c++ - std::mutex in shared memory not working

Question

I have a scenario where the shared memory area is exclusively accessed by two different processes. When I launch the processes, the first process successfully locks the mutex, updates the memory and unlock the mutex. But I observe that when the second process try to lock it, it is still in deadlock state, waiting for mutex to unlock.

Time difference between the mutex lock is 10s for first and second process.

I am using the std::mutex. Please tell me what I am missing.

Answer 1

An std::mutex instance is only scoped to a single process; it is not capable of interprocess synchronization/concurrency. It is only capable of synchronizing child threads within a parent process.

Look to use Boost or an interprocess synchronization library instead.