Adding upstream version 86.0.1.upstream/86.0.1upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 520 insertions, 0 deletions

diff --git a/dom/ipc/tests/browser_ProcessPriorityManager.js b/dom/ipc/tests/browser_ProcessPriorityManager.js
new file mode 100644
index 0000000000..b74b2b84cd
--- /dev/null
+++ b/dom/ipc/tests/browser_ProcessPriorityManager.js
@@ -0,0 +1,520 @@
+/* Any copyright is dedicated to the Public Domain.
+   http://creativecommons.org/publicdomain/zero/1.0/ */
+
+"use strict";
+
+const PRIORITY_SET_TOPIC =
+  "process-priority-manager:TEST-ONLY:process-priority-set";
+
+// Copied from Hal.cpp
+const PROCESS_PRIORITY_FOREGROUND = "FOREGROUND";
+const PROCESS_PRIORITY_BACKGROUND_PERCEIVABLE = "BACKGROUND_PERCEIVABLE";
+const PROCESS_PRIORITY_BACKGROUND = "BACKGROUND";
+
+// This is how many milliseconds we'll wait for a process priority
+// change before we assume that it's just not happening.
+const WAIT_FOR_CHANGE_TIME_MS = 2000;
+
+/**
+ * This class is responsible for watching process priority changes, and
+ * mapping them to tabs in a single window.
+ */
+class TabPriorityWatcher {
+  /**
+   * Constructing a TabPriorityWatcher should happen before any tests
+   * start when there's only a single tab in the window.
+   *
+   * Callers must call `destroy()` on any instance that is constructed
+   * when the test is completed.
+   *
+   * @param tabbrowser (<tabbrowser>)
+   *   The tabbrowser (gBrowser) for the window to be tested.
+   */
+  constructor(tabbrowser) {
+    this.tabbrowser = tabbrowser;
+    Assert.equal(
+      tabbrowser.tabs.length,
+      1,
+      "TabPriorityWatcher must be constructed in a window " +
+        "with a single tab to start."
+    );
+
+    this.priorityMap = new WeakMap();
+    this.priorityMap.set(
+      this.tabbrowser.selectedBrowser,
+      PROCESS_PRIORITY_FOREGROUND
+    );
+    this.noChangeBrowsers = new WeakMap();
+    Services.obs.addObserver(this, PRIORITY_SET_TOPIC);
+  }
+
+  /**
+   * Cleans up lingering references for an instance of
+   * TabPriorityWatcher to avoid leaks. This should be called when
+   * finishing the test.
+   */
+  destroy() {
+    Services.obs.removeObserver(this, PRIORITY_SET_TOPIC);
+    this.window = null;
+  }
+
+  /**
+   * Returns a Promise that resolves when a particular <browser>
+   * has its content process reach a particular priority. Will
+   * eventually time out if that priority is never reached.
+   *
+   * @param browser (<browser>)
+   *   The <browser> that we expect to change priority.
+   * @param expectedPriority (String)
+   *   One of the PROCESS_PRIORITY_ constants defined at the
+   *   top of this file.
+   * @return Promise
+   * @resolves undefined
+   *   Once the browser reaches the expected priority.
+   */
+  async waitForPriorityChange(browser, expectedPriority) {
+    return TestUtils.waitForCondition(() => {
+      let currentPriority = this.priorityMap.get(browser);
+      if (currentPriority == expectedPriority) {
+        Assert.ok(
+          true,
+          `Browser at ${browser.currentURI.spec} reached expected ` +
+            `priority: ${currentPriority}`
+        );
+        return true;
+      }
+      return false;
+    }, `Waiting for browser at ${browser.currentURI.spec} to reach priority ` + expectedPriority);
+  }
+
+  /**
+   * Returns a Promise that resolves after a duration of
+   * WAIT_FOR_CHANGE_TIME_MS. During that time, if the passed browser
+   * changes priority, a test failure will be registered.
+   *
+   * @param browser (<browser>)
+   *   The <browser> that we expect to change priority.
+   * @return Promise
+   * @resolves undefined
+   *   Once the WAIT_FOR_CHANGE_TIME_MS duration has passed.
+   */
+  async ensureNoPriorityChange(browser) {
+    this.noChangeBrowsers.set(browser, null);
+    // eslint-disable-next-line mozilla/no-arbitrary-setTimeout
+    await new Promise(resolve => setTimeout(resolve, WAIT_FOR_CHANGE_TIME_MS));
+    let priority = this.noChangeBrowsers.get(browser);
+    Assert.equal(
+      priority,
+      null,
+      `Should have seen no process priority change for a browser at ${browser.currentURI.spec}`
+    );
+    this.noChangeBrowsers.delete(browser);
+  }
+
+  /**
+   * Makes sure that a particular foreground browser has been
+   * registered in the priority map. This is needed because browsers are
+   * only registered when their priorities change - and if a browser's
+   * priority never changes during a test, then they wouldn't be registered.
+   *
+   * The passed browser must be a foreground browser, since it's assumed that
+   * the associated content process is running with foreground priority.
+   *
+   * @param browser (browser)
+   *   A _foreground_ browser.
+   */
+  ensureForegroundRegistered(browser) {
+    if (!this.priorityMap.has(browser)) {
+      this.priorityMap.set(browser, PROCESS_PRIORITY_FOREGROUND);
+    }
+  }
+
+  /**
+   * Synchronously returns the priority of a particular browser's
+   * content process.
+   *
+   * @param browser (browser)
+   *   The browser to get the content process priority for.
+   * @return String
+   *   The priority that the browser's content process is at.
+   */
+  currentPriority(browser) {
+    return this.priorityMap.get(browser);
+  }
+
+  /**
+   * A utility function that takes a string passed via the
+   * PRIORITY_SET_TOPIC observer notification and extracts the
+   * childID and priority string.
+   *
+   * @param ppmDataString (String)
+   *   The string data passed through the PRIORITY_SET_TOPIC observer
+   *   notification.
+   * @return Object
+   *   An object with the following properties:
+   *
+   *   childID (Number)
+   *     The ID of the content process that changed priority.
+   *
+   *   priority (String)
+   *     The priority that the content process was set to.
+   */
+  parsePPMData(ppmDataString) {
+    let [childIDStr, priority] = ppmDataString.split(":");
+    return {
+      childID: parseInt(childIDStr, 10),
+      priority,
+    };
+  }
+
+  /** nsIObserver **/
+  observe(subject, topic, data) {
+    if (topic != PRIORITY_SET_TOPIC) {
+      Assert.ok(false, "TabPriorityWatcher is observing the wrong topic");
+      return;
+    }
+
+    let { childID, priority } = this.parsePPMData(data);
+    for (let browser of this.tabbrowser.browsers) {
+      if (browser.frameLoader.childID == childID) {
+        info(
+          `Browser at: ${browser.currentURI.spec} transitioning to ${priority}`
+        );
+        if (this.noChangeBrowsers.has(browser)) {
+          this.noChangeBrowsers.set(browser, priority);
+        }
+        this.priorityMap.set(browser, priority);
+      }
+    }
+  }
+}
+
+let gTabPriorityWatcher;
+
+add_task(async function setup() {
+  // We need to turn on testMode for the process priority manager in
+  // order to receive the observer notifications that this test relies on.
+  await SpecialPowers.pushPrefEnv({
+    set: [
+      ["dom.ipc.processPriorityManager.testMode", true],
+      ["dom.ipc.processPriorityManager.enabled", true],
+    ],
+  });
+  gTabPriorityWatcher = new TabPriorityWatcher(gBrowser);
+});
+
+registerCleanupFunction(() => {
+  gTabPriorityWatcher.destroy();
+  gTabPriorityWatcher = null;
+});
+
+/**
+ * Utility function that switches the current tabbrowser from one
+ * tab to another, and ensures that the tab that goes into the background
+ * has (or reaches) a particular content process priority.
+ *
+ * It is expected that the fromTab and toTab belong to two separate content
+ * processes.
+ *
+ * @param Object
+ *   An object with the following properties:
+ *
+ *   fromTab (<tab>)
+ *     The tab that will be switched from to the toTab. The fromTab
+ *     is the one that will be going into the background.
+ *
+ *   toTab (<tab>)
+ *     The tab that will be switched to from the fromTab. The toTab
+ *     is presumed to start in the background, and will enter the
+ *     foreground.
+ *
+ *   fromTabExpectedPriority (String)
+ *     The priority that the content process for the fromTab is
+ *     expected to be (or reach) after the tab goes into the background.
+ *     This should be one of the PROCESS_PRIORITY_ strings defined at the
+ *     top of the file.
+ *
+ * @return Promise
+ * @resolves undefined
+ *   Once the tab switch is complete, and the two content processes for the
+ *   tabs have reached the expected priority levels.
+ */
+async function assertPriorityChangeOnBackground({
+  fromTab,
+  toTab,
+  fromTabExpectedPriority,
+}) {
+  let fromBrowser = fromTab.linkedBrowser;
+  let toBrowser = toTab.linkedBrowser;
+
+  // If the tabs aren't running in separate processes, none of the
+  // rest of this is going to work.
+  Assert.notEqual(
+    toBrowser.frameLoader.remoteTab.osPid,
+    fromBrowser.frameLoader.remoteTab.osPid,
+    "Tabs should be running in separate processes."
+  );
+
+  gTabPriorityWatcher.ensureForegroundRegistered(fromBrowser);
+
+  let fromPromise;
+  if (
+    gTabPriorityWatcher.currentPriority(fromBrowser) == fromTabExpectedPriority
+  ) {
+    fromPromise = gTabPriorityWatcher.ensureNoPriorityChange(fromBrowser);
+  } else {
+    fromPromise = gTabPriorityWatcher.waitForPriorityChange(
+      fromBrowser,
+      fromTabExpectedPriority
+    );
+  }
+
+  let toPromise;
+  if (
+    gTabPriorityWatcher.currentPriority(toBrowser) ==
+    PROCESS_PRIORITY_FOREGROUND
+  ) {
+    toPromise = gTabPriorityWatcher.ensureNoPriorityChange(toBrowser);
+  } else {
+    toPromise = gTabPriorityWatcher.waitForPriorityChange(
+      toBrowser,
+      PROCESS_PRIORITY_FOREGROUND
+    );
+  }
+
+  await BrowserTestUtils.switchTab(gBrowser, toTab);
+  await Promise.all([fromPromise, toPromise]);
+}
+
+/**
+ * Test that if a normal tab goes into the background,
+ * it has its process priority lowered to
+ * PROCESS_PRIORITY_BACKGROUND.
+ */
+add_task(async function test_normal_background_tab() {
+  let originalTab = gBrowser.selectedTab;
+
+  await BrowserTestUtils.withNewTab("http://example.com", async browser => {
+    let tab = gBrowser.getTabForBrowser(browser);
+    await assertPriorityChangeOnBackground({
+      fromTab: tab,
+      toTab: originalTab,
+      fromTabExpectedPriority: PROCESS_PRIORITY_BACKGROUND,
+    });
+
+    await assertPriorityChangeOnBackground({
+      fromTab: originalTab,
+      toTab: tab,
+      fromTabExpectedPriority: PROCESS_PRIORITY_BACKGROUND,
+    });
+  });
+});
+
+/**
+ * Test that if a tab with video goes into the background,
+ * it has its process priority lowered to
+ * PROCESS_PRIORITY_BACKGROUND_PERCEIVABLE if it has no audio,
+ * and that it has its priority remain at
+ * PROCESS_PRIORITY_FOREGROUND if it does have audio.
+ */
+add_task(async function test_video_background_tab() {
+  let originalTab = gBrowser.selectedTab;
+
+  await BrowserTestUtils.withNewTab("http://example.com", async browser => {
+    // Let's load up a video in the tab, but mute it, so that this tab should
+    // reach PROCESS_PRIORITY_BACKGROUND_PERCEIVABLE.
+    await SpecialPowers.spawn(browser, [], async () => {
+      let video = content.document.createElement("video");
+      video.src = "http://mochi.test:8888/browser/dom/ipc/tests/short.mp4";
+      video.muted = true;
+      content.document.body.appendChild(video);
+      // We'll loop the video to avoid it ending before the test is done.
+      video.loop = true;
+      await video.play();
+    });
+
+    let tab = gBrowser.getTabForBrowser(browser);
+
+    // The tab with the muted video should reach
+    // PROCESS_PRIORITY_BACKGROUND_PERCEIVABLE when backgrounded.
+    await assertPriorityChangeOnBackground({
+      fromTab: tab,
+      toTab: originalTab,
+      fromTabExpectedPriority: PROCESS_PRIORITY_BACKGROUND_PERCEIVABLE,
+    });
+
+    // Now switch back. The initial blank tab should reach
+    // PROCESS_PRIORITY_BACKGROUND when backgrounded.
+    await assertPriorityChangeOnBackground({
+      fromTab: originalTab,
+      toTab: tab,
+      fromTabExpectedPriority: PROCESS_PRIORITY_BACKGROUND,
+    });
+
+    // Let's unmute the video now.
+    await SpecialPowers.spawn(browser, [], async () => {
+      let video = content.document.querySelector("video");
+      video.muted = false;
+    });
+
+    // The tab with the unmuted video should stay at
+    // PROCESS_PRIORITY_FOREGROUND when backgrounded.
+    await assertPriorityChangeOnBackground({
+      fromTab: tab,
+      toTab: originalTab,
+      fromTabExpectedPriority: PROCESS_PRIORITY_FOREGROUND,
+    });
+
+    // Now switch back. The initial blank tab should reach
+    // PROCESS_PRIORITY_BACKGROUND when backgrounded.
+    await assertPriorityChangeOnBackground({
+      fromTab: originalTab,
+      toTab: tab,
+      fromTabExpectedPriority: PROCESS_PRIORITY_BACKGROUND,
+    });
+  });
+});
+
+/**
+ * Test that if a tab with a playing <audio> element goes into
+ * the background, the process priority does not change, unless
+ * that audio is muted (in which case, it reaches
+ * PROCESS_PRIORITY_BACKGROUND).
+ */
+add_task(async function test_audio_background_tab() {
+  let originalTab = gBrowser.selectedTab;
+
+  await BrowserTestUtils.withNewTab("http://example.com", async browser => {
+    // Let's load up some audio in the tab, but mute it, so that this tab should
+    // reach PROCESS_PRIORITY_BACKGROUND.
+    await SpecialPowers.spawn(browser, [], async () => {
+      let audio = content.document.createElement("audio");
+      audio.src = "http://mochi.test:8888/browser/dom/ipc/tests/owl.mp3";
+      audio.muted = true;
+      content.document.body.appendChild(audio);
+      // We'll loop the audio to avoid it ending before the test is done.
+      audio.loop = true;
+      await audio.play();
+    });
+
+    let tab = gBrowser.getTabForBrowser(browser);
+
+    // The tab with the muted audio should reach
+    // PROCESS_PRIORITY_BACKGROUND when backgrounded.
+    await assertPriorityChangeOnBackground({
+      fromTab: tab,
+      toTab: originalTab,
+      fromTabExpectedPriority: PROCESS_PRIORITY_BACKGROUND,
+    });
+
+    // Now switch back. The initial blank tab should reach
+    // PROCESS_PRIORITY_BACKGROUND when backgrounded.
+    await assertPriorityChangeOnBackground({
+      fromTab: originalTab,
+      toTab: tab,
+      fromTabExpectedPriority: PROCESS_PRIORITY_BACKGROUND,
+    });
+
+    // Now unmute the audio. Unfortuntely, there's a bit of a race here,
+    // since the wakelock on the audio element is released and then
+    // re-acquired if the audio reaches its end and loops around. This
+    // will cause an unexpected priority change on the content process.
+    //
+    // To avoid this race, we'll seek the audio back to the beginning,
+    // and lower its playback rate to the minimum to increase the
+    // likelihood that the check completes before the audio loops around.
+    await SpecialPowers.spawn(browser, [], async () => {
+      let audio = content.document.querySelector("audio");
+      let seeked = ContentTaskUtils.waitForEvent(audio, "seeked");
+      audio.muted = false;
+      // 0.25 is the minimum playback rate that still keeps the audio audible.
+      audio.playbackRate = 0.25;
+      audio.currentTime = 0;
+      await seeked;
+    });
+
+    // The tab with the unmuted audio should stay at
+    // PROCESS_PRIORITY_FOREGROUND when backgrounded.
+    await assertPriorityChangeOnBackground({
+      fromTab: tab,
+      toTab: originalTab,
+      fromTabExpectedPriority: PROCESS_PRIORITY_FOREGROUND,
+    });
+
+    // Now switch back. The initial blank tab should reach
+    // PROCESS_PRIORITY_BACKGROUND when backgrounded.
+    await assertPriorityChangeOnBackground({
+      fromTab: originalTab,
+      toTab: tab,
+      fromTabExpectedPriority: PROCESS_PRIORITY_BACKGROUND,
+    });
+  });
+});
+
+/**
+ * Test that if a tab with a WebAudio playing goes into the background,
+ * the process priority does not change, unless that WebAudio context is
+ * suspended.
+ */
+add_task(async function test_web_audio_background_tab() {
+  let originalTab = gBrowser.selectedTab;
+
+  await BrowserTestUtils.withNewTab("http://example.com", async browser => {
+    // Let's synthesize a basic square wave as WebAudio.
+    await SpecialPowers.spawn(browser, [], async () => {
+      let audioCtx = new content.AudioContext();
+      let oscillator = audioCtx.createOscillator();
+      oscillator.type = "square";
+      oscillator.frequency.setValueAtTime(440, audioCtx.currentTime);
+      oscillator.connect(audioCtx.destination);
+      oscillator.start();
+      while (audioCtx.state != "running") {
+        info(`wait until AudioContext starts running`);
+        await new Promise(r => (audioCtx.onstatechange = r));
+      }
+      // we'll stash the AudioContext away so that it's easier to access
+      // in the next SpecialPowers.spawn.
+      content.audioCtx = audioCtx;
+    });
+
+    let tab = gBrowser.getTabForBrowser(browser);
+
+    // The tab with the WebAudio should stay at
+    // PROCESS_PRIORITY_FOREGROUND when backgrounded.
+    await assertPriorityChangeOnBackground({
+      fromTab: tab,
+      toTab: originalTab,
+      fromTabExpectedPriority: PROCESS_PRIORITY_FOREGROUND,
+    });
+
+    // Now switch back. The initial blank tab should reach
+    // PROCESS_PRIORITY_BACKGROUND when backgrounded.
+    await assertPriorityChangeOnBackground({
+      fromTab: originalTab,
+      toTab: tab,
+      fromTabExpectedPriority: PROCESS_PRIORITY_BACKGROUND,
+    });
+
+    // Now suspend the WebAudio. This will cause it to stop
+    // playing.
+    await SpecialPowers.spawn(browser, [], async () => {
+      content.audioCtx.suspend();
+    });
+
+    // The tab with the suspended WebAudio should reach
+    // PROCESS_PRIORITY_BACKGROUND when backgrounded.
+    await assertPriorityChangeOnBackground({
+      fromTab: tab,
+      toTab: originalTab,
+      fromTabExpectedPriority: PROCESS_PRIORITY_BACKGROUND,
+    });
+
+    // Now switch back. The initial blank tab should reach
+    // PROCESS_PRIORITY_BACKGROUND when backgrounded.
+    await assertPriorityChangeOnBackground({
+      fromTab: originalTab,
+      toTab: tab,
+      fromTabExpectedPriority: PROCESS_PRIORITY_BACKGROUND,
+    });
+  });
+});