Re: [boost] Review Request: future library (N2561/Williams version)

From: Anthony Williams (anthony_w.geo_at_[hidden])
Date: 2008-05-14 04:55:12

"vicente.botet" <vicente.botet_at_[hidden]> writes:

> Why you don't allow multiple callbacks? I suposse that this is related to 
> the implementation of do_callback
>
> void do_callback(boost::unique_lock<boost::mutex>& lock)
> {
>     if(callback && !done)
>     {
>         boost::function<void()> local_callback=callback;
>         relocker relock(lock);
>         local_callback();
>     }
> }
>
> You need to call all the callbacks with the mutex unlock, and you need to 
> protect from other concurrent set_wait_callback. So you will need to copy 
> the list of callbacks before unlock.
>
> Is this correct?

That is correct with respect to the implementation, but I don't actually see
the need for multiple callbacks. The callbacks are set as part of the promise
or packaged_task. I can't imagine why that would require multiple
callbacks. In any case, the user can provide that facility on their own if
required.

Anthony
-- 
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