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.
17 * THIS MATERIAL IS PROVIDED AS IS, WITH ABSOLUTELY NO WARRANTY EXPRESSED
18 * OR IMPLIED. ANY USE IS AT YOUR OWN RISK.
20 * Permission is hereby granted to use or copy this program
21 * for any purpose, provided the above notices are retained on all copies.
22 * Permission to modify the code and to distribute modified code is granted,
23 * provided the above notices are retained, and a notice that the code was
24 * modified is included with the above copyright notice.
27 * Copyright 2001-2003 Ximian, Inc
28 * Copyright 2003-2010 Novell, Inc.
29 * Copyright 2011 Xamarin, Inc.
31 * Permission is hereby granted, free of charge, to any person obtaining
32 * a copy of this software and associated documentation files (the
33 * "Software"), to deal in the Software without restriction, including
34 * without limitation the rights to use, copy, modify, merge, publish,
35 * distribute, sublicense, and/or sell copies of the Software, and to
36 * permit persons to whom the Software is furnished to do so, subject to
37 * the following conditions:
39 * The above copyright notice and this permission notice shall be
40 * included in all copies or substantial portions of the Software.
42 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
43 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
44 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
45 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
46 * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
47 * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
48 * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
51 * Important: allocation provides always zeroed memory, having to do
52 * a memset after allocation is deadly for performance.
53 * Memory usage at startup is currently as follows:
55 * 64 KB internal space
57 * We should provide a small memory config with half the sizes
59 * We currently try to make as few mono assumptions as possible:
60 * 1) 2-word header with no GC pointers in it (first vtable, second to store the
62 * 2) gc descriptor is the second word in the vtable (first word in the class)
63 * 3) 8 byte alignment is the minimum and enough (not true for special structures (SIMD), FIXME)
64 * 4) there is a function to get an object's size and the number of
65 * elements in an array.
66 * 5) we know the special way bounds are allocated for complex arrays
67 * 6) we know about proxies and how to treat them when domains are unloaded
69 * Always try to keep stack usage to a minimum: no recursive behaviour
70 * and no large stack allocs.
72 * General description.
73 * Objects are initially allocated in a nursery using a fast bump-pointer technique.
74 * When the nursery is full we start a nursery collection: this is performed with a
76 * When the old generation is full we start a copying GC of the old generation as well:
77 * this will be changed to mark&sweep with copying when fragmentation becomes to severe
78 * in the future. Maybe we'll even do both during the same collection like IMMIX.
80 * The things that complicate this description are:
81 * *) pinned objects: we can't move them so we need to keep track of them
82 * *) no precise info of the thread stacks and registers: we need to be able to
83 * quickly find the objects that may be referenced conservatively and pin them
84 * (this makes the first issues more important)
85 * *) large objects are too expensive to be dealt with using copying GC: we handle them
86 * with mark/sweep during major collections
87 * *) some objects need to not move even if they are small (interned strings, Type handles):
88 * we use mark/sweep for them, too: they are not allocated in the nursery, but inside
89 * PinnedChunks regions
95 *) we could have a function pointer in MonoClass to implement
96 customized write barriers for value types
98 *) investigate the stuff needed to advance a thread to a GC-safe
99 point (single-stepping, read from unmapped memory etc) and implement it.
100 This would enable us to inline allocations and write barriers, for example,
101 or at least parts of them, like the write barrier checks.
102 We may need this also for handling precise info on stacks, even simple things
103 as having uninitialized data on the stack and having to wait for the prolog
104 to zero it. Not an issue for the last frame that we scan conservatively.
105 We could always not trust the value in the slots anyway.
107 *) modify the jit to save info about references in stack locations:
108 this can be done just for locals as a start, so that at least
109 part of the stack is handled precisely.
111 *) test/fix endianess issues
113 *) Implement a card table as the write barrier instead of remembered
114 sets? Card tables are not easy to implement with our current
115 memory layout. We have several different kinds of major heap
116 objects: Small objects in regular blocks, small objects in pinned
117 chunks and LOS objects. If we just have a pointer we have no way
118 to tell which kind of object it points into, therefore we cannot
119 know where its card table is. The least we have to do to make
120 this happen is to get rid of write barriers for indirect stores.
123 *) Get rid of write barriers for indirect stores. We can do this by
124 telling the GC to wbarrier-register an object once we do an ldloca
125 or ldelema on it, and to unregister it once it's not used anymore
126 (it can only travel downwards on the stack). The problem with
127 unregistering is that it needs to happen eventually no matter
128 what, even if exceptions are thrown, the thread aborts, etc.
129 Rodrigo suggested that we could do only the registering part and
130 let the collector find out (pessimistically) when it's safe to
131 unregister, namely when the stack pointer of the thread that
132 registered the object is higher than it was when the registering
133 happened. This might make for a good first implementation to get
134 some data on performance.
136 *) Some sort of blacklist support? Blacklists is a concept from the
137 Boehm GC: if during a conservative scan we find pointers to an
138 area which we might use as heap, we mark that area as unusable, so
139 pointer retention by random pinning pointers is reduced.
141 *) experiment with max small object size (very small right now - 2kb,
142 because it's tied to the max freelist size)
144 *) add an option to mmap the whole heap in one chunk: it makes for many
145 simplifications in the checks (put the nursery at the top and just use a single
146 check for inclusion/exclusion): the issue this has is that on 32 bit systems it's
147 not flexible (too much of the address space may be used by default or we can't
148 increase the heap as needed) and we'd need a race-free mechanism to return memory
149 back to the system (mprotect(PROT_NONE) will still keep the memory allocated if it
150 was written to, munmap is needed, but the following mmap may not find the same segment
153 *) memzero the major fragments after restarting the world and optionally a smaller
156 *) investigate having fragment zeroing threads
158 *) separate locks for finalization and other minor stuff to reduce
161 *) try a different copying order to improve memory locality
163 *) a thread abort after a store but before the write barrier will
164 prevent the write barrier from executing
166 *) specialized dynamically generated markers/copiers
168 *) Dynamically adjust TLAB size to the number of threads. If we have
169 too many threads that do allocation, we might need smaller TLABs,
170 and we might get better performance with larger TLABs if we only
171 have a handful of threads. We could sum up the space left in all
172 assigned TLABs and if that's more than some percentage of the
173 nursery size, reduce the TLAB size.
175 *) Explore placing unreachable objects on unused nursery memory.
176 Instead of memset'ng a region to zero, place an int[] covering it.
177 A good place to start is add_nursery_frag. The tricky thing here is
178 placing those objects atomically outside of a collection.
180 *) Allocation should use asymmetric Dekker synchronization:
181 http://blogs.oracle.com/dave/resource/Asymmetric-Dekker-Synchronization.txt
182 This should help weak consistency archs.
189 #define _XOPEN_SOURCE
190 #define _DARWIN_C_SOURCE
196 #ifdef HAVE_PTHREAD_H
199 #ifdef HAVE_SEMAPHORE_H
200 #include <semaphore.h>
208 #include "metadata/sgen-gc.h"
209 #include "metadata/metadata-internals.h"
210 #include "metadata/class-internals.h"
211 #include "metadata/gc-internal.h"
212 #include "metadata/object-internals.h"
213 #include "metadata/threads.h"
214 #include "metadata/sgen-cardtable.h"
215 #include "metadata/sgen-ssb.h"
216 #include "metadata/sgen-protocol.h"
217 #include "metadata/sgen-archdep.h"
218 #include "metadata/sgen-bridge.h"
219 #include "metadata/sgen-memory-governor.h"
220 #include "metadata/mono-gc.h"
221 #include "metadata/method-builder.h"
222 #include "metadata/profiler-private.h"
223 #include "metadata/monitor.h"
224 #include "metadata/threadpool-internals.h"
225 #include "metadata/mempool-internals.h"
226 #include "metadata/marshal.h"
227 #include "metadata/runtime.h"
228 #include "metadata/sgen-cardtable.h"
229 #include "metadata/sgen-pinning.h"
230 #include "metadata/sgen-workers.h"
231 #include "utils/mono-mmap.h"
232 #include "utils/mono-time.h"
233 #include "utils/mono-semaphore.h"
234 #include "utils/mono-counters.h"
235 #include "utils/mono-proclib.h"
236 #include "utils/mono-memory-model.h"
237 #include "utils/mono-logger-internal.h"
238 #include "utils/dtrace.h"
240 #include <mono/utils/mono-logger-internal.h>
241 #include <mono/utils/memcheck.h>
243 #if defined(__MACH__)
244 #include "utils/mach-support.h"
247 #define OPDEF(a,b,c,d,e,f,g,h,i,j) \
251 #include "mono/cil/opcode.def"
257 #undef pthread_create
259 #undef pthread_detach
262 * ######################################################################
263 * ######## Types and constants used by the GC.
264 * ######################################################################
267 /* 0 means not initialized, 1 is initialized, -1 means in progress */
268 static int gc_initialized = 0;
269 /* If set, check if we need to do something every X allocations */
270 gboolean has_per_allocation_action;
271 /* If set, do a heap check every X allocation */
272 guint32 verify_before_allocs = 0;
273 /* If set, do a minor collection before every X allocation */
274 guint32 collect_before_allocs = 0;
275 /* If set, do a whole heap check before each collection */
276 static gboolean whole_heap_check_before_collection = FALSE;
277 /* If set, do a heap consistency check before each minor collection */
278 static gboolean consistency_check_at_minor_collection = FALSE;
279 /* If set, check that there are no references to the domain left at domain unload */
280 static gboolean xdomain_checks = FALSE;
281 /* If not null, dump the heap after each collection into this file */
282 static FILE *heap_dump_file = NULL;
283 /* If set, mark stacks conservatively, even if precise marking is possible */
284 static gboolean conservative_stack_mark = FALSE;
285 /* If set, do a plausibility check on the scan_starts before and after
287 static gboolean do_scan_starts_check = FALSE;
288 static gboolean nursery_collection_is_parallel = FALSE;
289 static gboolean disable_minor_collections = FALSE;
290 static gboolean disable_major_collections = FALSE;
291 gboolean do_pin_stats = FALSE;
292 static gboolean do_verify_nursery = FALSE;
293 static gboolean do_dump_nursery_content = FALSE;
295 #ifdef HEAVY_STATISTICS
296 long long stat_objects_alloced_degraded = 0;
297 long long stat_bytes_alloced_degraded = 0;
299 long long stat_copy_object_called_nursery = 0;
300 long long stat_objects_copied_nursery = 0;
301 long long stat_copy_object_called_major = 0;
302 long long stat_objects_copied_major = 0;
304 long long stat_scan_object_called_nursery = 0;
305 long long stat_scan_object_called_major = 0;
307 long long stat_slots_allocated_in_vain;
309 long long stat_nursery_copy_object_failed_from_space = 0;
310 long long stat_nursery_copy_object_failed_forwarded = 0;
311 long long stat_nursery_copy_object_failed_pinned = 0;
312 long long stat_nursery_copy_object_failed_to_space = 0;
314 static int stat_wbarrier_set_field = 0;
315 static int stat_wbarrier_set_arrayref = 0;
316 static int stat_wbarrier_arrayref_copy = 0;
317 static int stat_wbarrier_generic_store = 0;
318 static int stat_wbarrier_set_root = 0;
319 static int stat_wbarrier_value_copy = 0;
320 static int stat_wbarrier_object_copy = 0;
323 int stat_minor_gcs = 0;
324 int stat_major_gcs = 0;
326 static long long stat_pinned_objects = 0;
328 static long long time_minor_pre_collection_fragment_clear = 0;
329 static long long time_minor_pinning = 0;
330 static long long time_minor_scan_remsets = 0;
331 static long long time_minor_scan_pinned = 0;
332 static long long time_minor_scan_registered_roots = 0;
333 static long long time_minor_scan_thread_data = 0;
334 static long long time_minor_finish_gray_stack = 0;
335 static long long time_minor_fragment_creation = 0;
337 static long long time_major_pre_collection_fragment_clear = 0;
338 static long long time_major_pinning = 0;
339 static long long time_major_scan_pinned = 0;
340 static long long time_major_scan_registered_roots = 0;
341 static long long time_major_scan_thread_data = 0;
342 static long long time_major_scan_alloc_pinned = 0;
343 static long long time_major_scan_finalized = 0;
344 static long long time_major_scan_big_objects = 0;
345 static long long time_major_finish_gray_stack = 0;
346 static long long time_major_free_bigobjs = 0;
347 static long long time_major_los_sweep = 0;
348 static long long time_major_sweep = 0;
349 static long long time_major_fragment_creation = 0;
351 int gc_debug_level = 0;
356 mono_gc_flush_info (void)
358 fflush (gc_debug_file);
362 #define TV_DECLARE SGEN_TV_DECLARE
363 #define TV_GETTIME SGEN_TV_GETTIME
364 #define TV_ELAPSED SGEN_TV_ELAPSED
365 #define TV_ELAPSED_MS SGEN_TV_ELAPSED_MS
367 #define ALIGN_TO(val,align) ((((guint64)val) + ((align) - 1)) & ~((align) - 1))
369 NurseryClearPolicy nursery_clear_policy = CLEAR_AT_TLAB_CREATION;
371 /* the runtime can register areas of memory as roots: we keep two lists of roots,
372 * a pinned root set for conservatively scanned roots and a normal one for
373 * precisely scanned roots (currently implemented as a single list).
375 typedef struct _RootRecord RootRecord;
381 #define object_is_forwarded SGEN_OBJECT_IS_FORWARDED
382 #define object_is_pinned SGEN_OBJECT_IS_PINNED
383 #define pin_object SGEN_PIN_OBJECT
384 #define unpin_object SGEN_UNPIN_OBJECT
386 #define ptr_in_nursery sgen_ptr_in_nursery
388 #define LOAD_VTABLE SGEN_LOAD_VTABLE
391 safe_name (void* obj)
393 MonoVTable *vt = (MonoVTable*)LOAD_VTABLE (obj);
394 return vt->klass->name;
397 #define safe_object_get_size sgen_safe_object_get_size
400 sgen_safe_name (void* obj)
402 return safe_name (obj);
406 * ######################################################################
407 * ######## Global data.
408 * ######################################################################
410 LOCK_DECLARE (gc_mutex);
411 static int gc_disabled = 0;
413 static gboolean use_cardtable;
415 #define SCAN_START_SIZE SGEN_SCAN_START_SIZE
417 static mword pagesize = 4096;
418 int degraded_mode = 0;
420 static mword bytes_pinned_from_failed_allocation = 0;
422 GCMemSection *nursery_section = NULL;
423 static mword lowest_heap_address = ~(mword)0;
424 static mword highest_heap_address = 0;
426 static LOCK_DECLARE (interruption_mutex);
427 static LOCK_DECLARE (pin_queue_mutex);
429 #define LOCK_PIN_QUEUE mono_mutex_lock (&pin_queue_mutex)
430 #define UNLOCK_PIN_QUEUE mono_mutex_unlock (&pin_queue_mutex)
432 typedef struct _FinalizeReadyEntry FinalizeReadyEntry;
433 struct _FinalizeReadyEntry {
434 FinalizeReadyEntry *next;
438 typedef struct _EphemeronLinkNode EphemeronLinkNode;
440 struct _EphemeronLinkNode {
441 EphemeronLinkNode *next;
450 int current_collection_generation = -1;
453 * The link pointer is hidden by negating each bit. We use the lowest
454 * bit of the link (before negation) to store whether it needs
455 * resurrection tracking.
457 #define HIDE_POINTER(p,t) ((gpointer)(~((gulong)(p)|((t)?1:0))))
458 #define REVEAL_POINTER(p) ((gpointer)((~(gulong)(p))&~3L))
460 /* objects that are ready to be finalized */
461 static FinalizeReadyEntry *fin_ready_list = NULL;
462 static FinalizeReadyEntry *critical_fin_list = NULL;
464 static EphemeronLinkNode *ephemeron_list;
466 static int num_ready_finalizers = 0;
467 static int no_finalize = 0;
470 ROOT_TYPE_NORMAL = 0, /* "normal" roots */
471 ROOT_TYPE_PINNED = 1, /* roots without a GC descriptor */
472 ROOT_TYPE_WBARRIER = 2, /* roots with a write barrier */
476 /* registered roots: the key to the hash is the root start address */
478 * Different kinds of roots are kept separate to speed up pin_from_roots () for example.
480 static SgenHashTable roots_hash [ROOT_TYPE_NUM] = {
481 SGEN_HASH_TABLE_INIT (INTERNAL_MEM_ROOTS_TABLE, INTERNAL_MEM_ROOT_RECORD, sizeof (RootRecord), mono_aligned_addr_hash, NULL),
482 SGEN_HASH_TABLE_INIT (INTERNAL_MEM_ROOTS_TABLE, INTERNAL_MEM_ROOT_RECORD, sizeof (RootRecord), mono_aligned_addr_hash, NULL),
483 SGEN_HASH_TABLE_INIT (INTERNAL_MEM_ROOTS_TABLE, INTERNAL_MEM_ROOT_RECORD, sizeof (RootRecord), mono_aligned_addr_hash, NULL)
485 static mword roots_size = 0; /* amount of memory in the root set */
487 #define GC_ROOT_NUM 32
490 void *objects [GC_ROOT_NUM];
491 int root_types [GC_ROOT_NUM];
492 uintptr_t extra_info [GC_ROOT_NUM];
496 notify_gc_roots (GCRootReport *report)
500 mono_profiler_gc_roots (report->count, report->objects, report->root_types, report->extra_info);
505 add_profile_gc_root (GCRootReport *report, void *object, int rtype, uintptr_t extra_info)
507 if (report->count == GC_ROOT_NUM)
508 notify_gc_roots (report);
509 report->objects [report->count] = object;
510 report->root_types [report->count] = rtype;
511 report->extra_info [report->count++] = (uintptr_t)((MonoVTable*)LOAD_VTABLE (object))->klass;
514 MonoNativeTlsKey thread_info_key;
516 #ifdef HAVE_KW_THREAD
517 __thread SgenThreadInfo *thread_info;
518 __thread gpointer *store_remset_buffer;
519 __thread long store_remset_buffer_index;
520 __thread char *stack_end;
521 __thread long *store_remset_buffer_index_addr;
524 /* The size of a TLAB */
525 /* The bigger the value, the less often we have to go to the slow path to allocate a new
526 * one, but the more space is wasted by threads not allocating much memory.
528 * FIXME: Make this self-tuning for each thread.
530 guint32 tlab_size = (1024 * 4);
532 #define MAX_SMALL_OBJ_SIZE SGEN_MAX_SMALL_OBJ_SIZE
534 /* Functions supplied by the runtime to be called by the GC */
535 static MonoGCCallbacks gc_callbacks;
537 #define ALLOC_ALIGN SGEN_ALLOC_ALIGN
538 #define ALLOC_ALIGN_BITS SGEN_ALLOC_ALIGN_BITS
540 #define ALIGN_UP SGEN_ALIGN_UP
542 #define MOVED_OBJECTS_NUM 64
543 static void *moved_objects [MOVED_OBJECTS_NUM];
544 static int moved_objects_idx = 0;
546 /* Vtable of the objects used to fill out nursery fragments before a collection */
547 static MonoVTable *array_fill_vtable;
549 #ifdef SGEN_DEBUG_INTERNAL_ALLOC
550 MonoNativeThreadId main_gc_thread = NULL;
553 /*Object was pinned during the current collection*/
554 static mword objects_pinned;
557 * ######################################################################
558 * ######## Macros and function declarations.
559 * ######################################################################
563 align_pointer (void *ptr)
565 mword p = (mword)ptr;
566 p += sizeof (gpointer) - 1;
567 p &= ~ (sizeof (gpointer) - 1);
571 typedef SgenGrayQueue GrayQueue;
573 /* forward declarations */
574 static int stop_world (int generation);
575 static int restart_world (int generation, GGTimingInfo *timing);
576 static void scan_thread_data (void *start_nursery, void *end_nursery, gboolean precise, GrayQueue *queue);
577 static void scan_from_registered_roots (CopyOrMarkObjectFunc copy_func, char *addr_start, char *addr_end, int root_type, GrayQueue *queue);
578 static void scan_finalizer_entries (CopyOrMarkObjectFunc copy_func, FinalizeReadyEntry *list, GrayQueue *queue);
579 static void report_finalizer_roots (void);
580 static void report_registered_roots (void);
581 static void find_pinning_ref_from_thread (char *obj, size_t size);
582 static void update_current_thread_stack (void *start);
583 static void collect_bridge_objects (CopyOrMarkObjectFunc copy_func, char *start, char *end, int generation, GrayQueue *queue);
584 static void finalize_in_range (CopyOrMarkObjectFunc copy_func, char *start, char *end, int generation, GrayQueue *queue);
585 static void process_fin_stage_entries (void);
586 static void null_link_in_range (CopyOrMarkObjectFunc copy_func, char *start, char *end, int generation, gboolean before_finalization, GrayQueue *queue);
587 static void null_links_for_domain (MonoDomain *domain, int generation);
588 static void remove_finalizers_for_domain (MonoDomain *domain, int generation);
589 static void process_dislink_stage_entries (void);
591 static void pin_from_roots (void *start_nursery, void *end_nursery, GrayQueue *queue);
592 static int pin_objects_from_addresses (GCMemSection *section, void **start, void **end, void *start_nursery, void *end_nursery, GrayQueue *queue);
593 static void finish_gray_stack (char *start_addr, char *end_addr, int generation, GrayQueue *queue);
595 static void mono_gc_register_disappearing_link (MonoObject *obj, void **link, gboolean track, gboolean in_gc);
596 static gboolean mono_gc_is_critical_method (MonoMethod *method);
598 void mono_gc_scan_for_specific_ref (MonoObject *key, gboolean precise);
601 static void init_stats (void);
603 static int mark_ephemerons_in_range (CopyOrMarkObjectFunc copy_func, char *start, char *end, GrayQueue *queue);
604 static void clear_unreachable_ephemerons (CopyOrMarkObjectFunc copy_func, char *start, char *end, GrayQueue *queue);
605 static void null_ephemerons_for_domain (MonoDomain *domain);
607 SgenObjectOperations current_object_ops;
608 SgenMajorCollector major_collector;
609 SgenMinorCollector sgen_minor_collector;
610 static GrayQueue gray_queue;
612 static SgenRemeberedSet remset;
615 #define WORKERS_DISTRIBUTE_GRAY_QUEUE (sgen_collection_is_parallel () ? sgen_workers_get_distribute_gray_queue () : &gray_queue)
617 static SgenGrayQueue*
618 sgen_workers_get_job_gray_queue (WorkerData *worker_data)
620 return worker_data ? &worker_data->private_gray_queue : WORKERS_DISTRIBUTE_GRAY_QUEUE;
624 is_xdomain_ref_allowed (gpointer *ptr, char *obj, MonoDomain *domain)
626 MonoObject *o = (MonoObject*)(obj);
627 MonoObject *ref = (MonoObject*)*(ptr);
628 int offset = (char*)(ptr) - (char*)o;
630 if (o->vtable->klass == mono_defaults.thread_class && offset == G_STRUCT_OFFSET (MonoThread, internal_thread))
632 if (o->vtable->klass == mono_defaults.internal_thread_class && offset == G_STRUCT_OFFSET (MonoInternalThread, current_appcontext))
634 if (mono_class_has_parent_fast (o->vtable->klass, mono_defaults.real_proxy_class) &&
635 offset == G_STRUCT_OFFSET (MonoRealProxy, unwrapped_server))
637 /* Thread.cached_culture_info */
638 if (!strcmp (ref->vtable->klass->name_space, "System.Globalization") &&
639 !strcmp (ref->vtable->klass->name, "CultureInfo") &&
640 !strcmp(o->vtable->klass->name_space, "System") &&
641 !strcmp(o->vtable->klass->name, "Object[]"))
644 * 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
645 * at System.IO.MemoryStream..ctor (byte[]) [0x00017] in /home/schani/Work/novell/trunk/mcs/class/corlib/System.IO/MemoryStream.cs:81
646 * at (wrapper remoting-invoke-with-check) System.IO.MemoryStream..ctor (byte[]) <IL 0x00020, 0xffffffff>
647 * at System.Runtime.Remoting.Messaging.CADMethodCallMessage.GetArguments () [0x0000d] in /home/schani/Work/novell/trunk/mcs/class/corlib/System.Runtime.Remoting.Messaging/CADMessages.cs:327
648 * 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
649 * 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
650 * at (wrapper remoting-invoke-with-check) System.AppDomain.ProcessMessageInDomain (byte[],System.Runtime.Remoting.Messaging.CADMethodCallMessage,byte[]&,System.Runtime.Remoting.Messaging.CADMethodReturnMessage&) <IL 0x0003d, 0xffffffff>
651 * 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
652 * at (wrapper runtime-invoke) object.runtime_invoke_CrossAppDomainSink/ProcessMessageRes_object_object (object,intptr,intptr,intptr) <IL 0x0004c, 0xffffffff>
654 if (!strcmp (ref->vtable->klass->name_space, "System") &&
655 !strcmp (ref->vtable->klass->name, "Byte[]") &&
656 !strcmp (o->vtable->klass->name_space, "System.IO") &&
657 !strcmp (o->vtable->klass->name, "MemoryStream"))
659 /* append_job() in threadpool.c */
660 if (!strcmp (ref->vtable->klass->name_space, "System.Runtime.Remoting.Messaging") &&
661 !strcmp (ref->vtable->klass->name, "AsyncResult") &&
662 !strcmp (o->vtable->klass->name_space, "System") &&
663 !strcmp (o->vtable->klass->name, "Object[]") &&
664 mono_thread_pool_is_queue_array ((MonoArray*) o))
670 check_reference_for_xdomain (gpointer *ptr, char *obj, MonoDomain *domain)
672 MonoObject *o = (MonoObject*)(obj);
673 MonoObject *ref = (MonoObject*)*(ptr);
674 int offset = (char*)(ptr) - (char*)o;
676 MonoClassField *field;
679 if (!ref || ref->vtable->domain == domain)
681 if (is_xdomain_ref_allowed (ptr, obj, domain))
685 for (class = o->vtable->klass; class; class = class->parent) {
688 for (i = 0; i < class->field.count; ++i) {
689 if (class->fields[i].offset == offset) {
690 field = &class->fields[i];
698 if (ref->vtable->klass == mono_defaults.string_class)
699 str = mono_string_to_utf8 ((MonoString*)ref);
702 g_print ("xdomain reference in %p (%s.%s) at offset %d (%s) to %p (%s.%s) (%s) - pointed to by:\n",
703 o, o->vtable->klass->name_space, o->vtable->klass->name,
704 offset, field ? field->name : "",
705 ref, ref->vtable->klass->name_space, ref->vtable->klass->name, str ? str : "");
706 mono_gc_scan_for_specific_ref (o, TRUE);
712 #define HANDLE_PTR(ptr,obj) check_reference_for_xdomain ((ptr), (obj), domain)
715 scan_object_for_xdomain_refs (char *start, mword size, void *data)
717 MonoDomain *domain = ((MonoObject*)start)->vtable->domain;
719 #include "sgen-scan-object.h"
722 static gboolean scan_object_for_specific_ref_precise = TRUE;
725 #define HANDLE_PTR(ptr,obj) do { \
726 if ((MonoObject*)*(ptr) == key) { \
727 g_print ("found ref to %p in object %p (%s) at offset %td\n", \
728 key, (obj), safe_name ((obj)), ((char*)(ptr) - (char*)(obj))); \
733 scan_object_for_specific_ref (char *start, MonoObject *key)
737 if ((forwarded = SGEN_OBJECT_IS_FORWARDED (start)))
740 if (scan_object_for_specific_ref_precise) {
741 #include "sgen-scan-object.h"
743 mword *words = (mword*)start;
744 size_t size = safe_object_get_size ((MonoObject*)start);
746 for (i = 0; i < size / sizeof (mword); ++i) {
747 if (words [i] == (mword)key) {
748 g_print ("found possible ref to %p in object %p (%s) at offset %td\n",
749 key, start, safe_name (start), i * sizeof (mword));
756 sgen_scan_area_with_callback (char *start, char *end, IterateObjectCallbackFunc callback, void *data, gboolean allow_flags)
758 while (start < end) {
762 if (!*(void**)start) {
763 start += sizeof (void*); /* should be ALLOC_ALIGN, really */
768 if (!(obj = SGEN_OBJECT_IS_FORWARDED (start)))
774 size = ALIGN_UP (safe_object_get_size ((MonoObject*)obj));
776 if ((MonoVTable*)SGEN_LOAD_VTABLE (obj) != array_fill_vtable)
777 callback (obj, size, data);
784 scan_object_for_specific_ref_callback (char *obj, size_t size, MonoObject *key)
786 scan_object_for_specific_ref (obj, key);
790 check_root_obj_specific_ref (RootRecord *root, MonoObject *key, MonoObject *obj)
794 g_print ("found ref to %p in root record %p\n", key, root);
797 static MonoObject *check_key = NULL;
798 static RootRecord *check_root = NULL;
801 check_root_obj_specific_ref_from_marker (void **obj)
803 check_root_obj_specific_ref (check_root, check_key, *obj);
807 scan_roots_for_specific_ref (MonoObject *key, int root_type)
813 SGEN_HASH_TABLE_FOREACH (&roots_hash [root_type], start_root, root) {
814 mword desc = root->root_desc;
818 switch (desc & ROOT_DESC_TYPE_MASK) {
819 case ROOT_DESC_BITMAP:
820 desc >>= ROOT_DESC_TYPE_SHIFT;
823 check_root_obj_specific_ref (root, key, *start_root);
828 case ROOT_DESC_COMPLEX: {
829 gsize *bitmap_data = sgen_get_complex_descriptor_bitmap (desc);
830 int bwords = (*bitmap_data) - 1;
831 void **start_run = start_root;
833 while (bwords-- > 0) {
834 gsize bmap = *bitmap_data++;
835 void **objptr = start_run;
838 check_root_obj_specific_ref (root, key, *objptr);
842 start_run += GC_BITS_PER_WORD;
846 case ROOT_DESC_USER: {
847 MonoGCRootMarkFunc marker = sgen_get_user_descriptor_func (desc);
848 marker (start_root, check_root_obj_specific_ref_from_marker);
851 case ROOT_DESC_RUN_LEN:
852 g_assert_not_reached ();
854 g_assert_not_reached ();
856 } SGEN_HASH_TABLE_FOREACH_END;
863 mono_gc_scan_for_specific_ref (MonoObject *key, gboolean precise)
868 scan_object_for_specific_ref_precise = precise;
870 sgen_scan_area_with_callback (nursery_section->data, nursery_section->end_data,
871 (IterateObjectCallbackFunc)scan_object_for_specific_ref_callback, key, TRUE);
873 major_collector.iterate_objects (TRUE, TRUE, (IterateObjectCallbackFunc)scan_object_for_specific_ref_callback, key);
875 sgen_los_iterate_objects ((IterateObjectCallbackFunc)scan_object_for_specific_ref_callback, key);
877 scan_roots_for_specific_ref (key, ROOT_TYPE_NORMAL);
878 scan_roots_for_specific_ref (key, ROOT_TYPE_WBARRIER);
880 SGEN_HASH_TABLE_FOREACH (&roots_hash [ROOT_TYPE_PINNED], ptr, root) {
881 while (ptr < (void**)root->end_root) {
882 check_root_obj_specific_ref (root, *ptr, key);
885 } SGEN_HASH_TABLE_FOREACH_END;
889 need_remove_object_for_domain (char *start, MonoDomain *domain)
891 if (mono_object_domain (start) == domain) {
892 DEBUG (4, fprintf (gc_debug_file, "Need to cleanup object %p\n", start));
893 binary_protocol_cleanup (start, (gpointer)LOAD_VTABLE (start), safe_object_get_size ((MonoObject*)start));
900 process_object_for_domain_clearing (char *start, MonoDomain *domain)
902 GCVTable *vt = (GCVTable*)LOAD_VTABLE (start);
903 if (vt->klass == mono_defaults.internal_thread_class)
904 g_assert (mono_object_domain (start) == mono_get_root_domain ());
905 /* The object could be a proxy for an object in the domain
907 if (mono_class_has_parent_fast (vt->klass, mono_defaults.real_proxy_class)) {
908 MonoObject *server = ((MonoRealProxy*)start)->unwrapped_server;
910 /* The server could already have been zeroed out, so
911 we need to check for that, too. */
912 if (server && (!LOAD_VTABLE (server) || mono_object_domain (server) == domain)) {
913 DEBUG (4, fprintf (gc_debug_file, "Cleaning up remote pointer in %p to object %p\n",
915 ((MonoRealProxy*)start)->unwrapped_server = NULL;
920 static MonoDomain *check_domain = NULL;
923 check_obj_not_in_domain (void **o)
925 g_assert (((MonoObject*)(*o))->vtable->domain != check_domain);
929 scan_for_registered_roots_in_domain (MonoDomain *domain, int root_type)
933 check_domain = domain;
934 SGEN_HASH_TABLE_FOREACH (&roots_hash [root_type], start_root, root) {
935 mword desc = root->root_desc;
937 /* The MonoDomain struct is allowed to hold
938 references to objects in its own domain. */
939 if (start_root == (void**)domain)
942 switch (desc & ROOT_DESC_TYPE_MASK) {
943 case ROOT_DESC_BITMAP:
944 desc >>= ROOT_DESC_TYPE_SHIFT;
946 if ((desc & 1) && *start_root)
947 check_obj_not_in_domain (*start_root);
952 case ROOT_DESC_COMPLEX: {
953 gsize *bitmap_data = sgen_get_complex_descriptor_bitmap (desc);
954 int bwords = (*bitmap_data) - 1;
955 void **start_run = start_root;
957 while (bwords-- > 0) {
958 gsize bmap = *bitmap_data++;
959 void **objptr = start_run;
961 if ((bmap & 1) && *objptr)
962 check_obj_not_in_domain (*objptr);
966 start_run += GC_BITS_PER_WORD;
970 case ROOT_DESC_USER: {
971 MonoGCRootMarkFunc marker = sgen_get_user_descriptor_func (desc);
972 marker (start_root, check_obj_not_in_domain);
975 case ROOT_DESC_RUN_LEN:
976 g_assert_not_reached ();
978 g_assert_not_reached ();
980 } SGEN_HASH_TABLE_FOREACH_END;
986 check_for_xdomain_refs (void)
990 sgen_scan_area_with_callback (nursery_section->data, nursery_section->end_data,
991 (IterateObjectCallbackFunc)scan_object_for_xdomain_refs, NULL, FALSE);
993 major_collector.iterate_objects (TRUE, TRUE, (IterateObjectCallbackFunc)scan_object_for_xdomain_refs, NULL);
995 for (bigobj = los_object_list; bigobj; bigobj = bigobj->next)
996 scan_object_for_xdomain_refs (bigobj->data, bigobj->size, NULL);
1000 clear_domain_process_object (char *obj, MonoDomain *domain)
1004 process_object_for_domain_clearing (obj, domain);
1005 remove = need_remove_object_for_domain (obj, domain);
1007 if (remove && ((MonoObject*)obj)->synchronisation) {
1008 void **dislink = mono_monitor_get_object_monitor_weak_link ((MonoObject*)obj);
1010 mono_gc_register_disappearing_link (NULL, dislink, FALSE, TRUE);
1017 clear_domain_process_minor_object_callback (char *obj, size_t size, MonoDomain *domain)
1019 if (clear_domain_process_object (obj, domain))
1020 memset (obj, 0, size);
1024 clear_domain_process_major_object_callback (char *obj, size_t size, MonoDomain *domain)
1026 clear_domain_process_object (obj, domain);
1030 clear_domain_free_major_non_pinned_object_callback (char *obj, size_t size, MonoDomain *domain)
1032 if (need_remove_object_for_domain (obj, domain))
1033 major_collector.free_non_pinned_object (obj, size);
1037 clear_domain_free_major_pinned_object_callback (char *obj, size_t size, MonoDomain *domain)
1039 if (need_remove_object_for_domain (obj, domain))
1040 major_collector.free_pinned_object (obj, size);
1044 * When appdomains are unloaded we can easily remove objects that have finalizers,
1045 * but all the others could still be present in random places on the heap.
1046 * We need a sweep to get rid of them even though it's going to be costly
1048 * The reason we need to remove them is because we access the vtable and class
1049 * structures to know the object size and the reference bitmap: once the domain is
1050 * unloaded the point to random memory.
1053 mono_gc_clear_domain (MonoDomain * domain)
1055 LOSObject *bigobj, *prev;
1060 process_fin_stage_entries ();
1061 process_dislink_stage_entries ();
1063 sgen_clear_nursery_fragments ();
1065 if (xdomain_checks && domain != mono_get_root_domain ()) {
1066 scan_for_registered_roots_in_domain (domain, ROOT_TYPE_NORMAL);
1067 scan_for_registered_roots_in_domain (domain, ROOT_TYPE_WBARRIER);
1068 check_for_xdomain_refs ();
1071 /*Ephemerons and dislinks must be processed before LOS since they might end up pointing
1072 to memory returned to the OS.*/
1073 null_ephemerons_for_domain (domain);
1075 for (i = GENERATION_NURSERY; i < GENERATION_MAX; ++i)
1076 null_links_for_domain (domain, i);
1078 for (i = GENERATION_NURSERY; i < GENERATION_MAX; ++i)
1079 remove_finalizers_for_domain (domain, i);
1081 sgen_scan_area_with_callback (nursery_section->data, nursery_section->end_data,
1082 (IterateObjectCallbackFunc)clear_domain_process_minor_object_callback, domain, FALSE);
1084 /* We need two passes over major and large objects because
1085 freeing such objects might give their memory back to the OS
1086 (in the case of large objects) or obliterate its vtable
1087 (pinned objects with major-copying or pinned and non-pinned
1088 objects with major-mark&sweep), but we might need to
1089 dereference a pointer from an object to another object if
1090 the first object is a proxy. */
1091 major_collector.iterate_objects (TRUE, TRUE, (IterateObjectCallbackFunc)clear_domain_process_major_object_callback, domain);
1092 for (bigobj = los_object_list; bigobj; bigobj = bigobj->next)
1093 clear_domain_process_object (bigobj->data, domain);
1096 for (bigobj = los_object_list; bigobj;) {
1097 if (need_remove_object_for_domain (bigobj->data, domain)) {
1098 LOSObject *to_free = bigobj;
1100 prev->next = bigobj->next;
1102 los_object_list = bigobj->next;
1103 bigobj = bigobj->next;
1104 DEBUG (4, fprintf (gc_debug_file, "Freeing large object %p\n",
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 (G_UNLIKELY (do_pin_stats)) {
1116 if (domain == mono_get_root_domain ())
1117 sgen_pin_stats_print_class_stats ();
1124 * sgen_add_to_global_remset:
1126 * The global remset contains locations which point into newspace after
1127 * a minor collection. This can happen if the objects they point to are pinned.
1129 * LOCKING: If called from a parallel collector, the global remset
1130 * lock must be held. For serial collectors that is not necessary.
1133 sgen_add_to_global_remset (gpointer ptr)
1135 remset.record_pointer (ptr);
1139 * sgen_drain_gray_stack:
1141 * Scan objects in the gray stack until the stack is empty. This should be called
1142 * frequently after each object is copied, to achieve better locality and cache
1146 sgen_drain_gray_stack (GrayQueue *queue, int max_objs)
1149 ScanObjectFunc scan_func = current_object_ops.scan_object;
1151 if (max_objs == -1) {
1153 GRAY_OBJECT_DEQUEUE (queue, obj);
1156 DEBUG (9, fprintf (gc_debug_file, "Precise gray object scan %p (%s)\n", obj, safe_name (obj)));
1157 scan_func (obj, queue);
1163 for (i = 0; i != max_objs; ++i) {
1164 GRAY_OBJECT_DEQUEUE (queue, obj);
1167 DEBUG (9, fprintf (gc_debug_file, "Precise gray object scan %p (%s)\n", obj, safe_name (obj)));
1168 scan_func (obj, queue);
1170 } while (max_objs < 0);
1176 * Addresses from start to end are already sorted. This function finds
1177 * the object header for each address and pins the object. The
1178 * addresses must be inside the passed section. The (start of the)
1179 * address array is overwritten with the addresses of the actually
1180 * pinned objects. Return the number of pinned objects.
1183 pin_objects_from_addresses (GCMemSection *section, void **start, void **end, void *start_nursery, void *end_nursery, GrayQueue *queue)
1188 void *last_obj = NULL;
1189 size_t last_obj_size = 0;
1192 void **definitely_pinned = start;
1194 sgen_nursery_allocator_prepare_for_pinning ();
1196 while (start < end) {
1198 /* the range check should be reduntant */
1199 if (addr != last && addr >= start_nursery && addr < end_nursery) {
1200 DEBUG (5, fprintf (gc_debug_file, "Considering pinning addr %p\n", addr));
1201 /* multiple pointers to the same object */
1202 if (addr >= last_obj && (char*)addr < (char*)last_obj + last_obj_size) {
1206 idx = ((char*)addr - (char*)section->data) / SCAN_START_SIZE;
1207 g_assert (idx < section->num_scan_start);
1208 search_start = (void*)section->scan_starts [idx];
1209 if (!search_start || search_start > addr) {
1212 search_start = section->scan_starts [idx];
1213 if (search_start && search_start <= addr)
1216 if (!search_start || search_start > addr)
1217 search_start = start_nursery;
1219 if (search_start < last_obj)
1220 search_start = (char*)last_obj + last_obj_size;
1221 /* now addr should be in an object a short distance from search_start
1222 * Note that search_start must point to zeroed mem or point to an object.
1226 if (!*(void**)search_start) {
1227 /* Consistency check */
1229 for (frag = nursery_fragments; frag; frag = frag->next) {
1230 if (search_start >= frag->fragment_start && search_start < frag->fragment_end)
1231 g_assert_not_reached ();
1235 search_start = (void*)ALIGN_UP ((mword)search_start + sizeof (gpointer));
1238 last_obj = search_start;
1239 last_obj_size = ALIGN_UP (safe_object_get_size ((MonoObject*)search_start));
1241 if (((MonoObject*)last_obj)->synchronisation == GINT_TO_POINTER (-1)) {
1242 /* Marks the beginning of a nursery fragment, skip */
1244 DEBUG (8, fprintf (gc_debug_file, "Pinned try match %p (%s), size %zd\n", last_obj, safe_name (last_obj), last_obj_size));
1245 if (addr >= search_start && (char*)addr < (char*)last_obj + last_obj_size) {
1246 DEBUG (4, fprintf (gc_debug_file, "Pinned object %p, vtable %p (%s), count %d\n", search_start, *(void**)search_start, safe_name (search_start), count));
1247 binary_protocol_pin (search_start, (gpointer)LOAD_VTABLE (search_start), safe_object_get_size (search_start));
1248 if (MONO_GC_OBJ_PINNED_ENABLED ()) {
1249 int gen = sgen_ptr_in_nursery (search_start) ? GENERATION_NURSERY : GENERATION_OLD;
1250 MONO_GC_OBJ_PINNED (search_start, sgen_safe_object_get_size (search_start), NULL, gen);
1252 pin_object (search_start);
1253 GRAY_OBJECT_ENQUEUE (queue, search_start);
1254 if (G_UNLIKELY (do_pin_stats))
1255 sgen_pin_stats_register_object (search_start, last_obj_size);
1256 definitely_pinned [count] = search_start;
1261 /* skip to the next object */
1262 search_start = (void*)((char*)search_start + last_obj_size);
1263 } while (search_start <= addr);
1264 /* we either pinned the correct object or we ignored the addr because
1265 * it points to unused zeroed memory.
1271 //printf ("effective pinned: %d (at the end: %d)\n", count, (char*)end_nursery - (char*)last);
1272 if (mono_profiler_get_events () & MONO_PROFILE_GC_ROOTS) {
1273 GCRootReport report;
1275 for (idx = 0; idx < count; ++idx)
1276 add_profile_gc_root (&report, definitely_pinned [idx], MONO_PROFILE_GC_ROOT_PINNING | MONO_PROFILE_GC_ROOT_MISC, 0);
1277 notify_gc_roots (&report);
1279 stat_pinned_objects += count;
1284 sgen_pin_objects_in_section (GCMemSection *section, GrayQueue *queue)
1286 int num_entries = section->pin_queue_num_entries;
1288 void **start = section->pin_queue_start;
1290 reduced_to = pin_objects_from_addresses (section, start, start + num_entries,
1291 section->data, section->next_data, queue);
1292 section->pin_queue_num_entries = reduced_to;
1294 section->pin_queue_start = NULL;
1300 sgen_pin_object (void *object, GrayQueue *queue)
1302 if (sgen_collection_is_parallel ()) {
1304 /*object arrives pinned*/
1305 sgen_pin_stage_ptr (object);
1309 SGEN_PIN_OBJECT (object);
1310 sgen_pin_stage_ptr (object);
1312 if (G_UNLIKELY (do_pin_stats))
1313 sgen_pin_stats_register_object (object, safe_object_get_size (object));
1315 GRAY_OBJECT_ENQUEUE (queue, object);
1316 binary_protocol_pin (object, (gpointer)LOAD_VTABLE (object), safe_object_get_size (object));
1317 if (MONO_GC_OBJ_PINNED_ENABLED ()) {
1318 int gen = sgen_ptr_in_nursery (object) ? GENERATION_NURSERY : GENERATION_OLD;
1319 MONO_GC_OBJ_PINNED (object, sgen_safe_object_get_size (object), NULL, gen);
1324 sgen_parallel_pin_or_update (void **ptr, void *obj, MonoVTable *vt, SgenGrayQueue *queue)
1328 gboolean major_pinned = FALSE;
1330 if (sgen_ptr_in_nursery (obj)) {
1331 if (SGEN_CAS_PTR (obj, (void*)((mword)vt | SGEN_PINNED_BIT), vt) == vt) {
1332 sgen_pin_object (obj, queue);
1336 major_collector.pin_major_object (obj, queue);
1337 major_pinned = TRUE;
1340 vtable_word = *(mword*)obj;
1341 /*someone else forwarded it, update the pointer and bail out*/
1342 if (vtable_word & SGEN_FORWARDED_BIT) {
1343 *ptr = (void*)(vtable_word & ~SGEN_VTABLE_BITS_MASK);
1347 /*someone pinned it, nothing to do.*/
1348 if (vtable_word & SGEN_PINNED_BIT || major_pinned)
1353 /* Sort the addresses in array in increasing order.
1354 * Done using a by-the book heap sort. Which has decent and stable performance, is pretty cache efficient.
1357 sgen_sort_addresses (void **array, int size)
1362 for (i = 1; i < size; ++i) {
1365 int parent = (child - 1) / 2;
1367 if (array [parent] >= array [child])
1370 tmp = array [parent];
1371 array [parent] = array [child];
1372 array [child] = tmp;
1378 for (i = size - 1; i > 0; --i) {
1381 array [i] = array [0];
1387 while (root * 2 + 1 <= end) {
1388 int child = root * 2 + 1;
1390 if (child < end && array [child] < array [child + 1])
1392 if (array [root] >= array [child])
1396 array [root] = array [child];
1397 array [child] = tmp;
1405 * Scan the memory between start and end and queue values which could be pointers
1406 * to the area between start_nursery and end_nursery for later consideration.
1407 * Typically used for thread stacks.
1410 conservatively_pin_objects_from (void **start, void **end, void *start_nursery, void *end_nursery, int pin_type)
1413 while (start < end) {
1414 if (*start >= start_nursery && *start < end_nursery) {
1416 * *start can point to the middle of an object
1417 * note: should we handle pointing at the end of an object?
1418 * pinning in C# code disallows pointing at the end of an object
1419 * but there is some small chance that an optimizing C compiler
1420 * may keep the only reference to an object by pointing
1421 * at the end of it. We ignore this small chance for now.
1422 * Pointers to the end of an object are indistinguishable
1423 * from pointers to the start of the next object in memory
1424 * so if we allow that we'd need to pin two objects...
1425 * We queue the pointer in an array, the
1426 * array will then be sorted and uniqued. This way
1427 * we can coalesce several pinning pointers and it should
1428 * be faster since we'd do a memory scan with increasing
1429 * addresses. Note: we can align the address to the allocation
1430 * alignment, so the unique process is more effective.
1432 mword addr = (mword)*start;
1433 addr &= ~(ALLOC_ALIGN - 1);
1434 if (addr >= (mword)start_nursery && addr < (mword)end_nursery)
1435 sgen_pin_stage_ptr ((void*)addr);
1436 if (G_UNLIKELY (do_pin_stats)) {
1437 if (ptr_in_nursery ((void*)addr))
1438 sgen_pin_stats_register_address ((char*)addr, pin_type);
1440 DEBUG (6, if (count) fprintf (gc_debug_file, "Pinning address %p from %p\n", (void*)addr, start));
1445 DEBUG (7, if (count) fprintf (gc_debug_file, "found %d potential pinned heap pointers\n", count));
1449 * Debugging function: find in the conservative roots where @obj is being pinned.
1451 static G_GNUC_UNUSED void
1452 find_pinning_reference (char *obj, size_t size)
1456 char *endobj = obj + size;
1458 SGEN_HASH_TABLE_FOREACH (&roots_hash [ROOT_TYPE_NORMAL], start, root) {
1459 /* if desc is non-null it has precise info */
1460 if (!root->root_desc) {
1461 while (start < (char**)root->end_root) {
1462 if (*start >= obj && *start < endobj) {
1463 DEBUG (0, fprintf (gc_debug_file, "Object %p referenced in pinned roots %p-%p\n", obj, start, root->end_root));
1468 } SGEN_HASH_TABLE_FOREACH_END;
1470 find_pinning_ref_from_thread (obj, size);
1474 * The first thing we do in a collection is to identify pinned objects.
1475 * This function considers all the areas of memory that need to be
1476 * conservatively scanned.
1479 pin_from_roots (void *start_nursery, void *end_nursery, GrayQueue *queue)
1483 DEBUG (2, fprintf (gc_debug_file, "Scanning pinned roots (%d bytes, %d/%d entries)\n", (int)roots_size, roots_hash [ROOT_TYPE_NORMAL].num_entries, roots_hash [ROOT_TYPE_PINNED].num_entries));
1484 /* objects pinned from the API are inside these roots */
1485 SGEN_HASH_TABLE_FOREACH (&roots_hash [ROOT_TYPE_PINNED], start_root, root) {
1486 DEBUG (6, fprintf (gc_debug_file, "Pinned roots %p-%p\n", start_root, root->end_root));
1487 conservatively_pin_objects_from (start_root, (void**)root->end_root, start_nursery, end_nursery, PIN_TYPE_OTHER);
1488 } SGEN_HASH_TABLE_FOREACH_END;
1489 /* now deal with the thread stacks
1490 * in the future we should be able to conservatively scan only:
1491 * *) the cpu registers
1492 * *) the unmanaged stack frames
1493 * *) the _last_ managed stack frame
1494 * *) pointers slots in managed frames
1496 scan_thread_data (start_nursery, end_nursery, FALSE, queue);
1500 CopyOrMarkObjectFunc func;
1502 } UserCopyOrMarkData;
1504 static MonoNativeTlsKey user_copy_or_mark_key;
1507 init_user_copy_or_mark_key (void)
1509 mono_native_tls_alloc (&user_copy_or_mark_key, NULL);
1513 set_user_copy_or_mark_data (UserCopyOrMarkData *data)
1515 mono_native_tls_set_value (user_copy_or_mark_key, data);
1519 single_arg_user_copy_or_mark (void **obj)
1521 UserCopyOrMarkData *data = mono_native_tls_get_value (user_copy_or_mark_key);
1523 data->func (obj, data->queue);
1527 * The memory area from start_root to end_root contains pointers to objects.
1528 * Their position is precisely described by @desc (this means that the pointer
1529 * can be either NULL or the pointer to the start of an object).
1530 * This functions copies them to to_space updates them.
1532 * This function is not thread-safe!
1535 precisely_scan_objects_from (CopyOrMarkObjectFunc copy_func, void** start_root, void** end_root, char* n_start, char *n_end, mword desc, GrayQueue *queue)
1537 switch (desc & ROOT_DESC_TYPE_MASK) {
1538 case ROOT_DESC_BITMAP:
1539 desc >>= ROOT_DESC_TYPE_SHIFT;
1541 if ((desc & 1) && *start_root) {
1542 copy_func (start_root, queue);
1543 DEBUG (9, fprintf (gc_debug_file, "Overwrote root at %p with %p\n", start_root, *start_root));
1544 sgen_drain_gray_stack (queue, -1);
1550 case ROOT_DESC_COMPLEX: {
1551 gsize *bitmap_data = sgen_get_complex_descriptor_bitmap (desc);
1552 int bwords = (*bitmap_data) - 1;
1553 void **start_run = start_root;
1555 while (bwords-- > 0) {
1556 gsize bmap = *bitmap_data++;
1557 void **objptr = start_run;
1559 if ((bmap & 1) && *objptr) {
1560 copy_func (objptr, queue);
1561 DEBUG (9, fprintf (gc_debug_file, "Overwrote root at %p with %p\n", objptr, *objptr));
1562 sgen_drain_gray_stack (queue, -1);
1567 start_run += GC_BITS_PER_WORD;
1571 case ROOT_DESC_USER: {
1572 UserCopyOrMarkData data = { copy_func, queue };
1573 MonoGCRootMarkFunc marker = sgen_get_user_descriptor_func (desc);
1574 set_user_copy_or_mark_data (&data);
1575 marker (start_root, single_arg_user_copy_or_mark);
1576 set_user_copy_or_mark_data (NULL);
1579 case ROOT_DESC_RUN_LEN:
1580 g_assert_not_reached ();
1582 g_assert_not_reached ();
1587 reset_heap_boundaries (void)
1589 lowest_heap_address = ~(mword)0;
1590 highest_heap_address = 0;
1594 sgen_update_heap_boundaries (mword low, mword high)
1599 old = lowest_heap_address;
1602 } while (SGEN_CAS_PTR ((gpointer*)&lowest_heap_address, (gpointer)low, (gpointer)old) != (gpointer)old);
1605 old = highest_heap_address;
1608 } while (SGEN_CAS_PTR ((gpointer*)&highest_heap_address, (gpointer)high, (gpointer)old) != (gpointer)old);
1612 * Allocate and setup the data structures needed to be able to allocate objects
1613 * in the nursery. The nursery is stored in nursery_section.
1616 alloc_nursery (void)
1618 GCMemSection *section;
1623 if (nursery_section)
1625 DEBUG (2, fprintf (gc_debug_file, "Allocating nursery size: %lu\n", (unsigned long)sgen_nursery_size));
1626 /* later we will alloc a larger area for the nursery but only activate
1627 * what we need. The rest will be used as expansion if we have too many pinned
1628 * objects in the existing nursery.
1630 /* FIXME: handle OOM */
1631 section = sgen_alloc_internal (INTERNAL_MEM_SECTION);
1633 alloc_size = sgen_nursery_size;
1635 /* If there isn't enough space even for the nursery we should simply abort. */
1636 g_assert (sgen_memgov_try_alloc_space (alloc_size, SPACE_NURSERY));
1638 #ifdef SGEN_ALIGN_NURSERY
1639 data = major_collector.alloc_heap (alloc_size, alloc_size, DEFAULT_NURSERY_BITS);
1641 data = major_collector.alloc_heap (alloc_size, 0, DEFAULT_NURSERY_BITS);
1643 sgen_update_heap_boundaries ((mword)data, (mword)(data + sgen_nursery_size));
1644 DEBUG (4, fprintf (gc_debug_file, "Expanding nursery size (%p-%p): %lu, total: %lu\n", data, data + alloc_size, (unsigned long)sgen_nursery_size, (unsigned long)mono_gc_get_heap_size ()));
1645 section->data = section->next_data = data;
1646 section->size = alloc_size;
1647 section->end_data = data + sgen_nursery_size;
1648 scan_starts = (alloc_size + SCAN_START_SIZE - 1) / SCAN_START_SIZE;
1649 section->scan_starts = sgen_alloc_internal_dynamic (sizeof (char*) * scan_starts, INTERNAL_MEM_SCAN_STARTS, TRUE);
1650 section->num_scan_start = scan_starts;
1651 section->block.role = MEMORY_ROLE_GEN0;
1652 section->block.next = NULL;
1654 nursery_section = section;
1656 sgen_nursery_allocator_set_nursery_bounds (data, data + sgen_nursery_size);
1660 mono_gc_get_nursery (int *shift_bits, size_t *size)
1662 *size = sgen_nursery_size;
1663 #ifdef SGEN_ALIGN_NURSERY
1664 *shift_bits = DEFAULT_NURSERY_BITS;
1668 return sgen_get_nursery_start ();
1672 mono_gc_set_current_thread_appdomain (MonoDomain *domain)
1674 SgenThreadInfo *info = mono_thread_info_current ();
1676 /* Could be called from sgen_thread_unregister () with a NULL info */
1679 info->stopped_domain = domain;
1684 mono_gc_precise_stack_mark_enabled (void)
1686 return !conservative_stack_mark;
1690 mono_gc_get_logfile (void)
1692 return sgen_get_logfile ();
1696 report_finalizer_roots_list (FinalizeReadyEntry *list)
1698 GCRootReport report;
1699 FinalizeReadyEntry *fin;
1702 for (fin = list; fin; fin = fin->next) {
1705 add_profile_gc_root (&report, fin->object, MONO_PROFILE_GC_ROOT_FINALIZER, 0);
1707 notify_gc_roots (&report);
1711 report_finalizer_roots (void)
1713 report_finalizer_roots_list (fin_ready_list);
1714 report_finalizer_roots_list (critical_fin_list);
1717 static GCRootReport *root_report;
1720 single_arg_report_root (void **obj)
1723 add_profile_gc_root (root_report, *obj, MONO_PROFILE_GC_ROOT_OTHER, 0);
1727 precisely_report_roots_from (GCRootReport *report, void** start_root, void** end_root, mword desc)
1729 switch (desc & ROOT_DESC_TYPE_MASK) {
1730 case ROOT_DESC_BITMAP:
1731 desc >>= ROOT_DESC_TYPE_SHIFT;
1733 if ((desc & 1) && *start_root) {
1734 add_profile_gc_root (report, *start_root, MONO_PROFILE_GC_ROOT_OTHER, 0);
1740 case ROOT_DESC_COMPLEX: {
1741 gsize *bitmap_data = sgen_get_complex_descriptor_bitmap (desc);
1742 int bwords = (*bitmap_data) - 1;
1743 void **start_run = start_root;
1745 while (bwords-- > 0) {
1746 gsize bmap = *bitmap_data++;
1747 void **objptr = start_run;
1749 if ((bmap & 1) && *objptr) {
1750 add_profile_gc_root (report, *objptr, MONO_PROFILE_GC_ROOT_OTHER, 0);
1755 start_run += GC_BITS_PER_WORD;
1759 case ROOT_DESC_USER: {
1760 MonoGCRootMarkFunc marker = sgen_get_user_descriptor_func (desc);
1761 root_report = report;
1762 marker (start_root, single_arg_report_root);
1765 case ROOT_DESC_RUN_LEN:
1766 g_assert_not_reached ();
1768 g_assert_not_reached ();
1773 report_registered_roots_by_type (int root_type)
1775 GCRootReport report;
1779 SGEN_HASH_TABLE_FOREACH (&roots_hash [root_type], start_root, root) {
1780 DEBUG (6, fprintf (gc_debug_file, "Precise root scan %p-%p (desc: %p)\n", start_root, root->end_root, (void*)root->root_desc));
1781 precisely_report_roots_from (&report, start_root, (void**)root->end_root, root->root_desc);
1782 } SGEN_HASH_TABLE_FOREACH_END;
1783 notify_gc_roots (&report);
1787 report_registered_roots (void)
1789 report_registered_roots_by_type (ROOT_TYPE_NORMAL);
1790 report_registered_roots_by_type (ROOT_TYPE_WBARRIER);
1794 scan_finalizer_entries (CopyOrMarkObjectFunc copy_func, FinalizeReadyEntry *list, GrayQueue *queue)
1796 FinalizeReadyEntry *fin;
1798 for (fin = list; fin; fin = fin->next) {
1801 DEBUG (5, fprintf (gc_debug_file, "Scan of fin ready object: %p (%s)\n", fin->object, safe_name (fin->object)));
1802 copy_func (&fin->object, queue);
1807 generation_name (int generation)
1809 switch (generation) {
1810 case GENERATION_NURSERY: return "nursery";
1811 case GENERATION_OLD: return "old";
1812 default: g_assert_not_reached ();
1818 stw_bridge_process (void)
1820 sgen_bridge_processing_stw_step ();
1824 bridge_process (void)
1826 sgen_bridge_processing_finish ();
1829 SgenObjectOperations *
1830 sgen_get_current_object_ops (void){
1831 return ¤t_object_ops;
1836 finish_gray_stack (char *start_addr, char *end_addr, int generation, GrayQueue *queue)
1840 int done_with_ephemerons, ephemeron_rounds = 0;
1841 CopyOrMarkObjectFunc copy_func = current_object_ops.copy_or_mark_object;
1844 * We copied all the reachable objects. Now it's the time to copy
1845 * the objects that were not referenced by the roots, but by the copied objects.
1846 * we built a stack of objects pointed to by gray_start: they are
1847 * additional roots and we may add more items as we go.
1848 * We loop until gray_start == gray_objects which means no more objects have
1849 * been added. Note this is iterative: no recursion is involved.
1850 * We need to walk the LO list as well in search of marked big objects
1851 * (use a flag since this is needed only on major collections). We need to loop
1852 * here as well, so keep a counter of marked LO (increasing it in copy_object).
1853 * To achieve better cache locality and cache usage, we drain the gray stack
1854 * frequently, after each object is copied, and just finish the work here.
1856 sgen_drain_gray_stack (queue, -1);
1858 DEBUG (2, fprintf (gc_debug_file, "%s generation done\n", generation_name (generation)));
1861 Reset bridge data, we might have lingering data from a previous collection if this is a major
1862 collection trigged by minor overflow.
1864 We must reset the gathered bridges since their original block might be evacuated due to major
1865 fragmentation in the meanwhile and the bridge code should not have to deal with that.
1867 sgen_bridge_reset_data ();
1870 * Walk the ephemeron tables marking all values with reachable keys. This must be completely done
1871 * before processing finalizable objects or non-tracking weak hamdle to avoid finalizing/clearing
1872 * objects that are in fact reachable.
1874 done_with_ephemerons = 0;
1876 done_with_ephemerons = mark_ephemerons_in_range (copy_func, start_addr, end_addr, queue);
1877 sgen_drain_gray_stack (queue, -1);
1879 } while (!done_with_ephemerons);
1881 sgen_scan_togglerefs (copy_func, start_addr, end_addr, queue);
1882 if (generation == GENERATION_OLD)
1883 sgen_scan_togglerefs (copy_func, sgen_get_nursery_start (), sgen_get_nursery_end (), queue);
1885 if (sgen_need_bridge_processing ()) {
1886 collect_bridge_objects (copy_func, start_addr, end_addr, generation, queue);
1887 if (generation == GENERATION_OLD)
1888 collect_bridge_objects (copy_func, sgen_get_nursery_start (), sgen_get_nursery_end (), GENERATION_NURSERY, queue);
1892 Make sure we drain the gray stack before processing disappearing links and finalizers.
1893 If we don't make sure it is empty we might wrongly see a live object as dead.
1895 sgen_drain_gray_stack (queue, -1);
1898 We must clear weak links that don't track resurrection before processing object ready for
1899 finalization so they can be cleared before that.
1901 null_link_in_range (copy_func, start_addr, end_addr, generation, TRUE, queue);
1902 if (generation == GENERATION_OLD)
1903 null_link_in_range (copy_func, start_addr, end_addr, GENERATION_NURSERY, TRUE, queue);
1906 /* walk the finalization queue and move also the objects that need to be
1907 * finalized: use the finalized objects as new roots so the objects they depend
1908 * on are also not reclaimed. As with the roots above, only objects in the nursery
1909 * are marked/copied.
1911 finalize_in_range (copy_func, start_addr, end_addr, generation, queue);
1912 if (generation == GENERATION_OLD)
1913 finalize_in_range (copy_func, sgen_get_nursery_start (), sgen_get_nursery_end (), GENERATION_NURSERY, queue);
1914 /* drain the new stack that might have been created */
1915 DEBUG (6, fprintf (gc_debug_file, "Precise scan of gray area post fin\n"));
1916 sgen_drain_gray_stack (queue, -1);
1919 * This must be done again after processing finalizable objects since CWL slots are cleared only after the key is finalized.
1921 done_with_ephemerons = 0;
1923 done_with_ephemerons = mark_ephemerons_in_range (copy_func, start_addr, end_addr, queue);
1924 sgen_drain_gray_stack (queue, -1);
1926 } while (!done_with_ephemerons);
1929 * Clear ephemeron pairs with unreachable keys.
1930 * We pass the copy func so we can figure out if an array was promoted or not.
1932 clear_unreachable_ephemerons (copy_func, start_addr, end_addr, queue);
1935 DEBUG (2, fprintf (gc_debug_file, "Finalize queue handling scan for %s generation: %d usecs %d ephemeron roundss\n", generation_name (generation), TV_ELAPSED (atv, btv), ephemeron_rounds));
1938 * handle disappearing links
1939 * Note we do this after checking the finalization queue because if an object
1940 * survives (at least long enough to be finalized) we don't clear the link.
1941 * This also deals with a possible issue with the monitor reclamation: with the Boehm
1942 * GC a finalized object my lose the monitor because it is cleared before the finalizer is
1945 g_assert (sgen_gray_object_queue_is_empty (queue));
1947 null_link_in_range (copy_func, start_addr, end_addr, generation, FALSE, queue);
1948 if (generation == GENERATION_OLD)
1949 null_link_in_range (copy_func, start_addr, end_addr, GENERATION_NURSERY, FALSE, queue);
1950 if (sgen_gray_object_queue_is_empty (queue))
1952 sgen_drain_gray_stack (queue, -1);
1955 g_assert (sgen_gray_object_queue_is_empty (queue));
1959 sgen_check_section_scan_starts (GCMemSection *section)
1962 for (i = 0; i < section->num_scan_start; ++i) {
1963 if (section->scan_starts [i]) {
1964 guint size = safe_object_get_size ((MonoObject*) section->scan_starts [i]);
1965 g_assert (size >= sizeof (MonoObject) && size <= MAX_SMALL_OBJ_SIZE);
1971 check_scan_starts (void)
1973 if (!do_scan_starts_check)
1975 sgen_check_section_scan_starts (nursery_section);
1976 major_collector.check_scan_starts ();
1980 scan_from_registered_roots (CopyOrMarkObjectFunc copy_func, char *addr_start, char *addr_end, int root_type, GrayQueue *queue)
1984 SGEN_HASH_TABLE_FOREACH (&roots_hash [root_type], start_root, root) {
1985 DEBUG (6, fprintf (gc_debug_file, "Precise root scan %p-%p (desc: %p)\n", start_root, root->end_root, (void*)root->root_desc));
1986 precisely_scan_objects_from (copy_func, start_root, (void**)root->end_root, addr_start, addr_end, root->root_desc, queue);
1987 } SGEN_HASH_TABLE_FOREACH_END;
1991 sgen_dump_occupied (char *start, char *end, char *section_start)
1993 fprintf (heap_dump_file, "<occupied offset=\"%td\" size=\"%td\"/>\n", start - section_start, end - start);
1997 sgen_dump_section (GCMemSection *section, const char *type)
1999 char *start = section->data;
2000 char *end = section->data + section->size;
2001 char *occ_start = NULL;
2003 char *old_start = NULL; /* just for debugging */
2005 fprintf (heap_dump_file, "<section type=\"%s\" size=\"%lu\">\n", type, (unsigned long)section->size);
2007 while (start < end) {
2011 if (!*(void**)start) {
2013 sgen_dump_occupied (occ_start, start, section->data);
2016 start += sizeof (void*); /* should be ALLOC_ALIGN, really */
2019 g_assert (start < section->next_data);
2024 vt = (GCVTable*)LOAD_VTABLE (start);
2027 size = ALIGN_UP (safe_object_get_size ((MonoObject*) start));
2030 fprintf (heap_dump_file, "<object offset=\"%d\" class=\"%s.%s\" size=\"%d\"/>\n",
2031 start - section->data,
2032 vt->klass->name_space, vt->klass->name,
2040 sgen_dump_occupied (occ_start, start, section->data);
2042 fprintf (heap_dump_file, "</section>\n");
2046 dump_object (MonoObject *obj, gboolean dump_location)
2048 static char class_name [1024];
2050 MonoClass *class = mono_object_class (obj);
2054 * Python's XML parser is too stupid to parse angle brackets
2055 * in strings, so we just ignore them;
2058 while (class->name [i] && j < sizeof (class_name) - 1) {
2059 if (!strchr ("<>\"", class->name [i]))
2060 class_name [j++] = class->name [i];
2063 g_assert (j < sizeof (class_name));
2066 fprintf (heap_dump_file, "<object class=\"%s.%s\" size=\"%d\"",
2067 class->name_space, class_name,
2068 safe_object_get_size (obj));
2069 if (dump_location) {
2070 const char *location;
2071 if (ptr_in_nursery (obj))
2072 location = "nursery";
2073 else if (safe_object_get_size (obj) <= MAX_SMALL_OBJ_SIZE)
2077 fprintf (heap_dump_file, " location=\"%s\"", location);
2079 fprintf (heap_dump_file, "/>\n");
2083 dump_heap (const char *type, int num, const char *reason)
2088 fprintf (heap_dump_file, "<collection type=\"%s\" num=\"%d\"", type, num);
2090 fprintf (heap_dump_file, " reason=\"%s\"", reason);
2091 fprintf (heap_dump_file, ">\n");
2092 fprintf (heap_dump_file, "<other-mem-usage type=\"mempools\" size=\"%ld\"/>\n", mono_mempool_get_bytes_allocated ());
2093 sgen_dump_internal_mem_usage (heap_dump_file);
2094 fprintf (heap_dump_file, "<pinned type=\"stack\" bytes=\"%zu\"/>\n", sgen_pin_stats_get_pinned_byte_count (PIN_TYPE_STACK));
2095 /* fprintf (heap_dump_file, "<pinned type=\"static-data\" bytes=\"%d\"/>\n", pinned_byte_counts [PIN_TYPE_STATIC_DATA]); */
2096 fprintf (heap_dump_file, "<pinned type=\"other\" bytes=\"%zu\"/>\n", sgen_pin_stats_get_pinned_byte_count (PIN_TYPE_OTHER));
2098 fprintf (heap_dump_file, "<pinned-objects>\n");
2099 for (list = sgen_pin_stats_get_object_list (); list; list = list->next)
2100 dump_object (list->obj, TRUE);
2101 fprintf (heap_dump_file, "</pinned-objects>\n");
2103 sgen_dump_section (nursery_section, "nursery");
2105 major_collector.dump_heap (heap_dump_file);
2107 fprintf (heap_dump_file, "<los>\n");
2108 for (bigobj = los_object_list; bigobj; bigobj = bigobj->next)
2109 dump_object ((MonoObject*)bigobj->data, FALSE);
2110 fprintf (heap_dump_file, "</los>\n");
2112 fprintf (heap_dump_file, "</collection>\n");
2116 sgen_register_moved_object (void *obj, void *destination)
2118 g_assert (mono_profiler_events & MONO_PROFILE_GC_MOVES);
2120 /* FIXME: handle this for parallel collector */
2121 g_assert (!sgen_collection_is_parallel ());
2123 if (moved_objects_idx == MOVED_OBJECTS_NUM) {
2124 mono_profiler_gc_moves (moved_objects, moved_objects_idx);
2125 moved_objects_idx = 0;
2127 moved_objects [moved_objects_idx++] = obj;
2128 moved_objects [moved_objects_idx++] = destination;
2134 static gboolean inited = FALSE;
2139 mono_counters_register ("Minor fragment clear", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_minor_pre_collection_fragment_clear);
2140 mono_counters_register ("Minor pinning", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_minor_pinning);
2141 mono_counters_register ("Minor scan remembered set", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_minor_scan_remsets);
2142 mono_counters_register ("Minor scan pinned", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_minor_scan_pinned);
2143 mono_counters_register ("Minor scan registered roots", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_minor_scan_registered_roots);
2144 mono_counters_register ("Minor scan thread data", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_minor_scan_thread_data);
2145 mono_counters_register ("Minor finish gray stack", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_minor_finish_gray_stack);
2146 mono_counters_register ("Minor fragment creation", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_minor_fragment_creation);
2148 mono_counters_register ("Major fragment clear", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_major_pre_collection_fragment_clear);
2149 mono_counters_register ("Major pinning", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_major_pinning);
2150 mono_counters_register ("Major scan pinned", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_major_scan_pinned);
2151 mono_counters_register ("Major scan registered roots", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_major_scan_registered_roots);
2152 mono_counters_register ("Major scan thread data", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_major_scan_thread_data);
2153 mono_counters_register ("Major scan alloc_pinned", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_major_scan_alloc_pinned);
2154 mono_counters_register ("Major scan finalized", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_major_scan_finalized);
2155 mono_counters_register ("Major scan big objects", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_major_scan_big_objects);
2156 mono_counters_register ("Major finish gray stack", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_major_finish_gray_stack);
2157 mono_counters_register ("Major free big objects", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_major_free_bigobjs);
2158 mono_counters_register ("Major LOS sweep", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_major_los_sweep);
2159 mono_counters_register ("Major sweep", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_major_sweep);
2160 mono_counters_register ("Major fragment creation", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_major_fragment_creation);
2162 mono_counters_register ("Number of pinned objects", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_pinned_objects);
2164 #ifdef HEAVY_STATISTICS
2165 mono_counters_register ("WBarrier set field", MONO_COUNTER_GC | MONO_COUNTER_INT, &stat_wbarrier_set_field);
2166 mono_counters_register ("WBarrier set arrayref", MONO_COUNTER_GC | MONO_COUNTER_INT, &stat_wbarrier_set_arrayref);
2167 mono_counters_register ("WBarrier arrayref copy", MONO_COUNTER_GC | MONO_COUNTER_INT, &stat_wbarrier_arrayref_copy);
2168 mono_counters_register ("WBarrier generic store called", MONO_COUNTER_GC | MONO_COUNTER_INT, &stat_wbarrier_generic_store);
2169 mono_counters_register ("WBarrier set root", MONO_COUNTER_GC | MONO_COUNTER_INT, &stat_wbarrier_set_root);
2170 mono_counters_register ("WBarrier value copy", MONO_COUNTER_GC | MONO_COUNTER_INT, &stat_wbarrier_value_copy);
2171 mono_counters_register ("WBarrier object copy", MONO_COUNTER_GC | MONO_COUNTER_INT, &stat_wbarrier_object_copy);
2173 mono_counters_register ("# objects allocated degraded", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_objects_alloced_degraded);
2174 mono_counters_register ("bytes allocated degraded", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_bytes_alloced_degraded);
2176 mono_counters_register ("# copy_object() called (nursery)", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_copy_object_called_nursery);
2177 mono_counters_register ("# objects copied (nursery)", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_objects_copied_nursery);
2178 mono_counters_register ("# copy_object() called (major)", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_copy_object_called_major);
2179 mono_counters_register ("# objects copied (major)", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_objects_copied_major);
2181 mono_counters_register ("# scan_object() called (nursery)", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_scan_object_called_nursery);
2182 mono_counters_register ("# scan_object() called (major)", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_scan_object_called_major);
2184 mono_counters_register ("Slots allocated in vain", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_slots_allocated_in_vain);
2186 mono_counters_register ("# nursery copy_object() failed from space", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_nursery_copy_object_failed_from_space);
2187 mono_counters_register ("# nursery copy_object() failed forwarded", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_nursery_copy_object_failed_forwarded);
2188 mono_counters_register ("# nursery copy_object() failed pinned", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_nursery_copy_object_failed_pinned);
2189 mono_counters_register ("# nursery copy_object() failed to space", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_nursery_copy_object_failed_to_space);
2191 sgen_nursery_allocator_init_heavy_stats ();
2192 sgen_alloc_init_heavy_stats ();
2200 reset_pinned_from_failed_allocation (void)
2202 bytes_pinned_from_failed_allocation = 0;
2206 sgen_set_pinned_from_failed_allocation (mword objsize)
2208 bytes_pinned_from_failed_allocation += objsize;
2212 sgen_collection_is_parallel (void)
2214 switch (current_collection_generation) {
2215 case GENERATION_NURSERY:
2216 return nursery_collection_is_parallel;
2217 case GENERATION_OLD:
2218 return major_collector.is_parallel;
2220 g_error ("Invalid current generation %d", current_collection_generation);
2228 } FinishRememberedSetScanJobData;
2231 job_finish_remembered_set_scan (WorkerData *worker_data, void *job_data_untyped)
2233 FinishRememberedSetScanJobData *job_data = job_data_untyped;
2235 remset.finish_scan_remsets (job_data->heap_start, job_data->heap_end, sgen_workers_get_job_gray_queue (worker_data));
2240 CopyOrMarkObjectFunc func;
2244 } ScanFromRegisteredRootsJobData;
2247 job_scan_from_registered_roots (WorkerData *worker_data, void *job_data_untyped)
2249 ScanFromRegisteredRootsJobData *job_data = job_data_untyped;
2251 scan_from_registered_roots (job_data->func,
2252 job_data->heap_start, job_data->heap_end,
2253 job_data->root_type,
2254 sgen_workers_get_job_gray_queue (worker_data));
2261 } ScanThreadDataJobData;
2264 job_scan_thread_data (WorkerData *worker_data, void *job_data_untyped)
2266 ScanThreadDataJobData *job_data = job_data_untyped;
2268 scan_thread_data (job_data->heap_start, job_data->heap_end, TRUE,
2269 sgen_workers_get_job_gray_queue (worker_data));
2274 FinalizeReadyEntry *list;
2275 } ScanFinalizerEntriesJobData;
2278 job_scan_finalizer_entries (WorkerData *worker_data, void *job_data_untyped)
2280 ScanFinalizerEntriesJobData *job_data = job_data_untyped;
2282 scan_finalizer_entries (current_object_ops.copy_or_mark_object,
2284 sgen_workers_get_job_gray_queue (worker_data));
2288 verify_scan_starts (char *start, char *end)
2292 for (i = 0; i < nursery_section->num_scan_start; ++i) {
2293 char *addr = nursery_section->scan_starts [i];
2294 if (addr > start && addr < end)
2295 fprintf (gc_debug_file, "NFC-BAD SCAN START [%d] %p for obj [%p %p]\n", i, addr, start, end);
2300 verify_nursery (void)
2302 char *start, *end, *cur, *hole_start;
2304 if (!do_verify_nursery)
2307 /*This cleans up unused fragments */
2308 sgen_nursery_allocator_prepare_for_pinning ();
2310 hole_start = start = cur = sgen_get_nursery_start ();
2311 end = sgen_get_nursery_end ();
2316 if (!*(void**)cur) {
2317 cur += sizeof (void*);
2321 if (object_is_forwarded (cur))
2322 fprintf (gc_debug_file, "FORWARDED OBJ %p\n", cur);
2323 else if (object_is_pinned (cur))
2324 fprintf (gc_debug_file, "PINNED OBJ %p\n", cur);
2326 ss = safe_object_get_size ((MonoObject*)cur);
2327 size = ALIGN_UP (safe_object_get_size ((MonoObject*)cur));
2328 verify_scan_starts (cur, cur + size);
2329 if (do_dump_nursery_content) {
2330 if (cur > hole_start)
2331 fprintf (gc_debug_file, "HOLE [%p %p %d]\n", hole_start, cur, (int)(cur - hole_start));
2332 fprintf (gc_debug_file, "OBJ [%p %p %d %d %s %d]\n", cur, cur + size, (int)size, (int)ss, sgen_safe_name ((MonoObject*)cur), (gpointer)LOAD_VTABLE (cur) == sgen_get_array_fill_vtable ());
2337 fflush (gc_debug_file);
2341 * Collect objects in the nursery. Returns whether to trigger a major
2345 collect_nursery (void)
2347 gboolean needs_major;
2348 size_t max_garbage_amount;
2350 FinishRememberedSetScanJobData frssjd;
2351 ScanFromRegisteredRootsJobData scrrjd_normal, scrrjd_wbarrier;
2352 ScanFinalizerEntriesJobData sfejd_fin_ready, sfejd_critical_fin;
2353 ScanThreadDataJobData stdjd;
2354 mword fragment_total;
2355 TV_DECLARE (all_atv);
2356 TV_DECLARE (all_btv);
2360 if (disable_minor_collections)
2363 MONO_GC_BEGIN (GENERATION_NURSERY);
2367 mono_perfcounters->gc_collections0++;
2369 current_collection_generation = GENERATION_NURSERY;
2370 if (sgen_collection_is_parallel ())
2371 current_object_ops = sgen_minor_collector.parallel_ops;
2373 current_object_ops = sgen_minor_collector.serial_ops;
2375 reset_pinned_from_failed_allocation ();
2377 binary_protocol_collection (GENERATION_NURSERY);
2378 check_scan_starts ();
2380 sgen_nursery_alloc_prepare_for_minor ();
2384 nursery_next = sgen_nursery_alloc_get_upper_alloc_bound ();
2385 /* FIXME: optimize later to use the higher address where an object can be present */
2386 nursery_next = MAX (nursery_next, sgen_get_nursery_end ());
2388 DEBUG (1, fprintf (gc_debug_file, "Start nursery collection %d %p-%p, size: %d\n", stat_minor_gcs, sgen_get_nursery_start (), nursery_next, (int)(nursery_next - sgen_get_nursery_start ())));
2389 max_garbage_amount = nursery_next - sgen_get_nursery_start ();
2390 g_assert (nursery_section->size >= max_garbage_amount);
2392 /* world must be stopped already */
2393 TV_GETTIME (all_atv);
2397 time_minor_pre_collection_fragment_clear += TV_ELAPSED (atv, btv);
2399 if (xdomain_checks) {
2400 sgen_clear_nursery_fragments ();
2401 check_for_xdomain_refs ();
2404 nursery_section->next_data = nursery_next;
2406 major_collector.start_nursery_collection ();
2408 sgen_memgov_minor_collection_start ();
2410 sgen_gray_object_queue_init (&gray_queue);
2411 sgen_workers_init_distribute_gray_queue ();
2414 gc_stats.minor_gc_count ++;
2416 if (remset.prepare_for_minor_collection)
2417 remset.prepare_for_minor_collection ();
2419 process_fin_stage_entries ();
2420 process_dislink_stage_entries ();
2422 /* pin from pinned handles */
2423 sgen_init_pinning ();
2424 mono_profiler_gc_event (MONO_GC_EVENT_MARK_START, 0);
2425 pin_from_roots (sgen_get_nursery_start (), nursery_next, WORKERS_DISTRIBUTE_GRAY_QUEUE);
2426 /* identify pinned objects */
2427 sgen_optimize_pin_queue (0);
2428 sgen_pinning_setup_section (nursery_section);
2429 sgen_pin_objects_in_section (nursery_section, WORKERS_DISTRIBUTE_GRAY_QUEUE);
2430 sgen_pinning_trim_queue_to_section (nursery_section);
2433 time_minor_pinning += TV_ELAPSED (btv, atv);
2434 DEBUG (2, fprintf (gc_debug_file, "Finding pinned pointers: %d in %d usecs\n", sgen_get_pinned_count (), TV_ELAPSED (btv, atv)));
2435 DEBUG (4, fprintf (gc_debug_file, "Start scan with %d pinned objects\n", sgen_get_pinned_count ()));
2437 if (whole_heap_check_before_collection)
2438 sgen_check_whole_heap ();
2439 if (consistency_check_at_minor_collection)
2440 sgen_check_consistency ();
2442 sgen_workers_start_all_workers ();
2445 * Perform the sequential part of remembered set scanning.
2446 * This usually involves scanning global information that might later be produced by evacuation.
2448 if (remset.begin_scan_remsets)
2449 remset.begin_scan_remsets (sgen_get_nursery_start (), nursery_next, WORKERS_DISTRIBUTE_GRAY_QUEUE);
2451 sgen_workers_start_marking ();
2453 frssjd.heap_start = sgen_get_nursery_start ();
2454 frssjd.heap_end = nursery_next;
2455 sgen_workers_enqueue_job (job_finish_remembered_set_scan, &frssjd);
2457 /* we don't have complete write barrier yet, so we scan all the old generation sections */
2459 time_minor_scan_remsets += TV_ELAPSED (atv, btv);
2460 DEBUG (2, fprintf (gc_debug_file, "Old generation scan: %d usecs\n", TV_ELAPSED (atv, btv)));
2462 if (!sgen_collection_is_parallel ())
2463 sgen_drain_gray_stack (&gray_queue, -1);
2465 if (mono_profiler_get_events () & MONO_PROFILE_GC_ROOTS)
2466 report_registered_roots ();
2467 if (mono_profiler_get_events () & MONO_PROFILE_GC_ROOTS)
2468 report_finalizer_roots ();
2470 time_minor_scan_pinned += TV_ELAPSED (btv, atv);
2472 /* registered roots, this includes static fields */
2473 scrrjd_normal.func = current_object_ops.copy_or_mark_object;
2474 scrrjd_normal.heap_start = sgen_get_nursery_start ();
2475 scrrjd_normal.heap_end = nursery_next;
2476 scrrjd_normal.root_type = ROOT_TYPE_NORMAL;
2477 sgen_workers_enqueue_job (job_scan_from_registered_roots, &scrrjd_normal);
2479 scrrjd_wbarrier.func = current_object_ops.copy_or_mark_object;
2480 scrrjd_wbarrier.heap_start = sgen_get_nursery_start ();
2481 scrrjd_wbarrier.heap_end = nursery_next;
2482 scrrjd_wbarrier.root_type = ROOT_TYPE_WBARRIER;
2483 sgen_workers_enqueue_job (job_scan_from_registered_roots, &scrrjd_wbarrier);
2486 time_minor_scan_registered_roots += TV_ELAPSED (atv, btv);
2489 stdjd.heap_start = sgen_get_nursery_start ();
2490 stdjd.heap_end = nursery_next;
2491 sgen_workers_enqueue_job (job_scan_thread_data, &stdjd);
2494 time_minor_scan_thread_data += TV_ELAPSED (btv, atv);
2497 if (sgen_collection_is_parallel ()) {
2498 while (!sgen_gray_object_queue_is_empty (WORKERS_DISTRIBUTE_GRAY_QUEUE)) {
2499 sgen_workers_distribute_gray_queue_sections ();
2503 sgen_workers_join ();
2505 if (sgen_collection_is_parallel ())
2506 g_assert (sgen_gray_object_queue_is_empty (&gray_queue));
2508 /* Scan the list of objects ready for finalization. If */
2509 sfejd_fin_ready.list = fin_ready_list;
2510 sgen_workers_enqueue_job (job_scan_finalizer_entries, &sfejd_fin_ready);
2512 sfejd_critical_fin.list = critical_fin_list;
2513 sgen_workers_enqueue_job (job_scan_finalizer_entries, &sfejd_critical_fin);
2515 finish_gray_stack (sgen_get_nursery_start (), nursery_next, GENERATION_NURSERY, &gray_queue);
2517 time_minor_finish_gray_stack += TV_ELAPSED (btv, atv);
2518 mono_profiler_gc_event (MONO_GC_EVENT_MARK_END, 0);
2521 * The (single-threaded) finalization code might have done
2522 * some copying/marking so we can only reset the GC thread's
2523 * worker data here instead of earlier when we joined the
2526 sgen_workers_reset_data ();
2528 if (objects_pinned) {
2529 sgen_optimize_pin_queue (0);
2530 sgen_pinning_setup_section (nursery_section);
2533 /* walk the pin_queue, build up the fragment list of free memory, unmark
2534 * pinned objects as we go, memzero() the empty fragments so they are ready for the
2537 mono_profiler_gc_event (MONO_GC_EVENT_RECLAIM_START, 0);
2538 fragment_total = sgen_build_nursery_fragments (nursery_section, nursery_section->pin_queue_start, nursery_section->pin_queue_num_entries);
2539 if (!fragment_total)
2542 /* Clear TLABs for all threads */
2543 sgen_clear_tlabs ();
2545 mono_profiler_gc_event (MONO_GC_EVENT_RECLAIM_END, 0);
2547 time_minor_fragment_creation += TV_ELAPSED (atv, btv);
2548 DEBUG (2, fprintf (gc_debug_file, "Fragment creation: %d usecs, %lu bytes available\n", TV_ELAPSED (atv, btv), (unsigned long)fragment_total));
2550 if (consistency_check_at_minor_collection)
2551 sgen_check_major_refs ();
2553 major_collector.finish_nursery_collection ();
2555 TV_GETTIME (all_btv);
2556 gc_stats.minor_gc_time_usecs += TV_ELAPSED (all_atv, all_btv);
2559 dump_heap ("minor", stat_minor_gcs - 1, NULL);
2561 /* prepare the pin queue for the next collection */
2562 sgen_finish_pinning ();
2563 if (fin_ready_list || critical_fin_list) {
2564 DEBUG (4, fprintf (gc_debug_file, "Finalizer-thread wakeup: ready %d\n", num_ready_finalizers));
2565 mono_gc_finalize_notify ();
2567 sgen_pin_stats_reset ();
2569 g_assert (sgen_gray_object_queue_is_empty (&gray_queue));
2571 if (remset.finish_minor_collection)
2572 remset.finish_minor_collection ();
2574 check_scan_starts ();
2576 binary_protocol_flush_buffers (FALSE);
2578 sgen_memgov_minor_collection_end ();
2580 /*objects are late pinned because of lack of memory, so a major is a good call*/
2581 needs_major = objects_pinned > 0;
2582 current_collection_generation = -1;
2585 MONO_GC_END (GENERATION_NURSERY);
2591 major_do_collection (const char *reason)
2593 LOSObject *bigobj, *prevbo;
2594 TV_DECLARE (all_atv);
2595 TV_DECLARE (all_btv);
2598 /* FIXME: only use these values for the precise scan
2599 * note that to_space pointers should be excluded anyway...
2601 char *heap_start = NULL;
2602 char *heap_end = (char*)-1;
2603 int old_next_pin_slot;
2604 ScanFromRegisteredRootsJobData scrrjd_normal, scrrjd_wbarrier;
2605 ScanThreadDataJobData stdjd;
2606 ScanFinalizerEntriesJobData sfejd_fin_ready, sfejd_critical_fin;
2608 MONO_GC_BEGIN (GENERATION_OLD);
2610 current_collection_generation = GENERATION_OLD;
2611 mono_perfcounters->gc_collections1++;
2613 current_object_ops = major_collector.major_ops;
2615 reset_pinned_from_failed_allocation ();
2617 sgen_memgov_major_collection_start ();
2619 //count_ref_nonref_objs ();
2620 //consistency_check ();
2622 binary_protocol_collection (GENERATION_OLD);
2623 check_scan_starts ();
2625 sgen_gray_object_queue_init (&gray_queue);
2626 sgen_workers_init_distribute_gray_queue ();
2627 sgen_nursery_alloc_prepare_for_major ();
2630 DEBUG (1, fprintf (gc_debug_file, "Start major collection %d\n", stat_major_gcs));
2632 gc_stats.major_gc_count ++;
2634 /* world must be stopped already */
2635 TV_GETTIME (all_atv);
2638 /* Pinning depends on this */
2639 sgen_clear_nursery_fragments ();
2641 if (whole_heap_check_before_collection)
2642 sgen_check_whole_heap ();
2645 time_major_pre_collection_fragment_clear += TV_ELAPSED (atv, btv);
2647 nursery_section->next_data = sgen_get_nursery_end ();
2648 /* we should also coalesce scanning from sections close to each other
2649 * and deal with pointers outside of the sections later.
2652 if (major_collector.start_major_collection)
2653 major_collector.start_major_collection ();
2656 *major_collector.have_swept = FALSE;
2658 if (xdomain_checks) {
2659 sgen_clear_nursery_fragments ();
2660 check_for_xdomain_refs ();
2663 /* Remsets are not useful for a major collection */
2664 remset.prepare_for_major_collection ();
2666 process_fin_stage_entries ();
2667 process_dislink_stage_entries ();
2670 sgen_init_pinning ();
2671 DEBUG (6, fprintf (gc_debug_file, "Collecting pinned addresses\n"));
2672 pin_from_roots ((void*)lowest_heap_address, (void*)highest_heap_address, WORKERS_DISTRIBUTE_GRAY_QUEUE);
2673 sgen_optimize_pin_queue (0);
2676 * pin_queue now contains all candidate pointers, sorted and
2677 * uniqued. We must do two passes now to figure out which
2678 * objects are pinned.
2680 * The first is to find within the pin_queue the area for each
2681 * section. This requires that the pin_queue be sorted. We
2682 * also process the LOS objects and pinned chunks here.
2684 * The second, destructive, pass is to reduce the section
2685 * areas to pointers to the actually pinned objects.
2687 DEBUG (6, fprintf (gc_debug_file, "Pinning from sections\n"));
2688 /* first pass for the sections */
2689 sgen_find_section_pin_queue_start_end (nursery_section);
2690 major_collector.find_pin_queue_start_ends (WORKERS_DISTRIBUTE_GRAY_QUEUE);
2691 /* identify possible pointers to the insize of large objects */
2692 DEBUG (6, fprintf (gc_debug_file, "Pinning from large objects\n"));
2693 for (bigobj = los_object_list; bigobj; bigobj = bigobj->next) {
2695 gboolean profile_roots = mono_profiler_get_events () & MONO_PROFILE_GC_ROOTS;
2696 GCRootReport report;
2698 if (sgen_find_optimized_pin_queue_area (bigobj->data, (char*)bigobj->data + bigobj->size, &dummy)) {
2699 binary_protocol_pin (bigobj->data, (gpointer)LOAD_VTABLE (bigobj->data), safe_object_get_size (bigobj->data));
2700 if (MONO_GC_OBJ_PINNED_ENABLED ()) {
2701 MONO_GC_OBJ_PINNED (bigobj->data, sgen_safe_object_get_size ((MonoObject*)bigobj->data), NULL, GENERATION_OLD);
2703 pin_object (bigobj->data);
2704 /* FIXME: only enqueue if object has references */
2705 GRAY_OBJECT_ENQUEUE (WORKERS_DISTRIBUTE_GRAY_QUEUE, bigobj->data);
2706 if (G_UNLIKELY (do_pin_stats))
2707 sgen_pin_stats_register_object ((char*) bigobj->data, safe_object_get_size ((MonoObject*) bigobj->data));
2708 DEBUG (6, fprintf (gc_debug_file, "Marked large object %p (%s) size: %lu from roots\n", bigobj->data, safe_name (bigobj->data), (unsigned long)bigobj->size));
2711 add_profile_gc_root (&report, bigobj->data, MONO_PROFILE_GC_ROOT_PINNING | MONO_PROFILE_GC_ROOT_MISC, 0);
2714 notify_gc_roots (&report);
2716 /* second pass for the sections */
2717 sgen_pin_objects_in_section (nursery_section, WORKERS_DISTRIBUTE_GRAY_QUEUE);
2718 major_collector.pin_objects (WORKERS_DISTRIBUTE_GRAY_QUEUE);
2719 old_next_pin_slot = sgen_get_pinned_count ();
2722 time_major_pinning += TV_ELAPSED (atv, btv);
2723 DEBUG (2, fprintf (gc_debug_file, "Finding pinned pointers: %d in %d usecs\n", sgen_get_pinned_count (), TV_ELAPSED (atv, btv)));
2724 DEBUG (4, fprintf (gc_debug_file, "Start scan with %d pinned objects\n", sgen_get_pinned_count ()));
2726 major_collector.init_to_space ();
2728 #ifdef SGEN_DEBUG_INTERNAL_ALLOC
2729 main_gc_thread = mono_native_thread_self ();
2732 sgen_workers_start_all_workers ();
2733 sgen_workers_start_marking ();
2735 if (mono_profiler_get_events () & MONO_PROFILE_GC_ROOTS)
2736 report_registered_roots ();
2738 time_major_scan_pinned += TV_ELAPSED (btv, atv);
2740 /* registered roots, this includes static fields */
2741 scrrjd_normal.func = current_object_ops.copy_or_mark_object;
2742 scrrjd_normal.heap_start = heap_start;
2743 scrrjd_normal.heap_end = heap_end;
2744 scrrjd_normal.root_type = ROOT_TYPE_NORMAL;
2745 sgen_workers_enqueue_job (job_scan_from_registered_roots, &scrrjd_normal);
2747 scrrjd_wbarrier.func = current_object_ops.copy_or_mark_object;
2748 scrrjd_wbarrier.heap_start = heap_start;
2749 scrrjd_wbarrier.heap_end = heap_end;
2750 scrrjd_wbarrier.root_type = ROOT_TYPE_WBARRIER;
2751 sgen_workers_enqueue_job (job_scan_from_registered_roots, &scrrjd_wbarrier);
2754 time_major_scan_registered_roots += TV_ELAPSED (atv, btv);
2757 stdjd.heap_start = heap_start;
2758 stdjd.heap_end = heap_end;
2759 sgen_workers_enqueue_job (job_scan_thread_data, &stdjd);
2762 time_major_scan_thread_data += TV_ELAPSED (btv, atv);
2765 time_major_scan_alloc_pinned += TV_ELAPSED (atv, btv);
2767 if (mono_profiler_get_events () & MONO_PROFILE_GC_ROOTS)
2768 report_finalizer_roots ();
2770 /* scan the list of objects ready for finalization */
2771 sfejd_fin_ready.list = fin_ready_list;
2772 sgen_workers_enqueue_job (job_scan_finalizer_entries, &sfejd_fin_ready);
2774 sfejd_critical_fin.list = critical_fin_list;
2775 sgen_workers_enqueue_job (job_scan_finalizer_entries, &sfejd_critical_fin);
2778 time_major_scan_finalized += TV_ELAPSED (btv, atv);
2779 DEBUG (2, fprintf (gc_debug_file, "Root scan: %d usecs\n", TV_ELAPSED (btv, atv)));
2782 time_major_scan_big_objects += TV_ELAPSED (atv, btv);
2784 if (major_collector.is_parallel) {
2785 while (!sgen_gray_object_queue_is_empty (WORKERS_DISTRIBUTE_GRAY_QUEUE)) {
2786 sgen_workers_distribute_gray_queue_sections ();
2790 sgen_workers_join ();
2792 #ifdef SGEN_DEBUG_INTERNAL_ALLOC
2793 main_gc_thread = NULL;
2796 if (major_collector.is_parallel)
2797 g_assert (sgen_gray_object_queue_is_empty (&gray_queue));
2799 /* all the objects in the heap */
2800 finish_gray_stack (heap_start, heap_end, GENERATION_OLD, &gray_queue);
2802 time_major_finish_gray_stack += TV_ELAPSED (btv, atv);
2805 * The (single-threaded) finalization code might have done
2806 * some copying/marking so we can only reset the GC thread's
2807 * worker data here instead of earlier when we joined the
2810 sgen_workers_reset_data ();
2812 if (objects_pinned) {
2813 /*This is slow, but we just OOM'd*/
2814 sgen_pin_queue_clear_discarded_entries (nursery_section, old_next_pin_slot);
2815 sgen_optimize_pin_queue (0);
2816 sgen_find_section_pin_queue_start_end (nursery_section);
2820 reset_heap_boundaries ();
2821 sgen_update_heap_boundaries ((mword)sgen_get_nursery_start (), (mword)sgen_get_nursery_end ());
2823 /* sweep the big objects list */
2825 for (bigobj = los_object_list; bigobj;) {
2826 if (object_is_pinned (bigobj->data)) {
2827 unpin_object (bigobj->data);
2828 sgen_update_heap_boundaries ((mword)bigobj->data, (mword)bigobj->data + bigobj->size);
2831 /* not referenced anywhere, so we can free it */
2833 prevbo->next = bigobj->next;
2835 los_object_list = bigobj->next;
2837 bigobj = bigobj->next;
2838 sgen_los_free_object (to_free);
2842 bigobj = bigobj->next;
2846 time_major_free_bigobjs += TV_ELAPSED (atv, btv);
2851 time_major_los_sweep += TV_ELAPSED (btv, atv);
2853 major_collector.sweep ();
2856 time_major_sweep += TV_ELAPSED (atv, btv);
2858 /* walk the pin_queue, build up the fragment list of free memory, unmark
2859 * pinned objects as we go, memzero() the empty fragments so they are ready for the
2862 if (!sgen_build_nursery_fragments (nursery_section, nursery_section->pin_queue_start, nursery_section->pin_queue_num_entries))
2865 /* Clear TLABs for all threads */
2866 sgen_clear_tlabs ();
2869 time_major_fragment_creation += TV_ELAPSED (btv, atv);
2871 TV_GETTIME (all_btv);
2872 gc_stats.major_gc_time_usecs += TV_ELAPSED (all_atv, all_btv);
2875 dump_heap ("major", stat_major_gcs - 1, reason);
2877 /* prepare the pin queue for the next collection */
2878 sgen_finish_pinning ();
2880 if (fin_ready_list || critical_fin_list) {
2881 DEBUG (4, fprintf (gc_debug_file, "Finalizer-thread wakeup: ready %d\n", num_ready_finalizers));
2882 mono_gc_finalize_notify ();
2884 sgen_pin_stats_reset ();
2886 g_assert (sgen_gray_object_queue_is_empty (&gray_queue));
2888 sgen_memgov_major_collection_end ();
2889 current_collection_generation = -1;
2891 major_collector.finish_major_collection ();
2893 check_scan_starts ();
2895 binary_protocol_flush_buffers (FALSE);
2897 //consistency_check ();
2899 MONO_GC_END (GENERATION_OLD);
2901 return bytes_pinned_from_failed_allocation > 0;
2904 static gboolean major_do_collection (const char *reason);
2907 * Ensure an allocation request for @size will succeed by freeing enough memory.
2909 * LOCKING: The GC lock MUST be held.
2912 sgen_ensure_free_space (size_t size)
2914 int generation_to_collect = -1;
2915 const char *reason = NULL;
2918 if (size > SGEN_MAX_SMALL_OBJ_SIZE) {
2919 if (sgen_need_major_collection (size)) {
2920 reason = "LOS overflow";
2921 generation_to_collect = GENERATION_OLD;
2924 if (degraded_mode) {
2925 if (sgen_need_major_collection (size)) {
2926 reason = "Degraded mode overflow";
2927 generation_to_collect = GENERATION_OLD;
2929 } else if (sgen_need_major_collection (size)) {
2930 reason = "Minor allowance";
2931 generation_to_collect = GENERATION_OLD;
2933 generation_to_collect = GENERATION_NURSERY;
2934 reason = "Nursery full";
2938 if (generation_to_collect == -1)
2940 sgen_perform_collection (size, generation_to_collect, reason);
2944 sgen_perform_collection (size_t requested_size, int generation_to_collect, const char *reason)
2946 TV_DECLARE (gc_end);
2947 GGTimingInfo infos [2];
2948 int overflow_generation_to_collect = -1;
2949 const char *overflow_reason = NULL;
2951 memset (infos, 0, sizeof (infos));
2952 mono_profiler_gc_event (MONO_GC_EVENT_START, generation_to_collect);
2954 infos [0].generation = generation_to_collect;
2955 infos [0].reason = reason;
2956 infos [0].is_overflow = FALSE;
2957 TV_GETTIME (infos [0].total_time);
2958 infos [1].generation = -1;
2960 stop_world (generation_to_collect);
2961 //FIXME extract overflow reason
2962 if (generation_to_collect == GENERATION_NURSERY) {
2963 if (collect_nursery ()) {
2964 overflow_generation_to_collect = GENERATION_OLD;
2965 overflow_reason = "Minor overflow";
2968 if (major_do_collection (reason)) {
2969 overflow_generation_to_collect = GENERATION_NURSERY;
2970 overflow_reason = "Excessive pinning";
2974 TV_GETTIME (gc_end);
2975 infos [0].total_time = SGEN_TV_ELAPSED (infos [0].total_time, gc_end);
2978 if (overflow_generation_to_collect != -1) {
2979 mono_profiler_gc_event (MONO_GC_EVENT_START, overflow_generation_to_collect);
2980 infos [1].generation = overflow_generation_to_collect;
2981 infos [1].reason = overflow_reason;
2982 infos [1].is_overflow = TRUE;
2983 infos [1].total_time = gc_end;
2985 if (overflow_generation_to_collect == GENERATION_NURSERY)
2988 major_do_collection (overflow_reason);
2990 TV_GETTIME (gc_end);
2991 infos [1].total_time = SGEN_TV_ELAPSED (infos [1].total_time, gc_end);
2993 /* keep events symmetric */
2994 mono_profiler_gc_event (MONO_GC_EVENT_END, overflow_generation_to_collect);
2997 DEBUG (2, fprintf (gc_debug_file, "Heap size: %lu, LOS size: %lu\n", (unsigned long)mono_gc_get_heap_size (), (unsigned long)los_memory_usage));
2999 /* this also sets the proper pointers for the next allocation */
3000 if (generation_to_collect == GENERATION_NURSERY && !sgen_can_alloc_size (requested_size)) {
3001 /* TypeBuilder and MonoMethod are killing mcs with fragmentation */
3002 DEBUG (1, fprintf (gc_debug_file, "nursery collection didn't find enough room for %zd alloc (%d pinned)\n", requested_size, sgen_get_pinned_count ()));
3003 sgen_dump_pin_queue ();
3007 restart_world (generation_to_collect, infos);
3009 mono_profiler_gc_event (MONO_GC_EVENT_END, generation_to_collect);
3013 * ######################################################################
3014 * ######## Memory allocation from the OS
3015 * ######################################################################
3016 * This section of code deals with getting memory from the OS and
3017 * allocating memory for GC-internal data structures.
3018 * Internal memory can be handled with a freelist for small objects.
3024 G_GNUC_UNUSED static void
3025 report_internal_mem_usage (void)
3027 printf ("Internal memory usage:\n");
3028 sgen_report_internal_mem_usage ();
3029 printf ("Pinned memory usage:\n");
3030 major_collector.report_pinned_memory_usage ();
3034 * ######################################################################
3035 * ######## Finalization support
3036 * ######################################################################
3040 * If the object has been forwarded it means it's still referenced from a root.
3041 * If it is pinned it's still alive as well.
3042 * A LOS object is only alive if we have pinned it.
3043 * Return TRUE if @obj is ready to be finalized.
3045 static inline gboolean
3046 sgen_is_object_alive (void *object)
3048 if (ptr_in_nursery (object))
3049 return sgen_nursery_is_object_alive (object);
3050 /* Oldgen objects can be pinned and forwarded too */
3051 if (SGEN_OBJECT_IS_PINNED (object) || SGEN_OBJECT_IS_FORWARDED (object))
3053 return major_collector.is_object_live (object);
3057 sgen_gc_is_object_ready_for_finalization (void *object)
3059 return !sgen_is_object_alive (object);
3063 has_critical_finalizer (MonoObject *obj)
3067 if (!mono_defaults.critical_finalizer_object)
3070 class = ((MonoVTable*)LOAD_VTABLE (obj))->klass;
3072 return mono_class_has_parent_fast (class, mono_defaults.critical_finalizer_object);
3076 queue_finalization_entry (MonoObject *obj) {
3077 FinalizeReadyEntry *entry = sgen_alloc_internal (INTERNAL_MEM_FINALIZE_READY_ENTRY);
3078 entry->object = obj;
3079 if (has_critical_finalizer (obj)) {
3080 entry->next = critical_fin_list;
3081 critical_fin_list = entry;
3083 entry->next = fin_ready_list;
3084 fin_ready_list = entry;
3089 object_is_reachable (char *object, char *start, char *end)
3091 /*This happens for non nursery objects during minor collections. We just treat all objects as alive.*/
3092 if (object < start || object >= end)
3095 return sgen_is_object_alive (object);
3098 #include "sgen-fin-weak-hash.c"
3101 sgen_object_is_live (void *obj)
3103 if (ptr_in_nursery (obj))
3104 return object_is_pinned (obj);
3105 /* FIXME This is semantically wrong! All tenured object are considered alive during a nursery collection. */
3106 if (current_collection_generation == GENERATION_NURSERY)
3108 return major_collector.is_object_live (obj);
3111 /* LOCKING: requires that the GC lock is held */
3113 null_ephemerons_for_domain (MonoDomain *domain)
3115 EphemeronLinkNode *current = ephemeron_list, *prev = NULL;
3118 MonoObject *object = (MonoObject*)current->array;
3120 if (object && !object->vtable) {
3121 EphemeronLinkNode *tmp = current;
3124 prev->next = current->next;
3126 ephemeron_list = current->next;
3128 current = current->next;
3129 sgen_free_internal (tmp, INTERNAL_MEM_EPHEMERON_LINK);
3132 current = current->next;
3137 /* LOCKING: requires that the GC lock is held */
3139 clear_unreachable_ephemerons (CopyOrMarkObjectFunc copy_func, char *start, char *end, GrayQueue *queue)
3141 int was_in_nursery, was_promoted;
3142 EphemeronLinkNode *current = ephemeron_list, *prev = NULL;
3144 Ephemeron *cur, *array_end;
3148 char *object = current->array;
3150 if (!object_is_reachable (object, start, end)) {
3151 EphemeronLinkNode *tmp = current;
3153 DEBUG (5, fprintf (gc_debug_file, "Dead Ephemeron array at %p\n", object));
3156 prev->next = current->next;
3158 ephemeron_list = current->next;
3160 current = current->next;
3161 sgen_free_internal (tmp, INTERNAL_MEM_EPHEMERON_LINK);
3166 was_in_nursery = ptr_in_nursery (object);
3167 copy_func ((void**)&object, queue);
3168 current->array = object;
3170 /*The array was promoted, add global remsets for key/values left behind in nursery.*/
3171 was_promoted = was_in_nursery && !ptr_in_nursery (object);
3173 DEBUG (5, fprintf (gc_debug_file, "Clearing unreachable entries for ephemeron array at %p\n", object));
3175 array = (MonoArray*)object;
3176 cur = mono_array_addr (array, Ephemeron, 0);
3177 array_end = cur + mono_array_length_fast (array);
3178 tombstone = (char*)((MonoVTable*)LOAD_VTABLE (object))->domain->ephemeron_tombstone;
3180 for (; cur < array_end; ++cur) {
3181 char *key = (char*)cur->key;
3183 if (!key || key == tombstone)
3186 DEBUG (5, fprintf (gc_debug_file, "[%td] key %p (%s) value %p (%s)\n", cur - mono_array_addr (array, Ephemeron, 0),
3187 key, object_is_reachable (key, start, end) ? "reachable" : "unreachable",
3188 cur->value, cur->value && object_is_reachable (cur->value, start, end) ? "reachable" : "unreachable"));
3190 if (!object_is_reachable (key, start, end)) {
3191 cur->key = tombstone;
3197 if (ptr_in_nursery (key)) {/*key was not promoted*/
3198 DEBUG (5, fprintf (gc_debug_file, "\tAdded remset to key %p\n", key));
3199 sgen_add_to_global_remset (&cur->key);
3201 if (ptr_in_nursery (cur->value)) {/*value was not promoted*/
3202 DEBUG (5, fprintf (gc_debug_file, "\tAdded remset to value %p\n", cur->value));
3203 sgen_add_to_global_remset (&cur->value);
3208 current = current->next;
3212 /* LOCKING: requires that the GC lock is held */
3214 mark_ephemerons_in_range (CopyOrMarkObjectFunc copy_func, char *start, char *end, GrayQueue *queue)
3216 int nothing_marked = 1;
3217 EphemeronLinkNode *current = ephemeron_list;
3219 Ephemeron *cur, *array_end;
3222 for (current = ephemeron_list; current; current = current->next) {
3223 char *object = current->array;
3224 DEBUG (5, fprintf (gc_debug_file, "Ephemeron array at %p\n", object));
3227 For now we process all ephemerons during all collections.
3228 Ideally we should use remset information to partially scan those
3230 We already emit write barriers for Ephemeron fields, it's
3231 just that we don't process them.
3233 /*if (object < start || object >= end)
3236 /*It has to be alive*/
3237 if (!object_is_reachable (object, start, end)) {
3238 DEBUG (5, fprintf (gc_debug_file, "\tnot reachable\n"));
3242 copy_func ((void**)&object, queue);
3244 array = (MonoArray*)object;
3245 cur = mono_array_addr (array, Ephemeron, 0);
3246 array_end = cur + mono_array_length_fast (array);
3247 tombstone = (char*)((MonoVTable*)LOAD_VTABLE (object))->domain->ephemeron_tombstone;
3249 for (; cur < array_end; ++cur) {
3250 char *key = cur->key;
3252 if (!key || key == tombstone)
3255 DEBUG (5, fprintf (gc_debug_file, "[%td] key %p (%s) value %p (%s)\n", cur - mono_array_addr (array, Ephemeron, 0),
3256 key, object_is_reachable (key, start, end) ? "reachable" : "unreachable",
3257 cur->value, cur->value && object_is_reachable (cur->value, start, end) ? "reachable" : "unreachable"));
3259 if (object_is_reachable (key, start, end)) {
3260 char *value = cur->value;
3262 copy_func ((void**)&cur->key, queue);
3264 if (!object_is_reachable (value, start, end))
3266 copy_func ((void**)&cur->value, queue);
3272 DEBUG (5, fprintf (gc_debug_file, "Ephemeron run finished. Is it done %d\n", nothing_marked));
3273 return nothing_marked;
3277 mono_gc_invoke_finalizers (void)
3279 FinalizeReadyEntry *entry = NULL;
3280 gboolean entry_is_critical = FALSE;
3283 /* FIXME: batch to reduce lock contention */
3284 while (fin_ready_list || critical_fin_list) {
3288 FinalizeReadyEntry **list = entry_is_critical ? &critical_fin_list : &fin_ready_list;
3290 /* We have finalized entry in the last
3291 interation, now we need to remove it from
3294 *list = entry->next;
3296 FinalizeReadyEntry *e = *list;
3297 while (e->next != entry)
3299 e->next = entry->next;
3301 sgen_free_internal (entry, INTERNAL_MEM_FINALIZE_READY_ENTRY);
3305 /* Now look for the first non-null entry. */
3306 for (entry = fin_ready_list; entry && !entry->object; entry = entry->next)
3309 entry_is_critical = FALSE;
3311 entry_is_critical = TRUE;
3312 for (entry = critical_fin_list; entry && !entry->object; entry = entry->next)
3317 g_assert (entry->object);
3318 num_ready_finalizers--;
3319 obj = entry->object;
3320 entry->object = NULL;
3321 DEBUG (7, fprintf (gc_debug_file, "Finalizing object %p (%s)\n", obj, safe_name (obj)));
3329 g_assert (entry->object == NULL);
3331 /* the object is on the stack so it is pinned */
3332 /*g_print ("Calling finalizer for object: %p (%s)\n", entry->object, safe_name (entry->object));*/
3333 mono_gc_run_finalize (obj, NULL);
3340 mono_gc_pending_finalizers (void)
3342 return fin_ready_list || critical_fin_list;
3346 * ######################################################################
3347 * ######## registered roots support
3348 * ######################################################################
3352 * We do not coalesce roots.
3355 mono_gc_register_root_inner (char *start, size_t size, void *descr, int root_type)
3357 RootRecord new_root;
3360 for (i = 0; i < ROOT_TYPE_NUM; ++i) {
3361 RootRecord *root = sgen_hash_table_lookup (&roots_hash [i], start);
3362 /* we allow changing the size and the descriptor (for thread statics etc) */
3364 size_t old_size = root->end_root - start;
3365 root->end_root = start + size;
3366 g_assert (((root->root_desc != 0) && (descr != NULL)) ||
3367 ((root->root_desc == 0) && (descr == NULL)));
3368 root->root_desc = (mword)descr;
3370 roots_size -= old_size;
3376 new_root.end_root = start + size;
3377 new_root.root_desc = (mword)descr;
3379 sgen_hash_table_replace (&roots_hash [root_type], start, &new_root, NULL);
3382 DEBUG (3, fprintf (gc_debug_file, "Added root for range: %p-%p, descr: %p (%d/%d bytes)\n", start, new_root.end_root, descr, (int)size, (int)roots_size));
3389 mono_gc_register_root (char *start, size_t size, void *descr)
3391 return mono_gc_register_root_inner (start, size, descr, descr ? ROOT_TYPE_NORMAL : ROOT_TYPE_PINNED);
3395 mono_gc_register_root_wbarrier (char *start, size_t size, void *descr)
3397 return mono_gc_register_root_inner (start, size, descr, ROOT_TYPE_WBARRIER);
3401 mono_gc_deregister_root (char* addr)
3407 for (root_type = 0; root_type < ROOT_TYPE_NUM; ++root_type) {
3408 if (sgen_hash_table_remove (&roots_hash [root_type], addr, &root))
3409 roots_size -= (root.end_root - addr);
3415 * ######################################################################
3416 * ######## Thread handling (stop/start code)
3417 * ######################################################################
3420 unsigned int sgen_global_stop_count = 0;
3423 static MonoContext cur_thread_ctx = {0};
3425 static mword cur_thread_regs [ARCH_NUM_REGS] = {0};
3429 update_current_thread_stack (void *start)
3431 int stack_guard = 0;
3432 #ifndef USE_MONO_CTX
3433 void *ptr = cur_thread_regs;
3435 SgenThreadInfo *info = mono_thread_info_current ();
3437 info->stack_start = align_pointer (&stack_guard);
3438 g_assert (info->stack_start >= info->stack_start_limit && info->stack_start < info->stack_end);
3440 MONO_CONTEXT_GET_CURRENT (cur_thread_ctx);
3441 info->monoctx = &cur_thread_ctx;
3442 if (gc_callbacks.thread_suspend_func)
3443 gc_callbacks.thread_suspend_func (info->runtime_data, NULL, info->monoctx);
3445 ARCH_STORE_REGS (ptr);
3446 info->stopped_regs = ptr;
3447 if (gc_callbacks.thread_suspend_func)
3448 gc_callbacks.thread_suspend_func (info->runtime_data, NULL, NULL);
3453 sgen_fill_thread_info_for_suspend (SgenThreadInfo *info)
3455 if (remset.fill_thread_info_for_suspend)
3456 remset.fill_thread_info_for_suspend (info);
3460 is_ip_in_managed_allocator (MonoDomain *domain, gpointer ip);
3463 restart_threads_until_none_in_managed_allocator (void)
3465 SgenThreadInfo *info;
3466 int num_threads_died = 0;
3467 int sleep_duration = -1;
3470 int restart_count = 0, restarted_count = 0;
3471 /* restart all threads that stopped in the
3473 FOREACH_THREAD_SAFE (info) {
3475 if (info->skip || info->gc_disabled || !info->joined_stw)
3477 if (!info->thread_is_dying && (!info->stack_start || info->in_critical_region ||
3478 is_ip_in_managed_allocator (info->stopped_domain, info->stopped_ip))) {
3479 binary_protocol_thread_restart ((gpointer)mono_thread_info_get_tid (info));
3480 result = sgen_resume_thread (info);
3487 /* we set the stopped_ip to
3488 NULL for threads which
3489 we're not restarting so
3490 that we can easily identify
3492 info->stopped_ip = NULL;
3493 info->stopped_domain = NULL;
3495 } END_FOREACH_THREAD_SAFE
3496 /* if no threads were restarted, we're done */
3497 if (restart_count == 0)
3500 /* wait for the threads to signal their restart */
3501 sgen_wait_for_suspend_ack (restart_count);
3503 if (sleep_duration < 0) {
3511 g_usleep (sleep_duration);
3512 sleep_duration += 10;
3515 /* stop them again */
3516 FOREACH_THREAD (info) {
3518 if (info->skip || info->stopped_ip == NULL)
3520 result = sgen_suspend_thread (info);
3527 } END_FOREACH_THREAD
3528 /* some threads might have died */
3529 num_threads_died += restart_count - restarted_count;
3530 /* wait for the threads to signal their suspension
3532 sgen_wait_for_suspend_ack (restarted_count);
3535 return num_threads_died;
3539 acquire_gc_locks (void)
3542 mono_thread_info_suspend_lock ();
3546 release_gc_locks (void)
3548 mono_thread_info_suspend_unlock ();
3549 UNLOCK_INTERRUPTION;
3552 static TV_DECLARE (stop_world_time);
3553 static unsigned long max_pause_usec = 0;
3555 /* LOCKING: assumes the GC lock is held */
3557 stop_world (int generation)
3561 /*XXX this is the right stop, thought might not be the nicest place to put it*/
3562 sgen_process_togglerefs ();
3564 mono_profiler_gc_event (MONO_GC_EVENT_PRE_STOP_WORLD, generation);
3565 acquire_gc_locks ();
3567 update_current_thread_stack (&count);
3569 sgen_global_stop_count++;
3570 DEBUG (3, fprintf (gc_debug_file, "stopping world n %d from %p %p\n", sgen_global_stop_count, mono_thread_info_current (), (gpointer)mono_native_thread_id_get ()));
3571 TV_GETTIME (stop_world_time);
3572 count = sgen_thread_handshake (TRUE);
3573 dead = restart_threads_until_none_in_managed_allocator ();
3575 g_error ("More threads have died (%d) that been initialy suspended %d", dead, count);
3578 DEBUG (3, fprintf (gc_debug_file, "world stopped %d thread(s)\n", count));
3579 mono_profiler_gc_event (MONO_GC_EVENT_POST_STOP_WORLD, generation);
3581 sgen_memgov_collection_start (generation);
3586 /* LOCKING: assumes the GC lock is held */
3588 restart_world (int generation, GGTimingInfo *timing)
3591 SgenThreadInfo *info;
3592 TV_DECLARE (end_sw);
3593 TV_DECLARE (end_bridge);
3594 unsigned long usec, bridge_usec;
3596 /* notify the profiler of the leftovers */
3597 if (G_UNLIKELY (mono_profiler_events & MONO_PROFILE_GC_MOVES)) {
3598 if (moved_objects_idx) {
3599 mono_profiler_gc_moves (moved_objects, moved_objects_idx);
3600 moved_objects_idx = 0;
3603 mono_profiler_gc_event (MONO_GC_EVENT_PRE_START_WORLD, generation);
3604 FOREACH_THREAD (info) {
3605 info->stack_start = NULL;
3607 info->monoctx = NULL;
3609 info->stopped_regs = NULL;
3611 } END_FOREACH_THREAD
3613 stw_bridge_process ();
3614 release_gc_locks ();
3616 count = sgen_thread_handshake (FALSE);
3617 TV_GETTIME (end_sw);
3618 usec = TV_ELAPSED (stop_world_time, end_sw);
3619 max_pause_usec = MAX (usec, max_pause_usec);
3620 DEBUG (2, fprintf (gc_debug_file, "restarted %d thread(s) (pause time: %d usec, max: %d)\n", count, (int)usec, (int)max_pause_usec));
3621 mono_profiler_gc_event (MONO_GC_EVENT_POST_START_WORLD, generation);
3625 TV_GETTIME (end_bridge);
3626 bridge_usec = TV_ELAPSED (end_sw, end_bridge);
3629 timing [0].stw_time = usec;
3630 timing [0].bridge_time = bridge_usec;
3633 sgen_memgov_collection_end (generation, timing, timing ? 2 : 0);
3639 sgen_get_current_collection_generation (void)
3641 return current_collection_generation;
3645 mono_gc_set_gc_callbacks (MonoGCCallbacks *callbacks)
3647 gc_callbacks = *callbacks;
3651 mono_gc_get_gc_callbacks ()
3653 return &gc_callbacks;
3656 /* Variables holding start/end nursery so it won't have to be passed at every call */
3657 static void *scan_area_arg_start, *scan_area_arg_end;
3660 mono_gc_conservatively_scan_area (void *start, void *end)
3662 conservatively_pin_objects_from (start, end, scan_area_arg_start, scan_area_arg_end, PIN_TYPE_STACK);
3666 mono_gc_scan_object (void *obj)
3668 UserCopyOrMarkData *data = mono_native_tls_get_value (user_copy_or_mark_key);
3669 current_object_ops.copy_or_mark_object (&obj, data->queue);
3674 * Mark from thread stacks and registers.
3677 scan_thread_data (void *start_nursery, void *end_nursery, gboolean precise, GrayQueue *queue)
3679 SgenThreadInfo *info;
3681 scan_area_arg_start = start_nursery;
3682 scan_area_arg_end = end_nursery;
3684 FOREACH_THREAD (info) {
3686 DEBUG (3, fprintf (gc_debug_file, "Skipping dead thread %p, range: %p-%p, size: %td\n", info, info->stack_start, info->stack_end, (char*)info->stack_end - (char*)info->stack_start));
3689 if (info->gc_disabled) {
3690 DEBUG (3, fprintf (gc_debug_file, "GC disabled for thread %p, range: %p-%p, size: %td\n", info, info->stack_start, info->stack_end, (char*)info->stack_end - (char*)info->stack_start));
3694 if (!info->joined_stw) {
3695 DEBUG (3, fprintf (gc_debug_file, "Skipping thread not seen in STW %p, range: %p-%p, size: %td\n", info, info->stack_start, info->stack_end, (char*)info->stack_end - (char*)info->stack_start));
3699 DEBUG (3, fprintf (gc_debug_file, "Scanning thread %p, range: %p-%p, size: %td, pinned=%d\n", info, info->stack_start, info->stack_end, (char*)info->stack_end - (char*)info->stack_start, sgen_get_pinned_count ()));
3700 if (!info->thread_is_dying) {
3701 if (gc_callbacks.thread_mark_func && !conservative_stack_mark) {
3702 UserCopyOrMarkData data = { NULL, queue };
3703 set_user_copy_or_mark_data (&data);
3704 gc_callbacks.thread_mark_func (info->runtime_data, info->stack_start, info->stack_end, precise);
3705 set_user_copy_or_mark_data (NULL);
3706 } else if (!precise) {
3707 conservatively_pin_objects_from (info->stack_start, info->stack_end, start_nursery, end_nursery, PIN_TYPE_STACK);
3712 if (!info->thread_is_dying && !precise)
3713 conservatively_pin_objects_from ((void**)info->monoctx, (void**)info->monoctx + ARCH_NUM_REGS,
3714 start_nursery, end_nursery, PIN_TYPE_STACK);
3716 if (!info->thread_is_dying && !precise)
3717 conservatively_pin_objects_from (info->stopped_regs, info->stopped_regs + ARCH_NUM_REGS,
3718 start_nursery, end_nursery, PIN_TYPE_STACK);
3720 } END_FOREACH_THREAD
3724 find_pinning_ref_from_thread (char *obj, size_t size)
3727 SgenThreadInfo *info;
3728 char *endobj = obj + size;
3730 FOREACH_THREAD (info) {
3731 char **start = (char**)info->stack_start;
3734 while (start < (char**)info->stack_end) {
3735 if (*start >= obj && *start < endobj) {
3736 DEBUG (0, fprintf (gc_debug_file, "Object %p referenced in thread %p (id %p) at %p, stack: %p-%p\n", obj, info, (gpointer)mono_thread_info_get_tid (info), start, info->stack_start, info->stack_end));
3741 for (j = 0; j < ARCH_NUM_REGS; ++j) {
3743 mword w = ((mword*)info->monoctx) [j];
3745 mword w = (mword)info->stopped_regs [j];
3748 if (w >= (mword)obj && w < (mword)obj + size)
3749 DEBUG (0, fprintf (gc_debug_file, "Object %p referenced in saved reg %d of thread %p (id %p)\n", obj, j, info, (gpointer)mono_thread_info_get_tid (info)));
3750 } END_FOREACH_THREAD
3755 ptr_on_stack (void *ptr)
3757 gpointer stack_start = &stack_start;
3758 SgenThreadInfo *info = mono_thread_info_current ();
3760 if (ptr >= stack_start && ptr < (gpointer)info->stack_end)
3766 sgen_thread_register (SgenThreadInfo* info, void *addr)
3768 #ifndef HAVE_KW_THREAD
3769 SgenThreadInfo *__thread_info__ = info;
3773 #ifndef HAVE_KW_THREAD
3774 info->tlab_start = info->tlab_next = info->tlab_temp_end = info->tlab_real_end = NULL;
3776 g_assert (!mono_native_tls_get_value (thread_info_key));
3777 mono_native_tls_set_value (thread_info_key, info);
3782 #if !defined(__MACH__)
3783 info->stop_count = -1;
3787 info->joined_stw = FALSE;
3788 info->doing_handshake = FALSE;
3789 info->thread_is_dying = FALSE;
3790 info->stack_start = NULL;
3791 info->store_remset_buffer_addr = &STORE_REMSET_BUFFER;
3792 info->store_remset_buffer_index_addr = &STORE_REMSET_BUFFER_INDEX;
3793 info->stopped_ip = NULL;
3794 info->stopped_domain = NULL;
3796 info->monoctx = NULL;
3798 info->stopped_regs = NULL;
3801 sgen_init_tlab_info (info);
3803 binary_protocol_thread_register ((gpointer)mono_thread_info_get_tid (info));
3805 #ifdef HAVE_KW_THREAD
3806 store_remset_buffer_index_addr = &store_remset_buffer_index;
3809 #if defined(__MACH__)
3810 info->mach_port = mach_thread_self ();
3813 /* try to get it with attributes first */
3814 #if defined(HAVE_PTHREAD_GETATTR_NP) && defined(HAVE_PTHREAD_ATTR_GETSTACK)
3818 pthread_attr_t attr;
3819 pthread_getattr_np (pthread_self (), &attr);
3820 pthread_attr_getstack (&attr, &sstart, &size);
3821 info->stack_start_limit = sstart;
3822 info->stack_end = (char*)sstart + size;
3823 pthread_attr_destroy (&attr);
3825 #elif defined(HAVE_PTHREAD_GET_STACKSIZE_NP) && defined(HAVE_PTHREAD_GET_STACKADDR_NP)
3826 info->stack_end = (char*)pthread_get_stackaddr_np (pthread_self ());
3827 info->stack_start_limit = (char*)info->stack_end - pthread_get_stacksize_np (pthread_self ());
3830 /* FIXME: we assume the stack grows down */
3831 gsize stack_bottom = (gsize)addr;
3832 stack_bottom += 4095;
3833 stack_bottom &= ~4095;
3834 info->stack_end = (char*)stack_bottom;
3838 #ifdef HAVE_KW_THREAD
3839 stack_end = info->stack_end;
3842 if (remset.register_thread)
3843 remset.register_thread (info);
3845 DEBUG (3, fprintf (gc_debug_file, "registered thread %p (%p) stack end %p\n", info, (gpointer)mono_thread_info_get_tid (info), info->stack_end));
3847 if (gc_callbacks.thread_attach_func)
3848 info->runtime_data = gc_callbacks.thread_attach_func ();
3855 sgen_wbarrier_cleanup_thread (SgenThreadInfo *p)
3857 if (remset.cleanup_thread)
3858 remset.cleanup_thread (p);
3862 sgen_thread_unregister (SgenThreadInfo *p)
3864 /* If a delegate is passed to native code and invoked on a thread we dont
3865 * know about, the jit will register it with mono_jit_thread_attach, but
3866 * we have no way of knowing when that thread goes away. SGen has a TSD
3867 * so we assume that if the domain is still registered, we can detach
3870 if (mono_domain_get ())
3871 mono_thread_detach (mono_thread_current ());
3873 p->thread_is_dying = TRUE;
3876 There is a race condition between a thread finishing executing and been removed
3877 from the GC thread set.
3878 This happens on posix systems when TLS data is been cleaned-up, libpthread will
3879 set the thread_info slot to NULL before calling the cleanup function. This
3880 opens a window in which the thread is registered but has a NULL TLS.
3882 The suspend signal handler needs TLS data to know where to store thread state
3883 data or otherwise it will simply ignore the thread.
3885 This solution works because the thread doing STW will wait until all threads been
3886 suspended handshake back, so there is no race between the doing_hankshake test
3887 and the suspend_thread call.
3889 This is not required on systems that do synchronous STW as those can deal with
3890 the above race at suspend time.
3892 FIXME: I believe we could avoid this by using mono_thread_info_lookup when
3893 mono_thread_info_current returns NULL. Or fix mono_thread_info_lookup to do so.
3895 #if (defined(__MACH__) && MONO_MACH_ARCH_SUPPORTED) || !defined(HAVE_PTHREAD_KILL)
3898 while (!TRYLOCK_GC) {
3899 if (!sgen_park_current_thread_if_doing_handshake (p))
3905 binary_protocol_thread_unregister ((gpointer)mono_thread_info_get_tid (p));
3906 DEBUG (3, fprintf (gc_debug_file, "unregister thread %p (%p)\n", p, (gpointer)mono_thread_info_get_tid (p)));
3908 #if defined(__MACH__)
3909 mach_port_deallocate (current_task (), p->mach_port);
3912 if (gc_callbacks.thread_detach_func) {
3913 gc_callbacks.thread_detach_func (p->runtime_data);
3914 p->runtime_data = NULL;
3916 sgen_wbarrier_cleanup_thread (p);
3918 mono_threads_unregister_current_thread (p);
3924 sgen_thread_attach (SgenThreadInfo *info)
3927 /*this is odd, can we get attached before the gc is inited?*/
3931 if (gc_callbacks.thread_attach_func && !info->runtime_data)
3932 info->runtime_data = gc_callbacks.thread_attach_func ();
3935 mono_gc_register_thread (void *baseptr)
3937 return mono_thread_info_attach (baseptr) != NULL;
3941 * mono_gc_set_stack_end:
3943 * Set the end of the current threads stack to STACK_END. The stack space between
3944 * STACK_END and the real end of the threads stack will not be scanned during collections.
3947 mono_gc_set_stack_end (void *stack_end)
3949 SgenThreadInfo *info;
3952 info = mono_thread_info_current ();
3954 g_assert (stack_end < info->stack_end);
3955 info->stack_end = stack_end;
3960 #if USE_PTHREAD_INTERCEPT
3964 mono_gc_pthread_create (pthread_t *new_thread, const pthread_attr_t *attr, void *(*start_routine)(void *), void *arg)
3966 return pthread_create (new_thread, attr, start_routine, arg);
3970 mono_gc_pthread_join (pthread_t thread, void **retval)
3972 return pthread_join (thread, retval);
3976 mono_gc_pthread_detach (pthread_t thread)
3978 return pthread_detach (thread);
3982 mono_gc_pthread_exit (void *retval)
3984 pthread_exit (retval);
3987 #endif /* USE_PTHREAD_INTERCEPT */
3990 * ######################################################################
3991 * ######## Write barriers
3992 * ######################################################################
3996 * Note: the write barriers first do the needed GC work and then do the actual store:
3997 * this way the value is visible to the conservative GC scan after the write barrier
3998 * itself. If a GC interrupts the barrier in the middle, value will be kept alive by
3999 * the conservative scan, otherwise by the remembered set scan.
4002 mono_gc_wbarrier_set_field (MonoObject *obj, gpointer field_ptr, MonoObject* value)
4004 HEAVY_STAT (++stat_wbarrier_set_field);
4005 if (ptr_in_nursery (field_ptr)) {
4006 *(void**)field_ptr = value;
4009 DEBUG (8, fprintf (gc_debug_file, "Adding remset at %p\n", field_ptr));
4011 binary_protocol_wbarrier (field_ptr, value, value->vtable);
4013 remset.wbarrier_set_field (obj, field_ptr, value);
4017 mono_gc_wbarrier_set_arrayref (MonoArray *arr, gpointer slot_ptr, MonoObject* value)
4019 HEAVY_STAT (++stat_wbarrier_set_arrayref);
4020 if (ptr_in_nursery (slot_ptr)) {
4021 *(void**)slot_ptr = value;
4024 DEBUG (8, fprintf (gc_debug_file, "Adding remset at %p\n", slot_ptr));
4026 binary_protocol_wbarrier (slot_ptr, value, value->vtable);
4028 remset.wbarrier_set_arrayref (arr, slot_ptr, value);
4032 mono_gc_wbarrier_arrayref_copy (gpointer dest_ptr, gpointer src_ptr, int count)
4034 HEAVY_STAT (++stat_wbarrier_arrayref_copy);
4035 /*This check can be done without taking a lock since dest_ptr array is pinned*/
4036 if (ptr_in_nursery (dest_ptr) || count <= 0) {
4037 mono_gc_memmove (dest_ptr, src_ptr, count * sizeof (gpointer));
4041 #ifdef SGEN_BINARY_PROTOCOL
4044 for (i = 0; i < count; ++i) {
4045 gpointer dest = (gpointer*)dest_ptr + i;
4046 gpointer obj = *((gpointer*)src_ptr + i);
4048 binary_protocol_wbarrier (dest, obj, (gpointer)LOAD_VTABLE (obj));
4053 remset.wbarrier_arrayref_copy (dest_ptr, src_ptr, count);
4056 static char *found_obj;
4059 find_object_for_ptr_callback (char *obj, size_t size, void *user_data)
4061 char *ptr = user_data;
4063 if (ptr >= obj && ptr < obj + size) {
4064 g_assert (!found_obj);
4069 /* for use in the debugger */
4070 char* find_object_for_ptr (char *ptr);
4072 find_object_for_ptr (char *ptr)
4074 if (ptr >= nursery_section->data && ptr < nursery_section->end_data) {
4076 sgen_scan_area_with_callback (nursery_section->data, nursery_section->end_data,
4077 find_object_for_ptr_callback, ptr, TRUE);
4083 sgen_los_iterate_objects (find_object_for_ptr_callback, ptr);
4088 * Very inefficient, but this is debugging code, supposed to
4089 * be called from gdb, so we don't care.
4092 major_collector.iterate_objects (TRUE, TRUE, find_object_for_ptr_callback, ptr);
4097 mono_gc_wbarrier_generic_nostore (gpointer ptr)
4099 HEAVY_STAT (++stat_wbarrier_generic_store);
4101 #ifdef XDOMAIN_CHECKS_IN_WBARRIER
4102 /* FIXME: ptr_in_heap must be called with the GC lock held */
4103 if (xdomain_checks && *(MonoObject**)ptr && ptr_in_heap (ptr)) {
4104 char *start = find_object_for_ptr (ptr);
4105 MonoObject *value = *(MonoObject**)ptr;
4109 MonoObject *obj = (MonoObject*)start;
4110 if (obj->vtable->domain != value->vtable->domain)
4111 g_assert (is_xdomain_ref_allowed (ptr, start, obj->vtable->domain));
4117 if (*(gpointer*)ptr)
4118 binary_protocol_wbarrier (ptr, *(gpointer*)ptr, (gpointer)LOAD_VTABLE (*(gpointer*)ptr));
4120 if (ptr_in_nursery (ptr) || ptr_on_stack (ptr) || !ptr_in_nursery (*(gpointer*)ptr)) {
4121 DEBUG (8, fprintf (gc_debug_file, "Skipping remset at %p\n", ptr));
4125 DEBUG (8, fprintf (gc_debug_file, "Adding remset at %p\n", ptr));
4127 remset.wbarrier_generic_nostore (ptr);
4131 mono_gc_wbarrier_generic_store (gpointer ptr, MonoObject* value)
4133 DEBUG (8, fprintf (gc_debug_file, "Wbarrier store at %p to %p (%s)\n", ptr, value, value ? safe_name (value) : "null"));
4134 *(void**)ptr = value;
4135 if (ptr_in_nursery (value))
4136 mono_gc_wbarrier_generic_nostore (ptr);
4137 sgen_dummy_use (value);
4140 void mono_gc_wbarrier_value_copy_bitmap (gpointer _dest, gpointer _src, int size, unsigned bitmap)
4142 mword *dest = _dest;
4147 mono_gc_wbarrier_generic_store (dest, (MonoObject*)*src);
4152 size -= SIZEOF_VOID_P;
4157 #ifdef SGEN_BINARY_PROTOCOL
4159 #define HANDLE_PTR(ptr,obj) do { \
4160 gpointer o = *(gpointer*)(ptr); \
4162 gpointer d = ((char*)dest) + ((char*)(ptr) - (char*)(obj)); \
4163 binary_protocol_wbarrier (d, o, (gpointer) LOAD_VTABLE (o)); \
4168 scan_object_for_binary_protocol_copy_wbarrier (gpointer dest, char *start, mword desc)
4170 #define SCAN_OBJECT_NOVTABLE
4171 #include "sgen-scan-object.h"
4176 mono_gc_wbarrier_value_copy (gpointer dest, gpointer src, int count, MonoClass *klass)
4178 HEAVY_STAT (++stat_wbarrier_value_copy);
4179 g_assert (klass->valuetype);
4181 DEBUG (8, fprintf (gc_debug_file, "Adding value remset at %p, count %d, descr %p for class %s (%p)\n", dest, count, klass->gc_descr, klass->name, klass));
4183 if (ptr_in_nursery (dest) || ptr_on_stack (dest) || !SGEN_CLASS_HAS_REFERENCES (klass)) {
4184 size_t element_size = mono_class_value_size (klass, NULL);
4185 size_t size = count * element_size;
4186 mono_gc_memmove (dest, src, size);
4190 #ifdef SGEN_BINARY_PROTOCOL
4193 for (i = 0; i < count; ++i) {
4194 scan_object_for_binary_protocol_copy_wbarrier ((char*)dest + i * element_size,
4195 (char*)src + i * element_size - sizeof (MonoObject),
4196 (mword) klass->gc_descr);
4201 remset.wbarrier_value_copy (dest, src, count, klass);
4205 * mono_gc_wbarrier_object_copy:
4207 * Write barrier to call when obj is the result of a clone or copy of an object.
4210 mono_gc_wbarrier_object_copy (MonoObject* obj, MonoObject *src)
4214 HEAVY_STAT (++stat_wbarrier_object_copy);
4216 if (ptr_in_nursery (obj) || ptr_on_stack (obj)) {
4217 size = mono_object_class (obj)->instance_size;
4218 mono_gc_memmove ((char*)obj + sizeof (MonoObject), (char*)src + sizeof (MonoObject),
4219 size - sizeof (MonoObject));
4223 #ifdef SGEN_BINARY_PROTOCOL
4224 scan_object_for_binary_protocol_copy_wbarrier (obj, (char*)src, (mword) src->vtable->gc_descr);
4227 remset.wbarrier_object_copy (obj, src);
4232 * ######################################################################
4233 * ######## Other mono public interface functions.
4234 * ######################################################################
4237 #define REFS_SIZE 128
4240 MonoGCReferences callback;
4244 MonoObject *refs [REFS_SIZE];
4245 uintptr_t offsets [REFS_SIZE];
4249 #define HANDLE_PTR(ptr,obj) do { \
4251 if (hwi->count == REFS_SIZE) { \
4252 hwi->callback ((MonoObject*)start, mono_object_class (start), hwi->called? 0: size, hwi->count, hwi->refs, hwi->offsets, hwi->data); \
4256 hwi->offsets [hwi->count] = (char*)(ptr)-(char*)start; \
4257 hwi->refs [hwi->count++] = *(ptr); \
4262 collect_references (HeapWalkInfo *hwi, char *start, size_t size)
4264 #include "sgen-scan-object.h"
4268 walk_references (char *start, size_t size, void *data)
4270 HeapWalkInfo *hwi = data;
4273 collect_references (hwi, start, size);
4274 if (hwi->count || !hwi->called)
4275 hwi->callback ((MonoObject*)start, mono_object_class (start), hwi->called? 0: size, hwi->count, hwi->refs, hwi->offsets, hwi->data);
4279 * mono_gc_walk_heap:
4280 * @flags: flags for future use
4281 * @callback: a function pointer called for each object in the heap
4282 * @data: a user data pointer that is passed to callback
4284 * This function can be used to iterate over all the live objects in the heap:
4285 * for each object, @callback is invoked, providing info about the object's
4286 * location in memory, its class, its size and the objects it references.
4287 * For each referenced object it's offset from the object address is
4288 * reported in the offsets array.
4289 * The object references may be buffered, so the callback may be invoked
4290 * multiple times for the same object: in all but the first call, the size
4291 * argument will be zero.
4292 * Note that this function can be only called in the #MONO_GC_EVENT_PRE_START_WORLD
4293 * profiler event handler.
4295 * Returns: a non-zero value if the GC doesn't support heap walking
4298 mono_gc_walk_heap (int flags, MonoGCReferences callback, void *data)
4303 hwi.callback = callback;
4306 sgen_clear_nursery_fragments ();
4307 sgen_scan_area_with_callback (nursery_section->data, nursery_section->end_data, walk_references, &hwi, FALSE);
4309 major_collector.iterate_objects (TRUE, TRUE, walk_references, &hwi);
4310 sgen_los_iterate_objects (walk_references, &hwi);
4316 mono_gc_collect (int generation)
4321 sgen_perform_collection (0, generation, "user request");
4326 mono_gc_max_generation (void)
4332 mono_gc_collection_count (int generation)
4334 if (generation == 0)
4335 return stat_minor_gcs;
4336 return stat_major_gcs;
4340 mono_gc_get_used_size (void)
4344 tot = los_memory_usage;
4345 tot += nursery_section->next_data - nursery_section->data;
4346 tot += major_collector.get_used_size ();
4347 /* FIXME: account for pinned objects */
4353 mono_gc_disable (void)
4361 mono_gc_enable (void)
4369 mono_gc_get_los_limit (void)
4371 return MAX_SMALL_OBJ_SIZE;
4375 mono_gc_user_markers_supported (void)
4381 mono_object_is_alive (MonoObject* o)
4387 mono_gc_get_generation (MonoObject *obj)
4389 if (ptr_in_nursery (obj))
4395 mono_gc_enable_events (void)
4400 mono_gc_weak_link_add (void **link_addr, MonoObject *obj, gboolean track)
4402 mono_gc_register_disappearing_link (obj, link_addr, track, FALSE);
4406 mono_gc_weak_link_remove (void **link_addr)
4408 mono_gc_register_disappearing_link (NULL, link_addr, FALSE, FALSE);
4412 mono_gc_weak_link_get (void **link_addr)
4416 return (MonoObject*) REVEAL_POINTER (*link_addr);
4420 mono_gc_ephemeron_array_add (MonoObject *obj)
4422 EphemeronLinkNode *node;
4426 node = sgen_alloc_internal (INTERNAL_MEM_EPHEMERON_LINK);
4431 node->array = (char*)obj;
4432 node->next = ephemeron_list;
4433 ephemeron_list = node;
4435 DEBUG (5, fprintf (gc_debug_file, "Registered ephemeron array %p\n", obj));
4442 mono_gc_invoke_with_gc_lock (MonoGCLockedCallbackFunc func, void *data)
4446 result = func (data);
4447 UNLOCK_INTERRUPTION;
4452 mono_gc_is_gc_thread (void)
4456 result = mono_thread_info_current () != NULL;
4462 is_critical_method (MonoMethod *method)
4464 return mono_runtime_is_critical_method (method) || mono_gc_is_critical_method (method);
4468 mono_gc_base_init (void)
4470 MonoThreadInfoCallbacks cb;
4473 char *major_collector_opt = NULL;
4474 char *minor_collector_opt = NULL;
4476 glong soft_limit = 0;
4480 gboolean debug_print_allowance = FALSE;
4481 double allowance_ratio = 0, save_target = 0;
4484 result = InterlockedCompareExchange (&gc_initialized, -1, 0);
4487 /* already inited */
4490 /* being inited by another thread */
4494 /* we will init it */
4497 g_assert_not_reached ();
4499 } while (result != 0);
4501 LOCK_INIT (gc_mutex);
4503 pagesize = mono_pagesize ();
4504 gc_debug_file = stderr;
4506 cb.thread_register = sgen_thread_register;
4507 cb.thread_unregister = sgen_thread_unregister;
4508 cb.thread_attach = sgen_thread_attach;
4509 cb.mono_method_is_critical = (gpointer)is_critical_method;
4511 cb.mono_gc_pthread_create = (gpointer)mono_gc_pthread_create;
4514 mono_threads_init (&cb, sizeof (SgenThreadInfo));
4516 LOCK_INIT (interruption_mutex);
4517 LOCK_INIT (pin_queue_mutex);
4519 init_user_copy_or_mark_key ();
4521 if ((env = getenv ("MONO_GC_PARAMS"))) {
4522 opts = g_strsplit (env, ",", -1);
4523 for (ptr = opts; *ptr; ++ptr) {
4525 if (g_str_has_prefix (opt, "major=")) {
4526 opt = strchr (opt, '=') + 1;
4527 major_collector_opt = g_strdup (opt);
4528 } else if (g_str_has_prefix (opt, "minor=")) {
4529 opt = strchr (opt, '=') + 1;
4530 minor_collector_opt = g_strdup (opt);
4538 sgen_init_internal_allocator ();
4539 sgen_init_nursery_allocator ();
4541 sgen_register_fixed_internal_mem_type (INTERNAL_MEM_SECTION, SGEN_SIZEOF_GC_MEM_SECTION);
4542 sgen_register_fixed_internal_mem_type (INTERNAL_MEM_FINALIZE_READY_ENTRY, sizeof (FinalizeReadyEntry));
4543 sgen_register_fixed_internal_mem_type (INTERNAL_MEM_GRAY_QUEUE, sizeof (GrayQueueSection));
4544 g_assert (sizeof (GenericStoreRememberedSet) == sizeof (gpointer) * STORE_REMSET_BUFFER_SIZE);
4545 sgen_register_fixed_internal_mem_type (INTERNAL_MEM_STORE_REMSET, sizeof (GenericStoreRememberedSet));
4546 sgen_register_fixed_internal_mem_type (INTERNAL_MEM_EPHEMERON_LINK, sizeof (EphemeronLinkNode));
4548 #ifndef HAVE_KW_THREAD
4549 mono_native_tls_alloc (&thread_info_key, NULL);
4553 * This needs to happen before any internal allocations because
4554 * it inits the small id which is required for hazard pointer
4559 mono_thread_info_attach (&dummy);
4561 if (!minor_collector_opt) {
4562 sgen_simple_nursery_init (&sgen_minor_collector);
4564 if (!strcmp (minor_collector_opt, "simple"))
4565 sgen_simple_nursery_init (&sgen_minor_collector);
4566 else if (!strcmp (minor_collector_opt, "split"))
4567 sgen_split_nursery_init (&sgen_minor_collector);
4569 fprintf (stderr, "Unknown minor collector `%s'.\n", minor_collector_opt);
4574 if (!major_collector_opt || !strcmp (major_collector_opt, "marksweep")) {
4575 sgen_marksweep_init (&major_collector);
4576 } else if (!major_collector_opt || !strcmp (major_collector_opt, "marksweep-fixed")) {
4577 sgen_marksweep_fixed_init (&major_collector);
4578 } else if (!major_collector_opt || !strcmp (major_collector_opt, "marksweep-par")) {
4579 sgen_marksweep_par_init (&major_collector);
4580 } else if (!major_collector_opt || !strcmp (major_collector_opt, "marksweep-fixed-par")) {
4581 sgen_marksweep_fixed_par_init (&major_collector);
4582 } else if (!strcmp (major_collector_opt, "copying")) {
4583 sgen_copying_init (&major_collector);
4585 fprintf (stderr, "Unknown major collector `%s'.\n", major_collector_opt);
4589 #ifdef SGEN_HAVE_CARDTABLE
4590 use_cardtable = major_collector.supports_cardtable;
4592 use_cardtable = FALSE;
4595 num_workers = mono_cpu_count ();
4596 g_assert (num_workers > 0);
4597 if (num_workers > 16)
4600 ///* Keep this the default for now */
4601 /* Precise marking is broken on all supported targets. Disable until fixed. */
4602 conservative_stack_mark = TRUE;
4604 sgen_nursery_size = DEFAULT_NURSERY_SIZE;
4607 for (ptr = opts; *ptr; ++ptr) {
4609 if (g_str_has_prefix (opt, "major="))
4611 if (g_str_has_prefix (opt, "minor="))
4613 if (g_str_has_prefix (opt, "wbarrier=")) {
4614 opt = strchr (opt, '=') + 1;
4615 if (strcmp (opt, "remset") == 0) {
4616 use_cardtable = FALSE;
4617 } else if (strcmp (opt, "cardtable") == 0) {
4618 if (!use_cardtable) {
4619 if (major_collector.supports_cardtable)
4620 fprintf (stderr, "The cardtable write barrier is not supported on this platform.\n");
4622 fprintf (stderr, "The major collector does not support the cardtable write barrier.\n");
4626 fprintf (stderr, "wbarrier must either be `remset' or `cardtable'.");
4631 if (g_str_has_prefix (opt, "max-heap-size=")) {
4632 opt = strchr (opt, '=') + 1;
4633 if (*opt && mono_gc_parse_environment_string_extract_number (opt, &max_heap)) {
4634 if ((max_heap & (mono_pagesize () - 1))) {
4635 fprintf (stderr, "max-heap-size size must be a multiple of %d.\n", mono_pagesize ());
4639 fprintf (stderr, "max-heap-size must be an integer.\n");
4644 if (g_str_has_prefix (opt, "soft-heap-limit=")) {
4645 opt = strchr (opt, '=') + 1;
4646 if (*opt && mono_gc_parse_environment_string_extract_number (opt, &soft_limit)) {
4647 if (soft_limit <= 0) {
4648 fprintf (stderr, "soft-heap-limit must be positive.\n");
4652 fprintf (stderr, "soft-heap-limit must be an integer.\n");
4657 if (g_str_has_prefix (opt, "workers=")) {
4660 if (!major_collector.is_parallel) {
4661 fprintf (stderr, "The workers= option can only be used for parallel collectors.");
4664 opt = strchr (opt, '=') + 1;
4665 val = strtol (opt, &endptr, 10);
4666 if (!*opt || *endptr) {
4667 fprintf (stderr, "Cannot parse the workers= option value.");
4670 if (val <= 0 || val > 16) {
4671 fprintf (stderr, "The number of workers must be in the range 1 to 16.");
4674 num_workers = (int)val;
4677 if (g_str_has_prefix (opt, "stack-mark=")) {
4678 opt = strchr (opt, '=') + 1;
4679 if (!strcmp (opt, "precise")) {
4680 conservative_stack_mark = FALSE;
4681 } else if (!strcmp (opt, "conservative")) {
4682 conservative_stack_mark = TRUE;
4684 fprintf (stderr, "Invalid value '%s' for stack-mark= option, possible values are: 'precise', 'conservative'.\n", opt);
4689 if (g_str_has_prefix (opt, "bridge=")) {
4690 opt = strchr (opt, '=') + 1;
4691 sgen_register_test_bridge_callbacks (g_strdup (opt));
4695 if (g_str_has_prefix (opt, "nursery-size=")) {
4697 opt = strchr (opt, '=') + 1;
4698 if (*opt && mono_gc_parse_environment_string_extract_number (opt, &val)) {
4699 sgen_nursery_size = val;
4700 #ifdef SGEN_ALIGN_NURSERY
4701 if ((val & (val - 1))) {
4702 fprintf (stderr, "The nursery size must be a power of two.\n");
4706 if (val < SGEN_MAX_NURSERY_WASTE) {
4707 fprintf (stderr, "The nursery size must be at least %d bytes.\n", SGEN_MAX_NURSERY_WASTE);
4711 sgen_nursery_bits = 0;
4712 while (1 << (++ sgen_nursery_bits) != sgen_nursery_size)
4716 fprintf (stderr, "nursery-size must be an integer.\n");
4722 if (g_str_has_prefix (opt, "save-target-ratio=")) {
4724 opt = strchr (opt, '=') + 1;
4725 save_target = strtod (opt, &endptr);
4726 if (endptr == opt) {
4727 fprintf (stderr, "save-target-ratio must be a number.");
4730 if (save_target < SGEN_MIN_SAVE_TARGET_RATIO || save_target > SGEN_MAX_SAVE_TARGET_RATIO) {
4731 fprintf (stderr, "save-target-ratio must be between %.2f - %.2f.", SGEN_MIN_SAVE_TARGET_RATIO, SGEN_MAX_SAVE_TARGET_RATIO);
4736 if (g_str_has_prefix (opt, "default-allowance-ratio=")) {
4738 opt = strchr (opt, '=') + 1;
4740 allowance_ratio = strtod (opt, &endptr);
4741 if (endptr == opt) {
4742 fprintf (stderr, "save-target-ratio must be a number.");
4745 if (allowance_ratio < SGEN_MIN_ALLOWANCE_NURSERY_SIZE_RATIO || allowance_ratio > SGEN_MIN_ALLOWANCE_NURSERY_SIZE_RATIO) {
4746 fprintf (stderr, "default-allowance-ratio must be between %.2f - %.2f.", SGEN_MIN_ALLOWANCE_NURSERY_SIZE_RATIO, SGEN_MIN_ALLOWANCE_NURSERY_SIZE_RATIO);
4752 if (major_collector.handle_gc_param && major_collector.handle_gc_param (opt))
4755 if (sgen_minor_collector.handle_gc_param && sgen_minor_collector.handle_gc_param (opt))
4758 fprintf (stderr, "MONO_GC_PARAMS must be a comma-delimited list of one or more of the following:\n");
4759 fprintf (stderr, " max-heap-size=N (where N is an integer, possibly with a k, m or a g suffix)\n");
4760 fprintf (stderr, " soft-heap-limit=n (where N is an integer, possibly with a k, m or a g suffix)\n");
4761 fprintf (stderr, " nursery-size=N (where N is an integer, possibly with a k, m or a g suffix)\n");
4762 fprintf (stderr, " major=COLLECTOR (where COLLECTOR is `marksweep', `marksweep-par' or `copying')\n");
4763 fprintf (stderr, " minor=COLLECTOR (where COLLECTOR is `simple' or `split')\n");
4764 fprintf (stderr, " wbarrier=WBARRIER (where WBARRIER is `remset' or `cardtable')\n");
4765 fprintf (stderr, " stack-mark=MARK-METHOD (where MARK-METHOD is 'precise' or 'conservative')\n");
4766 if (major_collector.print_gc_param_usage)
4767 major_collector.print_gc_param_usage ();
4768 if (sgen_minor_collector.print_gc_param_usage)
4769 sgen_minor_collector.print_gc_param_usage ();
4770 fprintf (stderr, " Experimental options:\n");
4771 fprintf (stderr, " save-target-ratio=R (where R must be between %.2f - %.2f).\n", SGEN_MIN_SAVE_TARGET_RATIO, SGEN_MAX_SAVE_TARGET_RATIO);
4772 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);
4778 if (major_collector.is_parallel)
4779 sgen_workers_init (num_workers);
4781 if (major_collector_opt)
4782 g_free (major_collector_opt);
4784 if (minor_collector_opt)
4785 g_free (minor_collector_opt);
4789 if ((env = getenv ("MONO_GC_DEBUG"))) {
4790 opts = g_strsplit (env, ",", -1);
4791 for (ptr = opts; ptr && *ptr; ptr ++) {
4793 if (opt [0] >= '0' && opt [0] <= '9') {
4794 gc_debug_level = atoi (opt);
4800 char *rf = g_strdup_printf ("%s.%d", opt, GetCurrentProcessId ());
4802 char *rf = g_strdup_printf ("%s.%d", opt, getpid ());
4804 gc_debug_file = fopen (rf, "wb");
4806 gc_debug_file = stderr;
4809 } else if (!strcmp (opt, "print-allowance")) {
4810 debug_print_allowance = TRUE;
4811 } else if (!strcmp (opt, "print-pinning")) {
4812 do_pin_stats = TRUE;
4813 } else if (!strcmp (opt, "verify-before-allocs")) {
4814 verify_before_allocs = 1;
4815 has_per_allocation_action = TRUE;
4816 } else if (g_str_has_prefix (opt, "verify-before-allocs=")) {
4817 char *arg = strchr (opt, '=') + 1;
4818 verify_before_allocs = atoi (arg);
4819 has_per_allocation_action = TRUE;
4820 } else if (!strcmp (opt, "collect-before-allocs")) {
4821 collect_before_allocs = 1;
4822 has_per_allocation_action = TRUE;
4823 } else if (g_str_has_prefix (opt, "collect-before-allocs=")) {
4824 char *arg = strchr (opt, '=') + 1;
4825 has_per_allocation_action = TRUE;
4826 collect_before_allocs = atoi (arg);
4827 } else if (!strcmp (opt, "verify-before-collections")) {
4828 whole_heap_check_before_collection = TRUE;
4829 } else if (!strcmp (opt, "check-at-minor-collections")) {
4830 consistency_check_at_minor_collection = TRUE;
4831 nursery_clear_policy = CLEAR_AT_GC;
4832 } else if (!strcmp (opt, "xdomain-checks")) {
4833 xdomain_checks = TRUE;
4834 } else if (!strcmp (opt, "clear-at-gc")) {
4835 nursery_clear_policy = CLEAR_AT_GC;
4836 } else if (!strcmp (opt, "clear-nursery-at-gc")) {
4837 nursery_clear_policy = CLEAR_AT_GC;
4838 } else if (!strcmp (opt, "check-scan-starts")) {
4839 do_scan_starts_check = TRUE;
4840 } else if (!strcmp (opt, "verify-nursery-at-minor-gc")) {
4841 do_verify_nursery = TRUE;
4842 } else if (!strcmp (opt, "dump-nursery-at-minor-gc")) {
4843 do_dump_nursery_content = TRUE;
4844 } else if (!strcmp (opt, "disable-minor")) {
4845 disable_minor_collections = TRUE;
4846 } else if (!strcmp (opt, "disable-major")) {
4847 disable_major_collections = TRUE;
4848 } else if (g_str_has_prefix (opt, "heap-dump=")) {
4849 char *filename = strchr (opt, '=') + 1;
4850 nursery_clear_policy = CLEAR_AT_GC;
4851 heap_dump_file = fopen (filename, "w");
4852 if (heap_dump_file) {
4853 fprintf (heap_dump_file, "<sgen-dump>\n");
4854 do_pin_stats = TRUE;
4856 #ifdef SGEN_BINARY_PROTOCOL
4857 } else if (g_str_has_prefix (opt, "binary-protocol=")) {
4858 char *filename = strchr (opt, '=') + 1;
4859 binary_protocol_init (filename);
4861 fprintf (stderr, "Warning: Cardtable write barriers will not be binary-protocolled.\n");
4864 fprintf (stderr, "Invalid format for the MONO_GC_DEBUG env variable: '%s'\n", env);
4865 fprintf (stderr, "The format is: MONO_GC_DEBUG=[l[:filename]|<option>]+ where l is a debug level 0-9.\n");
4866 fprintf (stderr, "Valid options are:\n");
4867 fprintf (stderr, " collect-before-allocs[=<n>]\n");
4868 fprintf (stderr, " verify-before-allocs[=<n>]\n");
4869 fprintf (stderr, " check-at-minor-collections\n");
4870 fprintf (stderr, " verify-before-collections\n");
4871 fprintf (stderr, " disable-minor\n");
4872 fprintf (stderr, " disable-major\n");
4873 fprintf (stderr, " xdomain-checks\n");
4874 fprintf (stderr, " clear-at-gc\n");
4875 fprintf (stderr, " print-allowance\n");
4876 fprintf (stderr, " print-pinning\n");
4883 if (major_collector.is_parallel) {
4884 if (heap_dump_file) {
4885 fprintf (stderr, "Error: Cannot do heap dump with the parallel collector.\n");
4889 fprintf (stderr, "Error: Cannot gather pinning statistics with the parallel collector.\n");
4894 if (major_collector.post_param_init)
4895 major_collector.post_param_init ();
4897 sgen_memgov_init (max_heap, soft_limit, debug_print_allowance, allowance_ratio, save_target);
4899 memset (&remset, 0, sizeof (remset));
4901 #ifdef SGEN_HAVE_CARDTABLE
4903 sgen_card_table_init (&remset);
4906 sgen_ssb_init (&remset);
4908 if (remset.register_thread)
4909 remset.register_thread (mono_thread_info_current ());
4915 mono_gc_get_gc_name (void)
4920 static MonoMethod *write_barrier_method;
4923 mono_gc_is_critical_method (MonoMethod *method)
4925 return (method == write_barrier_method || sgen_is_managed_allocator (method));
4929 is_ip_in_managed_allocator (MonoDomain *domain, gpointer ip)
4933 if (!mono_thread_internal_current ())
4934 /* Happens during thread attach */
4939 ji = mono_jit_info_table_find (domain, ip);
4943 return mono_gc_is_critical_method (ji->method);
4947 emit_nursery_check (MonoMethodBuilder *mb, int *nursery_check_return_labels)
4949 memset (nursery_check_return_labels, 0, sizeof (int) * 3);
4950 #ifdef SGEN_ALIGN_NURSERY
4951 // if (ptr_in_nursery (ptr)) return;
4953 * Masking out the bits might be faster, but we would have to use 64 bit
4954 * immediates, which might be slower.
4956 mono_mb_emit_ldarg (mb, 0);
4957 mono_mb_emit_icon (mb, DEFAULT_NURSERY_BITS);
4958 mono_mb_emit_byte (mb, CEE_SHR_UN);
4959 mono_mb_emit_icon (mb, (mword)sgen_get_nursery_start () >> DEFAULT_NURSERY_BITS);
4960 nursery_check_return_labels [0] = mono_mb_emit_branch (mb, CEE_BEQ);
4962 // if (!ptr_in_nursery (*ptr)) return;
4963 mono_mb_emit_ldarg (mb, 0);
4964 mono_mb_emit_byte (mb, CEE_LDIND_I);
4965 mono_mb_emit_icon (mb, DEFAULT_NURSERY_BITS);
4966 mono_mb_emit_byte (mb, CEE_SHR_UN);
4967 mono_mb_emit_icon (mb, (mword)sgen_get_nursery_start () >> DEFAULT_NURSERY_BITS);
4968 nursery_check_return_labels [1] = mono_mb_emit_branch (mb, CEE_BNE_UN);
4970 int label_continue1, label_continue2;
4971 int dereferenced_var;
4973 // if (ptr < (sgen_get_nursery_start ())) goto continue;
4974 mono_mb_emit_ldarg (mb, 0);
4975 mono_mb_emit_ptr (mb, (gpointer) sgen_get_nursery_start ());
4976 label_continue_1 = mono_mb_emit_branch (mb, CEE_BLT);
4978 // if (ptr >= sgen_get_nursery_end ())) goto continue;
4979 mono_mb_emit_ldarg (mb, 0);
4980 mono_mb_emit_ptr (mb, (gpointer) sgen_get_nursery_end ());
4981 label_continue_2 = mono_mb_emit_branch (mb, CEE_BGE);
4984 nursery_check_return_labels [0] = mono_mb_emit_branch (mb, CEE_BR);
4987 mono_mb_patch_branch (mb, label_continue_1);
4988 mono_mb_patch_branch (mb, label_continue_2);
4990 // Dereference and store in local var
4991 dereferenced_var = mono_mb_add_local (mb, &mono_defaults.int_class->byval_arg);
4992 mono_mb_emit_ldarg (mb, 0);
4993 mono_mb_emit_byte (mb, CEE_LDIND_I);
4994 mono_mb_emit_stloc (mb, dereferenced_var);
4996 // if (*ptr < sgen_get_nursery_start ()) return;
4997 mono_mb_emit_ldloc (mb, dereferenced_var);
4998 mono_mb_emit_ptr (mb, (gpointer) sgen_get_nursery_start ());
4999 nursery_check_return_labels [1] = mono_mb_emit_branch (mb, CEE_BLT);
5001 // if (*ptr >= sgen_get_nursery_end ()) return;
5002 mono_mb_emit_ldloc (mb, dereferenced_var);
5003 mono_mb_emit_ptr (mb, (gpointer) sgen_get_nursery_end ());
5004 nursery_check_return_labels [2] = mono_mb_emit_branch (mb, CEE_BGE);
5009 mono_gc_get_write_barrier (void)
5012 MonoMethodBuilder *mb;
5013 MonoMethodSignature *sig;
5014 #ifdef MANAGED_WBARRIER
5015 int i, nursery_check_labels [3];
5016 int label_no_wb_3, label_no_wb_4, label_need_wb, label_slow_path;
5017 int buffer_var, buffer_index_var, dummy_var;
5019 #ifdef HAVE_KW_THREAD
5020 int stack_end_offset = -1, store_remset_buffer_offset = -1;
5021 int store_remset_buffer_index_offset = -1, store_remset_buffer_index_addr_offset = -1;
5023 MONO_THREAD_VAR_OFFSET (stack_end, stack_end_offset);
5024 g_assert (stack_end_offset != -1);
5025 MONO_THREAD_VAR_OFFSET (store_remset_buffer, store_remset_buffer_offset);
5026 g_assert (store_remset_buffer_offset != -1);
5027 MONO_THREAD_VAR_OFFSET (store_remset_buffer_index, store_remset_buffer_index_offset);
5028 g_assert (store_remset_buffer_index_offset != -1);
5029 MONO_THREAD_VAR_OFFSET (store_remset_buffer_index_addr, store_remset_buffer_index_addr_offset);
5030 g_assert (store_remset_buffer_index_addr_offset != -1);
5034 // FIXME: Maybe create a separate version for ctors (the branch would be
5035 // correctly predicted more times)
5036 if (write_barrier_method)
5037 return write_barrier_method;
5039 /* Create the IL version of mono_gc_barrier_generic_store () */
5040 sig = mono_metadata_signature_alloc (mono_defaults.corlib, 1);
5041 sig->ret = &mono_defaults.void_class->byval_arg;
5042 sig->params [0] = &mono_defaults.int_class->byval_arg;
5044 mb = mono_mb_new (mono_defaults.object_class, "wbarrier", MONO_WRAPPER_WRITE_BARRIER);
5046 #ifdef MANAGED_WBARRIER
5047 if (use_cardtable) {
5048 emit_nursery_check (mb, nursery_check_labels);
5050 addr = sgen_cardtable + ((address >> CARD_BITS) & CARD_MASK)
5054 LDC_PTR sgen_cardtable
5056 address >> CARD_BITS
5060 if (SGEN_HAVE_OVERLAPPING_CARDS) {
5061 LDC_PTR card_table_mask
5068 mono_mb_emit_ptr (mb, sgen_cardtable);
5069 mono_mb_emit_ldarg (mb, 0);
5070 mono_mb_emit_icon (mb, CARD_BITS);
5071 mono_mb_emit_byte (mb, CEE_SHR_UN);
5072 #ifdef SGEN_HAVE_OVERLAPPING_CARDS
5073 mono_mb_emit_ptr (mb, (gpointer)CARD_MASK);
5074 mono_mb_emit_byte (mb, CEE_AND);
5076 mono_mb_emit_byte (mb, CEE_ADD);
5077 mono_mb_emit_icon (mb, 1);
5078 mono_mb_emit_byte (mb, CEE_STIND_I1);
5081 for (i = 0; i < 3; ++i) {
5082 if (nursery_check_labels [i])
5083 mono_mb_patch_branch (mb, nursery_check_labels [i]);
5085 mono_mb_emit_byte (mb, CEE_RET);
5086 } else if (mono_runtime_has_tls_get ()) {
5087 emit_nursery_check (mb, nursery_check_labels);
5089 // if (ptr >= stack_end) goto need_wb;
5090 mono_mb_emit_ldarg (mb, 0);
5091 EMIT_TLS_ACCESS (mb, stack_end, stack_end_offset);
5092 label_need_wb = mono_mb_emit_branch (mb, CEE_BGE_UN);
5094 // if (ptr >= stack_start) return;
5095 dummy_var = mono_mb_add_local (mb, &mono_defaults.int_class->byval_arg);
5096 mono_mb_emit_ldarg (mb, 0);
5097 mono_mb_emit_ldloc_addr (mb, dummy_var);
5098 label_no_wb_3 = mono_mb_emit_branch (mb, CEE_BGE_UN);
5101 mono_mb_patch_branch (mb, label_need_wb);
5103 // buffer = STORE_REMSET_BUFFER;
5104 buffer_var = mono_mb_add_local (mb, &mono_defaults.int_class->byval_arg);
5105 EMIT_TLS_ACCESS (mb, store_remset_buffer, store_remset_buffer_offset);
5106 mono_mb_emit_stloc (mb, buffer_var);
5108 // buffer_index = STORE_REMSET_BUFFER_INDEX;
5109 buffer_index_var = mono_mb_add_local (mb, &mono_defaults.int_class->byval_arg);
5110 EMIT_TLS_ACCESS (mb, store_remset_buffer_index, store_remset_buffer_index_offset);
5111 mono_mb_emit_stloc (mb, buffer_index_var);
5113 // if (buffer [buffer_index] == ptr) return;
5114 mono_mb_emit_ldloc (mb, buffer_var);
5115 mono_mb_emit_ldloc (mb, buffer_index_var);
5116 g_assert (sizeof (gpointer) == 4 || sizeof (gpointer) == 8);
5117 mono_mb_emit_icon (mb, sizeof (gpointer) == 4 ? 2 : 3);
5118 mono_mb_emit_byte (mb, CEE_SHL);
5119 mono_mb_emit_byte (mb, CEE_ADD);
5120 mono_mb_emit_byte (mb, CEE_LDIND_I);
5121 mono_mb_emit_ldarg (mb, 0);
5122 label_no_wb_4 = mono_mb_emit_branch (mb, CEE_BEQ);
5125 mono_mb_emit_ldloc (mb, buffer_index_var);
5126 mono_mb_emit_icon (mb, 1);
5127 mono_mb_emit_byte (mb, CEE_ADD);
5128 mono_mb_emit_stloc (mb, buffer_index_var);
5130 // if (buffer_index >= STORE_REMSET_BUFFER_SIZE) goto slow_path;
5131 mono_mb_emit_ldloc (mb, buffer_index_var);
5132 mono_mb_emit_icon (mb, STORE_REMSET_BUFFER_SIZE);
5133 label_slow_path = mono_mb_emit_branch (mb, CEE_BGE);
5135 // buffer [buffer_index] = ptr;
5136 mono_mb_emit_ldloc (mb, buffer_var);
5137 mono_mb_emit_ldloc (mb, buffer_index_var);
5138 g_assert (sizeof (gpointer) == 4 || sizeof (gpointer) == 8);
5139 mono_mb_emit_icon (mb, sizeof (gpointer) == 4 ? 2 : 3);
5140 mono_mb_emit_byte (mb, CEE_SHL);
5141 mono_mb_emit_byte (mb, CEE_ADD);
5142 mono_mb_emit_ldarg (mb, 0);
5143 mono_mb_emit_byte (mb, CEE_STIND_I);
5145 // STORE_REMSET_BUFFER_INDEX = buffer_index;
5146 EMIT_TLS_ACCESS (mb, store_remset_buffer_index_addr, store_remset_buffer_index_addr_offset);
5147 mono_mb_emit_ldloc (mb, buffer_index_var);
5148 mono_mb_emit_byte (mb, CEE_STIND_I);
5151 for (i = 0; i < 3; ++i) {
5152 if (nursery_check_labels [i])
5153 mono_mb_patch_branch (mb, nursery_check_labels [i]);
5155 mono_mb_patch_branch (mb, label_no_wb_3);
5156 mono_mb_patch_branch (mb, label_no_wb_4);
5157 mono_mb_emit_byte (mb, CEE_RET);
5160 mono_mb_patch_branch (mb, label_slow_path);
5162 mono_mb_emit_ldarg (mb, 0);
5163 mono_mb_emit_icall (mb, mono_gc_wbarrier_generic_nostore);
5164 mono_mb_emit_byte (mb, CEE_RET);
5168 mono_mb_emit_ldarg (mb, 0);
5169 mono_mb_emit_icall (mb, mono_gc_wbarrier_generic_nostore);
5170 mono_mb_emit_byte (mb, CEE_RET);
5173 res = mono_mb_create_method (mb, sig, 16);
5176 mono_loader_lock ();
5177 if (write_barrier_method) {
5178 /* Already created */
5179 mono_free_method (res);
5181 /* double-checked locking */
5182 mono_memory_barrier ();
5183 write_barrier_method = res;
5185 mono_loader_unlock ();
5187 return write_barrier_method;
5191 mono_gc_get_description (void)
5193 return g_strdup ("sgen");
5197 mono_gc_set_desktop_mode (void)
5202 mono_gc_is_moving (void)
5208 mono_gc_is_disabled (void)
5214 sgen_debug_printf (int level, const char *format, ...)
5218 if (level > gc_debug_level)
5221 va_start (ap, format);
5222 vfprintf (gc_debug_file, format, ap);
5227 sgen_get_logfile (void)
5229 return gc_debug_file;
5233 BOOL APIENTRY mono_gc_dllmain (HMODULE module_handle, DWORD reason, LPVOID reserved)
5240 sgen_get_nursery_clear_policy (void)
5242 return nursery_clear_policy;
5246 sgen_get_array_fill_vtable (void)
5248 if (!array_fill_vtable) {
5249 static MonoClass klass;
5250 static MonoVTable vtable;
5253 MonoDomain *domain = mono_get_root_domain ();
5256 klass.element_class = mono_defaults.byte_class;
5258 klass.instance_size = sizeof (MonoArray);
5259 klass.sizes.element_size = 1;
5260 klass.name = "array_filler_type";
5262 vtable.klass = &klass;
5264 vtable.gc_descr = mono_gc_make_descr_for_array (TRUE, &bmap, 0, 1);
5267 array_fill_vtable = &vtable;
5269 return array_fill_vtable;
5279 sgen_gc_unlock (void)
5285 sgen_major_collector_iterate_live_block_ranges (sgen_cardtable_block_callback callback)
5287 major_collector.iterate_live_block_ranges (callback);
5291 sgen_major_collector_scan_card_table (SgenGrayQueue *queue)
5293 major_collector.scan_card_table (queue);
5297 sgen_get_major_collector (void)
5299 return &major_collector;
5302 void mono_gc_set_skip_thread (gboolean skip)
5304 SgenThreadInfo *info = mono_thread_info_current ();
5307 info->gc_disabled = skip;
5312 sgen_get_remset (void)
5318 mono_gc_get_vtable_bits (MonoClass *class)
5320 if (sgen_need_bridge_processing () && sgen_is_bridge_class (class))
5321 return SGEN_GC_BIT_BRIDGE_OBJECT;
5326 mono_gc_register_altstack (gpointer stack, gint32 stack_size, gpointer altstack, gint32 altstack_size)
5333 sgen_check_whole_heap_stw (void)
5336 sgen_clear_nursery_fragments ();
5337 sgen_check_whole_heap ();
5338 restart_world (0, NULL);
5341 #endif /* HAVE_SGEN_GC */