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.
190 #ifdef HAVE_PTHREAD_H
193 #ifdef HAVE_SEMAPHORE_H
194 #include <semaphore.h>
205 #define _XOPEN_SOURCE
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/mono-gc.h"
220 #include "metadata/method-builder.h"
221 #include "metadata/profiler-private.h"
222 #include "metadata/monitor.h"
223 #include "metadata/threadpool-internals.h"
224 #include "metadata/mempool-internals.h"
225 #include "metadata/marshal.h"
226 #include "metadata/runtime.h"
227 #include "metadata/sgen-cardtable.h"
228 #include "metadata/sgen-pinning.h"
229 #include "metadata/sgen-workers.h"
230 #include "utils/mono-mmap.h"
231 #include "utils/mono-time.h"
232 #include "utils/mono-semaphore.h"
233 #include "utils/mono-counters.h"
234 #include "utils/mono-proclib.h"
235 #include "utils/mono-memory-model.h"
236 #include "utils/mono-logger-internal.h"
238 #include <mono/utils/mono-logger-internal.h>
239 #include <mono/utils/memcheck.h>
241 #if defined(__MACH__)
242 #include "utils/mach-support.h"
245 #define OPDEF(a,b,c,d,e,f,g,h,i,j) \
249 #include "mono/cil/opcode.def"
255 #undef pthread_create
257 #undef pthread_detach
260 * ######################################################################
261 * ######## Types and constants used by the GC.
262 * ######################################################################
265 /* 0 means not initialized, 1 is initialized, -1 means in progress */
266 static gint32 gc_initialized = 0;
267 /* If set, do a minor collection before every X allocation */
268 guint32 collect_before_allocs = 0;
269 /* If set, do a heap consistency check before each minor collection */
270 static gboolean consistency_check_at_minor_collection = FALSE;
271 /* If set, check that there are no references to the domain left at domain unload */
272 static gboolean xdomain_checks = FALSE;
273 /* If not null, dump the heap after each collection into this file */
274 static FILE *heap_dump_file = NULL;
275 /* If set, mark stacks conservatively, even if precise marking is possible */
276 static gboolean conservative_stack_mark = FALSE;
277 /* If set, do a plausibility check on the scan_starts before and after
279 static gboolean do_scan_starts_check = FALSE;
280 static gboolean nursery_collection_is_parallel = FALSE;
281 static gboolean disable_minor_collections = FALSE;
282 static gboolean disable_major_collections = FALSE;
283 gboolean do_pin_stats = FALSE;
284 static gboolean do_verify_nursery = FALSE;
285 static gboolean do_dump_nursery_content = FALSE;
287 #ifdef HEAVY_STATISTICS
288 long long stat_objects_alloced_degraded = 0;
289 long long stat_bytes_alloced_degraded = 0;
291 long long stat_copy_object_called_nursery = 0;
292 long long stat_objects_copied_nursery = 0;
293 long long stat_copy_object_called_major = 0;
294 long long stat_objects_copied_major = 0;
296 long long stat_scan_object_called_nursery = 0;
297 long long stat_scan_object_called_major = 0;
299 long long stat_nursery_copy_object_failed_from_space = 0;
300 long long stat_nursery_copy_object_failed_forwarded = 0;
301 long long stat_nursery_copy_object_failed_pinned = 0;
303 static int stat_wbarrier_set_field = 0;
304 static int stat_wbarrier_set_arrayref = 0;
305 static int stat_wbarrier_arrayref_copy = 0;
306 static int stat_wbarrier_generic_store = 0;
307 static int stat_wbarrier_set_root = 0;
308 static int stat_wbarrier_value_copy = 0;
309 static int stat_wbarrier_object_copy = 0;
312 int stat_minor_gcs = 0;
313 int stat_major_gcs = 0;
315 static long long stat_pinned_objects = 0;
317 static long long time_minor_pre_collection_fragment_clear = 0;
318 static long long time_minor_pinning = 0;
319 static long long time_minor_scan_remsets = 0;
320 static long long time_minor_scan_pinned = 0;
321 static long long time_minor_scan_registered_roots = 0;
322 static long long time_minor_scan_thread_data = 0;
323 static long long time_minor_finish_gray_stack = 0;
324 static long long time_minor_fragment_creation = 0;
326 static long long time_major_pre_collection_fragment_clear = 0;
327 static long long time_major_pinning = 0;
328 static long long time_major_scan_pinned = 0;
329 static long long time_major_scan_registered_roots = 0;
330 static long long time_major_scan_thread_data = 0;
331 static long long time_major_scan_alloc_pinned = 0;
332 static long long time_major_scan_finalized = 0;
333 static long long time_major_scan_big_objects = 0;
334 static long long time_major_finish_gray_stack = 0;
335 static long long time_major_free_bigobjs = 0;
336 static long long time_major_los_sweep = 0;
337 static long long time_major_sweep = 0;
338 static long long time_major_fragment_creation = 0;
340 int gc_debug_level = 0;
342 static gboolean debug_print_allowance = FALSE;
346 mono_gc_flush_info (void)
348 fflush (gc_debug_file);
352 #define TV_DECLARE SGEN_TV_DECLARE
353 #define TV_GETTIME SGEN_TV_GETTIME
354 #define TV_ELAPSED SGEN_TV_ELAPSED
355 #define TV_ELAPSED_MS SGEN_TV_ELAPSED_MS
357 #define ALIGN_TO(val,align) ((((guint64)val) + ((align) - 1)) & ~((align) - 1))
359 NurseryClearPolicy nursery_clear_policy = CLEAR_AT_TLAB_CREATION;
361 /* the runtime can register areas of memory as roots: we keep two lists of roots,
362 * a pinned root set for conservatively scanned roots and a normal one for
363 * precisely scanned roots (currently implemented as a single list).
365 typedef struct _RootRecord RootRecord;
371 #define object_is_forwarded SGEN_OBJECT_IS_FORWARDED
372 #define object_is_pinned SGEN_OBJECT_IS_PINNED
373 #define pin_object SGEN_PIN_OBJECT
374 #define unpin_object SGEN_UNPIN_OBJECT
376 #define ptr_in_nursery mono_sgen_ptr_in_nursery
378 #define LOAD_VTABLE SGEN_LOAD_VTABLE
381 safe_name (void* obj)
383 MonoVTable *vt = (MonoVTable*)LOAD_VTABLE (obj);
384 return vt->klass->name;
387 #define safe_object_get_size mono_sgen_safe_object_get_size
390 mono_sgen_safe_name (void* obj)
392 return safe_name (obj);
396 * ######################################################################
397 * ######## Global data.
398 * ######################################################################
400 LOCK_DECLARE (gc_mutex);
401 static int gc_disabled = 0;
403 static gboolean use_cardtable;
405 #define MIN_MINOR_COLLECTION_ALLOWANCE (DEFAULT_NURSERY_SIZE * 4)
407 #define SCAN_START_SIZE SGEN_SCAN_START_SIZE
409 static mword pagesize = 4096;
410 static mword nursery_size;
411 int degraded_mode = 0;
413 static mword bytes_pinned_from_failed_allocation = 0;
415 static mword total_alloc = 0;
416 /* use this to tune when to do a major/minor collection */
417 static mword memory_pressure = 0;
418 static mword minor_collection_allowance;
419 static int minor_collection_sections_alloced = 0;
422 /* GC Logging stats */
423 static int last_major_num_sections = 0;
424 static int last_los_memory_usage = 0;
425 static gboolean major_collection_happened = FALSE;
427 GCMemSection *nursery_section = NULL;
428 static mword lowest_heap_address = ~(mword)0;
429 static mword highest_heap_address = 0;
431 static LOCK_DECLARE (interruption_mutex);
432 static LOCK_DECLARE (pin_queue_mutex);
434 #define LOCK_PIN_QUEUE mono_mutex_lock (&pin_queue_mutex)
435 #define UNLOCK_PIN_QUEUE mono_mutex_unlock (&pin_queue_mutex)
437 typedef struct _FinalizeReadyEntry FinalizeReadyEntry;
438 struct _FinalizeReadyEntry {
439 FinalizeReadyEntry *next;
443 typedef struct _EphemeronLinkNode EphemeronLinkNode;
445 struct _EphemeronLinkNode {
446 EphemeronLinkNode *next;
455 int current_collection_generation = -1;
458 * The link pointer is hidden by negating each bit. We use the lowest
459 * bit of the link (before negation) to store whether it needs
460 * resurrection tracking.
462 #define HIDE_POINTER(p,t) ((gpointer)(~((gulong)(p)|((t)?1:0))))
463 #define REVEAL_POINTER(p) ((gpointer)((~(gulong)(p))&~3L))
465 /* objects that are ready to be finalized */
466 static FinalizeReadyEntry *fin_ready_list = NULL;
467 static FinalizeReadyEntry *critical_fin_list = NULL;
469 static EphemeronLinkNode *ephemeron_list;
471 static int num_ready_finalizers = 0;
472 static int no_finalize = 0;
475 ROOT_TYPE_NORMAL = 0, /* "normal" roots */
476 ROOT_TYPE_PINNED = 1, /* roots without a GC descriptor */
477 ROOT_TYPE_WBARRIER = 2, /* roots with a write barrier */
481 /* registered roots: the key to the hash is the root start address */
483 * Different kinds of roots are kept separate to speed up pin_from_roots () for example.
485 static SgenHashTable roots_hash [ROOT_TYPE_NUM] = {
486 SGEN_HASH_TABLE_INIT (INTERNAL_MEM_ROOTS_TABLE, INTERNAL_MEM_ROOT_RECORD, sizeof (RootRecord), mono_aligned_addr_hash, NULL),
487 SGEN_HASH_TABLE_INIT (INTERNAL_MEM_ROOTS_TABLE, INTERNAL_MEM_ROOT_RECORD, sizeof (RootRecord), mono_aligned_addr_hash, NULL),
488 SGEN_HASH_TABLE_INIT (INTERNAL_MEM_ROOTS_TABLE, INTERNAL_MEM_ROOT_RECORD, sizeof (RootRecord), mono_aligned_addr_hash, NULL)
490 static mword roots_size = 0; /* amount of memory in the root set */
492 #define GC_ROOT_NUM 32
495 void *objects [GC_ROOT_NUM];
496 int root_types [GC_ROOT_NUM];
497 uintptr_t extra_info [GC_ROOT_NUM];
501 notify_gc_roots (GCRootReport *report)
505 mono_profiler_gc_roots (report->count, report->objects, report->root_types, report->extra_info);
510 add_profile_gc_root (GCRootReport *report, void *object, int rtype, uintptr_t extra_info)
512 if (report->count == GC_ROOT_NUM)
513 notify_gc_roots (report);
514 report->objects [report->count] = object;
515 report->root_types [report->count] = rtype;
516 report->extra_info [report->count++] = (uintptr_t)((MonoVTable*)LOAD_VTABLE (object))->klass;
519 MonoNativeTlsKey thread_info_key;
521 #ifdef HAVE_KW_THREAD
522 __thread SgenThreadInfo *thread_info;
523 __thread gpointer *store_remset_buffer;
524 __thread long store_remset_buffer_index;
525 __thread char *stack_end;
526 __thread long *store_remset_buffer_index_addr;
529 /* The size of a TLAB */
530 /* The bigger the value, the less often we have to go to the slow path to allocate a new
531 * one, but the more space is wasted by threads not allocating much memory.
533 * FIXME: Make this self-tuning for each thread.
535 guint32 tlab_size = (1024 * 4);
537 #define MAX_SMALL_OBJ_SIZE SGEN_MAX_SMALL_OBJ_SIZE
539 /* Functions supplied by the runtime to be called by the GC */
540 static MonoGCCallbacks gc_callbacks;
542 #define ALLOC_ALIGN SGEN_ALLOC_ALIGN
543 #define ALLOC_ALIGN_BITS SGEN_ALLOC_ALIGN_BITS
545 #define ALIGN_UP SGEN_ALIGN_UP
547 #define MOVED_OBJECTS_NUM 64
548 static void *moved_objects [MOVED_OBJECTS_NUM];
549 static int moved_objects_idx = 0;
551 /* Vtable of the objects used to fill out nursery fragments before a collection */
552 static MonoVTable *array_fill_vtable;
554 #ifdef SGEN_DEBUG_INTERNAL_ALLOC
555 MonoNativeThreadId main_gc_thread = NULL;
559 * ######################################################################
560 * ######## Heap size accounting
561 * ######################################################################
564 static mword max_heap_size = ((mword)0)- ((mword)1);
565 static mword soft_heap_limit = ((mword)0) - ((mword)1);
566 static mword allocated_heap;
568 /*Object was pinned during the current collection*/
569 static mword objects_pinned;
572 mono_sgen_release_space (mword size, int space)
574 allocated_heap -= size;
578 available_free_space (void)
580 return max_heap_size - MIN (allocated_heap, max_heap_size);
584 mono_sgen_try_alloc_space (mword size, int space)
586 if (available_free_space () < size)
589 allocated_heap += size;
590 mono_runtime_resource_check_limit (MONO_RESOURCE_GC_HEAP, allocated_heap);
595 init_heap_size_limits (glong max_heap, glong soft_limit)
598 soft_heap_limit = soft_limit;
603 if (max_heap < soft_limit) {
604 fprintf (stderr, "max-heap-size must be at least as large as soft-heap-limit.\n");
608 if (max_heap < nursery_size * 4) {
609 fprintf (stderr, "max-heap-size must be at least 4 times larger than nursery size.\n");
612 max_heap_size = max_heap - nursery_size;
616 * ######################################################################
617 * ######## Macros and function declarations.
618 * ######################################################################
622 align_pointer (void *ptr)
624 mword p = (mword)ptr;
625 p += sizeof (gpointer) - 1;
626 p &= ~ (sizeof (gpointer) - 1);
630 typedef SgenGrayQueue GrayQueue;
632 /* forward declarations */
633 static int stop_world (int generation);
634 static int restart_world (int generation);
635 static void scan_thread_data (void *start_nursery, void *end_nursery, gboolean precise, GrayQueue *queue);
636 static void scan_from_registered_roots (CopyOrMarkObjectFunc copy_func, char *addr_start, char *addr_end, int root_type, GrayQueue *queue);
637 static void scan_finalizer_entries (CopyOrMarkObjectFunc copy_func, FinalizeReadyEntry *list, GrayQueue *queue);
638 static void report_finalizer_roots (void);
639 static void report_registered_roots (void);
640 static void find_pinning_ref_from_thread (char *obj, size_t size);
641 static void update_current_thread_stack (void *start);
642 static void collect_bridge_objects (CopyOrMarkObjectFunc copy_func, char *start, char *end, int generation, GrayQueue *queue);
643 static void finalize_in_range (CopyOrMarkObjectFunc copy_func, char *start, char *end, int generation, GrayQueue *queue);
644 static void process_fin_stage_entries (void);
645 static void null_link_in_range (CopyOrMarkObjectFunc copy_func, char *start, char *end, int generation, gboolean before_finalization, GrayQueue *queue);
646 static void null_links_for_domain (MonoDomain *domain, int generation);
647 static void process_dislink_stage_entries (void);
649 static void pin_from_roots (void *start_nursery, void *end_nursery, GrayQueue *queue);
650 static int pin_objects_from_addresses (GCMemSection *section, void **start, void **end, void *start_nursery, void *end_nursery, GrayQueue *queue);
651 static void finish_gray_stack (char *start_addr, char *end_addr, int generation, GrayQueue *queue);
652 static gboolean need_major_collection (mword space_needed);
653 static void major_collection (const char *reason);
655 static void mono_gc_register_disappearing_link (MonoObject *obj, void **link, gboolean track, gboolean in_gc);
656 static gboolean mono_gc_is_critical_method (MonoMethod *method);
658 void mono_gc_scan_for_specific_ref (MonoObject *key, gboolean precise);
660 static void init_stats (void);
662 static int mark_ephemerons_in_range (CopyOrMarkObjectFunc copy_func, char *start, char *end, GrayQueue *queue);
663 static void clear_unreachable_ephemerons (CopyOrMarkObjectFunc copy_func, char *start, char *end, GrayQueue *queue);
664 static void null_ephemerons_for_domain (MonoDomain *domain);
666 SgenMajorCollector major_collector;
667 static GrayQueue gray_queue;
669 static SgenRemeberedSet remset;
672 #define WORKERS_DISTRIBUTE_GRAY_QUEUE (mono_sgen_collection_is_parallel () ? mono_sgen_workers_get_distribute_gray_queue () : &gray_queue)
674 static SgenGrayQueue*
675 mono_sgen_workers_get_job_gray_queue (WorkerData *worker_data)
677 return worker_data ? &worker_data->private_gray_queue : WORKERS_DISTRIBUTE_GRAY_QUEUE;
681 is_xdomain_ref_allowed (gpointer *ptr, char *obj, MonoDomain *domain)
683 MonoObject *o = (MonoObject*)(obj);
684 MonoObject *ref = (MonoObject*)*(ptr);
685 int offset = (char*)(ptr) - (char*)o;
687 if (o->vtable->klass == mono_defaults.thread_class && offset == G_STRUCT_OFFSET (MonoThread, internal_thread))
689 if (o->vtable->klass == mono_defaults.internal_thread_class && offset == G_STRUCT_OFFSET (MonoInternalThread, current_appcontext))
691 if (mono_class_has_parent_fast (o->vtable->klass, mono_defaults.real_proxy_class) &&
692 offset == G_STRUCT_OFFSET (MonoRealProxy, unwrapped_server))
694 /* Thread.cached_culture_info */
695 if (!strcmp (ref->vtable->klass->name_space, "System.Globalization") &&
696 !strcmp (ref->vtable->klass->name, "CultureInfo") &&
697 !strcmp(o->vtable->klass->name_space, "System") &&
698 !strcmp(o->vtable->klass->name, "Object[]"))
701 * 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
702 * at System.IO.MemoryStream..ctor (byte[]) [0x00017] in /home/schani/Work/novell/trunk/mcs/class/corlib/System.IO/MemoryStream.cs:81
703 * at (wrapper remoting-invoke-with-check) System.IO.MemoryStream..ctor (byte[]) <IL 0x00020, 0xffffffff>
704 * at System.Runtime.Remoting.Messaging.CADMethodCallMessage.GetArguments () [0x0000d] in /home/schani/Work/novell/trunk/mcs/class/corlib/System.Runtime.Remoting.Messaging/CADMessages.cs:327
705 * 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
706 * 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
707 * at (wrapper remoting-invoke-with-check) System.AppDomain.ProcessMessageInDomain (byte[],System.Runtime.Remoting.Messaging.CADMethodCallMessage,byte[]&,System.Runtime.Remoting.Messaging.CADMethodReturnMessage&) <IL 0x0003d, 0xffffffff>
708 * 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
709 * at (wrapper runtime-invoke) object.runtime_invoke_CrossAppDomainSink/ProcessMessageRes_object_object (object,intptr,intptr,intptr) <IL 0x0004c, 0xffffffff>
711 if (!strcmp (ref->vtable->klass->name_space, "System") &&
712 !strcmp (ref->vtable->klass->name, "Byte[]") &&
713 !strcmp (o->vtable->klass->name_space, "System.IO") &&
714 !strcmp (o->vtable->klass->name, "MemoryStream"))
716 /* append_job() in threadpool.c */
717 if (!strcmp (ref->vtable->klass->name_space, "System.Runtime.Remoting.Messaging") &&
718 !strcmp (ref->vtable->klass->name, "AsyncResult") &&
719 !strcmp (o->vtable->klass->name_space, "System") &&
720 !strcmp (o->vtable->klass->name, "Object[]") &&
721 mono_thread_pool_is_queue_array ((MonoArray*) o))
727 check_reference_for_xdomain (gpointer *ptr, char *obj, MonoDomain *domain)
729 MonoObject *o = (MonoObject*)(obj);
730 MonoObject *ref = (MonoObject*)*(ptr);
731 int offset = (char*)(ptr) - (char*)o;
733 MonoClassField *field;
736 if (!ref || ref->vtable->domain == domain)
738 if (is_xdomain_ref_allowed (ptr, obj, domain))
742 for (class = o->vtable->klass; class; class = class->parent) {
745 for (i = 0; i < class->field.count; ++i) {
746 if (class->fields[i].offset == offset) {
747 field = &class->fields[i];
755 if (ref->vtable->klass == mono_defaults.string_class)
756 str = mono_string_to_utf8 ((MonoString*)ref);
759 g_print ("xdomain reference in %p (%s.%s) at offset %d (%s) to %p (%s.%s) (%s) - pointed to by:\n",
760 o, o->vtable->klass->name_space, o->vtable->klass->name,
761 offset, field ? field->name : "",
762 ref, ref->vtable->klass->name_space, ref->vtable->klass->name, str ? str : "");
763 mono_gc_scan_for_specific_ref (o, TRUE);
769 #define HANDLE_PTR(ptr,obj) check_reference_for_xdomain ((ptr), (obj), domain)
772 scan_object_for_xdomain_refs (char *start, mword size, void *data)
774 MonoDomain *domain = ((MonoObject*)start)->vtable->domain;
776 #include "sgen-scan-object.h"
779 static gboolean scan_object_for_specific_ref_precise = TRUE;
782 #define HANDLE_PTR(ptr,obj) do { \
783 if ((MonoObject*)*(ptr) == key) { \
784 g_print ("found ref to %p in object %p (%s) at offset %td\n", \
785 key, (obj), safe_name ((obj)), ((char*)(ptr) - (char*)(obj))); \
790 scan_object_for_specific_ref (char *start, MonoObject *key)
794 if ((forwarded = SGEN_OBJECT_IS_FORWARDED (start)))
797 if (scan_object_for_specific_ref_precise) {
798 #include "sgen-scan-object.h"
800 mword *words = (mword*)start;
801 size_t size = safe_object_get_size ((MonoObject*)start);
803 for (i = 0; i < size / sizeof (mword); ++i) {
804 if (words [i] == (mword)key) {
805 g_print ("found possible ref to %p in object %p (%s) at offset %td\n",
806 key, start, safe_name (start), i * sizeof (mword));
813 mono_sgen_scan_area_with_callback (char *start, char *end, IterateObjectCallbackFunc callback, void *data, gboolean allow_flags)
815 while (start < end) {
819 if (!*(void**)start) {
820 start += sizeof (void*); /* should be ALLOC_ALIGN, really */
825 if (!(obj = SGEN_OBJECT_IS_FORWARDED (start)))
831 size = ALIGN_UP (safe_object_get_size ((MonoObject*)obj));
833 if ((MonoVTable*)SGEN_LOAD_VTABLE (obj) != array_fill_vtable)
834 callback (obj, size, data);
841 scan_object_for_specific_ref_callback (char *obj, size_t size, MonoObject *key)
843 scan_object_for_specific_ref (obj, key);
847 check_root_obj_specific_ref (RootRecord *root, MonoObject *key, MonoObject *obj)
851 g_print ("found ref to %p in root record %p\n", key, root);
854 static MonoObject *check_key = NULL;
855 static RootRecord *check_root = NULL;
858 check_root_obj_specific_ref_from_marker (void **obj)
860 check_root_obj_specific_ref (check_root, check_key, *obj);
864 scan_roots_for_specific_ref (MonoObject *key, int root_type)
870 SGEN_HASH_TABLE_FOREACH (&roots_hash [root_type], start_root, root) {
871 mword desc = root->root_desc;
875 switch (desc & ROOT_DESC_TYPE_MASK) {
876 case ROOT_DESC_BITMAP:
877 desc >>= ROOT_DESC_TYPE_SHIFT;
880 check_root_obj_specific_ref (root, key, *start_root);
885 case ROOT_DESC_COMPLEX: {
886 gsize *bitmap_data = mono_sgen_get_complex_descriptor_bitmap (desc);
887 int bwords = (*bitmap_data) - 1;
888 void **start_run = start_root;
890 while (bwords-- > 0) {
891 gsize bmap = *bitmap_data++;
892 void **objptr = start_run;
895 check_root_obj_specific_ref (root, key, *objptr);
899 start_run += GC_BITS_PER_WORD;
903 case ROOT_DESC_USER: {
904 MonoGCRootMarkFunc marker = mono_sgen_get_user_descriptor_func (desc);
905 marker (start_root, check_root_obj_specific_ref_from_marker);
908 case ROOT_DESC_RUN_LEN:
909 g_assert_not_reached ();
911 g_assert_not_reached ();
913 } SGEN_HASH_TABLE_FOREACH_END;
920 mono_gc_scan_for_specific_ref (MonoObject *key, gboolean precise)
925 scan_object_for_specific_ref_precise = precise;
927 mono_sgen_scan_area_with_callback (nursery_section->data, nursery_section->end_data,
928 (IterateObjectCallbackFunc)scan_object_for_specific_ref_callback, key, TRUE);
930 major_collector.iterate_objects (TRUE, TRUE, (IterateObjectCallbackFunc)scan_object_for_specific_ref_callback, key);
932 mono_sgen_los_iterate_objects ((IterateObjectCallbackFunc)scan_object_for_specific_ref_callback, key);
934 scan_roots_for_specific_ref (key, ROOT_TYPE_NORMAL);
935 scan_roots_for_specific_ref (key, ROOT_TYPE_WBARRIER);
937 SGEN_HASH_TABLE_FOREACH (&roots_hash [ROOT_TYPE_PINNED], ptr, root) {
938 while (ptr < (void**)root->end_root) {
939 check_root_obj_specific_ref (root, *ptr, key);
942 } SGEN_HASH_TABLE_FOREACH_END;
946 need_remove_object_for_domain (char *start, MonoDomain *domain)
948 if (mono_object_domain (start) == domain) {
949 DEBUG (4, fprintf (gc_debug_file, "Need to cleanup object %p\n", start));
950 binary_protocol_cleanup (start, (gpointer)LOAD_VTABLE (start), safe_object_get_size ((MonoObject*)start));
957 process_object_for_domain_clearing (char *start, MonoDomain *domain)
959 GCVTable *vt = (GCVTable*)LOAD_VTABLE (start);
960 if (vt->klass == mono_defaults.internal_thread_class)
961 g_assert (mono_object_domain (start) == mono_get_root_domain ());
962 /* The object could be a proxy for an object in the domain
964 if (mono_class_has_parent_fast (vt->klass, mono_defaults.real_proxy_class)) {
965 MonoObject *server = ((MonoRealProxy*)start)->unwrapped_server;
967 /* The server could already have been zeroed out, so
968 we need to check for that, too. */
969 if (server && (!LOAD_VTABLE (server) || mono_object_domain (server) == domain)) {
970 DEBUG (4, fprintf (gc_debug_file, "Cleaning up remote pointer in %p to object %p\n",
972 ((MonoRealProxy*)start)->unwrapped_server = NULL;
977 static MonoDomain *check_domain = NULL;
980 check_obj_not_in_domain (void **o)
982 g_assert (((MonoObject*)(*o))->vtable->domain != check_domain);
986 scan_for_registered_roots_in_domain (MonoDomain *domain, int root_type)
990 check_domain = domain;
991 SGEN_HASH_TABLE_FOREACH (&roots_hash [root_type], start_root, root) {
992 mword desc = root->root_desc;
994 /* The MonoDomain struct is allowed to hold
995 references to objects in its own domain. */
996 if (start_root == (void**)domain)
999 switch (desc & ROOT_DESC_TYPE_MASK) {
1000 case ROOT_DESC_BITMAP:
1001 desc >>= ROOT_DESC_TYPE_SHIFT;
1003 if ((desc & 1) && *start_root)
1004 check_obj_not_in_domain (*start_root);
1009 case ROOT_DESC_COMPLEX: {
1010 gsize *bitmap_data = mono_sgen_get_complex_descriptor_bitmap (desc);
1011 int bwords = (*bitmap_data) - 1;
1012 void **start_run = start_root;
1014 while (bwords-- > 0) {
1015 gsize bmap = *bitmap_data++;
1016 void **objptr = start_run;
1018 if ((bmap & 1) && *objptr)
1019 check_obj_not_in_domain (*objptr);
1023 start_run += GC_BITS_PER_WORD;
1027 case ROOT_DESC_USER: {
1028 MonoGCRootMarkFunc marker = mono_sgen_get_user_descriptor_func (desc);
1029 marker (start_root, check_obj_not_in_domain);
1032 case ROOT_DESC_RUN_LEN:
1033 g_assert_not_reached ();
1035 g_assert_not_reached ();
1037 } SGEN_HASH_TABLE_FOREACH_END;
1039 check_domain = NULL;
1043 check_for_xdomain_refs (void)
1047 mono_sgen_scan_area_with_callback (nursery_section->data, nursery_section->end_data,
1048 (IterateObjectCallbackFunc)scan_object_for_xdomain_refs, NULL, FALSE);
1050 major_collector.iterate_objects (TRUE, TRUE, (IterateObjectCallbackFunc)scan_object_for_xdomain_refs, NULL);
1052 for (bigobj = los_object_list; bigobj; bigobj = bigobj->next)
1053 scan_object_for_xdomain_refs (bigobj->data, bigobj->size, NULL);
1057 clear_domain_process_object (char *obj, MonoDomain *domain)
1061 process_object_for_domain_clearing (obj, domain);
1062 remove = need_remove_object_for_domain (obj, domain);
1064 if (remove && ((MonoObject*)obj)->synchronisation) {
1065 void **dislink = mono_monitor_get_object_monitor_weak_link ((MonoObject*)obj);
1067 mono_gc_register_disappearing_link (NULL, dislink, FALSE, TRUE);
1074 clear_domain_process_minor_object_callback (char *obj, size_t size, MonoDomain *domain)
1076 if (clear_domain_process_object (obj, domain))
1077 memset (obj, 0, size);
1081 clear_domain_process_major_object_callback (char *obj, size_t size, MonoDomain *domain)
1083 clear_domain_process_object (obj, domain);
1087 clear_domain_free_major_non_pinned_object_callback (char *obj, size_t size, MonoDomain *domain)
1089 if (need_remove_object_for_domain (obj, domain))
1090 major_collector.free_non_pinned_object (obj, size);
1094 clear_domain_free_major_pinned_object_callback (char *obj, size_t size, MonoDomain *domain)
1096 if (need_remove_object_for_domain (obj, domain))
1097 major_collector.free_pinned_object (obj, size);
1101 * When appdomains are unloaded we can easily remove objects that have finalizers,
1102 * but all the others could still be present in random places on the heap.
1103 * We need a sweep to get rid of them even though it's going to be costly
1105 * The reason we need to remove them is because we access the vtable and class
1106 * structures to know the object size and the reference bitmap: once the domain is
1107 * unloaded the point to random memory.
1110 mono_gc_clear_domain (MonoDomain * domain)
1112 LOSObject *bigobj, *prev;
1117 process_fin_stage_entries ();
1118 process_dislink_stage_entries ();
1120 mono_sgen_clear_nursery_fragments ();
1122 if (xdomain_checks && domain != mono_get_root_domain ()) {
1123 scan_for_registered_roots_in_domain (domain, ROOT_TYPE_NORMAL);
1124 scan_for_registered_roots_in_domain (domain, ROOT_TYPE_WBARRIER);
1125 check_for_xdomain_refs ();
1128 mono_sgen_scan_area_with_callback (nursery_section->data, nursery_section->end_data,
1129 (IterateObjectCallbackFunc)clear_domain_process_minor_object_callback, domain, FALSE);
1131 /*Ephemerons and dislinks must be processed before LOS since they might end up pointing
1132 to memory returned to the OS.*/
1133 null_ephemerons_for_domain (domain);
1135 for (i = GENERATION_NURSERY; i < GENERATION_MAX; ++i)
1136 null_links_for_domain (domain, i);
1138 /* We need two passes over major and large objects because
1139 freeing such objects might give their memory back to the OS
1140 (in the case of large objects) or obliterate its vtable
1141 (pinned objects with major-copying or pinned and non-pinned
1142 objects with major-mark&sweep), but we might need to
1143 dereference a pointer from an object to another object if
1144 the first object is a proxy. */
1145 major_collector.iterate_objects (TRUE, TRUE, (IterateObjectCallbackFunc)clear_domain_process_major_object_callback, domain);
1146 for (bigobj = los_object_list; bigobj; bigobj = bigobj->next)
1147 clear_domain_process_object (bigobj->data, domain);
1150 for (bigobj = los_object_list; bigobj;) {
1151 if (need_remove_object_for_domain (bigobj->data, domain)) {
1152 LOSObject *to_free = bigobj;
1154 prev->next = bigobj->next;
1156 los_object_list = bigobj->next;
1157 bigobj = bigobj->next;
1158 DEBUG (4, fprintf (gc_debug_file, "Freeing large object %p\n",
1160 mono_sgen_los_free_object (to_free);
1164 bigobj = bigobj->next;
1166 major_collector.iterate_objects (TRUE, FALSE, (IterateObjectCallbackFunc)clear_domain_free_major_non_pinned_object_callback, domain);
1167 major_collector.iterate_objects (FALSE, TRUE, (IterateObjectCallbackFunc)clear_domain_free_major_pinned_object_callback, domain);
1169 if (G_UNLIKELY (do_pin_stats)) {
1170 if (domain == mono_get_root_domain ())
1171 mono_sgen_pin_stats_print_class_stats ();
1178 * mono_sgen_add_to_global_remset:
1180 * The global remset contains locations which point into newspace after
1181 * a minor collection. This can happen if the objects they point to are pinned.
1183 * LOCKING: If called from a parallel collector, the global remset
1184 * lock must be held. For serial collectors that is not necessary.
1187 mono_sgen_add_to_global_remset (gpointer ptr)
1189 remset.record_pointer (ptr);
1193 * mono_sgen_drain_gray_stack:
1195 * Scan objects in the gray stack until the stack is empty. This should be called
1196 * frequently after each object is copied, to achieve better locality and cache
1200 mono_sgen_drain_gray_stack (GrayQueue *queue, int max_objs)
1204 if (current_collection_generation == GENERATION_NURSERY) {
1205 ScanObjectFunc scan_func = mono_sgen_get_minor_scan_object ();
1208 GRAY_OBJECT_DEQUEUE (queue, obj);
1211 DEBUG (9, fprintf (gc_debug_file, "Precise gray object scan %p (%s)\n", obj, safe_name (obj)));
1212 scan_func (obj, queue);
1217 if (mono_sgen_collection_is_parallel () && mono_sgen_workers_is_distributed_queue (queue))
1221 for (i = 0; i != max_objs; ++i) {
1222 GRAY_OBJECT_DEQUEUE (queue, obj);
1225 DEBUG (9, fprintf (gc_debug_file, "Precise gray object scan %p (%s)\n", obj, safe_name (obj)));
1226 major_collector.major_scan_object (obj, queue);
1228 } while (max_objs < 0);
1234 * Addresses from start to end are already sorted. This function finds
1235 * the object header for each address and pins the object. The
1236 * addresses must be inside the passed section. The (start of the)
1237 * address array is overwritten with the addresses of the actually
1238 * pinned objects. Return the number of pinned objects.
1241 pin_objects_from_addresses (GCMemSection *section, void **start, void **end, void *start_nursery, void *end_nursery, GrayQueue *queue)
1246 void *last_obj = NULL;
1247 size_t last_obj_size = 0;
1250 void **definitely_pinned = start;
1252 mono_sgen_nursery_allocator_prepare_for_pinning ();
1254 while (start < end) {
1256 /* the range check should be reduntant */
1257 if (addr != last && addr >= start_nursery && addr < end_nursery) {
1258 DEBUG (5, fprintf (gc_debug_file, "Considering pinning addr %p\n", addr));
1259 /* multiple pointers to the same object */
1260 if (addr >= last_obj && (char*)addr < (char*)last_obj + last_obj_size) {
1264 idx = ((char*)addr - (char*)section->data) / SCAN_START_SIZE;
1265 g_assert (idx < section->num_scan_start);
1266 search_start = (void*)section->scan_starts [idx];
1267 if (!search_start || search_start > addr) {
1270 search_start = section->scan_starts [idx];
1271 if (search_start && search_start <= addr)
1274 if (!search_start || search_start > addr)
1275 search_start = start_nursery;
1277 if (search_start < last_obj)
1278 search_start = (char*)last_obj + last_obj_size;
1279 /* now addr should be in an object a short distance from search_start
1280 * Note that search_start must point to zeroed mem or point to an object.
1284 if (!*(void**)search_start) {
1285 /* Consistency check */
1287 for (frag = nursery_fragments; frag; frag = frag->next) {
1288 if (search_start >= frag->fragment_start && search_start < frag->fragment_end)
1289 g_assert_not_reached ();
1293 search_start = (void*)ALIGN_UP ((mword)search_start + sizeof (gpointer));
1296 last_obj = search_start;
1297 last_obj_size = ALIGN_UP (safe_object_get_size ((MonoObject*)search_start));
1299 if (((MonoObject*)last_obj)->synchronisation == GINT_TO_POINTER (-1)) {
1300 /* Marks the beginning of a nursery fragment, skip */
1302 DEBUG (8, fprintf (gc_debug_file, "Pinned try match %p (%s), size %zd\n", last_obj, safe_name (last_obj), last_obj_size));
1303 if (addr >= search_start && (char*)addr < (char*)last_obj + last_obj_size) {
1304 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));
1305 binary_protocol_pin (search_start, (gpointer)LOAD_VTABLE (search_start), safe_object_get_size (search_start));
1306 pin_object (search_start);
1307 GRAY_OBJECT_ENQUEUE (queue, search_start);
1308 if (G_UNLIKELY (do_pin_stats))
1309 mono_sgen_pin_stats_register_object (search_start, last_obj_size);
1310 definitely_pinned [count] = search_start;
1315 /* skip to the next object */
1316 search_start = (void*)((char*)search_start + last_obj_size);
1317 } while (search_start <= addr);
1318 /* we either pinned the correct object or we ignored the addr because
1319 * it points to unused zeroed memory.
1325 //printf ("effective pinned: %d (at the end: %d)\n", count, (char*)end_nursery - (char*)last);
1326 if (mono_profiler_get_events () & MONO_PROFILE_GC_ROOTS) {
1327 GCRootReport report;
1329 for (idx = 0; idx < count; ++idx)
1330 add_profile_gc_root (&report, definitely_pinned [idx], MONO_PROFILE_GC_ROOT_PINNING | MONO_PROFILE_GC_ROOT_MISC, 0);
1331 notify_gc_roots (&report);
1333 stat_pinned_objects += count;
1338 mono_sgen_pin_objects_in_section (GCMemSection *section, GrayQueue *queue)
1340 int num_entries = section->pin_queue_num_entries;
1342 void **start = section->pin_queue_start;
1344 reduced_to = pin_objects_from_addresses (section, start, start + num_entries,
1345 section->data, section->next_data, queue);
1346 section->pin_queue_num_entries = reduced_to;
1348 section->pin_queue_start = NULL;
1354 mono_sgen_pin_object (void *object, GrayQueue *queue)
1356 if (mono_sgen_collection_is_parallel ()) {
1358 /*object arrives pinned*/
1359 mono_sgen_pin_stage_ptr (object);
1363 SGEN_PIN_OBJECT (object);
1364 mono_sgen_pin_stage_ptr (object);
1366 if (G_UNLIKELY (do_pin_stats))
1367 mono_sgen_pin_stats_register_object (object, safe_object_get_size (object));
1369 GRAY_OBJECT_ENQUEUE (queue, object);
1370 binary_protocol_pin (object, (gpointer)LOAD_VTABLE (object), safe_object_get_size (object));
1373 /* Sort the addresses in array in increasing order.
1374 * Done using a by-the book heap sort. Which has decent and stable performance, is pretty cache efficient.
1377 mono_sgen_sort_addresses (void **array, int size)
1382 for (i = 1; i < size; ++i) {
1385 int parent = (child - 1) / 2;
1387 if (array [parent] >= array [child])
1390 tmp = array [parent];
1391 array [parent] = array [child];
1392 array [child] = tmp;
1398 for (i = size - 1; i > 0; --i) {
1401 array [i] = array [0];
1407 while (root * 2 + 1 <= end) {
1408 int child = root * 2 + 1;
1410 if (child < end && array [child] < array [child + 1])
1412 if (array [root] >= array [child])
1416 array [root] = array [child];
1417 array [child] = tmp;
1425 * Scan the memory between start and end and queue values which could be pointers
1426 * to the area between start_nursery and end_nursery for later consideration.
1427 * Typically used for thread stacks.
1430 conservatively_pin_objects_from (void **start, void **end, void *start_nursery, void *end_nursery, int pin_type)
1433 while (start < end) {
1434 if (*start >= start_nursery && *start < end_nursery) {
1436 * *start can point to the middle of an object
1437 * note: should we handle pointing at the end of an object?
1438 * pinning in C# code disallows pointing at the end of an object
1439 * but there is some small chance that an optimizing C compiler
1440 * may keep the only reference to an object by pointing
1441 * at the end of it. We ignore this small chance for now.
1442 * Pointers to the end of an object are indistinguishable
1443 * from pointers to the start of the next object in memory
1444 * so if we allow that we'd need to pin two objects...
1445 * We queue the pointer in an array, the
1446 * array will then be sorted and uniqued. This way
1447 * we can coalesce several pinning pointers and it should
1448 * be faster since we'd do a memory scan with increasing
1449 * addresses. Note: we can align the address to the allocation
1450 * alignment, so the unique process is more effective.
1452 mword addr = (mword)*start;
1453 addr &= ~(ALLOC_ALIGN - 1);
1454 if (addr >= (mword)start_nursery && addr < (mword)end_nursery)
1455 mono_sgen_pin_stage_ptr ((void*)addr);
1456 if (G_UNLIKELY (do_pin_stats)) {
1457 if (ptr_in_nursery ((void*)addr))
1458 mono_sgen_pin_stats_register_address ((char*)addr, pin_type);
1460 DEBUG (6, if (count) fprintf (gc_debug_file, "Pinning address %p from %p\n", (void*)addr, start));
1465 DEBUG (7, if (count) fprintf (gc_debug_file, "found %d potential pinned heap pointers\n", count));
1469 * Debugging function: find in the conservative roots where @obj is being pinned.
1471 static G_GNUC_UNUSED void
1472 find_pinning_reference (char *obj, size_t size)
1476 char *endobj = obj + size;
1478 SGEN_HASH_TABLE_FOREACH (&roots_hash [ROOT_TYPE_NORMAL], start, root) {
1479 /* if desc is non-null it has precise info */
1480 if (!root->root_desc) {
1481 while (start < (char**)root->end_root) {
1482 if (*start >= obj && *start < endobj) {
1483 DEBUG (0, fprintf (gc_debug_file, "Object %p referenced in pinned roots %p-%p\n", obj, start, root->end_root));
1488 } SGEN_HASH_TABLE_FOREACH_END;
1490 find_pinning_ref_from_thread (obj, size);
1494 * The first thing we do in a collection is to identify pinned objects.
1495 * This function considers all the areas of memory that need to be
1496 * conservatively scanned.
1499 pin_from_roots (void *start_nursery, void *end_nursery, GrayQueue *queue)
1503 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));
1504 /* objects pinned from the API are inside these roots */
1505 SGEN_HASH_TABLE_FOREACH (&roots_hash [ROOT_TYPE_PINNED], start_root, root) {
1506 DEBUG (6, fprintf (gc_debug_file, "Pinned roots %p-%p\n", start_root, root->end_root));
1507 conservatively_pin_objects_from (start_root, (void**)root->end_root, start_nursery, end_nursery, PIN_TYPE_OTHER);
1508 } SGEN_HASH_TABLE_FOREACH_END;
1509 /* now deal with the thread stacks
1510 * in the future we should be able to conservatively scan only:
1511 * *) the cpu registers
1512 * *) the unmanaged stack frames
1513 * *) the _last_ managed stack frame
1514 * *) pointers slots in managed frames
1516 scan_thread_data (start_nursery, end_nursery, FALSE, queue);
1520 CopyOrMarkObjectFunc func;
1522 } UserCopyOrMarkData;
1524 static MonoNativeTlsKey user_copy_or_mark_key;
1527 init_user_copy_or_mark_key (void)
1529 mono_native_tls_alloc (&user_copy_or_mark_key, NULL);
1533 set_user_copy_or_mark_data (UserCopyOrMarkData *data)
1535 mono_native_tls_set_value (user_copy_or_mark_key, data);
1539 single_arg_user_copy_or_mark (void **obj)
1541 UserCopyOrMarkData *data = mono_native_tls_get_value (user_copy_or_mark_key);
1543 data->func (obj, data->queue);
1547 * The memory area from start_root to end_root contains pointers to objects.
1548 * Their position is precisely described by @desc (this means that the pointer
1549 * can be either NULL or the pointer to the start of an object).
1550 * This functions copies them to to_space updates them.
1552 * This function is not thread-safe!
1555 precisely_scan_objects_from (CopyOrMarkObjectFunc copy_func, void** start_root, void** end_root, char* n_start, char *n_end, mword desc, GrayQueue *queue)
1557 switch (desc & ROOT_DESC_TYPE_MASK) {
1558 case ROOT_DESC_BITMAP:
1559 desc >>= ROOT_DESC_TYPE_SHIFT;
1561 if ((desc & 1) && *start_root) {
1562 copy_func (start_root, queue);
1563 DEBUG (9, fprintf (gc_debug_file, "Overwrote root at %p with %p\n", start_root, *start_root));
1564 mono_sgen_drain_gray_stack (queue, -1);
1570 case ROOT_DESC_COMPLEX: {
1571 gsize *bitmap_data = mono_sgen_get_complex_descriptor_bitmap (desc);
1572 int bwords = (*bitmap_data) - 1;
1573 void **start_run = start_root;
1575 while (bwords-- > 0) {
1576 gsize bmap = *bitmap_data++;
1577 void **objptr = start_run;
1579 if ((bmap & 1) && *objptr) {
1580 copy_func (objptr, queue);
1581 DEBUG (9, fprintf (gc_debug_file, "Overwrote root at %p with %p\n", objptr, *objptr));
1582 mono_sgen_drain_gray_stack (queue, -1);
1587 start_run += GC_BITS_PER_WORD;
1591 case ROOT_DESC_USER: {
1592 UserCopyOrMarkData data = { copy_func, queue };
1593 MonoGCRootMarkFunc marker = mono_sgen_get_user_descriptor_func (desc);
1594 set_user_copy_or_mark_data (&data);
1595 marker (start_root, single_arg_user_copy_or_mark);
1596 set_user_copy_or_mark_data (NULL);
1599 case ROOT_DESC_RUN_LEN:
1600 g_assert_not_reached ();
1602 g_assert_not_reached ();
1607 reset_heap_boundaries (void)
1609 lowest_heap_address = ~(mword)0;
1610 highest_heap_address = 0;
1614 mono_sgen_update_heap_boundaries (mword low, mword high)
1619 old = lowest_heap_address;
1622 } while (SGEN_CAS_PTR ((gpointer*)&lowest_heap_address, (gpointer)low, (gpointer)old) != (gpointer)old);
1625 old = highest_heap_address;
1628 } while (SGEN_CAS_PTR ((gpointer*)&highest_heap_address, (gpointer)high, (gpointer)old) != (gpointer)old);
1631 static unsigned long
1632 prot_flags_for_activate (int activate)
1634 unsigned long prot_flags = activate? MONO_MMAP_READ|MONO_MMAP_WRITE: MONO_MMAP_NONE;
1635 return prot_flags | MONO_MMAP_PRIVATE | MONO_MMAP_ANON;
1639 * Allocate a big chunk of memory from the OS (usually 64KB to several megabytes).
1640 * This must not require any lock.
1643 mono_sgen_alloc_os_memory (size_t size, int activate)
1645 void *ptr = mono_valloc (0, size, prot_flags_for_activate (activate));
1648 total_alloc += size;
1653 /* size must be a power of 2 */
1655 mono_sgen_alloc_os_memory_aligned (mword size, mword alignment, gboolean activate)
1657 void *ptr = mono_valloc_aligned (size, alignment, prot_flags_for_activate (activate));
1660 total_alloc += size;
1666 * Free the memory returned by mono_sgen_alloc_os_memory (), returning it to the OS.
1669 mono_sgen_free_os_memory (void *addr, size_t size)
1671 mono_vfree (addr, size);
1673 total_alloc -= size;
1677 * Allocate and setup the data structures needed to be able to allocate objects
1678 * in the nursery. The nursery is stored in nursery_section.
1681 alloc_nursery (void)
1683 GCMemSection *section;
1688 if (nursery_section)
1690 DEBUG (2, fprintf (gc_debug_file, "Allocating nursery size: %lu\n", (unsigned long)nursery_size));
1691 /* later we will alloc a larger area for the nursery but only activate
1692 * what we need. The rest will be used as expansion if we have too many pinned
1693 * objects in the existing nursery.
1695 /* FIXME: handle OOM */
1696 section = mono_sgen_alloc_internal (INTERNAL_MEM_SECTION);
1698 g_assert (nursery_size == DEFAULT_NURSERY_SIZE);
1699 alloc_size = nursery_size;
1700 #ifdef SGEN_ALIGN_NURSERY
1701 data = major_collector.alloc_heap (alloc_size, alloc_size, DEFAULT_NURSERY_BITS);
1703 data = major_collector.alloc_heap (alloc_size, 0, DEFAULT_NURSERY_BITS);
1705 mono_sgen_update_heap_boundaries ((mword)data, (mword)(data + nursery_size));
1706 DEBUG (4, fprintf (gc_debug_file, "Expanding nursery size (%p-%p): %lu, total: %lu\n", data, data + alloc_size, (unsigned long)nursery_size, (unsigned long)total_alloc));
1707 section->data = section->next_data = data;
1708 section->size = alloc_size;
1709 section->end_data = data + nursery_size;
1710 scan_starts = (alloc_size + SCAN_START_SIZE - 1) / SCAN_START_SIZE;
1711 section->scan_starts = mono_sgen_alloc_internal_dynamic (sizeof (char*) * scan_starts, INTERNAL_MEM_SCAN_STARTS);
1712 section->num_scan_start = scan_starts;
1713 section->block.role = MEMORY_ROLE_GEN0;
1714 section->block.next = NULL;
1716 nursery_section = section;
1718 mono_sgen_nursery_allocator_set_nursery_bounds (data, data + nursery_size);
1722 mono_gc_get_nursery (int *shift_bits, size_t *size)
1724 *size = nursery_size;
1725 #ifdef SGEN_ALIGN_NURSERY
1726 *shift_bits = DEFAULT_NURSERY_BITS;
1730 return mono_sgen_get_nursery_start ();
1734 mono_gc_set_current_thread_appdomain (MonoDomain *domain)
1736 SgenThreadInfo *info = mono_thread_info_current ();
1738 /* Could be called from sgen_thread_unregister () with a NULL info */
1741 info->stopped_domain = domain;
1746 mono_gc_precise_stack_mark_enabled (void)
1748 return !conservative_stack_mark;
1752 mono_gc_get_logfile (void)
1754 return mono_sgen_get_logfile ();
1758 report_finalizer_roots_list (FinalizeReadyEntry *list)
1760 GCRootReport report;
1761 FinalizeReadyEntry *fin;
1764 for (fin = list; fin; fin = fin->next) {
1767 add_profile_gc_root (&report, fin->object, MONO_PROFILE_GC_ROOT_FINALIZER, 0);
1769 notify_gc_roots (&report);
1773 report_finalizer_roots (void)
1775 report_finalizer_roots_list (fin_ready_list);
1776 report_finalizer_roots_list (critical_fin_list);
1779 static GCRootReport *root_report;
1782 single_arg_report_root (void **obj)
1785 add_profile_gc_root (root_report, *obj, MONO_PROFILE_GC_ROOT_OTHER, 0);
1789 precisely_report_roots_from (GCRootReport *report, void** start_root, void** end_root, mword desc)
1791 switch (desc & ROOT_DESC_TYPE_MASK) {
1792 case ROOT_DESC_BITMAP:
1793 desc >>= ROOT_DESC_TYPE_SHIFT;
1795 if ((desc & 1) && *start_root) {
1796 add_profile_gc_root (report, *start_root, MONO_PROFILE_GC_ROOT_OTHER, 0);
1802 case ROOT_DESC_COMPLEX: {
1803 gsize *bitmap_data = mono_sgen_get_complex_descriptor_bitmap (desc);
1804 int bwords = (*bitmap_data) - 1;
1805 void **start_run = start_root;
1807 while (bwords-- > 0) {
1808 gsize bmap = *bitmap_data++;
1809 void **objptr = start_run;
1811 if ((bmap & 1) && *objptr) {
1812 add_profile_gc_root (report, *objptr, MONO_PROFILE_GC_ROOT_OTHER, 0);
1817 start_run += GC_BITS_PER_WORD;
1821 case ROOT_DESC_USER: {
1822 MonoGCRootMarkFunc marker = mono_sgen_get_user_descriptor_func (desc);
1823 root_report = report;
1824 marker (start_root, single_arg_report_root);
1827 case ROOT_DESC_RUN_LEN:
1828 g_assert_not_reached ();
1830 g_assert_not_reached ();
1835 report_registered_roots_by_type (int root_type)
1837 GCRootReport report;
1841 SGEN_HASH_TABLE_FOREACH (&roots_hash [root_type], start_root, root) {
1842 DEBUG (6, fprintf (gc_debug_file, "Precise root scan %p-%p (desc: %p)\n", start_root, root->end_root, (void*)root->root_desc));
1843 precisely_report_roots_from (&report, start_root, (void**)root->end_root, root->root_desc);
1844 } SGEN_HASH_TABLE_FOREACH_END;
1845 notify_gc_roots (&report);
1849 report_registered_roots (void)
1851 report_registered_roots_by_type (ROOT_TYPE_NORMAL);
1852 report_registered_roots_by_type (ROOT_TYPE_WBARRIER);
1856 scan_finalizer_entries (CopyOrMarkObjectFunc copy_func, FinalizeReadyEntry *list, GrayQueue *queue)
1858 FinalizeReadyEntry *fin;
1860 for (fin = list; fin; fin = fin->next) {
1863 DEBUG (5, fprintf (gc_debug_file, "Scan of fin ready object: %p (%s)\n", fin->object, safe_name (fin->object)));
1864 copy_func (&fin->object, queue);
1869 generation_name (int generation)
1871 switch (generation) {
1872 case GENERATION_NURSERY: return "nursery";
1873 case GENERATION_OLD: return "old";
1874 default: g_assert_not_reached ();
1880 stw_bridge_process (void)
1882 mono_sgen_bridge_processing_stw_step ();
1886 bridge_process (void)
1888 mono_sgen_bridge_processing_finish ();
1891 CopyOrMarkObjectFunc
1892 mono_sgen_get_copy_object (void)
1894 if (current_collection_generation == GENERATION_NURSERY) {
1895 if (mono_sgen_collection_is_parallel ())
1896 return major_collector.copy_object;
1898 return major_collector.nopar_copy_object;
1900 return major_collector.copy_or_mark_object;
1905 mono_sgen_get_minor_scan_object (void)
1907 g_assert (current_collection_generation == GENERATION_NURSERY);
1909 if (mono_sgen_collection_is_parallel ())
1910 return major_collector.minor_scan_object;
1912 return major_collector.nopar_minor_scan_object;
1916 mono_sgen_get_minor_scan_vtype (void)
1918 g_assert (current_collection_generation == GENERATION_NURSERY);
1920 if (mono_sgen_collection_is_parallel ())
1921 return major_collector.minor_scan_vtype;
1923 return major_collector.nopar_minor_scan_vtype;
1927 finish_gray_stack (char *start_addr, char *end_addr, int generation, GrayQueue *queue)
1932 int done_with_ephemerons, ephemeron_rounds = 0;
1934 CopyOrMarkObjectFunc copy_func = mono_sgen_get_copy_object ();
1937 * We copied all the reachable objects. Now it's the time to copy
1938 * the objects that were not referenced by the roots, but by the copied objects.
1939 * we built a stack of objects pointed to by gray_start: they are
1940 * additional roots and we may add more items as we go.
1941 * We loop until gray_start == gray_objects which means no more objects have
1942 * been added. Note this is iterative: no recursion is involved.
1943 * We need to walk the LO list as well in search of marked big objects
1944 * (use a flag since this is needed only on major collections). We need to loop
1945 * here as well, so keep a counter of marked LO (increasing it in copy_object).
1946 * To achieve better cache locality and cache usage, we drain the gray stack
1947 * frequently, after each object is copied, and just finish the work here.
1949 mono_sgen_drain_gray_stack (queue, -1);
1951 DEBUG (2, fprintf (gc_debug_file, "%s generation done\n", generation_name (generation)));
1954 Reset bridge data, we might have lingering data from a previous collection if this is a major
1955 collection trigged by minor overflow.
1957 We must reset the gathered bridges since their original block might be evacuated due to major
1958 fragmentation in the meanwhile and the bridge code should not have to deal with that.
1960 mono_sgen_bridge_reset_data ();
1963 * Walk the ephemeron tables marking all values with reachable keys. This must be completely done
1964 * before processing finalizable objects or non-tracking weak hamdle to avoid finalizing/clearing
1965 * objects that are in fact reachable.
1967 done_with_ephemerons = 0;
1969 done_with_ephemerons = mark_ephemerons_in_range (copy_func, start_addr, end_addr, queue);
1970 mono_sgen_drain_gray_stack (queue, -1);
1972 } while (!done_with_ephemerons);
1974 mono_sgen_scan_togglerefs (copy_func, start_addr, end_addr, queue);
1975 if (generation == GENERATION_OLD)
1976 mono_sgen_scan_togglerefs (copy_func, mono_sgen_get_nursery_start (), mono_sgen_get_nursery_end (), queue);
1978 if (mono_sgen_need_bridge_processing ()) {
1979 collect_bridge_objects (copy_func, start_addr, end_addr, generation, queue);
1980 if (generation == GENERATION_OLD)
1981 collect_bridge_objects (copy_func, mono_sgen_get_nursery_start (), mono_sgen_get_nursery_end (), GENERATION_NURSERY, queue);
1982 mono_sgen_drain_gray_stack (queue, -1);
1986 We must clear weak links that don't track resurrection before processing object ready for
1987 finalization so they can be cleared before that.
1989 null_link_in_range (copy_func, start_addr, end_addr, generation, TRUE, queue);
1990 if (generation == GENERATION_OLD)
1991 null_link_in_range (copy_func, start_addr, end_addr, GENERATION_NURSERY, TRUE, queue);
1994 /* walk the finalization queue and move also the objects that need to be
1995 * finalized: use the finalized objects as new roots so the objects they depend
1996 * on are also not reclaimed. As with the roots above, only objects in the nursery
1997 * are marked/copied.
1998 * We need a loop here, since objects ready for finalizers may reference other objects
1999 * that are fin-ready. Speedup with a flag?
2003 fin_ready = num_ready_finalizers;
2004 finalize_in_range (copy_func, start_addr, end_addr, generation, queue);
2005 if (generation == GENERATION_OLD)
2006 finalize_in_range (copy_func, mono_sgen_get_nursery_start (), mono_sgen_get_nursery_end (), GENERATION_NURSERY, queue);
2008 if (fin_ready != num_ready_finalizers)
2011 /* drain the new stack that might have been created */
2012 DEBUG (6, fprintf (gc_debug_file, "Precise scan of gray area post fin\n"));
2013 mono_sgen_drain_gray_stack (queue, -1);
2014 } while (fin_ready != num_ready_finalizers);
2016 if (mono_sgen_need_bridge_processing ())
2017 g_assert (num_loops <= 1);
2020 * This must be done again after processing finalizable objects since CWL slots are cleared only after the key is finalized.
2022 done_with_ephemerons = 0;
2024 done_with_ephemerons = mark_ephemerons_in_range (copy_func, start_addr, end_addr, queue);
2025 mono_sgen_drain_gray_stack (queue, -1);
2027 } while (!done_with_ephemerons);
2030 * Clear ephemeron pairs with unreachable keys.
2031 * We pass the copy func so we can figure out if an array was promoted or not.
2033 clear_unreachable_ephemerons (copy_func, start_addr, end_addr, queue);
2036 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));
2039 * handle disappearing links
2040 * Note we do this after checking the finalization queue because if an object
2041 * survives (at least long enough to be finalized) we don't clear the link.
2042 * This also deals with a possible issue with the monitor reclamation: with the Boehm
2043 * GC a finalized object my lose the monitor because it is cleared before the finalizer is
2046 g_assert (mono_sgen_gray_object_queue_is_empty (queue));
2048 null_link_in_range (copy_func, start_addr, end_addr, generation, FALSE, queue);
2049 if (generation == GENERATION_OLD)
2050 null_link_in_range (copy_func, start_addr, end_addr, GENERATION_NURSERY, FALSE, queue);
2051 if (mono_sgen_gray_object_queue_is_empty (queue))
2053 mono_sgen_drain_gray_stack (queue, -1);
2056 g_assert (mono_sgen_gray_object_queue_is_empty (queue));
2060 mono_sgen_check_section_scan_starts (GCMemSection *section)
2063 for (i = 0; i < section->num_scan_start; ++i) {
2064 if (section->scan_starts [i]) {
2065 guint size = safe_object_get_size ((MonoObject*) section->scan_starts [i]);
2066 g_assert (size >= sizeof (MonoObject) && size <= MAX_SMALL_OBJ_SIZE);
2072 check_scan_starts (void)
2074 if (!do_scan_starts_check)
2076 mono_sgen_check_section_scan_starts (nursery_section);
2077 major_collector.check_scan_starts ();
2081 scan_from_registered_roots (CopyOrMarkObjectFunc copy_func, char *addr_start, char *addr_end, int root_type, GrayQueue *queue)
2085 SGEN_HASH_TABLE_FOREACH (&roots_hash [root_type], start_root, root) {
2086 DEBUG (6, fprintf (gc_debug_file, "Precise root scan %p-%p (desc: %p)\n", start_root, root->end_root, (void*)root->root_desc));
2087 precisely_scan_objects_from (copy_func, start_root, (void**)root->end_root, addr_start, addr_end, root->root_desc, queue);
2088 } SGEN_HASH_TABLE_FOREACH_END;
2092 mono_sgen_dump_occupied (char *start, char *end, char *section_start)
2094 fprintf (heap_dump_file, "<occupied offset=\"%td\" size=\"%td\"/>\n", start - section_start, end - start);
2098 mono_sgen_dump_section (GCMemSection *section, const char *type)
2100 char *start = section->data;
2101 char *end = section->data + section->size;
2102 char *occ_start = NULL;
2104 char *old_start = NULL; /* just for debugging */
2106 fprintf (heap_dump_file, "<section type=\"%s\" size=\"%lu\">\n", type, (unsigned long)section->size);
2108 while (start < end) {
2112 if (!*(void**)start) {
2114 mono_sgen_dump_occupied (occ_start, start, section->data);
2117 start += sizeof (void*); /* should be ALLOC_ALIGN, really */
2120 g_assert (start < section->next_data);
2125 vt = (GCVTable*)LOAD_VTABLE (start);
2128 size = ALIGN_UP (safe_object_get_size ((MonoObject*) start));
2131 fprintf (heap_dump_file, "<object offset=\"%d\" class=\"%s.%s\" size=\"%d\"/>\n",
2132 start - section->data,
2133 vt->klass->name_space, vt->klass->name,
2141 mono_sgen_dump_occupied (occ_start, start, section->data);
2143 fprintf (heap_dump_file, "</section>\n");
2147 dump_object (MonoObject *obj, gboolean dump_location)
2149 static char class_name [1024];
2151 MonoClass *class = mono_object_class (obj);
2155 * Python's XML parser is too stupid to parse angle brackets
2156 * in strings, so we just ignore them;
2159 while (class->name [i] && j < sizeof (class_name) - 1) {
2160 if (!strchr ("<>\"", class->name [i]))
2161 class_name [j++] = class->name [i];
2164 g_assert (j < sizeof (class_name));
2167 fprintf (heap_dump_file, "<object class=\"%s.%s\" size=\"%d\"",
2168 class->name_space, class_name,
2169 safe_object_get_size (obj));
2170 if (dump_location) {
2171 const char *location;
2172 if (ptr_in_nursery (obj))
2173 location = "nursery";
2174 else if (safe_object_get_size (obj) <= MAX_SMALL_OBJ_SIZE)
2178 fprintf (heap_dump_file, " location=\"%s\"", location);
2180 fprintf (heap_dump_file, "/>\n");
2184 dump_heap (const char *type, int num, const char *reason)
2189 fprintf (heap_dump_file, "<collection type=\"%s\" num=\"%d\"", type, num);
2191 fprintf (heap_dump_file, " reason=\"%s\"", reason);
2192 fprintf (heap_dump_file, ">\n");
2193 fprintf (heap_dump_file, "<other-mem-usage type=\"mempools\" size=\"%ld\"/>\n", mono_mempool_get_bytes_allocated ());
2194 mono_sgen_dump_internal_mem_usage (heap_dump_file);
2195 fprintf (heap_dump_file, "<pinned type=\"stack\" bytes=\"%zu\"/>\n", mono_sgen_pin_stats_get_pinned_byte_count (PIN_TYPE_STACK));
2196 /* fprintf (heap_dump_file, "<pinned type=\"static-data\" bytes=\"%d\"/>\n", pinned_byte_counts [PIN_TYPE_STATIC_DATA]); */
2197 fprintf (heap_dump_file, "<pinned type=\"other\" bytes=\"%zu\"/>\n", mono_sgen_pin_stats_get_pinned_byte_count (PIN_TYPE_OTHER));
2199 fprintf (heap_dump_file, "<pinned-objects>\n");
2200 for (list = mono_sgen_pin_stats_get_object_list (); list; list = list->next)
2201 dump_object (list->obj, TRUE);
2202 fprintf (heap_dump_file, "</pinned-objects>\n");
2204 mono_sgen_dump_section (nursery_section, "nursery");
2206 major_collector.dump_heap (heap_dump_file);
2208 fprintf (heap_dump_file, "<los>\n");
2209 for (bigobj = los_object_list; bigobj; bigobj = bigobj->next)
2210 dump_object ((MonoObject*)bigobj->data, FALSE);
2211 fprintf (heap_dump_file, "</los>\n");
2213 fprintf (heap_dump_file, "</collection>\n");
2217 mono_sgen_register_moved_object (void *obj, void *destination)
2219 g_assert (mono_profiler_events & MONO_PROFILE_GC_MOVES);
2221 /* FIXME: handle this for parallel collector */
2222 g_assert (!mono_sgen_collection_is_parallel ());
2224 if (moved_objects_idx == MOVED_OBJECTS_NUM) {
2225 mono_profiler_gc_moves (moved_objects, moved_objects_idx);
2226 moved_objects_idx = 0;
2228 moved_objects [moved_objects_idx++] = obj;
2229 moved_objects [moved_objects_idx++] = destination;
2235 static gboolean inited = FALSE;
2240 mono_counters_register ("Minor fragment clear", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_minor_pre_collection_fragment_clear);
2241 mono_counters_register ("Minor pinning", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_minor_pinning);
2242 mono_counters_register ("Minor scan remembered set", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_minor_scan_remsets);
2243 mono_counters_register ("Minor scan pinned", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_minor_scan_pinned);
2244 mono_counters_register ("Minor scan registered roots", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_minor_scan_registered_roots);
2245 mono_counters_register ("Minor scan thread data", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_minor_scan_thread_data);
2246 mono_counters_register ("Minor finish gray stack", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_minor_finish_gray_stack);
2247 mono_counters_register ("Minor fragment creation", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_minor_fragment_creation);
2249 mono_counters_register ("Major fragment clear", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_major_pre_collection_fragment_clear);
2250 mono_counters_register ("Major pinning", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_major_pinning);
2251 mono_counters_register ("Major scan pinned", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_major_scan_pinned);
2252 mono_counters_register ("Major scan registered roots", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_major_scan_registered_roots);
2253 mono_counters_register ("Major scan thread data", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_major_scan_thread_data);
2254 mono_counters_register ("Major scan alloc_pinned", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_major_scan_alloc_pinned);
2255 mono_counters_register ("Major scan finalized", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_major_scan_finalized);
2256 mono_counters_register ("Major scan big objects", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_major_scan_big_objects);
2257 mono_counters_register ("Major finish gray stack", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_major_finish_gray_stack);
2258 mono_counters_register ("Major free big objects", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_major_free_bigobjs);
2259 mono_counters_register ("Major LOS sweep", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_major_los_sweep);
2260 mono_counters_register ("Major sweep", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_major_sweep);
2261 mono_counters_register ("Major fragment creation", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_major_fragment_creation);
2263 mono_counters_register ("Number of pinned objects", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_pinned_objects);
2265 #ifdef HEAVY_STATISTICS
2266 mono_counters_register ("WBarrier set field", MONO_COUNTER_GC | MONO_COUNTER_INT, &stat_wbarrier_set_field);
2267 mono_counters_register ("WBarrier set arrayref", MONO_COUNTER_GC | MONO_COUNTER_INT, &stat_wbarrier_set_arrayref);
2268 mono_counters_register ("WBarrier arrayref copy", MONO_COUNTER_GC | MONO_COUNTER_INT, &stat_wbarrier_arrayref_copy);
2269 mono_counters_register ("WBarrier generic store called", MONO_COUNTER_GC | MONO_COUNTER_INT, &stat_wbarrier_generic_store);
2270 mono_counters_register ("WBarrier set root", MONO_COUNTER_GC | MONO_COUNTER_INT, &stat_wbarrier_set_root);
2271 mono_counters_register ("WBarrier value copy", MONO_COUNTER_GC | MONO_COUNTER_INT, &stat_wbarrier_value_copy);
2272 mono_counters_register ("WBarrier object copy", MONO_COUNTER_GC | MONO_COUNTER_INT, &stat_wbarrier_object_copy);
2274 mono_counters_register ("# objects allocated degraded", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_objects_alloced_degraded);
2275 mono_counters_register ("bytes allocated degraded", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_bytes_alloced_degraded);
2277 mono_counters_register ("# copy_object() called (nursery)", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_copy_object_called_nursery);
2278 mono_counters_register ("# objects copied (nursery)", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_objects_copied_nursery);
2279 mono_counters_register ("# copy_object() called (major)", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_copy_object_called_major);
2280 mono_counters_register ("# objects copied (major)", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_objects_copied_major);
2282 mono_counters_register ("# scan_object() called (nursery)", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_scan_object_called_nursery);
2283 mono_counters_register ("# scan_object() called (major)", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_scan_object_called_major);
2285 mono_counters_register ("# nursery copy_object() failed from space", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_nursery_copy_object_failed_from_space);
2286 mono_counters_register ("# nursery copy_object() failed forwarded", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_nursery_copy_object_failed_forwarded);
2287 mono_counters_register ("# nursery copy_object() failed pinned", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_nursery_copy_object_failed_pinned);
2289 mono_sgen_nursery_allocator_init_heavy_stats ();
2290 mono_sgen_alloc_init_heavy_stats ();
2296 static gboolean need_calculate_minor_collection_allowance;
2298 static int last_collection_old_num_major_sections;
2299 static mword last_collection_los_memory_usage = 0;
2300 static mword last_collection_old_los_memory_usage;
2301 static mword last_collection_los_memory_alloced;
2304 reset_minor_collection_allowance (void)
2306 need_calculate_minor_collection_allowance = TRUE;
2310 try_calculate_minor_collection_allowance (gboolean overwrite)
2312 int num_major_sections, num_major_sections_saved, save_target, allowance_target;
2313 mword los_memory_saved, new_major, new_heap_size;
2316 g_assert (need_calculate_minor_collection_allowance);
2318 if (!need_calculate_minor_collection_allowance)
2321 if (!*major_collector.have_swept) {
2323 minor_collection_allowance = MIN_MINOR_COLLECTION_ALLOWANCE;
2327 num_major_sections = major_collector.get_num_major_sections ();
2329 num_major_sections_saved = MAX (last_collection_old_num_major_sections - num_major_sections, 0);
2330 los_memory_saved = MAX (last_collection_old_los_memory_usage - last_collection_los_memory_usage, 1);
2332 new_major = num_major_sections * major_collector.section_size;
2333 new_heap_size = new_major + last_collection_los_memory_usage;
2336 * FIXME: Why is save_target half the major memory plus half the
2337 * LOS memory saved? Shouldn't it be half the major memory
2338 * saved plus half the LOS memory saved? Or half the whole heap
2341 save_target = (new_major + los_memory_saved) / 2;
2344 * We aim to allow the allocation of as many sections as is
2345 * necessary to reclaim save_target sections in the next
2346 * collection. We assume the collection pattern won't change.
2347 * In the last cycle, we had num_major_sections_saved for
2348 * minor_collection_sections_alloced. Assuming things won't
2349 * change, this must be the same ratio as save_target for
2350 * allowance_target, i.e.
2352 * num_major_sections_saved save_target
2353 * --------------------------------- == ----------------
2354 * minor_collection_sections_alloced allowance_target
2358 allowance_target = (mword)((double)save_target * (double)(minor_collection_sections_alloced * major_collector.section_size + last_collection_los_memory_alloced) / (double)(num_major_sections_saved * major_collector.section_size + los_memory_saved));
2360 minor_collection_allowance = MAX (MIN (allowance_target, num_major_sections * major_collector.section_size + los_memory_usage), MIN_MINOR_COLLECTION_ALLOWANCE);
2362 if (new_heap_size + minor_collection_allowance > soft_heap_limit) {
2363 if (new_heap_size > soft_heap_limit)
2364 minor_collection_allowance = MIN_MINOR_COLLECTION_ALLOWANCE;
2366 minor_collection_allowance = MAX (soft_heap_limit - new_heap_size, MIN_MINOR_COLLECTION_ALLOWANCE);
2369 if (debug_print_allowance) {
2370 mword old_major = last_collection_old_num_major_sections * major_collector.section_size;
2372 fprintf (gc_debug_file, "Before collection: %ld bytes (%ld major, %ld LOS)\n",
2373 old_major + last_collection_old_los_memory_usage, old_major, last_collection_old_los_memory_usage);
2374 fprintf (gc_debug_file, "After collection: %ld bytes (%ld major, %ld LOS)\n",
2375 new_heap_size, new_major, last_collection_los_memory_usage);
2376 fprintf (gc_debug_file, "Allowance: %ld bytes\n", minor_collection_allowance);
2379 if (major_collector.have_computed_minor_collection_allowance)
2380 major_collector.have_computed_minor_collection_allowance ();
2382 need_calculate_minor_collection_allowance = FALSE;
2386 need_major_collection (mword space_needed)
2388 mword los_alloced = los_memory_usage - MIN (last_collection_los_memory_usage, los_memory_usage);
2389 return (space_needed > available_free_space ()) ||
2390 minor_collection_sections_alloced * major_collector.section_size + los_alloced > minor_collection_allowance;
2394 mono_sgen_need_major_collection (mword space_needed)
2396 return need_major_collection (space_needed);
2400 reset_pinned_from_failed_allocation (void)
2402 bytes_pinned_from_failed_allocation = 0;
2406 mono_sgen_set_pinned_from_failed_allocation (mword objsize)
2408 bytes_pinned_from_failed_allocation += objsize;
2412 mono_sgen_collection_is_parallel (void)
2414 switch (current_collection_generation) {
2415 case GENERATION_NURSERY:
2416 return nursery_collection_is_parallel;
2417 case GENERATION_OLD:
2418 return major_collector.is_parallel;
2420 g_assert_not_reached ();
2425 mono_sgen_nursery_collection_is_parallel (void)
2427 return nursery_collection_is_parallel;
2434 } FinishRememberedSetScanJobData;
2437 job_finish_remembered_set_scan (WorkerData *worker_data, void *job_data_untyped)
2439 FinishRememberedSetScanJobData *job_data = job_data_untyped;
2441 remset.finish_scan_remsets (job_data->heap_start, job_data->heap_end, mono_sgen_workers_get_job_gray_queue (worker_data));
2446 CopyOrMarkObjectFunc func;
2450 } ScanFromRegisteredRootsJobData;
2453 job_scan_from_registered_roots (WorkerData *worker_data, void *job_data_untyped)
2455 ScanFromRegisteredRootsJobData *job_data = job_data_untyped;
2457 scan_from_registered_roots (job_data->func,
2458 job_data->heap_start, job_data->heap_end,
2459 job_data->root_type,
2460 mono_sgen_workers_get_job_gray_queue (worker_data));
2467 } ScanThreadDataJobData;
2470 job_scan_thread_data (WorkerData *worker_data, void *job_data_untyped)
2472 ScanThreadDataJobData *job_data = job_data_untyped;
2474 scan_thread_data (job_data->heap_start, job_data->heap_end, TRUE,
2475 mono_sgen_workers_get_job_gray_queue (worker_data));
2479 verify_scan_starts (char *start, char *end)
2483 for (i = 0; i < nursery_section->num_scan_start; ++i) {
2484 char *addr = nursery_section->scan_starts [i];
2485 if (addr > start && addr < end)
2486 fprintf (gc_debug_file, "NFC-BAD SCAN START [%d] %p for obj [%p %p]\n", i, addr, start, end);
2491 verify_nursery (void)
2493 char *start, *end, *cur, *hole_start;
2495 if (!do_verify_nursery)
2498 /*This cleans up unused fragments */
2499 mono_sgen_nursery_allocator_prepare_for_pinning ();
2501 hole_start = start = cur = mono_sgen_get_nursery_start ();
2502 end = mono_sgen_get_nursery_end ();
2507 if (!*(void**)cur) {
2508 cur += sizeof (void*);
2512 if (object_is_forwarded (cur))
2513 fprintf (gc_debug_file, "FORWARDED OBJ %p\n", cur);
2514 else if (object_is_pinned (cur))
2515 fprintf (gc_debug_file, "PINNED OBJ %p\n", cur);
2517 ss = safe_object_get_size ((MonoObject*)cur);
2518 size = ALIGN_UP (safe_object_get_size ((MonoObject*)cur));
2519 verify_scan_starts (cur, cur + size);
2520 if (do_dump_nursery_content) {
2521 if (cur > hole_start)
2522 fprintf (gc_debug_file, "HOLE [%p %p %d]\n", hole_start, cur, (int)(cur - hole_start));
2523 fprintf (gc_debug_file, "OBJ [%p %p %d %d %s %d]\n", cur, cur + size, (int)size, (int)ss, mono_sgen_safe_name ((MonoObject*)cur), (gpointer)LOAD_VTABLE (cur) == mono_sgen_get_array_fill_vtable ());
2528 fflush (gc_debug_file);
2532 * Collect objects in the nursery. Returns whether to trigger a major
2536 collect_nursery (size_t requested_size)
2538 gboolean needs_major;
2539 size_t max_garbage_amount;
2541 FinishRememberedSetScanJobData frssjd;
2542 ScanFromRegisteredRootsJobData scrrjd_normal, scrrjd_wbarrier;
2543 ScanThreadDataJobData stdjd;
2544 mword fragment_total;
2545 TV_DECLARE (all_atv);
2546 TV_DECLARE (all_btv);
2550 if (disable_minor_collections)
2555 mono_perfcounters->gc_collections0++;
2557 current_collection_generation = GENERATION_NURSERY;
2559 reset_pinned_from_failed_allocation ();
2561 binary_protocol_collection (GENERATION_NURSERY);
2562 check_scan_starts ();
2566 nursery_next = mono_sgen_nursery_alloc_get_upper_alloc_bound ();
2567 /* FIXME: optimize later to use the higher address where an object can be present */
2568 nursery_next = MAX (nursery_next, mono_sgen_get_nursery_end ());
2570 DEBUG (1, fprintf (gc_debug_file, "Start nursery collection %d %p-%p, size: %d\n", stat_minor_gcs, mono_sgen_get_nursery_start (), nursery_next, (int)(nursery_next - mono_sgen_get_nursery_start ())));
2571 max_garbage_amount = nursery_next - mono_sgen_get_nursery_start ();
2572 g_assert (nursery_section->size >= max_garbage_amount);
2574 /* world must be stopped already */
2575 TV_GETTIME (all_atv);
2578 /* Pinning no longer depends on clearing all nursery fragments */
2579 mono_sgen_clear_current_nursery_fragment ();
2582 time_minor_pre_collection_fragment_clear += TV_ELAPSED (atv, btv);
2585 check_for_xdomain_refs ();
2587 nursery_section->next_data = nursery_next;
2589 major_collector.start_nursery_collection ();
2591 try_calculate_minor_collection_allowance (FALSE);
2593 mono_sgen_gray_object_queue_init (&gray_queue);
2594 mono_sgen_workers_init_distribute_gray_queue ();
2597 mono_stats.minor_gc_count ++;
2599 if (remset.prepare_for_minor_collection)
2600 remset.prepare_for_minor_collection ();
2602 process_fin_stage_entries ();
2603 process_dislink_stage_entries ();
2605 /* pin from pinned handles */
2606 mono_sgen_init_pinning ();
2607 mono_profiler_gc_event (MONO_GC_EVENT_MARK_START, 0);
2608 pin_from_roots (mono_sgen_get_nursery_start (), nursery_next, WORKERS_DISTRIBUTE_GRAY_QUEUE);
2609 /* identify pinned objects */
2610 mono_sgen_optimize_pin_queue (0);
2611 mono_sgen_pinning_setup_section (nursery_section);
2612 mono_sgen_pin_objects_in_section (nursery_section, WORKERS_DISTRIBUTE_GRAY_QUEUE);
2613 mono_sgen_pinning_trim_queue_to_section (nursery_section);
2616 time_minor_pinning += TV_ELAPSED (btv, atv);
2617 DEBUG (2, fprintf (gc_debug_file, "Finding pinned pointers: %d in %d usecs\n", mono_sgen_get_pinned_count (), TV_ELAPSED (btv, atv)));
2618 DEBUG (4, fprintf (gc_debug_file, "Start scan with %d pinned objects\n", mono_sgen_get_pinned_count ()));
2620 if (consistency_check_at_minor_collection)
2621 mono_sgen_check_consistency ();
2623 mono_sgen_workers_start_all_workers ();
2626 * Perform the sequential part of remembered set scanning.
2627 * This usually involves scanning global information that might later be produced by evacuation.
2629 if (remset.begin_scan_remsets)
2630 remset.begin_scan_remsets (mono_sgen_get_nursery_start (), nursery_next, WORKERS_DISTRIBUTE_GRAY_QUEUE);
2632 mono_sgen_workers_start_marking ();
2634 frssjd.heap_start = mono_sgen_get_nursery_start ();
2635 frssjd.heap_end = nursery_next;
2636 mono_sgen_workers_enqueue_job (job_finish_remembered_set_scan, &frssjd);
2638 /* we don't have complete write barrier yet, so we scan all the old generation sections */
2640 time_minor_scan_remsets += TV_ELAPSED (atv, btv);
2641 DEBUG (2, fprintf (gc_debug_file, "Old generation scan: %d usecs\n", TV_ELAPSED (atv, btv)));
2643 if (!mono_sgen_collection_is_parallel ())
2644 mono_sgen_drain_gray_stack (&gray_queue, -1);
2646 if (mono_profiler_get_events () & MONO_PROFILE_GC_ROOTS)
2647 report_registered_roots ();
2648 if (mono_profiler_get_events () & MONO_PROFILE_GC_ROOTS)
2649 report_finalizer_roots ();
2651 time_minor_scan_pinned += TV_ELAPSED (btv, atv);
2653 /* registered roots, this includes static fields */
2654 scrrjd_normal.func = mono_sgen_collection_is_parallel () ? major_collector.copy_object : major_collector.nopar_copy_object;
2655 scrrjd_normal.heap_start = mono_sgen_get_nursery_start ();
2656 scrrjd_normal.heap_end = nursery_next;
2657 scrrjd_normal.root_type = ROOT_TYPE_NORMAL;
2658 mono_sgen_workers_enqueue_job (job_scan_from_registered_roots, &scrrjd_normal);
2660 scrrjd_wbarrier.func = mono_sgen_collection_is_parallel () ? major_collector.copy_object : major_collector.nopar_copy_object;
2661 scrrjd_wbarrier.heap_start = mono_sgen_get_nursery_start ();
2662 scrrjd_wbarrier.heap_end = nursery_next;
2663 scrrjd_wbarrier.root_type = ROOT_TYPE_WBARRIER;
2664 mono_sgen_workers_enqueue_job (job_scan_from_registered_roots, &scrrjd_wbarrier);
2667 time_minor_scan_registered_roots += TV_ELAPSED (atv, btv);
2670 stdjd.heap_start = mono_sgen_get_nursery_start ();
2671 stdjd.heap_end = nursery_next;
2672 mono_sgen_workers_enqueue_job (job_scan_thread_data, &stdjd);
2675 time_minor_scan_thread_data += TV_ELAPSED (btv, atv);
2678 if (mono_sgen_collection_is_parallel ()) {
2679 while (!mono_sgen_gray_object_queue_is_empty (WORKERS_DISTRIBUTE_GRAY_QUEUE)) {
2680 mono_sgen_workers_distribute_gray_queue_sections ();
2684 mono_sgen_workers_join ();
2686 if (mono_sgen_collection_is_parallel ())
2687 g_assert (mono_sgen_gray_object_queue_is_empty (&gray_queue));
2689 finish_gray_stack (mono_sgen_get_nursery_start (), nursery_next, GENERATION_NURSERY, &gray_queue);
2691 time_minor_finish_gray_stack += TV_ELAPSED (btv, atv);
2692 mono_profiler_gc_event (MONO_GC_EVENT_MARK_END, 0);
2695 * The (single-threaded) finalization code might have done
2696 * some copying/marking so we can only reset the GC thread's
2697 * worker data here instead of earlier when we joined the
2700 mono_sgen_workers_reset_data ();
2702 if (objects_pinned) {
2703 mono_sgen_optimize_pin_queue (0);
2704 mono_sgen_pinning_setup_section (nursery_section);
2707 /* walk the pin_queue, build up the fragment list of free memory, unmark
2708 * pinned objects as we go, memzero() the empty fragments so they are ready for the
2711 mono_profiler_gc_event (MONO_GC_EVENT_RECLAIM_START, 0);
2712 fragment_total = mono_sgen_build_nursery_fragments (nursery_section, nursery_section->pin_queue_start, nursery_section->pin_queue_num_entries);
2713 if (!fragment_total)
2716 /* Clear TLABs for all threads */
2717 mono_sgen_clear_tlabs ();
2719 mono_profiler_gc_event (MONO_GC_EVENT_RECLAIM_END, 0);
2721 time_minor_fragment_creation += TV_ELAPSED (atv, btv);
2722 DEBUG (2, fprintf (gc_debug_file, "Fragment creation: %d usecs, %lu bytes available\n", TV_ELAPSED (atv, btv), (unsigned long)fragment_total));
2724 if (consistency_check_at_minor_collection)
2725 mono_sgen_check_major_refs ();
2727 major_collector.finish_nursery_collection ();
2729 TV_GETTIME (all_btv);
2730 mono_stats.minor_gc_time_usecs += TV_ELAPSED (all_atv, all_btv);
2733 dump_heap ("minor", stat_minor_gcs - 1, NULL);
2735 /* prepare the pin queue for the next collection */
2736 mono_sgen_finish_pinning ();
2737 if (fin_ready_list || critical_fin_list) {
2738 DEBUG (4, fprintf (gc_debug_file, "Finalizer-thread wakeup: ready %d\n", num_ready_finalizers));
2739 mono_gc_finalize_notify ();
2741 mono_sgen_pin_stats_reset ();
2743 g_assert (mono_sgen_gray_object_queue_is_empty (&gray_queue));
2745 if (remset.finish_minor_collection)
2746 remset.finish_minor_collection ();
2748 check_scan_starts ();
2750 binary_protocol_flush_buffers (FALSE);
2752 /*objects are late pinned because of lack of memory, so a major is a good call*/
2753 needs_major = need_major_collection (0) || objects_pinned;
2754 current_collection_generation = -1;
2761 mono_sgen_collect_nursery_no_lock (size_t requested_size)
2763 gint64 gc_start_time;
2765 mono_profiler_gc_event (MONO_GC_EVENT_START, 0);
2766 gc_start_time = mono_100ns_ticks ();
2769 collect_nursery (requested_size);
2772 mono_trace_message (MONO_TRACE_GC, "minor gc took %d usecs", (mono_100ns_ticks () - gc_start_time) / 10);
2773 mono_profiler_gc_event (MONO_GC_EVENT_END, 0);
2778 FinalizeReadyEntry *list;
2779 } ScanFinalizerEntriesJobData;
2782 job_scan_finalizer_entries (WorkerData *worker_data, void *job_data_untyped)
2784 ScanFinalizerEntriesJobData *job_data = job_data_untyped;
2786 scan_finalizer_entries (major_collector.copy_or_mark_object,
2788 mono_sgen_workers_get_job_gray_queue (worker_data));
2792 major_do_collection (const char *reason)
2794 LOSObject *bigobj, *prevbo;
2795 TV_DECLARE (all_atv);
2796 TV_DECLARE (all_btv);
2799 /* FIXME: only use these values for the precise scan
2800 * note that to_space pointers should be excluded anyway...
2802 char *heap_start = NULL;
2803 char *heap_end = (char*)-1;
2804 int old_next_pin_slot;
2805 ScanFromRegisteredRootsJobData scrrjd_normal, scrrjd_wbarrier;
2806 ScanThreadDataJobData stdjd;
2807 ScanFinalizerEntriesJobData sfejd_fin_ready, sfejd_critical_fin;
2809 mono_perfcounters->gc_collections1++;
2811 reset_pinned_from_failed_allocation ();
2813 last_collection_old_num_major_sections = major_collector.get_num_major_sections ();
2816 * A domain could have been freed, resulting in
2817 * los_memory_usage being less than last_collection_los_memory_usage.
2819 last_collection_los_memory_alloced = los_memory_usage - MIN (last_collection_los_memory_usage, los_memory_usage);
2820 last_collection_old_los_memory_usage = los_memory_usage;
2823 //count_ref_nonref_objs ();
2824 //consistency_check ();
2826 binary_protocol_collection (GENERATION_OLD);
2827 check_scan_starts ();
2828 mono_sgen_gray_object_queue_init (&gray_queue);
2829 mono_sgen_workers_init_distribute_gray_queue ();
2832 DEBUG (1, fprintf (gc_debug_file, "Start major collection %d\n", stat_major_gcs));
2834 mono_stats.major_gc_count ++;
2836 /* world must be stopped already */
2837 TV_GETTIME (all_atv);
2840 /* Pinning depends on this */
2841 mono_sgen_clear_nursery_fragments ();
2844 time_major_pre_collection_fragment_clear += TV_ELAPSED (atv, btv);
2846 nursery_section->next_data = mono_sgen_get_nursery_end ();
2847 /* we should also coalesce scanning from sections close to each other
2848 * and deal with pointers outside of the sections later.
2851 if (major_collector.start_major_collection)
2852 major_collector.start_major_collection ();
2854 *major_collector.have_swept = FALSE;
2855 reset_minor_collection_allowance ();
2858 check_for_xdomain_refs ();
2860 /* Remsets are not useful for a major collection */
2861 remset.prepare_for_major_collection ();
2863 process_fin_stage_entries ();
2864 process_dislink_stage_entries ();
2867 mono_sgen_init_pinning ();
2868 DEBUG (6, fprintf (gc_debug_file, "Collecting pinned addresses\n"));
2869 pin_from_roots ((void*)lowest_heap_address, (void*)highest_heap_address, WORKERS_DISTRIBUTE_GRAY_QUEUE);
2870 mono_sgen_optimize_pin_queue (0);
2873 * pin_queue now contains all candidate pointers, sorted and
2874 * uniqued. We must do two passes now to figure out which
2875 * objects are pinned.
2877 * The first is to find within the pin_queue the area for each
2878 * section. This requires that the pin_queue be sorted. We
2879 * also process the LOS objects and pinned chunks here.
2881 * The second, destructive, pass is to reduce the section
2882 * areas to pointers to the actually pinned objects.
2884 DEBUG (6, fprintf (gc_debug_file, "Pinning from sections\n"));
2885 /* first pass for the sections */
2886 mono_sgen_find_section_pin_queue_start_end (nursery_section);
2887 major_collector.find_pin_queue_start_ends (WORKERS_DISTRIBUTE_GRAY_QUEUE);
2888 /* identify possible pointers to the insize of large objects */
2889 DEBUG (6, fprintf (gc_debug_file, "Pinning from large objects\n"));
2890 for (bigobj = los_object_list; bigobj; bigobj = bigobj->next) {
2892 gboolean profile_roots = mono_profiler_get_events () & MONO_PROFILE_GC_ROOTS;
2893 GCRootReport report;
2895 if (mono_sgen_find_optimized_pin_queue_area (bigobj->data, (char*)bigobj->data + bigobj->size, &dummy)) {
2896 binary_protocol_pin (bigobj->data, (gpointer)LOAD_VTABLE (bigobj->data), safe_object_get_size (bigobj->data));
2897 pin_object (bigobj->data);
2898 /* FIXME: only enqueue if object has references */
2899 GRAY_OBJECT_ENQUEUE (WORKERS_DISTRIBUTE_GRAY_QUEUE, bigobj->data);
2900 if (G_UNLIKELY (do_pin_stats))
2901 mono_sgen_pin_stats_register_object ((char*) bigobj->data, safe_object_get_size ((MonoObject*) bigobj->data));
2902 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));
2905 add_profile_gc_root (&report, bigobj->data, MONO_PROFILE_GC_ROOT_PINNING | MONO_PROFILE_GC_ROOT_MISC, 0);
2908 notify_gc_roots (&report);
2910 /* second pass for the sections */
2911 mono_sgen_pin_objects_in_section (nursery_section, WORKERS_DISTRIBUTE_GRAY_QUEUE);
2912 major_collector.pin_objects (WORKERS_DISTRIBUTE_GRAY_QUEUE);
2913 old_next_pin_slot = mono_sgen_get_pinned_count ();
2916 time_major_pinning += TV_ELAPSED (atv, btv);
2917 DEBUG (2, fprintf (gc_debug_file, "Finding pinned pointers: %d in %d usecs\n", mono_sgen_get_pinned_count (), TV_ELAPSED (atv, btv)));
2918 DEBUG (4, fprintf (gc_debug_file, "Start scan with %d pinned objects\n", mono_sgen_get_pinned_count ()));
2920 major_collector.init_to_space ();
2922 #ifdef SGEN_DEBUG_INTERNAL_ALLOC
2923 main_gc_thread = mono_native_thread_self ();
2926 mono_sgen_workers_start_all_workers ();
2927 mono_sgen_workers_start_marking ();
2929 if (mono_profiler_get_events () & MONO_PROFILE_GC_ROOTS)
2930 report_registered_roots ();
2932 time_major_scan_pinned += TV_ELAPSED (btv, atv);
2934 /* registered roots, this includes static fields */
2935 scrrjd_normal.func = major_collector.copy_or_mark_object;
2936 scrrjd_normal.heap_start = heap_start;
2937 scrrjd_normal.heap_end = heap_end;
2938 scrrjd_normal.root_type = ROOT_TYPE_NORMAL;
2939 mono_sgen_workers_enqueue_job (job_scan_from_registered_roots, &scrrjd_normal);
2941 scrrjd_wbarrier.func = major_collector.copy_or_mark_object;
2942 scrrjd_wbarrier.heap_start = heap_start;
2943 scrrjd_wbarrier.heap_end = heap_end;
2944 scrrjd_wbarrier.root_type = ROOT_TYPE_WBARRIER;
2945 mono_sgen_workers_enqueue_job (job_scan_from_registered_roots, &scrrjd_wbarrier);
2948 time_major_scan_registered_roots += TV_ELAPSED (atv, btv);
2951 stdjd.heap_start = heap_start;
2952 stdjd.heap_end = heap_end;
2953 mono_sgen_workers_enqueue_job (job_scan_thread_data, &stdjd);
2956 time_major_scan_thread_data += TV_ELAPSED (btv, atv);
2959 time_major_scan_alloc_pinned += TV_ELAPSED (atv, btv);
2961 if (mono_profiler_get_events () & MONO_PROFILE_GC_ROOTS)
2962 report_finalizer_roots ();
2964 /* scan the list of objects ready for finalization */
2965 sfejd_fin_ready.list = fin_ready_list;
2966 mono_sgen_workers_enqueue_job (job_scan_finalizer_entries, &sfejd_fin_ready);
2968 sfejd_critical_fin.list = critical_fin_list;
2969 mono_sgen_workers_enqueue_job (job_scan_finalizer_entries, &sfejd_critical_fin);
2972 time_major_scan_finalized += TV_ELAPSED (btv, atv);
2973 DEBUG (2, fprintf (gc_debug_file, "Root scan: %d usecs\n", TV_ELAPSED (btv, atv)));
2976 time_major_scan_big_objects += TV_ELAPSED (atv, btv);
2978 if (major_collector.is_parallel) {
2979 while (!mono_sgen_gray_object_queue_is_empty (WORKERS_DISTRIBUTE_GRAY_QUEUE)) {
2980 mono_sgen_workers_distribute_gray_queue_sections ();
2984 mono_sgen_workers_join ();
2986 #ifdef SGEN_DEBUG_INTERNAL_ALLOC
2987 main_gc_thread = NULL;
2990 if (major_collector.is_parallel)
2991 g_assert (mono_sgen_gray_object_queue_is_empty (&gray_queue));
2993 /* all the objects in the heap */
2994 finish_gray_stack (heap_start, heap_end, GENERATION_OLD, &gray_queue);
2996 time_major_finish_gray_stack += TV_ELAPSED (btv, atv);
2999 * The (single-threaded) finalization code might have done
3000 * some copying/marking so we can only reset the GC thread's
3001 * worker data here instead of earlier when we joined the
3004 mono_sgen_workers_reset_data ();
3006 if (objects_pinned) {
3007 /*This is slow, but we just OOM'd*/
3008 mono_sgen_pin_queue_clear_discarded_entries (nursery_section, old_next_pin_slot);
3009 mono_sgen_optimize_pin_queue (0);
3010 mono_sgen_find_section_pin_queue_start_end (nursery_section);
3014 reset_heap_boundaries ();
3015 mono_sgen_update_heap_boundaries ((mword)mono_sgen_get_nursery_start (), (mword)mono_sgen_get_nursery_end ());
3017 /* sweep the big objects list */
3019 for (bigobj = los_object_list; bigobj;) {
3020 if (object_is_pinned (bigobj->data)) {
3021 unpin_object (bigobj->data);
3022 mono_sgen_update_heap_boundaries ((mword)bigobj->data, (mword)bigobj->data + bigobj->size);
3025 /* not referenced anywhere, so we can free it */
3027 prevbo->next = bigobj->next;
3029 los_object_list = bigobj->next;
3031 bigobj = bigobj->next;
3032 mono_sgen_los_free_object (to_free);
3036 bigobj = bigobj->next;
3040 time_major_free_bigobjs += TV_ELAPSED (atv, btv);
3042 mono_sgen_los_sweep ();
3045 time_major_los_sweep += TV_ELAPSED (btv, atv);
3047 major_collector.sweep ();
3050 time_major_sweep += TV_ELAPSED (atv, btv);
3052 /* walk the pin_queue, build up the fragment list of free memory, unmark
3053 * pinned objects as we go, memzero() the empty fragments so they are ready for the
3056 if (!mono_sgen_build_nursery_fragments (nursery_section, nursery_section->pin_queue_start, nursery_section->pin_queue_num_entries))
3059 /* Clear TLABs for all threads */
3060 mono_sgen_clear_tlabs ();
3063 time_major_fragment_creation += TV_ELAPSED (btv, atv);
3065 TV_GETTIME (all_btv);
3066 mono_stats.major_gc_time_usecs += TV_ELAPSED (all_atv, all_btv);
3069 dump_heap ("major", stat_major_gcs - 1, reason);
3071 /* prepare the pin queue for the next collection */
3072 mono_sgen_finish_pinning ();
3074 if (fin_ready_list || critical_fin_list) {
3075 DEBUG (4, fprintf (gc_debug_file, "Finalizer-thread wakeup: ready %d\n", num_ready_finalizers));
3076 mono_gc_finalize_notify ();
3078 mono_sgen_pin_stats_reset ();
3080 g_assert (mono_sgen_gray_object_queue_is_empty (&gray_queue));
3082 try_calculate_minor_collection_allowance (TRUE);
3084 minor_collection_sections_alloced = 0;
3085 last_collection_los_memory_usage = los_memory_usage;
3087 major_collector.finish_major_collection ();
3089 check_scan_starts ();
3091 binary_protocol_flush_buffers (FALSE);
3093 //consistency_check ();
3095 return bytes_pinned_from_failed_allocation > 0;
3099 major_collection (const char *reason)
3101 gboolean need_minor_collection;
3103 if (disable_major_collections) {
3104 collect_nursery (0);
3108 major_collection_happened = TRUE;
3109 current_collection_generation = GENERATION_OLD;
3110 need_minor_collection = major_do_collection (reason);
3111 current_collection_generation = -1;
3113 if (need_minor_collection)
3114 collect_nursery (0);
3118 sgen_collect_major_no_lock (const char *reason)
3120 gint64 gc_start_time;
3122 mono_profiler_gc_event (MONO_GC_EVENT_START, 1);
3123 gc_start_time = mono_100ns_ticks ();
3125 major_collection (reason);
3127 mono_trace_message (MONO_TRACE_GC, "major gc took %d usecs", (mono_100ns_ticks () - gc_start_time) / 10);
3128 mono_profiler_gc_event (MONO_GC_EVENT_END, 1);
3132 * When deciding if it's better to collect or to expand, keep track
3133 * of how much garbage was reclaimed with the last collection: if it's too
3135 * This is called when we could not allocate a small object.
3137 static void __attribute__((noinline))
3138 minor_collect_or_expand_inner (size_t size)
3140 int do_minor_collection = 1;
3142 g_assert (nursery_section);
3143 if (do_minor_collection) {
3144 gint64 total_gc_time, major_gc_time = 0;
3146 mono_profiler_gc_event (MONO_GC_EVENT_START, 0);
3147 total_gc_time = mono_100ns_ticks ();
3150 if (collect_nursery (size)) {
3151 mono_profiler_gc_event (MONO_GC_EVENT_START, 1);
3152 major_gc_time = mono_100ns_ticks ();
3154 major_collection ("minor overflow");
3156 /* keep events symmetric */
3157 major_gc_time = mono_100ns_ticks () - major_gc_time;
3158 mono_profiler_gc_event (MONO_GC_EVENT_END, 1);
3160 DEBUG (2, fprintf (gc_debug_file, "Heap size: %lu, LOS size: %lu\n", (unsigned long)total_alloc, (unsigned long)los_memory_usage));
3163 total_gc_time = mono_100ns_ticks () - total_gc_time;
3165 mono_trace_message (MONO_TRACE_GC, "overflow major gc took %d usecs minor gc took %d usecs", total_gc_time / 10, (total_gc_time - major_gc_time) / 10);
3167 mono_trace_message (MONO_TRACE_GC, "minor gc took %d usecs", total_gc_time / 10);
3169 /* this also sets the proper pointers for the next allocation */
3170 if (!mono_sgen_can_alloc_size (size)) {
3171 /* TypeBuilder and MonoMethod are killing mcs with fragmentation */
3172 DEBUG (1, fprintf (gc_debug_file, "nursery collection didn't find enough room for %zd alloc (%d pinned)\n", size, mono_sgen_get_pinned_count ()));
3173 mono_sgen_dump_pin_queue ();
3176 mono_profiler_gc_event (MONO_GC_EVENT_END, 0);
3178 //report_internal_mem_usage ();
3182 mono_sgen_minor_collect_or_expand_inner (size_t size)
3184 minor_collect_or_expand_inner (size);
3188 * ######################################################################
3189 * ######## Memory allocation from the OS
3190 * ######################################################################
3191 * This section of code deals with getting memory from the OS and
3192 * allocating memory for GC-internal data structures.
3193 * Internal memory can be handled with a freelist for small objects.
3199 G_GNUC_UNUSED static void
3200 report_internal_mem_usage (void)
3202 printf ("Internal memory usage:\n");
3203 mono_sgen_report_internal_mem_usage ();
3204 printf ("Pinned memory usage:\n");
3205 major_collector.report_pinned_memory_usage ();
3209 * ######################################################################
3210 * ######## Finalization support
3211 * ######################################################################
3215 * this is valid for the nursery: if the object has been forwarded it means it's
3216 * still refrenced from a root. If it is pinned it's still alive as well.
3217 * Return TRUE if @obj is ready to be finalized.
3219 #define object_is_fin_ready(obj) (!object_is_pinned (obj) && !object_is_forwarded (obj))
3223 mono_sgen_gc_is_object_ready_for_finalization (void *object)
3225 return !major_collector.is_object_live (object) && object_is_fin_ready (object);
3229 has_critical_finalizer (MonoObject *obj)
3233 if (!mono_defaults.critical_finalizer_object)
3236 class = ((MonoVTable*)LOAD_VTABLE (obj))->klass;
3238 return mono_class_has_parent_fast (class, mono_defaults.critical_finalizer_object);
3242 queue_finalization_entry (MonoObject *obj) {
3243 FinalizeReadyEntry *entry = mono_sgen_alloc_internal (INTERNAL_MEM_FINALIZE_READY_ENTRY);
3244 entry->object = obj;
3245 if (has_critical_finalizer (obj)) {
3246 entry->next = critical_fin_list;
3247 critical_fin_list = entry;
3249 entry->next = fin_ready_list;
3250 fin_ready_list = entry;
3255 object_is_reachable (char *object, char *start, char *end)
3257 /*This happens for non nursery objects during minor collections. We just treat all objects as alive.*/
3258 if (object < start || object >= end)
3260 return !object_is_fin_ready (object) || major_collector.is_object_live (object);
3263 #include "sgen-fin-weak-hash.c"
3266 mono_sgen_object_is_live (void *obj)
3268 if (ptr_in_nursery (obj))
3269 return object_is_pinned (obj);
3270 if (current_collection_generation == GENERATION_NURSERY)
3272 return major_collector.is_object_live (obj);
3275 /* LOCKING: requires that the GC lock is held */
3277 null_ephemerons_for_domain (MonoDomain *domain)
3279 EphemeronLinkNode *current = ephemeron_list, *prev = NULL;
3282 MonoObject *object = (MonoObject*)current->array;
3284 if (object && !object->vtable) {
3285 EphemeronLinkNode *tmp = current;
3288 prev->next = current->next;
3290 ephemeron_list = current->next;
3292 current = current->next;
3293 mono_sgen_free_internal (tmp, INTERNAL_MEM_EPHEMERON_LINK);
3296 current = current->next;
3301 /* LOCKING: requires that the GC lock is held */
3303 clear_unreachable_ephemerons (CopyOrMarkObjectFunc copy_func, char *start, char *end, GrayQueue *queue)
3305 int was_in_nursery, was_promoted;
3306 EphemeronLinkNode *current = ephemeron_list, *prev = NULL;
3308 Ephemeron *cur, *array_end;
3312 char *object = current->array;
3314 if (!object_is_reachable (object, start, end)) {
3315 EphemeronLinkNode *tmp = current;
3317 DEBUG (5, fprintf (gc_debug_file, "Dead Ephemeron array at %p\n", object));
3320 prev->next = current->next;
3322 ephemeron_list = current->next;
3324 current = current->next;
3325 mono_sgen_free_internal (tmp, INTERNAL_MEM_EPHEMERON_LINK);
3330 was_in_nursery = ptr_in_nursery (object);
3331 copy_func ((void**)&object, queue);
3332 current->array = object;
3334 /*The array was promoted, add global remsets for key/values left behind in nursery.*/
3335 was_promoted = was_in_nursery && !ptr_in_nursery (object);
3337 DEBUG (5, fprintf (gc_debug_file, "Clearing unreachable entries for ephemeron array at %p\n", object));
3339 array = (MonoArray*)object;
3340 cur = mono_array_addr (array, Ephemeron, 0);
3341 array_end = cur + mono_array_length_fast (array);
3342 tombstone = (char*)((MonoVTable*)LOAD_VTABLE (object))->domain->ephemeron_tombstone;
3344 for (; cur < array_end; ++cur) {
3345 char *key = (char*)cur->key;
3347 if (!key || key == tombstone)
3350 DEBUG (5, fprintf (gc_debug_file, "[%td] key %p (%s) value %p (%s)\n", cur - mono_array_addr (array, Ephemeron, 0),
3351 key, object_is_reachable (key, start, end) ? "reachable" : "unreachable",
3352 cur->value, cur->value && object_is_reachable (cur->value, start, end) ? "reachable" : "unreachable"));
3354 if (!object_is_reachable (key, start, end)) {
3355 cur->key = tombstone;
3361 if (ptr_in_nursery (key)) {/*key was not promoted*/
3362 DEBUG (5, fprintf (gc_debug_file, "\tAdded remset to key %p\n", key));
3363 mono_sgen_add_to_global_remset (&cur->key);
3365 if (ptr_in_nursery (cur->value)) {/*value was not promoted*/
3366 DEBUG (5, fprintf (gc_debug_file, "\tAdded remset to value %p\n", cur->value));
3367 mono_sgen_add_to_global_remset (&cur->value);
3372 current = current->next;
3376 /* LOCKING: requires that the GC lock is held */
3378 mark_ephemerons_in_range (CopyOrMarkObjectFunc copy_func, char *start, char *end, GrayQueue *queue)
3380 int nothing_marked = 1;
3381 EphemeronLinkNode *current = ephemeron_list;
3383 Ephemeron *cur, *array_end;
3386 for (current = ephemeron_list; current; current = current->next) {
3387 char *object = current->array;
3388 DEBUG (5, fprintf (gc_debug_file, "Ephemeron array at %p\n", object));
3391 For now we process all ephemerons during all collections.
3392 Ideally we should use remset information to partially scan those
3394 We already emit write barriers for Ephemeron fields, it's
3395 just that we don't process them.
3397 /*if (object < start || object >= end)
3400 /*It has to be alive*/
3401 if (!object_is_reachable (object, start, end)) {
3402 DEBUG (5, fprintf (gc_debug_file, "\tnot reachable\n"));
3406 copy_func ((void**)&object, queue);
3408 array = (MonoArray*)object;
3409 cur = mono_array_addr (array, Ephemeron, 0);
3410 array_end = cur + mono_array_length_fast (array);
3411 tombstone = (char*)((MonoVTable*)LOAD_VTABLE (object))->domain->ephemeron_tombstone;
3413 for (; cur < array_end; ++cur) {
3414 char *key = cur->key;
3416 if (!key || key == tombstone)
3419 DEBUG (5, fprintf (gc_debug_file, "[%td] key %p (%s) value %p (%s)\n", cur - mono_array_addr (array, Ephemeron, 0),
3420 key, object_is_reachable (key, start, end) ? "reachable" : "unreachable",
3421 cur->value, cur->value && object_is_reachable (cur->value, start, end) ? "reachable" : "unreachable"));
3423 if (object_is_reachable (key, start, end)) {
3424 char *value = cur->value;
3426 copy_func ((void**)&cur->key, queue);
3428 if (!object_is_reachable (value, start, end))
3430 copy_func ((void**)&cur->value, queue);
3436 DEBUG (5, fprintf (gc_debug_file, "Ephemeron run finished. Is it done %d\n", nothing_marked));
3437 return nothing_marked;
3441 mono_gc_invoke_finalizers (void)
3443 FinalizeReadyEntry *entry = NULL;
3444 gboolean entry_is_critical = FALSE;
3447 /* FIXME: batch to reduce lock contention */
3448 while (fin_ready_list || critical_fin_list) {
3452 FinalizeReadyEntry **list = entry_is_critical ? &critical_fin_list : &fin_ready_list;
3454 /* We have finalized entry in the last
3455 interation, now we need to remove it from
3458 *list = entry->next;
3460 FinalizeReadyEntry *e = *list;
3461 while (e->next != entry)
3463 e->next = entry->next;
3465 mono_sgen_free_internal (entry, INTERNAL_MEM_FINALIZE_READY_ENTRY);
3469 /* Now look for the first non-null entry. */
3470 for (entry = fin_ready_list; entry && !entry->object; entry = entry->next)
3473 entry_is_critical = FALSE;
3475 entry_is_critical = TRUE;
3476 for (entry = critical_fin_list; entry && !entry->object; entry = entry->next)
3481 g_assert (entry->object);
3482 num_ready_finalizers--;
3483 obj = entry->object;
3484 entry->object = NULL;
3485 DEBUG (7, fprintf (gc_debug_file, "Finalizing object %p (%s)\n", obj, safe_name (obj)));
3493 g_assert (entry->object == NULL);
3495 /* the object is on the stack so it is pinned */
3496 /*g_print ("Calling finalizer for object: %p (%s)\n", entry->object, safe_name (entry->object));*/
3497 mono_gc_run_finalize (obj, NULL);
3504 mono_gc_pending_finalizers (void)
3506 return fin_ready_list || critical_fin_list;
3509 /* Negative value to remove */
3511 mono_gc_add_memory_pressure (gint64 value)
3513 /* FIXME: Use interlocked functions */
3515 memory_pressure += value;
3520 mono_sgen_register_major_sections_alloced (int num_sections)
3522 minor_collection_sections_alloced += num_sections;
3526 mono_sgen_get_minor_collection_allowance (void)
3528 return minor_collection_allowance;
3532 * ######################################################################
3533 * ######## registered roots support
3534 * ######################################################################
3538 * We do not coalesce roots.
3541 mono_gc_register_root_inner (char *start, size_t size, void *descr, int root_type)
3543 RootRecord new_root;
3546 for (i = 0; i < ROOT_TYPE_NUM; ++i) {
3547 RootRecord *root = mono_sgen_hash_table_lookup (&roots_hash [i], start);
3548 /* we allow changing the size and the descriptor (for thread statics etc) */
3550 size_t old_size = root->end_root - start;
3551 root->end_root = start + size;
3552 g_assert (((root->root_desc != 0) && (descr != NULL)) ||
3553 ((root->root_desc == 0) && (descr == NULL)));
3554 root->root_desc = (mword)descr;
3556 roots_size -= old_size;
3562 new_root.end_root = start + size;
3563 new_root.root_desc = (mword)descr;
3565 mono_sgen_hash_table_replace (&roots_hash [root_type], start, &new_root);
3568 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));
3575 mono_gc_register_root (char *start, size_t size, void *descr)
3577 return mono_gc_register_root_inner (start, size, descr, descr ? ROOT_TYPE_NORMAL : ROOT_TYPE_PINNED);
3581 mono_gc_register_root_wbarrier (char *start, size_t size, void *descr)
3583 return mono_gc_register_root_inner (start, size, descr, ROOT_TYPE_WBARRIER);
3587 mono_gc_deregister_root (char* addr)
3593 for (root_type = 0; root_type < ROOT_TYPE_NUM; ++root_type) {
3594 if (mono_sgen_hash_table_remove (&roots_hash [root_type], addr, &root))
3595 roots_size -= (root.end_root - addr);
3601 * ######################################################################
3602 * ######## Thread handling (stop/start code)
3603 * ######################################################################
3606 unsigned int mono_sgen_global_stop_count = 0;
3609 static MonoContext cur_thread_ctx = {0};
3611 static mword cur_thread_regs [ARCH_NUM_REGS] = {0};
3615 update_current_thread_stack (void *start)
3617 int stack_guard = 0;
3618 #ifndef USE_MONO_CTX
3619 void *ptr = cur_thread_regs;
3621 SgenThreadInfo *info = mono_thread_info_current ();
3623 info->stack_start = align_pointer (&stack_guard);
3624 g_assert (info->stack_start >= info->stack_start_limit && info->stack_start < info->stack_end);
3626 MONO_CONTEXT_GET_CURRENT (cur_thread_ctx);
3627 info->monoctx = &cur_thread_ctx;
3629 ARCH_STORE_REGS (ptr);
3630 info->stopped_regs = ptr;
3632 if (gc_callbacks.thread_suspend_func)
3633 gc_callbacks.thread_suspend_func (info->runtime_data, NULL);
3637 mono_sgen_fill_thread_info_for_suspend (SgenThreadInfo *info)
3639 if (remset.fill_thread_info_for_suspend)
3640 remset.fill_thread_info_for_suspend (info);
3644 is_ip_in_managed_allocator (MonoDomain *domain, gpointer ip);
3647 restart_threads_until_none_in_managed_allocator (void)
3649 SgenThreadInfo *info;
3650 int num_threads_died = 0;
3651 int sleep_duration = -1;
3654 int restart_count = 0, restarted_count = 0;
3655 /* restart all threads that stopped in the
3657 FOREACH_THREAD_SAFE (info) {
3659 if (info->skip || info->gc_disabled)
3661 if (!info->thread_is_dying && (!info->stack_start || info->in_critical_region ||
3662 is_ip_in_managed_allocator (info->stopped_domain, info->stopped_ip))) {
3663 binary_protocol_thread_restart ((gpointer)mono_thread_info_get_tid (info));
3664 result = mono_sgen_resume_thread (info);
3671 /* we set the stopped_ip to
3672 NULL for threads which
3673 we're not restarting so
3674 that we can easily identify
3676 info->stopped_ip = NULL;
3677 info->stopped_domain = NULL;
3679 } END_FOREACH_THREAD_SAFE
3680 /* if no threads were restarted, we're done */
3681 if (restart_count == 0)
3684 /* wait for the threads to signal their restart */
3685 mono_sgen_wait_for_suspend_ack (restart_count);
3687 if (sleep_duration < 0) {
3695 g_usleep (sleep_duration);
3696 sleep_duration += 10;
3699 /* stop them again */
3700 FOREACH_THREAD (info) {
3702 if (info->skip || info->stopped_ip == NULL)
3704 result = mono_sgen_suspend_thread (info);
3711 } END_FOREACH_THREAD
3712 /* some threads might have died */
3713 num_threads_died += restart_count - restarted_count;
3714 /* wait for the threads to signal their suspension
3716 mono_sgen_wait_for_suspend_ack (restart_count);
3719 return num_threads_died;
3723 acquire_gc_locks (void)
3726 mono_thread_info_suspend_lock ();
3730 release_gc_locks (void)
3732 mono_thread_info_suspend_unlock ();
3733 UNLOCK_INTERRUPTION;
3736 static TV_DECLARE (stop_world_time);
3737 static unsigned long max_pause_usec = 0;
3739 /* LOCKING: assumes the GC lock is held */
3741 stop_world (int generation)
3745 /*XXX this is the right stop, thought might not be the nicest place to put it*/
3746 mono_sgen_process_togglerefs ();
3748 mono_profiler_gc_event (MONO_GC_EVENT_PRE_STOP_WORLD, generation);
3749 acquire_gc_locks ();
3751 update_current_thread_stack (&count);
3753 mono_sgen_global_stop_count++;
3754 DEBUG (3, fprintf (gc_debug_file, "stopping world n %d from %p %p\n", mono_sgen_global_stop_count, mono_thread_info_current (), (gpointer)mono_native_thread_id_get ()));
3755 TV_GETTIME (stop_world_time);
3756 count = mono_sgen_thread_handshake (TRUE);
3757 count -= restart_threads_until_none_in_managed_allocator ();
3758 g_assert (count >= 0);
3759 DEBUG (3, fprintf (gc_debug_file, "world stopped %d thread(s)\n", count));
3760 mono_profiler_gc_event (MONO_GC_EVENT_POST_STOP_WORLD, generation);
3762 last_major_num_sections = major_collector.get_num_major_sections ();
3763 last_los_memory_usage = los_memory_usage;
3764 major_collection_happened = FALSE;
3768 /* LOCKING: assumes the GC lock is held */
3770 restart_world (int generation)
3772 int count, num_major_sections;
3773 SgenThreadInfo *info;
3774 TV_DECLARE (end_sw);
3775 TV_DECLARE (end_bridge);
3776 unsigned long usec, bridge_usec;
3778 /* notify the profiler of the leftovers */
3779 if (G_UNLIKELY (mono_profiler_events & MONO_PROFILE_GC_MOVES)) {
3780 if (moved_objects_idx) {
3781 mono_profiler_gc_moves (moved_objects, moved_objects_idx);
3782 moved_objects_idx = 0;
3785 mono_profiler_gc_event (MONO_GC_EVENT_PRE_START_WORLD, generation);
3786 FOREACH_THREAD (info) {
3787 info->stack_start = NULL;
3789 info->monoctx = NULL;
3791 info->stopped_regs = NULL;
3793 } END_FOREACH_THREAD
3795 stw_bridge_process ();
3796 release_gc_locks ();
3798 count = mono_sgen_thread_handshake (FALSE);
3799 TV_GETTIME (end_sw);
3800 usec = TV_ELAPSED (stop_world_time, end_sw);
3801 max_pause_usec = MAX (usec, max_pause_usec);
3802 DEBUG (2, fprintf (gc_debug_file, "restarted %d thread(s) (pause time: %d usec, max: %d)\n", count, (int)usec, (int)max_pause_usec));
3803 mono_profiler_gc_event (MONO_GC_EVENT_POST_START_WORLD, generation);
3807 TV_GETTIME (end_bridge);
3808 bridge_usec = TV_ELAPSED (end_sw, end_bridge);
3810 num_major_sections = major_collector.get_num_major_sections ();
3811 if (major_collection_happened)
3812 mono_trace (G_LOG_LEVEL_INFO, MONO_TRACE_GC, "GC_MAJOR: %s pause %.2fms, bridge %.2fms major %dK/%dK los %dK/%dK",
3813 generation ? "" : "(minor overflow)",
3814 (int)usec / 1000.0f, (int)bridge_usec / 1000.0f,
3815 major_collector.section_size * num_major_sections / 1024,
3816 major_collector.section_size * last_major_num_sections / 1024,
3817 los_memory_usage / 1024,
3818 last_los_memory_usage / 1024);
3820 mono_trace (G_LOG_LEVEL_INFO, MONO_TRACE_GC, "GC_MINOR: pause %.2fms, bridge %.2fms promoted %dK major %dK los %dK",
3821 (int)usec / 1000.0f, (int)bridge_usec / 1000.0f,
3822 (num_major_sections - last_major_num_sections) * major_collector.section_size / 1024,
3823 major_collector.section_size * num_major_sections / 1024,
3824 los_memory_usage / 1024);
3830 mono_sgen_get_current_collection_generation (void)
3832 return current_collection_generation;
3836 mono_gc_set_gc_callbacks (MonoGCCallbacks *callbacks)
3838 gc_callbacks = *callbacks;
3842 mono_gc_get_gc_callbacks ()
3844 return &gc_callbacks;
3847 /* Variables holding start/end nursery so it won't have to be passed at every call */
3848 static void *scan_area_arg_start, *scan_area_arg_end;
3851 mono_gc_conservatively_scan_area (void *start, void *end)
3853 conservatively_pin_objects_from (start, end, scan_area_arg_start, scan_area_arg_end, PIN_TYPE_STACK);
3857 mono_gc_scan_object (void *obj)
3859 UserCopyOrMarkData *data = mono_native_tls_get_value (user_copy_or_mark_key);
3861 if (current_collection_generation == GENERATION_NURSERY) {
3862 if (mono_sgen_collection_is_parallel ())
3863 major_collector.copy_object (&obj, data->queue);
3865 major_collector.nopar_copy_object (&obj, data->queue);
3867 major_collector.copy_or_mark_object (&obj, data->queue);
3873 * Mark from thread stacks and registers.
3876 scan_thread_data (void *start_nursery, void *end_nursery, gboolean precise, GrayQueue *queue)
3878 SgenThreadInfo *info;
3880 scan_area_arg_start = start_nursery;
3881 scan_area_arg_end = end_nursery;
3883 FOREACH_THREAD (info) {
3885 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));
3888 if (info->gc_disabled) {
3889 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));
3892 DEBUG (3, fprintf (gc_debug_file, "Scanning thread %p, range: %p-%p, size: %ld, pinned=%d\n", info, info->stack_start, info->stack_end, (char*)info->stack_end - (char*)info->stack_start, mono_sgen_get_pinned_count ()));
3893 if (!info->thread_is_dying) {
3894 if (gc_callbacks.thread_mark_func && !conservative_stack_mark) {
3895 UserCopyOrMarkData data = { NULL, queue };
3896 set_user_copy_or_mark_data (&data);
3897 gc_callbacks.thread_mark_func (info->runtime_data, info->stack_start, info->stack_end, precise);
3898 set_user_copy_or_mark_data (NULL);
3899 } else if (!precise) {
3900 conservatively_pin_objects_from (info->stack_start, info->stack_end, start_nursery, end_nursery, PIN_TYPE_STACK);
3905 if (!info->thread_is_dying && !precise)
3906 conservatively_pin_objects_from ((void**)info->monoctx, (void**)info->monoctx + ARCH_NUM_REGS,
3907 start_nursery, end_nursery, PIN_TYPE_STACK);
3909 if (!info->thread_is_dying && !precise)
3910 conservatively_pin_objects_from (info->stopped_regs, info->stopped_regs + ARCH_NUM_REGS,
3911 start_nursery, end_nursery, PIN_TYPE_STACK);
3913 } END_FOREACH_THREAD
3917 find_pinning_ref_from_thread (char *obj, size_t size)
3920 SgenThreadInfo *info;
3921 char *endobj = obj + size;
3923 FOREACH_THREAD (info) {
3924 char **start = (char**)info->stack_start;
3927 while (start < (char**)info->stack_end) {
3928 if (*start >= obj && *start < endobj) {
3929 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));
3934 for (j = 0; j < ARCH_NUM_REGS; ++j) {
3936 mword w = ((mword*)info->monoctx) [j];
3938 mword w = (mword)info->stopped_regs [j];
3941 if (w >= (mword)obj && w < (mword)obj + size)
3942 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)));
3943 } END_FOREACH_THREAD
3948 ptr_on_stack (void *ptr)
3950 gpointer stack_start = &stack_start;
3951 SgenThreadInfo *info = mono_thread_info_current ();
3953 if (ptr >= stack_start && ptr < (gpointer)info->stack_end)
3959 sgen_thread_register (SgenThreadInfo* info, void *addr)
3961 #ifndef HAVE_KW_THREAD
3962 SgenThreadInfo *__thread_info__ = info;
3966 #ifndef HAVE_KW_THREAD
3967 info->tlab_start = info->tlab_next = info->tlab_temp_end = info->tlab_real_end = NULL;
3969 g_assert (!mono_native_tls_get_value (thread_info_key));
3970 mono_native_tls_set_value (thread_info_key, info);
3975 #if !defined(__MACH__)
3976 info->stop_count = -1;
3980 info->doing_handshake = FALSE;
3981 info->thread_is_dying = FALSE;
3982 info->stack_start = NULL;
3983 info->store_remset_buffer_addr = &STORE_REMSET_BUFFER;
3984 info->store_remset_buffer_index_addr = &STORE_REMSET_BUFFER_INDEX;
3985 info->stopped_ip = NULL;
3986 info->stopped_domain = NULL;
3988 info->monoctx = NULL;
3990 info->stopped_regs = NULL;
3993 mono_sgen_init_tlab_info (info);
3995 binary_protocol_thread_register ((gpointer)mono_thread_info_get_tid (info));
3997 #ifdef HAVE_KW_THREAD
3998 store_remset_buffer_index_addr = &store_remset_buffer_index;
4001 #if defined(__MACH__)
4002 info->mach_port = mach_thread_self ();
4005 /* try to get it with attributes first */
4006 #if defined(HAVE_PTHREAD_GETATTR_NP) && defined(HAVE_PTHREAD_ATTR_GETSTACK)
4010 pthread_attr_t attr;
4011 pthread_getattr_np (pthread_self (), &attr);
4012 pthread_attr_getstack (&attr, &sstart, &size);
4013 info->stack_start_limit = sstart;
4014 info->stack_end = (char*)sstart + size;
4015 pthread_attr_destroy (&attr);
4017 #elif defined(HAVE_PTHREAD_GET_STACKSIZE_NP) && defined(HAVE_PTHREAD_GET_STACKADDR_NP)
4018 info->stack_end = (char*)pthread_get_stackaddr_np (pthread_self ());
4019 info->stack_start_limit = (char*)info->stack_end - pthread_get_stacksize_np (pthread_self ());
4022 /* FIXME: we assume the stack grows down */
4023 gsize stack_bottom = (gsize)addr;
4024 stack_bottom += 4095;
4025 stack_bottom &= ~4095;
4026 info->stack_end = (char*)stack_bottom;
4030 #ifdef HAVE_KW_THREAD
4031 stack_end = info->stack_end;
4034 if (remset.register_thread)
4035 remset.register_thread (info);
4037 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));
4039 if (gc_callbacks.thread_attach_func)
4040 info->runtime_data = gc_callbacks.thread_attach_func ();
4047 mono_sgen_wbarrier_cleanup_thread (SgenThreadInfo *p)
4049 if (remset.cleanup_thread)
4050 remset.cleanup_thread (p);
4054 sgen_thread_unregister (SgenThreadInfo *p)
4056 /* If a delegate is passed to native code and invoked on a thread we dont
4057 * know about, the jit will register it with mono_jit_thread_attach, but
4058 * we have no way of knowing when that thread goes away. SGen has a TSD
4059 * so we assume that if the domain is still registered, we can detach
4062 if (mono_domain_get ())
4063 mono_thread_detach (mono_thread_current ());
4065 p->thread_is_dying = TRUE;
4068 There is a race condition between a thread finishing executing and been removed
4069 from the GC thread set.
4070 This happens on posix systems when TLS data is been cleaned-up, libpthread will
4071 set the thread_info slot to NULL before calling the cleanup function. This
4072 opens a window in which the thread is registered but has a NULL TLS.
4074 The suspend signal handler needs TLS data to know where to store thread state
4075 data or otherwise it will simply ignore the thread.
4077 This solution works because the thread doing STW will wait until all threads been
4078 suspended handshake back, so there is no race between the doing_hankshake test
4079 and the suspend_thread call.
4081 This is not required on systems that do synchronous STW as those can deal with
4082 the above race at suspend time.
4084 FIXME: I believe we could avoid this by using mono_thread_info_lookup when
4085 mono_thread_info_current returns NULL. Or fix mono_thread_info_lookup to do so.
4087 #if (defined(__MACH__) && MONO_MACH_ARCH_SUPPORTED) || !defined(HAVE_PTHREAD_KILL)
4090 while (!TRYLOCK_GC) {
4091 if (!mono_sgen_park_current_thread_if_doing_handshake (p))
4096 binary_protocol_thread_unregister ((gpointer)mono_thread_info_get_tid (p));
4097 DEBUG (3, fprintf (gc_debug_file, "unregister thread %p (%p)\n", p, (gpointer)mono_thread_info_get_tid (p)));
4099 #if defined(__MACH__)
4100 mach_port_deallocate (current_task (), p->mach_port);
4103 if (gc_callbacks.thread_detach_func) {
4104 gc_callbacks.thread_detach_func (p->runtime_data);
4105 p->runtime_data = NULL;
4107 mono_sgen_wbarrier_cleanup_thread (p);
4109 mono_threads_unregister_current_thread (p);
4115 sgen_thread_attach (SgenThreadInfo *info)
4118 /*this is odd, can we get attached before the gc is inited?*/
4122 if (gc_callbacks.thread_attach_func && !info->runtime_data)
4123 info->runtime_data = gc_callbacks.thread_attach_func ();
4126 mono_gc_register_thread (void *baseptr)
4128 return mono_thread_info_attach (baseptr) != NULL;
4132 * mono_gc_set_stack_end:
4134 * Set the end of the current threads stack to STACK_END. The stack space between
4135 * STACK_END and the real end of the threads stack will not be scanned during collections.
4138 mono_gc_set_stack_end (void *stack_end)
4140 SgenThreadInfo *info;
4143 info = mono_thread_info_current ();
4145 g_assert (stack_end < info->stack_end);
4146 info->stack_end = stack_end;
4151 #if USE_PTHREAD_INTERCEPT
4155 mono_gc_pthread_create (pthread_t *new_thread, const pthread_attr_t *attr, void *(*start_routine)(void *), void *arg)
4157 return pthread_create (new_thread, attr, start_routine, arg);
4161 mono_gc_pthread_join (pthread_t thread, void **retval)
4163 return pthread_join (thread, retval);
4167 mono_gc_pthread_detach (pthread_t thread)
4169 return pthread_detach (thread);
4173 mono_gc_pthread_exit (void *retval)
4175 pthread_exit (retval);
4178 #endif /* USE_PTHREAD_INTERCEPT */
4181 * ######################################################################
4182 * ######## Write barriers
4183 * ######################################################################
4187 * Note: the write barriers first do the needed GC work and then do the actual store:
4188 * this way the value is visible to the conservative GC scan after the write barrier
4189 * itself. If a GC interrupts the barrier in the middle, value will be kept alive by
4190 * the conservative scan, otherwise by the remembered set scan.
4193 mono_gc_wbarrier_set_field (MonoObject *obj, gpointer field_ptr, MonoObject* value)
4195 HEAVY_STAT (++stat_wbarrier_set_field);
4196 if (ptr_in_nursery (field_ptr)) {
4197 *(void**)field_ptr = value;
4200 DEBUG (8, fprintf (gc_debug_file, "Adding remset at %p\n", field_ptr));
4202 binary_protocol_wbarrier (field_ptr, value, value->vtable);
4204 remset.wbarrier_set_field (obj, field_ptr, value);
4208 mono_gc_wbarrier_set_arrayref (MonoArray *arr, gpointer slot_ptr, MonoObject* value)
4210 HEAVY_STAT (++stat_wbarrier_set_arrayref);
4211 if (ptr_in_nursery (slot_ptr)) {
4212 *(void**)slot_ptr = value;
4215 DEBUG (8, fprintf (gc_debug_file, "Adding remset at %p\n", slot_ptr));
4217 binary_protocol_wbarrier (slot_ptr, value, value->vtable);
4219 remset.wbarrier_set_arrayref (arr, slot_ptr, value);
4223 mono_gc_wbarrier_arrayref_copy (gpointer dest_ptr, gpointer src_ptr, int count)
4225 HEAVY_STAT (++stat_wbarrier_arrayref_copy);
4226 /*This check can be done without taking a lock since dest_ptr array is pinned*/
4227 if (ptr_in_nursery (dest_ptr) || count <= 0) {
4228 mono_gc_memmove (dest_ptr, src_ptr, count * sizeof (gpointer));
4232 #ifdef SGEN_BINARY_PROTOCOL
4235 for (i = 0; i < count; ++i) {
4236 gpointer dest = (gpointer*)dest_ptr + i;
4237 gpointer obj = *((gpointer*)src_ptr + i);
4239 binary_protocol_wbarrier (dest, obj, (gpointer)LOAD_VTABLE (obj));
4244 remset.wbarrier_arrayref_copy (dest_ptr, src_ptr, count);
4247 static char *found_obj;
4250 find_object_for_ptr_callback (char *obj, size_t size, void *user_data)
4252 char *ptr = user_data;
4254 if (ptr >= obj && ptr < obj + size) {
4255 g_assert (!found_obj);
4260 /* for use in the debugger */
4261 char* find_object_for_ptr (char *ptr);
4263 find_object_for_ptr (char *ptr)
4265 if (ptr >= nursery_section->data && ptr < nursery_section->end_data) {
4267 mono_sgen_scan_area_with_callback (nursery_section->data, nursery_section->end_data,
4268 find_object_for_ptr_callback, ptr, TRUE);
4274 mono_sgen_los_iterate_objects (find_object_for_ptr_callback, ptr);
4279 * Very inefficient, but this is debugging code, supposed to
4280 * be called from gdb, so we don't care.
4283 major_collector.iterate_objects (TRUE, TRUE, find_object_for_ptr_callback, ptr);
4288 mono_gc_wbarrier_generic_nostore (gpointer ptr)
4290 HEAVY_STAT (++stat_wbarrier_generic_store);
4292 #ifdef XDOMAIN_CHECKS_IN_WBARRIER
4293 /* FIXME: ptr_in_heap must be called with the GC lock held */
4294 if (xdomain_checks && *(MonoObject**)ptr && ptr_in_heap (ptr)) {
4295 char *start = find_object_for_ptr (ptr);
4296 MonoObject *value = *(MonoObject**)ptr;
4300 MonoObject *obj = (MonoObject*)start;
4301 if (obj->vtable->domain != value->vtable->domain)
4302 g_assert (is_xdomain_ref_allowed (ptr, start, obj->vtable->domain));
4308 if (*(gpointer*)ptr)
4309 binary_protocol_wbarrier (ptr, *(gpointer*)ptr, (gpointer)LOAD_VTABLE (*(gpointer*)ptr));
4311 if (ptr_in_nursery (ptr) || ptr_on_stack (ptr) || !ptr_in_nursery (*(gpointer*)ptr)) {
4312 DEBUG (8, fprintf (gc_debug_file, "Skipping remset at %p\n", ptr));
4316 DEBUG (8, fprintf (gc_debug_file, "Adding remset at %p\n", ptr));
4318 remset.wbarrier_generic_nostore (ptr);
4322 mono_gc_wbarrier_generic_store (gpointer ptr, MonoObject* value)
4324 DEBUG (8, fprintf (gc_debug_file, "Wbarrier store at %p to %p (%s)\n", ptr, value, value ? safe_name (value) : "null"));
4325 *(void**)ptr = value;
4326 if (ptr_in_nursery (value))
4327 mono_gc_wbarrier_generic_nostore (ptr);
4328 mono_sgen_dummy_use (value);
4331 void mono_gc_wbarrier_value_copy_bitmap (gpointer _dest, gpointer _src, int size, unsigned bitmap)
4333 mword *dest = _dest;
4338 mono_gc_wbarrier_generic_store (dest, (MonoObject*)*src);
4343 size -= SIZEOF_VOID_P;
4348 #ifdef SGEN_BINARY_PROTOCOL
4350 #define HANDLE_PTR(ptr,obj) do { \
4351 gpointer o = *(gpointer*)(ptr); \
4353 gpointer d = ((char*)dest) + ((char*)(ptr) - (char*)(obj)); \
4354 binary_protocol_wbarrier (d, o, (gpointer) LOAD_VTABLE (o)); \
4359 scan_object_for_binary_protocol_copy_wbarrier (gpointer dest, char *start, mword desc)
4361 #define SCAN_OBJECT_NOVTABLE
4362 #include "sgen-scan-object.h"
4367 mono_gc_wbarrier_value_copy (gpointer dest, gpointer src, int count, MonoClass *klass)
4369 HEAVY_STAT (++stat_wbarrier_value_copy);
4370 g_assert (klass->valuetype);
4372 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));
4374 if (ptr_in_nursery (dest) || ptr_on_stack (dest) || !SGEN_CLASS_HAS_REFERENCES (klass)) {
4375 size_t element_size = mono_class_value_size (klass, NULL);
4376 size_t size = count * element_size;
4377 mono_gc_memmove (dest, src, size);
4381 #ifdef SGEN_BINARY_PROTOCOL
4384 for (i = 0; i < count; ++i) {
4385 scan_object_for_binary_protocol_copy_wbarrier ((char*)dest + i * element_size,
4386 (char*)src + i * element_size - sizeof (MonoObject),
4387 (mword) klass->gc_descr);
4392 remset.wbarrier_value_copy (dest, src, count, klass);
4396 * mono_gc_wbarrier_object_copy:
4398 * Write barrier to call when obj is the result of a clone or copy of an object.
4401 mono_gc_wbarrier_object_copy (MonoObject* obj, MonoObject *src)
4405 HEAVY_STAT (++stat_wbarrier_object_copy);
4407 if (ptr_in_nursery (obj) || ptr_on_stack (obj)) {
4408 size = mono_object_class (obj)->instance_size;
4409 mono_gc_memmove ((char*)obj + sizeof (MonoObject), (char*)src + sizeof (MonoObject),
4410 size - sizeof (MonoObject));
4414 #ifdef SGEN_BINARY_PROTOCOL
4415 scan_object_for_binary_protocol_copy_wbarrier (obj, (char*)src, (mword) src->vtable->gc_descr);
4418 remset.wbarrier_object_copy (obj, src);
4422 * ######################################################################
4423 * ######## Other mono public interface functions.
4424 * ######################################################################
4427 #define REFS_SIZE 128
4430 MonoGCReferences callback;
4434 MonoObject *refs [REFS_SIZE];
4435 uintptr_t offsets [REFS_SIZE];
4439 #define HANDLE_PTR(ptr,obj) do { \
4441 if (hwi->count == REFS_SIZE) { \
4442 hwi->callback ((MonoObject*)start, mono_object_class (start), hwi->called? 0: size, hwi->count, hwi->refs, hwi->offsets, hwi->data); \
4446 hwi->offsets [hwi->count] = (char*)(ptr)-(char*)start; \
4447 hwi->refs [hwi->count++] = *(ptr); \
4452 collect_references (HeapWalkInfo *hwi, char *start, size_t size)
4454 #include "sgen-scan-object.h"
4458 walk_references (char *start, size_t size, void *data)
4460 HeapWalkInfo *hwi = data;
4463 collect_references (hwi, start, size);
4464 if (hwi->count || !hwi->called)
4465 hwi->callback ((MonoObject*)start, mono_object_class (start), hwi->called? 0: size, hwi->count, hwi->refs, hwi->offsets, hwi->data);
4469 * mono_gc_walk_heap:
4470 * @flags: flags for future use
4471 * @callback: a function pointer called for each object in the heap
4472 * @data: a user data pointer that is passed to callback
4474 * This function can be used to iterate over all the live objects in the heap:
4475 * for each object, @callback is invoked, providing info about the object's
4476 * location in memory, its class, its size and the objects it references.
4477 * For each referenced object it's offset from the object address is
4478 * reported in the offsets array.
4479 * The object references may be buffered, so the callback may be invoked
4480 * multiple times for the same object: in all but the first call, the size
4481 * argument will be zero.
4482 * Note that this function can be only called in the #MONO_GC_EVENT_PRE_START_WORLD
4483 * profiler event handler.
4485 * Returns: a non-zero value if the GC doesn't support heap walking
4488 mono_gc_walk_heap (int flags, MonoGCReferences callback, void *data)
4493 hwi.callback = callback;
4496 mono_sgen_clear_nursery_fragments ();
4497 mono_sgen_scan_area_with_callback (nursery_section->data, nursery_section->end_data, walk_references, &hwi, FALSE);
4499 major_collector.iterate_objects (TRUE, TRUE, walk_references, &hwi);
4500 mono_sgen_los_iterate_objects (walk_references, &hwi);
4506 mono_gc_collect (int generation)
4511 mono_profiler_gc_event (MONO_GC_EVENT_START, generation);
4512 stop_world (generation);
4513 if (generation == 0) {
4514 collect_nursery (0);
4516 major_collection ("user request");
4518 restart_world (generation);
4519 mono_profiler_gc_event (MONO_GC_EVENT_END, generation);
4524 mono_gc_max_generation (void)
4530 mono_gc_collection_count (int generation)
4532 if (generation == 0)
4533 return stat_minor_gcs;
4534 return stat_major_gcs;
4538 mono_gc_get_used_size (void)
4542 tot = los_memory_usage;
4543 tot += nursery_section->next_data - nursery_section->data;
4544 tot += major_collector.get_used_size ();
4545 /* FIXME: account for pinned objects */
4551 mono_gc_get_heap_size (void)
4557 mono_gc_disable (void)
4565 mono_gc_enable (void)
4573 mono_gc_get_los_limit (void)
4575 return MAX_SMALL_OBJ_SIZE;
4579 mono_object_is_alive (MonoObject* o)
4585 mono_gc_get_generation (MonoObject *obj)
4587 if (ptr_in_nursery (obj))
4593 mono_gc_enable_events (void)
4598 mono_gc_weak_link_add (void **link_addr, MonoObject *obj, gboolean track)
4600 mono_gc_register_disappearing_link (obj, link_addr, track, FALSE);
4604 mono_gc_weak_link_remove (void **link_addr)
4606 mono_gc_register_disappearing_link (NULL, link_addr, FALSE, FALSE);
4610 mono_gc_weak_link_get (void **link_addr)
4614 return (MonoObject*) REVEAL_POINTER (*link_addr);
4618 mono_gc_ephemeron_array_add (MonoObject *obj)
4620 EphemeronLinkNode *node;
4624 node = mono_sgen_alloc_internal (INTERNAL_MEM_EPHEMERON_LINK);
4629 node->array = (char*)obj;
4630 node->next = ephemeron_list;
4631 ephemeron_list = node;
4633 DEBUG (5, fprintf (gc_debug_file, "Registered ephemeron array %p\n", obj));
4640 mono_gc_invoke_with_gc_lock (MonoGCLockedCallbackFunc func, void *data)
4644 result = func (data);
4645 UNLOCK_INTERRUPTION;
4650 mono_gc_is_gc_thread (void)
4654 result = mono_thread_info_current () != NULL;
4660 is_critical_method (MonoMethod *method)
4662 return mono_runtime_is_critical_method (method) || mono_gc_is_critical_method (method);
4666 mono_gc_base_init (void)
4668 MonoThreadInfoCallbacks cb;
4671 char *major_collector_opt = NULL;
4673 glong soft_limit = 0;
4679 result = InterlockedCompareExchange (&gc_initialized, -1, 0);
4682 /* already inited */
4685 /* being inited by another thread */
4689 /* we will init it */
4692 g_assert_not_reached ();
4694 } while (result != 0);
4696 LOCK_INIT (gc_mutex);
4698 pagesize = mono_pagesize ();
4699 gc_debug_file = stderr;
4701 cb.thread_register = sgen_thread_register;
4702 cb.thread_unregister = sgen_thread_unregister;
4703 cb.thread_attach = sgen_thread_attach;
4704 cb.mono_method_is_critical = (gpointer)is_critical_method;
4706 cb.mono_gc_pthread_create = (gpointer)mono_gc_pthread_create;
4709 mono_threads_init (&cb, sizeof (SgenThreadInfo));
4711 LOCK_INIT (interruption_mutex);
4712 LOCK_INIT (pin_queue_mutex);
4714 init_user_copy_or_mark_key ();
4716 if ((env = getenv ("MONO_GC_PARAMS"))) {
4717 opts = g_strsplit (env, ",", -1);
4718 for (ptr = opts; *ptr; ++ptr) {
4720 if (g_str_has_prefix (opt, "major=")) {
4721 opt = strchr (opt, '=') + 1;
4722 major_collector_opt = g_strdup (opt);
4730 mono_sgen_init_internal_allocator ();
4731 mono_sgen_init_nursery_allocator ();
4733 mono_sgen_register_fixed_internal_mem_type (INTERNAL_MEM_SECTION, SGEN_SIZEOF_GC_MEM_SECTION);
4734 mono_sgen_register_fixed_internal_mem_type (INTERNAL_MEM_FINALIZE_READY_ENTRY, sizeof (FinalizeReadyEntry));
4735 mono_sgen_register_fixed_internal_mem_type (INTERNAL_MEM_GRAY_QUEUE, sizeof (GrayQueueSection));
4736 g_assert (sizeof (GenericStoreRememberedSet) == sizeof (gpointer) * STORE_REMSET_BUFFER_SIZE);
4737 mono_sgen_register_fixed_internal_mem_type (INTERNAL_MEM_STORE_REMSET, sizeof (GenericStoreRememberedSet));
4738 mono_sgen_register_fixed_internal_mem_type (INTERNAL_MEM_EPHEMERON_LINK, sizeof (EphemeronLinkNode));
4740 #ifndef HAVE_KW_THREAD
4741 mono_native_tls_alloc (&thread_info_key, NULL);
4745 * This needs to happen before any internal allocations because
4746 * it inits the small id which is required for hazard pointer
4749 mono_sgen_os_init ();
4751 mono_thread_info_attach (&dummy);
4753 if (!major_collector_opt || !strcmp (major_collector_opt, "marksweep")) {
4754 mono_sgen_marksweep_init (&major_collector);
4755 } else if (!major_collector_opt || !strcmp (major_collector_opt, "marksweep-fixed")) {
4756 mono_sgen_marksweep_fixed_init (&major_collector);
4757 } else if (!major_collector_opt || !strcmp (major_collector_opt, "marksweep-par")) {
4758 mono_sgen_marksweep_par_init (&major_collector);
4759 } else if (!major_collector_opt || !strcmp (major_collector_opt, "marksweep-fixed-par")) {
4760 mono_sgen_marksweep_fixed_par_init (&major_collector);
4761 } else if (!strcmp (major_collector_opt, "copying")) {
4762 mono_sgen_copying_init (&major_collector);
4764 fprintf (stderr, "Unknown major collector `%s'.\n", major_collector_opt);
4768 #ifdef SGEN_HAVE_CARDTABLE
4769 use_cardtable = major_collector.supports_cardtable;
4771 use_cardtable = FALSE;
4774 num_workers = mono_cpu_count ();
4775 g_assert (num_workers > 0);
4776 if (num_workers > 16)
4779 ///* Keep this the default for now */
4781 conservative_stack_mark = TRUE;
4785 for (ptr = opts; *ptr; ++ptr) {
4787 if (g_str_has_prefix (opt, "major="))
4789 if (g_str_has_prefix (opt, "wbarrier=")) {
4790 opt = strchr (opt, '=') + 1;
4791 if (strcmp (opt, "remset") == 0) {
4792 use_cardtable = FALSE;
4793 } else if (strcmp (opt, "cardtable") == 0) {
4794 if (!use_cardtable) {
4795 if (major_collector.supports_cardtable)
4796 fprintf (stderr, "The cardtable write barrier is not supported on this platform.\n");
4798 fprintf (stderr, "The major collector does not support the cardtable write barrier.\n");
4804 if (g_str_has_prefix (opt, "max-heap-size=")) {
4805 opt = strchr (opt, '=') + 1;
4806 if (*opt && mono_gc_parse_environment_string_extract_number (opt, &max_heap)) {
4807 if ((max_heap & (mono_pagesize () - 1))) {
4808 fprintf (stderr, "max-heap-size size must be a multiple of %d.\n", mono_pagesize ());
4812 fprintf (stderr, "max-heap-size must be an integer.\n");
4817 if (g_str_has_prefix (opt, "soft-heap-limit=")) {
4818 opt = strchr (opt, '=') + 1;
4819 if (*opt && mono_gc_parse_environment_string_extract_number (opt, &soft_limit)) {
4820 if (soft_limit <= 0) {
4821 fprintf (stderr, "soft-heap-limit must be positive.\n");
4825 fprintf (stderr, "soft-heap-limit must be an integer.\n");
4830 if (g_str_has_prefix (opt, "workers=")) {
4833 if (!major_collector.is_parallel) {
4834 fprintf (stderr, "The workers= option can only be used for parallel collectors.");
4837 opt = strchr (opt, '=') + 1;
4838 val = strtol (opt, &endptr, 10);
4839 if (!*opt || *endptr) {
4840 fprintf (stderr, "Cannot parse the workers= option value.");
4843 if (val <= 0 || val > 16) {
4844 fprintf (stderr, "The number of workers must be in the range 1 to 16.");
4847 num_workers = (int)val;
4850 if (g_str_has_prefix (opt, "stack-mark=")) {
4851 opt = strchr (opt, '=') + 1;
4852 if (!strcmp (opt, "precise")) {
4853 conservative_stack_mark = FALSE;
4854 } else if (!strcmp (opt, "conservative")) {
4855 conservative_stack_mark = TRUE;
4857 fprintf (stderr, "Invalid value '%s' for stack-mark= option, possible values are: 'precise', 'conservative'.\n", opt);
4862 if (g_str_has_prefix (opt, "bridge=")) {
4863 opt = strchr (opt, '=') + 1;
4864 mono_sgen_register_test_bridge_callbacks (g_strdup (opt));
4868 if (g_str_has_prefix (opt, "nursery-size=")) {
4870 opt = strchr (opt, '=') + 1;
4871 if (*opt && mono_gc_parse_environment_string_extract_number (opt, &val)) {
4872 mono_sgen_nursery_size = val;
4873 #ifdef SGEN_ALIGN_NURSERY
4874 if ((val & (val - 1))) {
4875 fprintf (stderr, "The nursery size must be a power of two.\n");
4879 if (val < SGEN_MAX_NURSERY_WASTE) {
4880 fprintf (stderr, "The nursery size must be at least %d bytes.\n", SGEN_MAX_NURSERY_WASTE);
4884 mono_sgen_nursery_bits = 0;
4885 while (1 << (++ mono_sgen_nursery_bits) != mono_sgen_nursery_size)
4889 fprintf (stderr, "nursery-size must be an integer.\n");
4895 if (!(major_collector.handle_gc_param && major_collector.handle_gc_param (opt))) {
4896 fprintf (stderr, "MONO_GC_PARAMS must be a comma-delimited list of one or more of the following:\n");
4897 fprintf (stderr, " max-heap-size=N (where N is an integer, possibly with a k, m or a g suffix)\n");
4898 fprintf (stderr, " soft-heap-limit=n (where N is an integer, possibly with a k, m or a g suffix)\n");
4899 fprintf (stderr, " nursery-size=N (where N is an integer, possibly with a k, m or a g suffix)\n");
4900 fprintf (stderr, " major=COLLECTOR (where COLLECTOR is `marksweep', `marksweep-par' or `copying')\n");
4901 fprintf (stderr, " wbarrier=WBARRIER (where WBARRIER is `remset' or `cardtable')\n");
4902 fprintf (stderr, " stack-mark=MARK-METHOD (where MARK-METHOD is 'precise' or 'conservative')\n");
4903 if (major_collector.print_gc_param_usage)
4904 major_collector.print_gc_param_usage ();
4911 if (major_collector.is_parallel)
4912 mono_sgen_workers_init (num_workers);
4914 if (major_collector_opt)
4915 g_free (major_collector_opt);
4917 nursery_size = DEFAULT_NURSERY_SIZE;
4918 minor_collection_allowance = MIN_MINOR_COLLECTION_ALLOWANCE;
4919 init_heap_size_limits (max_heap, soft_limit);
4923 if ((env = getenv ("MONO_GC_DEBUG"))) {
4924 opts = g_strsplit (env, ",", -1);
4925 for (ptr = opts; ptr && *ptr; ptr ++) {
4927 if (opt [0] >= '0' && opt [0] <= '9') {
4928 gc_debug_level = atoi (opt);
4933 char *rf = g_strdup_printf ("%s.%d", opt, getpid ());
4934 gc_debug_file = fopen (rf, "wb");
4936 gc_debug_file = stderr;
4939 } else if (!strcmp (opt, "print-allowance")) {
4940 debug_print_allowance = TRUE;
4941 } else if (!strcmp (opt, "print-pinning")) {
4942 do_pin_stats = TRUE;
4943 } else if (!strcmp (opt, "collect-before-allocs")) {
4944 collect_before_allocs = 1;
4945 } else if (g_str_has_prefix (opt, "collect-before-allocs=")) {
4946 char *arg = strchr (opt, '=') + 1;
4947 collect_before_allocs = atoi (arg);
4948 } else if (!strcmp (opt, "check-at-minor-collections")) {
4949 consistency_check_at_minor_collection = TRUE;
4950 nursery_clear_policy = CLEAR_AT_GC;
4951 } else if (!strcmp (opt, "xdomain-checks")) {
4952 xdomain_checks = TRUE;
4953 } else if (!strcmp (opt, "clear-at-gc")) {
4954 nursery_clear_policy = CLEAR_AT_GC;
4955 } else if (!strcmp (opt, "clear-nursery-at-gc")) {
4956 nursery_clear_policy = CLEAR_AT_GC;
4957 } else if (!strcmp (opt, "check-scan-starts")) {
4958 do_scan_starts_check = TRUE;
4959 } else if (!strcmp (opt, "verify-nursery-at-minor-gc")) {
4960 do_verify_nursery = TRUE;
4961 } else if (!strcmp (opt, "dump-nursery-at-minor-gc")) {
4962 do_dump_nursery_content = TRUE;
4963 } else if (!strcmp (opt, "disable-minor")) {
4964 disable_minor_collections = TRUE;
4965 } else if (!strcmp (opt, "disable-major")) {
4966 disable_major_collections = TRUE;
4967 } else if (g_str_has_prefix (opt, "heap-dump=")) {
4968 char *filename = strchr (opt, '=') + 1;
4969 nursery_clear_policy = CLEAR_AT_GC;
4970 heap_dump_file = fopen (filename, "w");
4971 if (heap_dump_file) {
4972 fprintf (heap_dump_file, "<sgen-dump>\n");
4973 do_pin_stats = TRUE;
4975 #ifdef SGEN_BINARY_PROTOCOL
4976 } else if (g_str_has_prefix (opt, "binary-protocol=")) {
4977 char *filename = strchr (opt, '=') + 1;
4978 binary_protocol_init (filename);
4980 fprintf (stderr, "Warning: Cardtable write barriers will not be binary-protocolled.\n");
4983 fprintf (stderr, "Invalid format for the MONO_GC_DEBUG env variable: '%s'\n", env);
4984 fprintf (stderr, "The format is: MONO_GC_DEBUG=[l[:filename]|<option>]+ where l is a debug level 0-9.\n");
4985 fprintf (stderr, "Valid options are:\n");
4986 fprintf (stderr, " collect-before-allocs[=<n>]\n");
4987 fprintf (stderr, " check-at-minor-collections\n");
4988 fprintf (stderr, " disable-minor\n");
4989 fprintf (stderr, " disable-major\n");
4990 fprintf (stderr, " xdomain-checks\n");
4991 fprintf (stderr, " clear-at-gc\n");
4992 fprintf (stderr, " print-allowance\n");
4993 fprintf (stderr, " print-pinning\n");
5000 if (major_collector.is_parallel) {
5001 if (heap_dump_file) {
5002 fprintf (stderr, "Error: Cannot do heap dump with the parallel collector.\n");
5006 fprintf (stderr, "Error: Cannot gather pinning statistics with the parallel collector.\n");
5011 if (major_collector.post_param_init)
5012 major_collector.post_param_init ();
5014 memset (&remset, 0, sizeof (remset));
5016 #ifdef SGEN_HAVE_CARDTABLE
5018 sgen_card_table_init (&remset);
5021 mono_sgen_ssb_init (&remset);
5023 if (remset.register_thread)
5024 remset.register_thread (mono_thread_info_current ());
5030 mono_gc_get_gc_name (void)
5035 static MonoMethod *write_barrier_method;
5038 mono_gc_is_critical_method (MonoMethod *method)
5040 return (method == write_barrier_method || mono_sgen_is_managed_allocator (method));
5044 is_ip_in_managed_allocator (MonoDomain *domain, gpointer ip)
5048 if (!mono_thread_internal_current ())
5049 /* Happens during thread attach */
5054 ji = mono_jit_info_table_find (domain, ip);
5058 return mono_gc_is_critical_method (ji->method);
5062 emit_nursery_check (MonoMethodBuilder *mb, int *nursery_check_return_labels)
5064 memset (nursery_check_return_labels, 0, sizeof (int) * 3);
5065 #ifdef SGEN_ALIGN_NURSERY
5066 // if (ptr_in_nursery (ptr)) return;
5068 * Masking out the bits might be faster, but we would have to use 64 bit
5069 * immediates, which might be slower.
5071 mono_mb_emit_ldarg (mb, 0);
5072 mono_mb_emit_icon (mb, DEFAULT_NURSERY_BITS);
5073 mono_mb_emit_byte (mb, CEE_SHR_UN);
5074 mono_mb_emit_icon (mb, (mword)mono_sgen_get_nursery_start () >> DEFAULT_NURSERY_BITS);
5075 nursery_check_return_labels [0] = mono_mb_emit_branch (mb, CEE_BEQ);
5077 // if (!ptr_in_nursery (*ptr)) return;
5078 mono_mb_emit_ldarg (mb, 0);
5079 mono_mb_emit_byte (mb, CEE_LDIND_I);
5080 mono_mb_emit_icon (mb, DEFAULT_NURSERY_BITS);
5081 mono_mb_emit_byte (mb, CEE_SHR_UN);
5082 mono_mb_emit_icon (mb, (mword)mono_sgen_get_nursery_start () >> DEFAULT_NURSERY_BITS);
5083 nursery_check_return_labels [1] = mono_mb_emit_branch (mb, CEE_BNE_UN);
5085 int label_continue1, label_continue2;
5086 int dereferenced_var;
5088 // if (ptr < (mono_sgen_get_nursery_start ())) goto continue;
5089 mono_mb_emit_ldarg (mb, 0);
5090 mono_mb_emit_ptr (mb, (gpointer) mono_sgen_get_nursery_start ());
5091 label_continue_1 = mono_mb_emit_branch (mb, CEE_BLT);
5093 // if (ptr >= mono_sgen_get_nursery_end ())) goto continue;
5094 mono_mb_emit_ldarg (mb, 0);
5095 mono_mb_emit_ptr (mb, (gpointer) mono_sgen_get_nursery_end ());
5096 label_continue_2 = mono_mb_emit_branch (mb, CEE_BGE);
5099 nursery_check_return_labels [0] = mono_mb_emit_branch (mb, CEE_BR);
5102 mono_mb_patch_branch (mb, label_continue_1);
5103 mono_mb_patch_branch (mb, label_continue_2);
5105 // Dereference and store in local var
5106 dereferenced_var = mono_mb_add_local (mb, &mono_defaults.int_class->byval_arg);
5107 mono_mb_emit_ldarg (mb, 0);
5108 mono_mb_emit_byte (mb, CEE_LDIND_I);
5109 mono_mb_emit_stloc (mb, dereferenced_var);
5111 // if (*ptr < mono_sgen_get_nursery_start ()) return;
5112 mono_mb_emit_ldloc (mb, dereferenced_var);
5113 mono_mb_emit_ptr (mb, (gpointer) mono_sgen_get_nursery_start ());
5114 nursery_check_return_labels [1] = mono_mb_emit_branch (mb, CEE_BLT);
5116 // if (*ptr >= mono_sgen_get_nursery_end ()) return;
5117 mono_mb_emit_ldloc (mb, dereferenced_var);
5118 mono_mb_emit_ptr (mb, (gpointer) mono_sgen_get_nursery_end ());
5119 nursery_check_return_labels [2] = mono_mb_emit_branch (mb, CEE_BGE);
5124 mono_gc_get_write_barrier (void)
5127 MonoMethodBuilder *mb;
5128 MonoMethodSignature *sig;
5129 #ifdef MANAGED_WBARRIER
5130 int i, nursery_check_labels [3];
5131 int label_no_wb_3, label_no_wb_4, label_need_wb, label_slow_path;
5132 int buffer_var, buffer_index_var, dummy_var;
5134 #ifdef HAVE_KW_THREAD
5135 int stack_end_offset = -1, store_remset_buffer_offset = -1;
5136 int store_remset_buffer_index_offset = -1, store_remset_buffer_index_addr_offset = -1;
5138 MONO_THREAD_VAR_OFFSET (stack_end, stack_end_offset);
5139 g_assert (stack_end_offset != -1);
5140 MONO_THREAD_VAR_OFFSET (store_remset_buffer, store_remset_buffer_offset);
5141 g_assert (store_remset_buffer_offset != -1);
5142 MONO_THREAD_VAR_OFFSET (store_remset_buffer_index, store_remset_buffer_index_offset);
5143 g_assert (store_remset_buffer_index_offset != -1);
5144 MONO_THREAD_VAR_OFFSET (store_remset_buffer_index_addr, store_remset_buffer_index_addr_offset);
5145 g_assert (store_remset_buffer_index_addr_offset != -1);
5149 // FIXME: Maybe create a separate version for ctors (the branch would be
5150 // correctly predicted more times)
5151 if (write_barrier_method)
5152 return write_barrier_method;
5154 /* Create the IL version of mono_gc_barrier_generic_store () */
5155 sig = mono_metadata_signature_alloc (mono_defaults.corlib, 1);
5156 sig->ret = &mono_defaults.void_class->byval_arg;
5157 sig->params [0] = &mono_defaults.int_class->byval_arg;
5159 mb = mono_mb_new (mono_defaults.object_class, "wbarrier", MONO_WRAPPER_WRITE_BARRIER);
5161 #ifdef MANAGED_WBARRIER
5162 if (use_cardtable) {
5163 emit_nursery_check (mb, nursery_check_labels);
5165 addr = sgen_cardtable + ((address >> CARD_BITS) & CARD_MASK)
5169 LDC_PTR sgen_cardtable
5171 address >> CARD_BITS
5175 if (SGEN_HAVE_OVERLAPPING_CARDS) {
5176 LDC_PTR card_table_mask
5183 mono_mb_emit_ptr (mb, sgen_cardtable);
5184 mono_mb_emit_ldarg (mb, 0);
5185 mono_mb_emit_icon (mb, CARD_BITS);
5186 mono_mb_emit_byte (mb, CEE_SHR_UN);
5187 #ifdef SGEN_HAVE_OVERLAPPING_CARDS
5188 mono_mb_emit_ptr (mb, (gpointer)CARD_MASK);
5189 mono_mb_emit_byte (mb, CEE_AND);
5191 mono_mb_emit_byte (mb, CEE_ADD);
5192 mono_mb_emit_icon (mb, 1);
5193 mono_mb_emit_byte (mb, CEE_STIND_I1);
5196 for (i = 0; i < 3; ++i) {
5197 if (nursery_check_labels [i])
5198 mono_mb_patch_branch (mb, nursery_check_labels [i]);
5200 mono_mb_emit_byte (mb, CEE_RET);
5201 } else if (mono_runtime_has_tls_get ()) {
5202 emit_nursery_check (mb, nursery_check_labels);
5204 // if (ptr >= stack_end) goto need_wb;
5205 mono_mb_emit_ldarg (mb, 0);
5206 EMIT_TLS_ACCESS (mb, stack_end, stack_end_offset);
5207 label_need_wb = mono_mb_emit_branch (mb, CEE_BGE_UN);
5209 // if (ptr >= stack_start) return;
5210 dummy_var = mono_mb_add_local (mb, &mono_defaults.int_class->byval_arg);
5211 mono_mb_emit_ldarg (mb, 0);
5212 mono_mb_emit_ldloc_addr (mb, dummy_var);
5213 label_no_wb_3 = mono_mb_emit_branch (mb, CEE_BGE_UN);
5216 mono_mb_patch_branch (mb, label_need_wb);
5218 // buffer = STORE_REMSET_BUFFER;
5219 buffer_var = mono_mb_add_local (mb, &mono_defaults.int_class->byval_arg);
5220 EMIT_TLS_ACCESS (mb, store_remset_buffer, store_remset_buffer_offset);
5221 mono_mb_emit_stloc (mb, buffer_var);
5223 // buffer_index = STORE_REMSET_BUFFER_INDEX;
5224 buffer_index_var = mono_mb_add_local (mb, &mono_defaults.int_class->byval_arg);
5225 EMIT_TLS_ACCESS (mb, store_remset_buffer_index, store_remset_buffer_index_offset);
5226 mono_mb_emit_stloc (mb, buffer_index_var);
5228 // if (buffer [buffer_index] == ptr) return;
5229 mono_mb_emit_ldloc (mb, buffer_var);
5230 mono_mb_emit_ldloc (mb, buffer_index_var);
5231 g_assert (sizeof (gpointer) == 4 || sizeof (gpointer) == 8);
5232 mono_mb_emit_icon (mb, sizeof (gpointer) == 4 ? 2 : 3);
5233 mono_mb_emit_byte (mb, CEE_SHL);
5234 mono_mb_emit_byte (mb, CEE_ADD);
5235 mono_mb_emit_byte (mb, CEE_LDIND_I);
5236 mono_mb_emit_ldarg (mb, 0);
5237 label_no_wb_4 = mono_mb_emit_branch (mb, CEE_BEQ);
5240 mono_mb_emit_ldloc (mb, buffer_index_var);
5241 mono_mb_emit_icon (mb, 1);
5242 mono_mb_emit_byte (mb, CEE_ADD);
5243 mono_mb_emit_stloc (mb, buffer_index_var);
5245 // if (buffer_index >= STORE_REMSET_BUFFER_SIZE) goto slow_path;
5246 mono_mb_emit_ldloc (mb, buffer_index_var);
5247 mono_mb_emit_icon (mb, STORE_REMSET_BUFFER_SIZE);
5248 label_slow_path = mono_mb_emit_branch (mb, CEE_BGE);
5250 // buffer [buffer_index] = ptr;
5251 mono_mb_emit_ldloc (mb, buffer_var);
5252 mono_mb_emit_ldloc (mb, buffer_index_var);
5253 g_assert (sizeof (gpointer) == 4 || sizeof (gpointer) == 8);
5254 mono_mb_emit_icon (mb, sizeof (gpointer) == 4 ? 2 : 3);
5255 mono_mb_emit_byte (mb, CEE_SHL);
5256 mono_mb_emit_byte (mb, CEE_ADD);
5257 mono_mb_emit_ldarg (mb, 0);
5258 mono_mb_emit_byte (mb, CEE_STIND_I);
5260 // STORE_REMSET_BUFFER_INDEX = buffer_index;
5261 EMIT_TLS_ACCESS (mb, store_remset_buffer_index_addr, store_remset_buffer_index_addr_offset);
5262 mono_mb_emit_ldloc (mb, buffer_index_var);
5263 mono_mb_emit_byte (mb, CEE_STIND_I);
5266 for (i = 0; i < 3; ++i) {
5267 if (nursery_check_labels [i])
5268 mono_mb_patch_branch (mb, nursery_check_labels [i]);
5270 mono_mb_patch_branch (mb, label_no_wb_3);
5271 mono_mb_patch_branch (mb, label_no_wb_4);
5272 mono_mb_emit_byte (mb, CEE_RET);
5275 mono_mb_patch_branch (mb, label_slow_path);
5277 mono_mb_emit_ldarg (mb, 0);
5278 mono_mb_emit_icall (mb, mono_gc_wbarrier_generic_nostore);
5279 mono_mb_emit_byte (mb, CEE_RET);
5283 mono_mb_emit_ldarg (mb, 0);
5284 mono_mb_emit_icall (mb, mono_gc_wbarrier_generic_nostore);
5285 mono_mb_emit_byte (mb, CEE_RET);
5288 res = mono_mb_create_method (mb, sig, 16);
5291 mono_loader_lock ();
5292 if (write_barrier_method) {
5293 /* Already created */
5294 mono_free_method (res);
5296 /* double-checked locking */
5297 mono_memory_barrier ();
5298 write_barrier_method = res;
5300 mono_loader_unlock ();
5302 return write_barrier_method;
5306 mono_gc_get_description (void)
5308 return g_strdup ("sgen");
5312 mono_gc_set_desktop_mode (void)
5317 mono_gc_is_moving (void)
5323 mono_gc_is_disabled (void)
5329 mono_sgen_debug_printf (int level, const char *format, ...)
5333 if (level > gc_debug_level)
5336 va_start (ap, format);
5337 vfprintf (gc_debug_file, format, ap);
5342 mono_sgen_get_logfile (void)
5344 return gc_debug_file;
5348 BOOL APIENTRY mono_gc_dllmain (HMODULE module_handle, DWORD reason, LPVOID reserved)
5355 mono_sgen_get_nursery_clear_policy (void)
5357 return nursery_clear_policy;
5361 mono_sgen_get_array_fill_vtable (void)
5363 if (!array_fill_vtable) {
5364 static MonoClass klass;
5365 static MonoVTable vtable;
5368 MonoDomain *domain = mono_get_root_domain ();
5371 klass.element_class = mono_defaults.byte_class;
5373 klass.instance_size = sizeof (MonoArray);
5374 klass.sizes.element_size = 1;
5375 klass.name = "array_filler_type";
5377 vtable.klass = &klass;
5379 vtable.gc_descr = mono_gc_make_descr_for_array (TRUE, &bmap, 0, 1);
5382 array_fill_vtable = &vtable;
5384 return array_fill_vtable;
5388 mono_sgen_gc_lock (void)
5394 mono_sgen_gc_unlock (void)
5400 sgen_major_collector_iterate_live_block_ranges (sgen_cardtable_block_callback callback)
5402 major_collector.iterate_live_block_ranges (callback);
5406 sgen_major_collector_scan_card_table (SgenGrayQueue *queue)
5408 major_collector.scan_card_table (queue);
5412 mono_sgen_get_major_collector (void)
5414 return &major_collector;
5417 void mono_gc_set_skip_thread (gboolean skip)
5419 SgenThreadInfo *info = mono_thread_info_current ();
5422 info->gc_disabled = skip;
5427 mono_sgen_get_remset (void)
5433 mono_gc_get_vtable_bits (MonoClass *class)
5435 if (mono_sgen_need_bridge_processing () && mono_sgen_is_bridge_class (class))
5436 return SGEN_GC_BIT_BRIDGE_OBJECT;
5440 #endif /* HAVE_SGEN_GC */