Home | History | Annotate | Download | only in wtf 
      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
     81