server/mpm/event/event.c:2939: error: UNINITIALIZED_VALUE
  The value read from rv was never initialized.

server/mpm/event/event.c:2939:13: 
2937.         i = apr_atomic_dec32(&foo);
2938.         if (i >= 0) {
2939.             ap_log_error(APLOG_MARK, APLOG_CRIT, rv, NULL, APLOGNO(02405)
                  ^
2940.                          "atomics not working as expected");
2941.             return HTTP_INTERNAL_SERVER_ERROR;
