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// Copyright (c) 2012 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include "courgette/memory_allocator.h"
#include <stddef.h>
#include <stdint.h>
#include <map>
#include "base/files/file_util.h"
#include "base/strings/stringprintf.h"
#if defined(OS_WIN)
namespace {
// The file is created in the %TEMP% folder.
// NOTE: Since the file will be used as backing for a memory allocation,
// it will never be so big that size_t cannot represent its size.
base::File CreateTempFile() {
base::FilePath path;
if (!base::CreateTemporaryFile(&path))
return base::File();
int flags = base::File::FLAG_OPEN_ALWAYS | base::File::FLAG_READ |
base::File::FLAG_WRITE | base::File::FLAG_DELETE_ON_CLOSE |
base::File::FLAG_TEMPORARY;
return base::File(path, flags);
}
} // namespace
namespace courgette {
// FileMapping
FileMapping::FileMapping() : mapping_(NULL), view_(NULL) {
}
FileMapping::~FileMapping() {
Close();
}
bool FileMapping::InitializeView(size_t size) {
DCHECK(view_ == NULL);
DCHECK(mapping_ != NULL);
view_ = ::MapViewOfFile(mapping_, FILE_MAP_WRITE, 0, 0, size);
if (!view_) {
Close();
return false;
}
return true;
}
bool FileMapping::Create(HANDLE file, size_t size) {
DCHECK(file != INVALID_HANDLE_VALUE);
DCHECK(!valid());
mapping_ = ::CreateFileMapping(file, NULL, PAGE_READWRITE, 0, 0, NULL);
if (!mapping_)
return false;
return InitializeView(size);
}
void FileMapping::Close() {
if (view_)
::UnmapViewOfFile(view_);
if (mapping_)
::CloseHandle(mapping_);
mapping_ = NULL;
view_ = NULL;
}
bool FileMapping::valid() const {
return view_ != NULL;
}
void* FileMapping::view() const {
return view_;
}
// TempMapping
TempMapping::TempMapping() {
}
TempMapping::~TempMapping() {
}
bool TempMapping::Initialize(size_t size) {
file_ = CreateTempFile();
if (!file_.IsValid())
return false;
// TODO(tommi): The assumption here is that the alignment of pointers (this)
// is as strict or stricter than the alignment of the element type. This is
// not always true, e.g. __m128 has 16-byte alignment.
size += sizeof(this);
if (!file_.SetLength(size) ||
!mapping_.Create(file_.GetPlatformFile(), size)) {
file_.Close();
return false;
}
TempMapping** write = reinterpret_cast<TempMapping**>(mapping_.view());
write[0] = this;
return true;
}
void* TempMapping::memory() const {
uint8_t* mem = reinterpret_cast<uint8_t*>(mapping_.view());
// The 'this' pointer is written at the start of mapping_.view(), so
// go past it. (See Initialize()).
if (mem)
mem += sizeof(this);
DCHECK(mem);
return mem;
}
bool TempMapping::valid() const {
return mapping_.valid();
}
// static
TempMapping* TempMapping::GetMappingFromPtr(void* mem) {
TempMapping* ret = NULL;
if (mem) {
ret = reinterpret_cast<TempMapping**>(mem)[-1];
}
DCHECK(ret);
return ret;
}
} // namespace courgette
#endif // OS_WIN
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