Is it possible to use mutex in multiprocessing case on Linux/UNIX ?

Question

This is an interview question.

Is it possible to use mutex in multiprocessing case on Linux/UNIX ?

My idea: No, different processes have separate memory s

Answer 1

Not quite. POSIX threads has a concept of a process-shared attribute which can be used to create mutexes that can be operated on by multiple processes.

You can put such a mutex in shared memory so that multiple processes can all get at it.

Whether LINUX implements this., I'm not sure, I've never had a need to use it since it seems unnecessarily complex.

For a useful precis of attributes, see my answer to this question.