CMake/Source/cmFileLock.h
Ruslan Baratov e6db4c5a4e file: Add LOCK subcommand to do file and directory locking
Provide options to fail without blocking or to block up to a timeout.
Provide options to specify the scope containing the lock so it can be
released automatically at the end of a function, file, or process.

Extend the RunCMake.file test with cases covering the file(LOCK) command
usage and error cases.
2014-12-03 09:47:44 -05:00

75 lines
1.9 KiB
C++

/*============================================================================
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.
============================================================================*/
#ifndef cmFileLock_h
#define cmFileLock_h
#include "cmStandardIncludes.h"
#if defined(_WIN32)
# include <windows.h> // HANDLE
#endif
class cmFileLockResult;
/**
* @brief Cross-platform file locking.
* @details Under the hood this class use 'fcntl' for Unix-like platforms and
* 'LockFileEx'/'UnlockFileEx' for Win32 platform. Locks are exclusive and
* advisory.
*/
class cmFileLock
{
public:
cmFileLock();
~cmFileLock();
/**
* @brief Lock the file.
* @param timeoutSec Lock timeout. If -1 try until success or fatal error.
*/
cmFileLockResult Lock(const std::string& filename, unsigned timeoutSec);
/**
* @brief Unlock the file.
*/
cmFileLockResult Release();
/**
* @brief Check file is locked by this class.
* @details This function helps to find double locks (deadlocks) and to do
* explicit unlocks.
*/
bool IsLocked(const std::string& filename) const;
private:
cmFileLock(const cmFileLock&);
cmFileLock& operator=(const cmFileLock&);
cmFileLockResult OpenFile();
cmFileLockResult LockWithoutTimeout();
cmFileLockResult LockWithTimeout(unsigned timeoutSec);
#if defined(_WIN32)
typedef HANDLE FileId;
BOOL LockFile(DWORD flags);
#else
typedef int FileId;
int LockFile(int cmd, int type);
#endif
FileId File;
std::string Filename;
};
#endif // cmFileLock_h