|
Hi All, I not quit sure whether this is the right place to ask, if is not please tell me which mail list should I send to the mail, thanks. When run the POSIX test, some cases about pthread rwlock fail. Test steps are as follow: 1. Main thread set its shcedule policy as "SCHED_FIFO", with highest priority: sched_get_priority_min()+2. 2. Main thread read lock 'rwlock' 3. Create a writer thread, with schedule policy as "SCHED_FIFO", and priority using sched_get_priority_min()+1. 4. The thread write lock 'rwlock', should block. 5. Main thread create a reader thread, with schedule policy as "SCHED_FIFO", and priority sched_get_priority_min() 6. Reader thread read lock 'rwlock', should block, since there is a higher priority writer blocked on 'rwlock' But the reader thread doesn't block. Because in POSIX specification or pthread_rwlock_rdlock() manual page says: If the Thread Execution Scheduling option is supported, and the threads involved in the lock are executing with the scheduling policies SCHED_FIFO or SCHED_RR, the calling thread shall not acquire the lock if a writer holds the lock or if writers of higher or equal priority are blocked on the lock; otherwise, the call‐ ing thread shall acquire the lock. So it seems the implementation of pthread rwlock doesn't obey the POSIX specification, right? If so, if there is a plan to make eglibc rwlock obey the POSIX specification? I notice that there is a flag in pthread_rwlock_t to spec prefer read lock or right lock, but it doesn't care the priorities. Any reply is appreciate. Thanks, Kai |
_______________________________________________ Patches mailing list Patches@xxxxxxxxxx http://eglibc.org/cgi-bin/mailman/listinfo/patches