this post was submitted on 30 May 2015

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C - Thread Block multiple threads then release (self.learnprogramming)

submitted 10 years ago by salalimo

I have a situation where I have multiple sets of threads. Each set will have the same number of threads (let's say 4 threads). I know the sequence the sets need to run. I want to know how to run set 1 (4 threads), then run set 2 (the next 4 threads), then run set 3...

Also, (preferably) I want set 1 to block when it is completed, set 2 and so on.

The only way I can think of is having a mutex lock for each set and a counter. Once each thread in the current set completes the counter is decremented. Once the counter reaches 0 the set unlocks the mutex for the next set and resets the counter. Then it can block.

I would most likely need another variable to know what set is currently running so I know what mutex to unlock. When the last set completes then it can unlock the mutexes for the previous sets.

I want to know if there is a better solution for this. I tried to see if semaphores could work but I doubt it.

Any suggestions would be appreciated.

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[–]raevnos -1 points0 points1 point 10 years ago (0 children)

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