CMake/Source/cmFileLockWin32.cxx

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/*============================================================================
CMake - Cross Platform Makefile Generator
Copyright 2014 Ruslan Baratov
Distributed under the OSI-approved BSD License (the "License");
see accompanying file Copyright.txt for details.
This software is distributed WITHOUT ANY WARRANTY; without even the
implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
See the License for more information.
============================================================================*/
#include "cmFileLock.h"
#include "cmSystemTools.h"
#include <windows.h> // CreateFileW
cmFileLock::cmFileLock(): File(INVALID_HANDLE_VALUE)
{
}
cmFileLockResult cmFileLock::Release()
{
if (this->Filename.empty())
{
return cmFileLockResult::MakeOk();
}
const unsigned long len = static_cast<unsigned long>(-1);
static OVERLAPPED overlapped;
const DWORD reserved = 0;
const BOOL unlockResult = UnlockFileEx(
File,
reserved,
len,
len,
&overlapped
);
this->Filename = "";
CloseHandle(this->File);
this->File = INVALID_HANDLE_VALUE;
if (unlockResult)
{
return cmFileLockResult::MakeOk();
}
else
{
return cmFileLockResult::MakeSystem();
}
}
cmFileLockResult cmFileLock::OpenFile()
{
const DWORD access = GENERIC_READ | GENERIC_WRITE;
const DWORD shareMode = FILE_SHARE_READ | FILE_SHARE_WRITE;
const PSECURITY_ATTRIBUTES security = NULL;
const DWORD attr = 0;
const HANDLE templ = NULL;
this->File = CreateFileW(
cmSystemTools::ConvertToWindowsExtendedPath(this->Filename).c_str(),
access,
shareMode,
security,
OPEN_EXISTING,
attr,
templ
);
if (this->File == INVALID_HANDLE_VALUE)
{
return cmFileLockResult::MakeSystem();
}
else
{
return cmFileLockResult::MakeOk();
}
}
cmFileLockResult cmFileLock::LockWithoutTimeout()
{
if (!this->LockFile(LOCKFILE_EXCLUSIVE_LOCK))
{
return cmFileLockResult::MakeSystem();
}
else
{
return cmFileLockResult::MakeOk();
}
}
cmFileLockResult cmFileLock::LockWithTimeout(unsigned long seconds)
{
const DWORD flags = LOCKFILE_EXCLUSIVE_LOCK | LOCKFILE_FAIL_IMMEDIATELY;
while (true)
{
const BOOL result = this->LockFile(flags);
if (result)
{
return cmFileLockResult::MakeOk();
}
const DWORD error = GetLastError();
if (error != ERROR_LOCK_VIOLATION)
{
return cmFileLockResult::MakeSystem();
}
if (seconds == 0)
{
return cmFileLockResult::MakeTimeout();
}
--seconds;
cmSystemTools::Delay(1000);
}
}
BOOL cmFileLock::LockFile(DWORD flags)
{
const DWORD reserved = 0;
const unsigned long len = static_cast<unsigned long>(-1);
static OVERLAPPED overlapped;
return LockFileEx(
this->File,
flags,
reserved,
len,
len,
&overlapped
);
}