can pthread_mutexattr_setrobust apply to pthread_rwlock_t?

Question

the robustness of mutex is very important to my program since it can handle the case when a process died without releasing the mutex.

But according to the document, pthread_mutexattr_setrobust only apply to pthread_mutex_t, instead of pthread_rwlock_t, is there any approach to set the robustness of pthread_rwlock_t? Or its implementation is robust by default?

Answer 1

according to the document, pthread_mutexattr_setrobust only apply to pthread_mutex_t

More precisely, pthread_mutexattr_setrobust() sets a property of a pthread_mutexattr_t object, and these are used (only) for configuring objects of type pthread_mutex_t. This happens at initialization of the mutex via pthread_mutex_init().

The corresponding initialization function for read/write locks is pthread_rwlock_init(), and its documentation shows that the corresponding attribute object type, accepted by that function, is pthread_rwlockattr_t. Implementations may provide whatever properties they like as extensions, but the only one specified for this type by the current version of POSIX is pshared. Thus no, there is no (portable) robustness option for pthreads read/write locks.