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.
16 * Copyright 2001-2003 Ximian, Inc
17 * Copyright 2003-2010 Novell, Inc.
18 * Copyright 2011 Xamarin, Inc.
19 * Copyright (C) 2012 Xamarin Inc
21 * Licensed under the MIT license. See LICENSE file in the project root for full license information.
23 * Important: allocation provides always zeroed memory, having to do
24 * a memset after allocation is deadly for performance.
25 * Memory usage at startup is currently as follows:
27 * 64 KB internal space
29 * We should provide a small memory config with half the sizes
31 * We currently try to make as few mono assumptions as possible:
32 * 1) 2-word header with no GC pointers in it (first vtable, second to store the
34 * 2) gc descriptor is the second word in the vtable (first word in the class)
35 * 3) 8 byte alignment is the minimum and enough (not true for special structures (SIMD), FIXME)
36 * 4) there is a function to get an object's size and the number of
37 * elements in an array.
38 * 5) we know the special way bounds are allocated for complex arrays
39 * 6) we know about proxies and how to treat them when domains are unloaded
41 * Always try to keep stack usage to a minimum: no recursive behaviour
42 * and no large stack allocs.
44 * General description.
45 * Objects are initially allocated in a nursery using a fast bump-pointer technique.
46 * When the nursery is full we start a nursery collection: this is performed with a
48 * When the old generation is full we start a copying GC of the old generation as well:
49 * this will be changed to mark&sweep with copying when fragmentation becomes to severe
50 * in the future. Maybe we'll even do both during the same collection like IMMIX.
52 * The things that complicate this description are:
53 * *) pinned objects: we can't move them so we need to keep track of them
54 * *) no precise info of the thread stacks and registers: we need to be able to
55 * quickly find the objects that may be referenced conservatively and pin them
56 * (this makes the first issues more important)
57 * *) large objects are too expensive to be dealt with using copying GC: we handle them
58 * with mark/sweep during major collections
59 * *) some objects need to not move even if they are small (interned strings, Type handles):
60 * we use mark/sweep for them, too: they are not allocated in the nursery, but inside
61 * PinnedChunks regions
67 *) we could have a function pointer in MonoClass to implement
68 customized write barriers for value types
70 *) investigate the stuff needed to advance a thread to a GC-safe
71 point (single-stepping, read from unmapped memory etc) and implement it.
72 This would enable us to inline allocations and write barriers, for example,
73 or at least parts of them, like the write barrier checks.
74 We may need this also for handling precise info on stacks, even simple things
75 as having uninitialized data on the stack and having to wait for the prolog
76 to zero it. Not an issue for the last frame that we scan conservatively.
77 We could always not trust the value in the slots anyway.
79 *) modify the jit to save info about references in stack locations:
80 this can be done just for locals as a start, so that at least
81 part of the stack is handled precisely.
83 *) test/fix endianess issues
85 *) Implement a card table as the write barrier instead of remembered
86 sets? Card tables are not easy to implement with our current
87 memory layout. We have several different kinds of major heap
88 objects: Small objects in regular blocks, small objects in pinned
89 chunks and LOS objects. If we just have a pointer we have no way
90 to tell which kind of object it points into, therefore we cannot
91 know where its card table is. The least we have to do to make
92 this happen is to get rid of write barriers for indirect stores.
95 *) Get rid of write barriers for indirect stores. We can do this by
96 telling the GC to wbarrier-register an object once we do an ldloca
97 or ldelema on it, and to unregister it once it's not used anymore
98 (it can only travel downwards on the stack). The problem with
99 unregistering is that it needs to happen eventually no matter
100 what, even if exceptions are thrown, the thread aborts, etc.
101 Rodrigo suggested that we could do only the registering part and
102 let the collector find out (pessimistically) when it's safe to
103 unregister, namely when the stack pointer of the thread that
104 registered the object is higher than it was when the registering
105 happened. This might make for a good first implementation to get
106 some data on performance.
108 *) Some sort of blacklist support? Blacklists is a concept from the
109 Boehm GC: if during a conservative scan we find pointers to an
110 area which we might use as heap, we mark that area as unusable, so
111 pointer retention by random pinning pointers is reduced.
113 *) experiment with max small object size (very small right now - 2kb,
114 because it's tied to the max freelist size)
116 *) add an option to mmap the whole heap in one chunk: it makes for many
117 simplifications in the checks (put the nursery at the top and just use a single
118 check for inclusion/exclusion): the issue this has is that on 32 bit systems it's
119 not flexible (too much of the address space may be used by default or we can't
120 increase the heap as needed) and we'd need a race-free mechanism to return memory
121 back to the system (mprotect(PROT_NONE) will still keep the memory allocated if it
122 was written to, munmap is needed, but the following mmap may not find the same segment
125 *) memzero the major fragments after restarting the world and optionally a smaller
128 *) investigate having fragment zeroing threads
130 *) separate locks for finalization and other minor stuff to reduce
133 *) try a different copying order to improve memory locality
135 *) a thread abort after a store but before the write barrier will
136 prevent the write barrier from executing
138 *) specialized dynamically generated markers/copiers
140 *) Dynamically adjust TLAB size to the number of threads. If we have
141 too many threads that do allocation, we might need smaller TLABs,
142 and we might get better performance with larger TLABs if we only
143 have a handful of threads. We could sum up the space left in all
144 assigned TLABs and if that's more than some percentage of the
145 nursery size, reduce the TLAB size.
147 *) Explore placing unreachable objects on unused nursery memory.
148 Instead of memset'ng a region to zero, place an int[] covering it.
149 A good place to start is add_nursery_frag. The tricky thing here is
150 placing those objects atomically outside of a collection.
152 *) Allocation should use asymmetric Dekker synchronization:
153 http://blogs.oracle.com/dave/resource/Asymmetric-Dekker-Synchronization.txt
154 This should help weak consistency archs.
161 #define _XOPEN_SOURCE
162 #define _DARWIN_C_SOURCE
168 #ifdef HAVE_PTHREAD_H
171 #ifdef HAVE_PTHREAD_NP_H
172 #include <pthread_np.h>
180 #include "mono/sgen/sgen-gc.h"
181 #include "mono/sgen/sgen-cardtable.h"
182 #include "mono/sgen/sgen-protocol.h"
183 #include "mono/sgen/sgen-memory-governor.h"
184 #include "mono/sgen/sgen-hash-table.h"
185 #include "mono/sgen/sgen-pinning.h"
186 #include "mono/sgen/sgen-workers.h"
187 #include "mono/sgen/sgen-client.h"
188 #include "mono/sgen/sgen-pointer-queue.h"
189 #include "mono/sgen/gc-internal-agnostic.h"
190 #include "mono/utils/mono-proclib.h"
191 #include "mono/utils/mono-memory-model.h"
192 #include "mono/utils/hazard-pointer.h"
194 #include <mono/utils/memcheck.h>
196 #undef pthread_create
198 #undef pthread_detach
201 * ######################################################################
202 * ######## Types and constants used by the GC.
203 * ######################################################################
206 /* 0 means not initialized, 1 is initialized, -1 means in progress */
207 static int gc_initialized = 0;
208 /* If set, check if we need to do something every X allocations */
209 gboolean has_per_allocation_action;
210 /* If set, do a heap check every X allocation */
211 guint32 verify_before_allocs = 0;
212 /* If set, do a minor collection before every X allocation */
213 guint32 collect_before_allocs = 0;
214 /* If set, do a whole heap check before each collection */
215 static gboolean whole_heap_check_before_collection = FALSE;
216 /* If set, do a remset consistency check at various opportunities */
217 static gboolean remset_consistency_checks = FALSE;
218 /* If set, do a mod union consistency check before each finishing collection pause */
219 static gboolean mod_union_consistency_check = FALSE;
220 /* If set, check whether mark bits are consistent after major collections */
221 static gboolean check_mark_bits_after_major_collection = FALSE;
222 /* If set, check that all nursery objects are pinned/not pinned, depending on context */
223 static gboolean check_nursery_objects_pinned = FALSE;
224 /* If set, do a few checks when the concurrent collector is used */
225 static gboolean do_concurrent_checks = FALSE;
226 /* If set, do a plausibility check on the scan_starts before and after
228 static gboolean do_scan_starts_check = FALSE;
230 static gboolean disable_minor_collections = FALSE;
231 static gboolean disable_major_collections = FALSE;
232 static gboolean do_verify_nursery = FALSE;
233 static gboolean do_dump_nursery_content = FALSE;
234 static gboolean enable_nursery_canaries = FALSE;
236 static gboolean precleaning_enabled = TRUE;
238 #ifdef HEAVY_STATISTICS
239 guint64 stat_objects_alloced_degraded = 0;
240 guint64 stat_bytes_alloced_degraded = 0;
242 guint64 stat_copy_object_called_nursery = 0;
243 guint64 stat_objects_copied_nursery = 0;
244 guint64 stat_copy_object_called_major = 0;
245 guint64 stat_objects_copied_major = 0;
247 guint64 stat_scan_object_called_nursery = 0;
248 guint64 stat_scan_object_called_major = 0;
250 guint64 stat_slots_allocated_in_vain;
252 guint64 stat_nursery_copy_object_failed_from_space = 0;
253 guint64 stat_nursery_copy_object_failed_forwarded = 0;
254 guint64 stat_nursery_copy_object_failed_pinned = 0;
255 guint64 stat_nursery_copy_object_failed_to_space = 0;
257 static guint64 stat_wbarrier_add_to_global_remset = 0;
258 static guint64 stat_wbarrier_arrayref_copy = 0;
259 static guint64 stat_wbarrier_generic_store = 0;
260 static guint64 stat_wbarrier_generic_store_atomic = 0;
261 static guint64 stat_wbarrier_set_root = 0;
264 static guint64 stat_pinned_objects = 0;
266 static guint64 time_minor_pre_collection_fragment_clear = 0;
267 static guint64 time_minor_pinning = 0;
268 static guint64 time_minor_scan_remsets = 0;
269 static guint64 time_minor_scan_pinned = 0;
270 static guint64 time_minor_scan_roots = 0;
271 static guint64 time_minor_finish_gray_stack = 0;
272 static guint64 time_minor_fragment_creation = 0;
274 static guint64 time_major_pre_collection_fragment_clear = 0;
275 static guint64 time_major_pinning = 0;
276 static guint64 time_major_scan_pinned = 0;
277 static guint64 time_major_scan_roots = 0;
278 static guint64 time_major_scan_mod_union = 0;
279 static guint64 time_major_finish_gray_stack = 0;
280 static guint64 time_major_free_bigobjs = 0;
281 static guint64 time_major_los_sweep = 0;
282 static guint64 time_major_sweep = 0;
283 static guint64 time_major_fragment_creation = 0;
285 static guint64 time_max = 0;
287 static SGEN_TV_DECLARE (time_major_conc_collection_start);
288 static SGEN_TV_DECLARE (time_major_conc_collection_end);
290 int gc_debug_level = 0;
292 static char* gc_params_options;
293 static char* gc_debug_options;
297 mono_gc_flush_info (void)
299 fflush (gc_debug_file);
303 #define TV_DECLARE SGEN_TV_DECLARE
304 #define TV_GETTIME SGEN_TV_GETTIME
305 #define TV_ELAPSED SGEN_TV_ELAPSED
307 static SGEN_TV_DECLARE (sgen_init_timestamp);
309 NurseryClearPolicy nursery_clear_policy = CLEAR_AT_TLAB_CREATION;
311 #define object_is_forwarded SGEN_OBJECT_IS_FORWARDED
312 #define object_is_pinned SGEN_OBJECT_IS_PINNED
313 #define pin_object SGEN_PIN_OBJECT
315 #define ptr_in_nursery sgen_ptr_in_nursery
317 #define LOAD_VTABLE SGEN_LOAD_VTABLE
320 nursery_canaries_enabled (void)
322 return enable_nursery_canaries;
325 #define safe_object_get_size sgen_safe_object_get_size
327 #if defined(HAVE_CONC_GC_AS_DEFAULT)
328 /* Use concurrent major on deskstop platforms */
329 #define DEFAULT_MAJOR_INIT sgen_marksweep_conc_init
330 #define DEFAULT_MAJOR_NAME "marksweep-conc"
332 #define DEFAULT_MAJOR_INIT sgen_marksweep_init
333 #define DEFAULT_MAJOR_NAME "marksweep"
337 * ######################################################################
338 * ######## Global data.
339 * ######################################################################
341 MonoCoopMutex gc_mutex;
343 #define SCAN_START_SIZE SGEN_SCAN_START_SIZE
345 size_t degraded_mode = 0;
347 static mword bytes_pinned_from_failed_allocation = 0;
349 GCMemSection *nursery_section = NULL;
350 static volatile mword lowest_heap_address = ~(mword)0;
351 static volatile mword highest_heap_address = 0;
353 MonoCoopMutex sgen_interruption_mutex;
355 int current_collection_generation = -1;
356 static volatile gboolean concurrent_collection_in_progress = FALSE;
358 /* objects that are ready to be finalized */
359 static SgenPointerQueue fin_ready_queue = SGEN_POINTER_QUEUE_INIT (INTERNAL_MEM_FINALIZE_READY);
360 static SgenPointerQueue critical_fin_queue = SGEN_POINTER_QUEUE_INIT (INTERNAL_MEM_FINALIZE_READY);
362 /* registered roots: the key to the hash is the root start address */
364 * Different kinds of roots are kept separate to speed up pin_from_roots () for example.
366 SgenHashTable roots_hash [ROOT_TYPE_NUM] = {
367 SGEN_HASH_TABLE_INIT (INTERNAL_MEM_ROOTS_TABLE, INTERNAL_MEM_ROOT_RECORD, sizeof (RootRecord), sgen_aligned_addr_hash, NULL),
368 SGEN_HASH_TABLE_INIT (INTERNAL_MEM_ROOTS_TABLE, INTERNAL_MEM_ROOT_RECORD, sizeof (RootRecord), sgen_aligned_addr_hash, NULL),
369 SGEN_HASH_TABLE_INIT (INTERNAL_MEM_ROOTS_TABLE, INTERNAL_MEM_ROOT_RECORD, sizeof (RootRecord), sgen_aligned_addr_hash, NULL)
371 static mword roots_size = 0; /* amount of memory in the root set */
373 /* The size of a TLAB */
374 /* The bigger the value, the less often we have to go to the slow path to allocate a new
375 * one, but the more space is wasted by threads not allocating much memory.
377 * FIXME: Make this self-tuning for each thread.
379 guint32 tlab_size = (1024 * 4);
381 #define MAX_SMALL_OBJ_SIZE SGEN_MAX_SMALL_OBJ_SIZE
383 #define ALLOC_ALIGN SGEN_ALLOC_ALIGN
385 #define ALIGN_UP SGEN_ALIGN_UP
387 #ifdef SGEN_DEBUG_INTERNAL_ALLOC
388 MonoNativeThreadId main_gc_thread = NULL;
391 /*Object was pinned during the current collection*/
392 static mword objects_pinned;
395 * ######################################################################
396 * ######## Macros and function declarations.
397 * ######################################################################
400 /* forward declarations */
401 static void scan_from_registered_roots (char *addr_start, char *addr_end, int root_type, ScanCopyContext ctx);
403 static void pin_from_roots (void *start_nursery, void *end_nursery, ScanCopyContext ctx);
404 static void finish_gray_stack (int generation, ScanCopyContext ctx);
407 SgenMajorCollector major_collector;
408 SgenMinorCollector sgen_minor_collector;
410 static SgenRememberedSet remset;
413 * The gray queue a worker job must use. If we're not parallel or
414 * concurrent, we use the main gray queue.
416 static SgenGrayQueue*
417 sgen_workers_get_job_gray_queue (WorkerData *worker_data, SgenGrayQueue *default_gray_queue)
420 return &worker_data->private_gray_queue;
421 SGEN_ASSERT (0, default_gray_queue, "Why don't we have a default gray queue when we're not running in a worker thread?");
422 return default_gray_queue;
426 gray_queue_redirect (SgenGrayQueue *queue)
428 SGEN_ASSERT (0, concurrent_collection_in_progress, "Where are we redirecting the gray queue to, without a concurrent collection?");
430 sgen_workers_take_from_queue (queue);
434 sgen_scan_area_with_callback (char *start, char *end, IterateObjectCallbackFunc callback, void *data, gboolean allow_flags, gboolean fail_on_canaries)
436 while (start < end) {
440 if (!*(void**)start) {
441 start += sizeof (void*); /* should be ALLOC_ALIGN, really */
446 if (!(obj = (char *)SGEN_OBJECT_IS_FORWARDED (start)))
452 if (!sgen_client_object_is_array_fill ((GCObject*)obj)) {
453 CHECK_CANARY_FOR_OBJECT ((GCObject*)obj, fail_on_canaries);
454 size = ALIGN_UP (safe_object_get_size ((GCObject*)obj));
455 callback ((GCObject*)obj, size, data);
456 CANARIFY_SIZE (size);
458 size = ALIGN_UP (safe_object_get_size ((GCObject*)obj));
466 * sgen_add_to_global_remset:
468 * The global remset contains locations which point into newspace after
469 * a minor collection. This can happen if the objects they point to are pinned.
471 * LOCKING: If called from a parallel collector, the global remset
472 * lock must be held. For serial collectors that is not necessary.
475 sgen_add_to_global_remset (gpointer ptr, GCObject *obj)
477 SGEN_ASSERT (5, sgen_ptr_in_nursery (obj), "Target pointer of global remset must be in the nursery");
479 HEAVY_STAT (++stat_wbarrier_add_to_global_remset);
481 if (!major_collector.is_concurrent) {
482 SGEN_ASSERT (5, current_collection_generation != -1, "Global remsets can only be added during collections");
484 if (current_collection_generation == -1)
485 SGEN_ASSERT (5, sgen_concurrent_collection_in_progress (), "Global remsets outside of collection pauses can only be added by the concurrent collector");
488 if (!object_is_pinned (obj))
489 SGEN_ASSERT (5, sgen_minor_collector.is_split || sgen_concurrent_collection_in_progress (), "Non-pinned objects can only remain in nursery if it is a split nursery");
490 else if (sgen_cement_lookup_or_register (obj))
493 remset.record_pointer (ptr);
495 sgen_pin_stats_register_global_remset (obj);
497 SGEN_LOG (8, "Adding global remset for %p", ptr);
498 binary_protocol_global_remset (ptr, obj, (gpointer)SGEN_LOAD_VTABLE (obj));
502 * sgen_drain_gray_stack:
504 * Scan objects in the gray stack until the stack is empty. This should be called
505 * frequently after each object is copied, to achieve better locality and cache
510 sgen_drain_gray_stack (ScanCopyContext ctx)
512 SGEN_ASSERT (0, ctx.ops->drain_gray_stack, "Why do we have a scan/copy context with a missing drain gray stack function?");
514 return ctx.ops->drain_gray_stack (ctx.queue);
518 * Addresses in the pin queue are already sorted. This function finds
519 * the object header for each address and pins the object. The
520 * addresses must be inside the nursery section. The (start of the)
521 * address array is overwritten with the addresses of the actually
522 * pinned objects. Return the number of pinned objects.
525 pin_objects_from_nursery_pin_queue (gboolean do_scan_objects, ScanCopyContext ctx)
527 GCMemSection *section = nursery_section;
528 void **start = sgen_pinning_get_entry (section->pin_queue_first_entry);
529 void **end = sgen_pinning_get_entry (section->pin_queue_last_entry);
530 void *start_nursery = section->data;
531 void *end_nursery = section->next_data;
536 void *pinning_front = start_nursery;
538 void **definitely_pinned = start;
539 ScanObjectFunc scan_func = ctx.ops->scan_object;
540 SgenGrayQueue *queue = ctx.queue;
542 sgen_nursery_allocator_prepare_for_pinning ();
544 while (start < end) {
545 GCObject *obj_to_pin = NULL;
546 size_t obj_to_pin_size = 0;
551 SGEN_ASSERT (0, addr >= start_nursery && addr < end_nursery, "Potential pinning address out of range");
552 SGEN_ASSERT (0, addr >= last, "Pin queue not sorted");
559 SGEN_LOG (5, "Considering pinning addr %p", addr);
560 /* We've already processed everything up to pinning_front. */
561 if (addr < pinning_front) {
567 * Find the closest scan start <= addr. We might search backward in the
568 * scan_starts array because entries might be NULL. In the worst case we
569 * start at start_nursery.
571 idx = ((char*)addr - (char*)section->data) / SCAN_START_SIZE;
572 SGEN_ASSERT (0, idx < section->num_scan_start, "Scan start index out of range");
573 search_start = (void*)section->scan_starts [idx];
574 if (!search_start || search_start > addr) {
577 search_start = section->scan_starts [idx];
578 if (search_start && search_start <= addr)
581 if (!search_start || search_start > addr)
582 search_start = start_nursery;
586 * If the pinning front is closer than the scan start we found, start
587 * searching at the front.
589 if (search_start < pinning_front)
590 search_start = pinning_front;
593 * Now addr should be in an object a short distance from search_start.
595 * search_start must point to zeroed mem or point to an object.
598 size_t obj_size, canarified_obj_size;
601 if (!*(void**)search_start) {
602 search_start = (void*)ALIGN_UP ((mword)search_start + sizeof (gpointer));
603 /* The loop condition makes sure we don't overrun addr. */
607 canarified_obj_size = obj_size = ALIGN_UP (safe_object_get_size ((GCObject*)search_start));
610 * Filler arrays are marked by an invalid sync word. We don't
611 * consider them for pinning. They are not delimited by canaries,
614 if (!sgen_client_object_is_array_fill ((GCObject*)search_start)) {
615 CHECK_CANARY_FOR_OBJECT (search_start, TRUE);
616 CANARIFY_SIZE (canarified_obj_size);
618 if (addr >= search_start && (char*)addr < (char*)search_start + obj_size) {
619 /* This is the object we're looking for. */
620 obj_to_pin = (GCObject*)search_start;
621 obj_to_pin_size = canarified_obj_size;
626 /* Skip to the next object */
627 search_start = (void*)((char*)search_start + canarified_obj_size);
628 } while (search_start <= addr);
630 /* We've searched past the address we were looking for. */
632 pinning_front = search_start;
633 goto next_pin_queue_entry;
637 * We've found an object to pin. It might still be a dummy array, but we
638 * can advance the pinning front in any case.
640 pinning_front = (char*)obj_to_pin + obj_to_pin_size;
643 * If this is a dummy array marking the beginning of a nursery
644 * fragment, we don't pin it.
646 if (sgen_client_object_is_array_fill (obj_to_pin))
647 goto next_pin_queue_entry;
650 * Finally - pin the object!
652 desc = sgen_obj_get_descriptor_safe (obj_to_pin);
653 if (do_scan_objects) {
654 scan_func (obj_to_pin, desc, queue);
656 SGEN_LOG (4, "Pinned object %p, vtable %p (%s), count %d\n",
657 obj_to_pin, *(void**)obj_to_pin, sgen_client_vtable_get_name (SGEN_LOAD_VTABLE (obj_to_pin)), count);
658 binary_protocol_pin (obj_to_pin,
659 (gpointer)LOAD_VTABLE (obj_to_pin),
660 safe_object_get_size (obj_to_pin));
662 pin_object (obj_to_pin);
663 GRAY_OBJECT_ENQUEUE_SERIAL (queue, obj_to_pin, desc);
664 sgen_pin_stats_register_object (obj_to_pin, GENERATION_NURSERY);
665 definitely_pinned [count] = obj_to_pin;
668 if (concurrent_collection_in_progress)
669 sgen_pinning_register_pinned_in_nursery (obj_to_pin);
671 next_pin_queue_entry:
675 sgen_client_nursery_objects_pinned (definitely_pinned, count);
676 stat_pinned_objects += count;
681 pin_objects_in_nursery (gboolean do_scan_objects, ScanCopyContext ctx)
685 if (nursery_section->pin_queue_first_entry == nursery_section->pin_queue_last_entry)
688 reduced_to = pin_objects_from_nursery_pin_queue (do_scan_objects, ctx);
689 nursery_section->pin_queue_last_entry = nursery_section->pin_queue_first_entry + reduced_to;
693 * This function is only ever called (via `collector_pin_object()` in `sgen-copy-object.h`)
694 * when we can't promote an object because we're out of memory.
697 sgen_pin_object (GCObject *object, SgenGrayQueue *queue)
699 SGEN_ASSERT (0, sgen_ptr_in_nursery (object), "We're only supposed to use this for pinning nursery objects when out of memory.");
702 * All pinned objects are assumed to have been staged, so we need to stage as well.
703 * Also, the count of staged objects shows that "late pinning" happened.
705 sgen_pin_stage_ptr (object);
707 SGEN_PIN_OBJECT (object);
708 binary_protocol_pin (object, (gpointer)LOAD_VTABLE (object), safe_object_get_size (object));
711 sgen_pin_stats_register_object (object, GENERATION_NURSERY);
713 GRAY_OBJECT_ENQUEUE_SERIAL (queue, object, sgen_obj_get_descriptor_safe (object));
716 /* Sort the addresses in array in increasing order.
717 * Done using a by-the book heap sort. Which has decent and stable performance, is pretty cache efficient.
720 sgen_sort_addresses (void **array, size_t size)
725 for (i = 1; i < size; ++i) {
728 size_t parent = (child - 1) / 2;
730 if (array [parent] >= array [child])
733 tmp = array [parent];
734 array [parent] = array [child];
741 for (i = size - 1; i > 0; --i) {
744 array [i] = array [0];
750 while (root * 2 + 1 <= end) {
751 size_t child = root * 2 + 1;
753 if (child < end && array [child] < array [child + 1])
755 if (array [root] >= array [child])
759 array [root] = array [child];
768 * Scan the memory between start and end and queue values which could be pointers
769 * to the area between start_nursery and end_nursery for later consideration.
770 * Typically used for thread stacks.
773 sgen_conservatively_pin_objects_from (void **start, void **end, void *start_nursery, void *end_nursery, int pin_type)
777 SGEN_ASSERT (0, ((mword)start & (SIZEOF_VOID_P - 1)) == 0, "Why are we scanning for references in unaligned memory ?");
779 #if defined(VALGRIND_MAKE_MEM_DEFINED_IF_ADDRESSABLE) && !defined(_WIN64)
780 VALGRIND_MAKE_MEM_DEFINED_IF_ADDRESSABLE (start, (char*)end - (char*)start);
783 while (start < end) {
785 * *start can point to the middle of an object
786 * note: should we handle pointing at the end of an object?
787 * pinning in C# code disallows pointing at the end of an object
788 * but there is some small chance that an optimizing C compiler
789 * may keep the only reference to an object by pointing
790 * at the end of it. We ignore this small chance for now.
791 * Pointers to the end of an object are indistinguishable
792 * from pointers to the start of the next object in memory
793 * so if we allow that we'd need to pin two objects...
794 * We queue the pointer in an array, the
795 * array will then be sorted and uniqued. This way
796 * we can coalesce several pinning pointers and it should
797 * be faster since we'd do a memory scan with increasing
798 * addresses. Note: we can align the address to the allocation
799 * alignment, so the unique process is more effective.
801 mword addr = (mword)*start;
802 addr &= ~(ALLOC_ALIGN - 1);
803 if (addr >= (mword)start_nursery && addr < (mword)end_nursery) {
804 SGEN_LOG (6, "Pinning address %p from %p", (void*)addr, start);
805 sgen_pin_stage_ptr ((void*)addr);
806 binary_protocol_pin_stage (start, (void*)addr);
807 sgen_pin_stats_register_address ((char*)addr, pin_type);
813 SGEN_LOG (7, "found %d potential pinned heap pointers", count);
817 * The first thing we do in a collection is to identify pinned objects.
818 * This function considers all the areas of memory that need to be
819 * conservatively scanned.
822 pin_from_roots (void *start_nursery, void *end_nursery, ScanCopyContext ctx)
826 SGEN_LOG (2, "Scanning pinned roots (%d bytes, %d/%d entries)", (int)roots_size, roots_hash [ROOT_TYPE_NORMAL].num_entries, roots_hash [ROOT_TYPE_PINNED].num_entries);
827 /* objects pinned from the API are inside these roots */
828 SGEN_HASH_TABLE_FOREACH (&roots_hash [ROOT_TYPE_PINNED], void **, start_root, RootRecord *, root) {
829 SGEN_LOG (6, "Pinned roots %p-%p", start_root, root->end_root);
830 sgen_conservatively_pin_objects_from (start_root, (void**)root->end_root, start_nursery, end_nursery, PIN_TYPE_OTHER);
831 } SGEN_HASH_TABLE_FOREACH_END;
832 /* now deal with the thread stacks
833 * in the future we should be able to conservatively scan only:
834 * *) the cpu registers
835 * *) the unmanaged stack frames
836 * *) the _last_ managed stack frame
837 * *) pointers slots in managed frames
839 sgen_client_scan_thread_data (start_nursery, end_nursery, FALSE, ctx);
843 single_arg_user_copy_or_mark (GCObject **obj, void *gc_data)
845 ScanCopyContext *ctx = (ScanCopyContext *)gc_data;
846 ctx->ops->copy_or_mark_object (obj, ctx->queue);
850 * The memory area from start_root to end_root contains pointers to objects.
851 * Their position is precisely described by @desc (this means that the pointer
852 * can be either NULL or the pointer to the start of an object).
853 * This functions copies them to to_space updates them.
855 * This function is not thread-safe!
858 precisely_scan_objects_from (void** start_root, void** end_root, char* n_start, char *n_end, SgenDescriptor desc, ScanCopyContext ctx)
860 CopyOrMarkObjectFunc copy_func = ctx.ops->copy_or_mark_object;
861 SgenGrayQueue *queue = ctx.queue;
863 switch (desc & ROOT_DESC_TYPE_MASK) {
864 case ROOT_DESC_BITMAP:
865 desc >>= ROOT_DESC_TYPE_SHIFT;
867 if ((desc & 1) && *start_root) {
868 copy_func ((GCObject**)start_root, queue);
869 SGEN_LOG (9, "Overwrote root at %p with %p", start_root, *start_root);
875 case ROOT_DESC_COMPLEX: {
876 gsize *bitmap_data = (gsize *)sgen_get_complex_descriptor_bitmap (desc);
877 gsize bwords = (*bitmap_data) - 1;
878 void **start_run = start_root;
880 while (bwords-- > 0) {
881 gsize bmap = *bitmap_data++;
882 void **objptr = start_run;
884 if ((bmap & 1) && *objptr) {
885 copy_func ((GCObject**)objptr, queue);
886 SGEN_LOG (9, "Overwrote root at %p with %p", objptr, *objptr);
891 start_run += GC_BITS_PER_WORD;
895 case ROOT_DESC_USER: {
896 SgenUserRootMarkFunc marker = sgen_get_user_descriptor_func (desc);
897 marker (start_root, single_arg_user_copy_or_mark, &ctx);
900 case ROOT_DESC_RUN_LEN:
901 g_assert_not_reached ();
903 g_assert_not_reached ();
908 reset_heap_boundaries (void)
910 lowest_heap_address = ~(mword)0;
911 highest_heap_address = 0;
915 sgen_update_heap_boundaries (mword low, mword high)
920 old = lowest_heap_address;
923 } while (SGEN_CAS_PTR ((gpointer*)&lowest_heap_address, (gpointer)low, (gpointer)old) != (gpointer)old);
926 old = highest_heap_address;
929 } while (SGEN_CAS_PTR ((gpointer*)&highest_heap_address, (gpointer)high, (gpointer)old) != (gpointer)old);
933 * Allocate and setup the data structures needed to be able to allocate objects
934 * in the nursery. The nursery is stored in nursery_section.
939 GCMemSection *section;
946 SGEN_LOG (2, "Allocating nursery size: %zu", (size_t)sgen_nursery_size);
947 /* later we will alloc a larger area for the nursery but only activate
948 * what we need. The rest will be used as expansion if we have too many pinned
949 * objects in the existing nursery.
951 /* FIXME: handle OOM */
952 section = (GCMemSection *)sgen_alloc_internal (INTERNAL_MEM_SECTION);
954 alloc_size = sgen_nursery_size;
956 /* If there isn't enough space even for the nursery we should simply abort. */
957 g_assert (sgen_memgov_try_alloc_space (alloc_size, SPACE_NURSERY));
959 data = (char *)major_collector.alloc_heap (alloc_size, alloc_size, DEFAULT_NURSERY_BITS);
960 sgen_update_heap_boundaries ((mword)data, (mword)(data + sgen_nursery_size));
961 SGEN_LOG (4, "Expanding nursery size (%p-%p): %lu, total: %lu", data, data + alloc_size, (unsigned long)sgen_nursery_size, (unsigned long)sgen_gc_get_total_heap_allocation ());
962 section->data = section->next_data = data;
963 section->size = alloc_size;
964 section->end_data = data + sgen_nursery_size;
965 scan_starts = (alloc_size + SCAN_START_SIZE - 1) / SCAN_START_SIZE;
966 section->scan_starts = (char **)sgen_alloc_internal_dynamic (sizeof (char*) * scan_starts, INTERNAL_MEM_SCAN_STARTS, TRUE);
967 section->num_scan_start = scan_starts;
969 nursery_section = section;
971 sgen_nursery_allocator_set_nursery_bounds (data, data + sgen_nursery_size);
975 mono_gc_get_logfile (void)
977 return gc_debug_file;
981 mono_gc_params_set (const char* options)
983 if (gc_params_options)
984 g_free (gc_params_options);
986 gc_params_options = g_strdup (options);
990 mono_gc_debug_set (const char* options)
992 if (gc_debug_options)
993 g_free (gc_debug_options);
995 gc_debug_options = g_strdup (options);
999 scan_finalizer_entries (SgenPointerQueue *fin_queue, ScanCopyContext ctx)
1001 CopyOrMarkObjectFunc copy_func = ctx.ops->copy_or_mark_object;
1002 SgenGrayQueue *queue = ctx.queue;
1005 for (i = 0; i < fin_queue->next_slot; ++i) {
1006 GCObject *obj = (GCObject *)fin_queue->data [i];
1009 SGEN_LOG (5, "Scan of fin ready object: %p (%s)\n", obj, sgen_client_vtable_get_name (SGEN_LOAD_VTABLE (obj)));
1010 copy_func ((GCObject**)&fin_queue->data [i], queue);
1015 generation_name (int generation)
1017 switch (generation) {
1018 case GENERATION_NURSERY: return "nursery";
1019 case GENERATION_OLD: return "old";
1020 default: g_assert_not_reached ();
1025 sgen_generation_name (int generation)
1027 return generation_name (generation);
1031 finish_gray_stack (int generation, ScanCopyContext ctx)
1035 int done_with_ephemerons, ephemeron_rounds = 0;
1036 char *start_addr = generation == GENERATION_NURSERY ? sgen_get_nursery_start () : NULL;
1037 char *end_addr = generation == GENERATION_NURSERY ? sgen_get_nursery_end () : (char*)-1;
1038 SgenGrayQueue *queue = ctx.queue;
1040 binary_protocol_finish_gray_stack_start (sgen_timestamp (), generation);
1042 * We copied all the reachable objects. Now it's the time to copy
1043 * the objects that were not referenced by the roots, but by the copied objects.
1044 * we built a stack of objects pointed to by gray_start: they are
1045 * additional roots and we may add more items as we go.
1046 * We loop until gray_start == gray_objects which means no more objects have
1047 * been added. Note this is iterative: no recursion is involved.
1048 * We need to walk the LO list as well in search of marked big objects
1049 * (use a flag since this is needed only on major collections). We need to loop
1050 * here as well, so keep a counter of marked LO (increasing it in copy_object).
1051 * To achieve better cache locality and cache usage, we drain the gray stack
1052 * frequently, after each object is copied, and just finish the work here.
1054 sgen_drain_gray_stack (ctx);
1056 SGEN_LOG (2, "%s generation done", generation_name (generation));
1059 Reset bridge data, we might have lingering data from a previous collection if this is a major
1060 collection trigged by minor overflow.
1062 We must reset the gathered bridges since their original block might be evacuated due to major
1063 fragmentation in the meanwhile and the bridge code should not have to deal with that.
1065 if (sgen_client_bridge_need_processing ())
1066 sgen_client_bridge_reset_data ();
1069 * Mark all strong toggleref objects. This must be done before we walk ephemerons or finalizers
1070 * to ensure they see the full set of live objects.
1072 sgen_client_mark_togglerefs (start_addr, end_addr, ctx);
1075 * Walk the ephemeron tables marking all values with reachable keys. This must be completely done
1076 * before processing finalizable objects and non-tracking weak links to avoid finalizing/clearing
1077 * objects that are in fact reachable.
1079 done_with_ephemerons = 0;
1081 done_with_ephemerons = sgen_client_mark_ephemerons (ctx);
1082 sgen_drain_gray_stack (ctx);
1084 } while (!done_with_ephemerons);
1086 if (sgen_client_bridge_need_processing ()) {
1087 /*Make sure the gray stack is empty before we process bridge objects so we get liveness right*/
1088 sgen_drain_gray_stack (ctx);
1089 sgen_collect_bridge_objects (generation, ctx);
1090 if (generation == GENERATION_OLD)
1091 sgen_collect_bridge_objects (GENERATION_NURSERY, ctx);
1094 Do the first bridge step here, as the collector liveness state will become useless after that.
1096 An important optimization is to only proccess the possibly dead part of the object graph and skip
1097 over all live objects as we transitively know everything they point must be alive too.
1099 The above invariant is completely wrong if we let the gray queue be drained and mark/copy everything.
1101 This has the unfortunate side effect of making overflow collections perform the first step twice, but
1102 given we now have heuristics that perform major GC in anticipation of minor overflows this should not
1105 sgen_client_bridge_processing_stw_step ();
1109 Make sure we drain the gray stack before processing disappearing links and finalizers.
1110 If we don't make sure it is empty we might wrongly see a live object as dead.
1112 sgen_drain_gray_stack (ctx);
1115 We must clear weak links that don't track resurrection before processing object ready for
1116 finalization so they can be cleared before that.
1118 sgen_null_link_in_range (generation, ctx, FALSE);
1119 if (generation == GENERATION_OLD)
1120 sgen_null_link_in_range (GENERATION_NURSERY, ctx, FALSE);
1123 /* walk the finalization queue and move also the objects that need to be
1124 * finalized: use the finalized objects as new roots so the objects they depend
1125 * on are also not reclaimed. As with the roots above, only objects in the nursery
1126 * are marked/copied.
1128 sgen_finalize_in_range (generation, ctx);
1129 if (generation == GENERATION_OLD)
1130 sgen_finalize_in_range (GENERATION_NURSERY, ctx);
1131 /* drain the new stack that might have been created */
1132 SGEN_LOG (6, "Precise scan of gray area post fin");
1133 sgen_drain_gray_stack (ctx);
1136 * This must be done again after processing finalizable objects since CWL slots are cleared only after the key is finalized.
1138 done_with_ephemerons = 0;
1140 done_with_ephemerons = sgen_client_mark_ephemerons (ctx);
1141 sgen_drain_gray_stack (ctx);
1143 } while (!done_with_ephemerons);
1145 sgen_client_clear_unreachable_ephemerons (ctx);
1148 * We clear togglerefs only after all possible chances of revival are done.
1149 * This is semantically more inline with what users expect and it allows for
1150 * user finalizers to correctly interact with TR objects.
1152 sgen_client_clear_togglerefs (start_addr, end_addr, ctx);
1155 SGEN_LOG (2, "Finalize queue handling scan for %s generation: %lld usecs %d ephemeron rounds", generation_name (generation), (long long)TV_ELAPSED (atv, btv), ephemeron_rounds);
1158 * handle disappearing links
1159 * Note we do this after checking the finalization queue because if an object
1160 * survives (at least long enough to be finalized) we don't clear the link.
1161 * This also deals with a possible issue with the monitor reclamation: with the Boehm
1162 * GC a finalized object my lose the monitor because it is cleared before the finalizer is
1165 g_assert (sgen_gray_object_queue_is_empty (queue));
1167 sgen_null_link_in_range (generation, ctx, TRUE);
1168 if (generation == GENERATION_OLD)
1169 sgen_null_link_in_range (GENERATION_NURSERY, ctx, TRUE);
1170 if (sgen_gray_object_queue_is_empty (queue))
1172 sgen_drain_gray_stack (ctx);
1175 g_assert (sgen_gray_object_queue_is_empty (queue));
1177 binary_protocol_finish_gray_stack_end (sgen_timestamp (), generation);
1181 sgen_check_section_scan_starts (GCMemSection *section)
1184 for (i = 0; i < section->num_scan_start; ++i) {
1185 if (section->scan_starts [i]) {
1186 mword size = safe_object_get_size ((GCObject*) section->scan_starts [i]);
1187 SGEN_ASSERT (0, size >= SGEN_CLIENT_MINIMUM_OBJECT_SIZE && size <= MAX_SMALL_OBJ_SIZE, "Weird object size at scan starts.");
1193 check_scan_starts (void)
1195 if (!do_scan_starts_check)
1197 sgen_check_section_scan_starts (nursery_section);
1198 major_collector.check_scan_starts ();
1202 scan_from_registered_roots (char *addr_start, char *addr_end, int root_type, ScanCopyContext ctx)
1206 SGEN_HASH_TABLE_FOREACH (&roots_hash [root_type], void **, start_root, RootRecord *, root) {
1207 SGEN_LOG (6, "Precise root scan %p-%p (desc: %p)", start_root, root->end_root, (void*)root->root_desc);
1208 precisely_scan_objects_from (start_root, (void**)root->end_root, addr_start, addr_end, root->root_desc, ctx);
1209 } SGEN_HASH_TABLE_FOREACH_END;
1215 static gboolean inited = FALSE;
1220 mono_counters_register ("Collection max time", MONO_COUNTER_GC | MONO_COUNTER_ULONG | MONO_COUNTER_TIME | MONO_COUNTER_MONOTONIC, &time_max);
1222 mono_counters_register ("Minor fragment clear", MONO_COUNTER_GC | MONO_COUNTER_ULONG | MONO_COUNTER_TIME, &time_minor_pre_collection_fragment_clear);
1223 mono_counters_register ("Minor pinning", MONO_COUNTER_GC | MONO_COUNTER_ULONG | MONO_COUNTER_TIME, &time_minor_pinning);
1224 mono_counters_register ("Minor scan remembered set", MONO_COUNTER_GC | MONO_COUNTER_ULONG | MONO_COUNTER_TIME, &time_minor_scan_remsets);
1225 mono_counters_register ("Minor scan pinned", MONO_COUNTER_GC | MONO_COUNTER_ULONG | MONO_COUNTER_TIME, &time_minor_scan_pinned);
1226 mono_counters_register ("Minor scan roots", MONO_COUNTER_GC | MONO_COUNTER_ULONG | MONO_COUNTER_TIME, &time_minor_scan_roots);
1227 mono_counters_register ("Minor fragment creation", MONO_COUNTER_GC | MONO_COUNTER_ULONG | MONO_COUNTER_TIME, &time_minor_fragment_creation);
1229 mono_counters_register ("Major fragment clear", MONO_COUNTER_GC | MONO_COUNTER_ULONG | MONO_COUNTER_TIME, &time_major_pre_collection_fragment_clear);
1230 mono_counters_register ("Major pinning", MONO_COUNTER_GC | MONO_COUNTER_ULONG | MONO_COUNTER_TIME, &time_major_pinning);
1231 mono_counters_register ("Major scan pinned", MONO_COUNTER_GC | MONO_COUNTER_ULONG | MONO_COUNTER_TIME, &time_major_scan_pinned);
1232 mono_counters_register ("Major scan roots", MONO_COUNTER_GC | MONO_COUNTER_ULONG | MONO_COUNTER_TIME, &time_major_scan_roots);
1233 mono_counters_register ("Major scan mod union", MONO_COUNTER_GC | MONO_COUNTER_ULONG | MONO_COUNTER_TIME, &time_major_scan_mod_union);
1234 mono_counters_register ("Major finish gray stack", MONO_COUNTER_GC | MONO_COUNTER_ULONG | MONO_COUNTER_TIME, &time_major_finish_gray_stack);
1235 mono_counters_register ("Major free big objects", MONO_COUNTER_GC | MONO_COUNTER_ULONG | MONO_COUNTER_TIME, &time_major_free_bigobjs);
1236 mono_counters_register ("Major LOS sweep", MONO_COUNTER_GC | MONO_COUNTER_ULONG | MONO_COUNTER_TIME, &time_major_los_sweep);
1237 mono_counters_register ("Major sweep", MONO_COUNTER_GC | MONO_COUNTER_ULONG | MONO_COUNTER_TIME, &time_major_sweep);
1238 mono_counters_register ("Major fragment creation", MONO_COUNTER_GC | MONO_COUNTER_ULONG | MONO_COUNTER_TIME, &time_major_fragment_creation);
1240 mono_counters_register ("Number of pinned objects", MONO_COUNTER_GC | MONO_COUNTER_ULONG, &stat_pinned_objects);
1242 #ifdef HEAVY_STATISTICS
1243 mono_counters_register ("WBarrier remember pointer", MONO_COUNTER_GC | MONO_COUNTER_ULONG, &stat_wbarrier_add_to_global_remset);
1244 mono_counters_register ("WBarrier arrayref copy", MONO_COUNTER_GC | MONO_COUNTER_ULONG, &stat_wbarrier_arrayref_copy);
1245 mono_counters_register ("WBarrier generic store called", MONO_COUNTER_GC | MONO_COUNTER_ULONG, &stat_wbarrier_generic_store);
1246 mono_counters_register ("WBarrier generic atomic store called", MONO_COUNTER_GC | MONO_COUNTER_ULONG, &stat_wbarrier_generic_store_atomic);
1247 mono_counters_register ("WBarrier set root", MONO_COUNTER_GC | MONO_COUNTER_ULONG, &stat_wbarrier_set_root);
1249 mono_counters_register ("# objects allocated degraded", MONO_COUNTER_GC | MONO_COUNTER_ULONG, &stat_objects_alloced_degraded);
1250 mono_counters_register ("bytes allocated degraded", MONO_COUNTER_GC | MONO_COUNTER_ULONG, &stat_bytes_alloced_degraded);
1252 mono_counters_register ("# copy_object() called (nursery)", MONO_COUNTER_GC | MONO_COUNTER_ULONG, &stat_copy_object_called_nursery);
1253 mono_counters_register ("# objects copied (nursery)", MONO_COUNTER_GC | MONO_COUNTER_ULONG, &stat_objects_copied_nursery);
1254 mono_counters_register ("# copy_object() called (major)", MONO_COUNTER_GC | MONO_COUNTER_ULONG, &stat_copy_object_called_major);
1255 mono_counters_register ("# objects copied (major)", MONO_COUNTER_GC | MONO_COUNTER_ULONG, &stat_objects_copied_major);
1257 mono_counters_register ("# scan_object() called (nursery)", MONO_COUNTER_GC | MONO_COUNTER_ULONG, &stat_scan_object_called_nursery);
1258 mono_counters_register ("# scan_object() called (major)", MONO_COUNTER_GC | MONO_COUNTER_ULONG, &stat_scan_object_called_major);
1260 mono_counters_register ("Slots allocated in vain", MONO_COUNTER_GC | MONO_COUNTER_ULONG, &stat_slots_allocated_in_vain);
1262 mono_counters_register ("# nursery copy_object() failed from space", MONO_COUNTER_GC | MONO_COUNTER_ULONG, &stat_nursery_copy_object_failed_from_space);
1263 mono_counters_register ("# nursery copy_object() failed forwarded", MONO_COUNTER_GC | MONO_COUNTER_ULONG, &stat_nursery_copy_object_failed_forwarded);
1264 mono_counters_register ("# nursery copy_object() failed pinned", MONO_COUNTER_GC | MONO_COUNTER_ULONG, &stat_nursery_copy_object_failed_pinned);
1265 mono_counters_register ("# nursery copy_object() failed to space", MONO_COUNTER_GC | MONO_COUNTER_ULONG, &stat_nursery_copy_object_failed_to_space);
1267 sgen_nursery_allocator_init_heavy_stats ();
1275 reset_pinned_from_failed_allocation (void)
1277 bytes_pinned_from_failed_allocation = 0;
1281 sgen_set_pinned_from_failed_allocation (mword objsize)
1283 bytes_pinned_from_failed_allocation += objsize;
1287 sgen_collection_is_concurrent (void)
1289 switch (current_collection_generation) {
1290 case GENERATION_NURSERY:
1292 case GENERATION_OLD:
1293 return concurrent_collection_in_progress;
1295 g_error ("Invalid current generation %d", current_collection_generation);
1301 sgen_concurrent_collection_in_progress (void)
1303 return concurrent_collection_in_progress;
1307 SgenThreadPoolJob job;
1308 SgenObjectOperations *ops;
1309 SgenGrayQueue *gc_thread_gray_queue;
1317 static ScanCopyContext
1318 scan_copy_context_for_scan_job (void *worker_data_untyped, ScanJob *job)
1320 WorkerData *worker_data = (WorkerData *)worker_data_untyped;
1322 return CONTEXT_FROM_OBJECT_OPERATIONS (job->ops, sgen_workers_get_job_gray_queue (worker_data, job->gc_thread_gray_queue));
1326 job_remembered_set_scan (void *worker_data_untyped, SgenThreadPoolJob *job)
1328 remset.scan_remsets (scan_copy_context_for_scan_job (worker_data_untyped, (ScanJob*)job));
1336 } ScanFromRegisteredRootsJob;
1339 job_scan_from_registered_roots (void *worker_data_untyped, SgenThreadPoolJob *job)
1341 ScanFromRegisteredRootsJob *job_data = (ScanFromRegisteredRootsJob*)job;
1342 ScanCopyContext ctx = scan_copy_context_for_scan_job (worker_data_untyped, &job_data->scan_job);
1344 scan_from_registered_roots (job_data->heap_start, job_data->heap_end, job_data->root_type, ctx);
1351 } ScanThreadDataJob;
1354 job_scan_thread_data (void *worker_data_untyped, SgenThreadPoolJob *job)
1356 ScanThreadDataJob *job_data = (ScanThreadDataJob*)job;
1357 ScanCopyContext ctx = scan_copy_context_for_scan_job (worker_data_untyped, &job_data->scan_job);
1359 sgen_client_scan_thread_data (job_data->heap_start, job_data->heap_end, TRUE, ctx);
1364 SgenPointerQueue *queue;
1365 } ScanFinalizerEntriesJob;
1368 job_scan_finalizer_entries (void *worker_data_untyped, SgenThreadPoolJob *job)
1370 ScanFinalizerEntriesJob *job_data = (ScanFinalizerEntriesJob*)job;
1371 ScanCopyContext ctx = scan_copy_context_for_scan_job (worker_data_untyped, &job_data->scan_job);
1373 scan_finalizer_entries (job_data->queue, ctx);
1377 job_scan_major_mod_union_card_table (void *worker_data_untyped, SgenThreadPoolJob *job)
1379 ParallelScanJob *job_data = (ParallelScanJob*)job;
1380 ScanCopyContext ctx = scan_copy_context_for_scan_job (worker_data_untyped, (ScanJob*)job_data);
1382 g_assert (concurrent_collection_in_progress);
1383 major_collector.scan_card_table (CARDTABLE_SCAN_MOD_UNION, ctx, job_data->job_index, sgen_workers_get_job_split_count ());
1387 job_scan_los_mod_union_card_table (void *worker_data_untyped, SgenThreadPoolJob *job)
1389 ParallelScanJob *job_data = (ParallelScanJob*)job;
1390 ScanCopyContext ctx = scan_copy_context_for_scan_job (worker_data_untyped, (ScanJob*)job_data);
1392 g_assert (concurrent_collection_in_progress);
1393 sgen_los_scan_card_table (CARDTABLE_SCAN_MOD_UNION, ctx, job_data->job_index, sgen_workers_get_job_split_count ());
1397 job_major_mod_union_preclean (void *worker_data_untyped, SgenThreadPoolJob *job)
1399 ParallelScanJob *job_data = (ParallelScanJob*)job;
1400 ScanCopyContext ctx = scan_copy_context_for_scan_job (worker_data_untyped, (ScanJob*)job_data);
1402 g_assert (concurrent_collection_in_progress);
1404 major_collector.scan_card_table (CARDTABLE_SCAN_MOD_UNION_PRECLEAN, ctx, job_data->job_index, sgen_workers_get_job_split_count ());
1408 job_los_mod_union_preclean (void *worker_data_untyped, SgenThreadPoolJob *job)
1410 ParallelScanJob *job_data = (ParallelScanJob*)job;
1411 ScanCopyContext ctx = scan_copy_context_for_scan_job (worker_data_untyped, (ScanJob*)job_data);
1413 g_assert (concurrent_collection_in_progress);
1415 sgen_los_scan_card_table (CARDTABLE_SCAN_MOD_UNION_PRECLEAN, ctx, job_data->job_index, sgen_workers_get_job_split_count ());
1419 job_scan_last_pinned (void *worker_data_untyped, SgenThreadPoolJob *job)
1421 ScanJob *job_data = (ScanJob*)job;
1422 ScanCopyContext ctx = scan_copy_context_for_scan_job (worker_data_untyped, job_data);
1424 g_assert (concurrent_collection_in_progress);
1426 sgen_scan_pin_queue_objects (ctx);
1430 workers_finish_callback (void)
1432 ParallelScanJob *psj;
1434 int split_count = sgen_workers_get_job_split_count ();
1436 /* Mod union preclean jobs */
1437 for (i = 0; i < split_count; i++) {
1438 psj = (ParallelScanJob*)sgen_thread_pool_job_alloc ("preclean major mod union cardtable", job_major_mod_union_preclean, sizeof (ParallelScanJob));
1439 psj->scan_job.ops = sgen_workers_get_idle_func_object_ops ();
1440 psj->scan_job.gc_thread_gray_queue = NULL;
1442 sgen_workers_enqueue_job (&psj->scan_job.job, TRUE);
1445 for (i = 0; i < split_count; i++) {
1446 psj = (ParallelScanJob*)sgen_thread_pool_job_alloc ("preclean los mod union cardtable", job_los_mod_union_preclean, sizeof (ParallelScanJob));
1447 psj->scan_job.ops = sgen_workers_get_idle_func_object_ops ();
1448 psj->scan_job.gc_thread_gray_queue = NULL;
1450 sgen_workers_enqueue_job (&psj->scan_job.job, TRUE);
1453 sj = (ScanJob*)sgen_thread_pool_job_alloc ("scan last pinned", job_scan_last_pinned, sizeof (ScanJob));
1454 sj->ops = sgen_workers_get_idle_func_object_ops ();
1455 sj->gc_thread_gray_queue = NULL;
1456 sgen_workers_enqueue_job (&sj->job, TRUE);
1460 init_gray_queue (SgenGrayQueue *gc_thread_gray_queue, gboolean use_workers)
1463 sgen_workers_init_distribute_gray_queue ();
1464 sgen_gray_object_queue_init (gc_thread_gray_queue, NULL, TRUE);
1468 enqueue_scan_from_roots_jobs (SgenGrayQueue *gc_thread_gray_queue, char *heap_start, char *heap_end, SgenObjectOperations *ops, gboolean enqueue)
1470 ScanFromRegisteredRootsJob *scrrj;
1471 ScanThreadDataJob *stdj;
1472 ScanFinalizerEntriesJob *sfej;
1474 /* registered roots, this includes static fields */
1476 scrrj = (ScanFromRegisteredRootsJob*)sgen_thread_pool_job_alloc ("scan from registered roots normal", job_scan_from_registered_roots, sizeof (ScanFromRegisteredRootsJob));
1477 scrrj->scan_job.ops = ops;
1478 scrrj->scan_job.gc_thread_gray_queue = gc_thread_gray_queue;
1479 scrrj->heap_start = heap_start;
1480 scrrj->heap_end = heap_end;
1481 scrrj->root_type = ROOT_TYPE_NORMAL;
1482 sgen_workers_enqueue_job (&scrrj->scan_job.job, enqueue);
1484 scrrj = (ScanFromRegisteredRootsJob*)sgen_thread_pool_job_alloc ("scan from registered roots wbarrier", job_scan_from_registered_roots, sizeof (ScanFromRegisteredRootsJob));
1485 scrrj->scan_job.ops = ops;
1486 scrrj->scan_job.gc_thread_gray_queue = gc_thread_gray_queue;
1487 scrrj->heap_start = heap_start;
1488 scrrj->heap_end = heap_end;
1489 scrrj->root_type = ROOT_TYPE_WBARRIER;
1490 sgen_workers_enqueue_job (&scrrj->scan_job.job, enqueue);
1494 stdj = (ScanThreadDataJob*)sgen_thread_pool_job_alloc ("scan thread data", job_scan_thread_data, sizeof (ScanThreadDataJob));
1495 stdj->scan_job.ops = ops;
1496 stdj->scan_job.gc_thread_gray_queue = gc_thread_gray_queue;
1497 stdj->heap_start = heap_start;
1498 stdj->heap_end = heap_end;
1499 sgen_workers_enqueue_job (&stdj->scan_job.job, enqueue);
1501 /* Scan the list of objects ready for finalization. */
1503 sfej = (ScanFinalizerEntriesJob*)sgen_thread_pool_job_alloc ("scan finalizer entries", job_scan_finalizer_entries, sizeof (ScanFinalizerEntriesJob));
1504 sfej->scan_job.ops = ops;
1505 sfej->scan_job.gc_thread_gray_queue = gc_thread_gray_queue;
1506 sfej->queue = &fin_ready_queue;
1507 sgen_workers_enqueue_job (&sfej->scan_job.job, enqueue);
1509 sfej = (ScanFinalizerEntriesJob*)sgen_thread_pool_job_alloc ("scan critical finalizer entries", job_scan_finalizer_entries, sizeof (ScanFinalizerEntriesJob));
1510 sfej->scan_job.ops = ops;
1511 sfej->scan_job.gc_thread_gray_queue = gc_thread_gray_queue;
1512 sfej->queue = &critical_fin_queue;
1513 sgen_workers_enqueue_job (&sfej->scan_job.job, enqueue);
1517 * Perform a nursery collection.
1519 * Return whether any objects were late-pinned due to being out of memory.
1522 collect_nursery (const char *reason, gboolean is_overflow, SgenGrayQueue *unpin_queue)
1524 gboolean needs_major;
1525 size_t max_garbage_amount;
1527 mword fragment_total;
1529 SgenGrayQueue gc_thread_gray_queue;
1530 SgenObjectOperations *object_ops;
1531 ScanCopyContext ctx;
1534 SGEN_TV_DECLARE (last_minor_collection_start_tv);
1535 SGEN_TV_DECLARE (last_minor_collection_end_tv);
1537 if (disable_minor_collections)
1540 TV_GETTIME (last_minor_collection_start_tv);
1541 atv = last_minor_collection_start_tv;
1543 binary_protocol_collection_begin (gc_stats.minor_gc_count, GENERATION_NURSERY);
1545 if (sgen_concurrent_collection_in_progress ())
1546 object_ops = &sgen_minor_collector.serial_ops_with_concurrent_major;
1548 object_ops = &sgen_minor_collector.serial_ops;
1550 if (do_verify_nursery || do_dump_nursery_content)
1551 sgen_debug_verify_nursery (do_dump_nursery_content);
1553 current_collection_generation = GENERATION_NURSERY;
1555 SGEN_ASSERT (0, !sgen_collection_is_concurrent (), "Why is the nursery collection concurrent?");
1557 reset_pinned_from_failed_allocation ();
1559 check_scan_starts ();
1561 sgen_nursery_alloc_prepare_for_minor ();
1565 nursery_next = sgen_nursery_alloc_get_upper_alloc_bound ();
1566 /* FIXME: optimize later to use the higher address where an object can be present */
1567 nursery_next = MAX (nursery_next, sgen_get_nursery_end ());
1569 SGEN_LOG (1, "Start nursery collection %d %p-%p, size: %d", gc_stats.minor_gc_count, sgen_get_nursery_start (), nursery_next, (int)(nursery_next - sgen_get_nursery_start ()));
1570 max_garbage_amount = nursery_next - sgen_get_nursery_start ();
1571 g_assert (nursery_section->size >= max_garbage_amount);
1573 /* world must be stopped already */
1575 time_minor_pre_collection_fragment_clear += TV_ELAPSED (atv, btv);
1577 sgen_client_pre_collection_checks ();
1579 nursery_section->next_data = nursery_next;
1581 major_collector.start_nursery_collection ();
1583 sgen_memgov_minor_collection_start ();
1585 init_gray_queue (&gc_thread_gray_queue, FALSE);
1586 ctx = CONTEXT_FROM_OBJECT_OPERATIONS (object_ops, &gc_thread_gray_queue);
1588 gc_stats.minor_gc_count ++;
1590 sgen_process_fin_stage_entries ();
1592 /* pin from pinned handles */
1593 sgen_init_pinning ();
1594 sgen_client_binary_protocol_mark_start (GENERATION_NURSERY);
1595 pin_from_roots (sgen_get_nursery_start (), nursery_next, ctx);
1596 /* pin cemented objects */
1597 sgen_pin_cemented_objects ();
1598 /* identify pinned objects */
1599 sgen_optimize_pin_queue ();
1600 sgen_pinning_setup_section (nursery_section);
1602 pin_objects_in_nursery (FALSE, ctx);
1603 sgen_pinning_trim_queue_to_section (nursery_section);
1605 if (remset_consistency_checks)
1606 sgen_check_remset_consistency ();
1608 if (whole_heap_check_before_collection) {
1609 sgen_clear_nursery_fragments ();
1610 sgen_check_whole_heap (FALSE);
1614 time_minor_pinning += TV_ELAPSED (btv, atv);
1615 SGEN_LOG (2, "Finding pinned pointers: %zd in %lld usecs", sgen_get_pinned_count (), (long long)TV_ELAPSED (btv, atv));
1616 SGEN_LOG (4, "Start scan with %zd pinned objects", sgen_get_pinned_count ());
1618 sj = (ScanJob*)sgen_thread_pool_job_alloc ("scan remset", job_remembered_set_scan, sizeof (ScanJob));
1619 sj->ops = object_ops;
1620 sj->gc_thread_gray_queue = &gc_thread_gray_queue;
1621 sgen_workers_enqueue_job (&sj->job, FALSE);
1623 /* we don't have complete write barrier yet, so we scan all the old generation sections */
1625 time_minor_scan_remsets += TV_ELAPSED (atv, btv);
1626 SGEN_LOG (2, "Old generation scan: %lld usecs", (long long)TV_ELAPSED (atv, btv));
1628 sgen_pin_stats_report ();
1630 /* FIXME: Why do we do this at this specific, seemingly random, point? */
1631 sgen_client_collecting_minor (&fin_ready_queue, &critical_fin_queue);
1634 time_minor_scan_pinned += TV_ELAPSED (btv, atv);
1636 enqueue_scan_from_roots_jobs (&gc_thread_gray_queue, sgen_get_nursery_start (), nursery_next, object_ops, FALSE);
1639 time_minor_scan_roots += TV_ELAPSED (atv, btv);
1641 finish_gray_stack (GENERATION_NURSERY, ctx);
1644 time_minor_finish_gray_stack += TV_ELAPSED (btv, atv);
1645 sgen_client_binary_protocol_mark_end (GENERATION_NURSERY);
1647 if (objects_pinned) {
1648 sgen_optimize_pin_queue ();
1649 sgen_pinning_setup_section (nursery_section);
1653 * This is the latest point at which we can do this check, because
1654 * sgen_build_nursery_fragments() unpins nursery objects again.
1656 if (remset_consistency_checks)
1657 sgen_check_remset_consistency ();
1659 /* walk the pin_queue, build up the fragment list of free memory, unmark
1660 * pinned objects as we go, memzero() the empty fragments so they are ready for the
1663 sgen_client_binary_protocol_reclaim_start (GENERATION_NURSERY);
1664 fragment_total = sgen_build_nursery_fragments (nursery_section, unpin_queue);
1665 if (!fragment_total)
1668 /* Clear TLABs for all threads */
1669 sgen_clear_tlabs ();
1671 sgen_client_binary_protocol_reclaim_end (GENERATION_NURSERY);
1673 time_minor_fragment_creation += TV_ELAPSED (atv, btv);
1674 SGEN_LOG (2, "Fragment creation: %lld usecs, %lu bytes available", (long long)TV_ELAPSED (atv, btv), (unsigned long)fragment_total);
1676 if (remset_consistency_checks)
1677 sgen_check_major_refs ();
1679 major_collector.finish_nursery_collection ();
1681 TV_GETTIME (last_minor_collection_end_tv);
1682 gc_stats.minor_gc_time += TV_ELAPSED (last_minor_collection_start_tv, last_minor_collection_end_tv);
1684 sgen_debug_dump_heap ("minor", gc_stats.minor_gc_count - 1, NULL);
1686 /* prepare the pin queue for the next collection */
1687 sgen_finish_pinning ();
1688 if (sgen_have_pending_finalizers ()) {
1689 SGEN_LOG (4, "Finalizer-thread wakeup");
1690 sgen_client_finalize_notify ();
1692 sgen_pin_stats_reset ();
1693 /* clear cemented hash */
1694 sgen_cement_clear_below_threshold ();
1696 sgen_gray_object_queue_dispose (&gc_thread_gray_queue);
1698 remset.finish_minor_collection ();
1700 check_scan_starts ();
1702 binary_protocol_flush_buffers (FALSE);
1704 sgen_memgov_minor_collection_end (reason, is_overflow);
1706 /*objects are late pinned because of lack of memory, so a major is a good call*/
1707 needs_major = objects_pinned > 0;
1708 current_collection_generation = -1;
1711 binary_protocol_collection_end (gc_stats.minor_gc_count - 1, GENERATION_NURSERY, 0, 0);
1713 if (check_nursery_objects_pinned && !sgen_minor_collector.is_split)
1714 sgen_check_nursery_objects_pinned (unpin_queue != NULL);
1720 COPY_OR_MARK_FROM_ROOTS_SERIAL,
1721 COPY_OR_MARK_FROM_ROOTS_START_CONCURRENT,
1722 COPY_OR_MARK_FROM_ROOTS_FINISH_CONCURRENT
1723 } CopyOrMarkFromRootsMode;
1726 major_copy_or_mark_from_roots (SgenGrayQueue *gc_thread_gray_queue, size_t *old_next_pin_slot, CopyOrMarkFromRootsMode mode, SgenObjectOperations *object_ops_nopar, SgenObjectOperations *object_ops_par)
1731 /* FIXME: only use these values for the precise scan
1732 * note that to_space pointers should be excluded anyway...
1734 char *heap_start = NULL;
1735 char *heap_end = (char*)-1;
1736 ScanCopyContext ctx = CONTEXT_FROM_OBJECT_OPERATIONS (object_ops_nopar, gc_thread_gray_queue);
1737 gboolean concurrent = mode != COPY_OR_MARK_FROM_ROOTS_SERIAL;
1739 SGEN_ASSERT (0, !!concurrent == !!concurrent_collection_in_progress, "We've been called with the wrong mode.");
1741 if (mode == COPY_OR_MARK_FROM_ROOTS_START_CONCURRENT) {
1742 /*This cleans up unused fragments */
1743 sgen_nursery_allocator_prepare_for_pinning ();
1745 if (do_concurrent_checks)
1746 sgen_debug_check_nursery_is_clean ();
1748 /* The concurrent collector doesn't touch the nursery. */
1749 sgen_nursery_alloc_prepare_for_major ();
1754 /* Pinning depends on this */
1755 sgen_clear_nursery_fragments ();
1757 if (whole_heap_check_before_collection)
1758 sgen_check_whole_heap (TRUE);
1761 time_major_pre_collection_fragment_clear += TV_ELAPSED (atv, btv);
1763 if (!sgen_collection_is_concurrent ())
1764 nursery_section->next_data = sgen_get_nursery_end ();
1765 /* we should also coalesce scanning from sections close to each other
1766 * and deal with pointers outside of the sections later.
1771 sgen_client_pre_collection_checks ();
1773 if (mode != COPY_OR_MARK_FROM_ROOTS_START_CONCURRENT) {
1774 /* Remsets are not useful for a major collection */
1775 remset.clear_cards ();
1778 sgen_process_fin_stage_entries ();
1781 sgen_init_pinning ();
1782 SGEN_LOG (6, "Collecting pinned addresses");
1783 pin_from_roots ((void*)lowest_heap_address, (void*)highest_heap_address, ctx);
1784 if (mode == COPY_OR_MARK_FROM_ROOTS_FINISH_CONCURRENT) {
1785 /* Pin cemented objects that were forced */
1786 sgen_pin_cemented_objects ();
1788 sgen_optimize_pin_queue ();
1789 if (mode == COPY_OR_MARK_FROM_ROOTS_START_CONCURRENT) {
1791 * Cemented objects that are in the pinned list will be marked. When
1792 * marking concurrently we won't mark mod-union cards for these objects.
1793 * Instead they will remain cemented until the next major collection,
1794 * when we will recheck if they are still pinned in the roots.
1796 sgen_cement_force_pinned ();
1799 sgen_client_collecting_major_1 ();
1802 * pin_queue now contains all candidate pointers, sorted and
1803 * uniqued. We must do two passes now to figure out which
1804 * objects are pinned.
1806 * The first is to find within the pin_queue the area for each
1807 * section. This requires that the pin_queue be sorted. We
1808 * also process the LOS objects and pinned chunks here.
1810 * The second, destructive, pass is to reduce the section
1811 * areas to pointers to the actually pinned objects.
1813 SGEN_LOG (6, "Pinning from sections");
1814 /* first pass for the sections */
1815 sgen_find_section_pin_queue_start_end (nursery_section);
1816 /* identify possible pointers to the insize of large objects */
1817 SGEN_LOG (6, "Pinning from large objects");
1818 for (bigobj = los_object_list; bigobj; bigobj = bigobj->next) {
1820 if (sgen_find_optimized_pin_queue_area ((char*)bigobj->data, (char*)bigobj->data + sgen_los_object_size (bigobj), &dummy, &dummy)) {
1821 binary_protocol_pin (bigobj->data, (gpointer)LOAD_VTABLE (bigobj->data), safe_object_get_size (bigobj->data));
1823 if (sgen_los_object_is_pinned (bigobj->data)) {
1824 SGEN_ASSERT (0, mode == COPY_OR_MARK_FROM_ROOTS_FINISH_CONCURRENT, "LOS objects can only be pinned here after concurrent marking.");
1827 sgen_los_pin_object (bigobj->data);
1828 if (SGEN_OBJECT_HAS_REFERENCES (bigobj->data))
1829 GRAY_OBJECT_ENQUEUE_SERIAL (gc_thread_gray_queue, bigobj->data, sgen_obj_get_descriptor ((GCObject*)bigobj->data));
1830 sgen_pin_stats_register_object (bigobj->data, GENERATION_OLD);
1831 SGEN_LOG (6, "Marked large object %p (%s) size: %lu from roots", bigobj->data,
1832 sgen_client_vtable_get_name (SGEN_LOAD_VTABLE (bigobj->data)),
1833 (unsigned long)sgen_los_object_size (bigobj));
1835 sgen_client_pinned_los_object (bigobj->data);
1839 pin_objects_in_nursery (mode == COPY_OR_MARK_FROM_ROOTS_START_CONCURRENT, ctx);
1840 if (check_nursery_objects_pinned && !sgen_minor_collector.is_split)
1841 sgen_check_nursery_objects_pinned (mode != COPY_OR_MARK_FROM_ROOTS_START_CONCURRENT);
1843 major_collector.pin_objects (gc_thread_gray_queue);
1844 if (old_next_pin_slot)
1845 *old_next_pin_slot = sgen_get_pinned_count ();
1848 time_major_pinning += TV_ELAPSED (atv, btv);
1849 SGEN_LOG (2, "Finding pinned pointers: %zd in %lld usecs", sgen_get_pinned_count (), (long long)TV_ELAPSED (atv, btv));
1850 SGEN_LOG (4, "Start scan with %zd pinned objects", sgen_get_pinned_count ());
1852 major_collector.init_to_space ();
1854 SGEN_ASSERT (0, sgen_workers_all_done (), "Why are the workers not done when we start or finish a major collection?");
1855 if (mode == COPY_OR_MARK_FROM_ROOTS_FINISH_CONCURRENT) {
1856 sgen_workers_set_num_active_workers (0);
1857 if (sgen_workers_have_idle_work ()) {
1859 * We force the finish of the worker with the new object ops context
1860 * which can also do copying. We need to have finished pinning.
1862 sgen_workers_start_all_workers (object_ops_nopar, object_ops_par, NULL);
1864 sgen_workers_join ();
1868 #ifdef SGEN_DEBUG_INTERNAL_ALLOC
1869 main_gc_thread = mono_native_thread_self ();
1872 sgen_client_collecting_major_2 ();
1875 time_major_scan_pinned += TV_ELAPSED (btv, atv);
1877 sgen_client_collecting_major_3 (&fin_ready_queue, &critical_fin_queue);
1879 enqueue_scan_from_roots_jobs (gc_thread_gray_queue, heap_start, heap_end, object_ops_nopar, FALSE);
1882 time_major_scan_roots += TV_ELAPSED (atv, btv);
1885 * We start the concurrent worker after pinning and after we scanned the roots
1886 * in order to make sure that the worker does not finish before handling all
1889 if (mode == COPY_OR_MARK_FROM_ROOTS_START_CONCURRENT) {
1890 sgen_workers_set_num_active_workers (1);
1891 gray_queue_redirect (gc_thread_gray_queue);
1892 if (precleaning_enabled) {
1893 sgen_workers_start_all_workers (object_ops_nopar, object_ops_par, workers_finish_callback);
1895 sgen_workers_start_all_workers (object_ops_nopar, object_ops_par, NULL);
1899 if (mode == COPY_OR_MARK_FROM_ROOTS_FINISH_CONCURRENT) {
1900 int i, split_count = sgen_workers_get_job_split_count ();
1902 gray_queue_redirect (gc_thread_gray_queue);
1904 /* Mod union card table */
1905 for (i = 0; i < split_count; i++) {
1906 ParallelScanJob *psj;
1908 psj = (ParallelScanJob*)sgen_thread_pool_job_alloc ("scan mod union cardtable", job_scan_major_mod_union_card_table, sizeof (ParallelScanJob));
1909 psj->scan_job.ops = object_ops_par ? object_ops_par : object_ops_nopar;
1910 psj->scan_job.gc_thread_gray_queue = NULL;
1912 sgen_workers_enqueue_job (&psj->scan_job.job, TRUE);
1914 psj = (ParallelScanJob*)sgen_thread_pool_job_alloc ("scan LOS mod union cardtable", job_scan_los_mod_union_card_table, sizeof (ParallelScanJob));
1915 psj->scan_job.ops = object_ops_par ? object_ops_par : object_ops_nopar;
1916 psj->scan_job.gc_thread_gray_queue = NULL;
1918 sgen_workers_enqueue_job (&psj->scan_job.job, TRUE);
1922 * If we enqueue a job while workers are running we need to sgen_workers_ensure_awake
1923 * in order to make sure that we are running the idle func and draining all worker
1924 * gray queues. The operation of starting workers implies this, so we start them after
1925 * in order to avoid doing this operation twice. The workers will drain the main gray
1926 * stack that contained roots and pinned objects and also scan the mod union card
1929 sgen_workers_start_all_workers (object_ops_nopar, object_ops_par, NULL);
1930 sgen_workers_join ();
1933 sgen_pin_stats_report ();
1935 if (mode == COPY_OR_MARK_FROM_ROOTS_START_CONCURRENT) {
1936 sgen_finish_pinning ();
1938 sgen_pin_stats_reset ();
1940 if (do_concurrent_checks)
1941 sgen_debug_check_nursery_is_clean ();
1946 major_start_collection (SgenGrayQueue *gc_thread_gray_queue, const char *reason, gboolean concurrent, size_t *old_next_pin_slot)
1948 SgenObjectOperations *object_ops_nopar, *object_ops_par = NULL;
1950 binary_protocol_collection_begin (gc_stats.major_gc_count, GENERATION_OLD);
1952 current_collection_generation = GENERATION_OLD;
1954 sgen_workers_assert_gray_queue_is_empty ();
1957 sgen_cement_reset ();
1960 g_assert (major_collector.is_concurrent);
1961 concurrent_collection_in_progress = TRUE;
1963 object_ops_nopar = &major_collector.major_ops_concurrent_start;
1964 if (major_collector.is_parallel)
1965 object_ops_par = &major_collector.major_ops_conc_par_start;
1968 object_ops_nopar = &major_collector.major_ops_serial;
1971 reset_pinned_from_failed_allocation ();
1973 sgen_memgov_major_collection_start (concurrent, reason);
1975 //count_ref_nonref_objs ();
1976 //consistency_check ();
1978 check_scan_starts ();
1981 SGEN_LOG (1, "Start major collection %d", gc_stats.major_gc_count);
1982 gc_stats.major_gc_count ++;
1984 if (major_collector.start_major_collection)
1985 major_collector.start_major_collection ();
1987 major_copy_or_mark_from_roots (gc_thread_gray_queue, old_next_pin_slot, concurrent ? COPY_OR_MARK_FROM_ROOTS_START_CONCURRENT : COPY_OR_MARK_FROM_ROOTS_SERIAL, object_ops_nopar, object_ops_par);
1991 major_finish_collection (SgenGrayQueue *gc_thread_gray_queue, const char *reason, gboolean is_overflow, size_t old_next_pin_slot, gboolean forced)
1993 ScannedObjectCounts counts;
1994 SgenObjectOperations *object_ops_nopar;
1995 mword fragment_total;
2001 if (concurrent_collection_in_progress) {
2002 SgenObjectOperations *object_ops_par = NULL;
2004 object_ops_nopar = &major_collector.major_ops_concurrent_finish;
2005 if (major_collector.is_parallel)
2006 object_ops_par = &major_collector.major_ops_conc_par_finish;
2008 major_copy_or_mark_from_roots (gc_thread_gray_queue, NULL, COPY_OR_MARK_FROM_ROOTS_FINISH_CONCURRENT, object_ops_nopar, object_ops_par);
2010 #ifdef SGEN_DEBUG_INTERNAL_ALLOC
2011 main_gc_thread = NULL;
2014 object_ops_nopar = &major_collector.major_ops_serial;
2017 sgen_workers_assert_gray_queue_is_empty ();
2019 finish_gray_stack (GENERATION_OLD, CONTEXT_FROM_OBJECT_OPERATIONS (object_ops_nopar, gc_thread_gray_queue));
2021 time_major_finish_gray_stack += TV_ELAPSED (btv, atv);
2023 SGEN_ASSERT (0, sgen_workers_all_done (), "Can't have workers working after joining");
2025 if (objects_pinned) {
2026 g_assert (!concurrent_collection_in_progress);
2029 * This is slow, but we just OOM'd.
2031 * See comment at `sgen_pin_queue_clear_discarded_entries` for how the pin
2032 * queue is laid out at this point.
2034 sgen_pin_queue_clear_discarded_entries (nursery_section, old_next_pin_slot);
2036 * We need to reestablish all pinned nursery objects in the pin queue
2037 * because they're needed for fragment creation. Unpinning happens by
2038 * walking the whole queue, so it's not necessary to reestablish where major
2039 * heap block pins are - all we care is that they're still in there
2042 sgen_optimize_pin_queue ();
2043 sgen_find_section_pin_queue_start_end (nursery_section);
2047 reset_heap_boundaries ();
2048 sgen_update_heap_boundaries ((mword)sgen_get_nursery_start (), (mword)sgen_get_nursery_end ());
2050 /* walk the pin_queue, build up the fragment list of free memory, unmark
2051 * pinned objects as we go, memzero() the empty fragments so they are ready for the
2054 fragment_total = sgen_build_nursery_fragments (nursery_section, NULL);
2055 if (!fragment_total)
2057 SGEN_LOG (4, "Free space in nursery after major %ld", (long)fragment_total);
2059 if (do_concurrent_checks && concurrent_collection_in_progress)
2060 sgen_debug_check_nursery_is_clean ();
2062 /* prepare the pin queue for the next collection */
2063 sgen_finish_pinning ();
2065 /* Clear TLABs for all threads */
2066 sgen_clear_tlabs ();
2068 sgen_pin_stats_reset ();
2070 sgen_cement_clear_below_threshold ();
2072 if (check_mark_bits_after_major_collection)
2073 sgen_check_heap_marked (concurrent_collection_in_progress);
2076 time_major_fragment_creation += TV_ELAPSED (atv, btv);
2078 binary_protocol_sweep_begin (GENERATION_OLD, !major_collector.sweeps_lazily);
2079 sgen_memgov_major_pre_sweep ();
2082 time_major_free_bigobjs += TV_ELAPSED (btv, atv);
2087 time_major_los_sweep += TV_ELAPSED (atv, btv);
2089 major_collector.sweep ();
2091 binary_protocol_sweep_end (GENERATION_OLD, !major_collector.sweeps_lazily);
2094 time_major_sweep += TV_ELAPSED (btv, atv);
2096 sgen_debug_dump_heap ("major", gc_stats.major_gc_count - 1, reason);
2098 if (sgen_have_pending_finalizers ()) {
2099 SGEN_LOG (4, "Finalizer-thread wakeup");
2100 sgen_client_finalize_notify ();
2103 sgen_memgov_major_collection_end (forced, concurrent_collection_in_progress, reason, is_overflow);
2104 current_collection_generation = -1;
2106 memset (&counts, 0, sizeof (ScannedObjectCounts));
2107 major_collector.finish_major_collection (&counts);
2109 sgen_workers_assert_gray_queue_is_empty ();
2111 SGEN_ASSERT (0, sgen_workers_all_done (), "Can't have workers working after major collection has finished");
2112 if (concurrent_collection_in_progress)
2113 concurrent_collection_in_progress = FALSE;
2115 check_scan_starts ();
2117 binary_protocol_flush_buffers (FALSE);
2119 //consistency_check ();
2121 binary_protocol_collection_end (gc_stats.major_gc_count - 1, GENERATION_OLD, counts.num_scanned_objects, counts.num_unique_scanned_objects);
2125 major_do_collection (const char *reason, gboolean is_overflow, gboolean forced)
2127 TV_DECLARE (time_start);
2128 TV_DECLARE (time_end);
2129 size_t old_next_pin_slot;
2130 SgenGrayQueue gc_thread_gray_queue;
2132 if (disable_major_collections)
2135 if (major_collector.get_and_reset_num_major_objects_marked) {
2136 long long num_marked = major_collector.get_and_reset_num_major_objects_marked ();
2137 g_assert (!num_marked);
2140 /* world must be stopped already */
2141 TV_GETTIME (time_start);
2143 init_gray_queue (&gc_thread_gray_queue, FALSE);
2144 major_start_collection (&gc_thread_gray_queue, reason, FALSE, &old_next_pin_slot);
2145 major_finish_collection (&gc_thread_gray_queue, reason, is_overflow, old_next_pin_slot, forced);
2146 sgen_gray_object_queue_dispose (&gc_thread_gray_queue);
2148 TV_GETTIME (time_end);
2149 gc_stats.major_gc_time += TV_ELAPSED (time_start, time_end);
2151 /* FIXME: also report this to the user, preferably in gc-end. */
2152 if (major_collector.get_and_reset_num_major_objects_marked)
2153 major_collector.get_and_reset_num_major_objects_marked ();
2155 return bytes_pinned_from_failed_allocation > 0;
2159 major_start_concurrent_collection (const char *reason)
2161 TV_DECLARE (time_start);
2162 TV_DECLARE (time_end);
2163 long long num_objects_marked;
2164 SgenGrayQueue gc_thread_gray_queue;
2166 if (disable_major_collections)
2169 TV_GETTIME (time_start);
2170 SGEN_TV_GETTIME (time_major_conc_collection_start);
2172 num_objects_marked = major_collector.get_and_reset_num_major_objects_marked ();
2173 g_assert (num_objects_marked == 0);
2175 binary_protocol_concurrent_start ();
2177 init_gray_queue (&gc_thread_gray_queue, TRUE);
2178 // FIXME: store reason and pass it when finishing
2179 major_start_collection (&gc_thread_gray_queue, reason, TRUE, NULL);
2180 sgen_gray_object_queue_dispose (&gc_thread_gray_queue);
2182 num_objects_marked = major_collector.get_and_reset_num_major_objects_marked ();
2184 TV_GETTIME (time_end);
2185 gc_stats.major_gc_time += TV_ELAPSED (time_start, time_end);
2187 current_collection_generation = -1;
2191 * Returns whether the major collection has finished.
2194 major_should_finish_concurrent_collection (void)
2196 return sgen_workers_all_done ();
2200 major_update_concurrent_collection (void)
2202 TV_DECLARE (total_start);
2203 TV_DECLARE (total_end);
2205 TV_GETTIME (total_start);
2207 binary_protocol_concurrent_update ();
2209 major_collector.update_cardtable_mod_union ();
2210 sgen_los_update_cardtable_mod_union ();
2212 TV_GETTIME (total_end);
2213 gc_stats.major_gc_time += TV_ELAPSED (total_start, total_end);
2217 major_finish_concurrent_collection (gboolean forced)
2219 SgenGrayQueue gc_thread_gray_queue;
2220 TV_DECLARE (total_start);
2221 TV_DECLARE (total_end);
2223 TV_GETTIME (total_start);
2225 binary_protocol_concurrent_finish ();
2228 * We need to stop all workers since we're updating the cardtable below.
2229 * The workers will be resumed with a finishing pause context to avoid
2230 * additional cardtable and object scanning.
2232 sgen_workers_stop_all_workers ();
2234 SGEN_TV_GETTIME (time_major_conc_collection_end);
2235 gc_stats.major_gc_time_concurrent += SGEN_TV_ELAPSED (time_major_conc_collection_start, time_major_conc_collection_end);
2237 major_collector.update_cardtable_mod_union ();
2238 sgen_los_update_cardtable_mod_union ();
2240 if (mod_union_consistency_check)
2241 sgen_check_mod_union_consistency ();
2243 current_collection_generation = GENERATION_OLD;
2244 sgen_cement_reset ();
2245 init_gray_queue (&gc_thread_gray_queue, FALSE);
2246 major_finish_collection (&gc_thread_gray_queue, "finishing", FALSE, -1, forced);
2247 sgen_gray_object_queue_dispose (&gc_thread_gray_queue);
2249 TV_GETTIME (total_end);
2250 gc_stats.major_gc_time += TV_ELAPSED (total_start, total_end);
2252 current_collection_generation = -1;
2256 * Ensure an allocation request for @size will succeed by freeing enough memory.
2258 * LOCKING: The GC lock MUST be held.
2261 sgen_ensure_free_space (size_t size, int generation)
2263 int generation_to_collect = -1;
2264 const char *reason = NULL;
2266 if (generation == GENERATION_OLD) {
2267 if (sgen_need_major_collection (size)) {
2268 reason = "LOS overflow";
2269 generation_to_collect = GENERATION_OLD;
2272 if (degraded_mode) {
2273 if (sgen_need_major_collection (size)) {
2274 reason = "Degraded mode overflow";
2275 generation_to_collect = GENERATION_OLD;
2277 } else if (sgen_need_major_collection (size)) {
2278 reason = concurrent_collection_in_progress ? "Forced finish concurrent collection" : "Minor allowance";
2279 generation_to_collect = GENERATION_OLD;
2281 generation_to_collect = GENERATION_NURSERY;
2282 reason = "Nursery full";
2286 if (generation_to_collect == -1) {
2287 if (concurrent_collection_in_progress && sgen_workers_all_done ()) {
2288 generation_to_collect = GENERATION_OLD;
2289 reason = "Finish concurrent collection";
2293 if (generation_to_collect == -1)
2295 sgen_perform_collection (size, generation_to_collect, reason, FALSE, TRUE);
2299 * LOCKING: Assumes the GC lock is held.
2302 sgen_perform_collection (size_t requested_size, int generation_to_collect, const char *reason, gboolean wait_to_finish, gboolean stw)
2304 TV_DECLARE (gc_total_start);
2305 TV_DECLARE (gc_total_end);
2306 int overflow_generation_to_collect = -1;
2307 int oldest_generation_collected = generation_to_collect;
2308 const char *overflow_reason = NULL;
2309 gboolean finish_concurrent = concurrent_collection_in_progress && (major_should_finish_concurrent_collection () || generation_to_collect == GENERATION_OLD);
2311 binary_protocol_collection_requested (generation_to_collect, requested_size, wait_to_finish ? 1 : 0);
2313 SGEN_ASSERT (0, generation_to_collect == GENERATION_NURSERY || generation_to_collect == GENERATION_OLD, "What generation is this?");
2316 sgen_stop_world (generation_to_collect);
2318 SGEN_ASSERT (0, sgen_is_world_stopped (), "We can only collect if the world is stopped");
2321 TV_GETTIME (gc_total_start);
2323 // FIXME: extract overflow reason
2324 // FIXME: minor overflow for concurrent case
2325 if (generation_to_collect == GENERATION_NURSERY && !finish_concurrent) {
2326 if (concurrent_collection_in_progress)
2327 major_update_concurrent_collection ();
2329 if (collect_nursery (reason, FALSE, NULL) && !concurrent_collection_in_progress) {
2330 overflow_generation_to_collect = GENERATION_OLD;
2331 overflow_reason = "Minor overflow";
2333 } else if (finish_concurrent) {
2334 major_finish_concurrent_collection (wait_to_finish);
2335 oldest_generation_collected = GENERATION_OLD;
2337 SGEN_ASSERT (0, generation_to_collect == GENERATION_OLD, "We should have handled nursery collections above");
2338 if (major_collector.is_concurrent && !wait_to_finish) {
2339 collect_nursery ("Concurrent start", FALSE, NULL);
2340 major_start_concurrent_collection (reason);
2341 oldest_generation_collected = GENERATION_NURSERY;
2342 } else if (major_do_collection (reason, FALSE, wait_to_finish)) {
2343 overflow_generation_to_collect = GENERATION_NURSERY;
2344 overflow_reason = "Excessive pinning";
2348 if (overflow_generation_to_collect != -1) {
2349 SGEN_ASSERT (0, !concurrent_collection_in_progress, "We don't yet support overflow collections with the concurrent collector");
2352 * We need to do an overflow collection, either because we ran out of memory
2353 * or the nursery is fully pinned.
2356 if (overflow_generation_to_collect == GENERATION_NURSERY)
2357 collect_nursery (overflow_reason, TRUE, NULL);
2359 major_do_collection (overflow_reason, TRUE, wait_to_finish);
2361 oldest_generation_collected = MAX (oldest_generation_collected, overflow_generation_to_collect);
2364 SGEN_LOG (2, "Heap size: %lu, LOS size: %lu", (unsigned long)sgen_gc_get_total_heap_allocation (), (unsigned long)los_memory_usage);
2366 /* this also sets the proper pointers for the next allocation */
2367 if (generation_to_collect == GENERATION_NURSERY && !sgen_can_alloc_size (requested_size)) {
2368 /* TypeBuilder and MonoMethod are killing mcs with fragmentation */
2369 SGEN_LOG (1, "nursery collection didn't find enough room for %zd alloc (%zd pinned)", requested_size, sgen_get_pinned_count ());
2370 sgen_dump_pin_queue ();
2374 TV_GETTIME (gc_total_end);
2375 time_max = MAX (time_max, TV_ELAPSED (gc_total_start, gc_total_end));
2378 sgen_restart_world (oldest_generation_collected);
2382 * ######################################################################
2383 * ######## Memory allocation from the OS
2384 * ######################################################################
2385 * This section of code deals with getting memory from the OS and
2386 * allocating memory for GC-internal data structures.
2387 * Internal memory can be handled with a freelist for small objects.
2393 G_GNUC_UNUSED static void
2394 report_internal_mem_usage (void)
2396 printf ("Internal memory usage:\n");
2397 sgen_report_internal_mem_usage ();
2398 printf ("Pinned memory usage:\n");
2399 major_collector.report_pinned_memory_usage ();
2403 * ######################################################################
2404 * ######## Finalization support
2405 * ######################################################################
2409 * If the object has been forwarded it means it's still referenced from a root.
2410 * If it is pinned it's still alive as well.
2411 * A LOS object is only alive if we have pinned it.
2412 * Return TRUE if @obj is ready to be finalized.
2414 static inline gboolean
2415 sgen_is_object_alive (GCObject *object)
2417 if (ptr_in_nursery (object))
2418 return sgen_nursery_is_object_alive (object);
2420 return sgen_major_is_object_alive (object);
2424 * This function returns true if @object is either alive and belongs to the
2425 * current collection - major collections are full heap, so old gen objects
2426 * are never alive during a minor collection.
2429 sgen_is_object_alive_and_on_current_collection (GCObject *object)
2431 if (ptr_in_nursery (object))
2432 return sgen_nursery_is_object_alive (object);
2434 if (current_collection_generation == GENERATION_NURSERY)
2437 return sgen_major_is_object_alive (object);
2442 sgen_gc_is_object_ready_for_finalization (GCObject *object)
2444 return !sgen_is_object_alive (object);
2448 sgen_queue_finalization_entry (GCObject *obj)
2450 gboolean critical = sgen_client_object_has_critical_finalizer (obj);
2452 sgen_pointer_queue_add (critical ? &critical_fin_queue : &fin_ready_queue, obj);
2454 sgen_client_object_queued_for_finalization (obj);
2458 sgen_object_is_live (GCObject *obj)
2460 return sgen_is_object_alive_and_on_current_collection (obj);
2464 * `System.GC.WaitForPendingFinalizers` first checks `sgen_have_pending_finalizers()` to
2465 * determine whether it can exit quickly. The latter must therefore only return FALSE if
2466 * all finalizers have really finished running.
2468 * `sgen_gc_invoke_finalizers()` first dequeues a finalizable object, and then finalizes it.
2469 * This means that just checking whether the queues are empty leaves the possibility that an
2470 * object might have been dequeued but not yet finalized. That's why we need the additional
2471 * flag `pending_unqueued_finalizer`.
2474 static volatile gboolean pending_unqueued_finalizer = FALSE;
2475 volatile gboolean sgen_suspend_finalizers = FALSE;
2478 sgen_set_suspend_finalizers (void)
2480 sgen_suspend_finalizers = TRUE;
2484 sgen_gc_invoke_finalizers (void)
2488 g_assert (!pending_unqueued_finalizer);
2490 /* FIXME: batch to reduce lock contention */
2491 while (sgen_have_pending_finalizers ()) {
2497 * We need to set `pending_unqueued_finalizer` before dequeing the
2498 * finalizable object.
2500 if (!sgen_pointer_queue_is_empty (&fin_ready_queue)) {
2501 pending_unqueued_finalizer = TRUE;
2502 mono_memory_write_barrier ();
2503 obj = (GCObject *)sgen_pointer_queue_pop (&fin_ready_queue);
2504 } else if (!sgen_pointer_queue_is_empty (&critical_fin_queue)) {
2505 pending_unqueued_finalizer = TRUE;
2506 mono_memory_write_barrier ();
2507 obj = (GCObject *)sgen_pointer_queue_pop (&critical_fin_queue);
2513 SGEN_LOG (7, "Finalizing object %p (%s)", obj, sgen_client_vtable_get_name (SGEN_LOAD_VTABLE (obj)));
2521 /* the object is on the stack so it is pinned */
2522 /*g_print ("Calling finalizer for object: %p (%s)\n", obj, sgen_client_object_safe_name (obj));*/
2523 sgen_client_run_finalize (obj);
2526 if (pending_unqueued_finalizer) {
2527 mono_memory_write_barrier ();
2528 pending_unqueued_finalizer = FALSE;
2535 sgen_have_pending_finalizers (void)
2537 if (sgen_suspend_finalizers)
2539 return pending_unqueued_finalizer || !sgen_pointer_queue_is_empty (&fin_ready_queue) || !sgen_pointer_queue_is_empty (&critical_fin_queue);
2543 * ######################################################################
2544 * ######## registered roots support
2545 * ######################################################################
2549 * We do not coalesce roots.
2552 sgen_register_root (char *start, size_t size, SgenDescriptor descr, int root_type, int source, const char *msg)
2554 RootRecord new_root;
2557 for (i = 0; i < ROOT_TYPE_NUM; ++i) {
2558 RootRecord *root = (RootRecord *)sgen_hash_table_lookup (&roots_hash [i], start);
2559 /* we allow changing the size and the descriptor (for thread statics etc) */
2561 size_t old_size = root->end_root - start;
2562 root->end_root = start + size;
2563 SGEN_ASSERT (0, !!root->root_desc == !!descr, "Can't change whether a root is precise or conservative.");
2564 SGEN_ASSERT (0, root->source == source, "Can't change a root's source identifier.");
2565 SGEN_ASSERT (0, !!root->msg == !!msg, "Can't change a root's message.");
2566 root->root_desc = descr;
2568 roots_size -= old_size;
2574 new_root.end_root = start + size;
2575 new_root.root_desc = descr;
2576 new_root.source = source;
2579 sgen_hash_table_replace (&roots_hash [root_type], start, &new_root, NULL);
2582 SGEN_LOG (3, "Added root for range: %p-%p, descr: %llx (%d/%d bytes)", start, new_root.end_root, (long long)descr, (int)size, (int)roots_size);
2589 sgen_deregister_root (char* addr)
2595 for (root_type = 0; root_type < ROOT_TYPE_NUM; ++root_type) {
2596 if (sgen_hash_table_remove (&roots_hash [root_type], addr, &root))
2597 roots_size -= (root.end_root - addr);
2603 * ######################################################################
2604 * ######## Thread handling (stop/start code)
2605 * ######################################################################
2609 sgen_get_current_collection_generation (void)
2611 return current_collection_generation;
2615 sgen_thread_register (SgenThreadInfo* info, void *stack_bottom_fallback)
2617 info->tlab_start = info->tlab_next = info->tlab_temp_end = info->tlab_real_end = NULL;
2619 sgen_client_thread_register (info, stack_bottom_fallback);
2625 sgen_thread_unregister (SgenThreadInfo *p)
2627 sgen_client_thread_unregister (p);
2631 * ######################################################################
2632 * ######## Write barriers
2633 * ######################################################################
2637 * Note: the write barriers first do the needed GC work and then do the actual store:
2638 * this way the value is visible to the conservative GC scan after the write barrier
2639 * itself. If a GC interrupts the barrier in the middle, value will be kept alive by
2640 * the conservative scan, otherwise by the remembered set scan.
2644 mono_gc_wbarrier_arrayref_copy (gpointer dest_ptr, gpointer src_ptr, int count)
2646 HEAVY_STAT (++stat_wbarrier_arrayref_copy);
2647 /*This check can be done without taking a lock since dest_ptr array is pinned*/
2648 if (ptr_in_nursery (dest_ptr) || count <= 0) {
2649 mono_gc_memmove_aligned (dest_ptr, src_ptr, count * sizeof (gpointer));
2653 #ifdef SGEN_HEAVY_BINARY_PROTOCOL
2654 if (binary_protocol_is_heavy_enabled ()) {
2656 for (i = 0; i < count; ++i) {
2657 gpointer dest = (gpointer*)dest_ptr + i;
2658 gpointer obj = *((gpointer*)src_ptr + i);
2660 binary_protocol_wbarrier (dest, obj, (gpointer)LOAD_VTABLE (obj));
2665 remset.wbarrier_arrayref_copy (dest_ptr, src_ptr, count);
2669 mono_gc_wbarrier_generic_nostore (gpointer ptr)
2673 HEAVY_STAT (++stat_wbarrier_generic_store);
2675 sgen_client_wbarrier_generic_nostore_check (ptr);
2677 obj = *(gpointer*)ptr;
2679 binary_protocol_wbarrier (ptr, obj, (gpointer)LOAD_VTABLE (obj));
2682 * We need to record old->old pointer locations for the
2683 * concurrent collector.
2685 if (!ptr_in_nursery (obj) && !concurrent_collection_in_progress) {
2686 SGEN_LOG (8, "Skipping remset at %p", ptr);
2690 SGEN_LOG (8, "Adding remset at %p", ptr);
2692 remset.wbarrier_generic_nostore (ptr);
2696 mono_gc_wbarrier_generic_store (gpointer ptr, GCObject* value)
2698 SGEN_LOG (8, "Wbarrier store at %p to %p (%s)", ptr, value, value ? sgen_client_vtable_get_name (SGEN_LOAD_VTABLE (value)) : "null");
2699 SGEN_UPDATE_REFERENCE_ALLOW_NULL (ptr, value);
2700 if (ptr_in_nursery (value) || concurrent_collection_in_progress)
2701 mono_gc_wbarrier_generic_nostore (ptr);
2702 sgen_dummy_use (value);
2705 /* Same as mono_gc_wbarrier_generic_store () but performs the store
2706 * as an atomic operation with release semantics.
2709 mono_gc_wbarrier_generic_store_atomic (gpointer ptr, GCObject *value)
2711 HEAVY_STAT (++stat_wbarrier_generic_store_atomic);
2713 SGEN_LOG (8, "Wbarrier atomic store at %p to %p (%s)", ptr, value, value ? sgen_client_vtable_get_name (SGEN_LOAD_VTABLE (value)) : "null");
2715 InterlockedWritePointer ((volatile gpointer *)ptr, value);
2717 if (ptr_in_nursery (value) || concurrent_collection_in_progress)
2718 mono_gc_wbarrier_generic_nostore (ptr);
2720 sgen_dummy_use (value);
2724 sgen_wbarrier_value_copy_bitmap (gpointer _dest, gpointer _src, int size, unsigned bitmap)
2726 GCObject **dest = (GCObject **)_dest;
2727 GCObject **src = (GCObject **)_src;
2731 mono_gc_wbarrier_generic_store (dest, *src);
2736 size -= SIZEOF_VOID_P;
2742 * ######################################################################
2743 * ######## Other mono public interface functions.
2744 * ######################################################################
2748 sgen_gc_collect (int generation)
2753 sgen_perform_collection (0, generation, "user request", TRUE, TRUE);
2758 sgen_gc_collection_count (int generation)
2760 if (generation == 0)
2761 return gc_stats.minor_gc_count;
2762 return gc_stats.major_gc_count;
2766 sgen_gc_get_used_size (void)
2770 tot = los_memory_usage;
2771 tot += nursery_section->next_data - nursery_section->data;
2772 tot += major_collector.get_used_size ();
2773 /* FIXME: account for pinned objects */
2779 sgen_env_var_error (const char *env_var, const char *fallback, const char *description_format, ...)
2783 va_start (ap, description_format);
2785 fprintf (stderr, "Warning: In environment variable `%s': ", env_var);
2786 vfprintf (stderr, description_format, ap);
2788 fprintf (stderr, " - %s", fallback);
2789 fprintf (stderr, "\n");
2795 parse_double_in_interval (const char *env_var, const char *opt_name, const char *opt, double min, double max, double *result)
2798 double val = strtod (opt, &endptr);
2799 if (endptr == opt) {
2800 sgen_env_var_error (env_var, "Using default value.", "`%s` must be a number.", opt_name);
2803 else if (val < min || val > max) {
2804 sgen_env_var_error (env_var, "Using default value.", "`%s` must be between %.2f - %.2f.", opt_name, min, max);
2816 char *major_collector_opt = NULL;
2817 char *minor_collector_opt = NULL;
2818 char *params_opts = NULL;
2819 char *debug_opts = NULL;
2820 size_t max_heap = 0;
2821 size_t soft_limit = 0;
2823 gboolean debug_print_allowance = FALSE;
2824 double allowance_ratio = 0, save_target = 0;
2825 gboolean cement_enabled = TRUE;
2828 result = InterlockedCompareExchange (&gc_initialized, -1, 0);
2831 /* already inited */
2834 /* being inited by another thread */
2835 mono_thread_info_usleep (1000);
2838 /* we will init it */
2841 g_assert_not_reached ();
2843 } while (result != 0);
2845 SGEN_TV_GETTIME (sgen_init_timestamp);
2847 #ifdef SGEN_WITHOUT_MONO
2848 mono_thread_smr_init ();
2851 mono_coop_mutex_init (&gc_mutex);
2853 gc_debug_file = stderr;
2855 mono_coop_mutex_init (&sgen_interruption_mutex);
2857 if ((env = g_getenv (MONO_GC_PARAMS_NAME)) || gc_params_options) {
2858 params_opts = g_strdup_printf ("%s,%s", gc_params_options ? gc_params_options : "", env ? env : "");
2862 opts = g_strsplit (params_opts, ",", -1);
2863 for (ptr = opts; *ptr; ++ptr) {
2865 if (g_str_has_prefix (opt, "major=")) {
2866 opt = strchr (opt, '=') + 1;
2867 major_collector_opt = g_strdup (opt);
2868 } else if (g_str_has_prefix (opt, "minor=")) {
2869 opt = strchr (opt, '=') + 1;
2870 minor_collector_opt = g_strdup (opt);
2878 sgen_init_internal_allocator ();
2879 sgen_init_nursery_allocator ();
2880 sgen_init_fin_weak_hash ();
2881 sgen_init_hash_table ();
2882 sgen_init_descriptors ();
2883 sgen_init_gray_queues ();
2884 sgen_init_allocator ();
2885 sgen_init_gchandles ();
2887 sgen_register_fixed_internal_mem_type (INTERNAL_MEM_SECTION, SGEN_SIZEOF_GC_MEM_SECTION);
2888 sgen_register_fixed_internal_mem_type (INTERNAL_MEM_GRAY_QUEUE, sizeof (GrayQueueSection));
2890 sgen_client_init ();
2892 if (!minor_collector_opt) {
2893 sgen_simple_nursery_init (&sgen_minor_collector);
2895 if (!strcmp (minor_collector_opt, "simple")) {
2897 sgen_simple_nursery_init (&sgen_minor_collector);
2898 } else if (!strcmp (minor_collector_opt, "split")) {
2899 sgen_split_nursery_init (&sgen_minor_collector);
2901 sgen_env_var_error (MONO_GC_PARAMS_NAME, "Using `simple` instead.", "Unknown minor collector `%s'.", minor_collector_opt);
2902 goto use_simple_nursery;
2906 if (!major_collector_opt) {
2908 DEFAULT_MAJOR_INIT (&major_collector);
2909 } else if (!strcmp (major_collector_opt, "marksweep")) {
2910 sgen_marksweep_init (&major_collector);
2911 } else if (!strcmp (major_collector_opt, "marksweep-conc")) {
2912 sgen_marksweep_conc_init (&major_collector);
2913 } else if (!strcmp (major_collector_opt, "marksweep-conc-par")) {
2914 sgen_marksweep_conc_par_init (&major_collector);
2916 sgen_env_var_error (MONO_GC_PARAMS_NAME, "Using `" DEFAULT_MAJOR_NAME "` instead.", "Unknown major collector `%s'.", major_collector_opt);
2917 goto use_default_major;
2920 sgen_nursery_size = DEFAULT_NURSERY_SIZE;
2923 gboolean usage_printed = FALSE;
2925 for (ptr = opts; *ptr; ++ptr) {
2927 if (!strcmp (opt, ""))
2929 if (g_str_has_prefix (opt, "major="))
2931 if (g_str_has_prefix (opt, "minor="))
2933 if (g_str_has_prefix (opt, "max-heap-size=")) {
2934 size_t page_size = mono_pagesize ();
2935 size_t max_heap_candidate = 0;
2936 opt = strchr (opt, '=') + 1;
2937 if (*opt && mono_gc_parse_environment_string_extract_number (opt, &max_heap_candidate)) {
2938 max_heap = (max_heap_candidate + page_size - 1) & ~(size_t)(page_size - 1);
2939 if (max_heap != max_heap_candidate)
2940 sgen_env_var_error (MONO_GC_PARAMS_NAME, "Rounding up.", "`max-heap-size` size must be a multiple of %d.", page_size);
2942 sgen_env_var_error (MONO_GC_PARAMS_NAME, NULL, "`max-heap-size` must be an integer.");
2946 if (g_str_has_prefix (opt, "soft-heap-limit=")) {
2947 opt = strchr (opt, '=') + 1;
2948 if (*opt && mono_gc_parse_environment_string_extract_number (opt, &soft_limit)) {
2949 if (soft_limit <= 0) {
2950 sgen_env_var_error (MONO_GC_PARAMS_NAME, NULL, "`soft-heap-limit` must be positive.");
2954 sgen_env_var_error (MONO_GC_PARAMS_NAME, NULL, "`soft-heap-limit` must be an integer.");
2960 if (g_str_has_prefix (opt, "nursery-size=")) {
2962 opt = strchr (opt, '=') + 1;
2963 if (*opt && mono_gc_parse_environment_string_extract_number (opt, &val)) {
2964 if ((val & (val - 1))) {
2965 sgen_env_var_error (MONO_GC_PARAMS_NAME, "Using default value.", "`nursery-size` must be a power of two.");
2969 if (val < SGEN_MAX_NURSERY_WASTE) {
2970 sgen_env_var_error (MONO_GC_PARAMS_NAME, "Using default value.",
2971 "`nursery-size` must be at least %d bytes.", SGEN_MAX_NURSERY_WASTE);
2975 sgen_nursery_size = val;
2976 sgen_nursery_bits = 0;
2977 while (ONE_P << (++ sgen_nursery_bits) != sgen_nursery_size)
2980 sgen_env_var_error (MONO_GC_PARAMS_NAME, "Using default value.", "`nursery-size` must be an integer.");
2986 if (g_str_has_prefix (opt, "save-target-ratio=")) {
2988 opt = strchr (opt, '=') + 1;
2989 if (parse_double_in_interval (MONO_GC_PARAMS_NAME, "save-target-ratio", opt,
2990 SGEN_MIN_SAVE_TARGET_RATIO, SGEN_MAX_SAVE_TARGET_RATIO, &val)) {
2995 if (g_str_has_prefix (opt, "default-allowance-ratio=")) {
2997 opt = strchr (opt, '=') + 1;
2998 if (parse_double_in_interval (MONO_GC_PARAMS_NAME, "default-allowance-ratio", opt,
2999 SGEN_MIN_ALLOWANCE_NURSERY_SIZE_RATIO, SGEN_MAX_ALLOWANCE_NURSERY_SIZE_RATIO, &val)) {
3000 allowance_ratio = val;
3005 if (!strcmp (opt, "cementing")) {
3006 cement_enabled = TRUE;
3009 if (!strcmp (opt, "no-cementing")) {
3010 cement_enabled = FALSE;
3014 if (!strcmp (opt, "precleaning")) {
3015 precleaning_enabled = TRUE;
3018 if (!strcmp (opt, "no-precleaning")) {
3019 precleaning_enabled = FALSE;
3023 if (major_collector.handle_gc_param && major_collector.handle_gc_param (opt))
3026 if (sgen_minor_collector.handle_gc_param && sgen_minor_collector.handle_gc_param (opt))
3029 if (sgen_client_handle_gc_param (opt))
3032 sgen_env_var_error (MONO_GC_PARAMS_NAME, "Ignoring.", "Unknown option `%s`.", opt);
3037 fprintf (stderr, "\n%s must be a comma-delimited list of one or more of the following:\n", MONO_GC_PARAMS_NAME);
3038 fprintf (stderr, " max-heap-size=N (where N is an integer, possibly with a k, m or a g suffix)\n");
3039 fprintf (stderr, " soft-heap-limit=n (where N is an integer, possibly with a k, m or a g suffix)\n");
3040 fprintf (stderr, " nursery-size=N (where N is an integer, possibly with a k, m or a g suffix)\n");
3041 fprintf (stderr, " major=COLLECTOR (where COLLECTOR is `marksweep', `marksweep-conc', `marksweep-par')\n");
3042 fprintf (stderr, " minor=COLLECTOR (where COLLECTOR is `simple' or `split')\n");
3043 fprintf (stderr, " wbarrier=WBARRIER (where WBARRIER is `remset' or `cardtable')\n");
3044 fprintf (stderr, " [no-]cementing\n");
3045 if (major_collector.print_gc_param_usage)
3046 major_collector.print_gc_param_usage ();
3047 if (sgen_minor_collector.print_gc_param_usage)
3048 sgen_minor_collector.print_gc_param_usage ();
3049 sgen_client_print_gc_params_usage ();
3050 fprintf (stderr, " Experimental options:\n");
3051 fprintf (stderr, " save-target-ratio=R (where R must be between %.2f - %.2f).\n", SGEN_MIN_SAVE_TARGET_RATIO, SGEN_MAX_SAVE_TARGET_RATIO);
3052 fprintf (stderr, " default-allowance-ratio=R (where R must be between %.2f - %.2f).\n", SGEN_MIN_ALLOWANCE_NURSERY_SIZE_RATIO, SGEN_MAX_ALLOWANCE_NURSERY_SIZE_RATIO);
3053 fprintf (stderr, "\n");
3055 usage_printed = TRUE;
3060 if (major_collector_opt)
3061 g_free (major_collector_opt);
3063 if (minor_collector_opt)
3064 g_free (minor_collector_opt);
3067 g_free (params_opts);
3071 sgen_pinning_init ();
3072 sgen_cement_init (cement_enabled);
3074 if ((env = g_getenv (MONO_GC_DEBUG_NAME)) || gc_debug_options) {
3075 debug_opts = g_strdup_printf ("%s,%s", gc_debug_options ? gc_debug_options : "", env ? env : "");
3079 gboolean usage_printed = FALSE;
3081 opts = g_strsplit (debug_opts, ",", -1);
3082 for (ptr = opts; ptr && *ptr; ptr ++) {
3084 if (!strcmp (opt, ""))
3086 if (opt [0] >= '0' && opt [0] <= '9') {
3087 gc_debug_level = atoi (opt);
3092 char *rf = g_strdup_printf ("%s.%d", opt, mono_process_current_pid ());
3093 gc_debug_file = fopen (rf, "wb");
3095 gc_debug_file = stderr;
3098 } else if (!strcmp (opt, "print-allowance")) {
3099 debug_print_allowance = TRUE;
3100 } else if (!strcmp (opt, "print-pinning")) {
3101 sgen_pin_stats_enable ();
3102 } else if (!strcmp (opt, "verify-before-allocs")) {
3103 verify_before_allocs = 1;
3104 has_per_allocation_action = TRUE;
3105 } else if (g_str_has_prefix (opt, "verify-before-allocs=")) {
3106 char *arg = strchr (opt, '=') + 1;
3107 verify_before_allocs = atoi (arg);
3108 has_per_allocation_action = TRUE;
3109 } else if (!strcmp (opt, "collect-before-allocs")) {
3110 collect_before_allocs = 1;
3111 has_per_allocation_action = TRUE;
3112 } else if (g_str_has_prefix (opt, "collect-before-allocs=")) {
3113 char *arg = strchr (opt, '=') + 1;
3114 has_per_allocation_action = TRUE;
3115 collect_before_allocs = atoi (arg);
3116 } else if (!strcmp (opt, "verify-before-collections")) {
3117 whole_heap_check_before_collection = TRUE;
3118 } else if (!strcmp (opt, "check-remset-consistency")) {
3119 remset_consistency_checks = TRUE;
3120 nursery_clear_policy = CLEAR_AT_GC;
3121 } else if (!strcmp (opt, "mod-union-consistency-check")) {
3122 if (!major_collector.is_concurrent) {
3123 sgen_env_var_error (MONO_GC_DEBUG_NAME, "Ignoring.", "`mod-union-consistency-check` only works with concurrent major collector.");
3126 mod_union_consistency_check = TRUE;
3127 } else if (!strcmp (opt, "check-mark-bits")) {
3128 check_mark_bits_after_major_collection = TRUE;
3129 } else if (!strcmp (opt, "check-nursery-pinned")) {
3130 check_nursery_objects_pinned = TRUE;
3131 } else if (!strcmp (opt, "clear-at-gc")) {
3132 nursery_clear_policy = CLEAR_AT_GC;
3133 } else if (!strcmp (opt, "clear-nursery-at-gc")) {
3134 nursery_clear_policy = CLEAR_AT_GC;
3135 } else if (!strcmp (opt, "clear-at-tlab-creation")) {
3136 nursery_clear_policy = CLEAR_AT_TLAB_CREATION;
3137 } else if (!strcmp (opt, "debug-clear-at-tlab-creation")) {
3138 nursery_clear_policy = CLEAR_AT_TLAB_CREATION_DEBUG;
3139 } else if (!strcmp (opt, "check-scan-starts")) {
3140 do_scan_starts_check = TRUE;
3141 } else if (!strcmp (opt, "verify-nursery-at-minor-gc")) {
3142 do_verify_nursery = TRUE;
3143 } else if (!strcmp (opt, "check-concurrent")) {
3144 if (!major_collector.is_concurrent) {
3145 sgen_env_var_error (MONO_GC_DEBUG_NAME, "Ignoring.", "`check-concurrent` only works with concurrent major collectors.");
3148 nursery_clear_policy = CLEAR_AT_GC;
3149 do_concurrent_checks = TRUE;
3150 } else if (!strcmp (opt, "dump-nursery-at-minor-gc")) {
3151 do_dump_nursery_content = TRUE;
3152 } else if (!strcmp (opt, "disable-minor")) {
3153 disable_minor_collections = TRUE;
3154 } else if (!strcmp (opt, "disable-major")) {
3155 disable_major_collections = TRUE;
3156 } else if (g_str_has_prefix (opt, "heap-dump=")) {
3157 char *filename = strchr (opt, '=') + 1;
3158 nursery_clear_policy = CLEAR_AT_GC;
3159 sgen_debug_enable_heap_dump (filename);
3160 } else if (g_str_has_prefix (opt, "binary-protocol=")) {
3161 char *filename = strchr (opt, '=') + 1;
3162 char *colon = strrchr (filename, ':');
3165 if (!mono_gc_parse_environment_string_extract_number (colon + 1, &limit)) {
3166 sgen_env_var_error (MONO_GC_DEBUG_NAME, "Ignoring limit.", "Binary protocol file size limit must be an integer.");
3171 binary_protocol_init (filename, (long long)limit);
3172 } else if (!strcmp (opt, "nursery-canaries")) {
3173 do_verify_nursery = TRUE;
3174 enable_nursery_canaries = TRUE;
3175 } else if (!sgen_client_handle_gc_debug (opt)) {
3176 sgen_env_var_error (MONO_GC_DEBUG_NAME, "Ignoring.", "Unknown option `%s`.", opt);
3181 fprintf (stderr, "\n%s must be of the format [<l>[:<filename>]|<option>]+ where <l> is a debug level 0-9.\n", MONO_GC_DEBUG_NAME);
3182 fprintf (stderr, "Valid <option>s are:\n");
3183 fprintf (stderr, " collect-before-allocs[=<n>]\n");
3184 fprintf (stderr, " verify-before-allocs[=<n>]\n");
3185 fprintf (stderr, " check-remset-consistency\n");
3186 fprintf (stderr, " check-mark-bits\n");
3187 fprintf (stderr, " check-nursery-pinned\n");
3188 fprintf (stderr, " verify-before-collections\n");
3189 fprintf (stderr, " verify-nursery-at-minor-gc\n");
3190 fprintf (stderr, " dump-nursery-at-minor-gc\n");
3191 fprintf (stderr, " disable-minor\n");
3192 fprintf (stderr, " disable-major\n");
3193 fprintf (stderr, " check-concurrent\n");
3194 fprintf (stderr, " clear-[nursery-]at-gc\n");
3195 fprintf (stderr, " clear-at-tlab-creation\n");
3196 fprintf (stderr, " debug-clear-at-tlab-creation\n");
3197 fprintf (stderr, " check-scan-starts\n");
3198 fprintf (stderr, " print-allowance\n");
3199 fprintf (stderr, " print-pinning\n");
3200 fprintf (stderr, " heap-dump=<filename>\n");
3201 fprintf (stderr, " binary-protocol=<filename>[:<file-size-limit>]\n");
3202 fprintf (stderr, " nursery-canaries\n");
3203 sgen_client_print_gc_debug_usage ();
3204 fprintf (stderr, "\n");
3206 usage_printed = TRUE;
3213 g_free (debug_opts);
3215 if (check_mark_bits_after_major_collection)
3216 nursery_clear_policy = CLEAR_AT_GC;
3218 if (major_collector.post_param_init)
3219 major_collector.post_param_init (&major_collector);
3221 if (major_collector.needs_thread_pool) {
3222 int num_workers = 1;
3223 if (major_collector.is_parallel) {
3224 /* FIXME Detect the number of physical cores, instead of logical */
3225 num_workers = mono_cpu_count () / 2;
3226 if (num_workers < 1)
3229 sgen_workers_init (num_workers, (SgenWorkerCallback) major_collector.worker_init_cb);
3232 sgen_memgov_init (max_heap, soft_limit, debug_print_allowance, allowance_ratio, save_target);
3234 memset (&remset, 0, sizeof (remset));
3236 sgen_card_table_init (&remset);
3238 sgen_register_root (NULL, 0, sgen_make_user_root_descriptor (sgen_mark_normal_gc_handles), ROOT_TYPE_NORMAL, MONO_ROOT_SOURCE_GC_HANDLE, "normal gc handles");
3242 sgen_init_bridge ();
3246 sgen_gc_initialized ()
3248 return gc_initialized > 0;
3252 sgen_get_nursery_clear_policy (void)
3254 return nursery_clear_policy;
3260 mono_coop_mutex_lock (&gc_mutex);
3264 sgen_gc_unlock (void)
3266 mono_coop_mutex_unlock (&gc_mutex);
3270 sgen_major_collector_iterate_live_block_ranges (sgen_cardtable_block_callback callback)
3272 major_collector.iterate_live_block_ranges (callback);
3276 sgen_major_collector_iterate_block_ranges (sgen_cardtable_block_callback callback)
3278 major_collector.iterate_block_ranges (callback);
3282 sgen_get_major_collector (void)
3284 return &major_collector;
3288 sgen_get_remset (void)
3294 count_cards (long long *major_total, long long *major_marked, long long *los_total, long long *los_marked)
3296 sgen_get_major_collector ()->count_cards (major_total, major_marked);
3297 sgen_los_count_cards (los_total, los_marked);
3300 static gboolean world_is_stopped = FALSE;
3302 /* LOCKING: assumes the GC lock is held */
3304 sgen_stop_world (int generation)
3306 long long major_total = -1, major_marked = -1, los_total = -1, los_marked = -1;
3308 SGEN_ASSERT (0, !world_is_stopped, "Why are we stopping a stopped world?");
3310 binary_protocol_world_stopping (generation, sgen_timestamp (), (gpointer) (gsize) mono_native_thread_id_get ());
3312 sgen_client_stop_world (generation);
3314 world_is_stopped = TRUE;
3316 if (binary_protocol_is_heavy_enabled ())
3317 count_cards (&major_total, &major_marked, &los_total, &los_marked);
3318 binary_protocol_world_stopped (generation, sgen_timestamp (), major_total, major_marked, los_total, los_marked);
3321 /* LOCKING: assumes the GC lock is held */
3323 sgen_restart_world (int generation)
3325 long long major_total = -1, major_marked = -1, los_total = -1, los_marked = -1;
3328 SGEN_ASSERT (0, world_is_stopped, "Why are we restarting a running world?");
3330 if (binary_protocol_is_heavy_enabled ())
3331 count_cards (&major_total, &major_marked, &los_total, &los_marked);
3332 binary_protocol_world_restarting (generation, sgen_timestamp (), major_total, major_marked, los_total, los_marked);
3334 world_is_stopped = FALSE;
3336 sgen_client_restart_world (generation, &stw_time);
3338 binary_protocol_world_restarted (generation, sgen_timestamp ());
3340 if (sgen_client_bridge_need_processing ())
3341 sgen_client_bridge_processing_finish (generation);
3343 sgen_memgov_collection_end (generation, stw_time);
3347 sgen_is_world_stopped (void)
3349 return world_is_stopped;
3353 sgen_check_whole_heap_stw (void)
3355 sgen_stop_world (0);
3356 sgen_clear_nursery_fragments ();
3357 sgen_check_whole_heap (TRUE);
3358 sgen_restart_world (0);
3362 sgen_timestamp (void)
3364 SGEN_TV_DECLARE (timestamp);
3365 SGEN_TV_GETTIME (timestamp);
3366 return SGEN_TV_ELAPSED (sgen_init_timestamp, timestamp);
3369 #endif /* HAVE_SGEN_GC */