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_generic_store_atomic = 0;
321 static int stat_wbarrier_set_root = 0;
322 static int stat_wbarrier_value_copy = 0;
323 static int stat_wbarrier_object_copy = 0;
326 int stat_minor_gcs = 0;
327 int stat_major_gcs = 0;
329 static long long stat_pinned_objects = 0;
331 static long long time_minor_pre_collection_fragment_clear = 0;
332 static long long time_minor_pinning = 0;
333 static long long time_minor_scan_remsets = 0;
334 static long long time_minor_scan_pinned = 0;
335 static long long time_minor_scan_registered_roots = 0;
336 static long long time_minor_scan_thread_data = 0;
337 static long long time_minor_finish_gray_stack = 0;
338 static long long time_minor_fragment_creation = 0;
340 static long long time_major_pre_collection_fragment_clear = 0;
341 static long long time_major_pinning = 0;
342 static long long time_major_scan_pinned = 0;
343 static long long time_major_scan_registered_roots = 0;
344 static long long time_major_scan_thread_data = 0;
345 static long long time_major_scan_alloc_pinned = 0;
346 static long long time_major_scan_finalized = 0;
347 static long long time_major_scan_big_objects = 0;
348 static long long time_major_finish_gray_stack = 0;
349 static long long time_major_free_bigobjs = 0;
350 static long long time_major_los_sweep = 0;
351 static long long time_major_sweep = 0;
352 static long long time_major_fragment_creation = 0;
354 int gc_debug_level = 0;
359 mono_gc_flush_info (void)
361 fflush (gc_debug_file);
365 #define TV_DECLARE SGEN_TV_DECLARE
366 #define TV_GETTIME SGEN_TV_GETTIME
367 #define TV_ELAPSED SGEN_TV_ELAPSED
368 #define TV_ELAPSED_MS SGEN_TV_ELAPSED_MS
370 #define ALIGN_TO(val,align) ((((guint64)val) + ((align) - 1)) & ~((align) - 1))
372 NurseryClearPolicy nursery_clear_policy = CLEAR_AT_TLAB_CREATION;
374 #define object_is_forwarded SGEN_OBJECT_IS_FORWARDED
375 #define object_is_pinned SGEN_OBJECT_IS_PINNED
376 #define pin_object SGEN_PIN_OBJECT
377 #define unpin_object SGEN_UNPIN_OBJECT
379 #define ptr_in_nursery sgen_ptr_in_nursery
381 #define LOAD_VTABLE SGEN_LOAD_VTABLE
384 safe_name (void* obj)
386 MonoVTable *vt = (MonoVTable*)LOAD_VTABLE (obj);
387 return vt->klass->name;
390 #define safe_object_get_size sgen_safe_object_get_size
393 sgen_safe_name (void* obj)
395 return safe_name (obj);
399 * ######################################################################
400 * ######## Global data.
401 * ######################################################################
403 LOCK_DECLARE (gc_mutex);
404 gboolean sgen_try_free_some_memory;
406 #define SCAN_START_SIZE SGEN_SCAN_START_SIZE
408 static mword pagesize = 4096;
409 int degraded_mode = 0;
411 static mword bytes_pinned_from_failed_allocation = 0;
413 GCMemSection *nursery_section = NULL;
414 static mword lowest_heap_address = ~(mword)0;
415 static mword highest_heap_address = 0;
417 LOCK_DECLARE (sgen_interruption_mutex);
418 static LOCK_DECLARE (pin_queue_mutex);
420 #define LOCK_PIN_QUEUE mono_mutex_lock (&pin_queue_mutex)
421 #define UNLOCK_PIN_QUEUE mono_mutex_unlock (&pin_queue_mutex)
423 typedef struct _FinalizeReadyEntry FinalizeReadyEntry;
424 struct _FinalizeReadyEntry {
425 FinalizeReadyEntry *next;
429 typedef struct _EphemeronLinkNode EphemeronLinkNode;
431 struct _EphemeronLinkNode {
432 EphemeronLinkNode *next;
441 int current_collection_generation = -1;
442 volatile gboolean concurrent_collection_in_progress = FALSE;
444 /* objects that are ready to be finalized */
445 static FinalizeReadyEntry *fin_ready_list = NULL;
446 static FinalizeReadyEntry *critical_fin_list = NULL;
448 static EphemeronLinkNode *ephemeron_list;
450 /* registered roots: the key to the hash is the root start address */
452 * Different kinds of roots are kept separate to speed up pin_from_roots () for example.
454 SgenHashTable roots_hash [ROOT_TYPE_NUM] = {
455 SGEN_HASH_TABLE_INIT (INTERNAL_MEM_ROOTS_TABLE, INTERNAL_MEM_ROOT_RECORD, sizeof (RootRecord), mono_aligned_addr_hash, NULL),
456 SGEN_HASH_TABLE_INIT (INTERNAL_MEM_ROOTS_TABLE, INTERNAL_MEM_ROOT_RECORD, sizeof (RootRecord), mono_aligned_addr_hash, NULL),
457 SGEN_HASH_TABLE_INIT (INTERNAL_MEM_ROOTS_TABLE, INTERNAL_MEM_ROOT_RECORD, sizeof (RootRecord), mono_aligned_addr_hash, NULL)
459 static mword roots_size = 0; /* amount of memory in the root set */
461 #define GC_ROOT_NUM 32
463 int count; /* must be the first field */
464 void *objects [GC_ROOT_NUM];
465 int root_types [GC_ROOT_NUM];
466 uintptr_t extra_info [GC_ROOT_NUM];
470 notify_gc_roots (GCRootReport *report)
474 mono_profiler_gc_roots (report->count, report->objects, report->root_types, report->extra_info);
479 add_profile_gc_root (GCRootReport *report, void *object, int rtype, uintptr_t extra_info)
481 if (report->count == GC_ROOT_NUM)
482 notify_gc_roots (report);
483 report->objects [report->count] = object;
484 report->root_types [report->count] = rtype;
485 report->extra_info [report->count++] = (uintptr_t)((MonoVTable*)LOAD_VTABLE (object))->klass;
488 MonoNativeTlsKey thread_info_key;
490 #ifdef HAVE_KW_THREAD
491 __thread SgenThreadInfo *sgen_thread_info;
492 __thread char *stack_end;
495 /* The size of a TLAB */
496 /* The bigger the value, the less often we have to go to the slow path to allocate a new
497 * one, but the more space is wasted by threads not allocating much memory.
499 * FIXME: Make this self-tuning for each thread.
501 guint32 tlab_size = (1024 * 4);
503 #define MAX_SMALL_OBJ_SIZE SGEN_MAX_SMALL_OBJ_SIZE
505 /* Functions supplied by the runtime to be called by the GC */
506 static MonoGCCallbacks gc_callbacks;
508 #define ALLOC_ALIGN SGEN_ALLOC_ALIGN
509 #define ALLOC_ALIGN_BITS SGEN_ALLOC_ALIGN_BITS
511 #define ALIGN_UP SGEN_ALIGN_UP
513 #define MOVED_OBJECTS_NUM 64
514 static void *moved_objects [MOVED_OBJECTS_NUM];
515 static int moved_objects_idx = 0;
517 /* Vtable of the objects used to fill out nursery fragments before a collection */
518 static MonoVTable *array_fill_vtable;
520 #ifdef SGEN_DEBUG_INTERNAL_ALLOC
521 MonoNativeThreadId main_gc_thread = NULL;
524 /*Object was pinned during the current collection*/
525 static mword objects_pinned;
528 * ######################################################################
529 * ######## Macros and function declarations.
530 * ######################################################################
534 align_pointer (void *ptr)
536 mword p = (mword)ptr;
537 p += sizeof (gpointer) - 1;
538 p &= ~ (sizeof (gpointer) - 1);
542 typedef SgenGrayQueue GrayQueue;
544 /* forward declarations */
545 static void scan_thread_data (void *start_nursery, void *end_nursery, gboolean precise, GrayQueue *queue);
546 static void scan_from_registered_roots (char *addr_start, char *addr_end, int root_type, ScanCopyContext ctx);
547 static void scan_finalizer_entries (FinalizeReadyEntry *list, ScanCopyContext ctx);
548 static void report_finalizer_roots (void);
549 static void report_registered_roots (void);
551 static void pin_from_roots (void *start_nursery, void *end_nursery, GrayQueue *queue);
552 static int pin_objects_from_addresses (GCMemSection *section, void **start, void **end, void *start_nursery, void *end_nursery, ScanCopyContext ctx);
553 static void finish_gray_stack (int generation, GrayQueue *queue);
555 void mono_gc_scan_for_specific_ref (MonoObject *key, gboolean precise);
558 static void init_stats (void);
560 static int mark_ephemerons_in_range (ScanCopyContext ctx);
561 static void clear_unreachable_ephemerons (ScanCopyContext ctx);
562 static void null_ephemerons_for_domain (MonoDomain *domain);
564 static gboolean major_update_or_finish_concurrent_collection (gboolean force_finish);
566 SgenObjectOperations current_object_ops;
567 SgenMajorCollector major_collector;
568 SgenMinorCollector sgen_minor_collector;
569 static GrayQueue gray_queue;
571 static SgenRemeberedSet remset;
573 /* The gray queue to use from the main collection thread. */
574 #define WORKERS_DISTRIBUTE_GRAY_QUEUE (&gray_queue)
577 * The gray queue a worker job must use. If we're not parallel or
578 * concurrent, we use the main gray queue.
580 static SgenGrayQueue*
581 sgen_workers_get_job_gray_queue (WorkerData *worker_data)
583 return worker_data ? &worker_data->private_gray_queue : WORKERS_DISTRIBUTE_GRAY_QUEUE;
587 gray_queue_redirect (SgenGrayQueue *queue)
589 gboolean wake = FALSE;
593 GrayQueueSection *section = sgen_gray_object_dequeue_section (queue);
596 sgen_section_gray_queue_enqueue (queue->alloc_prepare_data, section);
601 g_assert (concurrent_collection_in_progress ||
602 (current_collection_generation == GENERATION_OLD && major_collector.is_parallel));
603 if (sgen_workers_have_started ()) {
604 sgen_workers_wake_up_all ();
606 if (concurrent_collection_in_progress)
607 g_assert (current_collection_generation == -1);
613 is_xdomain_ref_allowed (gpointer *ptr, char *obj, MonoDomain *domain)
615 MonoObject *o = (MonoObject*)(obj);
616 MonoObject *ref = (MonoObject*)*(ptr);
617 int offset = (char*)(ptr) - (char*)o;
619 if (o->vtable->klass == mono_defaults.thread_class && offset == G_STRUCT_OFFSET (MonoThread, internal_thread))
621 if (o->vtable->klass == mono_defaults.internal_thread_class && offset == G_STRUCT_OFFSET (MonoInternalThread, current_appcontext))
624 #ifndef DISABLE_REMOTING
625 if (mono_defaults.real_proxy_class->supertypes && mono_class_has_parent_fast (o->vtable->klass, mono_defaults.real_proxy_class) &&
626 offset == G_STRUCT_OFFSET (MonoRealProxy, unwrapped_server))
629 /* Thread.cached_culture_info */
630 if (!strcmp (ref->vtable->klass->name_space, "System.Globalization") &&
631 !strcmp (ref->vtable->klass->name, "CultureInfo") &&
632 !strcmp(o->vtable->klass->name_space, "System") &&
633 !strcmp(o->vtable->klass->name, "Object[]"))
636 * 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
637 * at System.IO.MemoryStream..ctor (byte[]) [0x00017] in /home/schani/Work/novell/trunk/mcs/class/corlib/System.IO/MemoryStream.cs:81
638 * at (wrapper remoting-invoke-with-check) System.IO.MemoryStream..ctor (byte[]) <IL 0x00020, 0xffffffff>
639 * at System.Runtime.Remoting.Messaging.CADMethodCallMessage.GetArguments () [0x0000d] in /home/schani/Work/novell/trunk/mcs/class/corlib/System.Runtime.Remoting.Messaging/CADMessages.cs:327
640 * 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
641 * 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
642 * at (wrapper remoting-invoke-with-check) System.AppDomain.ProcessMessageInDomain (byte[],System.Runtime.Remoting.Messaging.CADMethodCallMessage,byte[]&,System.Runtime.Remoting.Messaging.CADMethodReturnMessage&) <IL 0x0003d, 0xffffffff>
643 * 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
644 * at (wrapper runtime-invoke) object.runtime_invoke_CrossAppDomainSink/ProcessMessageRes_object_object (object,intptr,intptr,intptr) <IL 0x0004c, 0xffffffff>
646 if (!strcmp (ref->vtable->klass->name_space, "System") &&
647 !strcmp (ref->vtable->klass->name, "Byte[]") &&
648 !strcmp (o->vtable->klass->name_space, "System.IO") &&
649 !strcmp (o->vtable->klass->name, "MemoryStream"))
651 /* append_job() in threadpool.c */
652 if (!strcmp (ref->vtable->klass->name_space, "System.Runtime.Remoting.Messaging") &&
653 !strcmp (ref->vtable->klass->name, "AsyncResult") &&
654 !strcmp (o->vtable->klass->name_space, "System") &&
655 !strcmp (o->vtable->klass->name, "Object[]") &&
656 mono_thread_pool_is_queue_array ((MonoArray*) o))
662 check_reference_for_xdomain (gpointer *ptr, char *obj, MonoDomain *domain)
664 MonoObject *o = (MonoObject*)(obj);
665 MonoObject *ref = (MonoObject*)*(ptr);
666 int offset = (char*)(ptr) - (char*)o;
668 MonoClassField *field;
671 if (!ref || ref->vtable->domain == domain)
673 if (is_xdomain_ref_allowed (ptr, obj, domain))
677 for (class = o->vtable->klass; class; class = class->parent) {
680 for (i = 0; i < class->field.count; ++i) {
681 if (class->fields[i].offset == offset) {
682 field = &class->fields[i];
690 if (ref->vtable->klass == mono_defaults.string_class)
691 str = mono_string_to_utf8 ((MonoString*)ref);
694 g_print ("xdomain reference in %p (%s.%s) at offset %d (%s) to %p (%s.%s) (%s) - pointed to by:\n",
695 o, o->vtable->klass->name_space, o->vtable->klass->name,
696 offset, field ? field->name : "",
697 ref, ref->vtable->klass->name_space, ref->vtable->klass->name, str ? str : "");
698 mono_gc_scan_for_specific_ref (o, TRUE);
704 #define HANDLE_PTR(ptr,obj) check_reference_for_xdomain ((ptr), (obj), domain)
707 scan_object_for_xdomain_refs (char *start, mword size, void *data)
709 MonoDomain *domain = ((MonoObject*)start)->vtable->domain;
711 #include "sgen-scan-object.h"
714 static gboolean scan_object_for_specific_ref_precise = TRUE;
717 #define HANDLE_PTR(ptr,obj) do { \
718 if ((MonoObject*)*(ptr) == key) { \
719 g_print ("found ref to %p in object %p (%s) at offset %td\n", \
720 key, (obj), safe_name ((obj)), ((char*)(ptr) - (char*)(obj))); \
725 scan_object_for_specific_ref (char *start, MonoObject *key)
729 if ((forwarded = SGEN_OBJECT_IS_FORWARDED (start)))
732 if (scan_object_for_specific_ref_precise) {
733 #include "sgen-scan-object.h"
735 mword *words = (mword*)start;
736 size_t size = safe_object_get_size ((MonoObject*)start);
738 for (i = 0; i < size / sizeof (mword); ++i) {
739 if (words [i] == (mword)key) {
740 g_print ("found possible ref to %p in object %p (%s) at offset %td\n",
741 key, start, safe_name (start), i * sizeof (mword));
748 sgen_scan_area_with_callback (char *start, char *end, IterateObjectCallbackFunc callback, void *data, gboolean allow_flags)
750 while (start < end) {
754 if (!*(void**)start) {
755 start += sizeof (void*); /* should be ALLOC_ALIGN, really */
760 if (!(obj = SGEN_OBJECT_IS_FORWARDED (start)))
766 size = ALIGN_UP (safe_object_get_size ((MonoObject*)obj));
768 if ((MonoVTable*)SGEN_LOAD_VTABLE (obj) != array_fill_vtable)
769 callback (obj, size, data);
776 scan_object_for_specific_ref_callback (char *obj, size_t size, MonoObject *key)
778 scan_object_for_specific_ref (obj, key);
782 check_root_obj_specific_ref (RootRecord *root, MonoObject *key, MonoObject *obj)
786 g_print ("found ref to %p in root record %p\n", key, root);
789 static MonoObject *check_key = NULL;
790 static RootRecord *check_root = NULL;
793 check_root_obj_specific_ref_from_marker (void **obj)
795 check_root_obj_specific_ref (check_root, check_key, *obj);
799 scan_roots_for_specific_ref (MonoObject *key, int root_type)
805 SGEN_HASH_TABLE_FOREACH (&roots_hash [root_type], start_root, root) {
806 mword desc = root->root_desc;
810 switch (desc & ROOT_DESC_TYPE_MASK) {
811 case ROOT_DESC_BITMAP:
812 desc >>= ROOT_DESC_TYPE_SHIFT;
815 check_root_obj_specific_ref (root, key, *start_root);
820 case ROOT_DESC_COMPLEX: {
821 gsize *bitmap_data = sgen_get_complex_descriptor_bitmap (desc);
822 int bwords = (*bitmap_data) - 1;
823 void **start_run = start_root;
825 while (bwords-- > 0) {
826 gsize bmap = *bitmap_data++;
827 void **objptr = start_run;
830 check_root_obj_specific_ref (root, key, *objptr);
834 start_run += GC_BITS_PER_WORD;
838 case ROOT_DESC_USER: {
839 MonoGCRootMarkFunc marker = sgen_get_user_descriptor_func (desc);
840 marker (start_root, check_root_obj_specific_ref_from_marker);
843 case ROOT_DESC_RUN_LEN:
844 g_assert_not_reached ();
846 g_assert_not_reached ();
848 } SGEN_HASH_TABLE_FOREACH_END;
855 mono_gc_scan_for_specific_ref (MonoObject *key, gboolean precise)
860 scan_object_for_specific_ref_precise = precise;
862 sgen_scan_area_with_callback (nursery_section->data, nursery_section->end_data,
863 (IterateObjectCallbackFunc)scan_object_for_specific_ref_callback, key, TRUE);
865 major_collector.iterate_objects (TRUE, TRUE, (IterateObjectCallbackFunc)scan_object_for_specific_ref_callback, key);
867 sgen_los_iterate_objects ((IterateObjectCallbackFunc)scan_object_for_specific_ref_callback, key);
869 scan_roots_for_specific_ref (key, ROOT_TYPE_NORMAL);
870 scan_roots_for_specific_ref (key, ROOT_TYPE_WBARRIER);
872 SGEN_HASH_TABLE_FOREACH (&roots_hash [ROOT_TYPE_PINNED], ptr, root) {
873 while (ptr < (void**)root->end_root) {
874 check_root_obj_specific_ref (root, *ptr, key);
877 } SGEN_HASH_TABLE_FOREACH_END;
881 need_remove_object_for_domain (char *start, MonoDomain *domain)
883 if (mono_object_domain (start) == domain) {
884 SGEN_LOG (4, "Need to cleanup object %p", start);
885 binary_protocol_cleanup (start, (gpointer)LOAD_VTABLE (start), safe_object_get_size ((MonoObject*)start));
892 process_object_for_domain_clearing (char *start, MonoDomain *domain)
894 GCVTable *vt = (GCVTable*)LOAD_VTABLE (start);
895 if (vt->klass == mono_defaults.internal_thread_class)
896 g_assert (mono_object_domain (start) == mono_get_root_domain ());
897 /* The object could be a proxy for an object in the domain
899 #ifndef DISABLE_REMOTING
900 if (mono_defaults.real_proxy_class->supertypes && mono_class_has_parent_fast (vt->klass, mono_defaults.real_proxy_class)) {
901 MonoObject *server = ((MonoRealProxy*)start)->unwrapped_server;
903 /* The server could already have been zeroed out, so
904 we need to check for that, too. */
905 if (server && (!LOAD_VTABLE (server) || mono_object_domain (server) == domain)) {
906 SGEN_LOG (4, "Cleaning up remote pointer in %p to object %p", start, server);
907 ((MonoRealProxy*)start)->unwrapped_server = NULL;
913 static MonoDomain *check_domain = NULL;
916 check_obj_not_in_domain (void **o)
918 g_assert (((MonoObject*)(*o))->vtable->domain != check_domain);
922 scan_for_registered_roots_in_domain (MonoDomain *domain, int root_type)
926 check_domain = domain;
927 SGEN_HASH_TABLE_FOREACH (&roots_hash [root_type], start_root, root) {
928 mword desc = root->root_desc;
930 /* The MonoDomain struct is allowed to hold
931 references to objects in its own domain. */
932 if (start_root == (void**)domain)
935 switch (desc & ROOT_DESC_TYPE_MASK) {
936 case ROOT_DESC_BITMAP:
937 desc >>= ROOT_DESC_TYPE_SHIFT;
939 if ((desc & 1) && *start_root)
940 check_obj_not_in_domain (*start_root);
945 case ROOT_DESC_COMPLEX: {
946 gsize *bitmap_data = sgen_get_complex_descriptor_bitmap (desc);
947 int bwords = (*bitmap_data) - 1;
948 void **start_run = start_root;
950 while (bwords-- > 0) {
951 gsize bmap = *bitmap_data++;
952 void **objptr = start_run;
954 if ((bmap & 1) && *objptr)
955 check_obj_not_in_domain (*objptr);
959 start_run += GC_BITS_PER_WORD;
963 case ROOT_DESC_USER: {
964 MonoGCRootMarkFunc marker = sgen_get_user_descriptor_func (desc);
965 marker (start_root, check_obj_not_in_domain);
968 case ROOT_DESC_RUN_LEN:
969 g_assert_not_reached ();
971 g_assert_not_reached ();
973 } SGEN_HASH_TABLE_FOREACH_END;
979 check_for_xdomain_refs (void)
983 sgen_scan_area_with_callback (nursery_section->data, nursery_section->end_data,
984 (IterateObjectCallbackFunc)scan_object_for_xdomain_refs, NULL, FALSE);
986 major_collector.iterate_objects (TRUE, TRUE, (IterateObjectCallbackFunc)scan_object_for_xdomain_refs, NULL);
988 for (bigobj = los_object_list; bigobj; bigobj = bigobj->next)
989 scan_object_for_xdomain_refs (bigobj->data, sgen_los_object_size (bigobj), NULL);
993 clear_domain_process_object (char *obj, MonoDomain *domain)
997 process_object_for_domain_clearing (obj, domain);
998 remove = need_remove_object_for_domain (obj, domain);
1000 if (remove && ((MonoObject*)obj)->synchronisation) {
1001 void **dislink = mono_monitor_get_object_monitor_weak_link ((MonoObject*)obj);
1003 sgen_register_disappearing_link (NULL, dislink, FALSE, TRUE);
1010 clear_domain_process_minor_object_callback (char *obj, size_t size, MonoDomain *domain)
1012 if (clear_domain_process_object (obj, domain))
1013 memset (obj, 0, size);
1017 clear_domain_process_major_object_callback (char *obj, size_t size, MonoDomain *domain)
1019 clear_domain_process_object (obj, domain);
1023 clear_domain_free_major_non_pinned_object_callback (char *obj, size_t size, MonoDomain *domain)
1025 if (need_remove_object_for_domain (obj, domain))
1026 major_collector.free_non_pinned_object (obj, size);
1030 clear_domain_free_major_pinned_object_callback (char *obj, size_t size, MonoDomain *domain)
1032 if (need_remove_object_for_domain (obj, domain))
1033 major_collector.free_pinned_object (obj, size);
1037 * When appdomains are unloaded we can easily remove objects that have finalizers,
1038 * but all the others could still be present in random places on the heap.
1039 * We need a sweep to get rid of them even though it's going to be costly
1041 * The reason we need to remove them is because we access the vtable and class
1042 * structures to know the object size and the reference bitmap: once the domain is
1043 * unloaded the point to random memory.
1046 mono_gc_clear_domain (MonoDomain * domain)
1048 LOSObject *bigobj, *prev;
1053 binary_protocol_domain_unload_begin (domain);
1055 sgen_stop_world (0);
1057 if (concurrent_collection_in_progress)
1058 sgen_perform_collection (0, GENERATION_OLD, "clear domain", TRUE);
1059 g_assert (!concurrent_collection_in_progress);
1061 sgen_process_fin_stage_entries ();
1062 sgen_process_dislink_stage_entries ();
1064 sgen_clear_nursery_fragments ();
1066 if (xdomain_checks && domain != mono_get_root_domain ()) {
1067 scan_for_registered_roots_in_domain (domain, ROOT_TYPE_NORMAL);
1068 scan_for_registered_roots_in_domain (domain, ROOT_TYPE_WBARRIER);
1069 check_for_xdomain_refs ();
1072 /*Ephemerons and dislinks must be processed before LOS since they might end up pointing
1073 to memory returned to the OS.*/
1074 null_ephemerons_for_domain (domain);
1076 for (i = GENERATION_NURSERY; i < GENERATION_MAX; ++i)
1077 sgen_null_links_for_domain (domain, i);
1079 for (i = GENERATION_NURSERY; i < GENERATION_MAX; ++i)
1080 sgen_remove_finalizers_for_domain (domain, i);
1082 sgen_scan_area_with_callback (nursery_section->data, nursery_section->end_data,
1083 (IterateObjectCallbackFunc)clear_domain_process_minor_object_callback, domain, FALSE);
1085 /* We need two passes over major and large objects because
1086 freeing such objects might give their memory back to the OS
1087 (in the case of large objects) or obliterate its vtable
1088 (pinned objects with major-copying or pinned and non-pinned
1089 objects with major-mark&sweep), but we might need to
1090 dereference a pointer from an object to another object if
1091 the first object is a proxy. */
1092 major_collector.iterate_objects (TRUE, TRUE, (IterateObjectCallbackFunc)clear_domain_process_major_object_callback, domain);
1093 for (bigobj = los_object_list; bigobj; bigobj = bigobj->next)
1094 clear_domain_process_object (bigobj->data, domain);
1097 for (bigobj = los_object_list; bigobj;) {
1098 if (need_remove_object_for_domain (bigobj->data, domain)) {
1099 LOSObject *to_free = bigobj;
1101 prev->next = bigobj->next;
1103 los_object_list = bigobj->next;
1104 bigobj = bigobj->next;
1105 SGEN_LOG (4, "Freeing large object %p", bigobj->data);
1106 sgen_los_free_object (to_free);
1110 bigobj = bigobj->next;
1112 major_collector.iterate_objects (TRUE, FALSE, (IterateObjectCallbackFunc)clear_domain_free_major_non_pinned_object_callback, domain);
1113 major_collector.iterate_objects (FALSE, TRUE, (IterateObjectCallbackFunc)clear_domain_free_major_pinned_object_callback, domain);
1115 if (domain == mono_get_root_domain ()) {
1116 if (G_UNLIKELY (do_pin_stats))
1117 sgen_pin_stats_print_class_stats ();
1118 sgen_object_layout_dump (stdout);
1121 sgen_restart_world (0, NULL);
1123 binary_protocol_domain_unload_end (domain);
1129 * sgen_add_to_global_remset:
1131 * The global remset contains locations which point into newspace after
1132 * a minor collection. This can happen if the objects they point to are pinned.
1134 * LOCKING: If called from a parallel collector, the global remset
1135 * lock must be held. For serial collectors that is not necessary.
1138 sgen_add_to_global_remset (gpointer ptr, gpointer obj)
1140 SGEN_ASSERT (5, sgen_ptr_in_nursery (obj), "Target pointer of global remset must be in the nursery");
1142 HEAVY_STAT (++stat_wbarrier_add_to_global_remset);
1144 if (!major_collector.is_concurrent) {
1145 SGEN_ASSERT (5, current_collection_generation != -1, "Global remsets can only be added during collections");
1147 if (current_collection_generation == -1)
1148 SGEN_ASSERT (5, sgen_concurrent_collection_in_progress (), "Global remsets outside of collection pauses can only be added by the concurrent collector");
1151 if (!object_is_pinned (obj))
1152 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");
1153 else if (sgen_cement_lookup_or_register (obj))
1156 remset.record_pointer (ptr);
1158 if (G_UNLIKELY (do_pin_stats))
1159 sgen_pin_stats_register_global_remset (obj);
1161 SGEN_LOG (8, "Adding global remset for %p", ptr);
1162 binary_protocol_global_remset (ptr, obj, (gpointer)SGEN_LOAD_VTABLE (obj));
1165 #ifdef ENABLE_DTRACE
1166 if (G_UNLIKELY (MONO_GC_GLOBAL_REMSET_ADD_ENABLED ())) {
1167 MonoVTable *vt = (MonoVTable*)LOAD_VTABLE (obj);
1168 MONO_GC_GLOBAL_REMSET_ADD ((mword)ptr, (mword)obj, sgen_safe_object_get_size (obj),
1169 vt->klass->name_space, vt->klass->name);
1175 * sgen_drain_gray_stack:
1177 * Scan objects in the gray stack until the stack is empty. This should be called
1178 * frequently after each object is copied, to achieve better locality and cache
1182 sgen_drain_gray_stack (int max_objs, ScanCopyContext ctx)
1185 ScanObjectFunc scan_func = ctx.scan_func;
1186 GrayQueue *queue = ctx.queue;
1188 if (max_objs == -1) {
1190 GRAY_OBJECT_DEQUEUE (queue, obj);
1193 SGEN_LOG (9, "Precise gray object scan %p (%s)", obj, safe_name (obj));
1194 scan_func (obj, queue);
1200 for (i = 0; i != max_objs; ++i) {
1201 GRAY_OBJECT_DEQUEUE (queue, obj);
1204 SGEN_LOG (9, "Precise gray object scan %p (%s)", obj, safe_name (obj));
1205 scan_func (obj, queue);
1207 } while (max_objs < 0);
1213 * Addresses from start to end are already sorted. This function finds
1214 * the object header for each address and pins the object. The
1215 * addresses must be inside the passed section. The (start of the)
1216 * address array is overwritten with the addresses of the actually
1217 * pinned objects. Return the number of pinned objects.
1220 pin_objects_from_addresses (GCMemSection *section, void **start, void **end, void *start_nursery, void *end_nursery, ScanCopyContext ctx)
1225 void *last_obj = NULL;
1226 size_t last_obj_size = 0;
1229 void **definitely_pinned = start;
1230 ScanObjectFunc scan_func = ctx.scan_func;
1231 SgenGrayQueue *queue = ctx.queue;
1233 sgen_nursery_allocator_prepare_for_pinning ();
1235 while (start < end) {
1237 /* the range check should be reduntant */
1238 if (addr != last && addr >= start_nursery && addr < end_nursery) {
1239 SGEN_LOG (5, "Considering pinning addr %p", addr);
1240 /* multiple pointers to the same object */
1241 if (addr >= last_obj && (char*)addr < (char*)last_obj + last_obj_size) {
1245 idx = ((char*)addr - (char*)section->data) / SCAN_START_SIZE;
1246 g_assert (idx < section->num_scan_start);
1247 search_start = (void*)section->scan_starts [idx];
1248 if (!search_start || search_start > addr) {
1251 search_start = section->scan_starts [idx];
1252 if (search_start && search_start <= addr)
1255 if (!search_start || search_start > addr)
1256 search_start = start_nursery;
1258 if (search_start < last_obj)
1259 search_start = (char*)last_obj + last_obj_size;
1260 /* now addr should be in an object a short distance from search_start
1261 * Note that search_start must point to zeroed mem or point to an object.
1265 if (!*(void**)search_start) {
1266 /* Consistency check */
1268 for (frag = nursery_fragments; frag; frag = frag->next) {
1269 if (search_start >= frag->fragment_start && search_start < frag->fragment_end)
1270 g_assert_not_reached ();
1274 search_start = (void*)ALIGN_UP ((mword)search_start + sizeof (gpointer));
1277 last_obj = search_start;
1278 last_obj_size = ALIGN_UP (safe_object_get_size ((MonoObject*)search_start));
1280 if (((MonoObject*)last_obj)->synchronisation == GINT_TO_POINTER (-1)) {
1281 /* Marks the beginning of a nursery fragment, skip */
1283 SGEN_LOG (8, "Pinned try match %p (%s), size %zd", last_obj, safe_name (last_obj), last_obj_size);
1284 if (addr >= search_start && (char*)addr < (char*)last_obj + last_obj_size) {
1286 scan_func (search_start, queue);
1288 SGEN_LOG (4, "Pinned object %p, vtable %p (%s), count %d\n",
1289 search_start, *(void**)search_start, safe_name (search_start), count);
1290 binary_protocol_pin (search_start,
1291 (gpointer)LOAD_VTABLE (search_start),
1292 safe_object_get_size (search_start));
1294 #ifdef ENABLE_DTRACE
1295 if (G_UNLIKELY (MONO_GC_OBJ_PINNED_ENABLED ())) {
1296 int gen = sgen_ptr_in_nursery (search_start) ? GENERATION_NURSERY : GENERATION_OLD;
1297 MonoVTable *vt = (MonoVTable*)LOAD_VTABLE (search_start);
1298 MONO_GC_OBJ_PINNED ((mword)search_start,
1299 sgen_safe_object_get_size (search_start),
1300 vt->klass->name_space, vt->klass->name, gen);
1304 pin_object (search_start);
1305 GRAY_OBJECT_ENQUEUE (queue, search_start);
1306 if (G_UNLIKELY (do_pin_stats))
1307 sgen_pin_stats_register_object (search_start, last_obj_size);
1308 definitely_pinned [count] = search_start;
1314 /* skip to the next object */
1315 search_start = (void*)((char*)search_start + last_obj_size);
1316 } while (search_start <= addr);
1317 /* we either pinned the correct object or we ignored the addr because
1318 * it points to unused zeroed memory.
1324 //printf ("effective pinned: %d (at the end: %d)\n", count, (char*)end_nursery - (char*)last);
1325 if (mono_profiler_get_events () & MONO_PROFILE_GC_ROOTS) {
1326 GCRootReport report;
1328 for (idx = 0; idx < count; ++idx)
1329 add_profile_gc_root (&report, definitely_pinned [idx], MONO_PROFILE_GC_ROOT_PINNING | MONO_PROFILE_GC_ROOT_MISC, 0);
1330 notify_gc_roots (&report);
1332 stat_pinned_objects += count;
1337 sgen_pin_objects_in_section (GCMemSection *section, ScanCopyContext ctx)
1339 int num_entries = section->pin_queue_num_entries;
1341 void **start = section->pin_queue_start;
1343 reduced_to = pin_objects_from_addresses (section, start, start + num_entries,
1344 section->data, section->next_data, ctx);
1345 section->pin_queue_num_entries = reduced_to;
1347 section->pin_queue_start = NULL;
1353 sgen_pin_object (void *object, GrayQueue *queue)
1355 g_assert (!concurrent_collection_in_progress);
1357 if (sgen_collection_is_parallel ()) {
1359 /*object arrives pinned*/
1360 sgen_pin_stage_ptr (object);
1364 SGEN_PIN_OBJECT (object);
1365 sgen_pin_stage_ptr (object);
1367 if (G_UNLIKELY (do_pin_stats))
1368 sgen_pin_stats_register_object (object, safe_object_get_size (object));
1370 GRAY_OBJECT_ENQUEUE (queue, object);
1371 binary_protocol_pin (object, (gpointer)LOAD_VTABLE (object), safe_object_get_size (object));
1373 #ifdef ENABLE_DTRACE
1374 if (G_UNLIKELY (MONO_GC_OBJ_PINNED_ENABLED ())) {
1375 int gen = sgen_ptr_in_nursery (object) ? GENERATION_NURSERY : GENERATION_OLD;
1376 MonoVTable *vt = (MonoVTable*)LOAD_VTABLE (object);
1377 MONO_GC_OBJ_PINNED ((mword)object, sgen_safe_object_get_size (object), vt->klass->name_space, vt->klass->name, gen);
1383 sgen_parallel_pin_or_update (void **ptr, void *obj, MonoVTable *vt, SgenGrayQueue *queue)
1387 gboolean major_pinned = FALSE;
1389 if (sgen_ptr_in_nursery (obj)) {
1390 if (SGEN_CAS_PTR (obj, (void*)((mword)vt | SGEN_PINNED_BIT), vt) == vt) {
1391 sgen_pin_object (obj, queue);
1395 major_collector.pin_major_object (obj, queue);
1396 major_pinned = TRUE;
1399 vtable_word = *(mword*)obj;
1400 /*someone else forwarded it, update the pointer and bail out*/
1401 if (vtable_word & SGEN_FORWARDED_BIT) {
1402 *ptr = (void*)(vtable_word & ~SGEN_VTABLE_BITS_MASK);
1406 /*someone pinned it, nothing to do.*/
1407 if (vtable_word & SGEN_PINNED_BIT || major_pinned)
1412 /* Sort the addresses in array in increasing order.
1413 * Done using a by-the book heap sort. Which has decent and stable performance, is pretty cache efficient.
1416 sgen_sort_addresses (void **array, int size)
1421 for (i = 1; i < size; ++i) {
1424 int parent = (child - 1) / 2;
1426 if (array [parent] >= array [child])
1429 tmp = array [parent];
1430 array [parent] = array [child];
1431 array [child] = tmp;
1437 for (i = size - 1; i > 0; --i) {
1440 array [i] = array [0];
1446 while (root * 2 + 1 <= end) {
1447 int child = root * 2 + 1;
1449 if (child < end && array [child] < array [child + 1])
1451 if (array [root] >= array [child])
1455 array [root] = array [child];
1456 array [child] = tmp;
1464 * Scan the memory between start and end and queue values which could be pointers
1465 * to the area between start_nursery and end_nursery for later consideration.
1466 * Typically used for thread stacks.
1469 conservatively_pin_objects_from (void **start, void **end, void *start_nursery, void *end_nursery, int pin_type)
1473 #ifdef VALGRIND_MAKE_MEM_DEFINED_IF_ADDRESSABLE
1474 VALGRIND_MAKE_MEM_DEFINED_IF_ADDRESSABLE (start, (char*)end - (char*)start);
1477 while (start < end) {
1478 if (*start >= start_nursery && *start < end_nursery) {
1480 * *start can point to the middle of an object
1481 * note: should we handle pointing at the end of an object?
1482 * pinning in C# code disallows pointing at the end of an object
1483 * but there is some small chance that an optimizing C compiler
1484 * may keep the only reference to an object by pointing
1485 * at the end of it. We ignore this small chance for now.
1486 * Pointers to the end of an object are indistinguishable
1487 * from pointers to the start of the next object in memory
1488 * so if we allow that we'd need to pin two objects...
1489 * We queue the pointer in an array, the
1490 * array will then be sorted and uniqued. This way
1491 * we can coalesce several pinning pointers and it should
1492 * be faster since we'd do a memory scan with increasing
1493 * addresses. Note: we can align the address to the allocation
1494 * alignment, so the unique process is more effective.
1496 mword addr = (mword)*start;
1497 addr &= ~(ALLOC_ALIGN - 1);
1498 if (addr >= (mword)start_nursery && addr < (mword)end_nursery) {
1499 SGEN_LOG (6, "Pinning address %p from %p", (void*)addr, start);
1500 sgen_pin_stage_ptr ((void*)addr);
1503 if (G_UNLIKELY (do_pin_stats)) {
1504 if (ptr_in_nursery ((void*)addr))
1505 sgen_pin_stats_register_address ((char*)addr, pin_type);
1511 SGEN_LOG (7, "found %d potential pinned heap pointers", count);
1515 * The first thing we do in a collection is to identify pinned objects.
1516 * This function considers all the areas of memory that need to be
1517 * conservatively scanned.
1520 pin_from_roots (void *start_nursery, void *end_nursery, GrayQueue *queue)
1524 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);
1525 /* objects pinned from the API are inside these roots */
1526 SGEN_HASH_TABLE_FOREACH (&roots_hash [ROOT_TYPE_PINNED], start_root, root) {
1527 SGEN_LOG (6, "Pinned roots %p-%p", start_root, root->end_root);
1528 conservatively_pin_objects_from (start_root, (void**)root->end_root, start_nursery, end_nursery, PIN_TYPE_OTHER);
1529 } SGEN_HASH_TABLE_FOREACH_END;
1530 /* now deal with the thread stacks
1531 * in the future we should be able to conservatively scan only:
1532 * *) the cpu registers
1533 * *) the unmanaged stack frames
1534 * *) the _last_ managed stack frame
1535 * *) pointers slots in managed frames
1537 scan_thread_data (start_nursery, end_nursery, FALSE, queue);
1541 unpin_objects_from_queue (SgenGrayQueue *queue)
1545 GRAY_OBJECT_DEQUEUE (queue, addr);
1548 g_assert (SGEN_OBJECT_IS_PINNED (addr));
1549 SGEN_UNPIN_OBJECT (addr);
1554 CopyOrMarkObjectFunc func;
1556 } UserCopyOrMarkData;
1558 static MonoNativeTlsKey user_copy_or_mark_key;
1561 init_user_copy_or_mark_key (void)
1563 mono_native_tls_alloc (&user_copy_or_mark_key, NULL);
1567 set_user_copy_or_mark_data (UserCopyOrMarkData *data)
1569 mono_native_tls_set_value (user_copy_or_mark_key, data);
1573 single_arg_user_copy_or_mark (void **obj)
1575 UserCopyOrMarkData *data = mono_native_tls_get_value (user_copy_or_mark_key);
1577 data->func (obj, data->queue);
1581 * The memory area from start_root to end_root contains pointers to objects.
1582 * Their position is precisely described by @desc (this means that the pointer
1583 * can be either NULL or the pointer to the start of an object).
1584 * This functions copies them to to_space updates them.
1586 * This function is not thread-safe!
1589 precisely_scan_objects_from (void** start_root, void** end_root, char* n_start, char *n_end, mword desc, ScanCopyContext ctx)
1591 CopyOrMarkObjectFunc copy_func = ctx.copy_func;
1592 SgenGrayQueue *queue = ctx.queue;
1594 switch (desc & ROOT_DESC_TYPE_MASK) {
1595 case ROOT_DESC_BITMAP:
1596 desc >>= ROOT_DESC_TYPE_SHIFT;
1598 if ((desc & 1) && *start_root) {
1599 copy_func (start_root, queue);
1600 SGEN_LOG (9, "Overwrote root at %p with %p", start_root, *start_root);
1601 sgen_drain_gray_stack (-1, ctx);
1607 case ROOT_DESC_COMPLEX: {
1608 gsize *bitmap_data = sgen_get_complex_descriptor_bitmap (desc);
1609 int bwords = (*bitmap_data) - 1;
1610 void **start_run = start_root;
1612 while (bwords-- > 0) {
1613 gsize bmap = *bitmap_data++;
1614 void **objptr = start_run;
1616 if ((bmap & 1) && *objptr) {
1617 copy_func (objptr, queue);
1618 SGEN_LOG (9, "Overwrote root at %p with %p", objptr, *objptr);
1619 sgen_drain_gray_stack (-1, ctx);
1624 start_run += GC_BITS_PER_WORD;
1628 case ROOT_DESC_USER: {
1629 UserCopyOrMarkData data = { copy_func, queue };
1630 MonoGCRootMarkFunc marker = sgen_get_user_descriptor_func (desc);
1631 set_user_copy_or_mark_data (&data);
1632 marker (start_root, single_arg_user_copy_or_mark);
1633 set_user_copy_or_mark_data (NULL);
1636 case ROOT_DESC_RUN_LEN:
1637 g_assert_not_reached ();
1639 g_assert_not_reached ();
1644 reset_heap_boundaries (void)
1646 lowest_heap_address = ~(mword)0;
1647 highest_heap_address = 0;
1651 sgen_update_heap_boundaries (mword low, mword high)
1656 old = lowest_heap_address;
1659 } while (SGEN_CAS_PTR ((gpointer*)&lowest_heap_address, (gpointer)low, (gpointer)old) != (gpointer)old);
1662 old = highest_heap_address;
1665 } while (SGEN_CAS_PTR ((gpointer*)&highest_heap_address, (gpointer)high, (gpointer)old) != (gpointer)old);
1669 * Allocate and setup the data structures needed to be able to allocate objects
1670 * in the nursery. The nursery is stored in nursery_section.
1673 alloc_nursery (void)
1675 GCMemSection *section;
1680 if (nursery_section)
1682 SGEN_LOG (2, "Allocating nursery size: %lu", (unsigned long)sgen_nursery_size);
1683 /* later we will alloc a larger area for the nursery but only activate
1684 * what we need. The rest will be used as expansion if we have too many pinned
1685 * objects in the existing nursery.
1687 /* FIXME: handle OOM */
1688 section = sgen_alloc_internal (INTERNAL_MEM_SECTION);
1690 alloc_size = sgen_nursery_size;
1692 /* If there isn't enough space even for the nursery we should simply abort. */
1693 g_assert (sgen_memgov_try_alloc_space (alloc_size, SPACE_NURSERY));
1695 #ifdef SGEN_ALIGN_NURSERY
1696 data = major_collector.alloc_heap (alloc_size, alloc_size, DEFAULT_NURSERY_BITS);
1698 data = major_collector.alloc_heap (alloc_size, 0, DEFAULT_NURSERY_BITS);
1700 sgen_update_heap_boundaries ((mword)data, (mword)(data + sgen_nursery_size));
1701 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 ());
1702 section->data = section->next_data = data;
1703 section->size = alloc_size;
1704 section->end_data = data + sgen_nursery_size;
1705 scan_starts = (alloc_size + SCAN_START_SIZE - 1) / SCAN_START_SIZE;
1706 section->scan_starts = sgen_alloc_internal_dynamic (sizeof (char*) * scan_starts, INTERNAL_MEM_SCAN_STARTS, TRUE);
1707 section->num_scan_start = scan_starts;
1709 nursery_section = section;
1711 sgen_nursery_allocator_set_nursery_bounds (data, data + sgen_nursery_size);
1715 mono_gc_get_nursery (int *shift_bits, size_t *size)
1717 *size = sgen_nursery_size;
1718 #ifdef SGEN_ALIGN_NURSERY
1719 *shift_bits = DEFAULT_NURSERY_BITS;
1723 return sgen_get_nursery_start ();
1727 mono_gc_set_current_thread_appdomain (MonoDomain *domain)
1729 SgenThreadInfo *info = mono_thread_info_current ();
1731 /* Could be called from sgen_thread_unregister () with a NULL info */
1734 info->stopped_domain = domain;
1739 mono_gc_precise_stack_mark_enabled (void)
1741 return !conservative_stack_mark;
1745 mono_gc_get_logfile (void)
1747 return gc_debug_file;
1751 report_finalizer_roots_list (FinalizeReadyEntry *list)
1753 GCRootReport report;
1754 FinalizeReadyEntry *fin;
1757 for (fin = list; fin; fin = fin->next) {
1760 add_profile_gc_root (&report, fin->object, MONO_PROFILE_GC_ROOT_FINALIZER, 0);
1762 notify_gc_roots (&report);
1766 report_finalizer_roots (void)
1768 report_finalizer_roots_list (fin_ready_list);
1769 report_finalizer_roots_list (critical_fin_list);
1772 static GCRootReport *root_report;
1775 single_arg_report_root (void **obj)
1778 add_profile_gc_root (root_report, *obj, MONO_PROFILE_GC_ROOT_OTHER, 0);
1782 precisely_report_roots_from (GCRootReport *report, void** start_root, void** end_root, mword desc)
1784 switch (desc & ROOT_DESC_TYPE_MASK) {
1785 case ROOT_DESC_BITMAP:
1786 desc >>= ROOT_DESC_TYPE_SHIFT;
1788 if ((desc & 1) && *start_root) {
1789 add_profile_gc_root (report, *start_root, MONO_PROFILE_GC_ROOT_OTHER, 0);
1795 case ROOT_DESC_COMPLEX: {
1796 gsize *bitmap_data = sgen_get_complex_descriptor_bitmap (desc);
1797 int bwords = (*bitmap_data) - 1;
1798 void **start_run = start_root;
1800 while (bwords-- > 0) {
1801 gsize bmap = *bitmap_data++;
1802 void **objptr = start_run;
1804 if ((bmap & 1) && *objptr) {
1805 add_profile_gc_root (report, *objptr, MONO_PROFILE_GC_ROOT_OTHER, 0);
1810 start_run += GC_BITS_PER_WORD;
1814 case ROOT_DESC_USER: {
1815 MonoGCRootMarkFunc marker = sgen_get_user_descriptor_func (desc);
1816 root_report = report;
1817 marker (start_root, single_arg_report_root);
1820 case ROOT_DESC_RUN_LEN:
1821 g_assert_not_reached ();
1823 g_assert_not_reached ();
1828 report_registered_roots_by_type (int root_type)
1830 GCRootReport report;
1834 SGEN_HASH_TABLE_FOREACH (&roots_hash [root_type], start_root, root) {
1835 SGEN_LOG (6, "Precise root scan %p-%p (desc: %p)", start_root, root->end_root, (void*)root->root_desc);
1836 precisely_report_roots_from (&report, start_root, (void**)root->end_root, root->root_desc);
1837 } SGEN_HASH_TABLE_FOREACH_END;
1838 notify_gc_roots (&report);
1842 report_registered_roots (void)
1844 report_registered_roots_by_type (ROOT_TYPE_NORMAL);
1845 report_registered_roots_by_type (ROOT_TYPE_WBARRIER);
1849 scan_finalizer_entries (FinalizeReadyEntry *list, ScanCopyContext ctx)
1851 CopyOrMarkObjectFunc copy_func = ctx.copy_func;
1852 SgenGrayQueue *queue = ctx.queue;
1853 FinalizeReadyEntry *fin;
1855 for (fin = list; fin; fin = fin->next) {
1858 SGEN_LOG (5, "Scan of fin ready object: %p (%s)\n", fin->object, safe_name (fin->object));
1859 copy_func (&fin->object, queue);
1864 generation_name (int generation)
1866 switch (generation) {
1867 case GENERATION_NURSERY: return "nursery";
1868 case GENERATION_OLD: return "old";
1869 default: g_assert_not_reached ();
1874 sgen_generation_name (int generation)
1876 return generation_name (generation);
1879 SgenObjectOperations *
1880 sgen_get_current_object_ops (void){
1881 return ¤t_object_ops;
1886 finish_gray_stack (int generation, GrayQueue *queue)
1890 int done_with_ephemerons, ephemeron_rounds = 0;
1891 CopyOrMarkObjectFunc copy_func = current_object_ops.copy_or_mark_object;
1892 ScanObjectFunc scan_func = current_object_ops.scan_object;
1893 ScanCopyContext ctx = { scan_func, copy_func, queue };
1894 char *start_addr = generation == GENERATION_NURSERY ? sgen_get_nursery_start () : NULL;
1895 char *end_addr = generation == GENERATION_NURSERY ? sgen_get_nursery_end () : (char*)-1;
1898 * We copied all the reachable objects. Now it's the time to copy
1899 * the objects that were not referenced by the roots, but by the copied objects.
1900 * we built a stack of objects pointed to by gray_start: they are
1901 * additional roots and we may add more items as we go.
1902 * We loop until gray_start == gray_objects which means no more objects have
1903 * been added. Note this is iterative: no recursion is involved.
1904 * We need to walk the LO list as well in search of marked big objects
1905 * (use a flag since this is needed only on major collections). We need to loop
1906 * here as well, so keep a counter of marked LO (increasing it in copy_object).
1907 * To achieve better cache locality and cache usage, we drain the gray stack
1908 * frequently, after each object is copied, and just finish the work here.
1910 sgen_drain_gray_stack (-1, ctx);
1912 SGEN_LOG (2, "%s generation done", generation_name (generation));
1915 Reset bridge data, we might have lingering data from a previous collection if this is a major
1916 collection trigged by minor overflow.
1918 We must reset the gathered bridges since their original block might be evacuated due to major
1919 fragmentation in the meanwhile and the bridge code should not have to deal with that.
1921 if (sgen_need_bridge_processing ())
1922 sgen_bridge_reset_data ();
1925 * Walk the ephemeron tables marking all values with reachable keys. This must be completely done
1926 * before processing finalizable objects and non-tracking weak links to avoid finalizing/clearing
1927 * objects that are in fact reachable.
1929 done_with_ephemerons = 0;
1931 done_with_ephemerons = mark_ephemerons_in_range (ctx);
1932 sgen_drain_gray_stack (-1, ctx);
1934 } while (!done_with_ephemerons);
1936 sgen_mark_togglerefs (start_addr, end_addr, ctx);
1938 if (sgen_need_bridge_processing ()) {
1939 /*Make sure the gray stack is empty before we process bridge objects so we get liveness right*/
1940 sgen_drain_gray_stack (-1, ctx);
1941 sgen_collect_bridge_objects (generation, ctx);
1942 if (generation == GENERATION_OLD)
1943 sgen_collect_bridge_objects (GENERATION_NURSERY, ctx);
1946 Do the first bridge step here, as the collector liveness state will become useless after that.
1948 An important optimization is to only proccess the possibly dead part of the object graph and skip
1949 over all live objects as we transitively know everything they point must be alive too.
1951 The above invariant is completely wrong if we let the gray queue be drained and mark/copy everything.
1953 This has the unfortunate side effect of making overflow collections perform the first step twice, but
1954 given we now have heuristics that perform major GC in anticipation of minor overflows this should not
1957 sgen_bridge_processing_stw_step ();
1961 Make sure we drain the gray stack before processing disappearing links and finalizers.
1962 If we don't make sure it is empty we might wrongly see a live object as dead.
1964 sgen_drain_gray_stack (-1, ctx);
1967 We must clear weak links that don't track resurrection before processing object ready for
1968 finalization so they can be cleared before that.
1970 sgen_null_link_in_range (generation, TRUE, ctx);
1971 if (generation == GENERATION_OLD)
1972 sgen_null_link_in_range (GENERATION_NURSERY, TRUE, ctx);
1975 /* walk the finalization queue and move also the objects that need to be
1976 * finalized: use the finalized objects as new roots so the objects they depend
1977 * on are also not reclaimed. As with the roots above, only objects in the nursery
1978 * are marked/copied.
1980 sgen_finalize_in_range (generation, ctx);
1981 if (generation == GENERATION_OLD)
1982 sgen_finalize_in_range (GENERATION_NURSERY, ctx);
1983 /* drain the new stack that might have been created */
1984 SGEN_LOG (6, "Precise scan of gray area post fin");
1985 sgen_drain_gray_stack (-1, ctx);
1988 * This must be done again after processing finalizable objects since CWL slots are cleared only after the key is finalized.
1990 done_with_ephemerons = 0;
1992 done_with_ephemerons = mark_ephemerons_in_range (ctx);
1993 sgen_drain_gray_stack (-1, ctx);
1995 } while (!done_with_ephemerons);
1998 * Clear ephemeron pairs with unreachable keys.
1999 * We pass the copy func so we can figure out if an array was promoted or not.
2001 clear_unreachable_ephemerons (ctx);
2004 * We clear togglerefs only after all possible chances of revival are done.
2005 * This is semantically more inline with what users expect and it allows for
2006 * user finalizers to correctly interact with TR objects.
2008 sgen_clear_togglerefs (start_addr, end_addr, ctx);
2011 SGEN_LOG (2, "Finalize queue handling scan for %s generation: %d usecs %d ephemeron rounds", generation_name (generation), TV_ELAPSED (atv, btv), ephemeron_rounds);
2014 * handle disappearing links
2015 * Note we do this after checking the finalization queue because if an object
2016 * survives (at least long enough to be finalized) we don't clear the link.
2017 * This also deals with a possible issue with the monitor reclamation: with the Boehm
2018 * GC a finalized object my lose the monitor because it is cleared before the finalizer is
2021 g_assert (sgen_gray_object_queue_is_empty (queue));
2023 sgen_null_link_in_range (generation, FALSE, ctx);
2024 if (generation == GENERATION_OLD)
2025 sgen_null_link_in_range (GENERATION_NURSERY, FALSE, ctx);
2026 if (sgen_gray_object_queue_is_empty (queue))
2028 sgen_drain_gray_stack (-1, ctx);
2031 g_assert (sgen_gray_object_queue_is_empty (queue));
2035 sgen_check_section_scan_starts (GCMemSection *section)
2038 for (i = 0; i < section->num_scan_start; ++i) {
2039 if (section->scan_starts [i]) {
2040 guint size = safe_object_get_size ((MonoObject*) section->scan_starts [i]);
2041 g_assert (size >= sizeof (MonoObject) && size <= MAX_SMALL_OBJ_SIZE);
2047 check_scan_starts (void)
2049 if (!do_scan_starts_check)
2051 sgen_check_section_scan_starts (nursery_section);
2052 major_collector.check_scan_starts ();
2056 scan_from_registered_roots (char *addr_start, char *addr_end, int root_type, ScanCopyContext ctx)
2060 SGEN_HASH_TABLE_FOREACH (&roots_hash [root_type], start_root, root) {
2061 SGEN_LOG (6, "Precise root scan %p-%p (desc: %p)", start_root, root->end_root, (void*)root->root_desc);
2062 precisely_scan_objects_from (start_root, (void**)root->end_root, addr_start, addr_end, root->root_desc, ctx);
2063 } SGEN_HASH_TABLE_FOREACH_END;
2067 sgen_dump_occupied (char *start, char *end, char *section_start)
2069 fprintf (heap_dump_file, "<occupied offset=\"%td\" size=\"%td\"/>\n", start - section_start, end - start);
2073 sgen_dump_section (GCMemSection *section, const char *type)
2075 char *start = section->data;
2076 char *end = section->data + section->size;
2077 char *occ_start = NULL;
2079 char *old_start = NULL; /* just for debugging */
2081 fprintf (heap_dump_file, "<section type=\"%s\" size=\"%lu\">\n", type, (unsigned long)section->size);
2083 while (start < end) {
2087 if (!*(void**)start) {
2089 sgen_dump_occupied (occ_start, start, section->data);
2092 start += sizeof (void*); /* should be ALLOC_ALIGN, really */
2095 g_assert (start < section->next_data);
2100 vt = (GCVTable*)LOAD_VTABLE (start);
2103 size = ALIGN_UP (safe_object_get_size ((MonoObject*) start));
2106 fprintf (heap_dump_file, "<object offset=\"%d\" class=\"%s.%s\" size=\"%d\"/>\n",
2107 start - section->data,
2108 vt->klass->name_space, vt->klass->name,
2116 sgen_dump_occupied (occ_start, start, section->data);
2118 fprintf (heap_dump_file, "</section>\n");
2122 dump_object (MonoObject *obj, gboolean dump_location)
2124 static char class_name [1024];
2126 MonoClass *class = mono_object_class (obj);
2130 * Python's XML parser is too stupid to parse angle brackets
2131 * in strings, so we just ignore them;
2134 while (class->name [i] && j < sizeof (class_name) - 1) {
2135 if (!strchr ("<>\"", class->name [i]))
2136 class_name [j++] = class->name [i];
2139 g_assert (j < sizeof (class_name));
2142 fprintf (heap_dump_file, "<object class=\"%s.%s\" size=\"%d\"",
2143 class->name_space, class_name,
2144 safe_object_get_size (obj));
2145 if (dump_location) {
2146 const char *location;
2147 if (ptr_in_nursery (obj))
2148 location = "nursery";
2149 else if (safe_object_get_size (obj) <= MAX_SMALL_OBJ_SIZE)
2153 fprintf (heap_dump_file, " location=\"%s\"", location);
2155 fprintf (heap_dump_file, "/>\n");
2159 dump_heap (const char *type, int num, const char *reason)
2164 fprintf (heap_dump_file, "<collection type=\"%s\" num=\"%d\"", type, num);
2166 fprintf (heap_dump_file, " reason=\"%s\"", reason);
2167 fprintf (heap_dump_file, ">\n");
2168 fprintf (heap_dump_file, "<other-mem-usage type=\"mempools\" size=\"%ld\"/>\n", mono_mempool_get_bytes_allocated ());
2169 sgen_dump_internal_mem_usage (heap_dump_file);
2170 fprintf (heap_dump_file, "<pinned type=\"stack\" bytes=\"%zu\"/>\n", sgen_pin_stats_get_pinned_byte_count (PIN_TYPE_STACK));
2171 /* fprintf (heap_dump_file, "<pinned type=\"static-data\" bytes=\"%d\"/>\n", pinned_byte_counts [PIN_TYPE_STATIC_DATA]); */
2172 fprintf (heap_dump_file, "<pinned type=\"other\" bytes=\"%zu\"/>\n", sgen_pin_stats_get_pinned_byte_count (PIN_TYPE_OTHER));
2174 fprintf (heap_dump_file, "<pinned-objects>\n");
2175 for (list = sgen_pin_stats_get_object_list (); list; list = list->next)
2176 dump_object (list->obj, TRUE);
2177 fprintf (heap_dump_file, "</pinned-objects>\n");
2179 sgen_dump_section (nursery_section, "nursery");
2181 major_collector.dump_heap (heap_dump_file);
2183 fprintf (heap_dump_file, "<los>\n");
2184 for (bigobj = los_object_list; bigobj; bigobj = bigobj->next)
2185 dump_object ((MonoObject*)bigobj->data, FALSE);
2186 fprintf (heap_dump_file, "</los>\n");
2188 fprintf (heap_dump_file, "</collection>\n");
2192 sgen_register_moved_object (void *obj, void *destination)
2194 g_assert (mono_profiler_events & MONO_PROFILE_GC_MOVES);
2196 /* FIXME: handle this for parallel collector */
2197 g_assert (!sgen_collection_is_parallel ());
2199 if (moved_objects_idx == MOVED_OBJECTS_NUM) {
2200 mono_profiler_gc_moves (moved_objects, moved_objects_idx);
2201 moved_objects_idx = 0;
2203 moved_objects [moved_objects_idx++] = obj;
2204 moved_objects [moved_objects_idx++] = destination;
2210 static gboolean inited = FALSE;
2215 mono_counters_register ("Minor fragment clear", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_minor_pre_collection_fragment_clear);
2216 mono_counters_register ("Minor pinning", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_minor_pinning);
2217 mono_counters_register ("Minor scan remembered set", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_minor_scan_remsets);
2218 mono_counters_register ("Minor scan pinned", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_minor_scan_pinned);
2219 mono_counters_register ("Minor scan registered roots", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_minor_scan_registered_roots);
2220 mono_counters_register ("Minor scan thread data", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_minor_scan_thread_data);
2221 mono_counters_register ("Minor finish gray stack", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_minor_finish_gray_stack);
2222 mono_counters_register ("Minor fragment creation", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_minor_fragment_creation);
2224 mono_counters_register ("Major fragment clear", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_major_pre_collection_fragment_clear);
2225 mono_counters_register ("Major pinning", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_major_pinning);
2226 mono_counters_register ("Major scan pinned", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_major_scan_pinned);
2227 mono_counters_register ("Major scan registered roots", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_major_scan_registered_roots);
2228 mono_counters_register ("Major scan thread data", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_major_scan_thread_data);
2229 mono_counters_register ("Major scan alloc_pinned", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_major_scan_alloc_pinned);
2230 mono_counters_register ("Major scan finalized", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_major_scan_finalized);
2231 mono_counters_register ("Major scan big objects", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_major_scan_big_objects);
2232 mono_counters_register ("Major finish gray stack", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_major_finish_gray_stack);
2233 mono_counters_register ("Major free big objects", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_major_free_bigobjs);
2234 mono_counters_register ("Major LOS sweep", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_major_los_sweep);
2235 mono_counters_register ("Major sweep", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_major_sweep);
2236 mono_counters_register ("Major fragment creation", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_major_fragment_creation);
2238 mono_counters_register ("Number of pinned objects", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_pinned_objects);
2240 #ifdef HEAVY_STATISTICS
2241 mono_counters_register ("WBarrier remember pointer", MONO_COUNTER_GC | MONO_COUNTER_INT, &stat_wbarrier_add_to_global_remset);
2242 mono_counters_register ("WBarrier set field", MONO_COUNTER_GC | MONO_COUNTER_INT, &stat_wbarrier_set_field);
2243 mono_counters_register ("WBarrier set arrayref", MONO_COUNTER_GC | MONO_COUNTER_INT, &stat_wbarrier_set_arrayref);
2244 mono_counters_register ("WBarrier arrayref copy", MONO_COUNTER_GC | MONO_COUNTER_INT, &stat_wbarrier_arrayref_copy);
2245 mono_counters_register ("WBarrier generic store called", MONO_COUNTER_GC | MONO_COUNTER_INT, &stat_wbarrier_generic_store);
2246 mono_counters_register ("WBarrier generic atomic store called", MONO_COUNTER_GC | MONO_COUNTER_INT, &stat_wbarrier_generic_store_atomic);
2247 mono_counters_register ("WBarrier set root", MONO_COUNTER_GC | MONO_COUNTER_INT, &stat_wbarrier_set_root);
2248 mono_counters_register ("WBarrier value copy", MONO_COUNTER_GC | MONO_COUNTER_INT, &stat_wbarrier_value_copy);
2249 mono_counters_register ("WBarrier object copy", MONO_COUNTER_GC | MONO_COUNTER_INT, &stat_wbarrier_object_copy);
2251 mono_counters_register ("# objects allocated degraded", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_objects_alloced_degraded);
2252 mono_counters_register ("bytes allocated degraded", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_bytes_alloced_degraded);
2254 mono_counters_register ("# copy_object() called (nursery)", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_copy_object_called_nursery);
2255 mono_counters_register ("# objects copied (nursery)", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_objects_copied_nursery);
2256 mono_counters_register ("# copy_object() called (major)", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_copy_object_called_major);
2257 mono_counters_register ("# objects copied (major)", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_objects_copied_major);
2259 mono_counters_register ("# scan_object() called (nursery)", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_scan_object_called_nursery);
2260 mono_counters_register ("# scan_object() called (major)", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_scan_object_called_major);
2262 mono_counters_register ("Slots allocated in vain", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_slots_allocated_in_vain);
2264 mono_counters_register ("# nursery copy_object() failed from space", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_nursery_copy_object_failed_from_space);
2265 mono_counters_register ("# nursery copy_object() failed forwarded", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_nursery_copy_object_failed_forwarded);
2266 mono_counters_register ("# nursery copy_object() failed pinned", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_nursery_copy_object_failed_pinned);
2267 mono_counters_register ("# nursery copy_object() failed to space", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_nursery_copy_object_failed_to_space);
2269 sgen_nursery_allocator_init_heavy_stats ();
2270 sgen_alloc_init_heavy_stats ();
2278 reset_pinned_from_failed_allocation (void)
2280 bytes_pinned_from_failed_allocation = 0;
2284 sgen_set_pinned_from_failed_allocation (mword objsize)
2286 bytes_pinned_from_failed_allocation += objsize;
2290 sgen_collection_is_parallel (void)
2292 switch (current_collection_generation) {
2293 case GENERATION_NURSERY:
2294 return nursery_collection_is_parallel;
2295 case GENERATION_OLD:
2296 return major_collector.is_parallel;
2298 g_error ("Invalid current generation %d", current_collection_generation);
2303 sgen_collection_is_concurrent (void)
2305 switch (current_collection_generation) {
2306 case GENERATION_NURSERY:
2308 case GENERATION_OLD:
2309 return concurrent_collection_in_progress;
2311 g_error ("Invalid current generation %d", current_collection_generation);
2316 sgen_concurrent_collection_in_progress (void)
2318 return concurrent_collection_in_progress;
2325 } FinishRememberedSetScanJobData;
2328 job_finish_remembered_set_scan (WorkerData *worker_data, void *job_data_untyped)
2330 FinishRememberedSetScanJobData *job_data = job_data_untyped;
2332 remset.finish_scan_remsets (job_data->heap_start, job_data->heap_end, sgen_workers_get_job_gray_queue (worker_data));
2333 sgen_free_internal_dynamic (job_data, sizeof (FinishRememberedSetScanJobData), INTERNAL_MEM_WORKER_JOB_DATA);
2338 CopyOrMarkObjectFunc copy_or_mark_func;
2339 ScanObjectFunc scan_func;
2343 } ScanFromRegisteredRootsJobData;
2346 job_scan_from_registered_roots (WorkerData *worker_data, void *job_data_untyped)
2348 ScanFromRegisteredRootsJobData *job_data = job_data_untyped;
2349 ScanCopyContext ctx = { job_data->scan_func, job_data->copy_or_mark_func,
2350 sgen_workers_get_job_gray_queue (worker_data) };
2352 scan_from_registered_roots (job_data->heap_start, job_data->heap_end, job_data->root_type, ctx);
2353 sgen_free_internal_dynamic (job_data, sizeof (ScanFromRegisteredRootsJobData), INTERNAL_MEM_WORKER_JOB_DATA);
2360 } ScanThreadDataJobData;
2363 job_scan_thread_data (WorkerData *worker_data, void *job_data_untyped)
2365 ScanThreadDataJobData *job_data = job_data_untyped;
2367 scan_thread_data (job_data->heap_start, job_data->heap_end, TRUE,
2368 sgen_workers_get_job_gray_queue (worker_data));
2369 sgen_free_internal_dynamic (job_data, sizeof (ScanThreadDataJobData), INTERNAL_MEM_WORKER_JOB_DATA);
2374 FinalizeReadyEntry *list;
2375 } ScanFinalizerEntriesJobData;
2378 job_scan_finalizer_entries (WorkerData *worker_data, void *job_data_untyped)
2380 ScanFinalizerEntriesJobData *job_data = job_data_untyped;
2381 ScanCopyContext ctx = { NULL, current_object_ops.copy_or_mark_object, sgen_workers_get_job_gray_queue (worker_data) };
2383 scan_finalizer_entries (job_data->list, ctx);
2384 sgen_free_internal_dynamic (job_data, sizeof (ScanFinalizerEntriesJobData), INTERNAL_MEM_WORKER_JOB_DATA);
2388 job_scan_major_mod_union_cardtable (WorkerData *worker_data, void *job_data_untyped)
2390 g_assert (concurrent_collection_in_progress);
2391 major_collector.scan_card_table (TRUE, sgen_workers_get_job_gray_queue (worker_data));
2395 job_scan_los_mod_union_cardtable (WorkerData *worker_data, void *job_data_untyped)
2397 g_assert (concurrent_collection_in_progress);
2398 sgen_los_scan_card_table (TRUE, sgen_workers_get_job_gray_queue (worker_data));
2402 verify_scan_starts (char *start, char *end)
2406 for (i = 0; i < nursery_section->num_scan_start; ++i) {
2407 char *addr = nursery_section->scan_starts [i];
2408 if (addr > start && addr < end)
2409 SGEN_LOG (1, "NFC-BAD SCAN START [%d] %p for obj [%p %p]", i, addr, start, end);
2414 verify_nursery (void)
2416 char *start, *end, *cur, *hole_start;
2418 if (!do_verify_nursery)
2421 /*This cleans up unused fragments */
2422 sgen_nursery_allocator_prepare_for_pinning ();
2424 hole_start = start = cur = sgen_get_nursery_start ();
2425 end = sgen_get_nursery_end ();
2430 if (!*(void**)cur) {
2431 cur += sizeof (void*);
2435 if (object_is_forwarded (cur))
2436 SGEN_LOG (1, "FORWARDED OBJ %p", cur);
2437 else if (object_is_pinned (cur))
2438 SGEN_LOG (1, "PINNED OBJ %p", cur);
2440 ss = safe_object_get_size ((MonoObject*)cur);
2441 size = ALIGN_UP (safe_object_get_size ((MonoObject*)cur));
2442 verify_scan_starts (cur, cur + size);
2443 if (do_dump_nursery_content) {
2444 if (cur > hole_start)
2445 SGEN_LOG (1, "HOLE [%p %p %d]", hole_start, cur, (int)(cur - hole_start));
2446 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 ());
2454 * Checks that no objects in the nursery are fowarded or pinned. This
2455 * is a precondition to restarting the mutator while doing a
2456 * concurrent collection. Note that we don't clear fragments because
2457 * we depend on that having happened earlier.
2460 check_nursery_is_clean (void)
2462 char *start, *end, *cur;
2464 start = cur = sgen_get_nursery_start ();
2465 end = sgen_get_nursery_end ();
2470 if (!*(void**)cur) {
2471 cur += sizeof (void*);
2475 g_assert (!object_is_forwarded (cur));
2476 g_assert (!object_is_pinned (cur));
2478 ss = safe_object_get_size ((MonoObject*)cur);
2479 size = ALIGN_UP (safe_object_get_size ((MonoObject*)cur));
2480 verify_scan_starts (cur, cur + size);
2487 init_gray_queue (void)
2489 if (sgen_collection_is_parallel () || sgen_collection_is_concurrent ()) {
2490 sgen_workers_init_distribute_gray_queue ();
2491 sgen_gray_object_queue_init_with_alloc_prepare (&gray_queue, NULL,
2492 gray_queue_redirect, sgen_workers_get_distribute_section_gray_queue ());
2494 sgen_gray_object_queue_init (&gray_queue, NULL);
2499 pin_stage_object_callback (char *obj, size_t size, void *data)
2501 sgen_pin_stage_ptr (obj);
2502 /* FIXME: do pin stats if enabled */
2506 * Collect objects in the nursery. Returns whether to trigger a major
2510 collect_nursery (SgenGrayQueue *unpin_queue, gboolean finish_up_concurrent_mark)
2512 gboolean needs_major;
2513 size_t max_garbage_amount;
2515 FinishRememberedSetScanJobData *frssjd;
2516 ScanFromRegisteredRootsJobData *scrrjd_normal, *scrrjd_wbarrier;
2517 ScanFinalizerEntriesJobData *sfejd_fin_ready, *sfejd_critical_fin;
2518 ScanThreadDataJobData *stdjd;
2519 mword fragment_total;
2520 ScanCopyContext ctx;
2521 TV_DECLARE (all_atv);
2522 TV_DECLARE (all_btv);
2526 if (disable_minor_collections)
2529 MONO_GC_BEGIN (GENERATION_NURSERY);
2530 binary_protocol_collection_begin (stat_minor_gcs, GENERATION_NURSERY);
2534 #ifndef DISABLE_PERFCOUNTERS
2535 mono_perfcounters->gc_collections0++;
2538 current_collection_generation = GENERATION_NURSERY;
2539 if (sgen_collection_is_parallel ())
2540 current_object_ops = sgen_minor_collector.parallel_ops;
2542 current_object_ops = sgen_minor_collector.serial_ops;
2544 reset_pinned_from_failed_allocation ();
2546 check_scan_starts ();
2548 sgen_nursery_alloc_prepare_for_minor ();
2552 nursery_next = sgen_nursery_alloc_get_upper_alloc_bound ();
2553 /* FIXME: optimize later to use the higher address where an object can be present */
2554 nursery_next = MAX (nursery_next, sgen_get_nursery_end ());
2556 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 ()));
2557 max_garbage_amount = nursery_next - sgen_get_nursery_start ();
2558 g_assert (nursery_section->size >= max_garbage_amount);
2560 /* world must be stopped already */
2561 TV_GETTIME (all_atv);
2565 time_minor_pre_collection_fragment_clear += TV_ELAPSED (atv, btv);
2567 if (xdomain_checks) {
2568 sgen_clear_nursery_fragments ();
2569 check_for_xdomain_refs ();
2572 nursery_section->next_data = nursery_next;
2574 major_collector.start_nursery_collection ();
2576 sgen_memgov_minor_collection_start ();
2581 gc_stats.minor_gc_count ++;
2583 MONO_GC_CHECKPOINT_1 (GENERATION_NURSERY);
2585 sgen_process_fin_stage_entries ();
2586 sgen_process_dislink_stage_entries ();
2588 MONO_GC_CHECKPOINT_2 (GENERATION_NURSERY);
2590 /* pin from pinned handles */
2591 sgen_init_pinning ();
2592 mono_profiler_gc_event (MONO_GC_EVENT_MARK_START, 0);
2593 pin_from_roots (sgen_get_nursery_start (), nursery_next, WORKERS_DISTRIBUTE_GRAY_QUEUE);
2594 /* pin cemented objects */
2595 sgen_cement_iterate (pin_stage_object_callback, NULL);
2596 /* identify pinned objects */
2597 sgen_optimize_pin_queue (0);
2598 sgen_pinning_setup_section (nursery_section);
2599 ctx.scan_func = NULL;
2600 ctx.copy_func = NULL;
2601 ctx.queue = WORKERS_DISTRIBUTE_GRAY_QUEUE;
2602 sgen_pin_objects_in_section (nursery_section, ctx);
2603 sgen_pinning_trim_queue_to_section (nursery_section);
2606 time_minor_pinning += TV_ELAPSED (btv, atv);
2607 SGEN_LOG (2, "Finding pinned pointers: %d in %d usecs", sgen_get_pinned_count (), TV_ELAPSED (btv, atv));
2608 SGEN_LOG (4, "Start scan with %d pinned objects", sgen_get_pinned_count ());
2610 MONO_GC_CHECKPOINT_3 (GENERATION_NURSERY);
2612 if (whole_heap_check_before_collection) {
2613 sgen_clear_nursery_fragments ();
2614 sgen_check_whole_heap (finish_up_concurrent_mark);
2616 if (consistency_check_at_minor_collection)
2617 sgen_check_consistency ();
2619 sgen_workers_start_all_workers ();
2620 sgen_workers_start_marking ();
2622 frssjd = sgen_alloc_internal_dynamic (sizeof (FinishRememberedSetScanJobData), INTERNAL_MEM_WORKER_JOB_DATA, TRUE);
2623 frssjd->heap_start = sgen_get_nursery_start ();
2624 frssjd->heap_end = nursery_next;
2625 sgen_workers_enqueue_job (job_finish_remembered_set_scan, frssjd);
2627 /* we don't have complete write barrier yet, so we scan all the old generation sections */
2629 time_minor_scan_remsets += TV_ELAPSED (atv, btv);
2630 SGEN_LOG (2, "Old generation scan: %d usecs", TV_ELAPSED (atv, btv));
2632 MONO_GC_CHECKPOINT_4 (GENERATION_NURSERY);
2634 if (!sgen_collection_is_parallel ()) {
2635 ctx.scan_func = current_object_ops.scan_object;
2636 ctx.copy_func = NULL;
2637 ctx.queue = &gray_queue;
2638 sgen_drain_gray_stack (-1, ctx);
2641 if (mono_profiler_get_events () & MONO_PROFILE_GC_ROOTS)
2642 report_registered_roots ();
2643 if (mono_profiler_get_events () & MONO_PROFILE_GC_ROOTS)
2644 report_finalizer_roots ();
2646 time_minor_scan_pinned += TV_ELAPSED (btv, atv);
2648 MONO_GC_CHECKPOINT_5 (GENERATION_NURSERY);
2650 /* registered roots, this includes static fields */
2651 scrrjd_normal = sgen_alloc_internal_dynamic (sizeof (ScanFromRegisteredRootsJobData), INTERNAL_MEM_WORKER_JOB_DATA, TRUE);
2652 scrrjd_normal->copy_or_mark_func = current_object_ops.copy_or_mark_object;
2653 scrrjd_normal->scan_func = current_object_ops.scan_object;
2654 scrrjd_normal->heap_start = sgen_get_nursery_start ();
2655 scrrjd_normal->heap_end = nursery_next;
2656 scrrjd_normal->root_type = ROOT_TYPE_NORMAL;
2657 sgen_workers_enqueue_job (job_scan_from_registered_roots, scrrjd_normal);
2659 scrrjd_wbarrier = sgen_alloc_internal_dynamic (sizeof (ScanFromRegisteredRootsJobData), INTERNAL_MEM_WORKER_JOB_DATA, TRUE);
2660 scrrjd_wbarrier->copy_or_mark_func = current_object_ops.copy_or_mark_object;
2661 scrrjd_wbarrier->scan_func = current_object_ops.scan_object;
2662 scrrjd_wbarrier->heap_start = sgen_get_nursery_start ();
2663 scrrjd_wbarrier->heap_end = nursery_next;
2664 scrrjd_wbarrier->root_type = ROOT_TYPE_WBARRIER;
2665 sgen_workers_enqueue_job (job_scan_from_registered_roots, scrrjd_wbarrier);
2668 time_minor_scan_registered_roots += TV_ELAPSED (atv, btv);
2670 MONO_GC_CHECKPOINT_6 (GENERATION_NURSERY);
2673 stdjd = sgen_alloc_internal_dynamic (sizeof (ScanThreadDataJobData), INTERNAL_MEM_WORKER_JOB_DATA, TRUE);
2674 stdjd->heap_start = sgen_get_nursery_start ();
2675 stdjd->heap_end = nursery_next;
2676 sgen_workers_enqueue_job (job_scan_thread_data, stdjd);
2679 time_minor_scan_thread_data += TV_ELAPSED (btv, atv);
2682 MONO_GC_CHECKPOINT_7 (GENERATION_NURSERY);
2684 g_assert (!sgen_collection_is_parallel () && !sgen_collection_is_concurrent ());
2686 if (sgen_collection_is_parallel () || sgen_collection_is_concurrent ())
2687 g_assert (sgen_gray_object_queue_is_empty (&gray_queue));
2689 /* Scan the list of objects ready for finalization. If */
2690 sfejd_fin_ready = sgen_alloc_internal_dynamic (sizeof (ScanFinalizerEntriesJobData), INTERNAL_MEM_WORKER_JOB_DATA, TRUE);
2691 sfejd_fin_ready->list = fin_ready_list;
2692 sgen_workers_enqueue_job (job_scan_finalizer_entries, sfejd_fin_ready);
2694 sfejd_critical_fin = sgen_alloc_internal_dynamic (sizeof (ScanFinalizerEntriesJobData), INTERNAL_MEM_WORKER_JOB_DATA, TRUE);
2695 sfejd_critical_fin->list = critical_fin_list;
2696 sgen_workers_enqueue_job (job_scan_finalizer_entries, sfejd_critical_fin);
2698 MONO_GC_CHECKPOINT_8 (GENERATION_NURSERY);
2700 finish_gray_stack (GENERATION_NURSERY, &gray_queue);
2702 time_minor_finish_gray_stack += TV_ELAPSED (btv, atv);
2703 mono_profiler_gc_event (MONO_GC_EVENT_MARK_END, 0);
2705 MONO_GC_CHECKPOINT_9 (GENERATION_NURSERY);
2708 * The (single-threaded) finalization code might have done
2709 * some copying/marking so we can only reset the GC thread's
2710 * worker data here instead of earlier when we joined the
2713 sgen_workers_reset_data ();
2715 if (objects_pinned) {
2716 sgen_optimize_pin_queue (0);
2717 sgen_pinning_setup_section (nursery_section);
2720 /* walk the pin_queue, build up the fragment list of free memory, unmark
2721 * pinned objects as we go, memzero() the empty fragments so they are ready for the
2724 mono_profiler_gc_event (MONO_GC_EVENT_RECLAIM_START, 0);
2725 fragment_total = sgen_build_nursery_fragments (nursery_section,
2726 nursery_section->pin_queue_start, nursery_section->pin_queue_num_entries,
2728 if (!fragment_total)
2731 /* Clear TLABs for all threads */
2732 sgen_clear_tlabs ();
2734 mono_profiler_gc_event (MONO_GC_EVENT_RECLAIM_END, 0);
2736 time_minor_fragment_creation += TV_ELAPSED (atv, btv);
2737 SGEN_LOG (2, "Fragment creation: %d usecs, %lu bytes available", TV_ELAPSED (atv, btv), (unsigned long)fragment_total);
2739 if (consistency_check_at_minor_collection)
2740 sgen_check_major_refs ();
2742 major_collector.finish_nursery_collection ();
2744 TV_GETTIME (all_btv);
2745 gc_stats.minor_gc_time_usecs += TV_ELAPSED (all_atv, all_btv);
2748 dump_heap ("minor", stat_minor_gcs - 1, NULL);
2750 /* prepare the pin queue for the next collection */
2751 sgen_finish_pinning ();
2752 if (fin_ready_list || critical_fin_list) {
2753 SGEN_LOG (4, "Finalizer-thread wakeup: ready %d", num_ready_finalizers);
2754 mono_gc_finalize_notify ();
2756 sgen_pin_stats_reset ();
2757 /* clear cemented hash */
2758 sgen_cement_clear_below_threshold ();
2760 g_assert (sgen_gray_object_queue_is_empty (&gray_queue));
2762 remset.finish_minor_collection ();
2764 check_scan_starts ();
2766 binary_protocol_flush_buffers (FALSE);
2768 sgen_memgov_minor_collection_end ();
2770 /*objects are late pinned because of lack of memory, so a major is a good call*/
2771 needs_major = objects_pinned > 0;
2772 current_collection_generation = -1;
2775 MONO_GC_END (GENERATION_NURSERY);
2776 binary_protocol_collection_end (stat_minor_gcs - 1, GENERATION_NURSERY);
2778 if (check_nursery_objects_pinned && !sgen_minor_collector.is_split)
2779 sgen_check_nursery_objects_pinned (unpin_queue != NULL);
2785 scan_nursery_objects_callback (char *obj, size_t size, ScanCopyContext *ctx)
2787 ctx->scan_func (obj, ctx->queue);
2791 scan_nursery_objects (ScanCopyContext ctx)
2793 sgen_scan_area_with_callback (nursery_section->data, nursery_section->end_data,
2794 (IterateObjectCallbackFunc)scan_nursery_objects_callback, (void*)&ctx, FALSE);
2798 major_copy_or_mark_from_roots (int *old_next_pin_slot, gboolean finish_up_concurrent_mark, gboolean scan_mod_union)
2803 /* FIXME: only use these values for the precise scan
2804 * note that to_space pointers should be excluded anyway...
2806 char *heap_start = NULL;
2807 char *heap_end = (char*)-1;
2808 gboolean profile_roots = mono_profiler_get_events () & MONO_PROFILE_GC_ROOTS;
2809 GCRootReport root_report = { 0 };
2810 ScanFromRegisteredRootsJobData *scrrjd_normal, *scrrjd_wbarrier;
2811 ScanThreadDataJobData *stdjd;
2812 ScanFinalizerEntriesJobData *sfejd_fin_ready, *sfejd_critical_fin;
2813 ScanCopyContext ctx;
2815 if (concurrent_collection_in_progress) {
2816 /*This cleans up unused fragments */
2817 sgen_nursery_allocator_prepare_for_pinning ();
2819 if (do_concurrent_checks)
2820 check_nursery_is_clean ();
2822 /* The concurrent collector doesn't touch the nursery. */
2823 sgen_nursery_alloc_prepare_for_major ();
2830 /* Pinning depends on this */
2831 sgen_clear_nursery_fragments ();
2833 if (whole_heap_check_before_collection)
2834 sgen_check_whole_heap (finish_up_concurrent_mark);
2837 time_major_pre_collection_fragment_clear += TV_ELAPSED (atv, btv);
2839 if (!sgen_collection_is_concurrent ())
2840 nursery_section->next_data = sgen_get_nursery_end ();
2841 /* we should also coalesce scanning from sections close to each other
2842 * and deal with pointers outside of the sections later.
2846 *major_collector.have_swept = FALSE;
2848 if (xdomain_checks) {
2849 sgen_clear_nursery_fragments ();
2850 check_for_xdomain_refs ();
2853 if (!concurrent_collection_in_progress) {
2854 /* Remsets are not useful for a major collection */
2855 remset.prepare_for_major_collection ();
2858 sgen_process_fin_stage_entries ();
2859 sgen_process_dislink_stage_entries ();
2862 sgen_init_pinning ();
2863 SGEN_LOG (6, "Collecting pinned addresses");
2864 pin_from_roots ((void*)lowest_heap_address, (void*)highest_heap_address, WORKERS_DISTRIBUTE_GRAY_QUEUE);
2866 if (!concurrent_collection_in_progress || finish_up_concurrent_mark) {
2867 if (major_collector.is_concurrent) {
2869 * The concurrent major collector cannot evict
2870 * yet, so we need to pin cemented objects to
2871 * not break some asserts.
2873 * FIXME: We could evict now!
2875 sgen_cement_iterate (pin_stage_object_callback, NULL);
2878 if (!concurrent_collection_in_progress)
2879 sgen_cement_reset ();
2882 sgen_optimize_pin_queue (0);
2885 * The concurrent collector doesn't move objects, neither on
2886 * the major heap nor in the nursery, so we can mark even
2887 * before pinning has finished. For the non-concurrent
2888 * collector we start the workers after pinning.
2890 if (concurrent_collection_in_progress) {
2891 sgen_workers_start_all_workers ();
2892 sgen_workers_start_marking ();
2896 * pin_queue now contains all candidate pointers, sorted and
2897 * uniqued. We must do two passes now to figure out which
2898 * objects are pinned.
2900 * The first is to find within the pin_queue the area for each
2901 * section. This requires that the pin_queue be sorted. We
2902 * also process the LOS objects and pinned chunks here.
2904 * The second, destructive, pass is to reduce the section
2905 * areas to pointers to the actually pinned objects.
2907 SGEN_LOG (6, "Pinning from sections");
2908 /* first pass for the sections */
2909 sgen_find_section_pin_queue_start_end (nursery_section);
2910 major_collector.find_pin_queue_start_ends (WORKERS_DISTRIBUTE_GRAY_QUEUE);
2911 /* identify possible pointers to the insize of large objects */
2912 SGEN_LOG (6, "Pinning from large objects");
2913 for (bigobj = los_object_list; bigobj; bigobj = bigobj->next) {
2915 if (sgen_find_optimized_pin_queue_area (bigobj->data, (char*)bigobj->data + sgen_los_object_size (bigobj), &dummy)) {
2916 binary_protocol_pin (bigobj->data, (gpointer)LOAD_VTABLE (bigobj->data), safe_object_get_size (((MonoObject*)(bigobj->data))));
2918 #ifdef ENABLE_DTRACE
2919 if (G_UNLIKELY (MONO_GC_OBJ_PINNED_ENABLED ())) {
2920 MonoVTable *vt = (MonoVTable*)LOAD_VTABLE (bigobj->data);
2921 MONO_GC_OBJ_PINNED ((mword)bigobj->data, sgen_safe_object_get_size ((MonoObject*)bigobj->data), vt->klass->name_space, vt->klass->name, GENERATION_OLD);
2925 if (sgen_los_object_is_pinned (bigobj->data)) {
2926 g_assert (finish_up_concurrent_mark);
2929 sgen_los_pin_object (bigobj->data);
2930 if (SGEN_OBJECT_HAS_REFERENCES (bigobj->data))
2931 GRAY_OBJECT_ENQUEUE (WORKERS_DISTRIBUTE_GRAY_QUEUE, bigobj->data);
2932 if (G_UNLIKELY (do_pin_stats))
2933 sgen_pin_stats_register_object ((char*) bigobj->data, safe_object_get_size ((MonoObject*) bigobj->data));
2934 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));
2937 add_profile_gc_root (&root_report, bigobj->data, MONO_PROFILE_GC_ROOT_PINNING | MONO_PROFILE_GC_ROOT_MISC, 0);
2941 notify_gc_roots (&root_report);
2942 /* second pass for the sections */
2943 ctx.scan_func = concurrent_collection_in_progress ? current_object_ops.scan_object : NULL;
2944 ctx.copy_func = NULL;
2945 ctx.queue = WORKERS_DISTRIBUTE_GRAY_QUEUE;
2948 * Concurrent mark never follows references into the nursery.
2949 * In the start and finish pauses we must scan live nursery
2950 * objects, though. We could simply scan all nursery objects,
2951 * but that would be conservative. The easiest way is to do a
2952 * nursery collection, which copies all live nursery objects
2953 * (except pinned ones, with the simple nursery) to the major
2954 * heap. Scanning the mod union table later will then scan
2955 * those promoted objects, provided they're reachable. Pinned
2956 * objects in the nursery - which we can trivially find in the
2957 * pinning queue - are treated as roots in the mark pauses.
2959 * The split nursery complicates the latter part because
2960 * non-pinned objects can survive in the nursery. That's why
2961 * we need to do a full front-to-back scan of the nursery,
2962 * marking all objects.
2964 * Non-concurrent mark evacuates from the nursery, so it's
2965 * sufficient to just scan pinned nursery objects.
2967 if (concurrent_collection_in_progress && sgen_minor_collector.is_split) {
2968 scan_nursery_objects (ctx);
2970 sgen_pin_objects_in_section (nursery_section, ctx);
2971 if (check_nursery_objects_pinned && !sgen_minor_collector.is_split)
2972 sgen_check_nursery_objects_pinned (!concurrent_collection_in_progress || finish_up_concurrent_mark);
2975 major_collector.pin_objects (WORKERS_DISTRIBUTE_GRAY_QUEUE);
2976 if (old_next_pin_slot)
2977 *old_next_pin_slot = sgen_get_pinned_count ();
2980 time_major_pinning += TV_ELAPSED (atv, btv);
2981 SGEN_LOG (2, "Finding pinned pointers: %d in %d usecs", sgen_get_pinned_count (), TV_ELAPSED (atv, btv));
2982 SGEN_LOG (4, "Start scan with %d pinned objects", sgen_get_pinned_count ());
2984 major_collector.init_to_space ();
2986 #ifdef SGEN_DEBUG_INTERNAL_ALLOC
2987 main_gc_thread = mono_native_thread_self ();
2990 if (!concurrent_collection_in_progress && major_collector.is_parallel) {
2991 sgen_workers_start_all_workers ();
2992 sgen_workers_start_marking ();
2995 if (mono_profiler_get_events () & MONO_PROFILE_GC_ROOTS)
2996 report_registered_roots ();
2998 time_major_scan_pinned += TV_ELAPSED (btv, atv);
3000 /* registered roots, this includes static fields */
3001 scrrjd_normal = sgen_alloc_internal_dynamic (sizeof (ScanFromRegisteredRootsJobData), INTERNAL_MEM_WORKER_JOB_DATA, TRUE);
3002 scrrjd_normal->copy_or_mark_func = current_object_ops.copy_or_mark_object;
3003 scrrjd_normal->scan_func = current_object_ops.scan_object;
3004 scrrjd_normal->heap_start = heap_start;
3005 scrrjd_normal->heap_end = heap_end;
3006 scrrjd_normal->root_type = ROOT_TYPE_NORMAL;
3007 sgen_workers_enqueue_job (job_scan_from_registered_roots, scrrjd_normal);
3009 scrrjd_wbarrier = sgen_alloc_internal_dynamic (sizeof (ScanFromRegisteredRootsJobData), INTERNAL_MEM_WORKER_JOB_DATA, TRUE);
3010 scrrjd_wbarrier->copy_or_mark_func = current_object_ops.copy_or_mark_object;
3011 scrrjd_wbarrier->scan_func = current_object_ops.scan_object;
3012 scrrjd_wbarrier->heap_start = heap_start;
3013 scrrjd_wbarrier->heap_end = heap_end;
3014 scrrjd_wbarrier->root_type = ROOT_TYPE_WBARRIER;
3015 sgen_workers_enqueue_job (job_scan_from_registered_roots, scrrjd_wbarrier);
3018 time_major_scan_registered_roots += TV_ELAPSED (atv, btv);
3021 stdjd = sgen_alloc_internal_dynamic (sizeof (ScanThreadDataJobData), INTERNAL_MEM_WORKER_JOB_DATA, TRUE);
3022 stdjd->heap_start = heap_start;
3023 stdjd->heap_end = heap_end;
3024 sgen_workers_enqueue_job (job_scan_thread_data, stdjd);
3027 time_major_scan_thread_data += TV_ELAPSED (btv, atv);
3030 time_major_scan_alloc_pinned += TV_ELAPSED (atv, btv);
3032 if (mono_profiler_get_events () & MONO_PROFILE_GC_ROOTS)
3033 report_finalizer_roots ();
3035 /* scan the list of objects ready for finalization */
3036 sfejd_fin_ready = sgen_alloc_internal_dynamic (sizeof (ScanFinalizerEntriesJobData), INTERNAL_MEM_WORKER_JOB_DATA, TRUE);
3037 sfejd_fin_ready->list = fin_ready_list;
3038 sgen_workers_enqueue_job (job_scan_finalizer_entries, sfejd_fin_ready);
3040 sfejd_critical_fin = sgen_alloc_internal_dynamic (sizeof (ScanFinalizerEntriesJobData), INTERNAL_MEM_WORKER_JOB_DATA, TRUE);
3041 sfejd_critical_fin->list = critical_fin_list;
3042 sgen_workers_enqueue_job (job_scan_finalizer_entries, sfejd_critical_fin);
3044 if (scan_mod_union) {
3045 g_assert (finish_up_concurrent_mark);
3047 /* Mod union card table */
3048 sgen_workers_enqueue_job (job_scan_major_mod_union_cardtable, NULL);
3049 sgen_workers_enqueue_job (job_scan_los_mod_union_cardtable, NULL);
3053 time_major_scan_finalized += TV_ELAPSED (btv, atv);
3054 SGEN_LOG (2, "Root scan: %d usecs", TV_ELAPSED (btv, atv));
3057 time_major_scan_big_objects += TV_ELAPSED (atv, btv);
3059 if (concurrent_collection_in_progress) {
3060 /* prepare the pin queue for the next collection */
3061 sgen_finish_pinning ();
3063 sgen_pin_stats_reset ();
3065 if (do_concurrent_checks)
3066 check_nursery_is_clean ();
3071 major_start_collection (gboolean concurrent, int *old_next_pin_slot)
3073 MONO_GC_BEGIN (GENERATION_OLD);
3074 binary_protocol_collection_begin (stat_major_gcs, GENERATION_OLD);
3076 current_collection_generation = GENERATION_OLD;
3077 #ifndef DISABLE_PERFCOUNTERS
3078 mono_perfcounters->gc_collections1++;
3081 g_assert (sgen_section_gray_queue_is_empty (sgen_workers_get_distribute_section_gray_queue ()));
3084 g_assert (major_collector.is_concurrent);
3085 concurrent_collection_in_progress = TRUE;
3087 sgen_cement_concurrent_start ();
3089 current_object_ops = major_collector.major_concurrent_ops;
3091 current_object_ops = major_collector.major_ops;
3094 reset_pinned_from_failed_allocation ();
3096 sgen_memgov_major_collection_start ();
3098 //count_ref_nonref_objs ();
3099 //consistency_check ();
3101 check_scan_starts ();
3104 SGEN_LOG (1, "Start major collection %d", stat_major_gcs);
3106 gc_stats.major_gc_count ++;
3108 if (major_collector.start_major_collection)
3109 major_collector.start_major_collection ();
3111 major_copy_or_mark_from_roots (old_next_pin_slot, FALSE, FALSE);
3115 wait_for_workers_to_finish (void)
3117 while (!sgen_workers_all_done ())
3124 if (concurrent_collection_in_progress || major_collector.is_parallel) {
3125 gray_queue_redirect (&gray_queue);
3126 sgen_workers_join ();
3129 g_assert (sgen_gray_object_queue_is_empty (&gray_queue));
3131 #ifdef SGEN_DEBUG_INTERNAL_ALLOC
3132 main_gc_thread = NULL;
3137 major_finish_collection (const char *reason, int old_next_pin_slot, gboolean scan_mod_union)
3139 LOSObject *bigobj, *prevbo;
3145 if (concurrent_collection_in_progress || major_collector.is_parallel)
3148 if (concurrent_collection_in_progress) {
3149 current_object_ops = major_collector.major_concurrent_ops;
3151 major_copy_or_mark_from_roots (NULL, TRUE, scan_mod_union);
3154 g_assert (sgen_gray_object_queue_is_empty (&gray_queue));
3156 if (do_concurrent_checks)
3157 check_nursery_is_clean ();
3159 current_object_ops = major_collector.major_ops;
3163 * The workers have stopped so we need to finish gray queue
3164 * work that might result from finalization in the main GC
3165 * thread. Redirection must therefore be turned off.
3167 sgen_gray_object_queue_disable_alloc_prepare (&gray_queue);
3168 g_assert (sgen_section_gray_queue_is_empty (sgen_workers_get_distribute_section_gray_queue ()));
3170 /* all the objects in the heap */
3171 finish_gray_stack (GENERATION_OLD, &gray_queue);
3173 time_major_finish_gray_stack += TV_ELAPSED (btv, atv);
3176 * The (single-threaded) finalization code might have done
3177 * some copying/marking so we can only reset the GC thread's
3178 * worker data here instead of earlier when we joined the
3181 sgen_workers_reset_data ();
3183 if (objects_pinned) {
3184 g_assert (!concurrent_collection_in_progress);
3186 /*This is slow, but we just OOM'd*/
3187 sgen_pin_queue_clear_discarded_entries (nursery_section, old_next_pin_slot);
3188 sgen_optimize_pin_queue (0);
3189 sgen_find_section_pin_queue_start_end (nursery_section);
3193 reset_heap_boundaries ();
3194 sgen_update_heap_boundaries ((mword)sgen_get_nursery_start (), (mword)sgen_get_nursery_end ());
3196 if (check_mark_bits_after_major_collection)
3197 sgen_check_major_heap_marked ();
3199 MONO_GC_SWEEP_BEGIN (GENERATION_OLD, !major_collector.sweeps_lazily);
3201 /* sweep the big objects list */
3203 for (bigobj = los_object_list; bigobj;) {
3204 g_assert (!object_is_pinned (bigobj->data));
3205 if (sgen_los_object_is_pinned (bigobj->data)) {
3206 sgen_los_unpin_object (bigobj->data);
3207 sgen_update_heap_boundaries ((mword)bigobj->data, (mword)bigobj->data + sgen_los_object_size (bigobj));
3210 /* not referenced anywhere, so we can free it */
3212 prevbo->next = bigobj->next;
3214 los_object_list = bigobj->next;
3216 bigobj = bigobj->next;
3217 sgen_los_free_object (to_free);
3221 bigobj = bigobj->next;
3225 time_major_free_bigobjs += TV_ELAPSED (atv, btv);
3230 time_major_los_sweep += TV_ELAPSED (btv, atv);
3232 major_collector.sweep ();
3234 MONO_GC_SWEEP_END (GENERATION_OLD, !major_collector.sweeps_lazily);
3237 time_major_sweep += TV_ELAPSED (atv, btv);
3239 if (!concurrent_collection_in_progress) {
3240 /* walk the pin_queue, build up the fragment list of free memory, unmark
3241 * pinned objects as we go, memzero() the empty fragments so they are ready for the
3244 if (!sgen_build_nursery_fragments (nursery_section, nursery_section->pin_queue_start, nursery_section->pin_queue_num_entries, NULL))
3247 /* prepare the pin queue for the next collection */
3248 sgen_finish_pinning ();
3250 /* Clear TLABs for all threads */
3251 sgen_clear_tlabs ();
3253 sgen_pin_stats_reset ();
3256 if (concurrent_collection_in_progress)
3257 sgen_cement_concurrent_finish ();
3258 sgen_cement_clear_below_threshold ();
3261 time_major_fragment_creation += TV_ELAPSED (btv, atv);
3264 dump_heap ("major", stat_major_gcs - 1, reason);
3266 if (fin_ready_list || critical_fin_list) {
3267 SGEN_LOG (4, "Finalizer-thread wakeup: ready %d", num_ready_finalizers);
3268 mono_gc_finalize_notify ();
3271 g_assert (sgen_gray_object_queue_is_empty (&gray_queue));
3273 sgen_memgov_major_collection_end ();
3274 current_collection_generation = -1;
3276 major_collector.finish_major_collection ();
3278 g_assert (sgen_section_gray_queue_is_empty (sgen_workers_get_distribute_section_gray_queue ()));
3280 if (concurrent_collection_in_progress)
3281 concurrent_collection_in_progress = FALSE;
3283 check_scan_starts ();
3285 binary_protocol_flush_buffers (FALSE);
3287 //consistency_check ();
3289 MONO_GC_END (GENERATION_OLD);
3290 binary_protocol_collection_end (stat_major_gcs - 1, GENERATION_OLD);
3294 major_do_collection (const char *reason)
3296 TV_DECLARE (all_atv);
3297 TV_DECLARE (all_btv);
3298 int old_next_pin_slot;
3300 if (disable_major_collections)
3303 if (major_collector.get_and_reset_num_major_objects_marked) {
3304 long long num_marked = major_collector.get_and_reset_num_major_objects_marked ();
3305 g_assert (!num_marked);
3308 /* world must be stopped already */
3309 TV_GETTIME (all_atv);
3311 major_start_collection (FALSE, &old_next_pin_slot);
3312 major_finish_collection (reason, old_next_pin_slot, FALSE);
3314 TV_GETTIME (all_btv);
3315 gc_stats.major_gc_time_usecs += TV_ELAPSED (all_atv, all_btv);
3317 /* FIXME: also report this to the user, preferably in gc-end. */
3318 if (major_collector.get_and_reset_num_major_objects_marked)
3319 major_collector.get_and_reset_num_major_objects_marked ();
3321 return bytes_pinned_from_failed_allocation > 0;
3325 major_start_concurrent_collection (const char *reason)
3327 long long num_objects_marked;
3329 if (disable_major_collections)
3332 num_objects_marked = major_collector.get_and_reset_num_major_objects_marked ();
3333 g_assert (num_objects_marked == 0);
3335 MONO_GC_CONCURRENT_START_BEGIN (GENERATION_OLD);
3337 // FIXME: store reason and pass it when finishing
3338 major_start_collection (TRUE, NULL);
3340 gray_queue_redirect (&gray_queue);
3341 sgen_workers_wait_for_jobs ();
3343 num_objects_marked = major_collector.get_and_reset_num_major_objects_marked ();
3344 MONO_GC_CONCURRENT_START_END (GENERATION_OLD, num_objects_marked);
3346 current_collection_generation = -1;
3350 major_update_or_finish_concurrent_collection (gboolean force_finish)
3352 SgenGrayQueue unpin_queue;
3353 memset (&unpin_queue, 0, sizeof (unpin_queue));
3355 MONO_GC_CONCURRENT_UPDATE_FINISH_BEGIN (GENERATION_OLD, major_collector.get_and_reset_num_major_objects_marked ());
3357 g_assert (sgen_gray_object_queue_is_empty (&gray_queue));
3359 if (!force_finish && !sgen_workers_all_done ()) {
3360 major_collector.update_cardtable_mod_union ();
3361 sgen_los_update_cardtable_mod_union ();
3363 MONO_GC_CONCURRENT_UPDATE_END (GENERATION_OLD, major_collector.get_and_reset_num_major_objects_marked ());
3368 * The major collector can add global remsets which are processed in the finishing
3369 * nursery collection, below. That implies that the workers must have finished
3370 * marking before the nursery collection is allowed to run, otherwise we might miss
3373 wait_for_workers_to_finish ();
3375 major_collector.update_cardtable_mod_union ();
3376 sgen_los_update_cardtable_mod_union ();
3378 collect_nursery (&unpin_queue, TRUE);
3380 if (mod_union_consistency_check)
3381 sgen_check_mod_union_consistency ();
3383 current_collection_generation = GENERATION_OLD;
3384 major_finish_collection ("finishing", -1, TRUE);
3386 if (whole_heap_check_before_collection)
3387 sgen_check_whole_heap (FALSE);
3389 unpin_objects_from_queue (&unpin_queue);
3390 sgen_gray_object_queue_deinit (&unpin_queue);
3392 MONO_GC_CONCURRENT_FINISH_END (GENERATION_OLD, major_collector.get_and_reset_num_major_objects_marked ());
3394 current_collection_generation = -1;
3400 * Ensure an allocation request for @size will succeed by freeing enough memory.
3402 * LOCKING: The GC lock MUST be held.
3405 sgen_ensure_free_space (size_t size)
3407 int generation_to_collect = -1;
3408 const char *reason = NULL;
3411 if (size > SGEN_MAX_SMALL_OBJ_SIZE) {
3412 if (sgen_need_major_collection (size)) {
3413 reason = "LOS overflow";
3414 generation_to_collect = GENERATION_OLD;
3417 if (degraded_mode) {
3418 if (sgen_need_major_collection (size)) {
3419 reason = "Degraded mode overflow";
3420 generation_to_collect = GENERATION_OLD;
3422 } else if (sgen_need_major_collection (size)) {
3423 reason = "Minor allowance";
3424 generation_to_collect = GENERATION_OLD;
3426 generation_to_collect = GENERATION_NURSERY;
3427 reason = "Nursery full";
3431 if (generation_to_collect == -1) {
3432 if (concurrent_collection_in_progress && sgen_workers_all_done ()) {
3433 generation_to_collect = GENERATION_OLD;
3434 reason = "Finish concurrent collection";
3438 if (generation_to_collect == -1)
3440 sgen_perform_collection (size, generation_to_collect, reason, FALSE);
3444 * LOCKING: Assumes the GC lock is held.
3447 sgen_perform_collection (size_t requested_size, int generation_to_collect, const char *reason, gboolean wait_to_finish)
3449 TV_DECLARE (gc_end);
3450 GGTimingInfo infos [2];
3451 int overflow_generation_to_collect = -1;
3452 int oldest_generation_collected = generation_to_collect;
3453 const char *overflow_reason = NULL;
3455 MONO_GC_REQUESTED (generation_to_collect, requested_size, wait_to_finish ? 1 : 0);
3457 binary_protocol_collection_force (generation_to_collect);
3459 g_assert (generation_to_collect == GENERATION_NURSERY || generation_to_collect == GENERATION_OLD);
3461 memset (infos, 0, sizeof (infos));
3462 mono_profiler_gc_event (MONO_GC_EVENT_START, generation_to_collect);
3464 infos [0].generation = generation_to_collect;
3465 infos [0].reason = reason;
3466 infos [0].is_overflow = FALSE;
3467 TV_GETTIME (infos [0].total_time);
3468 infos [1].generation = -1;
3470 sgen_stop_world (generation_to_collect);
3472 if (concurrent_collection_in_progress) {
3473 if (major_update_or_finish_concurrent_collection (wait_to_finish && generation_to_collect == GENERATION_OLD)) {
3474 oldest_generation_collected = GENERATION_OLD;
3477 if (generation_to_collect == GENERATION_OLD)
3480 if (generation_to_collect == GENERATION_OLD &&
3481 allow_synchronous_major &&
3482 major_collector.want_synchronous_collection &&
3483 *major_collector.want_synchronous_collection) {
3484 wait_to_finish = TRUE;
3488 //FIXME extract overflow reason
3489 if (generation_to_collect == GENERATION_NURSERY) {
3490 if (collect_nursery (NULL, FALSE)) {
3491 overflow_generation_to_collect = GENERATION_OLD;
3492 overflow_reason = "Minor overflow";
3495 if (major_collector.is_concurrent) {
3496 g_assert (!concurrent_collection_in_progress);
3497 if (!wait_to_finish)
3498 collect_nursery (NULL, FALSE);
3501 if (major_collector.is_concurrent && !wait_to_finish) {
3502 major_start_concurrent_collection (reason);
3503 // FIXME: set infos[0] properly
3506 if (major_do_collection (reason)) {
3507 overflow_generation_to_collect = GENERATION_NURSERY;
3508 overflow_reason = "Excessive pinning";
3513 TV_GETTIME (gc_end);
3514 infos [0].total_time = SGEN_TV_ELAPSED (infos [0].total_time, gc_end);
3517 if (!major_collector.is_concurrent && overflow_generation_to_collect != -1) {
3518 mono_profiler_gc_event (MONO_GC_EVENT_START, overflow_generation_to_collect);
3519 infos [1].generation = overflow_generation_to_collect;
3520 infos [1].reason = overflow_reason;
3521 infos [1].is_overflow = TRUE;
3522 infos [1].total_time = gc_end;
3524 if (overflow_generation_to_collect == GENERATION_NURSERY)
3525 collect_nursery (NULL, FALSE);
3527 major_do_collection (overflow_reason);
3529 TV_GETTIME (gc_end);
3530 infos [1].total_time = SGEN_TV_ELAPSED (infos [1].total_time, gc_end);
3532 /* keep events symmetric */
3533 mono_profiler_gc_event (MONO_GC_EVENT_END, overflow_generation_to_collect);
3535 oldest_generation_collected = MAX (oldest_generation_collected, overflow_generation_to_collect);
3538 SGEN_LOG (2, "Heap size: %lu, LOS size: %lu", (unsigned long)mono_gc_get_heap_size (), (unsigned long)los_memory_usage);
3540 /* this also sets the proper pointers for the next allocation */
3541 if (generation_to_collect == GENERATION_NURSERY && !sgen_can_alloc_size (requested_size)) {
3542 /* TypeBuilder and MonoMethod are killing mcs with fragmentation */
3543 SGEN_LOG (1, "nursery collection didn't find enough room for %zd alloc (%d pinned)", requested_size, sgen_get_pinned_count ());
3544 sgen_dump_pin_queue ();
3549 g_assert (sgen_gray_object_queue_is_empty (&gray_queue));
3551 sgen_restart_world (oldest_generation_collected, infos);
3553 mono_profiler_gc_event (MONO_GC_EVENT_END, generation_to_collect);
3557 * ######################################################################
3558 * ######## Memory allocation from the OS
3559 * ######################################################################
3560 * This section of code deals with getting memory from the OS and
3561 * allocating memory for GC-internal data structures.
3562 * Internal memory can be handled with a freelist for small objects.
3568 G_GNUC_UNUSED static void
3569 report_internal_mem_usage (void)
3571 printf ("Internal memory usage:\n");
3572 sgen_report_internal_mem_usage ();
3573 printf ("Pinned memory usage:\n");
3574 major_collector.report_pinned_memory_usage ();
3578 * ######################################################################
3579 * ######## Finalization support
3580 * ######################################################################
3583 static inline gboolean
3584 sgen_major_is_object_alive (void *object)
3588 /* Oldgen objects can be pinned and forwarded too */
3589 if (SGEN_OBJECT_IS_PINNED (object) || SGEN_OBJECT_IS_FORWARDED (object))
3593 * FIXME: major_collector.is_object_live() also calculates the
3594 * size. Avoid the double calculation.
3596 objsize = SGEN_ALIGN_UP (sgen_safe_object_get_size ((MonoObject*)object));
3597 if (objsize > SGEN_MAX_SMALL_OBJ_SIZE)
3598 return sgen_los_object_is_pinned (object);
3600 return major_collector.is_object_live (object);
3604 * If the object has been forwarded it means it's still referenced from a root.
3605 * If it is pinned it's still alive as well.
3606 * A LOS object is only alive if we have pinned it.
3607 * Return TRUE if @obj is ready to be finalized.
3609 static inline gboolean
3610 sgen_is_object_alive (void *object)
3612 if (ptr_in_nursery (object))
3613 return sgen_nursery_is_object_alive (object);
3615 return sgen_major_is_object_alive (object);
3619 * This function returns true if @object is either alive or it belongs to the old gen
3620 * and we're currently doing a minor collection.
3623 sgen_is_object_alive_for_current_gen (char *object)
3625 if (ptr_in_nursery (object))
3626 return sgen_nursery_is_object_alive (object);
3628 if (current_collection_generation == GENERATION_NURSERY)
3631 return sgen_major_is_object_alive (object);
3635 * This function returns true if @object is either alive and belongs to the
3636 * current collection - major collections are full heap, so old gen objects
3637 * are never alive during a minor collection.
3640 sgen_is_object_alive_and_on_current_collection (char *object)
3642 if (ptr_in_nursery (object))
3643 return sgen_nursery_is_object_alive (object);
3645 if (current_collection_generation == GENERATION_NURSERY)
3648 return sgen_major_is_object_alive (object);
3653 sgen_gc_is_object_ready_for_finalization (void *object)
3655 return !sgen_is_object_alive (object);
3659 has_critical_finalizer (MonoObject *obj)
3663 if (!mono_defaults.critical_finalizer_object)
3666 class = ((MonoVTable*)LOAD_VTABLE (obj))->klass;
3668 return mono_class_has_parent_fast (class, mono_defaults.critical_finalizer_object);
3672 sgen_queue_finalization_entry (MonoObject *obj)
3674 FinalizeReadyEntry *entry = sgen_alloc_internal (INTERNAL_MEM_FINALIZE_READY_ENTRY);
3675 gboolean critical = has_critical_finalizer (obj);
3676 entry->object = obj;
3678 entry->next = critical_fin_list;
3679 critical_fin_list = entry;
3681 entry->next = fin_ready_list;
3682 fin_ready_list = entry;
3685 #ifdef ENABLE_DTRACE
3686 if (G_UNLIKELY (MONO_GC_FINALIZE_ENQUEUE_ENABLED ())) {
3687 int gen = sgen_ptr_in_nursery (obj) ? GENERATION_NURSERY : GENERATION_OLD;
3688 MonoVTable *vt = (MonoVTable*)LOAD_VTABLE (obj);
3689 MONO_GC_FINALIZE_ENQUEUE ((mword)obj, sgen_safe_object_get_size (obj),
3690 vt->klass->name_space, vt->klass->name, gen, critical);
3696 sgen_object_is_live (void *obj)
3698 return sgen_is_object_alive_and_on_current_collection (obj);
3701 /* LOCKING: requires that the GC lock is held */
3703 null_ephemerons_for_domain (MonoDomain *domain)
3705 EphemeronLinkNode *current = ephemeron_list, *prev = NULL;
3708 MonoObject *object = (MonoObject*)current->array;
3710 if (object && !object->vtable) {
3711 EphemeronLinkNode *tmp = current;
3714 prev->next = current->next;
3716 ephemeron_list = current->next;
3718 current = current->next;
3719 sgen_free_internal (tmp, INTERNAL_MEM_EPHEMERON_LINK);
3722 current = current->next;
3727 /* LOCKING: requires that the GC lock is held */
3729 clear_unreachable_ephemerons (ScanCopyContext ctx)
3731 CopyOrMarkObjectFunc copy_func = ctx.copy_func;
3732 GrayQueue *queue = ctx.queue;
3733 EphemeronLinkNode *current = ephemeron_list, *prev = NULL;
3735 Ephemeron *cur, *array_end;
3739 char *object = current->array;
3741 if (!sgen_is_object_alive_for_current_gen (object)) {
3742 EphemeronLinkNode *tmp = current;
3744 SGEN_LOG (5, "Dead Ephemeron array at %p", object);
3747 prev->next = current->next;
3749 ephemeron_list = current->next;
3751 current = current->next;
3752 sgen_free_internal (tmp, INTERNAL_MEM_EPHEMERON_LINK);
3757 copy_func ((void**)&object, queue);
3758 current->array = object;
3760 SGEN_LOG (5, "Clearing unreachable entries for ephemeron array at %p", object);
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 = (char*)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 cur->key = tombstone;
3784 current = current->next;
3789 LOCKING: requires that the GC lock is held
3791 Limitations: We scan all ephemerons on every collection since the current design doesn't allow for a simple nursery/mature split.
3794 mark_ephemerons_in_range (ScanCopyContext ctx)
3796 CopyOrMarkObjectFunc copy_func = ctx.copy_func;
3797 GrayQueue *queue = ctx.queue;
3798 int nothing_marked = 1;
3799 EphemeronLinkNode *current = ephemeron_list;
3801 Ephemeron *cur, *array_end;
3804 for (current = ephemeron_list; current; current = current->next) {
3805 char *object = current->array;
3806 SGEN_LOG (5, "Ephemeron array at %p", object);
3808 /*It has to be alive*/
3809 if (!sgen_is_object_alive_for_current_gen (object)) {
3810 SGEN_LOG (5, "\tnot reachable");
3814 copy_func ((void**)&object, queue);
3816 array = (MonoArray*)object;
3817 cur = mono_array_addr (array, Ephemeron, 0);
3818 array_end = cur + mono_array_length_fast (array);
3819 tombstone = (char*)((MonoVTable*)LOAD_VTABLE (object))->domain->ephemeron_tombstone;
3821 for (; cur < array_end; ++cur) {
3822 char *key = cur->key;
3824 if (!key || key == tombstone)
3827 SGEN_LOG (5, "[%td] key %p (%s) value %p (%s)", cur - mono_array_addr (array, Ephemeron, 0),
3828 key, sgen_is_object_alive_for_current_gen (key) ? "reachable" : "unreachable",
3829 cur->value, cur->value && sgen_is_object_alive_for_current_gen (cur->value) ? "reachable" : "unreachable");
3831 if (sgen_is_object_alive_for_current_gen (key)) {
3832 char *value = cur->value;
3834 copy_func ((void**)&cur->key, queue);
3836 if (!sgen_is_object_alive_for_current_gen (value))
3838 copy_func ((void**)&cur->value, queue);
3844 SGEN_LOG (5, "Ephemeron run finished. Is it done %d", nothing_marked);
3845 return nothing_marked;
3849 mono_gc_invoke_finalizers (void)
3851 FinalizeReadyEntry *entry = NULL;
3852 gboolean entry_is_critical = FALSE;
3855 /* FIXME: batch to reduce lock contention */
3856 while (fin_ready_list || critical_fin_list) {
3860 FinalizeReadyEntry **list = entry_is_critical ? &critical_fin_list : &fin_ready_list;
3862 /* We have finalized entry in the last
3863 interation, now we need to remove it from
3866 *list = entry->next;
3868 FinalizeReadyEntry *e = *list;
3869 while (e->next != entry)
3871 e->next = entry->next;
3873 sgen_free_internal (entry, INTERNAL_MEM_FINALIZE_READY_ENTRY);
3877 /* Now look for the first non-null entry. */
3878 for (entry = fin_ready_list; entry && !entry->object; entry = entry->next)
3881 entry_is_critical = FALSE;
3883 entry_is_critical = TRUE;
3884 for (entry = critical_fin_list; entry && !entry->object; entry = entry->next)
3889 g_assert (entry->object);
3890 num_ready_finalizers--;
3891 obj = entry->object;
3892 entry->object = NULL;
3893 SGEN_LOG (7, "Finalizing object %p (%s)", obj, safe_name (obj));
3901 g_assert (entry->object == NULL);
3903 /* the object is on the stack so it is pinned */
3904 /*g_print ("Calling finalizer for object: %p (%s)\n", entry->object, safe_name (entry->object));*/
3905 mono_gc_run_finalize (obj, NULL);
3912 mono_gc_pending_finalizers (void)
3914 return fin_ready_list || critical_fin_list;
3918 * ######################################################################
3919 * ######## registered roots support
3920 * ######################################################################
3924 * We do not coalesce roots.
3927 mono_gc_register_root_inner (char *start, size_t size, void *descr, int root_type)
3929 RootRecord new_root;
3932 for (i = 0; i < ROOT_TYPE_NUM; ++i) {
3933 RootRecord *root = sgen_hash_table_lookup (&roots_hash [i], start);
3934 /* we allow changing the size and the descriptor (for thread statics etc) */
3936 size_t old_size = root->end_root - start;
3937 root->end_root = start + size;
3938 g_assert (((root->root_desc != 0) && (descr != NULL)) ||
3939 ((root->root_desc == 0) && (descr == NULL)));
3940 root->root_desc = (mword)descr;
3942 roots_size -= old_size;
3948 new_root.end_root = start + size;
3949 new_root.root_desc = (mword)descr;
3951 sgen_hash_table_replace (&roots_hash [root_type], start, &new_root, NULL);
3954 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);
3961 mono_gc_register_root (char *start, size_t size, void *descr)
3963 return mono_gc_register_root_inner (start, size, descr, descr ? ROOT_TYPE_NORMAL : ROOT_TYPE_PINNED);
3967 mono_gc_register_root_wbarrier (char *start, size_t size, void *descr)
3969 return mono_gc_register_root_inner (start, size, descr, ROOT_TYPE_WBARRIER);
3973 mono_gc_deregister_root (char* addr)
3979 for (root_type = 0; root_type < ROOT_TYPE_NUM; ++root_type) {
3980 if (sgen_hash_table_remove (&roots_hash [root_type], addr, &root))
3981 roots_size -= (root.end_root - addr);
3987 * ######################################################################
3988 * ######## Thread handling (stop/start code)
3989 * ######################################################################
3992 unsigned int sgen_global_stop_count = 0;
3995 sgen_get_current_collection_generation (void)
3997 return current_collection_generation;
4001 mono_gc_set_gc_callbacks (MonoGCCallbacks *callbacks)
4003 gc_callbacks = *callbacks;
4007 mono_gc_get_gc_callbacks ()
4009 return &gc_callbacks;
4012 /* Variables holding start/end nursery so it won't have to be passed at every call */
4013 static void *scan_area_arg_start, *scan_area_arg_end;
4016 mono_gc_conservatively_scan_area (void *start, void *end)
4018 conservatively_pin_objects_from (start, end, scan_area_arg_start, scan_area_arg_end, PIN_TYPE_STACK);
4022 mono_gc_scan_object (void *obj)
4024 UserCopyOrMarkData *data = mono_native_tls_get_value (user_copy_or_mark_key);
4025 current_object_ops.copy_or_mark_object (&obj, data->queue);
4030 * Mark from thread stacks and registers.
4033 scan_thread_data (void *start_nursery, void *end_nursery, gboolean precise, GrayQueue *queue)
4035 SgenThreadInfo *info;
4037 scan_area_arg_start = start_nursery;
4038 scan_area_arg_end = end_nursery;
4040 FOREACH_THREAD (info) {
4042 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);
4045 if (info->gc_disabled) {
4046 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);
4049 if (mono_thread_info_run_state (info) != STATE_RUNNING) {
4050 SGEN_LOG (3, "Skipping non-running thread %p, range: %p-%p, size: %td (state %d)", info, info->stack_start, info->stack_end, (char*)info->stack_end - (char*)info->stack_start, mono_thread_info_run_state (info));
4053 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 ());
4054 if (gc_callbacks.thread_mark_func && !conservative_stack_mark) {
4055 UserCopyOrMarkData data = { NULL, queue };
4056 set_user_copy_or_mark_data (&data);
4057 gc_callbacks.thread_mark_func (info->runtime_data, info->stack_start, info->stack_end, precise);
4058 set_user_copy_or_mark_data (NULL);
4059 } else if (!precise) {
4060 if (!conservative_stack_mark) {
4061 fprintf (stderr, "Precise stack mark not supported - disabling.\n");
4062 conservative_stack_mark = TRUE;
4064 conservatively_pin_objects_from (info->stack_start, info->stack_end, start_nursery, end_nursery, PIN_TYPE_STACK);
4069 conservatively_pin_objects_from ((void**)&info->ctx, (void**)&info->ctx + ARCH_NUM_REGS,
4070 start_nursery, end_nursery, PIN_TYPE_STACK);
4072 conservatively_pin_objects_from ((void**)&info->regs, (void**)&info->regs + ARCH_NUM_REGS,
4073 start_nursery, end_nursery, PIN_TYPE_STACK);
4076 } END_FOREACH_THREAD
4080 ptr_on_stack (void *ptr)
4082 gpointer stack_start = &stack_start;
4083 SgenThreadInfo *info = mono_thread_info_current ();
4085 if (ptr >= stack_start && ptr < (gpointer)info->stack_end)
4091 sgen_thread_register (SgenThreadInfo* info, void *addr)
4094 guint8 *staddr = NULL;
4096 #ifndef HAVE_KW_THREAD
4097 info->tlab_start = info->tlab_next = info->tlab_temp_end = info->tlab_real_end = NULL;
4099 g_assert (!mono_native_tls_get_value (thread_info_key));
4100 mono_native_tls_set_value (thread_info_key, info);
4102 sgen_thread_info = info;
4105 #ifdef SGEN_POSIX_STW
4106 info->stop_count = -1;
4110 info->stack_start = NULL;
4111 info->stopped_ip = NULL;
4112 info->stopped_domain = NULL;
4114 memset (&info->ctx, 0, sizeof (MonoContext));
4116 memset (&info->regs, 0, sizeof (info->regs));
4119 sgen_init_tlab_info (info);
4121 binary_protocol_thread_register ((gpointer)mono_thread_info_get_tid (info));
4123 /* On win32, stack_start_limit should be 0, since the stack can grow dynamically */
4125 mono_thread_info_get_stack_bounds (&staddr, &stsize);
4128 info->stack_start_limit = staddr;
4129 info->stack_end = staddr + stsize;
4131 gsize stack_bottom = (gsize)addr;
4132 stack_bottom += 4095;
4133 stack_bottom &= ~4095;
4134 info->stack_end = (char*)stack_bottom;
4137 #ifdef HAVE_KW_THREAD
4138 stack_end = info->stack_end;
4141 SGEN_LOG (3, "registered thread %p (%p) stack end %p", info, (gpointer)mono_thread_info_get_tid (info), info->stack_end);
4143 if (gc_callbacks.thread_attach_func)
4144 info->runtime_data = gc_callbacks.thread_attach_func ();
4149 sgen_thread_detach (SgenThreadInfo *p)
4151 /* If a delegate is passed to native code and invoked on a thread we dont
4152 * know about, the jit will register it with mono_jit_thread_attach, but
4153 * we have no way of knowing when that thread goes away. SGen has a TSD
4154 * so we assume that if the domain is still registered, we can detach
4157 if (mono_domain_get ())
4158 mono_thread_detach (mono_thread_current ());
4162 sgen_thread_unregister (SgenThreadInfo *p)
4164 MonoNativeThreadId tid;
4166 tid = mono_thread_info_get_tid (p);
4167 binary_protocol_thread_unregister ((gpointer)tid);
4168 SGEN_LOG (3, "unregister thread %p (%p)", p, (gpointer)tid);
4170 mono_threads_add_joinable_thread ((gpointer)tid);
4172 if (gc_callbacks.thread_detach_func) {
4173 gc_callbacks.thread_detach_func (p->runtime_data);
4174 p->runtime_data = NULL;
4180 sgen_thread_attach (SgenThreadInfo *info)
4183 /*this is odd, can we get attached before the gc is inited?*/
4187 if (gc_callbacks.thread_attach_func && !info->runtime_data)
4188 info->runtime_data = gc_callbacks.thread_attach_func ();
4191 mono_gc_register_thread (void *baseptr)
4193 return mono_thread_info_attach (baseptr) != NULL;
4197 * mono_gc_set_stack_end:
4199 * Set the end of the current threads stack to STACK_END. The stack space between
4200 * STACK_END and the real end of the threads stack will not be scanned during collections.
4203 mono_gc_set_stack_end (void *stack_end)
4205 SgenThreadInfo *info;
4208 info = mono_thread_info_current ();
4210 g_assert (stack_end < info->stack_end);
4211 info->stack_end = stack_end;
4216 #if USE_PTHREAD_INTERCEPT
4220 mono_gc_pthread_create (pthread_t *new_thread, const pthread_attr_t *attr, void *(*start_routine)(void *), void *arg)
4222 return pthread_create (new_thread, attr, start_routine, arg);
4226 mono_gc_pthread_join (pthread_t thread, void **retval)
4228 return pthread_join (thread, retval);
4232 mono_gc_pthread_detach (pthread_t thread)
4234 return pthread_detach (thread);
4238 mono_gc_pthread_exit (void *retval)
4240 mono_thread_info_detach ();
4241 pthread_exit (retval);
4244 #endif /* USE_PTHREAD_INTERCEPT */
4247 * ######################################################################
4248 * ######## Write barriers
4249 * ######################################################################
4253 * Note: the write barriers first do the needed GC work and then do the actual store:
4254 * this way the value is visible to the conservative GC scan after the write barrier
4255 * itself. If a GC interrupts the barrier in the middle, value will be kept alive by
4256 * the conservative scan, otherwise by the remembered set scan.
4259 mono_gc_wbarrier_set_field (MonoObject *obj, gpointer field_ptr, MonoObject* value)
4261 HEAVY_STAT (++stat_wbarrier_set_field);
4262 if (ptr_in_nursery (field_ptr)) {
4263 *(void**)field_ptr = value;
4266 SGEN_LOG (8, "Adding remset at %p", field_ptr);
4268 binary_protocol_wbarrier (field_ptr, value, value->vtable);
4270 remset.wbarrier_set_field (obj, field_ptr, value);
4274 mono_gc_wbarrier_set_arrayref (MonoArray *arr, gpointer slot_ptr, MonoObject* value)
4276 HEAVY_STAT (++stat_wbarrier_set_arrayref);
4277 if (ptr_in_nursery (slot_ptr)) {
4278 *(void**)slot_ptr = value;
4281 SGEN_LOG (8, "Adding remset at %p", slot_ptr);
4283 binary_protocol_wbarrier (slot_ptr, value, value->vtable);
4285 remset.wbarrier_set_arrayref (arr, slot_ptr, value);
4289 mono_gc_wbarrier_arrayref_copy (gpointer dest_ptr, gpointer src_ptr, int count)
4291 HEAVY_STAT (++stat_wbarrier_arrayref_copy);
4292 /*This check can be done without taking a lock since dest_ptr array is pinned*/
4293 if (ptr_in_nursery (dest_ptr) || count <= 0) {
4294 mono_gc_memmove_aligned (dest_ptr, src_ptr, count * sizeof (gpointer));
4298 #ifdef SGEN_BINARY_PROTOCOL
4301 for (i = 0; i < count; ++i) {
4302 gpointer dest = (gpointer*)dest_ptr + i;
4303 gpointer obj = *((gpointer*)src_ptr + i);
4305 binary_protocol_wbarrier (dest, obj, (gpointer)LOAD_VTABLE (obj));
4310 remset.wbarrier_arrayref_copy (dest_ptr, src_ptr, count);
4313 static char *found_obj;
4316 find_object_for_ptr_callback (char *obj, size_t size, void *user_data)
4318 char *ptr = user_data;
4320 if (ptr >= obj && ptr < obj + size) {
4321 g_assert (!found_obj);
4326 /* for use in the debugger */
4327 char* find_object_for_ptr (char *ptr);
4329 find_object_for_ptr (char *ptr)
4331 if (ptr >= nursery_section->data && ptr < nursery_section->end_data) {
4333 sgen_scan_area_with_callback (nursery_section->data, nursery_section->end_data,
4334 find_object_for_ptr_callback, ptr, TRUE);
4340 sgen_los_iterate_objects (find_object_for_ptr_callback, ptr);
4345 * Very inefficient, but this is debugging code, supposed to
4346 * be called from gdb, so we don't care.
4349 major_collector.iterate_objects (TRUE, TRUE, find_object_for_ptr_callback, ptr);
4354 mono_gc_wbarrier_generic_nostore (gpointer ptr)
4358 HEAVY_STAT (++stat_wbarrier_generic_store);
4360 #ifdef XDOMAIN_CHECKS_IN_WBARRIER
4361 /* FIXME: ptr_in_heap must be called with the GC lock held */
4362 if (xdomain_checks && *(MonoObject**)ptr && ptr_in_heap (ptr)) {
4363 char *start = find_object_for_ptr (ptr);
4364 MonoObject *value = *(MonoObject**)ptr;
4368 MonoObject *obj = (MonoObject*)start;
4369 if (obj->vtable->domain != value->vtable->domain)
4370 g_assert (is_xdomain_ref_allowed (ptr, start, obj->vtable->domain));
4376 obj = *(gpointer*)ptr;
4378 binary_protocol_wbarrier (ptr, obj, (gpointer)LOAD_VTABLE (obj));
4380 if (ptr_in_nursery (ptr) || ptr_on_stack (ptr)) {
4381 SGEN_LOG (8, "Skipping remset at %p", ptr);
4386 * We need to record old->old pointer locations for the
4387 * concurrent collector.
4389 if (!ptr_in_nursery (obj) && !concurrent_collection_in_progress) {
4390 SGEN_LOG (8, "Skipping remset at %p", ptr);
4394 SGEN_LOG (8, "Adding remset at %p", ptr);
4396 remset.wbarrier_generic_nostore (ptr);
4400 mono_gc_wbarrier_generic_store (gpointer ptr, MonoObject* value)
4402 SGEN_LOG (8, "Wbarrier store at %p to %p (%s)", ptr, value, value ? safe_name (value) : "null");
4403 *(void**)ptr = value;
4404 if (ptr_in_nursery (value))
4405 mono_gc_wbarrier_generic_nostore (ptr);
4406 sgen_dummy_use (value);
4409 /* Same as mono_gc_wbarrier_generic_store () but performs the store
4410 * as an atomic operation with release semantics.
4413 mono_gc_wbarrier_generic_store_atomic (gpointer ptr, MonoObject *value)
4415 HEAVY_STAT (++stat_wbarrier_generic_store_atomic);
4417 SGEN_LOG (8, "Wbarrier atomic store at %p to %p (%s)", ptr, value, value ? safe_name (value) : "null");
4419 InterlockedWritePointer (ptr, value);
4421 if (ptr_in_nursery (value))
4422 mono_gc_wbarrier_generic_nostore (ptr);
4424 sgen_dummy_use (value);
4427 void mono_gc_wbarrier_value_copy_bitmap (gpointer _dest, gpointer _src, int size, unsigned bitmap)
4429 mword *dest = _dest;
4434 mono_gc_wbarrier_generic_store (dest, (MonoObject*)*src);
4439 size -= SIZEOF_VOID_P;
4444 #ifdef SGEN_BINARY_PROTOCOL
4446 #define HANDLE_PTR(ptr,obj) do { \
4447 gpointer o = *(gpointer*)(ptr); \
4449 gpointer d = ((char*)dest) + ((char*)(ptr) - (char*)(obj)); \
4450 binary_protocol_wbarrier (d, o, (gpointer) LOAD_VTABLE (o)); \
4455 scan_object_for_binary_protocol_copy_wbarrier (gpointer dest, char *start, mword desc)
4457 #define SCAN_OBJECT_NOVTABLE
4458 #include "sgen-scan-object.h"
4463 mono_gc_wbarrier_value_copy (gpointer dest, gpointer src, int count, MonoClass *klass)
4465 HEAVY_STAT (++stat_wbarrier_value_copy);
4466 g_assert (klass->valuetype);
4468 SGEN_LOG (8, "Adding value remset at %p, count %d, descr %p for class %s (%p)", dest, count, klass->gc_descr, klass->name, klass);
4470 if (ptr_in_nursery (dest) || ptr_on_stack (dest) || !SGEN_CLASS_HAS_REFERENCES (klass)) {
4471 size_t element_size = mono_class_value_size (klass, NULL);
4472 size_t size = count * element_size;
4473 mono_gc_memmove_atomic (dest, src, size);
4477 #ifdef SGEN_BINARY_PROTOCOL
4479 size_t element_size = mono_class_value_size (klass, NULL);
4481 for (i = 0; i < count; ++i) {
4482 scan_object_for_binary_protocol_copy_wbarrier ((char*)dest + i * element_size,
4483 (char*)src + i * element_size - sizeof (MonoObject),
4484 (mword) klass->gc_descr);
4489 remset.wbarrier_value_copy (dest, src, count, klass);
4493 * mono_gc_wbarrier_object_copy:
4495 * Write barrier to call when obj is the result of a clone or copy of an object.
4498 mono_gc_wbarrier_object_copy (MonoObject* obj, MonoObject *src)
4502 HEAVY_STAT (++stat_wbarrier_object_copy);
4504 if (ptr_in_nursery (obj) || ptr_on_stack (obj)) {
4505 size = mono_object_class (obj)->instance_size;
4506 mono_gc_memmove_aligned ((char*)obj + sizeof (MonoObject), (char*)src + sizeof (MonoObject),
4507 size - sizeof (MonoObject));
4511 #ifdef SGEN_BINARY_PROTOCOL
4512 scan_object_for_binary_protocol_copy_wbarrier (obj, (char*)src, (mword) src->vtable->gc_descr);
4515 remset.wbarrier_object_copy (obj, src);
4520 * ######################################################################
4521 * ######## Other mono public interface functions.
4522 * ######################################################################
4525 #define REFS_SIZE 128
4528 MonoGCReferences callback;
4532 MonoObject *refs [REFS_SIZE];
4533 uintptr_t offsets [REFS_SIZE];
4537 #define HANDLE_PTR(ptr,obj) do { \
4539 if (hwi->count == REFS_SIZE) { \
4540 hwi->callback ((MonoObject*)start, mono_object_class (start), hwi->called? 0: size, hwi->count, hwi->refs, hwi->offsets, hwi->data); \
4544 hwi->offsets [hwi->count] = (char*)(ptr)-(char*)start; \
4545 hwi->refs [hwi->count++] = *(ptr); \
4550 collect_references (HeapWalkInfo *hwi, char *start, size_t size)
4552 #include "sgen-scan-object.h"
4556 walk_references (char *start, size_t size, void *data)
4558 HeapWalkInfo *hwi = data;
4561 collect_references (hwi, start, size);
4562 if (hwi->count || !hwi->called)
4563 hwi->callback ((MonoObject*)start, mono_object_class (start), hwi->called? 0: size, hwi->count, hwi->refs, hwi->offsets, hwi->data);
4567 * mono_gc_walk_heap:
4568 * @flags: flags for future use
4569 * @callback: a function pointer called for each object in the heap
4570 * @data: a user data pointer that is passed to callback
4572 * This function can be used to iterate over all the live objects in the heap:
4573 * for each object, @callback is invoked, providing info about the object's
4574 * location in memory, its class, its size and the objects it references.
4575 * For each referenced object it's offset from the object address is
4576 * reported in the offsets array.
4577 * The object references may be buffered, so the callback may be invoked
4578 * multiple times for the same object: in all but the first call, the size
4579 * argument will be zero.
4580 * Note that this function can be only called in the #MONO_GC_EVENT_PRE_START_WORLD
4581 * profiler event handler.
4583 * Returns: a non-zero value if the GC doesn't support heap walking
4586 mono_gc_walk_heap (int flags, MonoGCReferences callback, void *data)
4591 hwi.callback = callback;
4594 sgen_clear_nursery_fragments ();
4595 sgen_scan_area_with_callback (nursery_section->data, nursery_section->end_data, walk_references, &hwi, FALSE);
4597 major_collector.iterate_objects (TRUE, TRUE, walk_references, &hwi);
4598 sgen_los_iterate_objects (walk_references, &hwi);
4604 mono_gc_collect (int generation)
4609 sgen_perform_collection (0, generation, "user request", TRUE);
4614 mono_gc_max_generation (void)
4620 mono_gc_collection_count (int generation)
4622 if (generation == 0)
4623 return stat_minor_gcs;
4624 return stat_major_gcs;
4628 mono_gc_get_used_size (void)
4632 tot = los_memory_usage;
4633 tot += nursery_section->next_data - nursery_section->data;
4634 tot += major_collector.get_used_size ();
4635 /* FIXME: account for pinned objects */
4641 mono_gc_get_los_limit (void)
4643 return MAX_SMALL_OBJ_SIZE;
4647 mono_gc_user_markers_supported (void)
4653 mono_object_is_alive (MonoObject* o)
4659 mono_gc_get_generation (MonoObject *obj)
4661 if (ptr_in_nursery (obj))
4667 mono_gc_enable_events (void)
4672 mono_gc_weak_link_add (void **link_addr, MonoObject *obj, gboolean track)
4674 sgen_register_disappearing_link (obj, link_addr, track, FALSE);
4678 mono_gc_weak_link_remove (void **link_addr, gboolean track)
4680 sgen_register_disappearing_link (NULL, link_addr, track, FALSE);
4684 mono_gc_weak_link_get (void **link_addr)
4686 void * volatile *link_addr_volatile;
4690 link_addr_volatile = link_addr;
4691 ptr = (void*)*link_addr_volatile;
4693 * At this point we have a hidden pointer. If the GC runs
4694 * here, it will not recognize the hidden pointer as a
4695 * reference, and if the object behind it is not referenced
4696 * elsewhere, it will be freed. Once the world is restarted
4697 * we reveal the pointer, giving us a pointer to a freed
4698 * object. To make sure we don't return it, we load the
4699 * hidden pointer again. If it's still the same, we can be
4700 * sure the object reference is valid.
4703 obj = (MonoObject*) REVEAL_POINTER (ptr);
4707 mono_memory_barrier ();
4710 * During the second bridge processing step the world is
4711 * running again. That step processes all weak links once
4712 * more to null those that refer to dead objects. Before that
4713 * is completed, those links must not be followed, so we
4714 * conservatively wait for bridge processing when any weak
4715 * link is dereferenced.
4717 if (G_UNLIKELY (bridge_processing_in_progress))
4718 mono_gc_wait_for_bridge_processing ();
4720 if ((void*)*link_addr_volatile != ptr)
4727 mono_gc_ephemeron_array_add (MonoObject *obj)
4729 EphemeronLinkNode *node;
4733 node = sgen_alloc_internal (INTERNAL_MEM_EPHEMERON_LINK);
4738 node->array = (char*)obj;
4739 node->next = ephemeron_list;
4740 ephemeron_list = node;
4742 SGEN_LOG (5, "Registered ephemeron array %p", obj);
4749 mono_gc_set_allow_synchronous_major (gboolean flag)
4751 if (!major_collector.is_concurrent)
4754 allow_synchronous_major = flag;
4759 mono_gc_invoke_with_gc_lock (MonoGCLockedCallbackFunc func, void *data)
4763 result = func (data);
4764 UNLOCK_INTERRUPTION;
4769 mono_gc_is_gc_thread (void)
4773 result = mono_thread_info_current () != NULL;
4779 is_critical_method (MonoMethod *method)
4781 return mono_runtime_is_critical_method (method) || sgen_is_critical_method (method);
4785 sgen_env_var_error (const char *env_var, const char *fallback, const char *description_format, ...)
4789 va_start (ap, description_format);
4791 fprintf (stderr, "Warning: In environment variable `%s': ", env_var);
4792 vfprintf (stderr, description_format, ap);
4794 fprintf (stderr, " - %s", fallback);
4795 fprintf (stderr, "\n");
4801 parse_double_in_interval (const char *env_var, const char *opt_name, const char *opt, double min, double max, double *result)
4804 double val = strtod (opt, &endptr);
4805 if (endptr == opt) {
4806 sgen_env_var_error (env_var, "Using default value.", "`%s` must be a number.", opt_name);
4809 else if (val < min || val > max) {
4810 sgen_env_var_error (env_var, "Using default value.", "`%s` must be between %.2f - %.2f.", opt_name, min, max);
4818 mono_gc_base_init (void)
4820 MonoThreadInfoCallbacks cb;
4823 char *major_collector_opt = NULL;
4824 char *minor_collector_opt = NULL;
4826 glong soft_limit = 0;
4830 gboolean debug_print_allowance = FALSE;
4831 double allowance_ratio = 0, save_target = 0;
4832 gboolean have_split_nursery = FALSE;
4833 gboolean cement_enabled = TRUE;
4836 result = InterlockedCompareExchange (&gc_initialized, -1, 0);
4839 /* already inited */
4842 /* being inited by another thread */
4846 /* we will init it */
4849 g_assert_not_reached ();
4851 } while (result != 0);
4853 LOCK_INIT (gc_mutex);
4855 pagesize = mono_pagesize ();
4856 gc_debug_file = stderr;
4858 cb.thread_register = sgen_thread_register;
4859 cb.thread_detach = sgen_thread_detach;
4860 cb.thread_unregister = sgen_thread_unregister;
4861 cb.thread_attach = sgen_thread_attach;
4862 cb.mono_method_is_critical = (gpointer)is_critical_method;
4864 cb.thread_exit = mono_gc_pthread_exit;
4865 cb.mono_gc_pthread_create = (gpointer)mono_gc_pthread_create;
4868 mono_threads_init (&cb, sizeof (SgenThreadInfo));
4870 LOCK_INIT (sgen_interruption_mutex);
4871 LOCK_INIT (pin_queue_mutex);
4873 init_user_copy_or_mark_key ();
4875 if ((env = g_getenv (MONO_GC_PARAMS_NAME))) {
4876 opts = g_strsplit (env, ",", -1);
4877 for (ptr = opts; *ptr; ++ptr) {
4879 if (g_str_has_prefix (opt, "major=")) {
4880 opt = strchr (opt, '=') + 1;
4881 major_collector_opt = g_strdup (opt);
4882 } else if (g_str_has_prefix (opt, "minor=")) {
4883 opt = strchr (opt, '=') + 1;
4884 minor_collector_opt = g_strdup (opt);
4892 sgen_init_internal_allocator ();
4893 sgen_init_nursery_allocator ();
4894 sgen_init_fin_weak_hash ();
4896 sgen_register_fixed_internal_mem_type (INTERNAL_MEM_SECTION, SGEN_SIZEOF_GC_MEM_SECTION);
4897 sgen_register_fixed_internal_mem_type (INTERNAL_MEM_FINALIZE_READY_ENTRY, sizeof (FinalizeReadyEntry));
4898 sgen_register_fixed_internal_mem_type (INTERNAL_MEM_GRAY_QUEUE, sizeof (GrayQueueSection));
4899 sgen_register_fixed_internal_mem_type (INTERNAL_MEM_EPHEMERON_LINK, sizeof (EphemeronLinkNode));
4901 #ifndef HAVE_KW_THREAD
4902 mono_native_tls_alloc (&thread_info_key, NULL);
4903 #if defined(__APPLE__) || defined (HOST_WIN32)
4905 * CEE_MONO_TLS requires the tls offset, not the key, so the code below only works on darwin,
4906 * where the two are the same.
4908 mono_tls_key_set_offset (TLS_KEY_SGEN_THREAD_INFO, thread_info_key);
4912 int tls_offset = -1;
4913 MONO_THREAD_VAR_OFFSET (sgen_thread_info, tls_offset);
4914 mono_tls_key_set_offset (TLS_KEY_SGEN_THREAD_INFO, tls_offset);
4919 * This needs to happen before any internal allocations because
4920 * it inits the small id which is required for hazard pointer
4925 mono_thread_info_attach (&dummy);
4927 if (!minor_collector_opt) {
4928 sgen_simple_nursery_init (&sgen_minor_collector);
4930 if (!strcmp (minor_collector_opt, "simple")) {
4932 sgen_simple_nursery_init (&sgen_minor_collector);
4933 } else if (!strcmp (minor_collector_opt, "split")) {
4934 sgen_split_nursery_init (&sgen_minor_collector);
4935 have_split_nursery = TRUE;
4937 sgen_env_var_error (MONO_GC_PARAMS_NAME, "Using `simple` instead.", "Unknown minor collector `%s'.", minor_collector_opt);
4938 goto use_simple_nursery;
4942 if (!major_collector_opt || !strcmp (major_collector_opt, "marksweep")) {
4943 use_marksweep_major:
4944 sgen_marksweep_init (&major_collector);
4945 } else if (!major_collector_opt || !strcmp (major_collector_opt, "marksweep-fixed")) {
4946 sgen_marksweep_fixed_init (&major_collector);
4947 } else if (!major_collector_opt || !strcmp (major_collector_opt, "marksweep-par")) {
4948 sgen_marksweep_par_init (&major_collector);
4949 } else if (!major_collector_opt || !strcmp (major_collector_opt, "marksweep-fixed-par")) {
4950 sgen_marksweep_fixed_par_init (&major_collector);
4951 } else if (!major_collector_opt || !strcmp (major_collector_opt, "marksweep-conc")) {
4952 sgen_marksweep_conc_init (&major_collector);
4954 sgen_env_var_error (MONO_GC_PARAMS_NAME, "Using `marksweep` instead.", "Unknown major collector `%s'.", major_collector_opt);
4955 goto use_marksweep_major;
4958 if (have_split_nursery && major_collector.is_parallel) {
4959 sgen_env_var_error (MONO_GC_PARAMS_NAME, "Disabling split minor collector.", "`minor=split` is not supported with the parallel collector yet.");
4960 have_split_nursery = FALSE;
4963 num_workers = mono_cpu_count ();
4964 g_assert (num_workers > 0);
4965 if (num_workers > 16)
4968 ///* Keep this the default for now */
4969 /* Precise marking is broken on all supported targets. Disable until fixed. */
4970 conservative_stack_mark = TRUE;
4972 sgen_nursery_size = DEFAULT_NURSERY_SIZE;
4975 gboolean usage_printed = FALSE;
4977 for (ptr = opts; *ptr; ++ptr) {
4979 if (!strcmp (opt, ""))
4981 if (g_str_has_prefix (opt, "major="))
4983 if (g_str_has_prefix (opt, "minor="))
4985 if (g_str_has_prefix (opt, "max-heap-size=")) {
4986 glong max_heap_candidate = 0;
4987 opt = strchr (opt, '=') + 1;
4988 if (*opt && mono_gc_parse_environment_string_extract_number (opt, &max_heap_candidate)) {
4989 max_heap = (max_heap_candidate + mono_pagesize () - 1) & ~(glong)(mono_pagesize () - 1);
4990 if (max_heap != max_heap_candidate)
4991 sgen_env_var_error (MONO_GC_PARAMS_NAME, "Rounding up.", "`max-heap-size` size must be a multiple of %d.", mono_pagesize ());
4993 sgen_env_var_error (MONO_GC_PARAMS_NAME, NULL, "`max-heap-size` must be an integer.");
4997 if (g_str_has_prefix (opt, "soft-heap-limit=")) {
4998 opt = strchr (opt, '=') + 1;
4999 if (*opt && mono_gc_parse_environment_string_extract_number (opt, &soft_limit)) {
5000 if (soft_limit <= 0) {
5001 sgen_env_var_error (MONO_GC_PARAMS_NAME, NULL, "`soft-heap-limit` must be positive.");
5005 sgen_env_var_error (MONO_GC_PARAMS_NAME, NULL, "`soft-heap-limit` must be an integer.");
5009 if (g_str_has_prefix (opt, "workers=")) {
5012 if (!major_collector.is_parallel) {
5013 sgen_env_var_error (MONO_GC_PARAMS_NAME, "Ignoring.", "The `workers` option can only be used for parallel collectors.");
5016 opt = strchr (opt, '=') + 1;
5017 val = strtol (opt, &endptr, 10);
5018 if (!*opt || *endptr) {
5019 sgen_env_var_error (MONO_GC_PARAMS_NAME, "Ignoring.", "Cannot parse the `workers` option value.");
5022 if (val <= 0 || val > 16) {
5023 sgen_env_var_error (MONO_GC_PARAMS_NAME, "Using default value.", "The number of `workers` must be in the range 1 to 16.");
5026 num_workers = (int)val;
5029 if (g_str_has_prefix (opt, "stack-mark=")) {
5030 opt = strchr (opt, '=') + 1;
5031 if (!strcmp (opt, "precise")) {
5032 conservative_stack_mark = FALSE;
5033 } else if (!strcmp (opt, "conservative")) {
5034 conservative_stack_mark = TRUE;
5036 sgen_env_var_error (MONO_GC_PARAMS_NAME, conservative_stack_mark ? "Using `conservative`." : "Using `precise`.",
5037 "Invalid value `%s` for `stack-mark` option, possible values are: `precise`, `conservative`.", opt);
5041 if (g_str_has_prefix (opt, "bridge=")) {
5042 opt = strchr (opt, '=') + 1;
5043 sgen_register_test_bridge_callbacks (g_strdup (opt));
5046 if (g_str_has_prefix (opt, "toggleref-test")) {
5047 sgen_register_test_toggleref_callback ();
5052 if (g_str_has_prefix (opt, "nursery-size=")) {
5054 opt = strchr (opt, '=') + 1;
5055 if (*opt && mono_gc_parse_environment_string_extract_number (opt, &val)) {
5056 #ifdef SGEN_ALIGN_NURSERY
5057 if ((val & (val - 1))) {
5058 sgen_env_var_error (MONO_GC_PARAMS_NAME, "Using default value.", "`nursery-size` must be a power of two.");
5062 if (val < SGEN_MAX_NURSERY_WASTE) {
5063 sgen_env_var_error (MONO_GC_PARAMS_NAME, "Using default value.",
5064 "`nursery-size` must be at least %d bytes.\n", SGEN_MAX_NURSERY_WASTE);
5068 sgen_nursery_size = val;
5069 sgen_nursery_bits = 0;
5070 while (1 << (++ sgen_nursery_bits) != sgen_nursery_size)
5073 sgen_nursery_size = val;
5076 sgen_env_var_error (MONO_GC_PARAMS_NAME, "Using default value.", "`nursery-size` must be an integer.");
5082 if (g_str_has_prefix (opt, "save-target-ratio=")) {
5084 opt = strchr (opt, '=') + 1;
5085 if (parse_double_in_interval (MONO_GC_PARAMS_NAME, "save-target-ratio", opt,
5086 SGEN_MIN_SAVE_TARGET_RATIO, SGEN_MAX_SAVE_TARGET_RATIO, &val)) {
5091 if (g_str_has_prefix (opt, "default-allowance-ratio=")) {
5093 opt = strchr (opt, '=') + 1;
5094 if (parse_double_in_interval (MONO_GC_PARAMS_NAME, "default-allowance-ratio", opt,
5095 SGEN_MIN_ALLOWANCE_NURSERY_SIZE_RATIO, SGEN_MIN_ALLOWANCE_NURSERY_SIZE_RATIO, &val)) {
5096 allowance_ratio = val;
5100 if (g_str_has_prefix (opt, "allow-synchronous-major=")) {
5101 if (!major_collector.is_concurrent) {
5102 sgen_env_var_error (MONO_GC_PARAMS_NAME, "Ignoring.", "`allow-synchronous-major` is only valid for the concurrent major collector.");
5106 opt = strchr (opt, '=') + 1;
5108 if (!strcmp (opt, "yes")) {
5109 allow_synchronous_major = TRUE;
5110 } else if (!strcmp (opt, "no")) {
5111 allow_synchronous_major = FALSE;
5113 sgen_env_var_error (MONO_GC_PARAMS_NAME, "Using default value.", "`allow-synchronous-major` must be either `yes' or `no'.");
5118 if (!strcmp (opt, "cementing")) {
5119 if (major_collector.is_parallel) {
5120 sgen_env_var_error (MONO_GC_PARAMS_NAME, "Ignoring.", "`cementing` is not supported for the parallel major collector.");
5123 cement_enabled = TRUE;
5126 if (!strcmp (opt, "no-cementing")) {
5127 cement_enabled = FALSE;
5131 if (major_collector.handle_gc_param && major_collector.handle_gc_param (opt))
5134 if (sgen_minor_collector.handle_gc_param && sgen_minor_collector.handle_gc_param (opt))
5137 sgen_env_var_error (MONO_GC_PARAMS_NAME, "Ignoring.", "Unknown option `%s`.", opt);
5142 fprintf (stderr, "\n%s must be a comma-delimited list of one or more of the following:\n", MONO_GC_PARAMS_NAME);
5143 fprintf (stderr, " max-heap-size=N (where N is an integer, possibly with a k, m or a g suffix)\n");
5144 fprintf (stderr, " soft-heap-limit=n (where N is an integer, possibly with a k, m or a g suffix)\n");
5145 fprintf (stderr, " nursery-size=N (where N is an integer, possibly with a k, m or a g suffix)\n");
5146 fprintf (stderr, " major=COLLECTOR (where COLLECTOR is `marksweep', `marksweep-conc', `marksweep-par', 'marksweep-fixed' or 'marksweep-fixed-par')\n");
5147 fprintf (stderr, " minor=COLLECTOR (where COLLECTOR is `simple' or `split')\n");
5148 fprintf (stderr, " wbarrier=WBARRIER (where WBARRIER is `remset' or `cardtable')\n");
5149 fprintf (stderr, " stack-mark=MARK-METHOD (where MARK-METHOD is 'precise' or 'conservative')\n");
5150 fprintf (stderr, " [no-]cementing\n");
5151 if (major_collector.is_concurrent)
5152 fprintf (stderr, " allow-synchronous-major=FLAG (where FLAG is `yes' or `no')\n");
5153 if (major_collector.print_gc_param_usage)
5154 major_collector.print_gc_param_usage ();
5155 if (sgen_minor_collector.print_gc_param_usage)
5156 sgen_minor_collector.print_gc_param_usage ();
5157 fprintf (stderr, " Experimental options:\n");
5158 fprintf (stderr, " save-target-ratio=R (where R must be between %.2f - %.2f).\n", SGEN_MIN_SAVE_TARGET_RATIO, SGEN_MAX_SAVE_TARGET_RATIO);
5159 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);
5160 fprintf (stderr, "\n");
5162 usage_printed = TRUE;
5167 if (major_collector.is_parallel) {
5168 cement_enabled = FALSE;
5169 sgen_workers_init (num_workers);
5170 } else if (major_collector.is_concurrent) {
5171 sgen_workers_init (1);
5174 if (major_collector_opt)
5175 g_free (major_collector_opt);
5177 if (minor_collector_opt)
5178 g_free (minor_collector_opt);
5182 sgen_cement_init (cement_enabled);
5184 if ((env = g_getenv (MONO_GC_DEBUG_NAME))) {
5185 gboolean usage_printed = FALSE;
5187 opts = g_strsplit (env, ",", -1);
5188 for (ptr = opts; ptr && *ptr; ptr ++) {
5190 if (!strcmp (opt, ""))
5192 if (opt [0] >= '0' && opt [0] <= '9') {
5193 gc_debug_level = atoi (opt);
5199 char *rf = g_strdup_printf ("%s.%d", opt, GetCurrentProcessId ());
5201 char *rf = g_strdup_printf ("%s.%d", opt, getpid ());
5203 gc_debug_file = fopen (rf, "wb");
5205 gc_debug_file = stderr;
5208 } else if (!strcmp (opt, "print-allowance")) {
5209 debug_print_allowance = TRUE;
5210 } else if (!strcmp (opt, "print-pinning")) {
5211 do_pin_stats = TRUE;
5212 } else if (!strcmp (opt, "verify-before-allocs")) {
5213 verify_before_allocs = 1;
5214 has_per_allocation_action = TRUE;
5215 } else if (g_str_has_prefix (opt, "verify-before-allocs=")) {
5216 char *arg = strchr (opt, '=') + 1;
5217 verify_before_allocs = atoi (arg);
5218 has_per_allocation_action = TRUE;
5219 } else if (!strcmp (opt, "collect-before-allocs")) {
5220 collect_before_allocs = 1;
5221 has_per_allocation_action = TRUE;
5222 } else if (g_str_has_prefix (opt, "collect-before-allocs=")) {
5223 char *arg = strchr (opt, '=') + 1;
5224 has_per_allocation_action = TRUE;
5225 collect_before_allocs = atoi (arg);
5226 } else if (!strcmp (opt, "verify-before-collections")) {
5227 whole_heap_check_before_collection = TRUE;
5228 } else if (!strcmp (opt, "check-at-minor-collections")) {
5229 consistency_check_at_minor_collection = TRUE;
5230 nursery_clear_policy = CLEAR_AT_GC;
5231 } else if (!strcmp (opt, "mod-union-consistency-check")) {
5232 if (!major_collector.is_concurrent) {
5233 sgen_env_var_error (MONO_GC_DEBUG_NAME, "Ignoring.", "`mod-union-consistency-check` only works with concurrent major collector.");
5236 mod_union_consistency_check = TRUE;
5237 } else if (!strcmp (opt, "check-mark-bits")) {
5238 check_mark_bits_after_major_collection = TRUE;
5239 } else if (!strcmp (opt, "check-nursery-pinned")) {
5240 check_nursery_objects_pinned = TRUE;
5241 } else if (!strcmp (opt, "xdomain-checks")) {
5242 xdomain_checks = TRUE;
5243 } else if (!strcmp (opt, "clear-at-gc")) {
5244 nursery_clear_policy = CLEAR_AT_GC;
5245 } else if (!strcmp (opt, "clear-nursery-at-gc")) {
5246 nursery_clear_policy = CLEAR_AT_GC;
5247 } else if (!strcmp (opt, "check-scan-starts")) {
5248 do_scan_starts_check = TRUE;
5249 } else if (!strcmp (opt, "verify-nursery-at-minor-gc")) {
5250 do_verify_nursery = TRUE;
5251 } else if (!strcmp (opt, "check-concurrent")) {
5252 if (!major_collector.is_concurrent) {
5253 sgen_env_var_error (MONO_GC_DEBUG_NAME, "Ignoring.", "`check-concurrent` only works with concurrent major collectors.");
5256 do_concurrent_checks = TRUE;
5257 } else if (!strcmp (opt, "dump-nursery-at-minor-gc")) {
5258 do_dump_nursery_content = TRUE;
5259 } else if (!strcmp (opt, "no-managed-allocator")) {
5260 sgen_set_use_managed_allocator (FALSE);
5261 } else if (!strcmp (opt, "disable-minor")) {
5262 disable_minor_collections = TRUE;
5263 } else if (!strcmp (opt, "disable-major")) {
5264 disable_major_collections = TRUE;
5265 } else if (g_str_has_prefix (opt, "heap-dump=")) {
5266 char *filename = strchr (opt, '=') + 1;
5267 nursery_clear_policy = CLEAR_AT_GC;
5268 heap_dump_file = fopen (filename, "w");
5269 if (heap_dump_file) {
5270 fprintf (heap_dump_file, "<sgen-dump>\n");
5271 do_pin_stats = TRUE;
5273 #ifdef SGEN_BINARY_PROTOCOL
5274 } else if (g_str_has_prefix (opt, "binary-protocol=")) {
5275 char *filename = strchr (opt, '=') + 1;
5276 binary_protocol_init (filename);
5279 sgen_env_var_error (MONO_GC_DEBUG_NAME, "Ignoring.", "Unknown option `%s`.", opt);
5284 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);
5285 fprintf (stderr, "Valid <option>s are:\n");
5286 fprintf (stderr, " collect-before-allocs[=<n>]\n");
5287 fprintf (stderr, " verify-before-allocs[=<n>]\n");
5288 fprintf (stderr, " check-at-minor-collections\n");
5289 fprintf (stderr, " check-mark-bits\n");
5290 fprintf (stderr, " check-nursery-pinned\n");
5291 fprintf (stderr, " verify-before-collections\n");
5292 fprintf (stderr, " verify-nursery-at-minor-gc\n");
5293 fprintf (stderr, " dump-nursery-at-minor-gc\n");
5294 fprintf (stderr, " disable-minor\n");
5295 fprintf (stderr, " disable-major\n");
5296 fprintf (stderr, " xdomain-checks\n");
5297 fprintf (stderr, " check-concurrent\n");
5298 fprintf (stderr, " clear-at-gc\n");
5299 fprintf (stderr, " clear-nursery-at-gc\n");
5300 fprintf (stderr, " check-scan-starts\n");
5301 fprintf (stderr, " no-managed-allocator\n");
5302 fprintf (stderr, " print-allowance\n");
5303 fprintf (stderr, " print-pinning\n");
5304 fprintf (stderr, " heap-dump=<filename>\n");
5305 #ifdef SGEN_BINARY_PROTOCOL
5306 fprintf (stderr, " binary-protocol=<filename>\n");
5308 fprintf (stderr, "\n");
5310 usage_printed = TRUE;
5316 if (major_collector.is_parallel) {
5317 if (heap_dump_file) {
5318 sgen_env_var_error (MONO_GC_DEBUG_NAME, "Disabling.", "Cannot do `heap-dump` with the parallel collector.");
5319 fclose (heap_dump_file);
5320 heap_dump_file = NULL;
5323 sgen_env_var_error (MONO_GC_DEBUG_NAME, "Disabling.", "`print-pinning` is not supported with the parallel collector.");
5324 do_pin_stats = FALSE;
5328 if (major_collector.post_param_init)
5329 major_collector.post_param_init (&major_collector);
5331 sgen_memgov_init (max_heap, soft_limit, debug_print_allowance, allowance_ratio, save_target);
5333 memset (&remset, 0, sizeof (remset));
5335 sgen_card_table_init (&remset);
5341 mono_gc_get_gc_name (void)
5346 static MonoMethod *write_barrier_method;
5349 sgen_is_critical_method (MonoMethod *method)
5351 return (method == write_barrier_method || sgen_is_managed_allocator (method));
5355 sgen_has_critical_method (void)
5357 return write_barrier_method || sgen_has_managed_allocator ();
5363 emit_nursery_check (MonoMethodBuilder *mb, int *nursery_check_return_labels)
5365 memset (nursery_check_return_labels, 0, sizeof (int) * 3);
5366 #ifdef SGEN_ALIGN_NURSERY
5367 // if (ptr_in_nursery (ptr)) return;
5369 * Masking out the bits might be faster, but we would have to use 64 bit
5370 * immediates, which might be slower.
5372 mono_mb_emit_ldarg (mb, 0);
5373 mono_mb_emit_icon (mb, DEFAULT_NURSERY_BITS);
5374 mono_mb_emit_byte (mb, CEE_SHR_UN);
5375 mono_mb_emit_icon (mb, (mword)sgen_get_nursery_start () >> DEFAULT_NURSERY_BITS);
5376 nursery_check_return_labels [0] = mono_mb_emit_branch (mb, CEE_BEQ);
5378 if (!major_collector.is_concurrent) {
5379 // if (!ptr_in_nursery (*ptr)) return;
5380 mono_mb_emit_ldarg (mb, 0);
5381 mono_mb_emit_byte (mb, CEE_LDIND_I);
5382 mono_mb_emit_icon (mb, DEFAULT_NURSERY_BITS);
5383 mono_mb_emit_byte (mb, CEE_SHR_UN);
5384 mono_mb_emit_icon (mb, (mword)sgen_get_nursery_start () >> DEFAULT_NURSERY_BITS);
5385 nursery_check_return_labels [1] = mono_mb_emit_branch (mb, CEE_BNE_UN);
5388 int label_continue1, label_continue2;
5389 int dereferenced_var;
5391 // if (ptr < (sgen_get_nursery_start ())) goto continue;
5392 mono_mb_emit_ldarg (mb, 0);
5393 mono_mb_emit_ptr (mb, (gpointer) sgen_get_nursery_start ());
5394 label_continue_1 = mono_mb_emit_branch (mb, CEE_BLT);
5396 // if (ptr >= sgen_get_nursery_end ())) goto continue;
5397 mono_mb_emit_ldarg (mb, 0);
5398 mono_mb_emit_ptr (mb, (gpointer) sgen_get_nursery_end ());
5399 label_continue_2 = mono_mb_emit_branch (mb, CEE_BGE);
5402 nursery_check_return_labels [0] = mono_mb_emit_branch (mb, CEE_BR);
5405 mono_mb_patch_branch (mb, label_continue_1);
5406 mono_mb_patch_branch (mb, label_continue_2);
5408 // Dereference and store in local var
5409 dereferenced_var = mono_mb_add_local (mb, &mono_defaults.int_class->byval_arg);
5410 mono_mb_emit_ldarg (mb, 0);
5411 mono_mb_emit_byte (mb, CEE_LDIND_I);
5412 mono_mb_emit_stloc (mb, dereferenced_var);
5414 if (!major_collector.is_concurrent) {
5415 // if (*ptr < sgen_get_nursery_start ()) return;
5416 mono_mb_emit_ldloc (mb, dereferenced_var);
5417 mono_mb_emit_ptr (mb, (gpointer) sgen_get_nursery_start ());
5418 nursery_check_return_labels [1] = mono_mb_emit_branch (mb, CEE_BLT);
5420 // if (*ptr >= sgen_get_nursery_end ()) return;
5421 mono_mb_emit_ldloc (mb, dereferenced_var);
5422 mono_mb_emit_ptr (mb, (gpointer) sgen_get_nursery_end ());
5423 nursery_check_return_labels [2] = mono_mb_emit_branch (mb, CEE_BGE);
5430 mono_gc_get_write_barrier (void)
5433 MonoMethodBuilder *mb;
5434 MonoMethodSignature *sig;
5435 #ifdef MANAGED_WBARRIER
5436 int i, nursery_check_labels [3];
5438 #ifdef HAVE_KW_THREAD
5439 int stack_end_offset = -1;
5441 MONO_THREAD_VAR_OFFSET (stack_end, stack_end_offset);
5442 g_assert (stack_end_offset != -1);
5446 // FIXME: Maybe create a separate version for ctors (the branch would be
5447 // correctly predicted more times)
5448 if (write_barrier_method)
5449 return write_barrier_method;
5451 /* Create the IL version of mono_gc_barrier_generic_store () */
5452 sig = mono_metadata_signature_alloc (mono_defaults.corlib, 1);
5453 sig->ret = &mono_defaults.void_class->byval_arg;
5454 sig->params [0] = &mono_defaults.int_class->byval_arg;
5456 mb = mono_mb_new (mono_defaults.object_class, "wbarrier", MONO_WRAPPER_WRITE_BARRIER);
5459 #ifdef MANAGED_WBARRIER
5460 emit_nursery_check (mb, nursery_check_labels);
5462 addr = sgen_cardtable + ((address >> CARD_BITS) & CARD_MASK)
5466 LDC_PTR sgen_cardtable
5468 address >> CARD_BITS
5472 if (SGEN_HAVE_OVERLAPPING_CARDS) {
5473 LDC_PTR card_table_mask
5480 mono_mb_emit_ptr (mb, sgen_cardtable);
5481 mono_mb_emit_ldarg (mb, 0);
5482 mono_mb_emit_icon (mb, CARD_BITS);
5483 mono_mb_emit_byte (mb, CEE_SHR_UN);
5484 #ifdef SGEN_HAVE_OVERLAPPING_CARDS
5485 mono_mb_emit_ptr (mb, (gpointer)CARD_MASK);
5486 mono_mb_emit_byte (mb, CEE_AND);
5488 mono_mb_emit_byte (mb, CEE_ADD);
5489 mono_mb_emit_icon (mb, 1);
5490 mono_mb_emit_byte (mb, CEE_STIND_I1);
5493 for (i = 0; i < 3; ++i) {
5494 if (nursery_check_labels [i])
5495 mono_mb_patch_branch (mb, nursery_check_labels [i]);
5497 mono_mb_emit_byte (mb, CEE_RET);
5499 mono_mb_emit_ldarg (mb, 0);
5500 mono_mb_emit_icall (mb, mono_gc_wbarrier_generic_nostore);
5501 mono_mb_emit_byte (mb, CEE_RET);
5504 res = mono_mb_create_method (mb, sig, 16);
5508 if (write_barrier_method) {
5509 /* Already created */
5510 mono_free_method (res);
5512 /* double-checked locking */
5513 mono_memory_barrier ();
5514 write_barrier_method = res;
5518 return write_barrier_method;
5522 mono_gc_get_description (void)
5524 return g_strdup ("sgen");
5528 mono_gc_set_desktop_mode (void)
5533 mono_gc_is_moving (void)
5539 mono_gc_is_disabled (void)
5545 BOOL APIENTRY mono_gc_dllmain (HMODULE module_handle, DWORD reason, LPVOID reserved)
5552 sgen_get_nursery_clear_policy (void)
5554 return nursery_clear_policy;
5558 sgen_get_array_fill_vtable (void)
5560 if (!array_fill_vtable) {
5561 static MonoClass klass;
5562 static MonoVTable vtable;
5565 MonoDomain *domain = mono_get_root_domain ();
5568 klass.element_class = mono_defaults.byte_class;
5570 klass.instance_size = sizeof (MonoArray);
5571 klass.sizes.element_size = 1;
5572 klass.name = "array_filler_type";
5574 vtable.klass = &klass;
5576 vtable.gc_descr = mono_gc_make_descr_for_array (TRUE, &bmap, 0, 1);
5579 array_fill_vtable = &vtable;
5581 return array_fill_vtable;
5591 sgen_gc_unlock (void)
5593 gboolean try_free = sgen_try_free_some_memory;
5594 sgen_try_free_some_memory = FALSE;
5595 mono_mutex_unlock (&gc_mutex);
5596 MONO_GC_UNLOCKED ();
5598 mono_thread_hazardous_try_free_some ();
5602 sgen_major_collector_iterate_live_block_ranges (sgen_cardtable_block_callback callback)
5604 major_collector.iterate_live_block_ranges (callback);
5608 sgen_major_collector_scan_card_table (SgenGrayQueue *queue)
5610 major_collector.scan_card_table (FALSE, queue);
5614 sgen_get_major_collector (void)
5616 return &major_collector;
5619 void mono_gc_set_skip_thread (gboolean skip)
5621 SgenThreadInfo *info = mono_thread_info_current ();
5624 info->gc_disabled = skip;
5629 sgen_get_remset (void)
5635 mono_gc_get_vtable_bits (MonoClass *class)
5637 /* FIXME move this to the bridge code */
5638 if (!sgen_need_bridge_processing ())
5640 switch (sgen_bridge_class_kind (class)) {
5641 case GC_BRIDGE_TRANSPARENT_BRIDGE_CLASS:
5642 case GC_BRIDGE_OPAQUE_BRIDGE_CLASS:
5643 return SGEN_GC_BIT_BRIDGE_OBJECT;
5649 mono_gc_register_altstack (gpointer stack, gint32 stack_size, gpointer altstack, gint32 altstack_size)
5656 sgen_check_whole_heap_stw (void)
5658 sgen_stop_world (0);
5659 sgen_clear_nursery_fragments ();
5660 sgen_check_whole_heap (FALSE);
5661 sgen_restart_world (0, NULL);
5665 sgen_gc_event_moves (void)
5667 if (moved_objects_idx) {
5668 mono_profiler_gc_moves (moved_objects, moved_objects_idx);
5669 moved_objects_idx = 0;
5673 #endif /* HAVE_SGEN_GC */