use of PQconnectdb and PQfinish in a shared library

Hi all,
Using PQconnectdb and PQfinish each time a function is called from a
client, the function run well the first time is invoqued, but fails on
any subsequent call, at the first PQexec call, with respective kill -9
of the child process on the server.

To get it working, i've done something like:

static bool bfirsttime = false;
int4 any_function (text buf, int4 num )
{
    if( !bfirsttime ) {
        dbconn = PQconnectdb( conninfo );
        bfirsttime = true;
    }

    /* code... */

    /* dont close db in library */
    /* PQfinish( dbconn ); */
    return( 0 );
}

Hum, the connection is never closed, it should be possible to do it in a
cleaner way...

Any hint?

Thx,
Alex