Pthread c++ and mutex

Question

a question about pthread and mutex.

I have architecture producer consumer with a shared queue.

I have two queue operations: push and pop.

for both of these operation I use a mutex (lock - implementation - unlock).

I did not understand a thing...

Just use mutexes?
Need I to use signal or wait to wakeup of a thread?
When a thread finds the mutex locked, this thread will locked (lock mutex is a blocking operation?)

Your question is very general. Signals and mutexes are used together most commonly and it is all very dependent on your use case. Concurrent programming is a difficult topic unless you invest some up front study to understand some key-concepts. I would recommend you try that first and come back with more specific issues. (I didn't down vote you though). — Dennis, Jun 10 '13 at 17:31

score 2 · Accepted Answer · answered Jun 10 '13 at 17:29

Whenever you are sharing a common resource, using mutex is the best way to go. Sometimes semaphores might be required.
You do not need to use a signal to wake up a thread, unless you put it to sleep yourself. Usually if a thread hits a mutex that is locked it will wait. The CPU scheduling algorithm will take care of the thread, and you can be sure that it will be woken up once mutex unlocks without any performance issues.
The thread will not be locked once it finds a mutex that is blocked. The thread will simply enter waiting queue until cpu scheduling algorithm decides it should be taken out. But it really depends on your definition of what you percieve as locked.

Also please rephrase a question a little bit, it was hard to understand.

1 Answers1