3 * Simple generational GC.
6 * Paolo Molaro (lupus@ximian.com)
7 * Rodrigo Kumpera (kumpera@gmail.com)
9 * Copyright 2005-2011 Novell, Inc (http://www.novell.com)
10 * Copyright 2011 Xamarin Inc (http://www.xamarin.com)
12 * Thread start/stop adapted from Boehm's GC:
13 * Copyright (c) 1994 by Xerox Corporation. All rights reserved.
14 * Copyright (c) 1996 by Silicon Graphics. All rights reserved.
15 * Copyright (c) 1998 by Fergus Henderson. All rights reserved.
16 * Copyright (c) 2000-2004 by Hewlett-Packard Company. All rights reserved.
17 * Copyright 2001-2003 Ximian, Inc
18 * Copyright 2003-2010 Novell, Inc.
19 * Copyright 2011 Xamarin, Inc.
20 * Copyright (C) 2012 Xamarin Inc
22 * Licensed under the MIT license. See LICENSE file in the project root for full license information.
24 * Important: allocation provides always zeroed memory, having to do
25 * a memset after allocation is deadly for performance.
26 * Memory usage at startup is currently as follows:
28 * 64 KB internal space
30 * We should provide a small memory config with half the sizes
32 * We currently try to make as few mono assumptions as possible:
33 * 1) 2-word header with no GC pointers in it (first vtable, second to store the
35 * 2) gc descriptor is the second word in the vtable (first word in the class)
36 * 3) 8 byte alignment is the minimum and enough (not true for special structures (SIMD), FIXME)
37 * 4) there is a function to get an object's size and the number of
38 * elements in an array.
39 * 5) we know the special way bounds are allocated for complex arrays
40 * 6) we know about proxies and how to treat them when domains are unloaded
42 * Always try to keep stack usage to a minimum: no recursive behaviour
43 * and no large stack allocs.
45 * General description.
46 * Objects are initially allocated in a nursery using a fast bump-pointer technique.
47 * When the nursery is full we start a nursery collection: this is performed with a
49 * When the old generation is full we start a copying GC of the old generation as well:
50 * this will be changed to mark&sweep with copying when fragmentation becomes to severe
51 * in the future. Maybe we'll even do both during the same collection like IMMIX.
53 * The things that complicate this description are:
54 * *) pinned objects: we can't move them so we need to keep track of them
55 * *) no precise info of the thread stacks and registers: we need to be able to
56 * quickly find the objects that may be referenced conservatively and pin them
57 * (this makes the first issues more important)
58 * *) large objects are too expensive to be dealt with using copying GC: we handle them
59 * with mark/sweep during major collections
60 * *) some objects need to not move even if they are small (interned strings, Type handles):
61 * we use mark/sweep for them, too: they are not allocated in the nursery, but inside
62 * PinnedChunks regions
68 *) we could have a function pointer in MonoClass to implement
69 customized write barriers for value types
71 *) investigate the stuff needed to advance a thread to a GC-safe
72 point (single-stepping, read from unmapped memory etc) and implement it.
73 This would enable us to inline allocations and write barriers, for example,
74 or at least parts of them, like the write barrier checks.
75 We may need this also for handling precise info on stacks, even simple things
76 as having uninitialized data on the stack and having to wait for the prolog
77 to zero it. Not an issue for the last frame that we scan conservatively.
78 We could always not trust the value in the slots anyway.
80 *) modify the jit to save info about references in stack locations:
81 this can be done just for locals as a start, so that at least
82 part of the stack is handled precisely.
84 *) test/fix endianess issues
86 *) Implement a card table as the write barrier instead of remembered
87 sets? Card tables are not easy to implement with our current
88 memory layout. We have several different kinds of major heap
89 objects: Small objects in regular blocks, small objects in pinned
90 chunks and LOS objects. If we just have a pointer we have no way
91 to tell which kind of object it points into, therefore we cannot
92 know where its card table is. The least we have to do to make
93 this happen is to get rid of write barriers for indirect stores.
96 *) Get rid of write barriers for indirect stores. We can do this by
97 telling the GC to wbarrier-register an object once we do an ldloca
98 or ldelema on it, and to unregister it once it's not used anymore
99 (it can only travel downwards on the stack). The problem with
100 unregistering is that it needs to happen eventually no matter
101 what, even if exceptions are thrown, the thread aborts, etc.
102 Rodrigo suggested that we could do only the registering part and
103 let the collector find out (pessimistically) when it's safe to
104 unregister, namely when the stack pointer of the thread that
105 registered the object is higher than it was when the registering
106 happened. This might make for a good first implementation to get
107 some data on performance.
109 *) Some sort of blacklist support? Blacklists is a concept from the
110 Boehm GC: if during a conservative scan we find pointers to an
111 area which we might use as heap, we mark that area as unusable, so
112 pointer retention by random pinning pointers is reduced.
114 *) experiment with max small object size (very small right now - 2kb,
115 because it's tied to the max freelist size)
117 *) add an option to mmap the whole heap in one chunk: it makes for many
118 simplifications in the checks (put the nursery at the top and just use a single
119 check for inclusion/exclusion): the issue this has is that on 32 bit systems it's
120 not flexible (too much of the address space may be used by default or we can't
121 increase the heap as needed) and we'd need a race-free mechanism to return memory
122 back to the system (mprotect(PROT_NONE) will still keep the memory allocated if it
123 was written to, munmap is needed, but the following mmap may not find the same segment
126 *) memzero the major fragments after restarting the world and optionally a smaller
129 *) investigate having fragment zeroing threads
131 *) separate locks for finalization and other minor stuff to reduce
134 *) try a different copying order to improve memory locality
136 *) a thread abort after a store but before the write barrier will
137 prevent the write barrier from executing
139 *) specialized dynamically generated markers/copiers
141 *) Dynamically adjust TLAB size to the number of threads. If we have
142 too many threads that do allocation, we might need smaller TLABs,
143 and we might get better performance with larger TLABs if we only
144 have a handful of threads. We could sum up the space left in all
145 assigned TLABs and if that's more than some percentage of the
146 nursery size, reduce the TLAB size.
148 *) Explore placing unreachable objects on unused nursery memory.
149 Instead of memset'ng a region to zero, place an int[] covering it.
150 A good place to start is add_nursery_frag. The tricky thing here is
151 placing those objects atomically outside of a collection.
153 *) Allocation should use asymmetric Dekker synchronization:
154 http://blogs.oracle.com/dave/resource/Asymmetric-Dekker-Synchronization.txt
155 This should help weak consistency archs.
162 #define _XOPEN_SOURCE
163 #define _DARWIN_C_SOURCE
169 #ifdef HAVE_PTHREAD_H
172 #ifdef HAVE_PTHREAD_NP_H
173 #include <pthread_np.h>
181 #include "mono/sgen/sgen-gc.h"
182 #include "mono/sgen/sgen-cardtable.h"
183 #include "mono/sgen/sgen-protocol.h"
184 #include "mono/sgen/sgen-memory-governor.h"
185 #include "mono/sgen/sgen-hash-table.h"
186 #include "mono/sgen/sgen-pinning.h"
187 #include "mono/sgen/sgen-workers.h"
188 #include "mono/sgen/sgen-client.h"
189 #include "mono/sgen/sgen-pointer-queue.h"
190 #include "mono/sgen/gc-internal-agnostic.h"
191 #include "mono/utils/mono-proclib.h"
192 #include "mono/utils/mono-memory-model.h"
193 #include "mono/utils/hazard-pointer.h"
195 #include <mono/utils/memcheck.h>
196 #include <mono/utils/mono-mmap-internals.h>
198 #undef pthread_create
200 #undef pthread_detach
203 * ######################################################################
204 * ######## Types and constants used by the GC.
205 * ######################################################################
208 /* 0 means not initialized, 1 is initialized, -1 means in progress */
209 static int gc_initialized = 0;
210 /* If set, check if we need to do something every X allocations */
211 gboolean has_per_allocation_action;
212 /* If set, do a heap check every X allocation */
213 guint32 verify_before_allocs = 0;
214 /* If set, do a minor collection before every X allocation */
215 guint32 collect_before_allocs = 0;
216 /* If set, do a whole heap check before each collection */
217 static gboolean whole_heap_check_before_collection = FALSE;
218 /* If set, do a remset consistency check at various opportunities */
219 static gboolean remset_consistency_checks = FALSE;
220 /* If set, do a mod union consistency check before each finishing collection pause */
221 static gboolean mod_union_consistency_check = FALSE;
222 /* If set, check whether mark bits are consistent after major collections */
223 static gboolean check_mark_bits_after_major_collection = FALSE;
224 /* If set, check that all nursery objects are pinned/not pinned, depending on context */
225 static gboolean check_nursery_objects_pinned = FALSE;
226 /* If set, do a few checks when the concurrent collector is used */
227 static gboolean do_concurrent_checks = FALSE;
228 /* If set, do a plausibility check on the scan_starts before and after
230 static gboolean do_scan_starts_check = FALSE;
232 static gboolean disable_minor_collections = FALSE;
233 static gboolean disable_major_collections = FALSE;
234 static gboolean do_verify_nursery = FALSE;
235 static gboolean do_dump_nursery_content = FALSE;
236 static gboolean enable_nursery_canaries = FALSE;
238 static gboolean precleaning_enabled = TRUE;
240 #ifdef HEAVY_STATISTICS
241 guint64 stat_objects_alloced_degraded = 0;
242 guint64 stat_bytes_alloced_degraded = 0;
244 guint64 stat_copy_object_called_nursery = 0;
245 guint64 stat_objects_copied_nursery = 0;
246 guint64 stat_copy_object_called_major = 0;
247 guint64 stat_objects_copied_major = 0;
249 guint64 stat_scan_object_called_nursery = 0;
250 guint64 stat_scan_object_called_major = 0;
252 guint64 stat_slots_allocated_in_vain;
254 guint64 stat_nursery_copy_object_failed_from_space = 0;
255 guint64 stat_nursery_copy_object_failed_forwarded = 0;
256 guint64 stat_nursery_copy_object_failed_pinned = 0;
257 guint64 stat_nursery_copy_object_failed_to_space = 0;
259 static guint64 stat_wbarrier_add_to_global_remset = 0;
260 static guint64 stat_wbarrier_arrayref_copy = 0;
261 static guint64 stat_wbarrier_generic_store = 0;
262 static guint64 stat_wbarrier_generic_store_atomic = 0;
263 static guint64 stat_wbarrier_set_root = 0;
266 static guint64 stat_pinned_objects = 0;
268 static guint64 time_minor_pre_collection_fragment_clear = 0;
269 static guint64 time_minor_pinning = 0;
270 static guint64 time_minor_scan_remsets = 0;
271 static guint64 time_minor_scan_major_blocks = 0;
272 static guint64 time_minor_scan_los = 0;
273 static guint64 time_minor_scan_pinned = 0;
274 static guint64 time_minor_scan_roots = 0;
275 static guint64 time_minor_finish_gray_stack = 0;
276 static guint64 time_minor_fragment_creation = 0;
278 static guint64 time_major_pre_collection_fragment_clear = 0;
279 static guint64 time_major_pinning = 0;
280 static guint64 time_major_scan_pinned = 0;
281 static guint64 time_major_scan_roots = 0;
282 static guint64 time_major_scan_mod_union = 0;
283 static guint64 time_major_finish_gray_stack = 0;
284 static guint64 time_major_free_bigobjs = 0;
285 static guint64 time_major_los_sweep = 0;
286 static guint64 time_major_sweep = 0;
287 static guint64 time_major_fragment_creation = 0;
289 static guint64 time_max = 0;
291 static SGEN_TV_DECLARE (time_major_conc_collection_start);
292 static SGEN_TV_DECLARE (time_major_conc_collection_end);
294 int gc_debug_level = 0;
296 static char* gc_params_options;
297 static char* gc_debug_options;
301 mono_gc_flush_info (void)
303 fflush (gc_debug_file);
307 #define TV_DECLARE SGEN_TV_DECLARE
308 #define TV_GETTIME SGEN_TV_GETTIME
309 #define TV_ELAPSED SGEN_TV_ELAPSED
311 static SGEN_TV_DECLARE (sgen_init_timestamp);
313 NurseryClearPolicy nursery_clear_policy = CLEAR_AT_TLAB_CREATION;
315 #define object_is_forwarded SGEN_OBJECT_IS_FORWARDED
316 #define object_is_pinned SGEN_OBJECT_IS_PINNED
317 #define pin_object SGEN_PIN_OBJECT
319 #define ptr_in_nursery sgen_ptr_in_nursery
321 #define LOAD_VTABLE SGEN_LOAD_VTABLE
324 nursery_canaries_enabled (void)
326 return enable_nursery_canaries;
329 #define safe_object_get_size sgen_safe_object_get_size
331 #if defined(HAVE_CONC_GC_AS_DEFAULT)
332 /* Use concurrent major on deskstop platforms */
333 #define DEFAULT_MAJOR_INIT sgen_marksweep_conc_init
334 #define DEFAULT_MAJOR_NAME "marksweep-conc"
336 #define DEFAULT_MAJOR_INIT sgen_marksweep_init
337 #define DEFAULT_MAJOR_NAME "marksweep"
341 * ######################################################################
342 * ######## Global data.
343 * ######################################################################
345 MonoCoopMutex gc_mutex;
347 #define SCAN_START_SIZE SGEN_SCAN_START_SIZE
349 size_t degraded_mode = 0;
351 static mword bytes_pinned_from_failed_allocation = 0;
353 GCMemSection *nursery_section = NULL;
354 static volatile mword lowest_heap_address = ~(mword)0;
355 static volatile mword highest_heap_address = 0;
357 MonoCoopMutex sgen_interruption_mutex;
359 int current_collection_generation = -1;
360 volatile gboolean concurrent_collection_in_progress = FALSE;
362 /* objects that are ready to be finalized */
363 static SgenPointerQueue fin_ready_queue = SGEN_POINTER_QUEUE_INIT (INTERNAL_MEM_FINALIZE_READY);
364 static SgenPointerQueue critical_fin_queue = SGEN_POINTER_QUEUE_INIT (INTERNAL_MEM_FINALIZE_READY);
366 /* registered roots: the key to the hash is the root start address */
368 * Different kinds of roots are kept separate to speed up pin_from_roots () for example.
370 SgenHashTable roots_hash [ROOT_TYPE_NUM] = {
371 SGEN_HASH_TABLE_INIT (INTERNAL_MEM_ROOTS_TABLE, INTERNAL_MEM_ROOT_RECORD, sizeof (RootRecord), sgen_aligned_addr_hash, NULL),
372 SGEN_HASH_TABLE_INIT (INTERNAL_MEM_ROOTS_TABLE, INTERNAL_MEM_ROOT_RECORD, sizeof (RootRecord), sgen_aligned_addr_hash, NULL),
373 SGEN_HASH_TABLE_INIT (INTERNAL_MEM_ROOTS_TABLE, INTERNAL_MEM_ROOT_RECORD, sizeof (RootRecord), sgen_aligned_addr_hash, NULL)
375 static mword roots_size = 0; /* amount of memory in the root set */
377 /* The size of a TLAB */
378 /* The bigger the value, the less often we have to go to the slow path to allocate a new
379 * one, but the more space is wasted by threads not allocating much memory.
381 * FIXME: Make this self-tuning for each thread.
383 guint32 tlab_size = (1024 * 4);
385 #define MAX_SMALL_OBJ_SIZE SGEN_MAX_SMALL_OBJ_SIZE
387 #define ALLOC_ALIGN SGEN_ALLOC_ALIGN
389 #define ALIGN_UP SGEN_ALIGN_UP
391 #ifdef SGEN_DEBUG_INTERNAL_ALLOC
392 MonoNativeThreadId main_gc_thread = NULL;
395 /*Object was pinned during the current collection*/
396 static mword objects_pinned;
399 * ######################################################################
400 * ######## Macros and function declarations.
401 * ######################################################################
404 /* forward declarations */
405 static void scan_from_registered_roots (char *addr_start, char *addr_end, int root_type, ScanCopyContext ctx);
407 static void pin_from_roots (void *start_nursery, void *end_nursery, ScanCopyContext ctx);
408 static void finish_gray_stack (int generation, ScanCopyContext ctx);
411 SgenMajorCollector major_collector;
412 SgenMinorCollector sgen_minor_collector;
414 static SgenRememberedSet remset;
417 * The gray queue a worker job must use. If we're not parallel or
418 * concurrent, we use the main gray queue.
420 static SgenGrayQueue*
421 sgen_workers_get_job_gray_queue (WorkerData *worker_data, SgenGrayQueue *default_gray_queue)
424 return &worker_data->private_gray_queue;
425 SGEN_ASSERT (0, default_gray_queue, "Why don't we have a default gray queue when we're not running in a worker thread?");
426 return default_gray_queue;
430 gray_queue_redirect (SgenGrayQueue *queue)
432 sgen_workers_take_from_queue (queue);
436 sgen_scan_area_with_callback (char *start, char *end, IterateObjectCallbackFunc callback, void *data, gboolean allow_flags, gboolean fail_on_canaries)
438 while (start < end) {
442 if (!*(void**)start) {
443 start += sizeof (void*); /* should be ALLOC_ALIGN, really */
448 if (!(obj = (char *)SGEN_OBJECT_IS_FORWARDED (start)))
454 if (!sgen_client_object_is_array_fill ((GCObject*)obj)) {
455 CHECK_CANARY_FOR_OBJECT ((GCObject*)obj, fail_on_canaries);
456 size = ALIGN_UP (safe_object_get_size ((GCObject*)obj));
457 callback ((GCObject*)obj, size, data);
458 CANARIFY_SIZE (size);
460 size = ALIGN_UP (safe_object_get_size ((GCObject*)obj));
468 * sgen_add_to_global_remset:
470 * The global remset contains locations which point into newspace after
471 * a minor collection. This can happen if the objects they point to are pinned.
473 * LOCKING: If called from a parallel collector, the global remset
474 * lock must be held. For serial collectors that is not necessary.
477 sgen_add_to_global_remset (gpointer ptr, GCObject *obj)
479 SGEN_ASSERT (5, sgen_ptr_in_nursery (obj), "Target pointer of global remset must be in the nursery");
481 HEAVY_STAT (++stat_wbarrier_add_to_global_remset);
483 if (!major_collector.is_concurrent) {
484 SGEN_ASSERT (5, current_collection_generation != -1, "Global remsets can only be added during collections");
486 if (current_collection_generation == -1)
487 SGEN_ASSERT (5, sgen_concurrent_collection_in_progress (), "Global remsets outside of collection pauses can only be added by the concurrent collector");
490 if (!object_is_pinned (obj))
491 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");
492 else if (sgen_cement_lookup_or_register (obj))
495 remset.record_pointer (ptr);
497 sgen_pin_stats_register_global_remset (obj);
499 SGEN_LOG (8, "Adding global remset for %p", ptr);
500 binary_protocol_global_remset (ptr, obj, (gpointer)SGEN_LOAD_VTABLE (obj));
504 * sgen_drain_gray_stack:
506 * Scan objects in the gray stack until the stack is empty. This should be called
507 * frequently after each object is copied, to achieve better locality and cache
512 sgen_drain_gray_stack (ScanCopyContext ctx)
514 SGEN_ASSERT (0, ctx.ops->drain_gray_stack, "Why do we have a scan/copy context with a missing drain gray stack function?");
516 return ctx.ops->drain_gray_stack (ctx.queue);
520 * Addresses in the pin queue are already sorted. This function finds
521 * the object header for each address and pins the object. The
522 * addresses must be inside the nursery section. The (start of the)
523 * address array is overwritten with the addresses of the actually
524 * pinned objects. Return the number of pinned objects.
527 pin_objects_from_nursery_pin_queue (gboolean do_scan_objects, ScanCopyContext ctx)
529 GCMemSection *section = nursery_section;
530 void **start = sgen_pinning_get_entry (section->pin_queue_first_entry);
531 void **end = sgen_pinning_get_entry (section->pin_queue_last_entry);
532 void *start_nursery = section->data;
533 void *end_nursery = section->end_data;
538 void *pinning_front = start_nursery;
540 void **definitely_pinned = start;
541 ScanObjectFunc scan_func = ctx.ops->scan_object;
542 SgenGrayQueue *queue = ctx.queue;
544 sgen_nursery_allocator_prepare_for_pinning ();
546 while (start < end) {
547 GCObject *obj_to_pin = NULL;
548 size_t obj_to_pin_size = 0;
553 SGEN_ASSERT (0, addr >= start_nursery && addr < end_nursery, "Potential pinning address out of range");
554 SGEN_ASSERT (0, addr >= last, "Pin queue not sorted");
561 SGEN_LOG (5, "Considering pinning addr %p", addr);
562 /* We've already processed everything up to pinning_front. */
563 if (addr < pinning_front) {
569 * Find the closest scan start <= addr. We might search backward in the
570 * scan_starts array because entries might be NULL. In the worst case we
571 * start at start_nursery.
573 idx = ((char*)addr - (char*)section->data) / SCAN_START_SIZE;
574 SGEN_ASSERT (0, idx < section->num_scan_start, "Scan start index out of range");
575 search_start = (void*)section->scan_starts [idx];
576 if (!search_start || search_start > addr) {
579 search_start = section->scan_starts [idx];
580 if (search_start && search_start <= addr)
583 if (!search_start || search_start > addr)
584 search_start = start_nursery;
588 * If the pinning front is closer than the scan start we found, start
589 * searching at the front.
591 if (search_start < pinning_front)
592 search_start = pinning_front;
595 * Now addr should be in an object a short distance from search_start.
597 * search_start must point to zeroed mem or point to an object.
600 size_t obj_size, canarified_obj_size;
603 if (!*(void**)search_start) {
604 search_start = (void*)ALIGN_UP ((mword)search_start + sizeof (gpointer));
605 /* The loop condition makes sure we don't overrun addr. */
609 canarified_obj_size = obj_size = ALIGN_UP (safe_object_get_size ((GCObject*)search_start));
612 * Filler arrays are marked by an invalid sync word. We don't
613 * consider them for pinning. They are not delimited by canaries,
616 if (!sgen_client_object_is_array_fill ((GCObject*)search_start)) {
617 CHECK_CANARY_FOR_OBJECT (search_start, TRUE);
618 CANARIFY_SIZE (canarified_obj_size);
620 if (addr >= search_start && (char*)addr < (char*)search_start + obj_size) {
621 /* This is the object we're looking for. */
622 obj_to_pin = (GCObject*)search_start;
623 obj_to_pin_size = canarified_obj_size;
628 /* Skip to the next object */
629 search_start = (void*)((char*)search_start + canarified_obj_size);
630 } while (search_start <= addr);
632 /* We've searched past the address we were looking for. */
634 pinning_front = search_start;
635 goto next_pin_queue_entry;
639 * We've found an object to pin. It might still be a dummy array, but we
640 * can advance the pinning front in any case.
642 pinning_front = (char*)obj_to_pin + obj_to_pin_size;
645 * If this is a dummy array marking the beginning of a nursery
646 * fragment, we don't pin it.
648 if (sgen_client_object_is_array_fill (obj_to_pin))
649 goto next_pin_queue_entry;
652 * Finally - pin the object!
654 desc = sgen_obj_get_descriptor_safe (obj_to_pin);
655 if (do_scan_objects) {
656 scan_func (obj_to_pin, desc, queue);
658 SGEN_LOG (4, "Pinned object %p, vtable %p (%s), count %d\n",
659 obj_to_pin, *(void**)obj_to_pin, sgen_client_vtable_get_name (SGEN_LOAD_VTABLE (obj_to_pin)), count);
660 binary_protocol_pin (obj_to_pin,
661 (gpointer)LOAD_VTABLE (obj_to_pin),
662 safe_object_get_size (obj_to_pin));
664 pin_object (obj_to_pin);
665 GRAY_OBJECT_ENQUEUE_SERIAL (queue, obj_to_pin, desc);
666 sgen_pin_stats_register_object (obj_to_pin, GENERATION_NURSERY);
667 definitely_pinned [count] = obj_to_pin;
670 if (concurrent_collection_in_progress)
671 sgen_pinning_register_pinned_in_nursery (obj_to_pin);
673 next_pin_queue_entry:
677 sgen_client_nursery_objects_pinned (definitely_pinned, count);
678 stat_pinned_objects += count;
683 pin_objects_in_nursery (gboolean do_scan_objects, ScanCopyContext ctx)
687 if (nursery_section->pin_queue_first_entry == nursery_section->pin_queue_last_entry)
690 reduced_to = pin_objects_from_nursery_pin_queue (do_scan_objects, ctx);
691 nursery_section->pin_queue_last_entry = nursery_section->pin_queue_first_entry + reduced_to;
695 * This function is only ever called (via `collector_pin_object()` in `sgen-copy-object.h`)
696 * when we can't promote an object because we're out of memory.
699 sgen_pin_object (GCObject *object, SgenGrayQueue *queue)
701 SGEN_ASSERT (0, sgen_ptr_in_nursery (object), "We're only supposed to use this for pinning nursery objects when out of memory.");
704 * All pinned objects are assumed to have been staged, so we need to stage as well.
705 * Also, the count of staged objects shows that "late pinning" happened.
707 sgen_pin_stage_ptr (object);
709 SGEN_PIN_OBJECT (object);
710 binary_protocol_pin (object, (gpointer)LOAD_VTABLE (object), safe_object_get_size (object));
713 sgen_pin_stats_register_object (object, GENERATION_NURSERY);
715 GRAY_OBJECT_ENQUEUE_SERIAL (queue, object, sgen_obj_get_descriptor_safe (object));
718 /* Sort the addresses in array in increasing order.
719 * Done using a by-the book heap sort. Which has decent and stable performance, is pretty cache efficient.
722 sgen_sort_addresses (void **array, size_t size)
727 for (i = 1; i < size; ++i) {
730 size_t parent = (child - 1) / 2;
732 if (array [parent] >= array [child])
735 tmp = array [parent];
736 array [parent] = array [child];
743 for (i = size - 1; i > 0; --i) {
746 array [i] = array [0];
752 while (root * 2 + 1 <= end) {
753 size_t child = root * 2 + 1;
755 if (child < end && array [child] < array [child + 1])
757 if (array [root] >= array [child])
761 array [root] = array [child];
770 * Scan the memory between start and end and queue values which could be pointers
771 * to the area between start_nursery and end_nursery for later consideration.
772 * Typically used for thread stacks.
775 sgen_conservatively_pin_objects_from (void **start, void **end, void *start_nursery, void *end_nursery, int pin_type)
779 SGEN_ASSERT (0, ((mword)start & (SIZEOF_VOID_P - 1)) == 0, "Why are we scanning for references in unaligned memory ?");
781 #if defined(VALGRIND_MAKE_MEM_DEFINED_IF_ADDRESSABLE) && !defined(_WIN64)
782 VALGRIND_MAKE_MEM_DEFINED_IF_ADDRESSABLE (start, (char*)end - (char*)start);
785 while (start < end) {
787 * *start can point to the middle of an object
788 * note: should we handle pointing at the end of an object?
789 * pinning in C# code disallows pointing at the end of an object
790 * but there is some small chance that an optimizing C compiler
791 * may keep the only reference to an object by pointing
792 * at the end of it. We ignore this small chance for now.
793 * Pointers to the end of an object are indistinguishable
794 * from pointers to the start of the next object in memory
795 * so if we allow that we'd need to pin two objects...
796 * We queue the pointer in an array, the
797 * array will then be sorted and uniqued. This way
798 * we can coalesce several pinning pointers and it should
799 * be faster since we'd do a memory scan with increasing
800 * addresses. Note: we can align the address to the allocation
801 * alignment, so the unique process is more effective.
803 mword addr = (mword)*start;
804 addr &= ~(ALLOC_ALIGN - 1);
805 if (addr >= (mword)start_nursery && addr < (mword)end_nursery) {
806 SGEN_LOG (6, "Pinning address %p from %p", (void*)addr, start);
807 sgen_pin_stage_ptr ((void*)addr);
808 binary_protocol_pin_stage (start, (void*)addr);
809 sgen_pin_stats_register_address ((char*)addr, pin_type);
815 SGEN_LOG (7, "found %d potential pinned heap pointers", count);
819 * The first thing we do in a collection is to identify pinned objects.
820 * This function considers all the areas of memory that need to be
821 * conservatively scanned.
824 pin_from_roots (void *start_nursery, void *end_nursery, ScanCopyContext ctx)
828 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);
829 /* objects pinned from the API are inside these roots */
830 SGEN_HASH_TABLE_FOREACH (&roots_hash [ROOT_TYPE_PINNED], void **, start_root, RootRecord *, root) {
831 SGEN_LOG (6, "Pinned roots %p-%p", start_root, root->end_root);
832 sgen_conservatively_pin_objects_from (start_root, (void**)root->end_root, start_nursery, end_nursery, PIN_TYPE_OTHER);
833 } SGEN_HASH_TABLE_FOREACH_END;
834 /* now deal with the thread stacks
835 * in the future we should be able to conservatively scan only:
836 * *) the cpu registers
837 * *) the unmanaged stack frames
838 * *) the _last_ managed stack frame
839 * *) pointers slots in managed frames
841 sgen_client_scan_thread_data (start_nursery, end_nursery, FALSE, ctx);
845 single_arg_user_copy_or_mark (GCObject **obj, void *gc_data)
847 ScanCopyContext *ctx = (ScanCopyContext *)gc_data;
848 ctx->ops->copy_or_mark_object (obj, ctx->queue);
852 * The memory area from start_root to end_root contains pointers to objects.
853 * Their position is precisely described by @desc (this means that the pointer
854 * can be either NULL or the pointer to the start of an object).
855 * This functions copies them to to_space updates them.
857 * This function is not thread-safe!
860 precisely_scan_objects_from (void** start_root, void** end_root, char* n_start, char *n_end, SgenDescriptor desc, ScanCopyContext ctx)
862 CopyOrMarkObjectFunc copy_func = ctx.ops->copy_or_mark_object;
863 ScanPtrFieldFunc scan_field_func = ctx.ops->scan_ptr_field;
864 SgenGrayQueue *queue = ctx.queue;
866 switch (desc & ROOT_DESC_TYPE_MASK) {
867 case ROOT_DESC_BITMAP:
868 desc >>= ROOT_DESC_TYPE_SHIFT;
870 if ((desc & 1) && *start_root) {
871 copy_func ((GCObject**)start_root, queue);
872 SGEN_LOG (9, "Overwrote root at %p with %p", start_root, *start_root);
878 case ROOT_DESC_COMPLEX: {
879 gsize *bitmap_data = (gsize *)sgen_get_complex_descriptor_bitmap (desc);
880 gsize bwords = (*bitmap_data) - 1;
881 void **start_run = start_root;
883 while (bwords-- > 0) {
884 gsize bmap = *bitmap_data++;
885 void **objptr = start_run;
887 if ((bmap & 1) && *objptr) {
888 copy_func ((GCObject**)objptr, queue);
889 SGEN_LOG (9, "Overwrote root at %p with %p", objptr, *objptr);
894 start_run += GC_BITS_PER_WORD;
898 case ROOT_DESC_VECTOR: {
901 for (p = start_root; p < end_root; p++) {
903 scan_field_func (NULL, (GCObject**)p, queue);
907 case ROOT_DESC_USER: {
908 SgenUserRootMarkFunc marker = sgen_get_user_descriptor_func (desc);
909 marker (start_root, single_arg_user_copy_or_mark, &ctx);
912 case ROOT_DESC_RUN_LEN:
913 g_assert_not_reached ();
915 g_assert_not_reached ();
920 reset_heap_boundaries (void)
922 lowest_heap_address = ~(mword)0;
923 highest_heap_address = 0;
927 sgen_update_heap_boundaries (mword low, mword high)
932 old = lowest_heap_address;
935 } while (SGEN_CAS_PTR ((gpointer*)&lowest_heap_address, (gpointer)low, (gpointer)old) != (gpointer)old);
938 old = highest_heap_address;
941 } while (SGEN_CAS_PTR ((gpointer*)&highest_heap_address, (gpointer)high, (gpointer)old) != (gpointer)old);
945 * Allocate and setup the data structures needed to be able to allocate objects
946 * in the nursery. The nursery is stored in nursery_section.
951 GCMemSection *section;
958 SGEN_LOG (2, "Allocating nursery size: %zu", (size_t)sgen_nursery_size);
959 /* later we will alloc a larger area for the nursery but only activate
960 * what we need. The rest will be used as expansion if we have too many pinned
961 * objects in the existing nursery.
963 /* FIXME: handle OOM */
964 section = (GCMemSection *)sgen_alloc_internal (INTERNAL_MEM_SECTION);
966 alloc_size = sgen_nursery_size;
968 /* If there isn't enough space even for the nursery we should simply abort. */
969 g_assert (sgen_memgov_try_alloc_space (alloc_size, SPACE_NURSERY));
971 data = (char *)major_collector.alloc_heap (alloc_size, alloc_size, sgen_nursery_bits);
972 sgen_update_heap_boundaries ((mword)data, (mword)(data + sgen_nursery_size));
973 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 ());
974 section->data = data;
975 section->end_data = data + sgen_nursery_size;
976 scan_starts = (alloc_size + SCAN_START_SIZE - 1) / SCAN_START_SIZE;
977 section->scan_starts = (char **)sgen_alloc_internal_dynamic (sizeof (char*) * scan_starts, INTERNAL_MEM_SCAN_STARTS, TRUE);
978 section->num_scan_start = scan_starts;
980 nursery_section = section;
982 sgen_nursery_allocator_set_nursery_bounds (data, data + sgen_nursery_size);
986 mono_gc_get_logfile (void)
988 return gc_debug_file;
992 mono_gc_params_set (const char* options)
994 if (gc_params_options)
995 g_free (gc_params_options);
997 gc_params_options = g_strdup (options);
1001 mono_gc_debug_set (const char* options)
1003 if (gc_debug_options)
1004 g_free (gc_debug_options);
1006 gc_debug_options = g_strdup (options);
1010 scan_finalizer_entries (SgenPointerQueue *fin_queue, ScanCopyContext ctx)
1012 CopyOrMarkObjectFunc copy_func = ctx.ops->copy_or_mark_object;
1013 SgenGrayQueue *queue = ctx.queue;
1016 for (i = 0; i < fin_queue->next_slot; ++i) {
1017 GCObject *obj = (GCObject *)fin_queue->data [i];
1020 SGEN_LOG (5, "Scan of fin ready object: %p (%s)\n", obj, sgen_client_vtable_get_name (SGEN_LOAD_VTABLE (obj)));
1021 copy_func ((GCObject**)&fin_queue->data [i], queue);
1026 generation_name (int generation)
1028 switch (generation) {
1029 case GENERATION_NURSERY: return "nursery";
1030 case GENERATION_OLD: return "old";
1031 default: g_assert_not_reached ();
1036 sgen_generation_name (int generation)
1038 return generation_name (generation);
1042 finish_gray_stack (int generation, ScanCopyContext ctx)
1046 int done_with_ephemerons, ephemeron_rounds = 0;
1047 char *start_addr = generation == GENERATION_NURSERY ? sgen_get_nursery_start () : NULL;
1048 char *end_addr = generation == GENERATION_NURSERY ? sgen_get_nursery_end () : (char*)-1;
1049 SgenGrayQueue *queue = ctx.queue;
1051 binary_protocol_finish_gray_stack_start (sgen_timestamp (), generation);
1053 * We copied all the reachable objects. Now it's the time to copy
1054 * the objects that were not referenced by the roots, but by the copied objects.
1055 * we built a stack of objects pointed to by gray_start: they are
1056 * additional roots and we may add more items as we go.
1057 * We loop until gray_start == gray_objects which means no more objects have
1058 * been added. Note this is iterative: no recursion is involved.
1059 * We need to walk the LO list as well in search of marked big objects
1060 * (use a flag since this is needed only on major collections). We need to loop
1061 * here as well, so keep a counter of marked LO (increasing it in copy_object).
1062 * To achieve better cache locality and cache usage, we drain the gray stack
1063 * frequently, after each object is copied, and just finish the work here.
1065 sgen_drain_gray_stack (ctx);
1067 SGEN_LOG (2, "%s generation done", generation_name (generation));
1070 Reset bridge data, we might have lingering data from a previous collection if this is a major
1071 collection trigged by minor overflow.
1073 We must reset the gathered bridges since their original block might be evacuated due to major
1074 fragmentation in the meanwhile and the bridge code should not have to deal with that.
1076 if (sgen_client_bridge_need_processing ())
1077 sgen_client_bridge_reset_data ();
1080 * Mark all strong toggleref objects. This must be done before we walk ephemerons or finalizers
1081 * to ensure they see the full set of live objects.
1083 sgen_client_mark_togglerefs (start_addr, end_addr, ctx);
1086 * Walk the ephemeron tables marking all values with reachable keys. This must be completely done
1087 * before processing finalizable objects and non-tracking weak links to avoid finalizing/clearing
1088 * objects that are in fact reachable.
1090 done_with_ephemerons = 0;
1092 done_with_ephemerons = sgen_client_mark_ephemerons (ctx);
1093 sgen_drain_gray_stack (ctx);
1095 } while (!done_with_ephemerons);
1097 if (sgen_client_bridge_need_processing ()) {
1098 /*Make sure the gray stack is empty before we process bridge objects so we get liveness right*/
1099 sgen_drain_gray_stack (ctx);
1100 sgen_collect_bridge_objects (generation, ctx);
1101 if (generation == GENERATION_OLD)
1102 sgen_collect_bridge_objects (GENERATION_NURSERY, ctx);
1105 Do the first bridge step here, as the collector liveness state will become useless after that.
1107 An important optimization is to only proccess the possibly dead part of the object graph and skip
1108 over all live objects as we transitively know everything they point must be alive too.
1110 The above invariant is completely wrong if we let the gray queue be drained and mark/copy everything.
1112 This has the unfortunate side effect of making overflow collections perform the first step twice, but
1113 given we now have heuristics that perform major GC in anticipation of minor overflows this should not
1116 sgen_client_bridge_processing_stw_step ();
1120 Make sure we drain the gray stack before processing disappearing links and finalizers.
1121 If we don't make sure it is empty we might wrongly see a live object as dead.
1123 sgen_drain_gray_stack (ctx);
1126 We must clear weak links that don't track resurrection before processing object ready for
1127 finalization so they can be cleared before that.
1129 sgen_null_link_in_range (generation, ctx, FALSE);
1130 if (generation == GENERATION_OLD)
1131 sgen_null_link_in_range (GENERATION_NURSERY, ctx, FALSE);
1134 /* walk the finalization queue and move also the objects that need to be
1135 * finalized: use the finalized objects as new roots so the objects they depend
1136 * on are also not reclaimed. As with the roots above, only objects in the nursery
1137 * are marked/copied.
1139 sgen_finalize_in_range (generation, ctx);
1140 if (generation == GENERATION_OLD)
1141 sgen_finalize_in_range (GENERATION_NURSERY, ctx);
1142 /* drain the new stack that might have been created */
1143 SGEN_LOG (6, "Precise scan of gray area post fin");
1144 sgen_drain_gray_stack (ctx);
1147 * This must be done again after processing finalizable objects since CWL slots are cleared only after the key is finalized.
1149 done_with_ephemerons = 0;
1151 done_with_ephemerons = sgen_client_mark_ephemerons (ctx);
1152 sgen_drain_gray_stack (ctx);
1154 } while (!done_with_ephemerons);
1156 sgen_client_clear_unreachable_ephemerons (ctx);
1159 * We clear togglerefs only after all possible chances of revival are done.
1160 * This is semantically more inline with what users expect and it allows for
1161 * user finalizers to correctly interact with TR objects.
1163 sgen_client_clear_togglerefs (start_addr, end_addr, ctx);
1166 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);
1169 * handle disappearing links
1170 * Note we do this after checking the finalization queue because if an object
1171 * survives (at least long enough to be finalized) we don't clear the link.
1172 * This also deals with a possible issue with the monitor reclamation: with the Boehm
1173 * GC a finalized object my lose the monitor because it is cleared before the finalizer is
1176 g_assert (sgen_gray_object_queue_is_empty (queue));
1178 sgen_null_link_in_range (generation, ctx, TRUE);
1179 if (generation == GENERATION_OLD)
1180 sgen_null_link_in_range (GENERATION_NURSERY, ctx, TRUE);
1181 if (sgen_gray_object_queue_is_empty (queue))
1183 sgen_drain_gray_stack (ctx);
1186 g_assert (sgen_gray_object_queue_is_empty (queue));
1188 binary_protocol_finish_gray_stack_end (sgen_timestamp (), generation);
1192 sgen_check_section_scan_starts (GCMemSection *section)
1195 for (i = 0; i < section->num_scan_start; ++i) {
1196 if (section->scan_starts [i]) {
1197 mword size = safe_object_get_size ((GCObject*) section->scan_starts [i]);
1198 SGEN_ASSERT (0, size >= SGEN_CLIENT_MINIMUM_OBJECT_SIZE && size <= MAX_SMALL_OBJ_SIZE, "Weird object size at scan starts.");
1204 check_scan_starts (void)
1206 if (!do_scan_starts_check)
1208 sgen_check_section_scan_starts (nursery_section);
1209 major_collector.check_scan_starts ();
1213 scan_from_registered_roots (char *addr_start, char *addr_end, int root_type, ScanCopyContext ctx)
1217 SGEN_HASH_TABLE_FOREACH (&roots_hash [root_type], void **, start_root, RootRecord *, root) {
1218 SGEN_LOG (6, "Precise root scan %p-%p (desc: %p)", start_root, root->end_root, (void*)root->root_desc);
1219 precisely_scan_objects_from (start_root, (void**)root->end_root, addr_start, addr_end, root->root_desc, ctx);
1220 } SGEN_HASH_TABLE_FOREACH_END;
1226 static gboolean inited = FALSE;
1231 mono_counters_register ("Collection max time", MONO_COUNTER_GC | MONO_COUNTER_ULONG | MONO_COUNTER_TIME | MONO_COUNTER_MONOTONIC, &time_max);
1233 mono_counters_register ("Minor fragment clear", MONO_COUNTER_GC | MONO_COUNTER_ULONG | MONO_COUNTER_TIME, &time_minor_pre_collection_fragment_clear);
1234 mono_counters_register ("Minor pinning", MONO_COUNTER_GC | MONO_COUNTER_ULONG | MONO_COUNTER_TIME, &time_minor_pinning);
1235 mono_counters_register ("Minor scan remembered set", MONO_COUNTER_GC | MONO_COUNTER_ULONG | MONO_COUNTER_TIME, &time_minor_scan_remsets);
1236 mono_counters_register ("Minor scan major blocks", MONO_COUNTER_GC | MONO_COUNTER_ULONG | MONO_COUNTER_TIME, &time_minor_scan_major_blocks);
1237 mono_counters_register ("Minor scan los", MONO_COUNTER_GC | MONO_COUNTER_ULONG | MONO_COUNTER_TIME, &time_minor_scan_los);
1238 mono_counters_register ("Minor scan pinned", MONO_COUNTER_GC | MONO_COUNTER_ULONG | MONO_COUNTER_TIME, &time_minor_scan_pinned);
1239 mono_counters_register ("Minor scan roots", MONO_COUNTER_GC | MONO_COUNTER_ULONG | MONO_COUNTER_TIME, &time_minor_scan_roots);
1240 mono_counters_register ("Minor fragment creation", MONO_COUNTER_GC | MONO_COUNTER_ULONG | MONO_COUNTER_TIME, &time_minor_fragment_creation);
1242 mono_counters_register ("Major fragment clear", MONO_COUNTER_GC | MONO_COUNTER_ULONG | MONO_COUNTER_TIME, &time_major_pre_collection_fragment_clear);
1243 mono_counters_register ("Major pinning", MONO_COUNTER_GC | MONO_COUNTER_ULONG | MONO_COUNTER_TIME, &time_major_pinning);
1244 mono_counters_register ("Major scan pinned", MONO_COUNTER_GC | MONO_COUNTER_ULONG | MONO_COUNTER_TIME, &time_major_scan_pinned);
1245 mono_counters_register ("Major scan roots", MONO_COUNTER_GC | MONO_COUNTER_ULONG | MONO_COUNTER_TIME, &time_major_scan_roots);
1246 mono_counters_register ("Major scan mod union", MONO_COUNTER_GC | MONO_COUNTER_ULONG | MONO_COUNTER_TIME, &time_major_scan_mod_union);
1247 mono_counters_register ("Major finish gray stack", MONO_COUNTER_GC | MONO_COUNTER_ULONG | MONO_COUNTER_TIME, &time_major_finish_gray_stack);
1248 mono_counters_register ("Major free big objects", MONO_COUNTER_GC | MONO_COUNTER_ULONG | MONO_COUNTER_TIME, &time_major_free_bigobjs);
1249 mono_counters_register ("Major LOS sweep", MONO_COUNTER_GC | MONO_COUNTER_ULONG | MONO_COUNTER_TIME, &time_major_los_sweep);
1250 mono_counters_register ("Major sweep", MONO_COUNTER_GC | MONO_COUNTER_ULONG | MONO_COUNTER_TIME, &time_major_sweep);
1251 mono_counters_register ("Major fragment creation", MONO_COUNTER_GC | MONO_COUNTER_ULONG | MONO_COUNTER_TIME, &time_major_fragment_creation);
1253 mono_counters_register ("Number of pinned objects", MONO_COUNTER_GC | MONO_COUNTER_ULONG, &stat_pinned_objects);
1255 #ifdef HEAVY_STATISTICS
1256 mono_counters_register ("WBarrier remember pointer", MONO_COUNTER_GC | MONO_COUNTER_ULONG, &stat_wbarrier_add_to_global_remset);
1257 mono_counters_register ("WBarrier arrayref copy", MONO_COUNTER_GC | MONO_COUNTER_ULONG, &stat_wbarrier_arrayref_copy);
1258 mono_counters_register ("WBarrier generic store called", MONO_COUNTER_GC | MONO_COUNTER_ULONG, &stat_wbarrier_generic_store);
1259 mono_counters_register ("WBarrier generic atomic store called", MONO_COUNTER_GC | MONO_COUNTER_ULONG, &stat_wbarrier_generic_store_atomic);
1260 mono_counters_register ("WBarrier set root", MONO_COUNTER_GC | MONO_COUNTER_ULONG, &stat_wbarrier_set_root);
1262 mono_counters_register ("# objects allocated degraded", MONO_COUNTER_GC | MONO_COUNTER_ULONG, &stat_objects_alloced_degraded);
1263 mono_counters_register ("bytes allocated degraded", MONO_COUNTER_GC | MONO_COUNTER_ULONG, &stat_bytes_alloced_degraded);
1265 mono_counters_register ("# copy_object() called (nursery)", MONO_COUNTER_GC | MONO_COUNTER_ULONG, &stat_copy_object_called_nursery);
1266 mono_counters_register ("# objects copied (nursery)", MONO_COUNTER_GC | MONO_COUNTER_ULONG, &stat_objects_copied_nursery);
1267 mono_counters_register ("# copy_object() called (major)", MONO_COUNTER_GC | MONO_COUNTER_ULONG, &stat_copy_object_called_major);
1268 mono_counters_register ("# objects copied (major)", MONO_COUNTER_GC | MONO_COUNTER_ULONG, &stat_objects_copied_major);
1270 mono_counters_register ("# scan_object() called (nursery)", MONO_COUNTER_GC | MONO_COUNTER_ULONG, &stat_scan_object_called_nursery);
1271 mono_counters_register ("# scan_object() called (major)", MONO_COUNTER_GC | MONO_COUNTER_ULONG, &stat_scan_object_called_major);
1273 mono_counters_register ("Slots allocated in vain", MONO_COUNTER_GC | MONO_COUNTER_ULONG, &stat_slots_allocated_in_vain);
1275 mono_counters_register ("# nursery copy_object() failed from space", MONO_COUNTER_GC | MONO_COUNTER_ULONG, &stat_nursery_copy_object_failed_from_space);
1276 mono_counters_register ("# nursery copy_object() failed forwarded", MONO_COUNTER_GC | MONO_COUNTER_ULONG, &stat_nursery_copy_object_failed_forwarded);
1277 mono_counters_register ("# nursery copy_object() failed pinned", MONO_COUNTER_GC | MONO_COUNTER_ULONG, &stat_nursery_copy_object_failed_pinned);
1278 mono_counters_register ("# nursery copy_object() failed to space", MONO_COUNTER_GC | MONO_COUNTER_ULONG, &stat_nursery_copy_object_failed_to_space);
1280 sgen_nursery_allocator_init_heavy_stats ();
1288 reset_pinned_from_failed_allocation (void)
1290 bytes_pinned_from_failed_allocation = 0;
1294 sgen_set_pinned_from_failed_allocation (mword objsize)
1296 bytes_pinned_from_failed_allocation += objsize;
1300 sgen_collection_is_concurrent (void)
1302 switch (current_collection_generation) {
1303 case GENERATION_NURSERY:
1305 case GENERATION_OLD:
1306 return concurrent_collection_in_progress;
1308 g_error ("Invalid current generation %d", current_collection_generation);
1314 sgen_concurrent_collection_in_progress (void)
1316 return concurrent_collection_in_progress;
1320 SgenThreadPoolJob job;
1321 SgenObjectOperations *ops;
1322 SgenGrayQueue *gc_thread_gray_queue;
1330 static ScanCopyContext
1331 scan_copy_context_for_scan_job (void *worker_data_untyped, ScanJob *job)
1333 WorkerData *worker_data = (WorkerData *)worker_data_untyped;
1335 return CONTEXT_FROM_OBJECT_OPERATIONS (job->ops, sgen_workers_get_job_gray_queue (worker_data, job->gc_thread_gray_queue));
1343 } ScanFromRegisteredRootsJob;
1346 job_scan_from_registered_roots (void *worker_data_untyped, SgenThreadPoolJob *job)
1348 ScanFromRegisteredRootsJob *job_data = (ScanFromRegisteredRootsJob*)job;
1349 ScanCopyContext ctx = scan_copy_context_for_scan_job (worker_data_untyped, &job_data->scan_job);
1351 scan_from_registered_roots (job_data->heap_start, job_data->heap_end, job_data->root_type, ctx);
1358 } ScanThreadDataJob;
1361 job_scan_thread_data (void *worker_data_untyped, SgenThreadPoolJob *job)
1363 ScanThreadDataJob *job_data = (ScanThreadDataJob*)job;
1364 ScanCopyContext ctx = scan_copy_context_for_scan_job (worker_data_untyped, &job_data->scan_job);
1366 sgen_client_scan_thread_data (job_data->heap_start, job_data->heap_end, TRUE, ctx);
1371 SgenPointerQueue *queue;
1372 } ScanFinalizerEntriesJob;
1375 job_scan_finalizer_entries (void *worker_data_untyped, SgenThreadPoolJob *job)
1377 ScanFinalizerEntriesJob *job_data = (ScanFinalizerEntriesJob*)job;
1378 ScanCopyContext ctx = scan_copy_context_for_scan_job (worker_data_untyped, &job_data->scan_job);
1380 scan_finalizer_entries (job_data->queue, ctx);
1384 job_scan_wbroots (void *worker_data_untyped, SgenThreadPoolJob *job)
1386 ScanJob *job_data = (ScanJob*)job;
1387 ScanCopyContext ctx = scan_copy_context_for_scan_job (worker_data_untyped, job_data);
1389 sgen_wbroots_scan_card_table (ctx);
1393 job_scan_major_card_table (void *worker_data_untyped, SgenThreadPoolJob *job)
1395 SGEN_TV_DECLARE (atv);
1396 SGEN_TV_DECLARE (btv);
1397 ParallelScanJob *job_data = (ParallelScanJob*)job;
1398 ScanCopyContext ctx = scan_copy_context_for_scan_job (worker_data_untyped, (ScanJob*)job_data);
1400 SGEN_TV_GETTIME (atv);
1401 major_collector.scan_card_table (CARDTABLE_SCAN_GLOBAL, ctx, job_data->job_index, sgen_workers_get_job_split_count ());
1402 SGEN_TV_GETTIME (btv);
1403 time_minor_scan_major_blocks += SGEN_TV_ELAPSED (atv, btv);
1407 job_scan_los_card_table (void *worker_data_untyped, SgenThreadPoolJob *job)
1409 SGEN_TV_DECLARE (atv);
1410 SGEN_TV_DECLARE (btv);
1411 ParallelScanJob *job_data = (ParallelScanJob*)job;
1412 ScanCopyContext ctx = scan_copy_context_for_scan_job (worker_data_untyped, (ScanJob*)job_data);
1414 SGEN_TV_GETTIME (atv);
1415 sgen_los_scan_card_table (CARDTABLE_SCAN_GLOBAL, ctx, job_data->job_index, sgen_workers_get_job_split_count ());
1416 SGEN_TV_GETTIME (btv);
1417 time_minor_scan_los += SGEN_TV_ELAPSED (atv, btv);
1421 job_scan_major_mod_union_card_table (void *worker_data_untyped, SgenThreadPoolJob *job)
1423 ParallelScanJob *job_data = (ParallelScanJob*)job;
1424 ScanCopyContext ctx = scan_copy_context_for_scan_job (worker_data_untyped, (ScanJob*)job_data);
1426 g_assert (concurrent_collection_in_progress);
1427 major_collector.scan_card_table (CARDTABLE_SCAN_MOD_UNION, ctx, job_data->job_index, sgen_workers_get_job_split_count ());
1431 job_scan_los_mod_union_card_table (void *worker_data_untyped, SgenThreadPoolJob *job)
1433 ParallelScanJob *job_data = (ParallelScanJob*)job;
1434 ScanCopyContext ctx = scan_copy_context_for_scan_job (worker_data_untyped, (ScanJob*)job_data);
1436 g_assert (concurrent_collection_in_progress);
1437 sgen_los_scan_card_table (CARDTABLE_SCAN_MOD_UNION, ctx, job_data->job_index, sgen_workers_get_job_split_count ());
1441 job_major_mod_union_preclean (void *worker_data_untyped, SgenThreadPoolJob *job)
1443 ParallelScanJob *job_data = (ParallelScanJob*)job;
1444 ScanCopyContext ctx = scan_copy_context_for_scan_job (worker_data_untyped, (ScanJob*)job_data);
1446 g_assert (concurrent_collection_in_progress);
1448 major_collector.scan_card_table (CARDTABLE_SCAN_MOD_UNION_PRECLEAN, ctx, job_data->job_index, sgen_workers_get_job_split_count ());
1452 job_los_mod_union_preclean (void *worker_data_untyped, SgenThreadPoolJob *job)
1454 ParallelScanJob *job_data = (ParallelScanJob*)job;
1455 ScanCopyContext ctx = scan_copy_context_for_scan_job (worker_data_untyped, (ScanJob*)job_data);
1457 g_assert (concurrent_collection_in_progress);
1459 sgen_los_scan_card_table (CARDTABLE_SCAN_MOD_UNION_PRECLEAN, ctx, job_data->job_index, sgen_workers_get_job_split_count ());
1463 job_scan_last_pinned (void *worker_data_untyped, SgenThreadPoolJob *job)
1465 ScanJob *job_data = (ScanJob*)job;
1466 ScanCopyContext ctx = scan_copy_context_for_scan_job (worker_data_untyped, job_data);
1468 g_assert (concurrent_collection_in_progress);
1470 sgen_scan_pin_queue_objects (ctx);
1474 workers_finish_callback (void)
1476 ParallelScanJob *psj;
1478 int split_count = sgen_workers_get_job_split_count ();
1480 /* Mod union preclean jobs */
1481 for (i = 0; i < split_count; i++) {
1482 psj = (ParallelScanJob*)sgen_thread_pool_job_alloc ("preclean major mod union cardtable", job_major_mod_union_preclean, sizeof (ParallelScanJob));
1483 psj->scan_job.ops = sgen_workers_get_idle_func_object_ops ();
1484 psj->scan_job.gc_thread_gray_queue = NULL;
1486 sgen_workers_enqueue_job (&psj->scan_job.job, TRUE);
1489 for (i = 0; i < split_count; i++) {
1490 psj = (ParallelScanJob*)sgen_thread_pool_job_alloc ("preclean los mod union cardtable", job_los_mod_union_preclean, sizeof (ParallelScanJob));
1491 psj->scan_job.ops = sgen_workers_get_idle_func_object_ops ();
1492 psj->scan_job.gc_thread_gray_queue = NULL;
1494 sgen_workers_enqueue_job (&psj->scan_job.job, TRUE);
1497 sj = (ScanJob*)sgen_thread_pool_job_alloc ("scan last pinned", job_scan_last_pinned, sizeof (ScanJob));
1498 sj->ops = sgen_workers_get_idle_func_object_ops ();
1499 sj->gc_thread_gray_queue = NULL;
1500 sgen_workers_enqueue_job (&sj->job, TRUE);
1504 init_gray_queue (SgenGrayQueue *gc_thread_gray_queue, gboolean use_workers)
1507 sgen_workers_init_distribute_gray_queue ();
1508 sgen_gray_object_queue_init (gc_thread_gray_queue, NULL, TRUE);
1512 enqueue_scan_remembered_set_jobs (SgenGrayQueue *gc_thread_gray_queue, SgenObjectOperations *ops, gboolean enqueue)
1514 int i, split_count = sgen_workers_get_job_split_count ();
1517 sj = (ScanJob*)sgen_thread_pool_job_alloc ("scan wbroots", job_scan_wbroots, sizeof (ScanJob));
1519 sj->gc_thread_gray_queue = gc_thread_gray_queue;
1520 sgen_workers_enqueue_job (&sj->job, enqueue);
1522 for (i = 0; i < split_count; i++) {
1523 ParallelScanJob *psj;
1525 psj = (ParallelScanJob*)sgen_thread_pool_job_alloc ("scan major remsets", job_scan_major_card_table, sizeof (ParallelScanJob));
1526 psj->scan_job.ops = ops;
1527 psj->scan_job.gc_thread_gray_queue = gc_thread_gray_queue;
1529 sgen_workers_enqueue_job (&psj->scan_job.job, enqueue);
1531 psj = (ParallelScanJob*)sgen_thread_pool_job_alloc ("scan LOS remsets", job_scan_los_card_table, sizeof (ParallelScanJob));
1532 psj->scan_job.ops = ops;
1533 psj->scan_job.gc_thread_gray_queue = gc_thread_gray_queue;
1535 sgen_workers_enqueue_job (&psj->scan_job.job, enqueue);
1540 enqueue_scan_from_roots_jobs (SgenGrayQueue *gc_thread_gray_queue, char *heap_start, char *heap_end, SgenObjectOperations *ops, gboolean enqueue)
1542 ScanFromRegisteredRootsJob *scrrj;
1543 ScanThreadDataJob *stdj;
1544 ScanFinalizerEntriesJob *sfej;
1546 /* registered roots, this includes static fields */
1548 scrrj = (ScanFromRegisteredRootsJob*)sgen_thread_pool_job_alloc ("scan from registered roots normal", job_scan_from_registered_roots, sizeof (ScanFromRegisteredRootsJob));
1549 scrrj->scan_job.ops = ops;
1550 scrrj->scan_job.gc_thread_gray_queue = gc_thread_gray_queue;
1551 scrrj->heap_start = heap_start;
1552 scrrj->heap_end = heap_end;
1553 scrrj->root_type = ROOT_TYPE_NORMAL;
1554 sgen_workers_enqueue_job (&scrrj->scan_job.job, enqueue);
1556 if (current_collection_generation == GENERATION_OLD) {
1557 /* During minors we scan the cardtable for these roots instead */
1558 scrrj = (ScanFromRegisteredRootsJob*)sgen_thread_pool_job_alloc ("scan from registered roots wbarrier", job_scan_from_registered_roots, sizeof (ScanFromRegisteredRootsJob));
1559 scrrj->scan_job.ops = ops;
1560 scrrj->scan_job.gc_thread_gray_queue = gc_thread_gray_queue;
1561 scrrj->heap_start = heap_start;
1562 scrrj->heap_end = heap_end;
1563 scrrj->root_type = ROOT_TYPE_WBARRIER;
1564 sgen_workers_enqueue_job (&scrrj->scan_job.job, enqueue);
1569 stdj = (ScanThreadDataJob*)sgen_thread_pool_job_alloc ("scan thread data", job_scan_thread_data, sizeof (ScanThreadDataJob));
1570 stdj->scan_job.ops = ops;
1571 stdj->scan_job.gc_thread_gray_queue = gc_thread_gray_queue;
1572 stdj->heap_start = heap_start;
1573 stdj->heap_end = heap_end;
1574 sgen_workers_enqueue_job (&stdj->scan_job.job, enqueue);
1576 /* Scan the list of objects ready for finalization. */
1578 sfej = (ScanFinalizerEntriesJob*)sgen_thread_pool_job_alloc ("scan finalizer entries", job_scan_finalizer_entries, sizeof (ScanFinalizerEntriesJob));
1579 sfej->scan_job.ops = ops;
1580 sfej->scan_job.gc_thread_gray_queue = gc_thread_gray_queue;
1581 sfej->queue = &fin_ready_queue;
1582 sgen_workers_enqueue_job (&sfej->scan_job.job, enqueue);
1584 sfej = (ScanFinalizerEntriesJob*)sgen_thread_pool_job_alloc ("scan critical finalizer entries", job_scan_finalizer_entries, sizeof (ScanFinalizerEntriesJob));
1585 sfej->scan_job.ops = ops;
1586 sfej->scan_job.gc_thread_gray_queue = gc_thread_gray_queue;
1587 sfej->queue = &critical_fin_queue;
1588 sgen_workers_enqueue_job (&sfej->scan_job.job, enqueue);
1592 * Perform a nursery collection.
1594 * Return whether any objects were late-pinned due to being out of memory.
1597 collect_nursery (const char *reason, gboolean is_overflow, SgenGrayQueue *unpin_queue)
1599 gboolean needs_major, is_parallel = FALSE;
1600 mword fragment_total;
1601 SgenGrayQueue gc_thread_gray_queue;
1602 SgenObjectOperations *object_ops_nopar, *object_ops_par = NULL;
1603 ScanCopyContext ctx;
1606 SGEN_TV_DECLARE (last_minor_collection_start_tv);
1607 SGEN_TV_DECLARE (last_minor_collection_end_tv);
1609 if (disable_minor_collections)
1612 TV_GETTIME (last_minor_collection_start_tv);
1613 atv = last_minor_collection_start_tv;
1615 binary_protocol_collection_begin (gc_stats.minor_gc_count, GENERATION_NURSERY);
1617 if (sgen_concurrent_collection_in_progress ()) {
1618 /* FIXME Support parallel nursery collections with concurrent major */
1619 object_ops_nopar = &sgen_minor_collector.serial_ops_with_concurrent_major;
1621 object_ops_nopar = &sgen_minor_collector.serial_ops;
1622 if (sgen_minor_collector.is_parallel) {
1623 object_ops_par = &sgen_minor_collector.parallel_ops;
1628 if (do_verify_nursery || do_dump_nursery_content)
1629 sgen_debug_verify_nursery (do_dump_nursery_content);
1631 current_collection_generation = GENERATION_NURSERY;
1633 SGEN_ASSERT (0, !sgen_collection_is_concurrent (), "Why is the nursery collection concurrent?");
1635 reset_pinned_from_failed_allocation ();
1637 check_scan_starts ();
1639 sgen_nursery_alloc_prepare_for_minor ();
1644 SGEN_LOG (1, "Start nursery collection %d %p-%p, size: %d", gc_stats.minor_gc_count, nursery_section->data, nursery_section->end_data, (int)(nursery_section->end_data - nursery_section->data));
1646 /* world must be stopped already */
1648 time_minor_pre_collection_fragment_clear += TV_ELAPSED (atv, btv);
1650 sgen_client_pre_collection_checks ();
1652 major_collector.start_nursery_collection ();
1654 sgen_memgov_minor_collection_start ();
1656 init_gray_queue (&gc_thread_gray_queue, is_parallel);
1657 ctx = CONTEXT_FROM_OBJECT_OPERATIONS (object_ops_nopar, &gc_thread_gray_queue);
1659 gc_stats.minor_gc_count ++;
1661 sgen_process_fin_stage_entries ();
1663 /* pin from pinned handles */
1664 sgen_init_pinning ();
1665 sgen_client_binary_protocol_mark_start (GENERATION_NURSERY);
1666 pin_from_roots (nursery_section->data, nursery_section->end_data, ctx);
1667 /* pin cemented objects */
1668 sgen_pin_cemented_objects ();
1669 /* identify pinned objects */
1670 sgen_optimize_pin_queue ();
1671 sgen_pinning_setup_section (nursery_section);
1673 pin_objects_in_nursery (FALSE, ctx);
1674 sgen_pinning_trim_queue_to_section (nursery_section);
1676 if (remset_consistency_checks)
1677 sgen_check_remset_consistency ();
1679 if (whole_heap_check_before_collection) {
1680 sgen_clear_nursery_fragments ();
1681 sgen_check_whole_heap (FALSE);
1685 time_minor_pinning += TV_ELAPSED (btv, atv);
1686 SGEN_LOG (2, "Finding pinned pointers: %zd in %lld usecs", sgen_get_pinned_count (), (long long)TV_ELAPSED (btv, atv));
1687 SGEN_LOG (4, "Start scan with %zd pinned objects", sgen_get_pinned_count ());
1689 remset.start_scan_remsets ();
1691 enqueue_scan_remembered_set_jobs (&gc_thread_gray_queue, is_parallel ? object_ops_par : object_ops_nopar, is_parallel);
1693 /* we don't have complete write barrier yet, so we scan all the old generation sections */
1695 time_minor_scan_remsets += TV_ELAPSED (atv, btv);
1696 SGEN_LOG (2, "Old generation scan: %lld usecs", (long long)TV_ELAPSED (atv, btv));
1698 sgen_pin_stats_report ();
1700 /* FIXME: Why do we do this at this specific, seemingly random, point? */
1701 sgen_client_collecting_minor (&fin_ready_queue, &critical_fin_queue);
1704 time_minor_scan_pinned += TV_ELAPSED (btv, atv);
1706 enqueue_scan_from_roots_jobs (&gc_thread_gray_queue, nursery_section->data, nursery_section->end_data, is_parallel ? object_ops_par : object_ops_nopar, is_parallel);
1709 gray_queue_redirect (&gc_thread_gray_queue);
1710 sgen_workers_start_all_workers (object_ops_nopar, object_ops_par, NULL);
1711 sgen_workers_join ();
1715 time_minor_scan_roots += TV_ELAPSED (atv, btv);
1717 finish_gray_stack (GENERATION_NURSERY, ctx);
1720 time_minor_finish_gray_stack += TV_ELAPSED (btv, atv);
1721 sgen_client_binary_protocol_mark_end (GENERATION_NURSERY);
1723 if (objects_pinned) {
1724 sgen_optimize_pin_queue ();
1725 sgen_pinning_setup_section (nursery_section);
1729 * This is the latest point at which we can do this check, because
1730 * sgen_build_nursery_fragments() unpins nursery objects again.
1732 if (remset_consistency_checks)
1733 sgen_check_remset_consistency ();
1735 /* walk the pin_queue, build up the fragment list of free memory, unmark
1736 * pinned objects as we go, memzero() the empty fragments so they are ready for the
1739 sgen_client_binary_protocol_reclaim_start (GENERATION_NURSERY);
1740 fragment_total = sgen_build_nursery_fragments (nursery_section, unpin_queue);
1741 if (!fragment_total)
1744 /* Clear TLABs for all threads */
1745 sgen_clear_tlabs ();
1747 sgen_client_binary_protocol_reclaim_end (GENERATION_NURSERY);
1749 time_minor_fragment_creation += TV_ELAPSED (atv, btv);
1750 SGEN_LOG (2, "Fragment creation: %lld usecs, %lu bytes available", (long long)TV_ELAPSED (atv, btv), (unsigned long)fragment_total);
1752 if (remset_consistency_checks)
1753 sgen_check_major_refs ();
1755 major_collector.finish_nursery_collection ();
1757 TV_GETTIME (last_minor_collection_end_tv);
1758 gc_stats.minor_gc_time += TV_ELAPSED (last_minor_collection_start_tv, last_minor_collection_end_tv);
1760 sgen_debug_dump_heap ("minor", gc_stats.minor_gc_count - 1, NULL);
1762 /* prepare the pin queue for the next collection */
1763 sgen_finish_pinning ();
1764 if (sgen_have_pending_finalizers ()) {
1765 SGEN_LOG (4, "Finalizer-thread wakeup");
1766 sgen_client_finalize_notify ();
1768 sgen_pin_stats_reset ();
1769 /* clear cemented hash */
1770 sgen_cement_clear_below_threshold ();
1772 sgen_gray_object_queue_dispose (&gc_thread_gray_queue);
1774 check_scan_starts ();
1776 binary_protocol_flush_buffers (FALSE);
1778 sgen_memgov_minor_collection_end (reason, is_overflow);
1780 /*objects are late pinned because of lack of memory, so a major is a good call*/
1781 needs_major = objects_pinned > 0;
1782 current_collection_generation = -1;
1785 binary_protocol_collection_end (gc_stats.minor_gc_count - 1, GENERATION_NURSERY, 0, 0);
1787 if (check_nursery_objects_pinned && !sgen_minor_collector.is_split)
1788 sgen_check_nursery_objects_pinned (unpin_queue != NULL);
1794 COPY_OR_MARK_FROM_ROOTS_SERIAL,
1795 COPY_OR_MARK_FROM_ROOTS_START_CONCURRENT,
1796 COPY_OR_MARK_FROM_ROOTS_FINISH_CONCURRENT
1797 } CopyOrMarkFromRootsMode;
1800 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)
1805 /* FIXME: only use these values for the precise scan
1806 * note that to_space pointers should be excluded anyway...
1808 char *heap_start = NULL;
1809 char *heap_end = (char*)-1;
1810 ScanCopyContext ctx = CONTEXT_FROM_OBJECT_OPERATIONS (object_ops_nopar, gc_thread_gray_queue);
1811 gboolean concurrent = mode != COPY_OR_MARK_FROM_ROOTS_SERIAL;
1813 SGEN_ASSERT (0, !!concurrent == !!concurrent_collection_in_progress, "We've been called with the wrong mode.");
1815 if (mode == COPY_OR_MARK_FROM_ROOTS_START_CONCURRENT) {
1816 /*This cleans up unused fragments */
1817 sgen_nursery_allocator_prepare_for_pinning ();
1819 if (do_concurrent_checks)
1820 sgen_debug_check_nursery_is_clean ();
1822 /* The concurrent collector doesn't touch the nursery. */
1823 sgen_nursery_alloc_prepare_for_major ();
1828 /* Pinning depends on this */
1829 sgen_clear_nursery_fragments ();
1831 if (whole_heap_check_before_collection)
1832 sgen_check_whole_heap (TRUE);
1835 time_major_pre_collection_fragment_clear += TV_ELAPSED (atv, btv);
1839 sgen_client_pre_collection_checks ();
1841 if (mode != COPY_OR_MARK_FROM_ROOTS_START_CONCURRENT) {
1842 /* Remsets are not useful for a major collection */
1843 remset.clear_cards ();
1846 sgen_process_fin_stage_entries ();
1849 sgen_init_pinning ();
1850 SGEN_LOG (6, "Collecting pinned addresses");
1851 pin_from_roots ((void*)lowest_heap_address, (void*)highest_heap_address, ctx);
1852 if (mode == COPY_OR_MARK_FROM_ROOTS_FINISH_CONCURRENT) {
1853 /* Pin cemented objects that were forced */
1854 sgen_pin_cemented_objects ();
1856 sgen_optimize_pin_queue ();
1857 if (mode == COPY_OR_MARK_FROM_ROOTS_START_CONCURRENT) {
1859 * Cemented objects that are in the pinned list will be marked. When
1860 * marking concurrently we won't mark mod-union cards for these objects.
1861 * Instead they will remain cemented until the next major collection,
1862 * when we will recheck if they are still pinned in the roots.
1864 sgen_cement_force_pinned ();
1867 sgen_client_collecting_major_1 ();
1870 * pin_queue now contains all candidate pointers, sorted and
1871 * uniqued. We must do two passes now to figure out which
1872 * objects are pinned.
1874 * The first is to find within the pin_queue the area for each
1875 * section. This requires that the pin_queue be sorted. We
1876 * also process the LOS objects and pinned chunks here.
1878 * The second, destructive, pass is to reduce the section
1879 * areas to pointers to the actually pinned objects.
1881 SGEN_LOG (6, "Pinning from sections");
1882 /* first pass for the sections */
1883 sgen_find_section_pin_queue_start_end (nursery_section);
1884 /* identify possible pointers to the insize of large objects */
1885 SGEN_LOG (6, "Pinning from large objects");
1886 for (bigobj = los_object_list; bigobj; bigobj = bigobj->next) {
1888 if (sgen_find_optimized_pin_queue_area ((char*)bigobj->data, (char*)bigobj->data + sgen_los_object_size (bigobj), &dummy, &dummy)) {
1889 binary_protocol_pin (bigobj->data, (gpointer)LOAD_VTABLE (bigobj->data), safe_object_get_size (bigobj->data));
1891 if (sgen_los_object_is_pinned (bigobj->data)) {
1892 SGEN_ASSERT (0, mode == COPY_OR_MARK_FROM_ROOTS_FINISH_CONCURRENT, "LOS objects can only be pinned here after concurrent marking.");
1895 sgen_los_pin_object (bigobj->data);
1896 if (SGEN_OBJECT_HAS_REFERENCES (bigobj->data))
1897 GRAY_OBJECT_ENQUEUE_SERIAL (gc_thread_gray_queue, bigobj->data, sgen_obj_get_descriptor ((GCObject*)bigobj->data));
1898 sgen_pin_stats_register_object (bigobj->data, GENERATION_OLD);
1899 SGEN_LOG (6, "Marked large object %p (%s) size: %lu from roots", bigobj->data,
1900 sgen_client_vtable_get_name (SGEN_LOAD_VTABLE (bigobj->data)),
1901 (unsigned long)sgen_los_object_size (bigobj));
1903 sgen_client_pinned_los_object (bigobj->data);
1907 pin_objects_in_nursery (mode == COPY_OR_MARK_FROM_ROOTS_START_CONCURRENT, ctx);
1908 if (check_nursery_objects_pinned && !sgen_minor_collector.is_split)
1909 sgen_check_nursery_objects_pinned (mode != COPY_OR_MARK_FROM_ROOTS_START_CONCURRENT);
1911 major_collector.pin_objects (gc_thread_gray_queue);
1912 if (old_next_pin_slot)
1913 *old_next_pin_slot = sgen_get_pinned_count ();
1916 time_major_pinning += TV_ELAPSED (atv, btv);
1917 SGEN_LOG (2, "Finding pinned pointers: %zd in %lld usecs", sgen_get_pinned_count (), (long long)TV_ELAPSED (atv, btv));
1918 SGEN_LOG (4, "Start scan with %zd pinned objects", sgen_get_pinned_count ());
1920 major_collector.init_to_space ();
1922 SGEN_ASSERT (0, sgen_workers_all_done (), "Why are the workers not done when we start or finish a major collection?");
1923 if (mode == COPY_OR_MARK_FROM_ROOTS_FINISH_CONCURRENT) {
1924 if (object_ops_par != NULL)
1925 sgen_workers_set_num_active_workers (0);
1926 if (sgen_workers_have_idle_work ()) {
1928 * We force the finish of the worker with the new object ops context
1929 * which can also do copying. We need to have finished pinning.
1931 sgen_workers_start_all_workers (object_ops_nopar, object_ops_par, NULL);
1933 sgen_workers_join ();
1937 #ifdef SGEN_DEBUG_INTERNAL_ALLOC
1938 main_gc_thread = mono_native_thread_self ();
1941 sgen_client_collecting_major_2 ();
1944 time_major_scan_pinned += TV_ELAPSED (btv, atv);
1946 sgen_client_collecting_major_3 (&fin_ready_queue, &critical_fin_queue);
1948 enqueue_scan_from_roots_jobs (gc_thread_gray_queue, heap_start, heap_end, object_ops_nopar, FALSE);
1951 time_major_scan_roots += TV_ELAPSED (atv, btv);
1954 * We start the concurrent worker after pinning and after we scanned the roots
1955 * in order to make sure that the worker does not finish before handling all
1958 if (mode == COPY_OR_MARK_FROM_ROOTS_START_CONCURRENT) {
1959 sgen_workers_set_num_active_workers (1);
1960 gray_queue_redirect (gc_thread_gray_queue);
1961 if (precleaning_enabled) {
1962 sgen_workers_start_all_workers (object_ops_nopar, object_ops_par, workers_finish_callback);
1964 sgen_workers_start_all_workers (object_ops_nopar, object_ops_par, NULL);
1968 if (mode == COPY_OR_MARK_FROM_ROOTS_FINISH_CONCURRENT) {
1969 int i, split_count = sgen_workers_get_job_split_count ();
1970 gboolean parallel = object_ops_par != NULL;
1972 /* If we're not parallel we finish the collection on the gc thread */
1974 gray_queue_redirect (gc_thread_gray_queue);
1976 /* Mod union card table */
1977 for (i = 0; i < split_count; i++) {
1978 ParallelScanJob *psj;
1980 psj = (ParallelScanJob*)sgen_thread_pool_job_alloc ("scan mod union cardtable", job_scan_major_mod_union_card_table, sizeof (ParallelScanJob));
1981 psj->scan_job.ops = object_ops_par ? object_ops_par : object_ops_nopar;
1982 psj->scan_job.gc_thread_gray_queue = gc_thread_gray_queue;
1984 sgen_workers_enqueue_job (&psj->scan_job.job, parallel);
1986 psj = (ParallelScanJob*)sgen_thread_pool_job_alloc ("scan LOS mod union cardtable", job_scan_los_mod_union_card_table, sizeof (ParallelScanJob));
1987 psj->scan_job.ops = object_ops_par ? object_ops_par : object_ops_nopar;
1988 psj->scan_job.gc_thread_gray_queue = gc_thread_gray_queue;
1990 sgen_workers_enqueue_job (&psj->scan_job.job, parallel);
1995 * If we enqueue a job while workers are running we need to sgen_workers_ensure_awake
1996 * in order to make sure that we are running the idle func and draining all worker
1997 * gray queues. The operation of starting workers implies this, so we start them after
1998 * in order to avoid doing this operation twice. The workers will drain the main gray
1999 * stack that contained roots and pinned objects and also scan the mod union card
2002 sgen_workers_start_all_workers (object_ops_nopar, object_ops_par, NULL);
2003 sgen_workers_join ();
2007 sgen_pin_stats_report ();
2009 if (mode == COPY_OR_MARK_FROM_ROOTS_START_CONCURRENT) {
2010 sgen_finish_pinning ();
2012 sgen_pin_stats_reset ();
2014 if (do_concurrent_checks)
2015 sgen_debug_check_nursery_is_clean ();
2020 major_start_collection (SgenGrayQueue *gc_thread_gray_queue, const char *reason, gboolean concurrent, size_t *old_next_pin_slot)
2022 SgenObjectOperations *object_ops_nopar, *object_ops_par = NULL;
2024 binary_protocol_collection_begin (gc_stats.major_gc_count, GENERATION_OLD);
2026 current_collection_generation = GENERATION_OLD;
2028 sgen_workers_assert_gray_queue_is_empty ();
2031 sgen_cement_reset ();
2034 g_assert (major_collector.is_concurrent);
2035 concurrent_collection_in_progress = TRUE;
2037 object_ops_nopar = &major_collector.major_ops_concurrent_start;
2038 if (major_collector.is_parallel)
2039 object_ops_par = &major_collector.major_ops_conc_par_start;
2042 object_ops_nopar = &major_collector.major_ops_serial;
2045 reset_pinned_from_failed_allocation ();
2047 sgen_memgov_major_collection_start (concurrent, reason);
2049 //count_ref_nonref_objs ();
2050 //consistency_check ();
2052 check_scan_starts ();
2055 SGEN_LOG (1, "Start major collection %d", gc_stats.major_gc_count);
2056 gc_stats.major_gc_count ++;
2058 if (major_collector.start_major_collection)
2059 major_collector.start_major_collection ();
2061 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);
2065 major_finish_collection (SgenGrayQueue *gc_thread_gray_queue, const char *reason, gboolean is_overflow, size_t old_next_pin_slot, gboolean forced)
2067 ScannedObjectCounts counts;
2068 SgenObjectOperations *object_ops_nopar;
2069 mword fragment_total;
2075 if (concurrent_collection_in_progress) {
2076 SgenObjectOperations *object_ops_par = NULL;
2078 object_ops_nopar = &major_collector.major_ops_concurrent_finish;
2079 if (major_collector.is_parallel)
2080 object_ops_par = &major_collector.major_ops_conc_par_finish;
2082 major_copy_or_mark_from_roots (gc_thread_gray_queue, NULL, COPY_OR_MARK_FROM_ROOTS_FINISH_CONCURRENT, object_ops_nopar, object_ops_par);
2084 #ifdef SGEN_DEBUG_INTERNAL_ALLOC
2085 main_gc_thread = NULL;
2088 object_ops_nopar = &major_collector.major_ops_serial;
2091 sgen_workers_assert_gray_queue_is_empty ();
2093 finish_gray_stack (GENERATION_OLD, CONTEXT_FROM_OBJECT_OPERATIONS (object_ops_nopar, gc_thread_gray_queue));
2095 time_major_finish_gray_stack += TV_ELAPSED (btv, atv);
2097 SGEN_ASSERT (0, sgen_workers_all_done (), "Can't have workers working after joining");
2099 if (objects_pinned) {
2100 g_assert (!concurrent_collection_in_progress);
2103 * This is slow, but we just OOM'd.
2105 * See comment at `sgen_pin_queue_clear_discarded_entries` for how the pin
2106 * queue is laid out at this point.
2108 sgen_pin_queue_clear_discarded_entries (nursery_section, old_next_pin_slot);
2110 * We need to reestablish all pinned nursery objects in the pin queue
2111 * because they're needed for fragment creation. Unpinning happens by
2112 * walking the whole queue, so it's not necessary to reestablish where major
2113 * heap block pins are - all we care is that they're still in there
2116 sgen_optimize_pin_queue ();
2117 sgen_find_section_pin_queue_start_end (nursery_section);
2121 reset_heap_boundaries ();
2122 sgen_update_heap_boundaries ((mword)sgen_get_nursery_start (), (mword)sgen_get_nursery_end ());
2124 /* walk the pin_queue, build up the fragment list of free memory, unmark
2125 * pinned objects as we go, memzero() the empty fragments so they are ready for the
2128 fragment_total = sgen_build_nursery_fragments (nursery_section, NULL);
2129 if (!fragment_total)
2131 SGEN_LOG (4, "Free space in nursery after major %ld", (long)fragment_total);
2133 if (do_concurrent_checks && concurrent_collection_in_progress)
2134 sgen_debug_check_nursery_is_clean ();
2136 /* prepare the pin queue for the next collection */
2137 sgen_finish_pinning ();
2139 /* Clear TLABs for all threads */
2140 sgen_clear_tlabs ();
2142 sgen_pin_stats_reset ();
2144 sgen_cement_clear_below_threshold ();
2146 if (check_mark_bits_after_major_collection)
2147 sgen_check_heap_marked (concurrent_collection_in_progress);
2150 time_major_fragment_creation += TV_ELAPSED (atv, btv);
2152 binary_protocol_sweep_begin (GENERATION_OLD, !major_collector.sweeps_lazily);
2153 sgen_memgov_major_pre_sweep ();
2156 time_major_free_bigobjs += TV_ELAPSED (btv, atv);
2161 time_major_los_sweep += TV_ELAPSED (atv, btv);
2163 major_collector.sweep ();
2165 binary_protocol_sweep_end (GENERATION_OLD, !major_collector.sweeps_lazily);
2168 time_major_sweep += TV_ELAPSED (btv, atv);
2170 sgen_debug_dump_heap ("major", gc_stats.major_gc_count - 1, reason);
2172 if (sgen_have_pending_finalizers ()) {
2173 SGEN_LOG (4, "Finalizer-thread wakeup");
2174 sgen_client_finalize_notify ();
2177 sgen_memgov_major_collection_end (forced, concurrent_collection_in_progress, reason, is_overflow);
2178 current_collection_generation = -1;
2180 memset (&counts, 0, sizeof (ScannedObjectCounts));
2181 major_collector.finish_major_collection (&counts);
2183 sgen_workers_assert_gray_queue_is_empty ();
2185 SGEN_ASSERT (0, sgen_workers_all_done (), "Can't have workers working after major collection has finished");
2186 if (concurrent_collection_in_progress)
2187 concurrent_collection_in_progress = FALSE;
2189 check_scan_starts ();
2191 binary_protocol_flush_buffers (FALSE);
2193 //consistency_check ();
2195 binary_protocol_collection_end (gc_stats.major_gc_count - 1, GENERATION_OLD, counts.num_scanned_objects, counts.num_unique_scanned_objects);
2199 major_do_collection (const char *reason, gboolean is_overflow, gboolean forced)
2201 TV_DECLARE (time_start);
2202 TV_DECLARE (time_end);
2203 size_t old_next_pin_slot;
2204 SgenGrayQueue gc_thread_gray_queue;
2206 if (disable_major_collections)
2209 if (major_collector.get_and_reset_num_major_objects_marked) {
2210 long long num_marked = major_collector.get_and_reset_num_major_objects_marked ();
2211 g_assert (!num_marked);
2214 /* world must be stopped already */
2215 TV_GETTIME (time_start);
2217 init_gray_queue (&gc_thread_gray_queue, FALSE);
2218 major_start_collection (&gc_thread_gray_queue, reason, FALSE, &old_next_pin_slot);
2219 major_finish_collection (&gc_thread_gray_queue, reason, is_overflow, old_next_pin_slot, forced);
2220 sgen_gray_object_queue_dispose (&gc_thread_gray_queue);
2222 TV_GETTIME (time_end);
2223 gc_stats.major_gc_time += TV_ELAPSED (time_start, time_end);
2225 /* FIXME: also report this to the user, preferably in gc-end. */
2226 if (major_collector.get_and_reset_num_major_objects_marked)
2227 major_collector.get_and_reset_num_major_objects_marked ();
2229 return bytes_pinned_from_failed_allocation > 0;
2233 major_start_concurrent_collection (const char *reason)
2235 TV_DECLARE (time_start);
2236 TV_DECLARE (time_end);
2237 long long num_objects_marked;
2238 SgenGrayQueue gc_thread_gray_queue;
2240 if (disable_major_collections)
2243 TV_GETTIME (time_start);
2244 SGEN_TV_GETTIME (time_major_conc_collection_start);
2246 num_objects_marked = major_collector.get_and_reset_num_major_objects_marked ();
2247 g_assert (num_objects_marked == 0);
2249 binary_protocol_concurrent_start ();
2251 init_gray_queue (&gc_thread_gray_queue, TRUE);
2252 // FIXME: store reason and pass it when finishing
2253 major_start_collection (&gc_thread_gray_queue, reason, TRUE, NULL);
2254 sgen_gray_object_queue_dispose (&gc_thread_gray_queue);
2256 num_objects_marked = major_collector.get_and_reset_num_major_objects_marked ();
2258 TV_GETTIME (time_end);
2259 gc_stats.major_gc_time += TV_ELAPSED (time_start, time_end);
2261 current_collection_generation = -1;
2265 * Returns whether the major collection has finished.
2268 major_should_finish_concurrent_collection (void)
2270 return sgen_workers_all_done ();
2274 major_update_concurrent_collection (void)
2276 TV_DECLARE (total_start);
2277 TV_DECLARE (total_end);
2279 TV_GETTIME (total_start);
2281 binary_protocol_concurrent_update ();
2283 major_collector.update_cardtable_mod_union ();
2284 sgen_los_update_cardtable_mod_union ();
2286 TV_GETTIME (total_end);
2287 gc_stats.major_gc_time += TV_ELAPSED (total_start, total_end);
2291 major_finish_concurrent_collection (gboolean forced)
2293 SgenGrayQueue gc_thread_gray_queue;
2294 TV_DECLARE (total_start);
2295 TV_DECLARE (total_end);
2297 TV_GETTIME (total_start);
2299 binary_protocol_concurrent_finish ();
2302 * We need to stop all workers since we're updating the cardtable below.
2303 * The workers will be resumed with a finishing pause context to avoid
2304 * additional cardtable and object scanning.
2306 sgen_workers_stop_all_workers ();
2308 SGEN_TV_GETTIME (time_major_conc_collection_end);
2309 gc_stats.major_gc_time_concurrent += SGEN_TV_ELAPSED (time_major_conc_collection_start, time_major_conc_collection_end);
2311 major_collector.update_cardtable_mod_union ();
2312 sgen_los_update_cardtable_mod_union ();
2314 if (mod_union_consistency_check)
2315 sgen_check_mod_union_consistency ();
2317 current_collection_generation = GENERATION_OLD;
2318 sgen_cement_reset ();
2319 init_gray_queue (&gc_thread_gray_queue, FALSE);
2320 major_finish_collection (&gc_thread_gray_queue, "finishing", FALSE, -1, forced);
2321 sgen_gray_object_queue_dispose (&gc_thread_gray_queue);
2323 TV_GETTIME (total_end);
2324 gc_stats.major_gc_time += TV_ELAPSED (total_start, total_end);
2326 current_collection_generation = -1;
2330 * Ensure an allocation request for @size will succeed by freeing enough memory.
2332 * LOCKING: The GC lock MUST be held.
2335 sgen_ensure_free_space (size_t size, int generation)
2337 int generation_to_collect = -1;
2338 const char *reason = NULL;
2340 if (generation == GENERATION_OLD) {
2341 if (sgen_need_major_collection (size)) {
2342 reason = "LOS overflow";
2343 generation_to_collect = GENERATION_OLD;
2346 if (degraded_mode) {
2347 if (sgen_need_major_collection (size)) {
2348 reason = "Degraded mode overflow";
2349 generation_to_collect = GENERATION_OLD;
2351 } else if (sgen_need_major_collection (size)) {
2352 reason = concurrent_collection_in_progress ? "Forced finish concurrent collection" : "Minor allowance";
2353 generation_to_collect = GENERATION_OLD;
2355 generation_to_collect = GENERATION_NURSERY;
2356 reason = "Nursery full";
2360 if (generation_to_collect == -1) {
2361 if (concurrent_collection_in_progress && sgen_workers_all_done ()) {
2362 generation_to_collect = GENERATION_OLD;
2363 reason = "Finish concurrent collection";
2367 if (generation_to_collect == -1)
2369 sgen_perform_collection (size, generation_to_collect, reason, FALSE, TRUE);
2373 * LOCKING: Assumes the GC lock is held.
2376 sgen_perform_collection (size_t requested_size, int generation_to_collect, const char *reason, gboolean wait_to_finish, gboolean stw)
2378 TV_DECLARE (gc_total_start);
2379 TV_DECLARE (gc_total_end);
2380 int overflow_generation_to_collect = -1;
2381 int oldest_generation_collected = generation_to_collect;
2382 const char *overflow_reason = NULL;
2383 gboolean finish_concurrent = concurrent_collection_in_progress && (major_should_finish_concurrent_collection () || generation_to_collect == GENERATION_OLD);
2385 binary_protocol_collection_requested (generation_to_collect, requested_size, wait_to_finish ? 1 : 0);
2387 SGEN_ASSERT (0, generation_to_collect == GENERATION_NURSERY || generation_to_collect == GENERATION_OLD, "What generation is this?");
2390 sgen_stop_world (generation_to_collect);
2392 SGEN_ASSERT (0, sgen_is_world_stopped (), "We can only collect if the world is stopped");
2395 TV_GETTIME (gc_total_start);
2397 // FIXME: extract overflow reason
2398 // FIXME: minor overflow for concurrent case
2399 if (generation_to_collect == GENERATION_NURSERY && !finish_concurrent) {
2400 if (concurrent_collection_in_progress)
2401 major_update_concurrent_collection ();
2403 if (collect_nursery (reason, FALSE, NULL) && !concurrent_collection_in_progress) {
2404 overflow_generation_to_collect = GENERATION_OLD;
2405 overflow_reason = "Minor overflow";
2407 } else if (finish_concurrent) {
2408 major_finish_concurrent_collection (wait_to_finish);
2409 oldest_generation_collected = GENERATION_OLD;
2411 SGEN_ASSERT (0, generation_to_collect == GENERATION_OLD, "We should have handled nursery collections above");
2412 if (major_collector.is_concurrent && !wait_to_finish) {
2413 collect_nursery ("Concurrent start", FALSE, NULL);
2414 major_start_concurrent_collection (reason);
2415 oldest_generation_collected = GENERATION_NURSERY;
2416 } else if (major_do_collection (reason, FALSE, wait_to_finish)) {
2417 overflow_generation_to_collect = GENERATION_NURSERY;
2418 overflow_reason = "Excessive pinning";
2422 if (overflow_generation_to_collect != -1) {
2423 SGEN_ASSERT (0, !concurrent_collection_in_progress, "We don't yet support overflow collections with the concurrent collector");
2426 * We need to do an overflow collection, either because we ran out of memory
2427 * or the nursery is fully pinned.
2430 if (overflow_generation_to_collect == GENERATION_NURSERY)
2431 collect_nursery (overflow_reason, TRUE, NULL);
2433 major_do_collection (overflow_reason, TRUE, wait_to_finish);
2435 oldest_generation_collected = MAX (oldest_generation_collected, overflow_generation_to_collect);
2438 SGEN_LOG (2, "Heap size: %lu, LOS size: %lu", (unsigned long)sgen_gc_get_total_heap_allocation (), (unsigned long)los_memory_usage);
2440 /* this also sets the proper pointers for the next allocation */
2441 if (generation_to_collect == GENERATION_NURSERY && !sgen_can_alloc_size (requested_size)) {
2442 /* TypeBuilder and MonoMethod are killing mcs with fragmentation */
2443 SGEN_LOG (1, "nursery collection didn't find enough room for %zd alloc (%zd pinned)", requested_size, sgen_get_pinned_count ());
2444 sgen_dump_pin_queue ();
2448 TV_GETTIME (gc_total_end);
2449 time_max = MAX (time_max, TV_ELAPSED (gc_total_start, gc_total_end));
2452 sgen_restart_world (oldest_generation_collected);
2456 * ######################################################################
2457 * ######## Memory allocation from the OS
2458 * ######################################################################
2459 * This section of code deals with getting memory from the OS and
2460 * allocating memory for GC-internal data structures.
2461 * Internal memory can be handled with a freelist for small objects.
2467 G_GNUC_UNUSED static void
2468 report_internal_mem_usage (void)
2470 printf ("Internal memory usage:\n");
2471 sgen_report_internal_mem_usage ();
2472 printf ("Pinned memory usage:\n");
2473 major_collector.report_pinned_memory_usage ();
2477 * ######################################################################
2478 * ######## Finalization support
2479 * ######################################################################
2483 * If the object has been forwarded it means it's still referenced from a root.
2484 * If it is pinned it's still alive as well.
2485 * A LOS object is only alive if we have pinned it.
2486 * Return TRUE if @obj is ready to be finalized.
2488 static inline gboolean
2489 sgen_is_object_alive (GCObject *object)
2491 if (ptr_in_nursery (object))
2492 return sgen_nursery_is_object_alive (object);
2494 return sgen_major_is_object_alive (object);
2498 * This function returns true if @object is either alive and belongs to the
2499 * current collection - major collections are full heap, so old gen objects
2500 * are never alive during a minor collection.
2503 sgen_is_object_alive_and_on_current_collection (GCObject *object)
2505 if (ptr_in_nursery (object))
2506 return sgen_nursery_is_object_alive (object);
2508 if (current_collection_generation == GENERATION_NURSERY)
2511 return sgen_major_is_object_alive (object);
2516 sgen_gc_is_object_ready_for_finalization (GCObject *object)
2518 return !sgen_is_object_alive (object);
2522 sgen_queue_finalization_entry (GCObject *obj)
2524 gboolean critical = sgen_client_object_has_critical_finalizer (obj);
2526 sgen_pointer_queue_add (critical ? &critical_fin_queue : &fin_ready_queue, obj);
2528 sgen_client_object_queued_for_finalization (obj);
2532 sgen_object_is_live (GCObject *obj)
2534 return sgen_is_object_alive_and_on_current_collection (obj);
2538 * `System.GC.WaitForPendingFinalizers` first checks `sgen_have_pending_finalizers()` to
2539 * determine whether it can exit quickly. The latter must therefore only return FALSE if
2540 * all finalizers have really finished running.
2542 * `sgen_gc_invoke_finalizers()` first dequeues a finalizable object, and then finalizes it.
2543 * This means that just checking whether the queues are empty leaves the possibility that an
2544 * object might have been dequeued but not yet finalized. That's why we need the additional
2545 * flag `pending_unqueued_finalizer`.
2548 static volatile gboolean pending_unqueued_finalizer = FALSE;
2549 volatile gboolean sgen_suspend_finalizers = FALSE;
2552 sgen_set_suspend_finalizers (void)
2554 sgen_suspend_finalizers = TRUE;
2558 sgen_gc_invoke_finalizers (void)
2562 g_assert (!pending_unqueued_finalizer);
2564 /* FIXME: batch to reduce lock contention */
2565 while (sgen_have_pending_finalizers ()) {
2571 * We need to set `pending_unqueued_finalizer` before dequeing the
2572 * finalizable object.
2574 if (!sgen_pointer_queue_is_empty (&fin_ready_queue)) {
2575 pending_unqueued_finalizer = TRUE;
2576 mono_memory_write_barrier ();
2577 obj = (GCObject *)sgen_pointer_queue_pop (&fin_ready_queue);
2578 } else if (!sgen_pointer_queue_is_empty (&critical_fin_queue)) {
2579 pending_unqueued_finalizer = TRUE;
2580 mono_memory_write_barrier ();
2581 obj = (GCObject *)sgen_pointer_queue_pop (&critical_fin_queue);
2587 SGEN_LOG (7, "Finalizing object %p (%s)", obj, sgen_client_vtable_get_name (SGEN_LOAD_VTABLE (obj)));
2595 /* the object is on the stack so it is pinned */
2596 /*g_print ("Calling finalizer for object: %p (%s)\n", obj, sgen_client_object_safe_name (obj));*/
2597 sgen_client_run_finalize (obj);
2600 if (pending_unqueued_finalizer) {
2601 mono_memory_write_barrier ();
2602 pending_unqueued_finalizer = FALSE;
2609 sgen_have_pending_finalizers (void)
2611 if (sgen_suspend_finalizers)
2613 return pending_unqueued_finalizer || !sgen_pointer_queue_is_empty (&fin_ready_queue) || !sgen_pointer_queue_is_empty (&critical_fin_queue);
2617 * ######################################################################
2618 * ######## registered roots support
2619 * ######################################################################
2623 * We do not coalesce roots.
2626 sgen_register_root (char *start, size_t size, SgenDescriptor descr, int root_type, int source, const char *msg)
2628 RootRecord new_root;
2631 for (i = 0; i < ROOT_TYPE_NUM; ++i) {
2632 RootRecord *root = (RootRecord *)sgen_hash_table_lookup (&roots_hash [i], start);
2633 /* we allow changing the size and the descriptor (for thread statics etc) */
2635 size_t old_size = root->end_root - start;
2636 root->end_root = start + size;
2637 SGEN_ASSERT (0, !!root->root_desc == !!descr, "Can't change whether a root is precise or conservative.");
2638 SGEN_ASSERT (0, root->source == source, "Can't change a root's source identifier.");
2639 SGEN_ASSERT (0, !!root->msg == !!msg, "Can't change a root's message.");
2640 root->root_desc = descr;
2642 roots_size -= old_size;
2648 new_root.end_root = start + size;
2649 new_root.root_desc = descr;
2650 new_root.source = source;
2653 sgen_hash_table_replace (&roots_hash [root_type], start, &new_root, NULL);
2656 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);
2663 sgen_deregister_root (char* addr)
2669 for (root_type = 0; root_type < ROOT_TYPE_NUM; ++root_type) {
2670 if (sgen_hash_table_remove (&roots_hash [root_type], addr, &root))
2671 roots_size -= (root.end_root - addr);
2677 sgen_wbroots_iterate_live_block_ranges (sgen_cardtable_block_callback cb)
2681 SGEN_HASH_TABLE_FOREACH (&roots_hash [ROOT_TYPE_WBARRIER], void **, start_root, RootRecord *, root) {
2682 cb ((mword)start_root, (mword)root->end_root - (mword)start_root);
2683 } SGEN_HASH_TABLE_FOREACH_END;
2686 /* Root equivalent of sgen_client_cardtable_scan_object */
2688 sgen_wbroot_scan_card_table (void** start_root, mword size, ScanCopyContext ctx)
2690 ScanPtrFieldFunc scan_field_func = ctx.ops->scan_ptr_field;
2691 guint8 *card_data = sgen_card_table_get_card_scan_address ((mword)start_root);
2692 guint8 *card_base = card_data;
2693 mword card_count = sgen_card_table_number_of_cards_in_range ((mword)start_root, size);
2694 guint8 *card_data_end = card_data + card_count;
2695 mword extra_idx = 0;
2696 char *obj_start = sgen_card_table_align_pointer (start_root);
2697 char *obj_end = (char*)start_root + size;
2698 #ifdef SGEN_HAVE_OVERLAPPING_CARDS
2699 guint8 *overflow_scan_end = NULL;
2702 #ifdef SGEN_HAVE_OVERLAPPING_CARDS
2703 /*Check for overflow and if so, setup to scan in two steps*/
2704 if (card_data_end >= SGEN_SHADOW_CARDTABLE_END) {
2705 overflow_scan_end = sgen_shadow_cardtable + (card_data_end - SGEN_SHADOW_CARDTABLE_END);
2706 card_data_end = SGEN_SHADOW_CARDTABLE_END;
2712 card_data = sgen_find_next_card (card_data, card_data_end);
2714 for (; card_data < card_data_end; card_data = sgen_find_next_card (card_data + 1, card_data_end)) {
2715 size_t idx = (card_data - card_base) + extra_idx;
2716 char *start = (char*)(obj_start + idx * CARD_SIZE_IN_BYTES);
2717 char *card_end = start + CARD_SIZE_IN_BYTES;
2718 char *elem = start, *first_elem = start;
2721 * Don't clean first and last card on 32bit systems since they
2722 * may also be part from other roots.
2724 if (card_data != card_base && card_data != (card_data_end - 1))
2725 sgen_card_table_prepare_card_for_scanning (card_data);
2727 card_end = MIN (card_end, obj_end);
2729 if (elem < (char*)start_root)
2730 first_elem = elem = (char*)start_root;
2732 for (; elem < card_end; elem += SIZEOF_VOID_P) {
2733 if (*(GCObject**)elem)
2734 scan_field_func (NULL, (GCObject**)elem, ctx.queue);
2737 binary_protocol_card_scan (first_elem, elem - first_elem);
2740 #ifdef SGEN_HAVE_OVERLAPPING_CARDS
2741 if (overflow_scan_end) {
2742 extra_idx = card_data - card_base;
2743 card_base = card_data = sgen_shadow_cardtable;
2744 card_data_end = overflow_scan_end;
2745 overflow_scan_end = NULL;
2752 sgen_wbroots_scan_card_table (ScanCopyContext ctx)
2757 SGEN_HASH_TABLE_FOREACH (&roots_hash [ROOT_TYPE_WBARRIER], void **, start_root, RootRecord *, root) {
2758 SGEN_ASSERT (0, (root->root_desc & ROOT_DESC_TYPE_MASK) == ROOT_DESC_VECTOR, "Unsupported root type");
2760 sgen_wbroot_scan_card_table (start_root, (mword)root->end_root - (mword)start_root, ctx);
2761 } SGEN_HASH_TABLE_FOREACH_END;
2765 * ######################################################################
2766 * ######## Thread handling (stop/start code)
2767 * ######################################################################
2771 sgen_get_current_collection_generation (void)
2773 return current_collection_generation;
2777 sgen_thread_register (SgenThreadInfo* info, void *stack_bottom_fallback)
2779 info->tlab_start = info->tlab_next = info->tlab_temp_end = info->tlab_real_end = NULL;
2781 sgen_client_thread_register (info, stack_bottom_fallback);
2787 sgen_thread_unregister (SgenThreadInfo *p)
2789 sgen_client_thread_unregister (p);
2793 * ######################################################################
2794 * ######## Write barriers
2795 * ######################################################################
2799 * Note: the write barriers first do the needed GC work and then do the actual store:
2800 * this way the value is visible to the conservative GC scan after the write barrier
2801 * itself. If a GC interrupts the barrier in the middle, value will be kept alive by
2802 * the conservative scan, otherwise by the remembered set scan.
2806 * mono_gc_wbarrier_arrayref_copy:
2809 mono_gc_wbarrier_arrayref_copy (gpointer dest_ptr, gpointer src_ptr, int count)
2811 HEAVY_STAT (++stat_wbarrier_arrayref_copy);
2812 /*This check can be done without taking a lock since dest_ptr array is pinned*/
2813 if (ptr_in_nursery (dest_ptr) || count <= 0) {
2814 mono_gc_memmove_aligned (dest_ptr, src_ptr, count * sizeof (gpointer));
2818 #ifdef SGEN_HEAVY_BINARY_PROTOCOL
2819 if (binary_protocol_is_heavy_enabled ()) {
2821 for (i = 0; i < count; ++i) {
2822 gpointer dest = (gpointer*)dest_ptr + i;
2823 gpointer obj = *((gpointer*)src_ptr + i);
2825 binary_protocol_wbarrier (dest, obj, (gpointer)LOAD_VTABLE (obj));
2830 remset.wbarrier_arrayref_copy (dest_ptr, src_ptr, count);
2834 * mono_gc_wbarrier_generic_nostore:
2837 mono_gc_wbarrier_generic_nostore (gpointer ptr)
2841 HEAVY_STAT (++stat_wbarrier_generic_store);
2843 sgen_client_wbarrier_generic_nostore_check (ptr);
2845 obj = *(gpointer*)ptr;
2847 binary_protocol_wbarrier (ptr, obj, (gpointer)LOAD_VTABLE (obj));
2850 * We need to record old->old pointer locations for the
2851 * concurrent collector.
2853 if (!ptr_in_nursery (obj) && !concurrent_collection_in_progress) {
2854 SGEN_LOG (8, "Skipping remset at %p", ptr);
2858 SGEN_LOG (8, "Adding remset at %p", ptr);
2860 remset.wbarrier_generic_nostore (ptr);
2864 * mono_gc_wbarrier_generic_store:
2867 mono_gc_wbarrier_generic_store (gpointer ptr, GCObject* value)
2869 SGEN_LOG (8, "Wbarrier store at %p to %p (%s)", ptr, value, value ? sgen_client_vtable_get_name (SGEN_LOAD_VTABLE (value)) : "null");
2870 SGEN_UPDATE_REFERENCE_ALLOW_NULL (ptr, value);
2871 if (ptr_in_nursery (value) || concurrent_collection_in_progress)
2872 mono_gc_wbarrier_generic_nostore (ptr);
2873 sgen_dummy_use (value);
2877 * mono_gc_wbarrier_generic_store_atomic:
2878 * Same as \c mono_gc_wbarrier_generic_store but performs the store
2879 * as an atomic operation with release semantics.
2882 mono_gc_wbarrier_generic_store_atomic (gpointer ptr, GCObject *value)
2884 HEAVY_STAT (++stat_wbarrier_generic_store_atomic);
2886 SGEN_LOG (8, "Wbarrier atomic store at %p to %p (%s)", ptr, value, value ? sgen_client_vtable_get_name (SGEN_LOAD_VTABLE (value)) : "null");
2888 InterlockedWritePointer ((volatile gpointer *)ptr, value);
2890 if (ptr_in_nursery (value) || concurrent_collection_in_progress)
2891 mono_gc_wbarrier_generic_nostore (ptr);
2893 sgen_dummy_use (value);
2897 sgen_wbarrier_range_copy (gpointer _dest, gpointer _src, int size)
2899 remset.wbarrier_range_copy (_dest,_src, size);
2903 * ######################################################################
2904 * ######## Other mono public interface functions.
2905 * ######################################################################
2909 sgen_gc_collect (int generation)
2914 sgen_perform_collection (0, generation, "user request", TRUE, TRUE);
2919 sgen_gc_collection_count (int generation)
2921 if (generation == 0)
2922 return gc_stats.minor_gc_count;
2923 return gc_stats.major_gc_count;
2927 sgen_gc_get_used_size (void)
2931 tot = los_memory_usage;
2932 tot += nursery_section->end_data - nursery_section->data;
2933 tot += major_collector.get_used_size ();
2934 /* FIXME: account for pinned objects */
2940 sgen_env_var_error (const char *env_var, const char *fallback, const char *description_format, ...)
2944 va_start (ap, description_format);
2946 fprintf (stderr, "Warning: In environment variable `%s': ", env_var);
2947 vfprintf (stderr, description_format, ap);
2949 fprintf (stderr, " - %s", fallback);
2950 fprintf (stderr, "\n");
2956 parse_double_in_interval (const char *env_var, const char *opt_name, const char *opt, double min, double max, double *result)
2959 double val = strtod (opt, &endptr);
2960 if (endptr == opt) {
2961 sgen_env_var_error (env_var, "Using default value.", "`%s` must be a number.", opt_name);
2964 else if (val < min || val > max) {
2965 sgen_env_var_error (env_var, "Using default value.", "`%s` must be between %.2f - %.2f.", opt_name, min, max);
2977 char *major_collector_opt = NULL;
2978 char *minor_collector_opt = NULL;
2979 char *params_opts = NULL;
2980 char *debug_opts = NULL;
2981 size_t max_heap = 0;
2982 size_t soft_limit = 0;
2984 gboolean debug_print_allowance = FALSE;
2985 double allowance_ratio = 0, save_target = 0;
2986 gboolean cement_enabled = TRUE;
2989 result = InterlockedCompareExchange (&gc_initialized, -1, 0);
2992 /* already inited */
2995 /* being inited by another thread */
2996 mono_thread_info_usleep (1000);
2999 /* we will init it */
3002 g_assert_not_reached ();
3004 } while (result != 0);
3006 SGEN_TV_GETTIME (sgen_init_timestamp);
3008 #ifdef SGEN_WITHOUT_MONO
3009 mono_thread_smr_init ();
3012 mono_coop_mutex_init (&gc_mutex);
3014 gc_debug_file = stderr;
3016 mono_coop_mutex_init (&sgen_interruption_mutex);
3018 if ((env = g_getenv (MONO_GC_PARAMS_NAME)) || gc_params_options) {
3019 params_opts = g_strdup_printf ("%s,%s", gc_params_options ? gc_params_options : "", env ? env : "");
3024 opts = g_strsplit (params_opts, ",", -1);
3025 for (ptr = opts; *ptr; ++ptr) {
3027 if (g_str_has_prefix (opt, "major=")) {
3028 opt = strchr (opt, '=') + 1;
3029 major_collector_opt = g_strdup (opt);
3030 } else if (g_str_has_prefix (opt, "minor=")) {
3031 opt = strchr (opt, '=') + 1;
3032 minor_collector_opt = g_strdup (opt);
3040 sgen_init_internal_allocator ();
3041 sgen_init_nursery_allocator ();
3042 sgen_init_fin_weak_hash ();
3043 sgen_init_hash_table ();
3044 sgen_init_descriptors ();
3045 sgen_init_gray_queues ();
3046 sgen_init_allocator ();
3047 sgen_init_gchandles ();
3049 sgen_register_fixed_internal_mem_type (INTERNAL_MEM_SECTION, SGEN_SIZEOF_GC_MEM_SECTION);
3050 sgen_register_fixed_internal_mem_type (INTERNAL_MEM_GRAY_QUEUE, sizeof (GrayQueueSection));
3052 sgen_client_init ();
3054 if (!minor_collector_opt) {
3055 sgen_simple_nursery_init (&sgen_minor_collector, FALSE);
3057 if (!strcmp (minor_collector_opt, "simple")) {
3059 sgen_simple_nursery_init (&sgen_minor_collector, FALSE);
3060 } else if (!strcmp (minor_collector_opt, "simple-par")) {
3061 sgen_simple_nursery_init (&sgen_minor_collector, TRUE);
3062 } else if (!strcmp (minor_collector_opt, "split")) {
3063 sgen_split_nursery_init (&sgen_minor_collector);
3065 sgen_env_var_error (MONO_GC_PARAMS_NAME, "Using `simple` instead.", "Unknown minor collector `%s'.", minor_collector_opt);
3066 goto use_simple_nursery;
3070 if (!major_collector_opt) {
3072 DEFAULT_MAJOR_INIT (&major_collector);
3073 } else if (!strcmp (major_collector_opt, "marksweep")) {
3074 sgen_marksweep_init (&major_collector);
3075 } else if (!strcmp (major_collector_opt, "marksweep-conc")) {
3076 sgen_marksweep_conc_init (&major_collector);
3077 } else if (!strcmp (major_collector_opt, "marksweep-conc-par")) {
3078 sgen_marksweep_conc_par_init (&major_collector);
3080 sgen_env_var_error (MONO_GC_PARAMS_NAME, "Using `" DEFAULT_MAJOR_NAME "` instead.", "Unknown major collector `%s'.", major_collector_opt);
3081 goto use_default_major;
3085 gboolean usage_printed = FALSE;
3087 for (ptr = opts; *ptr; ++ptr) {
3089 if (!strcmp (opt, ""))
3091 if (g_str_has_prefix (opt, "major="))
3093 if (g_str_has_prefix (opt, "minor="))
3095 if (g_str_has_prefix (opt, "max-heap-size=")) {
3096 size_t page_size = mono_pagesize ();
3097 size_t max_heap_candidate = 0;
3098 opt = strchr (opt, '=') + 1;
3099 if (*opt && mono_gc_parse_environment_string_extract_number (opt, &max_heap_candidate)) {
3100 max_heap = (max_heap_candidate + page_size - 1) & ~(size_t)(page_size - 1);
3101 if (max_heap != max_heap_candidate)
3102 sgen_env_var_error (MONO_GC_PARAMS_NAME, "Rounding up.", "`max-heap-size` size must be a multiple of %d.", page_size);
3104 sgen_env_var_error (MONO_GC_PARAMS_NAME, NULL, "`max-heap-size` must be an integer.");
3108 if (g_str_has_prefix (opt, "soft-heap-limit=")) {
3109 opt = strchr (opt, '=') + 1;
3110 if (*opt && mono_gc_parse_environment_string_extract_number (opt, &soft_limit)) {
3111 if (soft_limit <= 0) {
3112 sgen_env_var_error (MONO_GC_PARAMS_NAME, NULL, "`soft-heap-limit` must be positive.");
3116 sgen_env_var_error (MONO_GC_PARAMS_NAME, NULL, "`soft-heap-limit` must be an integer.");
3120 if (g_str_has_prefix (opt, "nursery-size=")) {
3122 opt = strchr (opt, '=') + 1;
3123 if (*opt && mono_gc_parse_environment_string_extract_number (opt, &val)) {
3124 if ((val & (val - 1))) {
3125 sgen_env_var_error (MONO_GC_PARAMS_NAME, "Using default value.", "`nursery-size` must be a power of two.");
3129 if (val < SGEN_MAX_NURSERY_WASTE) {
3130 sgen_env_var_error (MONO_GC_PARAMS_NAME, "Using default value.",
3131 "`nursery-size` must be at least %d bytes.", SGEN_MAX_NURSERY_WASTE);
3135 sgen_nursery_size = val;
3136 sgen_nursery_bits = 0;
3137 while (ONE_P << (++ sgen_nursery_bits) != sgen_nursery_size)
3140 sgen_env_var_error (MONO_GC_PARAMS_NAME, "Using default value.", "`nursery-size` must be an integer.");
3145 if (g_str_has_prefix (opt, "save-target-ratio=")) {
3147 opt = strchr (opt, '=') + 1;
3148 if (parse_double_in_interval (MONO_GC_PARAMS_NAME, "save-target-ratio", opt,
3149 SGEN_MIN_SAVE_TARGET_RATIO, SGEN_MAX_SAVE_TARGET_RATIO, &val)) {
3154 if (g_str_has_prefix (opt, "default-allowance-ratio=")) {
3156 opt = strchr (opt, '=') + 1;
3157 if (parse_double_in_interval (MONO_GC_PARAMS_NAME, "default-allowance-ratio", opt,
3158 SGEN_MIN_ALLOWANCE_NURSERY_SIZE_RATIO, SGEN_MAX_ALLOWANCE_NURSERY_SIZE_RATIO, &val)) {
3159 allowance_ratio = val;
3164 if (!strcmp (opt, "cementing")) {
3165 cement_enabled = TRUE;
3168 if (!strcmp (opt, "no-cementing")) {
3169 cement_enabled = FALSE;
3173 if (!strcmp (opt, "precleaning")) {
3174 precleaning_enabled = TRUE;
3177 if (!strcmp (opt, "no-precleaning")) {
3178 precleaning_enabled = FALSE;
3182 if (major_collector.handle_gc_param && major_collector.handle_gc_param (opt))
3185 if (sgen_minor_collector.handle_gc_param && sgen_minor_collector.handle_gc_param (opt))
3188 if (sgen_client_handle_gc_param (opt))
3191 sgen_env_var_error (MONO_GC_PARAMS_NAME, "Ignoring.", "Unknown option `%s`.", opt);
3196 fprintf (stderr, "\n%s must be a comma-delimited list of one or more of the following:\n", MONO_GC_PARAMS_NAME);
3197 fprintf (stderr, " max-heap-size=N (where N is an integer, possibly with a k, m or a g suffix)\n");
3198 fprintf (stderr, " soft-heap-limit=n (where N is an integer, possibly with a k, m or a g suffix)\n");
3199 fprintf (stderr, " nursery-size=N (where N is an integer, possibly with a k, m or a g suffix)\n");
3200 fprintf (stderr, " major=COLLECTOR (where COLLECTOR is `marksweep', `marksweep-conc', `marksweep-par')\n");
3201 fprintf (stderr, " minor=COLLECTOR (where COLLECTOR is `simple' or `split')\n");
3202 fprintf (stderr, " wbarrier=WBARRIER (where WBARRIER is `remset' or `cardtable')\n");
3203 fprintf (stderr, " [no-]cementing\n");
3204 if (major_collector.print_gc_param_usage)
3205 major_collector.print_gc_param_usage ();
3206 if (sgen_minor_collector.print_gc_param_usage)
3207 sgen_minor_collector.print_gc_param_usage ();
3208 sgen_client_print_gc_params_usage ();
3209 fprintf (stderr, " Experimental options:\n");
3210 fprintf (stderr, " save-target-ratio=R (where R must be between %.2f - %.2f).\n", SGEN_MIN_SAVE_TARGET_RATIO, SGEN_MAX_SAVE_TARGET_RATIO);
3211 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);
3212 fprintf (stderr, "\n");
3214 usage_printed = TRUE;
3219 if (major_collector_opt)
3220 g_free (major_collector_opt);
3222 if (minor_collector_opt)
3223 g_free (minor_collector_opt);
3226 g_free (params_opts);
3230 sgen_pinning_init ();
3231 sgen_cement_init (cement_enabled);
3233 if ((env = g_getenv (MONO_GC_DEBUG_NAME)) || gc_debug_options) {
3234 debug_opts = g_strdup_printf ("%s,%s", gc_debug_options ? gc_debug_options : "", env ? env : "");
3239 gboolean usage_printed = FALSE;
3241 opts = g_strsplit (debug_opts, ",", -1);
3242 for (ptr = opts; ptr && *ptr; ptr ++) {
3244 if (!strcmp (opt, ""))
3246 if (opt [0] >= '0' && opt [0] <= '9') {
3247 gc_debug_level = atoi (opt);
3252 char *rf = g_strdup_printf ("%s.%d", opt, mono_process_current_pid ());
3253 gc_debug_file = fopen (rf, "wb");
3255 gc_debug_file = stderr;
3258 } else if (!strcmp (opt, "print-allowance")) {
3259 debug_print_allowance = TRUE;
3260 } else if (!strcmp (opt, "print-pinning")) {
3261 sgen_pin_stats_enable ();
3262 } else if (!strcmp (opt, "verify-before-allocs")) {
3263 verify_before_allocs = 1;
3264 has_per_allocation_action = TRUE;
3265 } else if (g_str_has_prefix (opt, "max-valloc-size=")) {
3266 size_t max_valloc_size;
3267 char *arg = strchr (opt, '=') + 1;
3268 if (*opt && mono_gc_parse_environment_string_extract_number (arg, &max_valloc_size)) {
3269 mono_valloc_set_limit (max_valloc_size);
3271 sgen_env_var_error (MONO_GC_DEBUG_NAME, NULL, "`max-valloc-size` must be an integer.");
3274 } else if (g_str_has_prefix (opt, "verify-before-allocs=")) {
3275 char *arg = strchr (opt, '=') + 1;
3276 verify_before_allocs = atoi (arg);
3277 has_per_allocation_action = TRUE;
3278 } else if (!strcmp (opt, "collect-before-allocs")) {
3279 collect_before_allocs = 1;
3280 has_per_allocation_action = TRUE;
3281 } else if (g_str_has_prefix (opt, "collect-before-allocs=")) {
3282 char *arg = strchr (opt, '=') + 1;
3283 has_per_allocation_action = TRUE;
3284 collect_before_allocs = atoi (arg);
3285 } else if (!strcmp (opt, "verify-before-collections")) {
3286 whole_heap_check_before_collection = TRUE;
3287 } else if (!strcmp (opt, "check-remset-consistency")) {
3288 remset_consistency_checks = TRUE;
3289 nursery_clear_policy = CLEAR_AT_GC;
3290 } else if (!strcmp (opt, "mod-union-consistency-check")) {
3291 if (!major_collector.is_concurrent) {
3292 sgen_env_var_error (MONO_GC_DEBUG_NAME, "Ignoring.", "`mod-union-consistency-check` only works with concurrent major collector.");
3295 mod_union_consistency_check = TRUE;
3296 } else if (!strcmp (opt, "check-mark-bits")) {
3297 check_mark_bits_after_major_collection = TRUE;
3298 } else if (!strcmp (opt, "check-nursery-pinned")) {
3299 check_nursery_objects_pinned = TRUE;
3300 } else if (!strcmp (opt, "clear-at-gc")) {
3301 nursery_clear_policy = CLEAR_AT_GC;
3302 } else if (!strcmp (opt, "clear-nursery-at-gc")) {
3303 nursery_clear_policy = CLEAR_AT_GC;
3304 } else if (!strcmp (opt, "clear-at-tlab-creation")) {
3305 nursery_clear_policy = CLEAR_AT_TLAB_CREATION;
3306 } else if (!strcmp (opt, "debug-clear-at-tlab-creation")) {
3307 nursery_clear_policy = CLEAR_AT_TLAB_CREATION_DEBUG;
3308 } else if (!strcmp (opt, "check-scan-starts")) {
3309 do_scan_starts_check = TRUE;
3310 } else if (!strcmp (opt, "verify-nursery-at-minor-gc")) {
3311 do_verify_nursery = TRUE;
3312 } else if (!strcmp (opt, "check-concurrent")) {
3313 if (!major_collector.is_concurrent) {
3314 sgen_env_var_error (MONO_GC_DEBUG_NAME, "Ignoring.", "`check-concurrent` only works with concurrent major collectors.");
3317 nursery_clear_policy = CLEAR_AT_GC;
3318 do_concurrent_checks = TRUE;
3319 } else if (!strcmp (opt, "dump-nursery-at-minor-gc")) {
3320 do_dump_nursery_content = TRUE;
3321 } else if (!strcmp (opt, "disable-minor")) {
3322 disable_minor_collections = TRUE;
3323 } else if (!strcmp (opt, "disable-major")) {
3324 disable_major_collections = TRUE;
3325 } else if (g_str_has_prefix (opt, "heap-dump=")) {
3326 char *filename = strchr (opt, '=') + 1;
3327 nursery_clear_policy = CLEAR_AT_GC;
3328 sgen_debug_enable_heap_dump (filename);
3329 } else if (g_str_has_prefix (opt, "binary-protocol=")) {
3330 char *filename = strchr (opt, '=') + 1;
3331 char *colon = strrchr (filename, ':');
3334 if (!mono_gc_parse_environment_string_extract_number (colon + 1, &limit)) {
3335 sgen_env_var_error (MONO_GC_DEBUG_NAME, "Ignoring limit.", "Binary protocol file size limit must be an integer.");
3340 binary_protocol_init (filename, (long long)limit);
3341 } else if (!strcmp (opt, "nursery-canaries")) {
3342 do_verify_nursery = TRUE;
3343 enable_nursery_canaries = TRUE;
3344 } else if (!sgen_client_handle_gc_debug (opt)) {
3345 sgen_env_var_error (MONO_GC_DEBUG_NAME, "Ignoring.", "Unknown option `%s`.", opt);
3350 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);
3351 fprintf (stderr, "Valid <option>s are:\n");
3352 fprintf (stderr, " collect-before-allocs[=<n>]\n");
3353 fprintf (stderr, " verify-before-allocs[=<n>]\n");
3354 fprintf (stderr, " max-valloc-size=N (where N is an integer, possibly with a k, m or a g suffix)\n");
3355 fprintf (stderr, " check-remset-consistency\n");
3356 fprintf (stderr, " check-mark-bits\n");
3357 fprintf (stderr, " check-nursery-pinned\n");
3358 fprintf (stderr, " verify-before-collections\n");
3359 fprintf (stderr, " verify-nursery-at-minor-gc\n");
3360 fprintf (stderr, " dump-nursery-at-minor-gc\n");
3361 fprintf (stderr, " disable-minor\n");
3362 fprintf (stderr, " disable-major\n");
3363 fprintf (stderr, " check-concurrent\n");
3364 fprintf (stderr, " clear-[nursery-]at-gc\n");
3365 fprintf (stderr, " clear-at-tlab-creation\n");
3366 fprintf (stderr, " debug-clear-at-tlab-creation\n");
3367 fprintf (stderr, " check-scan-starts\n");
3368 fprintf (stderr, " print-allowance\n");
3369 fprintf (stderr, " print-pinning\n");
3370 fprintf (stderr, " heap-dump=<filename>\n");
3371 fprintf (stderr, " binary-protocol=<filename>[:<file-size-limit>]\n");
3372 fprintf (stderr, " nursery-canaries\n");
3373 sgen_client_print_gc_debug_usage ();
3374 fprintf (stderr, "\n");
3376 usage_printed = TRUE;
3383 g_free (debug_opts);
3385 if (check_mark_bits_after_major_collection)
3386 nursery_clear_policy = CLEAR_AT_GC;
3388 if (major_collector.post_param_init)
3389 major_collector.post_param_init (&major_collector);
3391 if (major_collector.is_concurrent || sgen_minor_collector.is_parallel) {
3392 int num_workers = 1;
3393 if (major_collector.is_parallel || sgen_minor_collector.is_parallel) {
3394 /* FIXME Detect the number of physical cores, instead of logical */
3395 num_workers = mono_cpu_count () / 2;
3396 if (num_workers < 1)
3399 sgen_workers_init (num_workers, (SgenWorkerCallback) major_collector.worker_init_cb);
3402 sgen_memgov_init (max_heap, soft_limit, debug_print_allowance, allowance_ratio, save_target);
3404 memset (&remset, 0, sizeof (remset));
3406 sgen_card_table_init (&remset);
3408 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");
3412 sgen_init_bridge ();
3416 sgen_gc_initialized ()
3418 return gc_initialized > 0;
3422 sgen_get_nursery_clear_policy (void)
3424 return nursery_clear_policy;
3430 mono_coop_mutex_lock (&gc_mutex);
3434 sgen_gc_unlock (void)
3436 mono_coop_mutex_unlock (&gc_mutex);
3440 sgen_major_collector_iterate_live_block_ranges (sgen_cardtable_block_callback callback)
3442 major_collector.iterate_live_block_ranges (callback);
3446 sgen_major_collector_iterate_block_ranges (sgen_cardtable_block_callback callback)
3448 major_collector.iterate_block_ranges (callback);
3452 sgen_get_major_collector (void)
3454 return &major_collector;
3458 sgen_get_minor_collector (void)
3460 return &sgen_minor_collector;
3464 sgen_get_remset (void)
3470 count_cards (long long *major_total, long long *major_marked, long long *los_total, long long *los_marked)
3472 sgen_get_major_collector ()->count_cards (major_total, major_marked);
3473 sgen_los_count_cards (los_total, los_marked);
3476 static gboolean world_is_stopped = FALSE;
3478 /* LOCKING: assumes the GC lock is held */
3480 sgen_stop_world (int generation)
3482 long long major_total = -1, major_marked = -1, los_total = -1, los_marked = -1;
3484 SGEN_ASSERT (0, !world_is_stopped, "Why are we stopping a stopped world?");
3486 binary_protocol_world_stopping (generation, sgen_timestamp (), (gpointer) (gsize) mono_native_thread_id_get ());
3488 sgen_client_stop_world (generation);
3490 world_is_stopped = TRUE;
3492 if (binary_protocol_is_heavy_enabled ())
3493 count_cards (&major_total, &major_marked, &los_total, &los_marked);
3494 binary_protocol_world_stopped (generation, sgen_timestamp (), major_total, major_marked, los_total, los_marked);
3497 /* LOCKING: assumes the GC lock is held */
3499 sgen_restart_world (int generation)
3501 long long major_total = -1, major_marked = -1, los_total = -1, los_marked = -1;
3504 SGEN_ASSERT (0, world_is_stopped, "Why are we restarting a running world?");
3506 if (binary_protocol_is_heavy_enabled ())
3507 count_cards (&major_total, &major_marked, &los_total, &los_marked);
3508 binary_protocol_world_restarting (generation, sgen_timestamp (), major_total, major_marked, los_total, los_marked);
3510 world_is_stopped = FALSE;
3512 sgen_client_restart_world (generation, &stw_time);
3514 binary_protocol_world_restarted (generation, sgen_timestamp ());
3516 if (sgen_client_bridge_need_processing ())
3517 sgen_client_bridge_processing_finish (generation);
3519 sgen_memgov_collection_end (generation, stw_time);
3523 sgen_is_world_stopped (void)
3525 return world_is_stopped;
3529 sgen_check_whole_heap_stw (void)
3531 sgen_stop_world (0);
3532 sgen_clear_nursery_fragments ();
3533 sgen_check_whole_heap (TRUE);
3534 sgen_restart_world (0);
3538 sgen_timestamp (void)
3540 SGEN_TV_DECLARE (timestamp);
3541 SGEN_TV_GETTIME (timestamp);
3542 return SGEN_TV_ELAPSED (sgen_init_timestamp, timestamp);
3545 #endif /* HAVE_SGEN_GC */