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/*
* Copyright (C) 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 Library 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
* Library General Public License for more details.
*
* You should have received a copy of the GNU Library General Public License
* along with this library; see the file COPYING.LIB. If not, write to
* the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
* Boston, MA 02110-1301, USA.
*
*/
#ifndef WTF_FastMalloc_h
#define WTF_FastMalloc_h
#include "Platform.h"
#include "PossiblyNull.h"
#include <stdlib.h>
#include <new>
namespace WTF {
// These functions call CRASH() if an allocation fails.
void* fastMalloc(size_t);
void* fastZeroedMalloc(size_t);
void* fastCalloc(size_t numElements, size_t elementSize);
void* fastRealloc(void*, size_t);
struct TryMallocReturnValue {
TryMallocReturnValue(void* data)
: m_data(data)
{
}
TryMallocReturnValue(const TryMallocReturnValue& source)
: m_data(source.m_data)
{
source.m_data = 0;
}
~TryMallocReturnValue() { ASSERT(!m_data); }
template <typename T> bool getValue(T& data) WARN_UNUSED_RETURN;
template <typename T> operator PossiblyNull<T>()
{
T value;
getValue(value);
return PossiblyNull<T>(value);
}
private:
mutable void* m_data;
};
template <typename T> bool TryMallocReturnValue::getValue(T& data)
{
union u { void* data; T target; } res;
res.data = m_data;
data = res.target;
bool returnValue = !!m_data;
m_data = 0;
return returnValue;
}
TryMallocReturnValue tryFastMalloc(size_t n);
TryMallocReturnValue tryFastZeroedMalloc(size_t n);
TryMallocReturnValue tryFastCalloc(size_t n_elements, size_t element_size);
TryMallocReturnValue tryFastRealloc(void* p, size_t n);
void fastFree(void*);
#ifndef NDEBUG
void fastMallocForbid();
void fastMallocAllow();
#endif
void releaseFastMallocFreeMemory();
struct FastMallocStatistics {
size_t heapSize;
size_t freeSizeInHeap;
size_t freeSizeInCaches;
size_t returnedSize;
};
FastMallocStatistics fastMallocStatistics();
// This defines a type which holds an unsigned integer and is the same
// size as the minimally aligned memory allocation.
typedef unsigned long long AllocAlignmentInteger;
namespace Internal {
enum AllocType { // Start with an unusual number instead of zero, because zero is common.
AllocTypeMalloc = 0x375d6750, // Encompasses fastMalloc, fastZeroedMalloc, fastCalloc, fastRealloc.
AllocTypeClassNew, // Encompasses class operator new from FastAllocBase.
AllocTypeClassNewArray, // Encompasses class operator new[] from FastAllocBase.
AllocTypeFastNew, // Encompasses fastNew.
AllocTypeFastNewArray, // Encompasses fastNewArray.
AllocTypeNew, // Encompasses global operator new.
AllocTypeNewArray // Encompasses global operator new[].
};
}
#if ENABLE(FAST_MALLOC_MATCH_VALIDATION)
// Malloc validation is a scheme whereby a tag is attached to an
// allocation which identifies how it was originally allocated.
// This allows us to verify that the freeing operation matches the
// allocation operation. If memory is allocated with operator new[]
// but freed with free or delete, this system would detect that.
// In the implementation here, the tag is an integer prepended to
// the allocation memory which is assigned one of the AllocType
// enumeration values. An alternative implementation of this
// scheme could store the tag somewhere else or ignore it.
// Users of FastMalloc don't need to know or care how this tagging
// is implemented.
namespace Internal {
// Return the AllocType tag associated with the allocated block p.
inline AllocType fastMallocMatchValidationType(const void* p)
{
const AllocAlignmentInteger* type = static_cast<const AllocAlignmentInteger*>(p) - 1;
return static_cast<AllocType>(*type);
}
// Return the address of the AllocType tag associated with the allocated block p.
inline AllocAlignmentInteger* fastMallocMatchValidationValue(void* p)
{
return reinterpret_cast<AllocAlignmentInteger*>(static_cast<char*>(p) - sizeof(AllocAlignmentInteger));
}
// Set the AllocType tag to be associaged with the allocated block p.
inline void setFastMallocMatchValidationType(void* p, AllocType allocType)
{
AllocAlignmentInteger* type = static_cast<AllocAlignmentInteger*>(p) - 1;
*type = static_cast<AllocAlignmentInteger>(allocType);
}
// Handle a detected alloc/free mismatch. By default this calls CRASH().
void fastMallocMatchFailed(void* p);
} // namespace Internal
// This is a higher level function which is used by FastMalloc-using code.
inline void fastMallocMatchValidateMalloc(void* p, Internal::AllocType allocType)
{
if (!p)
return;
Internal::setFastMallocMatchValidationType(p, allocType);
}
// This is a higher level function which is used by FastMalloc-using code.
inline void fastMallocMatchValidateFree(void* p, Internal::AllocType allocType)
{
if (!p)
return;
if (Internal::fastMallocMatchValidationType(p) != allocType)
Internal::fastMallocMatchFailed(p);
Internal::setFastMallocMatchValidationType(p, Internal::AllocTypeMalloc); // Set it to this so that fastFree thinks it's OK.
}
#else
inline void fastMallocMatchValidateMalloc(void*, Internal::AllocType)
{
}
inline void fastMallocMatchValidateFree(void*, Internal::AllocType)
{
}
#endif
} // namespace WTF
using WTF::fastMalloc;
using WTF::fastZeroedMalloc;
using WTF::fastCalloc;
using WTF::fastRealloc;
using WTF::tryFastMalloc;
using WTF::tryFastZeroedMalloc;
using WTF::tryFastCalloc;
using WTF::tryFastRealloc;
using WTF::fastFree;
#ifndef NDEBUG
using WTF::fastMallocForbid;
using WTF::fastMallocAllow;
#endif
#if COMPILER(GCC) && PLATFORM(DARWIN)
#define WTF_PRIVATE_INLINE __private_extern__ inline __attribute__((always_inline))
#elif COMPILER(GCC)
#define WTF_PRIVATE_INLINE inline __attribute__((always_inline))
#elif COMPILER(MSVC)
#define WTF_PRIVATE_INLINE __forceinline
#else
#define WTF_PRIVATE_INLINE inline
#endif
#if !defined(_CRTDBG_MAP_ALLOC) && !(defined(USE_SYSTEM_MALLOC) && USE_SYSTEM_MALLOC)
// The nothrow functions here are actually not all that helpful, because fastMalloc will
// call CRASH() rather than returning 0, and returning 0 is what nothrow is all about.
// But since WebKit code never uses exceptions or nothrow at all, this is probably OK.
// Long term we will adopt FastAllocBase.h everywhere, and and replace this with
// debug-only code to make sure we don't use the system malloc via the default operator
// new by accident.
WTF_PRIVATE_INLINE void* operator new(size_t size) { return fastMalloc(size); }
WTF_PRIVATE_INLINE void* operator new(size_t size, const std::nothrow_t&) throw() { return fastMalloc(size); }
WTF_PRIVATE_INLINE void operator delete(void* p) { fastFree(p); }
WTF_PRIVATE_INLINE void operator delete(void* p, const std::nothrow_t&) throw() { fastFree(p); }
WTF_PRIVATE_INLINE void* operator new[](size_t size) { return fastMalloc(size); }
WTF_PRIVATE_INLINE void* operator new[](size_t size, const std::nothrow_t&) throw() { return fastMalloc(size); }
WTF_PRIVATE_INLINE void operator delete[](void* p) { fastFree(p); }
WTF_PRIVATE_INLINE void operator delete[](void* p, const std::nothrow_t&) throw() { fastFree(p); }
#endif
#endif /* WTF_FastMalloc_h */
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