nick at webthing
Feb 5, 2006, 8:09 AM
Post #3 of 3
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On Sunday 05 February 2006 06:12, Garrett Rooney wrote:
> > Is the following correct and complete for APR signals
> > to function across platforms?
> >
> > static void my_handler(int signum) {
> > apr_signal_block(signum) ;
> > /* do things */
> > apr_signal_unblock(signum) ;
> > }
> >
> > static void my_child_init(args) {
> > apr_signal(MY_SIGNAL, my_handler);
> > }
>
> That seems reasonable to me, although I suspect the behavior with
> regard to how signals interact with threads will vary from system to
> system, although apr_setup_signal_thread seems relevant to that part
> of the problem...
So it would seem. The worker and event MPMs both use that, and block
signals set up in a child_init hook. Looks like I can't do this in a
module:-(
The underlying problem is to implement graceful-stop of a single child
process. It seems I can't do that using the pod, because I can't select
a child process, so I'm trying to signal. The idea is;
* graceful signal --> close listeners
... delay ...
* TERM signal --> destroy pchild, apr_terminate, exit
... delay ...
* KILL signal as a last resort
I thought I had it wrapped up, but the IPC for the above eludes me.
Communicating by HTTP has the same problem as the pod: I don't
get to choose which child gets signalled, and it also has MPM issues.
Any alternative suggestions? Preferably without touching the core
code and (especially) the individual MPMs? Or do I need to do something
drastic like fork a new "supervised" MPM from worker?
--
Nick Kew
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