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/* Copyright (C) 2007-2008 The Android Open Source Project
**
** This software is licensed under the terms of the GNU General Public
** License version 2, as published by the Free Software Foundation, and
** may be copied, distributed, and modified under those terms.
**
** 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.
*/
#ifndef _ANDROID_UTILS_FILELOCK_H
#define _ANDROID_UTILS_FILELOCK_H
/** FILE LOCKS SUPPORT
**
** a FileLock is useful to prevent several emulator instances from using the same
** writable file (e.g. the userdata.img disk images).
**
** create a FileLock object with filelock_create(), the function will return
** NULL only if the corresponding path is already locked by another emulator
** of if the path is read-only.
**
** note that 'path' can designate a non-existing path and that the lock creation
** function can detect stale file locks that can longer when the emulator
** crashes unexpectedly, and will happily clean them for you.
**
** you can call filelock_release() to release a file lock explicitely. otherwise
** all file locks are automatically released when the program exits.
**/
typedef struct FileLock FileLock;
extern FileLock* filelock_create ( const char* path );
extern void filelock_release( FileLock* lock );
#endif /* _ANDROID_UTILS_FILELOCK_H */