Archive for the tag 'Semaphore'

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About Semaphore

About Semaphore

Semaphore a term used in UNIX for a variable which acts as a counter.

There may be times when two processes try to access the same file simultaneously. In this event we must control the access of the file when the other process is accessing. This is done by assigning value to semaphore.

Semaphore is stored in kernel so that it can be accessed by all processes.

Details of Semaphore

The command

$ ipcs –s

will give the list of existing semaphores.