pthread_mutexattr_setprioceiling Subroutine Purpose Sets the value of the prioceiling attribute of a mutex attributes object. Library Threads Library (libpthreads.a) Syntax #include
int pthread_mutexattr_setprioceiling (attr, prioceiling) pthread_mutexattr_t *attr; int prioceiling; Description The pthread_mutexattr_setprioceiling subroutine sets the value of the prioceiling attribute of the mutex attributes object attr. This attribute specifies the priority ceiling of the mutex created with this attributes object, used in the priority protection protocol to prevent priority inversions. It has no meaning if the mutex uses another protocol. Note: The pthread.h header file must be the first included file of each source file using the threads library. Parameters attr Specifies the mutex attributes object. prioceiling Specifies the priority ceiling to set. It must be in the range from 1 to 127, where 1 is the least favored priority, and 127 the most favored; it should be the priority of the highest priority thread that can lock the mutex lock, or higher. Setting a lower value may cause priority inversions. Return Values Upon successful completion, 0 is returned. Otherwise, an error code is returned. Error Codes The pthread_mutexattr_setprioceiling subroutine is unsuccessful if the following is true: EINVAL The attr or prioceiling parameters are not valid. ENOSYS The priority protection POSIX option is not implemented. EPERM The calling thread does not have sufficient privilege to perform the operation. Implementation Specifics This subroutine is part of the Base Operating System (BOS) Runtime. The implementation of this subroutine is dependent on the priority protection POSIX option. The priority protection POSIX option is not implemented in the current version of AIX. Related Information The pthread_mutexattr_getprioceiling subroutine, pthread_mutexattr_init subroutine, pthread_mutex_init subroutine, pthread_mutex_setprioceiling subroutine. Synchronization Scheduling. Threads Library Options and Threads Library Quick Reference.