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I have an object that uses pthreads. Its constructor creates several threads.

The class's destructor calls pthread_join on all these threads.

What would happen during a delete, if it didn't? I.e., what happens to a non-terminated thread, if the delete operator suddenly tries to deallocate the object?

Thanks in advance for all replies. :)

Christian Pedersen
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  • in the best case the program crashes. If not it goes haywire in the memory of your program – Hayt Sep 29 '16 at 13:32

1 Answers1

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With the join, your destructor will block until all of the joined threads have exited.

pthread_join

The pthread_join() function waits for the thread specified by thread to terminate. If that thread has already terminated, then pthread_join() returns immediately. The thread specified by thread must be joinable.

If you don't join with the threads, they will continue to run. This can have various consequences depending on if you invoke undefined behavior (eg, try to reference the deleted object after the destructor exits from one of the still running threads).

Deleting the pthread_t objects could have consequences depending on your system (I don't know every implementation of pthreads), but in general they're only references to the underlying system object representing the thread. So you will lose your reference to that thread, and potentially be unable to join with it later, but the thread would continue to run.

lcs
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