EXPORTED int mailbox_open_irlnb(const char *name, struct mailbox **mailboxptr)
{
    return mailbox_open_advanced(name,
                                 LOCK_SHARED|LOCK_NONBLOCK,
                                 /* cannot do nonblocking lock on index...why? */
                                 LOCK_SHARED,
                                 NULL, mailboxptr);
}
EXPORTED int mailbox_open_irlnb(const char *name, struct mailbox **mailboxptr)
{
    return mailbox_open_advanced(name,
                                 LOCK_SHARED|LOCK_NONBLOCK,
                                  
                                 LOCK_SHARED,
                                 NULL, mailboxptr);
}