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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 "SharedMemory.h"
#include "ArgumentDecoder.h"
#include "ArgumentEncoder.h"
#include <wtf/RefPtr.h>
namespace WebKit {
SharedMemory::Handle::Handle()
: m_handle(0)
, m_size(0)
{
}
SharedMemory::Handle::~Handle()
{
if (!m_handle)
return;
::CloseHandle(m_handle);
}
bool SharedMemory::Handle::isNull() const
{
return !m_handle;
}
void SharedMemory::Handle::encode(CoreIPC::ArgumentEncoder* encoder) const
{
encoder->encodeUInt64(m_size);
// Hand off ownership of our HANDLE to the receiving process. It will close it for us.
// FIXME: If the receiving process crashes before it receives the memory, the memory will be
// leaked. See <http://webkit.org/b/47502>.
encoder->encodeUInt64(reinterpret_cast<uint64_t>(m_handle));
m_handle = 0;
// Send along our PID so that the receiving process can duplicate the HANDLE for its own use.
encoder->encodeUInt32(::GetCurrentProcessId());
}
static bool getDuplicatedHandle(HANDLE sourceHandle, DWORD sourcePID, HANDLE& duplicatedHandle)
{
duplicatedHandle = 0;
if (!sourceHandle)
return true;
HANDLE sourceProcess = ::OpenProcess(PROCESS_DUP_HANDLE, FALSE, sourcePID);
if (!sourceProcess)
return false;
// Copy the handle into our process and close the handle that the sending process created for us.
BOOL success = ::DuplicateHandle(sourceProcess, sourceHandle, ::GetCurrentProcess(), &duplicatedHandle, 0, FALSE, DUPLICATE_SAME_ACCESS | DUPLICATE_CLOSE_SOURCE);
ASSERT_WITH_MESSAGE(success, "::DuplicateHandle failed with error %lu", ::GetLastError());
::CloseHandle(sourceProcess);
return success;
}
bool SharedMemory::Handle::decode(CoreIPC::ArgumentDecoder* decoder, Handle& handle)
{
ASSERT_ARG(handle, !handle.m_handle);
ASSERT_ARG(handle, !handle.m_size);
uint64_t size;
if (!decoder->decodeUInt64(size))
return false;
uint64_t sourceHandle;
if (!decoder->decodeUInt64(sourceHandle))
return false;
uint32_t sourcePID;
if (!decoder->decodeUInt32(sourcePID))
return false;
HANDLE duplicatedHandle;
if (!getDuplicatedHandle(reinterpret_cast<HANDLE>(sourceHandle), sourcePID, duplicatedHandle))
return false;
handle.m_handle = duplicatedHandle;
handle.m_size = size;
return true;
}
PassRefPtr<SharedMemory> SharedMemory::create(size_t size)
{
HANDLE handle = ::CreateFileMappingW(INVALID_HANDLE_VALUE, 0, PAGE_READWRITE, 0, size, 0);
if (!handle)
return 0;
void* baseAddress = ::MapViewOfFile(handle, FILE_MAP_ALL_ACCESS, 0, 0, size);
if (!baseAddress) {
::CloseHandle(handle);
return 0;
}
RefPtr<SharedMemory> memory = adoptRef(new SharedMemory);
memory->m_size = size;
memory->m_data = baseAddress;
memory->m_handle = handle;
return memory.release();
}
static DWORD accessRights(SharedMemory::Protection protection)
{
switch (protection) {
case SharedMemory::ReadOnly:
return FILE_MAP_READ;
case SharedMemory::ReadWrite:
// FILE_MAP_WRITE implies read access, too.
return FILE_MAP_WRITE;
}
ASSERT_NOT_REACHED();
return 0;
}
PassRefPtr<SharedMemory> SharedMemory::create(const Handle& handle, Protection protection)
{
if (handle.isNull())
return 0;
DWORD desiredAccess = accessRights(protection);
void* baseAddress = ::MapViewOfFile(handle.m_handle, desiredAccess, 0, 0, handle.m_size);
ASSERT_WITH_MESSAGE(baseAddress, "::MapViewOfFile failed with error %lu", ::GetLastError());
if (!baseAddress)
return 0;
RefPtr<SharedMemory> memory = adoptRef(new SharedMemory);
memory->m_size = handle.m_size;
memory->m_data = baseAddress;
// Adopt the HANDLE.
memory->m_handle = handle.m_handle;
handle.m_handle = 0;
return memory.release();
}
SharedMemory::~SharedMemory()
{
ASSERT(m_data);
ASSERT(m_handle);
::UnmapViewOfFile(m_data);
::CloseHandle(m_handle);
}
bool SharedMemory::createHandle(Handle& handle, Protection protection)
{
ASSERT_ARG(handle, !handle.m_handle);
ASSERT_ARG(handle, !handle.m_size);
HANDLE processHandle = ::GetCurrentProcess();
HANDLE duplicatedHandle;
if (!::DuplicateHandle(processHandle, m_handle, processHandle, &duplicatedHandle, accessRights(protection), FALSE, 0))
return false;
handle.m_handle = duplicatedHandle;
handle.m_size = m_size;
return true;
}
unsigned SharedMemory::systemPageSize()
{
static unsigned pageSize = 0;
if (!pageSize) {
SYSTEM_INFO systemInfo;
::GetSystemInfo(&systemInfo);
pageSize = systemInfo.dwPageSize;
}
return pageSize;
}
} // namespace WebKit
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