pthread_cancel          Allows a thread to request that it, or
                           another thread, terminate execution.

   pthread_cleanup_pop     Removes a cleanup handler routine from the
                           top of the cleanup stack and optionally
                           executes it.

   pthread_cleanup_push    Establishes a cleanup handler routine to
                           be executed when the thread exits or is
                           canceled.

   pthread_setcancelstate  Sets the current thread's cancelability
                           state.

   pthread_setcanceltype   Sets the current thread's cancelability
                           type.

   pthread_testcancel      Requests delivery of any pending
                           cancelation request to the current thread.