The function int pthread_rwlockattr_getpshared(const pthread_rwlockattr_t *restrict attr, int *restrict pshared); It shall obtain the value of the process-shared attribute from 'attr'. The process-shared attribute shall be set to PTHREAD_PROCESS_SHARED to permit a read-write lock to be operated upon by any thread that has access to the memory where the read-write lock is allocated, even if the read-write lock is allocated in memory that is shared by multiple processes. If the process-shared attribute is PTHREAD_PROCESS_PRIVATE, the read-write lock shall only be operated upon by threads created within the same process as the thread that initialized the read-write lock; if threads of different processes attempt to operate on such a read-write lock, the behavior is undefined. The default value of the process-shared attribute shall be PTHREAD_PROCESS_PRIVATE. Upon success, it returns 0, and stores the value of the process-shared attribute of 'attr' into 'pshared'. It MAY fail if: [EINVAL] - 'attr' is invalid. Shall not return an error code of [EINTR]