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/*
This file is part of the KDE libraries
Copyright (c) 2004 Waldo Bastian <bastian@kde.org>
This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Library General Public
License version 2 as published by the Free Software Foundation.
This library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Library General Public License for more details.
You should have received a copy of the GNU Library General Public License
along with this library; see the file COPYING.LIB. If not, write to
the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
Boston, MA 02110-1301, USA.
*/
#ifndef _KLOCKFILE_H_
#define _KLOCKFILE_H_
#include <tqstring.h>
#include <tqdatetime.h>
#include <ksharedptr.h>
/**
* The KLockFile class provides NFS safe lockfiles.
*
* @author Waldo Bastian <bastian@kde.org>
* @since 3.3
*/
class TDECORE_EXPORT KLockFile : public KShared
{
public:
typedef KSharedPtr<KLockFile> Ptr;
KLockFile(const TQString &file);
/**
* Destroys the object, releasing the lock if held
**/
~KLockFile();
/**
* Possible return values of the lock function.
*/
enum LockResult {
/**
* Lock was acquired successfully
*/
LockOK = 0,
/**
* The lock could not be acquired because it is held by another process
*/
LockFail,
/**
* The lock could not be acquired due to an error
*/
LockError,
/**
* A stale lock has been detected
*/
LockStale
};
enum LockOptions {
/**
* Return immediately, do not wait for the lock to become available
*/
LockNoBlock = 1,
/**
* Automatically remove a lock when a lock is detected that is stale
* for more than staleTime() seconds.
*/
LockForce = 2
};
/**
* Attempt to acquire the lock
*
* @param options A set of @ref LockOptions OR'ed together.
*/
LockResult lock(int options=0);
/**
* Returns whether the lock is held or not
*/
bool isLocked() const;
/**
* Release the lock
*/
void unlock();
/**
* Return the time in seconds after which a lock is considered stale
* The default is 30.
*/
int staleTime() const;
/**
* Set the time in seconds after which a lock is considered stale
*/
void setStaleTime(int _staleTime);
/**
* Returns the pid, hostname and appname of the process holding
* the lock after the lock functon has returned with LockStale.
* @returns false if the pid and hostname could not be determined
*/
bool getLockInfo(int &pid, TQString &hostname, TQString &appname);
private:
class KLockFilePrivate;
KLockFilePrivate *d;
};
#endif
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