LockFile.h

/*
** libutil++
** $Id: LockFile.h 1653 2016-02-28 19:54:59Z sella $
** Copyright (c) 2011-2016 Digital Genesis, LLC. All Rights Reserved.
** Released under the LGPL Version 2.1 License.
** http://www.digitalgenesis.com
*/

#ifndef __libutilxx__sella__util__LockFile_H__
#define __libutilxx__sella__util__LockFile_H__

#include "../../common.h"
#include "FileException.h"

#include <limits.h>
#include <stdlib.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <unistd.h>

#include <sys/types.h>
#include <sys/stat.h>
#include <time.h>
#include <stdio.h>
#include <stdlib.h>

#include <string>
#include <mutex>

namespace sella {
        namespace util {
                class LockFile;
        }
}

class sella::util::LockFile {
        public:
                static const useconds_t RetryInterval = 100000;

        public:
                LockFile(const std::string &fullpath, useconds_t staleAge = -1, bool removeStale = true, uid_t uid = -1, gid_t gid = -1, int mode = 0644) throw ();
                virtual ~LockFile();

                void setRemoveStale(bool on = true); /* Automatically remove stale on lock */
                void setStaleAge(useconds_t staleAge = -1) throw (); /* Never expires */
                void setUID(uid_t uid = -1) throw (); /* Don't change */
                void setGID(gid_t gid = -1) throw (); /* Don't change */
                void setMode(int mode = 0644) throw ();

                bool lock(useconds_t retryInterval = RetryInterval)  throw (FileException); /* Blocking create and lock lockfile */
                bool tryLock(void) throw (FileException); /* Attempt to create and lock lockfile */
                bool tryLockUntil(time_t timeout, useconds_t retryInterval = RetryInterval) throw (FileException); /* Attempt to create and lock lockfile */
                bool tryLockFor(time_t duration, useconds_t retryInterval = RetryInterval) throw (FileException); /* Attempt to create and lock lockfile */
                bool tryLockCount(int64_t retries, useconds_t retryInterval = RetryInterval)  throw (FileException); /* Blocking create and lock lockfile */
                bool unlock(void) throw (FileException); /* Unlock and remove lockfile */
                bool remove(void) throw (); /* Used to remove stale lock file - Will not remove locked lockfile */

                bool ownLock(void) throw ();
                bool isLocked(void) throw ();
                bool isStale(void) throw ();

        protected:
                bool lock_nonblock(void) throw (FileException);
                bool unlink(void) throw ();
                void close(void) throw ();

        private:
                std::string fullpath;
                useconds_t stale;
                bool removeStale;
                uid_t uid;
                gid_t gid;
                int mode;
                int fd;
                std::mutex mutex;
};

#endif

/*
** vim: noet ts=3 sw=3
*/