blob: b3058133d516e2cf7feb9b693253ea04fafd704a [file] [log] [blame]
/*
* Copyright (C) 2010, 2014 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 <wtf/OSAllocator.h>
#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, bool)
{
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)
{
void* result = VirtualAlloc(0, bytes, MEM_RESERVE | MEM_COMMIT, protection(writable, executable));
if (!result)
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)
{
// According to http://msdn.microsoft.com/en-us/library/aa366892(VS.85).aspx,
// bytes (i.e. dwSize) being 0 when dwFreeType is MEM_DECOMMIT means that we'll
// decommit the entire region allocated by VirtualAlloc() instead of decommitting
// nothing as we would expect. Hence, we should check if bytes is 0 and handle it
// appropriately before calling VirtualFree().
// See: https://bugs.webkit.org/show_bug.cgi?id=121972.
if (!bytes)
return;
// Silence warning about using MEM_DECOMMIT instead of MEM_RELEASE:
#pragma warning(suppress: 6250)
bool result = VirtualFree(address, bytes, MEM_DECOMMIT);
if (!result)
CRASH();
}
void OSAllocator::releaseDecommitted(void* address, size_t bytes)
{
// See comment in OSAllocator::decommit(). Similarly, when bytes is 0, we
// don't want to release anything. So, don't call VirtualFree() below.
if (!bytes)
return;
// 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();
}
void OSAllocator::hintMemoryNotNeededSoon(void*, size_t)
{
}
} // namespace WTF