Re: generic `struct serial' interface pipe for remote non-stop

[Eli Zaretskii <eliz at gnu dot org>]

> From: Pedro Alves <pedro@codesourcery.com>
> Date: Fri, 17 Oct 2008 21:54:49 +0100
> 
>  - Since async signal handlers are always checked before polling the
>    file descriptors, I can easily starve the file descriptor based
>    sources.  E.g., if I place several threads displace stepping a
>    breakpoint, forcing continuous remote traffic, the CLI becomes very,
>    very unresponsive, unusable really.  This is because stdin itself
>    is registered as a monitored (via select/poll) file descriptor.
> 
>  To solve this, I adjusted the event loop to give equal priority to
>  all event-sources (timers, async signal handlers, monitored file
>  descriptors).  The async signal handling was changed to instead
>  of immediatelly calling the associated callback, it installs an
>  event in the "ready" queue, just like the file-descriptor and
>  timer based sources.  I then make sure that I poll each of the
>  possible event sources once (select/poll with timeout 0 too).  If
>  if no event is found ready, then, we go blocking waiting for one
>  in select/poll.
> 
> I can sucessfully debug a non-stop linux gdbserver from both
> a linux host and a Windows (mingw32) host with this.
> 
> The remote.c changes below apply on top of the non-stop support
> patch I sent yesterday, and it's what I used to test, shown here
> so you could see what was required that change, in case you're
> curious about it.
> 
> Do you think it is a better alternative?

Yes, this is much better, IMO.  Thanks.