1473469 - Run MediaStreamGraph from a single thread

Status: RESOLVED FIXED

(Core :: Audio/Video: MediaStreamGraph, enhancement, P2)

Description

[Karl Tomlinson (:karlt)]

For the sake of the JS implementation (see bug 1458448) and for simplicity in GraphDriver, we'd like to run the MediaStreamGraph on a single thread.

The sensible way to do this would be to modify AudioIPC's API to allow the
client to specify the thread.  This project is therefore dependent on bug 1362220.

Rendering audio with the new AudioIPC API could look something like:

   while (WaitCode::StartRendering == stream->Wait()) {

      (buffer_ptr, bytes_to_render) = stream->BeginRender();

      graph->Render(buffer_ptr, bytes_to_render);

      stream->EndRender();
   }

Comment 1

[Andreas Pehrson [:pehrsons]]

Attachment: Bug 1473469 - Make MediaStreamGraph run on a single thread with AudioWorklets enabled. r?padenot

Comment 2

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/45c838c4137d
Make MediaStreamGraph run on a single thread with AudioWorklets enabled. r=padenot

Comment 3

[Natalia Csoregi [:nataliaCs]]

Backed out for various dom/worklet/failures

backout: https://hg.mozilla.org/integration/autoland/rev/163bec72cd71867012fe81c6f52aa2b5ef6a0ef3

push: https://treeherder.mozilla.org/#/jobs?repo=autoland&searchStr=linux%2Cx64%2Cquantumrender%2Cpgo%2Copt%2Cmochitests%2Cwith%2Ce10s%2Ctest-linux64-pgo-qr%2Fopt-mochitest-e10s-4%2Cm-e10s%284%29&revision=45c838c4137d1dcc65ac07dd893c313f5831b283&selectedJob=231281889

failure log e.g: https://treeherder.mozilla.org/logviewer.html#/jobs?job_id=231281889&repo=autoland&lineNumber=4043

e.g https://treeherder.mozilla.org/logviewer.html#/jobs?job_id=231282457&repo=autoland&lineNumber=5534

Comment 4

[Andreas Pehrson [:pehrsons]]

Thanks for backing out! I'll take a look.

Comment 5

[Andreas Pehrson [:pehrsons]]

These hangs happened when the audio callback got started faster than the GraphRunner's dedicated thread.

One case that I debugged with some logging, it took 25ms from MSG ctor to the first audio callback (e10s, cubeb sandbox), and 34ms for the GraphRunner thread to start running.

This made them both wait for each other.

I've made it so the audio callback will wait for the thread to start if it's early. Tests running at https://treeherder.mozilla.org/#/jobs?repo=try&revision=2051ae405f10e2d9863ed822e2e1d6718ec46928

Comment 6

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/6070ee57c329
Make MediaStreamGraph run on a single thread with AudioWorklets enabled. r=padenot

Comment 7

[Arthur Iakab [arthur_iakab]]

https://hg.mozilla.org/mozilla-central/rev/6070ee57c329