-
Notifications
You must be signed in to change notification settings - Fork 392
/
MemorySubSpaceSemiSpace.cpp
1104 lines (952 loc) · 45.1 KB
/
MemorySubSpaceSemiSpace.cpp
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
/*******************************************************************************
* Copyright (c) 1991, 2020 IBM Corp. and others
*
* This program and the accompanying materials are made available under
* the terms of the Eclipse Public License 2.0 which accompanies this
* distribution and is available at https://www.eclipse.org/legal/epl-2.0/
* or the Apache License, Version 2.0 which accompanies this distribution and
* is available at https://www.apache.org/licenses/LICENSE-2.0.
*
* This Source Code may also be made available under the following
* Secondary Licenses when the conditions for such availability set
* forth in the Eclipse Public License, v. 2.0 are satisfied: GNU
* General Public License, version 2 with the GNU Classpath
* Exception [1] and GNU General Public License, version 2 with the
* OpenJDK Assembly Exception [2].
*
* [1] https://www.gnu.org/software/classpath/license.html
* [2] http://openjdk.java.net/legal/assembly-exception.html
*
* SPDX-License-Identifier: EPL-2.0 OR Apache-2.0 OR GPL-2.0 WITH Classpath-exception-2.0 OR LicenseRef-GPL-2.0 WITH Assembly-exception
*******************************************************************************/
#include <math.h>
#include "omrcfg.h"
#include "modronopt.h"
#include "AllocateDescription.hpp"
#include "Collector.hpp"
#include "EnvironmentBase.hpp"
#include "GCExtensionsBase.hpp"
#include "Heap.hpp"
#include "HeapRegionManager.hpp"
#include "LargeObjectAllocateStats.hpp"
#include "MemoryPool.hpp"
#include "MemorySpace.hpp"
#include "MemorySubSpace.hpp"
#include "MemorySubSpaceRegionIterator.hpp"
#include "MemorySubSpaceSemiSpace.hpp"
#include "ParallelDispatcher.hpp"
#include "PhysicalSubArena.hpp"
#if defined(OMR_VALGRIND_MEMCHECK)
#include "MemcheckWrapper.hpp"
#endif /* defined(OMR_VALGRIND_MEMCHECK) */
#if defined(OMR_GC_MODRON_SCAVENGER)
/****************************************
* Allocation
****************************************
*/
void *
MM_MemorySubSpaceSemiSpace::allocateObject(MM_EnvironmentBase *env, MM_AllocateDescription *allocDescription, MM_MemorySubSpace *baseSubSpace, MM_MemorySubSpace *previousSubSpace, bool shouldCollectOnFailure)
{
Trc_MM_MSSSS_allocate_entry(env->getLanguageVMThread(), "Object", allocDescription->getBytesRequested(), this, getName(), baseSubSpace, previousSubSpace, (uintptr_t)shouldCollectOnFailure);
void *addr = NULL;
if (shouldCollectOnFailure) {
Trc_MM_MSSSS_allocate(env->getLanguageVMThread(), "Object", allocDescription->getBytesRequested(), 1);
addr = _memorySubSpaceAllocate->allocateObject(env, allocDescription, baseSubSpace, this, shouldCollectOnFailure);
} else {
if(previousSubSpace == _parent) {
Trc_MM_MSSSS_allocate(env->getLanguageVMThread(), "Object", allocDescription->getBytesRequested(), 2);
/* if we are coming from parent (after a Global GC), pass it down to Allocate */
addr = _memorySubSpaceAllocate->allocateObject(env, allocDescription, baseSubSpace, this, shouldCollectOnFailure);
} else if (previousSubSpace == this) {
/* if retrying after a recent GC (from allocationRequestFailed), pass it down to Allocate */
Trc_MM_MSSSS_allocate(env->getLanguageVMThread(), "Object", allocDescription->getBytesRequested(), 3);
addr = _memorySubSpaceAllocate->allocateObject(env, allocDescription, baseSubSpace, this, shouldCollectOnFailure);
} else {
/* Allocate subspace failed after a recent GC, try parent */
Trc_MM_MSSSS_allocate4(env->getLanguageVMThread(), "Object", allocDescription->getBytesRequested(), (uintptr_t)allocDescription->shouldClimb());
Assert_MM_true(previousSubSpace == _memorySubSpaceAllocate);
if (allocDescription->shouldClimb()) {
addr = _parent->allocateObject(env, allocDescription, baseSubSpace, this, shouldCollectOnFailure);
}
}
}
Trc_MM_MSSSS_allocate_exit(env->getLanguageVMThread(), "Object", allocDescription->getBytesRequested(), addr);
return addr;
}
void *
MM_MemorySubSpaceSemiSpace::allocationRequestFailed(MM_EnvironmentBase *env, MM_AllocateDescription *allocateDescription, AllocationType allocationType, MM_ObjectAllocationInterface *objectAllocationInterface, MM_MemorySubSpace *baseSubSpace, MM_MemorySubSpace *previousSubSpace)
{
Trc_MM_MSSSS_allocationRequestFailed_entry(env->getLanguageVMThread(), allocateDescription->getBytesRequested(), this, getName(), baseSubSpace, previousSubSpace, (uintptr_t)allocationType);
/* The baseSubSpace in this case isn't really valid - in the event of a scavenge, the baseSubSpace changes. The current subSpace will become the
* base for any restarts
*/
void *addr = NULL;
allocateDescription->saveObjects(env);
if (!env->acquireExclusiveVMAccessForGC(_collector, true, true)) {
allocateDescription->restoreObjects(env);
Trc_MM_MSSSS_allocationRequestFailed(env->getLanguageVMThread(), allocateDescription->getBytesRequested(), 1);
addr = allocateGeneric(env, allocateDescription, allocationType, objectAllocationInterface, _memorySubSpaceAllocate);
if(NULL != addr) {
Trc_MM_MSSSS_allocationRequestFailed_exit(env->getLanguageVMThread(), allocateDescription->getBytesRequested(), 1, addr);
return addr;
}
allocateDescription->saveObjects(env);
if (!env->acquireExclusiveVMAccessForGC(_collector)) {
allocateDescription->restoreObjects(env);
Trc_MM_MSSSS_allocationRequestFailed(env->getLanguageVMThread(), allocateDescription->getBytesRequested(), 2);
addr = allocateGeneric(env, allocateDescription, allocationType, objectAllocationInterface, _memorySubSpaceAllocate);
if(NULL != addr) {
/* Satisfied the allocate after having grabbed exclusive access to perform a GC (without actually performing the GC). Raise
* an event for tracing / verbose to report the occurrence.
*/
reportAcquiredExclusiveToSatisfyAllocate(env, allocateDescription);
Trc_MM_MSSSS_allocationRequestFailed_exit(env->getLanguageVMThread(), allocateDescription->getBytesRequested(), 2, addr);
return addr;
}
allocateDescription->saveObjects(env);
}
}
Assert_MM_mustHaveExclusiveVMAccess(env->getOmrVMThread());
reportAllocationFailureStart(env, allocateDescription);
allocateDescription->setAllocationType(allocationType);
/* we will pass this as the target subspace for the restarted allocation because the subspaces will swap, if the collection is
* successful, but not if we backout so we don't know which subspace will allocate until after the collect - our own allocation
* routines will call the correct child subspace.
*
* we might not be the only SemiSpace around (think NUMA). if so, we want to do scavenge on whole new space.
* OMRTODO we might be short-cutting here. more formal approach is to pass allocationRequestFailed to parent and he decides what to do
*/
MM_MemorySubSpace *topLevelMemorySubSpaceNew = getTopLevelMemorySubSpace(MEMORY_TYPE_NEW);
addr = _collector->garbageCollect(env, topLevelMemorySubSpaceNew, allocateDescription, J9MMCONSTANT_IMPLICIT_GC_DEFAULT, objectAllocationInterface, this, NULL);
allocateDescription->restoreObjects(env);
if(NULL != addr) {
reportAllocationFailureEnd(env);
Trc_MM_MSSSS_allocationRequestFailed_exit(env->getLanguageVMThread(), allocateDescription->getBytesRequested(), 3, addr);
return addr;
}
/* Potentially a more aggressive collect here */
/* Override the baseSubSpace with this - the allocate subspace can change through collections */
reportAllocationFailureEnd(env);
/*
* TLH: Should we not be checking "collect and climb" here or some such? why are we not calling the parent?
* Calling of parent for TLH is wrong because objects allocated into it on the in-line path won't have the OLD bit set
* CMVC 144061
*/
if (ALLOCATION_TYPE_TLH != allocationType) {
Trc_MM_MSSSS_allocationRequestFailed(env->getLanguageVMThread(), allocateDescription->getBytesRequested(), 3);
addr = _parent->allocationRequestFailed(env, allocateDescription, allocationType, objectAllocationInterface, this, this);
}
Trc_MM_MSSSS_allocationRequestFailed_exit(env->getLanguageVMThread(), allocateDescription->getBytesRequested(), 4, addr);
return addr;
}
void *
MM_MemorySubSpaceSemiSpace::allocateArrayletLeaf(MM_EnvironmentBase *env, MM_AllocateDescription *allocDescription, MM_MemorySubSpace *baseSubSpace, MM_MemorySubSpace *previousSubSpace, bool shouldCollectOnFailure)
{
void *addr = NULL;
if (shouldCollectOnFailure) {
addr = _memorySubSpaceAllocate->allocateArrayletLeaf(env, allocDescription, baseSubSpace, this, shouldCollectOnFailure);
} else {
if(previousSubSpace == _parent) {
/* if we are coming from parent (after a Global GC), pass it down to Allocate */
addr = _memorySubSpaceAllocate->allocateArrayletLeaf(env, allocDescription, baseSubSpace, this, shouldCollectOnFailure);
} else if (previousSubSpace == this) {
/* if retrying after a recent GC (from allocationRequestFailed), pass it down to Allocate */
addr = _memorySubSpaceAllocate->allocateArrayletLeaf(env, allocDescription, baseSubSpace, this, shouldCollectOnFailure);
} else {
/* Allocate subspace failed after a recent GC, try parent */
Assert_MM_true(previousSubSpace == _memorySubSpaceAllocate);
if (allocDescription->shouldClimb()) {
addr = _parent->allocateArrayletLeaf(env, allocDescription, baseSubSpace, this, shouldCollectOnFailure);
}
}
}
return addr;
}
void *
MM_MemorySubSpaceSemiSpace::allocateTLH(MM_EnvironmentBase *env, MM_AllocateDescription *allocDescription, MM_ObjectAllocationInterface *objectAllocationInterface, MM_MemorySubSpace *baseSubSpace, MM_MemorySubSpace *previousSubSpace, bool shouldCollectOnFailure)
{
/* We may receive this call from the MemorySubSpaceGeneric for which we are the parent but we shouldn't satisfy TLH allocates
* in this space (since that would allow us to fill old space before collecting new space) so just return NULL.
* This call has been observed on Vich configurations, at the very least.
*/
return NULL;
}
/****************************************
* Explicit Collection
****************************************
*/
void
MM_MemorySubSpaceSemiSpace::systemGarbageCollect(MM_EnvironmentBase *env, uint32_t gcCode)
{
if(_collector) {
env->acquireExclusiveVMAccessForGC(_collector);
reportSystemGCStart(env, gcCode);
_collector->garbageCollect(env, this, NULL, gcCode, NULL, NULL, NULL);
/* Handle abort from local collect */
if (_extensions->isScavengerBackOutFlagRaised()) {
_parent->getCollector()->garbageCollect(env, this, NULL, gcCode, NULL, NULL, NULL);
}
reportSystemGCEnd(env);
env->releaseExclusiveVMAccessForGC();
}
}
/**
* If the child subSpace is active return true, else return false.
*/
bool
MM_MemorySubSpaceSemiSpace::isChildActive(MM_MemorySubSpace *memorySubSpace)
{
return memorySubSpace == _memorySubSpaceAllocate;
}
/****************************************
* Sub Space Categorization
****************************************
*/
MM_MemorySubSpace *
MM_MemorySubSpaceSemiSpace::getDefaultMemorySubSpace()
{
return _memorySubSpaceAllocate;
}
bool
MM_MemorySubSpaceSemiSpace::isObjectInEvacuateMemory(omrobjectptr_t objectPtr)
{
/* check if the object in cached allocate (from GC perspective evacuate) ranges */
return ((void *)objectPtr >= _allocateSpaceBase) && ((void *)objectPtr < _allocateSpaceTop);
}
bool
MM_MemorySubSpaceSemiSpace::isObjectInNewSpace(omrobjectptr_t objectPtr)
{
return ((void *)objectPtr >= _survivorSpaceBase) && ((void *)objectPtr < _survivorSpaceTop);
}
bool
MM_MemorySubSpaceSemiSpace::isObjectInNewSpace(void *objectBase, void *objectTop)
{
return (objectBase >= _survivorSpaceBase) && (objectTop <= _survivorSpaceTop);
}
uintptr_t
MM_MemorySubSpaceSemiSpace::getMaxSpaceForObjectInEvacuateMemory(omrobjectptr_t objectPtr)
{
uintptr_t result = 0;
if (isObjectInEvacuateMemory(objectPtr)) {
result = (uintptr_t)_allocateSpaceTop - (uintptr_t)objectPtr;
}
return result;
}
/****************************************
* Free list building
****************************************
*/
uintptr_t
MM_MemorySubSpaceSemiSpace::getActiveMemorySize(uintptr_t includeMemoryType)
{
if (includeMemoryType & MEMORY_TYPE_NEW) {
if (_memorySubSpaceSurvivor == _memorySubSpaceEvacuate) {
return _memorySubSpaceAllocate->getActiveMemorySize() + _memorySubSpaceSurvivor->getActiveMemorySize();
} else if (_memorySubSpaceSurvivor == _memorySubSpaceAllocate) {
return _memorySubSpaceSurvivor->getActiveMemorySize() + _memorySubSpaceEvacuate->getActiveMemorySize();
} else if (_memorySubSpaceEvacuate == _memorySubSpaceAllocate) {
return _memorySubSpaceSurvivor->getActiveMemorySize() + _memorySubSpaceEvacuate->getActiveMemorySize();
} else {
Assert_MM_unreachable();
}
}
return 0;
}
/**
* @copydoc MM_MemorySubSpace::getActualActiveFreeMemorySize()
* The semispace implementation will only report free memory associated to the allocate memory subspace.
*/
uintptr_t
MM_MemorySubSpaceSemiSpace::getActualActiveFreeMemorySize()
{
return _memorySubSpaceAllocate->getActualActiveFreeMemorySize();
}
/**
* @copydoc MM_MemorySubSpace::getActualActiveFreeMemorySize(uintptr_t)
* The semispace implementation will only report free memory associated to the allocate memory subspace.
*/
uintptr_t
MM_MemorySubSpaceSemiSpace::getActualActiveFreeMemorySize(uintptr_t includeMemoryType)
{
if (includeMemoryType & MEMORY_TYPE_NEW){
return _memorySubSpaceAllocate->getActualActiveFreeMemorySize();
} else {
return 0;
}
}
/**
* @copydoc MM_MemorySubSpace::getApproximateActiveFreeMemorySize()
* The semispace implementation will only report free memory associated to the allocate memory subspace.
*/
uintptr_t
MM_MemorySubSpaceSemiSpace::getApproximateActiveFreeMemorySize()
{
return _memorySubSpaceAllocate->getApproximateActiveFreeMemorySize();
}
/**
* @copydoc MM_MemorySubSpace::getApproximateActiveFreeMemorySize(uintptr_t)
* The semispace implementation will only report free memory associated to the allocate memory subspace.
*/
uintptr_t
MM_MemorySubSpaceSemiSpace::getApproximateActiveFreeMemorySize(uintptr_t includeMemoryType)
{
if (includeMemoryType & MEMORY_TYPE_NEW){
return _memorySubSpaceAllocate->getApproximateActiveFreeMemorySize();
} else {
return 0;
}
}
uintptr_t
MM_MemorySubSpaceSemiSpace::getActiveSurvivorMemorySize(uintptr_t includeMemoryType)
{
if (getTypeFlags() & MEMORY_TYPE_NEW) {
return _memorySubSpaceSurvivor->getActiveMemorySize(MEMORY_TYPE_NEW);
} else {
return 0;
}
}
uintptr_t
MM_MemorySubSpaceSemiSpace::getApproximateActiveFreeSurvivorMemorySize(uintptr_t includeMemoryType)
{
if (includeMemoryType & MEMORY_TYPE_NEW){
return _memorySubSpaceSurvivor->getApproximateActiveFreeMemorySize();
} else {
return 0;
}
}
uintptr_t
MM_MemorySubSpaceSemiSpace::getActualActiveFreeSurvivorMemorySize(uintptr_t includeMemoryType)
{
if (getTypeFlags() & MEMORY_TYPE_NEW) {
return _memorySubSpaceSurvivor->getActiveMemorySize(MEMORY_TYPE_NEW);
} else {
return 0;
}
}
void
MM_MemorySubSpaceSemiSpace::abandonHeapChunk(void *addrBase, void *addrTop)
{
Assert_MM_unreachable();
}
/**
*/
void
MM_MemorySubSpaceSemiSpace::mergeHeapStats(MM_HeapStats *heapStats)
{
_memorySubSpaceAllocate->mergeHeapStats(heapStats);
_memorySubSpaceSurvivor->mergeHeapStats(heapStats);
}
void
MM_MemorySubSpaceSemiSpace::mergeHeapStats(MM_HeapStats *heapStats, uintptr_t includeMemoryType)
{
if (includeMemoryType & MEMORY_TYPE_NEW){
_memorySubSpaceAllocate->mergeHeapStats(heapStats);
_memorySubSpaceSurvivor->mergeHeapStats(heapStats);
}
}
/**
* Initialization
*/
MM_MemorySubSpaceSemiSpace *
MM_MemorySubSpaceSemiSpace::newInstance(MM_EnvironmentBase *env, MM_Collector *collector, MM_PhysicalSubArena *physicalSubArena, MM_MemorySubSpace *memorySubSpaceAllocate, MM_MemorySubSpace *memorySubSpaceSurvivor, bool usesGlobalCollector, uintptr_t minimumSize, uintptr_t initialSize, uintptr_t maximumSize)
{
MM_MemorySubSpaceSemiSpace *memorySubSpace;
memorySubSpace = (MM_MemorySubSpaceSemiSpace *)env->getForge()->allocate(sizeof(MM_MemorySubSpaceSemiSpace), OMR::GC::AllocationCategory::FIXED, OMR_GET_CALLSITE());
if (memorySubSpace) {
new(memorySubSpace) MM_MemorySubSpaceSemiSpace(env, collector, physicalSubArena, memorySubSpaceAllocate, memorySubSpaceSurvivor, usesGlobalCollector, minimumSize, initialSize, maximumSize);
if (!memorySubSpace->initialize(env)) {
memorySubSpace->kill(env);
memorySubSpace = NULL;
}
}
return memorySubSpace;
}
bool
MM_MemorySubSpaceSemiSpace::initialize(MM_EnvironmentBase *env)
{
if(!MM_MemorySubSpace::initialize(env)) {
return false;
}
_previousBytesFlipped = getMinimumSize() / 2;
_tiltedAverageBytesFlipped = _previousBytesFlipped;
_tiltedAverageBytesFlippedDelta = _previousBytesFlipped;
#if defined(OMR_GC_CONCURRENT_SCAVENGER)
/* we are clueless about initial allocation rate and its deviation, but small non-zero values
* are still better than 0 values, to help with faster learning of real values.
*/
_avgBytesAllocatedDuringConcurrent = getMinimumSize() / 10;
_deviationBytesAllocatedDuringConcurrent = (float)_avgBytesAllocatedDuringConcurrent / 10;
#endif /* OMR_GC_CONCURRENT_SCAVENGER */
/* register the children */
registerMemorySubSpace(_memorySubSpaceSurvivor);
registerMemorySubSpace(_memorySubSpaceAllocate);
_memorySubSpaceSurvivor->isAllocatable(false);
/* this memoryPool can be used by scavenger, maximum tlh size should be max(_extensions->tlhMaximumSize, _extensions->scavengerScanCacheMaximumSize) */
uintptr_t tlhMaximumSize = OMR_MAX(_extensions->tlhMaximumSize, _extensions->scavengerScanCacheMaximumSize);
_largeObjectAllocateStats = MM_LargeObjectAllocateStats::newInstance(env, (uint16_t)_extensions->largeObjectAllocationProfilingTopK, _extensions->largeObjectAllocationProfilingThreshold, _extensions->largeObjectAllocationProfilingVeryLargeObjectThreshold, (float)_extensions->largeObjectAllocationProfilingSizeClassRatio / (float)100.0,
_extensions->heap->getMaximumMemorySize(), tlhMaximumSize + _extensions->minimumFreeEntrySize, _extensions->tlhMinimumSize);
if (NULL == _largeObjectAllocateStats) {
return false;
}
return true;
}
void
MM_MemorySubSpaceSemiSpace::tearDown(MM_EnvironmentBase *env)
{
MM_MemorySubSpace::tearDown(env);
if (NULL != _largeObjectAllocateStats) {
_largeObjectAllocateStats->kill(env);
_largeObjectAllocateStats = NULL;
}
}
/****************************************
* Type specific functionality
****************************************
*/
void
MM_MemorySubSpaceSemiSpace::flip(MM_EnvironmentBase *env, Flip_step step)
{
#if defined(OMR_GC_CONCURRENT_SCAVENGER)
OMRPORT_ACCESS_FROM_OMRPORT(env->getPortLibrary());
bool debug = _extensions->debugTiltedScavenge;
#endif
switch (step) {
case set_evacuate:
_memorySubSpaceEvacuate = _memorySubSpaceAllocate;
_memorySubSpaceEvacuate->isAllocatable(false);
break;
case set_allocate:
_memorySubSpaceAllocate = _memorySubSpaceSurvivor;
_memorySubSpaceAllocate->isAllocatable(true);
/* Let know MemorySpace about new default MemorySubSpace */
getMemorySpace()->setDefaultMemorySubSpace(getDefaultMemorySubSpace());
break;
case disable_allocation:
_memorySubSpaceAllocate->isAllocatable(false);
break;
case restore_allocation:
_memorySubSpaceAllocate->isAllocatable(true);
break;
case restore_allocation_and_set_survivor:
_memorySubSpaceAllocate->isAllocatable(true);
_memorySubSpaceSurvivor = _memorySubSpaceEvacuate;
#if defined(OMR_GC_CONCURRENT_SCAVENGER)
_bytesAllocatedDuringConcurrent = _extensions->allocationStats.bytesAllocated();
_avgBytesAllocatedDuringConcurrent = (uintptr_t)MM_Math::weightedAverage((float)_avgBytesAllocatedDuringConcurrent,
(float)(_bytesAllocatedDuringConcurrent), 0.7f);
_deviationBytesAllocatedDuringConcurrent = ((float)_bytesAllocatedDuringConcurrent - (float)_avgBytesAllocatedDuringConcurrent);
_avgDeviationBytesAllocatedDuringConcurrent =
sqrtf(MM_Math::weightedAverage(_avgDeviationBytesAllocatedDuringConcurrent * _avgDeviationBytesAllocatedDuringConcurrent,
(float)_deviationBytesAllocatedDuringConcurrent * _deviationBytesAllocatedDuringConcurrent, 0.7f));
#endif /* OMR_GC_CONCURRENT_SCAVENGER */
break;
#if defined(OMR_GC_CONCURRENT_SCAVENGER)
case backout:
Assert_MM_true(_extensions->concurrentScavenger);
/* We have objects on both sides of Nursery. We will unify the two sides and do a compacting slide (after percolate global GC)
* Enforce Allocate be in low address range, since compact slide in percolate global GC moves objects to low addresses.
* Note: _allocateSpaceBase/Top are stale (not updated in set_allocate), since they are overloaded to point to Evacuate during an active cycle
*/
if (_allocateSpaceBase < _survivorSpaceBase) {
_memorySubSpaceAllocate = _memorySubSpaceEvacuate;
_memorySubSpaceEvacuate = _memorySubSpaceSurvivor;
getMemorySpace()->setDefaultMemorySubSpace(getDefaultMemorySubSpace());
if(debug) {
omrtty_printf("tilt backout _allocateSpaceBase/Top %llx/%llx _survivorSpaceBase/Top %llx/%llx tilt sizes %llx %llx\n",
_allocateSpaceBase, _allocateSpaceTop, _survivorSpaceBase, _survivorSpaceTop,
(uintptr_t)_allocateSpaceTop - (uintptr_t)_allocateSpaceBase + (uintptr_t)_survivorSpaceTop - (uintptr_t)_survivorSpaceBase, (uintptr_t)0);
}
} else {
_memorySubSpaceSurvivor = _memorySubSpaceEvacuate;
cacheRanges(_memorySubSpaceAllocate, &_allocateSpaceBase, &_allocateSpaceTop);
cacheRanges(_memorySubSpaceSurvivor, &_survivorSpaceBase, &_survivorSpaceTop);
if(debug) {
omrtty_printf("tilt backout forced flip _allocateSpaceBase/Top %llx/%llx _survivorSpaceBase/Top %llx/%llx tilt sizes %llx %llx\n",
_allocateSpaceBase, _allocateSpaceTop, _survivorSpaceBase, _survivorSpaceTop,
(uintptr_t)_allocateSpaceTop - (uintptr_t)_allocateSpaceBase + (uintptr_t)_survivorSpaceTop - (uintptr_t)_survivorSpaceBase, (uintptr_t)0);
}
}
/* Tilt 100% on PhysicalSubArena level (leave SubSpaces unchanged). Give everything to the low address (Allocate) part */
_physicalSubArena->tilt(env, (uintptr_t)_allocateSpaceTop - (uintptr_t)_allocateSpaceBase + (uintptr_t)_survivorSpaceTop - (uintptr_t)_survivorSpaceBase, (uintptr_t)0, false);
/* disable potentially successful allocation (in case of forced abort) to trigger another (percolate) GC */
_memorySubSpaceAllocate->isAllocatable(false);
getMemorySpace()->getTenureMemorySubSpace()->isAllocatable(false);
break;
case restore_tilt_after_percolate:
{
Assert_MM_true(_extensions->concurrentScavenger);
uintptr_t lastFreeEntrySize = 0;
MM_HeapLinkedFreeHeader *lastFreeEntry = getDefaultMemorySubSpace()->getMemoryPool()->getLastFreeEntry();
if (NULL != lastFreeEntry) {
lastFreeEntrySize = lastFreeEntry->getSize();
if(debug) {
omrtty_printf("tilt restore_tilt_after_percolate last free entry %llx size %llx\n",
lastFreeEntry, lastFreeEntrySize);
}
/* rely on the last free entry only if at the very end of SemiSpace (no objects after it) */
if (((uintptr_t)lastFreeEntry + lastFreeEntrySize) != OMR_MAX((uintptr_t)_allocateSpaceTop, (uintptr_t)_survivorSpaceTop)) {
lastFreeEntrySize = 0;
}
}
/* Make Survivor space from the last free entry in the unified Nursery */
uintptr_t heapAlignedLastFreeEntrySize = MM_Math::roundToFloor(_extensions->heapAlignment, lastFreeEntrySize);
/* Region size is aligned to Concurrent Scavenger Page Section size already */
heapAlignedLastFreeEntrySize = MM_Math::roundToFloor(_extensions->regionSize, heapAlignedLastFreeEntrySize);
if(debug) {
omrtty_printf("tilt restore_tilt_after_percolate heapAlignedLastFreeEntry %llx section (%llx) aligned size %llx\n",
lastFreeEntrySize, _extensions->getConcurrentScavengerPageSectionSize(), heapAlignedLastFreeEntrySize);
}
/* allocate/survivor base/top still hold the values from before when we did 100% tilt */
uintptr_t allocateSize = (uintptr_t)_allocateSpaceTop - (uintptr_t)_allocateSpaceBase;
uintptr_t survivorSize = (uintptr_t)_survivorSpaceTop - (uintptr_t)_survivorSpaceBase;
if (allocateSize < survivorSize) {
allocateSize = survivorSize;
survivorSize = (uintptr_t)_allocateSpaceTop - (uintptr_t)_allocateSpaceBase;
}
if(debug) {
omrtty_printf("tilt restore_tilt_after_percolate allocateSize %llx survivorSize %llx\n", allocateSize, survivorSize);
}
if (heapAlignedLastFreeEntrySize < survivorSize) {
allocateSize += (survivorSize - heapAlignedLastFreeEntrySize);
survivorSize = heapAlignedLastFreeEntrySize;
}
if(debug) {
omrtty_printf("tilt restore_tilt_after_percolate adjusted allocateSize %llx survivorSize %llx\n", allocateSize, survivorSize);
}
tilt(env, allocateSize, survivorSize);
/* Restore allocation, which we had disabled in the backout step */
_memorySubSpaceAllocate->isAllocatable(true);
getMemorySpace()->getTenureMemorySubSpace()->isAllocatable(true);
_extensions->setScavengerBackOutState(backOutFlagCleared);
}
break;
#endif /* OMR_GC_CONCURRENT_SCAVENGER */
default:
Assert_MM_unreachable();
}
}
void
MM_MemorySubSpaceSemiSpace::cacheRanges(MM_MemorySubSpace *subSpace, void **base, void **top)
{
GC_MemorySubSpaceRegionIterator regionIterator(subSpace);
MM_HeapRegionDescriptor* region = regionIterator.nextRegion();
Assert_MM_true(NULL != region);
Assert_MM_true(NULL == regionIterator.nextRegion());
*base = region->getLowAddress();
*top = region->getHighAddress();
}
void
MM_MemorySubSpaceSemiSpace::mainSetupForGC(MM_EnvironmentBase *env)
{
/* cache allocate (effectively evacuate for GC) ranges */
cacheRanges(_memorySubSpaceAllocate, &_allocateSpaceBase, &_allocateSpaceTop);
cacheRanges(_memorySubSpaceSurvivor, &_survivorSpaceBase, &_survivorSpaceTop);
flip(env, set_evacuate);
}
void
MM_MemorySubSpaceSemiSpace::poisonEvacuateSpace()
{
/* poison allocate (effectively effectively evacuate for the caller, GC) */
const uintptr_t pattern = (uintptr_t)-1;
uintptr_t* current = (uintptr_t*) _allocateSpaceBase;
uintptr_t* end = (uintptr_t*) _allocateSpaceTop;
#if defined(OMR_VALGRIND_MEMCHECK)
//clear dead objects before getting their size bits overwritten.
valgrindClearRange(_extensions,(uintptr_t) _allocateSpaceBase, (uintptr_t) _allocateSpaceTop - (uintptr_t) _allocateSpaceBase);
//The space is already dead (objects).... lets redefine so it can be poisoned!
valgrindMakeMemDefined((uintptr_t) _allocateSpaceBase, (uintptr_t) _allocateSpaceTop - (uintptr_t) _allocateSpaceBase);
#endif /* defined(OMR_VALGRIND_MEMCHECK) */
while (current < end) {
*current = pattern;
current += 1;
}
#if defined(OMR_VALGRIND_MEMCHECK)
valgrindMakeMemNoaccess((uintptr_t) _allocateSpaceBase, (uintptr_t) _allocateSpaceTop - (uintptr_t) _allocateSpaceBase);
#endif /* defined(OMR_VALGRIND_MEMCHECK) */
}
void
MM_MemorySubSpaceSemiSpace::tilt(MM_EnvironmentBase *env, uintptr_t allocateSpaceSize, uintptr_t survivorSpaceSize)
{
_physicalSubArena->tilt(env, allocateSpaceSize, survivorSpaceSize);
}
void
MM_MemorySubSpaceSemiSpace::tilt(MM_EnvironmentBase *env, uintptr_t survivorSpaceSizeRatioRequest)
{
_physicalSubArena->tilt(env, survivorSpaceSizeRatioRequest);
}
void
MM_MemorySubSpaceSemiSpace::mainTeardownForSuccessfulGC(MM_EnvironmentBase *env)
{
_memorySubSpaceEvacuate->rebuildFreeList(env);
/* Flip the memory space allocate profile */
if (!_extensions->isConcurrentScavengerEnabled()) {
flip(env, set_allocate);
flip(env, disable_allocation);
}
flip(env, restore_allocation_and_set_survivor);
/* Adjust memory between the semi spaces where applicable */
checkResize(env);
performResize(env);
}
void
MM_MemorySubSpaceSemiSpace::mainTeardownForAbortedGC(MM_EnvironmentBase *env)
{
/* Build free list in survivor. */
if (_extensions->isConcurrentScavengerEnabled()) {
/* There might be live objects in Survivor (newly allocated one since the start of Concurrent Scavenge cycle)
* Sweep in percolate global will rebuild it, so we can skip it here
*/
flip(env, backout);
} else {
_memorySubSpaceSurvivor->rebuildFreeList(env);
/* Restoring allocation after aborted scavenge will probably not help with re-attempts to allocate immediately after an aborted scavenge,
* but still we have to restore it at some point for attempts after percolate GC. It's simplest to do it right away.
*/
flip(env, restore_allocation);
}
}
/**
* Adjust the sub space memory by tilting the split between allocate and survivor space.
*/
void
MM_MemorySubSpaceSemiSpace::checkSubSpaceMemoryPostCollectTilt(MM_EnvironmentBase *env)
{
MM_GCExtensionsBase *extensions = MM_GCExtensionsBase::getExtensions(env->getOmrVM());
if(extensions->tiltedScavenge) {
uintptr_t flipBytes;
uintptr_t flipBytesDelta;
bool debug = extensions->debugTiltedScavenge;
OMRPORT_ACCESS_FROM_OMRPORT(env->getPortLibrary());
uintptr_t currentSize = getTopLevelMemorySubSpace(MEMORY_TYPE_NEW)->getCurrentSize();
if(debug) {
omrtty_printf("\nTilt check:\n");
}
flipBytes = extensions->scavengerStats._flipBytes + extensions->scavengerStats._failedFlipBytes;
if(debug) {
omrtty_printf("\tBytes flip:%zu fail:%zu total:%zu\n",
extensions->scavengerStats._flipBytes,
extensions->scavengerStats._failedFlipBytes,
flipBytes);
}
/* Determine the absolute value of the change in bytes flipped since the last scavenge */
if(flipBytes > _previousBytesFlipped) {
flipBytesDelta = flipBytes - _previousBytesFlipped;
} else {
flipBytesDelta = _previousBytesFlipped - flipBytes;
}
if(debug) {
omrtty_printf("\tflip delta from last (%zu):%zu\n", _previousBytesFlipped, flipBytesDelta);
}
/* Current flip count becomes previous */
_previousBytesFlipped = flipBytes;
/* The average bytes flipped weighted average is more heavily affected if the current size is
* greater than the current average
*/
if(debug) {
omrtty_printf("\tcurrent average bytes flipped: %zu (avg delta %zu)\n",
_tiltedAverageBytesFlipped,
_tiltedAverageBytesFlippedDelta);
}
/* Check if there was any failed to flip objects - which puts us into a bit of a panic mode */
if(0 != extensions->scavengerStats._failedFlipCount) {
/* Panic mode - the current numbers should heavily influence the averages */
if(debug) {
omrtty_printf("\tfailed flip weight\n");
}
_tiltedAverageBytesFlipped = (uintptr_t)MM_Math::weightedAverage((float)_tiltedAverageBytesFlipped, (float)flipBytes, 0.0f);
_tiltedAverageBytesFlippedDelta = (uintptr_t)MM_Math::weightedAverage((float)_tiltedAverageBytesFlippedDelta, (float)flipBytesDelta, 0.0f);
} else {
/* No panic situation - determine the new tilt ratio through normal means */
if(flipBytes > _tiltedAverageBytesFlipped) {
if(debug) {
omrtty_printf("\tincrease flip weight\n");
}
_tiltedAverageBytesFlipped = (uintptr_t)MM_Math::weightedAverage((float)_tiltedAverageBytesFlipped, (float)flipBytes, 0.2f);
_tiltedAverageBytesFlippedDelta = (uintptr_t)MM_Math::weightedAverage((float)_tiltedAverageBytesFlippedDelta, (float)flipBytesDelta, 0.2f);
} else {
if(debug) {
omrtty_printf("\tdecrease flip weight\n");
}
_tiltedAverageBytesFlipped = (uintptr_t)MM_Math::weightedAverage((float)_tiltedAverageBytesFlipped, (float)flipBytes, 0.8f);
_tiltedAverageBytesFlippedDelta = (uintptr_t)MM_Math::weightedAverage((float)_tiltedAverageBytesFlippedDelta, (float)flipBytesDelta, 0.8f);
}
}
if(debug) {
omrtty_printf("\tnew average bytes flipped: %zu (avg delta %zu)\n",
_tiltedAverageBytesFlipped,
_tiltedAverageBytesFlippedDelta);
}
/* Calculate the desired survivor space ratio */
double survivorSizeAmplification = 1.04 + extensions->dispatcher->threadCount() / 100.0;
double desiredSurvivorSize = (_tiltedAverageBytesFlipped + _tiltedAverageBytesFlippedDelta) * survivorSizeAmplification;
#if defined(OMR_GC_CONCURRENT_SCAVENGER)
if (_extensions->isConcurrentScavengerEnabled()) {
/* Account for mutator allocated objects in hybrid survivor/allocated during concurrent phase of Concurrent Scavenger */
desiredSurvivorSize += _avgBytesAllocatedDuringConcurrent * 1.1
+ extensions->concurrentScavengerAllocDeviationBoost * (uintptr_t)_avgDeviationBytesAllocatedDuringConcurrent
+ extensions->concurrentScavengerSlack;
if (debug) {
omrtty_printf("\tmutator bytesAllocated current %zu average %zu\n", _bytesAllocatedDuringConcurrent, _avgBytesAllocatedDuringConcurrent);
omrtty_printf("\tmutator bytesAllocated deviation current %f average %f (%f%% of average allocation)\n",
_deviationBytesAllocatedDuringConcurrent, _avgDeviationBytesAllocatedDuringConcurrent,
_avgDeviationBytesAllocatedDuringConcurrent * 100 / _avgBytesAllocatedDuringConcurrent);
}
}
#endif /* OMR_GC_CONCURRENT_SCAVENGER */
_desiredSurvivorSpaceRatio = desiredSurvivorSize / currentSize;
if(debug) {
omrtty_printf("\tDesired survivor size: %zu ratio: %zu\n",
(uintptr_t)(currentSize * _desiredSurvivorSpaceRatio), (uintptr_t) (_desiredSurvivorSpaceRatio * 100));
}
/* Sanity check for lowest possible ratio */
if (_desiredSurvivorSpaceRatio < extensions->survivorSpaceMinimumSizeRatio) {
_desiredSurvivorSpaceRatio = extensions->survivorSpaceMinimumSizeRatio;
}
/* Never hand out more than 50% to the survivor */
if (_desiredSurvivorSpaceRatio > extensions->survivorSpaceMaximumSizeRatio) {
_desiredSurvivorSpaceRatio = extensions->survivorSpaceMaximumSizeRatio;
}
/* we have flipped already, so to get old survivor space ratio we fetch allocate size */
double previousSurvivorSpaceRatio = (double) _memorySubSpaceAllocate->getActiveMemorySize() / currentSize;
/* Do not let survivor space shrink by more than the maximum tilt increase */
assume0(previousSurvivorSpaceRatio >= extensions->tiltedScavengeMaximumIncrease);
if (_desiredSurvivorSpaceRatio < (previousSurvivorSpaceRatio - extensions->tiltedScavengeMaximumIncrease)) {
_desiredSurvivorSpaceRatio = previousSurvivorSpaceRatio - extensions->tiltedScavengeMaximumIncrease;
}
if(debug) {
omrtty_printf("\tPrevious survivor ratio: %zu\n", (uintptr_t) (previousSurvivorSpaceRatio * 100));
omrtty_printf("\tAdjusted survivor size: %zu ratio: %zu\n",(uintptr_t)(currentSize * _desiredSurvivorSpaceRatio),
(uintptr_t) (_desiredSurvivorSpaceRatio * 100));
}
}
}
/**
* Adjust the sub space memory by resizing the allocate and survivor space (expand or contract).
*/
void
MM_MemorySubSpaceSemiSpace::checkSubSpaceMemoryPostCollectResize(MM_EnvironmentBase *env)
{
MM_GCExtensionsBase *extensions = MM_GCExtensionsBase::getExtensions(env->getOmrVM());
uintptr_t regionSize = extensions->getHeap()->getHeapRegionManager()->getRegionSize();
if(extensions->dynamicNewSpaceSizing) {
bool doDynamicNewSpaceSizing = true;
bool debug = extensions->debugDynamicNewSpaceSizing;
OMRPORT_ACCESS_FROM_OMRPORT(env->getPortLibrary());
if(debug) {
omrtty_printf("New space resize check:\n");
}
if (extensions->scavengerStats._gcCount == 1){
if(debug) {
omrtty_printf("\tNo previous scavenge - ABORTING\n");
}
doDynamicNewSpaceSizing = false;
}
/* the wall clock might be shifted backwards externally */
if (extensions->scavengerStats._startTime < _lastScavengeEndTime) {
/* clock has been shifted backwards between scavenges */
if(debug) {
omrtty_printf("\tClock shifted backwards between scavenges - ABORTING\n");
}
doDynamicNewSpaceSizing = false;
}
if (extensions->scavengerStats._endTime < extensions->scavengerStats._startTime) {
/* clock has been shifted backwards at the time of the scavenge */
if(debug) {
omrtty_printf("\tClock shifted backwards at the time of the scavenge - ABORTING\n");
}
doDynamicNewSpaceSizing = false;
}
uint64_t intervalTime = omrtime_hires_delta(_lastScavengeEndTime, extensions->scavengerStats._endTime, OMRPORT_TIME_DELTA_IN_MICROSECONDS);
if(0 == intervalTime) {
if(debug) {
omrtty_printf("\tInterval time 0 - ABORTING\n");
}
doDynamicNewSpaceSizing = false;
}
uint64_t scavengeTime = omrtime_hires_delta(extensions->scavengerStats._startTime, extensions->scavengerStats._endTime, OMRPORT_TIME_DELTA_IN_MICROSECONDS );
if(0 == scavengeTime) {
if(debug) {
omrtty_printf("\tScavenge time 0 - ABORTING\n");
}
doDynamicNewSpaceSizing = false;
}
_lastScavengeEndTime = extensions->scavengerStats._endTime;
if (doDynamicNewSpaceSizing) {
double expectedTimeRatio = (extensions->dnssExpectedTimeRatioMaximum + extensions->dnssExpectedTimeRatioMinimum) / 2;
/* Find the ratio of time to scavenge versus the interval time since the last scavenge */
double timeRatio = (double)((int64_t)scavengeTime) / (double)((int64_t) intervalTime);
if(debug) {
omrtty_printf("\tTime scav:%llu interval:%llu ratio:%lf\n", scavengeTime, intervalTime, timeRatio);
}
#if defined(OMR_GC_CONCURRENT_SCAVENGER)
if (_extensions->isConcurrentScavengerEnabled()) {
/* In CS world, we cannot easily measure GC overhead. This is just a simple adjustment, which is somewhat ok for light to medium
* loaded systems. In overloaded systems (where GC background threads are starved and GC prolonged), we may expand more than necessary.
* Multi JVM configuration may skew this even more (perhaps it's better to base it on CPU count, rather than GC thread count?). */
timeRatio = timeRatio * _extensions->concurrentScavengerBackgroundThreads / _extensions->dispatcher->activeThreadCount();
if(debug) {
omrtty_printf("\tCS adjusted ratio:%lf\n", timeRatio);
}
}
#endif /* OMR_GC_CONCURRENT_SCAVENGER */
if(debug) {
omrtty_printf("\tAverage scavenge time ratio: %lf -> ", _averageScavengeTimeRatio);
}
/* Based on the current time ratio versus the average time ratio, determine what weight to assign when
* calculating the new average
*/
double weight;
if(timeRatio > _averageScavengeTimeRatio) {
if(timeRatio > expectedTimeRatio) {
if(timeRatio > extensions->dnssExpectedTimeRatioMaximum) {
weight = extensions->dnssWeightedTimeRatioFactorIncreaseLarge;
} else {
weight = extensions->dnssWeightedTimeRatioFactorIncreaseMedium;
}
} else {
weight = extensions->dnssWeightedTimeRatioFactorIncreaseSmall;
}
} else {
weight = extensions->dnssWeightedTimeRatioFactorDecrease;
}
/* Weight determined - calculate the new average */
_averageScavengeTimeRatio = (timeRatio * weight) + (_averageScavengeTimeRatio * (1.0 - weight));
if(debug) {
omrtty_printf("%lf (weight %lf)\n", _averageScavengeTimeRatio, weight);
}
/* If the average scavenge to interval ratio is greater than the maximum, try to expand */
if((_averageScavengeTimeRatio > extensions->dnssExpectedTimeRatioMaximum)
&& (NULL != _physicalSubArena) && _physicalSubArena->canExpand(env) && (maxExpansionInSpace(env) != 0)) {
double desiredExpansionFactor, adjustedExpansionFactor;
/* Try to reach 50% of the expected time ratio through expansion */
desiredExpansionFactor = _averageScavengeTimeRatio - (expectedTimeRatio / 2);
if (desiredExpansionFactor > extensions->dnssMaximumExpansion) {
adjustedExpansionFactor = extensions->dnssMaximumExpansion;
} else if (desiredExpansionFactor < extensions->dnssMinimumExpansion) {
adjustedExpansionFactor = extensions->dnssMinimumExpansion;
} else {
adjustedExpansionFactor = desiredExpansionFactor;
}
/* Adjust the average scavenge to interval ratio */
_averageScavengeTimeRatio -= adjustedExpansionFactor;
_expansionSize = MM_Math::roundToCeiling(extensions->heapAlignment, (uintptr_t)(getCurrentSize() * adjustedExpansionFactor));
_expansionSize = MM_Math::roundToCeiling(2 * regionSize, _expansionSize);
if(debug) {
omrtty_printf("\tExpand decision - expandFactor desired: %lf adjusted: %lf size: %u\n", desiredExpansionFactor, adjustedExpansionFactor, _expansionSize);
omrtty_printf("\tExpand decision - current size: %d expanded size: %d\n", getCurrentSize(), getCurrentSize() + _expansionSize);
omrtty_printf("\tExpand decision - new time ratio:%lf\n\n\n", _averageScavengeTimeRatio);
}
extensions->heap->getResizeStats()->setLastExpandReason(SCAV_RATIO_TOO_HIGH);
}
/* If the average scavenge to interval ratio is less than the minimum, try to contract */
if(_averageScavengeTimeRatio < extensions->dnssExpectedTimeRatioMinimum
&& (NULL != _physicalSubArena) && _physicalSubArena->canContract(env) && (maxContractionInSpace(env) != 0)) {
double desiredContractionFactor, adjustedContractionFactor;
/* Try to reach 200% of the expected minimum time ratio through contraction */
desiredContractionFactor = OMR_MIN(extensions->dnssExpectedTimeRatioMinimum * 2, expectedTimeRatio);
desiredContractionFactor = desiredContractionFactor - _averageScavengeTimeRatio;
if (desiredContractionFactor > extensions->dnssMaximumContraction) {
adjustedContractionFactor = extensions->dnssMaximumContraction;
} else if (desiredContractionFactor < extensions->dnssMinimumContraction) {
adjustedContractionFactor = extensions->dnssMinimumContraction;
} else {
adjustedContractionFactor = desiredContractionFactor;
}
/* Adjust the average scavenge to interval ratio */
_averageScavengeTimeRatio += adjustedContractionFactor;
_contractionSize = MM_Math::roundToCeiling(extensions->heapAlignment, (uintptr_t)(getCurrentSize() * adjustedContractionFactor));
_contractionSize = MM_Math::roundToCeiling(regionSize, _contractionSize);
if(debug) {
omrtty_printf("\tContract decision - contractFactor desired: %lf adjusted: %lf size: %u\n", desiredContractionFactor, adjustedContractionFactor, _contractionSize);
omrtty_printf("\tContract decision - current size: %d contracted size: %d\n", getCurrentSize(), getCurrentSize() - _contractionSize);
omrtty_printf("\tContract decision - new time ratio:%lf\n\n\n", _averageScavengeTimeRatio);