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 static 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 static long long stat_objects_alloced = 0;
289 static long long stat_bytes_alloced = 0;
290 long long stat_objects_alloced_degraded = 0;
291 long long stat_bytes_alloced_degraded = 0;
292 static long long stat_bytes_alloced_los = 0;
294 long long stat_copy_object_called_nursery = 0;
295 long long stat_objects_copied_nursery = 0;
296 long long stat_copy_object_called_major = 0;
297 long long stat_objects_copied_major = 0;
299 long long stat_scan_object_called_nursery = 0;
300 long long stat_scan_object_called_major = 0;
302 long long stat_nursery_copy_object_failed_from_space = 0;
303 long long stat_nursery_copy_object_failed_forwarded = 0;
304 long long stat_nursery_copy_object_failed_pinned = 0;
306 static long long stat_store_remsets = 0;
307 static long long stat_store_remsets_unique = 0;
308 static long long stat_saved_remsets_1 = 0;
309 static long long stat_saved_remsets_2 = 0;
310 static long long stat_local_remsets_processed = 0;
311 static long long stat_global_remsets_added = 0;
312 static long long stat_global_remsets_readded = 0;
313 static long long stat_global_remsets_processed = 0;
314 static long long stat_global_remsets_discarded = 0;
316 static int stat_wbarrier_set_field = 0;
317 static int stat_wbarrier_set_arrayref = 0;
318 static int stat_wbarrier_arrayref_copy = 0;
319 static int stat_wbarrier_generic_store = 0;
320 static int stat_wbarrier_generic_store_remset = 0;
321 static int stat_wbarrier_set_root = 0;
322 static int stat_wbarrier_value_copy = 0;
323 static int stat_wbarrier_object_copy = 0;
326 int stat_minor_gcs = 0;
327 int stat_major_gcs = 0;
329 static long long stat_pinned_objects = 0;
331 static long long time_minor_pre_collection_fragment_clear = 0;
332 static long long time_minor_pinning = 0;
333 static long long time_minor_scan_remsets = 0;
334 static long long time_minor_scan_card_table = 0;
335 static long long time_minor_scan_pinned = 0;
336 static long long time_minor_scan_registered_roots = 0;
337 static long long time_minor_scan_thread_data = 0;
338 static long long time_minor_finish_gray_stack = 0;
339 static long long time_minor_fragment_creation = 0;
341 static long long time_major_pre_collection_fragment_clear = 0;
342 static long long time_major_pinning = 0;
343 static long long time_major_scan_pinned = 0;
344 static long long time_major_scan_registered_roots = 0;
345 static long long time_major_scan_thread_data = 0;
346 static long long time_major_scan_alloc_pinned = 0;
347 static long long time_major_scan_finalized = 0;
348 static long long time_major_scan_big_objects = 0;
349 static long long time_major_finish_gray_stack = 0;
350 static long long time_major_free_bigobjs = 0;
351 static long long time_major_los_sweep = 0;
352 static long long time_major_sweep = 0;
353 static long long time_major_fragment_creation = 0;
355 int gc_debug_level = 0;
357 static gboolean debug_print_allowance = FALSE;
361 mono_gc_flush_info (void)
363 fflush (gc_debug_file);
368 * Define this to allow the user to change the nursery size by
369 * specifying its value in the MONO_GC_PARAMS environmental
370 * variable. See mono_gc_base_init for details.
372 #define USER_CONFIG 1
374 #define TV_DECLARE SGEN_TV_DECLARE
375 #define TV_GETTIME SGEN_TV_GETTIME
376 #define TV_ELAPSED SGEN_TV_ELAPSED
377 #define TV_ELAPSED_MS SGEN_TV_ELAPSED_MS
379 #define ALIGN_TO(val,align) ((((guint64)val) + ((align) - 1)) & ~((align) - 1))
381 NurseryClearPolicy nursery_clear_policy = CLEAR_AT_TLAB_CREATION;
383 /* the runtime can register areas of memory as roots: we keep two lists of roots,
384 * a pinned root set for conservatively scanned roots and a normal one for
385 * precisely scanned roots (currently implemented as a single list).
387 typedef struct _RootRecord RootRecord;
393 #ifdef HAVE_KW_THREAD
394 static __thread RememberedSet *remembered_set MONO_TLS_FAST;
396 static MonoNativeTlsKey remembered_set_key;
397 RememberedSet *global_remset;
398 RememberedSet *freed_thread_remsets;
399 GenericStoreRememberedSet *generic_store_remsets = NULL;
401 /*A two slots cache for recently inserted remsets */
402 static gpointer global_remset_cache [2];
404 /* FIXME: later choose a size that takes into account the RememberedSet struct
405 * and doesn't waste any alloc paddin space.
407 #define DEFAULT_REMSET_SIZE 1024
408 static RememberedSet* alloc_remset (int size, gpointer id, gboolean global);
410 #define object_is_forwarded SGEN_OBJECT_IS_FORWARDED
411 #define object_is_pinned SGEN_OBJECT_IS_PINNED
412 #define pin_object SGEN_PIN_OBJECT
413 #define unpin_object SGEN_UNPIN_OBJECT
415 #define ptr_in_nursery(p) (SGEN_PTR_IN_NURSERY ((p), DEFAULT_NURSERY_BITS, nursery_start, nursery_end))
417 #define LOAD_VTABLE SGEN_LOAD_VTABLE
420 safe_name (void* obj)
422 MonoVTable *vt = (MonoVTable*)LOAD_VTABLE (obj);
423 return vt->klass->name;
426 #define safe_object_get_size mono_sgen_safe_object_get_size
429 mono_sgen_safe_name (void* obj)
431 return safe_name (obj);
435 * ######################################################################
436 * ######## Global data.
437 * ######################################################################
439 LOCK_DECLARE (gc_mutex);
440 static int gc_disabled = 0;
442 gboolean use_cardtable;
446 /* good sizes are 512KB-1MB: larger ones increase a lot memzeroing time */
447 #define DEFAULT_NURSERY_SIZE (default_nursery_size)
448 int default_nursery_size = (1 << 22);
449 #ifdef SGEN_ALIGN_NURSERY
450 /* The number of trailing 0 bits in DEFAULT_NURSERY_SIZE */
451 #define DEFAULT_NURSERY_BITS (default_nursery_bits)
452 static int default_nursery_bits = 22;
457 #define DEFAULT_NURSERY_SIZE (4*1024*1024)
458 #ifdef SGEN_ALIGN_NURSERY
459 #define DEFAULT_NURSERY_BITS 22
464 #ifndef SGEN_ALIGN_NURSERY
465 #define DEFAULT_NURSERY_BITS -1
468 #define MIN_MINOR_COLLECTION_ALLOWANCE (DEFAULT_NURSERY_SIZE * 4)
470 #define SCAN_START_SIZE SGEN_SCAN_START_SIZE
472 static mword pagesize = 4096;
473 static mword nursery_size;
474 int degraded_mode = 0;
476 static mword bytes_pinned_from_failed_allocation = 0;
478 static mword total_alloc = 0;
479 /* use this to tune when to do a major/minor collection */
480 static mword memory_pressure = 0;
481 static mword minor_collection_allowance;
482 static int minor_collection_sections_alloced = 0;
485 /* GC Logging stats */
486 static int last_major_num_sections = 0;
487 static int last_los_memory_usage = 0;
488 static gboolean major_collection_happened = FALSE;
490 GCMemSection *nursery_section = NULL;
491 static mword lowest_heap_address = ~(mword)0;
492 static mword highest_heap_address = 0;
494 static LOCK_DECLARE (interruption_mutex);
495 static LOCK_DECLARE (global_remset_mutex);
496 static LOCK_DECLARE (pin_queue_mutex);
498 #define LOCK_GLOBAL_REMSET mono_mutex_lock (&global_remset_mutex)
499 #define UNLOCK_GLOBAL_REMSET mono_mutex_unlock (&global_remset_mutex)
501 #define LOCK_PIN_QUEUE mono_mutex_lock (&pin_queue_mutex)
502 #define UNLOCK_PIN_QUEUE mono_mutex_unlock (&pin_queue_mutex)
504 typedef struct _FinalizeReadyEntry FinalizeReadyEntry;
505 struct _FinalizeReadyEntry {
506 FinalizeReadyEntry *next;
510 typedef struct _EphemeronLinkNode EphemeronLinkNode;
512 struct _EphemeronLinkNode {
513 EphemeronLinkNode *next;
522 int current_collection_generation = -1;
525 * The link pointer is hidden by negating each bit. We use the lowest
526 * bit of the link (before negation) to store whether it needs
527 * resurrection tracking.
529 #define HIDE_POINTER(p,t) ((gpointer)(~((gulong)(p)|((t)?1:0))))
530 #define REVEAL_POINTER(p) ((gpointer)((~(gulong)(p))&~3L))
532 /* objects that are ready to be finalized */
533 static FinalizeReadyEntry *fin_ready_list = NULL;
534 static FinalizeReadyEntry *critical_fin_list = NULL;
536 static EphemeronLinkNode *ephemeron_list;
538 static int num_ready_finalizers = 0;
539 static int no_finalize = 0;
542 ROOT_TYPE_NORMAL = 0, /* "normal" roots */
543 ROOT_TYPE_PINNED = 1, /* roots without a GC descriptor */
544 ROOT_TYPE_WBARRIER = 2, /* roots with a write barrier */
548 /* registered roots: the key to the hash is the root start address */
550 * Different kinds of roots are kept separate to speed up pin_from_roots () for example.
552 static SgenHashTable roots_hash [ROOT_TYPE_NUM] = {
553 SGEN_HASH_TABLE_INIT (INTERNAL_MEM_ROOTS_TABLE, INTERNAL_MEM_ROOT_RECORD, sizeof (RootRecord), mono_aligned_addr_hash, NULL),
554 SGEN_HASH_TABLE_INIT (INTERNAL_MEM_ROOTS_TABLE, INTERNAL_MEM_ROOT_RECORD, sizeof (RootRecord), mono_aligned_addr_hash, NULL),
555 SGEN_HASH_TABLE_INIT (INTERNAL_MEM_ROOTS_TABLE, INTERNAL_MEM_ROOT_RECORD, sizeof (RootRecord), mono_aligned_addr_hash, NULL)
557 static mword roots_size = 0; /* amount of memory in the root set */
559 #define GC_ROOT_NUM 32
562 void *objects [GC_ROOT_NUM];
563 int root_types [GC_ROOT_NUM];
564 uintptr_t extra_info [GC_ROOT_NUM];
568 notify_gc_roots (GCRootReport *report)
572 mono_profiler_gc_roots (report->count, report->objects, report->root_types, report->extra_info);
577 add_profile_gc_root (GCRootReport *report, void *object, int rtype, uintptr_t extra_info)
579 if (report->count == GC_ROOT_NUM)
580 notify_gc_roots (report);
581 report->objects [report->count] = object;
582 report->root_types [report->count] = rtype;
583 report->extra_info [report->count++] = (uintptr_t)((MonoVTable*)LOAD_VTABLE (object))->klass;
587 * The current allocation cursors
588 * We allocate objects in the nursery.
589 * The nursery is the area between nursery_start and nursery_end.
590 * nursery_frag_real_end points to the end of the currently used nursery fragment.
591 * nursery_first_pinned_start points to the start of the first pinned object in the nursery
592 * nursery_last_pinned_end points to the end of the last pinned object in the nursery
593 * At the next allocation, the area of the nursery where objects can be present is
594 * between MIN(nursery_first_pinned_start, first_fragment_start) and
595 * MAX(nursery_last_pinned_end, nursery_frag_real_end)
597 static char *nursery_start = NULL;
598 static char *nursery_end = NULL;
599 static char *nursery_alloc_bound = NULL;
601 MonoNativeTlsKey thread_info_key;
603 #ifdef HAVE_KW_THREAD
604 __thread SgenThreadInfo *thread_info;
605 __thread gpointer *store_remset_buffer;
606 __thread long store_remset_buffer_index;
607 __thread char *stack_end;
608 __thread long *store_remset_buffer_index_addr;
611 /* The size of a TLAB */
612 /* The bigger the value, the less often we have to go to the slow path to allocate a new
613 * one, but the more space is wasted by threads not allocating much memory.
615 * FIXME: Make this self-tuning for each thread.
617 guint32 tlab_size = (1024 * 4);
619 #define MAX_SMALL_OBJ_SIZE SGEN_MAX_SMALL_OBJ_SIZE
621 /* Functions supplied by the runtime to be called by the GC */
622 static MonoGCCallbacks gc_callbacks;
624 #define ALLOC_ALIGN SGEN_ALLOC_ALIGN
625 #define ALLOC_ALIGN_BITS SGEN_ALLOC_ALIGN_BITS
627 #define ALIGN_UP SGEN_ALIGN_UP
629 #define MOVED_OBJECTS_NUM 64
630 static void *moved_objects [MOVED_OBJECTS_NUM];
631 static int moved_objects_idx = 0;
633 /* Vtable of the objects used to fill out nursery fragments before a collection */
634 static MonoVTable *array_fill_vtable;
636 #ifdef SGEN_DEBUG_INTERNAL_ALLOC
637 MonoNativeThreadId main_gc_thread = NULL;
641 * ######################################################################
642 * ######## Heap size accounting
643 * ######################################################################
646 static mword max_heap_size = ((mword)0)- ((mword)1);
647 static mword soft_heap_limit = ((mword)0) - ((mword)1);
648 static mword allocated_heap;
650 /*Object was pinned during the current collection*/
651 static mword objects_pinned;
654 mono_sgen_release_space (mword size, int space)
656 allocated_heap -= size;
660 available_free_space (void)
662 return max_heap_size - MIN (allocated_heap, max_heap_size);
666 mono_sgen_try_alloc_space (mword size, int space)
668 if (available_free_space () < size)
671 allocated_heap += size;
672 mono_runtime_resource_check_limit (MONO_RESOURCE_GC_HEAP, allocated_heap);
677 init_heap_size_limits (glong max_heap, glong soft_limit)
680 soft_heap_limit = soft_limit;
685 if (max_heap < soft_limit) {
686 fprintf (stderr, "max-heap-size must be at least as large as soft-heap-limit.\n");
690 if (max_heap < nursery_size * 4) {
691 fprintf (stderr, "max-heap-size must be at least 4 times larger than nursery size.\n");
694 max_heap_size = max_heap - nursery_size;
698 * ######################################################################
699 * ######## Macros and function declarations.
700 * ######################################################################
704 align_pointer (void *ptr)
706 mword p = (mword)ptr;
707 p += sizeof (gpointer) - 1;
708 p &= ~ (sizeof (gpointer) - 1);
712 typedef SgenGrayQueue GrayQueue;
714 /* forward declarations */
715 static int stop_world (int generation);
716 static int restart_world (int generation);
717 static void scan_thread_data (void *start_nursery, void *end_nursery, gboolean precise, GrayQueue *queue);
718 static void scan_from_global_remsets (void *start_nursery, void *end_nursery, GrayQueue *queue);
719 static void scan_from_remsets (void *start_nursery, void *end_nursery, GrayQueue *queue);
720 static void scan_from_registered_roots (CopyOrMarkObjectFunc copy_func, char *addr_start, char *addr_end, int root_type, GrayQueue *queue);
721 static void scan_finalizer_entries (CopyOrMarkObjectFunc copy_func, FinalizeReadyEntry *list, GrayQueue *queue);
722 static void report_finalizer_roots (void);
723 static void report_registered_roots (void);
724 static void find_pinning_ref_from_thread (char *obj, size_t size);
725 static void update_current_thread_stack (void *start);
726 static void collect_bridge_objects (CopyOrMarkObjectFunc copy_func, char *start, char *end, int generation, GrayQueue *queue);
727 static void finalize_in_range (CopyOrMarkObjectFunc copy_func, char *start, char *end, int generation, GrayQueue *queue);
728 static void process_fin_stage_entries (void);
729 static void null_link_in_range (CopyOrMarkObjectFunc copy_func, char *start, char *end, int generation, gboolean before_finalization, GrayQueue *queue);
730 static void null_links_for_domain (MonoDomain *domain, int generation);
731 static void process_dislink_stage_entries (void);
733 static void pin_from_roots (void *start_nursery, void *end_nursery, GrayQueue *queue);
734 static int pin_objects_from_addresses (GCMemSection *section, void **start, void **end, void *start_nursery, void *end_nursery, GrayQueue *queue);
735 static void clear_remsets (void);
736 static void finish_gray_stack (char *start_addr, char *end_addr, int generation, GrayQueue *queue);
737 static gboolean need_major_collection (mword space_needed);
738 static void major_collection (const char *reason);
740 static void mono_gc_register_disappearing_link (MonoObject *obj, void **link, gboolean track, gboolean in_gc);
741 static gboolean mono_gc_is_critical_method (MonoMethod *method);
743 void mono_gc_scan_for_specific_ref (MonoObject *key, gboolean precise);
745 static void init_stats (void);
747 static int mark_ephemerons_in_range (CopyOrMarkObjectFunc copy_func, char *start, char *end, GrayQueue *queue);
748 static void clear_unreachable_ephemerons (CopyOrMarkObjectFunc copy_func, char *start, char *end, GrayQueue *queue);
749 static void null_ephemerons_for_domain (MonoDomain *domain);
751 SgenMajorCollector major_collector;
752 static GrayQueue gray_queue;
756 #define WORKERS_DISTRIBUTE_GRAY_QUEUE (mono_sgen_collection_is_parallel () ? mono_sgen_workers_get_distribute_gray_queue () : &gray_queue)
758 static SgenGrayQueue*
759 mono_sgen_workers_get_job_gray_queue (WorkerData *worker_data)
761 return worker_data ? &worker_data->private_gray_queue : WORKERS_DISTRIBUTE_GRAY_QUEUE;
765 is_xdomain_ref_allowed (gpointer *ptr, char *obj, MonoDomain *domain)
767 MonoObject *o = (MonoObject*)(obj);
768 MonoObject *ref = (MonoObject*)*(ptr);
769 int offset = (char*)(ptr) - (char*)o;
771 if (o->vtable->klass == mono_defaults.thread_class && offset == G_STRUCT_OFFSET (MonoThread, internal_thread))
773 if (o->vtable->klass == mono_defaults.internal_thread_class && offset == G_STRUCT_OFFSET (MonoInternalThread, current_appcontext))
775 if (mono_class_has_parent_fast (o->vtable->klass, mono_defaults.real_proxy_class) &&
776 offset == G_STRUCT_OFFSET (MonoRealProxy, unwrapped_server))
778 /* Thread.cached_culture_info */
779 if (!strcmp (ref->vtable->klass->name_space, "System.Globalization") &&
780 !strcmp (ref->vtable->klass->name, "CultureInfo") &&
781 !strcmp(o->vtable->klass->name_space, "System") &&
782 !strcmp(o->vtable->klass->name, "Object[]"))
785 * 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
786 * at System.IO.MemoryStream..ctor (byte[]) [0x00017] in /home/schani/Work/novell/trunk/mcs/class/corlib/System.IO/MemoryStream.cs:81
787 * at (wrapper remoting-invoke-with-check) System.IO.MemoryStream..ctor (byte[]) <IL 0x00020, 0xffffffff>
788 * at System.Runtime.Remoting.Messaging.CADMethodCallMessage.GetArguments () [0x0000d] in /home/schani/Work/novell/trunk/mcs/class/corlib/System.Runtime.Remoting.Messaging/CADMessages.cs:327
789 * 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
790 * 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
791 * at (wrapper remoting-invoke-with-check) System.AppDomain.ProcessMessageInDomain (byte[],System.Runtime.Remoting.Messaging.CADMethodCallMessage,byte[]&,System.Runtime.Remoting.Messaging.CADMethodReturnMessage&) <IL 0x0003d, 0xffffffff>
792 * 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
793 * at (wrapper runtime-invoke) object.runtime_invoke_CrossAppDomainSink/ProcessMessageRes_object_object (object,intptr,intptr,intptr) <IL 0x0004c, 0xffffffff>
795 if (!strcmp (ref->vtable->klass->name_space, "System") &&
796 !strcmp (ref->vtable->klass->name, "Byte[]") &&
797 !strcmp (o->vtable->klass->name_space, "System.IO") &&
798 !strcmp (o->vtable->klass->name, "MemoryStream"))
800 /* append_job() in threadpool.c */
801 if (!strcmp (ref->vtable->klass->name_space, "System.Runtime.Remoting.Messaging") &&
802 !strcmp (ref->vtable->klass->name, "AsyncResult") &&
803 !strcmp (o->vtable->klass->name_space, "System") &&
804 !strcmp (o->vtable->klass->name, "Object[]") &&
805 mono_thread_pool_is_queue_array ((MonoArray*) o))
811 check_reference_for_xdomain (gpointer *ptr, char *obj, MonoDomain *domain)
813 MonoObject *o = (MonoObject*)(obj);
814 MonoObject *ref = (MonoObject*)*(ptr);
815 int offset = (char*)(ptr) - (char*)o;
817 MonoClassField *field;
820 if (!ref || ref->vtable->domain == domain)
822 if (is_xdomain_ref_allowed (ptr, obj, domain))
826 for (class = o->vtable->klass; class; class = class->parent) {
829 for (i = 0; i < class->field.count; ++i) {
830 if (class->fields[i].offset == offset) {
831 field = &class->fields[i];
839 if (ref->vtable->klass == mono_defaults.string_class)
840 str = mono_string_to_utf8 ((MonoString*)ref);
843 g_print ("xdomain reference in %p (%s.%s) at offset %d (%s) to %p (%s.%s) (%s) - pointed to by:\n",
844 o, o->vtable->klass->name_space, o->vtable->klass->name,
845 offset, field ? field->name : "",
846 ref, ref->vtable->klass->name_space, ref->vtable->klass->name, str ? str : "");
847 mono_gc_scan_for_specific_ref (o, TRUE);
853 #define HANDLE_PTR(ptr,obj) check_reference_for_xdomain ((ptr), (obj), domain)
856 scan_object_for_xdomain_refs (char *start, mword size, void *data)
858 MonoDomain *domain = ((MonoObject*)start)->vtable->domain;
860 #include "sgen-scan-object.h"
863 static gboolean scan_object_for_specific_ref_precise = TRUE;
866 #define HANDLE_PTR(ptr,obj) do { \
867 if ((MonoObject*)*(ptr) == key) { \
868 g_print ("found ref to %p in object %p (%s) at offset %td\n", \
869 key, (obj), safe_name ((obj)), ((char*)(ptr) - (char*)(obj))); \
874 scan_object_for_specific_ref (char *start, MonoObject *key)
878 if ((forwarded = SGEN_OBJECT_IS_FORWARDED (start)))
881 if (scan_object_for_specific_ref_precise) {
882 #include "sgen-scan-object.h"
884 mword *words = (mword*)start;
885 size_t size = safe_object_get_size ((MonoObject*)start);
887 for (i = 0; i < size / sizeof (mword); ++i) {
888 if (words [i] == (mword)key) {
889 g_print ("found possible ref to %p in object %p (%s) at offset %td\n",
890 key, start, safe_name (start), i * sizeof (mword));
897 mono_sgen_scan_area_with_callback (char *start, char *end, IterateObjectCallbackFunc callback, void *data, gboolean allow_flags)
899 while (start < end) {
903 if (!*(void**)start) {
904 start += sizeof (void*); /* should be ALLOC_ALIGN, really */
909 if (!(obj = SGEN_OBJECT_IS_FORWARDED (start)))
915 size = ALIGN_UP (safe_object_get_size ((MonoObject*)obj));
917 callback (obj, size, data);
924 scan_object_for_specific_ref_callback (char *obj, size_t size, MonoObject *key)
926 scan_object_for_specific_ref (obj, key);
930 check_root_obj_specific_ref (RootRecord *root, MonoObject *key, MonoObject *obj)
934 g_print ("found ref to %p in root record %p\n", key, root);
937 static MonoObject *check_key = NULL;
938 static RootRecord *check_root = NULL;
941 check_root_obj_specific_ref_from_marker (void **obj)
943 check_root_obj_specific_ref (check_root, check_key, *obj);
947 scan_roots_for_specific_ref (MonoObject *key, int root_type)
953 SGEN_HASH_TABLE_FOREACH (&roots_hash [root_type], start_root, root) {
954 mword desc = root->root_desc;
958 switch (desc & ROOT_DESC_TYPE_MASK) {
959 case ROOT_DESC_BITMAP:
960 desc >>= ROOT_DESC_TYPE_SHIFT;
963 check_root_obj_specific_ref (root, key, *start_root);
968 case ROOT_DESC_COMPLEX: {
969 gsize *bitmap_data = mono_sgen_get_complex_descriptor_bitmap (desc);
970 int bwords = (*bitmap_data) - 1;
971 void **start_run = start_root;
973 while (bwords-- > 0) {
974 gsize bmap = *bitmap_data++;
975 void **objptr = start_run;
978 check_root_obj_specific_ref (root, key, *objptr);
982 start_run += GC_BITS_PER_WORD;
986 case ROOT_DESC_USER: {
987 MonoGCRootMarkFunc marker = mono_sgen_get_user_descriptor_func (desc);
988 marker (start_root, check_root_obj_specific_ref_from_marker);
991 case ROOT_DESC_RUN_LEN:
992 g_assert_not_reached ();
994 g_assert_not_reached ();
996 } SGEN_HASH_TABLE_FOREACH_END;
1003 mono_gc_scan_for_specific_ref (MonoObject *key, gboolean precise)
1008 scan_object_for_specific_ref_precise = precise;
1010 mono_sgen_scan_area_with_callback (nursery_section->data, nursery_section->end_data,
1011 (IterateObjectCallbackFunc)scan_object_for_specific_ref_callback, key, TRUE);
1013 major_collector.iterate_objects (TRUE, TRUE, (IterateObjectCallbackFunc)scan_object_for_specific_ref_callback, key);
1015 mono_sgen_los_iterate_objects ((IterateObjectCallbackFunc)scan_object_for_specific_ref_callback, key);
1017 scan_roots_for_specific_ref (key, ROOT_TYPE_NORMAL);
1018 scan_roots_for_specific_ref (key, ROOT_TYPE_WBARRIER);
1020 SGEN_HASH_TABLE_FOREACH (&roots_hash [ROOT_TYPE_PINNED], ptr, root) {
1021 while (ptr < (void**)root->end_root) {
1022 check_root_obj_specific_ref (root, *ptr, key);
1025 } SGEN_HASH_TABLE_FOREACH_END;
1029 need_remove_object_for_domain (char *start, MonoDomain *domain)
1031 if (mono_object_domain (start) == domain) {
1032 DEBUG (4, fprintf (gc_debug_file, "Need to cleanup object %p\n", start));
1033 binary_protocol_cleanup (start, (gpointer)LOAD_VTABLE (start), safe_object_get_size ((MonoObject*)start));
1040 process_object_for_domain_clearing (char *start, MonoDomain *domain)
1042 GCVTable *vt = (GCVTable*)LOAD_VTABLE (start);
1043 if (vt->klass == mono_defaults.internal_thread_class)
1044 g_assert (mono_object_domain (start) == mono_get_root_domain ());
1045 /* The object could be a proxy for an object in the domain
1047 if (mono_class_has_parent_fast (vt->klass, mono_defaults.real_proxy_class)) {
1048 MonoObject *server = ((MonoRealProxy*)start)->unwrapped_server;
1050 /* The server could already have been zeroed out, so
1051 we need to check for that, too. */
1052 if (server && (!LOAD_VTABLE (server) || mono_object_domain (server) == domain)) {
1053 DEBUG (4, fprintf (gc_debug_file, "Cleaning up remote pointer in %p to object %p\n",
1055 ((MonoRealProxy*)start)->unwrapped_server = NULL;
1060 static MonoDomain *check_domain = NULL;
1063 check_obj_not_in_domain (void **o)
1065 g_assert (((MonoObject*)(*o))->vtable->domain != check_domain);
1069 scan_for_registered_roots_in_domain (MonoDomain *domain, int root_type)
1073 check_domain = domain;
1074 SGEN_HASH_TABLE_FOREACH (&roots_hash [root_type], start_root, root) {
1075 mword desc = root->root_desc;
1077 /* The MonoDomain struct is allowed to hold
1078 references to objects in its own domain. */
1079 if (start_root == (void**)domain)
1082 switch (desc & ROOT_DESC_TYPE_MASK) {
1083 case ROOT_DESC_BITMAP:
1084 desc >>= ROOT_DESC_TYPE_SHIFT;
1086 if ((desc & 1) && *start_root)
1087 check_obj_not_in_domain (*start_root);
1092 case ROOT_DESC_COMPLEX: {
1093 gsize *bitmap_data = mono_sgen_get_complex_descriptor_bitmap (desc);
1094 int bwords = (*bitmap_data) - 1;
1095 void **start_run = start_root;
1097 while (bwords-- > 0) {
1098 gsize bmap = *bitmap_data++;
1099 void **objptr = start_run;
1101 if ((bmap & 1) && *objptr)
1102 check_obj_not_in_domain (*objptr);
1106 start_run += GC_BITS_PER_WORD;
1110 case ROOT_DESC_USER: {
1111 MonoGCRootMarkFunc marker = mono_sgen_get_user_descriptor_func (desc);
1112 marker (start_root, check_obj_not_in_domain);
1115 case ROOT_DESC_RUN_LEN:
1116 g_assert_not_reached ();
1118 g_assert_not_reached ();
1120 } SGEN_HASH_TABLE_FOREACH_END;
1122 check_domain = NULL;
1126 check_for_xdomain_refs (void)
1130 mono_sgen_scan_area_with_callback (nursery_section->data, nursery_section->end_data,
1131 (IterateObjectCallbackFunc)scan_object_for_xdomain_refs, NULL, FALSE);
1133 major_collector.iterate_objects (TRUE, TRUE, (IterateObjectCallbackFunc)scan_object_for_xdomain_refs, NULL);
1135 for (bigobj = los_object_list; bigobj; bigobj = bigobj->next)
1136 scan_object_for_xdomain_refs (bigobj->data, bigobj->size, NULL);
1140 clear_domain_process_object (char *obj, MonoDomain *domain)
1144 process_object_for_domain_clearing (obj, domain);
1145 remove = need_remove_object_for_domain (obj, domain);
1147 if (remove && ((MonoObject*)obj)->synchronisation) {
1148 void **dislink = mono_monitor_get_object_monitor_weak_link ((MonoObject*)obj);
1150 mono_gc_register_disappearing_link (NULL, dislink, FALSE, TRUE);
1157 clear_domain_process_minor_object_callback (char *obj, size_t size, MonoDomain *domain)
1159 if (clear_domain_process_object (obj, domain))
1160 memset (obj, 0, size);
1164 clear_domain_process_major_object_callback (char *obj, size_t size, MonoDomain *domain)
1166 clear_domain_process_object (obj, domain);
1170 clear_domain_free_major_non_pinned_object_callback (char *obj, size_t size, MonoDomain *domain)
1172 if (need_remove_object_for_domain (obj, domain))
1173 major_collector.free_non_pinned_object (obj, size);
1177 clear_domain_free_major_pinned_object_callback (char *obj, size_t size, MonoDomain *domain)
1179 if (need_remove_object_for_domain (obj, domain))
1180 major_collector.free_pinned_object (obj, size);
1184 * When appdomains are unloaded we can easily remove objects that have finalizers,
1185 * but all the others could still be present in random places on the heap.
1186 * We need a sweep to get rid of them even though it's going to be costly
1188 * The reason we need to remove them is because we access the vtable and class
1189 * structures to know the object size and the reference bitmap: once the domain is
1190 * unloaded the point to random memory.
1193 mono_gc_clear_domain (MonoDomain * domain)
1195 LOSObject *bigobj, *prev;
1200 process_fin_stage_entries ();
1201 process_dislink_stage_entries ();
1203 mono_sgen_clear_nursery_fragments ();
1205 if (xdomain_checks && domain != mono_get_root_domain ()) {
1206 scan_for_registered_roots_in_domain (domain, ROOT_TYPE_NORMAL);
1207 scan_for_registered_roots_in_domain (domain, ROOT_TYPE_WBARRIER);
1208 check_for_xdomain_refs ();
1211 mono_sgen_scan_area_with_callback (nursery_section->data, nursery_section->end_data,
1212 (IterateObjectCallbackFunc)clear_domain_process_minor_object_callback, domain, FALSE);
1214 /*Ephemerons and dislinks must be processed before LOS since they might end up pointing
1215 to memory returned to the OS.*/
1216 null_ephemerons_for_domain (domain);
1218 for (i = GENERATION_NURSERY; i < GENERATION_MAX; ++i)
1219 null_links_for_domain (domain, i);
1221 /* We need two passes over major and large objects because
1222 freeing such objects might give their memory back to the OS
1223 (in the case of large objects) or obliterate its vtable
1224 (pinned objects with major-copying or pinned and non-pinned
1225 objects with major-mark&sweep), but we might need to
1226 dereference a pointer from an object to another object if
1227 the first object is a proxy. */
1228 major_collector.iterate_objects (TRUE, TRUE, (IterateObjectCallbackFunc)clear_domain_process_major_object_callback, domain);
1229 for (bigobj = los_object_list; bigobj; bigobj = bigobj->next)
1230 clear_domain_process_object (bigobj->data, domain);
1233 for (bigobj = los_object_list; bigobj;) {
1234 if (need_remove_object_for_domain (bigobj->data, domain)) {
1235 LOSObject *to_free = bigobj;
1237 prev->next = bigobj->next;
1239 los_object_list = bigobj->next;
1240 bigobj = bigobj->next;
1241 DEBUG (4, fprintf (gc_debug_file, "Freeing large object %p\n",
1243 mono_sgen_los_free_object (to_free);
1247 bigobj = bigobj->next;
1249 major_collector.iterate_objects (TRUE, FALSE, (IterateObjectCallbackFunc)clear_domain_free_major_non_pinned_object_callback, domain);
1250 major_collector.iterate_objects (FALSE, TRUE, (IterateObjectCallbackFunc)clear_domain_free_major_pinned_object_callback, domain);
1252 if (G_UNLIKELY (do_pin_stats)) {
1253 if (domain == mono_get_root_domain ())
1254 mono_sgen_pin_stats_print_class_stats ();
1261 global_remset_cache_clear (void)
1263 memset (global_remset_cache, 0, sizeof (global_remset_cache));
1267 * Tries to check if a given remset location was already added to the global remset.
1270 * A 2 entry, LRU cache of recently saw location remsets.
1272 * It's hand-coded instead of done using loops to reduce the number of memory references on cache hit.
1274 * Returns TRUE is the element was added..
1277 global_remset_location_was_not_added (gpointer ptr)
1280 gpointer first = global_remset_cache [0], second;
1282 HEAVY_STAT (++stat_global_remsets_discarded);
1286 second = global_remset_cache [1];
1288 if (second == ptr) {
1289 /*Move the second to the front*/
1290 global_remset_cache [0] = second;
1291 global_remset_cache [1] = first;
1293 HEAVY_STAT (++stat_global_remsets_discarded);
1297 global_remset_cache [0] = second;
1298 global_remset_cache [1] = ptr;
1303 * mono_sgen_add_to_global_remset:
1305 * The global remset contains locations which point into newspace after
1306 * a minor collection. This can happen if the objects they point to are pinned.
1308 * LOCKING: If called from a parallel collector, the global remset
1309 * lock must be held. For serial collectors that is not necessary.
1312 mono_sgen_add_to_global_remset (gpointer ptr)
1315 gboolean lock = mono_sgen_collection_is_parallel ();
1316 gpointer obj = *(gpointer*)ptr;
1318 if (use_cardtable) {
1319 sgen_card_table_mark_address ((mword)ptr);
1323 g_assert (!ptr_in_nursery (ptr) && ptr_in_nursery (obj));
1328 if (!global_remset_location_was_not_added (ptr))
1331 if (G_UNLIKELY (do_pin_stats))
1332 mono_sgen_pin_stats_register_global_remset (obj);
1334 DEBUG (8, fprintf (gc_debug_file, "Adding global remset for %p\n", ptr));
1335 binary_protocol_global_remset (ptr, *(gpointer*)ptr, (gpointer)LOAD_VTABLE (obj));
1337 HEAVY_STAT (++stat_global_remsets_added);
1340 * FIXME: If an object remains pinned, we need to add it at every minor collection.
1341 * To avoid uncontrolled growth of the global remset, only add each pointer once.
1343 if (global_remset->store_next + 3 < global_remset->end_set) {
1344 *(global_remset->store_next++) = (mword)ptr;
1347 rs = alloc_remset (global_remset->end_set - global_remset->data, NULL, TRUE);
1348 rs->next = global_remset;
1350 *(global_remset->store_next++) = (mword)ptr;
1353 int global_rs_size = 0;
1355 for (rs = global_remset; rs; rs = rs->next) {
1356 global_rs_size += rs->store_next - rs->data;
1358 DEBUG (4, fprintf (gc_debug_file, "Global remset now has size %d\n", global_rs_size));
1363 UNLOCK_GLOBAL_REMSET;
1367 * mono_sgen_drain_gray_stack:
1369 * Scan objects in the gray stack until the stack is empty. This should be called
1370 * frequently after each object is copied, to achieve better locality and cache
1374 mono_sgen_drain_gray_stack (GrayQueue *queue, int max_objs)
1378 if (current_collection_generation == GENERATION_NURSERY) {
1379 ScanObjectFunc scan_func = mono_sgen_get_minor_scan_object ();
1382 GRAY_OBJECT_DEQUEUE (queue, obj);
1385 DEBUG (9, fprintf (gc_debug_file, "Precise gray object scan %p (%s)\n", obj, safe_name (obj)));
1386 scan_func (obj, queue);
1391 if (mono_sgen_collection_is_parallel () && mono_sgen_workers_is_distributed_queue (queue))
1395 for (i = 0; i != max_objs; ++i) {
1396 GRAY_OBJECT_DEQUEUE (queue, obj);
1399 DEBUG (9, fprintf (gc_debug_file, "Precise gray object scan %p (%s)\n", obj, safe_name (obj)));
1400 major_collector.major_scan_object (obj, queue);
1402 } while (max_objs < 0);
1408 * Addresses from start to end are already sorted. This function finds
1409 * the object header for each address and pins the object. The
1410 * addresses must be inside the passed section. The (start of the)
1411 * address array is overwritten with the addresses of the actually
1412 * pinned objects. Return the number of pinned objects.
1415 pin_objects_from_addresses (GCMemSection *section, void **start, void **end, void *start_nursery, void *end_nursery, GrayQueue *queue)
1420 void *last_obj = NULL;
1421 size_t last_obj_size = 0;
1424 void **definitely_pinned = start;
1426 mono_sgen_nursery_allocator_prepare_for_pinning ();
1428 while (start < end) {
1430 /* the range check should be reduntant */
1431 if (addr != last && addr >= start_nursery && addr < end_nursery) {
1432 DEBUG (5, fprintf (gc_debug_file, "Considering pinning addr %p\n", addr));
1433 /* multiple pointers to the same object */
1434 if (addr >= last_obj && (char*)addr < (char*)last_obj + last_obj_size) {
1438 idx = ((char*)addr - (char*)section->data) / SCAN_START_SIZE;
1439 g_assert (idx < section->num_scan_start);
1440 search_start = (void*)section->scan_starts [idx];
1441 if (!search_start || search_start > addr) {
1444 search_start = section->scan_starts [idx];
1445 if (search_start && search_start <= addr)
1448 if (!search_start || search_start > addr)
1449 search_start = start_nursery;
1451 if (search_start < last_obj)
1452 search_start = (char*)last_obj + last_obj_size;
1453 /* now addr should be in an object a short distance from search_start
1454 * Note that search_start must point to zeroed mem or point to an object.
1458 if (!*(void**)search_start) {
1459 /* Consistency check */
1461 for (frag = nursery_fragments; frag; frag = frag->next) {
1462 if (search_start >= frag->fragment_start && search_start < frag->fragment_end)
1463 g_assert_not_reached ();
1467 search_start = (void*)ALIGN_UP ((mword)search_start + sizeof (gpointer));
1470 last_obj = search_start;
1471 last_obj_size = ALIGN_UP (safe_object_get_size ((MonoObject*)search_start));
1473 if (((MonoObject*)last_obj)->synchronisation == GINT_TO_POINTER (-1)) {
1474 /* Marks the beginning of a nursery fragment, skip */
1476 DEBUG (8, fprintf (gc_debug_file, "Pinned try match %p (%s), size %zd\n", last_obj, safe_name (last_obj), last_obj_size));
1477 if (addr >= search_start && (char*)addr < (char*)last_obj + last_obj_size) {
1478 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));
1479 binary_protocol_pin (search_start, (gpointer)LOAD_VTABLE (search_start), safe_object_get_size (search_start));
1480 pin_object (search_start);
1481 GRAY_OBJECT_ENQUEUE (queue, search_start);
1482 if (G_UNLIKELY (do_pin_stats))
1483 mono_sgen_pin_stats_register_object (search_start, last_obj_size);
1484 definitely_pinned [count] = search_start;
1489 /* skip to the next object */
1490 search_start = (void*)((char*)search_start + last_obj_size);
1491 } while (search_start <= addr);
1492 /* we either pinned the correct object or we ignored the addr because
1493 * it points to unused zeroed memory.
1499 //printf ("effective pinned: %d (at the end: %d)\n", count, (char*)end_nursery - (char*)last);
1500 if (mono_profiler_get_events () & MONO_PROFILE_GC_ROOTS) {
1501 GCRootReport report;
1503 for (idx = 0; idx < count; ++idx)
1504 add_profile_gc_root (&report, definitely_pinned [idx], MONO_PROFILE_GC_ROOT_PINNING | MONO_PROFILE_GC_ROOT_MISC, 0);
1505 notify_gc_roots (&report);
1507 stat_pinned_objects += count;
1512 mono_sgen_pin_objects_in_section (GCMemSection *section, GrayQueue *queue)
1514 int num_entries = section->pin_queue_num_entries;
1516 void **start = section->pin_queue_start;
1518 reduced_to = pin_objects_from_addresses (section, start, start + num_entries,
1519 section->data, section->next_data, queue);
1520 section->pin_queue_num_entries = reduced_to;
1522 section->pin_queue_start = NULL;
1528 mono_sgen_pin_object (void *object, GrayQueue *queue)
1530 if (mono_sgen_collection_is_parallel ()) {
1532 /*object arrives pinned*/
1533 mono_sgen_pin_stage_ptr (object);
1537 SGEN_PIN_OBJECT (object);
1538 mono_sgen_pin_stage_ptr (object);
1540 if (G_UNLIKELY (do_pin_stats))
1541 mono_sgen_pin_stats_register_object (object, safe_object_get_size (object));
1543 GRAY_OBJECT_ENQUEUE (queue, object);
1544 binary_protocol_pin (object, (gpointer)LOAD_VTABLE (object), safe_object_get_size (object));
1547 /* Sort the addresses in array in increasing order.
1548 * Done using a by-the book heap sort. Which has decent and stable performance, is pretty cache efficient.
1551 mono_sgen_sort_addresses (void **array, int size)
1556 for (i = 1; i < size; ++i) {
1559 int parent = (child - 1) / 2;
1561 if (array [parent] >= array [child])
1564 tmp = array [parent];
1565 array [parent] = array [child];
1566 array [child] = tmp;
1572 for (i = size - 1; i > 0; --i) {
1575 array [i] = array [0];
1581 while (root * 2 + 1 <= end) {
1582 int child = root * 2 + 1;
1584 if (child < end && array [child] < array [child + 1])
1586 if (array [root] >= array [child])
1590 array [root] = array [child];
1591 array [child] = tmp;
1599 * Scan the memory between start and end and queue values which could be pointers
1600 * to the area between start_nursery and end_nursery for later consideration.
1601 * Typically used for thread stacks.
1604 conservatively_pin_objects_from (void **start, void **end, void *start_nursery, void *end_nursery, int pin_type)
1607 while (start < end) {
1608 if (*start >= start_nursery && *start < end_nursery) {
1610 * *start can point to the middle of an object
1611 * note: should we handle pointing at the end of an object?
1612 * pinning in C# code disallows pointing at the end of an object
1613 * but there is some small chance that an optimizing C compiler
1614 * may keep the only reference to an object by pointing
1615 * at the end of it. We ignore this small chance for now.
1616 * Pointers to the end of an object are indistinguishable
1617 * from pointers to the start of the next object in memory
1618 * so if we allow that we'd need to pin two objects...
1619 * We queue the pointer in an array, the
1620 * array will then be sorted and uniqued. This way
1621 * we can coalesce several pinning pointers and it should
1622 * be faster since we'd do a memory scan with increasing
1623 * addresses. Note: we can align the address to the allocation
1624 * alignment, so the unique process is more effective.
1626 mword addr = (mword)*start;
1627 addr &= ~(ALLOC_ALIGN - 1);
1628 if (addr >= (mword)start_nursery && addr < (mword)end_nursery)
1629 mono_sgen_pin_stage_ptr ((void*)addr);
1630 if (G_UNLIKELY (do_pin_stats)) {
1631 if (ptr_in_nursery (addr))
1632 mono_sgen_pin_stats_register_address ((char*)addr, pin_type);
1634 DEBUG (6, if (count) fprintf (gc_debug_file, "Pinning address %p from %p\n", (void*)addr, start));
1639 DEBUG (7, if (count) fprintf (gc_debug_file, "found %d potential pinned heap pointers\n", count));
1643 * Debugging function: find in the conservative roots where @obj is being pinned.
1645 static G_GNUC_UNUSED void
1646 find_pinning_reference (char *obj, size_t size)
1650 char *endobj = obj + size;
1652 SGEN_HASH_TABLE_FOREACH (&roots_hash [ROOT_TYPE_NORMAL], start, root) {
1653 /* if desc is non-null it has precise info */
1654 if (!root->root_desc) {
1655 while (start < (char**)root->end_root) {
1656 if (*start >= obj && *start < endobj) {
1657 DEBUG (0, fprintf (gc_debug_file, "Object %p referenced in pinned roots %p-%p\n", obj, start, root->end_root));
1662 } SGEN_HASH_TABLE_FOREACH_END;
1664 find_pinning_ref_from_thread (obj, size);
1668 * The first thing we do in a collection is to identify pinned objects.
1669 * This function considers all the areas of memory that need to be
1670 * conservatively scanned.
1673 pin_from_roots (void *start_nursery, void *end_nursery, GrayQueue *queue)
1677 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));
1678 /* objects pinned from the API are inside these roots */
1679 SGEN_HASH_TABLE_FOREACH (&roots_hash [ROOT_TYPE_PINNED], start_root, root) {
1680 DEBUG (6, fprintf (gc_debug_file, "Pinned roots %p-%p\n", start_root, root->end_root));
1681 conservatively_pin_objects_from (start_root, (void**)root->end_root, start_nursery, end_nursery, PIN_TYPE_OTHER);
1682 } SGEN_HASH_TABLE_FOREACH_END;
1683 /* now deal with the thread stacks
1684 * in the future we should be able to conservatively scan only:
1685 * *) the cpu registers
1686 * *) the unmanaged stack frames
1687 * *) the _last_ managed stack frame
1688 * *) pointers slots in managed frames
1690 scan_thread_data (start_nursery, end_nursery, FALSE, queue);
1694 CopyOrMarkObjectFunc func;
1696 } UserCopyOrMarkData;
1698 static MonoNativeTlsKey user_copy_or_mark_key;
1701 init_user_copy_or_mark_key (void)
1703 mono_native_tls_alloc (&user_copy_or_mark_key, NULL);
1707 set_user_copy_or_mark_data (UserCopyOrMarkData *data)
1709 mono_native_tls_set_value (user_copy_or_mark_key, data);
1713 single_arg_user_copy_or_mark (void **obj)
1715 UserCopyOrMarkData *data = mono_native_tls_get_value (user_copy_or_mark_key);
1717 data->func (obj, data->queue);
1721 * The memory area from start_root to end_root contains pointers to objects.
1722 * Their position is precisely described by @desc (this means that the pointer
1723 * can be either NULL or the pointer to the start of an object).
1724 * This functions copies them to to_space updates them.
1726 * This function is not thread-safe!
1729 precisely_scan_objects_from (CopyOrMarkObjectFunc copy_func, void** start_root, void** end_root, char* n_start, char *n_end, mword desc, GrayQueue *queue)
1731 switch (desc & ROOT_DESC_TYPE_MASK) {
1732 case ROOT_DESC_BITMAP:
1733 desc >>= ROOT_DESC_TYPE_SHIFT;
1735 if ((desc & 1) && *start_root) {
1736 copy_func (start_root, queue);
1737 DEBUG (9, fprintf (gc_debug_file, "Overwrote root at %p with %p\n", start_root, *start_root));
1738 mono_sgen_drain_gray_stack (queue, -1);
1744 case ROOT_DESC_COMPLEX: {
1745 gsize *bitmap_data = mono_sgen_get_complex_descriptor_bitmap (desc);
1746 int bwords = (*bitmap_data) - 1;
1747 void **start_run = start_root;
1749 while (bwords-- > 0) {
1750 gsize bmap = *bitmap_data++;
1751 void **objptr = start_run;
1753 if ((bmap & 1) && *objptr) {
1754 copy_func (objptr, queue);
1755 DEBUG (9, fprintf (gc_debug_file, "Overwrote root at %p with %p\n", objptr, *objptr));
1756 mono_sgen_drain_gray_stack (queue, -1);
1761 start_run += GC_BITS_PER_WORD;
1765 case ROOT_DESC_USER: {
1766 UserCopyOrMarkData data = { copy_func, queue };
1767 MonoGCRootMarkFunc marker = mono_sgen_get_user_descriptor_func (desc);
1768 set_user_copy_or_mark_data (&data);
1769 marker (start_root, single_arg_user_copy_or_mark);
1770 set_user_copy_or_mark_data (NULL);
1773 case ROOT_DESC_RUN_LEN:
1774 g_assert_not_reached ();
1776 g_assert_not_reached ();
1781 reset_heap_boundaries (void)
1783 lowest_heap_address = ~(mword)0;
1784 highest_heap_address = 0;
1788 mono_sgen_update_heap_boundaries (mword low, mword high)
1793 old = lowest_heap_address;
1796 } while (SGEN_CAS_PTR ((gpointer*)&lowest_heap_address, (gpointer)low, (gpointer)old) != (gpointer)old);
1799 old = highest_heap_address;
1802 } while (SGEN_CAS_PTR ((gpointer*)&highest_heap_address, (gpointer)high, (gpointer)old) != (gpointer)old);
1805 static unsigned long
1806 prot_flags_for_activate (int activate)
1808 unsigned long prot_flags = activate? MONO_MMAP_READ|MONO_MMAP_WRITE: MONO_MMAP_NONE;
1809 return prot_flags | MONO_MMAP_PRIVATE | MONO_MMAP_ANON;
1813 * Allocate a big chunk of memory from the OS (usually 64KB to several megabytes).
1814 * This must not require any lock.
1817 mono_sgen_alloc_os_memory (size_t size, int activate)
1819 void *ptr = mono_valloc (0, size, prot_flags_for_activate (activate));
1822 total_alloc += size;
1827 /* size must be a power of 2 */
1829 mono_sgen_alloc_os_memory_aligned (mword size, mword alignment, gboolean activate)
1831 void *ptr = mono_valloc_aligned (size, alignment, prot_flags_for_activate (activate));
1834 total_alloc += size;
1840 * Free the memory returned by mono_sgen_alloc_os_memory (), returning it to the OS.
1843 mono_sgen_free_os_memory (void *addr, size_t size)
1845 mono_vfree (addr, size);
1847 total_alloc -= size;
1851 * Allocate and setup the data structures needed to be able to allocate objects
1852 * in the nursery. The nursery is stored in nursery_section.
1855 alloc_nursery (void)
1857 GCMemSection *section;
1862 if (nursery_section)
1864 DEBUG (2, fprintf (gc_debug_file, "Allocating nursery size: %lu\n", (unsigned long)nursery_size));
1865 /* later we will alloc a larger area for the nursery but only activate
1866 * what we need. The rest will be used as expansion if we have too many pinned
1867 * objects in the existing nursery.
1869 /* FIXME: handle OOM */
1870 section = mono_sgen_alloc_internal (INTERNAL_MEM_SECTION);
1872 g_assert (nursery_size == DEFAULT_NURSERY_SIZE);
1873 alloc_size = nursery_size;
1874 #ifdef SGEN_ALIGN_NURSERY
1875 data = major_collector.alloc_heap (alloc_size, alloc_size, DEFAULT_NURSERY_BITS);
1877 data = major_collector.alloc_heap (alloc_size, 0, DEFAULT_NURSERY_BITS);
1879 nursery_start = data;
1880 nursery_end = nursery_start + nursery_size;
1881 mono_sgen_update_heap_boundaries ((mword)nursery_start, (mword)nursery_end);
1882 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));
1883 section->data = section->next_data = data;
1884 section->size = alloc_size;
1885 section->end_data = nursery_end;
1886 scan_starts = (alloc_size + SCAN_START_SIZE - 1) / SCAN_START_SIZE;
1887 section->scan_starts = mono_sgen_alloc_internal_dynamic (sizeof (char*) * scan_starts, INTERNAL_MEM_SCAN_STARTS);
1888 section->num_scan_start = scan_starts;
1889 section->block.role = MEMORY_ROLE_GEN0;
1890 section->block.next = NULL;
1892 nursery_section = section;
1894 mono_sgen_nursery_allocator_set_nursery_bounds (nursery_start, nursery_end);
1898 mono_gc_get_nursery (int *shift_bits, size_t *size)
1900 *size = nursery_size;
1901 #ifdef SGEN_ALIGN_NURSERY
1902 *shift_bits = DEFAULT_NURSERY_BITS;
1906 return nursery_start;
1910 mono_gc_set_current_thread_appdomain (MonoDomain *domain)
1912 SgenThreadInfo *info = mono_thread_info_current ();
1914 /* Could be called from sgen_thread_unregister () with a NULL info */
1917 info->stopped_domain = domain;
1922 mono_gc_precise_stack_mark_enabled (void)
1924 return !conservative_stack_mark;
1928 mono_gc_get_logfile (void)
1930 return mono_sgen_get_logfile ();
1934 report_finalizer_roots_list (FinalizeReadyEntry *list)
1936 GCRootReport report;
1937 FinalizeReadyEntry *fin;
1940 for (fin = list; fin; fin = fin->next) {
1943 add_profile_gc_root (&report, fin->object, MONO_PROFILE_GC_ROOT_FINALIZER, 0);
1945 notify_gc_roots (&report);
1949 report_finalizer_roots (void)
1951 report_finalizer_roots_list (fin_ready_list);
1952 report_finalizer_roots_list (critical_fin_list);
1955 static GCRootReport *root_report;
1958 single_arg_report_root (void **obj)
1961 add_profile_gc_root (root_report, *obj, MONO_PROFILE_GC_ROOT_OTHER, 0);
1965 precisely_report_roots_from (GCRootReport *report, void** start_root, void** end_root, mword desc)
1967 switch (desc & ROOT_DESC_TYPE_MASK) {
1968 case ROOT_DESC_BITMAP:
1969 desc >>= ROOT_DESC_TYPE_SHIFT;
1971 if ((desc & 1) && *start_root) {
1972 add_profile_gc_root (report, *start_root, MONO_PROFILE_GC_ROOT_OTHER, 0);
1978 case ROOT_DESC_COMPLEX: {
1979 gsize *bitmap_data = mono_sgen_get_complex_descriptor_bitmap (desc);
1980 int bwords = (*bitmap_data) - 1;
1981 void **start_run = start_root;
1983 while (bwords-- > 0) {
1984 gsize bmap = *bitmap_data++;
1985 void **objptr = start_run;
1987 if ((bmap & 1) && *objptr) {
1988 add_profile_gc_root (report, *objptr, MONO_PROFILE_GC_ROOT_OTHER, 0);
1993 start_run += GC_BITS_PER_WORD;
1997 case ROOT_DESC_USER: {
1998 MonoGCRootMarkFunc marker = mono_sgen_get_user_descriptor_func (desc);
1999 root_report = report;
2000 marker (start_root, single_arg_report_root);
2003 case ROOT_DESC_RUN_LEN:
2004 g_assert_not_reached ();
2006 g_assert_not_reached ();
2011 report_registered_roots_by_type (int root_type)
2013 GCRootReport report;
2017 SGEN_HASH_TABLE_FOREACH (&roots_hash [root_type], start_root, root) {
2018 DEBUG (6, fprintf (gc_debug_file, "Precise root scan %p-%p (desc: %p)\n", start_root, root->end_root, (void*)root->root_desc));
2019 precisely_report_roots_from (&report, start_root, (void**)root->end_root, root->root_desc);
2020 } SGEN_HASH_TABLE_FOREACH_END;
2021 notify_gc_roots (&report);
2025 report_registered_roots (void)
2027 report_registered_roots_by_type (ROOT_TYPE_NORMAL);
2028 report_registered_roots_by_type (ROOT_TYPE_WBARRIER);
2032 scan_finalizer_entries (CopyOrMarkObjectFunc copy_func, FinalizeReadyEntry *list, GrayQueue *queue)
2034 FinalizeReadyEntry *fin;
2036 for (fin = list; fin; fin = fin->next) {
2039 DEBUG (5, fprintf (gc_debug_file, "Scan of fin ready object: %p (%s)\n", fin->object, safe_name (fin->object)));
2040 copy_func (&fin->object, queue);
2045 generation_name (int generation)
2047 switch (generation) {
2048 case GENERATION_NURSERY: return "nursery";
2049 case GENERATION_OLD: return "old";
2050 default: g_assert_not_reached ();
2056 stw_bridge_process (void)
2058 mono_sgen_bridge_processing_stw_step ();
2062 bridge_process (void)
2064 mono_sgen_bridge_processing_finish ();
2067 CopyOrMarkObjectFunc
2068 mono_sgen_get_copy_object (void)
2070 if (current_collection_generation == GENERATION_NURSERY) {
2071 if (mono_sgen_collection_is_parallel ())
2072 return major_collector.copy_object;
2074 return major_collector.nopar_copy_object;
2076 return major_collector.copy_or_mark_object;
2081 mono_sgen_get_minor_scan_object (void)
2083 g_assert (current_collection_generation == GENERATION_NURSERY);
2085 if (mono_sgen_collection_is_parallel ())
2086 return major_collector.minor_scan_object;
2088 return major_collector.nopar_minor_scan_object;
2092 mono_sgen_get_minor_scan_vtype (void)
2094 g_assert (current_collection_generation == GENERATION_NURSERY);
2096 if (mono_sgen_collection_is_parallel ())
2097 return major_collector.minor_scan_vtype;
2099 return major_collector.nopar_minor_scan_vtype;
2103 finish_gray_stack (char *start_addr, char *end_addr, int generation, GrayQueue *queue)
2108 int done_with_ephemerons, ephemeron_rounds = 0;
2110 CopyOrMarkObjectFunc copy_func = mono_sgen_get_copy_object ();
2113 * We copied all the reachable objects. Now it's the time to copy
2114 * the objects that were not referenced by the roots, but by the copied objects.
2115 * we built a stack of objects pointed to by gray_start: they are
2116 * additional roots and we may add more items as we go.
2117 * We loop until gray_start == gray_objects which means no more objects have
2118 * been added. Note this is iterative: no recursion is involved.
2119 * We need to walk the LO list as well in search of marked big objects
2120 * (use a flag since this is needed only on major collections). We need to loop
2121 * here as well, so keep a counter of marked LO (increasing it in copy_object).
2122 * To achieve better cache locality and cache usage, we drain the gray stack
2123 * frequently, after each object is copied, and just finish the work here.
2125 mono_sgen_drain_gray_stack (queue, -1);
2127 DEBUG (2, fprintf (gc_debug_file, "%s generation done\n", generation_name (generation)));
2130 Reset bridge data, we might have lingering data from a previous collection if this is a major
2131 collection trigged by minor overflow.
2133 We must reset the gathered bridges since their original block might be evacuated due to major
2134 fragmentation in the meanwhile and the bridge code should not have to deal with that.
2136 mono_sgen_bridge_reset_data ();
2139 * Walk the ephemeron tables marking all values with reachable keys. This must be completely done
2140 * before processing finalizable objects or non-tracking weak hamdle to avoid finalizing/clearing
2141 * objects that are in fact reachable.
2143 done_with_ephemerons = 0;
2145 done_with_ephemerons = mark_ephemerons_in_range (copy_func, start_addr, end_addr, queue);
2146 mono_sgen_drain_gray_stack (queue, -1);
2148 } while (!done_with_ephemerons);
2150 mono_sgen_scan_togglerefs (copy_func, start_addr, end_addr, queue);
2151 if (generation == GENERATION_OLD)
2152 mono_sgen_scan_togglerefs (copy_func, nursery_start, nursery_end, queue);
2154 if (mono_sgen_need_bridge_processing ()) {
2155 collect_bridge_objects (copy_func, start_addr, end_addr, generation, queue);
2156 if (generation == GENERATION_OLD)
2157 collect_bridge_objects (copy_func, nursery_start, nursery_end, GENERATION_NURSERY, queue);
2158 mono_sgen_drain_gray_stack (queue, -1);
2162 We must clear weak links that don't track resurrection before processing object ready for
2163 finalization so they can be cleared before that.
2165 null_link_in_range (copy_func, start_addr, end_addr, generation, TRUE, queue);
2166 if (generation == GENERATION_OLD)
2167 null_link_in_range (copy_func, start_addr, end_addr, GENERATION_NURSERY, TRUE, queue);
2170 /* walk the finalization queue and move also the objects that need to be
2171 * finalized: use the finalized objects as new roots so the objects they depend
2172 * on are also not reclaimed. As with the roots above, only objects in the nursery
2173 * are marked/copied.
2174 * We need a loop here, since objects ready for finalizers may reference other objects
2175 * that are fin-ready. Speedup with a flag?
2179 fin_ready = num_ready_finalizers;
2180 finalize_in_range (copy_func, start_addr, end_addr, generation, queue);
2181 if (generation == GENERATION_OLD)
2182 finalize_in_range (copy_func, nursery_start, nursery_end, GENERATION_NURSERY, queue);
2184 if (fin_ready != num_ready_finalizers)
2187 /* drain the new stack that might have been created */
2188 DEBUG (6, fprintf (gc_debug_file, "Precise scan of gray area post fin\n"));
2189 mono_sgen_drain_gray_stack (queue, -1);
2190 } while (fin_ready != num_ready_finalizers);
2192 if (mono_sgen_need_bridge_processing ())
2193 g_assert (num_loops <= 1);
2196 * This must be done again after processing finalizable objects since CWL slots are cleared only after the key is finalized.
2198 done_with_ephemerons = 0;
2200 done_with_ephemerons = mark_ephemerons_in_range (copy_func, start_addr, end_addr, queue);
2201 mono_sgen_drain_gray_stack (queue, -1);
2203 } while (!done_with_ephemerons);
2206 * Clear ephemeron pairs with unreachable keys.
2207 * We pass the copy func so we can figure out if an array was promoted or not.
2209 clear_unreachable_ephemerons (copy_func, start_addr, end_addr, queue);
2212 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));
2215 * handle disappearing links
2216 * Note we do this after checking the finalization queue because if an object
2217 * survives (at least long enough to be finalized) we don't clear the link.
2218 * This also deals with a possible issue with the monitor reclamation: with the Boehm
2219 * GC a finalized object my lose the monitor because it is cleared before the finalizer is
2222 g_assert (mono_sgen_gray_object_queue_is_empty (queue));
2224 null_link_in_range (copy_func, start_addr, end_addr, generation, FALSE, queue);
2225 if (generation == GENERATION_OLD)
2226 null_link_in_range (copy_func, start_addr, end_addr, GENERATION_NURSERY, FALSE, queue);
2227 if (mono_sgen_gray_object_queue_is_empty (queue))
2229 mono_sgen_drain_gray_stack (queue, -1);
2232 g_assert (mono_sgen_gray_object_queue_is_empty (queue));
2236 mono_sgen_check_section_scan_starts (GCMemSection *section)
2239 for (i = 0; i < section->num_scan_start; ++i) {
2240 if (section->scan_starts [i]) {
2241 guint size = safe_object_get_size ((MonoObject*) section->scan_starts [i]);
2242 g_assert (size >= sizeof (MonoObject) && size <= MAX_SMALL_OBJ_SIZE);
2248 check_scan_starts (void)
2250 if (!do_scan_starts_check)
2252 mono_sgen_check_section_scan_starts (nursery_section);
2253 major_collector.check_scan_starts ();
2257 scan_from_registered_roots (CopyOrMarkObjectFunc copy_func, char *addr_start, char *addr_end, int root_type, GrayQueue *queue)
2261 SGEN_HASH_TABLE_FOREACH (&roots_hash [root_type], start_root, root) {
2262 DEBUG (6, fprintf (gc_debug_file, "Precise root scan %p-%p (desc: %p)\n", start_root, root->end_root, (void*)root->root_desc));
2263 precisely_scan_objects_from (copy_func, start_root, (void**)root->end_root, addr_start, addr_end, root->root_desc, queue);
2264 } SGEN_HASH_TABLE_FOREACH_END;
2268 mono_sgen_dump_occupied (char *start, char *end, char *section_start)
2270 fprintf (heap_dump_file, "<occupied offset=\"%td\" size=\"%td\"/>\n", start - section_start, end - start);
2274 mono_sgen_dump_section (GCMemSection *section, const char *type)
2276 char *start = section->data;
2277 char *end = section->data + section->size;
2278 char *occ_start = NULL;
2280 char *old_start = NULL; /* just for debugging */
2282 fprintf (heap_dump_file, "<section type=\"%s\" size=\"%lu\">\n", type, (unsigned long)section->size);
2284 while (start < end) {
2288 if (!*(void**)start) {
2290 mono_sgen_dump_occupied (occ_start, start, section->data);
2293 start += sizeof (void*); /* should be ALLOC_ALIGN, really */
2296 g_assert (start < section->next_data);
2301 vt = (GCVTable*)LOAD_VTABLE (start);
2304 size = ALIGN_UP (safe_object_get_size ((MonoObject*) start));
2307 fprintf (heap_dump_file, "<object offset=\"%d\" class=\"%s.%s\" size=\"%d\"/>\n",
2308 start - section->data,
2309 vt->klass->name_space, vt->klass->name,
2317 mono_sgen_dump_occupied (occ_start, start, section->data);
2319 fprintf (heap_dump_file, "</section>\n");
2323 dump_object (MonoObject *obj, gboolean dump_location)
2325 static char class_name [1024];
2327 MonoClass *class = mono_object_class (obj);
2331 * Python's XML parser is too stupid to parse angle brackets
2332 * in strings, so we just ignore them;
2335 while (class->name [i] && j < sizeof (class_name) - 1) {
2336 if (!strchr ("<>\"", class->name [i]))
2337 class_name [j++] = class->name [i];
2340 g_assert (j < sizeof (class_name));
2343 fprintf (heap_dump_file, "<object class=\"%s.%s\" size=\"%d\"",
2344 class->name_space, class_name,
2345 safe_object_get_size (obj));
2346 if (dump_location) {
2347 const char *location;
2348 if (ptr_in_nursery (obj))
2349 location = "nursery";
2350 else if (safe_object_get_size (obj) <= MAX_SMALL_OBJ_SIZE)
2354 fprintf (heap_dump_file, " location=\"%s\"", location);
2356 fprintf (heap_dump_file, "/>\n");
2360 dump_heap (const char *type, int num, const char *reason)
2365 fprintf (heap_dump_file, "<collection type=\"%s\" num=\"%d\"", type, num);
2367 fprintf (heap_dump_file, " reason=\"%s\"", reason);
2368 fprintf (heap_dump_file, ">\n");
2369 fprintf (heap_dump_file, "<other-mem-usage type=\"mempools\" size=\"%ld\"/>\n", mono_mempool_get_bytes_allocated ());
2370 mono_sgen_dump_internal_mem_usage (heap_dump_file);
2371 fprintf (heap_dump_file, "<pinned type=\"stack\" bytes=\"%zu\"/>\n", mono_sgen_pin_stats_get_pinned_byte_count (PIN_TYPE_STACK));
2372 /* fprintf (heap_dump_file, "<pinned type=\"static-data\" bytes=\"%d\"/>\n", pinned_byte_counts [PIN_TYPE_STATIC_DATA]); */
2373 fprintf (heap_dump_file, "<pinned type=\"other\" bytes=\"%zu\"/>\n", mono_sgen_pin_stats_get_pinned_byte_count (PIN_TYPE_OTHER));
2375 fprintf (heap_dump_file, "<pinned-objects>\n");
2376 for (list = mono_sgen_pin_stats_get_object_list (); list; list = list->next)
2377 dump_object (list->obj, TRUE);
2378 fprintf (heap_dump_file, "</pinned-objects>\n");
2380 mono_sgen_dump_section (nursery_section, "nursery");
2382 major_collector.dump_heap (heap_dump_file);
2384 fprintf (heap_dump_file, "<los>\n");
2385 for (bigobj = los_object_list; bigobj; bigobj = bigobj->next)
2386 dump_object ((MonoObject*)bigobj->data, FALSE);
2387 fprintf (heap_dump_file, "</los>\n");
2389 fprintf (heap_dump_file, "</collection>\n");
2393 mono_sgen_register_moved_object (void *obj, void *destination)
2395 g_assert (mono_profiler_events & MONO_PROFILE_GC_MOVES);
2397 /* FIXME: handle this for parallel collector */
2398 g_assert (!mono_sgen_collection_is_parallel ());
2400 if (moved_objects_idx == MOVED_OBJECTS_NUM) {
2401 mono_profiler_gc_moves (moved_objects, moved_objects_idx);
2402 moved_objects_idx = 0;
2404 moved_objects [moved_objects_idx++] = obj;
2405 moved_objects [moved_objects_idx++] = destination;
2411 static gboolean inited = FALSE;
2416 mono_counters_register ("Minor fragment clear", MONO_COUNTER_GC | MONO_COUNTER_LONG, &time_minor_pre_collection_fragment_clear);
2417 mono_counters_register ("Minor pinning", MONO_COUNTER_GC | MONO_COUNTER_LONG, &time_minor_pinning);
2418 mono_counters_register ("Minor scan remsets", MONO_COUNTER_GC | MONO_COUNTER_LONG, &time_minor_scan_remsets);
2419 mono_counters_register ("Minor scan cardtables", MONO_COUNTER_GC | MONO_COUNTER_LONG, &time_minor_scan_card_table);
2420 mono_counters_register ("Minor scan pinned", MONO_COUNTER_GC | MONO_COUNTER_LONG, &time_minor_scan_pinned);
2421 mono_counters_register ("Minor scan registered roots", MONO_COUNTER_GC | MONO_COUNTER_LONG, &time_minor_scan_registered_roots);
2422 mono_counters_register ("Minor scan thread data", MONO_COUNTER_GC | MONO_COUNTER_LONG, &time_minor_scan_thread_data);
2423 mono_counters_register ("Minor finish gray stack", MONO_COUNTER_GC | MONO_COUNTER_LONG, &time_minor_finish_gray_stack);
2424 mono_counters_register ("Minor fragment creation", MONO_COUNTER_GC | MONO_COUNTER_LONG, &time_minor_fragment_creation);
2426 mono_counters_register ("Major fragment clear", MONO_COUNTER_GC | MONO_COUNTER_LONG, &time_major_pre_collection_fragment_clear);
2427 mono_counters_register ("Major pinning", MONO_COUNTER_GC | MONO_COUNTER_LONG, &time_major_pinning);
2428 mono_counters_register ("Major scan pinned", MONO_COUNTER_GC | MONO_COUNTER_LONG, &time_major_scan_pinned);
2429 mono_counters_register ("Major scan registered roots", MONO_COUNTER_GC | MONO_COUNTER_LONG, &time_major_scan_registered_roots);
2430 mono_counters_register ("Major scan thread data", MONO_COUNTER_GC | MONO_COUNTER_LONG, &time_major_scan_thread_data);
2431 mono_counters_register ("Major scan alloc_pinned", MONO_COUNTER_GC | MONO_COUNTER_LONG, &time_major_scan_alloc_pinned);
2432 mono_counters_register ("Major scan finalized", MONO_COUNTER_GC | MONO_COUNTER_LONG, &time_major_scan_finalized);
2433 mono_counters_register ("Major scan big objects", MONO_COUNTER_GC | MONO_COUNTER_LONG, &time_major_scan_big_objects);
2434 mono_counters_register ("Major finish gray stack", MONO_COUNTER_GC | MONO_COUNTER_LONG, &time_major_finish_gray_stack);
2435 mono_counters_register ("Major free big objects", MONO_COUNTER_GC | MONO_COUNTER_LONG, &time_major_free_bigobjs);
2436 mono_counters_register ("Major LOS sweep", MONO_COUNTER_GC | MONO_COUNTER_LONG, &time_major_los_sweep);
2437 mono_counters_register ("Major sweep", MONO_COUNTER_GC | MONO_COUNTER_LONG, &time_major_sweep);
2438 mono_counters_register ("Major fragment creation", MONO_COUNTER_GC | MONO_COUNTER_LONG, &time_major_fragment_creation);
2440 mono_counters_register ("Number of pinned objects", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_pinned_objects);
2442 #ifdef HEAVY_STATISTICS
2443 mono_counters_register ("WBarrier set field", MONO_COUNTER_GC | MONO_COUNTER_INT, &stat_wbarrier_set_field);
2444 mono_counters_register ("WBarrier set arrayref", MONO_COUNTER_GC | MONO_COUNTER_INT, &stat_wbarrier_set_arrayref);
2445 mono_counters_register ("WBarrier arrayref copy", MONO_COUNTER_GC | MONO_COUNTER_INT, &stat_wbarrier_arrayref_copy);
2446 mono_counters_register ("WBarrier generic store called", MONO_COUNTER_GC | MONO_COUNTER_INT, &stat_wbarrier_generic_store);
2447 mono_counters_register ("WBarrier generic store stored", MONO_COUNTER_GC | MONO_COUNTER_INT, &stat_wbarrier_generic_store_remset);
2448 mono_counters_register ("WBarrier set root", MONO_COUNTER_GC | MONO_COUNTER_INT, &stat_wbarrier_set_root);
2449 mono_counters_register ("WBarrier value copy", MONO_COUNTER_GC | MONO_COUNTER_INT, &stat_wbarrier_value_copy);
2450 mono_counters_register ("WBarrier object copy", MONO_COUNTER_GC | MONO_COUNTER_INT, &stat_wbarrier_object_copy);
2452 mono_counters_register ("# objects allocated", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_objects_alloced);
2453 mono_counters_register ("bytes allocated", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_bytes_alloced);
2454 mono_counters_register ("# objects allocated degraded", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_objects_alloced_degraded);
2455 mono_counters_register ("bytes allocated degraded", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_bytes_alloced_degraded);
2456 mono_counters_register ("bytes allocated in LOS", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_bytes_alloced_los);
2458 mono_counters_register ("# copy_object() called (nursery)", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_copy_object_called_nursery);
2459 mono_counters_register ("# objects copied (nursery)", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_objects_copied_nursery);
2460 mono_counters_register ("# copy_object() called (major)", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_copy_object_called_major);
2461 mono_counters_register ("# objects copied (major)", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_objects_copied_major);
2463 mono_counters_register ("# scan_object() called (nursery)", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_scan_object_called_nursery);
2464 mono_counters_register ("# scan_object() called (major)", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_scan_object_called_major);
2466 mono_counters_register ("# nursery copy_object() failed from space", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_nursery_copy_object_failed_from_space);
2467 mono_counters_register ("# nursery copy_object() failed forwarded", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_nursery_copy_object_failed_forwarded);
2468 mono_counters_register ("# nursery copy_object() failed pinned", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_nursery_copy_object_failed_pinned);
2470 mono_sgen_nursery_allocator_init_heavy_stats ();
2472 mono_counters_register ("Store remsets", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_store_remsets);
2473 mono_counters_register ("Unique store remsets", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_store_remsets_unique);
2474 mono_counters_register ("Saved remsets 1", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_saved_remsets_1);
2475 mono_counters_register ("Saved remsets 2", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_saved_remsets_2);
2476 mono_counters_register ("Non-global remsets processed", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_local_remsets_processed);
2477 mono_counters_register ("Global remsets added", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_global_remsets_added);
2478 mono_counters_register ("Global remsets re-added", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_global_remsets_readded);
2479 mono_counters_register ("Global remsets processed", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_global_remsets_processed);
2480 mono_counters_register ("Global remsets discarded", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_global_remsets_discarded);
2486 static gboolean need_calculate_minor_collection_allowance;
2488 static int last_collection_old_num_major_sections;
2489 static mword last_collection_los_memory_usage = 0;
2490 static mword last_collection_old_los_memory_usage;
2491 static mword last_collection_los_memory_alloced;
2494 reset_minor_collection_allowance (void)
2496 need_calculate_minor_collection_allowance = TRUE;
2500 try_calculate_minor_collection_allowance (gboolean overwrite)
2502 int num_major_sections, num_major_sections_saved, save_target, allowance_target;
2503 mword los_memory_saved, new_major, new_heap_size;
2506 g_assert (need_calculate_minor_collection_allowance);
2508 if (!need_calculate_minor_collection_allowance)
2511 if (!*major_collector.have_swept) {
2513 minor_collection_allowance = MIN_MINOR_COLLECTION_ALLOWANCE;
2517 num_major_sections = major_collector.get_num_major_sections ();
2519 num_major_sections_saved = MAX (last_collection_old_num_major_sections - num_major_sections, 0);
2520 los_memory_saved = MAX (last_collection_old_los_memory_usage - last_collection_los_memory_usage, 1);
2522 new_major = num_major_sections * major_collector.section_size;
2523 new_heap_size = new_major + last_collection_los_memory_usage;
2526 * FIXME: Why is save_target half the major memory plus half the
2527 * LOS memory saved? Shouldn't it be half the major memory
2528 * saved plus half the LOS memory saved? Or half the whole heap
2531 save_target = (new_major + los_memory_saved) / 2;
2534 * We aim to allow the allocation of as many sections as is
2535 * necessary to reclaim save_target sections in the next
2536 * collection. We assume the collection pattern won't change.
2537 * In the last cycle, we had num_major_sections_saved for
2538 * minor_collection_sections_alloced. Assuming things won't
2539 * change, this must be the same ratio as save_target for
2540 * allowance_target, i.e.
2542 * num_major_sections_saved save_target
2543 * --------------------------------- == ----------------
2544 * minor_collection_sections_alloced allowance_target
2548 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));
2550 minor_collection_allowance = MAX (MIN (allowance_target, num_major_sections * major_collector.section_size + los_memory_usage), MIN_MINOR_COLLECTION_ALLOWANCE);
2552 if (new_heap_size + minor_collection_allowance > soft_heap_limit) {
2553 if (new_heap_size > soft_heap_limit)
2554 minor_collection_allowance = MIN_MINOR_COLLECTION_ALLOWANCE;
2556 minor_collection_allowance = MAX (soft_heap_limit - new_heap_size, MIN_MINOR_COLLECTION_ALLOWANCE);
2559 if (debug_print_allowance) {
2560 mword old_major = last_collection_old_num_major_sections * major_collector.section_size;
2562 fprintf (gc_debug_file, "Before collection: %ld bytes (%ld major, %ld LOS)\n",
2563 old_major + last_collection_old_los_memory_usage, old_major, last_collection_old_los_memory_usage);
2564 fprintf (gc_debug_file, "After collection: %ld bytes (%ld major, %ld LOS)\n",
2565 new_heap_size, new_major, last_collection_los_memory_usage);
2566 fprintf (gc_debug_file, "Allowance: %ld bytes\n", minor_collection_allowance);
2569 if (major_collector.have_computed_minor_collection_allowance)
2570 major_collector.have_computed_minor_collection_allowance ();
2572 need_calculate_minor_collection_allowance = FALSE;
2576 need_major_collection (mword space_needed)
2578 mword los_alloced = los_memory_usage - MIN (last_collection_los_memory_usage, los_memory_usage);
2579 return (space_needed > available_free_space ()) ||
2580 minor_collection_sections_alloced * major_collector.section_size + los_alloced > minor_collection_allowance;
2584 mono_sgen_need_major_collection (mword space_needed)
2586 return need_major_collection (space_needed);
2590 reset_pinned_from_failed_allocation (void)
2592 bytes_pinned_from_failed_allocation = 0;
2596 mono_sgen_set_pinned_from_failed_allocation (mword objsize)
2598 bytes_pinned_from_failed_allocation += objsize;
2602 mono_sgen_collection_is_parallel (void)
2604 switch (current_collection_generation) {
2605 case GENERATION_NURSERY:
2606 return nursery_collection_is_parallel;
2607 case GENERATION_OLD:
2608 return major_collector.is_parallel;
2610 g_assert_not_reached ();
2615 mono_sgen_nursery_collection_is_parallel (void)
2617 return nursery_collection_is_parallel;
2624 } ScanFromRemsetsJobData;
2627 job_scan_from_remsets (WorkerData *worker_data, void *job_data_untyped)
2629 ScanFromRemsetsJobData *job_data = job_data_untyped;
2631 scan_from_remsets (job_data->heap_start, job_data->heap_end, mono_sgen_workers_get_job_gray_queue (worker_data));
2636 CopyOrMarkObjectFunc func;
2640 } ScanFromRegisteredRootsJobData;
2643 job_scan_from_registered_roots (WorkerData *worker_data, void *job_data_untyped)
2645 ScanFromRegisteredRootsJobData *job_data = job_data_untyped;
2647 scan_from_registered_roots (job_data->func,
2648 job_data->heap_start, job_data->heap_end,
2649 job_data->root_type,
2650 mono_sgen_workers_get_job_gray_queue (worker_data));
2657 } ScanThreadDataJobData;
2660 job_scan_thread_data (WorkerData *worker_data, void *job_data_untyped)
2662 ScanThreadDataJobData *job_data = job_data_untyped;
2664 scan_thread_data (job_data->heap_start, job_data->heap_end, TRUE,
2665 mono_sgen_workers_get_job_gray_queue (worker_data));
2669 verify_scan_starts (char *start, char *end)
2673 for (i = 0; i < nursery_section->num_scan_start; ++i) {
2674 char *addr = nursery_section->scan_starts [i];
2675 if (addr > start && addr < end)
2676 fprintf (gc_debug_file, "NFC-BAD SCAN START [%d] %p for obj [%p %p]\n", i, addr, start, end);
2681 verify_nursery (void)
2683 char *start, *end, *cur, *hole_start;
2685 if (!do_verify_nursery)
2688 /*This cleans up unused fragments */
2689 mono_sgen_nursery_allocator_prepare_for_pinning ();
2691 hole_start = start = cur = nursery_start;
2697 if (!*(void**)cur) {
2698 cur += sizeof (void*);
2702 if (object_is_forwarded (cur))
2703 fprintf (gc_debug_file, "FORWARDED OBJ %p\n", cur);
2704 else if (object_is_pinned (cur))
2705 fprintf (gc_debug_file, "PINNED OBJ %p\n", cur);
2707 ss = safe_object_get_size ((MonoObject*)cur);
2708 size = ALIGN_UP (safe_object_get_size ((MonoObject*)cur));
2709 verify_scan_starts (cur, cur + size);
2710 if (do_dump_nursery_content) {
2711 if (cur > hole_start)
2712 fprintf (gc_debug_file, "HOLE [%p %p %d]\n", hole_start, cur, (int)(cur - hole_start));
2713 fprintf (gc_debug_file, "OBJ [%p %p %d %d %s %d]\n", cur, cur + size, (int)size, (int)ss, mono_sgen_safe_name ((MonoObject*)cur), (gpointer)LOAD_VTABLE (cur) == mono_sgen_get_array_fill_vtable ());
2718 fflush (gc_debug_file);
2722 * Collect objects in the nursery. Returns whether to trigger a major
2726 collect_nursery (size_t requested_size)
2728 gboolean needs_major;
2729 size_t max_garbage_amount;
2731 ScanFromRemsetsJobData sfrjd;
2732 ScanFromRegisteredRootsJobData scrrjd_normal, scrrjd_wbarrier;
2733 ScanThreadDataJobData stdjd;
2734 mword fragment_total;
2735 TV_DECLARE (all_atv);
2736 TV_DECLARE (all_btv);
2740 if (disable_minor_collections)
2745 mono_perfcounters->gc_collections0++;
2747 current_collection_generation = GENERATION_NURSERY;
2749 reset_pinned_from_failed_allocation ();
2751 binary_protocol_collection (GENERATION_NURSERY);
2752 check_scan_starts ();
2756 nursery_next = mono_sgen_nursery_alloc_get_upper_alloc_bound ();
2757 /* FIXME: optimize later to use the higher address where an object can be present */
2758 nursery_next = MAX (nursery_next, nursery_end);
2760 nursery_alloc_bound = nursery_next;
2762 DEBUG (1, fprintf (gc_debug_file, "Start nursery collection %d %p-%p, size: %d\n", stat_minor_gcs, nursery_start, nursery_next, (int)(nursery_next - nursery_start)));
2763 max_garbage_amount = nursery_next - nursery_start;
2764 g_assert (nursery_section->size >= max_garbage_amount);
2766 /* world must be stopped already */
2767 TV_GETTIME (all_atv);
2770 /* Pinning no longer depends on clearing all nursery fragments */
2771 mono_sgen_clear_current_nursery_fragment ();
2774 time_minor_pre_collection_fragment_clear += TV_ELAPSED_MS (atv, btv);
2777 check_for_xdomain_refs ();
2779 nursery_section->next_data = nursery_next;
2781 major_collector.start_nursery_collection ();
2783 try_calculate_minor_collection_allowance (FALSE);
2785 mono_sgen_gray_object_queue_init (&gray_queue);
2786 mono_sgen_workers_init_distribute_gray_queue ();
2789 mono_stats.minor_gc_count ++;
2791 global_remset_cache_clear ();
2793 process_fin_stage_entries ();
2794 process_dislink_stage_entries ();
2796 /* pin from pinned handles */
2797 mono_sgen_init_pinning ();
2798 mono_profiler_gc_event (MONO_GC_EVENT_MARK_START, 0);
2799 pin_from_roots (nursery_start, nursery_next, WORKERS_DISTRIBUTE_GRAY_QUEUE);
2800 /* identify pinned objects */
2801 mono_sgen_optimize_pin_queue (0);
2802 mono_sgen_pinning_setup_section (nursery_section);
2803 mono_sgen_pin_objects_in_section (nursery_section, WORKERS_DISTRIBUTE_GRAY_QUEUE);
2806 time_minor_pinning += TV_ELAPSED_MS (btv, atv);
2807 DEBUG (2, fprintf (gc_debug_file, "Finding pinned pointers: %d in %d usecs\n", mono_sgen_get_pinned_count (), TV_ELAPSED (btv, atv)));
2808 DEBUG (4, fprintf (gc_debug_file, "Start scan with %d pinned objects\n", mono_sgen_get_pinned_count ()));
2810 if (consistency_check_at_minor_collection)
2811 mono_sgen_check_consistency ();
2813 mono_sgen_workers_start_all_workers ();
2816 * Walk all the roots and copy the young objects to the old
2817 * generation, starting from to_space.
2819 * The global remsets must be processed before the workers start
2820 * marking because they might add global remsets.
2822 scan_from_global_remsets (nursery_start, nursery_next, WORKERS_DISTRIBUTE_GRAY_QUEUE);
2824 mono_sgen_workers_start_marking ();
2826 sfrjd.heap_start = nursery_start;
2827 sfrjd.heap_end = nursery_next;
2828 mono_sgen_workers_enqueue_job (job_scan_from_remsets, &sfrjd);
2830 /* we don't have complete write barrier yet, so we scan all the old generation sections */
2832 time_minor_scan_remsets += TV_ELAPSED_MS (atv, btv);
2833 DEBUG (2, fprintf (gc_debug_file, "Old generation scan: %d usecs\n", TV_ELAPSED (atv, btv)));
2835 if (use_cardtable) {
2837 sgen_card_tables_collect_stats (TRUE);
2838 sgen_scan_from_card_tables (nursery_start, nursery_next, WORKERS_DISTRIBUTE_GRAY_QUEUE);
2840 time_minor_scan_card_table += TV_ELAPSED_MS (atv, btv);
2843 if (!mono_sgen_collection_is_parallel ())
2844 mono_sgen_drain_gray_stack (&gray_queue, -1);
2846 if (mono_profiler_get_events () & MONO_PROFILE_GC_ROOTS)
2847 report_registered_roots ();
2848 if (mono_profiler_get_events () & MONO_PROFILE_GC_ROOTS)
2849 report_finalizer_roots ();
2851 time_minor_scan_pinned += TV_ELAPSED_MS (btv, atv);
2853 /* registered roots, this includes static fields */
2854 scrrjd_normal.func = mono_sgen_collection_is_parallel () ? major_collector.copy_object : major_collector.nopar_copy_object;
2855 scrrjd_normal.heap_start = nursery_start;
2856 scrrjd_normal.heap_end = nursery_next;
2857 scrrjd_normal.root_type = ROOT_TYPE_NORMAL;
2858 mono_sgen_workers_enqueue_job (job_scan_from_registered_roots, &scrrjd_normal);
2860 scrrjd_wbarrier.func = mono_sgen_collection_is_parallel () ? major_collector.copy_object : major_collector.nopar_copy_object;
2861 scrrjd_wbarrier.heap_start = nursery_start;
2862 scrrjd_wbarrier.heap_end = nursery_next;
2863 scrrjd_wbarrier.root_type = ROOT_TYPE_WBARRIER;
2864 mono_sgen_workers_enqueue_job (job_scan_from_registered_roots, &scrrjd_wbarrier);
2867 time_minor_scan_registered_roots += TV_ELAPSED_MS (atv, btv);
2870 stdjd.heap_start = nursery_start;
2871 stdjd.heap_end = nursery_next;
2872 mono_sgen_workers_enqueue_job (job_scan_thread_data, &stdjd);
2875 time_minor_scan_thread_data += TV_ELAPSED_MS (btv, atv);
2878 if (mono_sgen_collection_is_parallel ()) {
2879 while (!mono_sgen_gray_object_queue_is_empty (WORKERS_DISTRIBUTE_GRAY_QUEUE)) {
2880 mono_sgen_workers_distribute_gray_queue_sections ();
2884 mono_sgen_workers_join ();
2886 if (mono_sgen_collection_is_parallel ())
2887 g_assert (mono_sgen_gray_object_queue_is_empty (&gray_queue));
2889 finish_gray_stack (nursery_start, nursery_next, GENERATION_NURSERY, &gray_queue);
2891 time_minor_finish_gray_stack += TV_ELAPSED_MS (btv, atv);
2892 mono_profiler_gc_event (MONO_GC_EVENT_MARK_END, 0);
2895 * The (single-threaded) finalization code might have done
2896 * some copying/marking so we can only reset the GC thread's
2897 * worker data here instead of earlier when we joined the
2900 mono_sgen_workers_reset_data ();
2902 if (objects_pinned) {
2903 mono_sgen_optimize_pin_queue (0);
2904 mono_sgen_pinning_setup_section (nursery_section);
2907 /* walk the pin_queue, build up the fragment list of free memory, unmark
2908 * pinned objects as we go, memzero() the empty fragments so they are ready for the
2911 mono_profiler_gc_event (MONO_GC_EVENT_RECLAIM_START, 0);
2912 fragment_total = mono_sgen_build_nursery_fragments (nursery_section, nursery_section->pin_queue_start, nursery_section->pin_queue_num_entries);
2913 if (!fragment_total)
2916 /* Clear TLABs for all threads */
2917 mono_sgen_clear_tlabs ();
2919 mono_profiler_gc_event (MONO_GC_EVENT_RECLAIM_END, 0);
2921 time_minor_fragment_creation += TV_ELAPSED_MS (atv, btv);
2922 DEBUG (2, fprintf (gc_debug_file, "Fragment creation: %d usecs, %lu bytes available\n", TV_ELAPSED (atv, btv), (unsigned long)fragment_total));
2924 if (consistency_check_at_minor_collection)
2925 mono_sgen_check_major_refs ();
2927 major_collector.finish_nursery_collection ();
2929 TV_GETTIME (all_btv);
2930 mono_stats.minor_gc_time_usecs += TV_ELAPSED (all_atv, all_btv);
2933 dump_heap ("minor", stat_minor_gcs - 1, NULL);
2935 /* prepare the pin queue for the next collection */
2936 mono_sgen_finish_pinning ();
2937 if (fin_ready_list || critical_fin_list) {
2938 DEBUG (4, fprintf (gc_debug_file, "Finalizer-thread wakeup: ready %d\n", num_ready_finalizers));
2939 mono_gc_finalize_notify ();
2941 mono_sgen_pin_stats_reset ();
2943 g_assert (mono_sgen_gray_object_queue_is_empty (&gray_queue));
2946 sgen_card_tables_collect_stats (FALSE);
2948 check_scan_starts ();
2950 binary_protocol_flush_buffers (FALSE);
2952 /*objects are late pinned because of lack of memory, so a major is a good call*/
2953 needs_major = need_major_collection (0) || objects_pinned;
2954 current_collection_generation = -1;
2961 mono_sgen_collect_nursery_no_lock (size_t requested_size)
2963 gint64 gc_start_time;
2965 mono_profiler_gc_event (MONO_GC_EVENT_START, 0);
2966 gc_start_time = mono_100ns_ticks ();
2969 collect_nursery (requested_size);
2972 mono_trace_message (MONO_TRACE_GC, "minor gc took %d usecs", (mono_100ns_ticks () - gc_start_time) / 10);
2973 mono_profiler_gc_event (MONO_GC_EVENT_END, 0);
2978 FinalizeReadyEntry *list;
2979 } ScanFinalizerEntriesJobData;
2982 job_scan_finalizer_entries (WorkerData *worker_data, void *job_data_untyped)
2984 ScanFinalizerEntriesJobData *job_data = job_data_untyped;
2986 scan_finalizer_entries (major_collector.copy_or_mark_object,
2988 mono_sgen_workers_get_job_gray_queue (worker_data));
2992 major_do_collection (const char *reason)
2994 LOSObject *bigobj, *prevbo;
2995 TV_DECLARE (all_atv);
2996 TV_DECLARE (all_btv);
2999 /* FIXME: only use these values for the precise scan
3000 * note that to_space pointers should be excluded anyway...
3002 char *heap_start = NULL;
3003 char *heap_end = (char*)-1;
3004 int old_next_pin_slot;
3005 ScanFromRegisteredRootsJobData scrrjd_normal, scrrjd_wbarrier;
3006 ScanThreadDataJobData stdjd;
3007 ScanFinalizerEntriesJobData sfejd_fin_ready, sfejd_critical_fin;
3009 mono_perfcounters->gc_collections1++;
3011 reset_pinned_from_failed_allocation ();
3013 last_collection_old_num_major_sections = major_collector.get_num_major_sections ();
3016 * A domain could have been freed, resulting in
3017 * los_memory_usage being less than last_collection_los_memory_usage.
3019 last_collection_los_memory_alloced = los_memory_usage - MIN (last_collection_los_memory_usage, los_memory_usage);
3020 last_collection_old_los_memory_usage = los_memory_usage;
3023 //count_ref_nonref_objs ();
3024 //consistency_check ();
3026 binary_protocol_collection (GENERATION_OLD);
3027 check_scan_starts ();
3028 mono_sgen_gray_object_queue_init (&gray_queue);
3029 mono_sgen_workers_init_distribute_gray_queue ();
3032 DEBUG (1, fprintf (gc_debug_file, "Start major collection %d\n", stat_major_gcs));
3034 mono_stats.major_gc_count ++;
3036 /* world must be stopped already */
3037 TV_GETTIME (all_atv);
3040 /* Pinning depends on this */
3041 mono_sgen_clear_nursery_fragments ();
3044 time_major_pre_collection_fragment_clear += TV_ELAPSED_MS (atv, btv);
3046 nursery_section->next_data = nursery_end;
3047 /* we should also coalesce scanning from sections close to each other
3048 * and deal with pointers outside of the sections later.
3051 if (major_collector.start_major_collection)
3052 major_collector.start_major_collection ();
3054 *major_collector.have_swept = FALSE;
3055 reset_minor_collection_allowance ();
3058 check_for_xdomain_refs ();
3060 /* The remsets are not useful for a major collection */
3062 global_remset_cache_clear ();
3064 sgen_card_table_clear ();
3066 process_fin_stage_entries ();
3067 process_dislink_stage_entries ();
3070 mono_sgen_init_pinning ();
3071 DEBUG (6, fprintf (gc_debug_file, "Collecting pinned addresses\n"));
3072 pin_from_roots ((void*)lowest_heap_address, (void*)highest_heap_address, WORKERS_DISTRIBUTE_GRAY_QUEUE);
3073 mono_sgen_optimize_pin_queue (0);
3076 * pin_queue now contains all candidate pointers, sorted and
3077 * uniqued. We must do two passes now to figure out which
3078 * objects are pinned.
3080 * The first is to find within the pin_queue the area for each
3081 * section. This requires that the pin_queue be sorted. We
3082 * also process the LOS objects and pinned chunks here.
3084 * The second, destructive, pass is to reduce the section
3085 * areas to pointers to the actually pinned objects.
3087 DEBUG (6, fprintf (gc_debug_file, "Pinning from sections\n"));
3088 /* first pass for the sections */
3089 mono_sgen_find_section_pin_queue_start_end (nursery_section);
3090 major_collector.find_pin_queue_start_ends (WORKERS_DISTRIBUTE_GRAY_QUEUE);
3091 /* identify possible pointers to the insize of large objects */
3092 DEBUG (6, fprintf (gc_debug_file, "Pinning from large objects\n"));
3093 for (bigobj = los_object_list; bigobj; bigobj = bigobj->next) {
3095 gboolean profile_roots = mono_profiler_get_events () & MONO_PROFILE_GC_ROOTS;
3096 GCRootReport report;
3098 if (mono_sgen_find_optimized_pin_queue_area (bigobj->data, (char*)bigobj->data + bigobj->size, &dummy)) {
3099 binary_protocol_pin (bigobj->data, (gpointer)LOAD_VTABLE (bigobj->data), safe_object_get_size (bigobj->data));
3100 pin_object (bigobj->data);
3101 /* FIXME: only enqueue if object has references */
3102 GRAY_OBJECT_ENQUEUE (WORKERS_DISTRIBUTE_GRAY_QUEUE, bigobj->data);
3103 if (G_UNLIKELY (do_pin_stats))
3104 mono_sgen_pin_stats_register_object ((char*) bigobj->data, safe_object_get_size ((MonoObject*) bigobj->data));
3105 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));
3108 add_profile_gc_root (&report, bigobj->data, MONO_PROFILE_GC_ROOT_PINNING | MONO_PROFILE_GC_ROOT_MISC, 0);
3111 notify_gc_roots (&report);
3113 /* second pass for the sections */
3114 mono_sgen_pin_objects_in_section (nursery_section, WORKERS_DISTRIBUTE_GRAY_QUEUE);
3115 major_collector.pin_objects (WORKERS_DISTRIBUTE_GRAY_QUEUE);
3116 old_next_pin_slot = mono_sgen_get_pinned_count ();
3119 time_major_pinning += TV_ELAPSED_MS (atv, btv);
3120 DEBUG (2, fprintf (gc_debug_file, "Finding pinned pointers: %d in %d usecs\n", mono_sgen_get_pinned_count (), TV_ELAPSED (atv, btv)));
3121 DEBUG (4, fprintf (gc_debug_file, "Start scan with %d pinned objects\n", mono_sgen_get_pinned_count ()));
3123 major_collector.init_to_space ();
3125 #ifdef SGEN_DEBUG_INTERNAL_ALLOC
3126 main_gc_thread = mono_native_thread_self ();
3129 mono_sgen_workers_start_all_workers ();
3130 mono_sgen_workers_start_marking ();
3132 if (mono_profiler_get_events () & MONO_PROFILE_GC_ROOTS)
3133 report_registered_roots ();
3135 time_major_scan_pinned += TV_ELAPSED_MS (btv, atv);
3137 /* registered roots, this includes static fields */
3138 scrrjd_normal.func = major_collector.copy_or_mark_object;
3139 scrrjd_normal.heap_start = heap_start;
3140 scrrjd_normal.heap_end = heap_end;
3141 scrrjd_normal.root_type = ROOT_TYPE_NORMAL;
3142 mono_sgen_workers_enqueue_job (job_scan_from_registered_roots, &scrrjd_normal);
3144 scrrjd_wbarrier.func = major_collector.copy_or_mark_object;
3145 scrrjd_wbarrier.heap_start = heap_start;
3146 scrrjd_wbarrier.heap_end = heap_end;
3147 scrrjd_wbarrier.root_type = ROOT_TYPE_WBARRIER;
3148 mono_sgen_workers_enqueue_job (job_scan_from_registered_roots, &scrrjd_wbarrier);
3151 time_major_scan_registered_roots += TV_ELAPSED_MS (atv, btv);
3154 stdjd.heap_start = heap_start;
3155 stdjd.heap_end = heap_end;
3156 mono_sgen_workers_enqueue_job (job_scan_thread_data, &stdjd);
3159 time_major_scan_thread_data += TV_ELAPSED_MS (btv, atv);
3162 time_major_scan_alloc_pinned += TV_ELAPSED_MS (atv, btv);
3164 if (mono_profiler_get_events () & MONO_PROFILE_GC_ROOTS)
3165 report_finalizer_roots ();
3167 /* scan the list of objects ready for finalization */
3168 sfejd_fin_ready.list = fin_ready_list;
3169 mono_sgen_workers_enqueue_job (job_scan_finalizer_entries, &sfejd_fin_ready);
3171 sfejd_critical_fin.list = critical_fin_list;
3172 mono_sgen_workers_enqueue_job (job_scan_finalizer_entries, &sfejd_critical_fin);
3175 time_major_scan_finalized += TV_ELAPSED_MS (btv, atv);
3176 DEBUG (2, fprintf (gc_debug_file, "Root scan: %d usecs\n", TV_ELAPSED (btv, atv)));
3179 time_major_scan_big_objects += TV_ELAPSED_MS (atv, btv);
3181 if (major_collector.is_parallel) {
3182 while (!mono_sgen_gray_object_queue_is_empty (WORKERS_DISTRIBUTE_GRAY_QUEUE)) {
3183 mono_sgen_workers_distribute_gray_queue_sections ();
3187 mono_sgen_workers_join ();
3189 #ifdef SGEN_DEBUG_INTERNAL_ALLOC
3190 main_gc_thread = NULL;
3193 if (major_collector.is_parallel)
3194 g_assert (mono_sgen_gray_object_queue_is_empty (&gray_queue));
3196 /* all the objects in the heap */
3197 finish_gray_stack (heap_start, heap_end, GENERATION_OLD, &gray_queue);
3199 time_major_finish_gray_stack += TV_ELAPSED_MS (btv, atv);
3202 * The (single-threaded) finalization code might have done
3203 * some copying/marking so we can only reset the GC thread's
3204 * worker data here instead of earlier when we joined the
3207 mono_sgen_workers_reset_data ();
3209 if (objects_pinned) {
3210 /*This is slow, but we just OOM'd*/
3211 mono_sgen_pin_queue_clear_discarded_entries (nursery_section, old_next_pin_slot);
3212 mono_sgen_optimize_pin_queue (0);
3213 mono_sgen_find_section_pin_queue_start_end (nursery_section);
3217 reset_heap_boundaries ();
3218 mono_sgen_update_heap_boundaries ((mword)nursery_start, (mword)nursery_end);
3220 /* sweep the big objects list */
3222 for (bigobj = los_object_list; bigobj;) {
3223 if (object_is_pinned (bigobj->data)) {
3224 unpin_object (bigobj->data);
3225 mono_sgen_update_heap_boundaries ((mword)bigobj->data, (mword)bigobj->data + bigobj->size);
3228 /* not referenced anywhere, so we can free it */
3230 prevbo->next = bigobj->next;
3232 los_object_list = bigobj->next;
3234 bigobj = bigobj->next;
3235 mono_sgen_los_free_object (to_free);
3239 bigobj = bigobj->next;
3243 time_major_free_bigobjs += TV_ELAPSED_MS (atv, btv);
3245 mono_sgen_los_sweep ();
3248 time_major_los_sweep += TV_ELAPSED_MS (btv, atv);
3250 major_collector.sweep ();
3253 time_major_sweep += TV_ELAPSED_MS (atv, btv);
3255 /* walk the pin_queue, build up the fragment list of free memory, unmark
3256 * pinned objects as we go, memzero() the empty fragments so they are ready for the
3259 if (!mono_sgen_build_nursery_fragments (nursery_section, nursery_section->pin_queue_start, nursery_section->pin_queue_num_entries))
3262 /* Clear TLABs for all threads */
3263 mono_sgen_clear_tlabs ();
3266 time_major_fragment_creation += TV_ELAPSED_MS (btv, atv);
3268 TV_GETTIME (all_btv);
3269 mono_stats.major_gc_time_usecs += TV_ELAPSED (all_atv, all_btv);
3272 dump_heap ("major", stat_major_gcs - 1, reason);
3274 /* prepare the pin queue for the next collection */
3275 mono_sgen_finish_pinning ();
3277 if (fin_ready_list || critical_fin_list) {
3278 DEBUG (4, fprintf (gc_debug_file, "Finalizer-thread wakeup: ready %d\n", num_ready_finalizers));
3279 mono_gc_finalize_notify ();
3281 mono_sgen_pin_stats_reset ();
3283 g_assert (mono_sgen_gray_object_queue_is_empty (&gray_queue));
3285 try_calculate_minor_collection_allowance (TRUE);
3287 minor_collection_sections_alloced = 0;
3288 last_collection_los_memory_usage = los_memory_usage;
3290 major_collector.finish_major_collection ();
3292 check_scan_starts ();
3294 binary_protocol_flush_buffers (FALSE);
3296 //consistency_check ();
3298 return bytes_pinned_from_failed_allocation > 0;
3302 major_collection (const char *reason)
3304 gboolean need_minor_collection;
3306 if (disable_major_collections) {
3307 collect_nursery (0);
3311 major_collection_happened = TRUE;
3312 current_collection_generation = GENERATION_OLD;
3313 need_minor_collection = major_do_collection (reason);
3314 current_collection_generation = -1;
3316 if (need_minor_collection)
3317 collect_nursery (0);
3321 sgen_collect_major_no_lock (const char *reason)
3323 gint64 gc_start_time;
3325 mono_profiler_gc_event (MONO_GC_EVENT_START, 1);
3326 gc_start_time = mono_100ns_ticks ();
3328 major_collection (reason);
3330 mono_trace_message (MONO_TRACE_GC, "major gc took %d usecs", (mono_100ns_ticks () - gc_start_time) / 10);
3331 mono_profiler_gc_event (MONO_GC_EVENT_END, 1);
3335 * When deciding if it's better to collect or to expand, keep track
3336 * of how much garbage was reclaimed with the last collection: if it's too
3338 * This is called when we could not allocate a small object.
3340 static void __attribute__((noinline))
3341 minor_collect_or_expand_inner (size_t size)
3343 int do_minor_collection = 1;
3345 g_assert (nursery_section);
3346 if (do_minor_collection) {
3347 gint64 total_gc_time, major_gc_time = 0;
3349 mono_profiler_gc_event (MONO_GC_EVENT_START, 0);
3350 total_gc_time = mono_100ns_ticks ();
3353 if (collect_nursery (size)) {
3354 mono_profiler_gc_event (MONO_GC_EVENT_START, 1);
3355 major_gc_time = mono_100ns_ticks ();
3357 major_collection ("minor overflow");
3359 /* keep events symmetric */
3360 major_gc_time = mono_100ns_ticks () - major_gc_time;
3361 mono_profiler_gc_event (MONO_GC_EVENT_END, 1);
3363 DEBUG (2, fprintf (gc_debug_file, "Heap size: %lu, LOS size: %lu\n", (unsigned long)total_alloc, (unsigned long)los_memory_usage));
3366 total_gc_time = mono_100ns_ticks () - total_gc_time;
3368 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);
3370 mono_trace_message (MONO_TRACE_GC, "minor gc took %d usecs", total_gc_time / 10);
3372 /* this also sets the proper pointers for the next allocation */
3373 if (!mono_sgen_can_alloc_size (size)) {
3374 /* TypeBuilder and MonoMethod are killing mcs with fragmentation */
3375 DEBUG (1, fprintf (gc_debug_file, "nursery collection didn't find enough room for %zd alloc (%d pinned)\n", size, mono_sgen_get_pinned_count ()));
3376 mono_sgen_dump_pin_queue ();
3379 mono_profiler_gc_event (MONO_GC_EVENT_END, 0);
3381 //report_internal_mem_usage ();
3385 mono_sgen_minor_collect_or_expand_inner (size_t size)
3387 minor_collect_or_expand_inner (size);
3391 * ######################################################################
3392 * ######## Memory allocation from the OS
3393 * ######################################################################
3394 * This section of code deals with getting memory from the OS and
3395 * allocating memory for GC-internal data structures.
3396 * Internal memory can be handled with a freelist for small objects.
3402 G_GNUC_UNUSED static void
3403 report_internal_mem_usage (void)
3405 printf ("Internal memory usage:\n");
3406 mono_sgen_report_internal_mem_usage ();
3407 printf ("Pinned memory usage:\n");
3408 major_collector.report_pinned_memory_usage ();
3412 * ######################################################################
3413 * ######## Finalization support
3414 * ######################################################################
3418 * this is valid for the nursery: if the object has been forwarded it means it's
3419 * still refrenced from a root. If it is pinned it's still alive as well.
3420 * Return TRUE if @obj is ready to be finalized.
3422 #define object_is_fin_ready(obj) (!object_is_pinned (obj) && !object_is_forwarded (obj))
3426 mono_sgen_gc_is_object_ready_for_finalization (void *object)
3428 return !major_collector.is_object_live (object) && object_is_fin_ready (object);
3432 has_critical_finalizer (MonoObject *obj)
3436 if (!mono_defaults.critical_finalizer_object)
3439 class = ((MonoVTable*)LOAD_VTABLE (obj))->klass;
3441 return mono_class_has_parent_fast (class, mono_defaults.critical_finalizer_object);
3445 queue_finalization_entry (MonoObject *obj) {
3446 FinalizeReadyEntry *entry = mono_sgen_alloc_internal (INTERNAL_MEM_FINALIZE_READY_ENTRY);
3447 entry->object = obj;
3448 if (has_critical_finalizer (obj)) {
3449 entry->next = critical_fin_list;
3450 critical_fin_list = entry;
3452 entry->next = fin_ready_list;
3453 fin_ready_list = entry;
3458 object_is_reachable (char *object, char *start, char *end)
3460 /*This happens for non nursery objects during minor collections. We just treat all objects as alive.*/
3461 if (object < start || object >= end)
3463 return !object_is_fin_ready (object) || major_collector.is_object_live (object);
3466 #include "sgen-fin-weak-hash.c"
3469 mono_sgen_object_is_live (void *obj)
3471 if (ptr_in_nursery (obj))
3472 return object_is_pinned (obj);
3473 if (current_collection_generation == GENERATION_NURSERY)
3475 return major_collector.is_object_live (obj);
3478 /* LOCKING: requires that the GC lock is held */
3480 null_ephemerons_for_domain (MonoDomain *domain)
3482 EphemeronLinkNode *current = ephemeron_list, *prev = NULL;
3485 MonoObject *object = (MonoObject*)current->array;
3487 if (object && !object->vtable) {
3488 EphemeronLinkNode *tmp = current;
3491 prev->next = current->next;
3493 ephemeron_list = current->next;
3495 current = current->next;
3496 mono_sgen_free_internal (tmp, INTERNAL_MEM_EPHEMERON_LINK);
3499 current = current->next;
3504 /* LOCKING: requires that the GC lock is held */
3506 clear_unreachable_ephemerons (CopyOrMarkObjectFunc copy_func, char *start, char *end, GrayQueue *queue)
3508 int was_in_nursery, was_promoted;
3509 EphemeronLinkNode *current = ephemeron_list, *prev = NULL;
3511 Ephemeron *cur, *array_end;
3515 char *object = current->array;
3517 if (!object_is_reachable (object, start, end)) {
3518 EphemeronLinkNode *tmp = current;
3520 DEBUG (5, fprintf (gc_debug_file, "Dead Ephemeron array at %p\n", object));
3523 prev->next = current->next;
3525 ephemeron_list = current->next;
3527 current = current->next;
3528 mono_sgen_free_internal (tmp, INTERNAL_MEM_EPHEMERON_LINK);
3533 was_in_nursery = ptr_in_nursery (object);
3534 copy_func ((void**)&object, queue);
3535 current->array = object;
3537 /*The array was promoted, add global remsets for key/values left behind in nursery.*/
3538 was_promoted = was_in_nursery && !ptr_in_nursery (object);
3540 DEBUG (5, fprintf (gc_debug_file, "Clearing unreachable entries for ephemeron array at %p\n", object));
3542 array = (MonoArray*)object;
3543 cur = mono_array_addr (array, Ephemeron, 0);
3544 array_end = cur + mono_array_length_fast (array);
3545 tombstone = (char*)((MonoVTable*)LOAD_VTABLE (object))->domain->ephemeron_tombstone;
3547 for (; cur < array_end; ++cur) {
3548 char *key = (char*)cur->key;
3550 if (!key || key == tombstone)
3553 DEBUG (5, fprintf (gc_debug_file, "[%td] key %p (%s) value %p (%s)\n", cur - mono_array_addr (array, Ephemeron, 0),
3554 key, object_is_reachable (key, start, end) ? "reachable" : "unreachable",
3555 cur->value, cur->value && object_is_reachable (cur->value, start, end) ? "reachable" : "unreachable"));
3557 if (!object_is_reachable (key, start, end)) {
3558 cur->key = tombstone;
3564 if (ptr_in_nursery (key)) {/*key was not promoted*/
3565 DEBUG (5, fprintf (gc_debug_file, "\tAdded remset to key %p\n", key));
3566 mono_sgen_add_to_global_remset (&cur->key);
3568 if (ptr_in_nursery (cur->value)) {/*value was not promoted*/
3569 DEBUG (5, fprintf (gc_debug_file, "\tAdded remset to value %p\n", cur->value));
3570 mono_sgen_add_to_global_remset (&cur->value);
3575 current = current->next;
3579 /* LOCKING: requires that the GC lock is held */
3581 mark_ephemerons_in_range (CopyOrMarkObjectFunc copy_func, char *start, char *end, GrayQueue *queue)
3583 int nothing_marked = 1;
3584 EphemeronLinkNode *current = ephemeron_list;
3586 Ephemeron *cur, *array_end;
3589 for (current = ephemeron_list; current; current = current->next) {
3590 char *object = current->array;
3591 DEBUG (5, fprintf (gc_debug_file, "Ephemeron array at %p\n", object));
3594 For now we process all ephemerons during all collections.
3595 Ideally we should use remset information to partially scan those
3597 We already emit write barriers for Ephemeron fields, it's
3598 just that we don't process them.
3600 /*if (object < start || object >= end)
3603 /*It has to be alive*/
3604 if (!object_is_reachable (object, start, end)) {
3605 DEBUG (5, fprintf (gc_debug_file, "\tnot reachable\n"));
3609 copy_func ((void**)&object, queue);
3611 array = (MonoArray*)object;
3612 cur = mono_array_addr (array, Ephemeron, 0);
3613 array_end = cur + mono_array_length_fast (array);
3614 tombstone = (char*)((MonoVTable*)LOAD_VTABLE (object))->domain->ephemeron_tombstone;
3616 for (; cur < array_end; ++cur) {
3617 char *key = cur->key;
3619 if (!key || key == tombstone)
3622 DEBUG (5, fprintf (gc_debug_file, "[%td] key %p (%s) value %p (%s)\n", cur - mono_array_addr (array, Ephemeron, 0),
3623 key, object_is_reachable (key, start, end) ? "reachable" : "unreachable",
3624 cur->value, cur->value && object_is_reachable (cur->value, start, end) ? "reachable" : "unreachable"));
3626 if (object_is_reachable (key, start, end)) {
3627 char *value = cur->value;
3629 copy_func ((void**)&cur->key, queue);
3631 if (!object_is_reachable (value, start, end))
3633 copy_func ((void**)&cur->value, queue);
3639 DEBUG (5, fprintf (gc_debug_file, "Ephemeron run finished. Is it done %d\n", nothing_marked));
3640 return nothing_marked;
3644 mono_gc_invoke_finalizers (void)
3646 FinalizeReadyEntry *entry = NULL;
3647 gboolean entry_is_critical = FALSE;
3650 /* FIXME: batch to reduce lock contention */
3651 while (fin_ready_list || critical_fin_list) {
3655 FinalizeReadyEntry **list = entry_is_critical ? &critical_fin_list : &fin_ready_list;
3657 /* We have finalized entry in the last
3658 interation, now we need to remove it from
3661 *list = entry->next;
3663 FinalizeReadyEntry *e = *list;
3664 while (e->next != entry)
3666 e->next = entry->next;
3668 mono_sgen_free_internal (entry, INTERNAL_MEM_FINALIZE_READY_ENTRY);
3672 /* Now look for the first non-null entry. */
3673 for (entry = fin_ready_list; entry && !entry->object; entry = entry->next)
3676 entry_is_critical = FALSE;
3678 entry_is_critical = TRUE;
3679 for (entry = critical_fin_list; entry && !entry->object; entry = entry->next)
3684 g_assert (entry->object);
3685 num_ready_finalizers--;
3686 obj = entry->object;
3687 entry->object = NULL;
3688 DEBUG (7, fprintf (gc_debug_file, "Finalizing object %p (%s)\n", obj, safe_name (obj)));
3696 g_assert (entry->object == NULL);
3698 /* the object is on the stack so it is pinned */
3699 /*g_print ("Calling finalizer for object: %p (%s)\n", entry->object, safe_name (entry->object));*/
3700 mono_gc_run_finalize (obj, NULL);
3707 mono_gc_pending_finalizers (void)
3709 return fin_ready_list || critical_fin_list;
3712 /* Negative value to remove */
3714 mono_gc_add_memory_pressure (gint64 value)
3716 /* FIXME: Use interlocked functions */
3718 memory_pressure += value;
3723 mono_sgen_register_major_sections_alloced (int num_sections)
3725 minor_collection_sections_alloced += num_sections;
3729 mono_sgen_get_minor_collection_allowance (void)
3731 return minor_collection_allowance;
3735 * ######################################################################
3736 * ######## registered roots support
3737 * ######################################################################
3741 * We do not coalesce roots.
3744 mono_gc_register_root_inner (char *start, size_t size, void *descr, int root_type)
3746 RootRecord new_root;
3749 for (i = 0; i < ROOT_TYPE_NUM; ++i) {
3750 RootRecord *root = mono_sgen_hash_table_lookup (&roots_hash [i], start);
3751 /* we allow changing the size and the descriptor (for thread statics etc) */
3753 size_t old_size = root->end_root - start;
3754 root->end_root = start + size;
3755 g_assert (((root->root_desc != 0) && (descr != NULL)) ||
3756 ((root->root_desc == 0) && (descr == NULL)));
3757 root->root_desc = (mword)descr;
3759 roots_size -= old_size;
3765 new_root.end_root = start + size;
3766 new_root.root_desc = (mword)descr;
3768 mono_sgen_hash_table_replace (&roots_hash [root_type], start, &new_root);
3771 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));
3778 mono_gc_register_root (char *start, size_t size, void *descr)
3780 return mono_gc_register_root_inner (start, size, descr, descr ? ROOT_TYPE_NORMAL : ROOT_TYPE_PINNED);
3784 mono_gc_register_root_wbarrier (char *start, size_t size, void *descr)
3786 return mono_gc_register_root_inner (start, size, descr, ROOT_TYPE_WBARRIER);
3790 mono_gc_deregister_root (char* addr)
3796 for (root_type = 0; root_type < ROOT_TYPE_NUM; ++root_type) {
3797 if (mono_sgen_hash_table_remove (&roots_hash [root_type], addr, &root))
3798 roots_size -= (root.end_root - addr);
3804 * ######################################################################
3805 * ######## Thread handling (stop/start code)
3806 * ######################################################################
3809 unsigned int mono_sgen_global_stop_count = 0;
3812 static MonoContext cur_thread_ctx = {0};
3814 static mword cur_thread_regs [ARCH_NUM_REGS] = {0};
3818 update_current_thread_stack (void *start)
3820 int stack_guard = 0;
3821 #ifndef USE_MONO_CTX
3822 void *ptr = cur_thread_regs;
3824 SgenThreadInfo *info = mono_thread_info_current ();
3826 info->stack_start = align_pointer (&stack_guard);
3827 g_assert (info->stack_start >= info->stack_start_limit && info->stack_start < info->stack_end);
3829 MONO_CONTEXT_GET_CURRENT (cur_thread_ctx);
3830 info->monoctx = &cur_thread_ctx;
3832 ARCH_STORE_REGS (ptr);
3833 info->stopped_regs = ptr;
3835 if (gc_callbacks.thread_suspend_func)
3836 gc_callbacks.thread_suspend_func (info->runtime_data, NULL);
3840 mono_sgen_fill_thread_info_for_suspend (SgenThreadInfo *info)
3842 #ifdef HAVE_KW_THREAD
3843 /* update the remset info in the thread data structure */
3844 info->remset = remembered_set;
3849 * Define this and use the "xdomain-checks" MONO_GC_DEBUG option to
3850 * have cross-domain checks in the write barrier.
3852 //#define XDOMAIN_CHECKS_IN_WBARRIER
3854 #ifndef SGEN_BINARY_PROTOCOL
3855 #ifndef HEAVY_STATISTICS
3856 #define MANAGED_ALLOCATION
3857 #ifndef XDOMAIN_CHECKS_IN_WBARRIER
3858 #define MANAGED_WBARRIER
3864 is_ip_in_managed_allocator (MonoDomain *domain, gpointer ip);
3867 restart_threads_until_none_in_managed_allocator (void)
3869 SgenThreadInfo *info;
3870 int num_threads_died = 0;
3871 int sleep_duration = -1;
3874 int restart_count = 0, restarted_count = 0;
3875 /* restart all threads that stopped in the
3877 FOREACH_THREAD_SAFE (info) {
3879 if (info->skip || info->gc_disabled)
3881 if (!info->thread_is_dying && (!info->stack_start || info->in_critical_region ||
3882 is_ip_in_managed_allocator (info->stopped_domain, info->stopped_ip))) {
3883 binary_protocol_thread_restart ((gpointer)mono_thread_info_get_tid (info));
3884 result = mono_sgen_resume_thread (info);
3891 /* we set the stopped_ip to
3892 NULL for threads which
3893 we're not restarting so
3894 that we can easily identify
3896 info->stopped_ip = NULL;
3897 info->stopped_domain = NULL;
3899 } END_FOREACH_THREAD_SAFE
3900 /* if no threads were restarted, we're done */
3901 if (restart_count == 0)
3904 /* wait for the threads to signal their restart */
3905 mono_sgen_wait_for_suspend_ack (restart_count);
3907 if (sleep_duration < 0) {
3915 g_usleep (sleep_duration);
3916 sleep_duration += 10;
3919 /* stop them again */
3920 FOREACH_THREAD (info) {
3922 if (info->skip || info->stopped_ip == NULL)
3924 result = mono_sgen_suspend_thread (info);
3931 } END_FOREACH_THREAD
3932 /* some threads might have died */
3933 num_threads_died += restart_count - restarted_count;
3934 /* wait for the threads to signal their suspension
3936 mono_sgen_wait_for_suspend_ack (restart_count);
3939 return num_threads_died;
3943 acquire_gc_locks (void)
3946 mono_thread_info_suspend_lock ();
3950 release_gc_locks (void)
3952 mono_thread_info_suspend_unlock ();
3953 UNLOCK_INTERRUPTION;
3956 static TV_DECLARE (stop_world_time);
3957 static unsigned long max_pause_usec = 0;
3959 /* LOCKING: assumes the GC lock is held */
3961 stop_world (int generation)
3965 /*XXX this is the right stop, thought might not be the nicest place to put it*/
3966 mono_sgen_process_togglerefs ();
3968 mono_profiler_gc_event (MONO_GC_EVENT_PRE_STOP_WORLD, generation);
3969 acquire_gc_locks ();
3971 update_current_thread_stack (&count);
3973 mono_sgen_global_stop_count++;
3974 DEBUG (3, fprintf (gc_debug_file, "stopping world n %d from %p %p\n", mono_sgen_global_stop_count, mono_thread_info_current (), (gpointer)mono_native_thread_id_get ()));
3975 TV_GETTIME (stop_world_time);
3976 count = mono_sgen_thread_handshake (TRUE);
3977 count -= restart_threads_until_none_in_managed_allocator ();
3978 g_assert (count >= 0);
3979 DEBUG (3, fprintf (gc_debug_file, "world stopped %d thread(s)\n", count));
3980 mono_profiler_gc_event (MONO_GC_EVENT_POST_STOP_WORLD, generation);
3982 last_major_num_sections = major_collector.get_num_major_sections ();
3983 last_los_memory_usage = los_memory_usage;
3984 major_collection_happened = FALSE;
3988 /* LOCKING: assumes the GC lock is held */
3990 restart_world (int generation)
3992 int count, num_major_sections;
3993 SgenThreadInfo *info;
3994 TV_DECLARE (end_sw);
3995 TV_DECLARE (end_bridge);
3996 unsigned long usec, bridge_usec;
3998 /* notify the profiler of the leftovers */
3999 if (G_UNLIKELY (mono_profiler_events & MONO_PROFILE_GC_MOVES)) {
4000 if (moved_objects_idx) {
4001 mono_profiler_gc_moves (moved_objects, moved_objects_idx);
4002 moved_objects_idx = 0;
4005 mono_profiler_gc_event (MONO_GC_EVENT_PRE_START_WORLD, generation);
4006 FOREACH_THREAD (info) {
4007 info->stack_start = NULL;
4009 info->monoctx = NULL;
4011 info->stopped_regs = NULL;
4013 } END_FOREACH_THREAD
4015 stw_bridge_process ();
4016 release_gc_locks ();
4018 count = mono_sgen_thread_handshake (FALSE);
4019 TV_GETTIME (end_sw);
4020 usec = TV_ELAPSED (stop_world_time, end_sw);
4021 max_pause_usec = MAX (usec, max_pause_usec);
4022 DEBUG (2, fprintf (gc_debug_file, "restarted %d thread(s) (pause time: %d usec, max: %d)\n", count, (int)usec, (int)max_pause_usec));
4023 mono_profiler_gc_event (MONO_GC_EVENT_POST_START_WORLD, generation);
4027 TV_GETTIME (end_bridge);
4028 bridge_usec = TV_ELAPSED (end_sw, end_bridge);
4030 num_major_sections = major_collector.get_num_major_sections ();
4031 if (major_collection_happened)
4032 mono_trace (G_LOG_LEVEL_INFO, MONO_TRACE_GC, "GC_MAJOR: %s pause %.2fms, bridge %.2fms major %dK/%dK los %dK/%dK",
4033 generation ? "" : "(minor overflow)",
4034 (int)usec / 1000.0f, (int)bridge_usec / 1000.0f,
4035 major_collector.section_size * num_major_sections / 1024,
4036 major_collector.section_size * last_major_num_sections / 1024,
4037 los_memory_usage / 1024,
4038 last_los_memory_usage / 1024);
4040 mono_trace (G_LOG_LEVEL_INFO, MONO_TRACE_GC, "GC_MINOR: pause %.2fms, bridge %.2fms promoted %dK major %dK los %dK",
4041 (int)usec / 1000.0f, (int)bridge_usec / 1000.0f,
4042 (num_major_sections - last_major_num_sections) * major_collector.section_size / 1024,
4043 major_collector.section_size * num_major_sections / 1024,
4044 los_memory_usage / 1024);
4050 mono_sgen_get_current_collection_generation (void)
4052 return current_collection_generation;
4056 mono_gc_set_gc_callbacks (MonoGCCallbacks *callbacks)
4058 gc_callbacks = *callbacks;
4062 mono_gc_get_gc_callbacks ()
4064 return &gc_callbacks;
4067 /* Variables holding start/end nursery so it won't have to be passed at every call */
4068 static void *scan_area_arg_start, *scan_area_arg_end;
4071 mono_gc_conservatively_scan_area (void *start, void *end)
4073 conservatively_pin_objects_from (start, end, scan_area_arg_start, scan_area_arg_end, PIN_TYPE_STACK);
4077 mono_gc_scan_object (void *obj)
4079 UserCopyOrMarkData *data = mono_native_tls_get_value (user_copy_or_mark_key);
4081 if (current_collection_generation == GENERATION_NURSERY) {
4082 if (mono_sgen_collection_is_parallel ())
4083 major_collector.copy_object (&obj, data->queue);
4085 major_collector.nopar_copy_object (&obj, data->queue);
4087 major_collector.copy_or_mark_object (&obj, data->queue);
4093 * Mark from thread stacks and registers.
4096 scan_thread_data (void *start_nursery, void *end_nursery, gboolean precise, GrayQueue *queue)
4098 SgenThreadInfo *info;
4100 scan_area_arg_start = start_nursery;
4101 scan_area_arg_end = end_nursery;
4103 FOREACH_THREAD (info) {
4105 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));
4108 if (info->gc_disabled) {
4109 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));
4112 DEBUG (3, fprintf (gc_debug_file, "Scanning thread %p, range: %p-%p, size: %ld, pinned=%d\n", info, info->stack_start, info->stack_end, (char*)info->stack_end - (char*)info->stack_start, mono_sgen_get_pinned_count ()));
4113 if (!info->thread_is_dying) {
4114 if (gc_callbacks.thread_mark_func && !conservative_stack_mark) {
4115 UserCopyOrMarkData data = { NULL, queue };
4116 set_user_copy_or_mark_data (&data);
4117 gc_callbacks.thread_mark_func (info->runtime_data, info->stack_start, info->stack_end, precise);
4118 set_user_copy_or_mark_data (NULL);
4119 } else if (!precise) {
4120 conservatively_pin_objects_from (info->stack_start, info->stack_end, start_nursery, end_nursery, PIN_TYPE_STACK);
4125 if (!info->thread_is_dying && !precise)
4126 conservatively_pin_objects_from ((void**)info->monoctx, (void**)info->monoctx + ARCH_NUM_REGS,
4127 start_nursery, end_nursery, PIN_TYPE_STACK);
4129 if (!info->thread_is_dying && !precise)
4130 conservatively_pin_objects_from (info->stopped_regs, info->stopped_regs + ARCH_NUM_REGS,
4131 start_nursery, end_nursery, PIN_TYPE_STACK);
4133 } END_FOREACH_THREAD
4137 find_pinning_ref_from_thread (char *obj, size_t size)
4140 SgenThreadInfo *info;
4141 char *endobj = obj + size;
4143 FOREACH_THREAD (info) {
4144 char **start = (char**)info->stack_start;
4147 while (start < (char**)info->stack_end) {
4148 if (*start >= obj && *start < endobj) {
4149 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));
4154 for (j = 0; j < ARCH_NUM_REGS; ++j) {
4156 mword w = ((mword*)info->monoctx) [j];
4158 mword w = (mword)info->stopped_regs [j];
4161 if (w >= (mword)obj && w < (mword)obj + size)
4162 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)));
4163 } END_FOREACH_THREAD
4168 ptr_on_stack (void *ptr)
4170 gpointer stack_start = &stack_start;
4171 SgenThreadInfo *info = mono_thread_info_current ();
4173 if (ptr >= stack_start && ptr < (gpointer)info->stack_end)
4179 handle_remset (mword *p, void *start_nursery, void *end_nursery, gboolean global, GrayQueue *queue)
4186 HEAVY_STAT (++stat_global_remsets_processed);
4188 HEAVY_STAT (++stat_local_remsets_processed);
4190 /* FIXME: exclude stack locations */
4191 switch ((*p) & REMSET_TYPE_MASK) {
4192 case REMSET_LOCATION:
4194 //__builtin_prefetch (ptr);
4195 if (((void*)ptr < start_nursery || (void*)ptr >= end_nursery)) {
4196 gpointer old = *ptr;
4197 major_collector.copy_object (ptr, queue);
4198 DEBUG (9, fprintf (gc_debug_file, "Overwrote remset at %p with %p\n", ptr, *ptr));
4200 binary_protocol_ptr_update (ptr, old, *ptr, (gpointer)LOAD_VTABLE (*ptr), safe_object_get_size (*ptr));
4201 if (!global && *ptr >= start_nursery && *ptr < end_nursery) {
4203 * If the object is pinned, each reference to it from nonpinned objects
4204 * becomes part of the global remset, which can grow very large.
4206 DEBUG (9, fprintf (gc_debug_file, "Add to global remset because of pinning %p (%p %s)\n", ptr, *ptr, safe_name (*ptr)));
4207 mono_sgen_add_to_global_remset (ptr);
4210 DEBUG (9, fprintf (gc_debug_file, "Skipping remset at %p holding %p\n", ptr, *ptr));
4214 ptr = (void**)(*p & ~REMSET_TYPE_MASK);
4215 if (((void*)ptr >= start_nursery && (void*)ptr < end_nursery))
4218 while (count-- > 0) {
4219 major_collector.copy_object (ptr, queue);
4220 DEBUG (9, fprintf (gc_debug_file, "Overwrote remset at %p with %p (count: %d)\n", ptr, *ptr, (int)count));
4221 if (!global && *ptr >= start_nursery && *ptr < end_nursery)
4222 mono_sgen_add_to_global_remset (ptr);
4227 ptr = (void**)(*p & ~REMSET_TYPE_MASK);
4228 if (((void*)ptr >= start_nursery && (void*)ptr < end_nursery))
4230 mono_sgen_get_minor_scan_object () ((char*)ptr, queue);
4232 case REMSET_VTYPE: {
4233 ScanVTypeFunc scan_vtype = mono_sgen_get_minor_scan_vtype ();
4236 ptr = (void**)(*p & ~REMSET_TYPE_MASK);
4237 if (((void*)ptr >= start_nursery && (void*)ptr < end_nursery))
4242 while (count-- > 0) {
4243 scan_vtype ((char*)ptr, desc, queue);
4244 ptr = (void**)((char*)ptr + skip_size);
4249 g_assert_not_reached ();
4254 #ifdef HEAVY_STATISTICS
4256 collect_store_remsets (RememberedSet *remset, mword *bumper)
4258 mword *p = remset->data;
4263 while (p < remset->store_next) {
4264 switch ((*p) & REMSET_TYPE_MASK) {
4265 case REMSET_LOCATION:
4268 ++stat_saved_remsets_1;
4270 if (*p == last1 || *p == last2) {
4271 ++stat_saved_remsets_2;
4288 g_assert_not_reached ();
4298 RememberedSet *remset;
4300 SgenThreadInfo *info;
4302 mword *addresses, *bumper, *p, *r;
4304 FOREACH_THREAD (info) {
4305 for (remset = info->remset; remset; remset = remset->next)
4306 size += remset->store_next - remset->data;
4307 } END_FOREACH_THREAD
4308 for (remset = freed_thread_remsets; remset; remset = remset->next)
4309 size += remset->store_next - remset->data;
4310 for (remset = global_remset; remset; remset = remset->next)
4311 size += remset->store_next - remset->data;
4313 bumper = addresses = mono_sgen_alloc_internal_dynamic (sizeof (mword) * size, INTERNAL_MEM_STATISTICS);
4315 FOREACH_THREAD (info) {
4316 for (remset = info->remset; remset; remset = remset->next)
4317 bumper = collect_store_remsets (remset, bumper);
4318 } END_FOREACH_THREAD
4319 for (remset = global_remset; remset; remset = remset->next)
4320 bumper = collect_store_remsets (remset, bumper);
4321 for (remset = freed_thread_remsets; remset; remset = remset->next)
4322 bumper = collect_store_remsets (remset, bumper);
4324 g_assert (bumper <= addresses + size);
4326 stat_store_remsets += bumper - addresses;
4328 mono_sgen_sort_addresses ((void**)addresses, bumper - addresses);
4331 while (r < bumper) {
4337 stat_store_remsets_unique += p - addresses;
4339 mono_sgen_free_internal_dynamic (addresses, sizeof (mword) * size, INTERNAL_MEM_STATISTICS);
4344 clear_thread_store_remset_buffer (SgenThreadInfo *info)
4346 *info->store_remset_buffer_index_addr = 0;
4347 /* See the comment at the end of sgen_thread_unregister() */
4348 if (*info->store_remset_buffer_addr)
4349 memset (*info->store_remset_buffer_addr, 0, sizeof (gpointer) * STORE_REMSET_BUFFER_SIZE);
4353 remset_byte_size (RememberedSet *remset)
4355 return sizeof (RememberedSet) + (remset->end_set - remset->data) * sizeof (gpointer);
4359 scan_from_global_remsets (void *start_nursery, void *end_nursery, GrayQueue *queue)
4361 RememberedSet *remset;
4362 mword *p, *next_p, *store_pos;
4364 /* the global one */
4365 for (remset = global_remset; remset; remset = remset->next) {
4366 DEBUG (4, fprintf (gc_debug_file, "Scanning global remset range: %p-%p, size: %td\n", remset->data, remset->store_next, remset->store_next - remset->data));
4367 store_pos = remset->data;
4368 for (p = remset->data; p < remset->store_next; p = next_p) {
4369 void **ptr = (void**)p [0];
4371 /*Ignore previously processed remset.*/
4372 if (!global_remset_location_was_not_added (ptr)) {
4377 next_p = handle_remset (p, start_nursery, end_nursery, TRUE, queue);
4380 * Clear global remsets of locations which no longer point to the
4381 * nursery. Otherwise, they could grow indefinitely between major
4384 * Since all global remsets are location remsets, we don't need to unmask the pointer.
4386 if (ptr_in_nursery (*ptr)) {
4387 *store_pos ++ = p [0];
4388 HEAVY_STAT (++stat_global_remsets_readded);
4392 /* Truncate the remset */
4393 remset->store_next = store_pos;
4398 scan_from_remsets (void *start_nursery, void *end_nursery, GrayQueue *queue)
4401 SgenThreadInfo *info;
4402 RememberedSet *remset;
4403 GenericStoreRememberedSet *store_remset;
4406 #ifdef HEAVY_STATISTICS
4410 /* the generic store ones */
4411 store_remset = generic_store_remsets;
4412 while (store_remset) {
4413 GenericStoreRememberedSet *next = store_remset->next;
4415 for (i = 0; i < STORE_REMSET_BUFFER_SIZE - 1; ++i) {
4416 gpointer addr = store_remset->data [i];
4418 handle_remset ((mword*)&addr, start_nursery, end_nursery, FALSE, queue);
4421 mono_sgen_free_internal (store_remset, INTERNAL_MEM_STORE_REMSET);
4423 store_remset = next;
4425 generic_store_remsets = NULL;
4427 /* the per-thread ones */
4428 FOREACH_THREAD (info) {
4429 RememberedSet *next;
4431 for (remset = info->remset; remset; remset = next) {
4432 DEBUG (4, fprintf (gc_debug_file, "Scanning remset for thread %p, range: %p-%p, size: %td\n", info, remset->data, remset->store_next, remset->store_next - remset->data));
4433 for (p = remset->data; p < remset->store_next;)
4434 p = handle_remset (p, start_nursery, end_nursery, FALSE, queue);
4435 remset->store_next = remset->data;
4436 next = remset->next;
4437 remset->next = NULL;
4438 if (remset != info->remset) {
4439 DEBUG (4, fprintf (gc_debug_file, "Freed remset at %p\n", remset->data));
4440 mono_sgen_free_internal_dynamic (remset, remset_byte_size (remset), INTERNAL_MEM_REMSET);
4443 for (j = 0; j < *info->store_remset_buffer_index_addr; ++j)
4444 handle_remset ((mword*)*info->store_remset_buffer_addr + j + 1, start_nursery, end_nursery, FALSE, queue);
4445 clear_thread_store_remset_buffer (info);
4446 } END_FOREACH_THREAD
4448 /* the freed thread ones */
4449 while (freed_thread_remsets) {
4450 RememberedSet *next;
4451 remset = freed_thread_remsets;
4452 DEBUG (4, fprintf (gc_debug_file, "Scanning remset for freed thread, range: %p-%p, size: %td\n", remset->data, remset->store_next, remset->store_next - remset->data));
4453 for (p = remset->data; p < remset->store_next;)
4454 p = handle_remset (p, start_nursery, end_nursery, FALSE, queue);
4455 next = remset->next;
4456 DEBUG (4, fprintf (gc_debug_file, "Freed remset at %p\n", remset->data));
4457 mono_sgen_free_internal_dynamic (remset, remset_byte_size (remset), INTERNAL_MEM_REMSET);
4458 freed_thread_remsets = next;
4463 * Clear the info in the remembered sets: we're doing a major collection, so
4464 * the per-thread ones are not needed and the global ones will be reconstructed
4468 clear_remsets (void)
4470 SgenThreadInfo *info;
4471 RememberedSet *remset, *next;
4473 /* the global list */
4474 for (remset = global_remset; remset; remset = next) {
4475 remset->store_next = remset->data;
4476 next = remset->next;
4477 remset->next = NULL;
4478 if (remset != global_remset) {
4479 DEBUG (4, fprintf (gc_debug_file, "Freed remset at %p\n", remset->data));
4480 mono_sgen_free_internal_dynamic (remset, remset_byte_size (remset), INTERNAL_MEM_REMSET);
4483 /* the generic store ones */
4484 while (generic_store_remsets) {
4485 GenericStoreRememberedSet *gs_next = generic_store_remsets->next;
4486 mono_sgen_free_internal (generic_store_remsets, INTERNAL_MEM_STORE_REMSET);
4487 generic_store_remsets = gs_next;
4489 /* the per-thread ones */
4490 FOREACH_THREAD (info) {
4491 for (remset = info->remset; remset; remset = next) {
4492 remset->store_next = remset->data;
4493 next = remset->next;
4494 remset->next = NULL;
4495 if (remset != info->remset) {
4496 DEBUG (3, fprintf (gc_debug_file, "Freed remset at %p\n", remset->data));
4497 mono_sgen_free_internal_dynamic (remset, remset_byte_size (remset), INTERNAL_MEM_REMSET);
4500 clear_thread_store_remset_buffer (info);
4501 } END_FOREACH_THREAD
4503 /* the freed thread ones */
4504 while (freed_thread_remsets) {
4505 next = freed_thread_remsets->next;
4506 DEBUG (4, fprintf (gc_debug_file, "Freed remset at %p\n", freed_thread_remsets->data));
4507 mono_sgen_free_internal_dynamic (freed_thread_remsets, remset_byte_size (freed_thread_remsets), INTERNAL_MEM_REMSET);
4508 freed_thread_remsets = next;
4513 sgen_thread_register (SgenThreadInfo* info, void *addr)
4515 #ifndef HAVE_KW_THREAD
4516 SgenThreadInfo *__thread_info__ = info;
4520 #ifndef HAVE_KW_THREAD
4521 info->tlab_start = info->tlab_next = info->tlab_temp_end = info->tlab_real_end = NULL;
4523 g_assert (!mono_native_tls_get_value (thread_info_key));
4524 mono_native_tls_set_value (thread_info_key, info);
4529 #if !defined(__MACH__)
4530 info->stop_count = -1;
4534 info->doing_handshake = FALSE;
4535 info->thread_is_dying = FALSE;
4536 info->stack_start = NULL;
4537 info->store_remset_buffer_addr = &STORE_REMSET_BUFFER;
4538 info->store_remset_buffer_index_addr = &STORE_REMSET_BUFFER_INDEX;
4539 info->stopped_ip = NULL;
4540 info->stopped_domain = NULL;
4542 info->monoctx = NULL;
4544 info->stopped_regs = NULL;
4547 mono_sgen_init_tlab_info (info);
4549 binary_protocol_thread_register ((gpointer)mono_thread_info_get_tid (info));
4551 #ifdef HAVE_KW_THREAD
4552 store_remset_buffer_index_addr = &store_remset_buffer_index;
4555 #if defined(__MACH__)
4556 info->mach_port = mach_thread_self ();
4559 /* try to get it with attributes first */
4560 #if defined(HAVE_PTHREAD_GETATTR_NP) && defined(HAVE_PTHREAD_ATTR_GETSTACK)
4564 pthread_attr_t attr;
4565 pthread_getattr_np (pthread_self (), &attr);
4566 pthread_attr_getstack (&attr, &sstart, &size);
4567 info->stack_start_limit = sstart;
4568 info->stack_end = (char*)sstart + size;
4569 pthread_attr_destroy (&attr);
4571 #elif defined(HAVE_PTHREAD_GET_STACKSIZE_NP) && defined(HAVE_PTHREAD_GET_STACKADDR_NP)
4572 info->stack_end = (char*)pthread_get_stackaddr_np (pthread_self ());
4573 info->stack_start_limit = (char*)info->stack_end - pthread_get_stacksize_np (pthread_self ());
4576 /* FIXME: we assume the stack grows down */
4577 gsize stack_bottom = (gsize)addr;
4578 stack_bottom += 4095;
4579 stack_bottom &= ~4095;
4580 info->stack_end = (char*)stack_bottom;
4584 #ifdef HAVE_KW_THREAD
4585 stack_end = info->stack_end;
4588 info->remset = alloc_remset (DEFAULT_REMSET_SIZE, info, FALSE);
4589 mono_native_tls_set_value (remembered_set_key, info->remset);
4590 #ifdef HAVE_KW_THREAD
4591 remembered_set = info->remset;
4594 STORE_REMSET_BUFFER = mono_sgen_alloc_internal (INTERNAL_MEM_STORE_REMSET);
4595 STORE_REMSET_BUFFER_INDEX = 0;
4597 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));
4599 if (gc_callbacks.thread_attach_func)
4600 info->runtime_data = gc_callbacks.thread_attach_func ();
4607 add_generic_store_remset_from_buffer (gpointer *buffer)
4609 GenericStoreRememberedSet *remset = mono_sgen_alloc_internal (INTERNAL_MEM_STORE_REMSET);
4610 memcpy (remset->data, buffer + 1, sizeof (gpointer) * (STORE_REMSET_BUFFER_SIZE - 1));
4611 remset->next = generic_store_remsets;
4612 generic_store_remsets = remset;
4616 sgen_thread_unregister (SgenThreadInfo *p)
4618 RememberedSet *rset;
4620 /* If a delegate is passed to native code and invoked on a thread we dont
4621 * know about, the jit will register it with mono_jit_thread_attach, but
4622 * we have no way of knowing when that thread goes away. SGen has a TSD
4623 * so we assume that if the domain is still registered, we can detach
4626 if (mono_domain_get ())
4627 mono_thread_detach (mono_thread_current ());
4629 p->thread_is_dying = TRUE;
4632 There is a race condition between a thread finishing executing and been removed
4633 from the GC thread set.
4634 This happens on posix systems when TLS data is been cleaned-up, libpthread will
4635 set the thread_info slot to NULL before calling the cleanup function. This
4636 opens a window in which the thread is registered but has a NULL TLS.
4638 The suspend signal handler needs TLS data to know where to store thread state
4639 data or otherwise it will simply ignore the thread.
4641 This solution works because the thread doing STW will wait until all threads been
4642 suspended handshake back, so there is no race between the doing_hankshake test
4643 and the suspend_thread call.
4645 This is not required on systems that do synchronous STW as those can deal with
4646 the above race at suspend time.
4648 FIXME: I believe we could avoid this by using mono_thread_info_lookup when
4649 mono_thread_info_current returns NULL. Or fix mono_thread_info_lookup to do so.
4651 #if (defined(__MACH__) && MONO_MACH_ARCH_SUPPORTED) || !defined(HAVE_PTHREAD_KILL)
4654 while (!TRYLOCK_GC) {
4655 if (!mono_sgen_park_current_thread_if_doing_handshake (p))
4660 binary_protocol_thread_unregister ((gpointer)mono_thread_info_get_tid (p));
4661 DEBUG (3, fprintf (gc_debug_file, "unregister thread %p (%p)\n", p, (gpointer)mono_thread_info_get_tid (p)));
4663 #if defined(__MACH__)
4664 mach_port_deallocate (current_task (), p->mach_port);
4667 if (gc_callbacks.thread_detach_func) {
4668 gc_callbacks.thread_detach_func (p->runtime_data);
4669 p->runtime_data = NULL;
4673 if (freed_thread_remsets) {
4674 for (rset = p->remset; rset->next; rset = rset->next)
4676 rset->next = freed_thread_remsets;
4677 freed_thread_remsets = p->remset;
4679 freed_thread_remsets = p->remset;
4682 if (*p->store_remset_buffer_index_addr)
4683 add_generic_store_remset_from_buffer (*p->store_remset_buffer_addr);
4684 mono_sgen_free_internal (*p->store_remset_buffer_addr, INTERNAL_MEM_STORE_REMSET);
4686 * This is currently not strictly required, but we do it
4687 * anyway in case we change thread unregistering:
4689 * If the thread is removed from the thread list after
4690 * unregistering (this is currently not the case), and a
4691 * collection occurs, clear_remsets() would want to memset
4692 * this buffer, which would either clobber memory or crash.
4694 *p->store_remset_buffer_addr = NULL;
4696 mono_threads_unregister_current_thread (p);
4702 sgen_thread_attach (SgenThreadInfo *info)
4705 /*this is odd, can we get attached before the gc is inited?*/
4709 if (gc_callbacks.thread_attach_func && !info->runtime_data)
4710 info->runtime_data = gc_callbacks.thread_attach_func ();
4713 mono_gc_register_thread (void *baseptr)
4715 return mono_thread_info_attach (baseptr) != NULL;
4719 * mono_gc_set_stack_end:
4721 * Set the end of the current threads stack to STACK_END. The stack space between
4722 * STACK_END and the real end of the threads stack will not be scanned during collections.
4725 mono_gc_set_stack_end (void *stack_end)
4727 SgenThreadInfo *info;
4730 info = mono_thread_info_current ();
4732 g_assert (stack_end < info->stack_end);
4733 info->stack_end = stack_end;
4738 #if USE_PTHREAD_INTERCEPT
4742 mono_gc_pthread_create (pthread_t *new_thread, const pthread_attr_t *attr, void *(*start_routine)(void *), void *arg)
4744 return pthread_create (new_thread, attr, start_routine, arg);
4748 mono_gc_pthread_join (pthread_t thread, void **retval)
4750 return pthread_join (thread, retval);
4754 mono_gc_pthread_detach (pthread_t thread)
4756 return pthread_detach (thread);
4760 mono_gc_pthread_exit (void *retval)
4762 pthread_exit (retval);
4765 #endif /* USE_PTHREAD_INTERCEPT */
4768 * ######################################################################
4769 * ######## Write barriers
4770 * ######################################################################
4774 * This causes the compile to extend the liveness of 'v' till the call to dummy_use
4777 dummy_use (gpointer v) {
4778 __asm__ volatile ("" : "=r"(v) : "r"(v));
4783 mono_sgen_alloc_remset (int size, gpointer id, gboolean global)
4785 return alloc_remset (size, id, global);
4788 static RememberedSet*
4789 alloc_remset (int size, gpointer id, gboolean global)
4791 RememberedSet* res = mono_sgen_alloc_internal_dynamic (sizeof (RememberedSet) + (size * sizeof (gpointer)), INTERNAL_MEM_REMSET);
4792 res->store_next = res->data;
4793 res->end_set = res->data + size;
4795 DEBUG (4, fprintf (gc_debug_file, "Allocated%s remset size %d at %p for %p\n", global ? " global" : "", size, res->data, id));
4800 * Note: the write barriers first do the needed GC work and then do the actual store:
4801 * this way the value is visible to the conservative GC scan after the write barrier
4802 * itself. If a GC interrupts the barrier in the middle, value will be kept alive by
4803 * the conservative scan, otherwise by the remembered set scan.
4806 mono_gc_wbarrier_set_field (MonoObject *obj, gpointer field_ptr, MonoObject* value)
4808 HEAVY_STAT (++stat_wbarrier_set_field);
4809 if (ptr_in_nursery (field_ptr)) {
4810 *(void**)field_ptr = value;
4813 DEBUG (8, fprintf (gc_debug_file, "Adding remset at %p\n", field_ptr));
4815 binary_protocol_wbarrier (field_ptr, value, value->vtable);
4818 mono_sgen_card_table_wbarrier_set_field (obj, field_ptr, value);
4820 mono_sgen_ssb_wbarrier_set_field (obj, field_ptr, value);
4824 mono_gc_wbarrier_set_arrayref (MonoArray *arr, gpointer slot_ptr, MonoObject* value)
4826 HEAVY_STAT (++stat_wbarrier_set_arrayref);
4827 if (ptr_in_nursery (slot_ptr)) {
4828 *(void**)slot_ptr = value;
4831 DEBUG (8, fprintf (gc_debug_file, "Adding remset at %p\n", slot_ptr));
4833 binary_protocol_wbarrier (slot_ptr, value, value->vtable);
4836 mono_sgen_card_table_wbarrier_set_arrayref (arr, slot_ptr, value);
4838 mono_sgen_ssb_wbarrier_set_arrayref (arr, slot_ptr, value);
4842 mono_gc_wbarrier_arrayref_copy (gpointer dest_ptr, gpointer src_ptr, int count)
4844 HEAVY_STAT (++stat_wbarrier_arrayref_copy);
4845 /*This check can be done without taking a lock since dest_ptr array is pinned*/
4846 if (ptr_in_nursery (dest_ptr) || count <= 0) {
4847 mono_gc_memmove (dest_ptr, src_ptr, count * sizeof (gpointer));
4851 #ifdef SGEN_BINARY_PROTOCOL
4854 for (i = 0; i < count; ++i) {
4855 gpointer dest = (gpointer*)dest_ptr + i;
4856 gpointer obj = *((gpointer*)src_ptr + i);
4858 binary_protocol_wbarrier (dest, obj, (gpointer)LOAD_VTABLE (obj));
4864 mono_sgen_card_table_wbarrier_arrayref_copy (dest_ptr, src_ptr, count);
4866 mono_sgen_ssb_wbarrier_arrayref_copy (dest_ptr, src_ptr, count);
4869 static char *found_obj;
4872 find_object_for_ptr_callback (char *obj, size_t size, void *user_data)
4874 char *ptr = user_data;
4876 if (ptr >= obj && ptr < obj + size) {
4877 g_assert (!found_obj);
4882 /* for use in the debugger */
4883 char* find_object_for_ptr (char *ptr);
4885 find_object_for_ptr (char *ptr)
4887 if (ptr >= nursery_section->data && ptr < nursery_section->end_data) {
4889 mono_sgen_scan_area_with_callback (nursery_section->data, nursery_section->end_data,
4890 find_object_for_ptr_callback, ptr, TRUE);
4896 mono_sgen_los_iterate_objects (find_object_for_ptr_callback, ptr);
4901 * Very inefficient, but this is debugging code, supposed to
4902 * be called from gdb, so we don't care.
4905 major_collector.iterate_objects (TRUE, TRUE, find_object_for_ptr_callback, ptr);
4910 mono_gc_wbarrier_generic_nostore (gpointer ptr)
4912 HEAVY_STAT (++stat_wbarrier_generic_store);
4914 #ifdef XDOMAIN_CHECKS_IN_WBARRIER
4915 /* FIXME: ptr_in_heap must be called with the GC lock held */
4916 if (xdomain_checks && *(MonoObject**)ptr && ptr_in_heap (ptr)) {
4917 char *start = find_object_for_ptr (ptr);
4918 MonoObject *value = *(MonoObject**)ptr;
4922 MonoObject *obj = (MonoObject*)start;
4923 if (obj->vtable->domain != value->vtable->domain)
4924 g_assert (is_xdomain_ref_allowed (ptr, start, obj->vtable->domain));
4930 if (*(gpointer*)ptr)
4931 binary_protocol_wbarrier (ptr, *(gpointer*)ptr, (gpointer)LOAD_VTABLE (*(gpointer*)ptr));
4933 if (ptr_in_nursery (ptr) || ptr_on_stack (ptr) || !ptr_in_nursery (*(gpointer*)ptr)) {
4934 DEBUG (8, fprintf (gc_debug_file, "Skipping remset at %p\n", ptr));
4938 DEBUG (8, fprintf (gc_debug_file, "Adding remset at %p\n", ptr));
4941 mono_sgen_card_table_wbarrier_generic_nostore (ptr);
4943 mono_sgen_ssb_wbarrier_generic_nostore (ptr);
4947 mono_gc_wbarrier_generic_store (gpointer ptr, MonoObject* value)
4949 DEBUG (8, fprintf (gc_debug_file, "Wbarrier store at %p to %p (%s)\n", ptr, value, value ? safe_name (value) : "null"));
4950 *(void**)ptr = value;
4951 if (ptr_in_nursery (value))
4952 mono_gc_wbarrier_generic_nostore (ptr);
4956 void mono_gc_wbarrier_value_copy_bitmap (gpointer _dest, gpointer _src, int size, unsigned bitmap)
4958 mword *dest = _dest;
4963 mono_gc_wbarrier_generic_store (dest, (MonoObject*)*src);
4968 size -= SIZEOF_VOID_P;
4973 #ifdef SGEN_BINARY_PROTOCOL
4975 #define HANDLE_PTR(ptr,obj) do { \
4976 gpointer o = *(gpointer*)(ptr); \
4978 gpointer d = ((char*)dest) + ((char*)(ptr) - (char*)(obj)); \
4979 binary_protocol_wbarrier (d, o, (gpointer) LOAD_VTABLE (o)); \
4984 scan_object_for_binary_protocol_copy_wbarrier (gpointer dest, char *start, mword desc)
4986 #define SCAN_OBJECT_NOVTABLE
4987 #include "sgen-scan-object.h"
4992 mono_gc_wbarrier_value_copy (gpointer dest, gpointer src, int count, MonoClass *klass)
4994 HEAVY_STAT (++stat_wbarrier_value_copy);
4995 g_assert (klass->valuetype);
4997 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));
4999 if (ptr_in_nursery (dest) || ptr_on_stack (dest) || !SGEN_CLASS_HAS_REFERENCES (klass)) {
5000 size_t element_size = mono_class_value_size (klass, NULL);
5001 size_t size = count * element_size;
5002 mono_gc_memmove (dest, src, size);
5006 #ifdef SGEN_BINARY_PROTOCOL
5009 for (i = 0; i < count; ++i) {
5010 scan_object_for_binary_protocol_copy_wbarrier ((char*)dest + i * element_size,
5011 (char*)src + i * element_size - sizeof (MonoObject),
5012 (mword) klass->gc_descr);
5018 mono_sgen_card_table_wbarrier_value_copy (dest, src, count, klass);
5020 mono_sgen_ssb_wbarrier_value_copy (dest, src, count, klass);
5024 * mono_gc_wbarrier_object_copy:
5026 * Write barrier to call when obj is the result of a clone or copy of an object.
5029 mono_gc_wbarrier_object_copy (MonoObject* obj, MonoObject *src)
5033 if (ptr_in_nursery (obj) || ptr_on_stack (obj)) {
5034 size = mono_object_class (obj)->instance_size;
5035 mono_gc_memmove ((char*)obj + sizeof (MonoObject), (char*)src + sizeof (MonoObject),
5036 size - sizeof (MonoObject));
5040 #ifdef SGEN_BINARY_PROTOCOL
5041 scan_object_for_binary_protocol_copy_wbarrier (obj, (char*)src, (mword) src->vtable->gc_descr);
5045 mono_sgen_card_table_wbarrier_object_copy (obj, src);
5047 mono_sgen_ssb_wbarrier_object_copy (obj, src);
5051 * ######################################################################
5052 * ######## Other mono public interface functions.
5053 * ######################################################################
5056 #define REFS_SIZE 128
5059 MonoGCReferences callback;
5063 MonoObject *refs [REFS_SIZE];
5064 uintptr_t offsets [REFS_SIZE];
5068 #define HANDLE_PTR(ptr,obj) do { \
5070 if (hwi->count == REFS_SIZE) { \
5071 hwi->callback ((MonoObject*)start, mono_object_class (start), hwi->called? 0: size, hwi->count, hwi->refs, hwi->offsets, hwi->data); \
5075 hwi->offsets [hwi->count] = (char*)(ptr)-(char*)start; \
5076 hwi->refs [hwi->count++] = *(ptr); \
5081 collect_references (HeapWalkInfo *hwi, char *start, size_t size)
5083 #include "sgen-scan-object.h"
5087 walk_references (char *start, size_t size, void *data)
5089 HeapWalkInfo *hwi = data;
5092 collect_references (hwi, start, size);
5093 if (hwi->count || !hwi->called)
5094 hwi->callback ((MonoObject*)start, mono_object_class (start), hwi->called? 0: size, hwi->count, hwi->refs, hwi->offsets, hwi->data);
5098 * mono_gc_walk_heap:
5099 * @flags: flags for future use
5100 * @callback: a function pointer called for each object in the heap
5101 * @data: a user data pointer that is passed to callback
5103 * This function can be used to iterate over all the live objects in the heap:
5104 * for each object, @callback is invoked, providing info about the object's
5105 * location in memory, its class, its size and the objects it references.
5106 * For each referenced object it's offset from the object address is
5107 * reported in the offsets array.
5108 * The object references may be buffered, so the callback may be invoked
5109 * multiple times for the same object: in all but the first call, the size
5110 * argument will be zero.
5111 * Note that this function can be only called in the #MONO_GC_EVENT_PRE_START_WORLD
5112 * profiler event handler.
5114 * Returns: a non-zero value if the GC doesn't support heap walking
5117 mono_gc_walk_heap (int flags, MonoGCReferences callback, void *data)
5122 hwi.callback = callback;
5125 mono_sgen_clear_nursery_fragments ();
5126 mono_sgen_scan_area_with_callback (nursery_section->data, nursery_section->end_data, walk_references, &hwi, FALSE);
5128 major_collector.iterate_objects (TRUE, TRUE, walk_references, &hwi);
5129 mono_sgen_los_iterate_objects (walk_references, &hwi);
5135 mono_gc_collect (int generation)
5140 mono_profiler_gc_event (MONO_GC_EVENT_START, generation);
5141 stop_world (generation);
5142 if (generation == 0) {
5143 collect_nursery (0);
5145 major_collection ("user request");
5147 restart_world (generation);
5148 mono_profiler_gc_event (MONO_GC_EVENT_END, generation);
5153 mono_gc_max_generation (void)
5159 mono_gc_collection_count (int generation)
5161 if (generation == 0)
5162 return stat_minor_gcs;
5163 return stat_major_gcs;
5167 mono_gc_get_used_size (void)
5171 tot = los_memory_usage;
5172 tot += nursery_section->next_data - nursery_section->data;
5173 tot += major_collector.get_used_size ();
5174 /* FIXME: account for pinned objects */
5180 mono_gc_get_heap_size (void)
5186 mono_gc_disable (void)
5194 mono_gc_enable (void)
5202 mono_gc_get_los_limit (void)
5204 return MAX_SMALL_OBJ_SIZE;
5208 mono_object_is_alive (MonoObject* o)
5214 mono_gc_get_generation (MonoObject *obj)
5216 if (ptr_in_nursery (obj))
5222 mono_gc_enable_events (void)
5227 mono_gc_weak_link_add (void **link_addr, MonoObject *obj, gboolean track)
5229 mono_gc_register_disappearing_link (obj, link_addr, track, FALSE);
5233 mono_gc_weak_link_remove (void **link_addr)
5235 mono_gc_register_disappearing_link (NULL, link_addr, FALSE, FALSE);
5239 mono_gc_weak_link_get (void **link_addr)
5243 return (MonoObject*) REVEAL_POINTER (*link_addr);
5247 mono_gc_ephemeron_array_add (MonoObject *obj)
5249 EphemeronLinkNode *node;
5253 node = mono_sgen_alloc_internal (INTERNAL_MEM_EPHEMERON_LINK);
5258 node->array = (char*)obj;
5259 node->next = ephemeron_list;
5260 ephemeron_list = node;
5262 DEBUG (5, fprintf (gc_debug_file, "Registered ephemeron array %p\n", obj));
5269 mono_gc_invoke_with_gc_lock (MonoGCLockedCallbackFunc func, void *data)
5273 result = func (data);
5274 UNLOCK_INTERRUPTION;
5279 mono_gc_is_gc_thread (void)
5283 result = mono_thread_info_current () != NULL;
5289 is_critical_method (MonoMethod *method)
5291 return mono_runtime_is_critical_method (method) || mono_gc_is_critical_method (method);
5295 mono_gc_base_init (void)
5297 MonoThreadInfoCallbacks cb;
5300 char *major_collector_opt = NULL;
5302 glong soft_limit = 0;
5308 result = InterlockedCompareExchange (&gc_initialized, -1, 0);
5311 /* already inited */
5314 /* being inited by another thread */
5318 /* we will init it */
5321 g_assert_not_reached ();
5323 } while (result != 0);
5325 LOCK_INIT (gc_mutex);
5327 pagesize = mono_pagesize ();
5328 gc_debug_file = stderr;
5330 cb.thread_register = sgen_thread_register;
5331 cb.thread_unregister = sgen_thread_unregister;
5332 cb.thread_attach = sgen_thread_attach;
5333 cb.mono_method_is_critical = (gpointer)is_critical_method;
5335 cb.mono_gc_pthread_create = (gpointer)mono_gc_pthread_create;
5338 mono_threads_init (&cb, sizeof (SgenThreadInfo));
5340 LOCK_INIT (interruption_mutex);
5341 LOCK_INIT (global_remset_mutex);
5342 LOCK_INIT (pin_queue_mutex);
5344 init_user_copy_or_mark_key ();
5346 if ((env = getenv ("MONO_GC_PARAMS"))) {
5347 opts = g_strsplit (env, ",", -1);
5348 for (ptr = opts; *ptr; ++ptr) {
5350 if (g_str_has_prefix (opt, "major=")) {
5351 opt = strchr (opt, '=') + 1;
5352 major_collector_opt = g_strdup (opt);
5360 mono_sgen_init_internal_allocator ();
5361 mono_sgen_init_nursery_allocator ();
5363 mono_sgen_register_fixed_internal_mem_type (INTERNAL_MEM_SECTION, SGEN_SIZEOF_GC_MEM_SECTION);
5364 mono_sgen_register_fixed_internal_mem_type (INTERNAL_MEM_FINALIZE_READY_ENTRY, sizeof (FinalizeReadyEntry));
5365 mono_sgen_register_fixed_internal_mem_type (INTERNAL_MEM_GRAY_QUEUE, sizeof (GrayQueueSection));
5366 g_assert (sizeof (GenericStoreRememberedSet) == sizeof (gpointer) * STORE_REMSET_BUFFER_SIZE);
5367 mono_sgen_register_fixed_internal_mem_type (INTERNAL_MEM_STORE_REMSET, sizeof (GenericStoreRememberedSet));
5368 mono_sgen_register_fixed_internal_mem_type (INTERNAL_MEM_EPHEMERON_LINK, sizeof (EphemeronLinkNode));
5370 mono_native_tls_alloc (&remembered_set_key, NULL);
5372 #ifndef HAVE_KW_THREAD
5373 mono_native_tls_alloc (&thread_info_key, NULL);
5377 * This needs to happen before any internal allocations because
5378 * it inits the small id which is required for hazard pointer
5381 mono_sgen_os_init ();
5383 mono_thread_info_attach (&dummy);
5385 if (!major_collector_opt || !strcmp (major_collector_opt, "marksweep")) {
5386 mono_sgen_marksweep_init (&major_collector);
5387 } else if (!major_collector_opt || !strcmp (major_collector_opt, "marksweep-fixed")) {
5388 mono_sgen_marksweep_fixed_init (&major_collector);
5389 } else if (!major_collector_opt || !strcmp (major_collector_opt, "marksweep-par")) {
5390 mono_sgen_marksweep_par_init (&major_collector);
5391 } else if (!major_collector_opt || !strcmp (major_collector_opt, "marksweep-fixed-par")) {
5392 mono_sgen_marksweep_fixed_par_init (&major_collector);
5393 } else if (!strcmp (major_collector_opt, "copying")) {
5394 mono_sgen_copying_init (&major_collector);
5396 fprintf (stderr, "Unknown major collector `%s'.\n", major_collector_opt);
5400 #ifdef SGEN_HAVE_CARDTABLE
5401 use_cardtable = major_collector.supports_cardtable;
5403 use_cardtable = FALSE;
5406 num_workers = mono_cpu_count ();
5407 g_assert (num_workers > 0);
5408 if (num_workers > 16)
5411 ///* Keep this the default for now */
5412 //conservative_stack_mark = TRUE;
5415 for (ptr = opts; *ptr; ++ptr) {
5417 if (g_str_has_prefix (opt, "major="))
5419 if (g_str_has_prefix (opt, "wbarrier=")) {
5420 opt = strchr (opt, '=') + 1;
5421 if (strcmp (opt, "remset") == 0) {
5422 use_cardtable = FALSE;
5423 } else if (strcmp (opt, "cardtable") == 0) {
5424 if (!use_cardtable) {
5425 if (major_collector.supports_cardtable)
5426 fprintf (stderr, "The cardtable write barrier is not supported on this platform.\n");
5428 fprintf (stderr, "The major collector does not support the cardtable write barrier.\n");
5434 if (g_str_has_prefix (opt, "max-heap-size=")) {
5435 opt = strchr (opt, '=') + 1;
5436 if (*opt && mono_gc_parse_environment_string_extract_number (opt, &max_heap)) {
5437 if ((max_heap & (mono_pagesize () - 1))) {
5438 fprintf (stderr, "max-heap-size size must be a multiple of %d.\n", mono_pagesize ());
5442 fprintf (stderr, "max-heap-size must be an integer.\n");
5447 if (g_str_has_prefix (opt, "soft-heap-limit=")) {
5448 opt = strchr (opt, '=') + 1;
5449 if (*opt && mono_gc_parse_environment_string_extract_number (opt, &soft_limit)) {
5450 if (soft_limit <= 0) {
5451 fprintf (stderr, "soft-heap-limit must be positive.\n");
5455 fprintf (stderr, "soft-heap-limit must be an integer.\n");
5460 if (g_str_has_prefix (opt, "workers=")) {
5463 if (!major_collector.is_parallel) {
5464 fprintf (stderr, "The workers= option can only be used for parallel collectors.");
5467 opt = strchr (opt, '=') + 1;
5468 val = strtol (opt, &endptr, 10);
5469 if (!*opt || *endptr) {
5470 fprintf (stderr, "Cannot parse the workers= option value.");
5473 if (val <= 0 || val > 16) {
5474 fprintf (stderr, "The number of workers must be in the range 1 to 16.");
5477 num_workers = (int)val;
5480 if (g_str_has_prefix (opt, "stack-mark=")) {
5481 opt = strchr (opt, '=') + 1;
5482 if (!strcmp (opt, "precise")) {
5483 conservative_stack_mark = FALSE;
5484 } else if (!strcmp (opt, "conservative")) {
5485 conservative_stack_mark = TRUE;
5487 fprintf (stderr, "Invalid value '%s' for stack-mark= option, possible values are: 'precise', 'conservative'.\n", opt);
5492 if (g_str_has_prefix (opt, "bridge=")) {
5493 opt = strchr (opt, '=') + 1;
5494 mono_sgen_register_test_bridge_callbacks (g_strdup (opt));
5498 if (g_str_has_prefix (opt, "nursery-size=")) {
5500 opt = strchr (opt, '=') + 1;
5501 if (*opt && mono_gc_parse_environment_string_extract_number (opt, &val)) {
5502 default_nursery_size = val;
5503 #ifdef SGEN_ALIGN_NURSERY
5504 if ((val & (val - 1))) {
5505 fprintf (stderr, "The nursery size must be a power of two.\n");
5509 if (val < SGEN_MAX_NURSERY_WASTE) {
5510 fprintf (stderr, "The nursery size must be at least %d bytes.\n", SGEN_MAX_NURSERY_WASTE);
5514 default_nursery_bits = 0;
5515 while (1 << (++ default_nursery_bits) != default_nursery_size)
5519 fprintf (stderr, "nursery-size must be an integer.\n");
5525 if (!(major_collector.handle_gc_param && major_collector.handle_gc_param (opt))) {
5526 fprintf (stderr, "MONO_GC_PARAMS must be a comma-delimited list of one or more of the following:\n");
5527 fprintf (stderr, " max-heap-size=N (where N is an integer, possibly with a k, m or a g suffix)\n");
5528 fprintf (stderr, " soft-heap-limit=n (where N is an integer, possibly with a k, m or a g suffix)\n");
5529 fprintf (stderr, " nursery-size=N (where N is an integer, possibly with a k, m or a g suffix)\n");
5530 fprintf (stderr, " major=COLLECTOR (where COLLECTOR is `marksweep', `marksweep-par' or `copying')\n");
5531 fprintf (stderr, " wbarrier=WBARRIER (where WBARRIER is `remset' or `cardtable')\n");
5532 fprintf (stderr, " stack-mark=MARK-METHOD (where MARK-METHOD is 'precise' or 'conservative')\n");
5533 if (major_collector.print_gc_param_usage)
5534 major_collector.print_gc_param_usage ();
5541 if (major_collector.is_parallel)
5542 mono_sgen_workers_init (num_workers);
5544 if (major_collector_opt)
5545 g_free (major_collector_opt);
5547 nursery_size = DEFAULT_NURSERY_SIZE;
5548 minor_collection_allowance = MIN_MINOR_COLLECTION_ALLOWANCE;
5549 init_heap_size_limits (max_heap, soft_limit);
5553 if ((env = getenv ("MONO_GC_DEBUG"))) {
5554 opts = g_strsplit (env, ",", -1);
5555 for (ptr = opts; ptr && *ptr; ptr ++) {
5557 if (opt [0] >= '0' && opt [0] <= '9') {
5558 gc_debug_level = atoi (opt);
5563 char *rf = g_strdup_printf ("%s.%d", opt, getpid ());
5564 gc_debug_file = fopen (rf, "wb");
5566 gc_debug_file = stderr;
5569 } else if (!strcmp (opt, "print-allowance")) {
5570 debug_print_allowance = TRUE;
5571 } else if (!strcmp (opt, "print-pinning")) {
5572 do_pin_stats = TRUE;
5573 } else if (!strcmp (opt, "collect-before-allocs")) {
5574 collect_before_allocs = 1;
5575 } else if (g_str_has_prefix (opt, "collect-before-allocs=")) {
5576 char *arg = strchr (opt, '=') + 1;
5577 collect_before_allocs = atoi (arg);
5578 } else if (!strcmp (opt, "check-at-minor-collections")) {
5579 consistency_check_at_minor_collection = TRUE;
5580 nursery_clear_policy = CLEAR_AT_GC;
5581 } else if (!strcmp (opt, "xdomain-checks")) {
5582 xdomain_checks = TRUE;
5583 } else if (!strcmp (opt, "clear-at-gc")) {
5584 nursery_clear_policy = CLEAR_AT_GC;
5585 } else if (!strcmp (opt, "clear-nursery-at-gc")) {
5586 nursery_clear_policy = CLEAR_AT_GC;
5587 } else if (!strcmp (opt, "check-scan-starts")) {
5588 do_scan_starts_check = TRUE;
5589 } else if (!strcmp (opt, "verify-nursery-at-minor-gc")) {
5590 do_verify_nursery = TRUE;
5591 } else if (!strcmp (opt, "dump-nursery-at-minor-gc")) {
5592 do_dump_nursery_content = TRUE;
5593 } else if (!strcmp (opt, "disable-minor")) {
5594 disable_minor_collections = TRUE;
5595 } else if (!strcmp (opt, "disable-major")) {
5596 disable_major_collections = TRUE;
5597 } else if (g_str_has_prefix (opt, "heap-dump=")) {
5598 char *filename = strchr (opt, '=') + 1;
5599 nursery_clear_policy = CLEAR_AT_GC;
5600 heap_dump_file = fopen (filename, "w");
5601 if (heap_dump_file) {
5602 fprintf (heap_dump_file, "<sgen-dump>\n");
5603 do_pin_stats = TRUE;
5605 #ifdef SGEN_BINARY_PROTOCOL
5606 } else if (g_str_has_prefix (opt, "binary-protocol=")) {
5607 char *filename = strchr (opt, '=') + 1;
5608 binary_protocol_init (filename);
5610 fprintf (stderr, "Warning: Cardtable write barriers will not be binary-protocolled.\n");
5613 fprintf (stderr, "Invalid format for the MONO_GC_DEBUG env variable: '%s'\n", env);
5614 fprintf (stderr, "The format is: MONO_GC_DEBUG=[l[:filename]|<option>]+ where l is a debug level 0-9.\n");
5615 fprintf (stderr, "Valid options are:\n");
5616 fprintf (stderr, " collect-before-allocs[=<n>]\n");
5617 fprintf (stderr, " check-at-minor-collections\n");
5618 fprintf (stderr, " disable-minor\n");
5619 fprintf (stderr, " disable-major\n");
5620 fprintf (stderr, " xdomain-checks\n");
5621 fprintf (stderr, " clear-at-gc\n");
5622 fprintf (stderr, " print-allowance\n");
5623 fprintf (stderr, " print-pinning\n");
5630 if (major_collector.is_parallel) {
5631 if (heap_dump_file) {
5632 fprintf (stderr, "Error: Cannot do heap dump with the parallel collector.\n");
5636 fprintf (stderr, "Error: Cannot gather pinning statistics with the parallel collector.\n");
5641 if (major_collector.post_param_init)
5642 major_collector.post_param_init ();
5644 global_remset = alloc_remset (1024, NULL, FALSE);
5645 global_remset->next = NULL;
5648 sgen_card_table_init ();
5654 mono_gc_get_gc_name (void)
5659 static MonoMethod *write_barrier_method;
5662 mono_gc_is_critical_method (MonoMethod *method)
5664 return (method == write_barrier_method || mono_sgen_is_managed_allocator (method));
5668 is_ip_in_managed_allocator (MonoDomain *domain, gpointer ip)
5672 if (!mono_thread_internal_current ())
5673 /* Happens during thread attach */
5678 ji = mono_jit_info_table_find (domain, ip);
5682 return mono_gc_is_critical_method (ji->method);
5686 emit_nursery_check (MonoMethodBuilder *mb, int *nursery_check_return_labels)
5688 memset (nursery_check_return_labels, 0, sizeof (int) * 3);
5689 #ifdef SGEN_ALIGN_NURSERY
5690 // if (ptr_in_nursery (ptr)) return;
5692 * Masking out the bits might be faster, but we would have to use 64 bit
5693 * immediates, which might be slower.
5695 mono_mb_emit_ldarg (mb, 0);
5696 mono_mb_emit_icon (mb, DEFAULT_NURSERY_BITS);
5697 mono_mb_emit_byte (mb, CEE_SHR_UN);
5698 mono_mb_emit_icon (mb, (mword)nursery_start >> DEFAULT_NURSERY_BITS);
5699 nursery_check_return_labels [0] = mono_mb_emit_branch (mb, CEE_BEQ);
5701 // if (!ptr_in_nursery (*ptr)) return;
5702 mono_mb_emit_ldarg (mb, 0);
5703 mono_mb_emit_byte (mb, CEE_LDIND_I);
5704 mono_mb_emit_icon (mb, DEFAULT_NURSERY_BITS);
5705 mono_mb_emit_byte (mb, CEE_SHR_UN);
5706 mono_mb_emit_icon (mb, (mword)nursery_start >> DEFAULT_NURSERY_BITS);
5707 nursery_check_return_labels [1] = mono_mb_emit_branch (mb, CEE_BNE_UN);
5709 int label_continue1, label_continue2;
5710 int dereferenced_var;
5712 // if (ptr < (nursery_start)) goto continue;
5713 mono_mb_emit_ldarg (mb, 0);
5714 mono_mb_emit_ptr (mb, (gpointer) nursery_start);
5715 label_continue_1 = mono_mb_emit_branch (mb, CEE_BLT);
5717 // if (ptr >= nursery_end)) goto continue;
5718 mono_mb_emit_ldarg (mb, 0);
5719 mono_mb_emit_ptr (mb, (gpointer) nursery_end);
5720 label_continue_2 = mono_mb_emit_branch (mb, CEE_BGE);
5723 nursery_check_return_labels [0] = mono_mb_emit_branch (mb, CEE_BR);
5726 mono_mb_patch_branch (mb, label_continue_1);
5727 mono_mb_patch_branch (mb, label_continue_2);
5729 // Dereference and store in local var
5730 dereferenced_var = mono_mb_add_local (mb, &mono_defaults.int_class->byval_arg);
5731 mono_mb_emit_ldarg (mb, 0);
5732 mono_mb_emit_byte (mb, CEE_LDIND_I);
5733 mono_mb_emit_stloc (mb, dereferenced_var);
5735 // if (*ptr < nursery_start) return;
5736 mono_mb_emit_ldloc (mb, dereferenced_var);
5737 mono_mb_emit_ptr (mb, (gpointer) nursery_start);
5738 nursery_check_return_labels [1] = mono_mb_emit_branch (mb, CEE_BLT);
5740 // if (*ptr >= nursery_end) return;
5741 mono_mb_emit_ldloc (mb, dereferenced_var);
5742 mono_mb_emit_ptr (mb, (gpointer) nursery_end);
5743 nursery_check_return_labels [2] = mono_mb_emit_branch (mb, CEE_BGE);
5748 mono_gc_get_write_barrier (void)
5751 MonoMethodBuilder *mb;
5752 MonoMethodSignature *sig;
5753 #ifdef MANAGED_WBARRIER
5754 int i, nursery_check_labels [3];
5755 int label_no_wb_3, label_no_wb_4, label_need_wb, label_slow_path;
5756 int buffer_var, buffer_index_var, dummy_var;
5758 #ifdef HAVE_KW_THREAD
5759 int stack_end_offset = -1, store_remset_buffer_offset = -1;
5760 int store_remset_buffer_index_offset = -1, store_remset_buffer_index_addr_offset = -1;
5762 MONO_THREAD_VAR_OFFSET (stack_end, stack_end_offset);
5763 g_assert (stack_end_offset != -1);
5764 MONO_THREAD_VAR_OFFSET (store_remset_buffer, store_remset_buffer_offset);
5765 g_assert (store_remset_buffer_offset != -1);
5766 MONO_THREAD_VAR_OFFSET (store_remset_buffer_index, store_remset_buffer_index_offset);
5767 g_assert (store_remset_buffer_index_offset != -1);
5768 MONO_THREAD_VAR_OFFSET (store_remset_buffer_index_addr, store_remset_buffer_index_addr_offset);
5769 g_assert (store_remset_buffer_index_addr_offset != -1);
5773 // FIXME: Maybe create a separate version for ctors (the branch would be
5774 // correctly predicted more times)
5775 if (write_barrier_method)
5776 return write_barrier_method;
5778 /* Create the IL version of mono_gc_barrier_generic_store () */
5779 sig = mono_metadata_signature_alloc (mono_defaults.corlib, 1);
5780 sig->ret = &mono_defaults.void_class->byval_arg;
5781 sig->params [0] = &mono_defaults.int_class->byval_arg;
5783 mb = mono_mb_new (mono_defaults.object_class, "wbarrier", MONO_WRAPPER_WRITE_BARRIER);
5785 #ifdef MANAGED_WBARRIER
5786 if (use_cardtable) {
5787 emit_nursery_check (mb, nursery_check_labels);
5789 addr = sgen_cardtable + ((address >> CARD_BITS) & CARD_MASK)
5793 LDC_PTR sgen_cardtable
5795 address >> CARD_BITS
5799 if (SGEN_HAVE_OVERLAPPING_CARDS) {
5800 LDC_PTR card_table_mask
5807 mono_mb_emit_ptr (mb, sgen_cardtable);
5808 mono_mb_emit_ldarg (mb, 0);
5809 mono_mb_emit_icon (mb, CARD_BITS);
5810 mono_mb_emit_byte (mb, CEE_SHR_UN);
5811 #ifdef SGEN_HAVE_OVERLAPPING_CARDS
5812 mono_mb_emit_ptr (mb, (gpointer)CARD_MASK);
5813 mono_mb_emit_byte (mb, CEE_AND);
5815 mono_mb_emit_byte (mb, CEE_ADD);
5816 mono_mb_emit_icon (mb, 1);
5817 mono_mb_emit_byte (mb, CEE_STIND_I1);
5820 for (i = 0; i < 3; ++i) {
5821 if (nursery_check_labels [i])
5822 mono_mb_patch_branch (mb, nursery_check_labels [i]);
5824 mono_mb_emit_byte (mb, CEE_RET);
5825 } else if (mono_runtime_has_tls_get ()) {
5826 emit_nursery_check (mb, nursery_check_labels);
5828 // if (ptr >= stack_end) goto need_wb;
5829 mono_mb_emit_ldarg (mb, 0);
5830 EMIT_TLS_ACCESS (mb, stack_end, stack_end_offset);
5831 label_need_wb = mono_mb_emit_branch (mb, CEE_BGE_UN);
5833 // if (ptr >= stack_start) return;
5834 dummy_var = mono_mb_add_local (mb, &mono_defaults.int_class->byval_arg);
5835 mono_mb_emit_ldarg (mb, 0);
5836 mono_mb_emit_ldloc_addr (mb, dummy_var);
5837 label_no_wb_3 = mono_mb_emit_branch (mb, CEE_BGE_UN);
5840 mono_mb_patch_branch (mb, label_need_wb);
5842 // buffer = STORE_REMSET_BUFFER;
5843 buffer_var = mono_mb_add_local (mb, &mono_defaults.int_class->byval_arg);
5844 EMIT_TLS_ACCESS (mb, store_remset_buffer, store_remset_buffer_offset);
5845 mono_mb_emit_stloc (mb, buffer_var);
5847 // buffer_index = STORE_REMSET_BUFFER_INDEX;
5848 buffer_index_var = mono_mb_add_local (mb, &mono_defaults.int_class->byval_arg);
5849 EMIT_TLS_ACCESS (mb, store_remset_buffer_index, store_remset_buffer_index_offset);
5850 mono_mb_emit_stloc (mb, buffer_index_var);
5852 // if (buffer [buffer_index] == ptr) return;
5853 mono_mb_emit_ldloc (mb, buffer_var);
5854 mono_mb_emit_ldloc (mb, buffer_index_var);
5855 g_assert (sizeof (gpointer) == 4 || sizeof (gpointer) == 8);
5856 mono_mb_emit_icon (mb, sizeof (gpointer) == 4 ? 2 : 3);
5857 mono_mb_emit_byte (mb, CEE_SHL);
5858 mono_mb_emit_byte (mb, CEE_ADD);
5859 mono_mb_emit_byte (mb, CEE_LDIND_I);
5860 mono_mb_emit_ldarg (mb, 0);
5861 label_no_wb_4 = mono_mb_emit_branch (mb, CEE_BEQ);
5864 mono_mb_emit_ldloc (mb, buffer_index_var);
5865 mono_mb_emit_icon (mb, 1);
5866 mono_mb_emit_byte (mb, CEE_ADD);
5867 mono_mb_emit_stloc (mb, buffer_index_var);
5869 // if (buffer_index >= STORE_REMSET_BUFFER_SIZE) goto slow_path;
5870 mono_mb_emit_ldloc (mb, buffer_index_var);
5871 mono_mb_emit_icon (mb, STORE_REMSET_BUFFER_SIZE);
5872 label_slow_path = mono_mb_emit_branch (mb, CEE_BGE);
5874 // buffer [buffer_index] = ptr;
5875 mono_mb_emit_ldloc (mb, buffer_var);
5876 mono_mb_emit_ldloc (mb, buffer_index_var);
5877 g_assert (sizeof (gpointer) == 4 || sizeof (gpointer) == 8);
5878 mono_mb_emit_icon (mb, sizeof (gpointer) == 4 ? 2 : 3);
5879 mono_mb_emit_byte (mb, CEE_SHL);
5880 mono_mb_emit_byte (mb, CEE_ADD);
5881 mono_mb_emit_ldarg (mb, 0);
5882 mono_mb_emit_byte (mb, CEE_STIND_I);
5884 // STORE_REMSET_BUFFER_INDEX = buffer_index;
5885 EMIT_TLS_ACCESS (mb, store_remset_buffer_index_addr, store_remset_buffer_index_addr_offset);
5886 mono_mb_emit_ldloc (mb, buffer_index_var);
5887 mono_mb_emit_byte (mb, CEE_STIND_I);
5890 for (i = 0; i < 3; ++i) {
5891 if (nursery_check_labels [i])
5892 mono_mb_patch_branch (mb, nursery_check_labels [i]);
5894 mono_mb_patch_branch (mb, label_no_wb_3);
5895 mono_mb_patch_branch (mb, label_no_wb_4);
5896 mono_mb_emit_byte (mb, CEE_RET);
5899 mono_mb_patch_branch (mb, label_slow_path);
5901 mono_mb_emit_ldarg (mb, 0);
5902 mono_mb_emit_icall (mb, mono_gc_wbarrier_generic_nostore);
5903 mono_mb_emit_byte (mb, CEE_RET);
5907 mono_mb_emit_ldarg (mb, 0);
5908 mono_mb_emit_icall (mb, mono_gc_wbarrier_generic_nostore);
5909 mono_mb_emit_byte (mb, CEE_RET);
5912 res = mono_mb_create_method (mb, sig, 16);
5915 mono_loader_lock ();
5916 if (write_barrier_method) {
5917 /* Already created */
5918 mono_free_method (res);
5920 /* double-checked locking */
5921 mono_memory_barrier ();
5922 write_barrier_method = res;
5924 mono_loader_unlock ();
5926 return write_barrier_method;
5930 mono_gc_get_description (void)
5932 return g_strdup ("sgen");
5936 mono_gc_set_desktop_mode (void)
5941 mono_gc_is_moving (void)
5947 mono_gc_is_disabled (void)
5953 mono_sgen_debug_printf (int level, const char *format, ...)
5957 if (level > gc_debug_level)
5960 va_start (ap, format);
5961 vfprintf (gc_debug_file, format, ap);
5966 mono_sgen_get_logfile (void)
5968 return gc_debug_file;
5972 BOOL APIENTRY mono_gc_dllmain (HMODULE module_handle, DWORD reason, LPVOID reserved)
5979 mono_sgen_get_nursery_clear_policy (void)
5981 return nursery_clear_policy;
5985 mono_sgen_get_array_fill_vtable (void)
5987 if (!array_fill_vtable) {
5988 static MonoClass klass;
5989 static MonoVTable vtable;
5992 MonoDomain *domain = mono_get_root_domain ();
5995 klass.element_class = mono_defaults.byte_class;
5997 klass.instance_size = sizeof (MonoArray);
5998 klass.sizes.element_size = 1;
5999 klass.name = "array_filler_type";
6001 vtable.klass = &klass;
6003 vtable.gc_descr = mono_gc_make_descr_for_array (TRUE, &bmap, 0, 1);
6006 array_fill_vtable = &vtable;
6008 return array_fill_vtable;
6012 mono_sgen_gc_lock (void)
6018 mono_sgen_gc_unlock (void)
6024 sgen_major_collector_iterate_live_block_ranges (sgen_cardtable_block_callback callback)
6026 major_collector.iterate_live_block_ranges (callback);
6030 sgen_major_collector_scan_card_table (SgenGrayQueue *queue)
6032 major_collector.scan_card_table (queue);
6036 mono_sgen_ptr_in_nursery (void *p)
6038 return SGEN_PTR_IN_NURSERY ((p), DEFAULT_NURSERY_BITS, nursery_start, nursery_end);
6042 mono_sgen_get_major_collector (void)
6044 return &major_collector;
6047 void mono_gc_set_skip_thread (gboolean skip)
6049 SgenThreadInfo *info = mono_thread_info_current ();
6052 info->gc_disabled = skip;
6056 #endif /* HAVE_SGEN_GC */