[x264-devel] Updated (and hopefully final) threaded slicetype patch

[Jason Garrett-Glaser]

On Mon, Apr 6, 2009 at 9:33 AM, David DeHaven <dave at sagetv.com> wrote:
>
>>>> Please find version 13 (lucky # 13) of the threaded slicetype patch.
>>>>  This
>>>> patch is overhauled to be more "windows" friendly (read: no use of
>>>> usleep)
>>>> and strictly use pthread_cond_wait/broadcast.
>>>
>>> Could you please explain why a simple
>>> #define usleep(t) Sleep((t)/1000)
>>> would not be work? Is it because you need more than a millisecond of
>>> accuracy?
>>
>> The patch used to use spin loops for synchronization, e.g:
>>
>> while(condition isn't true)
>> {
>> usleep(100);
>> }
>>
>> I said these should be replaced with cond_wait, but this made the
>> patch much much slower, which makes me suspect it's waiting when it
>> shouldn't; the overhead of pthreads should be minimal.
>
> What about pthread conditions is minimal?

The fact that it's only done once per frame?

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