lkml.org 
[lkml]   [2007]   [Feb]   [19]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
Subject[Qeustion][Maybe BUG?] simaltaneous wait and SIGCHLD handling
Hi,

From SUSv3, I expected SIGCHLD from dead processes (already reaped by wait(2))
should be cleared. But it seems that such situation is not handled in Linux.

Here is a test program. set sigchld handler and call waitpid() in main().

==
#include <stdio.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <signal.h>

int sigchld_handler(int sig,siginfo_t *info, void *uc)
{
fprintf(stderr,"Letter from the hell...(%d)\n",info->si_pid);
}

int main(int argc, char *argv)
{
struct sigaction act;
sigset_t block;
int status;
pid_t pid;

sigemptyset(&block);
sigaddset(&block, SIGCHLD);
act.sa_sigaction = sigchld_handler;
act.sa_mask = block;
act.sa_flags = SA_SIGINFO|SA_RESTART;
sigaction(SIGCHLD,&act,NULL);

pid = fork();
if (!pid) {
sleep(3);
exit(0);
}
sigprocmask(SIG_BLOCK, &block, NULL);
pid = waitpid(pid, &status, 0);
fprintf(stderr,"wait end -> %d\n",pid);
sigprocmask(SIG_UNBLOCK, &block, NULL);
exit(0);
}
==
Result is here
==
[kamezawa@casares ~]$ ./waittest
wait end -> 5841
Letter from the hell...(5841)
==

Is this an expected result ? I think SIGCHLD shouldn't be delivered.

-Kame

-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/

\
 
 \ /
  Last update: 2007-02-19 07:17    [W:0.471 / U:0.384 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site