[CRIU] [PATCH 13/14] restore: collect signals from zombies (v2)

[Andrew Vagin]

On Fri, Jan 18, 2013 at 02:36:36PM +0400, Pavel Emelyanov wrote:
> > +
> > +	for_each_pstree_item(pi) {
> > +		if (pi->state == TASK_HELPER)
> > +			continue;
> > +		ret = (int) futex_get(&task_entries->nr_in_progress);
> > +		if (ret < 0)
> > +			goto out;
> > +		futex_set_and_wake(&task_entries->pid, pi->pid.virt);
> > +		pr_info("Wait %d\n", pi->pid.virt);
> > +		futex_wait_while(&task_entries->nr_in_progress, ret);
> > +	}
> > +
> 
> > @@ -749,6 +755,10 @@ long __export_restore_task(struct task_restore_core_args *args)
> >  	act.rt_sa_restorer = cr_restore_rt;
> >  	sys_sigaction(SIGCHLD, &act, NULL, sizeof(rt_sigset_t));
> >  
> > +	restore_finish_stage(CR_STATE_RESTORE_PREP_ZOMBIES);
> > +	futex_wait_until(&task_entries->pid, my_pid);
> > +	restore_finish_stage(CR_STATE_RESTORE_ZOMBIES);
> 
> Why do we need to serialize the alive tasks restoration?

Alive tasks handles SIGCHLD in sigzombie_handler.
crtools doesn't know who is alive and who is not alive.

> 
> > +
> >  	sys_sigaction(SIGCHLD, &args->sigchld_act, NULL, sizeof(rt_sigset_t));
> >  
> >  	ret = restore_signals(args->siginfo, args->siginfo_nr, 1);
> > 
> 
>