Asynchronous interface help?

I'm working on using PostgreSQL to synchronize two seperate web connections
for some silly authentication reasons. I'm adding a method to PHP that will
allow the generation of a page to wait on a named notify from another
backend process. It doesn't seem to work correctly. Here's the abridged
version of the code...

PHP_FUNCTION(pg_wait) {
zval **timeout, **pgsql_link;
int id = -1;
fd_set rfds;
int retval;
PGconn *pgsql;
PGnotify *notify;
struct timeval tv;
char *buf;
int nbytes;
int trycount=0;

/* ... */

ZEND_FETCH_RESOURCE2(pgsql, PGconn *, pgsql_link, id, "PostgreSQL link", le_link, le_plink);
convert_to_long_ex(timeout);

FD_ZERO(&rfds);
FD_SET(PQsocket(pgsql), &rfds);

tv.tv_sec = Z_STRVAL_PP(timeout);
tv.tv_usec = 0;

retval = select(1, &rfds, NULL, NULL, &tv);
if(retval) {
PQconsumeInput(pgsql);
notify = PQnotifies(pgsql);
if(notify) {
nbytes = strlen(notify->relname)+1;
buf = emalloc(nbytes);
memcpy(buf, notify->relname, nbytes);
free(notify);

/* ... */

}
} else {
printf("Timed out. Socket==%d\n", PQsocket(pgsql));
RETURN_FALSE;
}

This always seems to time out. Is there some mode that I need to put
the backend into in order to make the socket valid? I'm getting a
non-stdio/stdout/stderr value back from PQsocket, so things can't be
too messed up.

The following code seems to work, but polls--we would much rather
block on select().

while(trycount < Z_STRVAL_PP(timeout)) {
PQconsumeInput(pgsql);
notify = PQnotifies(pgsql);
if(notify) {
nbytes = strlen(notify->relname)+1;
buf = emalloc(nbytes);
memcpy(buf, notify->relname, nbytes);
free(notify);

/* ... */
}
sleep(1);
trycount++;
}

Anyone have any ideas?

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Adam Haberlach |A cat spends her life conflicted between a
adam(at)newsnipple(dot)com |deep, passionate, and profound desire for
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'88 EX500 |profound desire to avoid getting wet.