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/* flint_lock.h: database locking for flint backend.
*
* Copyright (C) 2005,2006,2007 Olly Betts
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License as
* published by the Free Software Foundation; either version 2 of the
* License, or (at your option) any later version.
*
* This program 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 General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301
* USA
*/
#ifndef XAPIAN_INCLUDED_FLINT_LOCK_H
#define XAPIAN_INCLUDED_FLINT_LOCK_H
#include <string>
#if defined __CYGWIN__ || defined __WIN32__
# include "safewindows.h"
#elif defined __EMX__
# define INCL_DOS
# define INCL_DOSERRORS
# include <os2.h>
#else
# include <sys/types.h>
#endif
class FlintLock {
std::string filename;
#if defined __CYGWIN__ || defined __WIN32__
HANDLE hFile;
#elif defined __EMX__
HFILE hFile;
#else
int fd;
pid_t pid;
#endif
public:
typedef enum {
SUCCESS, // We got the lock!
INUSE, // Already locked by someone else.
UNSUPPORTED, // Locking probably not supported (e.g. NFS without lockd).
UNKNOWN // The attempt failed for some unspecified reason.
} reason;
#if defined __CYGWIN__ || defined __WIN32__
FlintLock(const std::string &filename_)
: filename(filename_), hFile(INVALID_HANDLE_VALUE) { }
operator bool() { return hFile != INVALID_HANDLE_VALUE; }
#elif defined __EMX__
FlintLock(const std::string &filename_)
: filename(filename_), hFile(NULLHANDLE) { }
operator bool() { return hFile != NULLHANDLE; }
#else
FlintLock(const std::string &filename_) : filename(filename_), fd(-1) { }
operator bool() { return fd != -1; }
#endif
// Release any lock held when we're destroyed.
~FlintLock() { release(); }
reason lock(bool exclusive);
void release();
};
#endif // XAPIAN_INCLUDED_FLINT_LOCK_H
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