Message10670

Also used in the package youtube-dl for file locking support:

    import fcntl

    def _lock_file(f, exclusive):
        fcntl.flock(f, fcntl.LOCK_EX if exclusive else fcntl.LOCK_SH)

    def _unlock_file(f):
        fcntl.flock(f, fcntl.LOCK_UN)

This specific functionality is implementable with https://docs.oracle.com/javase/7/docs/api/java/nio/channels/FileLock.html, which is likely to be portable than JNR for this particular support (based on previous experience - use JNR only when nothing else is available in Java).