third_party/WebKit/Source/wtf/Partitions.h

/*
 * Copyright (C) 2013 Google Inc. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are
 * met:
 *
 *     * Redistributions of source code must retain the above copyright
 * notice, this list of conditions and the following disclaimer.
 *     * Redistributions in binary form must reproduce the above
 * copyright notice, this list of conditions and the following disclaimer
 * in the documentation and/or other materials provided with the
 * distribution.
 *     * Neither the name of Google Inc. nor the names of its
 * contributors may be used to endorse or promote products derived from
 * this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#ifndef Partitions_h
#define Partitions_h

#include "wtf/PartitionAlloc.h"
#include "wtf/WTF.h"
#include "wtf/WTFExport.h"
#include <string.h>

namespace WTF {

class WTF_EXPORT Partitions {
public:
    // Name of allocator used by tracing for marking sub-allocations while take
    // memory snapshots.
    static const char* const kAllocatedObjectPoolName;

    static void initialize(HistogramEnumerationFunction);
    static void shutdown();
    ALWAYS_INLINE static PartitionRootGeneric* bufferPartition()
    {
        ASSERT(s_initialized);
        return m_bufferAllocator.root();
    }

    ALWAYS_INLINE static PartitionRootGeneric* fastMallocPartition()
    {
        ASSERT(s_initialized);
        return m_fastMallocAllocator.root();
    }

    ALWAYS_INLINE static PartitionRoot* nodePartition()
    {
        ASSERT(s_initialized);
        return m_nodeAllocator.root();
    }
    ALWAYS_INLINE static PartitionRoot* layoutPartition()
    {
        ASSERT(s_initialized);
        return m_layoutAllocator.root();
    }

    static size_t currentDOMMemoryUsage()
    {
        ASSERT(s_initialized);
        return m_nodeAllocator.root()->totalSizeOfCommittedPages;
    }

    static size_t totalSizeOfCommittedPages()
    {
        size_t totalSize = 0;
        totalSize += m_fastMallocAllocator.root()->totalSizeOfCommittedPages;
        totalSize += m_bufferAllocator.root()->totalSizeOfCommittedPages;
        totalSize += m_nodeAllocator.root()->totalSizeOfCommittedPages;
        totalSize += m_layoutAllocator.root()->totalSizeOfCommittedPages;
        return totalSize;
    }

    static void decommitFreeableMemory();

    static void reportMemoryUsageHistogram();

    static void dumpMemoryStats(bool isLightDump, PartitionStatsDumper*);

    ALWAYS_INLINE static void* bufferMalloc(size_t n, const char* typeName)
    {
        return partitionAllocGeneric(bufferPartition(), n, typeName);
    }
    ALWAYS_INLINE static void bufferFree(void* p)
    {
        partitionFreeGeneric(bufferPartition(), p);
    }
    ALWAYS_INLINE static size_t bufferActualSize(size_t n)
    {
        return partitionAllocActualSize(bufferPartition(), n);
    }
    static void* fastMalloc(size_t n, const char* typeName)
    {
        return partitionAllocGeneric(Partitions::fastMallocPartition(), n, typeName);
    }
    static void* fastZeroedMalloc(size_t n, const char* typeName)
    {
        void* result = fastMalloc(n, typeName);
        memset(result, 0, n);
        return result;
    }
    static void* fastRealloc(void* p, size_t n, const char* typeName)
    {
        return partitionReallocGeneric(Partitions::fastMallocPartition(), p, n, typeName);
    }
    static void fastFree(void* p)
    {
        partitionFreeGeneric(Partitions::fastMallocPartition(), p);
    }

    static void handleOutOfMemory();

private:
    static SpinLock s_initializationLock;
    static bool s_initialized;

    // We have the following four partitions.
    //   - Node partition: A partition to allocate Nodes. We prepare a
    //     dedicated partition for Nodes because Nodes are likely to be
    //     a source of use-after-frees. Another reason is for performance:
    //     Since Nodes are guaranteed to be used only by the main
    //     thread, we can bypass acquiring a lock. Also we can improve memory
    //     locality by putting Nodes together.
    //   - Layout object partition: A partition to allocate LayoutObjects.
    //     we prepare a dedicated partition for the same reason as Nodes.
    //   - Buffer partition: A partition to allocate objects that have a strong
    //     risk where the length and/or the contents are exploited from user
    //     scripts. Vectors, HashTables, ArrayBufferContents and Strings are
    //     allocated in the buffer partition.
    //   - Fast malloc partition: A partition to allocate all other objects.
    static PartitionAllocatorGeneric m_fastMallocAllocator;
    static PartitionAllocatorGeneric m_bufferAllocator;
    static SizeSpecificPartitionAllocator<3328> m_nodeAllocator;
    static SizeSpecificPartitionAllocator<1024> m_layoutAllocator;
    static HistogramEnumerationFunction m_histogramEnumeration;
};

} // namespace WTF

#endif // Partitions_h