Re: [boost] [thread] Does this condition wrapper perform better than the wrapped condition?

From: Anthony Williams (anthony_w.geo_at_[hidden])
Date: 2008-05-19 16:47:19

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

> In the Join library I have see the following idiom
>
>     mutex mtx;
>     condition_variable cond;
>     unsigned num_blocked;
>
>     void foo() {
>         unique_lock l(mtx);
>         ++num_blocked;
>         cond.wait(lock);
>         --num_blocked;
>     
>         // ...
>     }
>
>     void foo() {
>         unique_lock l(mtx);
>         // ...
>         if (num_blocked > 0) cond.notify_one();
>         // ...
>     }
>
> Does this perform better in some contexts? if yes in which ones?

It really shouldn't do. The check is part of the notify.

Anthony
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