131 lines
3.2 KiB
C
131 lines
3.2 KiB
C
/* $NetBSD: poll3w.c,v 1.2 2002/11/30 09:32:58 jdolecek Exp $ */
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/*-
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* Copyright (c) 2002 The NetBSD Foundation, Inc.
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 3. All advertising materials mentioning features or use of this software
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* must display the following acknowledgement:
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* This product includes software developed by the NetBSD
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* Foundation, Inc. and its contributors.
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* 4. Neither the name of The NetBSD Foundation nor the names of its
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* contributors may be used to endorse or promote products derived
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* from this software without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
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* ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
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* TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
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* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
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* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
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* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
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* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
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* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
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* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
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* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
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* POSSIBILITY OF SUCH DAMAGE.
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*/
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/*
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* Check for 3-way collision for descriptor. First child comes
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* and polls on descriptor, second child comes and polls, first
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* child times out and exits, third child comes and polls.
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* When the wakeup event happens, the two remaining children
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* should both be awaken.
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*/
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#include <sys/types.h>
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#include <sys/wait.h>
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#include <poll.h>
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#include <stdio.h>
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#include <unistd.h>
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int desc;
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static void
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child1(void)
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{
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struct pollfd pfd;
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pfd.fd = desc;
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pfd.events = POLLIN | POLLHUP | POLLOUT;
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(void) poll(&pfd, 1, 2000);
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printf("child1 exit\n");
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}
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static void
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child2(void)
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{
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struct pollfd pfd;
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pfd.fd = desc;
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pfd.events = POLLIN | POLLHUP | POLLOUT;
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sleep(1);
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(void) poll(&pfd, 1, INFTIM);
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printf("child2 exit\n");
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}
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static void
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child3(void)
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{
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struct pollfd pfd;
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sleep(5);
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pfd.fd = desc;
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pfd.events = POLLIN | POLLHUP | POLLOUT;
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(void) poll(&pfd, 1, INFTIM);
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printf("child3 exit\n");
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}
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int main(void);
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int
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main(void)
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{
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int pf[2];
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int status, i;
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pipe(pf);
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desc = pf[0];
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if (fork() == 0) {
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close(pf[1]);
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child1();
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_exit(0);
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}
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if (fork() == 0) {
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close(pf[1]);
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child2();
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_exit(0);
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}
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if (fork() == 0) {
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close(pf[1]);
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child3();
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_exit(0);
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}
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sleep(10);
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printf("parent write\n");
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write(pf[1], "konec\n", 6);
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for(i=0; i < 3; i++)
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wait(&status);
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printf("parent terminated\n");
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return (0);
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}
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