RETURN VALUES
The pthread_mutexattr_getkind_np function returns a positive value representing the "kind" of the mutex attribute attr if successful; otherwise the value -1 is returned and the global variable errno is set to indicate the error.
.Rv -std pthread_mutexattr_setkind_np
ERRORS
The pthread_mutexattr_getkind_np and pthread_mutexattr_setkind_np functions will fail if:
