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/*
* Copyright (C) 2010 Apple 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:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. 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.
*
* THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS 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 APPLE INC. OR ITS CONTRIBUTORS
* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
* THE POSSIBILITY OF SUCH DAMAGE.
*/
#include "config.h"
#include "OSAllocator.h"
#include "PageBlock.h"
#if OS(WINDOWS)
#include "windows.h"
#include <wtf/Assertions.h>
namespace WTF {
static inline DWORD protection(bool writable, bool executable)
{
return executable ?
(writable ? PAGE_EXECUTE_READWRITE : PAGE_EXECUTE_READ) :
(writable ? PAGE_READWRITE : PAGE_READONLY);
}
void* OSAllocator::reserveUncommitted(size_t bytes, Usage, bool writable, bool executable)
{
void* result = VirtualAlloc(0, bytes, MEM_RESERVE, protection(writable, executable));
if (!result)
CRASH();
return result;
}
void* OSAllocator::reserveAndCommit(size_t bytes, Usage, bool writable, bool executable,
bool includesGuardPages)
{
void* result = VirtualAlloc(0, bytes, MEM_RESERVE | MEM_COMMIT, protection(writable, executable));
if (!result)
CRASH();
if (includesGuardPages) {
size_t guardSize = pageSize();
DWORD oldProtect;
if (!VirtualProtect(result, guardSize, protection(false, false), &oldProtect) ||
!VirtualProtect(static_cast<char*>(result) + bytes - guardSize, guardSize,
protection(false, false), &oldProtect))
CRASH();
}
return result;
}
void OSAllocator::commit(void* address, size_t bytes, bool writable, bool executable)
{
void* result = VirtualAlloc(address, bytes, MEM_COMMIT, protection(writable, executable));
if (!result)
CRASH();
}
void OSAllocator::decommit(void* address, size_t bytes)
{
bool result = VirtualFree(address, bytes, MEM_DECOMMIT);
if (!result)
CRASH();
}
void OSAllocator::releaseDecommitted(void* address, size_t bytes)
{
(void) bytes; // suppress unused formal parameter warning
// According to http://msdn.microsoft.com/en-us/library/aa366892(VS.85).aspx,
// dwSize must be 0 if dwFreeType is MEM_RELEASE.
bool result = VirtualFree(address, 0, MEM_RELEASE);
if (!result)
CRASH();
}
} // namespace WTF
#endif // OS(WINDOWS)
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