1 /**
2 * Copyright (c) 2021-2022 Huawei Device Co., Ltd.
3 * Licensed under the Apache License, Version 2.0 (the "License");
4 * you may not use this file except in compliance with the License.
5 * You may obtain a copy of the License at
6 *
7 * http://www.apache.org/licenses/LICENSE-2.0
8 *
9 * Unless required by applicable law or agreed to in writing, software
10 * distributed under the License is distributed on an "AS IS" BASIS,
11 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12 * See the License for the specific language governing permissions and
13 * limitations under the License.
14 */
15
16 #include "runtime/mem/gc/gen-gc/gen-gc.h"
17 #include "runtime/mem/gc/gc_root-inl.h"
18 #include "runtime/mem/object_helpers-inl.h"
19 #include "runtime/include/panda_vm.h"
20 #include "runtime/mem/gc/card_table-inl.h"
21 #include "runtime/timing.h"
22 #include "runtime/mem/pygote_space_allocator-inl.h"
23 #include "runtime/mem/gc/static/gc_marker_static-inl.h"
24 #include "runtime/mem/gc/dynamic/gc_marker_dynamic-inl.h"
25 #include "runtime/mem/gc/generational-gc-base-inl.h"
26
27 namespace panda::mem {
28
29 template <class LanguageConfig>
GenGC(ObjectAllocatorBase * objectAllocator,const GCSettings & settings)30 GenGC<LanguageConfig>::GenGC(ObjectAllocatorBase *objectAllocator, const GCSettings &settings)
31 : GenerationalGC<LanguageConfig>(objectAllocator, settings),
32 marker_(this),
33 isExplicitConcurrentGcEnabled_(settings.IsExplicitConcurrentGcEnabled())
34 {
35 this->SetType(GCType::GEN_GC);
36 this->SetTLABsSupported();
37 }
38
39 template <class LanguageConfig>
InitializeImpl()40 void GenGC<LanguageConfig>::InitializeImpl()
41 {
42 // GC saved the PandaVM instance, so we get allocator from the PandaVM.
43 InternalAllocatorPtr allocator = this->GetInternalAllocator();
44 this->CreateCardTable(allocator, PoolManager::GetMmapMemPool()->GetMinObjectAddress(),
45 PoolManager::GetMmapMemPool()->GetTotalObjectSize());
46 auto barrierSet = allocator->New<GCGenBarrierSet>(allocator, this->GetCardTable(), CardTable::GetCardBits(),
47 CardTable::GetCardDirtyValue());
48 ASSERT(barrierSet != nullptr);
49 this->SetGCBarrierSet(barrierSet);
50 LOG_DEBUG_GC << "GenGC initialized";
51 }
52
53 template <class LanguageConfig>
ShouldRunTenuredGC(const GCTask & task)54 bool GenGC<LanguageConfig>::ShouldRunTenuredGC(const GCTask &task)
55 {
56 return task.reason == GCTaskCause::HEAP_USAGE_THRESHOLD_CAUSE;
57 }
58
59 template <class LanguageConfig>
ShouldRunFullGC(const GCTask & task,bool haveEnoughSpaceForYoung) const60 bool GenGC<LanguageConfig>::ShouldRunFullGC(const GCTask &task, bool haveEnoughSpaceForYoung) const
61 {
62 return !haveEnoughSpaceForYoung || task.reason == GCTaskCause::OOM_CAUSE || this->IsExplicitFull(task) ||
63 this->IsOnPygoteFork() || task.reason == GCTaskCause::STARTUP_COMPLETE_CAUSE;
64 }
65
66 template <class LanguageConfig>
RunPhasesImpl(GCTask & task)67 void GenGC<LanguageConfig>::RunPhasesImpl(GCTask &task)
68 {
69 LOG(DEBUG, GC) << "GenGC start";
70 uint64_t footprintBefore = this->GetPandaVm()->GetMemStats()->GetFootprintHeap();
71 LOG_DEBUG_GC << "Footprint before GC: " << footprintBefore;
72 if (this->IsLogDetailedGcInfoEnabled()) {
73 this->footprintList_.clear();
74 this->footprintList_.push_back({"Footprint before GC", footprintBefore});
75 }
76 uint64_t youngTotalTime = 0;
77 {
78 ScopedTiming t("Generational GC", *this->GetTiming());
79 this->memStats_.Reset();
80 // We trigger a full gc at first pygote fork
81 if (ShouldRunFullGC(task, HaveEnoughSpaceToMove())) {
82 GCScopedPauseStats scopedPauseStats(this->GetPandaVm()->GetGCStats());
83 marker_.BindBitmaps(true); // clear pygote live bitmaps, we will rebuild it
84 this->GetObjectGenAllocator()->InvalidateSpaceData();
85 this->GetObjectGenAllocator()->UpdateSpaceData();
86 RunFullGC(task);
87 } else {
88 {
89 GCScopedPauseStats scopedPauseStats(this->GetPandaVm()->GetGCStats());
90 time::Timer timer(&youngTotalTime, true);
91 marker_.BindBitmaps(false);
92 this->GetObjectGenAllocator()->InvalidateSpaceData();
93 this->GetObjectGenAllocator()->UpdateSpaceData();
94 LOG_DEBUG_GC << "Young range: " << this->GetObjectAllocator()->GetYoungSpaceMemRanges().at(0);
95 RunYoungGC(task);
96 if (youngTotalTime > 0) {
97 this->GetStats()->AddTimeValue(youngTotalTime, TimeTypeStats::YOUNG_TOTAL_TIME);
98 }
99 uint64_t footprintYoung = this->GetPandaVm()->GetMemStats()->GetFootprintHeap();
100 LOG_DEBUG_GC << "Footprint after young: " << footprintYoung;
101 if (this->IsLogDetailedGcInfoEnabled()) {
102 this->footprintList_.push_back({"Footprint after young", footprintYoung});
103 }
104 }
105 if (ShouldRunTenuredGC(task)) {
106 marker_.BindBitmaps(true); // clear pygote live bitmaps, we will rebuild it
107 this->GetObjectGenAllocator()->InvalidateSpaceData();
108 this->GetObjectGenAllocator()->UpdateSpaceData();
109 RunTenuredGC(task);
110 }
111 }
112 }
113 uint64_t footprintAfter = this->GetPandaVm()->GetMemStats()->GetFootprintHeap();
114 LOG_DEBUG_GC << "Footprint after GC: " << footprintAfter;
115 if (this->IsLogDetailedGcInfoEnabled()) {
116 this->footprintList_.push_back({"Footprint after GC", footprintAfter});
117 }
118 }
119
120 template <class LanguageConfig>
PreStartupImp()121 void GenGC<LanguageConfig>::PreStartupImp()
122 {
123 GenerationalGC<LanguageConfig>::DisableTenuredGC();
124 }
125
126 template <class LanguageConfig>
InitGCBits(panda::ObjectHeader * objHeader)127 void GenGC<LanguageConfig>::InitGCBits(panda::ObjectHeader *objHeader)
128 {
129 if (UNLIKELY(this->GetGCPhase() == GCPhase::GC_PHASE_SWEEP) &&
130 (!this->GetObjectAllocator()->IsObjectInYoungSpace(objHeader))) {
131 objHeader->SetMarkedForGC();
132 // do unmark if out of sweep phase otherwise we may miss it in sweep
133 if (UNLIKELY(this->GetGCPhase() != GCPhase::GC_PHASE_SWEEP)) {
134 objHeader->SetUnMarkedForGC();
135 }
136 } else {
137 objHeader->SetUnMarkedForGC();
138 }
139 LOG_DEBUG_GC << "Init gc bits for object: " << std::hex << objHeader << " bit: " << objHeader->IsMarkedForGC()
140 << ", is marked = " << IsMarked(objHeader);
141 }
142
143 template <class LanguageConfig>
InitGCBitsForAllocationInTLAB(panda::ObjectHeader * objHeader)144 void GenGC<LanguageConfig>::InitGCBitsForAllocationInTLAB(panda::ObjectHeader *objHeader)
145 {
146 // Compiler will allocate objects in TLABs only in young space
147 // Therefore, set unmarked for GC here.
148 objHeader->SetUnMarkedForGC();
149 }
150
151 template <class LanguageConfig>
RunYoungGC(GCTask & task)152 void GenGC<LanguageConfig>::RunYoungGC(GCTask &task)
153 {
154 GCScope<TRACE_TIMING> scopedTrace(__FUNCTION__, this);
155 LOG_DEBUG_GC << "GenGC RunYoungGC start";
156 uint64_t youngPauseTime;
157 {
158 NoAtomicGCMarkerScope scope(&this->marker_);
159 time::Timer timer(&youngPauseTime, true);
160 // NOLINTNEXTLINE(performance-unnecessary-value-param)
161 MarkYoung(task);
162 CollectYoungAndMove();
163 this->GetCardTable()->ClearAll();
164 }
165 if (youngPauseTime > 0) {
166 this->GetStats()->AddTimeValue(youngPauseTime, TimeTypeStats::YOUNG_PAUSED_TIME);
167 }
168 LOG_DEBUG_GC << "GenGC RunYoungGC end";
169 task.collectionType = GCCollectionType::YOUNG;
170 }
171
172 template <class LanguageConfig>
MarkYoung(const GCTask & task)173 void GenGC<LanguageConfig>::MarkYoung(const GCTask &task)
174 {
175 GCScope<TRACE_TIMING_PHASE> scope(__FUNCTION__, this, GCPhase::GC_PHASE_MARK_YOUNG);
176
177 // Iterate over roots and add other roots
178 GCMarkingStackType objectsStack(this);
179 ASSERT(this->GetObjectAllocator()->GetYoungSpaceMemRanges().size() == 1);
180 auto youngMr = this->GetObjectAllocator()->GetYoungSpaceMemRanges().at(0);
181 GCRootVisitor gcMarkYoung = [&objectsStack, &youngMr, this](const GCRoot &gcRoot) {
182 // Skip non-young roots
183 auto rootObjectPtr = gcRoot.GetObjectHeader();
184 ASSERT(rootObjectPtr != nullptr);
185 if (!youngMr.IsAddressInRange(ToUintPtr(rootObjectPtr))) {
186 LOG_DEBUG_GC << "Skip root for young mark: " << std::hex << rootObjectPtr;
187 return;
188 }
189 LOG(DEBUG, GC) << "root " << GetDebugInfoAboutObject(rootObjectPtr);
190 if (this->MarkObjectIfNotMarked(rootObjectPtr)) {
191 objectsStack.PushToStack(gcRoot.GetType(), rootObjectPtr);
192 this->MarkYoungStack(&objectsStack);
193 }
194 };
195 {
196 GCScope<TRACE_TIMING> markingYoungRootsTrace("Marking roots young", this);
197 this->VisitRoots(gcMarkYoung,
198 VisitGCRootFlags::ACCESS_ROOT_NONE | VisitGCRootFlags::ACCESS_ROOT_AOT_STRINGS_ONLY_YOUNG);
199 }
200 {
201 ScopedTiming visitCardTableRootsTiming("VisitCardTableRoots", *this->GetTiming());
202 LOG_DEBUG_GC << "START Marking tenured -> young roots";
203 MemRangeChecker tenuredRangeChecker = [&youngMr](MemRange &memRange) -> bool {
204 return !youngMr.IsIntersect(memRange);
205 };
206 ObjectChecker tenuredRangeYoungObjectChecker = [&youngMr](const ObjectHeader *objectHeader) -> bool {
207 return youngMr.IsAddressInRange(ToUintPtr(objectHeader));
208 };
209
210 ObjectChecker fromObjectChecker = []([[maybe_unused]] const ObjectHeader *objectHeader) -> bool {
211 return true;
212 };
213
214 this->VisitCardTableRoots(this->GetCardTable(), gcMarkYoung, tenuredRangeChecker,
215 tenuredRangeYoungObjectChecker, fromObjectChecker,
216 CardTableProcessedFlag::VISIT_MARKED | CardTableProcessedFlag::VISIT_PROCESSED);
217 }
218 // reference-processor in VisitCardTableRoots can add new objects to stack
219 this->MarkYoungStack(&objectsStack);
220 LOG_DEBUG_GC << "END Marking tenured -> young roots";
221 auto refClearPred = [this]([[maybe_unused]] const ObjectHeader *obj) { return this->InGCSweepRange(obj); };
222 this->GetPandaVm()->HandleReferences(task, refClearPred);
223 }
224
225 template <class LanguageConfig>
MarkYoungStack(GCMarkingStackType * stack)226 void GenGC<LanguageConfig>::MarkYoungStack(GCMarkingStackType *stack)
227 {
228 trace::ScopedTrace scopedTrace(__FUNCTION__);
229 ASSERT(stack != nullptr);
230 auto allocator = this->GetObjectAllocator();
231 auto &youngRanges = allocator->GetYoungSpaceMemRanges();
232 auto refPred = [this](const ObjectHeader *obj) { return this->InGCSweepRange(obj); };
233 while (!stack->Empty()) {
234 auto *object = this->PopObjectFromStack(stack);
235 ValidateObject(nullptr, object);
236 auto *cls = object->template ClassAddr<BaseClass>();
237 LOG_DEBUG_GC << "current object " << GetDebugInfoAboutObject(object);
238
239 bool inRange = false;
240 for (const auto &r : youngRanges) {
241 if (r.IsAddressInRange(ToUintPtr(object))) {
242 inRange = true;
243 break;
244 }
245 }
246 if (inRange) {
247 marker_.MarkInstance(stack, object, cls, refPred);
248 }
249 }
250 }
251
252 template <class LanguageConfig>
CollectVerificationInfo(const MemRange & youngMemRange)253 HeapVerifierIntoGC<LanguageConfig> GenGC<LanguageConfig>::CollectVerificationInfo(const MemRange &youngMemRange)
254 {
255 HeapVerifierIntoGC<LanguageConfig> youngVerifier(this->GetPandaVm()->GetHeapManager());
256 if (this->GetSettings()->IntoGCHeapVerification() && !this->IsFullGC()) {
257 ScopedTiming collectVerificationTiming("CollectVerificationInfo", *this->GetTiming());
258 youngVerifier.CollectVerificationInfo(PandaVector<MemRange>(1U, youngMemRange));
259 }
260 return youngVerifier;
261 }
262
263 template <class LanguageConfig>
VerifyCollectAndMove(HeapVerifierIntoGC<LanguageConfig> && youngVerifier)264 void GenGC<LanguageConfig>::VerifyCollectAndMove(HeapVerifierIntoGC<LanguageConfig> &&youngVerifier)
265 {
266 if (this->GetSettings()->IntoGCHeapVerification() && !this->IsFullGC()) {
267 ScopedTiming verificationTiming("Verification", *this->GetTiming());
268 size_t failsCount = youngVerifier.VerifyAll();
269 if (this->GetSettings()->FailOnHeapVerification() && failsCount > 0) {
270 LOG(FATAL, GC) << "Heap was corrupted during GC, HeapVerifier found " << failsCount << " corruptions";
271 }
272 }
273 }
274
275 // NOLINTNEXTLINE(readability-function-size)
276 template <class LanguageConfig>
CollectYoungAndMove()277 void GenGC<LanguageConfig>::CollectYoungAndMove()
278 {
279 GCScope<TRACE_TIMING_PHASE> scope(__FUNCTION__, this, GCPhase::GC_PHASE_COLLECT_YOUNG_AND_MOVE);
280 LOG_DEBUG_GC << "== GenGC CollectYoungAndMove start ==";
281 // NOTE(dtrubenkov): add assert that we in STW
282 PandaVector<ObjectHeader *> movedObjects;
283 size_t prevMovedSize = this->GetPandaVm()->GetMemStats()->GetLastYoungObjectsMovedBytes();
284 constexpr size_t MINIMAL_PREALLOC_MOVE_OBJ = 32U;
285 // Adaptive preallocate buffer for moved_objects to avoid useless reallocations
286 movedObjects.reserve(std::max(MINIMAL_PREALLOC_MOVE_OBJ, prevMovedSize / GetMinimalObjectSize()));
287 size_t youngMoveSize = 0;
288 size_t youngMoveCount = 0;
289 size_t youngDeleteSize = 0;
290 size_t youngDeleteCount = 0;
291 size_t bytesInHeapBeforeMove = this->GetPandaVm()->GetMemStats()->GetFootprintHeap();
292
293 auto *objectAllocator = this->GetObjectGenAllocator();
294 ASSERT(this->GetObjectAllocator()->GetYoungSpaceMemRanges().size() == 1);
295 auto youngMemRange = this->GetObjectAllocator()->GetYoungSpaceMemRanges().at(0);
296 HeapVerifierIntoGC<LanguageConfig> youngVerifier = CollectVerificationInfo(youngMemRange);
297
298 std::function<void(ObjectHeader * objectHeader)> moveVisitor(
299 [this, &objectAllocator, &movedObjects, &youngMoveSize, &youngMoveCount, &youngDeleteSize,
300 &youngDeleteCount](ObjectHeader *objectHeader) -> void {
301 size_t size = GetObjectSize(objectHeader);
302 ASSERT(size <= ObjectAllocatorGen<>::GetYoungAllocMaxSize());
303 // Use aligned size here, because we need to proceed MemStats correctly.
304 size_t alignedSize = GetAlignedObjectSize(size);
305 if (objectHeader->IsMarkedForGC<false>()) {
306 auto dst = reinterpret_cast<ObjectHeader *>(objectAllocator->AllocateTenuredWithoutLocks(size));
307 ASSERT(dst != nullptr);
308 memcpy_s(dst, size, objectHeader, size);
309 youngMoveSize += alignedSize;
310 youngMoveCount++;
311 LOG_DEBUG_OBJECT_EVENTS << "MOVE object " << objectHeader << " -> " << dst << ", size = " << size;
312 movedObjects.push_back(dst);
313 // set unmarked dst
314 UnMarkObject(dst);
315 this->SetForwardAddress(objectHeader, dst);
316 } else {
317 LOG_DEBUG_OBJECT_EVENTS << "DELETE OBJECT young: " << objectHeader;
318 ++youngDeleteCount;
319 youngDeleteSize += alignedSize;
320 }
321 // We will record all object in MemStats as SPACE_TYPE_OBJECT, so check it
322 ASSERT(PoolManager::GetMmapMemPool()->GetSpaceTypeForAddr(objectHeader) == SpaceType::SPACE_TYPE_OBJECT);
323 });
324 {
325 ScopedTiming moveTiming("MoveAndSweep", *this->GetTiming());
326 objectAllocator->IterateOverYoungObjects(moveVisitor);
327 }
328 this->memStats_.RecordSizeMovedYoung(youngMoveSize);
329 this->memStats_.RecordCountMovedYoung(youngMoveCount);
330 this->memStats_.RecordSizeFreedYoung(youngDeleteSize);
331 this->memStats_.RecordCountFreedYoung(youngDeleteCount);
332 UpdateRefsToMovedObjects(&movedObjects);
333 this->VerifyCollectAndMove(std::move(youngVerifier));
334 SweepYoungVmRefs();
335 // Remove young
336 objectAllocator->ResetYoungAllocator();
337
338 this->UpdateMemStats(bytesInHeapBeforeMove, false);
339
340 LOG_DEBUG_GC << "== GenGC CollectYoungAndMove end ==";
341 }
342
343 template <class LanguageConfig>
UpdateRefsToMovedObjects(PandaVector<ObjectHeader * > * movedObjects)344 void GenGC<LanguageConfig>::UpdateRefsToMovedObjects(PandaVector<ObjectHeader *> *movedObjects)
345 {
346 GCScope<TRACE_TIMING> scope("UpdateRefsToMovedObjects", this);
347
348 auto objAllocator = this->GetObjectAllocator();
349 // Update references exyoung -> young
350 LOG_DEBUG_GC << "process moved objects cnt = " << std::dec << movedObjects->size();
351 LOG_DEBUG_GC << "=== Update exyoung -> young references. START. ===";
352 for (auto obj : *movedObjects) {
353 ObjectHelpers<LanguageConfig::LANG_TYPE>::UpdateRefsToMovedObjects(obj);
354 }
355
356 LOG_DEBUG_GC << "=== Update exyoung -> young references. END. ===";
357 // update references tenured -> young
358 LOG_DEBUG_GC << "=== Update tenured -> young references. START. ===";
359 auto youngSpace = objAllocator->GetYoungSpaceMemRanges().at(0);
360 auto updateRefsInObject(
361 [](ObjectHeader *obj) { ObjectHelpers<LanguageConfig::LANG_TYPE>::UpdateRefsToMovedObjects(obj); });
362 this->GetCardTable()->VisitMarked(
363 [&updateRefsInObject, &objAllocator, &youngSpace](const MemRange &memRange) {
364 if (!youngSpace.Contains(memRange)) {
365 objAllocator->IterateOverObjectsInRange(memRange, updateRefsInObject);
366 }
367 },
368 CardTableProcessedFlag::VISIT_MARKED | CardTableProcessedFlag::VISIT_PROCESSED);
369 LOG_DEBUG_GC << "=== Update tenured -> young references. END. ===";
370 this->CommonUpdateRefsToMovedObjects();
371 }
372
373 template <class LanguageConfig>
RunTenuredGC(GCTask & task)374 void GenGC<LanguageConfig>::RunTenuredGC(GCTask &task)
375 {
376 GCScope<TRACE_TIMING> scope(__FUNCTION__, this);
377 LOG_DEBUG_GC << "GC tenured start";
378 GCMarkingStackType objectsStack(this);
379 {
380 GCScopedPauseStats scopedPauseStats(this->GetPandaVm()->GetGCStats(), nullptr, PauseTypeStats::COMMON_PAUSE);
381 {
382 ScopedTiming unMarkTiming("UnMark", *this->GetTiming());
383 // Unmark all because no filter out tenured when mark young
384 // NOTE(dtrubenk): remove this
385 this->GetObjectAllocator()->IterateOverObjects([this](ObjectHeader *obj) { this->marker_.UnMark(obj); });
386 }
387 InitialMark(&objectsStack);
388 }
389 this->ConcurrentMark(&objectsStack);
390 // NOLINTNEXTLINE(performance-unnecessary-value-param)
391 ReMark(&objectsStack, task);
392
393 ASSERT(objectsStack.Empty());
394 {
395 ScopedTiming unMarkYoungTiming("UnMarkYoung", *this->GetTiming());
396 this->GetObjectAllocator()->IterateOverYoungObjects([this](ObjectHeader *obj) { this->marker_.UnMark(obj); });
397 }
398 Sweep<true>();
399 LOG_DEBUG_GC << "GC tenured end";
400 task.collectionType = GCCollectionType::TENURED;
401 }
402
403 // Full GC is ran on pause
404 template <class LanguageConfig>
RunFullGC(GCTask & task)405 void GenGC<LanguageConfig>::RunFullGC(GCTask &task)
406 {
407 GCScope<TRACE_TIMING> fullGcScope(__FUNCTION__, this);
408 LOG_DEBUG_GC << "Full GC start";
409 this->SetFullGC(true);
410 {
411 ScopedTiming unMarkTiming("UnMark", *this->GetTiming());
412 this->GetObjectAllocator()->IterateOverObjects([this](ObjectHeader *obj) { this->marker_.UnMark(obj); });
413 }
414 FullMark(task);
415 Sweep<false>();
416 // Young GC
417 if (LIKELY(HaveEnoughSpaceToMove())) {
418 // We already marked objects above so just collect and move
419 CollectYoungAndMove();
420 this->GetCardTable()->ClearAll();
421 }
422 this->SetFullGC(false);
423 LOG_DEBUG_GC << "Full GC end";
424 task.collectionType = GCCollectionType::FULL;
425 }
426
427 template <class LanguageConfig>
MarkRoots(GCMarkingStackType * objectsStack,CardTableVisitFlag visitCardTableRoots,const ReferenceCheckPredicateT & refPred,VisitGCRootFlags flags)428 void GenGC<LanguageConfig>::MarkRoots(GCMarkingStackType *objectsStack, CardTableVisitFlag visitCardTableRoots,
429 const ReferenceCheckPredicateT &refPred, VisitGCRootFlags flags)
430 {
431 trace::ScopedTrace scopedTrace(__FUNCTION__);
432 GCRootVisitor gcMarkRoots = [this, &objectsStack, &refPred](const GCRoot &gcRoot) {
433 ObjectHeader *rootObject = gcRoot.GetObjectHeader();
434 ObjectHeader *fromObject = gcRoot.GetFromObjectHeader();
435 LOG_DEBUG_GC << "Handle root " << GetDebugInfoAboutObject(rootObject);
436 if (UNLIKELY(fromObject != nullptr) &&
437 this->IsReference(fromObject->NotAtomicClassAddr<BaseClass>(), fromObject, refPred)) {
438 LOG_DEBUG_GC << "Add reference: " << GetDebugInfoAboutObject(fromObject) << " to stack";
439 marker_.Mark(fromObject);
440 this->ProcessReference(objectsStack, fromObject->NotAtomicClassAddr<BaseClass>(), fromObject,
441 GC::EmptyReferenceProcessPredicate);
442 } else {
443 // we should always add this object to the stack, because we could mark this object in InitialMark, but
444 // write to some fields in ConcurrentMark - need to iterate over all fields again, MarkObjectIfNotMarked
445 // can't be used here
446 marker_.Mark(rootObject);
447 objectsStack->PushToStack(gcRoot.GetType(), rootObject);
448 }
449 };
450 this->VisitRoots(gcMarkRoots, flags);
451 if (visitCardTableRoots == CardTableVisitFlag::VISIT_ENABLED) {
452 auto allocator = this->GetObjectAllocator();
453 ASSERT(allocator->GetYoungSpaceMemRanges().size() == 1);
454 MemRange youngMr = allocator->GetYoungSpaceMemRanges().at(0);
455 MemRangeChecker youngRangeChecker = []([[maybe_unused]] MemRange &memRange) -> bool { return true; };
456 ObjectChecker youngRangeTenuredObjectChecker = [&youngMr](const ObjectHeader *objectHeader) -> bool {
457 return !youngMr.IsAddressInRange(ToUintPtr(objectHeader));
458 };
459 ObjectChecker fromObjectChecker = [&youngMr, this](const ObjectHeader *objectHeader) -> bool {
460 // Don't visit objects which are in tenured and not marked.
461 return youngMr.IsAddressInRange(ToUintPtr(objectHeader)) || IsMarked(objectHeader);
462 };
463 this->VisitCardTableRoots(this->GetCardTable(), gcMarkRoots, youngRangeChecker, youngRangeTenuredObjectChecker,
464 fromObjectChecker, CardTableProcessedFlag::VISIT_MARKED);
465 }
466 }
467
468 template <class LanguageConfig>
InitialMark(GCMarkingStackType * objectsStack)469 void GenGC<LanguageConfig>::InitialMark(GCMarkingStackType *objectsStack)
470 {
471 GCScope<TRACE_TIMING_PHASE> gcScope(__FUNCTION__, this, GCPhase::GC_PHASE_INITIAL_MARK);
472 {
473 NoAtomicGCMarkerScope scope(&this->marker_);
474 auto refPred = [this](const ObjectHeader *obj) { return this->InGCSweepRange(obj); };
475 MarkRoots(objectsStack, CardTableVisitFlag::VISIT_DISABLED, refPred,
476 VisitGCRootFlags::ACCESS_ROOT_NONE | VisitGCRootFlags::START_RECORDING_NEW_ROOT);
477 }
478 }
479
480 template <class LanguageConfig>
ConcurrentMark(GCMarkingStackType * objectsStack)481 NO_THREAD_SAFETY_ANALYSIS void GenGC<LanguageConfig>::ConcurrentMark(GCMarkingStackType *objectsStack)
482 {
483 GCScope<TRACE_TIMING_PHASE> scopedFunc(__FUNCTION__, this, GCPhase::GC_PHASE_MARK);
484 ConcurrentScope concurrentScope(this);
485 auto *objectAllocator = this->GetObjectAllocator();
486 this->MarkImpl(
487 &marker_, objectsStack, CardTableVisitFlag::VISIT_ENABLED,
488 // Process 'weak' references as regular object on concurrent phase to avoid
489 // concurrent access to referent
490 []([[maybe_unused]] const ObjectHeader *obj) { return false; },
491 // non-young mem range checker
492 [objectAllocator](MemRange &memRange) { return !objectAllocator->IsIntersectedWithYoung(memRange); });
493 }
494
495 template <class LanguageConfig>
ReMark(GCMarkingStackType * objectsStack,const GCTask & task)496 void GenGC<LanguageConfig>::ReMark(GCMarkingStackType *objectsStack, const GCTask &task)
497 {
498 GCScope<TRACE_TIMING_PHASE> gcScope(__FUNCTION__, this, GCPhase::GC_PHASE_REMARK);
499 GCScopedPauseStats scopedPauseStats(this->GetPandaVm()->GetGCStats(), nullptr, PauseTypeStats::REMARK_PAUSE);
500
501 // NOTE(dtrubenkov): consider iterational concurrent marking of card table
502 {
503 NoAtomicGCMarkerScope scope(&this->marker_);
504 auto refPred = [this](const ObjectHeader *obj) { return this->InGCSweepRange(obj); };
505 MarkRoots(objectsStack, CardTableVisitFlag::VISIT_ENABLED, refPred,
506 VisitGCRootFlags::ACCESS_ROOT_ONLY_NEW | VisitGCRootFlags::END_RECORDING_NEW_ROOT);
507 this->MarkStack(&marker_, objectsStack, GC::EmptyMarkPreprocess, refPred);
508 {
509 ScopedTiming t1("VisitInternalStringTable", *this->GetTiming());
510 this->GetPandaVm()->VisitStringTable(
511 [this, &objectsStack](ObjectHeader *str) {
512 if (this->MarkObjectIfNotMarked(str)) {
513 ASSERT(str != nullptr);
514 objectsStack->PushToStack(RootType::STRING_TABLE, str);
515 }
516 },
517 VisitGCRootFlags::ACCESS_ROOT_ONLY_NEW | VisitGCRootFlags::END_RECORDING_NEW_ROOT);
518 this->MarkStack(&marker_, objectsStack, GC::EmptyMarkPreprocess, refPred);
519 }
520 // NOLINTNEXTLINE(performance-unnecessary-value-param)
521 this->GetPandaVm()->HandleReferences(task, GC::EmptyReferenceProcessPredicate);
522 }
523 }
524
525 template <class LanguageConfig>
FullMark(const GCTask & task)526 void GenGC<LanguageConfig>::FullMark(const GCTask &task)
527 {
528 GCScope<TRACE_TIMING_PHASE> fullMarkScope(__FUNCTION__, this, GCPhase::GC_PHASE_MARK);
529 NoAtomicGCMarkerScope markerScope(&this->marker_);
530
531 GCMarkingStackType objectsStack(this);
532 VisitGCRootFlags flags = VisitGCRootFlags::ACCESS_ROOT_ALL;
533 auto refPred = GC::EmptyReferenceProcessPredicate;
534 // Mark all reachable objects
535 MarkRoots(&objectsStack, CardTableVisitFlag::VISIT_DISABLED, refPred, flags);
536 this->GetPandaVm()->VisitStringTable(
537 [this, &objectsStack](ObjectHeader *str) {
538 if (this->MarkObjectIfNotMarked(str)) {
539 ASSERT(str != nullptr);
540 objectsStack.PushToStack(RootType::STRING_TABLE, str);
541 }
542 },
543 flags);
544 this->MarkStack(&marker_, &objectsStack, GC::EmptyMarkPreprocess, refPred);
545 auto refClearPred = []([[maybe_unused]] const ObjectHeader *obj) { return true; };
546 // NOLINTNEXTLINE(performance-unnecessary-value-param)
547 this->GetPandaVm()->HandleReferences(task, refClearPred);
548 }
549
550 template <class LanguageConfig>
MarkReferences(GCMarkingStackType * references,GCPhase gcPhase)551 void GenGC<LanguageConfig>::MarkReferences(GCMarkingStackType *references, GCPhase gcPhase)
552 {
553 trace::ScopedTrace scopedTrace(__FUNCTION__);
554 LOG_DEBUG_GC << "Start marking " << references->Size() << " references";
555 auto refPred = [this](const ObjectHeader *obj) { return this->InGCSweepRange(obj); };
556 if (gcPhase == GCPhase::GC_PHASE_MARK_YOUNG) {
557 this->MarkYoungStack(references);
558 } else if (gcPhase == GCPhase::GC_PHASE_INITIAL_MARK || gcPhase == GCPhase::GC_PHASE_MARK ||
559 gcPhase == GCPhase::GC_PHASE_REMARK) {
560 this->MarkStack(&marker_, references, GC::EmptyMarkPreprocess, refPred);
561 } else {
562 UNREACHABLE();
563 }
564 }
565
566 template <class LanguageConfig>
MarkObject(ObjectHeader * object)567 void GenGC<LanguageConfig>::MarkObject(ObjectHeader *object)
568 {
569 marker_.Mark(object);
570 }
571
572 template <class LanguageConfig>
UnMarkObject(ObjectHeader * objectHeader)573 void GenGC<LanguageConfig>::UnMarkObject(ObjectHeader *objectHeader)
574 {
575 LOG_DEBUG_GC << "Set unmark for GC " << GetDebugInfoAboutObject(objectHeader);
576 this->marker_.UnMark(objectHeader);
577 }
578
579 template <class LanguageConfig>
IsMarked(const ObjectHeader * object) const580 bool GenGC<LanguageConfig>::IsMarked(const ObjectHeader *object) const
581 {
582 return this->marker_.IsMarked(object);
583 }
584
585 // NO_THREAD_SAFETY_ANALYSIS because clang thread safety analysis
586 template <class LanguageConfig>
587 template <bool CONCURRENT>
Sweep()588 NO_THREAD_SAFETY_ANALYSIS void GenGC<LanguageConfig>::Sweep()
589 {
590 GCScope<TRACE_TIMING> gcScope(__FUNCTION__, this);
591 ConcurrentScope concurrentScope(this, false);
592 size_t freedObjectSize = 0U;
593 size_t freedObjectCount = 0U;
594
595 // NB! can't move block out of brace, we need to make sure GC_PHASE_SWEEP cleared
596 {
597 GCScopedPhase scopedPhase(this, GCPhase::GC_PHASE_SWEEP);
598 // NOTE(dtrubenkov): make concurrent
599 ASSERT(this->GetObjectAllocator()->GetYoungSpaceMemRanges().size() == 1);
600 // new strings may be created in young space during tenured gc, we shouldn't collect them
601 auto youngMemRange = this->GetObjectAllocator()->GetYoungSpaceMemRanges().at(0);
602 this->GetPandaVm()->SweepVmRefs([this, &youngMemRange](ObjectHeader *object) {
603 if (youngMemRange.IsAddressInRange(ToUintPtr(object))) {
604 return ObjectStatus::ALIVE_OBJECT;
605 }
606 return this->marker_.MarkChecker(object);
607 });
608 // NOLINTNEXTLINE(readability-braces-around-statements, bugprone-suspicious-semicolon)
609 if constexpr (CONCURRENT) {
610 concurrentScope.Start(); // enable concurrent after GC_PHASE_SWEEP has been set
611 }
612
613 // NOLINTNEXTLINE(readability-braces-around-statements, bugprone-suspicious-semicolon)
614 if constexpr (CONCURRENT && LanguageConfig::MT_MODE == MT_MODE_MULTI) {
615 // Run monitor deflation again, to avoid object was reclaimed before monitor deflate.
616 auto youngMr = this->GetObjectAllocator()->GetYoungSpaceMemRanges().at(0);
617 this->GetPandaVm()->GetMonitorPool()->DeflateMonitorsWithCallBack([&youngMr, this](Monitor *monitor) {
618 ObjectHeader *objectHeader = monitor->GetObject();
619 return (!IsMarked(objectHeader)) && (!youngMr.IsAddressInRange(ToUintPtr(objectHeader)));
620 });
621 }
622
623 this->GetObjectAllocator()->Collect(
624 [this, &freedObjectSize, &freedObjectCount](ObjectHeader *object) {
625 auto status = this->marker_.MarkChecker(object);
626 if (status == ObjectStatus::DEAD_OBJECT) {
627 LOG_DEBUG_OBJECT_EVENTS << "DELETE OBJECT tenured: " << object;
628 freedObjectSize += GetAlignedObjectSize(GetObjectSize(object));
629 freedObjectCount++;
630 }
631 return status;
632 },
633 GCCollectMode::GC_ALL);
634 this->GetObjectAllocator()->VisitAndRemoveFreePools([this](void *mem, size_t size) {
635 this->GetCardTable()->ClearCardRange(ToUintPtr(mem), ToUintPtr(mem) + size);
636 PoolManager::GetMmapMemPool()->FreePool(mem, size);
637 });
638 }
639
640 this->memStats_.RecordSizeFreedTenured(freedObjectSize);
641 this->memStats_.RecordCountFreedTenured(freedObjectCount);
642
643 // NOLINTNEXTLINE(readability-braces-around-statements, bugprone-suspicious-semicolon)
644 if constexpr (CONCURRENT) {
645 // In concurrent sweep phase, the new created objects may being marked in InitGCBits,
646 // so we need wait for that done, then we can safely unmark objects concurrent with mutator.
647 ASSERT(this->GetGCPhase() != GCPhase::GC_PHASE_SWEEP); // Make sure we are out of sweep scope
648 this->GetObjectAllocator()->IterateOverTenuredObjects([this](ObjectHeader *obj) { this->marker_.UnMark(obj); });
649 }
650 }
651
652 template <class LanguageConfig>
SweepYoungVmRefs()653 void GenGC<LanguageConfig>::SweepYoungVmRefs()
654 {
655 GCScope<TRACE_TIMING_PHASE> scope(__FUNCTION__, this, GCPhase::GC_PHASE_SWEEP);
656 // new strings may be created in young space during tenured gc, we shouldn't collect them
657 // Sweep string table here to avoid dangling references
658 ASSERT(this->GetObjectAllocator()->GetYoungSpaceMemRanges().size() == 1);
659 // new strings may be created in young space during tenured gc, we shouldn't collect them
660 auto youngMemRange = this->GetObjectAllocator()->GetYoungSpaceMemRanges().at(0);
661 this->GetPandaVm()->SweepVmRefs([&youngMemRange](ObjectHeader *objectHeader) {
662 if (youngMemRange.IsAddressInRange(ToUintPtr(objectHeader))) {
663 return ObjectStatus::DEAD_OBJECT;
664 }
665 return ObjectStatus::ALIVE_OBJECT;
666 });
667 }
668
669 template <class LanguageConfig>
InGCSweepRange(const ObjectHeader * obj) const670 bool GenGC<LanguageConfig>::InGCSweepRange(const ObjectHeader *obj) const
671 {
672 bool inYoungSpace = this->GetObjectAllocator()->IsObjectInYoungSpace(obj);
673 auto phase = this->GetGCPhase();
674 // Do young GC and the object is in the young space
675 if (phase == GCPhase::GC_PHASE_MARK_YOUNG && inYoungSpace) {
676 return true;
677 }
678
679 // Do tenured GC and the object is in the tenured space
680 if (phase != GCPhase::GC_PHASE_MARK_YOUNG && !inYoungSpace) {
681 return true;
682 }
683
684 return this->IsFullGC();
685 }
686
687 template <class LanguageConfig>
IsPostponeGCSupported() const688 bool GenGC<LanguageConfig>::IsPostponeGCSupported() const
689 {
690 // Gen GC doesn't support GC postponing because
691 // we have to move young space objects
692 return false;
693 }
694
695 template <class LanguageConfig>
HaveEnoughSpaceToMove() const696 bool GenGC<LanguageConfig>::HaveEnoughSpaceToMove() const
697 {
698 // hack for pools because we have 2 type of pools in tenures space, in bad cases objects can be moved to different
699 // spaces. And move 4M objects in bump-allocator to other allocator, may need more than 4M space in other allocator
700 // - so we need 3 empty pools.
701 // NOTE(xucheng) : remove the checker when we can do part young collection.
702 // The min num that can guarantee that we move all objects in young space.
703 constexpr size_t POOLS_NUM = 3;
704 return this->GetObjectAllocator()->HaveEnoughPoolsInObjectSpace(POOLS_NUM);
705 }
706
707 TEMPLATE_CLASS_LANGUAGE_CONFIG(GenGC);
708
709 } // namespace panda::mem
710