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SIGTERM

DISCUSSION Bubulac Tatiana 2 participants 4 messages May 21, 2002 – May 22, 2002

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Bubulac Tatiana

author
#0 lore raw

Hi,

I want to terminate a parent process that attach several shared
memory segments
with kill(pid, SIGTERM) but it fails to terminate.
Even if I give the command from command line it fails to terminate. If I give kill -9 pid it terminates but the shred memory segments
remains.

    Why I cannot terminate it with  SIGTERM signal?

    "....
    status = kill ((pid_t)pid, SIGTERM);
     printf("status = %d\n", status);
    ...."

The status is 0. The pid is correct.

TIA,
Bubulac Tatiana.

#1 lore raw
Quoted 7 lines · Bubulac Tatiana

I want to terminate a parent process that attach several shared
memory segments
with kill(pid, SIGTERM) but it fails to terminate.
Even if I give the command from command line it fails to terminate. If I give kill -9 pid it terminates but the shred memory segments
remains.
Why I cannot terminate it with SIGTERM signal?

Presumably the receiver has either blocked, ignored or caught SIGTERM.

Quoted 5 lines
    "....
    status = kill ((pid_t)pid, SIGTERM);
     printf("status = %d\n", status);
    ...."

The status is 0. The pid is correct.

That only tells you that the signal was sent. It doesn't tell you what the receiving process did as a result; the receiving process may not have even received the signal by the time that kill() returns.

Signature · 1 line
Glynn Clements <[email protected]>
author
#2 lore raw

That's right.

In the parent process I have the line no 6 where it blocks.

...
1 signal (SIGTERM, die);
2 signal (SIGALRM, dummy);
...
3 for (min = 0; min < 15 && not_done; min++)
4 {

5         alarm ((unsigned int) 60); /* wait for 1 minute */
6         pid = wait (&status);    /* Wait for a process to end */
7         alarm ((unsigned int) 0); /* Reset alarm */

....
8 }

The problem is that the child process did not catch the signal. I put a printf in the child signal handler
function.
If I give the "kill child_pid" also nothing happens. Of course if I give "kill -9 child_pid" the child is killed
and the parent will display "Normal termination".

Quoted 24 lines · Glynn Clements
Quoted 7 lines · Bubulac Tatiana

I want to terminate a parent process that attach several shared
memory segments
with kill(pid, SIGTERM) but it fails to terminate.
Even if I give the command from command line it fails to terminate. If I give kill -9 pid it terminates but the shred memory segments
remains.
Why I cannot terminate it with SIGTERM signal?

Presumably the receiver has either blocked, ignored or caught SIGTERM.

Quoted 5 lines
    "....
    status = kill ((pid_t)pid, SIGTERM);
     printf("status = %d\n", status);
    ...."

The status is 0. The pid is correct.

That only tells you that the signal was sent. It doesn't tell you what the receiving process did as a result; the receiving process may not have even received the signal by the time that kill() returns.

--
Glynn Clements <[email protected]>

#3 lore raw
Quoted 11 lines · Bubulac Tatiana

In the parent process I have the line no 6 where it blocks.

...
1 signal (SIGTERM, die);
2 signal (SIGALRM, dummy);
...
3 for (min = 0; min < 15 && not_done; min++)
4 {

5         alarm ((unsigned int) 60); /* wait for 1 minute */
6         pid = wait (&status);    /* Wait for a process to end */
7         alarm ((unsigned int) 0); /* Reset alarm */
Quoted 7 lines

....
8 }

The problem is that the child process did not catch the signal. I put a printf in the child signal handler
function.
If I give the "kill child_pid" also nothing happens.

That suggests that the child *is* catching the signal. If the child didn't catch SIGTERM, it would die.

Try changing the child's signal handler to call fflush(), or to use write() instead of printf().

Signature · 1 line
Glynn Clements <[email protected]>