If you kill a process in Linux. All of its child processes should continue to run as orphan processes. This is the Linux compatible behavior for the case that Alan presented.
On Sun, Jan 15, 2023 at 10:31 PM Gregory Nutt <spudan...@gmail.com> wrote: > That wouldn’t be consistent with how Linux works, would it? I'm not an > expert on this topic and I am sure that other people on this list know more > about this than me. My understanding is that Linux has "session leaders" > which correspond to login sessions. For each terminal opened by the > session leader, a "controlling terminal" is created that has at least two > process groups: a foreground and a background process group which may > consist of several processes. Multiple process groups can be managed with > interfaces like setpgid(). Sessions can be managed with interfaces like > setsid(). > > > The process groups get killed when the terminal is closed (unless it is > daimonized). The kill command also supports syntax to kill process > groups. Killing all processes or killing of all child processes is not > supported AFAIK. > > > Sent from Mail <https://go.microsoft.com/fwlink/?LinkId=550986> for > Windows > > > > *From: *Xiang Xiao <xiaoxiang781...@gmail.com> > *Sent: *Sunday, January 15, 2023 9:54 PM > *To: *dev@nuttx.apache.org > *Subject: *Re: How to automatically kill all children threads when the > main thread die > > > > If CONFIG_SIG_DEFAULT, the kernel will terminate all child pthreads, but > > not child tasks. > > We can extend kill to support -P flag like pkill: > > https://linux.die.net/man/1/pkill > > -P ppid,... > > Only match processes whose parent process ID is listed. > > > > On Mon, Jan 16, 2023 at 10:14 AM Gregory Nutt <spudan...@gmail.com> wrote: > > > > > he > > > > > > > Ooops. No, you a re asking about tasks, not threads. That is > easier. > > > > The answer is no: One task exiting has not effect at all any other > > > tasks. > > > > > > > > > > The question is confusing because it asks about killing other threads > (aka > > > pthreads) when the main (task) exits. But the example shows only tasks > > > (main threads). > > > > > > https://cwiki.apache.org/confluence/display/NUTTX/Tasks+vs.+Threads+FAQ > > > > > > > > > > > > > >> On Sun, Jan 15, 2023 at 5:25 PM Alan C. Assis <acas...@gmail.com> > > > wrote: > > > >> > > > >>> Dear NuttXers, > > > >>> > > > >>> I want to know if there are some hidden configuration that forces all > > > >>> children to die when the father task die. > > > >>> > > > >>> Currently only teh main task dies: > > > >>> > > > >>> nsh> family & > > > >>> > > > >>> nsh> ps > > > >>> PID GROUP PRI POLICY TYPE NPX STATE EVENT SIGMASK > STACK > > > >>> COMMAND > > > >>> ... > > > >>> 27 27 100 RR Task --- Waiting Signal 00000000 > 004032 > > > >>> family > > > >>> 28 28 100 RR Task --- Waiting Semaphore 00000000 > > > >>> 004032 child1_daemon > > > >>> 29 29 100 RR Task --- Waiting Signal 00000000 > > > >>> 004032 child2_daemon > > > >>> 30 30 100 RR Task --- Waiting Signal 00000000 > > > >>> 001984 child3_daemon > > > >>> > > > >>> nsh> kill 27 > > > >>> nsh> ps > > > >>> PID GROUP PRI POLICY TYPE NPX STATE EVENT SIGMASK > STACK > > > >>> COMMAND > > > >>> ... > > > >>> 28 28 100 RR Task --- Waiting Signal 00000000 > > > >>> 004032 child1_daemon > > > >>> 29 29 100 RR Task --- Waiting Signal 00000000 > > > >>> 004032 child2_daemon > > > >>> 30 30 100 RR Task --- Waiting Signal 00000000 > > > >>> 001984 child3_daemon > > > >>> > > > >>> I could setup a signal handling to handle the kill signal in the main > > > >>> task and use it to change the value of some conditional variable that > > > >>> maintain the threads loop of each child running, this is is an > option, > > > >>> but maybe there are better option. > > > >>> > > > >>> Please let me know how you are solving this issue. > > > >>> > > > >>> BR, > > > >>> > > > >>> Alan > > > >>> > > > >> > > > > > >
