OCI time out !

How to determine the time out when a tabla is locked ? I have something like this, but what about if i make a select for update and another one have make the same I got with a lock undetermitated ? I mean i would like to get lockd for 30 secons after that get a code of error because tha table is lockd ....

if (olog(&lda, hda, sz, -1, szu, -1, szt,-1, (ub4) OCI_LM_DEF)) { printf ("No se puede establecer conexion con Base de Datos %s\n", sz); exit(1);
}

>> OOPENS, opens the specified cursor.

if (oopen(&cda, &lda, (text *) 0, -1, -1, (text *) 0, -1)) { printf ("No se ha podido crear el cursor para acceder al diccionario\n");
exit(1);
}

                 thanks ! Oscar