pthread_attr_setscope shall set the contentionscope attribute in the attr object. The contentionscope attribute may have the values PTHREAD_SCOPE_SYSTEM, signifying system scheduling contention scope, or PTHREAD_SCOPE_PROCESS, signifying process scheduling contention scope. If successful, pthread_attr_setscope functions return zero. If fail, an error number shall be returned to indicate the error. [EINVAL] The value of contentionscope is not valid. If fail, an error number shall be returned to indicate the error. [ENOTSUP] An attempt was made to set the attribute to an unsupported value. Shall not return an error code of [EINTR]