Daniel Jacobowitz wrote:
> On Wed, Feb 27, 2008 at 10:44:56PM +0000, Antony KING wrote:
>> The signal handler is the restored default handler, "handle_sigint". My  
>> target interface only substitutes that default SIGINT handler when  
>> implementing the target_wait() functionality (it is modelled on remote.c).
>>
>> My first thought was that QUIT should achieve the effect I need but  
>> quit_flag, as was pointed out, is not being set soon enough. Also,  
>> forcing an immediate_quit is not suitable since I would like to stop the  
>> stepping cleanly with a target SIGINT (plus it breaks my target  
>> interface, but that is my problem :-).
> 
> Why doesn't quit_flag get set?  That's how I think we ought to do
> this.  Avoid immediate_quit, that's dangerous to mess with.

In my grep'ing of the (6.6) sources, I could only find quit_flag being 
set when async_request_quit() is called, by the event processing loop. 
It is also set in request_quit() but this API does not seem to be used.

> I'm not sure why you'd want to use a target SIGINT for this case.
> If we're between steps, we should just make sure we don't send
> another step.  I suppose I hadn't thought about the case between
> stepping and waiting...

I was thinking that a target SIGINT notification would be suitable since 
this is what the user would see if they interrupted a continue; I did 
not think interrupting a step, from a user perspective, would be any 
different. Of course, it is a lie since the target did not generate the 
SIGINT and so this would be confusing, although for the targets I have 
to support this is not a problem. Also, it was just easier for me to see 
how to apply a fix without getting too mired in understanding how the 
target event handling worked in handle_inferior_event() :-) and the 
mechanics of cleanly stopping.

Anyway, I have attached a patch fyi, which is my attempt at providing a 
solution using a faked target SIGINT which seems to work for me. It is a 
bit of a bodge since it subverts the main event loop but ce la vie.

Cheers,

Antony.