wtf/OSAllocatorWin.cpp

   1 /*
   2  * Copyright (C) 2010 Apple Inc. All rights reserved.
   3  *
   4  * Redistribution and use in source and binary forms, with or without
   5  * modification, are permitted provided that the following conditions
   6  * are met:
   7  * 1. Redistributions of source code must retain the above copyright
   8  *    notice, this list of conditions and the following disclaimer.
   9  * 2. Redistributions in binary form must reproduce the above copyright
  10  *    notice, this list of conditions and the following disclaimer in the
  11  *    documentation and/or other materials provided with the distribution.
  12  *
  13  * THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS''
  14  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
  15  * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  16  * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS
  17  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  18  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  19  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  20  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
  21  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  22  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
  23  * THE POSSIBILITY OF SUCH DAMAGE.
  24  */
  25
  26 #include "config.h"
  27 #include "OSAllocator.h"
  28
  29 #include "windows.h"
  30 #include <wtf/Assertions.h>
  31
  32 namespace WTF {
  33
  34 static inline DWORD protection(bool writable, bool executable)
  35 {
  36     return executable ?
  37         (writable ? PAGE_EXECUTE_READWRITE : PAGE_EXECUTE_READ) :
  38         (writable ? PAGE_READWRITE : PAGE_READONLY);
  39 }
  40
  41 void* OSAllocator::reserveUncommitted(size_t bytes, Usage, bool writable, bool executable)
  42 {
  43     void* result = VirtualAlloc(0, bytes, MEM_RESERVE, protection(writable, executable));
  44     if (!result)
  45         CRASH();
  46     return result;
  47 }
  48
  49 void* OSAllocator::reserveAndCommit(size_t bytes, Usage, bool writable, bool executable)
  50 {
  51     void* result = VirtualAlloc(0, bytes, MEM_RESERVE | MEM_COMMIT, protection(writable, executable));
  52     if (!result)
  53         CRASH();
  54     return result;
  55 }
  56
  57 void OSAllocator::commit(void* address, size_t bytes, bool writable, bool executable)
  58 {
  59     void* result = VirtualAlloc(address, bytes, MEM_COMMIT, protection(writable, executable));
  60     if (!result)
  61         CRASH();
  62 }
  63
  64 void OSAllocator::decommit(void* address, size_t bytes)
  65 {
  66     bool result = VirtualFree(address, bytes, MEM_DECOMMIT);
  67     if (!result)
  68         CRASH();
  69 }
  70
  71 void OSAllocator::releaseDecommitted(void* address, size_t bytes)
  72 {
  73     // According to http://msdn.microsoft.com/en-us/library/aa366892(VS.85).aspx,
  74     // dwSize must be 0 if dwFreeType is MEM_RELEASE.
  75     bool result = VirtualFree(address, 0, MEM_RELEASE);
  76     if (!result)
  77         CRASH();
  78 }
  79
  80 } // namespace WTF