*)cur->key;
3716 if (!key || key == tombstone)
3719 SGEN_LOG (5, "[%td] key %p (%s) value %p (%s)", cur - mono_array_addr (array, Ephemeron, 0),
3720 key, sgen_is_object_alive_for_current_gen (key) ? "reachable" : "unreachable",
3721 cur->value, cur->value && sgen_is_object_alive_for_current_gen (cur->value) ? "reachable" : "unreachable");
3723 if (!sgen_is_object_alive_for_current_gen (key)) {
3724 cur->key = tombstone;
3730 current = current->next;
3735 LOCKING: requires that the GC lock is held
3737 Limitations: We scan all ephemerons on every collection since the current design doesn't allow for a simple nursery/mature split.
3740 mark_ephemerons_in_range (ScanCopyContext ctx)
3742 CopyOrMarkObjectFunc copy_func = ctx.copy_func;
3743 GrayQueue *queue = ctx.queue;
3744 int nothing_marked = 1;
3745 EphemeronLinkNode *current = ephemeron_list;
3747 Ephemeron *cur, *array_end;
3750 for (current = ephemeron_list; current; current = current->next) {
3751 char *object = current->array;
3752 SGEN_LOG (5, "Ephemeron array at %p", object);
3754 /*It has to be alive*/
3755 if (!sgen_is_object_alive_for_current_gen (object)) {
3756 SGEN_LOG (5, "\tnot reachable");
3760 copy_func ((void**)&object, queue);
3762 array = (MonoArray*)object;
3763 cur = mono_array_addr (array, Ephemeron, 0);
3764 array_end = cur + mono_array_length_fast (array);
3765 tombstone = (char*)((MonoVTable*)LOAD_VTABLE (object))->domain->ephemeron_tombstone;
3767 for (; cur < array_end; ++cur) {
3768 char *key = cur->key;
3770 if (!key || key == tombstone)
3773 SGEN_LOG (5, "[%td] key %p (%s) value %p (%s)", cur - mono_array_addr (array, Ephemeron, 0),
3774 key, sgen_is_object_alive_for_current_gen (key) ? "reachable" : "unreachable",
3775 cur->value, cur->value && sgen_is_object_alive_for_current_gen (cur->value) ? "reachable" : "unreachable");
3777 if (sgen_is_object_alive_for_current_gen (key)) {
3778 char *value = cur->value;
3780 copy_func ((void**)&cur->key, queue);
3782 if (!sgen_is_object_alive_for_current_gen (value))
3784 copy_func ((void**)&cur->value, queue);
3790 SGEN_LOG (5, "Ephemeron run finished. Is it done %d", nothing_marked);
3791 return nothing_marked;
3795 mono_gc_invoke_finalizers (void)
3797 FinalizeReadyEntry *entry = NULL;
3798 gboolean entry_is_critical = FALSE;
3801 /* FIXME: batch to reduce lock contention */
3802 while (fin_ready_list || critical_fin_list) {
3806 FinalizeReadyEntry **list = entry_is_critical ? &critical_fin_list : &fin_ready_list;
3808 /* We have finalized entry in the last
3809 interation, now we need to remove it from
3812 *list = entry->next;
3814 FinalizeReadyEntry *e = *list;
3815 while (e->next != entry)
3817 e->next = entry->next;
3819 sgen_free_internal (entry, INTERNAL_MEM_FINALIZE_READY_ENTRY);
3823 /* Now look for the first non-null entry. */
3824 for (entry = fin_ready_list; entry && !entry->object; entry = entry->next)
3827 entry_is_critical = FALSE;
3829 entry_is_critical = TRUE;
3830 for (entry = critical_fin_list; entry && !entry->object; entry = entry->next)
3835 g_assert (entry->object);
3836 num_ready_finalizers--;
3837 obj = entry->object;
3838 entry->object = NULL;
3839 SGEN_LOG (7, "Finalizing object %p (%s)", obj, safe_name (obj));
3847 g_assert (entry->object == NULL);
3849 /* the object is on the stack so it is pinned */
3850 /*g_print ("Calling finalizer for object: %p (%s)\n", entry->object, safe_name (entry->object));*/
3851 mono_gc_run_finalize (obj, NULL);
3858 mono_gc_pending_finalizers (void)
3860 return fin_ready_list || critical_fin_list;
3864 * ######################################################################
3865 * ######## registered roots support
3866 * ######################################################################
3870 * We do not coalesce roots.
3873 mono_gc_register_root_inner (char *start, size_t size, void *descr, int root_type)
3875 RootRecord new_root;
3878 for (i = 0; i < ROOT_TYPE_NUM; ++i) {
3879 RootRecord *root = sgen_hash_table_lookup (&roots_hash [i], start);
3880 /* we allow changing the size and the descriptor (for thread statics etc) */
3882 size_t old_size = root->end_root - start;
3883 root->end_root = start + size;
3884 g_assert (((root->root_desc != 0) && (descr != NULL)) ||
3885 ((root->root_desc == 0) && (descr == NULL)));
3886 root->root_desc = (mword)descr;
3888 roots_size -= old_size;
3894 new_root.end_root = start + size;
3895 new_root.root_desc = (mword)descr;
3897 sgen_hash_table_replace (&roots_hash [root_type], start, &new_root, NULL);
3900 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);
3907 mono_gc_register_root (char *start, size_t size, void *descr)
3909 return mono_gc_register_root_inner (start, size, descr, descr ? ROOT_TYPE_NORMAL : ROOT_TYPE_PINNED);
3913 mono_gc_register_root_wbarrier (char *start, size_t size, void *descr)
3915 return mono_gc_register_root_inner (start, size, descr, ROOT_TYPE_WBARRIER);
3919 mono_gc_deregister_root (char* addr)
3925 for (root_type = 0; root_type < ROOT_TYPE_NUM; ++root_type) {
3926 if (sgen_hash_table_remove (&roots_hash [root_type], addr, &root))
3927 roots_size -= (root.end_root - addr);
3933 * ######################################################################
3934 * ######## Thread handling (stop/start code)
3935 * ######################################################################
3938 unsigned int sgen_global_stop_count = 0;
3941 sgen_get_current_collection_generation (void)
3943 return current_collection_generation;
3947 mono_gc_set_gc_callbacks (MonoGCCallbacks *callbacks)
3949 gc_callbacks = *callbacks;
3953 mono_gc_get_gc_callbacks ()
3955 return &gc_callbacks;
3958 /* Variables holding start/end nursery so it won't have to be passed at every call */
3959 static void *scan_area_arg_start, *scan_area_arg_end;
3962 mono_gc_conservatively_scan_area (void *start, void *end)
3964 conservatively_pin_objects_from (start, end, scan_area_arg_start, scan_area_arg_end, PIN_TYPE_STACK);
3968 mono_gc_scan_object (void *obj)
3970 UserCopyOrMarkData *data = mono_native_tls_get_value (user_copy_or_mark_key);
3971 current_object_ops.copy_or_mark_object (&obj, data->queue);
3976 * Mark from thread stacks and registers.
3979 scan_thread_data (void *start_nursery, void *end_nursery, gboolean precise, GrayQueue *queue)
3981 SgenThreadInfo *info;
3983 scan_area_arg_start = start_nursery;
3984 scan_area_arg_end = end_nursery;
3986 FOREACH_THREAD (info) {
3988 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);
3991 if (info->gc_disabled) {
3992 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);
3996 if (!info->joined_stw) {
3997 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);
4001 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 ());
4002 if (!info->thread_is_dying) {
4003 if (gc_callbacks.thread_mark_func && !conservative_stack_mark) {
4004 UserCopyOrMarkData data = { NULL, queue };
4005 set_user_copy_or_mark_data (&data);
4006 gc_callbacks.thread_mark_func (info->runtime_data, info->stack_start, info->stack_end, precise);
4007 set_user_copy_or_mark_data (NULL);
4008 } else if (!precise) {
4009 if (!conservative_stack_mark) {
4010 fprintf (stderr, "Precise stack mark not supported - disabling.\n");
4011 conservative_stack_mark = TRUE;
4013 conservatively_pin_objects_from (info->stack_start, info->stack_end, start_nursery, end_nursery, PIN_TYPE_STACK);
4017 if (!info->thread_is_dying && !precise) {
4019 conservatively_pin_objects_from ((void**)&info->ctx, (void**)&info->ctx + ARCH_NUM_REGS,
4020 start_nursery, end_nursery, PIN_TYPE_STACK);
4022 conservatively_pin_objects_from (&info->regs, &info->regs + ARCH_NUM_REGS,
4023 start_nursery, end_nursery, PIN_TYPE_STACK);
4026 } END_FOREACH_THREAD
4030 ptr_on_stack (void *ptr)
4032 gpointer stack_start = &stack_start;
4033 SgenThreadInfo *info = mono_thread_info_current ();
4035 if (ptr >= stack_start && ptr < (gpointer)info->stack_end)
4041 sgen_thread_register (SgenThreadInfo* info, void *addr)
4044 #ifndef HAVE_KW_THREAD
4045 info->tlab_start = info->tlab_next = info->tlab_temp_end = info->tlab_real_end = NULL;
4047 g_assert (!mono_native_tls_get_value (thread_info_key));
4048 mono_native_tls_set_value (thread_info_key, info);
4050 sgen_thread_info = info;
4053 #if !defined(__MACH__)
4054 info->stop_count = -1;
4058 info->joined_stw = FALSE;
4059 info->doing_handshake = FALSE;
4060 info->thread_is_dying = FALSE;
4061 info->stack_start = NULL;
4062 info->stopped_ip = NULL;
4063 info->stopped_domain = NULL;
4065 memset (&info->ctx, 0, sizeof (MonoContext));
4067 memset (&info->regs, 0, sizeof (info->regs));
4070 sgen_init_tlab_info (info);
4072 binary_protocol_thread_register ((gpointer)mono_thread_info_get_tid (info));
4074 /* try to get it with attributes first */
4075 #if (defined(HAVE_PTHREAD_GETATTR_NP) || defined(HAVE_PTHREAD_ATTR_GET_NP)) && defined(HAVE_PTHREAD_ATTR_GETSTACK)
4079 pthread_attr_t attr;
4081 #if defined(HAVE_PTHREAD_GETATTR_NP)
4083 pthread_getattr_np (pthread_self (), &attr);
4084 #elif defined(HAVE_PTHREAD_ATTR_GET_NP)
4086 pthread_attr_init (&attr);
4087 pthread_attr_get_np (pthread_self (), &attr);
4089 #error Cannot determine which API is needed to retrieve pthread attributes.
4092 pthread_attr_getstack (&attr, &sstart, &size);
4093 info->stack_start_limit = sstart;
4094 info->stack_end = (char*)sstart + size;
4095 pthread_attr_destroy (&attr);
4097 #elif defined(HAVE_PTHREAD_GET_STACKSIZE_NP) && defined(HAVE_PTHREAD_GET_STACKADDR_NP)
4098 info->stack_end = (char*)pthread_get_stackaddr_np (pthread_self ());
4099 info->stack_start_limit = (char*)info->stack_end - pthread_get_stacksize_np (pthread_self ());
4102 /* FIXME: we assume the stack grows down */
4103 gsize stack_bottom = (gsize)addr;
4104 stack_bottom += 4095;
4105 stack_bottom &= ~4095;
4106 info->stack_end = (char*)stack_bottom;
4110 #ifdef HAVE_KW_THREAD
4111 stack_end = info->stack_end;
4114 SGEN_LOG (3, "registered thread %p (%p) stack end %p", info, (gpointer)mono_thread_info_get_tid (info), info->stack_end);
4116 if (gc_callbacks.thread_attach_func)
4117 info->runtime_data = gc_callbacks.thread_attach_func ();
4124 sgen_thread_unregister (SgenThreadInfo *p)
4126 /* If a delegate is passed to native code and invoked on a thread we dont
4127 * know about, the jit will register it with mono_jit_thread_attach, but
4128 * we have no way of knowing when that thread goes away. SGen has a TSD
4129 * so we assume that if the domain is still registered, we can detach
4132 if (mono_domain_get ())
4133 mono_thread_detach (mono_thread_current ());
4135 p->thread_is_dying = TRUE;
4138 There is a race condition between a thread finishing executing and been removed
4139 from the GC thread set.
4140 This happens on posix systems when TLS data is been cleaned-up, libpthread will
4141 set the thread_info slot to NULL before calling the cleanup function. This
4142 opens a window in which the thread is registered but has a NULL TLS.
4144 The suspend signal handler needs TLS data to know where to store thread state
4145 data or otherwise it will simply ignore the thread.
4147 This solution works because the thread doing STW will wait until all threads been
4148 suspended handshake back, so there is no race between the doing_hankshake test
4149 and the suspend_thread call.
4151 This is not required on systems that do synchronous STW as those can deal with
4152 the above race at suspend time.
4154 FIXME: I believe we could avoid this by using mono_thread_info_lookup when
4155 mono_thread_info_current returns NULL. Or fix mono_thread_info_lookup to do so.
4157 #if (defined(__MACH__) && MONO_MACH_ARCH_SUPPORTED) || !defined(HAVE_PTHREAD_KILL)
4160 while (!TRYLOCK_GC) {
4161 if (!sgen_park_current_thread_if_doing_handshake (p))
4167 binary_protocol_thread_unregister ((gpointer)mono_thread_info_get_tid (p));
4168 SGEN_LOG (3, "unregister thread %p (%p)", p, (gpointer)mono_thread_info_get_tid (p));
4170 if (gc_callbacks.thread_detach_func) {
4171 gc_callbacks.thread_detach_func (p->runtime_data);
4172 p->runtime_data = NULL;
4175 mono_threads_unregister_current_thread (p);
4181 sgen_thread_attach (SgenThreadInfo *info)
4184 /*this is odd, can we get attached before the gc is inited?*/
4188 if (gc_callbacks.thread_attach_func && !info->runtime_data)
4189 info->runtime_data = gc_callbacks.thread_attach_func ();
4192 mono_gc_register_thread (void *baseptr)
4194 return mono_thread_info_attach (baseptr) != NULL;
4198 * mono_gc_set_stack_end:
4200 * Set the end of the current threads stack to STACK_END. The stack space between
4201 * STACK_END and the real end of the threads stack will not be scanned during collections.
4204 mono_gc_set_stack_end (void *stack_end)
4206 SgenThreadInfo *info;
4209 info = mono_thread_info_current ();
4211 g_assert (stack_end < info->stack_end);
4212 info->stack_end = stack_end;
4217 #if USE_PTHREAD_INTERCEPT
4221 mono_gc_pthread_create (pthread_t *new_thread, const pthread_attr_t *attr, void *(*start_routine)(void *), void *arg)
4223 return pthread_create (new_thread, attr, start_routine, arg);
4227 mono_gc_pthread_join (pthread_t thread, void **retval)
4229 return pthread_join (thread, retval);
4233 mono_gc_pthread_detach (pthread_t thread)
4235 return pthread_detach (thread);
4239 mono_gc_pthread_exit (void *retval)
4241 mono_thread_info_dettach ();
4242 pthread_exit (retval);
4245 #endif /* USE_PTHREAD_INTERCEPT */
4248 * ######################################################################
4249 * ######## Write barriers
4250 * ######################################################################
4254 * Note: the write barriers first do the needed GC work and then do the actual store:
4255 * this way the value is visible to the conservative GC scan after the write barrier
4256 * itself. If a GC interrupts the barrier in the middle, value will be kept alive by
4257 * the conservative scan, otherwise by the remembered set scan.
4260 mono_gc_wbarrier_set_field (MonoObject *obj, gpointer field_ptr, MonoObject* value)
4262 HEAVY_STAT (++stat_wbarrier_set_field);
4263 if (ptr_in_nursery (field_ptr)) {
4264 *(void**)field_ptr = value;
4267 SGEN_LOG (8, "Adding remset at %p", field_ptr);
4269 binary_protocol_wbarrier (field_ptr, value, value->vtable);
4271 remset.wbarrier_set_field (obj, field_ptr, value);
4275 mono_gc_wbarrier_set_arrayref (MonoArray *arr, gpointer slot_ptr, MonoObject* value)
4277 HEAVY_STAT (++stat_wbarrier_set_arrayref);
4278 if (ptr_in_nursery (slot_ptr)) {
4279 *(void**)slot_ptr = value;
4282 SGEN_LOG (8, "Adding remset at %p", slot_ptr);
4284 binary_protocol_wbarrier (slot_ptr, value, value->vtable);
4286 remset.wbarrier_set_arrayref (arr, slot_ptr, value);
4290 mono_gc_wbarrier_arrayref_copy (gpointer dest_ptr, gpointer src_ptr, int count)
4292 HEAVY_STAT (++stat_wbarrier_arrayref_copy);
4293 /*This check can be done without taking a lock since dest_ptr array is pinned*/
4294 if (ptr_in_nursery (dest_ptr) || count <= 0) {
4295 mono_gc_memmove (dest_ptr, src_ptr, count * sizeof (gpointer));
4299 #ifdef SGEN_BINARY_PROTOCOL
4302 for (i = 0; i < count; ++i) {
4303 gpointer dest = (gpointer*)dest_ptr + i;
4304 gpointer obj = *((gpointer*)src_ptr + i);
4306 binary_protocol_wbarrier (dest, obj, (gpointer)LOAD_VTABLE (obj));
4311 remset.wbarrier_arrayref_copy (dest_ptr, src_ptr, count);
4314 static char *found_obj;
4317 find_object_for_ptr_callback (char *obj, size_t size, void *user_data)
4319 char *ptr = user_data;
4321 if (ptr >= obj && ptr < obj + size) {
4322 g_assert (!found_obj);
4327 /* for use in the debugger */
4328 char* find_object_for_ptr (char *ptr);
4330 find_object_for_ptr (char *ptr)
4332 if (ptr >= nursery_section->data && ptr < nursery_section->end_data) {
4334 sgen_scan_area_with_callback (nursery_section->data, nursery_section->end_data,
4335 find_object_for_ptr_callback, ptr, TRUE);
4341 sgen_los_iterate_objects (find_object_for_ptr_callback, ptr);
4346 * Very inefficient, but this is debugging code, supposed to
4347 * be called from gdb, so we don't care.
4350 major_collector.iterate_objects (TRUE, TRUE, find_object_for_ptr_callback, ptr);
4355 mono_gc_wbarrier_generic_nostore (gpointer ptr)
4359 HEAVY_STAT (++stat_wbarrier_generic_store);
4361 #ifdef XDOMAIN_CHECKS_IN_WBARRIER
4362 /* FIXME: ptr_in_heap must be called with the GC lock held */
4363 if (xdomain_checks && *(MonoObject**)ptr && ptr_in_heap (ptr)) {
4364 char *start = find_object_for_ptr (ptr);
4365 MonoObject *value = *(MonoObject**)ptr;
4369 MonoObject *obj = (MonoObject*)start;
4370 if (obj->vtable->domain != value->vtable->domain)
4371 g_assert (is_xdomain_ref_allowed (ptr, start, obj->vtable->domain));
4377 obj = *(gpointer*)ptr;
4379 binary_protocol_wbarrier (ptr, obj, (gpointer)LOAD_VTABLE (obj));
4381 if (ptr_in_nursery (ptr) || ptr_on_stack (ptr)) {
4382 SGEN_LOG (8, "Skipping remset at %p", ptr);
4387 * We need to record old->old pointer locations for the
4388 * concurrent collector.
4390 if (!ptr_in_nursery (obj) && !concurrent_collection_in_progress) {
4391 SGEN_LOG (8, "Skipping remset at %p", ptr);
4395 SGEN_LOG (8, "Adding remset at %p", ptr);
4397 remset.wbarrier_generic_nostore (ptr);
4401 mono_gc_wbarrier_generic_store (gpointer ptr, MonoObject* value)
4403 SGEN_LOG (8, "Wbarrier store at %p to %p (%s)", ptr, value, value ? safe_name (value) : "null");
4404 *(void**)ptr = value;
4405 if (ptr_in_nursery (value))
4406 mono_gc_wbarrier_generic_nostore (ptr);
4407 sgen_dummy_use (value);
4410 void mono_gc_wbarrier_value_copy_bitmap (gpointer _dest, gpointer _src, int size, unsigned bitmap)
4412 mword *dest = _dest;
4417 mono_gc_wbarrier_generic_store (dest, (MonoObject*)*src);
4422 size -= SIZEOF_VOID_P;
4427 #ifdef SGEN_BINARY_PROTOCOL
4429 #define HANDLE_PTR(ptr,obj) do { \
4430 gpointer o = *(gpointer*)(ptr); \
4432 gpointer d = ((char*)dest) + ((char*)(ptr) - (char*)(obj)); \
4433 binary_protocol_wbarrier (d, o, (gpointer) LOAD_VTABLE (o)); \
4438 scan_object_for_binary_protocol_copy_wbarrier (gpointer dest, char *start, mword desc)
4440 #define SCAN_OBJECT_NOVTABLE
4441 #include "sgen-scan-object.h"
4446 mono_gc_wbarrier_value_copy (gpointer dest, gpointer src, int count, MonoClass *klass)
4448 HEAVY_STAT (++stat_wbarrier_value_copy);
4449 g_assert (klass->valuetype);
4451 SGEN_LOG (8, "Adding value remset at %p, count %d, descr %p for class %s (%p)", dest, count, klass->gc_descr, klass->name, klass);
4453 if (ptr_in_nursery (dest) || ptr_on_stack (dest) || !SGEN_CLASS_HAS_REFERENCES (klass)) {
4454 size_t element_size = mono_class_value_size (klass, NULL);
4455 size_t size = count * element_size;
4456 mono_gc_memmove (dest, src, size);
4460 #ifdef SGEN_BINARY_PROTOCOL
4462 size_t element_size = mono_class_value_size (klass, NULL);
4464 for (i = 0; i < count; ++i) {
4465 scan_object_for_binary_protocol_copy_wbarrier ((char*)dest + i * element_size,
4466 (char*)src + i * element_size - sizeof (MonoObject),
4467 (mword) klass->gc_descr);
4472 remset.wbarrier_value_copy (dest, src, count, klass);
4476 * mono_gc_wbarrier_object_copy:
4478 * Write barrier to call when obj is the result of a clone or copy of an object.
4481 mono_gc_wbarrier_object_copy (MonoObject* obj, MonoObject *src)
4485 HEAVY_STAT (++stat_wbarrier_object_copy);
4487 if (ptr_in_nursery (obj) || ptr_on_stack (obj)) {
4488 size = mono_object_class (obj)->instance_size;
4489 mono_gc_memmove ((char*)obj + sizeof (MonoObject), (char*)src + sizeof (MonoObject),
4490 size - sizeof (MonoObject));
4494 #ifdef SGEN_BINARY_PROTOCOL
4495 scan_object_for_binary_protocol_copy_wbarrier (obj, (char*)src, (mword) src->vtable->gc_descr);
4498 remset.wbarrier_object_copy (obj, src);
4503 * ######################################################################
4504 * ######## Other mono public interface functions.
4505 * ######################################################################
4508 #define REFS_SIZE 128
4511 MonoGCReferences callback;
4515 MonoObject *refs [REFS_SIZE];
4516 uintptr_t offsets [REFS_SIZE];
4520 #define HANDLE_PTR(ptr,obj) do { \
4522 if (hwi->count == REFS_SIZE) { \
4523 hwi->callback ((MonoObject*)start, mono_object_class (start), hwi->called? 0: size, hwi->count, hwi->refs, hwi->offsets, hwi->data); \
4527 hwi->offsets [hwi->count] = (char*)(ptr)-(char*)start; \
4528 hwi->refs [hwi->count++] = *(ptr); \
4533 collect_references (HeapWalkInfo *hwi, char *start, size_t size)
4535 #include "sgen-scan-object.h"
4539 walk_references (char *start, size_t size, void *data)
4541 HeapWalkInfo *hwi = data;
4544 collect_references (hwi, start, size);
4545 if (hwi->count || !hwi->called)
4546 hwi->callback ((MonoObject*)start, mono_object_class (start), hwi->called? 0: size, hwi->count, hwi->refs, hwi->offsets, hwi->data);
4550 * mono_gc_walk_heap:
4551 * @flags: flags for future use
4552 * @callback: a function pointer called for each object in the heap
4553 * @data: a user data pointer that is passed to callback
4555 * This function can be used to iterate over all the live objects in the heap:
4556 * for each object, @callback is invoked, providing info about the object's
4557 * location in memory, its class, its size and the objects it references.
4558 * For each referenced object it's offset from the object address is
4559 * reported in the offsets array.
4560 * The object references may be buffered, so the callback may be invoked
4561 * multiple times for the same object: in all but the first call, the size
4562 * argument will be zero.
4563 * Note that this function can be only called in the #MONO_GC_EVENT_PRE_START_WORLD
4564 * profiler event handler.
4566 * Returns: a non-zero value if the GC doesn't support heap walking
4569 mono_gc_walk_heap (int flags, MonoGCReferences callback, void *data)
4574 hwi.callback = callback;
4577 sgen_clear_nursery_fragments ();
4578 sgen_scan_area_with_callback (nursery_section->data, nursery_section->end_data, walk_references, &hwi, FALSE);
4580 major_collector.iterate_objects (TRUE, TRUE, walk_references, &hwi);
4581 sgen_los_iterate_objects (walk_references, &hwi);
4587 mono_gc_collect (int generation)
4592 sgen_perform_collection (0, generation, "user request", TRUE);
4597 mono_gc_max_generation (void)
4603 mono_gc_collection_count (int generation)
4605 if (generation == 0)
4606 return stat_minor_gcs;
4607 return stat_major_gcs;
4611 mono_gc_get_used_size (void)
4615 tot = los_memory_usage;
4616 tot += nursery_section->next_data - nursery_section->data;
4617 tot += major_collector.get_used_size ();
4618 /* FIXME: account for pinned objects */
4624 mono_gc_get_los_limit (void)
4626 return MAX_SMALL_OBJ_SIZE;
4630 mono_gc_user_markers_supported (void)
4636 mono_object_is_alive (MonoObject* o)
4642 mono_gc_get_generation (MonoObject *obj)
4644 if (ptr_in_nursery (obj))
4650 mono_gc_enable_events (void)
4655 mono_gc_weak_link_add (void **link_addr, MonoObject *obj, gboolean track)
4657 sgen_register_disappearing_link (obj, link_addr, track, FALSE);
4661 mono_gc_weak_link_remove (void **link_addr, gboolean track)
4663 sgen_register_disappearing_link (NULL, link_addr, track, FALSE);
4667 mono_gc_weak_link_get (void **link_addr)
4669 void * volatile *link_addr_volatile;
4673 link_addr_volatile = link_addr;
4674 ptr = (void*)*link_addr_volatile;
4676 * At this point we have a hidden pointer. If the GC runs
4677 * here, it will not recognize the hidden pointer as a
4678 * reference, and if the object behind it is not referenced
4679 * elsewhere, it will be freed. Once the world is restarted
4680 * we reveal the pointer, giving us a pointer to a freed
4681 * object. To make sure we don't return it, we load the
4682 * hidden pointer again. If it's still the same, we can be
4683 * sure the object reference is valid.
4686 obj = (MonoObject*) REVEAL_POINTER (ptr);
4690 mono_memory_barrier ();
4693 * During the second bridge processing step the world is
4694 * running again. That step processes all weak links once
4695 * more to null those that refer to dead objects. Before that
4696 * is completed, those links must not be followed, so we
4697 * conservatively wait for bridge processing when any weak
4698 * link is dereferenced.
4700 if (G_UNLIKELY (bridge_processing_in_progress))
4701 mono_gc_wait_for_bridge_processing ();
4703 if ((void*)*link_addr_volatile != ptr)
4710 mono_gc_ephemeron_array_add (MonoObject *obj)
4712 EphemeronLinkNode *node;
4716 node = sgen_alloc_internal (INTERNAL_MEM_EPHEMERON_LINK);
4721 node->array = (char*)obj;
4722 node->next = ephemeron_list;
4723 ephemeron_list = node;
4725 SGEN_LOG (5, "Registered ephemeron array %p", obj);
4732 mono_gc_set_allow_synchronous_major (gboolean flag)
4734 if (!major_collector.is_concurrent)
4737 allow_synchronous_major = flag;
4742 mono_gc_invoke_with_gc_lock (MonoGCLockedCallbackFunc func, void *data)
4746 result = func (data);
4747 UNLOCK_INTERRUPTION;
4752 mono_gc_is_gc_thread (void)
4756 result = mono_thread_info_current () != NULL;
4762 is_critical_method (MonoMethod *method)
4764 return mono_runtime_is_critical_method (method) || sgen_is_critical_method (method);
4768 sgen_env_var_error (const char *env_var, const char *fallback, const char *description_format, ...)
4772 va_start (ap, description_format);
4774 fprintf (stderr, "Warning: In environment variable `%s': ", env_var);
4775 vfprintf (stderr, description_format, ap);
4777 fprintf (stderr, " - %s", fallback);
4778 fprintf (stderr, "\n");
4784 parse_double_in_interval (const char *env_var, const char *opt_name, const char *opt, double min, double max, double *result)
4787 double val = strtod (opt, &endptr);
4788 if (endptr == opt) {
4789 sgen_env_var_error (env_var, "Using default value.", "`%s` must be a number.", opt_name);
4792 else if (val < min || val > max) {
4793 sgen_env_var_error (env_var, "Using default value.", "`%s` must be between %.2f - %.2f.", opt_name, min, max);
4801 mono_gc_base_init (void)
4803 MonoThreadInfoCallbacks cb;
4806 char *major_collector_opt = NULL;
4807 char *minor_collector_opt = NULL;
4809 glong soft_limit = 0;
4813 gboolean debug_print_allowance = FALSE;
4814 double allowance_ratio = 0, save_target = 0;
4815 gboolean have_split_nursery = FALSE;
4816 gboolean cement_enabled = TRUE;
4819 result = InterlockedCompareExchange (&gc_initialized, -1, 0);
4822 /* already inited */
4825 /* being inited by another thread */
4829 /* we will init it */
4832 g_assert_not_reached ();
4834 } while (result != 0);
4836 LOCK_INIT (gc_mutex);
4838 pagesize = mono_pagesize ();
4839 gc_debug_file = stderr;
4841 cb.thread_register = sgen_thread_register;
4842 cb.thread_unregister = sgen_thread_unregister;
4843 cb.thread_attach = sgen_thread_attach;
4844 cb.mono_method_is_critical = (gpointer)is_critical_method;
4846 cb.mono_gc_pthread_create = (gpointer)mono_gc_pthread_create;
4849 mono_threads_init (&cb, sizeof (SgenThreadInfo));
4851 LOCK_INIT (sgen_interruption_mutex);
4852 LOCK_INIT (pin_queue_mutex);
4854 init_user_copy_or_mark_key ();
4856 if ((env = getenv (MONO_GC_PARAMS_NAME))) {
4857 opts = g_strsplit (env, ",", -1);
4858 for (ptr = opts; *ptr; ++ptr) {
4860 if (g_str_has_prefix (opt, "major=")) {
4861 opt = strchr (opt, '=') + 1;
4862 major_collector_opt = g_strdup (opt);
4863 } else if (g_str_has_prefix (opt, "minor=")) {
4864 opt = strchr (opt, '=') + 1;
4865 minor_collector_opt = g_strdup (opt);
4873 sgen_init_internal_allocator ();
4874 sgen_init_nursery_allocator ();
4875 sgen_init_fin_weak_hash ();
4877 sgen_register_fixed_internal_mem_type (INTERNAL_MEM_SECTION, SGEN_SIZEOF_GC_MEM_SECTION);
4878 sgen_register_fixed_internal_mem_type (INTERNAL_MEM_FINALIZE_READY_ENTRY, sizeof (FinalizeReadyEntry));
4879 sgen_register_fixed_internal_mem_type (INTERNAL_MEM_GRAY_QUEUE, sizeof (GrayQueueSection));
4880 sgen_register_fixed_internal_mem_type (INTERNAL_MEM_EPHEMERON_LINK, sizeof (EphemeronLinkNode));
4882 #ifndef HAVE_KW_THREAD
4883 mono_native_tls_alloc (&thread_info_key, NULL);
4887 * This needs to happen before any internal allocations because
4888 * it inits the small id which is required for hazard pointer
4893 mono_thread_info_attach (&dummy);
4895 if (!minor_collector_opt) {
4896 sgen_simple_nursery_init (&sgen_minor_collector);
4898 if (!strcmp (minor_collector_opt, "simple")) {
4900 sgen_simple_nursery_init (&sgen_minor_collector);
4901 } else if (!strcmp (minor_collector_opt, "split")) {
4902 sgen_split_nursery_init (&sgen_minor_collector);
4903 have_split_nursery = TRUE;
4905 sgen_env_var_error (MONO_GC_PARAMS_NAME, "Using `simple` instead.", "Unknown minor collector `%s'.", minor_collector_opt);
4906 goto use_simple_nursery;
4910 if (!major_collector_opt || !strcmp (major_collector_opt, "marksweep")) {
4911 use_marksweep_major:
4912 sgen_marksweep_init (&major_collector);
4913 } else if (!major_collector_opt || !strcmp (major_collector_opt, "marksweep-fixed")) {
4914 sgen_marksweep_fixed_init (&major_collector);
4915 } else if (!major_collector_opt || !strcmp (major_collector_opt, "marksweep-par")) {
4916 sgen_marksweep_par_init (&major_collector);
4917 } else if (!major_collector_opt || !strcmp (major_collector_opt, "marksweep-fixed-par")) {
4918 sgen_marksweep_fixed_par_init (&major_collector);
4919 } else if (!major_collector_opt || !strcmp (major_collector_opt, "marksweep-conc")) {
4920 sgen_marksweep_conc_init (&major_collector);
4922 sgen_env_var_error (MONO_GC_PARAMS_NAME, "Using `marksweep` instead.", "Unknown major collector `%s'.", major_collector_opt);
4923 goto use_marksweep_major;
4926 if (have_split_nursery && major_collector.is_parallel) {
4927 sgen_env_var_error (MONO_GC_PARAMS_NAME, "Disabling split minor collector.", "`minor=split` is not supported with the parallel collector yet.");
4928 have_split_nursery = FALSE;
4931 num_workers = mono_cpu_count ();
4932 g_assert (num_workers > 0);
4933 if (num_workers > 16)
4936 ///* Keep this the default for now */
4937 /* Precise marking is broken on all supported targets. Disable until fixed. */
4938 conservative_stack_mark = TRUE;
4940 sgen_nursery_size = DEFAULT_NURSERY_SIZE;
4943 gboolean usage_printed = FALSE;
4945 for (ptr = opts; *ptr; ++ptr) {
4947 if (!strcmp (opt, ""))
4949 if (g_str_has_prefix (opt, "major="))
4951 if (g_str_has_prefix (opt, "minor="))
4953 if (g_str_has_prefix (opt, "max-heap-size=")) {
4954 glong max_heap_candidate = 0;
4955 opt = strchr (opt, '=') + 1;
4956 if (*opt && mono_gc_parse_environment_string_extract_number (opt, &max_heap_candidate)) {
4957 max_heap = (max_heap_candidate + mono_pagesize () - 1) & ~(glong)(mono_pagesize () - 1);
4958 if (max_heap != max_heap_candidate)
4959 sgen_env_var_error (MONO_GC_PARAMS_NAME, "Rounding up.", "`max-heap-size` size must be a multiple of %d.", mono_pagesize ());
4961 sgen_env_var_error (MONO_GC_PARAMS_NAME, NULL, "`max-heap-size` must be an integer.");
4965 if (g_str_has_prefix (opt, "soft-heap-limit=")) {
4966 opt = strchr (opt, '=') + 1;
4967 if (*opt && mono_gc_parse_environment_string_extract_number (opt, &soft_limit)) {
4968 if (soft_limit <= 0) {
4969 sgen_env_var_error (MONO_GC_PARAMS_NAME, NULL, "`soft-heap-limit` must be positive.");
4973 sgen_env_var_error (MONO_GC_PARAMS_NAME, NULL, "`soft-heap-limit` must be an integer.");
4977 if (g_str_has_prefix (opt, "workers=")) {
4980 if (!major_collector.is_parallel) {
4981 sgen_env_var_error (MONO_GC_PARAMS_NAME, "Ignoring.", "The `workers` option can only be used for parallel collectors.");
4984 opt = strchr (opt, '=') + 1;
4985 val = strtol (opt, &endptr, 10);
4986 if (!*opt || *endptr) {
4987 sgen_env_var_error (MONO_GC_PARAMS_NAME, "Ignoring.", "Cannot parse the `workers` option value.");
4990 if (val <= 0 || val > 16) {
4991 sgen_env_var_error (MONO_GC_PARAMS_NAME, "Using default value.", "The number of `workers` must be in the range 1 to 16.");
4994 num_workers = (int)val;
4997 if (g_str_has_prefix (opt, "stack-mark=")) {
4998 opt = strchr (opt, '=') + 1;
4999 if (!strcmp (opt, "precise")) {
5000 conservative_stack_mark = FALSE;
5001 } else if (!strcmp (opt, "conservative")) {
5002 conservative_stack_mark = TRUE;
5004 sgen_env_var_error (MONO_GC_PARAMS_NAME, conservative_stack_mark ? "Using `conservative`." : "Using `precise`.",
5005 "Invalid value `%s` for `stack-mark` option, possible values are: `precise`, `conservative`.", opt);
5009 if (g_str_has_prefix (opt, "bridge=")) {
5010 opt = strchr (opt, '=') + 1;
5011 sgen_register_test_bridge_callbacks (g_strdup (opt));
5015 if (g_str_has_prefix (opt, "nursery-size=")) {
5017 opt = strchr (opt, '=') + 1;
5018 if (*opt && mono_gc_parse_environment_string_extract_number (opt, &val)) {
5019 #ifdef SGEN_ALIGN_NURSERY
5020 if ((val & (val - 1))) {
5021 sgen_env_var_error (MONO_GC_PARAMS_NAME, "Using default value.", "`nursery-size` must be a power of two.");
5025 if (val < SGEN_MAX_NURSERY_WASTE) {
5026 sgen_env_var_error (MONO_GC_PARAMS_NAME, "Using default value.",
5027 "`nursery-size` must be at least %d bytes.\n", SGEN_MAX_NURSERY_WASTE);
5031 sgen_nursery_size = val;
5032 sgen_nursery_bits = 0;
5033 while (1 << (++ sgen_nursery_bits) != sgen_nursery_size)
5036 sgen_nursery_size = val;
5039 sgen_env_var_error (MONO_GC_PARAMS_NAME, "Using default value.", "`nursery-size` must be an integer.");
5045 if (g_str_has_prefix (opt, "save-target-ratio=")) {
5047 opt = strchr (opt, '=') + 1;
5048 if (parse_double_in_interval (MONO_GC_PARAMS_NAME, "save-target-ratio", opt,
5049 SGEN_MIN_SAVE_TARGET_RATIO, SGEN_MAX_SAVE_TARGET_RATIO, &val)) {
5054 if (g_str_has_prefix (opt, "default-allowance-ratio=")) {
5056 opt = strchr (opt, '=') + 1;
5057 if (parse_double_in_interval (MONO_GC_PARAMS_NAME, "default-allowance-ratio", opt,
5058 SGEN_MIN_ALLOWANCE_NURSERY_SIZE_RATIO, SGEN_MIN_ALLOWANCE_NURSERY_SIZE_RATIO, &val)) {
5059 allowance_ratio = val;
5063 if (g_str_has_prefix (opt, "allow-synchronous-major=")) {
5064 if (!major_collector.is_concurrent) {
5065 sgen_env_var_error (MONO_GC_PARAMS_NAME, "Ignoring.", "`allow-synchronous-major` is only valid for the concurrent major collector.");
5069 opt = strchr (opt, '=') + 1;
5071 if (!strcmp (opt, "yes")) {
5072 allow_synchronous_major = TRUE;
5073 } else if (!strcmp (opt, "no")) {
5074 allow_synchronous_major = FALSE;
5076 sgen_env_var_error (MONO_GC_PARAMS_NAME, "Using default value.", "`allow-synchronous-major` must be either `yes' or `no'.");
5081 if (!strcmp (opt, "cementing")) {
5082 cement_enabled = TRUE;
5085 if (!strcmp (opt, "no-cementing")) {
5086 cement_enabled = FALSE;
5090 if (major_collector.handle_gc_param && major_collector.handle_gc_param (opt))
5093 if (sgen_minor_collector.handle_gc_param && sgen_minor_collector.handle_gc_param (opt))
5096 sgen_env_var_error (MONO_GC_PARAMS_NAME, "Ignoring.", "Unknown option `%s`.", opt);
5101 fprintf (stderr, "\n%s must be a comma-delimited list of one or more of the following:\n", MONO_GC_PARAMS_NAME);
5102 fprintf (stderr, " max-heap-size=N (where N is an integer, possibly with a k, m or a g suffix)\n");
5103 fprintf (stderr, " soft-heap-limit=n (where N is an integer, possibly with a k, m or a g suffix)\n");
5104 fprintf (stderr, " nursery-size=N (where N is an integer, possibly with a k, m or a g suffix)\n");
5105 fprintf (stderr, " major=COLLECTOR (where COLLECTOR is `marksweep', `marksweep-conc', `marksweep-par', 'marksweep-fixed' or 'marksweep-fixed-par')\n");
5106 fprintf (stderr, " minor=COLLECTOR (where COLLECTOR is `simple' or `split')\n");
5107 fprintf (stderr, " wbarrier=WBARRIER (where WBARRIER is `remset' or `cardtable')\n");
5108 fprintf (stderr, " stack-mark=MARK-METHOD (where MARK-METHOD is 'precise' or 'conservative')\n");
5109 fprintf (stderr, " [no-]cementing\n");
5110 if (major_collector.is_concurrent)
5111 fprintf (stderr, " allow-synchronous-major=FLAG (where FLAG is `yes' or `no')\n");
5112 if (major_collector.print_gc_param_usage)
5113 major_collector.print_gc_param_usage ();
5114 if (sgen_minor_collector.print_gc_param_usage)
5115 sgen_minor_collector.print_gc_param_usage ();
5116 fprintf (stderr, " Experimental options:\n");
5117 fprintf (stderr, " save-target-ratio=R (where R must be between %.2f - %.2f).\n", SGEN_MIN_SAVE_TARGET_RATIO, SGEN_MAX_SAVE_TARGET_RATIO);
5118 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);
5119 fprintf (stderr, "\n");
5121 usage_printed = TRUE;
5126 if (major_collector.is_parallel)
5127 sgen_workers_init (num_workers);
5128 else if (major_collector.is_concurrent)
5129 sgen_workers_init (1);
5131 if (major_collector_opt)
5132 g_free (major_collector_opt);
5134 if (minor_collector_opt)
5135 g_free (minor_collector_opt);
5139 sgen_cement_init (cement_enabled);
5141 if ((env = getenv (MONO_GC_DEBUG_NAME))) {
5142 gboolean usage_printed = FALSE;
5144 opts = g_strsplit (env, ",", -1);
5145 for (ptr = opts; ptr && *ptr; ptr ++) {
5147 if (!strcmp (opt, ""))
5149 if (opt [0] >= '0' && opt [0] <= '9') {
5150 gc_debug_level = atoi (opt);
5156 char *rf = g_strdup_printf ("%s.%d", opt, GetCurrentProcessId ());
5158 char *rf = g_strdup_printf ("%s.%d", opt, getpid ());
5160 gc_debug_file = fopen (rf, "wb");
5162 gc_debug_file = stderr;
5165 } else if (!strcmp (opt, "print-allowance")) {
5166 debug_print_allowance = TRUE;
5167 } else if (!strcmp (opt, "print-pinning")) {
5168 do_pin_stats = TRUE;
5169 } else if (!strcmp (opt, "verify-before-allocs")) {
5170 verify_before_allocs = 1;
5171 has_per_allocation_action = TRUE;
5172 } else if (g_str_has_prefix (opt, "verify-before-allocs=")) {
5173 char *arg = strchr (opt, '=') + 1;
5174 verify_before_allocs = atoi (arg);
5175 has_per_allocation_action = TRUE;
5176 } else if (!strcmp (opt, "collect-before-allocs")) {
5177 collect_before_allocs = 1;
5178 has_per_allocation_action = TRUE;
5179 } else if (g_str_has_prefix (opt, "collect-before-allocs=")) {
5180 char *arg = strchr (opt, '=') + 1;
5181 has_per_allocation_action = TRUE;
5182 collect_before_allocs = atoi (arg);
5183 } else if (!strcmp (opt, "verify-before-collections")) {
5184 whole_heap_check_before_collection = TRUE;
5185 } else if (!strcmp (opt, "check-at-minor-collections")) {
5186 consistency_check_at_minor_collection = TRUE;
5187 nursery_clear_policy = CLEAR_AT_GC;
5188 } else if (!strcmp (opt, "mod-union-consistency-check")) {
5189 if (!major_collector.is_concurrent) {
5190 sgen_env_var_error (MONO_GC_DEBUG_NAME, "Ignoring.", "`mod-union-consistency-check` only works with concurrent major collector.");
5193 mod_union_consistency_check = TRUE;
5194 } else if (!strcmp (opt, "check-mark-bits")) {
5195 check_mark_bits_after_major_collection = TRUE;
5196 } else if (!strcmp (opt, "check-nursery-pinned")) {
5197 check_nursery_objects_pinned = TRUE;
5198 } else if (!strcmp (opt, "xdomain-checks")) {
5199 xdomain_checks = TRUE;
5200 } else if (!strcmp (opt, "clear-at-gc")) {
5201 nursery_clear_policy = CLEAR_AT_GC;
5202 } else if (!strcmp (opt, "clear-nursery-at-gc")) {
5203 nursery_clear_policy = CLEAR_AT_GC;
5204 } else if (!strcmp (opt, "check-scan-starts")) {
5205 do_scan_starts_check = TRUE;
5206 } else if (!strcmp (opt, "verify-nursery-at-minor-gc")) {
5207 do_verify_nursery = TRUE;
5208 } else if (!strcmp (opt, "check-concurrent")) {
5209 if (!major_collector.is_concurrent) {
5210 sgen_env_var_error (MONO_GC_DEBUG_NAME, "Ignoring.", "`check-concurrent` only works with concurrent major collectors.");
5213 do_concurrent_checks = TRUE;
5214 } else if (!strcmp (opt, "dump-nursery-at-minor-gc")) {
5215 do_dump_nursery_content = TRUE;
5216 } else if (!strcmp (opt, "no-managed-allocator")) {
5217 sgen_set_use_managed_allocator (FALSE);
5218 } else if (!strcmp (opt, "disable-minor")) {
5219 disable_minor_collections = TRUE;
5220 } else if (!strcmp (opt, "disable-major")) {
5221 disable_major_collections = TRUE;
5222 } else if (g_str_has_prefix (opt, "heap-dump=")) {
5223 char *filename = strchr (opt, '=') + 1;
5224 nursery_clear_policy = CLEAR_AT_GC;
5225 heap_dump_file = fopen (filename, "w");
5226 if (heap_dump_file) {
5227 fprintf (heap_dump_file, "<sgen-dump>\n");
5228 do_pin_stats = TRUE;
5230 #ifdef SGEN_BINARY_PROTOCOL
5231 } else if (g_str_has_prefix (opt, "binary-protocol=")) {
5232 char *filename = strchr (opt, '=') + 1;
5233 binary_protocol_init (filename);
5236 sgen_env_var_error (MONO_GC_DEBUG_NAME, "Ignoring.", "Unknown option `%s`.", opt);
5241 fprintf (stderr, "\n%s must be of the format [<l>[:<filename>]|<option>]+ where <l> is a debug level 0-9.\n", MONO_GC_DEBUG_NAME);
5242 fprintf (stderr, "Valid <option>s are:\n");
5243 fprintf (stderr, " collect-before-allocs[=<n>]\n");
5244 fprintf (stderr, " verify-before-allocs[=<n>]\n");
5245 fprintf (stderr, " check-at-minor-collections\n");
5246 fprintf (stderr, " check-mark-bits\n");
5247 fprintf (stderr, " check-nursery-pinned\n");
5248 fprintf (stderr, " verify-before-collections\n");
5249 fprintf (stderr, " verify-nursery-at-minor-gc\n");
5250 fprintf (stderr, " dump-nursery-at-minor-gc\n");
5251 fprintf (stderr, " disable-minor\n");
5252 fprintf (stderr, " disable-major\n");
5253 fprintf (stderr, " xdomain-checks\n");
5254 fprintf (stderr, " check-concurrent\n");
5255 fprintf (stderr, " clear-at-gc\n");
5256 fprintf (stderr, " clear-nursery-at-gc\n");
5257 fprintf (stderr, " check-scan-starts\n");
5258 fprintf (stderr, " no-managed-allocator\n");
5259 fprintf (stderr, " print-allowance\n");
5260 fprintf (stderr, " print-pinning\n");
5261 fprintf (stderr, " heap-dump=<filename>\n");
5262 #ifdef SGEN_BINARY_PROTOCOL
5263 fprintf (stderr, " binary-protocol=<filename>\n");
5265 fprintf (stderr, "\n");
5267 usage_printed = TRUE;
5273 if (major_collector.is_parallel) {
5274 if (heap_dump_file) {
5275 sgen_env_var_error (MONO_GC_DEBUG_NAME, "Disabling.", "Cannot do `heap-dump` with the parallel collector.");
5276 fclose (heap_dump_file);
5277 heap_dump_file = NULL;
5280 sgen_env_var_error (MONO_GC_DEBUG_NAME, "Disabling.", "`print-pinning` is not supported with the parallel collector.");
5281 do_pin_stats = FALSE;
5285 if (major_collector.post_param_init)
5286 major_collector.post_param_init (&major_collector);
5288 sgen_memgov_init (max_heap, soft_limit, debug_print_allowance, allowance_ratio, save_target);
5290 memset (&remset, 0, sizeof (remset));
5292 sgen_card_table_init (&remset);
5298 mono_gc_get_gc_name (void)
5303 static MonoMethod *write_barrier_method;
5306 sgen_is_critical_method (MonoMethod *method)
5308 return (method == write_barrier_method || sgen_is_managed_allocator (method));
5312 sgen_has_critical_method (void)
5314 return write_barrier_method || sgen_has_managed_allocator ();
5320 emit_nursery_check (MonoMethodBuilder *mb, int *nursery_check_return_labels)
5322 memset (nursery_check_return_labels, 0, sizeof (int) * 3);
5323 #ifdef SGEN_ALIGN_NURSERY
5324 // if (ptr_in_nursery (ptr)) return;
5326 * Masking out the bits might be faster, but we would have to use 64 bit
5327 * immediates, which might be slower.
5329 mono_mb_emit_ldarg (mb, 0);
5330 mono_mb_emit_icon (mb, DEFAULT_NURSERY_BITS);
5331 mono_mb_emit_byte (mb, CEE_SHR_UN);
5332 mono_mb_emit_icon (mb, (mword)sgen_get_nursery_start () >> DEFAULT_NURSERY_BITS);
5333 nursery_check_return_labels [0] = mono_mb_emit_branch (mb, CEE_BEQ);
5335 if (!major_collector.is_concurrent) {
5336 // if (!ptr_in_nursery (*ptr)) return;
5337 mono_mb_emit_ldarg (mb, 0);
5338 mono_mb_emit_byte (mb, CEE_LDIND_I);
5339 mono_mb_emit_icon (mb, DEFAULT_NURSERY_BITS);
5340 mono_mb_emit_byte (mb, CEE_SHR_UN);
5341 mono_mb_emit_icon (mb, (mword)sgen_get_nursery_start () >> DEFAULT_NURSERY_BITS);
5342 nursery_check_return_labels [1] = mono_mb_emit_branch (mb, CEE_BNE_UN);
5345 int label_continue1, label_continue2;
5346 int dereferenced_var;
5348 // if (ptr < (sgen_get_nursery_start ())) goto continue;
5349 mono_mb_emit_ldarg (mb, 0);
5350 mono_mb_emit_ptr (mb, (gpointer) sgen_get_nursery_start ());
5351 label_continue_1 = mono_mb_emit_branch (mb, CEE_BLT);
5353 // if (ptr >= sgen_get_nursery_end ())) goto continue;
5354 mono_mb_emit_ldarg (mb, 0);
5355 mono_mb_emit_ptr (mb, (gpointer) sgen_get_nursery_end ());
5356 label_continue_2 = mono_mb_emit_branch (mb, CEE_BGE);
5359 nursery_check_return_labels [0] = mono_mb_emit_branch (mb, CEE_BR);
5362 mono_mb_patch_branch (mb, label_continue_1);
5363 mono_mb_patch_branch (mb, label_continue_2);
5365 // Dereference and store in local var
5366 dereferenced_var = mono_mb_add_local (mb, &mono_defaults.int_class->byval_arg);
5367 mono_mb_emit_ldarg (mb, 0);
5368 mono_mb_emit_byte (mb, CEE_LDIND_I);
5369 mono_mb_emit_stloc (mb, dereferenced_var);
5371 if (!major_collector.is_concurrent) {
5372 // if (*ptr < sgen_get_nursery_start ()) return;
5373 mono_mb_emit_ldloc (mb, dereferenced_var);
5374 mono_mb_emit_ptr (mb, (gpointer) sgen_get_nursery_start ());
5375 nursery_check_return_labels [1] = mono_mb_emit_branch (mb, CEE_BLT);
5377 // if (*ptr >= sgen_get_nursery_end ()) return;
5378 mono_mb_emit_ldloc (mb, dereferenced_var);
5379 mono_mb_emit_ptr (mb, (gpointer) sgen_get_nursery_end ());
5380 nursery_check_return_labels [2] = mono_mb_emit_branch (mb, CEE_BGE);
5387 mono_gc_get_write_barrier (void)
5390 MonoMethodBuilder *mb;
5391 MonoMethodSignature *sig;
5392 #ifdef MANAGED_WBARRIER
5393 int i, nursery_check_labels [3];
5395 #ifdef HAVE_KW_THREAD
5396 int stack_end_offset = -1;
5398 MONO_THREAD_VAR_OFFSET (stack_end, stack_end_offset);
5399 g_assert (stack_end_offset != -1);
5403 // FIXME: Maybe create a separate version for ctors (the branch would be
5404 // correctly predicted more times)
5405 if (write_barrier_method)
5406 return write_barrier_method;
5408 /* Create the IL version of mono_gc_barrier_generic_store () */
5409 sig = mono_metadata_signature_alloc (mono_defaults.corlib, 1);
5410 sig->ret = &mono_defaults.void_class->byval_arg;
5411 sig->params [0] = &mono_defaults.int_class->byval_arg;
5413 mb = mono_mb_new (mono_defaults.object_class, "wbarrier", MONO_WRAPPER_WRITE_BARRIER);
5416 #ifdef MANAGED_WBARRIER
5417 emit_nursery_check (mb, nursery_check_labels);
5419 addr = sgen_cardtable + ((address >> CARD_BITS) & CARD_MASK)
5423 LDC_PTR sgen_cardtable
5425 address >> CARD_BITS
5429 if (SGEN_HAVE_OVERLAPPING_CARDS) {
5430 LDC_PTR card_table_mask
5437 mono_mb_emit_ptr (mb, sgen_cardtable);
5438 mono_mb_emit_ldarg (mb, 0);
5439 mono_mb_emit_icon (mb, CARD_BITS);
5440 mono_mb_emit_byte (mb, CEE_SHR_UN);
5441 #ifdef SGEN_HAVE_OVERLAPPING_CARDS
5442 mono_mb_emit_ptr (mb, (gpointer)CARD_MASK);
5443 mono_mb_emit_byte (mb, CEE_AND);
5445 mono_mb_emit_byte (mb, CEE_ADD);
5446 mono_mb_emit_icon (mb, 1);
5447 mono_mb_emit_byte (mb, CEE_STIND_I1);
5450 for (i = 0; i < 3; ++i) {
5451 if (nursery_check_labels [i])
5452 mono_mb_patch_branch (mb, nursery_check_labels [i]);
5454 mono_mb_emit_byte (mb, CEE_RET);
5456 mono_mb_emit_ldarg (mb, 0);
5457 mono_mb_emit_icall (mb, mono_gc_wbarrier_generic_nostore);
5458 mono_mb_emit_byte (mb, CEE_RET);
5461 res = mono_mb_create_method (mb, sig, 16);
5464 mono_loader_lock ();
5465 if (write_barrier_method) {
5466 /* Already created */
5467 mono_free_method (res);
5469 /* double-checked locking */
5470 mono_memory_barrier ();
5471 write_barrier_method = res;
5473 mono_loader_unlock ();
5475 return write_barrier_method;
5479 mono_gc_get_description (void)
5481 return g_strdup ("sgen");
5485 mono_gc_set_desktop_mode (void)
5490 mono_gc_is_moving (void)
5496 mono_gc_is_disabled (void)
5502 BOOL APIENTRY mono_gc_dllmain (HMODULE module_handle, DWORD reason, LPVOID reserved)
5509 sgen_get_nursery_clear_policy (void)
5511 return nursery_clear_policy;
5515 sgen_get_array_fill_vtable (void)
5517 if (!array_fill_vtable) {
5518 static MonoClass klass;
5519 static MonoVTable vtable;
5522 MonoDomain *domain = mono_get_root_domain ();
5525 klass.element_class = mono_defaults.byte_class;
5527 klass.instance_size = sizeof (MonoArray);
5528 klass.sizes.element_size = 1;
5529 klass.name = "array_filler_type";
5531 vtable.klass = &klass;
5533 vtable.gc_descr = mono_gc_make_descr_for_array (TRUE, &bmap, 0, 1);
5536 array_fill_vtable = &vtable;
5538 return array_fill_vtable;
5548 sgen_gc_unlock (void)
5554 sgen_major_collector_iterate_live_block_ranges (sgen_cardtable_block_callback callback)
5556 major_collector.iterate_live_block_ranges (callback);
5560 sgen_major_collector_scan_card_table (SgenGrayQueue *queue)
5562 major_collector.scan_card_table (FALSE, queue);
5566 sgen_get_major_collector (void)
5568 return &major_collector;
5571 void mono_gc_set_skip_thread (gboolean skip)
5573 SgenThreadInfo *info = mono_thread_info_current ();
5576 info->gc_disabled = skip;
5581 sgen_get_remset (void)
5587 mono_gc_get_vtable_bits (MonoClass *class)
5589 if (sgen_need_bridge_processing () && sgen_is_bridge_class (class))
5590 return SGEN_GC_BIT_BRIDGE_OBJECT;
5595 mono_gc_register_altstack (gpointer stack, gint32 stack_size, gpointer altstack, gint32 altstack_size)
5602 sgen_check_whole_heap_stw (void)
5604 sgen_stop_world (0);
5605 sgen_clear_nursery_fragments ();
5606 sgen_check_whole_heap (FALSE);
5607 sgen_restart_world (0, NULL);
5611 sgen_gc_event_moves (void)
5613 if (moved_objects_idx) {
5614 mono_profiler_gc_moves (moved_objects, moved_objects_idx);
5615 moved_objects_idx = 0;
5619 #endif /* HAVE_SGEN_GC */