Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP
Path: utzoo!linus!philabs!seismo!hao!hplabs!sri-unix!gwyn@brl-vld
From: gwyn@brl-vld@sri-unix.UUCP
Newsgroups: net.unix-wizards
Subject: Re:  UNIX IPC
Message-ID: <11913@sri-arpa.UUCP>
Date: Wed, 21-Sep-83 15:50:35 EDT
Article-I.D.: sri-arpa.11913
Posted: Wed Sep 21 15:50:35 1983
Date-Received: Mon, 26-Sep-83 08:12:47 EDT
Lines: 10

From:      Doug Gwyn (VLD/VMB) <gwyn@brl-vld>

Signals have several bad properties for IPC:
	1.  They break "slow" (i.e. non-disk) i/o in progress
	    (the Berkeley "cure" for this is worse than the disease);
	2.  They reset the signal-catching state to SIG_DFL before
	    dispatching to a signal catcher (trying to fix this would
	    break code that depends on this side-effect);
	3.  Multiple signals do not stack or block the sender.
4.2BSD is supposed to provide a more flexible signal scheme.