Path: utzoo!attcan!utgpu!jarvis.csri.toronto.edu!mailrus!husc6!rice!sun-spots-request
From: JARMOLOWSKI%ESDSDF.decnet@crdgw1.ge.com (Tom Jarmolowski)
Newsgroups: comp.sys.sun
Subject: Sun hangs?
Keywords: SunOS
Message-ID: <321@brazos.Rice.edu>
Date: 19 Jul 89 13:48:00 GMT
Sender: root@rice.edu
Organization: Sun-Spots
Lines: 36
Approved: Sun-Spots@rice.edu
X-Sun-Spots-Digest: Volume 8, Issue 80, message 6 of 15

The following simple program will cause a Sun to hang in a bizarre state.
We have seen this behavior on Sun 3s and 4s under SunOS 3.x and 4.x.
After a few hundred iterations of the loop (a random number, usually
around 250).  Strange things happen.  Most programs executed from a tty or
pty hang.  New programs can be started from a mouse menu and USUALLY work
if they do not use a pty.  Does anyone have any idea what is wrong ?

P.S. It makes no difference if anything is connected to ttyb or not.

#include	<stdio.h>
#include	<fcntl.h>

main()
{
	int	fd;
	int	count = 0;

	while (1) {

		fd = open("/dev/ttyb", O_RDWR);
		write(fd, "junk", 4);

		/************************************************/		
		/* The next line is not required for the	*/
		/* bug to occur					*/
		/************************************************/
		printf("%d\n", count++);

		close(fd);
	}
}



				Tom Jarmolowski
				jarmolowski%esdsdf.decnet@ge-crd.arpa