Kill process handling

ajb181 · 09-23-2009, 05:05 PM

Hi all. Im new to linux and having problems killing a task in my app.

im sending

if (kill(_main_thread, SIGINT) ==-1)
{
os::sleep(100);
kill(_main_thread, SIGINT);
}

t = waitpid (_main_thread, NULL, WNOHANG);

and i keep getting the error message

ECHILD 10 /* No child processes */

from waitpid function call. I have check and it is calling the correct pid number of the task.

When i check the function list i see the task listed as a zombie process under the correct pid number.

THe app i am killing is mpg321. i check the source and this is what is done on the SIGINT

RETSIGTYPE handle_signals(int sig)
{
static struct timeval last_signal = { 0, 0 };
struct timeval curr_tv;

gettimeofday(&curr_tv, NULL);

if (sig == SIGINT)
{
DBG_INFO(("SIGINT Got\n"));
// if (((curr_tv.tv_sec - last_signal.tv_sec) * 1000000 + (curr_tv.tv_usec - last_signal.tv_usec)) < 1000000) /* Allow a short delay to kill mpg321 */
{
DBG_INFO(("SIGINT Quit\n"));
quit_now = 1;
}

last_signal.tv_sec = curr_tv.tv_sec;
last_signal.tv_usec = curr_tv.tv_usec;

stop_playing_file = 1;

}
else if (sig == -1) /* initialize */
{
last_signal.tv_sec = curr_tv.tv_sec;
last_signal.tv_usec = curr_tv.tv_usec;
}
}

and this is done on the exit of main

if(playdevice)
ao_close(playdevice);

ao_shutdown();
/*Restoring TTY*/
set_tty_restore();
if (ctty)
fclose(ctty);

return(0);

What signal is ment to be sent so the wait function will remove the program from the task list?

Thanks you your time
Alex

lutusp · 09-23-2009, 05:37 PM

Quote:

Originally Posted by ajb181

[ snip ]

What signal is ment to be sent so the wait function will remove the program from the task list?

Thanks you your time
Alex

In most cases, the reliable way to kill a process is:

Code:

# kill -9 PID

I am sure you will know how to create this same result in code.

ajb181 · 09-23-2009, 07:46 PM

If you could elaborate that would be fantastic.

Thanks Alex

lutusp · 09-23-2009, 08:52 PM

Quote:

Originally Posted by ajb181

If you could elaborate that would be fantastic.

Thanks Alex

If when replying you could quote the part you're having a problem with, that would be fantastic.

Rewrite your routine this way:

Code:

if (kill(_main_thread, SIGKILL) ==-1)
{
   os::sleep(100);
   kill(_main_thread, SIGKILL);
}

ajb181 · 09-24-2009, 09:18 PM

Have tried using SIGKILL with no success the task still zombies.

MPG321 only has handling for SIGINT .. See below

Code:

RETSIGTYPE handle_signals(int sig)
{
static struct timeval last_signal = { 0, 0 };
struct timeval curr_tv;

gettimeofday(&curr_tv, NULL);

if (sig == SIGINT)
{
DBG_INFO(("SIGINT Got\n"));
// if (((curr_tv.tv_sec - last_signal.tv_sec) * 1000000 + (curr_tv.tv_usec - last_signal.tv_usec)) < 1000000) /* Allow a short delay to kill mpg321 */
{
DBG_INFO(("SIGINT Quit\n"));
quit_now = 1;
}

last_signal.tv_sec = curr_tv.tv_sec;
last_signal.tv_usec = curr_tv.tv_usec;

stop_playing_file = 1;

}
else if (sig == -1) /* initialize */
{
last_signal.tv_sec = curr_tv.tv_sec;
last_signal.tv_usec = curr_tv.tv_usec;
}
}

ajb181 · 11-08-2009, 09:22 PM

I still do not have a solution for this problem. Could anyone Please help?

The thread calling waitpid is from the parent forked task.