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28 #ifndef TALK_BASE_FILELOCK_H_
29 #define TALK_BASE_FILELOCK_H_
33 #include "talk/base/constructormagic.h"
34 #include "talk/base/scoped_ptr.h"
40 // Implements a very simple cross process lock based on a file.
41 // When Lock(...) is called we try to open/create the file in read/write
42 // mode without any sharing. (Or locking it with flock(...) on Unix)
43 // If the process crash the OS will make sure that the file descriptor
44 // is released and another process can accuire the lock.
45 // This doesn't work on ancient OSX/Linux versions if used on NFS.
46 // (Nfs-client before: ~2.6 and Linux Kernel < 2.6.)
51 // Attempts to lock the file. The caller owns the returned
52 // lock object. Returns NULL if the file already was locked.
53 static FileLock* TryLock(const std::string& path);
57 FileLock(const std::string& path, FileStream* file);
63 scoped_ptr<FileStream> file_;
65 DISALLOW_EVIL_CONSTRUCTORS(FileLock);
68 } // namespace talk_base
70 #endif // TALK_BASE_FILELOCK_H_