On Tue, Mar 12, 2013 at 06:18:02PM +0530, Prabhu nath wrote: > I guess we should not mix mutex and condition variable. Both have their own > respective semantics. > *mutex* is used to serialize access to a shared resource among competing > threads. > *condition variable* is used to notify a* state change* of a resource to > the interested thread. > > In case of condition variable there is provision to explicitly notify a > single thread(pthread_cond_signal) or all the threads waiting on a > condition (or a state change) (pthread_cond_broadcast) > > Question was on pthread_mutex_unlock() that whether this function > invocation will trigger the movement of all the threads in the wait queue > to the ready queue. After pthread_mutex_unlock() is called , the mutex is release , then ,which stuff will reshcedule the threads in the waitqueue ? If do pthread_cond_signal() after each pthread_mutex_unlock() ,does it raise up the performence ? thanks! > If all the threads are of equal priority, then the first thread waiting for > the lock will be put to READY queue. > If there are variable priority threads waiting for the lock, then the > thread with highest priority would be woken up _______________________________________________ Kernelnewbies mailing list Kernelnewbies@xxxxxxxxxxxxxxxxx http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
