From owner-freebsd-bugs  Mon Sep  6  0:20:16 1999
Delivered-To: freebsd-bugs@freebsd.org
Received: from freefall.freebsd.org (freefall.FreeBSD.ORG [204.216.27.21])
	by hub.freebsd.org (Postfix) with ESMTP id 0CF6C152F3
	for <freebsd-bugs@FreeBSD.org>; Mon,  6 Sep 1999 00:20:15 -0700 (PDT)
	(envelope-from gnats@FreeBSD.org)
Received: (from gnats@localhost)
	by freefall.freebsd.org (8.9.3/8.9.2) id AAA32149;
	Mon, 6 Sep 1999 00:20:01 -0700 (PDT)
	(envelope-from gnats@FreeBSD.org)
Received: by hub.freebsd.org (Postfix, from userid 32767)
	id 397DE1520F; Mon,  6 Sep 1999 00:18:01 -0700 (PDT)
Message-Id: <19990906071801.397DE1520F@hub.freebsd.org>
Date: Mon,  6 Sep 1999 00:18:01 -0700 (PDT)
From: tarkhil@asteroid.svib.ru
To: freebsd-gnats-submit@freebsd.org
X-Send-Pr-Version: www-1.0
Subject: kern/13593: Problems with FIFO and select
Sender: owner-freebsd-bugs@FreeBSD.ORG
Precedence: bulk
X-Loop: FreeBSD.org


>Number:         13593
>Category:       kern
>Synopsis:       Problems with FIFO and select
>Confidential:   no
>Severity:       serious
>Priority:       low
>Responsible:    freebsd-bugs
>State:          open
>Quarter:        
>Keywords:       
>Date-Required:
>Class:          sw-bug
>Submitter-Id:   current-users
>Arrival-Date:   Mon Sep  6 00:20:01 PDT 1999
>Closed-Date:
>Last-Modified:
>Originator:     Alex Povolotsky
>Release:        3.2-STABLE
>Organization:
>Environment:
FreeBSD shuttle.svib.ru 3.0-19990619-STABLE FreeBSD 3.0-19990619-STABLE #0: Thu Jun 24 21:26:37 MSD 1999     root@shuttle.svib.ru:/mnt/usr/src/sys/compile/SHUTTLE  i386

>Description:
Attempt to open FIFO file with O_WRONLY|O_NONBLOCK results in Device not configured error.

However, when FIFO is opened with O_RDWR and O_NONBLOCK, every attempt 
to select(2) its handler for writing doesn't wait until someone opens
FIFO for reading, but instead FIFO is ready to write at every select.

>How-To-Repeat:
#include <stdio.h>
#include <fcntl.h>

main() {
	int control;
	if ((control = open("STATUS",O_WRONLY|O_NONBLOCK))<0) {
		perror("Could not open STATUS ");
		exit(1);
	}
	printf("STATUS ready\n");
	close(control);
	return(0);
}

>Fix:


>Release-Note:
>Audit-Trail:
>Unformatted:


To Unsubscribe: send mail to majordomo@FreeBSD.org
with "unsubscribe freebsd-bugs" in the body of the message