Path: utzoo!utgpu!news-server.csri.toronto.edu!rutgers!otello!yachaya!gongolo!peter
From: peter@gongolo.SUBLINK.org (Peter Komanns)
Newsgroups: comp.databases
Subject: Re: INFORMIX bug?
Summary: You have to do more...
Keywords: informix bug 4gl
Message-ID: <369@gongolo.SUBLINK.org>
Date: 24 Nov 90 13:49:04 GMT
References: <8330@pbhyf.PacBell.COM> <1990Nov20.221658.19496@informix.com> <8335@pbhyf.PacBell.COM>
Lines: 39

In article <8335@pbhyf.PacBell.COM>, jwas@PacBell.COM (Joe Wasik) writes:
> In article <1990Nov20.221658.19496@informix.com> markj@informix.com (Mark Jeske(Chicago Consultan)t) writes:
> >>In our case, since the Informix-4GL application starts up
> >>other background jobs, the sqlexec program hangs around until those other jobs
> >>are finished and it then interferes with the logoff process.
> 
> >I would try the following in your code before you exit.
> >
> >  close database
> >  call sqlexit()
> 
> While I admit I hadn't even considered doing a close, it's now been tried
> and unfortunately it doesn't work.
> 
> In fact, the sqlexit() function also appears to wait.  It seems to be waiting
> for confirmation that sqlexec back-end has died.  It doesn't get it, so the
> program hangs at the sqlexit() function.  An interrupt allows it to continue,
> but without killing the sqlexec back-end.
The back-end processor "sqlexec" uses a pipe() call to be activated, and
uses two SHORT variables, called  "_sqlpin" and "_sqpout".
In order to properly close the piping process you have to manage these
file (pipe) descriptors.
In fact, the same error ( sqlexec doesn't want to die ) occurs when:
 - you fork() your process and want the father to exit
 - you exec() another SQL based process
 - you system() another SQL process in the background ("&" at the end
   of the command).

I fixed this bug using fcntl() and setting the close-on-exec flag for
both the pipe descriptors above AND using sqlexit(),
and all works correctly.

Those two extern (global) variables aro undocumented, of course.

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