2 * sgen-nursery-allocator.c: Nursery allocation code.
4 * Copyright 2009-2010 Novell, Inc.
7 * Copyright 2011 Xamarin Inc (http://www.xamarin.com)
8 * Copyright (C) 2012 Xamarin Inc
10 * This library is free software; you can redistribute it and/or
11 * modify it under the terms of the GNU Library General Public
12 * License 2.0 as published by the Free Software Foundation;
14 * This library is distributed in the hope that it will be useful,
15 * but WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
17 * Library General Public License for more details.
19 * You should have received a copy of the GNU Library General Public
20 * License 2.0 along with this library; if not, write to the Free
21 * Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
25 * The young generation is divided into fragments. This is because
26 * we can hand one fragments to a thread for lock-less fast alloc and
27 * because the young generation ends up fragmented anyway by pinned objects.
28 * Once a collection is done, a list of fragments is created. When doing
29 * thread local alloc we use smallish nurseries so we allow new threads to
30 * allocate memory from gen0 without triggering a collection. Threads that
31 * are found to allocate lots of memory are given bigger fragments. This
32 * should make the finalizer thread use little nursery memory after a while.
33 * We should start assigning threads very small fragments: if there are many
34 * threads the nursery will be full of reserved space that the threads may not
35 * use at all, slowing down allocation speed.
36 * Thread local allocation is done from areas of memory Hotspot calls Thread Local
37 * Allocation Buffers (TLABs).
48 #ifdef HAVE_SEMAPHORE_H
49 #include <semaphore.h>
63 #include "metadata/sgen-gc.h"
64 #include "metadata/metadata-internals.h"
65 #include "metadata/class-internals.h"
66 #include "metadata/gc-internal.h"
67 #include "metadata/object-internals.h"
68 #include "metadata/threads.h"
69 #include "metadata/sgen-cardtable.h"
70 #include "metadata/sgen-protocol.h"
71 #include "metadata/sgen-archdep.h"
72 #include "metadata/sgen-bridge.h"
73 #include "metadata/sgen-memory-governor.h"
74 #include "metadata/mono-gc.h"
75 #include "metadata/method-builder.h"
76 #include "metadata/profiler-private.h"
77 #include "metadata/monitor.h"
78 #include "metadata/threadpool-internals.h"
79 #include "metadata/mempool-internals.h"
80 #include "metadata/marshal.h"
81 #include "utils/mono-mmap.h"
82 #include "utils/mono-time.h"
83 #include "utils/mono-semaphore.h"
84 #include "utils/mono-counters.h"
85 #include "utils/mono-proclib.h"
86 #include "utils/mono-threads.h"
88 /* Enable it so nursery allocation diagnostic data is collected */
89 //#define NALLOC_DEBUG 1
91 /* The mutator allocs from here. */
92 SgenFragmentAllocator mutator_allocator;
94 /* freeelist of fragment structures */
95 static SgenFragment *fragment_freelist = NULL;
97 /* Allocator cursors */
98 static char *nursery_last_pinned_end = NULL;
100 char *sgen_nursery_start;
101 char *sgen_nursery_end;
104 size_t sgen_nursery_size = (1 << 22);
105 #ifdef SGEN_ALIGN_NURSERY
106 int sgen_nursery_bits = 22;
110 char *sgen_space_bitmap MONO_INTERNAL;
111 size_t sgen_space_bitmap_size MONO_INTERNAL;
113 #ifdef HEAVY_STATISTICS
115 static gint32 stat_wasted_bytes_trailer = 0;
116 static gint32 stat_wasted_bytes_small_areas = 0;
117 static gint32 stat_wasted_bytes_discarded_fragments = 0;
118 static gint32 stat_nursery_alloc_requests = 0;
119 static gint32 stat_alloc_iterations = 0;
120 static gint32 stat_alloc_retries = 0;
122 static gint32 stat_nursery_alloc_range_requests = 0;
123 static gint32 stat_alloc_range_iterations = 0;
124 static gint32 stat_alloc_range_retries = 0;
128 /************************************Nursery allocation debugging *********************************************/
145 MonoNativeThreadId tid;
148 #define ALLOC_RECORD_COUNT 128000
151 static AllocRecord *alloc_records;
152 static volatile int next_record;
153 static volatile int alloc_count;
155 void dump_alloc_records (void);
156 void verify_alloc_records (void);
159 get_reason_name (AllocRecord *rec)
161 switch (rec->reason) {
162 case FIXED_ALLOC: return "fixed-alloc";
163 case RANGE_ALLOC: return "range-alloc";
164 case PINNING: return "pinning";
165 case BLOCK_ZEROING: return "block-zeroing";
166 case CLEAR_NURSERY_FRAGS: return "clear-nursery-frag";
167 default: return "invalid";
172 reset_alloc_records (void)
179 add_alloc_record (char *addr, size_t size, int reason)
181 int idx = InterlockedIncrement (&next_record) - 1;
182 alloc_records [idx].address = addr;
183 alloc_records [idx].size = size;
184 alloc_records [idx].reason = reason;
185 alloc_records [idx].seq = idx;
186 alloc_records [idx].tid = mono_native_thread_id_get ();
190 comp_alloc_record (const void *_a, const void *_b)
192 const AllocRecord *a = _a;
193 const AllocRecord *b = _b;
194 if (a->address == b->address)
195 return a->seq - b->seq;
196 return a->address - b->address;
199 #define rec_end(REC) ((REC)->address + (REC)->size)
202 dump_alloc_records (void)
205 sgen_qsort (alloc_records, next_record, sizeof (AllocRecord), comp_alloc_record);
207 printf ("------------------------------------DUMP RECORDS----------------------------\n");
208 for (i = 0; i < next_record; ++i) {
209 AllocRecord *rec = alloc_records + i;
210 printf ("obj [%p, %p] size %zd reason %s seq %d tid %zx\n", rec->address, rec_end (rec), rec->size, get_reason_name (rec), rec->seq, (size_t)rec->tid);
215 verify_alloc_records (void)
221 AllocRecord *prev = NULL;
223 sgen_qsort (alloc_records, next_record, sizeof (AllocRecord), comp_alloc_record);
224 printf ("------------------------------------DUMP RECORDS- %d %d---------------------------\n", next_record, alloc_count);
225 for (i = 0; i < next_record; ++i) {
226 AllocRecord *rec = alloc_records + i;
230 if (rec_end (prev) > rec->address)
231 printf ("WE GOT OVERLAPPING objects %p and %p\n", prev->address, rec->address);
232 if ((rec->address - rec_end (prev)) >= 8)
234 hole_size = rec->address - rec_end (prev);
235 max_hole = MAX (max_hole, hole_size);
237 printf ("obj [%p, %p] size %zd hole to prev %d reason %s seq %d tid %zx\n", rec->address, rec_end (rec), rec->size, hole_size, get_reason_name (rec), rec->seq, (size_t)rec->tid);
240 printf ("SUMMARY total alloc'd %d holes %d max_hole %d\n", total, holes, max_hole);
245 /*********************************************************************************/
248 static inline gpointer
249 mask (gpointer n, uintptr_t bit)
251 return (gpointer)(((uintptr_t)n) | bit);
254 static inline gpointer
257 return (gpointer)((uintptr_t)p & ~(uintptr_t)0x3);
260 static inline uintptr_t
261 get_mark (gpointer n)
263 return (uintptr_t)n & 0x1;
266 /*MUST be called with world stopped*/
268 sgen_fragment_allocator_alloc (void)
270 SgenFragment *frag = fragment_freelist;
272 fragment_freelist = frag->next_in_order;
273 frag->next = frag->next_in_order = NULL;
276 frag = sgen_alloc_internal (INTERNAL_MEM_FRAGMENT);
277 frag->next = frag->next_in_order = NULL;
282 sgen_fragment_allocator_add (SgenFragmentAllocator *allocator, char *start, char *end)
284 SgenFragment *fragment;
286 fragment = sgen_fragment_allocator_alloc ();
287 fragment->fragment_start = start;
288 fragment->fragment_next = start;
289 fragment->fragment_end = end;
290 fragment->next_in_order = fragment->next = unmask (allocator->region_head);
292 allocator->region_head = allocator->alloc_head = fragment;
293 g_assert (fragment->fragment_end > fragment->fragment_start);
297 sgen_fragment_allocator_release (SgenFragmentAllocator *allocator)
299 SgenFragment *last = allocator->region_head;
303 /* Find the last fragment in insert order */
304 for (; last->next_in_order; last = last->next_in_order) ;
306 last->next_in_order = fragment_freelist;
307 fragment_freelist = allocator->region_head;
308 allocator->alloc_head = allocator->region_head = NULL;
311 static SgenFragment**
312 find_previous_pointer_fragment (SgenFragmentAllocator *allocator, SgenFragment *frag)
315 SgenFragment *cur, *next;
321 prev = &allocator->alloc_head;
324 printf ("retry count for fppf is %d\n", count);
327 cur = unmask (*prev);
335 * We need to make sure that we dereference prev below
336 * after reading cur->next above, so we need a read
339 mono_memory_read_barrier ();
344 if (!get_mark (next)) {
349 next = unmask (next);
350 if (InterlockedCompareExchangePointer ((volatile gpointer*)prev, next, cur) != cur)
352 /*we must make sure that the next from cur->next happens after*/
353 mono_memory_write_barrier ();
356 cur = mono_lls_pointer_unmask (next);
362 claim_remaining_size (SgenFragment *frag, char *alloc_end)
364 /* All space used, nothing to claim. */
365 if (frag->fragment_end <= alloc_end)
368 /* Try to alloc all the remaining space. */
369 return InterlockedCompareExchangePointer ((volatile gpointer*)&frag->fragment_next, frag->fragment_end, alloc_end) == alloc_end;
373 par_alloc_from_fragment (SgenFragmentAllocator *allocator, SgenFragment *frag, size_t size)
375 char *p = frag->fragment_next;
376 char *end = p + size;
378 if (end > frag->fragment_end)
381 /* p = frag->fragment_next must happen before */
382 mono_memory_barrier ();
384 if (InterlockedCompareExchangePointer ((volatile gpointer*)&frag->fragment_next, end, p) != p)
387 if (frag->fragment_end - end < SGEN_MAX_NURSERY_WASTE) {
388 SgenFragment *next, **prev_ptr;
391 * Before we clean the remaining nursery, we must claim the remaining space
392 * as it could end up been used by the range allocator since it can end up
393 * allocating from this dying fragment as it doesn't respect SGEN_MAX_NURSERY_WASTE
394 * when doing second chance allocation.
396 if ((sgen_get_nursery_clear_policy () == CLEAR_AT_TLAB_CREATION || sgen_get_nursery_clear_policy () == CLEAR_AT_TLAB_CREATION_DEBUG) && claim_remaining_size (frag, end)) {
397 sgen_clear_range (end, frag->fragment_end);
398 HEAVY_STAT (InterlockedExchangeAdd (&stat_wasted_bytes_trailer, frag->fragment_end - end));
400 add_alloc_record (end, frag->fragment_end - end, BLOCK_ZEROING);
404 prev_ptr = find_previous_pointer_fragment (allocator, frag);
406 /*Use Michaels linked list remove*/
408 /*prev_ptr will be null if the fragment was removed concurrently */
413 if (!get_mark (next)) {
414 /*frag->next read must happen before the first CAS*/
415 mono_memory_write_barrier ();
417 /*Fail if the next node is removed concurrently and its CAS wins */
418 if (InterlockedCompareExchangePointer ((volatile gpointer*)&frag->next, mask (next, 1), next) != next) {
423 /* The second CAS must happen after the first CAS or frag->next. */
424 mono_memory_write_barrier ();
426 /* Fail if the previous node was deleted and its CAS wins */
427 if (InterlockedCompareExchangePointer ((volatile gpointer*)prev_ptr, unmask (next), frag) != frag) {
428 prev_ptr = find_previous_pointer_fragment (allocator, frag);
439 serial_alloc_from_fragment (SgenFragment **previous, SgenFragment *frag, size_t size)
441 char *p = frag->fragment_next;
442 char *end = p + size;
444 if (end > frag->fragment_end)
447 frag->fragment_next = end;
449 if (frag->fragment_end - end < SGEN_MAX_NURSERY_WASTE) {
450 *previous = frag->next;
452 /* Clear the remaining space, pinning depends on this. FIXME move this to use phony arrays */
453 memset (end, 0, frag->fragment_end - end);
455 *previous = frag->next;
462 sgen_fragment_allocator_par_alloc (SgenFragmentAllocator *allocator, size_t size)
467 InterlockedIncrement (&alloc_count);
471 for (frag = unmask (allocator->alloc_head); unmask (frag); frag = unmask (frag->next)) {
472 HEAVY_STAT (InterlockedIncrement (&stat_alloc_iterations));
474 if (size <= (size_t)(frag->fragment_end - frag->fragment_next)) {
475 void *p = par_alloc_from_fragment (allocator, frag, size);
477 HEAVY_STAT (InterlockedIncrement (&stat_alloc_retries));
481 add_alloc_record (p, size, FIXED_ALLOC);
490 sgen_fragment_allocator_serial_alloc (SgenFragmentAllocator *allocator, size_t size)
493 SgenFragment **previous;
495 InterlockedIncrement (&alloc_count);
498 previous = &allocator->alloc_head;
500 for (frag = *previous; frag; frag = *previous) {
501 char *p = serial_alloc_from_fragment (previous, frag, size);
503 HEAVY_STAT (InterlockedIncrement (&stat_alloc_iterations));
507 add_alloc_record (p, size, FIXED_ALLOC);
511 previous = &frag->next;
517 sgen_fragment_allocator_serial_range_alloc (SgenFragmentAllocator *allocator, size_t desired_size, size_t minimum_size, size_t *out_alloc_size)
519 SgenFragment *frag, **previous, *min_frag = NULL, **prev_min_frag = NULL;
520 size_t current_minimum = minimum_size;
523 InterlockedIncrement (&alloc_count);
526 previous = &allocator->alloc_head;
528 for (frag = *previous; frag; frag = *previous) {
529 size_t frag_size = frag->fragment_end - frag->fragment_next;
531 HEAVY_STAT (InterlockedIncrement (&stat_alloc_range_iterations));
533 if (desired_size <= frag_size) {
535 *out_alloc_size = desired_size;
537 p = serial_alloc_from_fragment (previous, frag, desired_size);
539 add_alloc_record (p, desired_size, RANGE_ALLOC);
543 if (current_minimum <= frag_size) {
545 prev_min_frag = previous;
546 current_minimum = frag_size;
548 previous = &frag->next;
553 size_t frag_size = min_frag->fragment_end - min_frag->fragment_next;
554 *out_alloc_size = frag_size;
556 p = serial_alloc_from_fragment (prev_min_frag, min_frag, frag_size);
559 add_alloc_record (p, frag_size, RANGE_ALLOC);
568 sgen_fragment_allocator_par_range_alloc (SgenFragmentAllocator *allocator, size_t desired_size, size_t minimum_size, size_t *out_alloc_size)
570 SgenFragment *frag, *min_frag;
571 size_t current_minimum;
575 current_minimum = minimum_size;
578 InterlockedIncrement (&alloc_count);
581 for (frag = unmask (allocator->alloc_head); frag; frag = unmask (frag->next)) {
582 size_t frag_size = frag->fragment_end - frag->fragment_next;
584 HEAVY_STAT (InterlockedIncrement (&stat_alloc_range_iterations));
586 if (desired_size <= frag_size) {
588 *out_alloc_size = desired_size;
590 p = par_alloc_from_fragment (allocator, frag, desired_size);
592 HEAVY_STAT (InterlockedIncrement (&stat_alloc_range_retries));
596 add_alloc_record (p, desired_size, RANGE_ALLOC);
600 if (current_minimum <= frag_size) {
602 current_minimum = frag_size;
606 /* The second fragment_next read should be ordered in respect to the first code block */
607 mono_memory_barrier ();
613 frag_size = min_frag->fragment_end - min_frag->fragment_next;
614 if (frag_size < minimum_size)
617 *out_alloc_size = frag_size;
619 mono_memory_barrier ();
620 p = par_alloc_from_fragment (allocator, min_frag, frag_size);
622 /*XXX restarting here is quite dubious given this is already second chance allocation. */
624 HEAVY_STAT (InterlockedIncrement (&stat_alloc_retries));
628 add_alloc_record (p, frag_size, RANGE_ALLOC);
637 sgen_clear_allocator_fragments (SgenFragmentAllocator *allocator)
641 for (frag = unmask (allocator->alloc_head); frag; frag = unmask (frag->next)) {
642 SGEN_LOG (4, "Clear nursery frag %p-%p", frag->fragment_next, frag->fragment_end);
643 sgen_clear_range (frag->fragment_next, frag->fragment_end);
645 add_alloc_record (frag->fragment_next, frag->fragment_end - frag->fragment_next, CLEAR_NURSERY_FRAGS);
650 /* Clear all remaining nursery fragments */
652 sgen_clear_nursery_fragments (void)
654 if (sgen_get_nursery_clear_policy () == CLEAR_AT_TLAB_CREATION || sgen_get_nursery_clear_policy () == CLEAR_AT_TLAB_CREATION_DEBUG) {
655 sgen_clear_allocator_fragments (&mutator_allocator);
656 sgen_minor_collector.clear_fragments ();
661 * Mark a given range of memory as invalid.
663 * This can be done either by zeroing memory or by placing
664 * a phony byte[] array. This keeps the heap forward walkable.
666 * This function ignores calls with a zero range, even if
667 * both start and end are NULL.
670 sgen_clear_range (char *start, char *end)
673 size_t size = end - start;
675 if ((start && !end) || (start > end))
676 g_error ("Invalid range [%p %p]", start, end);
678 if (size < sizeof (MonoArray)) {
679 memset (start, 0, size);
683 o = (MonoArray*)start;
684 o->obj.vtable = sgen_get_array_fill_vtable ();
685 /* Mark this as not a real object */
686 o->obj.synchronisation = GINT_TO_POINTER (-1);
688 o->max_length = (mono_array_size_t)(size - sizeof (MonoArray));
689 sgen_set_nursery_scan_start (start);
690 g_assert (start + sgen_safe_object_get_size ((MonoObject*)o) == end);
694 sgen_nursery_allocator_prepare_for_pinning (void)
696 sgen_clear_allocator_fragments (&mutator_allocator);
697 sgen_minor_collector.clear_fragments ();
700 static mword fragment_total = 0;
702 * We found a fragment of free memory in the nursery: memzero it and if
703 * it is big enough, add it to the list of fragments that can be used for
707 add_nursery_frag (SgenFragmentAllocator *allocator, size_t frag_size, char* frag_start, char* frag_end)
709 SGEN_LOG (4, "Found empty fragment: %p-%p, size: %zd", frag_start, frag_end, frag_size);
710 binary_protocol_empty (frag_start, frag_size);
711 MONO_GC_NURSERY_SWEPT ((mword)frag_start, frag_end - frag_start);
712 /* Not worth dealing with smaller fragments: need to tune */
713 if (frag_size >= SGEN_MAX_NURSERY_WASTE) {
714 /* memsetting just the first chunk start is bound to provide better cache locality */
715 if (sgen_get_nursery_clear_policy () == CLEAR_AT_GC)
716 memset (frag_start, 0, frag_size);
717 else if (sgen_get_nursery_clear_policy () == CLEAR_AT_TLAB_CREATION_DEBUG)
718 memset (frag_start, 0xff, frag_size);
721 /* XXX convert this into a flight record entry
722 printf ("\tfragment [%p %p] size %zd\n", frag_start, frag_end, frag_size);
725 sgen_fragment_allocator_add (allocator, frag_start, frag_end);
726 fragment_total += frag_size;
728 /* Clear unused fragments, pinning depends on this */
729 sgen_clear_range (frag_start, frag_end);
730 HEAVY_STAT (InterlockedExchangeAdd (&stat_wasted_bytes_small_areas, frag_size));
735 fragment_list_reverse (SgenFragmentAllocator *allocator)
737 SgenFragment *prev = NULL, *list = allocator->region_head;
739 SgenFragment *next = list->next;
741 list->next_in_order = prev;
746 allocator->region_head = allocator->alloc_head = prev;
750 sgen_build_nursery_fragments (GCMemSection *nursery_section, void **start, size_t num_entries, SgenGrayQueue *unpin_queue)
752 char *frag_start, *frag_end;
755 SgenFragment *frags_ranges;
758 reset_alloc_records ();
760 /*The mutator fragments are done. We no longer need them. */
761 sgen_fragment_allocator_release (&mutator_allocator);
763 frag_start = sgen_nursery_start;
766 /* The current nursery might give us a fragment list to exclude [start, next[*/
767 frags_ranges = sgen_minor_collector.build_fragments_get_exclude_head ();
769 /* clear scan starts */
770 memset (nursery_section->scan_starts, 0, nursery_section->num_scan_start * sizeof (gpointer));
772 while (i < num_entries || frags_ranges) {
775 SgenFragment *last_frag = NULL;
777 addr0 = addr1 = sgen_nursery_end;
781 addr1 = frags_ranges->fragment_start;
785 GRAY_OBJECT_ENQUEUE (unpin_queue, addr0, sgen_obj_get_descriptor_safe (addr0));
787 SGEN_UNPIN_OBJECT (addr0);
788 size = SGEN_ALIGN_UP (sgen_safe_object_get_size ((MonoObject*)addr0));
789 CANARIFY_SIZE (size);
790 sgen_set_nursery_scan_start (addr0);
795 size = frags_ranges->fragment_next - addr1;
796 last_frag = frags_ranges;
797 frags_ranges = frags_ranges->next_in_order;
800 frag_size = frag_end - frag_start;
805 g_assert (frag_size >= 0);
807 if (frag_size && size)
808 add_nursery_frag (&mutator_allocator, frag_size, frag_start, frag_end);
812 add_alloc_record (start [i], frag_size, PINNING);
814 frag_start = frag_end + frag_size;
817 nursery_last_pinned_end = frag_start;
818 frag_end = sgen_nursery_end;
819 frag_size = frag_end - frag_start;
821 add_nursery_frag (&mutator_allocator, frag_size, frag_start, frag_end);
823 /* Now it's safe to release the fragments exclude list. */
824 sgen_minor_collector.build_fragments_release_exclude_head ();
826 /* First we reorder the fragment list to be in ascending address order. This makes H/W prefetchers happier. */
827 fragment_list_reverse (&mutator_allocator);
829 /*The collector might want to do something with the final nursery fragment list.*/
830 sgen_minor_collector.build_fragments_finish (&mutator_allocator);
832 if (!unmask (mutator_allocator.alloc_head)) {
833 SGEN_LOG (1, "Nursery fully pinned (%zd)", num_entries);
834 for (i = 0; i < num_entries; ++i) {
835 SGEN_LOG (3, "Bastard pinning obj %p (%s), size: %zd", start [i], sgen_safe_name (start [i]), sgen_safe_object_get_size (start [i]));
838 return fragment_total;
842 sgen_nursery_alloc_get_upper_alloc_bound (void)
844 /*FIXME we need to calculate the collector upper bound as well, but this must be done in the previous GC. */
845 return sgen_nursery_end;
848 /*** Nursery memory allocation ***/
850 sgen_nursery_retire_region (void *address, ptrdiff_t size)
852 HEAVY_STAT (InterlockedExchangeAdd (&stat_wasted_bytes_discarded_fragments, size));
856 sgen_can_alloc_size (size_t size)
860 if (!SGEN_CAN_ALIGN_UP (size))
863 size = SGEN_ALIGN_UP (size);
865 for (frag = unmask (mutator_allocator.alloc_head); frag; frag = unmask (frag->next)) {
866 if ((size_t)(frag->fragment_end - frag->fragment_next) >= size)
873 sgen_nursery_alloc (size_t size)
875 SGEN_ASSERT (1, size >= sizeof (MonoObject) && size <= (SGEN_MAX_SMALL_OBJ_SIZE + CANARY_SIZE), "Invalid nursery object size");
877 SGEN_LOG (4, "Searching nursery for size: %zd", size);
878 size = SGEN_ALIGN_UP (size);
880 HEAVY_STAT (InterlockedIncrement (&stat_nursery_alloc_requests));
882 return sgen_fragment_allocator_par_alloc (&mutator_allocator, size);
886 sgen_nursery_alloc_range (size_t desired_size, size_t minimum_size, size_t *out_alloc_size)
888 SGEN_LOG (4, "Searching for byte range desired size: %zd minimum size %zd", desired_size, minimum_size);
890 HEAVY_STAT (InterlockedIncrement (&stat_nursery_alloc_range_requests));
892 return sgen_fragment_allocator_par_range_alloc (&mutator_allocator, desired_size, minimum_size, out_alloc_size);
895 /*** Initialization ***/
897 #ifdef HEAVY_STATISTICS
900 sgen_nursery_allocator_init_heavy_stats (void)
902 mono_counters_register ("bytes wasted trailer fragments", MONO_COUNTER_GC | MONO_COUNTER_INT, &stat_wasted_bytes_trailer);
903 mono_counters_register ("bytes wasted small areas", MONO_COUNTER_GC | MONO_COUNTER_INT, &stat_wasted_bytes_small_areas);
904 mono_counters_register ("bytes wasted discarded fragments", MONO_COUNTER_GC | MONO_COUNTER_INT, &stat_wasted_bytes_discarded_fragments);
906 mono_counters_register ("# nursery alloc requests", MONO_COUNTER_GC | MONO_COUNTER_INT, &stat_nursery_alloc_requests);
907 mono_counters_register ("# nursery alloc iterations", MONO_COUNTER_GC | MONO_COUNTER_INT, &stat_alloc_iterations);
908 mono_counters_register ("# nursery alloc retries", MONO_COUNTER_GC | MONO_COUNTER_INT, &stat_alloc_retries);
910 mono_counters_register ("# nursery alloc range requests", MONO_COUNTER_GC | MONO_COUNTER_INT, &stat_nursery_alloc_range_requests);
911 mono_counters_register ("# nursery alloc range iterations", MONO_COUNTER_GC | MONO_COUNTER_INT, &stat_alloc_range_iterations);
912 mono_counters_register ("# nursery alloc range restries", MONO_COUNTER_GC | MONO_COUNTER_INT, &stat_alloc_range_retries);
918 sgen_init_nursery_allocator (void)
920 sgen_register_fixed_internal_mem_type (INTERNAL_MEM_FRAGMENT, sizeof (SgenFragment));
922 alloc_records = sgen_alloc_os_memory (sizeof (AllocRecord) * ALLOC_RECORD_COUNT, SGEN_ALLOC_INTERNAL | SGEN_ALLOC_ACTIVATE, "debugging memory");
927 sgen_nursery_alloc_prepare_for_minor (void)
929 sgen_minor_collector.prepare_to_space (sgen_space_bitmap, sgen_space_bitmap_size);
933 sgen_nursery_alloc_prepare_for_major (void)
935 sgen_minor_collector.prepare_to_space (sgen_space_bitmap, sgen_space_bitmap_size);
939 sgen_nursery_allocator_set_nursery_bounds (char *start, char *end)
941 sgen_nursery_start = start;
942 sgen_nursery_end = end;
945 * This will not divide evenly for tiny nurseries (<4kb), so we make sure to be on
946 * the right side of things and round up. We could just do a MIN(1,x) instead,
947 * since the nursery size must be a power of 2.
949 sgen_space_bitmap_size = (end - start + SGEN_TO_SPACE_GRANULE_IN_BYTES * 8 - 1) / (SGEN_TO_SPACE_GRANULE_IN_BYTES * 8);
950 sgen_space_bitmap = g_malloc0 (sgen_space_bitmap_size);
952 /* Setup the single first large fragment */
953 sgen_minor_collector.init_nursery (&mutator_allocator, start, end);