To: Joe Murphy <joe.murphy@aersoft.ie>
Cc: "pgsql-interfaces@postgresql.org" <pgsql-interfaces@postgresql.org>
Subject: Re: libpq, threads and connection reset 
In-reply-to: <3D775423.78A43764@aersoft.com> 
References: <20020828025202.C74E81D1943C8@bjapp2.163.net>
	<3D7751B5.CE431206@aersoft.com> <3D775423.78A43764@aersoft.com>
Comments: In-reply-to Joe Murphy <joe.murphy@aersoft.ie>
	message dated "Thu, 05 Sep 2002 13:54:59 +0100"
Date: Thu, 05 Sep 2002 10:19:24 -0400
Message-ID: <29109.1031235564@sss.pgh.pa.us>
From: Tom Lane <tgl@sss.pgh.pa.us>

Joe Murphy <joe.murphy@aersoft.ie> writes:
>> The re-connect underlying call to connect returns -1 and errno = 0, so
>> it thinks the connection is "in progress" and tries
>> to complete the connection - but hangs on the select (poll)

Well, you have a bug in connect() if it's returning the wrong errno
in the multi-thread case.

However, our code in fe-connect.c reads like this:

    if (connect(conn->sock, &conn->raddr.sa, conn->raddr_len) < 0)
    {
        if (SOCK_ERRNO == EINTR)
            /* Interrupted system call - we'll just try again */
            goto retry1;

        if (SOCK_ERRNO == EINPROGRESS || SOCK_ERRNO == EWOULDBLOCK || SOCK_ERRNO == 0)
        {
            /*
             * This is fine - we're in non-blocking mode, and the
             * connection is in progress.
             */
            conn->status = CONNECTION_STARTED;
        }
        else
        {
            /* Something's gone wrong */
            connectFailureMessage(conn, SOCK_ERRNO);
            goto connect_errReturn;
        }

I wonder whether it's really a good idea to treat errno == 0 as
indicating "connection in progress".  Does anyone know of a platform
where zero is actually what is returned in this case?  The man pages
I can find all say that EINPROGRESS is returned.

			regards, tom lane