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_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_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_scan_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 SGEN_LOG (2, "Finalize queue handling scan for %s generation: %d usecs %d ephemeron rounds", generation_name (generation), TV_ELAPSED (atv, btv), ephemeron_rounds);
2007 * handle disappearing links
2008 * Note we do this after checking the finalization queue because if an object
2009 * survives (at least long enough to be finalized) we don't clear the link.
2010 * This also deals with a possible issue with the monitor reclamation: with the Boehm
2011 * GC a finalized object my lose the monitor because it is cleared before the finalizer is
2014 g_assert (sgen_gray_object_queue_is_empty (queue));
2016 sgen_null_link_in_range (generation, FALSE, ctx);
2017 if (generation == GENERATION_OLD)
2018 sgen_null_link_in_range (GENERATION_NURSERY, FALSE, ctx);
2019 if (sgen_gray_object_queue_is_empty (queue))
2021 sgen_drain_gray_stack (-1, ctx);
2024 g_assert (sgen_gray_object_queue_is_empty (queue));
2028 sgen_check_section_scan_starts (GCMemSection *section)
2031 for (i = 0; i < section->num_scan_start; ++i) {
2032 if (section->scan_starts [i]) {
2033 guint size = safe_object_get_size ((MonoObject*) section->scan_starts [i]);
2034 g_assert (size >= sizeof (MonoObject) && size <= MAX_SMALL_OBJ_SIZE);
2040 check_scan_starts (void)
2042 if (!do_scan_starts_check)
2044 sgen_check_section_scan_starts (nursery_section);
2045 major_collector.check_scan_starts ();
2049 scan_from_registered_roots (char *addr_start, char *addr_end, int root_type, ScanCopyContext ctx)
2053 SGEN_HASH_TABLE_FOREACH (&roots_hash [root_type], start_root, root) {
2054 SGEN_LOG (6, "Precise root scan %p-%p (desc: %p)", start_root, root->end_root, (void*)root->root_desc);
2055 precisely_scan_objects_from (start_root, (void**)root->end_root, addr_start, addr_end, root->root_desc, ctx);
2056 } SGEN_HASH_TABLE_FOREACH_END;
2060 sgen_dump_occupied (char *start, char *end, char *section_start)
2062 fprintf (heap_dump_file, "<occupied offset=\"%td\" size=\"%td\"/>\n", start - section_start, end - start);
2066 sgen_dump_section (GCMemSection *section, const char *type)
2068 char *start = section->data;
2069 char *end = section->data + section->size;
2070 char *occ_start = NULL;
2072 char *old_start = NULL; /* just for debugging */
2074 fprintf (heap_dump_file, "<section type=\"%s\" size=\"%lu\">\n", type, (unsigned long)section->size);
2076 while (start < end) {
2080 if (!*(void**)start) {
2082 sgen_dump_occupied (occ_start, start, section->data);
2085 start += sizeof (void*); /* should be ALLOC_ALIGN, really */
2088 g_assert (start < section->next_data);
2093 vt = (GCVTable*)LOAD_VTABLE (start);
2096 size = ALIGN_UP (safe_object_get_size ((MonoObject*) start));
2099 fprintf (heap_dump_file, "<object offset=\"%d\" class=\"%s.%s\" size=\"%d\"/>\n",
2100 start - section->data,
2101 vt->klass->name_space, vt->klass->name,
2109 sgen_dump_occupied (occ_start, start, section->data);
2111 fprintf (heap_dump_file, "</section>\n");
2115 dump_object (MonoObject *obj, gboolean dump_location)
2117 static char class_name [1024];
2119 MonoClass *class = mono_object_class (obj);
2123 * Python's XML parser is too stupid to parse angle brackets
2124 * in strings, so we just ignore them;
2127 while (class->name [i] && j < sizeof (class_name) - 1) {
2128 if (!strchr ("<>\"", class->name [i]))
2129 class_name [j++] = class->name [i];
2132 g_assert (j < sizeof (class_name));
2135 fprintf (heap_dump_file, "<object class=\"%s.%s\" size=\"%d\"",
2136 class->name_space, class_name,
2137 safe_object_get_size (obj));
2138 if (dump_location) {
2139 const char *location;
2140 if (ptr_in_nursery (obj))
2141 location = "nursery";
2142 else if (safe_object_get_size (obj) <= MAX_SMALL_OBJ_SIZE)
2146 fprintf (heap_dump_file, " location=\"%s\"", location);
2148 fprintf (heap_dump_file, "/>\n");
2152 dump_heap (const char *type, int num, const char *reason)
2157 fprintf (heap_dump_file, "<collection type=\"%s\" num=\"%d\"", type, num);
2159 fprintf (heap_dump_file, " reason=\"%s\"", reason);
2160 fprintf (heap_dump_file, ">\n");
2161 fprintf (heap_dump_file, "<other-mem-usage type=\"mempools\" size=\"%ld\"/>\n", mono_mempool_get_bytes_allocated ());
2162 sgen_dump_internal_mem_usage (heap_dump_file);
2163 fprintf (heap_dump_file, "<pinned type=\"stack\" bytes=\"%zu\"/>\n", sgen_pin_stats_get_pinned_byte_count (PIN_TYPE_STACK));
2164 /* fprintf (heap_dump_file, "<pinned type=\"static-data\" bytes=\"%d\"/>\n", pinned_byte_counts [PIN_TYPE_STATIC_DATA]); */
2165 fprintf (heap_dump_file, "<pinned type=\"other\" bytes=\"%zu\"/>\n", sgen_pin_stats_get_pinned_byte_count (PIN_TYPE_OTHER));
2167 fprintf (heap_dump_file, "<pinned-objects>\n");
2168 for (list = sgen_pin_stats_get_object_list (); list; list = list->next)
2169 dump_object (list->obj, TRUE);
2170 fprintf (heap_dump_file, "</pinned-objects>\n");
2172 sgen_dump_section (nursery_section, "nursery");
2174 major_collector.dump_heap (heap_dump_file);
2176 fprintf (heap_dump_file, "<los>\n");
2177 for (bigobj = los_object_list; bigobj; bigobj = bigobj->next)
2178 dump_object ((MonoObject*)bigobj->data, FALSE);
2179 fprintf (heap_dump_file, "</los>\n");
2181 fprintf (heap_dump_file, "</collection>\n");
2185 sgen_register_moved_object (void *obj, void *destination)
2187 g_assert (mono_profiler_events & MONO_PROFILE_GC_MOVES);
2189 /* FIXME: handle this for parallel collector */
2190 g_assert (!sgen_collection_is_parallel ());
2192 if (moved_objects_idx == MOVED_OBJECTS_NUM) {
2193 mono_profiler_gc_moves (moved_objects, moved_objects_idx);
2194 moved_objects_idx = 0;
2196 moved_objects [moved_objects_idx++] = obj;
2197 moved_objects [moved_objects_idx++] = destination;
2203 static gboolean inited = FALSE;
2208 mono_counters_register ("Minor fragment clear", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_minor_pre_collection_fragment_clear);
2209 mono_counters_register ("Minor pinning", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_minor_pinning);
2210 mono_counters_register ("Minor scan remembered set", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_minor_scan_remsets);
2211 mono_counters_register ("Minor scan pinned", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_minor_scan_pinned);
2212 mono_counters_register ("Minor scan registered roots", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_minor_scan_registered_roots);
2213 mono_counters_register ("Minor scan thread data", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_minor_scan_thread_data);
2214 mono_counters_register ("Minor finish gray stack", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_minor_finish_gray_stack);
2215 mono_counters_register ("Minor fragment creation", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_minor_fragment_creation);
2217 mono_counters_register ("Major fragment clear", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_major_pre_collection_fragment_clear);
2218 mono_counters_register ("Major pinning", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_major_pinning);
2219 mono_counters_register ("Major scan pinned", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_major_scan_pinned);
2220 mono_counters_register ("Major scan registered roots", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_major_scan_registered_roots);
2221 mono_counters_register ("Major scan thread data", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_major_scan_thread_data);
2222 mono_counters_register ("Major scan alloc_pinned", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_major_scan_alloc_pinned);
2223 mono_counters_register ("Major scan finalized", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_major_scan_finalized);
2224 mono_counters_register ("Major scan big objects", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_major_scan_big_objects);
2225 mono_counters_register ("Major finish gray stack", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_major_finish_gray_stack);
2226 mono_counters_register ("Major free big objects", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_major_free_bigobjs);
2227 mono_counters_register ("Major LOS sweep", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_major_los_sweep);
2228 mono_counters_register ("Major sweep", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_major_sweep);
2229 mono_counters_register ("Major fragment creation", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_major_fragment_creation);
2231 mono_counters_register ("Number of pinned objects", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_pinned_objects);
2233 #ifdef HEAVY_STATISTICS
2234 mono_counters_register ("WBarrier remember pointer", MONO_COUNTER_GC | MONO_COUNTER_INT, &stat_wbarrier_add_to_global_remset);
2235 mono_counters_register ("WBarrier set field", MONO_COUNTER_GC | MONO_COUNTER_INT, &stat_wbarrier_set_field);
2236 mono_counters_register ("WBarrier set arrayref", MONO_COUNTER_GC | MONO_COUNTER_INT, &stat_wbarrier_set_arrayref);
2237 mono_counters_register ("WBarrier arrayref copy", MONO_COUNTER_GC | MONO_COUNTER_INT, &stat_wbarrier_arrayref_copy);
2238 mono_counters_register ("WBarrier generic store called", MONO_COUNTER_GC | MONO_COUNTER_INT, &stat_wbarrier_generic_store);
2239 mono_counters_register ("WBarrier generic atomic store called", MONO_COUNTER_GC | MONO_COUNTER_INT, &stat_wbarrier_generic_store_atomic);
2240 mono_counters_register ("WBarrier set root", MONO_COUNTER_GC | MONO_COUNTER_INT, &stat_wbarrier_set_root);
2241 mono_counters_register ("WBarrier value copy", MONO_COUNTER_GC | MONO_COUNTER_INT, &stat_wbarrier_value_copy);
2242 mono_counters_register ("WBarrier object copy", MONO_COUNTER_GC | MONO_COUNTER_INT, &stat_wbarrier_object_copy);
2244 mono_counters_register ("# objects allocated degraded", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_objects_alloced_degraded);
2245 mono_counters_register ("bytes allocated degraded", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_bytes_alloced_degraded);
2247 mono_counters_register ("# copy_object() called (nursery)", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_copy_object_called_nursery);
2248 mono_counters_register ("# objects copied (nursery)", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_objects_copied_nursery);
2249 mono_counters_register ("# copy_object() called (major)", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_copy_object_called_major);
2250 mono_counters_register ("# objects copied (major)", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_objects_copied_major);
2252 mono_counters_register ("# scan_object() called (nursery)", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_scan_object_called_nursery);
2253 mono_counters_register ("# scan_object() called (major)", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_scan_object_called_major);
2255 mono_counters_register ("Slots allocated in vain", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_slots_allocated_in_vain);
2257 mono_counters_register ("# nursery copy_object() failed from space", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_nursery_copy_object_failed_from_space);
2258 mono_counters_register ("# nursery copy_object() failed forwarded", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_nursery_copy_object_failed_forwarded);
2259 mono_counters_register ("# nursery copy_object() failed pinned", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_nursery_copy_object_failed_pinned);
2260 mono_counters_register ("# nursery copy_object() failed to space", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_nursery_copy_object_failed_to_space);
2262 sgen_nursery_allocator_init_heavy_stats ();
2263 sgen_alloc_init_heavy_stats ();
2271 reset_pinned_from_failed_allocation (void)
2273 bytes_pinned_from_failed_allocation = 0;
2277 sgen_set_pinned_from_failed_allocation (mword objsize)
2279 bytes_pinned_from_failed_allocation += objsize;
2283 sgen_collection_is_parallel (void)
2285 switch (current_collection_generation) {
2286 case GENERATION_NURSERY:
2287 return nursery_collection_is_parallel;
2288 case GENERATION_OLD:
2289 return major_collector.is_parallel;
2291 g_error ("Invalid current generation %d", current_collection_generation);
2296 sgen_collection_is_concurrent (void)
2298 switch (current_collection_generation) {
2299 case GENERATION_NURSERY:
2301 case GENERATION_OLD:
2302 return concurrent_collection_in_progress;
2304 g_error ("Invalid current generation %d", current_collection_generation);
2309 sgen_concurrent_collection_in_progress (void)
2311 return concurrent_collection_in_progress;
2318 } FinishRememberedSetScanJobData;
2321 job_finish_remembered_set_scan (WorkerData *worker_data, void *job_data_untyped)
2323 FinishRememberedSetScanJobData *job_data = job_data_untyped;
2325 remset.finish_scan_remsets (job_data->heap_start, job_data->heap_end, sgen_workers_get_job_gray_queue (worker_data));
2326 sgen_free_internal_dynamic (job_data, sizeof (FinishRememberedSetScanJobData), INTERNAL_MEM_WORKER_JOB_DATA);
2331 CopyOrMarkObjectFunc copy_or_mark_func;
2332 ScanObjectFunc scan_func;
2336 } ScanFromRegisteredRootsJobData;
2339 job_scan_from_registered_roots (WorkerData *worker_data, void *job_data_untyped)
2341 ScanFromRegisteredRootsJobData *job_data = job_data_untyped;
2342 ScanCopyContext ctx = { job_data->scan_func, job_data->copy_or_mark_func,
2343 sgen_workers_get_job_gray_queue (worker_data) };
2345 scan_from_registered_roots (job_data->heap_start, job_data->heap_end, job_data->root_type, ctx);
2346 sgen_free_internal_dynamic (job_data, sizeof (ScanFromRegisteredRootsJobData), INTERNAL_MEM_WORKER_JOB_DATA);
2353 } ScanThreadDataJobData;
2356 job_scan_thread_data (WorkerData *worker_data, void *job_data_untyped)
2358 ScanThreadDataJobData *job_data = job_data_untyped;
2360 scan_thread_data (job_data->heap_start, job_data->heap_end, TRUE,
2361 sgen_workers_get_job_gray_queue (worker_data));
2362 sgen_free_internal_dynamic (job_data, sizeof (ScanThreadDataJobData), INTERNAL_MEM_WORKER_JOB_DATA);
2367 FinalizeReadyEntry *list;
2368 } ScanFinalizerEntriesJobData;
2371 job_scan_finalizer_entries (WorkerData *worker_data, void *job_data_untyped)
2373 ScanFinalizerEntriesJobData *job_data = job_data_untyped;
2374 ScanCopyContext ctx = { NULL, current_object_ops.copy_or_mark_object, sgen_workers_get_job_gray_queue (worker_data) };
2376 scan_finalizer_entries (job_data->list, ctx);
2377 sgen_free_internal_dynamic (job_data, sizeof (ScanFinalizerEntriesJobData), INTERNAL_MEM_WORKER_JOB_DATA);
2381 job_scan_major_mod_union_cardtable (WorkerData *worker_data, void *job_data_untyped)
2383 g_assert (concurrent_collection_in_progress);
2384 major_collector.scan_card_table (TRUE, sgen_workers_get_job_gray_queue (worker_data));
2388 job_scan_los_mod_union_cardtable (WorkerData *worker_data, void *job_data_untyped)
2390 g_assert (concurrent_collection_in_progress);
2391 sgen_los_scan_card_table (TRUE, sgen_workers_get_job_gray_queue (worker_data));
2395 verify_scan_starts (char *start, char *end)
2399 for (i = 0; i < nursery_section->num_scan_start; ++i) {
2400 char *addr = nursery_section->scan_starts [i];
2401 if (addr > start && addr < end)
2402 SGEN_LOG (1, "NFC-BAD SCAN START [%d] %p for obj [%p %p]", i, addr, start, end);
2407 verify_nursery (void)
2409 char *start, *end, *cur, *hole_start;
2411 if (!do_verify_nursery)
2414 /*This cleans up unused fragments */
2415 sgen_nursery_allocator_prepare_for_pinning ();
2417 hole_start = start = cur = sgen_get_nursery_start ();
2418 end = sgen_get_nursery_end ();
2423 if (!*(void**)cur) {
2424 cur += sizeof (void*);
2428 if (object_is_forwarded (cur))
2429 SGEN_LOG (1, "FORWARDED OBJ %p", cur);
2430 else if (object_is_pinned (cur))
2431 SGEN_LOG (1, "PINNED OBJ %p", cur);
2433 ss = safe_object_get_size ((MonoObject*)cur);
2434 size = ALIGN_UP (safe_object_get_size ((MonoObject*)cur));
2435 verify_scan_starts (cur, cur + size);
2436 if (do_dump_nursery_content) {
2437 if (cur > hole_start)
2438 SGEN_LOG (1, "HOLE [%p %p %d]", hole_start, cur, (int)(cur - hole_start));
2439 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 ());
2447 * Checks that no objects in the nursery are fowarded or pinned. This
2448 * is a precondition to restarting the mutator while doing a
2449 * concurrent collection. Note that we don't clear fragments because
2450 * we depend on that having happened earlier.
2453 check_nursery_is_clean (void)
2455 char *start, *end, *cur;
2457 start = cur = sgen_get_nursery_start ();
2458 end = sgen_get_nursery_end ();
2463 if (!*(void**)cur) {
2464 cur += sizeof (void*);
2468 g_assert (!object_is_forwarded (cur));
2469 g_assert (!object_is_pinned (cur));
2471 ss = safe_object_get_size ((MonoObject*)cur);
2472 size = ALIGN_UP (safe_object_get_size ((MonoObject*)cur));
2473 verify_scan_starts (cur, cur + size);
2480 init_gray_queue (void)
2482 if (sgen_collection_is_parallel () || sgen_collection_is_concurrent ()) {
2483 sgen_workers_init_distribute_gray_queue ();
2484 sgen_gray_object_queue_init_with_alloc_prepare (&gray_queue, NULL,
2485 gray_queue_redirect, sgen_workers_get_distribute_section_gray_queue ());
2487 sgen_gray_object_queue_init (&gray_queue, NULL);
2492 pin_stage_object_callback (char *obj, size_t size, void *data)
2494 sgen_pin_stage_ptr (obj);
2495 /* FIXME: do pin stats if enabled */
2499 * Collect objects in the nursery. Returns whether to trigger a major
2503 collect_nursery (SgenGrayQueue *unpin_queue, gboolean finish_up_concurrent_mark)
2505 gboolean needs_major;
2506 size_t max_garbage_amount;
2508 FinishRememberedSetScanJobData *frssjd;
2509 ScanFromRegisteredRootsJobData *scrrjd_normal, *scrrjd_wbarrier;
2510 ScanFinalizerEntriesJobData *sfejd_fin_ready, *sfejd_critical_fin;
2511 ScanThreadDataJobData *stdjd;
2512 mword fragment_total;
2513 ScanCopyContext ctx;
2514 TV_DECLARE (all_atv);
2515 TV_DECLARE (all_btv);
2519 if (disable_minor_collections)
2522 MONO_GC_BEGIN (GENERATION_NURSERY);
2523 binary_protocol_collection_begin (stat_minor_gcs, GENERATION_NURSERY);
2527 #ifndef DISABLE_PERFCOUNTERS
2528 mono_perfcounters->gc_collections0++;
2531 current_collection_generation = GENERATION_NURSERY;
2532 if (sgen_collection_is_parallel ())
2533 current_object_ops = sgen_minor_collector.parallel_ops;
2535 current_object_ops = sgen_minor_collector.serial_ops;
2537 reset_pinned_from_failed_allocation ();
2539 check_scan_starts ();
2541 sgen_nursery_alloc_prepare_for_minor ();
2545 nursery_next = sgen_nursery_alloc_get_upper_alloc_bound ();
2546 /* FIXME: optimize later to use the higher address where an object can be present */
2547 nursery_next = MAX (nursery_next, sgen_get_nursery_end ());
2549 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 ()));
2550 max_garbage_amount = nursery_next - sgen_get_nursery_start ();
2551 g_assert (nursery_section->size >= max_garbage_amount);
2553 /* world must be stopped already */
2554 TV_GETTIME (all_atv);
2558 time_minor_pre_collection_fragment_clear += TV_ELAPSED (atv, btv);
2560 if (xdomain_checks) {
2561 sgen_clear_nursery_fragments ();
2562 check_for_xdomain_refs ();
2565 nursery_section->next_data = nursery_next;
2567 major_collector.start_nursery_collection ();
2569 sgen_memgov_minor_collection_start ();
2574 gc_stats.minor_gc_count ++;
2576 MONO_GC_CHECKPOINT_1 (GENERATION_NURSERY);
2578 sgen_process_fin_stage_entries ();
2579 sgen_process_dislink_stage_entries ();
2581 MONO_GC_CHECKPOINT_2 (GENERATION_NURSERY);
2583 /* pin from pinned handles */
2584 sgen_init_pinning ();
2585 mono_profiler_gc_event (MONO_GC_EVENT_MARK_START, 0);
2586 pin_from_roots (sgen_get_nursery_start (), nursery_next, WORKERS_DISTRIBUTE_GRAY_QUEUE);
2587 /* pin cemented objects */
2588 sgen_cement_iterate (pin_stage_object_callback, NULL);
2589 /* identify pinned objects */
2590 sgen_optimize_pin_queue (0);
2591 sgen_pinning_setup_section (nursery_section);
2592 ctx.scan_func = NULL;
2593 ctx.copy_func = NULL;
2594 ctx.queue = WORKERS_DISTRIBUTE_GRAY_QUEUE;
2595 sgen_pin_objects_in_section (nursery_section, ctx);
2596 sgen_pinning_trim_queue_to_section (nursery_section);
2599 time_minor_pinning += TV_ELAPSED (btv, atv);
2600 SGEN_LOG (2, "Finding pinned pointers: %d in %d usecs", sgen_get_pinned_count (), TV_ELAPSED (btv, atv));
2601 SGEN_LOG (4, "Start scan with %d pinned objects", sgen_get_pinned_count ());
2603 MONO_GC_CHECKPOINT_3 (GENERATION_NURSERY);
2605 if (whole_heap_check_before_collection) {
2606 sgen_clear_nursery_fragments ();
2607 sgen_check_whole_heap (finish_up_concurrent_mark);
2609 if (consistency_check_at_minor_collection)
2610 sgen_check_consistency ();
2612 sgen_workers_start_all_workers ();
2613 sgen_workers_start_marking ();
2615 frssjd = sgen_alloc_internal_dynamic (sizeof (FinishRememberedSetScanJobData), INTERNAL_MEM_WORKER_JOB_DATA, TRUE);
2616 frssjd->heap_start = sgen_get_nursery_start ();
2617 frssjd->heap_end = nursery_next;
2618 sgen_workers_enqueue_job (job_finish_remembered_set_scan, frssjd);
2620 /* we don't have complete write barrier yet, so we scan all the old generation sections */
2622 time_minor_scan_remsets += TV_ELAPSED (atv, btv);
2623 SGEN_LOG (2, "Old generation scan: %d usecs", TV_ELAPSED (atv, btv));
2625 MONO_GC_CHECKPOINT_4 (GENERATION_NURSERY);
2627 if (!sgen_collection_is_parallel ()) {
2628 ctx.scan_func = current_object_ops.scan_object;
2629 ctx.copy_func = NULL;
2630 ctx.queue = &gray_queue;
2631 sgen_drain_gray_stack (-1, ctx);
2634 if (mono_profiler_get_events () & MONO_PROFILE_GC_ROOTS)
2635 report_registered_roots ();
2636 if (mono_profiler_get_events () & MONO_PROFILE_GC_ROOTS)
2637 report_finalizer_roots ();
2639 time_minor_scan_pinned += TV_ELAPSED (btv, atv);
2641 MONO_GC_CHECKPOINT_5 (GENERATION_NURSERY);
2643 /* registered roots, this includes static fields */
2644 scrrjd_normal = sgen_alloc_internal_dynamic (sizeof (ScanFromRegisteredRootsJobData), INTERNAL_MEM_WORKER_JOB_DATA, TRUE);
2645 scrrjd_normal->copy_or_mark_func = current_object_ops.copy_or_mark_object;
2646 scrrjd_normal->scan_func = current_object_ops.scan_object;
2647 scrrjd_normal->heap_start = sgen_get_nursery_start ();
2648 scrrjd_normal->heap_end = nursery_next;
2649 scrrjd_normal->root_type = ROOT_TYPE_NORMAL;
2650 sgen_workers_enqueue_job (job_scan_from_registered_roots, scrrjd_normal);
2652 scrrjd_wbarrier = sgen_alloc_internal_dynamic (sizeof (ScanFromRegisteredRootsJobData), INTERNAL_MEM_WORKER_JOB_DATA, TRUE);
2653 scrrjd_wbarrier->copy_or_mark_func = current_object_ops.copy_or_mark_object;
2654 scrrjd_wbarrier->scan_func = current_object_ops.scan_object;
2655 scrrjd_wbarrier->heap_start = sgen_get_nursery_start ();
2656 scrrjd_wbarrier->heap_end = nursery_next;
2657 scrrjd_wbarrier->root_type = ROOT_TYPE_WBARRIER;
2658 sgen_workers_enqueue_job (job_scan_from_registered_roots, scrrjd_wbarrier);
2661 time_minor_scan_registered_roots += TV_ELAPSED (atv, btv);
2663 MONO_GC_CHECKPOINT_6 (GENERATION_NURSERY);
2666 stdjd = sgen_alloc_internal_dynamic (sizeof (ScanThreadDataJobData), INTERNAL_MEM_WORKER_JOB_DATA, TRUE);
2667 stdjd->heap_start = sgen_get_nursery_start ();
2668 stdjd->heap_end = nursery_next;
2669 sgen_workers_enqueue_job (job_scan_thread_data, stdjd);
2672 time_minor_scan_thread_data += TV_ELAPSED (btv, atv);
2675 MONO_GC_CHECKPOINT_7 (GENERATION_NURSERY);
2677 g_assert (!sgen_collection_is_parallel () && !sgen_collection_is_concurrent ());
2679 if (sgen_collection_is_parallel () || sgen_collection_is_concurrent ())
2680 g_assert (sgen_gray_object_queue_is_empty (&gray_queue));
2682 /* Scan the list of objects ready for finalization. If */
2683 sfejd_fin_ready = sgen_alloc_internal_dynamic (sizeof (ScanFinalizerEntriesJobData), INTERNAL_MEM_WORKER_JOB_DATA, TRUE);
2684 sfejd_fin_ready->list = fin_ready_list;
2685 sgen_workers_enqueue_job (job_scan_finalizer_entries, sfejd_fin_ready);
2687 sfejd_critical_fin = sgen_alloc_internal_dynamic (sizeof (ScanFinalizerEntriesJobData), INTERNAL_MEM_WORKER_JOB_DATA, TRUE);
2688 sfejd_critical_fin->list = critical_fin_list;
2689 sgen_workers_enqueue_job (job_scan_finalizer_entries, sfejd_critical_fin);
2691 MONO_GC_CHECKPOINT_8 (GENERATION_NURSERY);
2693 finish_gray_stack (GENERATION_NURSERY, &gray_queue);
2695 time_minor_finish_gray_stack += TV_ELAPSED (btv, atv);
2696 mono_profiler_gc_event (MONO_GC_EVENT_MARK_END, 0);
2698 MONO_GC_CHECKPOINT_9 (GENERATION_NURSERY);
2701 * The (single-threaded) finalization code might have done
2702 * some copying/marking so we can only reset the GC thread's
2703 * worker data here instead of earlier when we joined the
2706 sgen_workers_reset_data ();
2708 if (objects_pinned) {
2709 sgen_optimize_pin_queue (0);
2710 sgen_pinning_setup_section (nursery_section);
2713 /* walk the pin_queue, build up the fragment list of free memory, unmark
2714 * pinned objects as we go, memzero() the empty fragments so they are ready for the
2717 mono_profiler_gc_event (MONO_GC_EVENT_RECLAIM_START, 0);
2718 fragment_total = sgen_build_nursery_fragments (nursery_section,
2719 nursery_section->pin_queue_start, nursery_section->pin_queue_num_entries,
2721 if (!fragment_total)
2724 /* Clear TLABs for all threads */
2725 sgen_clear_tlabs ();
2727 mono_profiler_gc_event (MONO_GC_EVENT_RECLAIM_END, 0);
2729 time_minor_fragment_creation += TV_ELAPSED (atv, btv);
2730 SGEN_LOG (2, "Fragment creation: %d usecs, %lu bytes available", TV_ELAPSED (atv, btv), (unsigned long)fragment_total);
2732 if (consistency_check_at_minor_collection)
2733 sgen_check_major_refs ();
2735 major_collector.finish_nursery_collection ();
2737 TV_GETTIME (all_btv);
2738 gc_stats.minor_gc_time_usecs += TV_ELAPSED (all_atv, all_btv);
2741 dump_heap ("minor", stat_minor_gcs - 1, NULL);
2743 /* prepare the pin queue for the next collection */
2744 sgen_finish_pinning ();
2745 if (fin_ready_list || critical_fin_list) {
2746 SGEN_LOG (4, "Finalizer-thread wakeup: ready %d", num_ready_finalizers);
2747 mono_gc_finalize_notify ();
2749 sgen_pin_stats_reset ();
2750 /* clear cemented hash */
2751 sgen_cement_clear_below_threshold ();
2753 g_assert (sgen_gray_object_queue_is_empty (&gray_queue));
2755 remset.finish_minor_collection ();
2757 check_scan_starts ();
2759 binary_protocol_flush_buffers (FALSE);
2761 sgen_memgov_minor_collection_end ();
2763 /*objects are late pinned because of lack of memory, so a major is a good call*/
2764 needs_major = objects_pinned > 0;
2765 current_collection_generation = -1;
2768 MONO_GC_END (GENERATION_NURSERY);
2769 binary_protocol_collection_end (stat_minor_gcs - 1, GENERATION_NURSERY);
2771 if (check_nursery_objects_pinned && !sgen_minor_collector.is_split)
2772 sgen_check_nursery_objects_pinned (unpin_queue != NULL);
2778 scan_nursery_objects_callback (char *obj, size_t size, ScanCopyContext *ctx)
2780 ctx->scan_func (obj, ctx->queue);
2784 scan_nursery_objects (ScanCopyContext ctx)
2786 sgen_scan_area_with_callback (nursery_section->data, nursery_section->end_data,
2787 (IterateObjectCallbackFunc)scan_nursery_objects_callback, (void*)&ctx, FALSE);
2791 major_copy_or_mark_from_roots (int *old_next_pin_slot, gboolean finish_up_concurrent_mark, gboolean scan_mod_union)
2796 /* FIXME: only use these values for the precise scan
2797 * note that to_space pointers should be excluded anyway...
2799 char *heap_start = NULL;
2800 char *heap_end = (char*)-1;
2801 gboolean profile_roots = mono_profiler_get_events () & MONO_PROFILE_GC_ROOTS;
2802 GCRootReport root_report = { 0 };
2803 ScanFromRegisteredRootsJobData *scrrjd_normal, *scrrjd_wbarrier;
2804 ScanThreadDataJobData *stdjd;
2805 ScanFinalizerEntriesJobData *sfejd_fin_ready, *sfejd_critical_fin;
2806 ScanCopyContext ctx;
2808 if (concurrent_collection_in_progress) {
2809 /*This cleans up unused fragments */
2810 sgen_nursery_allocator_prepare_for_pinning ();
2812 if (do_concurrent_checks)
2813 check_nursery_is_clean ();
2815 /* The concurrent collector doesn't touch the nursery. */
2816 sgen_nursery_alloc_prepare_for_major ();
2823 /* Pinning depends on this */
2824 sgen_clear_nursery_fragments ();
2826 if (whole_heap_check_before_collection)
2827 sgen_check_whole_heap (finish_up_concurrent_mark);
2830 time_major_pre_collection_fragment_clear += TV_ELAPSED (atv, btv);
2832 if (!sgen_collection_is_concurrent ())
2833 nursery_section->next_data = sgen_get_nursery_end ();
2834 /* we should also coalesce scanning from sections close to each other
2835 * and deal with pointers outside of the sections later.
2839 *major_collector.have_swept = FALSE;
2841 if (xdomain_checks) {
2842 sgen_clear_nursery_fragments ();
2843 check_for_xdomain_refs ();
2846 if (!concurrent_collection_in_progress) {
2847 /* Remsets are not useful for a major collection */
2848 remset.prepare_for_major_collection ();
2851 sgen_process_fin_stage_entries ();
2852 sgen_process_dislink_stage_entries ();
2855 sgen_init_pinning ();
2856 SGEN_LOG (6, "Collecting pinned addresses");
2857 pin_from_roots ((void*)lowest_heap_address, (void*)highest_heap_address, WORKERS_DISTRIBUTE_GRAY_QUEUE);
2859 if (!concurrent_collection_in_progress || finish_up_concurrent_mark) {
2860 if (major_collector.is_concurrent) {
2862 * The concurrent major collector cannot evict
2863 * yet, so we need to pin cemented objects to
2864 * not break some asserts.
2866 * FIXME: We could evict now!
2868 sgen_cement_iterate (pin_stage_object_callback, NULL);
2871 if (!concurrent_collection_in_progress)
2872 sgen_cement_reset ();
2875 sgen_optimize_pin_queue (0);
2878 * The concurrent collector doesn't move objects, neither on
2879 * the major heap nor in the nursery, so we can mark even
2880 * before pinning has finished. For the non-concurrent
2881 * collector we start the workers after pinning.
2883 if (concurrent_collection_in_progress) {
2884 sgen_workers_start_all_workers ();
2885 sgen_workers_start_marking ();
2889 * pin_queue now contains all candidate pointers, sorted and
2890 * uniqued. We must do two passes now to figure out which
2891 * objects are pinned.
2893 * The first is to find within the pin_queue the area for each
2894 * section. This requires that the pin_queue be sorted. We
2895 * also process the LOS objects and pinned chunks here.
2897 * The second, destructive, pass is to reduce the section
2898 * areas to pointers to the actually pinned objects.
2900 SGEN_LOG (6, "Pinning from sections");
2901 /* first pass for the sections */
2902 sgen_find_section_pin_queue_start_end (nursery_section);
2903 major_collector.find_pin_queue_start_ends (WORKERS_DISTRIBUTE_GRAY_QUEUE);
2904 /* identify possible pointers to the insize of large objects */
2905 SGEN_LOG (6, "Pinning from large objects");
2906 for (bigobj = los_object_list; bigobj; bigobj = bigobj->next) {
2908 if (sgen_find_optimized_pin_queue_area (bigobj->data, (char*)bigobj->data + sgen_los_object_size (bigobj), &dummy)) {
2909 binary_protocol_pin (bigobj->data, (gpointer)LOAD_VTABLE (bigobj->data), safe_object_get_size (((MonoObject*)(bigobj->data))));
2911 #ifdef ENABLE_DTRACE
2912 if (G_UNLIKELY (MONO_GC_OBJ_PINNED_ENABLED ())) {
2913 MonoVTable *vt = (MonoVTable*)LOAD_VTABLE (bigobj->data);
2914 MONO_GC_OBJ_PINNED ((mword)bigobj->data, sgen_safe_object_get_size ((MonoObject*)bigobj->data), vt->klass->name_space, vt->klass->name, GENERATION_OLD);
2918 if (sgen_los_object_is_pinned (bigobj->data)) {
2919 g_assert (finish_up_concurrent_mark);
2922 sgen_los_pin_object (bigobj->data);
2923 if (SGEN_OBJECT_HAS_REFERENCES (bigobj->data))
2924 GRAY_OBJECT_ENQUEUE (WORKERS_DISTRIBUTE_GRAY_QUEUE, bigobj->data);
2925 if (G_UNLIKELY (do_pin_stats))
2926 sgen_pin_stats_register_object ((char*) bigobj->data, safe_object_get_size ((MonoObject*) bigobj->data));
2927 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));
2930 add_profile_gc_root (&root_report, bigobj->data, MONO_PROFILE_GC_ROOT_PINNING | MONO_PROFILE_GC_ROOT_MISC, 0);
2934 notify_gc_roots (&root_report);
2935 /* second pass for the sections */
2936 ctx.scan_func = concurrent_collection_in_progress ? current_object_ops.scan_object : NULL;
2937 ctx.copy_func = NULL;
2938 ctx.queue = WORKERS_DISTRIBUTE_GRAY_QUEUE;
2941 * Concurrent mark never follows references into the nursery.
2942 * In the start and finish pauses we must scan live nursery
2943 * objects, though. We could simply scan all nursery objects,
2944 * but that would be conservative. The easiest way is to do a
2945 * nursery collection, which copies all live nursery objects
2946 * (except pinned ones, with the simple nursery) to the major
2947 * heap. Scanning the mod union table later will then scan
2948 * those promoted objects, provided they're reachable. Pinned
2949 * objects in the nursery - which we can trivially find in the
2950 * pinning queue - are treated as roots in the mark pauses.
2952 * The split nursery complicates the latter part because
2953 * non-pinned objects can survive in the nursery. That's why
2954 * we need to do a full front-to-back scan of the nursery,
2955 * marking all objects.
2957 * Non-concurrent mark evacuates from the nursery, so it's
2958 * sufficient to just scan pinned nursery objects.
2960 if (concurrent_collection_in_progress && sgen_minor_collector.is_split) {
2961 scan_nursery_objects (ctx);
2963 sgen_pin_objects_in_section (nursery_section, ctx);
2964 if (check_nursery_objects_pinned && !sgen_minor_collector.is_split)
2965 sgen_check_nursery_objects_pinned (!concurrent_collection_in_progress || finish_up_concurrent_mark);
2968 major_collector.pin_objects (WORKERS_DISTRIBUTE_GRAY_QUEUE);
2969 if (old_next_pin_slot)
2970 *old_next_pin_slot = sgen_get_pinned_count ();
2973 time_major_pinning += TV_ELAPSED (atv, btv);
2974 SGEN_LOG (2, "Finding pinned pointers: %d in %d usecs", sgen_get_pinned_count (), TV_ELAPSED (atv, btv));
2975 SGEN_LOG (4, "Start scan with %d pinned objects", sgen_get_pinned_count ());
2977 major_collector.init_to_space ();
2979 #ifdef SGEN_DEBUG_INTERNAL_ALLOC
2980 main_gc_thread = mono_native_thread_self ();
2983 if (!concurrent_collection_in_progress && major_collector.is_parallel) {
2984 sgen_workers_start_all_workers ();
2985 sgen_workers_start_marking ();
2988 if (mono_profiler_get_events () & MONO_PROFILE_GC_ROOTS)
2989 report_registered_roots ();
2991 time_major_scan_pinned += TV_ELAPSED (btv, atv);
2993 /* registered roots, this includes static fields */
2994 scrrjd_normal = sgen_alloc_internal_dynamic (sizeof (ScanFromRegisteredRootsJobData), INTERNAL_MEM_WORKER_JOB_DATA, TRUE);
2995 scrrjd_normal->copy_or_mark_func = current_object_ops.copy_or_mark_object;
2996 scrrjd_normal->scan_func = current_object_ops.scan_object;
2997 scrrjd_normal->heap_start = heap_start;
2998 scrrjd_normal->heap_end = heap_end;
2999 scrrjd_normal->root_type = ROOT_TYPE_NORMAL;
3000 sgen_workers_enqueue_job (job_scan_from_registered_roots, scrrjd_normal);
3002 scrrjd_wbarrier = sgen_alloc_internal_dynamic (sizeof (ScanFromRegisteredRootsJobData), INTERNAL_MEM_WORKER_JOB_DATA, TRUE);
3003 scrrjd_wbarrier->copy_or_mark_func = current_object_ops.copy_or_mark_object;
3004 scrrjd_wbarrier->scan_func = current_object_ops.scan_object;
3005 scrrjd_wbarrier->heap_start = heap_start;
3006 scrrjd_wbarrier->heap_end = heap_end;
3007 scrrjd_wbarrier->root_type = ROOT_TYPE_WBARRIER;
3008 sgen_workers_enqueue_job (job_scan_from_registered_roots, scrrjd_wbarrier);
3011 time_major_scan_registered_roots += TV_ELAPSED (atv, btv);
3014 stdjd = sgen_alloc_internal_dynamic (sizeof (ScanThreadDataJobData), INTERNAL_MEM_WORKER_JOB_DATA, TRUE);
3015 stdjd->heap_start = heap_start;
3016 stdjd->heap_end = heap_end;
3017 sgen_workers_enqueue_job (job_scan_thread_data, stdjd);
3020 time_major_scan_thread_data += TV_ELAPSED (btv, atv);
3023 time_major_scan_alloc_pinned += TV_ELAPSED (atv, btv);
3025 if (mono_profiler_get_events () & MONO_PROFILE_GC_ROOTS)
3026 report_finalizer_roots ();
3028 /* scan the list of objects ready for finalization */
3029 sfejd_fin_ready = sgen_alloc_internal_dynamic (sizeof (ScanFinalizerEntriesJobData), INTERNAL_MEM_WORKER_JOB_DATA, TRUE);
3030 sfejd_fin_ready->list = fin_ready_list;
3031 sgen_workers_enqueue_job (job_scan_finalizer_entries, sfejd_fin_ready);
3033 sfejd_critical_fin = sgen_alloc_internal_dynamic (sizeof (ScanFinalizerEntriesJobData), INTERNAL_MEM_WORKER_JOB_DATA, TRUE);
3034 sfejd_critical_fin->list = critical_fin_list;
3035 sgen_workers_enqueue_job (job_scan_finalizer_entries, sfejd_critical_fin);
3037 if (scan_mod_union) {
3038 g_assert (finish_up_concurrent_mark);
3040 /* Mod union card table */
3041 sgen_workers_enqueue_job (job_scan_major_mod_union_cardtable, NULL);
3042 sgen_workers_enqueue_job (job_scan_los_mod_union_cardtable, NULL);
3046 time_major_scan_finalized += TV_ELAPSED (btv, atv);
3047 SGEN_LOG (2, "Root scan: %d usecs", TV_ELAPSED (btv, atv));
3050 time_major_scan_big_objects += TV_ELAPSED (atv, btv);
3052 if (concurrent_collection_in_progress) {
3053 /* prepare the pin queue for the next collection */
3054 sgen_finish_pinning ();
3056 sgen_pin_stats_reset ();
3058 if (do_concurrent_checks)
3059 check_nursery_is_clean ();
3064 major_start_collection (gboolean concurrent, int *old_next_pin_slot)
3066 MONO_GC_BEGIN (GENERATION_OLD);
3067 binary_protocol_collection_begin (stat_major_gcs, GENERATION_OLD);
3069 current_collection_generation = GENERATION_OLD;
3070 #ifndef DISABLE_PERFCOUNTERS
3071 mono_perfcounters->gc_collections1++;
3074 g_assert (sgen_section_gray_queue_is_empty (sgen_workers_get_distribute_section_gray_queue ()));
3077 g_assert (major_collector.is_concurrent);
3078 concurrent_collection_in_progress = TRUE;
3080 sgen_cement_concurrent_start ();
3082 current_object_ops = major_collector.major_concurrent_ops;
3084 current_object_ops = major_collector.major_ops;
3087 reset_pinned_from_failed_allocation ();
3089 sgen_memgov_major_collection_start ();
3091 //count_ref_nonref_objs ();
3092 //consistency_check ();
3094 check_scan_starts ();
3097 SGEN_LOG (1, "Start major collection %d", stat_major_gcs);
3099 gc_stats.major_gc_count ++;
3101 if (major_collector.start_major_collection)
3102 major_collector.start_major_collection ();
3104 major_copy_or_mark_from_roots (old_next_pin_slot, FALSE, FALSE);
3108 wait_for_workers_to_finish (void)
3110 while (!sgen_workers_all_done ())
3117 if (concurrent_collection_in_progress || major_collector.is_parallel) {
3118 gray_queue_redirect (&gray_queue);
3119 sgen_workers_join ();
3122 g_assert (sgen_gray_object_queue_is_empty (&gray_queue));
3124 #ifdef SGEN_DEBUG_INTERNAL_ALLOC
3125 main_gc_thread = NULL;
3130 major_finish_collection (const char *reason, int old_next_pin_slot, gboolean scan_mod_union)
3132 LOSObject *bigobj, *prevbo;
3138 if (concurrent_collection_in_progress || major_collector.is_parallel)
3141 if (concurrent_collection_in_progress) {
3142 current_object_ops = major_collector.major_concurrent_ops;
3144 major_copy_or_mark_from_roots (NULL, TRUE, scan_mod_union);
3147 g_assert (sgen_gray_object_queue_is_empty (&gray_queue));
3149 if (do_concurrent_checks)
3150 check_nursery_is_clean ();
3152 current_object_ops = major_collector.major_ops;
3156 * The workers have stopped so we need to finish gray queue
3157 * work that might result from finalization in the main GC
3158 * thread. Redirection must therefore be turned off.
3160 sgen_gray_object_queue_disable_alloc_prepare (&gray_queue);
3161 g_assert (sgen_section_gray_queue_is_empty (sgen_workers_get_distribute_section_gray_queue ()));
3163 /* all the objects in the heap */
3164 finish_gray_stack (GENERATION_OLD, &gray_queue);
3166 time_major_finish_gray_stack += TV_ELAPSED (btv, atv);
3169 * The (single-threaded) finalization code might have done
3170 * some copying/marking so we can only reset the GC thread's
3171 * worker data here instead of earlier when we joined the
3174 sgen_workers_reset_data ();
3176 if (objects_pinned) {
3177 g_assert (!concurrent_collection_in_progress);
3179 /*This is slow, but we just OOM'd*/
3180 sgen_pin_queue_clear_discarded_entries (nursery_section, old_next_pin_slot);
3181 sgen_optimize_pin_queue (0);
3182 sgen_find_section_pin_queue_start_end (nursery_section);
3186 reset_heap_boundaries ();
3187 sgen_update_heap_boundaries ((mword)sgen_get_nursery_start (), (mword)sgen_get_nursery_end ());
3189 if (check_mark_bits_after_major_collection)
3190 sgen_check_major_heap_marked ();
3192 MONO_GC_SWEEP_BEGIN (GENERATION_OLD, !major_collector.sweeps_lazily);
3194 /* sweep the big objects list */
3196 for (bigobj = los_object_list; bigobj;) {
3197 g_assert (!object_is_pinned (bigobj->data));
3198 if (sgen_los_object_is_pinned (bigobj->data)) {
3199 sgen_los_unpin_object (bigobj->data);
3200 sgen_update_heap_boundaries ((mword)bigobj->data, (mword)bigobj->data + sgen_los_object_size (bigobj));
3203 /* not referenced anywhere, so we can free it */
3205 prevbo->next = bigobj->next;
3207 los_object_list = bigobj->next;
3209 bigobj = bigobj->next;
3210 sgen_los_free_object (to_free);
3214 bigobj = bigobj->next;
3218 time_major_free_bigobjs += TV_ELAPSED (atv, btv);
3223 time_major_los_sweep += TV_ELAPSED (btv, atv);
3225 major_collector.sweep ();
3227 MONO_GC_SWEEP_END (GENERATION_OLD, !major_collector.sweeps_lazily);
3230 time_major_sweep += TV_ELAPSED (atv, btv);
3232 if (!concurrent_collection_in_progress) {
3233 /* walk the pin_queue, build up the fragment list of free memory, unmark
3234 * pinned objects as we go, memzero() the empty fragments so they are ready for the
3237 if (!sgen_build_nursery_fragments (nursery_section, nursery_section->pin_queue_start, nursery_section->pin_queue_num_entries, NULL))
3240 /* prepare the pin queue for the next collection */
3241 sgen_finish_pinning ();
3243 /* Clear TLABs for all threads */
3244 sgen_clear_tlabs ();
3246 sgen_pin_stats_reset ();
3249 if (concurrent_collection_in_progress)
3250 sgen_cement_concurrent_finish ();
3251 sgen_cement_clear_below_threshold ();
3254 time_major_fragment_creation += TV_ELAPSED (btv, atv);
3257 dump_heap ("major", stat_major_gcs - 1, reason);
3259 if (fin_ready_list || critical_fin_list) {
3260 SGEN_LOG (4, "Finalizer-thread wakeup: ready %d", num_ready_finalizers);
3261 mono_gc_finalize_notify ();
3264 g_assert (sgen_gray_object_queue_is_empty (&gray_queue));
3266 sgen_memgov_major_collection_end ();
3267 current_collection_generation = -1;
3269 major_collector.finish_major_collection ();
3271 g_assert (sgen_section_gray_queue_is_empty (sgen_workers_get_distribute_section_gray_queue ()));
3273 if (concurrent_collection_in_progress)
3274 concurrent_collection_in_progress = FALSE;
3276 check_scan_starts ();
3278 binary_protocol_flush_buffers (FALSE);
3280 //consistency_check ();
3282 MONO_GC_END (GENERATION_OLD);
3283 binary_protocol_collection_end (stat_major_gcs - 1, GENERATION_OLD);
3287 major_do_collection (const char *reason)
3289 TV_DECLARE (all_atv);
3290 TV_DECLARE (all_btv);
3291 int old_next_pin_slot;
3293 if (disable_major_collections)
3296 if (major_collector.get_and_reset_num_major_objects_marked) {
3297 long long num_marked = major_collector.get_and_reset_num_major_objects_marked ();
3298 g_assert (!num_marked);
3301 /* world must be stopped already */
3302 TV_GETTIME (all_atv);
3304 major_start_collection (FALSE, &old_next_pin_slot);
3305 major_finish_collection (reason, old_next_pin_slot, FALSE);
3307 TV_GETTIME (all_btv);
3308 gc_stats.major_gc_time_usecs += TV_ELAPSED (all_atv, all_btv);
3310 /* FIXME: also report this to the user, preferably in gc-end. */
3311 if (major_collector.get_and_reset_num_major_objects_marked)
3312 major_collector.get_and_reset_num_major_objects_marked ();
3314 return bytes_pinned_from_failed_allocation > 0;
3318 major_start_concurrent_collection (const char *reason)
3320 long long num_objects_marked;
3322 if (disable_major_collections)
3325 num_objects_marked = major_collector.get_and_reset_num_major_objects_marked ();
3326 g_assert (num_objects_marked == 0);
3328 MONO_GC_CONCURRENT_START_BEGIN (GENERATION_OLD);
3330 // FIXME: store reason and pass it when finishing
3331 major_start_collection (TRUE, NULL);
3333 gray_queue_redirect (&gray_queue);
3334 sgen_workers_wait_for_jobs ();
3336 num_objects_marked = major_collector.get_and_reset_num_major_objects_marked ();
3337 MONO_GC_CONCURRENT_START_END (GENERATION_OLD, num_objects_marked);
3339 current_collection_generation = -1;
3343 major_update_or_finish_concurrent_collection (gboolean force_finish)
3345 SgenGrayQueue unpin_queue;
3346 memset (&unpin_queue, 0, sizeof (unpin_queue));
3348 MONO_GC_CONCURRENT_UPDATE_FINISH_BEGIN (GENERATION_OLD, major_collector.get_and_reset_num_major_objects_marked ());
3350 g_assert (sgen_gray_object_queue_is_empty (&gray_queue));
3352 if (!force_finish && !sgen_workers_all_done ()) {
3353 major_collector.update_cardtable_mod_union ();
3354 sgen_los_update_cardtable_mod_union ();
3356 MONO_GC_CONCURRENT_UPDATE_END (GENERATION_OLD, major_collector.get_and_reset_num_major_objects_marked ());
3361 * The major collector can add global remsets which are processed in the finishing
3362 * nursery collection, below. That implies that the workers must have finished
3363 * marking before the nursery collection is allowed to run, otherwise we might miss
3366 wait_for_workers_to_finish ();
3368 major_collector.update_cardtable_mod_union ();
3369 sgen_los_update_cardtable_mod_union ();
3371 collect_nursery (&unpin_queue, TRUE);
3373 if (mod_union_consistency_check)
3374 sgen_check_mod_union_consistency ();
3376 current_collection_generation = GENERATION_OLD;
3377 major_finish_collection ("finishing", -1, TRUE);
3379 if (whole_heap_check_before_collection)
3380 sgen_check_whole_heap (FALSE);
3382 unpin_objects_from_queue (&unpin_queue);
3383 sgen_gray_object_queue_deinit (&unpin_queue);
3385 MONO_GC_CONCURRENT_FINISH_END (GENERATION_OLD, major_collector.get_and_reset_num_major_objects_marked ());
3387 current_collection_generation = -1;
3393 * Ensure an allocation request for @size will succeed by freeing enough memory.
3395 * LOCKING: The GC lock MUST be held.
3398 sgen_ensure_free_space (size_t size)
3400 int generation_to_collect = -1;
3401 const char *reason = NULL;
3404 if (size > SGEN_MAX_SMALL_OBJ_SIZE) {
3405 if (sgen_need_major_collection (size)) {
3406 reason = "LOS overflow";
3407 generation_to_collect = GENERATION_OLD;
3410 if (degraded_mode) {
3411 if (sgen_need_major_collection (size)) {
3412 reason = "Degraded mode overflow";
3413 generation_to_collect = GENERATION_OLD;
3415 } else if (sgen_need_major_collection (size)) {
3416 reason = "Minor allowance";
3417 generation_to_collect = GENERATION_OLD;
3419 generation_to_collect = GENERATION_NURSERY;
3420 reason = "Nursery full";
3424 if (generation_to_collect == -1) {
3425 if (concurrent_collection_in_progress && sgen_workers_all_done ()) {
3426 generation_to_collect = GENERATION_OLD;
3427 reason = "Finish concurrent collection";
3431 if (generation_to_collect == -1)
3433 sgen_perform_collection (size, generation_to_collect, reason, FALSE);
3437 * LOCKING: Assumes the GC lock is held.
3440 sgen_perform_collection (size_t requested_size, int generation_to_collect, const char *reason, gboolean wait_to_finish)
3442 TV_DECLARE (gc_end);
3443 GGTimingInfo infos [2];
3444 int overflow_generation_to_collect = -1;
3445 int oldest_generation_collected = generation_to_collect;
3446 const char *overflow_reason = NULL;
3448 MONO_GC_REQUESTED (generation_to_collect, requested_size, wait_to_finish ? 1 : 0);
3450 binary_protocol_collection_force (generation_to_collect);
3452 g_assert (generation_to_collect == GENERATION_NURSERY || generation_to_collect == GENERATION_OLD);
3454 memset (infos, 0, sizeof (infos));
3455 mono_profiler_gc_event (MONO_GC_EVENT_START, generation_to_collect);
3457 infos [0].generation = generation_to_collect;
3458 infos [0].reason = reason;
3459 infos [0].is_overflow = FALSE;
3460 TV_GETTIME (infos [0].total_time);
3461 infos [1].generation = -1;
3463 sgen_stop_world (generation_to_collect);
3465 if (concurrent_collection_in_progress) {
3466 if (major_update_or_finish_concurrent_collection (wait_to_finish && generation_to_collect == GENERATION_OLD)) {
3467 oldest_generation_collected = GENERATION_OLD;
3470 if (generation_to_collect == GENERATION_OLD)
3473 if (generation_to_collect == GENERATION_OLD &&
3474 allow_synchronous_major &&
3475 major_collector.want_synchronous_collection &&
3476 *major_collector.want_synchronous_collection) {
3477 wait_to_finish = TRUE;
3481 //FIXME extract overflow reason
3482 if (generation_to_collect == GENERATION_NURSERY) {
3483 if (collect_nursery (NULL, FALSE)) {
3484 overflow_generation_to_collect = GENERATION_OLD;
3485 overflow_reason = "Minor overflow";
3488 if (major_collector.is_concurrent) {
3489 g_assert (!concurrent_collection_in_progress);
3490 if (!wait_to_finish)
3491 collect_nursery (NULL, FALSE);
3494 if (major_collector.is_concurrent && !wait_to_finish) {
3495 major_start_concurrent_collection (reason);
3496 // FIXME: set infos[0] properly
3499 if (major_do_collection (reason)) {
3500 overflow_generation_to_collect = GENERATION_NURSERY;
3501 overflow_reason = "Excessive pinning";
3506 TV_GETTIME (gc_end);
3507 infos [0].total_time = SGEN_TV_ELAPSED (infos [0].total_time, gc_end);
3510 if (!major_collector.is_concurrent && overflow_generation_to_collect != -1) {
3511 mono_profiler_gc_event (MONO_GC_EVENT_START, overflow_generation_to_collect);
3512 infos [1].generation = overflow_generation_to_collect;
3513 infos [1].reason = overflow_reason;
3514 infos [1].is_overflow = TRUE;
3515 infos [1].total_time = gc_end;
3517 if (overflow_generation_to_collect == GENERATION_NURSERY)
3518 collect_nursery (NULL, FALSE);
3520 major_do_collection (overflow_reason);
3522 TV_GETTIME (gc_end);
3523 infos [1].total_time = SGEN_TV_ELAPSED (infos [1].total_time, gc_end);
3525 /* keep events symmetric */
3526 mono_profiler_gc_event (MONO_GC_EVENT_END, overflow_generation_to_collect);
3528 oldest_generation_collected = MAX (oldest_generation_collected, overflow_generation_to_collect);
3531 SGEN_LOG (2, "Heap size: %lu, LOS size: %lu", (unsigned long)mono_gc_get_heap_size (), (unsigned long)los_memory_usage);
3533 /* this also sets the proper pointers for the next allocation */
3534 if (generation_to_collect == GENERATION_NURSERY && !sgen_can_alloc_size (requested_size)) {
3535 /* TypeBuilder and MonoMethod are killing mcs with fragmentation */
3536 SGEN_LOG (1, "nursery collection didn't find enough room for %zd alloc (%d pinned)", requested_size, sgen_get_pinned_count ());
3537 sgen_dump_pin_queue ();
3542 g_assert (sgen_gray_object_queue_is_empty (&gray_queue));
3544 sgen_restart_world (oldest_generation_collected, infos);
3546 mono_profiler_gc_event (MONO_GC_EVENT_END, generation_to_collect);
3550 * ######################################################################
3551 * ######## Memory allocation from the OS
3552 * ######################################################################
3553 * This section of code deals with getting memory from the OS and
3554 * allocating memory for GC-internal data structures.
3555 * Internal memory can be handled with a freelist for small objects.
3561 G_GNUC_UNUSED static void
3562 report_internal_mem_usage (void)
3564 printf ("Internal memory usage:\n");
3565 sgen_report_internal_mem_usage ();
3566 printf ("Pinned memory usage:\n");
3567 major_collector.report_pinned_memory_usage ();
3571 * ######################################################################
3572 * ######## Finalization support
3573 * ######################################################################
3576 static inline gboolean
3577 sgen_major_is_object_alive (void *object)
3581 /* Oldgen objects can be pinned and forwarded too */
3582 if (SGEN_OBJECT_IS_PINNED (object) || SGEN_OBJECT_IS_FORWARDED (object))
3586 * FIXME: major_collector.is_object_live() also calculates the
3587 * size. Avoid the double calculation.
3589 objsize = SGEN_ALIGN_UP (sgen_safe_object_get_size ((MonoObject*)object));
3590 if (objsize > SGEN_MAX_SMALL_OBJ_SIZE)
3591 return sgen_los_object_is_pinned (object);
3593 return major_collector.is_object_live (object);
3597 * If the object has been forwarded it means it's still referenced from a root.
3598 * If it is pinned it's still alive as well.
3599 * A LOS object is only alive if we have pinned it.
3600 * Return TRUE if @obj is ready to be finalized.
3602 static inline gboolean
3603 sgen_is_object_alive (void *object)
3605 if (ptr_in_nursery (object))
3606 return sgen_nursery_is_object_alive (object);
3608 return sgen_major_is_object_alive (object);
3612 * This function returns true if @object is either alive or it belongs to the old gen
3613 * and we're currently doing a minor collection.
3616 sgen_is_object_alive_for_current_gen (char *object)
3618 if (ptr_in_nursery (object))
3619 return sgen_nursery_is_object_alive (object);
3621 if (current_collection_generation == GENERATION_NURSERY)
3624 return sgen_major_is_object_alive (object);
3628 * This function returns true if @object is either alive and belongs to the
3629 * current collection - major collections are full heap, so old gen objects
3630 * are never alive during a minor collection.
3633 sgen_is_object_alive_and_on_current_collection (char *object)
3635 if (ptr_in_nursery (object))
3636 return sgen_nursery_is_object_alive (object);
3638 if (current_collection_generation == GENERATION_NURSERY)
3641 return sgen_major_is_object_alive (object);
3646 sgen_gc_is_object_ready_for_finalization (void *object)
3648 return !sgen_is_object_alive (object);
3652 has_critical_finalizer (MonoObject *obj)
3656 if (!mono_defaults.critical_finalizer_object)
3659 class = ((MonoVTable*)LOAD_VTABLE (obj))->klass;
3661 return mono_class_has_parent_fast (class, mono_defaults.critical_finalizer_object);
3665 sgen_queue_finalization_entry (MonoObject *obj)
3667 FinalizeReadyEntry *entry = sgen_alloc_internal (INTERNAL_MEM_FINALIZE_READY_ENTRY);
3668 gboolean critical = has_critical_finalizer (obj);
3669 entry->object = obj;
3671 entry->next = critical_fin_list;
3672 critical_fin_list = entry;
3674 entry->next = fin_ready_list;
3675 fin_ready_list = entry;
3678 #ifdef ENABLE_DTRACE
3679 if (G_UNLIKELY (MONO_GC_FINALIZE_ENQUEUE_ENABLED ())) {
3680 int gen = sgen_ptr_in_nursery (obj) ? GENERATION_NURSERY : GENERATION_OLD;
3681 MonoVTable *vt = (MonoVTable*)LOAD_VTABLE (obj);
3682 MONO_GC_FINALIZE_ENQUEUE ((mword)obj, sgen_safe_object_get_size (obj),
3683 vt->klass->name_space, vt->klass->name, gen, critical);
3689 sgen_object_is_live (void *obj)
3691 return sgen_is_object_alive_and_on_current_collection (obj);
3694 /* LOCKING: requires that the GC lock is held */
3696 null_ephemerons_for_domain (MonoDomain *domain)
3698 EphemeronLinkNode *current = ephemeron_list, *prev = NULL;
3701 MonoObject *object = (MonoObject*)current->array;
3703 if (object && !object->vtable) {
3704 EphemeronLinkNode *tmp = current;
3707 prev->next = current->next;
3709 ephemeron_list = current->next;
3711 current = current->next;
3712 sgen_free_internal (tmp, INTERNAL_MEM_EPHEMERON_LINK);
3715 current = current->next;
3720 /* LOCKING: requires that the GC lock is held */
3722 clear_unreachable_ephemerons (ScanCopyContext ctx)
3724 CopyOrMarkObjectFunc copy_func = ctx.copy_func;
3725 GrayQueue *queue = ctx.queue;
3726 EphemeronLinkNode *current = ephemeron_list, *prev = NULL;
3728 Ephemeron *cur, *array_end;
3732 char *object = current->array;
3734 if (!sgen_is_object_alive_for_current_gen (object)) {
3735 EphemeronLinkNode *tmp = current;
3737 SGEN_LOG (5, "Dead Ephemeron array at %p", object);
3740 prev->next = current->next;
3742 ephemeron_list = current->next;
3744 current = current->next;
3745 sgen_free_internal (tmp, INTERNAL_MEM_EPHEMERON_LINK);
3750 copy_func ((void**)&object, queue);
3751 current->array = object;
3753 SGEN_LOG (5, "Clearing unreachable entries for ephemeron array at %p", object);
3755 array = (MonoArray*)object;
3756 cur = mono_array_addr (array, Ephemeron, 0);
3757 array_end = cur + mono_array_length_fast (array);
3758 tombstone = (char*)((MonoVTable*)LOAD_VTABLE (object))->domain->ephemeron_tombstone;
3760 for (; cur < array_end; ++cur) {
3761 char *key = (char*)cur->key;
3763 if (!key || key == tombstone)
3766 SGEN_LOG (5, "[%td] key %p (%s) value %p (%s)", cur - mono_array_addr (array, Ephemeron, 0),
3767 key, sgen_is_object_alive_for_current_gen (key) ? "reachable" : "unreachable",
3768 cur->value, cur->value && sgen_is_object_alive_for_current_gen (cur->value) ? "reachable" : "unreachable");
3770 if (!sgen_is_object_alive_for_current_gen (key)) {
3771 cur->key = tombstone;
3777 current = current->next;
3782 LOCKING: requires that the GC lock is held
3784 Limitations: We scan all ephemerons on every collection since the current design doesn't allow for a simple nursery/mature split.
3787 mark_ephemerons_in_range (ScanCopyContext ctx)
3789 CopyOrMarkObjectFunc copy_func = ctx.copy_func;
3790 GrayQueue *queue = ctx.queue;
3791 int nothing_marked = 1;
3792 EphemeronLinkNode *current = ephemeron_list;
3794 Ephemeron *cur, *array_end;
3797 for (current = ephemeron_list; current; current = current->next) {
3798 char *object = current->array;
3799 SGEN_LOG (5, "Ephemeron array at %p", object);
3801 /*It has to be alive*/
3802 if (!sgen_is_object_alive_for_current_gen (object)) {
3803 SGEN_LOG (5, "\tnot reachable");
3807 copy_func ((void**)&object, queue);
3809 array = (MonoArray*)object;
3810 cur = mono_array_addr (array, Ephemeron, 0);
3811 array_end = cur + mono_array_length_fast (array);
3812 tombstone = (char*)((MonoVTable*)LOAD_VTABLE (object))->domain->ephemeron_tombstone;
3814 for (; cur < array_end; ++cur) {
3815 char *key = cur->key;
3817 if (!key || key == tombstone)
3820 SGEN_LOG (5, "[%td] key %p (%s) value %p (%s)", cur - mono_array_addr (array, Ephemeron, 0),
3821 key, sgen_is_object_alive_for_current_gen (key) ? "reachable" : "unreachable",
3822 cur->value, cur->value && sgen_is_object_alive_for_current_gen (cur->value) ? "reachable" : "unreachable");
3824 if (sgen_is_object_alive_for_current_gen (key)) {
3825 char *value = cur->value;
3827 copy_func ((void**)&cur->key, queue);
3829 if (!sgen_is_object_alive_for_current_gen (value))
3831 copy_func ((void**)&cur->value, queue);
3837 SGEN_LOG (5, "Ephemeron run finished. Is it done %d", nothing_marked);
3838 return nothing_marked;
3842 mono_gc_invoke_finalizers (void)
3844 FinalizeReadyEntry *entry = NULL;
3845 gboolean entry_is_critical = FALSE;
3848 /* FIXME: batch to reduce lock contention */
3849 while (fin_ready_list || critical_fin_list) {
3853 FinalizeReadyEntry **list = entry_is_critical ? &critical_fin_list : &fin_ready_list;
3855 /* We have finalized entry in the last
3856 interation, now we need to remove it from
3859 *list = entry->next;
3861 FinalizeReadyEntry *e = *list;
3862 while (e->next != entry)
3864 e->next = entry->next;
3866 sgen_free_internal (entry, INTERNAL_MEM_FINALIZE_READY_ENTRY);
3870 /* Now look for the first non-null entry. */
3871 for (entry = fin_ready_list; entry && !entry->object; entry = entry->next)
3874 entry_is_critical = FALSE;
3876 entry_is_critical = TRUE;
3877 for (entry = critical_fin_list; entry && !entry->object; entry = entry->next)
3882 g_assert (entry->object);
3883 num_ready_finalizers--;
3884 obj = entry->object;
3885 entry->object = NULL;
3886 SGEN_LOG (7, "Finalizing object %p (%s)", obj, safe_name (obj));
3894 g_assert (entry->object == NULL);
3896 /* the object is on the stack so it is pinned */
3897 /*g_print ("Calling finalizer for object: %p (%s)\n", entry->object, safe_name (entry->object));*/
3898 mono_gc_run_finalize (obj, NULL);
3905 mono_gc_pending_finalizers (void)
3907 return fin_ready_list || critical_fin_list;
3911 * ######################################################################
3912 * ######## registered roots support
3913 * ######################################################################
3917 * We do not coalesce roots.
3920 mono_gc_register_root_inner (char *start, size_t size, void *descr, int root_type)
3922 RootRecord new_root;
3925 for (i = 0; i < ROOT_TYPE_NUM; ++i) {
3926 RootRecord *root = sgen_hash_table_lookup (&roots_hash [i], start);
3927 /* we allow changing the size and the descriptor (for thread statics etc) */
3929 size_t old_size = root->end_root - start;
3930 root->end_root = start + size;
3931 g_assert (((root->root_desc != 0) && (descr != NULL)) ||
3932 ((root->root_desc == 0) && (descr == NULL)));
3933 root->root_desc = (mword)descr;
3935 roots_size -= old_size;
3941 new_root.end_root = start + size;
3942 new_root.root_desc = (mword)descr;
3944 sgen_hash_table_replace (&roots_hash [root_type], start, &new_root, NULL);
3947 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);
3954 mono_gc_register_root (char *start, size_t size, void *descr)
3956 return mono_gc_register_root_inner (start, size, descr, descr ? ROOT_TYPE_NORMAL : ROOT_TYPE_PINNED);
3960 mono_gc_register_root_wbarrier (char *start, size_t size, void *descr)
3962 return mono_gc_register_root_inner (start, size, descr, ROOT_TYPE_WBARRIER);
3966 mono_gc_deregister_root (char* addr)
3972 for (root_type = 0; root_type < ROOT_TYPE_NUM; ++root_type) {
3973 if (sgen_hash_table_remove (&roots_hash [root_type], addr, &root))
3974 roots_size -= (root.end_root - addr);
3980 * ######################################################################
3981 * ######## Thread handling (stop/start code)
3982 * ######################################################################
3985 unsigned int sgen_global_stop_count = 0;
3988 sgen_get_current_collection_generation (void)
3990 return current_collection_generation;
3994 mono_gc_set_gc_callbacks (MonoGCCallbacks *callbacks)
3996 gc_callbacks = *callbacks;
4000 mono_gc_get_gc_callbacks ()
4002 return &gc_callbacks;
4005 /* Variables holding start/end nursery so it won't have to be passed at every call */
4006 static void *scan_area_arg_start, *scan_area_arg_end;
4009 mono_gc_conservatively_scan_area (void *start, void *end)
4011 conservatively_pin_objects_from (start, end, scan_area_arg_start, scan_area_arg_end, PIN_TYPE_STACK);
4015 mono_gc_scan_object (void *obj)
4017 UserCopyOrMarkData *data = mono_native_tls_get_value (user_copy_or_mark_key);
4018 current_object_ops.copy_or_mark_object (&obj, data->queue);
4023 * Mark from thread stacks and registers.
4026 scan_thread_data (void *start_nursery, void *end_nursery, gboolean precise, GrayQueue *queue)
4028 SgenThreadInfo *info;
4030 scan_area_arg_start = start_nursery;
4031 scan_area_arg_end = end_nursery;
4033 FOREACH_THREAD (info) {
4035 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);
4038 if (info->gc_disabled) {
4039 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);
4042 if (mono_thread_info_run_state (info) != STATE_RUNNING) {
4043 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));
4046 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 ());
4047 if (gc_callbacks.thread_mark_func && !conservative_stack_mark) {
4048 UserCopyOrMarkData data = { NULL, queue };
4049 set_user_copy_or_mark_data (&data);
4050 gc_callbacks.thread_mark_func (info->runtime_data, info->stack_start, info->stack_end, precise);
4051 set_user_copy_or_mark_data (NULL);
4052 } else if (!precise) {
4053 if (!conservative_stack_mark) {
4054 fprintf (stderr, "Precise stack mark not supported - disabling.\n");
4055 conservative_stack_mark = TRUE;
4057 conservatively_pin_objects_from (info->stack_start, info->stack_end, start_nursery, end_nursery, PIN_TYPE_STACK);
4062 conservatively_pin_objects_from ((void**)&info->ctx, (void**)&info->ctx + ARCH_NUM_REGS,
4063 start_nursery, end_nursery, PIN_TYPE_STACK);
4065 conservatively_pin_objects_from ((void**)&info->regs, (void**)&info->regs + ARCH_NUM_REGS,
4066 start_nursery, end_nursery, PIN_TYPE_STACK);
4069 } END_FOREACH_THREAD
4073 ptr_on_stack (void *ptr)
4075 gpointer stack_start = &stack_start;
4076 SgenThreadInfo *info = mono_thread_info_current ();
4078 if (ptr >= stack_start && ptr < (gpointer)info->stack_end)
4084 sgen_thread_register (SgenThreadInfo* info, void *addr)
4087 guint8 *staddr = NULL;
4089 #ifndef HAVE_KW_THREAD
4090 info->tlab_start = info->tlab_next = info->tlab_temp_end = info->tlab_real_end = NULL;
4092 g_assert (!mono_native_tls_get_value (thread_info_key));
4093 mono_native_tls_set_value (thread_info_key, info);
4095 sgen_thread_info = info;
4098 #ifdef SGEN_POSIX_STW
4099 info->stop_count = -1;
4103 info->stack_start = NULL;
4104 info->stopped_ip = NULL;
4105 info->stopped_domain = NULL;
4107 memset (&info->ctx, 0, sizeof (MonoContext));
4109 memset (&info->regs, 0, sizeof (info->regs));
4112 sgen_init_tlab_info (info);
4114 binary_protocol_thread_register ((gpointer)mono_thread_info_get_tid (info));
4116 /* On win32, stack_start_limit should be 0, since the stack can grow dynamically */
4118 mono_thread_info_get_stack_bounds (&staddr, &stsize);
4121 info->stack_start_limit = staddr;
4122 info->stack_end = staddr + stsize;
4124 gsize stack_bottom = (gsize)addr;
4125 stack_bottom += 4095;
4126 stack_bottom &= ~4095;
4127 info->stack_end = (char*)stack_bottom;
4130 #ifdef HAVE_KW_THREAD
4131 stack_end = info->stack_end;
4134 SGEN_LOG (3, "registered thread %p (%p) stack end %p", info, (gpointer)mono_thread_info_get_tid (info), info->stack_end);
4136 if (gc_callbacks.thread_attach_func)
4137 info->runtime_data = gc_callbacks.thread_attach_func ();
4142 sgen_thread_detach (SgenThreadInfo *p)
4144 /* If a delegate is passed to native code and invoked on a thread we dont
4145 * know about, the jit will register it with mono_jit_thread_attach, but
4146 * we have no way of knowing when that thread goes away. SGen has a TSD
4147 * so we assume that if the domain is still registered, we can detach
4150 if (mono_domain_get ())
4151 mono_thread_detach (mono_thread_current ());
4155 sgen_thread_unregister (SgenThreadInfo *p)
4157 MonoNativeThreadId tid;
4159 tid = mono_thread_info_get_tid (p);
4160 binary_protocol_thread_unregister ((gpointer)tid);
4161 SGEN_LOG (3, "unregister thread %p (%p)", p, (gpointer)tid);
4163 mono_threads_add_joinable_thread ((gpointer)tid);
4165 if (gc_callbacks.thread_detach_func) {
4166 gc_callbacks.thread_detach_func (p->runtime_data);
4167 p->runtime_data = NULL;
4173 sgen_thread_attach (SgenThreadInfo *info)
4176 /*this is odd, can we get attached before the gc is inited?*/
4180 if (gc_callbacks.thread_attach_func && !info->runtime_data)
4181 info->runtime_data = gc_callbacks.thread_attach_func ();
4184 mono_gc_register_thread (void *baseptr)
4186 return mono_thread_info_attach (baseptr) != NULL;
4190 * mono_gc_set_stack_end:
4192 * Set the end of the current threads stack to STACK_END. The stack space between
4193 * STACK_END and the real end of the threads stack will not be scanned during collections.
4196 mono_gc_set_stack_end (void *stack_end)
4198 SgenThreadInfo *info;
4201 info = mono_thread_info_current ();
4203 g_assert (stack_end < info->stack_end);
4204 info->stack_end = stack_end;
4209 #if USE_PTHREAD_INTERCEPT
4213 mono_gc_pthread_create (pthread_t *new_thread, const pthread_attr_t *attr, void *(*start_routine)(void *), void *arg)
4215 return pthread_create (new_thread, attr, start_routine, arg);
4219 mono_gc_pthread_join (pthread_t thread, void **retval)
4221 return pthread_join (thread, retval);
4225 mono_gc_pthread_detach (pthread_t thread)
4227 return pthread_detach (thread);
4231 mono_gc_pthread_exit (void *retval)
4233 mono_thread_info_detach ();
4234 pthread_exit (retval);
4237 #endif /* USE_PTHREAD_INTERCEPT */
4240 * ######################################################################
4241 * ######## Write barriers
4242 * ######################################################################
4246 * Note: the write barriers first do the needed GC work and then do the actual store:
4247 * this way the value is visible to the conservative GC scan after the write barrier
4248 * itself. If a GC interrupts the barrier in the middle, value will be kept alive by
4249 * the conservative scan, otherwise by the remembered set scan.
4252 mono_gc_wbarrier_set_field (MonoObject *obj, gpointer field_ptr, MonoObject* value)
4254 HEAVY_STAT (++stat_wbarrier_set_field);
4255 if (ptr_in_nursery (field_ptr)) {
4256 *(void**)field_ptr = value;
4259 SGEN_LOG (8, "Adding remset at %p", field_ptr);
4261 binary_protocol_wbarrier (field_ptr, value, value->vtable);
4263 remset.wbarrier_set_field (obj, field_ptr, value);
4267 mono_gc_wbarrier_set_arrayref (MonoArray *arr, gpointer slot_ptr, MonoObject* value)
4269 HEAVY_STAT (++stat_wbarrier_set_arrayref);
4270 if (ptr_in_nursery (slot_ptr)) {
4271 *(void**)slot_ptr = value;
4274 SGEN_LOG (8, "Adding remset at %p", slot_ptr);
4276 binary_protocol_wbarrier (slot_ptr, value, value->vtable);
4278 remset.wbarrier_set_arrayref (arr, slot_ptr, value);
4282 mono_gc_wbarrier_arrayref_copy (gpointer dest_ptr, gpointer src_ptr, int count)
4284 HEAVY_STAT (++stat_wbarrier_arrayref_copy);
4285 /*This check can be done without taking a lock since dest_ptr array is pinned*/
4286 if (ptr_in_nursery (dest_ptr) || count <= 0) {
4287 mono_gc_memmove (dest_ptr, src_ptr, count * sizeof (gpointer));
4291 #ifdef SGEN_BINARY_PROTOCOL
4294 for (i = 0; i < count; ++i) {
4295 gpointer dest = (gpointer*)dest_ptr + i;
4296 gpointer obj = *((gpointer*)src_ptr + i);
4298 binary_protocol_wbarrier (dest, obj, (gpointer)LOAD_VTABLE (obj));
4303 remset.wbarrier_arrayref_copy (dest_ptr, src_ptr, count);
4306 static char *found_obj;
4309 find_object_for_ptr_callback (char *obj, size_t size, void *user_data)
4311 char *ptr = user_data;
4313 if (ptr >= obj && ptr < obj + size) {
4314 g_assert (!found_obj);
4319 /* for use in the debugger */
4320 char* find_object_for_ptr (char *ptr);
4322 find_object_for_ptr (char *ptr)
4324 if (ptr >= nursery_section->data && ptr < nursery_section->end_data) {
4326 sgen_scan_area_with_callback (nursery_section->data, nursery_section->end_data,
4327 find_object_for_ptr_callback, ptr, TRUE);
4333 sgen_los_iterate_objects (find_object_for_ptr_callback, ptr);
4338 * Very inefficient, but this is debugging code, supposed to
4339 * be called from gdb, so we don't care.
4342 major_collector.iterate_objects (TRUE, TRUE, find_object_for_ptr_callback, ptr);
4347 mono_gc_wbarrier_generic_nostore (gpointer ptr)
4351 HEAVY_STAT (++stat_wbarrier_generic_store);
4353 #ifdef XDOMAIN_CHECKS_IN_WBARRIER
4354 /* FIXME: ptr_in_heap must be called with the GC lock held */
4355 if (xdomain_checks && *(MonoObject**)ptr && ptr_in_heap (ptr)) {
4356 char *start = find_object_for_ptr (ptr);
4357 MonoObject *value = *(MonoObject**)ptr;
4361 MonoObject *obj = (MonoObject*)start;
4362 if (obj->vtable->domain != value->vtable->domain)
4363 g_assert (is_xdomain_ref_allowed (ptr, start, obj->vtable->domain));
4369 obj = *(gpointer*)ptr;
4371 binary_protocol_wbarrier (ptr, obj, (gpointer)LOAD_VTABLE (obj));
4373 if (ptr_in_nursery (ptr) || ptr_on_stack (ptr)) {
4374 SGEN_LOG (8, "Skipping remset at %p", ptr);
4379 * We need to record old->old pointer locations for the
4380 * concurrent collector.
4382 if (!ptr_in_nursery (obj) && !concurrent_collection_in_progress) {
4383 SGEN_LOG (8, "Skipping remset at %p", ptr);
4387 SGEN_LOG (8, "Adding remset at %p", ptr);
4389 remset.wbarrier_generic_nostore (ptr);
4393 mono_gc_wbarrier_generic_store (gpointer ptr, MonoObject* value)
4395 SGEN_LOG (8, "Wbarrier store at %p to %p (%s)", ptr, value, value ? safe_name (value) : "null");
4396 *(void**)ptr = value;
4397 if (ptr_in_nursery (value))
4398 mono_gc_wbarrier_generic_nostore (ptr);
4399 sgen_dummy_use (value);
4402 /* Same as mono_gc_wbarrier_generic_store () but performs the store
4403 * as an atomic operation with release semantics.
4406 mono_gc_wbarrier_generic_store_atomic (gpointer ptr, MonoObject *value)
4408 HEAVY_STAT (++stat_wbarrier_generic_store_atomic);
4410 SGEN_LOG (8, "Wbarrier atomic store at %p to %p (%s)", ptr, value, value ? safe_name (value) : "null");
4412 InterlockedWritePointer (ptr, value);
4414 if (ptr_in_nursery (value))
4415 mono_gc_wbarrier_generic_nostore (ptr);
4417 sgen_dummy_use (value);
4420 void mono_gc_wbarrier_value_copy_bitmap (gpointer _dest, gpointer _src, int size, unsigned bitmap)
4422 mword *dest = _dest;
4427 mono_gc_wbarrier_generic_store (dest, (MonoObject*)*src);
4432 size -= SIZEOF_VOID_P;
4437 #ifdef SGEN_BINARY_PROTOCOL
4439 #define HANDLE_PTR(ptr,obj) do { \
4440 gpointer o = *(gpointer*)(ptr); \
4442 gpointer d = ((char*)dest) + ((char*)(ptr) - (char*)(obj)); \
4443 binary_protocol_wbarrier (d, o, (gpointer) LOAD_VTABLE (o)); \
4448 scan_object_for_binary_protocol_copy_wbarrier (gpointer dest, char *start, mword desc)
4450 #define SCAN_OBJECT_NOVTABLE
4451 #include "sgen-scan-object.h"
4456 mono_gc_wbarrier_value_copy (gpointer dest, gpointer src, int count, MonoClass *klass)
4458 HEAVY_STAT (++stat_wbarrier_value_copy);
4459 g_assert (klass->valuetype);
4461 SGEN_LOG (8, "Adding value remset at %p, count %d, descr %p for class %s (%p)", dest, count, klass->gc_descr, klass->name, klass);
4463 if (ptr_in_nursery (dest) || ptr_on_stack (dest) || !SGEN_CLASS_HAS_REFERENCES (klass)) {
4464 size_t element_size = mono_class_value_size (klass, NULL);
4465 size_t size = count * element_size;
4466 mono_gc_memmove (dest, src, size);
4470 #ifdef SGEN_BINARY_PROTOCOL
4472 size_t element_size = mono_class_value_size (klass, NULL);
4474 for (i = 0; i < count; ++i) {
4475 scan_object_for_binary_protocol_copy_wbarrier ((char*)dest + i * element_size,
4476 (char*)src + i * element_size - sizeof (MonoObject),
4477 (mword) klass->gc_descr);
4482 remset.wbarrier_value_copy (dest, src, count, klass);
4486 * mono_gc_wbarrier_object_copy:
4488 * Write barrier to call when obj is the result of a clone or copy of an object.
4491 mono_gc_wbarrier_object_copy (MonoObject* obj, MonoObject *src)
4495 HEAVY_STAT (++stat_wbarrier_object_copy);
4497 if (ptr_in_nursery (obj) || ptr_on_stack (obj)) {
4498 size = mono_object_class (obj)->instance_size;
4499 mono_gc_memmove ((char*)obj + sizeof (MonoObject), (char*)src + sizeof (MonoObject),
4500 size - sizeof (MonoObject));
4504 #ifdef SGEN_BINARY_PROTOCOL
4505 scan_object_for_binary_protocol_copy_wbarrier (obj, (char*)src, (mword) src->vtable->gc_descr);
4508 remset.wbarrier_object_copy (obj, src);
4513 * ######################################################################
4514 * ######## Other mono public interface functions.
4515 * ######################################################################
4518 #define REFS_SIZE 128
4521 MonoGCReferences callback;
4525 MonoObject *refs [REFS_SIZE];
4526 uintptr_t offsets [REFS_SIZE];
4530 #define HANDLE_PTR(ptr,obj) do { \
4532 if (hwi->count == REFS_SIZE) { \
4533 hwi->callback ((MonoObject*)start, mono_object_class (start), hwi->called? 0: size, hwi->count, hwi->refs, hwi->offsets, hwi->data); \
4537 hwi->offsets [hwi->count] = (char*)(ptr)-(char*)start; \
4538 hwi->refs [hwi->count++] = *(ptr); \
4543 collect_references (HeapWalkInfo *hwi, char *start, size_t size)
4545 #include "sgen-scan-object.h"
4549 walk_references (char *start, size_t size, void *data)
4551 HeapWalkInfo *hwi = data;
4554 collect_references (hwi, start, size);
4555 if (hwi->count || !hwi->called)
4556 hwi->callback ((MonoObject*)start, mono_object_class (start), hwi->called? 0: size, hwi->count, hwi->refs, hwi->offsets, hwi->data);
4560 * mono_gc_walk_heap:
4561 * @flags: flags for future use
4562 * @callback: a function pointer called for each object in the heap
4563 * @data: a user data pointer that is passed to callback
4565 * This function can be used to iterate over all the live objects in the heap:
4566 * for each object, @callback is invoked, providing info about the object's
4567 * location in memory, its class, its size and the objects it references.
4568 * For each referenced object it's offset from the object address is
4569 * reported in the offsets array.
4570 * The object references may be buffered, so the callback may be invoked
4571 * multiple times for the same object: in all but the first call, the size
4572 * argument will be zero.
4573 * Note that this function can be only called in the #MONO_GC_EVENT_PRE_START_WORLD
4574 * profiler event handler.
4576 * Returns: a non-zero value if the GC doesn't support heap walking
4579 mono_gc_walk_heap (int flags, MonoGCReferences callback, void *data)
4584 hwi.callback = callback;
4587 sgen_clear_nursery_fragments ();
4588 sgen_scan_area_with_callback (nursery_section->data, nursery_section->end_data, walk_references, &hwi, FALSE);
4590 major_collector.iterate_objects (TRUE, TRUE, walk_references, &hwi);
4591 sgen_los_iterate_objects (walk_references, &hwi);
4597 mono_gc_collect (int generation)
4602 sgen_perform_collection (0, generation, "user request", TRUE);
4607 mono_gc_max_generation (void)
4613 mono_gc_collection_count (int generation)
4615 if (generation == 0)
4616 return stat_minor_gcs;
4617 return stat_major_gcs;
4621 mono_gc_get_used_size (void)
4625 tot = los_memory_usage;
4626 tot += nursery_section->next_data - nursery_section->data;
4627 tot += major_collector.get_used_size ();
4628 /* FIXME: account for pinned objects */
4634 mono_gc_get_los_limit (void)
4636 return MAX_SMALL_OBJ_SIZE;
4640 mono_gc_user_markers_supported (void)
4646 mono_object_is_alive (MonoObject* o)
4652 mono_gc_get_generation (MonoObject *obj)
4654 if (ptr_in_nursery (obj))
4660 mono_gc_enable_events (void)
4665 mono_gc_weak_link_add (void **link_addr, MonoObject *obj, gboolean track)
4667 sgen_register_disappearing_link (obj, link_addr, track, FALSE);
4671 mono_gc_weak_link_remove (void **link_addr, gboolean track)
4673 sgen_register_disappearing_link (NULL, link_addr, track, FALSE);
4677 mono_gc_weak_link_get (void **link_addr)
4679 void * volatile *link_addr_volatile;
4683 link_addr_volatile = link_addr;
4684 ptr = (void*)*link_addr_volatile;
4686 * At this point we have a hidden pointer. If the GC runs
4687 * here, it will not recognize the hidden pointer as a
4688 * reference, and if the object behind it is not referenced
4689 * elsewhere, it will be freed. Once the world is restarted
4690 * we reveal the pointer, giving us a pointer to a freed
4691 * object. To make sure we don't return it, we load the
4692 * hidden pointer again. If it's still the same, we can be
4693 * sure the object reference is valid.
4696 obj = (MonoObject*) REVEAL_POINTER (ptr);
4700 mono_memory_barrier ();
4703 * During the second bridge processing step the world is
4704 * running again. That step processes all weak links once
4705 * more to null those that refer to dead objects. Before that
4706 * is completed, those links must not be followed, so we
4707 * conservatively wait for bridge processing when any weak
4708 * link is dereferenced.
4710 if (G_UNLIKELY (bridge_processing_in_progress))
4711 mono_gc_wait_for_bridge_processing ();
4713 if ((void*)*link_addr_volatile != ptr)
4720 mono_gc_ephemeron_array_add (MonoObject *obj)
4722 EphemeronLinkNode *node;
4726 node = sgen_alloc_internal (INTERNAL_MEM_EPHEMERON_LINK);
4731 node->array = (char*)obj;
4732 node->next = ephemeron_list;
4733 ephemeron_list = node;
4735 SGEN_LOG (5, "Registered ephemeron array %p", obj);
4742 mono_gc_set_allow_synchronous_major (gboolean flag)
4744 if (!major_collector.is_concurrent)
4747 allow_synchronous_major = flag;
4752 mono_gc_invoke_with_gc_lock (MonoGCLockedCallbackFunc func, void *data)
4756 result = func (data);
4757 UNLOCK_INTERRUPTION;
4762 mono_gc_is_gc_thread (void)
4766 result = mono_thread_info_current () != NULL;
4772 is_critical_method (MonoMethod *method)
4774 return mono_runtime_is_critical_method (method) || sgen_is_critical_method (method);
4778 sgen_env_var_error (const char *env_var, const char *fallback, const char *description_format, ...)
4782 va_start (ap, description_format);
4784 fprintf (stderr, "Warning: In environment variable `%s': ", env_var);
4785 vfprintf (stderr, description_format, ap);
4787 fprintf (stderr, " - %s", fallback);
4788 fprintf (stderr, "\n");
4794 parse_double_in_interval (const char *env_var, const char *opt_name, const char *opt, double min, double max, double *result)
4797 double val = strtod (opt, &endptr);
4798 if (endptr == opt) {
4799 sgen_env_var_error (env_var, "Using default value.", "`%s` must be a number.", opt_name);
4802 else if (val < min || val > max) {
4803 sgen_env_var_error (env_var, "Using default value.", "`%s` must be between %.2f - %.2f.", opt_name, min, max);
4811 mono_gc_base_init (void)
4813 MonoThreadInfoCallbacks cb;
4816 char *major_collector_opt = NULL;
4817 char *minor_collector_opt = NULL;
4819 glong soft_limit = 0;
4823 gboolean debug_print_allowance = FALSE;
4824 double allowance_ratio = 0, save_target = 0;
4825 gboolean have_split_nursery = FALSE;
4826 gboolean cement_enabled = TRUE;
4829 result = InterlockedCompareExchange (&gc_initialized, -1, 0);
4832 /* already inited */
4835 /* being inited by another thread */
4839 /* we will init it */
4842 g_assert_not_reached ();
4844 } while (result != 0);
4846 LOCK_INIT (gc_mutex);
4848 pagesize = mono_pagesize ();
4849 gc_debug_file = stderr;
4851 cb.thread_register = sgen_thread_register;
4852 cb.thread_detach = sgen_thread_detach;
4853 cb.thread_unregister = sgen_thread_unregister;
4854 cb.thread_attach = sgen_thread_attach;
4855 cb.mono_method_is_critical = (gpointer)is_critical_method;
4857 cb.thread_exit = mono_gc_pthread_exit;
4858 cb.mono_gc_pthread_create = (gpointer)mono_gc_pthread_create;
4861 mono_threads_init (&cb, sizeof (SgenThreadInfo));
4863 LOCK_INIT (sgen_interruption_mutex);
4864 LOCK_INIT (pin_queue_mutex);
4866 init_user_copy_or_mark_key ();
4868 if ((env = g_getenv (MONO_GC_PARAMS_NAME))) {
4869 opts = g_strsplit (env, ",", -1);
4870 for (ptr = opts; *ptr; ++ptr) {
4872 if (g_str_has_prefix (opt, "major=")) {
4873 opt = strchr (opt, '=') + 1;
4874 major_collector_opt = g_strdup (opt);
4875 } else if (g_str_has_prefix (opt, "minor=")) {
4876 opt = strchr (opt, '=') + 1;
4877 minor_collector_opt = g_strdup (opt);
4885 sgen_init_internal_allocator ();
4886 sgen_init_nursery_allocator ();
4887 sgen_init_fin_weak_hash ();
4889 sgen_register_fixed_internal_mem_type (INTERNAL_MEM_SECTION, SGEN_SIZEOF_GC_MEM_SECTION);
4890 sgen_register_fixed_internal_mem_type (INTERNAL_MEM_FINALIZE_READY_ENTRY, sizeof (FinalizeReadyEntry));
4891 sgen_register_fixed_internal_mem_type (INTERNAL_MEM_GRAY_QUEUE, sizeof (GrayQueueSection));
4892 sgen_register_fixed_internal_mem_type (INTERNAL_MEM_EPHEMERON_LINK, sizeof (EphemeronLinkNode));
4894 #ifndef HAVE_KW_THREAD
4895 mono_native_tls_alloc (&thread_info_key, NULL);
4896 #if defined(__APPLE__) || defined (HOST_WIN32)
4898 * CEE_MONO_TLS requires the tls offset, not the key, so the code below only works on darwin,
4899 * where the two are the same.
4901 mono_tls_key_set_offset (TLS_KEY_SGEN_THREAD_INFO, thread_info_key);
4905 int tls_offset = -1;
4906 MONO_THREAD_VAR_OFFSET (sgen_thread_info, tls_offset);
4907 mono_tls_key_set_offset (TLS_KEY_SGEN_THREAD_INFO, tls_offset);
4912 * This needs to happen before any internal allocations because
4913 * it inits the small id which is required for hazard pointer
4918 mono_thread_info_attach (&dummy);
4920 if (!minor_collector_opt) {
4921 sgen_simple_nursery_init (&sgen_minor_collector);
4923 if (!strcmp (minor_collector_opt, "simple")) {
4925 sgen_simple_nursery_init (&sgen_minor_collector);
4926 } else if (!strcmp (minor_collector_opt, "split")) {
4927 sgen_split_nursery_init (&sgen_minor_collector);
4928 have_split_nursery = TRUE;
4930 sgen_env_var_error (MONO_GC_PARAMS_NAME, "Using `simple` instead.", "Unknown minor collector `%s'.", minor_collector_opt);
4931 goto use_simple_nursery;
4935 if (!major_collector_opt || !strcmp (major_collector_opt, "marksweep")) {
4936 use_marksweep_major:
4937 sgen_marksweep_init (&major_collector);
4938 } else if (!major_collector_opt || !strcmp (major_collector_opt, "marksweep-fixed")) {
4939 sgen_marksweep_fixed_init (&major_collector);
4940 } else if (!major_collector_opt || !strcmp (major_collector_opt, "marksweep-par")) {
4941 sgen_marksweep_par_init (&major_collector);
4942 } else if (!major_collector_opt || !strcmp (major_collector_opt, "marksweep-fixed-par")) {
4943 sgen_marksweep_fixed_par_init (&major_collector);
4944 } else if (!major_collector_opt || !strcmp (major_collector_opt, "marksweep-conc")) {
4945 sgen_marksweep_conc_init (&major_collector);
4947 sgen_env_var_error (MONO_GC_PARAMS_NAME, "Using `marksweep` instead.", "Unknown major collector `%s'.", major_collector_opt);
4948 goto use_marksweep_major;
4951 if (have_split_nursery && major_collector.is_parallel) {
4952 sgen_env_var_error (MONO_GC_PARAMS_NAME, "Disabling split minor collector.", "`minor=split` is not supported with the parallel collector yet.");
4953 have_split_nursery = FALSE;
4956 num_workers = mono_cpu_count ();
4957 g_assert (num_workers > 0);
4958 if (num_workers > 16)
4961 ///* Keep this the default for now */
4962 /* Precise marking is broken on all supported targets. Disable until fixed. */
4963 conservative_stack_mark = TRUE;
4965 sgen_nursery_size = DEFAULT_NURSERY_SIZE;
4968 gboolean usage_printed = FALSE;
4970 for (ptr = opts; *ptr; ++ptr) {
4972 if (!strcmp (opt, ""))
4974 if (g_str_has_prefix (opt, "major="))
4976 if (g_str_has_prefix (opt, "minor="))
4978 if (g_str_has_prefix (opt, "max-heap-size=")) {
4979 glong max_heap_candidate = 0;
4980 opt = strchr (opt, '=') + 1;
4981 if (*opt && mono_gc_parse_environment_string_extract_number (opt, &max_heap_candidate)) {
4982 max_heap = (max_heap_candidate + mono_pagesize () - 1) & ~(glong)(mono_pagesize () - 1);
4983 if (max_heap != max_heap_candidate)
4984 sgen_env_var_error (MONO_GC_PARAMS_NAME, "Rounding up.", "`max-heap-size` size must be a multiple of %d.", mono_pagesize ());
4986 sgen_env_var_error (MONO_GC_PARAMS_NAME, NULL, "`max-heap-size` must be an integer.");
4990 if (g_str_has_prefix (opt, "soft-heap-limit=")) {
4991 opt = strchr (opt, '=') + 1;
4992 if (*opt && mono_gc_parse_environment_string_extract_number (opt, &soft_limit)) {
4993 if (soft_limit <= 0) {
4994 sgen_env_var_error (MONO_GC_PARAMS_NAME, NULL, "`soft-heap-limit` must be positive.");
4998 sgen_env_var_error (MONO_GC_PARAMS_NAME, NULL, "`soft-heap-limit` must be an integer.");
5002 if (g_str_has_prefix (opt, "workers=")) {
5005 if (!major_collector.is_parallel) {
5006 sgen_env_var_error (MONO_GC_PARAMS_NAME, "Ignoring.", "The `workers` option can only be used for parallel collectors.");
5009 opt = strchr (opt, '=') + 1;
5010 val = strtol (opt, &endptr, 10);
5011 if (!*opt || *endptr) {
5012 sgen_env_var_error (MONO_GC_PARAMS_NAME, "Ignoring.", "Cannot parse the `workers` option value.");
5015 if (val <= 0 || val > 16) {
5016 sgen_env_var_error (MONO_GC_PARAMS_NAME, "Using default value.", "The number of `workers` must be in the range 1 to 16.");
5019 num_workers = (int)val;
5022 if (g_str_has_prefix (opt, "stack-mark=")) {
5023 opt = strchr (opt, '=') + 1;
5024 if (!strcmp (opt, "precise")) {
5025 conservative_stack_mark = FALSE;
5026 } else if (!strcmp (opt, "conservative")) {
5027 conservative_stack_mark = TRUE;
5029 sgen_env_var_error (MONO_GC_PARAMS_NAME, conservative_stack_mark ? "Using `conservative`." : "Using `precise`.",
5030 "Invalid value `%s` for `stack-mark` option, possible values are: `precise`, `conservative`.", opt);
5034 if (g_str_has_prefix (opt, "bridge=")) {
5035 opt = strchr (opt, '=') + 1;
5036 sgen_register_test_bridge_callbacks (g_strdup (opt));
5040 if (g_str_has_prefix (opt, "nursery-size=")) {
5042 opt = strchr (opt, '=') + 1;
5043 if (*opt && mono_gc_parse_environment_string_extract_number (opt, &val)) {
5044 #ifdef SGEN_ALIGN_NURSERY
5045 if ((val & (val - 1))) {
5046 sgen_env_var_error (MONO_GC_PARAMS_NAME, "Using default value.", "`nursery-size` must be a power of two.");
5050 if (val < SGEN_MAX_NURSERY_WASTE) {
5051 sgen_env_var_error (MONO_GC_PARAMS_NAME, "Using default value.",
5052 "`nursery-size` must be at least %d bytes.\n", SGEN_MAX_NURSERY_WASTE);
5056 sgen_nursery_size = val;
5057 sgen_nursery_bits = 0;
5058 while (1 << (++ sgen_nursery_bits) != sgen_nursery_size)
5061 sgen_nursery_size = val;
5064 sgen_env_var_error (MONO_GC_PARAMS_NAME, "Using default value.", "`nursery-size` must be an integer.");
5070 if (g_str_has_prefix (opt, "save-target-ratio=")) {
5072 opt = strchr (opt, '=') + 1;
5073 if (parse_double_in_interval (MONO_GC_PARAMS_NAME, "save-target-ratio", opt,
5074 SGEN_MIN_SAVE_TARGET_RATIO, SGEN_MAX_SAVE_TARGET_RATIO, &val)) {
5079 if (g_str_has_prefix (opt, "default-allowance-ratio=")) {
5081 opt = strchr (opt, '=') + 1;
5082 if (parse_double_in_interval (MONO_GC_PARAMS_NAME, "default-allowance-ratio", opt,
5083 SGEN_MIN_ALLOWANCE_NURSERY_SIZE_RATIO, SGEN_MIN_ALLOWANCE_NURSERY_SIZE_RATIO, &val)) {
5084 allowance_ratio = val;
5088 if (g_str_has_prefix (opt, "allow-synchronous-major=")) {
5089 if (!major_collector.is_concurrent) {
5090 sgen_env_var_error (MONO_GC_PARAMS_NAME, "Ignoring.", "`allow-synchronous-major` is only valid for the concurrent major collector.");
5094 opt = strchr (opt, '=') + 1;
5096 if (!strcmp (opt, "yes")) {
5097 allow_synchronous_major = TRUE;
5098 } else if (!strcmp (opt, "no")) {
5099 allow_synchronous_major = FALSE;
5101 sgen_env_var_error (MONO_GC_PARAMS_NAME, "Using default value.", "`allow-synchronous-major` must be either `yes' or `no'.");
5106 if (!strcmp (opt, "cementing")) {
5107 if (major_collector.is_parallel) {
5108 sgen_env_var_error (MONO_GC_PARAMS_NAME, "Ignoring.", "`cementing` is not supported for the parallel major collector.");
5111 cement_enabled = TRUE;
5114 if (!strcmp (opt, "no-cementing")) {
5115 cement_enabled = FALSE;
5119 if (major_collector.handle_gc_param && major_collector.handle_gc_param (opt))
5122 if (sgen_minor_collector.handle_gc_param && sgen_minor_collector.handle_gc_param (opt))
5125 sgen_env_var_error (MONO_GC_PARAMS_NAME, "Ignoring.", "Unknown option `%s`.", opt);
5130 fprintf (stderr, "\n%s must be a comma-delimited list of one or more of the following:\n", MONO_GC_PARAMS_NAME);
5131 fprintf (stderr, " max-heap-size=N (where N is an integer, possibly with a k, m or a g suffix)\n");
5132 fprintf (stderr, " soft-heap-limit=n (where N is an integer, possibly with a k, m or a g suffix)\n");
5133 fprintf (stderr, " nursery-size=N (where N is an integer, possibly with a k, m or a g suffix)\n");
5134 fprintf (stderr, " major=COLLECTOR (where COLLECTOR is `marksweep', `marksweep-conc', `marksweep-par', 'marksweep-fixed' or 'marksweep-fixed-par')\n");
5135 fprintf (stderr, " minor=COLLECTOR (where COLLECTOR is `simple' or `split')\n");
5136 fprintf (stderr, " wbarrier=WBARRIER (where WBARRIER is `remset' or `cardtable')\n");
5137 fprintf (stderr, " stack-mark=MARK-METHOD (where MARK-METHOD is 'precise' or 'conservative')\n");
5138 fprintf (stderr, " [no-]cementing\n");
5139 if (major_collector.is_concurrent)
5140 fprintf (stderr, " allow-synchronous-major=FLAG (where FLAG is `yes' or `no')\n");
5141 if (major_collector.print_gc_param_usage)
5142 major_collector.print_gc_param_usage ();
5143 if (sgen_minor_collector.print_gc_param_usage)
5144 sgen_minor_collector.print_gc_param_usage ();
5145 fprintf (stderr, " Experimental options:\n");
5146 fprintf (stderr, " save-target-ratio=R (where R must be between %.2f - %.2f).\n", SGEN_MIN_SAVE_TARGET_RATIO, SGEN_MAX_SAVE_TARGET_RATIO);
5147 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);
5148 fprintf (stderr, "\n");
5150 usage_printed = TRUE;
5155 if (major_collector.is_parallel) {
5156 cement_enabled = FALSE;
5157 sgen_workers_init (num_workers);
5158 } else if (major_collector.is_concurrent) {
5159 sgen_workers_init (1);
5162 if (major_collector_opt)
5163 g_free (major_collector_opt);
5165 if (minor_collector_opt)
5166 g_free (minor_collector_opt);
5170 sgen_cement_init (cement_enabled);
5172 if ((env = g_getenv (MONO_GC_DEBUG_NAME))) {
5173 gboolean usage_printed = FALSE;
5175 opts = g_strsplit (env, ",", -1);
5176 for (ptr = opts; ptr && *ptr; ptr ++) {
5178 if (!strcmp (opt, ""))
5180 if (opt [0] >= '0' && opt [0] <= '9') {
5181 gc_debug_level = atoi (opt);
5187 char *rf = g_strdup_printf ("%s.%d", opt, GetCurrentProcessId ());
5189 char *rf = g_strdup_printf ("%s.%d", opt, getpid ());
5191 gc_debug_file = fopen (rf, "wb");
5193 gc_debug_file = stderr;
5196 } else if (!strcmp (opt, "print-allowance")) {
5197 debug_print_allowance = TRUE;
5198 } else if (!strcmp (opt, "print-pinning")) {
5199 do_pin_stats = TRUE;
5200 } else if (!strcmp (opt, "verify-before-allocs")) {
5201 verify_before_allocs = 1;
5202 has_per_allocation_action = TRUE;
5203 } else if (g_str_has_prefix (opt, "verify-before-allocs=")) {
5204 char *arg = strchr (opt, '=') + 1;
5205 verify_before_allocs = atoi (arg);
5206 has_per_allocation_action = TRUE;
5207 } else if (!strcmp (opt, "collect-before-allocs")) {
5208 collect_before_allocs = 1;
5209 has_per_allocation_action = TRUE;
5210 } else if (g_str_has_prefix (opt, "collect-before-allocs=")) {
5211 char *arg = strchr (opt, '=') + 1;
5212 has_per_allocation_action = TRUE;
5213 collect_before_allocs = atoi (arg);
5214 } else if (!strcmp (opt, "verify-before-collections")) {
5215 whole_heap_check_before_collection = TRUE;
5216 } else if (!strcmp (opt, "check-at-minor-collections")) {
5217 consistency_check_at_minor_collection = TRUE;
5218 nursery_clear_policy = CLEAR_AT_GC;
5219 } else if (!strcmp (opt, "mod-union-consistency-check")) {
5220 if (!major_collector.is_concurrent) {
5221 sgen_env_var_error (MONO_GC_DEBUG_NAME, "Ignoring.", "`mod-union-consistency-check` only works with concurrent major collector.");
5224 mod_union_consistency_check = TRUE;
5225 } else if (!strcmp (opt, "check-mark-bits")) {
5226 check_mark_bits_after_major_collection = TRUE;
5227 } else if (!strcmp (opt, "check-nursery-pinned")) {
5228 check_nursery_objects_pinned = TRUE;
5229 } else if (!strcmp (opt, "xdomain-checks")) {
5230 xdomain_checks = TRUE;
5231 } else if (!strcmp (opt, "clear-at-gc")) {
5232 nursery_clear_policy = CLEAR_AT_GC;
5233 } else if (!strcmp (opt, "clear-nursery-at-gc")) {
5234 nursery_clear_policy = CLEAR_AT_GC;
5235 } else if (!strcmp (opt, "check-scan-starts")) {
5236 do_scan_starts_check = TRUE;
5237 } else if (!strcmp (opt, "verify-nursery-at-minor-gc")) {
5238 do_verify_nursery = TRUE;
5239 } else if (!strcmp (opt, "check-concurrent")) {
5240 if (!major_collector.is_concurrent) {
5241 sgen_env_var_error (MONO_GC_DEBUG_NAME, "Ignoring.", "`check-concurrent` only works with concurrent major collectors.");
5244 do_concurrent_checks = TRUE;
5245 } else if (!strcmp (opt, "dump-nursery-at-minor-gc")) {
5246 do_dump_nursery_content = TRUE;
5247 } else if (!strcmp (opt, "no-managed-allocator")) {
5248 sgen_set_use_managed_allocator (FALSE);
5249 } else if (!strcmp (opt, "disable-minor")) {
5250 disable_minor_collections = TRUE;
5251 } else if (!strcmp (opt, "disable-major")) {
5252 disable_major_collections = TRUE;
5253 } else if (g_str_has_prefix (opt, "heap-dump=")) {
5254 char *filename = strchr (opt, '=') + 1;
5255 nursery_clear_policy = CLEAR_AT_GC;
5256 heap_dump_file = fopen (filename, "w");
5257 if (heap_dump_file) {
5258 fprintf (heap_dump_file, "<sgen-dump>\n");
5259 do_pin_stats = TRUE;
5261 #ifdef SGEN_BINARY_PROTOCOL
5262 } else if (g_str_has_prefix (opt, "binary-protocol=")) {
5263 char *filename = strchr (opt, '=') + 1;
5264 binary_protocol_init (filename);
5267 sgen_env_var_error (MONO_GC_DEBUG_NAME, "Ignoring.", "Unknown option `%s`.", opt);
5272 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);
5273 fprintf (stderr, "Valid <option>s are:\n");
5274 fprintf (stderr, " collect-before-allocs[=<n>]\n");
5275 fprintf (stderr, " verify-before-allocs[=<n>]\n");
5276 fprintf (stderr, " check-at-minor-collections\n");
5277 fprintf (stderr, " check-mark-bits\n");
5278 fprintf (stderr, " check-nursery-pinned\n");
5279 fprintf (stderr, " verify-before-collections\n");
5280 fprintf (stderr, " verify-nursery-at-minor-gc\n");
5281 fprintf (stderr, " dump-nursery-at-minor-gc\n");
5282 fprintf (stderr, " disable-minor\n");
5283 fprintf (stderr, " disable-major\n");
5284 fprintf (stderr, " xdomain-checks\n");
5285 fprintf (stderr, " check-concurrent\n");
5286 fprintf (stderr, " clear-at-gc\n");
5287 fprintf (stderr, " clear-nursery-at-gc\n");
5288 fprintf (stderr, " check-scan-starts\n");
5289 fprintf (stderr, " no-managed-allocator\n");
5290 fprintf (stderr, " print-allowance\n");
5291 fprintf (stderr, " print-pinning\n");
5292 fprintf (stderr, " heap-dump=<filename>\n");
5293 #ifdef SGEN_BINARY_PROTOCOL
5294 fprintf (stderr, " binary-protocol=<filename>\n");
5296 fprintf (stderr, "\n");
5298 usage_printed = TRUE;
5304 if (major_collector.is_parallel) {
5305 if (heap_dump_file) {
5306 sgen_env_var_error (MONO_GC_DEBUG_NAME, "Disabling.", "Cannot do `heap-dump` with the parallel collector.");
5307 fclose (heap_dump_file);
5308 heap_dump_file = NULL;
5311 sgen_env_var_error (MONO_GC_DEBUG_NAME, "Disabling.", "`print-pinning` is not supported with the parallel collector.");
5312 do_pin_stats = FALSE;
5316 if (major_collector.post_param_init)
5317 major_collector.post_param_init (&major_collector);
5319 sgen_memgov_init (max_heap, soft_limit, debug_print_allowance, allowance_ratio, save_target);
5321 memset (&remset, 0, sizeof (remset));
5323 sgen_card_table_init (&remset);
5329 mono_gc_get_gc_name (void)
5334 static MonoMethod *write_barrier_method;
5337 sgen_is_critical_method (MonoMethod *method)
5339 return (method == write_barrier_method || sgen_is_managed_allocator (method));
5343 sgen_has_critical_method (void)
5345 return write_barrier_method || sgen_has_managed_allocator ();
5351 emit_nursery_check (MonoMethodBuilder *mb, int *nursery_check_return_labels)
5353 memset (nursery_check_return_labels, 0, sizeof (int) * 3);
5354 #ifdef SGEN_ALIGN_NURSERY
5355 // if (ptr_in_nursery (ptr)) return;
5357 * Masking out the bits might be faster, but we would have to use 64 bit
5358 * immediates, which might be slower.
5360 mono_mb_emit_ldarg (mb, 0);
5361 mono_mb_emit_icon (mb, DEFAULT_NURSERY_BITS);
5362 mono_mb_emit_byte (mb, CEE_SHR_UN);
5363 mono_mb_emit_icon (mb, (mword)sgen_get_nursery_start () >> DEFAULT_NURSERY_BITS);
5364 nursery_check_return_labels [0] = mono_mb_emit_branch (mb, CEE_BEQ);
5366 if (!major_collector.is_concurrent) {
5367 // if (!ptr_in_nursery (*ptr)) return;
5368 mono_mb_emit_ldarg (mb, 0);
5369 mono_mb_emit_byte (mb, CEE_LDIND_I);
5370 mono_mb_emit_icon (mb, DEFAULT_NURSERY_BITS);
5371 mono_mb_emit_byte (mb, CEE_SHR_UN);
5372 mono_mb_emit_icon (mb, (mword)sgen_get_nursery_start () >> DEFAULT_NURSERY_BITS);
5373 nursery_check_return_labels [1] = mono_mb_emit_branch (mb, CEE_BNE_UN);
5376 int label_continue1, label_continue2;
5377 int dereferenced_var;
5379 // if (ptr < (sgen_get_nursery_start ())) goto continue;
5380 mono_mb_emit_ldarg (mb, 0);
5381 mono_mb_emit_ptr (mb, (gpointer) sgen_get_nursery_start ());
5382 label_continue_1 = mono_mb_emit_branch (mb, CEE_BLT);
5384 // if (ptr >= sgen_get_nursery_end ())) goto continue;
5385 mono_mb_emit_ldarg (mb, 0);
5386 mono_mb_emit_ptr (mb, (gpointer) sgen_get_nursery_end ());
5387 label_continue_2 = mono_mb_emit_branch (mb, CEE_BGE);
5390 nursery_check_return_labels [0] = mono_mb_emit_branch (mb, CEE_BR);
5393 mono_mb_patch_branch (mb, label_continue_1);
5394 mono_mb_patch_branch (mb, label_continue_2);
5396 // Dereference and store in local var
5397 dereferenced_var = mono_mb_add_local (mb, &mono_defaults.int_class->byval_arg);
5398 mono_mb_emit_ldarg (mb, 0);
5399 mono_mb_emit_byte (mb, CEE_LDIND_I);
5400 mono_mb_emit_stloc (mb, dereferenced_var);
5402 if (!major_collector.is_concurrent) {
5403 // if (*ptr < sgen_get_nursery_start ()) return;
5404 mono_mb_emit_ldloc (mb, dereferenced_var);
5405 mono_mb_emit_ptr (mb, (gpointer) sgen_get_nursery_start ());
5406 nursery_check_return_labels [1] = mono_mb_emit_branch (mb, CEE_BLT);
5408 // if (*ptr >= sgen_get_nursery_end ()) return;
5409 mono_mb_emit_ldloc (mb, dereferenced_var);
5410 mono_mb_emit_ptr (mb, (gpointer) sgen_get_nursery_end ());
5411 nursery_check_return_labels [2] = mono_mb_emit_branch (mb, CEE_BGE);
5418 mono_gc_get_write_barrier (void)
5421 MonoMethodBuilder *mb;
5422 MonoMethodSignature *sig;
5423 #ifdef MANAGED_WBARRIER
5424 int i, nursery_check_labels [3];
5426 #ifdef HAVE_KW_THREAD
5427 int stack_end_offset = -1;
5429 MONO_THREAD_VAR_OFFSET (stack_end, stack_end_offset);
5430 g_assert (stack_end_offset != -1);
5434 // FIXME: Maybe create a separate version for ctors (the branch would be
5435 // correctly predicted more times)
5436 if (write_barrier_method)
5437 return write_barrier_method;
5439 /* Create the IL version of mono_gc_barrier_generic_store () */
5440 sig = mono_metadata_signature_alloc (mono_defaults.corlib, 1);
5441 sig->ret = &mono_defaults.void_class->byval_arg;
5442 sig->params [0] = &mono_defaults.int_class->byval_arg;
5444 mb = mono_mb_new (mono_defaults.object_class, "wbarrier", MONO_WRAPPER_WRITE_BARRIER);
5447 #ifdef MANAGED_WBARRIER
5448 emit_nursery_check (mb, nursery_check_labels);
5450 addr = sgen_cardtable + ((address >> CARD_BITS) & CARD_MASK)
5454 LDC_PTR sgen_cardtable
5456 address >> CARD_BITS
5460 if (SGEN_HAVE_OVERLAPPING_CARDS) {
5461 LDC_PTR card_table_mask
5468 mono_mb_emit_ptr (mb, sgen_cardtable);
5469 mono_mb_emit_ldarg (mb, 0);
5470 mono_mb_emit_icon (mb, CARD_BITS);
5471 mono_mb_emit_byte (mb, CEE_SHR_UN);
5472 #ifdef SGEN_HAVE_OVERLAPPING_CARDS
5473 mono_mb_emit_ptr (mb, (gpointer)CARD_MASK);
5474 mono_mb_emit_byte (mb, CEE_AND);
5476 mono_mb_emit_byte (mb, CEE_ADD);
5477 mono_mb_emit_icon (mb, 1);
5478 mono_mb_emit_byte (mb, CEE_STIND_I1);
5481 for (i = 0; i < 3; ++i) {
5482 if (nursery_check_labels [i])
5483 mono_mb_patch_branch (mb, nursery_check_labels [i]);
5485 mono_mb_emit_byte (mb, CEE_RET);
5487 mono_mb_emit_ldarg (mb, 0);
5488 mono_mb_emit_icall (mb, mono_gc_wbarrier_generic_nostore);
5489 mono_mb_emit_byte (mb, CEE_RET);
5492 res = mono_mb_create_method (mb, sig, 16);
5496 if (write_barrier_method) {
5497 /* Already created */
5498 mono_free_method (res);
5500 /* double-checked locking */
5501 mono_memory_barrier ();
5502 write_barrier_method = res;
5506 return write_barrier_method;
5510 mono_gc_get_description (void)
5512 return g_strdup ("sgen");
5516 mono_gc_set_desktop_mode (void)
5521 mono_gc_is_moving (void)
5527 mono_gc_is_disabled (void)
5533 BOOL APIENTRY mono_gc_dllmain (HMODULE module_handle, DWORD reason, LPVOID reserved)
5540 sgen_get_nursery_clear_policy (void)
5542 return nursery_clear_policy;
5546 sgen_get_array_fill_vtable (void)
5548 if (!array_fill_vtable) {
5549 static MonoClass klass;
5550 static MonoVTable vtable;
5553 MonoDomain *domain = mono_get_root_domain ();
5556 klass.element_class = mono_defaults.byte_class;
5558 klass.instance_size = sizeof (MonoArray);
5559 klass.sizes.element_size = 1;
5560 klass.name = "array_filler_type";
5562 vtable.klass = &klass;
5564 vtable.gc_descr = mono_gc_make_descr_for_array (TRUE, &bmap, 0, 1);
5567 array_fill_vtable = &vtable;
5569 return array_fill_vtable;
5579 sgen_gc_unlock (void)
5581 gboolean try_free = sgen_try_free_some_memory;
5582 sgen_try_free_some_memory = FALSE;
5583 mono_mutex_unlock (&gc_mutex);
5584 MONO_GC_UNLOCKED ();
5586 mono_thread_hazardous_try_free_some ();
5590 sgen_major_collector_iterate_live_block_ranges (sgen_cardtable_block_callback callback)
5592 major_collector.iterate_live_block_ranges (callback);
5596 sgen_major_collector_scan_card_table (SgenGrayQueue *queue)
5598 major_collector.scan_card_table (FALSE, queue);
5602 sgen_get_major_collector (void)
5604 return &major_collector;
5607 void mono_gc_set_skip_thread (gboolean skip)
5609 SgenThreadInfo *info = mono_thread_info_current ();
5612 info->gc_disabled = skip;
5617 sgen_get_remset (void)
5623 mono_gc_get_vtable_bits (MonoClass *class)
5625 if (sgen_need_bridge_processing () && sgen_is_bridge_class (class))
5626 return SGEN_GC_BIT_BRIDGE_OBJECT;
5631 mono_gc_register_altstack (gpointer stack, gint32 stack_size, gpointer altstack, gint32 altstack_size)
5638 sgen_check_whole_heap_stw (void)
5640 sgen_stop_world (0);
5641 sgen_clear_nursery_fragments ();
5642 sgen_check_whole_heap (FALSE);
5643 sgen_restart_world (0, NULL);
5647 sgen_gc_event_moves (void)
5649 if (moved_objects_idx) {
5650 mono_profiler_gc_moves (moved_objects, moved_objects_idx);
5651 moved_objects_idx = 0;
5655 #endif /* HAVE_SGEN_GC */