Re: [Simulavr-devel] Call Back remove

[Keith Gudger]

Ted:

Thanks.  I was hoping it was that easy.  I'll try it.

Keith

On Tue, 4 Nov 2003, Theodore A. Roth wrote:

> 
> 
> On Tue, 4 Nov 2003, Keith Gudger wrote:
> 
> > Ted:
> >
> > I'm working on imlementing the SPI function.  This function uses a "timer"
> > to count 8 (divided) clock ticks.  I was thinking that I'd "install" this
> > clock callback everytime the user loads the SPDR, and "remove" it when it
> > finished counting down.
> >
> > I don't, however, find any code for callback removal.  I found
> > "callback_destroy", but that doesn't remove it from the callback list
> > (which would be dangerous to do only that).  Do you know - does this code
> > exist?  (I don't even find a "dlist_remove" function).
> 
> The removal of a callback depends on the value returned from the
> callback function. From callback.h:
> 
>   typedef int (*CallBack_FP)( uint64_t time, AvrClass *data );
> 
>   enum _cb_ret_codes {
>       CB_RET_RETAIN = 0, /* Give the callback in the list and run it again */
>       CB_RET_REMOVE = 1, /* Remove callback from list */
>   };
> 
> The core calls callback_list_execute_all() which calls dlist_iterator()
> which executes all the callbacks and removes any callbacks from the list
> that ask to be removed via the returned value.
> 
> >
> > Am I on the right track here?  Thanks.
> 
> Essentially. Just install the callback, then, when the callback has seen
> 8 cycles, just return CB_RET_REMOVE and the callback is automagically
> removed from the list.
> 
> Ted Roth
> 
> 
>