Quoting Christian Seiler (christ...@iwakd.de): > The following rationale is for using the -t option: > > Currently, lxc-shutdown uses a subprocess for the timeout handling, > where a 'sleep $TIMEOUT' is executed, which will kill the main process > after the timeout has occurred, thus causing the main process to stop > the container hard with lxc-stop. > > On the other hand, if the timeout is not reached, the main process > kills the subprocess. The trouble now is that if you kill a shell that > is running in the background, the kill will only take effect as soon as > the program currently running in the shell exits. > > This in turn means that the subprocess will never terminate before > reaching the timeout. In an interactive shell, this does not matter, > since people will just not notice the process and lxc-shutdown returns > immediately. In a non-interactive enironment, however, there may be > circumstances that cause the calling program to wait until even that > subprocess is terminated, which means that shutdown will always take as > long as the timeout, even if the container shuts down quite a bit > earlier. > > This change makes sure that also all subprocesses of the background > process are killed from the main process. This will immediately > terminate the background process, thus ensuring the desired behaviour. > > Signed-off-by: Christian Seiler <christ...@iwakd.de>
Iiinteresting, thanks. Acked-by: Serge E. Hallyn <serge.hal...@ubuntu.com> > --- > src/lxc/lxc-shutdown.in | 6 ++++-- > 1 file changed, 4 insertions(+), 2 deletions(-) > > diff --git a/src/lxc/lxc-shutdown.in b/src/lxc/lxc-shutdown.in > index d82cebf..ee07f75 100644 > --- a/src/lxc/lxc-shutdown.in > +++ b/src/lxc/lxc-shutdown.in > @@ -131,7 +131,7 @@ fi > > if [ $timeout != "-1" ]; then > trap dolxcstop EXIT > - alarm $$ $timeout & > + alarm $$ $timeout 2>/dev/null & > alarmpid=$! > fi > > @@ -141,7 +141,9 @@ done > > if [ $timeout != "-1" ]; then > trap - EXIT > - kill $alarmpid > + # include subprocesses; otherwise, we may have to wait until sleep > completes > + # if called from a non-interactive context > + kill $alarmpid $(ps --no-headers --ppid $alarmpid -o pid) 2>/dev/null || > : > fi > > echo "Container $lxc_name has shut down" > -- > 1.7.10.4 > > > ------------------------------------------------------------------------------ > Own the Future-Intel(R) Level Up Game Demo Contest 2013 > Rise to greatness in Intel's independent game demo contest. Compete > for recognition, cash, and the chance to get your game on Steam. > $5K grand prize plus 10 genre and skill prizes. Submit your demo > by 6/6/13. http://altfarm.mediaplex.com/ad/ck/12124-176961-30367-2 > _______________________________________________ > Lxc-devel mailing list > Lxc-devel@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/lxc-devel ------------------------------------------------------------------------------ Own the Future-Intel® Level Up Game Demo Contest 2013 Rise to greatness in Intel's independent game demo contest. Compete for recognition, cash, and the chance to get your game on Steam. $5K grand prize plus 10 genre and skill prizes. Submit your demo by 6/6/13. http://p.sf.net/sfu/intel_levelupd2d _______________________________________________ Lxc-devel mailing list Lxc-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/lxc-devel
