For easier reading, this is what is happening:
--------------------------------------------------------------------------------
Thread T1(UI Thread) | Thread T2 (Non UI Thread)
|
----------------------------------------|---------------------------------------
[A] PrintTime(); pthread_cond_wait() |
|
| [X]
PrintTime(); pthread_cond_signal()|
|
|
[B] PrintTime(); |
|
--------------------------------------------------------------------------------
The current times printed at [A] [X] and [B] are:
[A]: t0
[X]: t0 + k
[B]: t0 + k + [1 second - 2 seconds],
The extra delay of 1-2 seconds at [B] is the issue, ideally it should be no
more
than the scheduler delay (10-15 ms).
Thanks,
Sarang.
On Fri, May 7, 2021 at 5:13 PM SK <[email protected]> wrote:
> Hello,
>
> With latest EMSDK 2.0.20 I'm trying to use wait and signal using
> pthread_cond_signal() and pthread_cond_wait() functions.
>
> I'm consistently seeing this issue between two non-UI threads that after a
> pthread_cond_signal() , a previously waiting pthread_cond_timedwait() only
> comes out after 1-2 seconds delay, expectation is that it should be ready
> at max within the scheduling interval.
>
> The first row shows time just before entering wait(), later are pairs of
> times of when actual event is generated and point just before signal() is
> called, there's barely any difference. Many such events pass until we come
> out of wait and see the last 'Post wait' is printed, it takes 1.56 seconds
> to return even though event is already signaled. All times are epoch times
> retrieved via clock_gettime(CLOCK_REALTIME, ...) option.
>
> Wait start time 1620415241.405
>
> Event generation time 1620415241.859 0.454
> Signaling time 1620415241.859 0.454
>
> Event generation time 1620415242.300 0.895
> Signaling time 1620415242.300 0.895
>
> Event generation time 1620415242.329 0.924
> Signaling time 1620415242.329 0.924
>
> Event generation time 1620415242.465 1.060
> Signaling time 1620415242.465 1.060
>
> Event generation time 1620415242.738 1.333
> Signaling time 1620415242.738 1.333
>
> Event generation time 1620415242.833 1.428
> Signaling time 1620415242.833 1.428
>
> Event generation time 1620415243.163 1.758
> Signaling time 1620415243.163 1.758
>
> Event generation time 1620415243.248 1.843
> Signaling time 1620415243.249 1.844
>
> Post wait time 1620415243.418 2.013 1.559
>
> Any pointers would be greatly appreciated.
>
> Thanks,
> Sarang.
>
> --
> You received this message because you are subscribed to the Google Groups
> "emscripten-discuss" group.
> To unsubscribe from this group and stop receiving emails from it, send an
> email to [email protected].
> To view this discussion on the web visit
> https://groups.google.com/d/msgid/emscripten-discuss/0e73db37-aa12-43fc-948e-ef9622f2dc03n%40googlegroups.com
> <https://groups.google.com/d/msgid/emscripten-discuss/0e73db37-aa12-43fc-948e-ef9622f2dc03n%40googlegroups.com?utm_medium=email&utm_source=footer>
> .
>
--
You received this message because you are subscribed to the Google Groups
"emscripten-discuss" group.
To unsubscribe from this group and stop receiving emails from it, send an email
to [email protected].
To view this discussion on the web visit
https://groups.google.com/d/msgid/emscripten-discuss/CAHqdETwuTPDxPjBVmCy%2BjU5p3UKxsiwvM9R1ERFURJmrH85p0g%40mail.gmail.com.
