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Each IPC object has a unique IPC identifier associated with it. When
we say ``IPC object'', we are speaking of a single message queue, semaphore set,
or shared memory segment.
This identifier is used within the kernel to uniquely identify an IPC object.
For example, to access a particular shared memory segment, the only item you
need is the unique ID value which has been assigned to that segment.
The uniqueness of an identifier is relevant to the type of object
in question. To illustrate this, assume a numeric identifier of ``12345''.
While there can never be two message queues with this same identifier, there
exists the distinct possibility of a message queue and, say, a shared memory
segment, which have the same numeric identifier.
Converted on:
Fri Mar 29 14:43:04 EST 1996
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