Re: Question about pthread_process_shared attribute

chsalvia@xxxxxxxxx wrote On 10/15/07 08:07,:
For interprocess synchronization mutexes, it seems some
implementations of posix threads support a PTHREAD_PROCESS_SHARED
flag, which can be used so that a mutex can work between processes,
rather than only between threads.

I have two questions about this:

1: In order for inter-process synchronization to work, does the
pthread_mutex_t object need to be placed in shared memory?

Suppose the mutex resides in Process P's private
memory, not shared with other processes. Now explain
how Process Q locks and unlocks a mutex that it can't
get access to, that it can't even see.

"It was on display in the bottom of a locked filing
cabinet stuck in a disused lavatory with a sign on
the door saying `Beware of the Leopard'." -- HHGttG

--
Eric.Sosman@xxxxxxx
.

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