Re: [fuse-devel] how to register a exit handler

[<the...@gm...>]

On Tue, Jun 14, 2011 at 2:06 AM, Hans Beckérus <han...@gm...> wrote:
> On 2011-06-14 1:42, the...@gm... wrote:
> I do have unmount and clean-up code after my event loops stops. But the
> problem is not when the event loop is
> stopped in a controlled fashion. I need to call fuse_exit() also for eg.
> SIGINT (CTRL-C).
> Registering my own signal handler for SIGINT could solve that, but then
> I do not know how to easily propagate the struct fuse*  to be able to
> call fuse_exit() for the correct instance. That is why I want to
> register a exit handler instead on session level using the
> fuse_session_ops::exit.
> But I can not find a suitable API function that can do that? And I do
> not want to go through fuse_create_session() which means I need to start
> using the fuse_lowlevel API.

You do not need to use the fuse low level APIs to get to the struct
fuse. You will not be able to use fuse_main() but you could use
fuse_setup() or fuse_new(), which both return the struct fuse for the
instance. You would then need to start the main loop. Before starting
the main loop you could save the struct fuse in a static variable that
your sighandler has access to.

BTW fuse_new() will require you to do more setup which is handled by
fuse_setup for you, but fuse_setup does call
fuse_set_signal_handlers().

>>> I tried to use fuse_set_signal_handlers() but that just made things
>>> worse :( Then I could not even break out of the foreground process using
>>> CTRL-C.
>>>
> Hmm, actually this was not working as expected. Using a *very* dirty
> trick I managed to register my own exit handler in fuse_session_ops
> (that is why I need some help doing it the proper way). Then if I also
> call fuse_set_signal_handlers() and just leave the exit handler empty,
> fuse_exit() is called automatically at SIGINT and my event loop
> terminates nicely. But, If I do not register a exit handler and only
> call fuse_set_signal_handlers()  SIGINT does not work, eg. fuse_exit()
> is never called and clean-up is not possible! This I can not explain.

This is strange since the fuse signal handlers for the most part just
call fuse_exit().

-nate