+++ /dev/null
-/*
- * Copyright (C) 1999-2000 Harri Porten (porten@kde.org)
- * Copyright (C) 2001 Peter Kelly (pmk@post.com)
- * Copyright (C) 2003, 2004, 2005, 2006, 2007, 2008, 2009 Apple Inc. All rights reserved.
- *
- * This library is free software; you can redistribute it and/or
- * modify it under the terms of the GNU Lesser General Public
- * License as published by the Free Software Foundation; either
- * version 2 of the License, or (at your option) any later version.
- *
- * This library is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
- * Lesser General Public License for more details.
- *
- * You should have received a copy of the GNU Lesser General Public
- * License along with this library; if not, write to the Free Software
- * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
- *
- */
-
-#ifndef Collector_h
-#define Collector_h
-
-#include "JSValue.h"
-#include <stddef.h>
-#include <string.h>
-#include <wtf/HashCountedSet.h>
-#include <wtf/HashSet.h>
-#include <wtf/Noncopyable.h>
-#include <wtf/OwnPtr.h>
-#include <wtf/StdLibExtras.h>
-#include <wtf/Threading.h>
-
-#if ENABLE(JSC_MULTIPLE_THREADS)
-#include <pthread.h>
-#endif
-
-#if OS(SYMBIAN)
-#include <wtf/symbian/BlockAllocatorSymbian.h>
-#endif
-
-#define ASSERT_CLASS_FITS_IN_CELL(class) COMPILE_ASSERT(sizeof(class) <= CELL_SIZE, class_fits_in_cell)
-
-namespace JSC {
-
- class CollectorBlock;
- class JSCell;
- class JSGlobalData;
- class JSValue;
- class MarkedArgumentBuffer;
- class MarkStack;
-
- enum OperationInProgress { NoOperation, Allocation, Collection };
-
- class LiveObjectIterator;
-
- struct CollectorHeap {
- size_t nextBlock;
- size_t nextCell;
- CollectorBlock** blocks;
-
- void* nextNumber;
-
- size_t numBlocks;
- size_t usedBlocks;
-
- size_t extraCost;
- bool didShrink;
-
- OperationInProgress operationInProgress;
- };
-
- class Heap : public Noncopyable {
- public:
- class Thread;
-
- void destroy();
-
- void* allocateNumber(size_t);
- void* allocate(size_t);
-
- bool isBusy(); // true if an allocation or collection is in progress
- void collectAllGarbage();
-
- static const size_t minExtraCost = 256;
- static const size_t maxExtraCost = 1024 * 1024;
-
- void reportExtraMemoryCost(size_t cost);
-
- size_t objectCount() const;
- struct Statistics {
- size_t size;
- size_t free;
- };
- Statistics statistics() const;
-
- void protect(JSValue);
- // Returns true if the value is no longer protected by any protect pointers
- // (though it may still be alive due to heap/stack references).
- bool unprotect(JSValue);
-
- static Heap* heap(JSValue); // 0 for immediate values
- static Heap* heap(JSCell*);
-
- size_t globalObjectCount();
- size_t protectedObjectCount();
- size_t protectedGlobalObjectCount();
- HashCountedSet<const char*>* protectedObjectTypeCounts();
- HashCountedSet<const char*>* objectTypeCounts();
-
- void registerThread(); // Only needs to be called by clients that can use the same heap from multiple threads.
-
- static bool isCellMarked(const JSCell*);
- static void markCell(JSCell*);
-
- void markConservatively(MarkStack&, void* start, void* end);
-
- void pushTempSortVector(WTF::Vector<ValueStringPair>*);
- void popTempSortVector(WTF::Vector<ValueStringPair>*);
-
- HashSet<MarkedArgumentBuffer*>& markListSet() { if (!m_markListSet) m_markListSet = new HashSet<MarkedArgumentBuffer*>; return *m_markListSet; }
-
- JSGlobalData* globalData() const { return m_globalData; }
- static bool isNumber(JSCell*);
-
- LiveObjectIterator primaryHeapBegin();
- LiveObjectIterator primaryHeapEnd();
-
- private:
- void reset();
- void sweep();
- static CollectorBlock* cellBlock(const JSCell*);
- static size_t cellOffset(const JSCell*);
-
- friend class JSGlobalData;
- Heap(JSGlobalData*);
- ~Heap();
-
- NEVER_INLINE CollectorBlock* allocateBlock();
- NEVER_INLINE void freeBlock(size_t);
- NEVER_INLINE void freeBlockPtr(CollectorBlock*);
- void freeBlocks();
- void resizeBlocks();
- void growBlocks(size_t neededBlocks);
- void shrinkBlocks(size_t neededBlocks);
- void clearMarkBits();
- void clearMarkBits(CollectorBlock*);
- size_t markedCells(size_t startBlock = 0, size_t startCell = 0) const;
-
- void recordExtraCost(size_t);
-
- void addToStatistics(Statistics&) const;
-
- void markRoots();
- void markProtectedObjects(MarkStack&);
- void markTempSortVectors(MarkStack&);
- void markCurrentThreadConservatively(MarkStack&);
- void markCurrentThreadConservativelyInternal(MarkStack&);
- void markOtherThreadConservatively(MarkStack&, Thread*);
- void markStackObjectsConservatively(MarkStack&);
-
- typedef HashCountedSet<JSCell*> ProtectCountSet;
-
- CollectorHeap m_heap;
-
- ProtectCountSet m_protectedValues;
- WTF::Vector<WTF::Vector<ValueStringPair>* > m_tempSortingVectors;
-
- HashSet<MarkedArgumentBuffer*>* m_markListSet;
-
-#if ENABLE(JSC_MULTIPLE_THREADS)
- void makeUsableFromMultipleThreads();
-
- static void unregisterThread(void*);
- void unregisterThread();
-
- Mutex m_registeredThreadsMutex;
- Thread* m_registeredThreads;
- pthread_key_t m_currentThreadRegistrar;
-#endif
-
-#if OS(SYMBIAN)
- // Allocates collector blocks with correct alignment
- WTF::AlignedBlockAllocator m_blockallocator;
-#endif
-
- JSGlobalData* m_globalData;
- };
-
- // tunable parameters
- template<size_t bytesPerWord> struct CellSize;
-
- // cell size needs to be a power of two for certain optimizations in collector.cpp
-#if USE(JSVALUE32)
- template<> struct CellSize<sizeof(uint32_t)> { static const size_t m_value = 32; };
-#else
- template<> struct CellSize<sizeof(uint32_t)> { static const size_t m_value = 64; };
-#endif
- template<> struct CellSize<sizeof(uint64_t)> { static const size_t m_value = 64; };
-
- const size_t BLOCK_SIZE = 64 * 1024; // 64k
-
- // derived constants
- const size_t BLOCK_OFFSET_MASK = BLOCK_SIZE - 1;
- const size_t BLOCK_MASK = ~BLOCK_OFFSET_MASK;
- const size_t MINIMUM_CELL_SIZE = CellSize<sizeof(void*)>::m_value;
- const size_t CELL_ARRAY_LENGTH = (MINIMUM_CELL_SIZE / sizeof(double)) + (MINIMUM_CELL_SIZE % sizeof(double) != 0 ? sizeof(double) : 0);
- const size_t CELL_SIZE = CELL_ARRAY_LENGTH * sizeof(double);
- const size_t SMALL_CELL_SIZE = CELL_SIZE / 2;
- const size_t CELL_MASK = CELL_SIZE - 1;
- const size_t CELL_ALIGN_MASK = ~CELL_MASK;
- const size_t CELLS_PER_BLOCK = (BLOCK_SIZE - sizeof(Heap*)) * 8 * CELL_SIZE / (8 * CELL_SIZE + 1) / CELL_SIZE; // one bitmap byte can represent 8 cells.
-
- const size_t BITMAP_SIZE = (CELLS_PER_BLOCK + 7) / 8;
- const size_t BITMAP_WORDS = (BITMAP_SIZE + 3) / sizeof(uint32_t);
-
- struct CollectorBitmap {
- uint32_t bits[BITMAP_WORDS];
- bool get(size_t n) const { return !!(bits[n >> 5] & (1 << (n & 0x1F))); }
- void set(size_t n) { bits[n >> 5] |= (1 << (n & 0x1F)); }
- void clear(size_t n) { bits[n >> 5] &= ~(1 << (n & 0x1F)); }
- void clearAll() { memset(bits, 0, sizeof(bits)); }
- size_t count(size_t startCell = 0)
- {
- size_t result = 0;
- for ( ; (startCell & 0x1F) != 0; ++startCell) {
- if (get(startCell))
- ++result;
- }
- for (size_t i = startCell >> 5; i < BITMAP_WORDS; ++i)
- result += WTF::bitCount(bits[i]);
- return result;
- }
- size_t isEmpty() // Much more efficient than testing count() == 0.
- {
- for (size_t i = 0; i < BITMAP_WORDS; ++i)
- if (bits[i] != 0)
- return false;
- return true;
- }
- };
-
- struct CollectorCell {
- double memory[CELL_ARRAY_LENGTH];
- };
-
- class CollectorBlock {
- public:
- CollectorCell cells[CELLS_PER_BLOCK];
- CollectorBitmap marked;
- Heap* heap;
- };
-
- struct HeapConstants {
- static const size_t cellSize = CELL_SIZE;
- static const size_t cellsPerBlock = CELLS_PER_BLOCK;
- typedef CollectorCell Cell;
- typedef CollectorBlock Block;
- };
-
- inline CollectorBlock* Heap::cellBlock(const JSCell* cell)
- {
- return reinterpret_cast<CollectorBlock*>(reinterpret_cast<uintptr_t>(cell) & BLOCK_MASK);
- }
-
- inline size_t Heap::cellOffset(const JSCell* cell)
- {
- return (reinterpret_cast<uintptr_t>(cell) & BLOCK_OFFSET_MASK) / CELL_SIZE;
- }
-
- inline bool Heap::isCellMarked(const JSCell* cell)
- {
- return cellBlock(cell)->marked.get(cellOffset(cell));
- }
-
- inline void Heap::markCell(JSCell* cell)
- {
- cellBlock(cell)->marked.set(cellOffset(cell));
- }
-
- inline void Heap::reportExtraMemoryCost(size_t cost)
- {
- if (cost > minExtraCost)
- recordExtraCost(cost);
- }
-
- inline void* Heap::allocateNumber(size_t s)
- {
- if (void* result = m_heap.nextNumber) {
- m_heap.nextNumber = 0;
- return result;
- }
-
- void* result = allocate(s);
- m_heap.nextNumber = static_cast<char*>(result) + (CELL_SIZE / 2);
- return result;
- }
-
-} // namespace JSC
-
-#endif /* Collector_h */
projects / apple / javascriptcore.git / blobdiff