Sig handler causing core dump

[Mark Brackett]

I'm a newbie to C programming...s o go easy. ;)
I'm forking child processes, and registering a signal handler with the following:
signal(SIGTERM, DieServer);
signal(SIGINT, DieServer);

DieServer is the following:
volatile sig_atomic_t dying_in_progre ss = 0;
void DieServer(int sig){
int result;
char dummy[0];
if(dying_in_pro gress) raise(sig);
dying_in_progre ss = 1;

// Now do the clean up actions:
if(debug==1) printf("SERVER PARENT->Received SIGEVENT %d.\n",sig);
wait();
close(client_so ckfd);
read(server_soc kfd,dummy,0);
result = close(server_so ckfd);
if(result==-1){
if(debug==1) printf("SERVER PARENT->Could not close socket\n");
perror("WARNING ");
}
signal(sig, SIG_DFL);
raise(sig);
}

The wait() causes a core dump if there's no children. How do I fix this?

[Artie Gold]

Re: Sig handler causing core dump

Mark Brackett wrote:[color=blue]
> I'm a newbie to C programming...s o go easy. ;)[/color]

OK. I'll be gentle.
[color=blue]
> I'm forking child processes, and registering a signal handler with the following:[/color]

Whoops. There is no such thing as `forking' in standard C...
[color=blue]
> signal(SIGTERM, DieServer);
> signal(SIGINT, DieServer);
>
> DieServer is the following:
> volatile sig_atomic_t dying_in_progre ss = 0;
> void DieServer(int sig){
> int result;
> char dummy[0];
> if(dying_in_pro gress) raise(sig);
> dying_in_progre ss = 1;
>
> // Now do the clean up actions:
> if(debug==1) printf("SERVER PARENT->Received SIGEVENT %d.\n",sig);
> wait();
> close(client_so ckfd);
> read(server_soc kfd,dummy,0);
> result = close(server_so ckfd);
> if(result==-1){
> if(debug==1) printf("SERVER PARENT->Could not close socket\n");
> perror("WARNING ");
> }
> signal(sig, SIG_DFL);
> raise(sig);
> }
>
> The wait() causes a core dump if there's no children. How do I fix this?[/color]
....nor read(), nor close() nor wait().

There *are* such things in POSIX, hence posting your question to
news:comp.unix. programmer would be the best course of action.

Gentle enough for you? ;-)

See you over there.

HTH,
--ag

--
Artie Gold -- Austin, Texas

http://it-matters.blogspot.com

[Dave Vandervies]

Re: Sig handler causing core dump

In article <dea053cf.04110 31441.5b526379@ posting.google. com>,
Mark Brackett <brackett@ufl.e du> wrote:[color=blue]
>I'm a newbie to C programming...s o go easy. ;)
>I'm forking child processes,[/color]
<snip>[color=blue]
>The wait() causes a core dump if there's no children. How do I fix this?[/color]

forking child processes, wait(), and a lot of what was in between that I
snipped are beyond the scope of the C language and therefore inappropriate
for comp.lang.c.

I suspect that comp.unix.progr ammer would be a better place to ask this.


dave

--
Dave Vandervies dj3vande@csclub .uwaterloo.ca
Hmm, a quote for posterity: "calling strlen() is a lengthy operation."
Is calling memmove() a 'moving experience?'
--Mike Wahler in comp.lang.c

[Mark Brackett]

Re: Sig handler causing core dump

dj3vande@csclub .uwaterloo.ca (Dave Vandervies) wrote in message news:<cmbn54$ld i$1@rumours.uwa terloo.ca>...[color=blue]
> In article <dea053cf.04110 31441.5b526379@ posting.google. com>,
> Mark Brackett <brackett@ufl.e du> wrote:[color=green]
> >I'm a newbie to C programming...s o go easy. ;)
> >I'm forking child processes,[/color]
> <snip>[color=green]
> >The wait() causes a core dump if there's no children. How do I fix this?[/color]
>
> forking child processes, wait(), and a lot of what was in between that I
> snipped are beyond the scope of the C language and therefore inappropriate
> for comp.lang.c.
>
> I suspect that comp.unix.progr ammer would be a better place to ask this.
>
>
> dave[/color]

Doh! Sorry for the faux pas....I'll try again over there. Thanks for
the gently delivered heads-ups.

--Mark Brackett