Do not resume a suspended BaseAudioContext when AudioWorklet starts

When AudioWorklet.addModule() activates the worklet thread, it re-starts the destination handler even when the context is suspended. This CL fixes the bug by restarting destination only when the context is in the "running" state. Bug: 950997 Test: external/wpt/webaudio/the-audio-api/the-audioworklet-interface/audioworklet-suspend.https.html Change-Id: I0b44e3fca23bd069fac21f709fc665e8eacc4dd3 Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1560140 Commit-Queue: Hongchan Choi <hongchan@chromium.org> Reviewed-by: Raymond Toy <rtoy@chromium.org> Cr-Commit-Position: refs/heads/master@{#649303}

Do not resume a suspended BaseAudioContext when AudioWorklet starts
When AudioWorklet.addModule() activates the worklet thread, it re-starts the destination handler even when the context is suspended. This CL fixes the bug by restarting destination only when the context is in the "running" state. Bug: 950997 Test: external/wpt/webaudio/the-audio-api/the-audioworklet-interface/audioworklet-suspend.https.html Change-Id: I0b44e3fca23bd069fac21f709fc665e8eacc4dd3 Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1560140 Commit-Queue: Hongchan Choi <hongchan@chromium.org> Reviewed-by: Raymond Toy <rtoy@chromium.org> Cr-Commit-Position: refs/heads/master@{#649303}
e525003f · Hongchan Choi · Commit Bot · c81a1cf3 · e525003f · e525003f
Commit e525003f authored Apr 09, 2019 by Hongchan Choi Committed by Commit Bot Apr 09, 2019
4 changed files
--- a/third_party/blink/renderer/modules/webaudio/base_audio_context.cc
+++ b/third_party/blink/renderer/modules/webaudio/base_audio_context.cc
@@ -813,10 +813,11 @@ void BaseAudioContext::NotifyWorkletIsReady() {
        audioWorklet()->GetMessagingProxy()->GetBackingWorkerThread();
  }

-  // If the context is running or suspended, restart the destination to switch
-  // the render thread with the worklet thread. Note that restarting can happen
-  // right after the context construction.
-  if (ContextState() != kClosed) {
+  // If the context is running, restart the destination to switch the render
+  // thread with the worklet thread. When the context is suspended, the next
+  // resume() call will start rendering with the worklet thread.
+  // Note that restarting can happen right after the context construction.
+  if (ContextState() == kRunning) {
    destination()->GetAudioDestinationHandler().RestartRendering();
  }
 }

--- a/third_party/blink/web_tests/external/wpt/webaudio/resources/audit.js
+++ b/third_party/blink/web_tests/external/wpt/webaudio/resources/audit.js
@@ -1210,6 +1210,18 @@ window.Audit = (function() {
      this._taskRunner._runNextTask();
    }

+    // Runs |subTask| |time| milliseconds later. |setTimeout| is not allowed in
+    // WPT linter, so a thin wrapper around the harness's |step_timeout| is
+    // used here.
+    timeout(subTask, time) {
+      async_test((test) => {
+        test.step_timeout(() => {
+          subTask();
+          test.done();
+        }, time);
+      });
+    }
+
    isPassed() {
      return this._state === TaskState.FINISHED && this._result;
    }

--- a/third_party/blink/web_tests/external/wpt/webaudio/the-audio-api/the-audioworklet-interface/audioworklet-suspend.https.html
+++ b/third_party/blink/web_tests/external/wpt/webaudio/the-audio-api/the-audioworklet-interface/audioworklet-suspend.https.html
+<!DOCTYPE html>
+<html>
+  <head>
+    <title>
+      Test if activation of worklet thread does not resume context rendering.
+    </title>
+    <script src="/resources/testharness.js"></script>
+    <script src="/resources/testharnessreport.js"></script>
+    <script src="/webaudio/resources/audit.js"></script>
+  </head>
+  <body>
+    <script id="layout-test-code">
+      const audit = Audit.createTaskRunner();
+      const context = new AudioContext();
+      const filePath = 'processors/dummy-processor.js';
+
+      // Suspends the context right away and then activate worklet. The current
+      // time must not advance since the context is suspended.
+      audit.define(
+          {label: 'load-worklet-and-suspend'},
+          async (task, should) => {
+            context.suspend();
+            const suspendTime = context.currentTime;
+            await context.audioWorklet.addModule(filePath);
+            const dummy = new AudioWorkletNode(context, 'dummy');
+            dummy.connect(context.destination);
+            task.timeout(() => {
+              should(context.currentTime, 'context.currentTime')
+                  .beEqualTo(suspendTime);
+              should(context.state, 'context.state').beEqualTo('suspended');
+              task.done();
+            }, 1000);
+          });
+
+      audit.run();
+    </script>
+  </body>
+</html>
--- a/third_party/blink/web_tests/webaudio/resources/audit.js
+++ b/third_party/blink/web_tests/webaudio/resources/audit.js
@@ -1202,6 +1202,18 @@ window.Audit = (function() {
      this._taskRunner._runNextTask();
    }

+    // Runs |subTask| |time| milliseconds later. |setTimeout| is not allowed in
+    // WPT linter, so a thin wrapper around the harness's |step_timeout| is
+    // used here.
+    timeout(subTask, time) {
+      async_test((test) => {
+        test.step_timeout(() => {
+          subTask();
+          test.done();
+        }, time);
+      });
+    }
+
    isPassed() {
      return this._state === TaskState.FINISHED && this._result;
    }