Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP
Posting-Version: version B 2.10.2 9/17/84; site godot.UUCP
Path: utzoo!watmath!clyde!cbosgd!ihnp4!godot!bruce
From: bruce@godot.UUCP (Bruce Nemnich)
Newsgroups: net.bugs.uucp,net.bugs.4bsd
Subject: Re: hung line help needed -- sendmail, not uucico
Message-ID: <589@godot.UUCP>
Date: Fri, 7-Dec-84 23:23:12 EST
Article-I.D.: godot.589
Posted: Fri Dec  7 23:23:12 1984
Date-Received: Mon, 10-Dec-84 17:23:15 EST
References: <85@daemon.UUCP> <33700001@trsvax.UUCP>
Reply-To: bruce@godot.UUCP (Bruce Nemnich)
Organization: Thinking Machines, Cambridge, MA
Lines: 17
Xref: watmath net.bugs.uucp:418 net.bugs.4bsd:1263
Summary: 

Well, it turns out this problem is not uucico's at all.  It turns out
that sendmail execs its mailers with SIGALRM blocked.  

4.2bsd sendmail comes configured for uucp mail with the "-r" uux option,
which prevents uucico from starting up immediately, in which case
SIGALRM doesn't matter.  However, I took out the -r in order to place
demand calls as soon as mail was processed; the resulting uucico then
inherits the blocked SIGALRM, so if anythnig happens to the connection
which would normally cause a timeout (typically trying to login), the
process will hang forever.

I haven't looked at sendmail for the cause yet, but a temporary
circumvention for uucico is to add a sigsetmask(0) at the top of main()
in cico.c.
-- 
--Bruce Nemnich, Thinking Machines Corporation, Cambridge, MA
  ihnp4!godot!bruce, bjn@mit-mc.arpa ... soon to be bruce@godot.arpa