pthread_rwlockattr_destroy(3C) destroys a read-write lock attributes object.
#include <pthread.h> int pthread_rwlockattr_destroy(pthread_rwlockattr_t *attr);
The effect of subsequent use of the object is undefined until the object is re-initialized by another call to pthread_rwlockattr_init(). An implementation can cause pthread_rwlockattr_destroy() to set the object referenced by attr to an invalid value.
The value specified by attr is invalid.