heap/Heap.h

   1 /*
   2  *  Copyright (C) 1999-2000 Harri Porten (porten@kde.org)
   3  *  Copyright (C) 2001 Peter Kelly (pmk@post.com)
   4  *  Copyright (C) 2003-2009, 2013-2014 Apple Inc. All rights reserved.
   5  *
   6  *  This library is free software; you can redistribute it and/or
   7  *  modify it under the terms of the GNU Lesser General Public
   8  *  License as published by the Free Software Foundation; either
   9  *  version 2 of the License, or (at your option) any later version.
  10  *
  11  *  This library is distributed in the hope that it will be useful,
  12  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14  *  Lesser General Public License for more details.
  15  *
  16  *  You should have received a copy of the GNU Lesser General Public
  17  *  License along with this library; if not, write to the Free Software
  18  *  Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
  19  *
  20  */
  21
  22 #ifndef Heap_h
  23 #define Heap_h
  24
  25 #include "ArrayBuffer.h"
  26 #include "BlockAllocator.h"
  27 #include "CodeBlockSet.h"
  28 #include "CopyVisitor.h"
  29 #include "GCIncomingRefCountedSet.h"
  30 #include "GCThreadSharedData.h"
  31 #include "HandleSet.h"
  32 #include "HandleStack.h"
  33 #include "HeapOperation.h"
  34 #include "JITStubRoutineSet.h"
  35 #include "MarkedAllocator.h"
  36 #include "MarkedBlock.h"
  37 #include "MarkedBlockSet.h"
  38 #include "MarkedSpace.h"
  39 #include "Options.h"
  40 #include "SlotVisitor.h"
  41 #include "StructureIDTable.h"
  42 #include "WeakHandleOwner.h"
  43 #include "WriteBarrierBuffer.h"
  44 #include "WriteBarrierSupport.h"
  45 #include <wtf/HashCountedSet.h>
  46 #include <wtf/HashSet.h>
  47
  48 namespace JSC {
  49
  50 class CopiedSpace;
  51 class CodeBlock;
  52 class ExecutableBase;
  53 class EdenGCActivityCallback;
  54 class FullGCActivityCallback;
  55 class GCActivityCallback;
  56 class GCAwareJITStubRoutine;
  57 class GlobalCodeBlock;
  58 class Heap;
  59 class HeapRootVisitor;
  60 class IncrementalSweeper;
  61 class JITStubRoutine;
  62 class JSCell;
  63 class VM;
  64 class JSStack;
  65 class JSValue;
  66 class LiveObjectIterator;
  67 class LLIntOffsetsExtractor;
  68 class MarkedArgumentBuffer;
  69 class WeakGCHandlePool;
  70 class SlotVisitor;
  71
  72 namespace DFG {
  73 class Worklist;
  74 }
  75
  76 static void* const zombifiedBits = reinterpret_cast<void*>(0xdeadbeef);
  77
  78 typedef std::pair<JSValue, WTF::String> ValueStringPair;
  79 typedef HashCountedSet<JSCell*> ProtectCountSet;
  80 typedef HashCountedSet<const char*> TypeCountSet;
  81
  82 enum HeapType { SmallHeap, LargeHeap };
  83
  84 class Heap {
  85     WTF_MAKE_NONCOPYABLE(Heap);
  86 public:
  87     friend class JIT;
  88     friend class DFG::SpeculativeJIT;
  89     friend class GCThreadSharedData;
  90     static Heap* heap(const JSValue); // 0 for immediate values
  91     static Heap* heap(const JSCell*);
  92
  93     // This constant determines how many blocks we iterate between checks of our
  94     // deadline when calling Heap::isPagedOut. Decreasing it will cause us to detect
  95     // overstepping our deadline more quickly, while increasing it will cause
  96     // our scan to run faster.
  97     static const unsigned s_timeCheckResolution = 16;
  98
  99     static bool isLive(const void*);
 100     static bool isMarked(const void*);
 101     static bool testAndSetMarked(const void*);
 102     static void setMarked(const void*);
 103     static bool isRemembered(const void*);
 104
 105     JS_EXPORT_PRIVATE void addToRememberedSet(const JSCell*);
 106     static bool isWriteBarrierEnabled();
 107     void writeBarrier(const JSCell*);
 108     void writeBarrier(const JSCell*, JSValue);
 109     void writeBarrier(const JSCell*, JSCell*);
 110
 111     WriteBarrierBuffer& writeBarrierBuffer() { return m_writeBarrierBuffer; }
 112     void flushWriteBarrierBuffer(JSCell*);
 113
 114     Heap(VM*, HeapType);
 115     ~Heap();
 116     JS_EXPORT_PRIVATE void lastChanceToFinalize();
 117
 118     VM* vm() const { return m_vm; }
 119     MarkedSpace& objectSpace() { return m_objectSpace; }
 120     MachineThreads& machineThreads() { return m_machineThreads; }
 121
 122     const SlotVisitor& slotVisitor() const { return m_slotVisitor; }
 123
 124     JS_EXPORT_PRIVATE GCActivityCallback* fullActivityCallback();
 125     JS_EXPORT_PRIVATE GCActivityCallback* edenActivityCallback();
 126     JS_EXPORT_PRIVATE void setFullActivityCallback(PassRefPtr<FullGCActivityCallback>);
 127     JS_EXPORT_PRIVATE void setEdenActivityCallback(PassRefPtr<EdenGCActivityCallback>);
 128     JS_EXPORT_PRIVATE void setGarbageCollectionTimerEnabled(bool);
 129
 130     JS_EXPORT_PRIVATE IncrementalSweeper* sweeper();
 131     JS_EXPORT_PRIVATE void setIncrementalSweeper(PassOwnPtr<IncrementalSweeper>);
 132
 133     // true if collection is in progress
 134     bool isCollecting();
 135     HeapOperation operationInProgress() { return m_operationInProgress; }
 136     // true if an allocation or collection is in progress
 137     bool isBusy();
 138
 139     MarkedAllocator& allocatorForObjectWithoutDestructor(size_t bytes) { return m_objectSpace.allocatorFor(bytes); }
 140     MarkedAllocator& allocatorForObjectWithNormalDestructor(size_t bytes) { return m_objectSpace.normalDestructorAllocatorFor(bytes); }
 141     MarkedAllocator& allocatorForObjectWithImmortalStructureDestructor(size_t bytes) { return m_objectSpace.immortalStructureDestructorAllocatorFor(bytes); }
 142     CopiedAllocator& storageAllocator() { return m_storageSpace.allocator(); }
 143     CheckedBoolean tryAllocateStorage(JSCell* intendedOwner, size_t, void**);
 144     CheckedBoolean tryReallocateStorage(JSCell* intendedOwner, void**, size_t, size_t);
 145     void ascribeOwner(JSCell* intendedOwner, void*);
 146
 147     typedef void (*Finalizer)(JSCell*);
 148     JS_EXPORT_PRIVATE void addFinalizer(JSCell*, Finalizer);
 149     void addCompiledCode(ExecutableBase*);
 150
 151     void notifyIsSafeToCollect() { m_isSafeToCollect = true; }
 152     bool isSafeToCollect() const { return m_isSafeToCollect; }
 153
 154     JS_EXPORT_PRIVATE void collectAllGarbage();
 155     bool shouldCollect();
 156     JS_EXPORT_PRIVATE void collect(HeapOperation collectionType = AnyCollection);
 157     bool collectIfNecessaryOrDefer(); // Returns true if it did collect.
 158
 159     void reportExtraMemoryCost(size_t cost);
 160     JS_EXPORT_PRIVATE void reportAbandonedObjectGraph();
 161
 162     JS_EXPORT_PRIVATE void protect(JSValue);
 163     JS_EXPORT_PRIVATE bool unprotect(JSValue); // True when the protect count drops to 0.
 164
 165     size_t extraSize(); // extra memory usage outside of pages allocated by the heap
 166     JS_EXPORT_PRIVATE size_t size();
 167     JS_EXPORT_PRIVATE size_t capacity();
 168     JS_EXPORT_PRIVATE size_t objectCount();
 169     JS_EXPORT_PRIVATE size_t globalObjectCount();
 170     JS_EXPORT_PRIVATE size_t protectedObjectCount();
 171     JS_EXPORT_PRIVATE size_t protectedGlobalObjectCount();
 172     JS_EXPORT_PRIVATE PassOwnPtr<TypeCountSet> protectedObjectTypeCounts();
 173     JS_EXPORT_PRIVATE PassOwnPtr<TypeCountSet> objectTypeCounts();
 174     void showStatistics();
 175
 176     void pushTempSortVector(Vector<ValueStringPair, 0, UnsafeVectorOverflow>*);
 177     void popTempSortVector(Vector<ValueStringPair, 0, UnsafeVectorOverflow>*);
 178
 179     HashSet<MarkedArgumentBuffer*>& markListSet();
 180
 181     template<typename Functor> typename Functor::ReturnType forEachProtectedCell(Functor&);
 182     template<typename Functor> typename Functor::ReturnType forEachProtectedCell();
 183     template<typename Functor> void forEachCodeBlock(Functor&);
 184
 185     HandleSet* handleSet() { return &m_handleSet; }
 186     HandleStack* handleStack() { return &m_handleStack; }
 187
 188     void willStartIterating();
 189     void didFinishIterating();
 190     void getConservativeRegisterRoots(HashSet<JSCell*>& roots);
 191
 192     double lastFullGCLength() const { return m_lastFullGCLength; }
 193     double lastEdenGCLength() const { return m_lastEdenGCLength; }
 194     void increaseLastFullGCLength(double amount) { m_lastFullGCLength += amount; }
 195
 196     size_t sizeBeforeLastEdenCollection() const { return m_sizeBeforeLastEdenCollect; }
 197     size_t sizeAfterLastEdenCollection() const { return m_sizeAfterLastEdenCollect; }
 198     size_t sizeBeforeLastFullCollection() const { return m_sizeBeforeLastFullCollect; }
 199     size_t sizeAfterLastFullCollection() const { return m_sizeAfterLastFullCollect; }
 200
 201     JS_EXPORT_PRIVATE void deleteAllCompiledCode();
 202     void deleteAllUnlinkedFunctionCode();
 203
 204     void didAllocate(size_t);
 205     void didAbandon(size_t);
 206
 207     bool isPagedOut(double deadline);
 208
 209     const JITStubRoutineSet& jitStubRoutines() { return m_jitStubRoutines; }
 210
 211     void addReference(JSCell*, ArrayBuffer*);
 212
 213     bool isDeferred() const { return !!m_deferralDepth || Options::disableGC(); }
 214
 215     BlockAllocator& blockAllocator();
 216     StructureIDTable& structureIDTable() { return m_structureIDTable; }
 217
 218 #if USE(CF)
 219         template<typename T> void releaseSoon(RetainPtr<T>&&);
 220 #endif
 221
 222     void removeCodeBlock(CodeBlock* cb) { m_codeBlocks.remove(cb); }
 223
 224     static bool isZombified(JSCell* cell) { return *(void**)cell == zombifiedBits; }
 225
 226 private:
 227     friend class CodeBlock;
 228     friend class CopiedBlock;
 229     friend class DeferGC;
 230     friend class DeferGCForAWhile;
 231     friend class DelayedReleaseScope;
 232     friend class GCAwareJITStubRoutine;
 233     friend class GCLogging;
 234     friend class HandleSet;
 235     friend class JITStubRoutine;
 236     friend class LLIntOffsetsExtractor;
 237     friend class MarkedSpace;
 238     friend class MarkedAllocator;
 239     friend class MarkedBlock;
 240     friend class CopiedSpace;
 241     friend class CopyVisitor;
 242     friend class RecursiveAllocationScope;
 243     friend class SlotVisitor;
 244     friend class SuperRegion;
 245     friend class IncrementalSweeper;
 246     friend class HeapStatistics;
 247     friend class VM;
 248     friend class WeakSet;
 249     template<typename T> friend void* allocateCell(Heap&);
 250     template<typename T> friend void* allocateCell(Heap&, size_t);
 251
 252     void* allocateWithImmortalStructureDestructor(size_t); // For use with special objects whose Structures never die.
 253     void* allocateWithNormalDestructor(size_t); // For use with objects that inherit directly or indirectly from JSDestructibleObject.
 254     void* allocateWithoutDestructor(size_t); // For use with objects without destructors.
 255
 256     static const size_t minExtraCost = 256;
 257     static const size_t maxExtraCost = 1024 * 1024;
 258
 259     class FinalizerOwner : public WeakHandleOwner {
 260         virtual void finalize(Handle<Unknown>, void* context) override;
 261     };
 262
 263     JS_EXPORT_PRIVATE bool isValidAllocation(size_t);
 264     JS_EXPORT_PRIVATE void reportExtraMemoryCostSlowCase(size_t);
 265
 266     void suspendCompilerThreads();
 267     void willStartCollection(HeapOperation collectionType);
 268     void deleteOldCode(double gcStartTime);
 269     void flushOldStructureIDTables();
 270     void flushWriteBarrierBuffer();
 271     void stopAllocation();
 272
 273     void markRoots(double gcStartTime);
 274     void gatherStackRoots(ConservativeRoots&, void** dummy);
 275     void gatherJSStackRoots(ConservativeRoots&);
 276     void gatherScratchBufferRoots(ConservativeRoots&);
 277     void clearLivenessData();
 278     void visitExternalRememberedSet();
 279     void visitSmallStrings();
 280     void visitConservativeRoots(ConservativeRoots&);
 281     void visitCompilerWorklistWeakReferences();
 282     void removeDeadCompilerWorklistEntries();
 283     void visitProtectedObjects(HeapRootVisitor&);
 284     void visitTempSortVectors(HeapRootVisitor&);
 285     void visitArgumentBuffers(HeapRootVisitor&);
 286     void visitException(HeapRootVisitor&);
 287     void visitStrongHandles(HeapRootVisitor&);
 288     void visitHandleStack(HeapRootVisitor&);
 289     void traceCodeBlocksAndJITStubRoutines();
 290     void converge();
 291     void visitWeakHandles(HeapRootVisitor&);
 292     void clearRememberedSet(Vector<const JSCell*>&);
 293     void updateObjectCounts(double gcStartTime);
 294     void resetVisitors();
 295
 296     void reapWeakHandles();
 297     void sweepArrayBuffers();
 298     void snapshotMarkedSpace();
 299     void deleteSourceProviderCaches();
 300     void notifyIncrementalSweeper();
 301     void rememberCurrentlyExecutingCodeBlocks();
 302     void resetAllocators();
 303     void copyBackingStores();
 304     void harvestWeakReferences();
 305     void finalizeUnconditionalFinalizers();
 306     void clearUnmarkedExecutables();
 307     void deleteUnmarkedCompiledCode();
 308     void updateAllocationLimits();
 309     void didFinishCollection(double gcStartTime);
 310     void resumeCompilerThreads();
 311     void zombifyDeadObjects();
 312     void markDeadObjects();
 313
 314     bool shouldDoFullCollection(HeapOperation requestedCollectionType) const;
 315     size_t sizeAfterCollect();
 316
 317     JSStack& stack();
 318
 319     void incrementDeferralDepth();
 320     void decrementDeferralDepth();
 321     void decrementDeferralDepthAndGCIfNeeded();
 322
 323     const HeapType m_heapType;
 324     const size_t m_ramSize;
 325     const size_t m_minBytesPerCycle;
 326     size_t m_sizeAfterLastCollect;
 327     size_t m_sizeAfterLastFullCollect;
 328     size_t m_sizeBeforeLastFullCollect;
 329     size_t m_sizeAfterLastEdenCollect;
 330     size_t m_sizeBeforeLastEdenCollect;
 331
 332     size_t m_bytesAllocatedThisCycle;
 333     size_t m_bytesAbandonedSinceLastFullCollect;
 334     size_t m_maxEdenSize;
 335     size_t m_maxHeapSize;
 336     bool m_shouldDoFullCollection;
 337     size_t m_totalBytesVisited;
 338     size_t m_totalBytesCopied;
 339
 340     HeapOperation m_operationInProgress;
 341     BlockAllocator m_blockAllocator;
 342     StructureIDTable m_structureIDTable;
 343     MarkedSpace m_objectSpace;
 344     CopiedSpace m_storageSpace;
 345     GCIncomingRefCountedSet<ArrayBuffer> m_arrayBuffers;
 346     size_t m_extraMemoryUsage;
 347
 348     HashSet<const JSCell*> m_copyingRememberedSet;
 349
 350     ProtectCountSet m_protectedValues;
 351     Vector<Vector<ValueStringPair, 0, UnsafeVectorOverflow>*> m_tempSortingVectors;
 352     OwnPtr<HashSet<MarkedArgumentBuffer*>> m_markListSet;
 353
 354     MachineThreads m_machineThreads;
 355
 356     GCThreadSharedData m_sharedData;
 357     SlotVisitor m_slotVisitor;
 358     CopyVisitor m_copyVisitor;
 359
 360     HandleSet m_handleSet;
 361     HandleStack m_handleStack;
 362     CodeBlockSet m_codeBlocks;
 363     JITStubRoutineSet m_jitStubRoutines;
 364     FinalizerOwner m_finalizerOwner;
 365
 366     bool m_isSafeToCollect;
 367
 368     WriteBarrierBuffer m_writeBarrierBuffer;
 369
 370     VM* m_vm;
 371     double m_lastFullGCLength;
 372     double m_lastEdenGCLength;
 373     double m_lastCodeDiscardTime;
 374
 375     DoublyLinkedList<ExecutableBase> m_compiledCode;
 376
 377     RefPtr<GCActivityCallback> m_fullActivityCallback;
 378     RefPtr<GCActivityCallback> m_edenActivityCallback;
 379     OwnPtr<IncrementalSweeper> m_sweeper;
 380     Vector<MarkedBlock*> m_blockSnapshot;
 381
 382     unsigned m_deferralDepth;
 383     Vector<DFG::Worklist*> m_suspendedCompilerWorklists;
 384 };
 385
 386 } // namespace JSC
 387
 388 #endif // Heap_h