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 (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);
2615 time_minor_pinning += TV_ELAPSED (btv, atv);
2616 DEBUG (2, fprintf (gc_debug_file, "Finding pinned pointers: %d in %d usecs\n", mono_sgen_get_pinned_count (), TV_ELAPSED (btv, atv)));
2617 DEBUG (4, fprintf (gc_debug_file, "Start scan with %d pinned objects\n", mono_sgen_get_pinned_count ()));
2619 if (consistency_check_at_minor_collection)
2620 mono_sgen_check_consistency ();
2622 mono_sgen_workers_start_all_workers ();
2625 * Perform the sequential part of remembered set scanning.
2626 * This usually involves scanning global information that might later be produced by evacuation.
2628 if (remset.begin_scan_remsets)
2629 remset.begin_scan_remsets (mono_sgen_get_nursery_start (), nursery_next, WORKERS_DISTRIBUTE_GRAY_QUEUE);
2631 mono_sgen_workers_start_marking ();
2633 frssjd.heap_start = mono_sgen_get_nursery_start ();
2634 frssjd.heap_end = nursery_next;
2635 mono_sgen_workers_enqueue_job (job_finish_remembered_set_scan, &frssjd);
2637 /* we don't have complete write barrier yet, so we scan all the old generation sections */
2639 time_minor_scan_remsets += TV_ELAPSED (atv, btv);
2640 DEBUG (2, fprintf (gc_debug_file, "Old generation scan: %d usecs\n", TV_ELAPSED (atv, btv)));
2642 if (!mono_sgen_collection_is_parallel ())
2643 mono_sgen_drain_gray_stack (&gray_queue, -1);
2645 if (mono_profiler_get_events () & MONO_PROFILE_GC_ROOTS)
2646 report_registered_roots ();
2647 if (mono_profiler_get_events () & MONO_PROFILE_GC_ROOTS)
2648 report_finalizer_roots ();
2650 time_minor_scan_pinned += TV_ELAPSED (btv, atv);
2652 /* registered roots, this includes static fields */
2653 scrrjd_normal.func = mono_sgen_collection_is_parallel () ? major_collector.copy_object : major_collector.nopar_copy_object;
2654 scrrjd_normal.heap_start = mono_sgen_get_nursery_start ();
2655 scrrjd_normal.heap_end = nursery_next;
2656 scrrjd_normal.root_type = ROOT_TYPE_NORMAL;
2657 mono_sgen_workers_enqueue_job (job_scan_from_registered_roots, &scrrjd_normal);
2659 scrrjd_wbarrier.func = mono_sgen_collection_is_parallel () ? major_collector.copy_object : major_collector.nopar_copy_object;
2660 scrrjd_wbarrier.heap_start = mono_sgen_get_nursery_start ();
2661 scrrjd_wbarrier.heap_end = nursery_next;
2662 scrrjd_wbarrier.root_type = ROOT_TYPE_WBARRIER;
2663 mono_sgen_workers_enqueue_job (job_scan_from_registered_roots, &scrrjd_wbarrier);
2666 time_minor_scan_registered_roots += TV_ELAPSED (atv, btv);
2669 stdjd.heap_start = mono_sgen_get_nursery_start ();
2670 stdjd.heap_end = nursery_next;
2671 mono_sgen_workers_enqueue_job (job_scan_thread_data, &stdjd);
2674 time_minor_scan_thread_data += TV_ELAPSED (btv, atv);
2677 if (mono_sgen_collection_is_parallel ()) {
2678 while (!mono_sgen_gray_object_queue_is_empty (WORKERS_DISTRIBUTE_GRAY_QUEUE)) {
2679 mono_sgen_workers_distribute_gray_queue_sections ();
2683 mono_sgen_workers_join ();
2685 if (mono_sgen_collection_is_parallel ())
2686 g_assert (mono_sgen_gray_object_queue_is_empty (&gray_queue));
2688 finish_gray_stack (mono_sgen_get_nursery_start (), nursery_next, GENERATION_NURSERY, &gray_queue);
2690 time_minor_finish_gray_stack += TV_ELAPSED (btv, atv);
2691 mono_profiler_gc_event (MONO_GC_EVENT_MARK_END, 0);
2694 * The (single-threaded) finalization code might have done
2695 * some copying/marking so we can only reset the GC thread's
2696 * worker data here instead of earlier when we joined the
2699 mono_sgen_workers_reset_data ();
2701 if (objects_pinned) {
2702 mono_sgen_optimize_pin_queue (0);
2703 mono_sgen_pinning_setup_section (nursery_section);
2706 /* walk the pin_queue, build up the fragment list of free memory, unmark
2707 * pinned objects as we go, memzero() the empty fragments so they are ready for the
2710 mono_profiler_gc_event (MONO_GC_EVENT_RECLAIM_START, 0);
2711 fragment_total = mono_sgen_build_nursery_fragments (nursery_section, nursery_section->pin_queue_start, nursery_section->pin_queue_num_entries);
2712 if (!fragment_total)
2715 /* Clear TLABs for all threads */
2716 mono_sgen_clear_tlabs ();
2718 mono_profiler_gc_event (MONO_GC_EVENT_RECLAIM_END, 0);
2720 time_minor_fragment_creation += TV_ELAPSED (atv, btv);
2721 DEBUG (2, fprintf (gc_debug_file, "Fragment creation: %d usecs, %lu bytes available\n", TV_ELAPSED (atv, btv), (unsigned long)fragment_total));
2723 if (consistency_check_at_minor_collection)
2724 mono_sgen_check_major_refs ();
2726 major_collector.finish_nursery_collection ();
2728 TV_GETTIME (all_btv);
2729 mono_stats.minor_gc_time_usecs += TV_ELAPSED (all_atv, all_btv);
2732 dump_heap ("minor", stat_minor_gcs - 1, NULL);
2734 /* prepare the pin queue for the next collection */
2735 mono_sgen_finish_pinning ();
2736 if (fin_ready_list || critical_fin_list) {
2737 DEBUG (4, fprintf (gc_debug_file, "Finalizer-thread wakeup: ready %d\n", num_ready_finalizers));
2738 mono_gc_finalize_notify ();
2740 mono_sgen_pin_stats_reset ();
2742 g_assert (mono_sgen_gray_object_queue_is_empty (&gray_queue));
2744 if (remset.finish_minor_collection)
2745 remset.finish_minor_collection ();
2747 check_scan_starts ();
2749 binary_protocol_flush_buffers (FALSE);
2751 /*objects are late pinned because of lack of memory, so a major is a good call*/
2752 needs_major = need_major_collection (0) || objects_pinned;
2753 current_collection_generation = -1;
2760 mono_sgen_collect_nursery_no_lock (size_t requested_size)
2762 gint64 gc_start_time;
2764 mono_profiler_gc_event (MONO_GC_EVENT_START, 0);
2765 gc_start_time = mono_100ns_ticks ();
2768 collect_nursery (requested_size);
2771 mono_trace_message (MONO_TRACE_GC, "minor gc took %d usecs", (mono_100ns_ticks () - gc_start_time) / 10);
2772 mono_profiler_gc_event (MONO_GC_EVENT_END, 0);
2777 FinalizeReadyEntry *list;
2778 } ScanFinalizerEntriesJobData;
2781 job_scan_finalizer_entries (WorkerData *worker_data, void *job_data_untyped)
2783 ScanFinalizerEntriesJobData *job_data = job_data_untyped;
2785 scan_finalizer_entries (major_collector.copy_or_mark_object,
2787 mono_sgen_workers_get_job_gray_queue (worker_data));
2791 major_do_collection (const char *reason)
2793 LOSObject *bigobj, *prevbo;
2794 TV_DECLARE (all_atv);
2795 TV_DECLARE (all_btv);
2798 /* FIXME: only use these values for the precise scan
2799 * note that to_space pointers should be excluded anyway...
2801 char *heap_start = NULL;
2802 char *heap_end = (char*)-1;
2803 int old_next_pin_slot;
2804 ScanFromRegisteredRootsJobData scrrjd_normal, scrrjd_wbarrier;
2805 ScanThreadDataJobData stdjd;
2806 ScanFinalizerEntriesJobData sfejd_fin_ready, sfejd_critical_fin;
2808 mono_perfcounters->gc_collections1++;
2810 reset_pinned_from_failed_allocation ();
2812 last_collection_old_num_major_sections = major_collector.get_num_major_sections ();
2815 * A domain could have been freed, resulting in
2816 * los_memory_usage being less than last_collection_los_memory_usage.
2818 last_collection_los_memory_alloced = los_memory_usage - MIN (last_collection_los_memory_usage, los_memory_usage);
2819 last_collection_old_los_memory_usage = los_memory_usage;
2822 //count_ref_nonref_objs ();
2823 //consistency_check ();
2825 binary_protocol_collection (GENERATION_OLD);
2826 check_scan_starts ();
2827 mono_sgen_gray_object_queue_init (&gray_queue);
2828 mono_sgen_workers_init_distribute_gray_queue ();
2831 DEBUG (1, fprintf (gc_debug_file, "Start major collection %d\n", stat_major_gcs));
2833 mono_stats.major_gc_count ++;
2835 /* world must be stopped already */
2836 TV_GETTIME (all_atv);
2839 /* Pinning depends on this */
2840 mono_sgen_clear_nursery_fragments ();
2843 time_major_pre_collection_fragment_clear += TV_ELAPSED (atv, btv);
2845 nursery_section->next_data = mono_sgen_get_nursery_end ();
2846 /* we should also coalesce scanning from sections close to each other
2847 * and deal with pointers outside of the sections later.
2850 if (major_collector.start_major_collection)
2851 major_collector.start_major_collection ();
2853 *major_collector.have_swept = FALSE;
2854 reset_minor_collection_allowance ();
2857 check_for_xdomain_refs ();
2859 /* Remsets are not useful for a major collection */
2860 remset.prepare_for_major_collection ();
2862 process_fin_stage_entries ();
2863 process_dislink_stage_entries ();
2866 mono_sgen_init_pinning ();
2867 DEBUG (6, fprintf (gc_debug_file, "Collecting pinned addresses\n"));
2868 pin_from_roots ((void*)lowest_heap_address, (void*)highest_heap_address, WORKERS_DISTRIBUTE_GRAY_QUEUE);
2869 mono_sgen_optimize_pin_queue (0);
2872 * pin_queue now contains all candidate pointers, sorted and
2873 * uniqued. We must do two passes now to figure out which
2874 * objects are pinned.
2876 * The first is to find within the pin_queue the area for each
2877 * section. This requires that the pin_queue be sorted. We
2878 * also process the LOS objects and pinned chunks here.
2880 * The second, destructive, pass is to reduce the section
2881 * areas to pointers to the actually pinned objects.
2883 DEBUG (6, fprintf (gc_debug_file, "Pinning from sections\n"));
2884 /* first pass for the sections */
2885 mono_sgen_find_section_pin_queue_start_end (nursery_section);
2886 major_collector.find_pin_queue_start_ends (WORKERS_DISTRIBUTE_GRAY_QUEUE);
2887 /* identify possible pointers to the insize of large objects */
2888 DEBUG (6, fprintf (gc_debug_file, "Pinning from large objects\n"));
2889 for (bigobj = los_object_list; bigobj; bigobj = bigobj->next) {
2891 gboolean profile_roots = mono_profiler_get_events () & MONO_PROFILE_GC_ROOTS;
2892 GCRootReport report;
2894 if (mono_sgen_find_optimized_pin_queue_area (bigobj->data, (char*)bigobj->data + bigobj->size, &dummy)) {
2895 binary_protocol_pin (bigobj->data, (gpointer)LOAD_VTABLE (bigobj->data), safe_object_get_size (bigobj->data));
2896 pin_object (bigobj->data);
2897 /* FIXME: only enqueue if object has references */
2898 GRAY_OBJECT_ENQUEUE (WORKERS_DISTRIBUTE_GRAY_QUEUE, bigobj->data);
2899 if (G_UNLIKELY (do_pin_stats))
2900 mono_sgen_pin_stats_register_object ((char*) bigobj->data, safe_object_get_size ((MonoObject*) bigobj->data));
2901 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));
2904 add_profile_gc_root (&report, bigobj->data, MONO_PROFILE_GC_ROOT_PINNING | MONO_PROFILE_GC_ROOT_MISC, 0);
2907 notify_gc_roots (&report);
2909 /* second pass for the sections */
2910 mono_sgen_pin_objects_in_section (nursery_section, WORKERS_DISTRIBUTE_GRAY_QUEUE);
2911 major_collector.pin_objects (WORKERS_DISTRIBUTE_GRAY_QUEUE);
2912 old_next_pin_slot = mono_sgen_get_pinned_count ();
2915 time_major_pinning += TV_ELAPSED (atv, btv);
2916 DEBUG (2, fprintf (gc_debug_file, "Finding pinned pointers: %d in %d usecs\n", mono_sgen_get_pinned_count (), TV_ELAPSED (atv, btv)));
2917 DEBUG (4, fprintf (gc_debug_file, "Start scan with %d pinned objects\n", mono_sgen_get_pinned_count ()));
2919 major_collector.init_to_space ();
2921 #ifdef SGEN_DEBUG_INTERNAL_ALLOC
2922 main_gc_thread = mono_native_thread_self ();
2925 mono_sgen_workers_start_all_workers ();
2926 mono_sgen_workers_start_marking ();
2928 if (mono_profiler_get_events () & MONO_PROFILE_GC_ROOTS)
2929 report_registered_roots ();
2931 time_major_scan_pinned += TV_ELAPSED (btv, atv);
2933 /* registered roots, this includes static fields */
2934 scrrjd_normal.func = major_collector.copy_or_mark_object;
2935 scrrjd_normal.heap_start = heap_start;
2936 scrrjd_normal.heap_end = heap_end;
2937 scrrjd_normal.root_type = ROOT_TYPE_NORMAL;
2938 mono_sgen_workers_enqueue_job (job_scan_from_registered_roots, &scrrjd_normal);
2940 scrrjd_wbarrier.func = major_collector.copy_or_mark_object;
2941 scrrjd_wbarrier.heap_start = heap_start;
2942 scrrjd_wbarrier.heap_end = heap_end;
2943 scrrjd_wbarrier.root_type = ROOT_TYPE_WBARRIER;
2944 mono_sgen_workers_enqueue_job (job_scan_from_registered_roots, &scrrjd_wbarrier);
2947 time_major_scan_registered_roots += TV_ELAPSED (atv, btv);
2950 stdjd.heap_start = heap_start;
2951 stdjd.heap_end = heap_end;
2952 mono_sgen_workers_enqueue_job (job_scan_thread_data, &stdjd);
2955 time_major_scan_thread_data += TV_ELAPSED (btv, atv);
2958 time_major_scan_alloc_pinned += TV_ELAPSED (atv, btv);
2960 if (mono_profiler_get_events () & MONO_PROFILE_GC_ROOTS)
2961 report_finalizer_roots ();
2963 /* scan the list of objects ready for finalization */
2964 sfejd_fin_ready.list = fin_ready_list;
2965 mono_sgen_workers_enqueue_job (job_scan_finalizer_entries, &sfejd_fin_ready);
2967 sfejd_critical_fin.list = critical_fin_list;
2968 mono_sgen_workers_enqueue_job (job_scan_finalizer_entries, &sfejd_critical_fin);
2971 time_major_scan_finalized += TV_ELAPSED (btv, atv);
2972 DEBUG (2, fprintf (gc_debug_file, "Root scan: %d usecs\n", TV_ELAPSED (btv, atv)));
2975 time_major_scan_big_objects += TV_ELAPSED (atv, btv);
2977 if (major_collector.is_parallel) {
2978 while (!mono_sgen_gray_object_queue_is_empty (WORKERS_DISTRIBUTE_GRAY_QUEUE)) {
2979 mono_sgen_workers_distribute_gray_queue_sections ();
2983 mono_sgen_workers_join ();
2985 #ifdef SGEN_DEBUG_INTERNAL_ALLOC
2986 main_gc_thread = NULL;
2989 if (major_collector.is_parallel)
2990 g_assert (mono_sgen_gray_object_queue_is_empty (&gray_queue));
2992 /* all the objects in the heap */
2993 finish_gray_stack (heap_start, heap_end, GENERATION_OLD, &gray_queue);
2995 time_major_finish_gray_stack += TV_ELAPSED (btv, atv);
2998 * The (single-threaded) finalization code might have done
2999 * some copying/marking so we can only reset the GC thread's
3000 * worker data here instead of earlier when we joined the
3003 mono_sgen_workers_reset_data ();
3005 if (objects_pinned) {
3006 /*This is slow, but we just OOM'd*/
3007 mono_sgen_pin_queue_clear_discarded_entries (nursery_section, old_next_pin_slot);
3008 mono_sgen_optimize_pin_queue (0);
3009 mono_sgen_find_section_pin_queue_start_end (nursery_section);
3013 reset_heap_boundaries ();
3014 mono_sgen_update_heap_boundaries ((mword)mono_sgen_get_nursery_start (), (mword)mono_sgen_get_nursery_end ());
3016 /* sweep the big objects list */
3018 for (bigobj = los_object_list; bigobj;) {
3019 if (object_is_pinned (bigobj->data)) {
3020 unpin_object (bigobj->data);
3021 mono_sgen_update_heap_boundaries ((mword)bigobj->data, (mword)bigobj->data + bigobj->size);
3024 /* not referenced anywhere, so we can free it */
3026 prevbo->next = bigobj->next;
3028 los_object_list = bigobj->next;
3030 bigobj = bigobj->next;
3031 mono_sgen_los_free_object (to_free);
3035 bigobj = bigobj->next;
3039 time_major_free_bigobjs += TV_ELAPSED (atv, btv);
3041 mono_sgen_los_sweep ();
3044 time_major_los_sweep += TV_ELAPSED (btv, atv);
3046 major_collector.sweep ();
3049 time_major_sweep += TV_ELAPSED (atv, btv);
3051 /* walk the pin_queue, build up the fragment list of free memory, unmark
3052 * pinned objects as we go, memzero() the empty fragments so they are ready for the
3055 if (!mono_sgen_build_nursery_fragments (nursery_section, nursery_section->pin_queue_start, nursery_section->pin_queue_num_entries))
3058 /* Clear TLABs for all threads */
3059 mono_sgen_clear_tlabs ();
3062 time_major_fragment_creation += TV_ELAPSED (btv, atv);
3064 TV_GETTIME (all_btv);
3065 mono_stats.major_gc_time_usecs += TV_ELAPSED (all_atv, all_btv);
3068 dump_heap ("major", stat_major_gcs - 1, reason);
3070 /* prepare the pin queue for the next collection */
3071 mono_sgen_finish_pinning ();
3073 if (fin_ready_list || critical_fin_list) {
3074 DEBUG (4, fprintf (gc_debug_file, "Finalizer-thread wakeup: ready %d\n", num_ready_finalizers));
3075 mono_gc_finalize_notify ();
3077 mono_sgen_pin_stats_reset ();
3079 g_assert (mono_sgen_gray_object_queue_is_empty (&gray_queue));
3081 try_calculate_minor_collection_allowance (TRUE);
3083 minor_collection_sections_alloced = 0;
3084 last_collection_los_memory_usage = los_memory_usage;
3086 major_collector.finish_major_collection ();
3088 check_scan_starts ();
3090 binary_protocol_flush_buffers (FALSE);
3092 //consistency_check ();
3094 return bytes_pinned_from_failed_allocation > 0;
3098 major_collection (const char *reason)
3100 gboolean need_minor_collection;
3102 if (disable_major_collections) {
3103 collect_nursery (0);
3107 major_collection_happened = TRUE;
3108 current_collection_generation = GENERATION_OLD;
3109 need_minor_collection = major_do_collection (reason);
3110 current_collection_generation = -1;
3112 if (need_minor_collection)
3113 collect_nursery (0);
3117 sgen_collect_major_no_lock (const char *reason)
3119 gint64 gc_start_time;
3121 mono_profiler_gc_event (MONO_GC_EVENT_START, 1);
3122 gc_start_time = mono_100ns_ticks ();
3124 major_collection (reason);
3126 mono_trace_message (MONO_TRACE_GC, "major gc took %d usecs", (mono_100ns_ticks () - gc_start_time) / 10);
3127 mono_profiler_gc_event (MONO_GC_EVENT_END, 1);
3131 * When deciding if it's better to collect or to expand, keep track
3132 * of how much garbage was reclaimed with the last collection: if it's too
3134 * This is called when we could not allocate a small object.
3136 static void __attribute__((noinline))
3137 minor_collect_or_expand_inner (size_t size)
3139 int do_minor_collection = 1;
3141 g_assert (nursery_section);
3142 if (do_minor_collection) {
3143 gint64 total_gc_time, major_gc_time = 0;
3145 mono_profiler_gc_event (MONO_GC_EVENT_START, 0);
3146 total_gc_time = mono_100ns_ticks ();
3149 if (collect_nursery (size)) {
3150 mono_profiler_gc_event (MONO_GC_EVENT_START, 1);
3151 major_gc_time = mono_100ns_ticks ();
3153 major_collection ("minor overflow");
3155 /* keep events symmetric */
3156 major_gc_time = mono_100ns_ticks () - major_gc_time;
3157 mono_profiler_gc_event (MONO_GC_EVENT_END, 1);
3159 DEBUG (2, fprintf (gc_debug_file, "Heap size: %lu, LOS size: %lu\n", (unsigned long)total_alloc, (unsigned long)los_memory_usage));
3162 total_gc_time = mono_100ns_ticks () - total_gc_time;
3164 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);
3166 mono_trace_message (MONO_TRACE_GC, "minor gc took %d usecs", total_gc_time / 10);
3168 /* this also sets the proper pointers for the next allocation */
3169 if (!mono_sgen_can_alloc_size (size)) {
3170 /* TypeBuilder and MonoMethod are killing mcs with fragmentation */
3171 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 ()));
3172 mono_sgen_dump_pin_queue ();
3175 mono_profiler_gc_event (MONO_GC_EVENT_END, 0);
3177 //report_internal_mem_usage ();
3181 mono_sgen_minor_collect_or_expand_inner (size_t size)
3183 minor_collect_or_expand_inner (size);
3187 * ######################################################################
3188 * ######## Memory allocation from the OS
3189 * ######################################################################
3190 * This section of code deals with getting memory from the OS and
3191 * allocating memory for GC-internal data structures.
3192 * Internal memory can be handled with a freelist for small objects.
3198 G_GNUC_UNUSED static void
3199 report_internal_mem_usage (void)
3201 printf ("Internal memory usage:\n");
3202 mono_sgen_report_internal_mem_usage ();
3203 printf ("Pinned memory usage:\n");
3204 major_collector.report_pinned_memory_usage ();
3208 * ######################################################################
3209 * ######## Finalization support
3210 * ######################################################################
3214 * this is valid for the nursery: if the object has been forwarded it means it's
3215 * still refrenced from a root. If it is pinned it's still alive as well.
3216 * Return TRUE if @obj is ready to be finalized.
3218 #define object_is_fin_ready(obj) (!object_is_pinned (obj) && !object_is_forwarded (obj))
3222 mono_sgen_gc_is_object_ready_for_finalization (void *object)
3224 return !major_collector.is_object_live (object) && object_is_fin_ready (object);
3228 has_critical_finalizer (MonoObject *obj)
3232 if (!mono_defaults.critical_finalizer_object)
3235 class = ((MonoVTable*)LOAD_VTABLE (obj))->klass;
3237 return mono_class_has_parent_fast (class, mono_defaults.critical_finalizer_object);
3241 queue_finalization_entry (MonoObject *obj) {
3242 FinalizeReadyEntry *entry = mono_sgen_alloc_internal (INTERNAL_MEM_FINALIZE_READY_ENTRY);
3243 entry->object = obj;
3244 if (has_critical_finalizer (obj)) {
3245 entry->next = critical_fin_list;
3246 critical_fin_list = entry;
3248 entry->next = fin_ready_list;
3249 fin_ready_list = entry;
3254 object_is_reachable (char *object, char *start, char *end)
3256 /*This happens for non nursery objects during minor collections. We just treat all objects as alive.*/
3257 if (object < start || object >= end)
3259 return !object_is_fin_ready (object) || major_collector.is_object_live (object);
3262 #include "sgen-fin-weak-hash.c"
3265 mono_sgen_object_is_live (void *obj)
3267 if (ptr_in_nursery (obj))
3268 return object_is_pinned (obj);
3269 if (current_collection_generation == GENERATION_NURSERY)
3271 return major_collector.is_object_live (obj);
3274 /* LOCKING: requires that the GC lock is held */
3276 null_ephemerons_for_domain (MonoDomain *domain)
3278 EphemeronLinkNode *current = ephemeron_list, *prev = NULL;
3281 MonoObject *object = (MonoObject*)current->array;
3283 if (object && !object->vtable) {
3284 EphemeronLinkNode *tmp = current;
3287 prev->next = current->next;
3289 ephemeron_list = current->next;
3291 current = current->next;
3292 mono_sgen_free_internal (tmp, INTERNAL_MEM_EPHEMERON_LINK);
3295 current = current->next;
3300 /* LOCKING: requires that the GC lock is held */
3302 clear_unreachable_ephemerons (CopyOrMarkObjectFunc copy_func, char *start, char *end, GrayQueue *queue)
3304 int was_in_nursery, was_promoted;
3305 EphemeronLinkNode *current = ephemeron_list, *prev = NULL;
3307 Ephemeron *cur, *array_end;
3311 char *object = current->array;
3313 if (!object_is_reachable (object, start, end)) {
3314 EphemeronLinkNode *tmp = current;
3316 DEBUG (5, fprintf (gc_debug_file, "Dead Ephemeron array at %p\n", object));
3319 prev->next = current->next;
3321 ephemeron_list = current->next;
3323 current = current->next;
3324 mono_sgen_free_internal (tmp, INTERNAL_MEM_EPHEMERON_LINK);
3329 was_in_nursery = ptr_in_nursery (object);
3330 copy_func ((void**)&object, queue);
3331 current->array = object;
3333 /*The array was promoted, add global remsets for key/values left behind in nursery.*/
3334 was_promoted = was_in_nursery && !ptr_in_nursery (object);
3336 DEBUG (5, fprintf (gc_debug_file, "Clearing unreachable entries for ephemeron array at %p\n", object));
3338 array = (MonoArray*)object;
3339 cur = mono_array_addr (array, Ephemeron, 0);
3340 array_end = cur + mono_array_length_fast (array);
3341 tombstone = (char*)((MonoVTable*)LOAD_VTABLE (object))->domain->ephemeron_tombstone;
3343 for (; cur < array_end; ++cur) {
3344 char *key = (char*)cur->key;
3346 if (!key || key == tombstone)
3349 DEBUG (5, fprintf (gc_debug_file, "[%td] key %p (%s) value %p (%s)\n", cur - mono_array_addr (array, Ephemeron, 0),
3350 key, object_is_reachable (key, start, end) ? "reachable" : "unreachable",
3351 cur->value, cur->value && object_is_reachable (cur->value, start, end) ? "reachable" : "unreachable"));
3353 if (!object_is_reachable (key, start, end)) {
3354 cur->key = tombstone;
3360 if (ptr_in_nursery (key)) {/*key was not promoted*/
3361 DEBUG (5, fprintf (gc_debug_file, "\tAdded remset to key %p\n", key));
3362 mono_sgen_add_to_global_remset (&cur->key);
3364 if (ptr_in_nursery (cur->value)) {/*value was not promoted*/
3365 DEBUG (5, fprintf (gc_debug_file, "\tAdded remset to value %p\n", cur->value));
3366 mono_sgen_add_to_global_remset (&cur->value);
3371 current = current->next;
3375 /* LOCKING: requires that the GC lock is held */
3377 mark_ephemerons_in_range (CopyOrMarkObjectFunc copy_func, char *start, char *end, GrayQueue *queue)
3379 int nothing_marked = 1;
3380 EphemeronLinkNode *current = ephemeron_list;
3382 Ephemeron *cur, *array_end;
3385 for (current = ephemeron_list; current; current = current->next) {
3386 char *object = current->array;
3387 DEBUG (5, fprintf (gc_debug_file, "Ephemeron array at %p\n", object));
3390 For now we process all ephemerons during all collections.
3391 Ideally we should use remset information to partially scan those
3393 We already emit write barriers for Ephemeron fields, it's
3394 just that we don't process them.
3396 /*if (object < start || object >= end)
3399 /*It has to be alive*/
3400 if (!object_is_reachable (object, start, end)) {
3401 DEBUG (5, fprintf (gc_debug_file, "\tnot reachable\n"));
3405 copy_func ((void**)&object, queue);
3407 array = (MonoArray*)object;
3408 cur = mono_array_addr (array, Ephemeron, 0);
3409 array_end = cur + mono_array_length_fast (array);
3410 tombstone = (char*)((MonoVTable*)LOAD_VTABLE (object))->domain->ephemeron_tombstone;
3412 for (; cur < array_end; ++cur) {
3413 char *key = cur->key;
3415 if (!key || key == tombstone)
3418 DEBUG (5, fprintf (gc_debug_file, "[%td] key %p (%s) value %p (%s)\n", cur - mono_array_addr (array, Ephemeron, 0),
3419 key, object_is_reachable (key, start, end) ? "reachable" : "unreachable",
3420 cur->value, cur->value && object_is_reachable (cur->value, start, end) ? "reachable" : "unreachable"));
3422 if (object_is_reachable (key, start, end)) {
3423 char *value = cur->value;
3425 copy_func ((void**)&cur->key, queue);
3427 if (!object_is_reachable (value, start, end))
3429 copy_func ((void**)&cur->value, queue);
3435 DEBUG (5, fprintf (gc_debug_file, "Ephemeron run finished. Is it done %d\n", nothing_marked));
3436 return nothing_marked;
3440 mono_gc_invoke_finalizers (void)
3442 FinalizeReadyEntry *entry = NULL;
3443 gboolean entry_is_critical = FALSE;
3446 /* FIXME: batch to reduce lock contention */
3447 while (fin_ready_list || critical_fin_list) {
3451 FinalizeReadyEntry **list = entry_is_critical ? &critical_fin_list : &fin_ready_list;
3453 /* We have finalized entry in the last
3454 interation, now we need to remove it from
3457 *list = entry->next;
3459 FinalizeReadyEntry *e = *list;
3460 while (e->next != entry)
3462 e->next = entry->next;
3464 mono_sgen_free_internal (entry, INTERNAL_MEM_FINALIZE_READY_ENTRY);
3468 /* Now look for the first non-null entry. */
3469 for (entry = fin_ready_list; entry && !entry->object; entry = entry->next)
3472 entry_is_critical = FALSE;
3474 entry_is_critical = TRUE;
3475 for (entry = critical_fin_list; entry && !entry->object; entry = entry->next)
3480 g_assert (entry->object);
3481 num_ready_finalizers--;
3482 obj = entry->object;
3483 entry->object = NULL;
3484 DEBUG (7, fprintf (gc_debug_file, "Finalizing object %p (%s)\n", obj, safe_name (obj)));
3492 g_assert (entry->object == NULL);
3494 /* the object is on the stack so it is pinned */
3495 /*g_print ("Calling finalizer for object: %p (%s)\n", entry->object, safe_name (entry->object));*/
3496 mono_gc_run_finalize (obj, NULL);
3503 mono_gc_pending_finalizers (void)
3505 return fin_ready_list || critical_fin_list;
3508 /* Negative value to remove */
3510 mono_gc_add_memory_pressure (gint64 value)
3512 /* FIXME: Use interlocked functions */
3514 memory_pressure += value;
3519 mono_sgen_register_major_sections_alloced (int num_sections)
3521 minor_collection_sections_alloced += num_sections;
3525 mono_sgen_get_minor_collection_allowance (void)
3527 return minor_collection_allowance;
3531 * ######################################################################
3532 * ######## registered roots support
3533 * ######################################################################
3537 * We do not coalesce roots.
3540 mono_gc_register_root_inner (char *start, size_t size, void *descr, int root_type)
3542 RootRecord new_root;
3545 for (i = 0; i < ROOT_TYPE_NUM; ++i) {
3546 RootRecord *root = mono_sgen_hash_table_lookup (&roots_hash [i], start);
3547 /* we allow changing the size and the descriptor (for thread statics etc) */
3549 size_t old_size = root->end_root - start;
3550 root->end_root = start + size;
3551 g_assert (((root->root_desc != 0) && (descr != NULL)) ||
3552 ((root->root_desc == 0) && (descr == NULL)));
3553 root->root_desc = (mword)descr;
3555 roots_size -= old_size;
3561 new_root.end_root = start + size;
3562 new_root.root_desc = (mword)descr;
3564 mono_sgen_hash_table_replace (&roots_hash [root_type], start, &new_root);
3567 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));
3574 mono_gc_register_root (char *start, size_t size, void *descr)
3576 return mono_gc_register_root_inner (start, size, descr, descr ? ROOT_TYPE_NORMAL : ROOT_TYPE_PINNED);
3580 mono_gc_register_root_wbarrier (char *start, size_t size, void *descr)
3582 return mono_gc_register_root_inner (start, size, descr, ROOT_TYPE_WBARRIER);
3586 mono_gc_deregister_root (char* addr)
3592 for (root_type = 0; root_type < ROOT_TYPE_NUM; ++root_type) {
3593 if (mono_sgen_hash_table_remove (&roots_hash [root_type], addr, &root))
3594 roots_size -= (root.end_root - addr);
3600 * ######################################################################
3601 * ######## Thread handling (stop/start code)
3602 * ######################################################################
3605 unsigned int mono_sgen_global_stop_count = 0;
3608 static MonoContext cur_thread_ctx = {0};
3610 static mword cur_thread_regs [ARCH_NUM_REGS] = {0};
3614 update_current_thread_stack (void *start)
3616 int stack_guard = 0;
3617 #ifndef USE_MONO_CTX
3618 void *ptr = cur_thread_regs;
3620 SgenThreadInfo *info = mono_thread_info_current ();
3622 info->stack_start = align_pointer (&stack_guard);
3623 g_assert (info->stack_start >= info->stack_start_limit && info->stack_start < info->stack_end);
3625 MONO_CONTEXT_GET_CURRENT (cur_thread_ctx);
3626 info->monoctx = &cur_thread_ctx;
3628 ARCH_STORE_REGS (ptr);
3629 info->stopped_regs = ptr;
3631 if (gc_callbacks.thread_suspend_func)
3632 gc_callbacks.thread_suspend_func (info->runtime_data, NULL);
3636 mono_sgen_fill_thread_info_for_suspend (SgenThreadInfo *info)
3638 if (remset.fill_thread_info_for_suspend)
3639 remset.fill_thread_info_for_suspend (info);
3643 is_ip_in_managed_allocator (MonoDomain *domain, gpointer ip);
3646 restart_threads_until_none_in_managed_allocator (void)
3648 SgenThreadInfo *info;
3649 int num_threads_died = 0;
3650 int sleep_duration = -1;
3653 int restart_count = 0, restarted_count = 0;
3654 /* restart all threads that stopped in the
3656 FOREACH_THREAD_SAFE (info) {
3658 if (info->skip || info->gc_disabled)
3660 if (!info->thread_is_dying && (!info->stack_start || info->in_critical_region ||
3661 is_ip_in_managed_allocator (info->stopped_domain, info->stopped_ip))) {
3662 binary_protocol_thread_restart ((gpointer)mono_thread_info_get_tid (info));
3663 result = mono_sgen_resume_thread (info);
3670 /* we set the stopped_ip to
3671 NULL for threads which
3672 we're not restarting so
3673 that we can easily identify
3675 info->stopped_ip = NULL;
3676 info->stopped_domain = NULL;
3678 } END_FOREACH_THREAD_SAFE
3679 /* if no threads were restarted, we're done */
3680 if (restart_count == 0)
3683 /* wait for the threads to signal their restart */
3684 mono_sgen_wait_for_suspend_ack (restart_count);
3686 if (sleep_duration < 0) {
3694 g_usleep (sleep_duration);
3695 sleep_duration += 10;
3698 /* stop them again */
3699 FOREACH_THREAD (info) {
3701 if (info->skip || info->stopped_ip == NULL)
3703 result = mono_sgen_suspend_thread (info);
3710 } END_FOREACH_THREAD
3711 /* some threads might have died */
3712 num_threads_died += restart_count - restarted_count;
3713 /* wait for the threads to signal their suspension
3715 mono_sgen_wait_for_suspend_ack (restart_count);
3718 return num_threads_died;
3722 acquire_gc_locks (void)
3725 mono_thread_info_suspend_lock ();
3729 release_gc_locks (void)
3731 mono_thread_info_suspend_unlock ();
3732 UNLOCK_INTERRUPTION;
3735 static TV_DECLARE (stop_world_time);
3736 static unsigned long max_pause_usec = 0;
3738 /* LOCKING: assumes the GC lock is held */
3740 stop_world (int generation)
3744 /*XXX this is the right stop, thought might not be the nicest place to put it*/
3745 mono_sgen_process_togglerefs ();
3747 mono_profiler_gc_event (MONO_GC_EVENT_PRE_STOP_WORLD, generation);
3748 acquire_gc_locks ();
3750 update_current_thread_stack (&count);
3752 mono_sgen_global_stop_count++;
3753 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 ()));
3754 TV_GETTIME (stop_world_time);
3755 count = mono_sgen_thread_handshake (TRUE);
3756 count -= restart_threads_until_none_in_managed_allocator ();
3757 g_assert (count >= 0);
3758 DEBUG (3, fprintf (gc_debug_file, "world stopped %d thread(s)\n", count));
3759 mono_profiler_gc_event (MONO_GC_EVENT_POST_STOP_WORLD, generation);
3761 last_major_num_sections = major_collector.get_num_major_sections ();
3762 last_los_memory_usage = los_memory_usage;
3763 major_collection_happened = FALSE;
3767 /* LOCKING: assumes the GC lock is held */
3769 restart_world (int generation)
3771 int count, num_major_sections;
3772 SgenThreadInfo *info;
3773 TV_DECLARE (end_sw);
3774 TV_DECLARE (end_bridge);
3775 unsigned long usec, bridge_usec;
3777 /* notify the profiler of the leftovers */
3778 if (G_UNLIKELY (mono_profiler_events & MONO_PROFILE_GC_MOVES)) {
3779 if (moved_objects_idx) {
3780 mono_profiler_gc_moves (moved_objects, moved_objects_idx);
3781 moved_objects_idx = 0;
3784 mono_profiler_gc_event (MONO_GC_EVENT_PRE_START_WORLD, generation);
3785 FOREACH_THREAD (info) {
3786 info->stack_start = NULL;
3788 info->monoctx = NULL;
3790 info->stopped_regs = NULL;
3792 } END_FOREACH_THREAD
3794 stw_bridge_process ();
3795 release_gc_locks ();
3797 count = mono_sgen_thread_handshake (FALSE);
3798 TV_GETTIME (end_sw);
3799 usec = TV_ELAPSED (stop_world_time, end_sw);
3800 max_pause_usec = MAX (usec, max_pause_usec);
3801 DEBUG (2, fprintf (gc_debug_file, "restarted %d thread(s) (pause time: %d usec, max: %d)\n", count, (int)usec, (int)max_pause_usec));
3802 mono_profiler_gc_event (MONO_GC_EVENT_POST_START_WORLD, generation);
3806 TV_GETTIME (end_bridge);
3807 bridge_usec = TV_ELAPSED (end_sw, end_bridge);
3809 num_major_sections = major_collector.get_num_major_sections ();
3810 if (major_collection_happened)
3811 mono_trace (G_LOG_LEVEL_INFO, MONO_TRACE_GC, "GC_MAJOR: %s pause %.2fms, bridge %.2fms major %dK/%dK los %dK/%dK",
3812 generation ? "" : "(minor overflow)",
3813 (int)usec / 1000.0f, (int)bridge_usec / 1000.0f,
3814 major_collector.section_size * num_major_sections / 1024,
3815 major_collector.section_size * last_major_num_sections / 1024,
3816 los_memory_usage / 1024,
3817 last_los_memory_usage / 1024);
3819 mono_trace (G_LOG_LEVEL_INFO, MONO_TRACE_GC, "GC_MINOR: pause %.2fms, bridge %.2fms promoted %dK major %dK los %dK",
3820 (int)usec / 1000.0f, (int)bridge_usec / 1000.0f,
3821 (num_major_sections - last_major_num_sections) * major_collector.section_size / 1024,
3822 major_collector.section_size * num_major_sections / 1024,
3823 los_memory_usage / 1024);
3829 mono_sgen_get_current_collection_generation (void)
3831 return current_collection_generation;
3835 mono_gc_set_gc_callbacks (MonoGCCallbacks *callbacks)
3837 gc_callbacks = *callbacks;
3841 mono_gc_get_gc_callbacks ()
3843 return &gc_callbacks;
3846 /* Variables holding start/end nursery so it won't have to be passed at every call */
3847 static void *scan_area_arg_start, *scan_area_arg_end;
3850 mono_gc_conservatively_scan_area (void *start, void *end)
3852 conservatively_pin_objects_from (start, end, scan_area_arg_start, scan_area_arg_end, PIN_TYPE_STACK);
3856 mono_gc_scan_object (void *obj)
3858 UserCopyOrMarkData *data = mono_native_tls_get_value (user_copy_or_mark_key);
3860 if (current_collection_generation == GENERATION_NURSERY) {
3861 if (mono_sgen_collection_is_parallel ())
3862 major_collector.copy_object (&obj, data->queue);
3864 major_collector.nopar_copy_object (&obj, data->queue);
3866 major_collector.copy_or_mark_object (&obj, data->queue);
3872 * Mark from thread stacks and registers.
3875 scan_thread_data (void *start_nursery, void *end_nursery, gboolean precise, GrayQueue *queue)
3877 SgenThreadInfo *info;
3879 scan_area_arg_start = start_nursery;
3880 scan_area_arg_end = end_nursery;
3882 FOREACH_THREAD (info) {
3884 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));
3887 if (info->gc_disabled) {
3888 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));
3891 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 ()));
3892 if (!info->thread_is_dying) {
3893 if (gc_callbacks.thread_mark_func && !conservative_stack_mark) {
3894 UserCopyOrMarkData data = { NULL, queue };
3895 set_user_copy_or_mark_data (&data);
3896 gc_callbacks.thread_mark_func (info->runtime_data, info->stack_start, info->stack_end, precise);
3897 set_user_copy_or_mark_data (NULL);
3898 } else if (!precise) {
3899 conservatively_pin_objects_from (info->stack_start, info->stack_end, start_nursery, end_nursery, PIN_TYPE_STACK);
3904 if (!info->thread_is_dying && !precise)
3905 conservatively_pin_objects_from ((void**)info->monoctx, (void**)info->monoctx + ARCH_NUM_REGS,
3906 start_nursery, end_nursery, PIN_TYPE_STACK);
3908 if (!info->thread_is_dying && !precise)
3909 conservatively_pin_objects_from (info->stopped_regs, info->stopped_regs + ARCH_NUM_REGS,
3910 start_nursery, end_nursery, PIN_TYPE_STACK);
3912 } END_FOREACH_THREAD
3916 find_pinning_ref_from_thread (char *obj, size_t size)
3919 SgenThreadInfo *info;
3920 char *endobj = obj + size;
3922 FOREACH_THREAD (info) {
3923 char **start = (char**)info->stack_start;
3926 while (start < (char**)info->stack_end) {
3927 if (*start >= obj && *start < endobj) {
3928 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));
3933 for (j = 0; j < ARCH_NUM_REGS; ++j) {
3935 mword w = ((mword*)info->monoctx) [j];
3937 mword w = (mword)info->stopped_regs [j];
3940 if (w >= (mword)obj && w < (mword)obj + size)
3941 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)));
3942 } END_FOREACH_THREAD
3947 ptr_on_stack (void *ptr)
3949 gpointer stack_start = &stack_start;
3950 SgenThreadInfo *info = mono_thread_info_current ();
3952 if (ptr >= stack_start && ptr < (gpointer)info->stack_end)
3958 sgen_thread_register (SgenThreadInfo* info, void *addr)
3960 #ifndef HAVE_KW_THREAD
3961 SgenThreadInfo *__thread_info__ = info;
3965 #ifndef HAVE_KW_THREAD
3966 info->tlab_start = info->tlab_next = info->tlab_temp_end = info->tlab_real_end = NULL;
3968 g_assert (!mono_native_tls_get_value (thread_info_key));
3969 mono_native_tls_set_value (thread_info_key, info);
3974 #if !defined(__MACH__)
3975 info->stop_count = -1;
3979 info->doing_handshake = FALSE;
3980 info->thread_is_dying = FALSE;
3981 info->stack_start = NULL;
3982 info->store_remset_buffer_addr = &STORE_REMSET_BUFFER;
3983 info->store_remset_buffer_index_addr = &STORE_REMSET_BUFFER_INDEX;
3984 info->stopped_ip = NULL;
3985 info->stopped_domain = NULL;
3987 info->monoctx = NULL;
3989 info->stopped_regs = NULL;
3992 mono_sgen_init_tlab_info (info);
3994 binary_protocol_thread_register ((gpointer)mono_thread_info_get_tid (info));
3996 #ifdef HAVE_KW_THREAD
3997 store_remset_buffer_index_addr = &store_remset_buffer_index;
4000 #if defined(__MACH__)
4001 info->mach_port = mach_thread_self ();
4004 /* try to get it with attributes first */
4005 #if defined(HAVE_PTHREAD_GETATTR_NP) && defined(HAVE_PTHREAD_ATTR_GETSTACK)
4009 pthread_attr_t attr;
4010 pthread_getattr_np (pthread_self (), &attr);
4011 pthread_attr_getstack (&attr, &sstart, &size);
4012 info->stack_start_limit = sstart;
4013 info->stack_end = (char*)sstart + size;
4014 pthread_attr_destroy (&attr);
4016 #elif defined(HAVE_PTHREAD_GET_STACKSIZE_NP) && defined(HAVE_PTHREAD_GET_STACKADDR_NP)
4017 info->stack_end = (char*)pthread_get_stackaddr_np (pthread_self ());
4018 info->stack_start_limit = (char*)info->stack_end - pthread_get_stacksize_np (pthread_self ());
4021 /* FIXME: we assume the stack grows down */
4022 gsize stack_bottom = (gsize)addr;
4023 stack_bottom += 4095;
4024 stack_bottom &= ~4095;
4025 info->stack_end = (char*)stack_bottom;
4029 #ifdef HAVE_KW_THREAD
4030 stack_end = info->stack_end;
4033 if (remset.register_thread)
4034 remset.register_thread (info);
4036 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));
4038 if (gc_callbacks.thread_attach_func)
4039 info->runtime_data = gc_callbacks.thread_attach_func ();
4046 mono_sgen_wbarrier_cleanup_thread (SgenThreadInfo *p)
4048 if (remset.cleanup_thread)
4049 remset.cleanup_thread (p);
4053 sgen_thread_unregister (SgenThreadInfo *p)
4055 /* If a delegate is passed to native code and invoked on a thread we dont
4056 * know about, the jit will register it with mono_jit_thread_attach, but
4057 * we have no way of knowing when that thread goes away. SGen has a TSD
4058 * so we assume that if the domain is still registered, we can detach
4061 if (mono_domain_get ())
4062 mono_thread_detach (mono_thread_current ());
4064 p->thread_is_dying = TRUE;
4067 There is a race condition between a thread finishing executing and been removed
4068 from the GC thread set.
4069 This happens on posix systems when TLS data is been cleaned-up, libpthread will
4070 set the thread_info slot to NULL before calling the cleanup function. This
4071 opens a window in which the thread is registered but has a NULL TLS.
4073 The suspend signal handler needs TLS data to know where to store thread state
4074 data or otherwise it will simply ignore the thread.
4076 This solution works because the thread doing STW will wait until all threads been
4077 suspended handshake back, so there is no race between the doing_hankshake test
4078 and the suspend_thread call.
4080 This is not required on systems that do synchronous STW as those can deal with
4081 the above race at suspend time.
4083 FIXME: I believe we could avoid this by using mono_thread_info_lookup when
4084 mono_thread_info_current returns NULL. Or fix mono_thread_info_lookup to do so.
4086 #if (defined(__MACH__) && MONO_MACH_ARCH_SUPPORTED) || !defined(HAVE_PTHREAD_KILL)
4089 while (!TRYLOCK_GC) {
4090 if (!mono_sgen_park_current_thread_if_doing_handshake (p))
4095 binary_protocol_thread_unregister ((gpointer)mono_thread_info_get_tid (p));
4096 DEBUG (3, fprintf (gc_debug_file, "unregister thread %p (%p)\n", p, (gpointer)mono_thread_info_get_tid (p)));
4098 #if defined(__MACH__)
4099 mach_port_deallocate (current_task (), p->mach_port);
4102 if (gc_callbacks.thread_detach_func) {
4103 gc_callbacks.thread_detach_func (p->runtime_data);
4104 p->runtime_data = NULL;
4106 mono_sgen_wbarrier_cleanup_thread (p);
4108 mono_threads_unregister_current_thread (p);
4114 sgen_thread_attach (SgenThreadInfo *info)
4117 /*this is odd, can we get attached before the gc is inited?*/
4121 if (gc_callbacks.thread_attach_func && !info->runtime_data)
4122 info->runtime_data = gc_callbacks.thread_attach_func ();
4125 mono_gc_register_thread (void *baseptr)
4127 return mono_thread_info_attach (baseptr) != NULL;
4131 * mono_gc_set_stack_end:
4133 * Set the end of the current threads stack to STACK_END. The stack space between
4134 * STACK_END and the real end of the threads stack will not be scanned during collections.
4137 mono_gc_set_stack_end (void *stack_end)
4139 SgenThreadInfo *info;
4142 info = mono_thread_info_current ();
4144 g_assert (stack_end < info->stack_end);
4145 info->stack_end = stack_end;
4150 #if USE_PTHREAD_INTERCEPT
4154 mono_gc_pthread_create (pthread_t *new_thread, const pthread_attr_t *attr, void *(*start_routine)(void *), void *arg)
4156 return pthread_create (new_thread, attr, start_routine, arg);
4160 mono_gc_pthread_join (pthread_t thread, void **retval)
4162 return pthread_join (thread, retval);
4166 mono_gc_pthread_detach (pthread_t thread)
4168 return pthread_detach (thread);
4172 mono_gc_pthread_exit (void *retval)
4174 pthread_exit (retval);
4177 #endif /* USE_PTHREAD_INTERCEPT */
4180 * ######################################################################
4181 * ######## Write barriers
4182 * ######################################################################
4186 * Note: the write barriers first do the needed GC work and then do the actual store:
4187 * this way the value is visible to the conservative GC scan after the write barrier
4188 * itself. If a GC interrupts the barrier in the middle, value will be kept alive by
4189 * the conservative scan, otherwise by the remembered set scan.
4192 mono_gc_wbarrier_set_field (MonoObject *obj, gpointer field_ptr, MonoObject* value)
4194 HEAVY_STAT (++stat_wbarrier_set_field);
4195 if (ptr_in_nursery (field_ptr)) {
4196 *(void**)field_ptr = value;
4199 DEBUG (8, fprintf (gc_debug_file, "Adding remset at %p\n", field_ptr));
4201 binary_protocol_wbarrier (field_ptr, value, value->vtable);
4203 remset.wbarrier_set_field (obj, field_ptr, value);
4207 mono_gc_wbarrier_set_arrayref (MonoArray *arr, gpointer slot_ptr, MonoObject* value)
4209 HEAVY_STAT (++stat_wbarrier_set_arrayref);
4210 if (ptr_in_nursery (slot_ptr)) {
4211 *(void**)slot_ptr = value;
4214 DEBUG (8, fprintf (gc_debug_file, "Adding remset at %p\n", slot_ptr));
4216 binary_protocol_wbarrier (slot_ptr, value, value->vtable);
4218 remset.wbarrier_set_arrayref (arr, slot_ptr, value);
4222 mono_gc_wbarrier_arrayref_copy (gpointer dest_ptr, gpointer src_ptr, int count)
4224 HEAVY_STAT (++stat_wbarrier_arrayref_copy);
4225 /*This check can be done without taking a lock since dest_ptr array is pinned*/
4226 if (ptr_in_nursery (dest_ptr) || count <= 0) {
4227 mono_gc_memmove (dest_ptr, src_ptr, count * sizeof (gpointer));
4231 #ifdef SGEN_BINARY_PROTOCOL
4234 for (i = 0; i < count; ++i) {
4235 gpointer dest = (gpointer*)dest_ptr + i;
4236 gpointer obj = *((gpointer*)src_ptr + i);
4238 binary_protocol_wbarrier (dest, obj, (gpointer)LOAD_VTABLE (obj));
4243 remset.wbarrier_arrayref_copy (dest_ptr, src_ptr, count);
4246 static char *found_obj;
4249 find_object_for_ptr_callback (char *obj, size_t size, void *user_data)
4251 char *ptr = user_data;
4253 if (ptr >= obj && ptr < obj + size) {
4254 g_assert (!found_obj);
4259 /* for use in the debugger */
4260 char* find_object_for_ptr (char *ptr);
4262 find_object_for_ptr (char *ptr)
4264 if (ptr >= nursery_section->data && ptr < nursery_section->end_data) {
4266 mono_sgen_scan_area_with_callback (nursery_section->data, nursery_section->end_data,
4267 find_object_for_ptr_callback, ptr, TRUE);
4273 mono_sgen_los_iterate_objects (find_object_for_ptr_callback, ptr);
4278 * Very inefficient, but this is debugging code, supposed to
4279 * be called from gdb, so we don't care.
4282 major_collector.iterate_objects (TRUE, TRUE, find_object_for_ptr_callback, ptr);
4287 mono_gc_wbarrier_generic_nostore (gpointer ptr)
4289 HEAVY_STAT (++stat_wbarrier_generic_store);
4291 #ifdef XDOMAIN_CHECKS_IN_WBARRIER
4292 /* FIXME: ptr_in_heap must be called with the GC lock held */
4293 if (xdomain_checks && *(MonoObject**)ptr && ptr_in_heap (ptr)) {
4294 char *start = find_object_for_ptr (ptr);
4295 MonoObject *value = *(MonoObject**)ptr;
4299 MonoObject *obj = (MonoObject*)start;
4300 if (obj->vtable->domain != value->vtable->domain)
4301 g_assert (is_xdomain_ref_allowed (ptr, start, obj->vtable->domain));
4307 if (*(gpointer*)ptr)
4308 binary_protocol_wbarrier (ptr, *(gpointer*)ptr, (gpointer)LOAD_VTABLE (*(gpointer*)ptr));
4310 if (ptr_in_nursery (ptr) || ptr_on_stack (ptr) || !ptr_in_nursery (*(gpointer*)ptr)) {
4311 DEBUG (8, fprintf (gc_debug_file, "Skipping remset at %p\n", ptr));
4315 DEBUG (8, fprintf (gc_debug_file, "Adding remset at %p\n", ptr));
4317 remset.wbarrier_generic_nostore (ptr);
4321 mono_gc_wbarrier_generic_store (gpointer ptr, MonoObject* value)
4323 DEBUG (8, fprintf (gc_debug_file, "Wbarrier store at %p to %p (%s)\n", ptr, value, value ? safe_name (value) : "null"));
4324 *(void**)ptr = value;
4325 if (ptr_in_nursery (value))
4326 mono_gc_wbarrier_generic_nostore (ptr);
4327 mono_sgen_dummy_use (value);
4330 void mono_gc_wbarrier_value_copy_bitmap (gpointer _dest, gpointer _src, int size, unsigned bitmap)
4332 mword *dest = _dest;
4337 mono_gc_wbarrier_generic_store (dest, (MonoObject*)*src);
4342 size -= SIZEOF_VOID_P;
4347 #ifdef SGEN_BINARY_PROTOCOL
4349 #define HANDLE_PTR(ptr,obj) do { \
4350 gpointer o = *(gpointer*)(ptr); \
4352 gpointer d = ((char*)dest) + ((char*)(ptr) - (char*)(obj)); \
4353 binary_protocol_wbarrier (d, o, (gpointer) LOAD_VTABLE (o)); \
4358 scan_object_for_binary_protocol_copy_wbarrier (gpointer dest, char *start, mword desc)
4360 #define SCAN_OBJECT_NOVTABLE
4361 #include "sgen-scan-object.h"
4366 mono_gc_wbarrier_value_copy (gpointer dest, gpointer src, int count, MonoClass *klass)
4368 HEAVY_STAT (++stat_wbarrier_value_copy);
4369 g_assert (klass->valuetype);
4371 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));
4373 if (ptr_in_nursery (dest) || ptr_on_stack (dest) || !SGEN_CLASS_HAS_REFERENCES (klass)) {
4374 size_t element_size = mono_class_value_size (klass, NULL);
4375 size_t size = count * element_size;
4376 mono_gc_memmove (dest, src, size);
4380 #ifdef SGEN_BINARY_PROTOCOL
4383 for (i = 0; i < count; ++i) {
4384 scan_object_for_binary_protocol_copy_wbarrier ((char*)dest + i * element_size,
4385 (char*)src + i * element_size - sizeof (MonoObject),
4386 (mword) klass->gc_descr);
4391 remset.wbarrier_value_copy (dest, src, count, klass);
4395 * mono_gc_wbarrier_object_copy:
4397 * Write barrier to call when obj is the result of a clone or copy of an object.
4400 mono_gc_wbarrier_object_copy (MonoObject* obj, MonoObject *src)
4404 HEAVY_STAT (++stat_wbarrier_object_copy);
4406 if (ptr_in_nursery (obj) || ptr_on_stack (obj)) {
4407 size = mono_object_class (obj)->instance_size;
4408 mono_gc_memmove ((char*)obj + sizeof (MonoObject), (char*)src + sizeof (MonoObject),
4409 size - sizeof (MonoObject));
4413 #ifdef SGEN_BINARY_PROTOCOL
4414 scan_object_for_binary_protocol_copy_wbarrier (obj, (char*)src, (mword) src->vtable->gc_descr);
4417 remset.wbarrier_object_copy (obj, src);
4421 * ######################################################################
4422 * ######## Other mono public interface functions.
4423 * ######################################################################
4426 #define REFS_SIZE 128
4429 MonoGCReferences callback;
4433 MonoObject *refs [REFS_SIZE];
4434 uintptr_t offsets [REFS_SIZE];
4438 #define HANDLE_PTR(ptr,obj) do { \
4440 if (hwi->count == REFS_SIZE) { \
4441 hwi->callback ((MonoObject*)start, mono_object_class (start), hwi->called? 0: size, hwi->count, hwi->refs, hwi->offsets, hwi->data); \
4445 hwi->offsets [hwi->count] = (char*)(ptr)-(char*)start; \
4446 hwi->refs [hwi->count++] = *(ptr); \
4451 collect_references (HeapWalkInfo *hwi, char *start, size_t size)
4453 #include "sgen-scan-object.h"
4457 walk_references (char *start, size_t size, void *data)
4459 HeapWalkInfo *hwi = data;
4462 collect_references (hwi, start, size);
4463 if (hwi->count || !hwi->called)
4464 hwi->callback ((MonoObject*)start, mono_object_class (start), hwi->called? 0: size, hwi->count, hwi->refs, hwi->offsets, hwi->data);
4468 * mono_gc_walk_heap:
4469 * @flags: flags for future use
4470 * @callback: a function pointer called for each object in the heap
4471 * @data: a user data pointer that is passed to callback
4473 * This function can be used to iterate over all the live objects in the heap:
4474 * for each object, @callback is invoked, providing info about the object's
4475 * location in memory, its class, its size and the objects it references.
4476 * For each referenced object it's offset from the object address is
4477 * reported in the offsets array.
4478 * The object references may be buffered, so the callback may be invoked
4479 * multiple times for the same object: in all but the first call, the size
4480 * argument will be zero.
4481 * Note that this function can be only called in the #MONO_GC_EVENT_PRE_START_WORLD
4482 * profiler event handler.
4484 * Returns: a non-zero value if the GC doesn't support heap walking
4487 mono_gc_walk_heap (int flags, MonoGCReferences callback, void *data)
4492 hwi.callback = callback;
4495 mono_sgen_clear_nursery_fragments ();
4496 mono_sgen_scan_area_with_callback (nursery_section->data, nursery_section->end_data, walk_references, &hwi, FALSE);
4498 major_collector.iterate_objects (TRUE, TRUE, walk_references, &hwi);
4499 mono_sgen_los_iterate_objects (walk_references, &hwi);
4505 mono_gc_collect (int generation)
4510 mono_profiler_gc_event (MONO_GC_EVENT_START, generation);
4511 stop_world (generation);
4512 if (generation == 0) {
4513 collect_nursery (0);
4515 major_collection ("user request");
4517 restart_world (generation);
4518 mono_profiler_gc_event (MONO_GC_EVENT_END, generation);
4523 mono_gc_max_generation (void)
4529 mono_gc_collection_count (int generation)
4531 if (generation == 0)
4532 return stat_minor_gcs;
4533 return stat_major_gcs;
4537 mono_gc_get_used_size (void)
4541 tot = los_memory_usage;
4542 tot += nursery_section->next_data - nursery_section->data;
4543 tot += major_collector.get_used_size ();
4544 /* FIXME: account for pinned objects */
4550 mono_gc_get_heap_size (void)
4556 mono_gc_disable (void)
4564 mono_gc_enable (void)
4572 mono_gc_get_los_limit (void)
4574 return MAX_SMALL_OBJ_SIZE;
4578 mono_object_is_alive (MonoObject* o)
4584 mono_gc_get_generation (MonoObject *obj)
4586 if (ptr_in_nursery (obj))
4592 mono_gc_enable_events (void)
4597 mono_gc_weak_link_add (void **link_addr, MonoObject *obj, gboolean track)
4599 mono_gc_register_disappearing_link (obj, link_addr, track, FALSE);
4603 mono_gc_weak_link_remove (void **link_addr)
4605 mono_gc_register_disappearing_link (NULL, link_addr, FALSE, FALSE);
4609 mono_gc_weak_link_get (void **link_addr)
4613 return (MonoObject*) REVEAL_POINTER (*link_addr);
4617 mono_gc_ephemeron_array_add (MonoObject *obj)
4619 EphemeronLinkNode *node;
4623 node = mono_sgen_alloc_internal (INTERNAL_MEM_EPHEMERON_LINK);
4628 node->array = (char*)obj;
4629 node->next = ephemeron_list;
4630 ephemeron_list = node;
4632 DEBUG (5, fprintf (gc_debug_file, "Registered ephemeron array %p\n", obj));
4639 mono_gc_invoke_with_gc_lock (MonoGCLockedCallbackFunc func, void *data)
4643 result = func (data);
4644 UNLOCK_INTERRUPTION;
4649 mono_gc_is_gc_thread (void)
4653 result = mono_thread_info_current () != NULL;
4659 is_critical_method (MonoMethod *method)
4661 return mono_runtime_is_critical_method (method) || mono_gc_is_critical_method (method);
4665 mono_gc_base_init (void)
4667 MonoThreadInfoCallbacks cb;
4670 char *major_collector_opt = NULL;
4672 glong soft_limit = 0;
4678 result = InterlockedCompareExchange (&gc_initialized, -1, 0);
4681 /* already inited */
4684 /* being inited by another thread */
4688 /* we will init it */
4691 g_assert_not_reached ();
4693 } while (result != 0);
4695 LOCK_INIT (gc_mutex);
4697 pagesize = mono_pagesize ();
4698 gc_debug_file = stderr;
4700 cb.thread_register = sgen_thread_register;
4701 cb.thread_unregister = sgen_thread_unregister;
4702 cb.thread_attach = sgen_thread_attach;
4703 cb.mono_method_is_critical = (gpointer)is_critical_method;
4705 cb.mono_gc_pthread_create = (gpointer)mono_gc_pthread_create;
4708 mono_threads_init (&cb, sizeof (SgenThreadInfo));
4710 LOCK_INIT (interruption_mutex);
4711 LOCK_INIT (pin_queue_mutex);
4713 init_user_copy_or_mark_key ();
4715 if ((env = getenv ("MONO_GC_PARAMS"))) {
4716 opts = g_strsplit (env, ",", -1);
4717 for (ptr = opts; *ptr; ++ptr) {
4719 if (g_str_has_prefix (opt, "major=")) {
4720 opt = strchr (opt, '=') + 1;
4721 major_collector_opt = g_strdup (opt);
4729 mono_sgen_init_internal_allocator ();
4730 mono_sgen_init_nursery_allocator ();
4732 mono_sgen_register_fixed_internal_mem_type (INTERNAL_MEM_SECTION, SGEN_SIZEOF_GC_MEM_SECTION);
4733 mono_sgen_register_fixed_internal_mem_type (INTERNAL_MEM_FINALIZE_READY_ENTRY, sizeof (FinalizeReadyEntry));
4734 mono_sgen_register_fixed_internal_mem_type (INTERNAL_MEM_GRAY_QUEUE, sizeof (GrayQueueSection));
4735 g_assert (sizeof (GenericStoreRememberedSet) == sizeof (gpointer) * STORE_REMSET_BUFFER_SIZE);
4736 mono_sgen_register_fixed_internal_mem_type (INTERNAL_MEM_STORE_REMSET, sizeof (GenericStoreRememberedSet));
4737 mono_sgen_register_fixed_internal_mem_type (INTERNAL_MEM_EPHEMERON_LINK, sizeof (EphemeronLinkNode));
4739 #ifndef HAVE_KW_THREAD
4740 mono_native_tls_alloc (&thread_info_key, NULL);
4744 * This needs to happen before any internal allocations because
4745 * it inits the small id which is required for hazard pointer
4748 mono_sgen_os_init ();
4750 mono_thread_info_attach (&dummy);
4752 if (!major_collector_opt || !strcmp (major_collector_opt, "marksweep")) {
4753 mono_sgen_marksweep_init (&major_collector);
4754 } else if (!major_collector_opt || !strcmp (major_collector_opt, "marksweep-fixed")) {
4755 mono_sgen_marksweep_fixed_init (&major_collector);
4756 } else if (!major_collector_opt || !strcmp (major_collector_opt, "marksweep-par")) {
4757 mono_sgen_marksweep_par_init (&major_collector);
4758 } else if (!major_collector_opt || !strcmp (major_collector_opt, "marksweep-fixed-par")) {
4759 mono_sgen_marksweep_fixed_par_init (&major_collector);
4760 } else if (!strcmp (major_collector_opt, "copying")) {
4761 mono_sgen_copying_init (&major_collector);
4763 fprintf (stderr, "Unknown major collector `%s'.\n", major_collector_opt);
4767 #ifdef SGEN_HAVE_CARDTABLE
4768 use_cardtable = major_collector.supports_cardtable;
4770 use_cardtable = FALSE;
4773 num_workers = mono_cpu_count ();
4774 g_assert (num_workers > 0);
4775 if (num_workers > 16)
4778 ///* Keep this the default for now */
4780 conservative_stack_mark = TRUE;
4784 for (ptr = opts; *ptr; ++ptr) {
4786 if (g_str_has_prefix (opt, "major="))
4788 if (g_str_has_prefix (opt, "wbarrier=")) {
4789 opt = strchr (opt, '=') + 1;
4790 if (strcmp (opt, "remset") == 0) {
4791 use_cardtable = FALSE;
4792 } else if (strcmp (opt, "cardtable") == 0) {
4793 if (!use_cardtable) {
4794 if (major_collector.supports_cardtable)
4795 fprintf (stderr, "The cardtable write barrier is not supported on this platform.\n");
4797 fprintf (stderr, "The major collector does not support the cardtable write barrier.\n");
4803 if (g_str_has_prefix (opt, "max-heap-size=")) {
4804 opt = strchr (opt, '=') + 1;
4805 if (*opt && mono_gc_parse_environment_string_extract_number (opt, &max_heap)) {
4806 if ((max_heap & (mono_pagesize () - 1))) {
4807 fprintf (stderr, "max-heap-size size must be a multiple of %d.\n", mono_pagesize ());
4811 fprintf (stderr, "max-heap-size must be an integer.\n");
4816 if (g_str_has_prefix (opt, "soft-heap-limit=")) {
4817 opt = strchr (opt, '=') + 1;
4818 if (*opt && mono_gc_parse_environment_string_extract_number (opt, &soft_limit)) {
4819 if (soft_limit <= 0) {
4820 fprintf (stderr, "soft-heap-limit must be positive.\n");
4824 fprintf (stderr, "soft-heap-limit must be an integer.\n");
4829 if (g_str_has_prefix (opt, "workers=")) {
4832 if (!major_collector.is_parallel) {
4833 fprintf (stderr, "The workers= option can only be used for parallel collectors.");
4836 opt = strchr (opt, '=') + 1;
4837 val = strtol (opt, &endptr, 10);
4838 if (!*opt || *endptr) {
4839 fprintf (stderr, "Cannot parse the workers= option value.");
4842 if (val <= 0 || val > 16) {
4843 fprintf (stderr, "The number of workers must be in the range 1 to 16.");
4846 num_workers = (int)val;
4849 if (g_str_has_prefix (opt, "stack-mark=")) {
4850 opt = strchr (opt, '=') + 1;
4851 if (!strcmp (opt, "precise")) {
4852 conservative_stack_mark = FALSE;
4853 } else if (!strcmp (opt, "conservative")) {
4854 conservative_stack_mark = TRUE;
4856 fprintf (stderr, "Invalid value '%s' for stack-mark= option, possible values are: 'precise', 'conservative'.\n", opt);
4861 if (g_str_has_prefix (opt, "bridge=")) {
4862 opt = strchr (opt, '=') + 1;
4863 mono_sgen_register_test_bridge_callbacks (g_strdup (opt));
4867 if (g_str_has_prefix (opt, "nursery-size=")) {
4869 opt = strchr (opt, '=') + 1;
4870 if (*opt && mono_gc_parse_environment_string_extract_number (opt, &val)) {
4871 mono_sgen_nursery_size = val;
4872 #ifdef SGEN_ALIGN_NURSERY
4873 if ((val & (val - 1))) {
4874 fprintf (stderr, "The nursery size must be a power of two.\n");
4878 if (val < SGEN_MAX_NURSERY_WASTE) {
4879 fprintf (stderr, "The nursery size must be at least %d bytes.\n", SGEN_MAX_NURSERY_WASTE);
4883 mono_sgen_nursery_bits = 0;
4884 while (1 << (++ mono_sgen_nursery_bits) != mono_sgen_nursery_size)
4888 fprintf (stderr, "nursery-size must be an integer.\n");
4894 if (!(major_collector.handle_gc_param && major_collector.handle_gc_param (opt))) {
4895 fprintf (stderr, "MONO_GC_PARAMS must be a comma-delimited list of one or more of the following:\n");
4896 fprintf (stderr, " max-heap-size=N (where N is an integer, possibly with a k, m or a g suffix)\n");
4897 fprintf (stderr, " soft-heap-limit=n (where N is an integer, possibly with a k, m or a g suffix)\n");
4898 fprintf (stderr, " nursery-size=N (where N is an integer, possibly with a k, m or a g suffix)\n");
4899 fprintf (stderr, " major=COLLECTOR (where COLLECTOR is `marksweep', `marksweep-par' or `copying')\n");
4900 fprintf (stderr, " wbarrier=WBARRIER (where WBARRIER is `remset' or `cardtable')\n");
4901 fprintf (stderr, " stack-mark=MARK-METHOD (where MARK-METHOD is 'precise' or 'conservative')\n");
4902 if (major_collector.print_gc_param_usage)
4903 major_collector.print_gc_param_usage ();
4910 if (major_collector.is_parallel)
4911 mono_sgen_workers_init (num_workers);
4913 if (major_collector_opt)
4914 g_free (major_collector_opt);
4916 nursery_size = DEFAULT_NURSERY_SIZE;
4917 minor_collection_allowance = MIN_MINOR_COLLECTION_ALLOWANCE;
4918 init_heap_size_limits (max_heap, soft_limit);
4922 if ((env = getenv ("MONO_GC_DEBUG"))) {
4923 opts = g_strsplit (env, ",", -1);
4924 for (ptr = opts; ptr && *ptr; ptr ++) {
4926 if (opt [0] >= '0' && opt [0] <= '9') {
4927 gc_debug_level = atoi (opt);
4932 char *rf = g_strdup_printf ("%s.%d", opt, getpid ());
4933 gc_debug_file = fopen (rf, "wb");
4935 gc_debug_file = stderr;
4938 } else if (!strcmp (opt, "print-allowance")) {
4939 debug_print_allowance = TRUE;
4940 } else if (!strcmp (opt, "print-pinning")) {
4941 do_pin_stats = TRUE;
4942 } else if (!strcmp (opt, "collect-before-allocs")) {
4943 collect_before_allocs = 1;
4944 } else if (g_str_has_prefix (opt, "collect-before-allocs=")) {
4945 char *arg = strchr (opt, '=') + 1;
4946 collect_before_allocs = atoi (arg);
4947 } else if (!strcmp (opt, "check-at-minor-collections")) {
4948 consistency_check_at_minor_collection = TRUE;
4949 nursery_clear_policy = CLEAR_AT_GC;
4950 } else if (!strcmp (opt, "xdomain-checks")) {
4951 xdomain_checks = TRUE;
4952 } else if (!strcmp (opt, "clear-at-gc")) {
4953 nursery_clear_policy = CLEAR_AT_GC;
4954 } else if (!strcmp (opt, "clear-nursery-at-gc")) {
4955 nursery_clear_policy = CLEAR_AT_GC;
4956 } else if (!strcmp (opt, "check-scan-starts")) {
4957 do_scan_starts_check = TRUE;
4958 } else if (!strcmp (opt, "verify-nursery-at-minor-gc")) {
4959 do_verify_nursery = TRUE;
4960 } else if (!strcmp (opt, "dump-nursery-at-minor-gc")) {
4961 do_dump_nursery_content = TRUE;
4962 } else if (!strcmp (opt, "disable-minor")) {
4963 disable_minor_collections = TRUE;
4964 } else if (!strcmp (opt, "disable-major")) {
4965 disable_major_collections = TRUE;
4966 } else if (g_str_has_prefix (opt, "heap-dump=")) {
4967 char *filename = strchr (opt, '=') + 1;
4968 nursery_clear_policy = CLEAR_AT_GC;
4969 heap_dump_file = fopen (filename, "w");
4970 if (heap_dump_file) {
4971 fprintf (heap_dump_file, "<sgen-dump>\n");
4972 do_pin_stats = TRUE;
4974 #ifdef SGEN_BINARY_PROTOCOL
4975 } else if (g_str_has_prefix (opt, "binary-protocol=")) {
4976 char *filename = strchr (opt, '=') + 1;
4977 binary_protocol_init (filename);
4979 fprintf (stderr, "Warning: Cardtable write barriers will not be binary-protocolled.\n");
4982 fprintf (stderr, "Invalid format for the MONO_GC_DEBUG env variable: '%s'\n", env);
4983 fprintf (stderr, "The format is: MONO_GC_DEBUG=[l[:filename]|<option>]+ where l is a debug level 0-9.\n");
4984 fprintf (stderr, "Valid options are:\n");
4985 fprintf (stderr, " collect-before-allocs[=<n>]\n");
4986 fprintf (stderr, " check-at-minor-collections\n");
4987 fprintf (stderr, " disable-minor\n");
4988 fprintf (stderr, " disable-major\n");
4989 fprintf (stderr, " xdomain-checks\n");
4990 fprintf (stderr, " clear-at-gc\n");
4991 fprintf (stderr, " print-allowance\n");
4992 fprintf (stderr, " print-pinning\n");
4999 if (major_collector.is_parallel) {
5000 if (heap_dump_file) {
5001 fprintf (stderr, "Error: Cannot do heap dump with the parallel collector.\n");
5005 fprintf (stderr, "Error: Cannot gather pinning statistics with the parallel collector.\n");
5010 if (major_collector.post_param_init)
5011 major_collector.post_param_init ();
5013 memset (&remset, 0, sizeof (remset));
5015 #ifdef SGEN_HAVE_CARDTABLE
5017 sgen_card_table_init (&remset);
5020 mono_sgen_ssb_init (&remset);
5022 if (remset.register_thread)
5023 remset.register_thread (mono_thread_info_current ());
5029 mono_gc_get_gc_name (void)
5034 static MonoMethod *write_barrier_method;
5037 mono_gc_is_critical_method (MonoMethod *method)
5039 return (method == write_barrier_method || mono_sgen_is_managed_allocator (method));
5043 is_ip_in_managed_allocator (MonoDomain *domain, gpointer ip)
5047 if (!mono_thread_internal_current ())
5048 /* Happens during thread attach */
5053 ji = mono_jit_info_table_find (domain, ip);
5057 return mono_gc_is_critical_method (ji->method);
5061 emit_nursery_check (MonoMethodBuilder *mb, int *nursery_check_return_labels)
5063 memset (nursery_check_return_labels, 0, sizeof (int) * 3);
5064 #ifdef SGEN_ALIGN_NURSERY
5065 // if (ptr_in_nursery (ptr)) return;
5067 * Masking out the bits might be faster, but we would have to use 64 bit
5068 * immediates, which might be slower.
5070 mono_mb_emit_ldarg (mb, 0);
5071 mono_mb_emit_icon (mb, DEFAULT_NURSERY_BITS);
5072 mono_mb_emit_byte (mb, CEE_SHR_UN);
5073 mono_mb_emit_icon (mb, (mword)mono_sgen_get_nursery_start () >> DEFAULT_NURSERY_BITS);
5074 nursery_check_return_labels [0] = mono_mb_emit_branch (mb, CEE_BEQ);
5076 // if (!ptr_in_nursery (*ptr)) return;
5077 mono_mb_emit_ldarg (mb, 0);
5078 mono_mb_emit_byte (mb, CEE_LDIND_I);
5079 mono_mb_emit_icon (mb, DEFAULT_NURSERY_BITS);
5080 mono_mb_emit_byte (mb, CEE_SHR_UN);
5081 mono_mb_emit_icon (mb, (mword)mono_sgen_get_nursery_start () >> DEFAULT_NURSERY_BITS);
5082 nursery_check_return_labels [1] = mono_mb_emit_branch (mb, CEE_BNE_UN);
5084 int label_continue1, label_continue2;
5085 int dereferenced_var;
5087 // if (ptr < (mono_sgen_get_nursery_start ())) goto continue;
5088 mono_mb_emit_ldarg (mb, 0);
5089 mono_mb_emit_ptr (mb, (gpointer) mono_sgen_get_nursery_start ());
5090 label_continue_1 = mono_mb_emit_branch (mb, CEE_BLT);
5092 // if (ptr >= mono_sgen_get_nursery_end ())) goto continue;
5093 mono_mb_emit_ldarg (mb, 0);
5094 mono_mb_emit_ptr (mb, (gpointer) mono_sgen_get_nursery_end ());
5095 label_continue_2 = mono_mb_emit_branch (mb, CEE_BGE);
5098 nursery_check_return_labels [0] = mono_mb_emit_branch (mb, CEE_BR);
5101 mono_mb_patch_branch (mb, label_continue_1);
5102 mono_mb_patch_branch (mb, label_continue_2);
5104 // Dereference and store in local var
5105 dereferenced_var = mono_mb_add_local (mb, &mono_defaults.int_class->byval_arg);
5106 mono_mb_emit_ldarg (mb, 0);
5107 mono_mb_emit_byte (mb, CEE_LDIND_I);
5108 mono_mb_emit_stloc (mb, dereferenced_var);
5110 // if (*ptr < mono_sgen_get_nursery_start ()) return;
5111 mono_mb_emit_ldloc (mb, dereferenced_var);
5112 mono_mb_emit_ptr (mb, (gpointer) mono_sgen_get_nursery_start ());
5113 nursery_check_return_labels [1] = mono_mb_emit_branch (mb, CEE_BLT);
5115 // if (*ptr >= mono_sgen_get_nursery_end ()) return;
5116 mono_mb_emit_ldloc (mb, dereferenced_var);
5117 mono_mb_emit_ptr (mb, (gpointer) mono_sgen_get_nursery_end ());
5118 nursery_check_return_labels [2] = mono_mb_emit_branch (mb, CEE_BGE);
5123 mono_gc_get_write_barrier (void)
5126 MonoMethodBuilder *mb;
5127 MonoMethodSignature *sig;
5128 #ifdef MANAGED_WBARRIER
5129 int i, nursery_check_labels [3];
5130 int label_no_wb_3, label_no_wb_4, label_need_wb, label_slow_path;
5131 int buffer_var, buffer_index_var, dummy_var;
5133 #ifdef HAVE_KW_THREAD
5134 int stack_end_offset = -1, store_remset_buffer_offset = -1;
5135 int store_remset_buffer_index_offset = -1, store_remset_buffer_index_addr_offset = -1;
5137 MONO_THREAD_VAR_OFFSET (stack_end, stack_end_offset);
5138 g_assert (stack_end_offset != -1);
5139 MONO_THREAD_VAR_OFFSET (store_remset_buffer, store_remset_buffer_offset);
5140 g_assert (store_remset_buffer_offset != -1);
5141 MONO_THREAD_VAR_OFFSET (store_remset_buffer_index, store_remset_buffer_index_offset);
5142 g_assert (store_remset_buffer_index_offset != -1);
5143 MONO_THREAD_VAR_OFFSET (store_remset_buffer_index_addr, store_remset_buffer_index_addr_offset);
5144 g_assert (store_remset_buffer_index_addr_offset != -1);
5148 // FIXME: Maybe create a separate version for ctors (the branch would be
5149 // correctly predicted more times)
5150 if (write_barrier_method)
5151 return write_barrier_method;
5153 /* Create the IL version of mono_gc_barrier_generic_store () */
5154 sig = mono_metadata_signature_alloc (mono_defaults.corlib, 1);
5155 sig->ret = &mono_defaults.void_class->byval_arg;
5156 sig->params [0] = &mono_defaults.int_class->byval_arg;
5158 mb = mono_mb_new (mono_defaults.object_class, "wbarrier", MONO_WRAPPER_WRITE_BARRIER);
5160 #ifdef MANAGED_WBARRIER
5161 if (use_cardtable) {
5162 emit_nursery_check (mb, nursery_check_labels);
5164 addr = sgen_cardtable + ((address >> CARD_BITS) & CARD_MASK)
5168 LDC_PTR sgen_cardtable
5170 address >> CARD_BITS
5174 if (SGEN_HAVE_OVERLAPPING_CARDS) {
5175 LDC_PTR card_table_mask
5182 mono_mb_emit_ptr (mb, sgen_cardtable);
5183 mono_mb_emit_ldarg (mb, 0);
5184 mono_mb_emit_icon (mb, CARD_BITS);
5185 mono_mb_emit_byte (mb, CEE_SHR_UN);
5186 #ifdef SGEN_HAVE_OVERLAPPING_CARDS
5187 mono_mb_emit_ptr (mb, (gpointer)CARD_MASK);
5188 mono_mb_emit_byte (mb, CEE_AND);
5190 mono_mb_emit_byte (mb, CEE_ADD);
5191 mono_mb_emit_icon (mb, 1);
5192 mono_mb_emit_byte (mb, CEE_STIND_I1);
5195 for (i = 0; i < 3; ++i) {
5196 if (nursery_check_labels [i])
5197 mono_mb_patch_branch (mb, nursery_check_labels [i]);
5199 mono_mb_emit_byte (mb, CEE_RET);
5200 } else if (mono_runtime_has_tls_get ()) {
5201 emit_nursery_check (mb, nursery_check_labels);
5203 // if (ptr >= stack_end) goto need_wb;
5204 mono_mb_emit_ldarg (mb, 0);
5205 EMIT_TLS_ACCESS (mb, stack_end, stack_end_offset);
5206 label_need_wb = mono_mb_emit_branch (mb, CEE_BGE_UN);
5208 // if (ptr >= stack_start) return;
5209 dummy_var = mono_mb_add_local (mb, &mono_defaults.int_class->byval_arg);
5210 mono_mb_emit_ldarg (mb, 0);
5211 mono_mb_emit_ldloc_addr (mb, dummy_var);
5212 label_no_wb_3 = mono_mb_emit_branch (mb, CEE_BGE_UN);
5215 mono_mb_patch_branch (mb, label_need_wb);
5217 // buffer = STORE_REMSET_BUFFER;
5218 buffer_var = mono_mb_add_local (mb, &mono_defaults.int_class->byval_arg);
5219 EMIT_TLS_ACCESS (mb, store_remset_buffer, store_remset_buffer_offset);
5220 mono_mb_emit_stloc (mb, buffer_var);
5222 // buffer_index = STORE_REMSET_BUFFER_INDEX;
5223 buffer_index_var = mono_mb_add_local (mb, &mono_defaults.int_class->byval_arg);
5224 EMIT_TLS_ACCESS (mb, store_remset_buffer_index, store_remset_buffer_index_offset);
5225 mono_mb_emit_stloc (mb, buffer_index_var);
5227 // if (buffer [buffer_index] == ptr) return;
5228 mono_mb_emit_ldloc (mb, buffer_var);
5229 mono_mb_emit_ldloc (mb, buffer_index_var);
5230 g_assert (sizeof (gpointer) == 4 || sizeof (gpointer) == 8);
5231 mono_mb_emit_icon (mb, sizeof (gpointer) == 4 ? 2 : 3);
5232 mono_mb_emit_byte (mb, CEE_SHL);
5233 mono_mb_emit_byte (mb, CEE_ADD);
5234 mono_mb_emit_byte (mb, CEE_LDIND_I);
5235 mono_mb_emit_ldarg (mb, 0);
5236 label_no_wb_4 = mono_mb_emit_branch (mb, CEE_BEQ);
5239 mono_mb_emit_ldloc (mb, buffer_index_var);
5240 mono_mb_emit_icon (mb, 1);
5241 mono_mb_emit_byte (mb, CEE_ADD);
5242 mono_mb_emit_stloc (mb, buffer_index_var);
5244 // if (buffer_index >= STORE_REMSET_BUFFER_SIZE) goto slow_path;
5245 mono_mb_emit_ldloc (mb, buffer_index_var);
5246 mono_mb_emit_icon (mb, STORE_REMSET_BUFFER_SIZE);
5247 label_slow_path = mono_mb_emit_branch (mb, CEE_BGE);
5249 // buffer [buffer_index] = ptr;
5250 mono_mb_emit_ldloc (mb, buffer_var);
5251 mono_mb_emit_ldloc (mb, buffer_index_var);
5252 g_assert (sizeof (gpointer) == 4 || sizeof (gpointer) == 8);
5253 mono_mb_emit_icon (mb, sizeof (gpointer) == 4 ? 2 : 3);
5254 mono_mb_emit_byte (mb, CEE_SHL);
5255 mono_mb_emit_byte (mb, CEE_ADD);
5256 mono_mb_emit_ldarg (mb, 0);
5257 mono_mb_emit_byte (mb, CEE_STIND_I);
5259 // STORE_REMSET_BUFFER_INDEX = buffer_index;
5260 EMIT_TLS_ACCESS (mb, store_remset_buffer_index_addr, store_remset_buffer_index_addr_offset);
5261 mono_mb_emit_ldloc (mb, buffer_index_var);
5262 mono_mb_emit_byte (mb, CEE_STIND_I);
5265 for (i = 0; i < 3; ++i) {
5266 if (nursery_check_labels [i])
5267 mono_mb_patch_branch (mb, nursery_check_labels [i]);
5269 mono_mb_patch_branch (mb, label_no_wb_3);
5270 mono_mb_patch_branch (mb, label_no_wb_4);
5271 mono_mb_emit_byte (mb, CEE_RET);
5274 mono_mb_patch_branch (mb, label_slow_path);
5276 mono_mb_emit_ldarg (mb, 0);
5277 mono_mb_emit_icall (mb, mono_gc_wbarrier_generic_nostore);
5278 mono_mb_emit_byte (mb, CEE_RET);
5282 mono_mb_emit_ldarg (mb, 0);
5283 mono_mb_emit_icall (mb, mono_gc_wbarrier_generic_nostore);
5284 mono_mb_emit_byte (mb, CEE_RET);
5287 res = mono_mb_create_method (mb, sig, 16);
5290 mono_loader_lock ();
5291 if (write_barrier_method) {
5292 /* Already created */
5293 mono_free_method (res);
5295 /* double-checked locking */
5296 mono_memory_barrier ();
5297 write_barrier_method = res;
5299 mono_loader_unlock ();
5301 return write_barrier_method;
5305 mono_gc_get_description (void)
5307 return g_strdup ("sgen");
5311 mono_gc_set_desktop_mode (void)
5316 mono_gc_is_moving (void)
5322 mono_gc_is_disabled (void)
5328 mono_sgen_debug_printf (int level, const char *format, ...)
5332 if (level > gc_debug_level)
5335 va_start (ap, format);
5336 vfprintf (gc_debug_file, format, ap);
5341 mono_sgen_get_logfile (void)
5343 return gc_debug_file;
5347 BOOL APIENTRY mono_gc_dllmain (HMODULE module_handle, DWORD reason, LPVOID reserved)
5354 mono_sgen_get_nursery_clear_policy (void)
5356 return nursery_clear_policy;
5360 mono_sgen_get_array_fill_vtable (void)
5362 if (!array_fill_vtable) {
5363 static MonoClass klass;
5364 static MonoVTable vtable;
5367 MonoDomain *domain = mono_get_root_domain ();
5370 klass.element_class = mono_defaults.byte_class;
5372 klass.instance_size = sizeof (MonoArray);
5373 klass.sizes.element_size = 1;
5374 klass.name = "array_filler_type";
5376 vtable.klass = &klass;
5378 vtable.gc_descr = mono_gc_make_descr_for_array (TRUE, &bmap, 0, 1);
5381 array_fill_vtable = &vtable;
5383 return array_fill_vtable;
5387 mono_sgen_gc_lock (void)
5393 mono_sgen_gc_unlock (void)
5399 sgen_major_collector_iterate_live_block_ranges (sgen_cardtable_block_callback callback)
5401 major_collector.iterate_live_block_ranges (callback);
5405 sgen_major_collector_scan_card_table (SgenGrayQueue *queue)
5407 major_collector.scan_card_table (queue);
5411 mono_sgen_get_major_collector (void)
5413 return &major_collector;
5416 void mono_gc_set_skip_thread (gboolean skip)
5418 SgenThreadInfo *info = mono_thread_info_current ();
5421 info->gc_disabled = skip;
5426 mono_sgen_get_remset (void)
5432 mono_gc_get_vtable_bits (MonoClass *class)
5434 if (mono_sgen_need_bridge_processing () && mono_sgen_is_bridge_class (class))
5435 return SGEN_GC_BIT_BRIDGE_OBJECT;
5439 #endif /* HAVE_SGEN_GC */