• Home
  • Line#
  • Scopes#
  • Navigate#
  • Raw
  • Download
1 /**
2  * Copyright (c) 2024 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 ark::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(ark::ObjectHeader * objHeader)127 void GenGC<LanguageConfig>::InitGCBits(ark::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(ark::ObjectHeader * objHeader)144 void GenGC<LanguageConfig>::InitGCBitsForAllocationInTLAB(ark::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 
292     auto *objectAllocator = this->GetObjectGenAllocator();
293     ASSERT(this->GetObjectAllocator()->GetYoungSpaceMemRanges().size() == 1);
294     auto youngMemRange = this->GetObjectAllocator()->GetYoungSpaceMemRanges().at(0);
295     HeapVerifierIntoGC<LanguageConfig> youngVerifier = CollectVerificationInfo(youngMemRange);
296 
297     std::function<void(ObjectHeader * objectHeader)> moveVisitor(
298         [this, &objectAllocator, &movedObjects, &youngMoveSize, &youngMoveCount, &youngDeleteSize,
299          &youngDeleteCount](ObjectHeader *objectHeader) -> void {
300             size_t size = GetObjectSize(objectHeader);
301             ASSERT(size <= Runtime::GetOptions().GetMaxTlabSize());
302             // Use aligned size here, because we need to proceed MemStats correctly.
303             size_t alignedSize = GetAlignedObjectSize(size);
304             if (objectHeader->IsMarkedForGC<false>()) {
305                 auto dst = reinterpret_cast<ObjectHeader *>(objectAllocator->AllocateTenuredWithoutLocks(size));
306                 ASSERT(dst != nullptr);
307                 memcpy_s(dst, size, objectHeader, size);
308                 youngMoveSize += alignedSize;
309                 youngMoveCount++;
310                 LOG_DEBUG_OBJECT_EVENTS << "MOVE object " << objectHeader << " -> " << dst << ", size = " << size;
311                 movedObjects.push_back(dst);
312                 // set unmarked dst
313                 UnMarkObject(dst);
314                 this->SetForwardAddress(objectHeader, dst);
315             } else {
316                 LOG_DEBUG_OBJECT_EVENTS << "DELETE OBJECT young: " << objectHeader;
317                 ++youngDeleteCount;
318                 youngDeleteSize += alignedSize;
319             }
320             // We will record all object in MemStats as SPACE_TYPE_OBJECT, so check it
321             ASSERT(PoolManager::GetMmapMemPool()->GetSpaceTypeForAddr(objectHeader) == SpaceType::SPACE_TYPE_OBJECT);
322         });
323     {
324         ScopedTiming moveTiming("MoveAndSweep", *this->GetTiming());
325         objectAllocator->IterateOverYoungObjects(moveVisitor);
326     }
327     this->memStats_.RecordYoungStats(youngMoveSize, youngMoveCount, youngDeleteSize, youngDeleteCount);
328     UpdateRefsToMovedObjects(&movedObjects);
329     this->VerifyCollectAndMove(std::move(youngVerifier));
330     SweepYoungVmRefs();
331     // Remove young
332     objectAllocator->ResetYoungAllocator();
333 
334     this->UpdateMemStats(this->GetPandaVm()->GetMemStats()->GetFootprintHeap(), false);
335 
336     LOG_DEBUG_GC << "== GenGC CollectYoungAndMove end ==";
337 }
338 
339 template <class LanguageConfig>
UpdateRefsToMovedObjects(PandaVector<ObjectHeader * > * movedObjects)340 void GenGC<LanguageConfig>::UpdateRefsToMovedObjects(PandaVector<ObjectHeader *> *movedObjects)
341 {
342     GCScope<TRACE_TIMING> scope("UpdateRefsToMovedObjects", this);
343 
344     auto objAllocator = this->GetObjectAllocator();
345     // Update references exyoung -> young
346     LOG_DEBUG_GC << "process moved objects cnt = " << std::dec << movedObjects->size();
347     LOG_DEBUG_GC << "=== Update exyoung -> young references. START. ===";
348     for (auto obj : *movedObjects) {
349         ObjectHelpers<LanguageConfig::LANG_TYPE>::UpdateRefsToMovedObjects(obj);
350     }
351 
352     LOG_DEBUG_GC << "=== Update exyoung -> young references. END. ===";
353     // update references tenured -> young
354     LOG_DEBUG_GC << "=== Update tenured -> young references. START. ===";
355     auto youngSpace = objAllocator->GetYoungSpaceMemRanges().at(0);
356     auto updateRefsInObject(
357         [](ObjectHeader *obj) { ObjectHelpers<LanguageConfig::LANG_TYPE>::UpdateRefsToMovedObjects(obj); });
358     this->GetCardTable()->VisitMarked(
359         [&updateRefsInObject, &objAllocator, &youngSpace](const MemRange &memRange) {
360             if (!youngSpace.Contains(memRange)) {
361                 objAllocator->IterateOverObjectsInRange(memRange, updateRefsInObject);
362             }
363         },
364         CardTableProcessedFlag::VISIT_MARKED | CardTableProcessedFlag::VISIT_PROCESSED);
365     LOG_DEBUG_GC << "=== Update tenured -> young references. END. ===";
366     this->CommonUpdateRefsToMovedObjects();
367 }
368 
369 template <class LanguageConfig>
RunTenuredGC(GCTask & task)370 void GenGC<LanguageConfig>::RunTenuredGC(GCTask &task)
371 {
372     GCScope<TRACE_TIMING> scope(__FUNCTION__, this);
373     LOG_DEBUG_GC << "GC tenured start";
374     GCMarkingStackType objectsStack(this);
375     {
376         GCScopedPauseStats scopedPauseStats(this->GetPandaVm()->GetGCStats(), nullptr, PauseTypeStats::COMMON_PAUSE);
377         {
378             ScopedTiming unMarkTiming("UnMark", *this->GetTiming());
379             // Unmark all because no filter out tenured when mark young
380             // NOTE(dtrubenk): remove this
381             this->GetObjectAllocator()->IterateOverObjects([this](ObjectHeader *obj) { this->marker_.UnMark(obj); });
382         }
383         InitialMark(&objectsStack);
384     }
385     this->ConcurrentMark(&objectsStack);
386     // NOLINTNEXTLINE(performance-unnecessary-value-param)
387     ReMark(&objectsStack, task);
388 
389     ASSERT(objectsStack.Empty());
390     {
391         ScopedTiming unMarkYoungTiming("UnMarkYoung", *this->GetTiming());
392         this->GetObjectAllocator()->IterateOverYoungObjects([this](ObjectHeader *obj) { this->marker_.UnMark(obj); });
393     }
394     Sweep<true>();
395     LOG_DEBUG_GC << "GC tenured end";
396     task.collectionType = GCCollectionType::TENURED;
397 }
398 
399 // Full GC is ran on pause
400 template <class LanguageConfig>
RunFullGC(GCTask & task)401 void GenGC<LanguageConfig>::RunFullGC(GCTask &task)
402 {
403     GCScope<TRACE_TIMING> fullGcScope(__FUNCTION__, this);
404     LOG_DEBUG_GC << "Full GC start";
405     this->SetFullGC(true);
406     {
407         ScopedTiming unMarkTiming("UnMark", *this->GetTiming());
408         this->GetObjectAllocator()->IterateOverObjects([this](ObjectHeader *obj) { this->marker_.UnMark(obj); });
409     }
410     FullMark(task);
411     Sweep<false>();
412     // Young GC
413     if (LIKELY(HaveEnoughSpaceToMove())) {
414         // We already marked objects above so just collect and move
415         CollectYoungAndMove();
416         this->GetCardTable()->ClearAll();
417     }
418     this->SetFullGC(false);
419     LOG_DEBUG_GC << "Full GC end";
420     task.collectionType = GCCollectionType::FULL;
421 }
422 
423 template <class LanguageConfig>
MarkRoots(GCMarkingStackType * objectsStack,CardTableVisitFlag visitCardTableRoots,const ReferenceCheckPredicateT & refPred,VisitGCRootFlags flags)424 void GenGC<LanguageConfig>::MarkRoots(GCMarkingStackType *objectsStack, CardTableVisitFlag visitCardTableRoots,
425                                       const ReferenceCheckPredicateT &refPred, VisitGCRootFlags flags)
426 {
427     trace::ScopedTrace scopedTrace(__FUNCTION__);
428     GCRootVisitor gcMarkRoots = [this, &objectsStack, &refPred](const GCRoot &gcRoot) {
429         ObjectHeader *rootObject = gcRoot.GetObjectHeader();
430         ObjectHeader *fromObject = gcRoot.GetFromObjectHeader();
431         LOG_DEBUG_GC << "Handle root " << GetDebugInfoAboutObject(rootObject);
432         if (UNLIKELY(fromObject != nullptr) &&
433             this->IsReference(fromObject->NotAtomicClassAddr<BaseClass>(), fromObject, refPred)) {
434             LOG_DEBUG_GC << "Add reference: " << GetDebugInfoAboutObject(fromObject) << " to stack";
435             marker_.Mark(fromObject);
436             this->ProcessReference(objectsStack, fromObject->NotAtomicClassAddr<BaseClass>(), fromObject,
437                                    GC::EmptyReferenceProcessPredicate);
438         } else {
439             // we should always add this object to the stack, because we could mark this object in InitialMark, but
440             // write to some fields in ConcurrentMark - need to iterate over all fields again, MarkObjectIfNotMarked
441             // can't be used here
442             marker_.Mark(rootObject);
443             objectsStack->PushToStack(gcRoot.GetType(), rootObject);
444         }
445     };
446     this->VisitRoots(gcMarkRoots, flags);
447     if (visitCardTableRoots == CardTableVisitFlag::VISIT_ENABLED) {
448         auto allocator = this->GetObjectAllocator();
449         ASSERT(allocator->GetYoungSpaceMemRanges().size() == 1);
450         MemRange youngMr = allocator->GetYoungSpaceMemRanges().at(0);
451         MemRangeChecker youngRangeChecker = []([[maybe_unused]] MemRange &memRange) -> bool { return true; };
452         ObjectChecker youngRangeTenuredObjectChecker = [&youngMr](const ObjectHeader *objectHeader) -> bool {
453             return !youngMr.IsAddressInRange(ToUintPtr(objectHeader));
454         };
455         ObjectChecker fromObjectChecker = [&youngMr, this](const ObjectHeader *objectHeader) -> bool {
456             // Don't visit objects which are in tenured and not marked.
457             return youngMr.IsAddressInRange(ToUintPtr(objectHeader)) || IsMarked(objectHeader);
458         };
459         this->VisitCardTableRoots(this->GetCardTable(), gcMarkRoots, youngRangeChecker, youngRangeTenuredObjectChecker,
460                                   fromObjectChecker, CardTableProcessedFlag::VISIT_MARKED);
461     }
462 }
463 
464 template <class LanguageConfig>
InitialMark(GCMarkingStackType * objectsStack)465 void GenGC<LanguageConfig>::InitialMark(GCMarkingStackType *objectsStack)
466 {
467     GCScope<TRACE_TIMING_PHASE> gcScope(__FUNCTION__, this, GCPhase::GC_PHASE_INITIAL_MARK);
468     {
469         NoAtomicGCMarkerScope scope(&this->marker_);
470         auto refPred = [this](const ObjectHeader *obj) { return this->InGCSweepRange(obj); };
471         MarkRoots(objectsStack, CardTableVisitFlag::VISIT_DISABLED, refPred,
472                   VisitGCRootFlags::ACCESS_ROOT_NONE | VisitGCRootFlags::START_RECORDING_NEW_ROOT);
473     }
474 }
475 
476 template <class LanguageConfig>
ConcurrentMark(GCMarkingStackType * objectsStack)477 NO_THREAD_SAFETY_ANALYSIS void GenGC<LanguageConfig>::ConcurrentMark(GCMarkingStackType *objectsStack)
478 {
479     GCScope<TRACE_TIMING_PHASE> scopedFunc(__FUNCTION__, this, GCPhase::GC_PHASE_MARK);
480     ConcurrentScope concurrentScope(this);
481     auto *objectAllocator = this->GetObjectAllocator();
482     this->MarkImpl(
483         &marker_, objectsStack, CardTableVisitFlag::VISIT_ENABLED,
484         // Process 'weak' references as regular object on concurrent phase to avoid
485         // concurrent access to referent
486         []([[maybe_unused]] const ObjectHeader *obj) { return false; },
487         // non-young mem range checker
488         [objectAllocator](MemRange &memRange) { return !objectAllocator->IsIntersectedWithYoung(memRange); });
489 }
490 
491 template <class LanguageConfig>
ReMark(GCMarkingStackType * objectsStack,const GCTask & task)492 void GenGC<LanguageConfig>::ReMark(GCMarkingStackType *objectsStack, const GCTask &task)
493 {
494     GCScope<TRACE_TIMING_PHASE> gcScope(__FUNCTION__, this, GCPhase::GC_PHASE_REMARK);
495     GCScopedPauseStats scopedPauseStats(this->GetPandaVm()->GetGCStats(), nullptr, PauseTypeStats::REMARK_PAUSE);
496 
497     // NOTE(dtrubenkov): consider iterational concurrent marking of card table
498     {
499         NoAtomicGCMarkerScope scope(&this->marker_);
500         auto refPred = [this](const ObjectHeader *obj) { return this->InGCSweepRange(obj); };
501         MarkRoots(objectsStack, CardTableVisitFlag::VISIT_ENABLED, refPred,
502                   VisitGCRootFlags::ACCESS_ROOT_ONLY_NEW | VisitGCRootFlags::END_RECORDING_NEW_ROOT);
503         this->MarkStack(&marker_, objectsStack, GC::EmptyMarkPreprocess, refPred);
504         {
505             ScopedTiming t1("VisitInternalStringTable", *this->GetTiming());
506             this->GetPandaVm()->VisitStringTable(
507                 [this, &objectsStack](ObjectHeader *str) {
508                     if (this->MarkObjectIfNotMarked(str)) {
509                         ASSERT(str != nullptr);
510                         objectsStack->PushToStack(RootType::STRING_TABLE, str);
511                     }
512                 },
513                 VisitGCRootFlags::ACCESS_ROOT_ONLY_NEW | VisitGCRootFlags::END_RECORDING_NEW_ROOT);
514             this->MarkStack(&marker_, objectsStack, GC::EmptyMarkPreprocess, refPred);
515         }
516         // NOLINTNEXTLINE(performance-unnecessary-value-param)
517         this->GetPandaVm()->HandleReferences(task, GC::EmptyReferenceProcessPredicate);
518     }
519 }
520 
521 template <class LanguageConfig>
FullMark(const GCTask & task)522 void GenGC<LanguageConfig>::FullMark(const GCTask &task)
523 {
524     GCScope<TRACE_TIMING_PHASE> fullMarkScope(__FUNCTION__, this, GCPhase::GC_PHASE_MARK);
525     NoAtomicGCMarkerScope markerScope(&this->marker_);
526 
527     GCMarkingStackType objectsStack(this);
528     VisitGCRootFlags flags = VisitGCRootFlags::ACCESS_ROOT_ALL;
529     auto refPred = GC::EmptyReferenceProcessPredicate;
530     // Mark all reachable objects
531     MarkRoots(&objectsStack, CardTableVisitFlag::VISIT_DISABLED, refPred, flags);
532     this->GetPandaVm()->VisitStringTable(
533         [this, &objectsStack](ObjectHeader *str) {
534             if (this->MarkObjectIfNotMarked(str)) {
535                 ASSERT(str != nullptr);
536                 objectsStack.PushToStack(RootType::STRING_TABLE, str);
537             }
538         },
539         flags);
540     this->MarkStack(&marker_, &objectsStack, GC::EmptyMarkPreprocess, refPred);
541     auto refClearPred = []([[maybe_unused]] const ObjectHeader *obj) { return true; };
542     // NOLINTNEXTLINE(performance-unnecessary-value-param)
543     this->GetPandaVm()->HandleReferences(task, refClearPred);
544 }
545 
546 template <class LanguageConfig>
MarkReferences(GCMarkingStackType * references,GCPhase gcPhase)547 void GenGC<LanguageConfig>::MarkReferences(GCMarkingStackType *references, GCPhase gcPhase)
548 {
549     trace::ScopedTrace scopedTrace(__FUNCTION__);
550     LOG_DEBUG_GC << "Start marking " << references->Size() << " references";
551     auto refPred = [this](const ObjectHeader *obj) { return this->InGCSweepRange(obj); };
552     if (gcPhase == GCPhase::GC_PHASE_MARK_YOUNG) {
553         this->MarkYoungStack(references);
554     } else if (gcPhase == GCPhase::GC_PHASE_INITIAL_MARK || gcPhase == GCPhase::GC_PHASE_MARK ||
555                gcPhase == GCPhase::GC_PHASE_REMARK) {
556         this->MarkStack(&marker_, references, GC::EmptyMarkPreprocess, refPred);
557     } else {
558         UNREACHABLE();
559     }
560 }
561 
562 template <class LanguageConfig>
MarkObject(ObjectHeader * object)563 void GenGC<LanguageConfig>::MarkObject(ObjectHeader *object)
564 {
565     marker_.Mark(object);
566 }
567 
568 template <class LanguageConfig>
UnMarkObject(ObjectHeader * objectHeader)569 void GenGC<LanguageConfig>::UnMarkObject(ObjectHeader *objectHeader)
570 {
571     LOG_DEBUG_GC << "Set unmark for GC " << GetDebugInfoAboutObject(objectHeader);
572     this->marker_.UnMark(objectHeader);
573 }
574 
575 template <class LanguageConfig>
IsMarked(const ObjectHeader * object) const576 bool GenGC<LanguageConfig>::IsMarked(const ObjectHeader *object) const
577 {
578     return this->marker_.IsMarked(object);
579 }
580 
581 // NO_THREAD_SAFETY_ANALYSIS because clang thread safety analysis
582 template <class LanguageConfig>
583 template <bool CONCURRENT>
Sweep()584 NO_THREAD_SAFETY_ANALYSIS void GenGC<LanguageConfig>::Sweep()
585 {
586     GCScope<TRACE_TIMING> gcScope(__FUNCTION__, this);
587     ConcurrentScope concurrentScope(this, false);
588     size_t freedObjectSize = 0U;
589     size_t freedObjectCount = 0U;
590 
591     // NB! can't move block out of brace, we need to make sure GC_PHASE_SWEEP cleared
592     {
593         GCScopedPhase scopedPhase(this, GCPhase::GC_PHASE_SWEEP);
594         // NOTE(dtrubenkov): make concurrent
595         ASSERT(this->GetObjectAllocator()->GetYoungSpaceMemRanges().size() == 1);
596         // new strings may be created in young space during tenured gc, we shouldn't collect them
597         auto youngMemRange = this->GetObjectAllocator()->GetYoungSpaceMemRanges().at(0);
598         this->GetPandaVm()->SweepVmRefs([this, &youngMemRange](ObjectHeader *object) {
599             if (youngMemRange.IsAddressInRange(ToUintPtr(object))) {
600                 return ObjectStatus::ALIVE_OBJECT;
601             }
602             return this->marker_.MarkChecker(object);
603         });
604         // NOLINTNEXTLINE(readability-braces-around-statements, bugprone-suspicious-semicolon)
605         if constexpr (CONCURRENT) {
606             concurrentScope.Start();  // enable concurrent after GC_PHASE_SWEEP has been set
607         }
608 
609         // NOLINTNEXTLINE(readability-braces-around-statements, bugprone-suspicious-semicolon)
610         if constexpr (CONCURRENT && LanguageConfig::MT_MODE != MT_MODE_SINGLE) {
611             // Run monitor deflation again, to avoid object was reclaimed before monitor deflate.
612             auto youngMr = this->GetObjectAllocator()->GetYoungSpaceMemRanges().at(0);
613             this->GetPandaVm()->GetMonitorPool()->DeflateMonitorsWithCallBack([&youngMr, this](Monitor *monitor) {
614                 ObjectHeader *objectHeader = monitor->GetObject();
615                 return (!IsMarked(objectHeader)) && (!youngMr.IsAddressInRange(ToUintPtr(objectHeader)));
616             });
617         }
618 
619         this->GetObjectAllocator()->Collect(
620             [this, &freedObjectSize, &freedObjectCount](ObjectHeader *object) {
621                 auto status = this->marker_.MarkChecker(object);
622                 if (status == ObjectStatus::DEAD_OBJECT) {
623                     LOG_DEBUG_OBJECT_EVENTS << "DELETE OBJECT tenured: " << object;
624                     freedObjectSize += GetAlignedObjectSize(GetObjectSize(object));
625                     freedObjectCount++;
626                 }
627                 return status;
628             },
629             GCCollectMode::GC_ALL);
630         this->GetObjectAllocator()->VisitAndRemoveFreePools([this](void *mem, size_t size) {
631             this->GetCardTable()->ClearCardRange(ToUintPtr(mem), ToUintPtr(mem) + size);
632             PoolManager::GetMmapMemPool()->FreePool(mem, size);
633         });
634     }
635 
636     this->memStats_.RecordSizeFreedTenured(freedObjectSize);
637     this->memStats_.RecordCountFreedTenured(freedObjectCount);
638 
639     // NOLINTNEXTLINE(readability-braces-around-statements, bugprone-suspicious-semicolon)
640     if constexpr (CONCURRENT) {
641         // In concurrent sweep phase, the new created objects may being marked in InitGCBits,
642         // so we need wait for that done, then we can safely unmark objects concurrent with mutator.
643         ASSERT(this->GetGCPhase() != GCPhase::GC_PHASE_SWEEP);  // Make sure we are out of sweep scope
644         this->GetObjectAllocator()->IterateOverTenuredObjects([this](ObjectHeader *obj) { this->marker_.UnMark(obj); });
645     }
646 }
647 
648 template <class LanguageConfig>
SweepYoungVmRefs()649 void GenGC<LanguageConfig>::SweepYoungVmRefs()
650 {
651     GCScope<TRACE_TIMING_PHASE> scope(__FUNCTION__, this, GCPhase::GC_PHASE_SWEEP);
652     // new strings may be created in young space during tenured gc, we shouldn't collect them
653     // Sweep string table here to avoid dangling references
654     ASSERT(this->GetObjectAllocator()->GetYoungSpaceMemRanges().size() == 1);
655     // new strings may be created in young space during tenured gc, we shouldn't collect them
656     auto youngMemRange = this->GetObjectAllocator()->GetYoungSpaceMemRanges().at(0);
657     this->GetPandaVm()->SweepVmRefs([&youngMemRange](ObjectHeader *objectHeader) {
658         if (youngMemRange.IsAddressInRange(ToUintPtr(objectHeader))) {
659             return ObjectStatus::DEAD_OBJECT;
660         }
661         return ObjectStatus::ALIVE_OBJECT;
662     });
663 }
664 
665 template <class LanguageConfig>
InGCSweepRange(const ObjectHeader * obj) const666 bool GenGC<LanguageConfig>::InGCSweepRange(const ObjectHeader *obj) const
667 {
668     bool inYoungSpace = this->GetObjectAllocator()->IsObjectInYoungSpace(obj);
669     auto phase = this->GetGCPhase();
670     // Do young GC and the object is in the young space
671     if (phase == GCPhase::GC_PHASE_MARK_YOUNG && inYoungSpace) {
672         return true;
673     }
674 
675     // Do tenured GC and the object is in the tenured space
676     if (phase != GCPhase::GC_PHASE_MARK_YOUNG && !inYoungSpace) {
677         return true;
678     }
679 
680     return this->IsFullGC();
681 }
682 
683 template <class LanguageConfig>
IsPostponeGCSupported() const684 bool GenGC<LanguageConfig>::IsPostponeGCSupported() const
685 {
686     // Gen GC doesn't support GC postponing because
687     // we have to move young space objects
688     return false;
689 }
690 
691 template <class LanguageConfig>
HaveEnoughSpaceToMove() const692 bool GenGC<LanguageConfig>::HaveEnoughSpaceToMove() const
693 {
694     // hack for pools because we have 2 type of pools in tenures space, in bad cases objects can be moved to different
695     // spaces. And move 4M objects in bump-allocator to other allocator, may need more than 4M space in other allocator
696     // - so we need 3 empty pools.
697     // NOTE(xucheng) : remove the checker when we can do part young collection.
698     // The min num that can guarantee that we move all objects in young space.
699     constexpr size_t POOLS_NUM = 3;
700     return this->GetObjectAllocator()->HaveEnoughPoolsInObjectSpace(POOLS_NUM);
701 }
702 
703 TEMPLATE_CLASS_LANGUAGE_CONFIG(GenGC);
704 
705 }  // namespace ark::mem
706