Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!ncar!noao!asuvax!mcdphx!estinc!fnf
From: fnf@estinc.UUCP (Fred Fish)
Newsgroups: comp.unix.xenix
Subject: Re: system lockup
Keywords: bug?
Message-ID: <62@estinc.UUCP>
Date: 16 Feb 89 15:55:50 GMT
References: <60@estinc.UUCP> <555@marob.MASA.COM>
Reply-To: fnf@estinc.UUCP (Fred Fish)
Organization: Enhanced Software Technologies, Inc.
Lines: 27

In article <555@marob.MASA.COM> daveh@marob.masa.com (Dave Hammond) writes:
<In article <60@estinc.UUCP> fnf@estinc.UUCP (Fred Fish) writes:
<<[...]
<<This simple program demonstrates the problem on my system:
<<
<<	static char buf [1024 * 1024];
<<	main ()
<<	{
<<		write (0, buf, sizeof (buf));
<<	}
<
<I'm not offering confirmation, but I am quite curious why you
<are writing to file descriptor 0, normally associated with your
<standard input -- a *read* descriptor.   Perhaps this is contributing
<to your problem?

This is a contrived example which demonstrates the system lockup.  The
application was attempting to write to a file that it had opened, but
the file descriptor was getting lost due to a program bug, causing it
to attempt to write to descriptor 0.  No, I would not normally attempt
to write 1Mb of null bytes to my standard input stream.  However, I
wouldn't expect such an attempt to bring the system to its knees.

-Fred
-- 
# Fred Fish, 1835 E. Belmont Drive, Tempe, AZ 85284,  USA
# 1-602-491-0048           asuvax!{nud,mcdphx}!estinc!fnf