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 ScanPtrFieldFunc scan_field_func = ctx.ops->scan_ptr_field;
862 SgenGrayQueue *queue = ctx.queue;
864 switch (desc & ROOT_DESC_TYPE_MASK) {
865 case ROOT_DESC_BITMAP:
866 desc >>= ROOT_DESC_TYPE_SHIFT;
868 if ((desc & 1) && *start_root) {
869 copy_func ((GCObject**)start_root, queue);
870 SGEN_LOG (9, "Overwrote root at %p with %p", start_root, *start_root);
876 case ROOT_DESC_COMPLEX: {
877 gsize *bitmap_data = (gsize *)sgen_get_complex_descriptor_bitmap (desc);
878 gsize bwords = (*bitmap_data) - 1;
879 void **start_run = start_root;
881 while (bwords-- > 0) {
882 gsize bmap = *bitmap_data++;
883 void **objptr = start_run;
885 if ((bmap & 1) && *objptr) {
886 copy_func ((GCObject**)objptr, queue);
887 SGEN_LOG (9, "Overwrote root at %p with %p", objptr, *objptr);
892 start_run += GC_BITS_PER_WORD;
896 case ROOT_DESC_VECTOR: {
899 for (p = start_root; p < end_root; p++) {
901 scan_field_func (NULL, (GCObject**)p, queue);
905 case ROOT_DESC_USER: {
906 SgenUserRootMarkFunc marker = sgen_get_user_descriptor_func (desc);
907 marker (start_root, single_arg_user_copy_or_mark, &ctx);
910 case ROOT_DESC_RUN_LEN:
911 g_assert_not_reached ();
913 g_assert_not_reached ();
918 reset_heap_boundaries (void)
920 lowest_heap_address = ~(mword)0;
921 highest_heap_address = 0;
925 sgen_update_heap_boundaries (mword low, mword high)
930 old = lowest_heap_address;
933 } while (SGEN_CAS_PTR ((gpointer*)&lowest_heap_address, (gpointer)low, (gpointer)old) != (gpointer)old);
936 old = highest_heap_address;
939 } while (SGEN_CAS_PTR ((gpointer*)&highest_heap_address, (gpointer)high, (gpointer)old) != (gpointer)old);
943 * Allocate and setup the data structures needed to be able to allocate objects
944 * in the nursery. The nursery is stored in nursery_section.
949 GCMemSection *section;
956 SGEN_LOG (2, "Allocating nursery size: %zu", (size_t)sgen_nursery_size);
957 /* later we will alloc a larger area for the nursery but only activate
958 * what we need. The rest will be used as expansion if we have too many pinned
959 * objects in the existing nursery.
961 /* FIXME: handle OOM */
962 section = (GCMemSection *)sgen_alloc_internal (INTERNAL_MEM_SECTION);
964 alloc_size = sgen_nursery_size;
966 /* If there isn't enough space even for the nursery we should simply abort. */
967 g_assert (sgen_memgov_try_alloc_space (alloc_size, SPACE_NURSERY));
969 data = (char *)major_collector.alloc_heap (alloc_size, alloc_size, DEFAULT_NURSERY_BITS);
970 sgen_update_heap_boundaries ((mword)data, (mword)(data + sgen_nursery_size));
971 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 ());
972 section->data = section->next_data = data;
973 section->size = alloc_size;
974 section->end_data = data + sgen_nursery_size;
975 scan_starts = (alloc_size + SCAN_START_SIZE - 1) / SCAN_START_SIZE;
976 section->scan_starts = (char **)sgen_alloc_internal_dynamic (sizeof (char*) * scan_starts, INTERNAL_MEM_SCAN_STARTS, TRUE);
977 section->num_scan_start = scan_starts;
979 nursery_section = section;
981 sgen_nursery_allocator_set_nursery_bounds (data, data + sgen_nursery_size);
985 mono_gc_get_logfile (void)
987 return gc_debug_file;
991 mono_gc_params_set (const char* options)
993 if (gc_params_options)
994 g_free (gc_params_options);
996 gc_params_options = g_strdup (options);
1000 mono_gc_debug_set (const char* options)
1002 if (gc_debug_options)
1003 g_free (gc_debug_options);
1005 gc_debug_options = g_strdup (options);
1009 scan_finalizer_entries (SgenPointerQueue *fin_queue, ScanCopyContext ctx)
1011 CopyOrMarkObjectFunc copy_func = ctx.ops->copy_or_mark_object;
1012 SgenGrayQueue *queue = ctx.queue;
1015 for (i = 0; i < fin_queue->next_slot; ++i) {
1016 GCObject *obj = (GCObject *)fin_queue->data [i];
1019 SGEN_LOG (5, "Scan of fin ready object: %p (%s)\n", obj, sgen_client_vtable_get_name (SGEN_LOAD_VTABLE (obj)));
1020 copy_func ((GCObject**)&fin_queue->data [i], queue);
1025 generation_name (int generation)
1027 switch (generation) {
1028 case GENERATION_NURSERY: return "nursery";
1029 case GENERATION_OLD: return "old";
1030 default: g_assert_not_reached ();
1035 sgen_generation_name (int generation)
1037 return generation_name (generation);
1041 finish_gray_stack (int generation, ScanCopyContext ctx)
1045 int done_with_ephemerons, ephemeron_rounds = 0;
1046 char *start_addr = generation == GENERATION_NURSERY ? sgen_get_nursery_start () : NULL;
1047 char *end_addr = generation == GENERATION_NURSERY ? sgen_get_nursery_end () : (char*)-1;
1048 SgenGrayQueue *queue = ctx.queue;
1050 binary_protocol_finish_gray_stack_start (sgen_timestamp (), generation);
1052 * We copied all the reachable objects. Now it's the time to copy
1053 * the objects that were not referenced by the roots, but by the copied objects.
1054 * we built a stack of objects pointed to by gray_start: they are
1055 * additional roots and we may add more items as we go.
1056 * We loop until gray_start == gray_objects which means no more objects have
1057 * been added. Note this is iterative: no recursion is involved.
1058 * We need to walk the LO list as well in search of marked big objects
1059 * (use a flag since this is needed only on major collections). We need to loop
1060 * here as well, so keep a counter of marked LO (increasing it in copy_object).
1061 * To achieve better cache locality and cache usage, we drain the gray stack
1062 * frequently, after each object is copied, and just finish the work here.
1064 sgen_drain_gray_stack (ctx);
1066 SGEN_LOG (2, "%s generation done", generation_name (generation));
1069 Reset bridge data, we might have lingering data from a previous collection if this is a major
1070 collection trigged by minor overflow.
1072 We must reset the gathered bridges since their original block might be evacuated due to major
1073 fragmentation in the meanwhile and the bridge code should not have to deal with that.
1075 if (sgen_client_bridge_need_processing ())
1076 sgen_client_bridge_reset_data ();
1079 * Mark all strong toggleref objects. This must be done before we walk ephemerons or finalizers
1080 * to ensure they see the full set of live objects.
1082 sgen_client_mark_togglerefs (start_addr, end_addr, ctx);
1085 * Walk the ephemeron tables marking all values with reachable keys. This must be completely done
1086 * before processing finalizable objects and non-tracking weak links to avoid finalizing/clearing
1087 * objects that are in fact reachable.
1089 done_with_ephemerons = 0;
1091 done_with_ephemerons = sgen_client_mark_ephemerons (ctx);
1092 sgen_drain_gray_stack (ctx);
1094 } while (!done_with_ephemerons);
1096 if (sgen_client_bridge_need_processing ()) {
1097 /*Make sure the gray stack is empty before we process bridge objects so we get liveness right*/
1098 sgen_drain_gray_stack (ctx);
1099 sgen_collect_bridge_objects (generation, ctx);
1100 if (generation == GENERATION_OLD)
1101 sgen_collect_bridge_objects (GENERATION_NURSERY, ctx);
1104 Do the first bridge step here, as the collector liveness state will become useless after that.
1106 An important optimization is to only proccess the possibly dead part of the object graph and skip
1107 over all live objects as we transitively know everything they point must be alive too.
1109 The above invariant is completely wrong if we let the gray queue be drained and mark/copy everything.
1111 This has the unfortunate side effect of making overflow collections perform the first step twice, but
1112 given we now have heuristics that perform major GC in anticipation of minor overflows this should not
1115 sgen_client_bridge_processing_stw_step ();
1119 Make sure we drain the gray stack before processing disappearing links and finalizers.
1120 If we don't make sure it is empty we might wrongly see a live object as dead.
1122 sgen_drain_gray_stack (ctx);
1125 We must clear weak links that don't track resurrection before processing object ready for
1126 finalization so they can be cleared before that.
1128 sgen_null_link_in_range (generation, ctx, FALSE);
1129 if (generation == GENERATION_OLD)
1130 sgen_null_link_in_range (GENERATION_NURSERY, ctx, FALSE);
1133 /* walk the finalization queue and move also the objects that need to be
1134 * finalized: use the finalized objects as new roots so the objects they depend
1135 * on are also not reclaimed. As with the roots above, only objects in the nursery
1136 * are marked/copied.
1138 sgen_finalize_in_range (generation, ctx);
1139 if (generation == GENERATION_OLD)
1140 sgen_finalize_in_range (GENERATION_NURSERY, ctx);
1141 /* drain the new stack that might have been created */
1142 SGEN_LOG (6, "Precise scan of gray area post fin");
1143 sgen_drain_gray_stack (ctx);
1146 * This must be done again after processing finalizable objects since CWL slots are cleared only after the key is finalized.
1148 done_with_ephemerons = 0;
1150 done_with_ephemerons = sgen_client_mark_ephemerons (ctx);
1151 sgen_drain_gray_stack (ctx);
1153 } while (!done_with_ephemerons);
1155 sgen_client_clear_unreachable_ephemerons (ctx);
1158 * We clear togglerefs only after all possible chances of revival are done.
1159 * This is semantically more inline with what users expect and it allows for
1160 * user finalizers to correctly interact with TR objects.
1162 sgen_client_clear_togglerefs (start_addr, end_addr, ctx);
1165 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);
1168 * handle disappearing links
1169 * Note we do this after checking the finalization queue because if an object
1170 * survives (at least long enough to be finalized) we don't clear the link.
1171 * This also deals with a possible issue with the monitor reclamation: with the Boehm
1172 * GC a finalized object my lose the monitor because it is cleared before the finalizer is
1175 g_assert (sgen_gray_object_queue_is_empty (queue));
1177 sgen_null_link_in_range (generation, ctx, TRUE);
1178 if (generation == GENERATION_OLD)
1179 sgen_null_link_in_range (GENERATION_NURSERY, ctx, TRUE);
1180 if (sgen_gray_object_queue_is_empty (queue))
1182 sgen_drain_gray_stack (ctx);
1185 g_assert (sgen_gray_object_queue_is_empty (queue));
1187 binary_protocol_finish_gray_stack_end (sgen_timestamp (), generation);
1191 sgen_check_section_scan_starts (GCMemSection *section)
1194 for (i = 0; i < section->num_scan_start; ++i) {
1195 if (section->scan_starts [i]) {
1196 mword size = safe_object_get_size ((GCObject*) section->scan_starts [i]);
1197 SGEN_ASSERT (0, size >= SGEN_CLIENT_MINIMUM_OBJECT_SIZE && size <= MAX_SMALL_OBJ_SIZE, "Weird object size at scan starts.");
1203 check_scan_starts (void)
1205 if (!do_scan_starts_check)
1207 sgen_check_section_scan_starts (nursery_section);
1208 major_collector.check_scan_starts ();
1212 scan_from_registered_roots (char *addr_start, char *addr_end, int root_type, ScanCopyContext ctx)
1216 SGEN_HASH_TABLE_FOREACH (&roots_hash [root_type], void **, start_root, RootRecord *, root) {
1217 SGEN_LOG (6, "Precise root scan %p-%p (desc: %p)", start_root, root->end_root, (void*)root->root_desc);
1218 precisely_scan_objects_from (start_root, (void**)root->end_root, addr_start, addr_end, root->root_desc, ctx);
1219 } SGEN_HASH_TABLE_FOREACH_END;
1225 static gboolean inited = FALSE;
1230 mono_counters_register ("Collection max time", MONO_COUNTER_GC | MONO_COUNTER_ULONG | MONO_COUNTER_TIME | MONO_COUNTER_MONOTONIC, &time_max);
1232 mono_counters_register ("Minor fragment clear", MONO_COUNTER_GC | MONO_COUNTER_ULONG | MONO_COUNTER_TIME, &time_minor_pre_collection_fragment_clear);
1233 mono_counters_register ("Minor pinning", MONO_COUNTER_GC | MONO_COUNTER_ULONG | MONO_COUNTER_TIME, &time_minor_pinning);
1234 mono_counters_register ("Minor scan remembered set", MONO_COUNTER_GC | MONO_COUNTER_ULONG | MONO_COUNTER_TIME, &time_minor_scan_remsets);
1235 mono_counters_register ("Minor scan pinned", MONO_COUNTER_GC | MONO_COUNTER_ULONG | MONO_COUNTER_TIME, &time_minor_scan_pinned);
1236 mono_counters_register ("Minor scan roots", MONO_COUNTER_GC | MONO_COUNTER_ULONG | MONO_COUNTER_TIME, &time_minor_scan_roots);
1237 mono_counters_register ("Minor fragment creation", MONO_COUNTER_GC | MONO_COUNTER_ULONG | MONO_COUNTER_TIME, &time_minor_fragment_creation);
1239 mono_counters_register ("Major fragment clear", MONO_COUNTER_GC | MONO_COUNTER_ULONG | MONO_COUNTER_TIME, &time_major_pre_collection_fragment_clear);
1240 mono_counters_register ("Major pinning", MONO_COUNTER_GC | MONO_COUNTER_ULONG | MONO_COUNTER_TIME, &time_major_pinning);
1241 mono_counters_register ("Major scan pinned", MONO_COUNTER_GC | MONO_COUNTER_ULONG | MONO_COUNTER_TIME, &time_major_scan_pinned);
1242 mono_counters_register ("Major scan roots", MONO_COUNTER_GC | MONO_COUNTER_ULONG | MONO_COUNTER_TIME, &time_major_scan_roots);
1243 mono_counters_register ("Major scan mod union", MONO_COUNTER_GC | MONO_COUNTER_ULONG | MONO_COUNTER_TIME, &time_major_scan_mod_union);
1244 mono_counters_register ("Major finish gray stack", MONO_COUNTER_GC | MONO_COUNTER_ULONG | MONO_COUNTER_TIME, &time_major_finish_gray_stack);
1245 mono_counters_register ("Major free big objects", MONO_COUNTER_GC | MONO_COUNTER_ULONG | MONO_COUNTER_TIME, &time_major_free_bigobjs);
1246 mono_counters_register ("Major LOS sweep", MONO_COUNTER_GC | MONO_COUNTER_ULONG | MONO_COUNTER_TIME, &time_major_los_sweep);
1247 mono_counters_register ("Major sweep", MONO_COUNTER_GC | MONO_COUNTER_ULONG | MONO_COUNTER_TIME, &time_major_sweep);
1248 mono_counters_register ("Major fragment creation", MONO_COUNTER_GC | MONO_COUNTER_ULONG | MONO_COUNTER_TIME, &time_major_fragment_creation);
1250 mono_counters_register ("Number of pinned objects", MONO_COUNTER_GC | MONO_COUNTER_ULONG, &stat_pinned_objects);
1252 #ifdef HEAVY_STATISTICS
1253 mono_counters_register ("WBarrier remember pointer", MONO_COUNTER_GC | MONO_COUNTER_ULONG, &stat_wbarrier_add_to_global_remset);
1254 mono_counters_register ("WBarrier arrayref copy", MONO_COUNTER_GC | MONO_COUNTER_ULONG, &stat_wbarrier_arrayref_copy);
1255 mono_counters_register ("WBarrier generic store called", MONO_COUNTER_GC | MONO_COUNTER_ULONG, &stat_wbarrier_generic_store);
1256 mono_counters_register ("WBarrier generic atomic store called", MONO_COUNTER_GC | MONO_COUNTER_ULONG, &stat_wbarrier_generic_store_atomic);
1257 mono_counters_register ("WBarrier set root", MONO_COUNTER_GC | MONO_COUNTER_ULONG, &stat_wbarrier_set_root);
1259 mono_counters_register ("# objects allocated degraded", MONO_COUNTER_GC | MONO_COUNTER_ULONG, &stat_objects_alloced_degraded);
1260 mono_counters_register ("bytes allocated degraded", MONO_COUNTER_GC | MONO_COUNTER_ULONG, &stat_bytes_alloced_degraded);
1262 mono_counters_register ("# copy_object() called (nursery)", MONO_COUNTER_GC | MONO_COUNTER_ULONG, &stat_copy_object_called_nursery);
1263 mono_counters_register ("# objects copied (nursery)", MONO_COUNTER_GC | MONO_COUNTER_ULONG, &stat_objects_copied_nursery);
1264 mono_counters_register ("# copy_object() called (major)", MONO_COUNTER_GC | MONO_COUNTER_ULONG, &stat_copy_object_called_major);
1265 mono_counters_register ("# objects copied (major)", MONO_COUNTER_GC | MONO_COUNTER_ULONG, &stat_objects_copied_major);
1267 mono_counters_register ("# scan_object() called (nursery)", MONO_COUNTER_GC | MONO_COUNTER_ULONG, &stat_scan_object_called_nursery);
1268 mono_counters_register ("# scan_object() called (major)", MONO_COUNTER_GC | MONO_COUNTER_ULONG, &stat_scan_object_called_major);
1270 mono_counters_register ("Slots allocated in vain", MONO_COUNTER_GC | MONO_COUNTER_ULONG, &stat_slots_allocated_in_vain);
1272 mono_counters_register ("# nursery copy_object() failed from space", MONO_COUNTER_GC | MONO_COUNTER_ULONG, &stat_nursery_copy_object_failed_from_space);
1273 mono_counters_register ("# nursery copy_object() failed forwarded", MONO_COUNTER_GC | MONO_COUNTER_ULONG, &stat_nursery_copy_object_failed_forwarded);
1274 mono_counters_register ("# nursery copy_object() failed pinned", MONO_COUNTER_GC | MONO_COUNTER_ULONG, &stat_nursery_copy_object_failed_pinned);
1275 mono_counters_register ("# nursery copy_object() failed to space", MONO_COUNTER_GC | MONO_COUNTER_ULONG, &stat_nursery_copy_object_failed_to_space);
1277 sgen_nursery_allocator_init_heavy_stats ();
1285 reset_pinned_from_failed_allocation (void)
1287 bytes_pinned_from_failed_allocation = 0;
1291 sgen_set_pinned_from_failed_allocation (mword objsize)
1293 bytes_pinned_from_failed_allocation += objsize;
1297 sgen_collection_is_concurrent (void)
1299 switch (current_collection_generation) {
1300 case GENERATION_NURSERY:
1302 case GENERATION_OLD:
1303 return concurrent_collection_in_progress;
1305 g_error ("Invalid current generation %d", current_collection_generation);
1311 sgen_concurrent_collection_in_progress (void)
1313 return concurrent_collection_in_progress;
1317 SgenThreadPoolJob job;
1318 SgenObjectOperations *ops;
1319 SgenGrayQueue *gc_thread_gray_queue;
1327 static ScanCopyContext
1328 scan_copy_context_for_scan_job (void *worker_data_untyped, ScanJob *job)
1330 WorkerData *worker_data = (WorkerData *)worker_data_untyped;
1332 return CONTEXT_FROM_OBJECT_OPERATIONS (job->ops, sgen_workers_get_job_gray_queue (worker_data, job->gc_thread_gray_queue));
1336 job_remembered_set_scan (void *worker_data_untyped, SgenThreadPoolJob *job)
1338 remset.scan_remsets (scan_copy_context_for_scan_job (worker_data_untyped, (ScanJob*)job));
1346 } ScanFromRegisteredRootsJob;
1349 job_scan_from_registered_roots (void *worker_data_untyped, SgenThreadPoolJob *job)
1351 ScanFromRegisteredRootsJob *job_data = (ScanFromRegisteredRootsJob*)job;
1352 ScanCopyContext ctx = scan_copy_context_for_scan_job (worker_data_untyped, &job_data->scan_job);
1354 scan_from_registered_roots (job_data->heap_start, job_data->heap_end, job_data->root_type, ctx);
1361 } ScanThreadDataJob;
1364 job_scan_thread_data (void *worker_data_untyped, SgenThreadPoolJob *job)
1366 ScanThreadDataJob *job_data = (ScanThreadDataJob*)job;
1367 ScanCopyContext ctx = scan_copy_context_for_scan_job (worker_data_untyped, &job_data->scan_job);
1369 sgen_client_scan_thread_data (job_data->heap_start, job_data->heap_end, TRUE, ctx);
1374 SgenPointerQueue *queue;
1375 } ScanFinalizerEntriesJob;
1378 job_scan_finalizer_entries (void *worker_data_untyped, SgenThreadPoolJob *job)
1380 ScanFinalizerEntriesJob *job_data = (ScanFinalizerEntriesJob*)job;
1381 ScanCopyContext ctx = scan_copy_context_for_scan_job (worker_data_untyped, &job_data->scan_job);
1383 scan_finalizer_entries (job_data->queue, ctx);
1387 job_scan_major_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 major_collector.scan_card_table (CARDTABLE_SCAN_MOD_UNION, ctx, job_data->job_index, sgen_workers_get_job_split_count ());
1397 job_scan_los_mod_union_card_table (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);
1403 sgen_los_scan_card_table (CARDTABLE_SCAN_MOD_UNION, ctx, job_data->job_index, sgen_workers_get_job_split_count ());
1407 job_major_mod_union_preclean (void *worker_data_untyped, SgenThreadPoolJob *job)
1409 ParallelScanJob *job_data = (ParallelScanJob*)job;
1410 ScanCopyContext ctx = scan_copy_context_for_scan_job (worker_data_untyped, (ScanJob*)job_data);
1412 g_assert (concurrent_collection_in_progress);
1414 major_collector.scan_card_table (CARDTABLE_SCAN_MOD_UNION_PRECLEAN, ctx, job_data->job_index, sgen_workers_get_job_split_count ());
1418 job_los_mod_union_preclean (void *worker_data_untyped, SgenThreadPoolJob *job)
1420 ParallelScanJob *job_data = (ParallelScanJob*)job;
1421 ScanCopyContext ctx = scan_copy_context_for_scan_job (worker_data_untyped, (ScanJob*)job_data);
1423 g_assert (concurrent_collection_in_progress);
1425 sgen_los_scan_card_table (CARDTABLE_SCAN_MOD_UNION_PRECLEAN, ctx, job_data->job_index, sgen_workers_get_job_split_count ());
1429 job_scan_last_pinned (void *worker_data_untyped, SgenThreadPoolJob *job)
1431 ScanJob *job_data = (ScanJob*)job;
1432 ScanCopyContext ctx = scan_copy_context_for_scan_job (worker_data_untyped, job_data);
1434 g_assert (concurrent_collection_in_progress);
1436 sgen_scan_pin_queue_objects (ctx);
1440 workers_finish_callback (void)
1442 ParallelScanJob *psj;
1444 int split_count = sgen_workers_get_job_split_count ();
1446 /* Mod union preclean jobs */
1447 for (i = 0; i < split_count; i++) {
1448 psj = (ParallelScanJob*)sgen_thread_pool_job_alloc ("preclean major mod union cardtable", job_major_mod_union_preclean, sizeof (ParallelScanJob));
1449 psj->scan_job.ops = sgen_workers_get_idle_func_object_ops ();
1450 psj->scan_job.gc_thread_gray_queue = NULL;
1452 sgen_workers_enqueue_job (&psj->scan_job.job, TRUE);
1455 for (i = 0; i < split_count; i++) {
1456 psj = (ParallelScanJob*)sgen_thread_pool_job_alloc ("preclean los mod union cardtable", job_los_mod_union_preclean, sizeof (ParallelScanJob));
1457 psj->scan_job.ops = sgen_workers_get_idle_func_object_ops ();
1458 psj->scan_job.gc_thread_gray_queue = NULL;
1460 sgen_workers_enqueue_job (&psj->scan_job.job, TRUE);
1463 sj = (ScanJob*)sgen_thread_pool_job_alloc ("scan last pinned", job_scan_last_pinned, sizeof (ScanJob));
1464 sj->ops = sgen_workers_get_idle_func_object_ops ();
1465 sj->gc_thread_gray_queue = NULL;
1466 sgen_workers_enqueue_job (&sj->job, TRUE);
1470 init_gray_queue (SgenGrayQueue *gc_thread_gray_queue, gboolean use_workers)
1473 sgen_workers_init_distribute_gray_queue ();
1474 sgen_gray_object_queue_init (gc_thread_gray_queue, NULL, TRUE);
1478 enqueue_scan_from_roots_jobs (SgenGrayQueue *gc_thread_gray_queue, char *heap_start, char *heap_end, SgenObjectOperations *ops, gboolean enqueue)
1480 ScanFromRegisteredRootsJob *scrrj;
1481 ScanThreadDataJob *stdj;
1482 ScanFinalizerEntriesJob *sfej;
1484 /* registered roots, this includes static fields */
1486 scrrj = (ScanFromRegisteredRootsJob*)sgen_thread_pool_job_alloc ("scan from registered roots normal", job_scan_from_registered_roots, sizeof (ScanFromRegisteredRootsJob));
1487 scrrj->scan_job.ops = ops;
1488 scrrj->scan_job.gc_thread_gray_queue = gc_thread_gray_queue;
1489 scrrj->heap_start = heap_start;
1490 scrrj->heap_end = heap_end;
1491 scrrj->root_type = ROOT_TYPE_NORMAL;
1492 sgen_workers_enqueue_job (&scrrj->scan_job.job, enqueue);
1494 if (current_collection_generation == GENERATION_OLD) {
1495 /* During minors we scan the cardtable for these roots instead */
1496 scrrj = (ScanFromRegisteredRootsJob*)sgen_thread_pool_job_alloc ("scan from registered roots wbarrier", job_scan_from_registered_roots, sizeof (ScanFromRegisteredRootsJob));
1497 scrrj->scan_job.ops = ops;
1498 scrrj->scan_job.gc_thread_gray_queue = gc_thread_gray_queue;
1499 scrrj->heap_start = heap_start;
1500 scrrj->heap_end = heap_end;
1501 scrrj->root_type = ROOT_TYPE_WBARRIER;
1502 sgen_workers_enqueue_job (&scrrj->scan_job.job, enqueue);
1507 stdj = (ScanThreadDataJob*)sgen_thread_pool_job_alloc ("scan thread data", job_scan_thread_data, sizeof (ScanThreadDataJob));
1508 stdj->scan_job.ops = ops;
1509 stdj->scan_job.gc_thread_gray_queue = gc_thread_gray_queue;
1510 stdj->heap_start = heap_start;
1511 stdj->heap_end = heap_end;
1512 sgen_workers_enqueue_job (&stdj->scan_job.job, enqueue);
1514 /* Scan the list of objects ready for finalization. */
1516 sfej = (ScanFinalizerEntriesJob*)sgen_thread_pool_job_alloc ("scan finalizer entries", job_scan_finalizer_entries, sizeof (ScanFinalizerEntriesJob));
1517 sfej->scan_job.ops = ops;
1518 sfej->scan_job.gc_thread_gray_queue = gc_thread_gray_queue;
1519 sfej->queue = &fin_ready_queue;
1520 sgen_workers_enqueue_job (&sfej->scan_job.job, enqueue);
1522 sfej = (ScanFinalizerEntriesJob*)sgen_thread_pool_job_alloc ("scan critical finalizer entries", job_scan_finalizer_entries, sizeof (ScanFinalizerEntriesJob));
1523 sfej->scan_job.ops = ops;
1524 sfej->scan_job.gc_thread_gray_queue = gc_thread_gray_queue;
1525 sfej->queue = &critical_fin_queue;
1526 sgen_workers_enqueue_job (&sfej->scan_job.job, enqueue);
1530 * Perform a nursery collection.
1532 * Return whether any objects were late-pinned due to being out of memory.
1535 collect_nursery (const char *reason, gboolean is_overflow, SgenGrayQueue *unpin_queue)
1537 gboolean needs_major;
1538 size_t max_garbage_amount;
1540 mword fragment_total;
1542 SgenGrayQueue gc_thread_gray_queue;
1543 SgenObjectOperations *object_ops;
1544 ScanCopyContext ctx;
1547 SGEN_TV_DECLARE (last_minor_collection_start_tv);
1548 SGEN_TV_DECLARE (last_minor_collection_end_tv);
1550 if (disable_minor_collections)
1553 TV_GETTIME (last_minor_collection_start_tv);
1554 atv = last_minor_collection_start_tv;
1556 binary_protocol_collection_begin (gc_stats.minor_gc_count, GENERATION_NURSERY);
1558 if (sgen_concurrent_collection_in_progress ())
1559 object_ops = &sgen_minor_collector.serial_ops_with_concurrent_major;
1561 object_ops = &sgen_minor_collector.serial_ops;
1563 if (do_verify_nursery || do_dump_nursery_content)
1564 sgen_debug_verify_nursery (do_dump_nursery_content);
1566 current_collection_generation = GENERATION_NURSERY;
1568 SGEN_ASSERT (0, !sgen_collection_is_concurrent (), "Why is the nursery collection concurrent?");
1570 reset_pinned_from_failed_allocation ();
1572 check_scan_starts ();
1574 sgen_nursery_alloc_prepare_for_minor ();
1578 nursery_next = sgen_nursery_alloc_get_upper_alloc_bound ();
1579 /* FIXME: optimize later to use the higher address where an object can be present */
1580 nursery_next = MAX (nursery_next, sgen_get_nursery_end ());
1582 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 ()));
1583 max_garbage_amount = nursery_next - sgen_get_nursery_start ();
1584 g_assert (nursery_section->size >= max_garbage_amount);
1586 /* world must be stopped already */
1588 time_minor_pre_collection_fragment_clear += TV_ELAPSED (atv, btv);
1590 sgen_client_pre_collection_checks ();
1592 nursery_section->next_data = nursery_next;
1594 major_collector.start_nursery_collection ();
1596 sgen_memgov_minor_collection_start ();
1598 init_gray_queue (&gc_thread_gray_queue, FALSE);
1599 ctx = CONTEXT_FROM_OBJECT_OPERATIONS (object_ops, &gc_thread_gray_queue);
1601 gc_stats.minor_gc_count ++;
1603 sgen_process_fin_stage_entries ();
1605 /* pin from pinned handles */
1606 sgen_init_pinning ();
1607 sgen_client_binary_protocol_mark_start (GENERATION_NURSERY);
1608 pin_from_roots (sgen_get_nursery_start (), nursery_next, ctx);
1609 /* pin cemented objects */
1610 sgen_pin_cemented_objects ();
1611 /* identify pinned objects */
1612 sgen_optimize_pin_queue ();
1613 sgen_pinning_setup_section (nursery_section);
1615 pin_objects_in_nursery (FALSE, ctx);
1616 sgen_pinning_trim_queue_to_section (nursery_section);
1618 if (remset_consistency_checks)
1619 sgen_check_remset_consistency ();
1621 if (whole_heap_check_before_collection) {
1622 sgen_clear_nursery_fragments ();
1623 sgen_check_whole_heap (FALSE);
1627 time_minor_pinning += TV_ELAPSED (btv, atv);
1628 SGEN_LOG (2, "Finding pinned pointers: %zd in %lld usecs", sgen_get_pinned_count (), (long long)TV_ELAPSED (btv, atv));
1629 SGEN_LOG (4, "Start scan with %zd pinned objects", sgen_get_pinned_count ());
1631 sj = (ScanJob*)sgen_thread_pool_job_alloc ("scan remset", job_remembered_set_scan, sizeof (ScanJob));
1632 sj->ops = object_ops;
1633 sj->gc_thread_gray_queue = &gc_thread_gray_queue;
1634 sgen_workers_enqueue_job (&sj->job, FALSE);
1636 /* we don't have complete write barrier yet, so we scan all the old generation sections */
1638 time_minor_scan_remsets += TV_ELAPSED (atv, btv);
1639 SGEN_LOG (2, "Old generation scan: %lld usecs", (long long)TV_ELAPSED (atv, btv));
1641 sgen_pin_stats_report ();
1643 /* FIXME: Why do we do this at this specific, seemingly random, point? */
1644 sgen_client_collecting_minor (&fin_ready_queue, &critical_fin_queue);
1647 time_minor_scan_pinned += TV_ELAPSED (btv, atv);
1649 enqueue_scan_from_roots_jobs (&gc_thread_gray_queue, sgen_get_nursery_start (), nursery_next, object_ops, FALSE);
1652 time_minor_scan_roots += TV_ELAPSED (atv, btv);
1654 finish_gray_stack (GENERATION_NURSERY, ctx);
1657 time_minor_finish_gray_stack += TV_ELAPSED (btv, atv);
1658 sgen_client_binary_protocol_mark_end (GENERATION_NURSERY);
1660 if (objects_pinned) {
1661 sgen_optimize_pin_queue ();
1662 sgen_pinning_setup_section (nursery_section);
1666 * This is the latest point at which we can do this check, because
1667 * sgen_build_nursery_fragments() unpins nursery objects again.
1669 if (remset_consistency_checks)
1670 sgen_check_remset_consistency ();
1672 /* walk the pin_queue, build up the fragment list of free memory, unmark
1673 * pinned objects as we go, memzero() the empty fragments so they are ready for the
1676 sgen_client_binary_protocol_reclaim_start (GENERATION_NURSERY);
1677 fragment_total = sgen_build_nursery_fragments (nursery_section, unpin_queue);
1678 if (!fragment_total)
1681 /* Clear TLABs for all threads */
1682 sgen_clear_tlabs ();
1684 sgen_client_binary_protocol_reclaim_end (GENERATION_NURSERY);
1686 time_minor_fragment_creation += TV_ELAPSED (atv, btv);
1687 SGEN_LOG (2, "Fragment creation: %lld usecs, %lu bytes available", (long long)TV_ELAPSED (atv, btv), (unsigned long)fragment_total);
1689 if (remset_consistency_checks)
1690 sgen_check_major_refs ();
1692 major_collector.finish_nursery_collection ();
1694 TV_GETTIME (last_minor_collection_end_tv);
1695 gc_stats.minor_gc_time += TV_ELAPSED (last_minor_collection_start_tv, last_minor_collection_end_tv);
1697 sgen_debug_dump_heap ("minor", gc_stats.minor_gc_count - 1, NULL);
1699 /* prepare the pin queue for the next collection */
1700 sgen_finish_pinning ();
1701 if (sgen_have_pending_finalizers ()) {
1702 SGEN_LOG (4, "Finalizer-thread wakeup");
1703 sgen_client_finalize_notify ();
1705 sgen_pin_stats_reset ();
1706 /* clear cemented hash */
1707 sgen_cement_clear_below_threshold ();
1709 sgen_gray_object_queue_dispose (&gc_thread_gray_queue);
1711 remset.finish_minor_collection ();
1713 check_scan_starts ();
1715 binary_protocol_flush_buffers (FALSE);
1717 sgen_memgov_minor_collection_end (reason, is_overflow);
1719 /*objects are late pinned because of lack of memory, so a major is a good call*/
1720 needs_major = objects_pinned > 0;
1721 current_collection_generation = -1;
1724 binary_protocol_collection_end (gc_stats.minor_gc_count - 1, GENERATION_NURSERY, 0, 0);
1726 if (check_nursery_objects_pinned && !sgen_minor_collector.is_split)
1727 sgen_check_nursery_objects_pinned (unpin_queue != NULL);
1733 COPY_OR_MARK_FROM_ROOTS_SERIAL,
1734 COPY_OR_MARK_FROM_ROOTS_START_CONCURRENT,
1735 COPY_OR_MARK_FROM_ROOTS_FINISH_CONCURRENT
1736 } CopyOrMarkFromRootsMode;
1739 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)
1744 /* FIXME: only use these values for the precise scan
1745 * note that to_space pointers should be excluded anyway...
1747 char *heap_start = NULL;
1748 char *heap_end = (char*)-1;
1749 ScanCopyContext ctx = CONTEXT_FROM_OBJECT_OPERATIONS (object_ops_nopar, gc_thread_gray_queue);
1750 gboolean concurrent = mode != COPY_OR_MARK_FROM_ROOTS_SERIAL;
1752 SGEN_ASSERT (0, !!concurrent == !!concurrent_collection_in_progress, "We've been called with the wrong mode.");
1754 if (mode == COPY_OR_MARK_FROM_ROOTS_START_CONCURRENT) {
1755 /*This cleans up unused fragments */
1756 sgen_nursery_allocator_prepare_for_pinning ();
1758 if (do_concurrent_checks)
1759 sgen_debug_check_nursery_is_clean ();
1761 /* The concurrent collector doesn't touch the nursery. */
1762 sgen_nursery_alloc_prepare_for_major ();
1767 /* Pinning depends on this */
1768 sgen_clear_nursery_fragments ();
1770 if (whole_heap_check_before_collection)
1771 sgen_check_whole_heap (TRUE);
1774 time_major_pre_collection_fragment_clear += TV_ELAPSED (atv, btv);
1776 if (!sgen_collection_is_concurrent ())
1777 nursery_section->next_data = sgen_get_nursery_end ();
1778 /* we should also coalesce scanning from sections close to each other
1779 * and deal with pointers outside of the sections later.
1784 sgen_client_pre_collection_checks ();
1786 if (mode != COPY_OR_MARK_FROM_ROOTS_START_CONCURRENT) {
1787 /* Remsets are not useful for a major collection */
1788 remset.clear_cards ();
1791 sgen_process_fin_stage_entries ();
1794 sgen_init_pinning ();
1795 SGEN_LOG (6, "Collecting pinned addresses");
1796 pin_from_roots ((void*)lowest_heap_address, (void*)highest_heap_address, ctx);
1797 if (mode == COPY_OR_MARK_FROM_ROOTS_FINISH_CONCURRENT) {
1798 /* Pin cemented objects that were forced */
1799 sgen_pin_cemented_objects ();
1801 sgen_optimize_pin_queue ();
1802 if (mode == COPY_OR_MARK_FROM_ROOTS_START_CONCURRENT) {
1804 * Cemented objects that are in the pinned list will be marked. When
1805 * marking concurrently we won't mark mod-union cards for these objects.
1806 * Instead they will remain cemented until the next major collection,
1807 * when we will recheck if they are still pinned in the roots.
1809 sgen_cement_force_pinned ();
1812 sgen_client_collecting_major_1 ();
1815 * pin_queue now contains all candidate pointers, sorted and
1816 * uniqued. We must do two passes now to figure out which
1817 * objects are pinned.
1819 * The first is to find within the pin_queue the area for each
1820 * section. This requires that the pin_queue be sorted. We
1821 * also process the LOS objects and pinned chunks here.
1823 * The second, destructive, pass is to reduce the section
1824 * areas to pointers to the actually pinned objects.
1826 SGEN_LOG (6, "Pinning from sections");
1827 /* first pass for the sections */
1828 sgen_find_section_pin_queue_start_end (nursery_section);
1829 /* identify possible pointers to the insize of large objects */
1830 SGEN_LOG (6, "Pinning from large objects");
1831 for (bigobj = los_object_list; bigobj; bigobj = bigobj->next) {
1833 if (sgen_find_optimized_pin_queue_area ((char*)bigobj->data, (char*)bigobj->data + sgen_los_object_size (bigobj), &dummy, &dummy)) {
1834 binary_protocol_pin (bigobj->data, (gpointer)LOAD_VTABLE (bigobj->data), safe_object_get_size (bigobj->data));
1836 if (sgen_los_object_is_pinned (bigobj->data)) {
1837 SGEN_ASSERT (0, mode == COPY_OR_MARK_FROM_ROOTS_FINISH_CONCURRENT, "LOS objects can only be pinned here after concurrent marking.");
1840 sgen_los_pin_object (bigobj->data);
1841 if (SGEN_OBJECT_HAS_REFERENCES (bigobj->data))
1842 GRAY_OBJECT_ENQUEUE_SERIAL (gc_thread_gray_queue, bigobj->data, sgen_obj_get_descriptor ((GCObject*)bigobj->data));
1843 sgen_pin_stats_register_object (bigobj->data, GENERATION_OLD);
1844 SGEN_LOG (6, "Marked large object %p (%s) size: %lu from roots", bigobj->data,
1845 sgen_client_vtable_get_name (SGEN_LOAD_VTABLE (bigobj->data)),
1846 (unsigned long)sgen_los_object_size (bigobj));
1848 sgen_client_pinned_los_object (bigobj->data);
1852 pin_objects_in_nursery (mode == COPY_OR_MARK_FROM_ROOTS_START_CONCURRENT, ctx);
1853 if (check_nursery_objects_pinned && !sgen_minor_collector.is_split)
1854 sgen_check_nursery_objects_pinned (mode != COPY_OR_MARK_FROM_ROOTS_START_CONCURRENT);
1856 major_collector.pin_objects (gc_thread_gray_queue);
1857 if (old_next_pin_slot)
1858 *old_next_pin_slot = sgen_get_pinned_count ();
1861 time_major_pinning += TV_ELAPSED (atv, btv);
1862 SGEN_LOG (2, "Finding pinned pointers: %zd in %lld usecs", sgen_get_pinned_count (), (long long)TV_ELAPSED (atv, btv));
1863 SGEN_LOG (4, "Start scan with %zd pinned objects", sgen_get_pinned_count ());
1865 major_collector.init_to_space ();
1867 SGEN_ASSERT (0, sgen_workers_all_done (), "Why are the workers not done when we start or finish a major collection?");
1868 if (mode == COPY_OR_MARK_FROM_ROOTS_FINISH_CONCURRENT) {
1869 sgen_workers_set_num_active_workers (0);
1870 if (sgen_workers_have_idle_work ()) {
1872 * We force the finish of the worker with the new object ops context
1873 * which can also do copying. We need to have finished pinning.
1875 sgen_workers_start_all_workers (object_ops_nopar, object_ops_par, NULL);
1877 sgen_workers_join ();
1881 #ifdef SGEN_DEBUG_INTERNAL_ALLOC
1882 main_gc_thread = mono_native_thread_self ();
1885 sgen_client_collecting_major_2 ();
1888 time_major_scan_pinned += TV_ELAPSED (btv, atv);
1890 sgen_client_collecting_major_3 (&fin_ready_queue, &critical_fin_queue);
1892 enqueue_scan_from_roots_jobs (gc_thread_gray_queue, heap_start, heap_end, object_ops_nopar, FALSE);
1895 time_major_scan_roots += TV_ELAPSED (atv, btv);
1898 * We start the concurrent worker after pinning and after we scanned the roots
1899 * in order to make sure that the worker does not finish before handling all
1902 if (mode == COPY_OR_MARK_FROM_ROOTS_START_CONCURRENT) {
1903 sgen_workers_set_num_active_workers (1);
1904 gray_queue_redirect (gc_thread_gray_queue);
1905 if (precleaning_enabled) {
1906 sgen_workers_start_all_workers (object_ops_nopar, object_ops_par, workers_finish_callback);
1908 sgen_workers_start_all_workers (object_ops_nopar, object_ops_par, NULL);
1912 if (mode == COPY_OR_MARK_FROM_ROOTS_FINISH_CONCURRENT) {
1913 int i, split_count = sgen_workers_get_job_split_count ();
1915 gray_queue_redirect (gc_thread_gray_queue);
1917 /* Mod union card table */
1918 for (i = 0; i < split_count; i++) {
1919 ParallelScanJob *psj;
1921 psj = (ParallelScanJob*)sgen_thread_pool_job_alloc ("scan mod union cardtable", job_scan_major_mod_union_card_table, sizeof (ParallelScanJob));
1922 psj->scan_job.ops = object_ops_par ? object_ops_par : object_ops_nopar;
1923 psj->scan_job.gc_thread_gray_queue = NULL;
1925 sgen_workers_enqueue_job (&psj->scan_job.job, TRUE);
1927 psj = (ParallelScanJob*)sgen_thread_pool_job_alloc ("scan LOS mod union cardtable", job_scan_los_mod_union_card_table, sizeof (ParallelScanJob));
1928 psj->scan_job.ops = object_ops_par ? object_ops_par : object_ops_nopar;
1929 psj->scan_job.gc_thread_gray_queue = NULL;
1931 sgen_workers_enqueue_job (&psj->scan_job.job, TRUE);
1935 * If we enqueue a job while workers are running we need to sgen_workers_ensure_awake
1936 * in order to make sure that we are running the idle func and draining all worker
1937 * gray queues. The operation of starting workers implies this, so we start them after
1938 * in order to avoid doing this operation twice. The workers will drain the main gray
1939 * stack that contained roots and pinned objects and also scan the mod union card
1942 sgen_workers_start_all_workers (object_ops_nopar, object_ops_par, NULL);
1943 sgen_workers_join ();
1946 sgen_pin_stats_report ();
1948 if (mode == COPY_OR_MARK_FROM_ROOTS_START_CONCURRENT) {
1949 sgen_finish_pinning ();
1951 sgen_pin_stats_reset ();
1953 if (do_concurrent_checks)
1954 sgen_debug_check_nursery_is_clean ();
1959 major_start_collection (SgenGrayQueue *gc_thread_gray_queue, const char *reason, gboolean concurrent, size_t *old_next_pin_slot)
1961 SgenObjectOperations *object_ops_nopar, *object_ops_par = NULL;
1963 binary_protocol_collection_begin (gc_stats.major_gc_count, GENERATION_OLD);
1965 current_collection_generation = GENERATION_OLD;
1967 sgen_workers_assert_gray_queue_is_empty ();
1970 sgen_cement_reset ();
1973 g_assert (major_collector.is_concurrent);
1974 concurrent_collection_in_progress = TRUE;
1976 object_ops_nopar = &major_collector.major_ops_concurrent_start;
1977 if (major_collector.is_parallel)
1978 object_ops_par = &major_collector.major_ops_conc_par_start;
1981 object_ops_nopar = &major_collector.major_ops_serial;
1984 reset_pinned_from_failed_allocation ();
1986 sgen_memgov_major_collection_start (concurrent, reason);
1988 //count_ref_nonref_objs ();
1989 //consistency_check ();
1991 check_scan_starts ();
1994 SGEN_LOG (1, "Start major collection %d", gc_stats.major_gc_count);
1995 gc_stats.major_gc_count ++;
1997 if (major_collector.start_major_collection)
1998 major_collector.start_major_collection ();
2000 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);
2004 major_finish_collection (SgenGrayQueue *gc_thread_gray_queue, const char *reason, gboolean is_overflow, size_t old_next_pin_slot, gboolean forced)
2006 ScannedObjectCounts counts;
2007 SgenObjectOperations *object_ops_nopar;
2008 mword fragment_total;
2014 if (concurrent_collection_in_progress) {
2015 SgenObjectOperations *object_ops_par = NULL;
2017 object_ops_nopar = &major_collector.major_ops_concurrent_finish;
2018 if (major_collector.is_parallel)
2019 object_ops_par = &major_collector.major_ops_conc_par_finish;
2021 major_copy_or_mark_from_roots (gc_thread_gray_queue, NULL, COPY_OR_MARK_FROM_ROOTS_FINISH_CONCURRENT, object_ops_nopar, object_ops_par);
2023 #ifdef SGEN_DEBUG_INTERNAL_ALLOC
2024 main_gc_thread = NULL;
2027 object_ops_nopar = &major_collector.major_ops_serial;
2030 sgen_workers_assert_gray_queue_is_empty ();
2032 finish_gray_stack (GENERATION_OLD, CONTEXT_FROM_OBJECT_OPERATIONS (object_ops_nopar, gc_thread_gray_queue));
2034 time_major_finish_gray_stack += TV_ELAPSED (btv, atv);
2036 SGEN_ASSERT (0, sgen_workers_all_done (), "Can't have workers working after joining");
2038 if (objects_pinned) {
2039 g_assert (!concurrent_collection_in_progress);
2042 * This is slow, but we just OOM'd.
2044 * See comment at `sgen_pin_queue_clear_discarded_entries` for how the pin
2045 * queue is laid out at this point.
2047 sgen_pin_queue_clear_discarded_entries (nursery_section, old_next_pin_slot);
2049 * We need to reestablish all pinned nursery objects in the pin queue
2050 * because they're needed for fragment creation. Unpinning happens by
2051 * walking the whole queue, so it's not necessary to reestablish where major
2052 * heap block pins are - all we care is that they're still in there
2055 sgen_optimize_pin_queue ();
2056 sgen_find_section_pin_queue_start_end (nursery_section);
2060 reset_heap_boundaries ();
2061 sgen_update_heap_boundaries ((mword)sgen_get_nursery_start (), (mword)sgen_get_nursery_end ());
2063 /* walk the pin_queue, build up the fragment list of free memory, unmark
2064 * pinned objects as we go, memzero() the empty fragments so they are ready for the
2067 fragment_total = sgen_build_nursery_fragments (nursery_section, NULL);
2068 if (!fragment_total)
2070 SGEN_LOG (4, "Free space in nursery after major %ld", (long)fragment_total);
2072 if (do_concurrent_checks && concurrent_collection_in_progress)
2073 sgen_debug_check_nursery_is_clean ();
2075 /* prepare the pin queue for the next collection */
2076 sgen_finish_pinning ();
2078 /* Clear TLABs for all threads */
2079 sgen_clear_tlabs ();
2081 sgen_pin_stats_reset ();
2083 sgen_cement_clear_below_threshold ();
2085 if (check_mark_bits_after_major_collection)
2086 sgen_check_heap_marked (concurrent_collection_in_progress);
2089 time_major_fragment_creation += TV_ELAPSED (atv, btv);
2091 binary_protocol_sweep_begin (GENERATION_OLD, !major_collector.sweeps_lazily);
2092 sgen_memgov_major_pre_sweep ();
2095 time_major_free_bigobjs += TV_ELAPSED (btv, atv);
2100 time_major_los_sweep += TV_ELAPSED (atv, btv);
2102 major_collector.sweep ();
2104 binary_protocol_sweep_end (GENERATION_OLD, !major_collector.sweeps_lazily);
2107 time_major_sweep += TV_ELAPSED (btv, atv);
2109 sgen_debug_dump_heap ("major", gc_stats.major_gc_count - 1, reason);
2111 if (sgen_have_pending_finalizers ()) {
2112 SGEN_LOG (4, "Finalizer-thread wakeup");
2113 sgen_client_finalize_notify ();
2116 sgen_memgov_major_collection_end (forced, concurrent_collection_in_progress, reason, is_overflow);
2117 current_collection_generation = -1;
2119 memset (&counts, 0, sizeof (ScannedObjectCounts));
2120 major_collector.finish_major_collection (&counts);
2122 sgen_workers_assert_gray_queue_is_empty ();
2124 SGEN_ASSERT (0, sgen_workers_all_done (), "Can't have workers working after major collection has finished");
2125 if (concurrent_collection_in_progress)
2126 concurrent_collection_in_progress = FALSE;
2128 check_scan_starts ();
2130 binary_protocol_flush_buffers (FALSE);
2132 //consistency_check ();
2134 binary_protocol_collection_end (gc_stats.major_gc_count - 1, GENERATION_OLD, counts.num_scanned_objects, counts.num_unique_scanned_objects);
2138 major_do_collection (const char *reason, gboolean is_overflow, gboolean forced)
2140 TV_DECLARE (time_start);
2141 TV_DECLARE (time_end);
2142 size_t old_next_pin_slot;
2143 SgenGrayQueue gc_thread_gray_queue;
2145 if (disable_major_collections)
2148 if (major_collector.get_and_reset_num_major_objects_marked) {
2149 long long num_marked = major_collector.get_and_reset_num_major_objects_marked ();
2150 g_assert (!num_marked);
2153 /* world must be stopped already */
2154 TV_GETTIME (time_start);
2156 init_gray_queue (&gc_thread_gray_queue, FALSE);
2157 major_start_collection (&gc_thread_gray_queue, reason, FALSE, &old_next_pin_slot);
2158 major_finish_collection (&gc_thread_gray_queue, reason, is_overflow, old_next_pin_slot, forced);
2159 sgen_gray_object_queue_dispose (&gc_thread_gray_queue);
2161 TV_GETTIME (time_end);
2162 gc_stats.major_gc_time += TV_ELAPSED (time_start, time_end);
2164 /* FIXME: also report this to the user, preferably in gc-end. */
2165 if (major_collector.get_and_reset_num_major_objects_marked)
2166 major_collector.get_and_reset_num_major_objects_marked ();
2168 return bytes_pinned_from_failed_allocation > 0;
2172 major_start_concurrent_collection (const char *reason)
2174 TV_DECLARE (time_start);
2175 TV_DECLARE (time_end);
2176 long long num_objects_marked;
2177 SgenGrayQueue gc_thread_gray_queue;
2179 if (disable_major_collections)
2182 TV_GETTIME (time_start);
2183 SGEN_TV_GETTIME (time_major_conc_collection_start);
2185 num_objects_marked = major_collector.get_and_reset_num_major_objects_marked ();
2186 g_assert (num_objects_marked == 0);
2188 binary_protocol_concurrent_start ();
2190 init_gray_queue (&gc_thread_gray_queue, TRUE);
2191 // FIXME: store reason and pass it when finishing
2192 major_start_collection (&gc_thread_gray_queue, reason, TRUE, NULL);
2193 sgen_gray_object_queue_dispose (&gc_thread_gray_queue);
2195 num_objects_marked = major_collector.get_and_reset_num_major_objects_marked ();
2197 TV_GETTIME (time_end);
2198 gc_stats.major_gc_time += TV_ELAPSED (time_start, time_end);
2200 current_collection_generation = -1;
2204 * Returns whether the major collection has finished.
2207 major_should_finish_concurrent_collection (void)
2209 return sgen_workers_all_done ();
2213 major_update_concurrent_collection (void)
2215 TV_DECLARE (total_start);
2216 TV_DECLARE (total_end);
2218 TV_GETTIME (total_start);
2220 binary_protocol_concurrent_update ();
2222 major_collector.update_cardtable_mod_union ();
2223 sgen_los_update_cardtable_mod_union ();
2225 TV_GETTIME (total_end);
2226 gc_stats.major_gc_time += TV_ELAPSED (total_start, total_end);
2230 major_finish_concurrent_collection (gboolean forced)
2232 SgenGrayQueue gc_thread_gray_queue;
2233 TV_DECLARE (total_start);
2234 TV_DECLARE (total_end);
2236 TV_GETTIME (total_start);
2238 binary_protocol_concurrent_finish ();
2241 * We need to stop all workers since we're updating the cardtable below.
2242 * The workers will be resumed with a finishing pause context to avoid
2243 * additional cardtable and object scanning.
2245 sgen_workers_stop_all_workers ();
2247 SGEN_TV_GETTIME (time_major_conc_collection_end);
2248 gc_stats.major_gc_time_concurrent += SGEN_TV_ELAPSED (time_major_conc_collection_start, time_major_conc_collection_end);
2250 major_collector.update_cardtable_mod_union ();
2251 sgen_los_update_cardtable_mod_union ();
2253 if (mod_union_consistency_check)
2254 sgen_check_mod_union_consistency ();
2256 current_collection_generation = GENERATION_OLD;
2257 sgen_cement_reset ();
2258 init_gray_queue (&gc_thread_gray_queue, FALSE);
2259 major_finish_collection (&gc_thread_gray_queue, "finishing", FALSE, -1, forced);
2260 sgen_gray_object_queue_dispose (&gc_thread_gray_queue);
2262 TV_GETTIME (total_end);
2263 gc_stats.major_gc_time += TV_ELAPSED (total_start, total_end);
2265 current_collection_generation = -1;
2269 * Ensure an allocation request for @size will succeed by freeing enough memory.
2271 * LOCKING: The GC lock MUST be held.
2274 sgen_ensure_free_space (size_t size, int generation)
2276 int generation_to_collect = -1;
2277 const char *reason = NULL;
2279 if (generation == GENERATION_OLD) {
2280 if (sgen_need_major_collection (size)) {
2281 reason = "LOS overflow";
2282 generation_to_collect = GENERATION_OLD;
2285 if (degraded_mode) {
2286 if (sgen_need_major_collection (size)) {
2287 reason = "Degraded mode overflow";
2288 generation_to_collect = GENERATION_OLD;
2290 } else if (sgen_need_major_collection (size)) {
2291 reason = concurrent_collection_in_progress ? "Forced finish concurrent collection" : "Minor allowance";
2292 generation_to_collect = GENERATION_OLD;
2294 generation_to_collect = GENERATION_NURSERY;
2295 reason = "Nursery full";
2299 if (generation_to_collect == -1) {
2300 if (concurrent_collection_in_progress && sgen_workers_all_done ()) {
2301 generation_to_collect = GENERATION_OLD;
2302 reason = "Finish concurrent collection";
2306 if (generation_to_collect == -1)
2308 sgen_perform_collection (size, generation_to_collect, reason, FALSE, TRUE);
2312 * LOCKING: Assumes the GC lock is held.
2315 sgen_perform_collection (size_t requested_size, int generation_to_collect, const char *reason, gboolean wait_to_finish, gboolean stw)
2317 TV_DECLARE (gc_total_start);
2318 TV_DECLARE (gc_total_end);
2319 int overflow_generation_to_collect = -1;
2320 int oldest_generation_collected = generation_to_collect;
2321 const char *overflow_reason = NULL;
2322 gboolean finish_concurrent = concurrent_collection_in_progress && (major_should_finish_concurrent_collection () || generation_to_collect == GENERATION_OLD);
2324 binary_protocol_collection_requested (generation_to_collect, requested_size, wait_to_finish ? 1 : 0);
2326 SGEN_ASSERT (0, generation_to_collect == GENERATION_NURSERY || generation_to_collect == GENERATION_OLD, "What generation is this?");
2329 sgen_stop_world (generation_to_collect);
2331 SGEN_ASSERT (0, sgen_is_world_stopped (), "We can only collect if the world is stopped");
2334 TV_GETTIME (gc_total_start);
2336 // FIXME: extract overflow reason
2337 // FIXME: minor overflow for concurrent case
2338 if (generation_to_collect == GENERATION_NURSERY && !finish_concurrent) {
2339 if (concurrent_collection_in_progress)
2340 major_update_concurrent_collection ();
2342 if (collect_nursery (reason, FALSE, NULL) && !concurrent_collection_in_progress) {
2343 overflow_generation_to_collect = GENERATION_OLD;
2344 overflow_reason = "Minor overflow";
2346 } else if (finish_concurrent) {
2347 major_finish_concurrent_collection (wait_to_finish);
2348 oldest_generation_collected = GENERATION_OLD;
2350 SGEN_ASSERT (0, generation_to_collect == GENERATION_OLD, "We should have handled nursery collections above");
2351 if (major_collector.is_concurrent && !wait_to_finish) {
2352 collect_nursery ("Concurrent start", FALSE, NULL);
2353 major_start_concurrent_collection (reason);
2354 oldest_generation_collected = GENERATION_NURSERY;
2355 } else if (major_do_collection (reason, FALSE, wait_to_finish)) {
2356 overflow_generation_to_collect = GENERATION_NURSERY;
2357 overflow_reason = "Excessive pinning";
2361 if (overflow_generation_to_collect != -1) {
2362 SGEN_ASSERT (0, !concurrent_collection_in_progress, "We don't yet support overflow collections with the concurrent collector");
2365 * We need to do an overflow collection, either because we ran out of memory
2366 * or the nursery is fully pinned.
2369 if (overflow_generation_to_collect == GENERATION_NURSERY)
2370 collect_nursery (overflow_reason, TRUE, NULL);
2372 major_do_collection (overflow_reason, TRUE, wait_to_finish);
2374 oldest_generation_collected = MAX (oldest_generation_collected, overflow_generation_to_collect);
2377 SGEN_LOG (2, "Heap size: %lu, LOS size: %lu", (unsigned long)sgen_gc_get_total_heap_allocation (), (unsigned long)los_memory_usage);
2379 /* this also sets the proper pointers for the next allocation */
2380 if (generation_to_collect == GENERATION_NURSERY && !sgen_can_alloc_size (requested_size)) {
2381 /* TypeBuilder and MonoMethod are killing mcs with fragmentation */
2382 SGEN_LOG (1, "nursery collection didn't find enough room for %zd alloc (%zd pinned)", requested_size, sgen_get_pinned_count ());
2383 sgen_dump_pin_queue ();
2387 TV_GETTIME (gc_total_end);
2388 time_max = MAX (time_max, TV_ELAPSED (gc_total_start, gc_total_end));
2391 sgen_restart_world (oldest_generation_collected);
2395 * ######################################################################
2396 * ######## Memory allocation from the OS
2397 * ######################################################################
2398 * This section of code deals with getting memory from the OS and
2399 * allocating memory for GC-internal data structures.
2400 * Internal memory can be handled with a freelist for small objects.
2406 G_GNUC_UNUSED static void
2407 report_internal_mem_usage (void)
2409 printf ("Internal memory usage:\n");
2410 sgen_report_internal_mem_usage ();
2411 printf ("Pinned memory usage:\n");
2412 major_collector.report_pinned_memory_usage ();
2416 * ######################################################################
2417 * ######## Finalization support
2418 * ######################################################################
2422 * If the object has been forwarded it means it's still referenced from a root.
2423 * If it is pinned it's still alive as well.
2424 * A LOS object is only alive if we have pinned it.
2425 * Return TRUE if @obj is ready to be finalized.
2427 static inline gboolean
2428 sgen_is_object_alive (GCObject *object)
2430 if (ptr_in_nursery (object))
2431 return sgen_nursery_is_object_alive (object);
2433 return sgen_major_is_object_alive (object);
2437 * This function returns true if @object is either alive and belongs to the
2438 * current collection - major collections are full heap, so old gen objects
2439 * are never alive during a minor collection.
2442 sgen_is_object_alive_and_on_current_collection (GCObject *object)
2444 if (ptr_in_nursery (object))
2445 return sgen_nursery_is_object_alive (object);
2447 if (current_collection_generation == GENERATION_NURSERY)
2450 return sgen_major_is_object_alive (object);
2455 sgen_gc_is_object_ready_for_finalization (GCObject *object)
2457 return !sgen_is_object_alive (object);
2461 sgen_queue_finalization_entry (GCObject *obj)
2463 gboolean critical = sgen_client_object_has_critical_finalizer (obj);
2465 sgen_pointer_queue_add (critical ? &critical_fin_queue : &fin_ready_queue, obj);
2467 sgen_client_object_queued_for_finalization (obj);
2471 sgen_object_is_live (GCObject *obj)
2473 return sgen_is_object_alive_and_on_current_collection (obj);
2477 * `System.GC.WaitForPendingFinalizers` first checks `sgen_have_pending_finalizers()` to
2478 * determine whether it can exit quickly. The latter must therefore only return FALSE if
2479 * all finalizers have really finished running.
2481 * `sgen_gc_invoke_finalizers()` first dequeues a finalizable object, and then finalizes it.
2482 * This means that just checking whether the queues are empty leaves the possibility that an
2483 * object might have been dequeued but not yet finalized. That's why we need the additional
2484 * flag `pending_unqueued_finalizer`.
2487 static volatile gboolean pending_unqueued_finalizer = FALSE;
2488 volatile gboolean sgen_suspend_finalizers = FALSE;
2491 sgen_set_suspend_finalizers (void)
2493 sgen_suspend_finalizers = TRUE;
2497 sgen_gc_invoke_finalizers (void)
2501 g_assert (!pending_unqueued_finalizer);
2503 /* FIXME: batch to reduce lock contention */
2504 while (sgen_have_pending_finalizers ()) {
2510 * We need to set `pending_unqueued_finalizer` before dequeing the
2511 * finalizable object.
2513 if (!sgen_pointer_queue_is_empty (&fin_ready_queue)) {
2514 pending_unqueued_finalizer = TRUE;
2515 mono_memory_write_barrier ();
2516 obj = (GCObject *)sgen_pointer_queue_pop (&fin_ready_queue);
2517 } else if (!sgen_pointer_queue_is_empty (&critical_fin_queue)) {
2518 pending_unqueued_finalizer = TRUE;
2519 mono_memory_write_barrier ();
2520 obj = (GCObject *)sgen_pointer_queue_pop (&critical_fin_queue);
2526 SGEN_LOG (7, "Finalizing object %p (%s)", obj, sgen_client_vtable_get_name (SGEN_LOAD_VTABLE (obj)));
2534 /* the object is on the stack so it is pinned */
2535 /*g_print ("Calling finalizer for object: %p (%s)\n", obj, sgen_client_object_safe_name (obj));*/
2536 sgen_client_run_finalize (obj);
2539 if (pending_unqueued_finalizer) {
2540 mono_memory_write_barrier ();
2541 pending_unqueued_finalizer = FALSE;
2548 sgen_have_pending_finalizers (void)
2550 if (sgen_suspend_finalizers)
2552 return pending_unqueued_finalizer || !sgen_pointer_queue_is_empty (&fin_ready_queue) || !sgen_pointer_queue_is_empty (&critical_fin_queue);
2556 * ######################################################################
2557 * ######## registered roots support
2558 * ######################################################################
2562 * We do not coalesce roots.
2565 sgen_register_root (char *start, size_t size, SgenDescriptor descr, int root_type, int source, const char *msg)
2567 RootRecord new_root;
2570 for (i = 0; i < ROOT_TYPE_NUM; ++i) {
2571 RootRecord *root = (RootRecord *)sgen_hash_table_lookup (&roots_hash [i], start);
2572 /* we allow changing the size and the descriptor (for thread statics etc) */
2574 size_t old_size = root->end_root - start;
2575 root->end_root = start + size;
2576 SGEN_ASSERT (0, !!root->root_desc == !!descr, "Can't change whether a root is precise or conservative.");
2577 SGEN_ASSERT (0, root->source == source, "Can't change a root's source identifier.");
2578 SGEN_ASSERT (0, !!root->msg == !!msg, "Can't change a root's message.");
2579 root->root_desc = descr;
2581 roots_size -= old_size;
2587 new_root.end_root = start + size;
2588 new_root.root_desc = descr;
2589 new_root.source = source;
2592 sgen_hash_table_replace (&roots_hash [root_type], start, &new_root, NULL);
2595 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);
2602 sgen_deregister_root (char* addr)
2608 for (root_type = 0; root_type < ROOT_TYPE_NUM; ++root_type) {
2609 if (sgen_hash_table_remove (&roots_hash [root_type], addr, &root))
2610 roots_size -= (root.end_root - addr);
2616 sgen_wbroots_iterate_live_block_ranges (sgen_cardtable_block_callback cb)
2620 SGEN_HASH_TABLE_FOREACH (&roots_hash [ROOT_TYPE_WBARRIER], void **, start_root, RootRecord *, root) {
2621 cb ((mword)start_root, (mword)root->end_root - (mword)start_root);
2622 } SGEN_HASH_TABLE_FOREACH_END;
2625 /* Root equivalent of sgen_client_cardtable_scan_object */
2627 sgen_wbroot_scan_card_table (void** start_root, mword size, ScanCopyContext ctx)
2629 ScanPtrFieldFunc scan_field_func = ctx.ops->scan_ptr_field;
2630 guint8 *card_data = sgen_card_table_get_card_scan_address ((mword)start_root);
2631 guint8 *card_base = card_data;
2632 mword card_count = sgen_card_table_number_of_cards_in_range ((mword)start_root, size);
2633 guint8 *card_data_end = card_data + card_count;
2634 mword extra_idx = 0;
2635 char *obj_start = sgen_card_table_align_pointer (start_root);
2636 char *obj_end = (char*)start_root + size;
2637 #ifdef SGEN_HAVE_OVERLAPPING_CARDS
2638 guint8 *overflow_scan_end = NULL;
2641 #ifdef SGEN_HAVE_OVERLAPPING_CARDS
2642 /*Check for overflow and if so, setup to scan in two steps*/
2643 if (card_data_end >= SGEN_SHADOW_CARDTABLE_END) {
2644 overflow_scan_end = sgen_shadow_cardtable + (card_data_end - SGEN_SHADOW_CARDTABLE_END);
2645 card_data_end = SGEN_SHADOW_CARDTABLE_END;
2651 card_data = sgen_find_next_card (card_data, card_data_end);
2653 for (; card_data < card_data_end; card_data = sgen_find_next_card (card_data + 1, card_data_end)) {
2654 size_t idx = (card_data - card_base) + extra_idx;
2655 char *start = (char*)(obj_start + idx * CARD_SIZE_IN_BYTES);
2656 char *card_end = start + CARD_SIZE_IN_BYTES;
2657 char *elem = start, *first_elem = start;
2660 * Don't clean first and last card on 32bit systems since they
2661 * may also be part from other roots.
2663 if (card_data != card_base && card_data != (card_data_end - 1))
2664 sgen_card_table_prepare_card_for_scanning (card_data);
2666 card_end = MIN (card_end, obj_end);
2668 if (elem < (char*)start_root)
2669 first_elem = elem = (char*)start_root;
2671 for (; elem < card_end; elem += SIZEOF_VOID_P) {
2672 if (*(GCObject**)elem)
2673 scan_field_func (NULL, (GCObject**)elem, ctx.queue);
2676 binary_protocol_card_scan (first_elem, elem - first_elem);
2679 #ifdef SGEN_HAVE_OVERLAPPING_CARDS
2680 if (overflow_scan_end) {
2681 extra_idx = card_data - card_base;
2682 card_base = card_data = sgen_shadow_cardtable;
2683 card_data_end = overflow_scan_end;
2684 overflow_scan_end = NULL;
2691 sgen_wbroots_scan_card_table (ScanCopyContext ctx)
2696 SGEN_HASH_TABLE_FOREACH (&roots_hash [ROOT_TYPE_WBARRIER], void **, start_root, RootRecord *, root) {
2697 SGEN_ASSERT (0, (root->root_desc & ROOT_DESC_TYPE_MASK) == ROOT_DESC_VECTOR, "Unsupported root type");
2699 sgen_wbroot_scan_card_table (start_root, (mword)root->end_root - (mword)start_root, ctx);
2700 } SGEN_HASH_TABLE_FOREACH_END;
2704 * ######################################################################
2705 * ######## Thread handling (stop/start code)
2706 * ######################################################################
2710 sgen_get_current_collection_generation (void)
2712 return current_collection_generation;
2716 sgen_thread_register (SgenThreadInfo* info, void *stack_bottom_fallback)
2718 info->tlab_start = info->tlab_next = info->tlab_temp_end = info->tlab_real_end = NULL;
2720 sgen_client_thread_register (info, stack_bottom_fallback);
2726 sgen_thread_unregister (SgenThreadInfo *p)
2728 sgen_client_thread_unregister (p);
2732 * ######################################################################
2733 * ######## Write barriers
2734 * ######################################################################
2738 * Note: the write barriers first do the needed GC work and then do the actual store:
2739 * this way the value is visible to the conservative GC scan after the write barrier
2740 * itself. If a GC interrupts the barrier in the middle, value will be kept alive by
2741 * the conservative scan, otherwise by the remembered set scan.
2745 mono_gc_wbarrier_arrayref_copy (gpointer dest_ptr, gpointer src_ptr, int count)
2747 HEAVY_STAT (++stat_wbarrier_arrayref_copy);
2748 /*This check can be done without taking a lock since dest_ptr array is pinned*/
2749 if (ptr_in_nursery (dest_ptr) || count <= 0) {
2750 mono_gc_memmove_aligned (dest_ptr, src_ptr, count * sizeof (gpointer));
2754 #ifdef SGEN_HEAVY_BINARY_PROTOCOL
2755 if (binary_protocol_is_heavy_enabled ()) {
2757 for (i = 0; i < count; ++i) {
2758 gpointer dest = (gpointer*)dest_ptr + i;
2759 gpointer obj = *((gpointer*)src_ptr + i);
2761 binary_protocol_wbarrier (dest, obj, (gpointer)LOAD_VTABLE (obj));
2766 remset.wbarrier_arrayref_copy (dest_ptr, src_ptr, count);
2770 mono_gc_wbarrier_generic_nostore (gpointer ptr)
2774 HEAVY_STAT (++stat_wbarrier_generic_store);
2776 sgen_client_wbarrier_generic_nostore_check (ptr);
2778 obj = *(gpointer*)ptr;
2780 binary_protocol_wbarrier (ptr, obj, (gpointer)LOAD_VTABLE (obj));
2783 * We need to record old->old pointer locations for the
2784 * concurrent collector.
2786 if (!ptr_in_nursery (obj) && !concurrent_collection_in_progress) {
2787 SGEN_LOG (8, "Skipping remset at %p", ptr);
2791 SGEN_LOG (8, "Adding remset at %p", ptr);
2793 remset.wbarrier_generic_nostore (ptr);
2797 mono_gc_wbarrier_generic_store (gpointer ptr, GCObject* value)
2799 SGEN_LOG (8, "Wbarrier store at %p to %p (%s)", ptr, value, value ? sgen_client_vtable_get_name (SGEN_LOAD_VTABLE (value)) : "null");
2800 SGEN_UPDATE_REFERENCE_ALLOW_NULL (ptr, value);
2801 if (ptr_in_nursery (value) || concurrent_collection_in_progress)
2802 mono_gc_wbarrier_generic_nostore (ptr);
2803 sgen_dummy_use (value);
2806 /* Same as mono_gc_wbarrier_generic_store () but performs the store
2807 * as an atomic operation with release semantics.
2810 mono_gc_wbarrier_generic_store_atomic (gpointer ptr, GCObject *value)
2812 HEAVY_STAT (++stat_wbarrier_generic_store_atomic);
2814 SGEN_LOG (8, "Wbarrier atomic store at %p to %p (%s)", ptr, value, value ? sgen_client_vtable_get_name (SGEN_LOAD_VTABLE (value)) : "null");
2816 InterlockedWritePointer ((volatile gpointer *)ptr, value);
2818 if (ptr_in_nursery (value) || concurrent_collection_in_progress)
2819 mono_gc_wbarrier_generic_nostore (ptr);
2821 sgen_dummy_use (value);
2825 sgen_wbarrier_value_copy_bitmap (gpointer _dest, gpointer _src, int size, unsigned bitmap)
2827 GCObject **dest = (GCObject **)_dest;
2828 GCObject **src = (GCObject **)_src;
2832 mono_gc_wbarrier_generic_store (dest, *src);
2837 size -= SIZEOF_VOID_P;
2843 * ######################################################################
2844 * ######## Other mono public interface functions.
2845 * ######################################################################
2849 sgen_gc_collect (int generation)
2854 sgen_perform_collection (0, generation, "user request", TRUE, TRUE);
2859 sgen_gc_collection_count (int generation)
2861 if (generation == 0)
2862 return gc_stats.minor_gc_count;
2863 return gc_stats.major_gc_count;
2867 sgen_gc_get_used_size (void)
2871 tot = los_memory_usage;
2872 tot += nursery_section->next_data - nursery_section->data;
2873 tot += major_collector.get_used_size ();
2874 /* FIXME: account for pinned objects */
2880 sgen_env_var_error (const char *env_var, const char *fallback, const char *description_format, ...)
2884 va_start (ap, description_format);
2886 fprintf (stderr, "Warning: In environment variable `%s': ", env_var);
2887 vfprintf (stderr, description_format, ap);
2889 fprintf (stderr, " - %s", fallback);
2890 fprintf (stderr, "\n");
2896 parse_double_in_interval (const char *env_var, const char *opt_name, const char *opt, double min, double max, double *result)
2899 double val = strtod (opt, &endptr);
2900 if (endptr == opt) {
2901 sgen_env_var_error (env_var, "Using default value.", "`%s` must be a number.", opt_name);
2904 else if (val < min || val > max) {
2905 sgen_env_var_error (env_var, "Using default value.", "`%s` must be between %.2f - %.2f.", opt_name, min, max);
2917 char *major_collector_opt = NULL;
2918 char *minor_collector_opt = NULL;
2919 char *params_opts = NULL;
2920 char *debug_opts = NULL;
2921 size_t max_heap = 0;
2922 size_t soft_limit = 0;
2924 gboolean debug_print_allowance = FALSE;
2925 double allowance_ratio = 0, save_target = 0;
2926 gboolean cement_enabled = TRUE;
2929 result = InterlockedCompareExchange (&gc_initialized, -1, 0);
2932 /* already inited */
2935 /* being inited by another thread */
2936 mono_thread_info_usleep (1000);
2939 /* we will init it */
2942 g_assert_not_reached ();
2944 } while (result != 0);
2946 SGEN_TV_GETTIME (sgen_init_timestamp);
2948 #ifdef SGEN_WITHOUT_MONO
2949 mono_thread_smr_init ();
2952 mono_coop_mutex_init (&gc_mutex);
2954 gc_debug_file = stderr;
2956 mono_coop_mutex_init (&sgen_interruption_mutex);
2958 if ((env = g_getenv (MONO_GC_PARAMS_NAME)) || gc_params_options) {
2959 params_opts = g_strdup_printf ("%s,%s", gc_params_options ? gc_params_options : "", env ? env : "");
2963 opts = g_strsplit (params_opts, ",", -1);
2964 for (ptr = opts; *ptr; ++ptr) {
2966 if (g_str_has_prefix (opt, "major=")) {
2967 opt = strchr (opt, '=') + 1;
2968 major_collector_opt = g_strdup (opt);
2969 } else if (g_str_has_prefix (opt, "minor=")) {
2970 opt = strchr (opt, '=') + 1;
2971 minor_collector_opt = g_strdup (opt);
2979 sgen_init_internal_allocator ();
2980 sgen_init_nursery_allocator ();
2981 sgen_init_fin_weak_hash ();
2982 sgen_init_hash_table ();
2983 sgen_init_descriptors ();
2984 sgen_init_gray_queues ();
2985 sgen_init_allocator ();
2986 sgen_init_gchandles ();
2988 sgen_register_fixed_internal_mem_type (INTERNAL_MEM_SECTION, SGEN_SIZEOF_GC_MEM_SECTION);
2989 sgen_register_fixed_internal_mem_type (INTERNAL_MEM_GRAY_QUEUE, sizeof (GrayQueueSection));
2991 sgen_client_init ();
2993 if (!minor_collector_opt) {
2994 sgen_simple_nursery_init (&sgen_minor_collector);
2996 if (!strcmp (minor_collector_opt, "simple")) {
2998 sgen_simple_nursery_init (&sgen_minor_collector);
2999 } else if (!strcmp (minor_collector_opt, "split")) {
3000 sgen_split_nursery_init (&sgen_minor_collector);
3002 sgen_env_var_error (MONO_GC_PARAMS_NAME, "Using `simple` instead.", "Unknown minor collector `%s'.", minor_collector_opt);
3003 goto use_simple_nursery;
3007 if (!major_collector_opt) {
3009 DEFAULT_MAJOR_INIT (&major_collector);
3010 } else if (!strcmp (major_collector_opt, "marksweep")) {
3011 sgen_marksweep_init (&major_collector);
3012 } else if (!strcmp (major_collector_opt, "marksweep-conc")) {
3013 sgen_marksweep_conc_init (&major_collector);
3014 } else if (!strcmp (major_collector_opt, "marksweep-conc-par")) {
3015 sgen_marksweep_conc_par_init (&major_collector);
3017 sgen_env_var_error (MONO_GC_PARAMS_NAME, "Using `" DEFAULT_MAJOR_NAME "` instead.", "Unknown major collector `%s'.", major_collector_opt);
3018 goto use_default_major;
3021 sgen_nursery_size = DEFAULT_NURSERY_SIZE;
3024 gboolean usage_printed = FALSE;
3026 for (ptr = opts; *ptr; ++ptr) {
3028 if (!strcmp (opt, ""))
3030 if (g_str_has_prefix (opt, "major="))
3032 if (g_str_has_prefix (opt, "minor="))
3034 if (g_str_has_prefix (opt, "max-heap-size=")) {
3035 size_t page_size = mono_pagesize ();
3036 size_t max_heap_candidate = 0;
3037 opt = strchr (opt, '=') + 1;
3038 if (*opt && mono_gc_parse_environment_string_extract_number (opt, &max_heap_candidate)) {
3039 max_heap = (max_heap_candidate + page_size - 1) & ~(size_t)(page_size - 1);
3040 if (max_heap != max_heap_candidate)
3041 sgen_env_var_error (MONO_GC_PARAMS_NAME, "Rounding up.", "`max-heap-size` size must be a multiple of %d.", page_size);
3043 sgen_env_var_error (MONO_GC_PARAMS_NAME, NULL, "`max-heap-size` must be an integer.");
3047 if (g_str_has_prefix (opt, "soft-heap-limit=")) {
3048 opt = strchr (opt, '=') + 1;
3049 if (*opt && mono_gc_parse_environment_string_extract_number (opt, &soft_limit)) {
3050 if (soft_limit <= 0) {
3051 sgen_env_var_error (MONO_GC_PARAMS_NAME, NULL, "`soft-heap-limit` must be positive.");
3055 sgen_env_var_error (MONO_GC_PARAMS_NAME, NULL, "`soft-heap-limit` must be an integer.");
3061 if (g_str_has_prefix (opt, "nursery-size=")) {
3063 opt = strchr (opt, '=') + 1;
3064 if (*opt && mono_gc_parse_environment_string_extract_number (opt, &val)) {
3065 if ((val & (val - 1))) {
3066 sgen_env_var_error (MONO_GC_PARAMS_NAME, "Using default value.", "`nursery-size` must be a power of two.");
3070 if (val < SGEN_MAX_NURSERY_WASTE) {
3071 sgen_env_var_error (MONO_GC_PARAMS_NAME, "Using default value.",
3072 "`nursery-size` must be at least %d bytes.", SGEN_MAX_NURSERY_WASTE);
3076 sgen_nursery_size = val;
3077 sgen_nursery_bits = 0;
3078 while (ONE_P << (++ sgen_nursery_bits) != sgen_nursery_size)
3081 sgen_env_var_error (MONO_GC_PARAMS_NAME, "Using default value.", "`nursery-size` must be an integer.");
3087 if (g_str_has_prefix (opt, "save-target-ratio=")) {
3089 opt = strchr (opt, '=') + 1;
3090 if (parse_double_in_interval (MONO_GC_PARAMS_NAME, "save-target-ratio", opt,
3091 SGEN_MIN_SAVE_TARGET_RATIO, SGEN_MAX_SAVE_TARGET_RATIO, &val)) {
3096 if (g_str_has_prefix (opt, "default-allowance-ratio=")) {
3098 opt = strchr (opt, '=') + 1;
3099 if (parse_double_in_interval (MONO_GC_PARAMS_NAME, "default-allowance-ratio", opt,
3100 SGEN_MIN_ALLOWANCE_NURSERY_SIZE_RATIO, SGEN_MAX_ALLOWANCE_NURSERY_SIZE_RATIO, &val)) {
3101 allowance_ratio = val;
3106 if (!strcmp (opt, "cementing")) {
3107 cement_enabled = TRUE;
3110 if (!strcmp (opt, "no-cementing")) {
3111 cement_enabled = FALSE;
3115 if (!strcmp (opt, "precleaning")) {
3116 precleaning_enabled = TRUE;
3119 if (!strcmp (opt, "no-precleaning")) {
3120 precleaning_enabled = FALSE;
3124 if (major_collector.handle_gc_param && major_collector.handle_gc_param (opt))
3127 if (sgen_minor_collector.handle_gc_param && sgen_minor_collector.handle_gc_param (opt))
3130 if (sgen_client_handle_gc_param (opt))
3133 sgen_env_var_error (MONO_GC_PARAMS_NAME, "Ignoring.", "Unknown option `%s`.", opt);
3138 fprintf (stderr, "\n%s must be a comma-delimited list of one or more of the following:\n", MONO_GC_PARAMS_NAME);
3139 fprintf (stderr, " max-heap-size=N (where N is an integer, possibly with a k, m or a g suffix)\n");
3140 fprintf (stderr, " soft-heap-limit=n (where N is an integer, possibly with a k, m or a g suffix)\n");
3141 fprintf (stderr, " nursery-size=N (where N is an integer, possibly with a k, m or a g suffix)\n");
3142 fprintf (stderr, " major=COLLECTOR (where COLLECTOR is `marksweep', `marksweep-conc', `marksweep-par')\n");
3143 fprintf (stderr, " minor=COLLECTOR (where COLLECTOR is `simple' or `split')\n");
3144 fprintf (stderr, " wbarrier=WBARRIER (where WBARRIER is `remset' or `cardtable')\n");
3145 fprintf (stderr, " [no-]cementing\n");
3146 if (major_collector.print_gc_param_usage)
3147 major_collector.print_gc_param_usage ();
3148 if (sgen_minor_collector.print_gc_param_usage)
3149 sgen_minor_collector.print_gc_param_usage ();
3150 sgen_client_print_gc_params_usage ();
3151 fprintf (stderr, " Experimental options:\n");
3152 fprintf (stderr, " save-target-ratio=R (where R must be between %.2f - %.2f).\n", SGEN_MIN_SAVE_TARGET_RATIO, SGEN_MAX_SAVE_TARGET_RATIO);
3153 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);
3154 fprintf (stderr, "\n");
3156 usage_printed = TRUE;
3161 if (major_collector_opt)
3162 g_free (major_collector_opt);
3164 if (minor_collector_opt)
3165 g_free (minor_collector_opt);
3168 g_free (params_opts);
3172 sgen_pinning_init ();
3173 sgen_cement_init (cement_enabled);
3175 if ((env = g_getenv (MONO_GC_DEBUG_NAME)) || gc_debug_options) {
3176 debug_opts = g_strdup_printf ("%s,%s", gc_debug_options ? gc_debug_options : "", env ? env : "");
3180 gboolean usage_printed = FALSE;
3182 opts = g_strsplit (debug_opts, ",", -1);
3183 for (ptr = opts; ptr && *ptr; ptr ++) {
3185 if (!strcmp (opt, ""))
3187 if (opt [0] >= '0' && opt [0] <= '9') {
3188 gc_debug_level = atoi (opt);
3193 char *rf = g_strdup_printf ("%s.%d", opt, mono_process_current_pid ());
3194 gc_debug_file = fopen (rf, "wb");
3196 gc_debug_file = stderr;
3199 } else if (!strcmp (opt, "print-allowance")) {
3200 debug_print_allowance = TRUE;
3201 } else if (!strcmp (opt, "print-pinning")) {
3202 sgen_pin_stats_enable ();
3203 } else if (!strcmp (opt, "verify-before-allocs")) {
3204 verify_before_allocs = 1;
3205 has_per_allocation_action = TRUE;
3206 } else if (g_str_has_prefix (opt, "verify-before-allocs=")) {
3207 char *arg = strchr (opt, '=') + 1;
3208 verify_before_allocs = atoi (arg);
3209 has_per_allocation_action = TRUE;
3210 } else if (!strcmp (opt, "collect-before-allocs")) {
3211 collect_before_allocs = 1;
3212 has_per_allocation_action = TRUE;
3213 } else if (g_str_has_prefix (opt, "collect-before-allocs=")) {
3214 char *arg = strchr (opt, '=') + 1;
3215 has_per_allocation_action = TRUE;
3216 collect_before_allocs = atoi (arg);
3217 } else if (!strcmp (opt, "verify-before-collections")) {
3218 whole_heap_check_before_collection = TRUE;
3219 } else if (!strcmp (opt, "check-remset-consistency")) {
3220 remset_consistency_checks = TRUE;
3221 nursery_clear_policy = CLEAR_AT_GC;
3222 } else if (!strcmp (opt, "mod-union-consistency-check")) {
3223 if (!major_collector.is_concurrent) {
3224 sgen_env_var_error (MONO_GC_DEBUG_NAME, "Ignoring.", "`mod-union-consistency-check` only works with concurrent major collector.");
3227 mod_union_consistency_check = TRUE;
3228 } else if (!strcmp (opt, "check-mark-bits")) {
3229 check_mark_bits_after_major_collection = TRUE;
3230 } else if (!strcmp (opt, "check-nursery-pinned")) {
3231 check_nursery_objects_pinned = TRUE;
3232 } else if (!strcmp (opt, "clear-at-gc")) {
3233 nursery_clear_policy = CLEAR_AT_GC;
3234 } else if (!strcmp (opt, "clear-nursery-at-gc")) {
3235 nursery_clear_policy = CLEAR_AT_GC;
3236 } else if (!strcmp (opt, "clear-at-tlab-creation")) {
3237 nursery_clear_policy = CLEAR_AT_TLAB_CREATION;
3238 } else if (!strcmp (opt, "debug-clear-at-tlab-creation")) {
3239 nursery_clear_policy = CLEAR_AT_TLAB_CREATION_DEBUG;
3240 } else if (!strcmp (opt, "check-scan-starts")) {
3241 do_scan_starts_check = TRUE;
3242 } else if (!strcmp (opt, "verify-nursery-at-minor-gc")) {
3243 do_verify_nursery = TRUE;
3244 } else if (!strcmp (opt, "check-concurrent")) {
3245 if (!major_collector.is_concurrent) {
3246 sgen_env_var_error (MONO_GC_DEBUG_NAME, "Ignoring.", "`check-concurrent` only works with concurrent major collectors.");
3249 nursery_clear_policy = CLEAR_AT_GC;
3250 do_concurrent_checks = TRUE;
3251 } else if (!strcmp (opt, "dump-nursery-at-minor-gc")) {
3252 do_dump_nursery_content = TRUE;
3253 } else if (!strcmp (opt, "disable-minor")) {
3254 disable_minor_collections = TRUE;
3255 } else if (!strcmp (opt, "disable-major")) {
3256 disable_major_collections = TRUE;
3257 } else if (g_str_has_prefix (opt, "heap-dump=")) {
3258 char *filename = strchr (opt, '=') + 1;
3259 nursery_clear_policy = CLEAR_AT_GC;
3260 sgen_debug_enable_heap_dump (filename);
3261 } else if (g_str_has_prefix (opt, "binary-protocol=")) {
3262 char *filename = strchr (opt, '=') + 1;
3263 char *colon = strrchr (filename, ':');
3266 if (!mono_gc_parse_environment_string_extract_number (colon + 1, &limit)) {
3267 sgen_env_var_error (MONO_GC_DEBUG_NAME, "Ignoring limit.", "Binary protocol file size limit must be an integer.");
3272 binary_protocol_init (filename, (long long)limit);
3273 } else if (!strcmp (opt, "nursery-canaries")) {
3274 do_verify_nursery = TRUE;
3275 enable_nursery_canaries = TRUE;
3276 } else if (!sgen_client_handle_gc_debug (opt)) {
3277 sgen_env_var_error (MONO_GC_DEBUG_NAME, "Ignoring.", "Unknown option `%s`.", opt);
3282 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);
3283 fprintf (stderr, "Valid <option>s are:\n");
3284 fprintf (stderr, " collect-before-allocs[=<n>]\n");
3285 fprintf (stderr, " verify-before-allocs[=<n>]\n");
3286 fprintf (stderr, " check-remset-consistency\n");
3287 fprintf (stderr, " check-mark-bits\n");
3288 fprintf (stderr, " check-nursery-pinned\n");
3289 fprintf (stderr, " verify-before-collections\n");
3290 fprintf (stderr, " verify-nursery-at-minor-gc\n");
3291 fprintf (stderr, " dump-nursery-at-minor-gc\n");
3292 fprintf (stderr, " disable-minor\n");
3293 fprintf (stderr, " disable-major\n");
3294 fprintf (stderr, " check-concurrent\n");
3295 fprintf (stderr, " clear-[nursery-]at-gc\n");
3296 fprintf (stderr, " clear-at-tlab-creation\n");
3297 fprintf (stderr, " debug-clear-at-tlab-creation\n");
3298 fprintf (stderr, " check-scan-starts\n");
3299 fprintf (stderr, " print-allowance\n");
3300 fprintf (stderr, " print-pinning\n");
3301 fprintf (stderr, " heap-dump=<filename>\n");
3302 fprintf (stderr, " binary-protocol=<filename>[:<file-size-limit>]\n");
3303 fprintf (stderr, " nursery-canaries\n");
3304 sgen_client_print_gc_debug_usage ();
3305 fprintf (stderr, "\n");
3307 usage_printed = TRUE;
3314 g_free (debug_opts);
3316 if (check_mark_bits_after_major_collection)
3317 nursery_clear_policy = CLEAR_AT_GC;
3319 if (major_collector.post_param_init)
3320 major_collector.post_param_init (&major_collector);
3322 if (major_collector.needs_thread_pool) {
3323 int num_workers = 1;
3324 if (major_collector.is_parallel) {
3325 /* FIXME Detect the number of physical cores, instead of logical */
3326 num_workers = mono_cpu_count () / 2;
3327 if (num_workers < 1)
3330 sgen_workers_init (num_workers, (SgenWorkerCallback) major_collector.worker_init_cb);
3333 sgen_memgov_init (max_heap, soft_limit, debug_print_allowance, allowance_ratio, save_target);
3335 memset (&remset, 0, sizeof (remset));
3337 sgen_card_table_init (&remset);
3339 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");
3343 sgen_init_bridge ();
3347 sgen_gc_initialized ()
3349 return gc_initialized > 0;
3353 sgen_get_nursery_clear_policy (void)
3355 return nursery_clear_policy;
3361 mono_coop_mutex_lock (&gc_mutex);
3365 sgen_gc_unlock (void)
3367 mono_coop_mutex_unlock (&gc_mutex);
3371 sgen_major_collector_iterate_live_block_ranges (sgen_cardtable_block_callback callback)
3373 major_collector.iterate_live_block_ranges (callback);
3377 sgen_major_collector_iterate_block_ranges (sgen_cardtable_block_callback callback)
3379 major_collector.iterate_block_ranges (callback);
3383 sgen_get_major_collector (void)
3385 return &major_collector;
3389 sgen_get_remset (void)
3395 count_cards (long long *major_total, long long *major_marked, long long *los_total, long long *los_marked)
3397 sgen_get_major_collector ()->count_cards (major_total, major_marked);
3398 sgen_los_count_cards (los_total, los_marked);
3401 static gboolean world_is_stopped = FALSE;
3403 /* LOCKING: assumes the GC lock is held */
3405 sgen_stop_world (int generation)
3407 long long major_total = -1, major_marked = -1, los_total = -1, los_marked = -1;
3409 SGEN_ASSERT (0, !world_is_stopped, "Why are we stopping a stopped world?");
3411 binary_protocol_world_stopping (generation, sgen_timestamp (), (gpointer) (gsize) mono_native_thread_id_get ());
3413 sgen_client_stop_world (generation);
3415 world_is_stopped = TRUE;
3417 if (binary_protocol_is_heavy_enabled ())
3418 count_cards (&major_total, &major_marked, &los_total, &los_marked);
3419 binary_protocol_world_stopped (generation, sgen_timestamp (), major_total, major_marked, los_total, los_marked);
3422 /* LOCKING: assumes the GC lock is held */
3424 sgen_restart_world (int generation)
3426 long long major_total = -1, major_marked = -1, los_total = -1, los_marked = -1;
3429 SGEN_ASSERT (0, world_is_stopped, "Why are we restarting a running world?");
3431 if (binary_protocol_is_heavy_enabled ())
3432 count_cards (&major_total, &major_marked, &los_total, &los_marked);
3433 binary_protocol_world_restarting (generation, sgen_timestamp (), major_total, major_marked, los_total, los_marked);
3435 world_is_stopped = FALSE;
3437 sgen_client_restart_world (generation, &stw_time);
3439 binary_protocol_world_restarted (generation, sgen_timestamp ());
3441 if (sgen_client_bridge_need_processing ())
3442 sgen_client_bridge_processing_finish (generation);
3444 sgen_memgov_collection_end (generation, stw_time);
3448 sgen_is_world_stopped (void)
3450 return world_is_stopped;
3454 sgen_check_whole_heap_stw (void)
3456 sgen_stop_world (0);
3457 sgen_clear_nursery_fragments ();
3458 sgen_check_whole_heap (TRUE);
3459 sgen_restart_world (0);
3463 sgen_timestamp (void)
3465 SGEN_TV_DECLARE (timestamp);
3466 SGEN_TV_GETTIME (timestamp);
3467 return SGEN_TV_ELAPSED (sgen_init_timestamp, timestamp);
3470 #endif /* HAVE_SGEN_GC */