[RFA] Use observers to report stop events.

[Vladimir Prus]

On Sunday 04 May 2008 12:25:54 Vladimir Prus wrote:
> On Thursday 01 May 2008 23:57:58 Daniel Jacobowitz wrote:
> > On Tue, Apr 29, 2008 at 10:10:30PM +0400, Vladimir Prus wrote:
> > > Here are 3 independent bits.
> > > 
> > > 1. Introduce the make_cleanup_restore_integer function. You're right
> > > that it can lead to bad results if one discards this cleanup, but then
> > > one should be careful with discarding cleanups anyway.
> > 
> > This patch looks fine except that ...
> > 
> > > 2. Modify the normal_stop observer not to fire in some cases. One
> > > case is when doing function call -- we don't announce the stop in CLI
> > > and for similar reason we don't have observer to be called. Also,
> > > for the benefit of next patch, we want the call to observer to
> > > be delayed until we print function return value, if we're doing finish.
> > 
> > ... unless I'm mistaken you have exactly the memory leak Joel warned
> > about, since finish_command discards continuations.
> > 
> > Am I correct that the cleanup for finish_command is never supposed to
> > survive the function returning?  It's run on error and discarded on
> > normal return.  So you could put the closure in a local variable,
> > maybe.
> > 
> >   struct foo_closure my_closure = { &my_global, my_global };
> >   make_cleanup (restore_integer, &my_closure); 
> 
> This is somewhat limiting. Instead, I've implemented a mechanism that
> allows a cleanup to well, "cleanup" its argument. I attach a patch
> for that.
> 
> I also attach a patch stop the 'finish_command_continuation' from
> accessing a cleanup is has no business with.
> 
> Are those two new patches, together with the previously posted one
> (changing stop_observer not to always fire) OK?

Ping?

- Volodya