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From: Archie Cobbs <archie@dellroad.org>
Message-Id: <200205011806.g41I6LF92589@arch20m.dellroad.org>
Subject: Re: Bug in pthread_cancel()
In-Reply-To: <200205011559.g41Fx4Z92027@arch20m.dellroad.org>
 "from Archie Cobbs at May 1, 2002 08:59:04 am"
To: Archie Cobbs <archie@dellroad.org>
Date: Wed, 1 May 2002 11:06:21 -0700 (PDT)
Cc: "Jeroen Ruigrok/asmodai" <asmodai@wxs.nl>,
	Daniel Eischen <eischen@pcnet1.pcnet.com>, freebsd-stable@FreeBSD.ORG
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Archie Cobbs writes:
> > And the testcase in the PR is solved adequately with it?

Below is a program that seems to demonstrate the problem.
Note that the thread is canceled before it exits, but it
doesn't reach a cancellation point until after it exits.

-Archie

__________________________________________________________________________
Archie Cobbs     *     Packet Design     *     http://www.packetdesign.com

#include <stdio.h>
#include <signal.h>
#include <unistd.h>
#include <errno.h>
#include <sched.h>
#include <pthread.h>
#include <err.h>

static void
thread_cleanup(void *arg)
{
	sched_yield();
	printf("Thread: executing cleanup...\n");
	pthread_testcancel();
}

static void *
thread_main(void *arg)
{
	pthread_cleanup_push(thread_cleanup, NULL);
	printf("Thread: sleeping 1 second...\n");
	sleep(1);
	printf("Thread: sending SIGTERM...\n");
	kill(getpid(), SIGTERM);
	sched_yield();
	printf("Thread: exiting...\n");
	return (NULL);
}

int
main(int argc, char **argv)
{
	pthread_t tid;
	sigset_t sigs;
	int sig;

	/* Spawn thread */
	printf("Main: spawning thread...\n");
	if ((errno = pthread_create(&tid, NULL, thread_main, NULL)) != 0)
		err(1, "pthread_create");

	/* Wait for signal */
	sigemptyset(&sigs);
	sigaddset(&sigs, SIGINT);
	sigaddset(&sigs, SIGTERM);
	if (sigprocmask(SIG_BLOCK, &sigs, NULL) == -1)
		err(1, "sigprocmask");
	printf("Main: waiting for signal...\n");
	if (sigwait(&sigs, &sig) == -1)
		err(1, "sigwait");

	/* Cancel thread */
	printf("Main: canceling thread...\n");
	pthread_cancel(tid);

	/* Done */
	usleep(500);
	printf("Main: exiting...\n");
	return (0);
}


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