OPTIMIST (likely to find the item in the list): Start with a shared lock, and without unlocking, "promote" to an exclusive lock once not found; make sure there is a timer on the attempt to prevent a deadlock, and if the timer goes off then unlock and retry from the top.

PESSIMIST (unlikely to find the item in the list): Use the exclusive lock from the beginning.

In reply to Re^4: File Locking by Anonymous Monk
in thread File Locking by turnstep

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