Will restarting a Unicorn process (via HUP signal) wait for worker threads?

Will restarting a Unicorn process (via HUP signal) wait for worker threads?

[Jason Hines]

In my application, I have some background jobs which are executed in
separate threads.  (using SuckerPunch/Celluloid framework)

If I send a HUP signal to the Unicorn master, the application is reloaded
and gracefully restarts the workers.    But, if those workers have child
threads, does Unicorn wait for those threads to finish before the restart
or are they terminated immediately?

Thanks in advance for any light shed here.

Re: Will restarting a Unicorn process (via HUP signal) wait for worker threads?

[Eric Wong]

Jason Hines <jason@greenhell.com> wrote:
> In my application, I have some background jobs which are executed in
> separate threads.  (using SuckerPunch/Celluloid framework)
> 
> If I send a HUP signal to the Unicorn master, the application is reloaded
> and gracefully restarts the workers.    But, if those workers have child
> threads, does Unicorn wait for those threads to finish before the restart
> or are they terminated immediately?

unicorn itself does not know about any threads spawned by the application.

However, you can setup an END/at_exit block in the worker to wait on
those threads since unicorn workers perform graceful exit:

	at_exit do
	  join_all_threads
	end