Thinking about kqueue's and pthread_cond_wait

[Alfred Perlstein]

It sounds really interesting, do you have a particular use-case
you can share that would show how to use this at a macro-level?

Why would someone kqueue on multiple (or single) condvars?

There's probably some exciting reasons why.

-Alfred

* Randall Stewart <rrs at lakerest.net> [100210 06:09] wrote:
> All:
> 
> I have once again come around to thinking about joining pthread cond  
> waits and
> kqueue's.
> 
> After thinking about it, I think its doable.. with something like a:
> 
> pthread_cond_wait_kqueue_np(kev, cond, mtx, ucontext)
> 
> Then you can use kev inside a kqueue i.e.
>  ret =  kevent(kq, kev, 1, outkev, 1, NULL);
> 
> Now when you saw the event:
>    if (kev.filter == EVFILT_UMTX){   /* not sure about the name here */
>         pthread_kqueue_cond_wait_ret_np(kev, cond, mtx, ucontext)
>         do_user_action(cond,mtx, ucontext);
>     }
> 
> Which would fill in the cond/mtx and ucontext for the user.
> 
> Now does this sound useful to anyone.. i.e. should I spend the time
> making it work?
> 
> The only down side to this is that it would have to allocate memory so
> one would need to do a:
> 
>     pthread_kqueue_cond_wait_free_np(kev)
> 
> After you were done.. and I think it would be best for this to
> be a ONE_SHOT.. i.e. you have to re-arm it if the event happens...
> Of course until you free it that can be as simple as passing the kev
> back down again (i.e. no pthread_cond_wait_kqueue_np() needed).
> 
> Comments? Thoughts?  i.e. especially is it worthwhile doing?
> 
> 
> Thanks
> 
> 
> R
> ------------------------------
> Randall Stewart
> 803-317-4952 (cell)
> 
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-- 
- Alfred Perlstein
.- AMA, VMOA #5191, 03 vmax, 92 gs500, 85 ch250
.- FreeBSD committer