A lock that is not automatically freed on unplanned program exit and unplanned systems restart is dangerous. It creates the possibility of a situation where a lock is thought to be held but isn't.

Having to poll the lock is inefficient (to varying degree). It can also prevent fairness (i.e. one particular process could wait forever for a lock if scheduling benefits other processes).

And now you know why flock was recommended.

In reply to Re: Lock File by ikegami
in thread Lock File by toniax

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