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_slots_allocated_in_vain;
301 long long stat_nursery_copy_object_failed_from_space = 0;
302 long long stat_nursery_copy_object_failed_forwarded = 0;
303 long long stat_nursery_copy_object_failed_pinned = 0;
304 long long stat_nursery_copy_object_failed_to_space = 0;
306 static int stat_wbarrier_set_field = 0;
307 static int stat_wbarrier_set_arrayref = 0;
308 static int stat_wbarrier_arrayref_copy = 0;
309 static int stat_wbarrier_generic_store = 0;
310 static int stat_wbarrier_set_root = 0;
311 static int stat_wbarrier_value_copy = 0;
312 static int stat_wbarrier_object_copy = 0;
315 int stat_minor_gcs = 0;
316 int stat_major_gcs = 0;
318 static long long stat_pinned_objects = 0;
320 static long long time_minor_pre_collection_fragment_clear = 0;
321 static long long time_minor_pinning = 0;
322 static long long time_minor_scan_remsets = 0;
323 static long long time_minor_scan_pinned = 0;
324 static long long time_minor_scan_registered_roots = 0;
325 static long long time_minor_scan_thread_data = 0;
326 static long long time_minor_finish_gray_stack = 0;
327 static long long time_minor_fragment_creation = 0;
329 static long long time_major_pre_collection_fragment_clear = 0;
330 static long long time_major_pinning = 0;
331 static long long time_major_scan_pinned = 0;
332 static long long time_major_scan_registered_roots = 0;
333 static long long time_major_scan_thread_data = 0;
334 static long long time_major_scan_alloc_pinned = 0;
335 static long long time_major_scan_finalized = 0;
336 static long long time_major_scan_big_objects = 0;
337 static long long time_major_finish_gray_stack = 0;
338 static long long time_major_free_bigobjs = 0;
339 static long long time_major_los_sweep = 0;
340 static long long time_major_sweep = 0;
341 static long long time_major_fragment_creation = 0;
343 int gc_debug_level = 0;
345 static gboolean debug_print_allowance = FALSE;
349 mono_gc_flush_info (void)
351 fflush (gc_debug_file);
355 #define TV_DECLARE SGEN_TV_DECLARE
356 #define TV_GETTIME SGEN_TV_GETTIME
357 #define TV_ELAPSED SGEN_TV_ELAPSED
358 #define TV_ELAPSED_MS SGEN_TV_ELAPSED_MS
360 #define ALIGN_TO(val,align) ((((guint64)val) + ((align) - 1)) & ~((align) - 1))
362 NurseryClearPolicy nursery_clear_policy = CLEAR_AT_TLAB_CREATION;
364 /* the runtime can register areas of memory as roots: we keep two lists of roots,
365 * a pinned root set for conservatively scanned roots and a normal one for
366 * precisely scanned roots (currently implemented as a single list).
368 typedef struct _RootRecord RootRecord;
374 #define object_is_forwarded SGEN_OBJECT_IS_FORWARDED
375 #define object_is_pinned SGEN_OBJECT_IS_PINNED
376 #define pin_object SGEN_PIN_OBJECT
377 #define unpin_object SGEN_UNPIN_OBJECT
379 #define ptr_in_nursery sgen_ptr_in_nursery
381 #define LOAD_VTABLE SGEN_LOAD_VTABLE
384 safe_name (void* obj)
386 MonoVTable *vt = (MonoVTable*)LOAD_VTABLE (obj);
387 return vt->klass->name;
390 #define safe_object_get_size sgen_safe_object_get_size
393 sgen_safe_name (void* obj)
395 return safe_name (obj);
399 * ######################################################################
400 * ######## Global data.
401 * ######################################################################
403 LOCK_DECLARE (gc_mutex);
404 static int gc_disabled = 0;
406 static gboolean use_cardtable;
408 #define MIN_MINOR_COLLECTION_ALLOWANCE (DEFAULT_NURSERY_SIZE * 4)
410 #define SCAN_START_SIZE SGEN_SCAN_START_SIZE
412 static mword pagesize = 4096;
413 static mword nursery_size;
414 int degraded_mode = 0;
416 static mword bytes_pinned_from_failed_allocation = 0;
418 static mword total_alloc = 0;
419 /* use this to tune when to do a major/minor collection */
420 static mword memory_pressure = 0;
421 static mword minor_collection_allowance;
422 static int minor_collection_sections_alloced = 0;
425 /* GC Logging stats */
426 static int last_major_num_sections = 0;
427 static int last_los_memory_usage = 0;
428 static gboolean major_collection_happened = FALSE;
430 GCMemSection *nursery_section = NULL;
431 static mword lowest_heap_address = ~(mword)0;
432 static mword highest_heap_address = 0;
434 static LOCK_DECLARE (interruption_mutex);
435 static LOCK_DECLARE (pin_queue_mutex);
437 #define LOCK_PIN_QUEUE mono_mutex_lock (&pin_queue_mutex)
438 #define UNLOCK_PIN_QUEUE mono_mutex_unlock (&pin_queue_mutex)
440 typedef struct _FinalizeReadyEntry FinalizeReadyEntry;
441 struct _FinalizeReadyEntry {
442 FinalizeReadyEntry *next;
446 typedef struct _EphemeronLinkNode EphemeronLinkNode;
448 struct _EphemeronLinkNode {
449 EphemeronLinkNode *next;
458 int current_collection_generation = -1;
461 * The link pointer is hidden by negating each bit. We use the lowest
462 * bit of the link (before negation) to store whether it needs
463 * resurrection tracking.
465 #define HIDE_POINTER(p,t) ((gpointer)(~((gulong)(p)|((t)?1:0))))
466 #define REVEAL_POINTER(p) ((gpointer)((~(gulong)(p))&~3L))
468 /* objects that are ready to be finalized */
469 static FinalizeReadyEntry *fin_ready_list = NULL;
470 static FinalizeReadyEntry *critical_fin_list = NULL;
472 static EphemeronLinkNode *ephemeron_list;
474 static int num_ready_finalizers = 0;
475 static int no_finalize = 0;
478 ROOT_TYPE_NORMAL = 0, /* "normal" roots */
479 ROOT_TYPE_PINNED = 1, /* roots without a GC descriptor */
480 ROOT_TYPE_WBARRIER = 2, /* roots with a write barrier */
484 /* registered roots: the key to the hash is the root start address */
486 * Different kinds of roots are kept separate to speed up pin_from_roots () for example.
488 static SgenHashTable roots_hash [ROOT_TYPE_NUM] = {
489 SGEN_HASH_TABLE_INIT (INTERNAL_MEM_ROOTS_TABLE, INTERNAL_MEM_ROOT_RECORD, sizeof (RootRecord), mono_aligned_addr_hash, NULL),
490 SGEN_HASH_TABLE_INIT (INTERNAL_MEM_ROOTS_TABLE, INTERNAL_MEM_ROOT_RECORD, sizeof (RootRecord), mono_aligned_addr_hash, NULL),
491 SGEN_HASH_TABLE_INIT (INTERNAL_MEM_ROOTS_TABLE, INTERNAL_MEM_ROOT_RECORD, sizeof (RootRecord), mono_aligned_addr_hash, NULL)
493 static mword roots_size = 0; /* amount of memory in the root set */
495 #define GC_ROOT_NUM 32
498 void *objects [GC_ROOT_NUM];
499 int root_types [GC_ROOT_NUM];
500 uintptr_t extra_info [GC_ROOT_NUM];
504 notify_gc_roots (GCRootReport *report)
508 mono_profiler_gc_roots (report->count, report->objects, report->root_types, report->extra_info);
513 add_profile_gc_root (GCRootReport *report, void *object, int rtype, uintptr_t extra_info)
515 if (report->count == GC_ROOT_NUM)
516 notify_gc_roots (report);
517 report->objects [report->count] = object;
518 report->root_types [report->count] = rtype;
519 report->extra_info [report->count++] = (uintptr_t)((MonoVTable*)LOAD_VTABLE (object))->klass;
522 MonoNativeTlsKey thread_info_key;
524 #ifdef HAVE_KW_THREAD
525 __thread SgenThreadInfo *thread_info;
526 __thread gpointer *store_remset_buffer;
527 __thread long store_remset_buffer_index;
528 __thread char *stack_end;
529 __thread long *store_remset_buffer_index_addr;
532 /* The size of a TLAB */
533 /* The bigger the value, the less often we have to go to the slow path to allocate a new
534 * one, but the more space is wasted by threads not allocating much memory.
536 * FIXME: Make this self-tuning for each thread.
538 guint32 tlab_size = (1024 * 4);
540 #define MAX_SMALL_OBJ_SIZE SGEN_MAX_SMALL_OBJ_SIZE
542 /* Functions supplied by the runtime to be called by the GC */
543 static MonoGCCallbacks gc_callbacks;
545 #define ALLOC_ALIGN SGEN_ALLOC_ALIGN
546 #define ALLOC_ALIGN_BITS SGEN_ALLOC_ALIGN_BITS
548 #define ALIGN_UP SGEN_ALIGN_UP
550 #define MOVED_OBJECTS_NUM 64
551 static void *moved_objects [MOVED_OBJECTS_NUM];
552 static int moved_objects_idx = 0;
554 /* Vtable of the objects used to fill out nursery fragments before a collection */
555 static MonoVTable *array_fill_vtable;
557 #ifdef SGEN_DEBUG_INTERNAL_ALLOC
558 MonoNativeThreadId main_gc_thread = NULL;
562 * ######################################################################
563 * ######## Heap size accounting
564 * ######################################################################
567 static mword max_heap_size = ((mword)0)- ((mword)1);
568 static mword soft_heap_limit = ((mword)0) - ((mword)1);
569 static mword allocated_heap;
571 /*Object was pinned during the current collection*/
572 static mword objects_pinned;
575 sgen_release_space (mword size, int space)
577 allocated_heap -= size;
581 available_free_space (void)
583 return max_heap_size - MIN (allocated_heap, max_heap_size);
587 sgen_try_alloc_space (mword size, int space)
589 if (available_free_space () < size)
592 allocated_heap += size;
593 mono_runtime_resource_check_limit (MONO_RESOURCE_GC_HEAP, allocated_heap);
598 init_heap_size_limits (glong max_heap, glong soft_limit)
601 soft_heap_limit = soft_limit;
606 if (max_heap < soft_limit) {
607 fprintf (stderr, "max-heap-size must be at least as large as soft-heap-limit.\n");
611 if (max_heap < nursery_size * 4) {
612 fprintf (stderr, "max-heap-size must be at least 4 times larger than nursery size.\n");
615 max_heap_size = max_heap - nursery_size;
619 * ######################################################################
620 * ######## Macros and function declarations.
621 * ######################################################################
625 align_pointer (void *ptr)
627 mword p = (mword)ptr;
628 p += sizeof (gpointer) - 1;
629 p &= ~ (sizeof (gpointer) - 1);
633 typedef SgenGrayQueue GrayQueue;
635 /* forward declarations */
636 static int stop_world (int generation);
637 static int restart_world (int generation);
638 static void scan_thread_data (void *start_nursery, void *end_nursery, gboolean precise, GrayQueue *queue);
639 static void scan_from_registered_roots (CopyOrMarkObjectFunc copy_func, char *addr_start, char *addr_end, int root_type, GrayQueue *queue);
640 static void scan_finalizer_entries (CopyOrMarkObjectFunc copy_func, FinalizeReadyEntry *list, GrayQueue *queue);
641 static void report_finalizer_roots (void);
642 static void report_registered_roots (void);
643 static void find_pinning_ref_from_thread (char *obj, size_t size);
644 static void update_current_thread_stack (void *start);
645 static void collect_bridge_objects (CopyOrMarkObjectFunc copy_func, char *start, char *end, int generation, GrayQueue *queue);
646 static void finalize_in_range (CopyOrMarkObjectFunc copy_func, char *start, char *end, int generation, GrayQueue *queue);
647 static void process_fin_stage_entries (void);
648 static void null_link_in_range (CopyOrMarkObjectFunc copy_func, char *start, char *end, int generation, gboolean before_finalization, GrayQueue *queue);
649 static void null_links_for_domain (MonoDomain *domain, int generation);
650 static void process_dislink_stage_entries (void);
652 static void pin_from_roots (void *start_nursery, void *end_nursery, GrayQueue *queue);
653 static int pin_objects_from_addresses (GCMemSection *section, void **start, void **end, void *start_nursery, void *end_nursery, GrayQueue *queue);
654 static void finish_gray_stack (char *start_addr, char *end_addr, int generation, GrayQueue *queue);
655 static gboolean need_major_collection (mword space_needed);
656 static void major_collection (const char *reason);
658 static void mono_gc_register_disappearing_link (MonoObject *obj, void **link, gboolean track, gboolean in_gc);
659 static gboolean mono_gc_is_critical_method (MonoMethod *method);
661 void mono_gc_scan_for_specific_ref (MonoObject *key, gboolean precise);
663 static void init_stats (void);
665 static int mark_ephemerons_in_range (CopyOrMarkObjectFunc copy_func, char *start, char *end, GrayQueue *queue);
666 static void clear_unreachable_ephemerons (CopyOrMarkObjectFunc copy_func, char *start, char *end, GrayQueue *queue);
667 static void null_ephemerons_for_domain (MonoDomain *domain);
669 SgenObjectOperations current_object_ops;
670 SgenMajorCollector major_collector;
671 SgenMinorCollector sgen_minor_collector;
672 static GrayQueue gray_queue;
674 static SgenRemeberedSet remset;
677 #define WORKERS_DISTRIBUTE_GRAY_QUEUE (sgen_collection_is_parallel () ? sgen_workers_get_distribute_gray_queue () : &gray_queue)
679 static SgenGrayQueue*
680 sgen_workers_get_job_gray_queue (WorkerData *worker_data)
682 return worker_data ? &worker_data->private_gray_queue : WORKERS_DISTRIBUTE_GRAY_QUEUE;
686 is_xdomain_ref_allowed (gpointer *ptr, char *obj, MonoDomain *domain)
688 MonoObject *o = (MonoObject*)(obj);
689 MonoObject *ref = (MonoObject*)*(ptr);
690 int offset = (char*)(ptr) - (char*)o;
692 if (o->vtable->klass == mono_defaults.thread_class && offset == G_STRUCT_OFFSET (MonoThread, internal_thread))
694 if (o->vtable->klass == mono_defaults.internal_thread_class && offset == G_STRUCT_OFFSET (MonoInternalThread, current_appcontext))
696 if (mono_class_has_parent_fast (o->vtable->klass, mono_defaults.real_proxy_class) &&
697 offset == G_STRUCT_OFFSET (MonoRealProxy, unwrapped_server))
699 /* Thread.cached_culture_info */
700 if (!strcmp (ref->vtable->klass->name_space, "System.Globalization") &&
701 !strcmp (ref->vtable->klass->name, "CultureInfo") &&
702 !strcmp(o->vtable->klass->name_space, "System") &&
703 !strcmp(o->vtable->klass->name, "Object[]"))
706 * 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
707 * at System.IO.MemoryStream..ctor (byte[]) [0x00017] in /home/schani/Work/novell/trunk/mcs/class/corlib/System.IO/MemoryStream.cs:81
708 * at (wrapper remoting-invoke-with-check) System.IO.MemoryStream..ctor (byte[]) <IL 0x00020, 0xffffffff>
709 * at System.Runtime.Remoting.Messaging.CADMethodCallMessage.GetArguments () [0x0000d] in /home/schani/Work/novell/trunk/mcs/class/corlib/System.Runtime.Remoting.Messaging/CADMessages.cs:327
710 * 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
711 * 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
712 * at (wrapper remoting-invoke-with-check) System.AppDomain.ProcessMessageInDomain (byte[],System.Runtime.Remoting.Messaging.CADMethodCallMessage,byte[]&,System.Runtime.Remoting.Messaging.CADMethodReturnMessage&) <IL 0x0003d, 0xffffffff>
713 * 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
714 * at (wrapper runtime-invoke) object.runtime_invoke_CrossAppDomainSink/ProcessMessageRes_object_object (object,intptr,intptr,intptr) <IL 0x0004c, 0xffffffff>
716 if (!strcmp (ref->vtable->klass->name_space, "System") &&
717 !strcmp (ref->vtable->klass->name, "Byte[]") &&
718 !strcmp (o->vtable->klass->name_space, "System.IO") &&
719 !strcmp (o->vtable->klass->name, "MemoryStream"))
721 /* append_job() in threadpool.c */
722 if (!strcmp (ref->vtable->klass->name_space, "System.Runtime.Remoting.Messaging") &&
723 !strcmp (ref->vtable->klass->name, "AsyncResult") &&
724 !strcmp (o->vtable->klass->name_space, "System") &&
725 !strcmp (o->vtable->klass->name, "Object[]") &&
726 mono_thread_pool_is_queue_array ((MonoArray*) o))
732 check_reference_for_xdomain (gpointer *ptr, char *obj, MonoDomain *domain)
734 MonoObject *o = (MonoObject*)(obj);
735 MonoObject *ref = (MonoObject*)*(ptr);
736 int offset = (char*)(ptr) - (char*)o;
738 MonoClassField *field;
741 if (!ref || ref->vtable->domain == domain)
743 if (is_xdomain_ref_allowed (ptr, obj, domain))
747 for (class = o->vtable->klass; class; class = class->parent) {
750 for (i = 0; i < class->field.count; ++i) {
751 if (class->fields[i].offset == offset) {
752 field = &class->fields[i];
760 if (ref->vtable->klass == mono_defaults.string_class)
761 str = mono_string_to_utf8 ((MonoString*)ref);
764 g_print ("xdomain reference in %p (%s.%s) at offset %d (%s) to %p (%s.%s) (%s) - pointed to by:\n",
765 o, o->vtable->klass->name_space, o->vtable->klass->name,
766 offset, field ? field->name : "",
767 ref, ref->vtable->klass->name_space, ref->vtable->klass->name, str ? str : "");
768 mono_gc_scan_for_specific_ref (o, TRUE);
774 #define HANDLE_PTR(ptr,obj) check_reference_for_xdomain ((ptr), (obj), domain)
777 scan_object_for_xdomain_refs (char *start, mword size, void *data)
779 MonoDomain *domain = ((MonoObject*)start)->vtable->domain;
781 #include "sgen-scan-object.h"
784 static gboolean scan_object_for_specific_ref_precise = TRUE;
787 #define HANDLE_PTR(ptr,obj) do { \
788 if ((MonoObject*)*(ptr) == key) { \
789 g_print ("found ref to %p in object %p (%s) at offset %td\n", \
790 key, (obj), safe_name ((obj)), ((char*)(ptr) - (char*)(obj))); \
795 scan_object_for_specific_ref (char *start, MonoObject *key)
799 if ((forwarded = SGEN_OBJECT_IS_FORWARDED (start)))
802 if (scan_object_for_specific_ref_precise) {
803 #include "sgen-scan-object.h"
805 mword *words = (mword*)start;
806 size_t size = safe_object_get_size ((MonoObject*)start);
808 for (i = 0; i < size / sizeof (mword); ++i) {
809 if (words [i] == (mword)key) {
810 g_print ("found possible ref to %p in object %p (%s) at offset %td\n",
811 key, start, safe_name (start), i * sizeof (mword));
818 sgen_scan_area_with_callback (char *start, char *end, IterateObjectCallbackFunc callback, void *data, gboolean allow_flags)
820 while (start < end) {
824 if (!*(void**)start) {
825 start += sizeof (void*); /* should be ALLOC_ALIGN, really */
830 if (!(obj = SGEN_OBJECT_IS_FORWARDED (start)))
836 size = ALIGN_UP (safe_object_get_size ((MonoObject*)obj));
838 if ((MonoVTable*)SGEN_LOAD_VTABLE (obj) != array_fill_vtable)
839 callback (obj, size, data);
846 scan_object_for_specific_ref_callback (char *obj, size_t size, MonoObject *key)
848 scan_object_for_specific_ref (obj, key);
852 check_root_obj_specific_ref (RootRecord *root, MonoObject *key, MonoObject *obj)
856 g_print ("found ref to %p in root record %p\n", key, root);
859 static MonoObject *check_key = NULL;
860 static RootRecord *check_root = NULL;
863 check_root_obj_specific_ref_from_marker (void **obj)
865 check_root_obj_specific_ref (check_root, check_key, *obj);
869 scan_roots_for_specific_ref (MonoObject *key, int root_type)
875 SGEN_HASH_TABLE_FOREACH (&roots_hash [root_type], start_root, root) {
876 mword desc = root->root_desc;
880 switch (desc & ROOT_DESC_TYPE_MASK) {
881 case ROOT_DESC_BITMAP:
882 desc >>= ROOT_DESC_TYPE_SHIFT;
885 check_root_obj_specific_ref (root, key, *start_root);
890 case ROOT_DESC_COMPLEX: {
891 gsize *bitmap_data = sgen_get_complex_descriptor_bitmap (desc);
892 int bwords = (*bitmap_data) - 1;
893 void **start_run = start_root;
895 while (bwords-- > 0) {
896 gsize bmap = *bitmap_data++;
897 void **objptr = start_run;
900 check_root_obj_specific_ref (root, key, *objptr);
904 start_run += GC_BITS_PER_WORD;
908 case ROOT_DESC_USER: {
909 MonoGCRootMarkFunc marker = sgen_get_user_descriptor_func (desc);
910 marker (start_root, check_root_obj_specific_ref_from_marker);
913 case ROOT_DESC_RUN_LEN:
914 g_assert_not_reached ();
916 g_assert_not_reached ();
918 } SGEN_HASH_TABLE_FOREACH_END;
925 mono_gc_scan_for_specific_ref (MonoObject *key, gboolean precise)
930 scan_object_for_specific_ref_precise = precise;
932 sgen_scan_area_with_callback (nursery_section->data, nursery_section->end_data,
933 (IterateObjectCallbackFunc)scan_object_for_specific_ref_callback, key, TRUE);
935 major_collector.iterate_objects (TRUE, TRUE, (IterateObjectCallbackFunc)scan_object_for_specific_ref_callback, key);
937 sgen_los_iterate_objects ((IterateObjectCallbackFunc)scan_object_for_specific_ref_callback, key);
939 scan_roots_for_specific_ref (key, ROOT_TYPE_NORMAL);
940 scan_roots_for_specific_ref (key, ROOT_TYPE_WBARRIER);
942 SGEN_HASH_TABLE_FOREACH (&roots_hash [ROOT_TYPE_PINNED], ptr, root) {
943 while (ptr < (void**)root->end_root) {
944 check_root_obj_specific_ref (root, *ptr, key);
947 } SGEN_HASH_TABLE_FOREACH_END;
951 need_remove_object_for_domain (char *start, MonoDomain *domain)
953 if (mono_object_domain (start) == domain) {
954 DEBUG (4, fprintf (gc_debug_file, "Need to cleanup object %p\n", start));
955 binary_protocol_cleanup (start, (gpointer)LOAD_VTABLE (start), safe_object_get_size ((MonoObject*)start));
962 process_object_for_domain_clearing (char *start, MonoDomain *domain)
964 GCVTable *vt = (GCVTable*)LOAD_VTABLE (start);
965 if (vt->klass == mono_defaults.internal_thread_class)
966 g_assert (mono_object_domain (start) == mono_get_root_domain ());
967 /* The object could be a proxy for an object in the domain
969 if (mono_class_has_parent_fast (vt->klass, mono_defaults.real_proxy_class)) {
970 MonoObject *server = ((MonoRealProxy*)start)->unwrapped_server;
972 /* The server could already have been zeroed out, so
973 we need to check for that, too. */
974 if (server && (!LOAD_VTABLE (server) || mono_object_domain (server) == domain)) {
975 DEBUG (4, fprintf (gc_debug_file, "Cleaning up remote pointer in %p to object %p\n",
977 ((MonoRealProxy*)start)->unwrapped_server = NULL;
982 static MonoDomain *check_domain = NULL;
985 check_obj_not_in_domain (void **o)
987 g_assert (((MonoObject*)(*o))->vtable->domain != check_domain);
991 scan_for_registered_roots_in_domain (MonoDomain *domain, int root_type)
995 check_domain = domain;
996 SGEN_HASH_TABLE_FOREACH (&roots_hash [root_type], start_root, root) {
997 mword desc = root->root_desc;
999 /* The MonoDomain struct is allowed to hold
1000 references to objects in its own domain. */
1001 if (start_root == (void**)domain)
1004 switch (desc & ROOT_DESC_TYPE_MASK) {
1005 case ROOT_DESC_BITMAP:
1006 desc >>= ROOT_DESC_TYPE_SHIFT;
1008 if ((desc & 1) && *start_root)
1009 check_obj_not_in_domain (*start_root);
1014 case ROOT_DESC_COMPLEX: {
1015 gsize *bitmap_data = sgen_get_complex_descriptor_bitmap (desc);
1016 int bwords = (*bitmap_data) - 1;
1017 void **start_run = start_root;
1019 while (bwords-- > 0) {
1020 gsize bmap = *bitmap_data++;
1021 void **objptr = start_run;
1023 if ((bmap & 1) && *objptr)
1024 check_obj_not_in_domain (*objptr);
1028 start_run += GC_BITS_PER_WORD;
1032 case ROOT_DESC_USER: {
1033 MonoGCRootMarkFunc marker = sgen_get_user_descriptor_func (desc);
1034 marker (start_root, check_obj_not_in_domain);
1037 case ROOT_DESC_RUN_LEN:
1038 g_assert_not_reached ();
1040 g_assert_not_reached ();
1042 } SGEN_HASH_TABLE_FOREACH_END;
1044 check_domain = NULL;
1048 check_for_xdomain_refs (void)
1052 sgen_scan_area_with_callback (nursery_section->data, nursery_section->end_data,
1053 (IterateObjectCallbackFunc)scan_object_for_xdomain_refs, NULL, FALSE);
1055 major_collector.iterate_objects (TRUE, TRUE, (IterateObjectCallbackFunc)scan_object_for_xdomain_refs, NULL);
1057 for (bigobj = los_object_list; bigobj; bigobj = bigobj->next)
1058 scan_object_for_xdomain_refs (bigobj->data, bigobj->size, NULL);
1062 clear_domain_process_object (char *obj, MonoDomain *domain)
1066 process_object_for_domain_clearing (obj, domain);
1067 remove = need_remove_object_for_domain (obj, domain);
1069 if (remove && ((MonoObject*)obj)->synchronisation) {
1070 void **dislink = mono_monitor_get_object_monitor_weak_link ((MonoObject*)obj);
1072 mono_gc_register_disappearing_link (NULL, dislink, FALSE, TRUE);
1079 clear_domain_process_minor_object_callback (char *obj, size_t size, MonoDomain *domain)
1081 if (clear_domain_process_object (obj, domain))
1082 memset (obj, 0, size);
1086 clear_domain_process_major_object_callback (char *obj, size_t size, MonoDomain *domain)
1088 clear_domain_process_object (obj, domain);
1092 clear_domain_free_major_non_pinned_object_callback (char *obj, size_t size, MonoDomain *domain)
1094 if (need_remove_object_for_domain (obj, domain))
1095 major_collector.free_non_pinned_object (obj, size);
1099 clear_domain_free_major_pinned_object_callback (char *obj, size_t size, MonoDomain *domain)
1101 if (need_remove_object_for_domain (obj, domain))
1102 major_collector.free_pinned_object (obj, size);
1106 * When appdomains are unloaded we can easily remove objects that have finalizers,
1107 * but all the others could still be present in random places on the heap.
1108 * We need a sweep to get rid of them even though it's going to be costly
1110 * The reason we need to remove them is because we access the vtable and class
1111 * structures to know the object size and the reference bitmap: once the domain is
1112 * unloaded the point to random memory.
1115 mono_gc_clear_domain (MonoDomain * domain)
1117 LOSObject *bigobj, *prev;
1122 process_fin_stage_entries ();
1123 process_dislink_stage_entries ();
1125 sgen_clear_nursery_fragments ();
1127 if (xdomain_checks && domain != mono_get_root_domain ()) {
1128 scan_for_registered_roots_in_domain (domain, ROOT_TYPE_NORMAL);
1129 scan_for_registered_roots_in_domain (domain, ROOT_TYPE_WBARRIER);
1130 check_for_xdomain_refs ();
1133 sgen_scan_area_with_callback (nursery_section->data, nursery_section->end_data,
1134 (IterateObjectCallbackFunc)clear_domain_process_minor_object_callback, domain, FALSE);
1136 /*Ephemerons and dislinks must be processed before LOS since they might end up pointing
1137 to memory returned to the OS.*/
1138 null_ephemerons_for_domain (domain);
1140 for (i = GENERATION_NURSERY; i < GENERATION_MAX; ++i)
1141 null_links_for_domain (domain, i);
1143 /* We need two passes over major and large objects because
1144 freeing such objects might give their memory back to the OS
1145 (in the case of large objects) or obliterate its vtable
1146 (pinned objects with major-copying or pinned and non-pinned
1147 objects with major-mark&sweep), but we might need to
1148 dereference a pointer from an object to another object if
1149 the first object is a proxy. */
1150 major_collector.iterate_objects (TRUE, TRUE, (IterateObjectCallbackFunc)clear_domain_process_major_object_callback, domain);
1151 for (bigobj = los_object_list; bigobj; bigobj = bigobj->next)
1152 clear_domain_process_object (bigobj->data, domain);
1155 for (bigobj = los_object_list; bigobj;) {
1156 if (need_remove_object_for_domain (bigobj->data, domain)) {
1157 LOSObject *to_free = bigobj;
1159 prev->next = bigobj->next;
1161 los_object_list = bigobj->next;
1162 bigobj = bigobj->next;
1163 DEBUG (4, fprintf (gc_debug_file, "Freeing large object %p\n",
1165 sgen_los_free_object (to_free);
1169 bigobj = bigobj->next;
1171 major_collector.iterate_objects (TRUE, FALSE, (IterateObjectCallbackFunc)clear_domain_free_major_non_pinned_object_callback, domain);
1172 major_collector.iterate_objects (FALSE, TRUE, (IterateObjectCallbackFunc)clear_domain_free_major_pinned_object_callback, domain);
1174 if (G_UNLIKELY (do_pin_stats)) {
1175 if (domain == mono_get_root_domain ())
1176 sgen_pin_stats_print_class_stats ();
1183 * sgen_add_to_global_remset:
1185 * The global remset contains locations which point into newspace after
1186 * a minor collection. This can happen if the objects they point to are pinned.
1188 * LOCKING: If called from a parallel collector, the global remset
1189 * lock must be held. For serial collectors that is not necessary.
1192 sgen_add_to_global_remset (gpointer ptr)
1194 remset.record_pointer (ptr);
1198 * sgen_drain_gray_stack:
1200 * Scan objects in the gray stack until the stack is empty. This should be called
1201 * frequently after each object is copied, to achieve better locality and cache
1205 sgen_drain_gray_stack (GrayQueue *queue, int max_objs)
1208 ScanObjectFunc scan_func = current_object_ops.scan_object;
1210 if (max_objs == -1) {
1212 GRAY_OBJECT_DEQUEUE (queue, obj);
1215 DEBUG (9, fprintf (gc_debug_file, "Precise gray object scan %p (%s)\n", obj, safe_name (obj)));
1216 scan_func (obj, queue);
1222 for (i = 0; i != max_objs; ++i) {
1223 GRAY_OBJECT_DEQUEUE (queue, obj);
1226 DEBUG (9, fprintf (gc_debug_file, "Precise gray object scan %p (%s)\n", obj, safe_name (obj)));
1227 scan_func (obj, queue);
1229 } while (max_objs < 0);
1235 * Addresses from start to end are already sorted. This function finds
1236 * the object header for each address and pins the object. The
1237 * addresses must be inside the passed section. The (start of the)
1238 * address array is overwritten with the addresses of the actually
1239 * pinned objects. Return the number of pinned objects.
1242 pin_objects_from_addresses (GCMemSection *section, void **start, void **end, void *start_nursery, void *end_nursery, GrayQueue *queue)
1247 void *last_obj = NULL;
1248 size_t last_obj_size = 0;
1251 void **definitely_pinned = start;
1253 sgen_nursery_allocator_prepare_for_pinning ();
1255 while (start < end) {
1257 /* the range check should be reduntant */
1258 if (addr != last && addr >= start_nursery && addr < end_nursery) {
1259 DEBUG (5, fprintf (gc_debug_file, "Considering pinning addr %p\n", addr));
1260 /* multiple pointers to the same object */
1261 if (addr >= last_obj && (char*)addr < (char*)last_obj + last_obj_size) {
1265 idx = ((char*)addr - (char*)section->data) / SCAN_START_SIZE;
1266 g_assert (idx < section->num_scan_start);
1267 search_start = (void*)section->scan_starts [idx];
1268 if (!search_start || search_start > addr) {
1271 search_start = section->scan_starts [idx];
1272 if (search_start && search_start <= addr)
1275 if (!search_start || search_start > addr)
1276 search_start = start_nursery;
1278 if (search_start < last_obj)
1279 search_start = (char*)last_obj + last_obj_size;
1280 /* now addr should be in an object a short distance from search_start
1281 * Note that search_start must point to zeroed mem or point to an object.
1285 if (!*(void**)search_start) {
1286 /* Consistency check */
1288 for (frag = nursery_fragments; frag; frag = frag->next) {
1289 if (search_start >= frag->fragment_start && search_start < frag->fragment_end)
1290 g_assert_not_reached ();
1294 search_start = (void*)ALIGN_UP ((mword)search_start + sizeof (gpointer));
1297 last_obj = search_start;
1298 last_obj_size = ALIGN_UP (safe_object_get_size ((MonoObject*)search_start));
1300 if (((MonoObject*)last_obj)->synchronisation == GINT_TO_POINTER (-1)) {
1301 /* Marks the beginning of a nursery fragment, skip */
1303 DEBUG (8, fprintf (gc_debug_file, "Pinned try match %p (%s), size %zd\n", last_obj, safe_name (last_obj), last_obj_size));
1304 if (addr >= search_start && (char*)addr < (char*)last_obj + last_obj_size) {
1305 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));
1306 binary_protocol_pin (search_start, (gpointer)LOAD_VTABLE (search_start), safe_object_get_size (search_start));
1307 pin_object (search_start);
1308 GRAY_OBJECT_ENQUEUE (queue, search_start);
1309 if (G_UNLIKELY (do_pin_stats))
1310 sgen_pin_stats_register_object (search_start, last_obj_size);
1311 definitely_pinned [count] = search_start;
1316 /* skip to the next object */
1317 search_start = (void*)((char*)search_start + last_obj_size);
1318 } while (search_start <= addr);
1319 /* we either pinned the correct object or we ignored the addr because
1320 * it points to unused zeroed memory.
1326 //printf ("effective pinned: %d (at the end: %d)\n", count, (char*)end_nursery - (char*)last);
1327 if (mono_profiler_get_events () & MONO_PROFILE_GC_ROOTS) {
1328 GCRootReport report;
1330 for (idx = 0; idx < count; ++idx)
1331 add_profile_gc_root (&report, definitely_pinned [idx], MONO_PROFILE_GC_ROOT_PINNING | MONO_PROFILE_GC_ROOT_MISC, 0);
1332 notify_gc_roots (&report);
1334 stat_pinned_objects += count;
1339 sgen_pin_objects_in_section (GCMemSection *section, GrayQueue *queue)
1341 int num_entries = section->pin_queue_num_entries;
1343 void **start = section->pin_queue_start;
1345 reduced_to = pin_objects_from_addresses (section, start, start + num_entries,
1346 section->data, section->next_data, queue);
1347 section->pin_queue_num_entries = reduced_to;
1349 section->pin_queue_start = NULL;
1355 sgen_pin_object (void *object, GrayQueue *queue)
1357 if (sgen_collection_is_parallel ()) {
1359 /*object arrives pinned*/
1360 sgen_pin_stage_ptr (object);
1364 SGEN_PIN_OBJECT (object);
1365 sgen_pin_stage_ptr (object);
1367 if (G_UNLIKELY (do_pin_stats))
1368 sgen_pin_stats_register_object (object, safe_object_get_size (object));
1370 GRAY_OBJECT_ENQUEUE (queue, object);
1371 binary_protocol_pin (object, (gpointer)LOAD_VTABLE (object), safe_object_get_size (object));
1375 sgen_parallel_pin_or_update (void **ptr, void *obj, MonoVTable *vt, SgenGrayQueue *queue)
1379 gboolean major_pinned = FALSE;
1381 if (sgen_ptr_in_nursery (obj)) {
1382 if (SGEN_CAS_PTR (obj, (void*)((mword)vt | SGEN_PINNED_BIT), vt) == vt) {
1383 sgen_pin_object (obj, queue);
1387 major_collector.pin_major_object (obj, queue);
1388 major_pinned = TRUE;
1391 vtable_word = *(mword*)obj;
1392 /*someone else forwarded it, update the pointer and bail out*/
1393 if (vtable_word & SGEN_FORWARDED_BIT) {
1394 *ptr = (void*)(vtable_word & ~SGEN_VTABLE_BITS_MASK);
1398 /*someone pinned it, nothing to do.*/
1399 if (vtable_word & SGEN_PINNED_BIT || major_pinned)
1404 /* Sort the addresses in array in increasing order.
1405 * Done using a by-the book heap sort. Which has decent and stable performance, is pretty cache efficient.
1408 sgen_sort_addresses (void **array, int size)
1413 for (i = 1; i < size; ++i) {
1416 int parent = (child - 1) / 2;
1418 if (array [parent] >= array [child])
1421 tmp = array [parent];
1422 array [parent] = array [child];
1423 array [child] = tmp;
1429 for (i = size - 1; i > 0; --i) {
1432 array [i] = array [0];
1438 while (root * 2 + 1 <= end) {
1439 int child = root * 2 + 1;
1441 if (child < end && array [child] < array [child + 1])
1443 if (array [root] >= array [child])
1447 array [root] = array [child];
1448 array [child] = tmp;
1456 * Scan the memory between start and end and queue values which could be pointers
1457 * to the area between start_nursery and end_nursery for later consideration.
1458 * Typically used for thread stacks.
1461 conservatively_pin_objects_from (void **start, void **end, void *start_nursery, void *end_nursery, int pin_type)
1464 while (start < end) {
1465 if (*start >= start_nursery && *start < end_nursery) {
1467 * *start can point to the middle of an object
1468 * note: should we handle pointing at the end of an object?
1469 * pinning in C# code disallows pointing at the end of an object
1470 * but there is some small chance that an optimizing C compiler
1471 * may keep the only reference to an object by pointing
1472 * at the end of it. We ignore this small chance for now.
1473 * Pointers to the end of an object are indistinguishable
1474 * from pointers to the start of the next object in memory
1475 * so if we allow that we'd need to pin two objects...
1476 * We queue the pointer in an array, the
1477 * array will then be sorted and uniqued. This way
1478 * we can coalesce several pinning pointers and it should
1479 * be faster since we'd do a memory scan with increasing
1480 * addresses. Note: we can align the address to the allocation
1481 * alignment, so the unique process is more effective.
1483 mword addr = (mword)*start;
1484 addr &= ~(ALLOC_ALIGN - 1);
1485 if (addr >= (mword)start_nursery && addr < (mword)end_nursery)
1486 sgen_pin_stage_ptr ((void*)addr);
1487 if (G_UNLIKELY (do_pin_stats)) {
1488 if (ptr_in_nursery ((void*)addr))
1489 sgen_pin_stats_register_address ((char*)addr, pin_type);
1491 DEBUG (6, if (count) fprintf (gc_debug_file, "Pinning address %p from %p\n", (void*)addr, start));
1496 DEBUG (7, if (count) fprintf (gc_debug_file, "found %d potential pinned heap pointers\n", count));
1500 * Debugging function: find in the conservative roots where @obj is being pinned.
1502 static G_GNUC_UNUSED void
1503 find_pinning_reference (char *obj, size_t size)
1507 char *endobj = obj + size;
1509 SGEN_HASH_TABLE_FOREACH (&roots_hash [ROOT_TYPE_NORMAL], start, root) {
1510 /* if desc is non-null it has precise info */
1511 if (!root->root_desc) {
1512 while (start < (char**)root->end_root) {
1513 if (*start >= obj && *start < endobj) {
1514 DEBUG (0, fprintf (gc_debug_file, "Object %p referenced in pinned roots %p-%p\n", obj, start, root->end_root));
1519 } SGEN_HASH_TABLE_FOREACH_END;
1521 find_pinning_ref_from_thread (obj, size);
1525 * The first thing we do in a collection is to identify pinned objects.
1526 * This function considers all the areas of memory that need to be
1527 * conservatively scanned.
1530 pin_from_roots (void *start_nursery, void *end_nursery, GrayQueue *queue)
1534 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));
1535 /* objects pinned from the API are inside these roots */
1536 SGEN_HASH_TABLE_FOREACH (&roots_hash [ROOT_TYPE_PINNED], start_root, root) {
1537 DEBUG (6, fprintf (gc_debug_file, "Pinned roots %p-%p\n", start_root, root->end_root));
1538 conservatively_pin_objects_from (start_root, (void**)root->end_root, start_nursery, end_nursery, PIN_TYPE_OTHER);
1539 } SGEN_HASH_TABLE_FOREACH_END;
1540 /* now deal with the thread stacks
1541 * in the future we should be able to conservatively scan only:
1542 * *) the cpu registers
1543 * *) the unmanaged stack frames
1544 * *) the _last_ managed stack frame
1545 * *) pointers slots in managed frames
1547 scan_thread_data (start_nursery, end_nursery, FALSE, queue);
1551 CopyOrMarkObjectFunc func;
1553 } UserCopyOrMarkData;
1555 static MonoNativeTlsKey user_copy_or_mark_key;
1558 init_user_copy_or_mark_key (void)
1560 mono_native_tls_alloc (&user_copy_or_mark_key, NULL);
1564 set_user_copy_or_mark_data (UserCopyOrMarkData *data)
1566 mono_native_tls_set_value (user_copy_or_mark_key, data);
1570 single_arg_user_copy_or_mark (void **obj)
1572 UserCopyOrMarkData *data = mono_native_tls_get_value (user_copy_or_mark_key);
1574 data->func (obj, data->queue);
1578 * The memory area from start_root to end_root contains pointers to objects.
1579 * Their position is precisely described by @desc (this means that the pointer
1580 * can be either NULL or the pointer to the start of an object).
1581 * This functions copies them to to_space updates them.
1583 * This function is not thread-safe!
1586 precisely_scan_objects_from (CopyOrMarkObjectFunc copy_func, void** start_root, void** end_root, char* n_start, char *n_end, mword desc, GrayQueue *queue)
1588 switch (desc & ROOT_DESC_TYPE_MASK) {
1589 case ROOT_DESC_BITMAP:
1590 desc >>= ROOT_DESC_TYPE_SHIFT;
1592 if ((desc & 1) && *start_root) {
1593 copy_func (start_root, queue);
1594 DEBUG (9, fprintf (gc_debug_file, "Overwrote root at %p with %p\n", start_root, *start_root));
1595 sgen_drain_gray_stack (queue, -1);
1601 case ROOT_DESC_COMPLEX: {
1602 gsize *bitmap_data = sgen_get_complex_descriptor_bitmap (desc);
1603 int bwords = (*bitmap_data) - 1;
1604 void **start_run = start_root;
1606 while (bwords-- > 0) {
1607 gsize bmap = *bitmap_data++;
1608 void **objptr = start_run;
1610 if ((bmap & 1) && *objptr) {
1611 copy_func (objptr, queue);
1612 DEBUG (9, fprintf (gc_debug_file, "Overwrote root at %p with %p\n", objptr, *objptr));
1613 sgen_drain_gray_stack (queue, -1);
1618 start_run += GC_BITS_PER_WORD;
1622 case ROOT_DESC_USER: {
1623 UserCopyOrMarkData data = { copy_func, queue };
1624 MonoGCRootMarkFunc marker = sgen_get_user_descriptor_func (desc);
1625 set_user_copy_or_mark_data (&data);
1626 marker (start_root, single_arg_user_copy_or_mark);
1627 set_user_copy_or_mark_data (NULL);
1630 case ROOT_DESC_RUN_LEN:
1631 g_assert_not_reached ();
1633 g_assert_not_reached ();
1638 reset_heap_boundaries (void)
1640 lowest_heap_address = ~(mword)0;
1641 highest_heap_address = 0;
1645 sgen_update_heap_boundaries (mword low, mword high)
1650 old = lowest_heap_address;
1653 } while (SGEN_CAS_PTR ((gpointer*)&lowest_heap_address, (gpointer)low, (gpointer)old) != (gpointer)old);
1656 old = highest_heap_address;
1659 } while (SGEN_CAS_PTR ((gpointer*)&highest_heap_address, (gpointer)high, (gpointer)old) != (gpointer)old);
1662 static unsigned long
1663 prot_flags_for_activate (int activate)
1665 unsigned long prot_flags = activate? MONO_MMAP_READ|MONO_MMAP_WRITE: MONO_MMAP_NONE;
1666 return prot_flags | MONO_MMAP_PRIVATE | MONO_MMAP_ANON;
1670 * Allocate a big chunk of memory from the OS (usually 64KB to several megabytes).
1671 * This must not require any lock.
1674 sgen_alloc_os_memory (size_t size, int activate)
1676 void *ptr = mono_valloc (0, size, prot_flags_for_activate (activate));
1679 total_alloc += size;
1684 /* size must be a power of 2 */
1686 sgen_alloc_os_memory_aligned (mword size, mword alignment, gboolean activate)
1688 void *ptr = mono_valloc_aligned (size, alignment, prot_flags_for_activate (activate));
1691 total_alloc += size;
1697 * Free the memory returned by sgen_alloc_os_memory (), returning it to the OS.
1700 sgen_free_os_memory (void *addr, size_t size)
1702 mono_vfree (addr, size);
1704 total_alloc -= size;
1708 * Allocate and setup the data structures needed to be able to allocate objects
1709 * in the nursery. The nursery is stored in nursery_section.
1712 alloc_nursery (void)
1714 GCMemSection *section;
1719 if (nursery_section)
1721 DEBUG (2, fprintf (gc_debug_file, "Allocating nursery size: %lu\n", (unsigned long)nursery_size));
1722 /* later we will alloc a larger area for the nursery but only activate
1723 * what we need. The rest will be used as expansion if we have too many pinned
1724 * objects in the existing nursery.
1726 /* FIXME: handle OOM */
1727 section = sgen_alloc_internal (INTERNAL_MEM_SECTION);
1729 g_assert (nursery_size == DEFAULT_NURSERY_SIZE);
1730 alloc_size = nursery_size;
1731 #ifdef SGEN_ALIGN_NURSERY
1732 data = major_collector.alloc_heap (alloc_size, alloc_size, DEFAULT_NURSERY_BITS);
1734 data = major_collector.alloc_heap (alloc_size, 0, DEFAULT_NURSERY_BITS);
1736 sgen_update_heap_boundaries ((mword)data, (mword)(data + nursery_size));
1737 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));
1738 section->data = section->next_data = data;
1739 section->size = alloc_size;
1740 section->end_data = data + nursery_size;
1741 scan_starts = (alloc_size + SCAN_START_SIZE - 1) / SCAN_START_SIZE;
1742 section->scan_starts = sgen_alloc_internal_dynamic (sizeof (char*) * scan_starts, INTERNAL_MEM_SCAN_STARTS);
1743 section->num_scan_start = scan_starts;
1744 section->block.role = MEMORY_ROLE_GEN0;
1745 section->block.next = NULL;
1747 nursery_section = section;
1749 sgen_nursery_allocator_set_nursery_bounds (data, data + nursery_size);
1753 mono_gc_get_nursery (int *shift_bits, size_t *size)
1755 *size = nursery_size;
1756 #ifdef SGEN_ALIGN_NURSERY
1757 *shift_bits = DEFAULT_NURSERY_BITS;
1761 return sgen_get_nursery_start ();
1765 mono_gc_set_current_thread_appdomain (MonoDomain *domain)
1767 SgenThreadInfo *info = mono_thread_info_current ();
1769 /* Could be called from sgen_thread_unregister () with a NULL info */
1772 info->stopped_domain = domain;
1777 mono_gc_precise_stack_mark_enabled (void)
1779 return !conservative_stack_mark;
1783 mono_gc_get_logfile (void)
1785 return sgen_get_logfile ();
1789 report_finalizer_roots_list (FinalizeReadyEntry *list)
1791 GCRootReport report;
1792 FinalizeReadyEntry *fin;
1795 for (fin = list; fin; fin = fin->next) {
1798 add_profile_gc_root (&report, fin->object, MONO_PROFILE_GC_ROOT_FINALIZER, 0);
1800 notify_gc_roots (&report);
1804 report_finalizer_roots (void)
1806 report_finalizer_roots_list (fin_ready_list);
1807 report_finalizer_roots_list (critical_fin_list);
1810 static GCRootReport *root_report;
1813 single_arg_report_root (void **obj)
1816 add_profile_gc_root (root_report, *obj, MONO_PROFILE_GC_ROOT_OTHER, 0);
1820 precisely_report_roots_from (GCRootReport *report, void** start_root, void** end_root, mword desc)
1822 switch (desc & ROOT_DESC_TYPE_MASK) {
1823 case ROOT_DESC_BITMAP:
1824 desc >>= ROOT_DESC_TYPE_SHIFT;
1826 if ((desc & 1) && *start_root) {
1827 add_profile_gc_root (report, *start_root, MONO_PROFILE_GC_ROOT_OTHER, 0);
1833 case ROOT_DESC_COMPLEX: {
1834 gsize *bitmap_data = sgen_get_complex_descriptor_bitmap (desc);
1835 int bwords = (*bitmap_data) - 1;
1836 void **start_run = start_root;
1838 while (bwords-- > 0) {
1839 gsize bmap = *bitmap_data++;
1840 void **objptr = start_run;
1842 if ((bmap & 1) && *objptr) {
1843 add_profile_gc_root (report, *objptr, MONO_PROFILE_GC_ROOT_OTHER, 0);
1848 start_run += GC_BITS_PER_WORD;
1852 case ROOT_DESC_USER: {
1853 MonoGCRootMarkFunc marker = sgen_get_user_descriptor_func (desc);
1854 root_report = report;
1855 marker (start_root, single_arg_report_root);
1858 case ROOT_DESC_RUN_LEN:
1859 g_assert_not_reached ();
1861 g_assert_not_reached ();
1866 report_registered_roots_by_type (int root_type)
1868 GCRootReport report;
1872 SGEN_HASH_TABLE_FOREACH (&roots_hash [root_type], start_root, root) {
1873 DEBUG (6, fprintf (gc_debug_file, "Precise root scan %p-%p (desc: %p)\n", start_root, root->end_root, (void*)root->root_desc));
1874 precisely_report_roots_from (&report, start_root, (void**)root->end_root, root->root_desc);
1875 } SGEN_HASH_TABLE_FOREACH_END;
1876 notify_gc_roots (&report);
1880 report_registered_roots (void)
1882 report_registered_roots_by_type (ROOT_TYPE_NORMAL);
1883 report_registered_roots_by_type (ROOT_TYPE_WBARRIER);
1887 scan_finalizer_entries (CopyOrMarkObjectFunc copy_func, FinalizeReadyEntry *list, GrayQueue *queue)
1889 FinalizeReadyEntry *fin;
1891 for (fin = list; fin; fin = fin->next) {
1894 DEBUG (5, fprintf (gc_debug_file, "Scan of fin ready object: %p (%s)\n", fin->object, safe_name (fin->object)));
1895 copy_func (&fin->object, queue);
1900 generation_name (int generation)
1902 switch (generation) {
1903 case GENERATION_NURSERY: return "nursery";
1904 case GENERATION_OLD: return "old";
1905 default: g_assert_not_reached ();
1911 stw_bridge_process (void)
1913 sgen_bridge_processing_stw_step ();
1917 bridge_process (void)
1919 sgen_bridge_processing_finish ();
1922 SgenObjectOperations *
1923 sgen_get_current_object_ops (void){
1924 return ¤t_object_ops;
1929 finish_gray_stack (char *start_addr, char *end_addr, int generation, GrayQueue *queue)
1933 int done_with_ephemerons, ephemeron_rounds = 0;
1934 CopyOrMarkObjectFunc copy_func = current_object_ops.copy_or_mark_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 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 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 sgen_drain_gray_stack (queue, -1);
1972 } while (!done_with_ephemerons);
1974 sgen_scan_togglerefs (copy_func, start_addr, end_addr, queue);
1975 if (generation == GENERATION_OLD)
1976 sgen_scan_togglerefs (copy_func, sgen_get_nursery_start (), sgen_get_nursery_end (), queue);
1978 if (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, sgen_get_nursery_start (), sgen_get_nursery_end (), GENERATION_NURSERY, queue);
1982 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.
1999 finalize_in_range (copy_func, start_addr, end_addr, generation, queue);
2000 if (generation == GENERATION_OLD)
2001 finalize_in_range (copy_func, sgen_get_nursery_start (), sgen_get_nursery_end (), GENERATION_NURSERY, queue);
2002 /* drain the new stack that might have been created */
2003 DEBUG (6, fprintf (gc_debug_file, "Precise scan of gray area post fin\n"));
2004 sgen_drain_gray_stack (queue, -1);
2007 * This must be done again after processing finalizable objects since CWL slots are cleared only after the key is finalized.
2009 done_with_ephemerons = 0;
2011 done_with_ephemerons = mark_ephemerons_in_range (copy_func, start_addr, end_addr, queue);
2012 sgen_drain_gray_stack (queue, -1);
2014 } while (!done_with_ephemerons);
2017 * Clear ephemeron pairs with unreachable keys.
2018 * We pass the copy func so we can figure out if an array was promoted or not.
2020 clear_unreachable_ephemerons (copy_func, start_addr, end_addr, queue);
2023 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));
2026 * handle disappearing links
2027 * Note we do this after checking the finalization queue because if an object
2028 * survives (at least long enough to be finalized) we don't clear the link.
2029 * This also deals with a possible issue with the monitor reclamation: with the Boehm
2030 * GC a finalized object my lose the monitor because it is cleared before the finalizer is
2033 g_assert (sgen_gray_object_queue_is_empty (queue));
2035 null_link_in_range (copy_func, start_addr, end_addr, generation, FALSE, queue);
2036 if (generation == GENERATION_OLD)
2037 null_link_in_range (copy_func, start_addr, end_addr, GENERATION_NURSERY, FALSE, queue);
2038 if (sgen_gray_object_queue_is_empty (queue))
2040 sgen_drain_gray_stack (queue, -1);
2043 g_assert (sgen_gray_object_queue_is_empty (queue));
2047 sgen_check_section_scan_starts (GCMemSection *section)
2050 for (i = 0; i < section->num_scan_start; ++i) {
2051 if (section->scan_starts [i]) {
2052 guint size = safe_object_get_size ((MonoObject*) section->scan_starts [i]);
2053 g_assert (size >= sizeof (MonoObject) && size <= MAX_SMALL_OBJ_SIZE);
2059 check_scan_starts (void)
2061 if (!do_scan_starts_check)
2063 sgen_check_section_scan_starts (nursery_section);
2064 major_collector.check_scan_starts ();
2068 scan_from_registered_roots (CopyOrMarkObjectFunc copy_func, char *addr_start, char *addr_end, int root_type, GrayQueue *queue)
2072 SGEN_HASH_TABLE_FOREACH (&roots_hash [root_type], start_root, root) {
2073 DEBUG (6, fprintf (gc_debug_file, "Precise root scan %p-%p (desc: %p)\n", start_root, root->end_root, (void*)root->root_desc));
2074 precisely_scan_objects_from (copy_func, start_root, (void**)root->end_root, addr_start, addr_end, root->root_desc, queue);
2075 } SGEN_HASH_TABLE_FOREACH_END;
2079 sgen_dump_occupied (char *start, char *end, char *section_start)
2081 fprintf (heap_dump_file, "<occupied offset=\"%td\" size=\"%td\"/>\n", start - section_start, end - start);
2085 sgen_dump_section (GCMemSection *section, const char *type)
2087 char *start = section->data;
2088 char *end = section->data + section->size;
2089 char *occ_start = NULL;
2091 char *old_start = NULL; /* just for debugging */
2093 fprintf (heap_dump_file, "<section type=\"%s\" size=\"%lu\">\n", type, (unsigned long)section->size);
2095 while (start < end) {
2099 if (!*(void**)start) {
2101 sgen_dump_occupied (occ_start, start, section->data);
2104 start += sizeof (void*); /* should be ALLOC_ALIGN, really */
2107 g_assert (start < section->next_data);
2112 vt = (GCVTable*)LOAD_VTABLE (start);
2115 size = ALIGN_UP (safe_object_get_size ((MonoObject*) start));
2118 fprintf (heap_dump_file, "<object offset=\"%d\" class=\"%s.%s\" size=\"%d\"/>\n",
2119 start - section->data,
2120 vt->klass->name_space, vt->klass->name,
2128 sgen_dump_occupied (occ_start, start, section->data);
2130 fprintf (heap_dump_file, "</section>\n");
2134 dump_object (MonoObject *obj, gboolean dump_location)
2136 static char class_name [1024];
2138 MonoClass *class = mono_object_class (obj);
2142 * Python's XML parser is too stupid to parse angle brackets
2143 * in strings, so we just ignore them;
2146 while (class->name [i] && j < sizeof (class_name) - 1) {
2147 if (!strchr ("<>\"", class->name [i]))
2148 class_name [j++] = class->name [i];
2151 g_assert (j < sizeof (class_name));
2154 fprintf (heap_dump_file, "<object class=\"%s.%s\" size=\"%d\"",
2155 class->name_space, class_name,
2156 safe_object_get_size (obj));
2157 if (dump_location) {
2158 const char *location;
2159 if (ptr_in_nursery (obj))
2160 location = "nursery";
2161 else if (safe_object_get_size (obj) <= MAX_SMALL_OBJ_SIZE)
2165 fprintf (heap_dump_file, " location=\"%s\"", location);
2167 fprintf (heap_dump_file, "/>\n");
2171 dump_heap (const char *type, int num, const char *reason)
2176 fprintf (heap_dump_file, "<collection type=\"%s\" num=\"%d\"", type, num);
2178 fprintf (heap_dump_file, " reason=\"%s\"", reason);
2179 fprintf (heap_dump_file, ">\n");
2180 fprintf (heap_dump_file, "<other-mem-usage type=\"mempools\" size=\"%ld\"/>\n", mono_mempool_get_bytes_allocated ());
2181 sgen_dump_internal_mem_usage (heap_dump_file);
2182 fprintf (heap_dump_file, "<pinned type=\"stack\" bytes=\"%zu\"/>\n", sgen_pin_stats_get_pinned_byte_count (PIN_TYPE_STACK));
2183 /* fprintf (heap_dump_file, "<pinned type=\"static-data\" bytes=\"%d\"/>\n", pinned_byte_counts [PIN_TYPE_STATIC_DATA]); */
2184 fprintf (heap_dump_file, "<pinned type=\"other\" bytes=\"%zu\"/>\n", sgen_pin_stats_get_pinned_byte_count (PIN_TYPE_OTHER));
2186 fprintf (heap_dump_file, "<pinned-objects>\n");
2187 for (list = sgen_pin_stats_get_object_list (); list; list = list->next)
2188 dump_object (list->obj, TRUE);
2189 fprintf (heap_dump_file, "</pinned-objects>\n");
2191 sgen_dump_section (nursery_section, "nursery");
2193 major_collector.dump_heap (heap_dump_file);
2195 fprintf (heap_dump_file, "<los>\n");
2196 for (bigobj = los_object_list; bigobj; bigobj = bigobj->next)
2197 dump_object ((MonoObject*)bigobj->data, FALSE);
2198 fprintf (heap_dump_file, "</los>\n");
2200 fprintf (heap_dump_file, "</collection>\n");
2204 sgen_register_moved_object (void *obj, void *destination)
2206 g_assert (mono_profiler_events & MONO_PROFILE_GC_MOVES);
2208 /* FIXME: handle this for parallel collector */
2209 g_assert (!sgen_collection_is_parallel ());
2211 if (moved_objects_idx == MOVED_OBJECTS_NUM) {
2212 mono_profiler_gc_moves (moved_objects, moved_objects_idx);
2213 moved_objects_idx = 0;
2215 moved_objects [moved_objects_idx++] = obj;
2216 moved_objects [moved_objects_idx++] = destination;
2222 static gboolean inited = FALSE;
2227 mono_counters_register ("Minor fragment clear", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_minor_pre_collection_fragment_clear);
2228 mono_counters_register ("Minor pinning", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_minor_pinning);
2229 mono_counters_register ("Minor scan remembered set", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_minor_scan_remsets);
2230 mono_counters_register ("Minor scan pinned", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_minor_scan_pinned);
2231 mono_counters_register ("Minor scan registered roots", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_minor_scan_registered_roots);
2232 mono_counters_register ("Minor scan thread data", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_minor_scan_thread_data);
2233 mono_counters_register ("Minor finish gray stack", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_minor_finish_gray_stack);
2234 mono_counters_register ("Minor fragment creation", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_minor_fragment_creation);
2236 mono_counters_register ("Major fragment clear", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_major_pre_collection_fragment_clear);
2237 mono_counters_register ("Major pinning", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_major_pinning);
2238 mono_counters_register ("Major scan pinned", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_major_scan_pinned);
2239 mono_counters_register ("Major scan registered roots", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_major_scan_registered_roots);
2240 mono_counters_register ("Major scan thread data", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_major_scan_thread_data);
2241 mono_counters_register ("Major scan alloc_pinned", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_major_scan_alloc_pinned);
2242 mono_counters_register ("Major scan finalized", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_major_scan_finalized);
2243 mono_counters_register ("Major scan big objects", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_major_scan_big_objects);
2244 mono_counters_register ("Major finish gray stack", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_major_finish_gray_stack);
2245 mono_counters_register ("Major free big objects", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_major_free_bigobjs);
2246 mono_counters_register ("Major LOS sweep", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_major_los_sweep);
2247 mono_counters_register ("Major sweep", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_major_sweep);
2248 mono_counters_register ("Major fragment creation", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_major_fragment_creation);
2250 mono_counters_register ("Number of pinned objects", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_pinned_objects);
2252 #ifdef HEAVY_STATISTICS
2253 mono_counters_register ("WBarrier set field", MONO_COUNTER_GC | MONO_COUNTER_INT, &stat_wbarrier_set_field);
2254 mono_counters_register ("WBarrier set arrayref", MONO_COUNTER_GC | MONO_COUNTER_INT, &stat_wbarrier_set_arrayref);
2255 mono_counters_register ("WBarrier arrayref copy", MONO_COUNTER_GC | MONO_COUNTER_INT, &stat_wbarrier_arrayref_copy);
2256 mono_counters_register ("WBarrier generic store called", MONO_COUNTER_GC | MONO_COUNTER_INT, &stat_wbarrier_generic_store);
2257 mono_counters_register ("WBarrier set root", MONO_COUNTER_GC | MONO_COUNTER_INT, &stat_wbarrier_set_root);
2258 mono_counters_register ("WBarrier value copy", MONO_COUNTER_GC | MONO_COUNTER_INT, &stat_wbarrier_value_copy);
2259 mono_counters_register ("WBarrier object copy", MONO_COUNTER_GC | MONO_COUNTER_INT, &stat_wbarrier_object_copy);
2261 mono_counters_register ("# objects allocated degraded", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_objects_alloced_degraded);
2262 mono_counters_register ("bytes allocated degraded", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_bytes_alloced_degraded);
2264 mono_counters_register ("# copy_object() called (nursery)", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_copy_object_called_nursery);
2265 mono_counters_register ("# objects copied (nursery)", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_objects_copied_nursery);
2266 mono_counters_register ("# copy_object() called (major)", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_copy_object_called_major);
2267 mono_counters_register ("# objects copied (major)", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_objects_copied_major);
2269 mono_counters_register ("# scan_object() called (nursery)", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_scan_object_called_nursery);
2270 mono_counters_register ("# scan_object() called (major)", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_scan_object_called_major);
2272 mono_counters_register ("Slots allocated in vain", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_slots_allocated_in_vain);
2274 mono_counters_register ("# nursery copy_object() failed from space", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_nursery_copy_object_failed_from_space);
2275 mono_counters_register ("# nursery copy_object() failed forwarded", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_nursery_copy_object_failed_forwarded);
2276 mono_counters_register ("# nursery copy_object() failed pinned", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_nursery_copy_object_failed_pinned);
2277 mono_counters_register ("# nursery copy_object() failed to space", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_nursery_copy_object_failed_to_space);
2279 sgen_nursery_allocator_init_heavy_stats ();
2280 sgen_alloc_init_heavy_stats ();
2286 static gboolean need_calculate_minor_collection_allowance;
2288 static int last_collection_old_num_major_sections;
2289 static mword last_collection_los_memory_usage = 0;
2290 static mword last_collection_old_los_memory_usage;
2291 static mword last_collection_los_memory_alloced;
2294 reset_minor_collection_allowance (void)
2296 need_calculate_minor_collection_allowance = TRUE;
2300 try_calculate_minor_collection_allowance (gboolean overwrite)
2302 int num_major_sections, num_major_sections_saved, save_target, allowance_target;
2303 mword los_memory_saved, new_major, new_heap_size;
2306 g_assert (need_calculate_minor_collection_allowance);
2308 if (!need_calculate_minor_collection_allowance)
2311 if (!*major_collector.have_swept) {
2313 minor_collection_allowance = MIN_MINOR_COLLECTION_ALLOWANCE;
2317 num_major_sections = major_collector.get_num_major_sections ();
2319 num_major_sections_saved = MAX (last_collection_old_num_major_sections - num_major_sections, 0);
2320 los_memory_saved = MAX (last_collection_old_los_memory_usage - last_collection_los_memory_usage, 1);
2322 new_major = num_major_sections * major_collector.section_size;
2323 new_heap_size = new_major + last_collection_los_memory_usage;
2326 * FIXME: Why is save_target half the major memory plus half the
2327 * LOS memory saved? Shouldn't it be half the major memory
2328 * saved plus half the LOS memory saved? Or half the whole heap
2331 save_target = (new_major + los_memory_saved) / 2;
2334 * We aim to allow the allocation of as many sections as is
2335 * necessary to reclaim save_target sections in the next
2336 * collection. We assume the collection pattern won't change.
2337 * In the last cycle, we had num_major_sections_saved for
2338 * minor_collection_sections_alloced. Assuming things won't
2339 * change, this must be the same ratio as save_target for
2340 * allowance_target, i.e.
2342 * num_major_sections_saved save_target
2343 * --------------------------------- == ----------------
2344 * minor_collection_sections_alloced allowance_target
2348 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));
2350 minor_collection_allowance = MAX (MIN (allowance_target, num_major_sections * major_collector.section_size + los_memory_usage), MIN_MINOR_COLLECTION_ALLOWANCE);
2352 if (new_heap_size + minor_collection_allowance > soft_heap_limit) {
2353 if (new_heap_size > soft_heap_limit)
2354 minor_collection_allowance = MIN_MINOR_COLLECTION_ALLOWANCE;
2356 minor_collection_allowance = MAX (soft_heap_limit - new_heap_size, MIN_MINOR_COLLECTION_ALLOWANCE);
2359 if (debug_print_allowance) {
2360 mword old_major = last_collection_old_num_major_sections * major_collector.section_size;
2362 fprintf (gc_debug_file, "Before collection: %ld bytes (%ld major, %ld LOS)\n",
2363 old_major + last_collection_old_los_memory_usage, old_major, last_collection_old_los_memory_usage);
2364 fprintf (gc_debug_file, "After collection: %ld bytes (%ld major, %ld LOS)\n",
2365 new_heap_size, new_major, last_collection_los_memory_usage);
2366 fprintf (gc_debug_file, "Allowance: %ld bytes\n", minor_collection_allowance);
2369 if (major_collector.have_computed_minor_collection_allowance)
2370 major_collector.have_computed_minor_collection_allowance ();
2372 need_calculate_minor_collection_allowance = FALSE;
2376 need_major_collection (mword space_needed)
2378 mword los_alloced = los_memory_usage - MIN (last_collection_los_memory_usage, los_memory_usage);
2379 return (space_needed > available_free_space ()) ||
2380 minor_collection_sections_alloced * major_collector.section_size + los_alloced > minor_collection_allowance;
2384 sgen_need_major_collection (mword space_needed)
2386 return need_major_collection (space_needed);
2390 reset_pinned_from_failed_allocation (void)
2392 bytes_pinned_from_failed_allocation = 0;
2396 sgen_set_pinned_from_failed_allocation (mword objsize)
2398 bytes_pinned_from_failed_allocation += objsize;
2402 sgen_collection_is_parallel (void)
2404 switch (current_collection_generation) {
2405 case GENERATION_NURSERY:
2406 return nursery_collection_is_parallel;
2407 case GENERATION_OLD:
2408 return major_collector.is_parallel;
2410 g_assert_not_reached ();
2418 } FinishRememberedSetScanJobData;
2421 job_finish_remembered_set_scan (WorkerData *worker_data, void *job_data_untyped)
2423 FinishRememberedSetScanJobData *job_data = job_data_untyped;
2425 remset.finish_scan_remsets (job_data->heap_start, job_data->heap_end, sgen_workers_get_job_gray_queue (worker_data));
2430 CopyOrMarkObjectFunc func;
2434 } ScanFromRegisteredRootsJobData;
2437 job_scan_from_registered_roots (WorkerData *worker_data, void *job_data_untyped)
2439 ScanFromRegisteredRootsJobData *job_data = job_data_untyped;
2441 scan_from_registered_roots (job_data->func,
2442 job_data->heap_start, job_data->heap_end,
2443 job_data->root_type,
2444 sgen_workers_get_job_gray_queue (worker_data));
2451 } ScanThreadDataJobData;
2454 job_scan_thread_data (WorkerData *worker_data, void *job_data_untyped)
2456 ScanThreadDataJobData *job_data = job_data_untyped;
2458 scan_thread_data (job_data->heap_start, job_data->heap_end, TRUE,
2459 sgen_workers_get_job_gray_queue (worker_data));
2464 FinalizeReadyEntry *list;
2465 } ScanFinalizerEntriesJobData;
2468 job_scan_finalizer_entries (WorkerData *worker_data, void *job_data_untyped)
2470 ScanFinalizerEntriesJobData *job_data = job_data_untyped;
2472 scan_finalizer_entries (current_object_ops.copy_or_mark_object,
2474 sgen_workers_get_job_gray_queue (worker_data));
2478 verify_scan_starts (char *start, char *end)
2482 for (i = 0; i < nursery_section->num_scan_start; ++i) {
2483 char *addr = nursery_section->scan_starts [i];
2484 if (addr > start && addr < end)
2485 fprintf (gc_debug_file, "NFC-BAD SCAN START [%d] %p for obj [%p %p]\n", i, addr, start, end);
2490 verify_nursery (void)
2492 char *start, *end, *cur, *hole_start;
2494 if (!do_verify_nursery)
2497 /*This cleans up unused fragments */
2498 sgen_nursery_allocator_prepare_for_pinning ();
2500 hole_start = start = cur = sgen_get_nursery_start ();
2501 end = sgen_get_nursery_end ();
2506 if (!*(void**)cur) {
2507 cur += sizeof (void*);
2511 if (object_is_forwarded (cur))
2512 fprintf (gc_debug_file, "FORWARDED OBJ %p\n", cur);
2513 else if (object_is_pinned (cur))
2514 fprintf (gc_debug_file, "PINNED OBJ %p\n", cur);
2516 ss = safe_object_get_size ((MonoObject*)cur);
2517 size = ALIGN_UP (safe_object_get_size ((MonoObject*)cur));
2518 verify_scan_starts (cur, cur + size);
2519 if (do_dump_nursery_content) {
2520 if (cur > hole_start)
2521 fprintf (gc_debug_file, "HOLE [%p %p %d]\n", hole_start, cur, (int)(cur - hole_start));
2522 fprintf (gc_debug_file, "OBJ [%p %p %d %d %s %d]\n", cur, cur + size, (int)size, (int)ss, sgen_safe_name ((MonoObject*)cur), (gpointer)LOAD_VTABLE (cur) == sgen_get_array_fill_vtable ());
2527 fflush (gc_debug_file);
2531 * Collect objects in the nursery. Returns whether to trigger a major
2535 collect_nursery (size_t requested_size)
2537 gboolean needs_major;
2538 size_t max_garbage_amount;
2540 FinishRememberedSetScanJobData frssjd;
2541 ScanFromRegisteredRootsJobData scrrjd_normal, scrrjd_wbarrier;
2542 ScanFinalizerEntriesJobData sfejd_fin_ready, sfejd_critical_fin;
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;
2558 if (sgen_collection_is_parallel ())
2559 current_object_ops = sgen_minor_collector.parallel_ops;
2561 current_object_ops = sgen_minor_collector.serial_ops;
2563 reset_pinned_from_failed_allocation ();
2565 binary_protocol_collection (GENERATION_NURSERY);
2566 check_scan_starts ();
2568 sgen_nursery_alloc_prepare_for_minor ();
2572 nursery_next = sgen_nursery_alloc_get_upper_alloc_bound ();
2573 /* FIXME: optimize later to use the higher address where an object can be present */
2574 nursery_next = MAX (nursery_next, sgen_get_nursery_end ());
2576 DEBUG (1, fprintf (gc_debug_file, "Start nursery collection %d %p-%p, size: %d\n", stat_minor_gcs, sgen_get_nursery_start (), nursery_next, (int)(nursery_next - sgen_get_nursery_start ())));
2577 max_garbage_amount = nursery_next - sgen_get_nursery_start ();
2578 g_assert (nursery_section->size >= max_garbage_amount);
2580 /* world must be stopped already */
2581 TV_GETTIME (all_atv);
2585 time_minor_pre_collection_fragment_clear += TV_ELAPSED (atv, btv);
2588 check_for_xdomain_refs ();
2590 nursery_section->next_data = nursery_next;
2592 major_collector.start_nursery_collection ();
2594 try_calculate_minor_collection_allowance (FALSE);
2596 sgen_gray_object_queue_init (&gray_queue);
2597 sgen_workers_init_distribute_gray_queue ();
2600 mono_stats.minor_gc_count ++;
2602 if (remset.prepare_for_minor_collection)
2603 remset.prepare_for_minor_collection ();
2605 process_fin_stage_entries ();
2606 process_dislink_stage_entries ();
2608 /* pin from pinned handles */
2609 sgen_init_pinning ();
2610 mono_profiler_gc_event (MONO_GC_EVENT_MARK_START, 0);
2611 pin_from_roots (sgen_get_nursery_start (), nursery_next, WORKERS_DISTRIBUTE_GRAY_QUEUE);
2612 /* identify pinned objects */
2613 sgen_optimize_pin_queue (0);
2614 sgen_pinning_setup_section (nursery_section);
2615 sgen_pin_objects_in_section (nursery_section, WORKERS_DISTRIBUTE_GRAY_QUEUE);
2616 sgen_pinning_trim_queue_to_section (nursery_section);
2619 time_minor_pinning += TV_ELAPSED (btv, atv);
2620 DEBUG (2, fprintf (gc_debug_file, "Finding pinned pointers: %d in %d usecs\n", sgen_get_pinned_count (), TV_ELAPSED (btv, atv)));
2621 DEBUG (4, fprintf (gc_debug_file, "Start scan with %d pinned objects\n", sgen_get_pinned_count ()));
2623 if (consistency_check_at_minor_collection)
2624 sgen_check_consistency ();
2626 sgen_workers_start_all_workers ();
2629 * Perform the sequential part of remembered set scanning.
2630 * This usually involves scanning global information that might later be produced by evacuation.
2632 if (remset.begin_scan_remsets)
2633 remset.begin_scan_remsets (sgen_get_nursery_start (), nursery_next, WORKERS_DISTRIBUTE_GRAY_QUEUE);
2635 sgen_workers_start_marking ();
2637 frssjd.heap_start = sgen_get_nursery_start ();
2638 frssjd.heap_end = nursery_next;
2639 sgen_workers_enqueue_job (job_finish_remembered_set_scan, &frssjd);
2641 /* we don't have complete write barrier yet, so we scan all the old generation sections */
2643 time_minor_scan_remsets += TV_ELAPSED (atv, btv);
2644 DEBUG (2, fprintf (gc_debug_file, "Old generation scan: %d usecs\n", TV_ELAPSED (atv, btv)));
2646 if (!sgen_collection_is_parallel ())
2647 sgen_drain_gray_stack (&gray_queue, -1);
2649 if (mono_profiler_get_events () & MONO_PROFILE_GC_ROOTS)
2650 report_registered_roots ();
2651 if (mono_profiler_get_events () & MONO_PROFILE_GC_ROOTS)
2652 report_finalizer_roots ();
2654 time_minor_scan_pinned += TV_ELAPSED (btv, atv);
2656 /* registered roots, this includes static fields */
2657 scrrjd_normal.func = current_object_ops.copy_or_mark_object;
2658 scrrjd_normal.heap_start = sgen_get_nursery_start ();
2659 scrrjd_normal.heap_end = nursery_next;
2660 scrrjd_normal.root_type = ROOT_TYPE_NORMAL;
2661 sgen_workers_enqueue_job (job_scan_from_registered_roots, &scrrjd_normal);
2663 scrrjd_wbarrier.func = current_object_ops.copy_or_mark_object;
2664 scrrjd_wbarrier.heap_start = sgen_get_nursery_start ();
2665 scrrjd_wbarrier.heap_end = nursery_next;
2666 scrrjd_wbarrier.root_type = ROOT_TYPE_WBARRIER;
2667 sgen_workers_enqueue_job (job_scan_from_registered_roots, &scrrjd_wbarrier);
2670 time_minor_scan_registered_roots += TV_ELAPSED (atv, btv);
2673 stdjd.heap_start = sgen_get_nursery_start ();
2674 stdjd.heap_end = nursery_next;
2675 sgen_workers_enqueue_job (job_scan_thread_data, &stdjd);
2678 time_minor_scan_thread_data += TV_ELAPSED (btv, atv);
2681 if (sgen_collection_is_parallel ()) {
2682 while (!sgen_gray_object_queue_is_empty (WORKERS_DISTRIBUTE_GRAY_QUEUE)) {
2683 sgen_workers_distribute_gray_queue_sections ();
2687 sgen_workers_join ();
2689 if (sgen_collection_is_parallel ())
2690 g_assert (sgen_gray_object_queue_is_empty (&gray_queue));
2692 /* Scan the list of objects ready for finalization. If */
2693 sfejd_fin_ready.list = fin_ready_list;
2694 sgen_workers_enqueue_job (job_scan_finalizer_entries, &sfejd_fin_ready);
2696 sfejd_critical_fin.list = critical_fin_list;
2697 sgen_workers_enqueue_job (job_scan_finalizer_entries, &sfejd_critical_fin);
2699 finish_gray_stack (sgen_get_nursery_start (), nursery_next, GENERATION_NURSERY, &gray_queue);
2701 time_minor_finish_gray_stack += TV_ELAPSED (btv, atv);
2702 mono_profiler_gc_event (MONO_GC_EVENT_MARK_END, 0);
2705 * The (single-threaded) finalization code might have done
2706 * some copying/marking so we can only reset the GC thread's
2707 * worker data here instead of earlier when we joined the
2710 sgen_workers_reset_data ();
2712 if (objects_pinned) {
2713 sgen_optimize_pin_queue (0);
2714 sgen_pinning_setup_section (nursery_section);
2717 /* walk the pin_queue, build up the fragment list of free memory, unmark
2718 * pinned objects as we go, memzero() the empty fragments so they are ready for the
2721 mono_profiler_gc_event (MONO_GC_EVENT_RECLAIM_START, 0);
2722 fragment_total = sgen_build_nursery_fragments (nursery_section, nursery_section->pin_queue_start, nursery_section->pin_queue_num_entries);
2723 if (!fragment_total)
2726 /* Clear TLABs for all threads */
2727 sgen_clear_tlabs ();
2729 mono_profiler_gc_event (MONO_GC_EVENT_RECLAIM_END, 0);
2731 time_minor_fragment_creation += TV_ELAPSED (atv, btv);
2732 DEBUG (2, fprintf (gc_debug_file, "Fragment creation: %d usecs, %lu bytes available\n", TV_ELAPSED (atv, btv), (unsigned long)fragment_total));
2734 if (consistency_check_at_minor_collection)
2735 sgen_check_major_refs ();
2737 major_collector.finish_nursery_collection ();
2739 TV_GETTIME (all_btv);
2740 mono_stats.minor_gc_time_usecs += TV_ELAPSED (all_atv, all_btv);
2743 dump_heap ("minor", stat_minor_gcs - 1, NULL);
2745 /* prepare the pin queue for the next collection */
2746 sgen_finish_pinning ();
2747 if (fin_ready_list || critical_fin_list) {
2748 DEBUG (4, fprintf (gc_debug_file, "Finalizer-thread wakeup: ready %d\n", num_ready_finalizers));
2749 mono_gc_finalize_notify ();
2751 sgen_pin_stats_reset ();
2753 g_assert (sgen_gray_object_queue_is_empty (&gray_queue));
2755 if (remset.finish_minor_collection)
2756 remset.finish_minor_collection ();
2758 check_scan_starts ();
2760 binary_protocol_flush_buffers (FALSE);
2762 /*objects are late pinned because of lack of memory, so a major is a good call*/
2763 needs_major = need_major_collection (0) || objects_pinned;
2764 current_collection_generation = -1;
2771 sgen_collect_nursery_no_lock (size_t requested_size)
2773 gint64 gc_start_time;
2775 mono_profiler_gc_event (MONO_GC_EVENT_START, 0);
2776 gc_start_time = mono_100ns_ticks ();
2779 collect_nursery (requested_size);
2782 mono_trace_message (MONO_TRACE_GC, "minor gc took %d usecs", (mono_100ns_ticks () - gc_start_time) / 10);
2783 mono_profiler_gc_event (MONO_GC_EVENT_END, 0);
2787 major_do_collection (const char *reason)
2789 LOSObject *bigobj, *prevbo;
2790 TV_DECLARE (all_atv);
2791 TV_DECLARE (all_btv);
2794 /* FIXME: only use these values for the precise scan
2795 * note that to_space pointers should be excluded anyway...
2797 char *heap_start = NULL;
2798 char *heap_end = (char*)-1;
2799 int old_next_pin_slot;
2800 ScanFromRegisteredRootsJobData scrrjd_normal, scrrjd_wbarrier;
2801 ScanThreadDataJobData stdjd;
2802 ScanFinalizerEntriesJobData sfejd_fin_ready, sfejd_critical_fin;
2804 mono_perfcounters->gc_collections1++;
2806 current_object_ops = major_collector.major_ops;
2808 reset_pinned_from_failed_allocation ();
2810 last_collection_old_num_major_sections = major_collector.get_num_major_sections ();
2813 * A domain could have been freed, resulting in
2814 * los_memory_usage being less than last_collection_los_memory_usage.
2816 last_collection_los_memory_alloced = los_memory_usage - MIN (last_collection_los_memory_usage, los_memory_usage);
2817 last_collection_old_los_memory_usage = los_memory_usage;
2820 //count_ref_nonref_objs ();
2821 //consistency_check ();
2823 binary_protocol_collection (GENERATION_OLD);
2824 check_scan_starts ();
2826 sgen_gray_object_queue_init (&gray_queue);
2827 sgen_workers_init_distribute_gray_queue ();
2828 sgen_nursery_alloc_prepare_for_major (reason);
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 sgen_clear_nursery_fragments ();
2843 time_major_pre_collection_fragment_clear += TV_ELAPSED (atv, btv);
2845 nursery_section->next_data = 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 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 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 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 (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 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 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 = 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", sgen_get_pinned_count (), TV_ELAPSED (atv, btv)));
2917 DEBUG (4, fprintf (gc_debug_file, "Start scan with %d pinned objects\n", 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 sgen_workers_start_all_workers ();
2926 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 = current_object_ops.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 sgen_workers_enqueue_job (job_scan_from_registered_roots, &scrrjd_normal);
2940 scrrjd_wbarrier.func = current_object_ops.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 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 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 sgen_workers_enqueue_job (job_scan_finalizer_entries, &sfejd_fin_ready);
2967 sfejd_critical_fin.list = critical_fin_list;
2968 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 (!sgen_gray_object_queue_is_empty (WORKERS_DISTRIBUTE_GRAY_QUEUE)) {
2979 sgen_workers_distribute_gray_queue_sections ();
2983 sgen_workers_join ();
2985 #ifdef SGEN_DEBUG_INTERNAL_ALLOC
2986 main_gc_thread = NULL;
2989 if (major_collector.is_parallel)
2990 g_assert (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 sgen_workers_reset_data ();
3005 if (objects_pinned) {
3006 /*This is slow, but we just OOM'd*/
3007 sgen_pin_queue_clear_discarded_entries (nursery_section, old_next_pin_slot);
3008 sgen_optimize_pin_queue (0);
3009 sgen_find_section_pin_queue_start_end (nursery_section);
3013 reset_heap_boundaries ();
3014 sgen_update_heap_boundaries ((mword)sgen_get_nursery_start (), (mword)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 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 sgen_los_free_object (to_free);
3035 bigobj = bigobj->next;
3039 time_major_free_bigobjs += TV_ELAPSED (atv, btv);
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 (!sgen_build_nursery_fragments (nursery_section, nursery_section->pin_queue_start, nursery_section->pin_queue_num_entries))
3058 /* Clear TLABs for all threads */
3059 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 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 sgen_pin_stats_reset ();
3079 g_assert (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 (!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, sgen_get_pinned_count ()));
3172 sgen_dump_pin_queue ();
3175 mono_profiler_gc_event (MONO_GC_EVENT_END, 0);
3177 //report_internal_mem_usage ();
3181 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 sgen_report_internal_mem_usage ();
3203 printf ("Pinned memory usage:\n");
3204 major_collector.report_pinned_memory_usage ();
3208 * ######################################################################
3209 * ######## Finalization support
3210 * ######################################################################
3214 * If the object has been forwarded it means it's still referenced from a root.
3215 * If it is pinned it's still alive as well.
3216 * A LOS object is only alive if we have pinned it.
3217 * Return TRUE if @obj is ready to be finalized.
3219 static inline gboolean
3220 sgen_is_object_alive (void *object)
3222 if (ptr_in_nursery (object))
3223 return sgen_nursery_is_object_alive (object);
3224 /* Oldgen objects can be pinned and forwarded too */
3225 if (SGEN_OBJECT_IS_PINNED (object) || SGEN_OBJECT_IS_FORWARDED (object))
3227 return major_collector.is_object_live (object);
3231 sgen_gc_is_object_ready_for_finalization (void *object)
3233 return !sgen_is_object_alive (object);
3237 has_critical_finalizer (MonoObject *obj)
3241 if (!mono_defaults.critical_finalizer_object)
3244 class = ((MonoVTable*)LOAD_VTABLE (obj))->klass;
3246 return mono_class_has_parent_fast (class, mono_defaults.critical_finalizer_object);
3250 queue_finalization_entry (MonoObject *obj) {
3251 FinalizeReadyEntry *entry = sgen_alloc_internal (INTERNAL_MEM_FINALIZE_READY_ENTRY);
3252 entry->object = obj;
3253 if (has_critical_finalizer (obj)) {
3254 entry->next = critical_fin_list;
3255 critical_fin_list = entry;
3257 entry->next = fin_ready_list;
3258 fin_ready_list = entry;
3263 object_is_reachable (char *object, char *start, char *end)
3265 /*This happens for non nursery objects during minor collections. We just treat all objects as alive.*/
3266 if (object < start || object >= end)
3269 return sgen_is_object_alive (object);
3272 #include "sgen-fin-weak-hash.c"
3275 sgen_object_is_live (void *obj)
3277 if (ptr_in_nursery (obj))
3278 return object_is_pinned (obj);
3279 /* FIXME This is semantically wrong! All tenured object are considered alive during a nursery collection. */
3280 if (current_collection_generation == GENERATION_NURSERY)
3282 return major_collector.is_object_live (obj);
3285 /* LOCKING: requires that the GC lock is held */
3287 null_ephemerons_for_domain (MonoDomain *domain)
3289 EphemeronLinkNode *current = ephemeron_list, *prev = NULL;
3292 MonoObject *object = (MonoObject*)current->array;
3294 if (object && !object->vtable) {
3295 EphemeronLinkNode *tmp = current;
3298 prev->next = current->next;
3300 ephemeron_list = current->next;
3302 current = current->next;
3303 sgen_free_internal (tmp, INTERNAL_MEM_EPHEMERON_LINK);
3306 current = current->next;
3311 /* LOCKING: requires that the GC lock is held */
3313 clear_unreachable_ephemerons (CopyOrMarkObjectFunc copy_func, char *start, char *end, GrayQueue *queue)
3315 int was_in_nursery, was_promoted;
3316 EphemeronLinkNode *current = ephemeron_list, *prev = NULL;
3318 Ephemeron *cur, *array_end;
3322 char *object = current->array;
3324 if (!object_is_reachable (object, start, end)) {
3325 EphemeronLinkNode *tmp = current;
3327 DEBUG (5, fprintf (gc_debug_file, "Dead Ephemeron array at %p\n", object));
3330 prev->next = current->next;
3332 ephemeron_list = current->next;
3334 current = current->next;
3335 sgen_free_internal (tmp, INTERNAL_MEM_EPHEMERON_LINK);
3340 was_in_nursery = ptr_in_nursery (object);
3341 copy_func ((void**)&object, queue);
3342 current->array = object;
3344 /*The array was promoted, add global remsets for key/values left behind in nursery.*/
3345 was_promoted = was_in_nursery && !ptr_in_nursery (object);
3347 DEBUG (5, fprintf (gc_debug_file, "Clearing unreachable entries for ephemeron array at %p\n", object));
3349 array = (MonoArray*)object;
3350 cur = mono_array_addr (array, Ephemeron, 0);
3351 array_end = cur + mono_array_length_fast (array);
3352 tombstone = (char*)((MonoVTable*)LOAD_VTABLE (object))->domain->ephemeron_tombstone;
3354 for (; cur < array_end; ++cur) {
3355 char *key = (char*)cur->key;
3357 if (!key || key == tombstone)
3360 DEBUG (5, fprintf (gc_debug_file, "[%td] key %p (%s) value %p (%s)\n", cur - mono_array_addr (array, Ephemeron, 0),
3361 key, object_is_reachable (key, start, end) ? "reachable" : "unreachable",
3362 cur->value, cur->value && object_is_reachable (cur->value, start, end) ? "reachable" : "unreachable"));
3364 if (!object_is_reachable (key, start, end)) {
3365 cur->key = tombstone;
3371 if (ptr_in_nursery (key)) {/*key was not promoted*/
3372 DEBUG (5, fprintf (gc_debug_file, "\tAdded remset to key %p\n", key));
3373 sgen_add_to_global_remset (&cur->key);
3375 if (ptr_in_nursery (cur->value)) {/*value was not promoted*/
3376 DEBUG (5, fprintf (gc_debug_file, "\tAdded remset to value %p\n", cur->value));
3377 sgen_add_to_global_remset (&cur->value);
3382 current = current->next;
3386 /* LOCKING: requires that the GC lock is held */
3388 mark_ephemerons_in_range (CopyOrMarkObjectFunc copy_func, char *start, char *end, GrayQueue *queue)
3390 int nothing_marked = 1;
3391 EphemeronLinkNode *current = ephemeron_list;
3393 Ephemeron *cur, *array_end;
3396 for (current = ephemeron_list; current; current = current->next) {
3397 char *object = current->array;
3398 DEBUG (5, fprintf (gc_debug_file, "Ephemeron array at %p\n", object));
3401 For now we process all ephemerons during all collections.
3402 Ideally we should use remset information to partially scan those
3404 We already emit write barriers for Ephemeron fields, it's
3405 just that we don't process them.
3407 /*if (object < start || object >= end)
3410 /*It has to be alive*/
3411 if (!object_is_reachable (object, start, end)) {
3412 DEBUG (5, fprintf (gc_debug_file, "\tnot reachable\n"));
3416 copy_func ((void**)&object, queue);
3418 array = (MonoArray*)object;
3419 cur = mono_array_addr (array, Ephemeron, 0);
3420 array_end = cur + mono_array_length_fast (array);
3421 tombstone = (char*)((MonoVTable*)LOAD_VTABLE (object))->domain->ephemeron_tombstone;
3423 for (; cur < array_end; ++cur) {
3424 char *key = cur->key;
3426 if (!key || key == tombstone)
3429 DEBUG (5, fprintf (gc_debug_file, "[%td] key %p (%s) value %p (%s)\n", cur - mono_array_addr (array, Ephemeron, 0),
3430 key, object_is_reachable (key, start, end) ? "reachable" : "unreachable",
3431 cur->value, cur->value && object_is_reachable (cur->value, start, end) ? "reachable" : "unreachable"));
3433 if (object_is_reachable (key, start, end)) {
3434 char *value = cur->value;
3436 copy_func ((void**)&cur->key, queue);
3438 if (!object_is_reachable (value, start, end))
3440 copy_func ((void**)&cur->value, queue);
3446 DEBUG (5, fprintf (gc_debug_file, "Ephemeron run finished. Is it done %d\n", nothing_marked));
3447 return nothing_marked;
3451 mono_gc_invoke_finalizers (void)
3453 FinalizeReadyEntry *entry = NULL;
3454 gboolean entry_is_critical = FALSE;
3457 /* FIXME: batch to reduce lock contention */
3458 while (fin_ready_list || critical_fin_list) {
3462 FinalizeReadyEntry **list = entry_is_critical ? &critical_fin_list : &fin_ready_list;
3464 /* We have finalized entry in the last
3465 interation, now we need to remove it from
3468 *list = entry->next;
3470 FinalizeReadyEntry *e = *list;
3471 while (e->next != entry)
3473 e->next = entry->next;
3475 sgen_free_internal (entry, INTERNAL_MEM_FINALIZE_READY_ENTRY);
3479 /* Now look for the first non-null entry. */
3480 for (entry = fin_ready_list; entry && !entry->object; entry = entry->next)
3483 entry_is_critical = FALSE;
3485 entry_is_critical = TRUE;
3486 for (entry = critical_fin_list; entry && !entry->object; entry = entry->next)
3491 g_assert (entry->object);
3492 num_ready_finalizers--;
3493 obj = entry->object;
3494 entry->object = NULL;
3495 DEBUG (7, fprintf (gc_debug_file, "Finalizing object %p (%s)\n", obj, safe_name (obj)));
3503 g_assert (entry->object == NULL);
3505 /* the object is on the stack so it is pinned */
3506 /*g_print ("Calling finalizer for object: %p (%s)\n", entry->object, safe_name (entry->object));*/
3507 mono_gc_run_finalize (obj, NULL);
3514 mono_gc_pending_finalizers (void)
3516 return fin_ready_list || critical_fin_list;
3519 /* Negative value to remove */
3521 mono_gc_add_memory_pressure (gint64 value)
3523 /* FIXME: Use interlocked functions */
3525 memory_pressure += value;
3530 sgen_register_major_sections_alloced (int num_sections)
3532 minor_collection_sections_alloced += num_sections;
3536 sgen_get_minor_collection_allowance (void)
3538 return minor_collection_allowance;
3542 * ######################################################################
3543 * ######## registered roots support
3544 * ######################################################################
3548 * We do not coalesce roots.
3551 mono_gc_register_root_inner (char *start, size_t size, void *descr, int root_type)
3553 RootRecord new_root;
3556 for (i = 0; i < ROOT_TYPE_NUM; ++i) {
3557 RootRecord *root = sgen_hash_table_lookup (&roots_hash [i], start);
3558 /* we allow changing the size and the descriptor (for thread statics etc) */
3560 size_t old_size = root->end_root - start;
3561 root->end_root = start + size;
3562 g_assert (((root->root_desc != 0) && (descr != NULL)) ||
3563 ((root->root_desc == 0) && (descr == NULL)));
3564 root->root_desc = (mword)descr;
3566 roots_size -= old_size;
3572 new_root.end_root = start + size;
3573 new_root.root_desc = (mword)descr;
3575 sgen_hash_table_replace (&roots_hash [root_type], start, &new_root);
3578 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));
3585 mono_gc_register_root (char *start, size_t size, void *descr)
3587 return mono_gc_register_root_inner (start, size, descr, descr ? ROOT_TYPE_NORMAL : ROOT_TYPE_PINNED);
3591 mono_gc_register_root_wbarrier (char *start, size_t size, void *descr)
3593 return mono_gc_register_root_inner (start, size, descr, ROOT_TYPE_WBARRIER);
3597 mono_gc_deregister_root (char* addr)
3603 for (root_type = 0; root_type < ROOT_TYPE_NUM; ++root_type) {
3604 if (sgen_hash_table_remove (&roots_hash [root_type], addr, &root))
3605 roots_size -= (root.end_root - addr);
3611 * ######################################################################
3612 * ######## Thread handling (stop/start code)
3613 * ######################################################################
3616 unsigned int sgen_global_stop_count = 0;
3619 static MonoContext cur_thread_ctx = {0};
3621 static mword cur_thread_regs [ARCH_NUM_REGS] = {0};
3625 update_current_thread_stack (void *start)
3627 int stack_guard = 0;
3628 #ifndef USE_MONO_CTX
3629 void *ptr = cur_thread_regs;
3631 SgenThreadInfo *info = mono_thread_info_current ();
3633 info->stack_start = align_pointer (&stack_guard);
3634 g_assert (info->stack_start >= info->stack_start_limit && info->stack_start < info->stack_end);
3636 MONO_CONTEXT_GET_CURRENT (cur_thread_ctx);
3637 info->monoctx = &cur_thread_ctx;
3639 ARCH_STORE_REGS (ptr);
3640 info->stopped_regs = ptr;
3642 if (gc_callbacks.thread_suspend_func)
3643 gc_callbacks.thread_suspend_func (info->runtime_data, NULL);
3647 sgen_fill_thread_info_for_suspend (SgenThreadInfo *info)
3649 if (remset.fill_thread_info_for_suspend)
3650 remset.fill_thread_info_for_suspend (info);
3654 is_ip_in_managed_allocator (MonoDomain *domain, gpointer ip);
3657 restart_threads_until_none_in_managed_allocator (void)
3659 SgenThreadInfo *info;
3660 int num_threads_died = 0;
3661 int sleep_duration = -1;
3664 int restart_count = 0, restarted_count = 0;
3665 /* restart all threads that stopped in the
3667 FOREACH_THREAD_SAFE (info) {
3669 if (info->skip || info->gc_disabled)
3671 if (!info->thread_is_dying && (!info->stack_start || info->in_critical_region ||
3672 is_ip_in_managed_allocator (info->stopped_domain, info->stopped_ip))) {
3673 binary_protocol_thread_restart ((gpointer)mono_thread_info_get_tid (info));
3674 result = sgen_resume_thread (info);
3681 /* we set the stopped_ip to
3682 NULL for threads which
3683 we're not restarting so
3684 that we can easily identify
3686 info->stopped_ip = NULL;
3687 info->stopped_domain = NULL;
3689 } END_FOREACH_THREAD_SAFE
3690 /* if no threads were restarted, we're done */
3691 if (restart_count == 0)
3694 /* wait for the threads to signal their restart */
3695 sgen_wait_for_suspend_ack (restart_count);
3697 if (sleep_duration < 0) {
3705 g_usleep (sleep_duration);
3706 sleep_duration += 10;
3709 /* stop them again */
3710 FOREACH_THREAD (info) {
3712 if (info->skip || info->stopped_ip == NULL)
3714 result = sgen_suspend_thread (info);
3721 } END_FOREACH_THREAD
3722 /* some threads might have died */
3723 num_threads_died += restart_count - restarted_count;
3724 /* wait for the threads to signal their suspension
3726 sgen_wait_for_suspend_ack (restart_count);
3729 return num_threads_died;
3733 acquire_gc_locks (void)
3736 mono_thread_info_suspend_lock ();
3740 release_gc_locks (void)
3742 mono_thread_info_suspend_unlock ();
3743 UNLOCK_INTERRUPTION;
3746 static TV_DECLARE (stop_world_time);
3747 static unsigned long max_pause_usec = 0;
3749 /* LOCKING: assumes the GC lock is held */
3751 stop_world (int generation)
3755 /*XXX this is the right stop, thought might not be the nicest place to put it*/
3756 sgen_process_togglerefs ();
3758 mono_profiler_gc_event (MONO_GC_EVENT_PRE_STOP_WORLD, generation);
3759 acquire_gc_locks ();
3761 update_current_thread_stack (&count);
3763 sgen_global_stop_count++;
3764 DEBUG (3, fprintf (gc_debug_file, "stopping world n %d from %p %p\n", sgen_global_stop_count, mono_thread_info_current (), (gpointer)mono_native_thread_id_get ()));
3765 TV_GETTIME (stop_world_time);
3766 count = sgen_thread_handshake (TRUE);
3767 count -= restart_threads_until_none_in_managed_allocator ();
3768 g_assert (count >= 0);
3769 DEBUG (3, fprintf (gc_debug_file, "world stopped %d thread(s)\n", count));
3770 mono_profiler_gc_event (MONO_GC_EVENT_POST_STOP_WORLD, generation);
3772 last_major_num_sections = major_collector.get_num_major_sections ();
3773 last_los_memory_usage = los_memory_usage;
3774 major_collection_happened = FALSE;
3778 /* LOCKING: assumes the GC lock is held */
3780 restart_world (int generation)
3782 int count, num_major_sections;
3783 SgenThreadInfo *info;
3784 TV_DECLARE (end_sw);
3785 TV_DECLARE (end_bridge);
3786 unsigned long usec, bridge_usec;
3788 /* notify the profiler of the leftovers */
3789 if (G_UNLIKELY (mono_profiler_events & MONO_PROFILE_GC_MOVES)) {
3790 if (moved_objects_idx) {
3791 mono_profiler_gc_moves (moved_objects, moved_objects_idx);
3792 moved_objects_idx = 0;
3795 mono_profiler_gc_event (MONO_GC_EVENT_PRE_START_WORLD, generation);
3796 FOREACH_THREAD (info) {
3797 info->stack_start = NULL;
3799 info->monoctx = NULL;
3801 info->stopped_regs = NULL;
3803 } END_FOREACH_THREAD
3805 stw_bridge_process ();
3806 release_gc_locks ();
3808 count = sgen_thread_handshake (FALSE);
3809 TV_GETTIME (end_sw);
3810 usec = TV_ELAPSED (stop_world_time, end_sw);
3811 max_pause_usec = MAX (usec, max_pause_usec);
3812 DEBUG (2, fprintf (gc_debug_file, "restarted %d thread(s) (pause time: %d usec, max: %d)\n", count, (int)usec, (int)max_pause_usec));
3813 mono_profiler_gc_event (MONO_GC_EVENT_POST_START_WORLD, generation);
3817 TV_GETTIME (end_bridge);
3818 bridge_usec = TV_ELAPSED (end_sw, end_bridge);
3820 num_major_sections = major_collector.get_num_major_sections ();
3821 if (major_collection_happened)
3822 mono_trace (G_LOG_LEVEL_INFO, MONO_TRACE_GC, "GC_MAJOR: %s pause %.2fms, bridge %.2fms major %dK/%dK los %dK/%dK",
3823 generation ? "" : "(minor overflow)",
3824 (int)usec / 1000.0f, (int)bridge_usec / 1000.0f,
3825 major_collector.section_size * num_major_sections / 1024,
3826 major_collector.section_size * last_major_num_sections / 1024,
3827 los_memory_usage / 1024,
3828 last_los_memory_usage / 1024);
3830 mono_trace (G_LOG_LEVEL_INFO, MONO_TRACE_GC, "GC_MINOR: pause %.2fms, bridge %.2fms promoted %dK major %dK los %dK",
3831 (int)usec / 1000.0f, (int)bridge_usec / 1000.0f,
3832 (num_major_sections - last_major_num_sections) * major_collector.section_size / 1024,
3833 major_collector.section_size * num_major_sections / 1024,
3834 los_memory_usage / 1024);
3840 sgen_get_current_collection_generation (void)
3842 return current_collection_generation;
3846 mono_gc_set_gc_callbacks (MonoGCCallbacks *callbacks)
3848 gc_callbacks = *callbacks;
3852 mono_gc_get_gc_callbacks ()
3854 return &gc_callbacks;
3857 /* Variables holding start/end nursery so it won't have to be passed at every call */
3858 static void *scan_area_arg_start, *scan_area_arg_end;
3861 mono_gc_conservatively_scan_area (void *start, void *end)
3863 conservatively_pin_objects_from (start, end, scan_area_arg_start, scan_area_arg_end, PIN_TYPE_STACK);
3867 mono_gc_scan_object (void *obj)
3869 UserCopyOrMarkData *data = mono_native_tls_get_value (user_copy_or_mark_key);
3870 current_object_ops.copy_or_mark_object (&obj, data->queue);
3875 * Mark from thread stacks and registers.
3878 scan_thread_data (void *start_nursery, void *end_nursery, gboolean precise, GrayQueue *queue)
3880 SgenThreadInfo *info;
3882 scan_area_arg_start = start_nursery;
3883 scan_area_arg_end = end_nursery;
3885 FOREACH_THREAD (info) {
3887 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));
3890 if (info->gc_disabled) {
3891 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));
3894 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, sgen_get_pinned_count ()));
3895 if (!info->thread_is_dying) {
3896 if (gc_callbacks.thread_mark_func && !conservative_stack_mark) {
3897 UserCopyOrMarkData data = { NULL, queue };
3898 set_user_copy_or_mark_data (&data);
3899 gc_callbacks.thread_mark_func (info->runtime_data, info->stack_start, info->stack_end, precise);
3900 set_user_copy_or_mark_data (NULL);
3901 } else if (!precise) {
3902 conservatively_pin_objects_from (info->stack_start, info->stack_end, start_nursery, end_nursery, PIN_TYPE_STACK);
3907 if (!info->thread_is_dying && !precise)
3908 conservatively_pin_objects_from ((void**)info->monoctx, (void**)info->monoctx + ARCH_NUM_REGS,
3909 start_nursery, end_nursery, PIN_TYPE_STACK);
3911 if (!info->thread_is_dying && !precise)
3912 conservatively_pin_objects_from (info->stopped_regs, info->stopped_regs + ARCH_NUM_REGS,
3913 start_nursery, end_nursery, PIN_TYPE_STACK);
3915 } END_FOREACH_THREAD
3919 find_pinning_ref_from_thread (char *obj, size_t size)
3922 SgenThreadInfo *info;
3923 char *endobj = obj + size;
3925 FOREACH_THREAD (info) {
3926 char **start = (char**)info->stack_start;
3929 while (start < (char**)info->stack_end) {
3930 if (*start >= obj && *start < endobj) {
3931 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));
3936 for (j = 0; j < ARCH_NUM_REGS; ++j) {
3938 mword w = ((mword*)info->monoctx) [j];
3940 mword w = (mword)info->stopped_regs [j];
3943 if (w >= (mword)obj && w < (mword)obj + size)
3944 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)));
3945 } END_FOREACH_THREAD
3950 ptr_on_stack (void *ptr)
3952 gpointer stack_start = &stack_start;
3953 SgenThreadInfo *info = mono_thread_info_current ();
3955 if (ptr >= stack_start && ptr < (gpointer)info->stack_end)
3961 sgen_thread_register (SgenThreadInfo* info, void *addr)
3963 #ifndef HAVE_KW_THREAD
3964 SgenThreadInfo *__thread_info__ = info;
3968 #ifndef HAVE_KW_THREAD
3969 info->tlab_start = info->tlab_next = info->tlab_temp_end = info->tlab_real_end = NULL;
3971 g_assert (!mono_native_tls_get_value (thread_info_key));
3972 mono_native_tls_set_value (thread_info_key, info);
3977 #if !defined(__MACH__)
3978 info->stop_count = -1;
3982 info->doing_handshake = FALSE;
3983 info->thread_is_dying = FALSE;
3984 info->stack_start = NULL;
3985 info->store_remset_buffer_addr = &STORE_REMSET_BUFFER;
3986 info->store_remset_buffer_index_addr = &STORE_REMSET_BUFFER_INDEX;
3987 info->stopped_ip = NULL;
3988 info->stopped_domain = NULL;
3990 info->monoctx = NULL;
3992 info->stopped_regs = NULL;
3995 sgen_init_tlab_info (info);
3997 binary_protocol_thread_register ((gpointer)mono_thread_info_get_tid (info));
3999 #ifdef HAVE_KW_THREAD
4000 store_remset_buffer_index_addr = &store_remset_buffer_index;
4003 #if defined(__MACH__)
4004 info->mach_port = mach_thread_self ();
4007 /* try to get it with attributes first */
4008 #if defined(HAVE_PTHREAD_GETATTR_NP) && defined(HAVE_PTHREAD_ATTR_GETSTACK)
4012 pthread_attr_t attr;
4013 pthread_getattr_np (pthread_self (), &attr);
4014 pthread_attr_getstack (&attr, &sstart, &size);
4015 info->stack_start_limit = sstart;
4016 info->stack_end = (char*)sstart + size;
4017 pthread_attr_destroy (&attr);
4019 #elif defined(HAVE_PTHREAD_GET_STACKSIZE_NP) && defined(HAVE_PTHREAD_GET_STACKADDR_NP)
4020 info->stack_end = (char*)pthread_get_stackaddr_np (pthread_self ());
4021 info->stack_start_limit = (char*)info->stack_end - pthread_get_stacksize_np (pthread_self ());
4024 /* FIXME: we assume the stack grows down */
4025 gsize stack_bottom = (gsize)addr;
4026 stack_bottom += 4095;
4027 stack_bottom &= ~4095;
4028 info->stack_end = (char*)stack_bottom;
4032 #ifdef HAVE_KW_THREAD
4033 stack_end = info->stack_end;
4036 if (remset.register_thread)
4037 remset.register_thread (info);
4039 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));
4041 if (gc_callbacks.thread_attach_func)
4042 info->runtime_data = gc_callbacks.thread_attach_func ();
4049 sgen_wbarrier_cleanup_thread (SgenThreadInfo *p)
4051 if (remset.cleanup_thread)
4052 remset.cleanup_thread (p);
4056 sgen_thread_unregister (SgenThreadInfo *p)
4058 /* If a delegate is passed to native code and invoked on a thread we dont
4059 * know about, the jit will register it with mono_jit_thread_attach, but
4060 * we have no way of knowing when that thread goes away. SGen has a TSD
4061 * so we assume that if the domain is still registered, we can detach
4064 if (mono_domain_get ())
4065 mono_thread_detach (mono_thread_current ());
4067 p->thread_is_dying = TRUE;
4070 There is a race condition between a thread finishing executing and been removed
4071 from the GC thread set.
4072 This happens on posix systems when TLS data is been cleaned-up, libpthread will
4073 set the thread_info slot to NULL before calling the cleanup function. This
4074 opens a window in which the thread is registered but has a NULL TLS.
4076 The suspend signal handler needs TLS data to know where to store thread state
4077 data or otherwise it will simply ignore the thread.
4079 This solution works because the thread doing STW will wait until all threads been
4080 suspended handshake back, so there is no race between the doing_hankshake test
4081 and the suspend_thread call.
4083 This is not required on systems that do synchronous STW as those can deal with
4084 the above race at suspend time.
4086 FIXME: I believe we could avoid this by using mono_thread_info_lookup when
4087 mono_thread_info_current returns NULL. Or fix mono_thread_info_lookup to do so.
4089 #if (defined(__MACH__) && MONO_MACH_ARCH_SUPPORTED) || !defined(HAVE_PTHREAD_KILL)
4092 while (!TRYLOCK_GC) {
4093 if (!sgen_park_current_thread_if_doing_handshake (p))
4098 binary_protocol_thread_unregister ((gpointer)mono_thread_info_get_tid (p));
4099 DEBUG (3, fprintf (gc_debug_file, "unregister thread %p (%p)\n", p, (gpointer)mono_thread_info_get_tid (p)));
4101 #if defined(__MACH__)
4102 mach_port_deallocate (current_task (), p->mach_port);
4105 if (gc_callbacks.thread_detach_func) {
4106 gc_callbacks.thread_detach_func (p->runtime_data);
4107 p->runtime_data = NULL;
4109 sgen_wbarrier_cleanup_thread (p);
4111 mono_threads_unregister_current_thread (p);
4117 sgen_thread_attach (SgenThreadInfo *info)
4120 /*this is odd, can we get attached before the gc is inited?*/
4124 if (gc_callbacks.thread_attach_func && !info->runtime_data)
4125 info->runtime_data = gc_callbacks.thread_attach_func ();
4128 mono_gc_register_thread (void *baseptr)
4130 return mono_thread_info_attach (baseptr) != NULL;
4134 * mono_gc_set_stack_end:
4136 * Set the end of the current threads stack to STACK_END. The stack space between
4137 * STACK_END and the real end of the threads stack will not be scanned during collections.
4140 mono_gc_set_stack_end (void *stack_end)
4142 SgenThreadInfo *info;
4145 info = mono_thread_info_current ();
4147 g_assert (stack_end < info->stack_end);
4148 info->stack_end = stack_end;
4153 #if USE_PTHREAD_INTERCEPT
4157 mono_gc_pthread_create (pthread_t *new_thread, const pthread_attr_t *attr, void *(*start_routine)(void *), void *arg)
4159 return pthread_create (new_thread, attr, start_routine, arg);
4163 mono_gc_pthread_join (pthread_t thread, void **retval)
4165 return pthread_join (thread, retval);
4169 mono_gc_pthread_detach (pthread_t thread)
4171 return pthread_detach (thread);
4175 mono_gc_pthread_exit (void *retval)
4177 pthread_exit (retval);
4180 #endif /* USE_PTHREAD_INTERCEPT */
4183 * ######################################################################
4184 * ######## Write barriers
4185 * ######################################################################
4189 * Note: the write barriers first do the needed GC work and then do the actual store:
4190 * this way the value is visible to the conservative GC scan after the write barrier
4191 * itself. If a GC interrupts the barrier in the middle, value will be kept alive by
4192 * the conservative scan, otherwise by the remembered set scan.
4195 mono_gc_wbarrier_set_field (MonoObject *obj, gpointer field_ptr, MonoObject* value)
4197 HEAVY_STAT (++stat_wbarrier_set_field);
4198 if (ptr_in_nursery (field_ptr)) {
4199 *(void**)field_ptr = value;
4202 DEBUG (8, fprintf (gc_debug_file, "Adding remset at %p\n", field_ptr));
4204 binary_protocol_wbarrier (field_ptr, value, value->vtable);
4206 remset.wbarrier_set_field (obj, field_ptr, value);
4210 mono_gc_wbarrier_set_arrayref (MonoArray *arr, gpointer slot_ptr, MonoObject* value)
4212 HEAVY_STAT (++stat_wbarrier_set_arrayref);
4213 if (ptr_in_nursery (slot_ptr)) {
4214 *(void**)slot_ptr = value;
4217 DEBUG (8, fprintf (gc_debug_file, "Adding remset at %p\n", slot_ptr));
4219 binary_protocol_wbarrier (slot_ptr, value, value->vtable);
4221 remset.wbarrier_set_arrayref (arr, slot_ptr, value);
4225 mono_gc_wbarrier_arrayref_copy (gpointer dest_ptr, gpointer src_ptr, int count)
4227 HEAVY_STAT (++stat_wbarrier_arrayref_copy);
4228 /*This check can be done without taking a lock since dest_ptr array is pinned*/
4229 if (ptr_in_nursery (dest_ptr) || count <= 0) {
4230 mono_gc_memmove (dest_ptr, src_ptr, count * sizeof (gpointer));
4234 #ifdef SGEN_BINARY_PROTOCOL
4237 for (i = 0; i < count; ++i) {
4238 gpointer dest = (gpointer*)dest_ptr + i;
4239 gpointer obj = *((gpointer*)src_ptr + i);
4241 binary_protocol_wbarrier (dest, obj, (gpointer)LOAD_VTABLE (obj));
4246 remset.wbarrier_arrayref_copy (dest_ptr, src_ptr, count);
4249 static char *found_obj;
4252 find_object_for_ptr_callback (char *obj, size_t size, void *user_data)
4254 char *ptr = user_data;
4256 if (ptr >= obj && ptr < obj + size) {
4257 g_assert (!found_obj);
4262 /* for use in the debugger */
4263 char* find_object_for_ptr (char *ptr);
4265 find_object_for_ptr (char *ptr)
4267 if (ptr >= nursery_section->data && ptr < nursery_section->end_data) {
4269 sgen_scan_area_with_callback (nursery_section->data, nursery_section->end_data,
4270 find_object_for_ptr_callback, ptr, TRUE);
4276 sgen_los_iterate_objects (find_object_for_ptr_callback, ptr);
4281 * Very inefficient, but this is debugging code, supposed to
4282 * be called from gdb, so we don't care.
4285 major_collector.iterate_objects (TRUE, TRUE, find_object_for_ptr_callback, ptr);
4290 mono_gc_wbarrier_generic_nostore (gpointer ptr)
4292 HEAVY_STAT (++stat_wbarrier_generic_store);
4294 #ifdef XDOMAIN_CHECKS_IN_WBARRIER
4295 /* FIXME: ptr_in_heap must be called with the GC lock held */
4296 if (xdomain_checks && *(MonoObject**)ptr && ptr_in_heap (ptr)) {
4297 char *start = find_object_for_ptr (ptr);
4298 MonoObject *value = *(MonoObject**)ptr;
4302 MonoObject *obj = (MonoObject*)start;
4303 if (obj->vtable->domain != value->vtable->domain)
4304 g_assert (is_xdomain_ref_allowed (ptr, start, obj->vtable->domain));
4310 if (*(gpointer*)ptr)
4311 binary_protocol_wbarrier (ptr, *(gpointer*)ptr, (gpointer)LOAD_VTABLE (*(gpointer*)ptr));
4313 if (ptr_in_nursery (ptr) || ptr_on_stack (ptr) || !ptr_in_nursery (*(gpointer*)ptr)) {
4314 DEBUG (8, fprintf (gc_debug_file, "Skipping remset at %p\n", ptr));
4318 DEBUG (8, fprintf (gc_debug_file, "Adding remset at %p\n", ptr));
4320 remset.wbarrier_generic_nostore (ptr);
4324 mono_gc_wbarrier_generic_store (gpointer ptr, MonoObject* value)
4326 DEBUG (8, fprintf (gc_debug_file, "Wbarrier store at %p to %p (%s)\n", ptr, value, value ? safe_name (value) : "null"));
4327 *(void**)ptr = value;
4328 if (ptr_in_nursery (value))
4329 mono_gc_wbarrier_generic_nostore (ptr);
4330 sgen_dummy_use (value);
4333 void mono_gc_wbarrier_value_copy_bitmap (gpointer _dest, gpointer _src, int size, unsigned bitmap)
4335 mword *dest = _dest;
4340 mono_gc_wbarrier_generic_store (dest, (MonoObject*)*src);
4345 size -= SIZEOF_VOID_P;
4350 #ifdef SGEN_BINARY_PROTOCOL
4352 #define HANDLE_PTR(ptr,obj) do { \
4353 gpointer o = *(gpointer*)(ptr); \
4355 gpointer d = ((char*)dest) + ((char*)(ptr) - (char*)(obj)); \
4356 binary_protocol_wbarrier (d, o, (gpointer) LOAD_VTABLE (o)); \
4361 scan_object_for_binary_protocol_copy_wbarrier (gpointer dest, char *start, mword desc)
4363 #define SCAN_OBJECT_NOVTABLE
4364 #include "sgen-scan-object.h"
4369 mono_gc_wbarrier_value_copy (gpointer dest, gpointer src, int count, MonoClass *klass)
4371 HEAVY_STAT (++stat_wbarrier_value_copy);
4372 g_assert (klass->valuetype);
4374 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));
4376 if (ptr_in_nursery (dest) || ptr_on_stack (dest) || !SGEN_CLASS_HAS_REFERENCES (klass)) {
4377 size_t element_size = mono_class_value_size (klass, NULL);
4378 size_t size = count * element_size;
4379 mono_gc_memmove (dest, src, size);
4383 #ifdef SGEN_BINARY_PROTOCOL
4386 for (i = 0; i < count; ++i) {
4387 scan_object_for_binary_protocol_copy_wbarrier ((char*)dest + i * element_size,
4388 (char*)src + i * element_size - sizeof (MonoObject),
4389 (mword) klass->gc_descr);
4394 remset.wbarrier_value_copy (dest, src, count, klass);
4398 * mono_gc_wbarrier_object_copy:
4400 * Write barrier to call when obj is the result of a clone or copy of an object.
4403 mono_gc_wbarrier_object_copy (MonoObject* obj, MonoObject *src)
4407 HEAVY_STAT (++stat_wbarrier_object_copy);
4409 if (ptr_in_nursery (obj) || ptr_on_stack (obj)) {
4410 size = mono_object_class (obj)->instance_size;
4411 mono_gc_memmove ((char*)obj + sizeof (MonoObject), (char*)src + sizeof (MonoObject),
4412 size - sizeof (MonoObject));
4416 #ifdef SGEN_BINARY_PROTOCOL
4417 scan_object_for_binary_protocol_copy_wbarrier (obj, (char*)src, (mword) src->vtable->gc_descr);
4420 remset.wbarrier_object_copy (obj, src);
4424 * ######################################################################
4425 * ######## Other mono public interface functions.
4426 * ######################################################################
4429 #define REFS_SIZE 128
4432 MonoGCReferences callback;
4436 MonoObject *refs [REFS_SIZE];
4437 uintptr_t offsets [REFS_SIZE];
4441 #define HANDLE_PTR(ptr,obj) do { \
4443 if (hwi->count == REFS_SIZE) { \
4444 hwi->callback ((MonoObject*)start, mono_object_class (start), hwi->called? 0: size, hwi->count, hwi->refs, hwi->offsets, hwi->data); \
4448 hwi->offsets [hwi->count] = (char*)(ptr)-(char*)start; \
4449 hwi->refs [hwi->count++] = *(ptr); \
4454 collect_references (HeapWalkInfo *hwi, char *start, size_t size)
4456 #include "sgen-scan-object.h"
4460 walk_references (char *start, size_t size, void *data)
4462 HeapWalkInfo *hwi = data;
4465 collect_references (hwi, start, size);
4466 if (hwi->count || !hwi->called)
4467 hwi->callback ((MonoObject*)start, mono_object_class (start), hwi->called? 0: size, hwi->count, hwi->refs, hwi->offsets, hwi->data);
4471 * mono_gc_walk_heap:
4472 * @flags: flags for future use
4473 * @callback: a function pointer called for each object in the heap
4474 * @data: a user data pointer that is passed to callback
4476 * This function can be used to iterate over all the live objects in the heap:
4477 * for each object, @callback is invoked, providing info about the object's
4478 * location in memory, its class, its size and the objects it references.
4479 * For each referenced object it's offset from the object address is
4480 * reported in the offsets array.
4481 * The object references may be buffered, so the callback may be invoked
4482 * multiple times for the same object: in all but the first call, the size
4483 * argument will be zero.
4484 * Note that this function can be only called in the #MONO_GC_EVENT_PRE_START_WORLD
4485 * profiler event handler.
4487 * Returns: a non-zero value if the GC doesn't support heap walking
4490 mono_gc_walk_heap (int flags, MonoGCReferences callback, void *data)
4495 hwi.callback = callback;
4498 sgen_clear_nursery_fragments ();
4499 sgen_scan_area_with_callback (nursery_section->data, nursery_section->end_data, walk_references, &hwi, FALSE);
4501 major_collector.iterate_objects (TRUE, TRUE, walk_references, &hwi);
4502 sgen_los_iterate_objects (walk_references, &hwi);
4508 mono_gc_collect (int generation)
4513 mono_profiler_gc_event (MONO_GC_EVENT_START, generation);
4514 stop_world (generation);
4515 if (generation == 0) {
4516 collect_nursery (0);
4518 major_collection ("user request");
4520 restart_world (generation);
4521 mono_profiler_gc_event (MONO_GC_EVENT_END, generation);
4526 mono_gc_max_generation (void)
4532 mono_gc_collection_count (int generation)
4534 if (generation == 0)
4535 return stat_minor_gcs;
4536 return stat_major_gcs;
4540 mono_gc_get_used_size (void)
4544 tot = los_memory_usage;
4545 tot += nursery_section->next_data - nursery_section->data;
4546 tot += major_collector.get_used_size ();
4547 /* FIXME: account for pinned objects */
4553 mono_gc_get_heap_size (void)
4559 mono_gc_disable (void)
4567 mono_gc_enable (void)
4575 mono_gc_get_los_limit (void)
4577 return MAX_SMALL_OBJ_SIZE;
4581 mono_object_is_alive (MonoObject* o)
4587 mono_gc_get_generation (MonoObject *obj)
4589 if (ptr_in_nursery (obj))
4595 mono_gc_enable_events (void)
4600 mono_gc_weak_link_add (void **link_addr, MonoObject *obj, gboolean track)
4602 mono_gc_register_disappearing_link (obj, link_addr, track, FALSE);
4606 mono_gc_weak_link_remove (void **link_addr)
4608 mono_gc_register_disappearing_link (NULL, link_addr, FALSE, FALSE);
4612 mono_gc_weak_link_get (void **link_addr)
4616 return (MonoObject*) REVEAL_POINTER (*link_addr);
4620 mono_gc_ephemeron_array_add (MonoObject *obj)
4622 EphemeronLinkNode *node;
4626 node = sgen_alloc_internal (INTERNAL_MEM_EPHEMERON_LINK);
4631 node->array = (char*)obj;
4632 node->next = ephemeron_list;
4633 ephemeron_list = node;
4635 DEBUG (5, fprintf (gc_debug_file, "Registered ephemeron array %p\n", obj));
4642 mono_gc_invoke_with_gc_lock (MonoGCLockedCallbackFunc func, void *data)
4646 result = func (data);
4647 UNLOCK_INTERRUPTION;
4652 mono_gc_is_gc_thread (void)
4656 result = mono_thread_info_current () != NULL;
4662 is_critical_method (MonoMethod *method)
4664 return mono_runtime_is_critical_method (method) || mono_gc_is_critical_method (method);
4668 mono_gc_base_init (void)
4670 MonoThreadInfoCallbacks cb;
4673 char *major_collector_opt = NULL;
4674 char *minor_collector_opt = NULL;
4676 glong soft_limit = 0;
4682 result = InterlockedCompareExchange (&gc_initialized, -1, 0);
4685 /* already inited */
4688 /* being inited by another thread */
4692 /* we will init it */
4695 g_assert_not_reached ();
4697 } while (result != 0);
4699 LOCK_INIT (gc_mutex);
4701 pagesize = mono_pagesize ();
4702 gc_debug_file = stderr;
4704 cb.thread_register = sgen_thread_register;
4705 cb.thread_unregister = sgen_thread_unregister;
4706 cb.thread_attach = sgen_thread_attach;
4707 cb.mono_method_is_critical = (gpointer)is_critical_method;
4709 cb.mono_gc_pthread_create = (gpointer)mono_gc_pthread_create;
4712 mono_threads_init (&cb, sizeof (SgenThreadInfo));
4714 LOCK_INIT (interruption_mutex);
4715 LOCK_INIT (pin_queue_mutex);
4717 init_user_copy_or_mark_key ();
4719 if ((env = getenv ("MONO_GC_PARAMS"))) {
4720 opts = g_strsplit (env, ",", -1);
4721 for (ptr = opts; *ptr; ++ptr) {
4723 if (g_str_has_prefix (opt, "major=")) {
4724 opt = strchr (opt, '=') + 1;
4725 major_collector_opt = g_strdup (opt);
4726 } else if (g_str_has_prefix (opt, "minor=")) {
4727 opt = strchr (opt, '=') + 1;
4728 minor_collector_opt = g_strdup (opt);
4736 sgen_init_internal_allocator ();
4737 sgen_init_nursery_allocator ();
4739 sgen_register_fixed_internal_mem_type (INTERNAL_MEM_SECTION, SGEN_SIZEOF_GC_MEM_SECTION);
4740 sgen_register_fixed_internal_mem_type (INTERNAL_MEM_FINALIZE_READY_ENTRY, sizeof (FinalizeReadyEntry));
4741 sgen_register_fixed_internal_mem_type (INTERNAL_MEM_GRAY_QUEUE, sizeof (GrayQueueSection));
4742 g_assert (sizeof (GenericStoreRememberedSet) == sizeof (gpointer) * STORE_REMSET_BUFFER_SIZE);
4743 sgen_register_fixed_internal_mem_type (INTERNAL_MEM_STORE_REMSET, sizeof (GenericStoreRememberedSet));
4744 sgen_register_fixed_internal_mem_type (INTERNAL_MEM_EPHEMERON_LINK, sizeof (EphemeronLinkNode));
4746 #ifndef HAVE_KW_THREAD
4747 mono_native_tls_alloc (&thread_info_key, NULL);
4751 * This needs to happen before any internal allocations because
4752 * it inits the small id which is required for hazard pointer
4757 mono_thread_info_attach (&dummy);
4759 if (!minor_collector_opt) {
4760 sgen_simple_nursery_init (&sgen_minor_collector);
4762 if (!strcmp (minor_collector_opt, "simple"))
4763 sgen_simple_nursery_init (&sgen_minor_collector);
4764 else if (!strcmp (minor_collector_opt, "split"))
4765 sgen_split_nursery_init (&sgen_minor_collector);
4767 fprintf (stderr, "Unknown minor collector `%s'.\n", minor_collector_opt);
4773 if (!major_collector_opt || !strcmp (major_collector_opt, "marksweep")) {
4774 sgen_marksweep_init (&major_collector);
4775 } else if (!major_collector_opt || !strcmp (major_collector_opt, "marksweep-fixed")) {
4776 sgen_marksweep_fixed_init (&major_collector);
4777 } else if (!major_collector_opt || !strcmp (major_collector_opt, "marksweep-par")) {
4778 sgen_marksweep_par_init (&major_collector);
4779 } else if (!major_collector_opt || !strcmp (major_collector_opt, "marksweep-fixed-par")) {
4780 sgen_marksweep_fixed_par_init (&major_collector);
4781 } else if (!strcmp (major_collector_opt, "copying")) {
4782 sgen_copying_init (&major_collector);
4784 fprintf (stderr, "Unknown major collector `%s'.\n", major_collector_opt);
4788 #ifdef SGEN_HAVE_CARDTABLE
4789 use_cardtable = major_collector.supports_cardtable;
4791 use_cardtable = FALSE;
4794 num_workers = mono_cpu_count ();
4795 g_assert (num_workers > 0);
4796 if (num_workers > 16)
4799 ///* Keep this the default for now */
4801 conservative_stack_mark = TRUE;
4805 for (ptr = opts; *ptr; ++ptr) {
4807 if (g_str_has_prefix (opt, "major="))
4809 if (g_str_has_prefix (opt, "minor="))
4811 if (g_str_has_prefix (opt, "wbarrier=")) {
4812 opt = strchr (opt, '=') + 1;
4813 if (strcmp (opt, "remset") == 0) {
4814 use_cardtable = FALSE;
4815 } else if (strcmp (opt, "cardtable") == 0) {
4816 if (!use_cardtable) {
4817 if (major_collector.supports_cardtable)
4818 fprintf (stderr, "The cardtable write barrier is not supported on this platform.\n");
4820 fprintf (stderr, "The major collector does not support the cardtable write barrier.\n");
4826 if (g_str_has_prefix (opt, "max-heap-size=")) {
4827 opt = strchr (opt, '=') + 1;
4828 if (*opt && mono_gc_parse_environment_string_extract_number (opt, &max_heap)) {
4829 if ((max_heap & (mono_pagesize () - 1))) {
4830 fprintf (stderr, "max-heap-size size must be a multiple of %d.\n", mono_pagesize ());
4834 fprintf (stderr, "max-heap-size must be an integer.\n");
4839 if (g_str_has_prefix (opt, "soft-heap-limit=")) {
4840 opt = strchr (opt, '=') + 1;
4841 if (*opt && mono_gc_parse_environment_string_extract_number (opt, &soft_limit)) {
4842 if (soft_limit <= 0) {
4843 fprintf (stderr, "soft-heap-limit must be positive.\n");
4847 fprintf (stderr, "soft-heap-limit must be an integer.\n");
4852 if (g_str_has_prefix (opt, "workers=")) {
4855 if (!major_collector.is_parallel) {
4856 fprintf (stderr, "The workers= option can only be used for parallel collectors.");
4859 opt = strchr (opt, '=') + 1;
4860 val = strtol (opt, &endptr, 10);
4861 if (!*opt || *endptr) {
4862 fprintf (stderr, "Cannot parse the workers= option value.");
4865 if (val <= 0 || val > 16) {
4866 fprintf (stderr, "The number of workers must be in the range 1 to 16.");
4869 num_workers = (int)val;
4872 if (g_str_has_prefix (opt, "stack-mark=")) {
4873 opt = strchr (opt, '=') + 1;
4874 if (!strcmp (opt, "precise")) {
4875 conservative_stack_mark = FALSE;
4876 } else if (!strcmp (opt, "conservative")) {
4877 conservative_stack_mark = TRUE;
4879 fprintf (stderr, "Invalid value '%s' for stack-mark= option, possible values are: 'precise', 'conservative'.\n", opt);
4884 if (g_str_has_prefix (opt, "bridge=")) {
4885 opt = strchr (opt, '=') + 1;
4886 sgen_register_test_bridge_callbacks (g_strdup (opt));
4890 if (g_str_has_prefix (opt, "nursery-size=")) {
4892 opt = strchr (opt, '=') + 1;
4893 if (*opt && mono_gc_parse_environment_string_extract_number (opt, &val)) {
4894 sgen_nursery_size = val;
4895 #ifdef SGEN_ALIGN_NURSERY
4896 if ((val & (val - 1))) {
4897 fprintf (stderr, "The nursery size must be a power of two.\n");
4901 if (val < SGEN_MAX_NURSERY_WASTE) {
4902 fprintf (stderr, "The nursery size must be at least %d bytes.\n", SGEN_MAX_NURSERY_WASTE);
4906 sgen_nursery_bits = 0;
4907 while (1 << (++ sgen_nursery_bits) != sgen_nursery_size)
4911 fprintf (stderr, "nursery-size must be an integer.\n");
4917 if (major_collector.handle_gc_param && major_collector.handle_gc_param (opt))
4920 if (sgen_minor_collector.handle_gc_param && sgen_minor_collector.handle_gc_param (opt))
4923 fprintf (stderr, "MONO_GC_PARAMS must be a comma-delimited list of one or more of the following:\n");
4924 fprintf (stderr, " max-heap-size=N (where N is an integer, possibly with a k, m or a g suffix)\n");
4925 fprintf (stderr, " soft-heap-limit=n (where N is an integer, possibly with a k, m or a g suffix)\n");
4926 fprintf (stderr, " nursery-size=N (where N is an integer, possibly with a k, m or a g suffix)\n");
4927 fprintf (stderr, " major=COLLECTOR (where COLLECTOR is `marksweep', `marksweep-par' or `copying')\n");
4928 fprintf (stderr, " minor=COLLECTOR (where COLLECTOR is `simple' or `split')\n");
4929 fprintf (stderr, " wbarrier=WBARRIER (where WBARRIER is `remset' or `cardtable')\n");
4930 fprintf (stderr, " stack-mark=MARK-METHOD (where MARK-METHOD is 'precise' or 'conservative')\n");
4931 if (major_collector.print_gc_param_usage)
4932 major_collector.print_gc_param_usage ();
4933 if (sgen_minor_collector.print_gc_param_usage)
4934 sgen_minor_collector.print_gc_param_usage ();
4940 if (major_collector.is_parallel)
4941 sgen_workers_init (num_workers);
4943 if (major_collector_opt)
4944 g_free (major_collector_opt);
4946 nursery_size = DEFAULT_NURSERY_SIZE;
4947 minor_collection_allowance = MIN_MINOR_COLLECTION_ALLOWANCE;
4948 init_heap_size_limits (max_heap, soft_limit);
4952 if ((env = getenv ("MONO_GC_DEBUG"))) {
4953 opts = g_strsplit (env, ",", -1);
4954 for (ptr = opts; ptr && *ptr; ptr ++) {
4956 if (opt [0] >= '0' && opt [0] <= '9') {
4957 gc_debug_level = atoi (opt);
4962 char *rf = g_strdup_printf ("%s.%d", opt, getpid ());
4963 gc_debug_file = fopen (rf, "wb");
4965 gc_debug_file = stderr;
4968 } else if (!strcmp (opt, "print-allowance")) {
4969 debug_print_allowance = TRUE;
4970 } else if (!strcmp (opt, "print-pinning")) {
4971 do_pin_stats = TRUE;
4972 } else if (!strcmp (opt, "collect-before-allocs")) {
4973 collect_before_allocs = 1;
4974 } else if (g_str_has_prefix (opt, "collect-before-allocs=")) {
4975 char *arg = strchr (opt, '=') + 1;
4976 collect_before_allocs = atoi (arg);
4977 } else if (!strcmp (opt, "check-at-minor-collections")) {
4978 consistency_check_at_minor_collection = TRUE;
4979 nursery_clear_policy = CLEAR_AT_GC;
4980 } else if (!strcmp (opt, "xdomain-checks")) {
4981 xdomain_checks = TRUE;
4982 } else if (!strcmp (opt, "clear-at-gc")) {
4983 nursery_clear_policy = CLEAR_AT_GC;
4984 } else if (!strcmp (opt, "clear-nursery-at-gc")) {
4985 nursery_clear_policy = CLEAR_AT_GC;
4986 } else if (!strcmp (opt, "check-scan-starts")) {
4987 do_scan_starts_check = TRUE;
4988 } else if (!strcmp (opt, "verify-nursery-at-minor-gc")) {
4989 do_verify_nursery = TRUE;
4990 } else if (!strcmp (opt, "dump-nursery-at-minor-gc")) {
4991 do_dump_nursery_content = TRUE;
4992 } else if (!strcmp (opt, "disable-minor")) {
4993 disable_minor_collections = TRUE;
4994 } else if (!strcmp (opt, "disable-major")) {
4995 disable_major_collections = TRUE;
4996 } else if (g_str_has_prefix (opt, "heap-dump=")) {
4997 char *filename = strchr (opt, '=') + 1;
4998 nursery_clear_policy = CLEAR_AT_GC;
4999 heap_dump_file = fopen (filename, "w");
5000 if (heap_dump_file) {
5001 fprintf (heap_dump_file, "<sgen-dump>\n");
5002 do_pin_stats = TRUE;
5004 #ifdef SGEN_BINARY_PROTOCOL
5005 } else if (g_str_has_prefix (opt, "binary-protocol=")) {
5006 char *filename = strchr (opt, '=') + 1;
5007 binary_protocol_init (filename);
5009 fprintf (stderr, "Warning: Cardtable write barriers will not be binary-protocolled.\n");
5012 fprintf (stderr, "Invalid format for the MONO_GC_DEBUG env variable: '%s'\n", env);
5013 fprintf (stderr, "The format is: MONO_GC_DEBUG=[l[:filename]|<option>]+ where l is a debug level 0-9.\n");
5014 fprintf (stderr, "Valid options are:\n");
5015 fprintf (stderr, " collect-before-allocs[=<n>]\n");
5016 fprintf (stderr, " check-at-minor-collections\n");
5017 fprintf (stderr, " disable-minor\n");
5018 fprintf (stderr, " disable-major\n");
5019 fprintf (stderr, " xdomain-checks\n");
5020 fprintf (stderr, " clear-at-gc\n");
5021 fprintf (stderr, " print-allowance\n");
5022 fprintf (stderr, " print-pinning\n");
5029 if (major_collector.is_parallel) {
5030 if (heap_dump_file) {
5031 fprintf (stderr, "Error: Cannot do heap dump with the parallel collector.\n");
5035 fprintf (stderr, "Error: Cannot gather pinning statistics with the parallel collector.\n");
5040 if (major_collector.post_param_init)
5041 major_collector.post_param_init ();
5043 memset (&remset, 0, sizeof (remset));
5045 #ifdef SGEN_HAVE_CARDTABLE
5047 sgen_card_table_init (&remset);
5050 sgen_ssb_init (&remset);
5052 if (remset.register_thread)
5053 remset.register_thread (mono_thread_info_current ());
5059 mono_gc_get_gc_name (void)
5064 static MonoMethod *write_barrier_method;
5067 mono_gc_is_critical_method (MonoMethod *method)
5069 return (method == write_barrier_method || sgen_is_managed_allocator (method));
5073 is_ip_in_managed_allocator (MonoDomain *domain, gpointer ip)
5077 if (!mono_thread_internal_current ())
5078 /* Happens during thread attach */
5083 ji = mono_jit_info_table_find (domain, ip);
5087 return mono_gc_is_critical_method (ji->method);
5091 emit_nursery_check (MonoMethodBuilder *mb, int *nursery_check_return_labels)
5093 memset (nursery_check_return_labels, 0, sizeof (int) * 3);
5094 #ifdef SGEN_ALIGN_NURSERY
5095 // if (ptr_in_nursery (ptr)) return;
5097 * Masking out the bits might be faster, but we would have to use 64 bit
5098 * immediates, which might be slower.
5100 mono_mb_emit_ldarg (mb, 0);
5101 mono_mb_emit_icon (mb, DEFAULT_NURSERY_BITS);
5102 mono_mb_emit_byte (mb, CEE_SHR_UN);
5103 mono_mb_emit_icon (mb, (mword)sgen_get_nursery_start () >> DEFAULT_NURSERY_BITS);
5104 nursery_check_return_labels [0] = mono_mb_emit_branch (mb, CEE_BEQ);
5106 // if (!ptr_in_nursery (*ptr)) return;
5107 mono_mb_emit_ldarg (mb, 0);
5108 mono_mb_emit_byte (mb, CEE_LDIND_I);
5109 mono_mb_emit_icon (mb, DEFAULT_NURSERY_BITS);
5110 mono_mb_emit_byte (mb, CEE_SHR_UN);
5111 mono_mb_emit_icon (mb, (mword)sgen_get_nursery_start () >> DEFAULT_NURSERY_BITS);
5112 nursery_check_return_labels [1] = mono_mb_emit_branch (mb, CEE_BNE_UN);
5114 int label_continue1, label_continue2;
5115 int dereferenced_var;
5117 // if (ptr < (sgen_get_nursery_start ())) goto continue;
5118 mono_mb_emit_ldarg (mb, 0);
5119 mono_mb_emit_ptr (mb, (gpointer) sgen_get_nursery_start ());
5120 label_continue_1 = mono_mb_emit_branch (mb, CEE_BLT);
5122 // if (ptr >= sgen_get_nursery_end ())) goto continue;
5123 mono_mb_emit_ldarg (mb, 0);
5124 mono_mb_emit_ptr (mb, (gpointer) sgen_get_nursery_end ());
5125 label_continue_2 = mono_mb_emit_branch (mb, CEE_BGE);
5128 nursery_check_return_labels [0] = mono_mb_emit_branch (mb, CEE_BR);
5131 mono_mb_patch_branch (mb, label_continue_1);
5132 mono_mb_patch_branch (mb, label_continue_2);
5134 // Dereference and store in local var
5135 dereferenced_var = mono_mb_add_local (mb, &mono_defaults.int_class->byval_arg);
5136 mono_mb_emit_ldarg (mb, 0);
5137 mono_mb_emit_byte (mb, CEE_LDIND_I);
5138 mono_mb_emit_stloc (mb, dereferenced_var);
5140 // if (*ptr < sgen_get_nursery_start ()) return;
5141 mono_mb_emit_ldloc (mb, dereferenced_var);
5142 mono_mb_emit_ptr (mb, (gpointer) sgen_get_nursery_start ());
5143 nursery_check_return_labels [1] = mono_mb_emit_branch (mb, CEE_BLT);
5145 // if (*ptr >= sgen_get_nursery_end ()) return;
5146 mono_mb_emit_ldloc (mb, dereferenced_var);
5147 mono_mb_emit_ptr (mb, (gpointer) sgen_get_nursery_end ());
5148 nursery_check_return_labels [2] = mono_mb_emit_branch (mb, CEE_BGE);
5153 mono_gc_get_write_barrier (void)
5156 MonoMethodBuilder *mb;
5157 MonoMethodSignature *sig;
5158 #ifdef MANAGED_WBARRIER
5159 int i, nursery_check_labels [3];
5160 int label_no_wb_3, label_no_wb_4, label_need_wb, label_slow_path;
5161 int buffer_var, buffer_index_var, dummy_var;
5163 #ifdef HAVE_KW_THREAD
5164 int stack_end_offset = -1, store_remset_buffer_offset = -1;
5165 int store_remset_buffer_index_offset = -1, store_remset_buffer_index_addr_offset = -1;
5167 MONO_THREAD_VAR_OFFSET (stack_end, stack_end_offset);
5168 g_assert (stack_end_offset != -1);
5169 MONO_THREAD_VAR_OFFSET (store_remset_buffer, store_remset_buffer_offset);
5170 g_assert (store_remset_buffer_offset != -1);
5171 MONO_THREAD_VAR_OFFSET (store_remset_buffer_index, store_remset_buffer_index_offset);
5172 g_assert (store_remset_buffer_index_offset != -1);
5173 MONO_THREAD_VAR_OFFSET (store_remset_buffer_index_addr, store_remset_buffer_index_addr_offset);
5174 g_assert (store_remset_buffer_index_addr_offset != -1);
5178 // FIXME: Maybe create a separate version for ctors (the branch would be
5179 // correctly predicted more times)
5180 if (write_barrier_method)
5181 return write_barrier_method;
5183 /* Create the IL version of mono_gc_barrier_generic_store () */
5184 sig = mono_metadata_signature_alloc (mono_defaults.corlib, 1);
5185 sig->ret = &mono_defaults.void_class->byval_arg;
5186 sig->params [0] = &mono_defaults.int_class->byval_arg;
5188 mb = mono_mb_new (mono_defaults.object_class, "wbarrier", MONO_WRAPPER_WRITE_BARRIER);
5190 #ifdef MANAGED_WBARRIER
5191 if (use_cardtable) {
5192 emit_nursery_check (mb, nursery_check_labels);
5194 addr = sgen_cardtable + ((address >> CARD_BITS) & CARD_MASK)
5198 LDC_PTR sgen_cardtable
5200 address >> CARD_BITS
5204 if (SGEN_HAVE_OVERLAPPING_CARDS) {
5205 LDC_PTR card_table_mask
5212 mono_mb_emit_ptr (mb, sgen_cardtable);
5213 mono_mb_emit_ldarg (mb, 0);
5214 mono_mb_emit_icon (mb, CARD_BITS);
5215 mono_mb_emit_byte (mb, CEE_SHR_UN);
5216 #ifdef SGEN_HAVE_OVERLAPPING_CARDS
5217 mono_mb_emit_ptr (mb, (gpointer)CARD_MASK);
5218 mono_mb_emit_byte (mb, CEE_AND);
5220 mono_mb_emit_byte (mb, CEE_ADD);
5221 mono_mb_emit_icon (mb, 1);
5222 mono_mb_emit_byte (mb, CEE_STIND_I1);
5225 for (i = 0; i < 3; ++i) {
5226 if (nursery_check_labels [i])
5227 mono_mb_patch_branch (mb, nursery_check_labels [i]);
5229 mono_mb_emit_byte (mb, CEE_RET);
5230 } else if (mono_runtime_has_tls_get ()) {
5231 emit_nursery_check (mb, nursery_check_labels);
5233 // if (ptr >= stack_end) goto need_wb;
5234 mono_mb_emit_ldarg (mb, 0);
5235 EMIT_TLS_ACCESS (mb, stack_end, stack_end_offset);
5236 label_need_wb = mono_mb_emit_branch (mb, CEE_BGE_UN);
5238 // if (ptr >= stack_start) return;
5239 dummy_var = mono_mb_add_local (mb, &mono_defaults.int_class->byval_arg);
5240 mono_mb_emit_ldarg (mb, 0);
5241 mono_mb_emit_ldloc_addr (mb, dummy_var);
5242 label_no_wb_3 = mono_mb_emit_branch (mb, CEE_BGE_UN);
5245 mono_mb_patch_branch (mb, label_need_wb);
5247 // buffer = STORE_REMSET_BUFFER;
5248 buffer_var = mono_mb_add_local (mb, &mono_defaults.int_class->byval_arg);
5249 EMIT_TLS_ACCESS (mb, store_remset_buffer, store_remset_buffer_offset);
5250 mono_mb_emit_stloc (mb, buffer_var);
5252 // buffer_index = STORE_REMSET_BUFFER_INDEX;
5253 buffer_index_var = mono_mb_add_local (mb, &mono_defaults.int_class->byval_arg);
5254 EMIT_TLS_ACCESS (mb, store_remset_buffer_index, store_remset_buffer_index_offset);
5255 mono_mb_emit_stloc (mb, buffer_index_var);
5257 // if (buffer [buffer_index] == ptr) return;
5258 mono_mb_emit_ldloc (mb, buffer_var);
5259 mono_mb_emit_ldloc (mb, buffer_index_var);
5260 g_assert (sizeof (gpointer) == 4 || sizeof (gpointer) == 8);
5261 mono_mb_emit_icon (mb, sizeof (gpointer) == 4 ? 2 : 3);
5262 mono_mb_emit_byte (mb, CEE_SHL);
5263 mono_mb_emit_byte (mb, CEE_ADD);
5264 mono_mb_emit_byte (mb, CEE_LDIND_I);
5265 mono_mb_emit_ldarg (mb, 0);
5266 label_no_wb_4 = mono_mb_emit_branch (mb, CEE_BEQ);
5269 mono_mb_emit_ldloc (mb, buffer_index_var);
5270 mono_mb_emit_icon (mb, 1);
5271 mono_mb_emit_byte (mb, CEE_ADD);
5272 mono_mb_emit_stloc (mb, buffer_index_var);
5274 // if (buffer_index >= STORE_REMSET_BUFFER_SIZE) goto slow_path;
5275 mono_mb_emit_ldloc (mb, buffer_index_var);
5276 mono_mb_emit_icon (mb, STORE_REMSET_BUFFER_SIZE);
5277 label_slow_path = mono_mb_emit_branch (mb, CEE_BGE);
5279 // buffer [buffer_index] = ptr;
5280 mono_mb_emit_ldloc (mb, buffer_var);
5281 mono_mb_emit_ldloc (mb, buffer_index_var);
5282 g_assert (sizeof (gpointer) == 4 || sizeof (gpointer) == 8);
5283 mono_mb_emit_icon (mb, sizeof (gpointer) == 4 ? 2 : 3);
5284 mono_mb_emit_byte (mb, CEE_SHL);
5285 mono_mb_emit_byte (mb, CEE_ADD);
5286 mono_mb_emit_ldarg (mb, 0);
5287 mono_mb_emit_byte (mb, CEE_STIND_I);
5289 // STORE_REMSET_BUFFER_INDEX = buffer_index;
5290 EMIT_TLS_ACCESS (mb, store_remset_buffer_index_addr, store_remset_buffer_index_addr_offset);
5291 mono_mb_emit_ldloc (mb, buffer_index_var);
5292 mono_mb_emit_byte (mb, CEE_STIND_I);
5295 for (i = 0; i < 3; ++i) {
5296 if (nursery_check_labels [i])
5297 mono_mb_patch_branch (mb, nursery_check_labels [i]);
5299 mono_mb_patch_branch (mb, label_no_wb_3);
5300 mono_mb_patch_branch (mb, label_no_wb_4);
5301 mono_mb_emit_byte (mb, CEE_RET);
5304 mono_mb_patch_branch (mb, label_slow_path);
5306 mono_mb_emit_ldarg (mb, 0);
5307 mono_mb_emit_icall (mb, mono_gc_wbarrier_generic_nostore);
5308 mono_mb_emit_byte (mb, CEE_RET);
5312 mono_mb_emit_ldarg (mb, 0);
5313 mono_mb_emit_icall (mb, mono_gc_wbarrier_generic_nostore);
5314 mono_mb_emit_byte (mb, CEE_RET);
5317 res = mono_mb_create_method (mb, sig, 16);
5320 mono_loader_lock ();
5321 if (write_barrier_method) {
5322 /* Already created */
5323 mono_free_method (res);
5325 /* double-checked locking */
5326 mono_memory_barrier ();
5327 write_barrier_method = res;
5329 mono_loader_unlock ();
5331 return write_barrier_method;
5335 mono_gc_get_description (void)
5337 return g_strdup ("sgen");
5341 mono_gc_set_desktop_mode (void)
5346 mono_gc_is_moving (void)
5352 mono_gc_is_disabled (void)
5358 sgen_debug_printf (int level, const char *format, ...)
5362 if (level > gc_debug_level)
5365 va_start (ap, format);
5366 vfprintf (gc_debug_file, format, ap);
5371 sgen_get_logfile (void)
5373 return gc_debug_file;
5377 BOOL APIENTRY mono_gc_dllmain (HMODULE module_handle, DWORD reason, LPVOID reserved)
5384 sgen_get_nursery_clear_policy (void)
5386 return nursery_clear_policy;
5390 sgen_get_array_fill_vtable (void)
5392 if (!array_fill_vtable) {
5393 static MonoClass klass;
5394 static MonoVTable vtable;
5397 MonoDomain *domain = mono_get_root_domain ();
5400 klass.element_class = mono_defaults.byte_class;
5402 klass.instance_size = sizeof (MonoArray);
5403 klass.sizes.element_size = 1;
5404 klass.name = "array_filler_type";
5406 vtable.klass = &klass;
5408 vtable.gc_descr = mono_gc_make_descr_for_array (TRUE, &bmap, 0, 1);
5411 array_fill_vtable = &vtable;
5413 return array_fill_vtable;
5423 sgen_gc_unlock (void)
5429 sgen_major_collector_iterate_live_block_ranges (sgen_cardtable_block_callback callback)
5431 major_collector.iterate_live_block_ranges (callback);
5435 sgen_major_collector_scan_card_table (SgenGrayQueue *queue)
5437 major_collector.scan_card_table (queue);
5441 sgen_get_major_collector (void)
5443 return &major_collector;
5446 void mono_gc_set_skip_thread (gboolean skip)
5448 SgenThreadInfo *info = mono_thread_info_current ();
5451 info->gc_disabled = skip;
5456 sgen_get_remset (void)
5462 mono_gc_get_vtable_bits (MonoClass *class)
5464 if (sgen_need_bridge_processing () && sgen_is_bridge_class (class))
5465 return SGEN_GC_BIT_BRIDGE_OBJECT;
5469 #endif /* HAVE_SGEN_GC */