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+/* -*- indent-tabs-mode: nil; js-indent-level: 2 -*-
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+import { XPCOMUtils } from "resource://gre/modules/XPCOMUtils.sys.mjs";
+import { AppConstants } from "resource://gre/modules/AppConstants.sys.mjs";
+
+const lazy = {};
+
+ChromeUtils.defineESModuleGetters(lazy, {
+ PictureInPicture: "resource://gre/modules/PictureInPicture.sys.mjs",
+});
+
+XPCOMUtils.defineLazyPreferenceGetter(
+ lazy,
+ "gTabWarmingEnabled",
+ "browser.tabs.remote.warmup.enabled"
+);
+XPCOMUtils.defineLazyPreferenceGetter(
+ lazy,
+ "gTabWarmingMax",
+ "browser.tabs.remote.warmup.maxTabs"
+);
+XPCOMUtils.defineLazyPreferenceGetter(
+ lazy,
+ "gTabWarmingUnloadDelayMs",
+ "browser.tabs.remote.warmup.unloadDelayMs"
+);
+XPCOMUtils.defineLazyPreferenceGetter(
+ lazy,
+ "gTabCacheSize",
+ "browser.tabs.remote.tabCacheSize"
+);
+XPCOMUtils.defineLazyPreferenceGetter(
+ lazy,
+ "gTabUnloadDelay",
+ "browser.tabs.remote.unloadDelayMs",
+ 300
+);
+
+/**
+ * The tab switcher is responsible for asynchronously switching
+ * tabs in e10s. It waits until the new tab is ready (i.e., the
+ * layer tree is available) before switching to it. Then it
+ * unloads the layer tree for the old tab.
+ *
+ * The tab switcher is a state machine. For each tab, it
+ * maintains state about whether the layer tree for the tab is
+ * available, being loaded, being unloaded, or unavailable. It
+ * also keeps track of the tab currently being displayed, the tab
+ * it's trying to load, and the tab the user has asked to switch
+ * to. The switcher object is created upon tab switch. It is
+ * released when there are no pending tabs to load or unload.
+ *
+ * The following general principles have guided the design:
+ *
+ * 1. We only request one layer tree at a time. If the user
+ * switches to a different tab while waiting, we don't request
+ * the new layer tree until the old tab has loaded or timed out.
+ *
+ * 2. If loading the layers for a tab times out, we show the
+ * spinner and possibly request the layer tree for another tab if
+ * the user has requested one.
+ *
+ * 3. We discard layer trees on a delay. This way, if the user is
+ * switching among the same tabs frequently, we don't continually
+ * load the same tabs.
+ *
+ * It's important that we always show either the spinner or a tab
+ * whose layers are available. Otherwise the compositor will draw
+ * an entirely black frame, which is very jarring. To ensure this
+ * never happens when switching away from a tab, we assume the
+ * old tab might still be drawn until a MozAfterPaint event
+ * occurs. Because layout and compositing happen asynchronously,
+ * we don't have any other way of knowing when the switch
+ * actually takes place. Therefore, we don't unload the old tab
+ * until the next MozAfterPaint event.
+ */
+export class AsyncTabSwitcher {
+ constructor(tabbrowser) {
+ this.log("START");
+
+ // How long to wait for a tab's layers to load. After this
+ // time elapses, we're free to put up the spinner and start
+ // trying to load a different tab.
+ this.TAB_SWITCH_TIMEOUT = 400; // ms
+
+ // When the user hasn't switched tabs for this long, we unload
+ // layers for all tabs that aren't in use.
+ this.UNLOAD_DELAY = lazy.gTabUnloadDelay; // ms
+
+ // The next three tabs form the principal state variables.
+ // See the assertions in postActions for their invariants.
+
+ // Tab the user requested most recently.
+ this.requestedTab = tabbrowser.selectedTab;
+
+ // Tab we're currently trying to load.
+ this.loadingTab = null;
+
+ // We show this tab in case the requestedTab hasn't loaded yet.
+ this.lastVisibleTab = tabbrowser.selectedTab;
+
+ // Auxilliary state variables:
+
+ this.visibleTab = tabbrowser.selectedTab; // Tab that's on screen.
+ this.spinnerTab = null; // Tab showing a spinner.
+ this.blankTab = null; // Tab showing blank.
+ this.lastPrimaryTab = tabbrowser.selectedTab; // Tab with primary="true"
+
+ this.tabbrowser = tabbrowser;
+ this.window = tabbrowser.ownerGlobal;
+ this.loadTimer = null; // TAB_SWITCH_TIMEOUT nsITimer instance.
+ this.unloadTimer = null; // UNLOAD_DELAY nsITimer instance.
+
+ // Map from tabs to STATE_* (below).
+ this.tabState = new Map();
+
+ // True if we're in the midst of switching tabs.
+ this.switchInProgress = false;
+
+ // Transaction id for the composite that will show the requested
+ // tab for the first tab after a tab switch.
+ // Set to -1 when we're not waiting for notification of a
+ // completed switch.
+ this.switchPaintId = -1;
+
+ // Set of tabs that might be visible right now. We maintain
+ // this set because we can't be sure when a tab is actually
+ // drawn. A tab is added to this set when we ask to make it
+ // visible. All tabs but the most recently shown tab are
+ // removed from the set upon MozAfterPaint.
+ this.maybeVisibleTabs = new Set([tabbrowser.selectedTab]);
+
+ // This holds onto the set of tabs that we've been asked to warm up,
+ // and tabs are evicted once they're done loading or are unloaded.
+ this.warmingTabs = new WeakSet();
+
+ this.STATE_UNLOADED = 0;
+ this.STATE_LOADING = 1;
+ this.STATE_LOADED = 2;
+ this.STATE_UNLOADING = 3;
+
+ // re-entrancy guard:
+ this._processing = false;
+
+ // For telemetry, keeps track of what most recently cleared
+ // the loadTimer, which can tell us something about the cause
+ // of tab switch spinners.
+ this._loadTimerClearedBy = "none";
+
+ this._useDumpForLogging = false;
+ this._logInit = false;
+ this._logFlags = [];
+
+ this.window.addEventListener("MozAfterPaint", this);
+ this.window.addEventListener("MozLayerTreeReady", this);
+ this.window.addEventListener("MozLayerTreeCleared", this);
+ this.window.addEventListener("TabRemotenessChange", this);
+ this.window.addEventListener("SwapDocShells", this, true);
+ this.window.addEventListener("EndSwapDocShells", this, true);
+ this.window.document.addEventListener("visibilitychange", this);
+
+ let initialTab = this.requestedTab;
+ let initialBrowser = initialTab.linkedBrowser;
+
+ let tabIsLoaded =
+ !initialBrowser.isRemoteBrowser ||
+ initialBrowser.frameLoader.remoteTab?.hasLayers;
+
+ // If we minimized the window before the switcher was activated,
+ // we might have set the preserveLayers flag for the current
+ // browser. Let's clear it.
+ initialBrowser.preserveLayers(false);
+
+ if (!this.windowHidden) {
+ this.log("Initial tab is loaded?: " + tabIsLoaded);
+ this.setTabState(
+ initialTab,
+ tabIsLoaded ? this.STATE_LOADED : this.STATE_LOADING
+ );
+ }
+
+ for (let ppBrowser of this.tabbrowser._printPreviewBrowsers) {
+ let ppTab = this.tabbrowser.getTabForBrowser(ppBrowser);
+ let state = ppBrowser.hasLayers ? this.STATE_LOADED : this.STATE_LOADING;
+ this.setTabState(ppTab, state);
+ }
+ }
+
+ destroy() {
+ if (this.unloadTimer) {
+ this.clearTimer(this.unloadTimer);
+ this.unloadTimer = null;
+ }
+ if (this.loadTimer) {
+ this.clearTimer(this.loadTimer);
+ this.loadTimer = null;
+ }
+
+ this.window.removeEventListener("MozAfterPaint", this);
+ this.window.removeEventListener("MozLayerTreeReady", this);
+ this.window.removeEventListener("MozLayerTreeCleared", this);
+ this.window.removeEventListener("TabRemotenessChange", this);
+ this.window.removeEventListener("SwapDocShells", this, true);
+ this.window.removeEventListener("EndSwapDocShells", this, true);
+ this.window.document.removeEventListener("visibilitychange", this);
+
+ this.tabbrowser._switcher = null;
+ }
+
+ // Wraps nsITimer. Must not use the vanilla setTimeout and
+ // clearTimeout, because they will be blocked by nsIPromptService
+ // dialogs.
+ setTimer(callback, timeout) {
+ let event = {
+ notify: callback,
+ };
+
+ var timer = Cc["@mozilla.org/timer;1"].createInstance(Ci.nsITimer);
+ timer.initWithCallback(event, timeout, Ci.nsITimer.TYPE_ONE_SHOT);
+ return timer;
+ }
+
+ clearTimer(timer) {
+ timer.cancel();
+ }
+
+ getTabState(tab) {
+ let state = this.tabState.get(tab);
+
+ // As an optimization, we lazily evaluate the state of tabs
+ // that we've never seen before. Once we've figured it out,
+ // we stash it in our state map.
+ if (state === undefined) {
+ state = this.STATE_UNLOADED;
+
+ if (tab && tab.linkedPanel) {
+ let b = tab.linkedBrowser;
+ if (b.renderLayers && b.hasLayers) {
+ state = this.STATE_LOADED;
+ } else if (b.renderLayers && !b.hasLayers) {
+ state = this.STATE_LOADING;
+ } else if (!b.renderLayers && b.hasLayers) {
+ state = this.STATE_UNLOADING;
+ }
+ }
+
+ this.setTabStateNoAction(tab, state);
+ }
+
+ return state;
+ }
+
+ setTabStateNoAction(tab, state) {
+ if (state == this.STATE_UNLOADED) {
+ this.tabState.delete(tab);
+ } else {
+ this.tabState.set(tab, state);
+ }
+ }
+
+ setTabState(tab, state) {
+ if (state == this.getTabState(tab)) {
+ return;
+ }
+
+ this.setTabStateNoAction(tab, state);
+
+ let browser = tab.linkedBrowser;
+ let { remoteTab } = browser.frameLoader;
+ if (state == this.STATE_LOADING) {
+ this.assert(!this.windowHidden);
+
+ // If we're not in the process of warming this tab, we
+ // don't need to delay activating its DocShell.
+ if (!this.warmingTabs.has(tab)) {
+ browser.docShellIsActive = true;
+ }
+
+ if (remoteTab) {
+ browser.renderLayers = true;
+ remoteTab.priorityHint = true;
+ }
+ if (browser.hasLayers) {
+ this.onLayersReady(browser);
+ }
+ } else if (state == this.STATE_UNLOADING) {
+ this.unwarmTab(tab);
+ // Setting the docShell to be inactive will also cause it
+ // to stop rendering layers.
+ browser.docShellIsActive = false;
+ if (remoteTab) {
+ remoteTab.priorityHint = false;
+ }
+ if (!browser.hasLayers) {
+ this.onLayersCleared(browser);
+ }
+ } else if (state == this.STATE_LOADED) {
+ this.maybeActivateDocShell(tab);
+ }
+
+ if (!tab.linkedBrowser.isRemoteBrowser) {
+ // setTabState is potentially re-entrant, so we must re-get the state for
+ // this assertion.
+ let nonRemoteState = this.getTabState(tab);
+ // Non-remote tabs can never stay in the STATE_LOADING
+ // or STATE_UNLOADING states. By the time this function
+ // exits, a non-remote tab must be in STATE_LOADED or
+ // STATE_UNLOADED, since the painting and the layer
+ // upload happen synchronously.
+ this.assert(
+ nonRemoteState == this.STATE_UNLOADED ||
+ nonRemoteState == this.STATE_LOADED
+ );
+ }
+ }
+
+ get windowHidden() {
+ return this.window.document.hidden;
+ }
+
+ get tabLayerCache() {
+ return this.tabbrowser._tabLayerCache;
+ }
+
+ finish() {
+ this.log("FINISH");
+
+ this.assert(this.tabbrowser._switcher);
+ this.assert(this.tabbrowser._switcher === this);
+ this.assert(!this.spinnerTab);
+ this.assert(!this.blankTab);
+ this.assert(!this.loadTimer);
+ this.assert(!this.loadingTab);
+ this.assert(this.lastVisibleTab === this.requestedTab);
+ this.assert(
+ this.windowHidden ||
+ this.getTabState(this.requestedTab) == this.STATE_LOADED
+ );
+
+ this.destroy();
+
+ this.window.document.commandDispatcher.unlock();
+
+ let event = new this.window.CustomEvent("TabSwitchDone", {
+ bubbles: true,
+ cancelable: true,
+ });
+ this.tabbrowser.dispatchEvent(event);
+ }
+
+ // This function is called after all the main state changes to
+ // make sure we display the right tab.
+ updateDisplay() {
+ let requestedTabState = this.getTabState(this.requestedTab);
+ let requestedBrowser = this.requestedTab.linkedBrowser;
+
+ // It is often more desirable to show a blank tab when appropriate than
+ // the tab switch spinner - especially since the spinner is usually
+ // preceded by a perceived lag of TAB_SWITCH_TIMEOUT ms in the
+ // tab switch. We can hide this lag, and hide the time being spent
+ // constructing BrowserChild's, layer trees, etc, by showing a blank
+ // tab instead and focusing it immediately.
+ let shouldBeBlank = false;
+ if (requestedBrowser.isRemoteBrowser) {
+ // If a tab is remote and the window is not minimized, we can show a
+ // blank tab instead of a spinner in the following cases:
+ //
+ // 1. The tab has just crashed, and we haven't started showing the
+ // tab crashed page yet (in this case, the RemoteTab is null)
+ // 2. The tab has never presented, and has not finished loading
+ // a non-local-about: page.
+ //
+ // For (2), "finished loading a non-local-about: page" is
+ // determined by the busy state on the tab element and checking
+ // if the loaded URI is local.
+ let isBusy = this.requestedTab.hasAttribute("busy");
+ let isLocalAbout = requestedBrowser.currentURI.schemeIs("about");
+ let hasSufficientlyLoaded = !isBusy && !isLocalAbout;
+
+ let fl = requestedBrowser.frameLoader;
+ shouldBeBlank =
+ !this.windowHidden &&
+ (!fl.remoteTab ||
+ (!hasSufficientlyLoaded && !fl.remoteTab.hasPresented));
+
+ if (this.logging()) {
+ let flag = shouldBeBlank ? "blank" : "nonblank";
+ this.addLogFlag(
+ flag,
+ this.windowHidden,
+ fl.remoteTab,
+ isBusy,
+ isLocalAbout,
+ fl.remoteTab ? fl.remoteTab.hasPresented : 0
+ );
+ }
+ }
+
+ if (requestedBrowser.isRemoteBrowser) {
+ this.addLogFlag("isRemote");
+ }
+
+ // Figure out which tab we actually want visible right now.
+ let showTab = null;
+ if (
+ requestedTabState != this.STATE_LOADED &&
+ this.lastVisibleTab &&
+ this.loadTimer &&
+ !shouldBeBlank
+ ) {
+ // If we can't show the requestedTab, and lastVisibleTab is
+ // available, show it.
+ showTab = this.lastVisibleTab;
+ } else {
+ // Show the requested tab. If it's not available, we'll show the spinner or a blank tab.
+ showTab = this.requestedTab;
+ }
+
+ // First, let's deal with blank tabs, which we show instead
+ // of the spinner when the tab is not currently set up
+ // properly in the content process.
+ if (!shouldBeBlank && this.blankTab) {
+ this.blankTab.linkedBrowser.removeAttribute("blank");
+ this.blankTab = null;
+ } else if (shouldBeBlank && this.blankTab !== showTab) {
+ if (this.blankTab) {
+ this.blankTab.linkedBrowser.removeAttribute("blank");
+ }
+ this.blankTab = showTab;
+ this.blankTab.linkedBrowser.setAttribute("blank", "true");
+ }
+
+ // Show or hide the spinner as needed.
+ let needSpinner =
+ this.getTabState(showTab) != this.STATE_LOADED &&
+ !this.windowHidden &&
+ !shouldBeBlank &&
+ !this.loadTimer;
+
+ if (!needSpinner && this.spinnerTab) {
+ this.noteSpinnerHidden();
+ this.tabbrowser.tabpanels.removeAttribute("pendingpaint");
+ this.spinnerTab.linkedBrowser.removeAttribute("pendingpaint");
+ this.spinnerTab = null;
+ } else if (needSpinner && this.spinnerTab !== showTab) {
+ if (this.spinnerTab) {
+ this.spinnerTab.linkedBrowser.removeAttribute("pendingpaint");
+ } else {
+ this.noteSpinnerDisplayed();
+ }
+ this.spinnerTab = showTab;
+ this.tabbrowser.tabpanels.toggleAttribute("pendingpaint", true);
+ this.spinnerTab.linkedBrowser.toggleAttribute("pendingpaint", true);
+ }
+
+ // Switch to the tab we've decided to make visible.
+ if (this.visibleTab !== showTab) {
+ this.tabbrowser._adjustFocusBeforeTabSwitch(this.visibleTab, showTab);
+ this.visibleTab = showTab;
+
+ this.maybeVisibleTabs.add(showTab);
+
+ let tabpanels = this.tabbrowser.tabpanels;
+ let showPanel = this.tabbrowser.tabContainer.getRelatedElement(showTab);
+ let index = Array.prototype.indexOf.call(tabpanels.children, showPanel);
+ if (index != -1) {
+ this.log(`Switch to tab ${index} - ${this.tinfo(showTab)}`);
+ tabpanels.updateSelectedIndex(index);
+ if (showTab === this.requestedTab) {
+ if (requestedTabState == this.STATE_LOADED) {
+ // The new tab will be made visible in the next paint, record the expected
+ // transaction id for that, and we'll mark when we get notified of its
+ // completion.
+ this.switchPaintId = this.window.windowUtils.lastTransactionId + 1;
+ } else {
+ this.noteMakingTabVisibleWithoutLayers();
+ }
+
+ this.tabbrowser._adjustFocusAfterTabSwitch(showTab);
+ this.window.gURLBar.afterTabSwitchFocusChange();
+ this.maybeActivateDocShell(this.requestedTab);
+ }
+ }
+
+ // This doesn't necessarily exist if we're a new window and haven't switched tabs yet
+ if (this.lastVisibleTab) {
+ this.lastVisibleTab._visuallySelected = false;
+ }
+
+ this.visibleTab._visuallySelected = true;
+ }
+
+ this.lastVisibleTab = this.visibleTab;
+ }
+
+ assert(cond) {
+ if (!cond) {
+ dump("Assertion failure\n" + Error().stack);
+
+ // Don't break a user's browser if an assertion fails.
+ if (AppConstants.DEBUG) {
+ throw new Error("Assertion failure");
+ }
+ }
+ }
+
+ maybeClearLoadTimer(caller) {
+ if (this.loadingTab) {
+ this._loadTimerClearedBy = caller;
+ this.loadingTab = null;
+ if (this.loadTimer) {
+ this.clearTimer(this.loadTimer);
+ this.loadTimer = null;
+ }
+ }
+ }
+
+ // We've decided to try to load requestedTab.
+ loadRequestedTab() {
+ this.assert(!this.loadTimer);
+ this.assert(!this.windowHidden);
+
+ // loadingTab can be non-null here if we timed out loading the current tab.
+ // In that case we just overwrite it with a different tab; it's had its chance.
+ this.loadingTab = this.requestedTab;
+ this.log("Loading tab " + this.tinfo(this.loadingTab));
+
+ this.loadTimer = this.setTimer(
+ () => this.handleEvent({ type: "loadTimeout" }),
+ this.TAB_SWITCH_TIMEOUT
+ );
+ this.setTabState(this.requestedTab, this.STATE_LOADING);
+ }
+
+ maybeActivateDocShell(tab) {
+ // If we've reached the point where the requested tab has entered
+ // the loaded state, but the DocShell is still not yet active, we
+ // should activate it.
+ let browser = tab.linkedBrowser;
+ let state = this.getTabState(tab);
+ let canCheckDocShellState =
+ !browser.mDestroyed &&
+ (browser.docShell || browser.frameLoader.remoteTab);
+ if (
+ tab == this.requestedTab &&
+ canCheckDocShellState &&
+ state == this.STATE_LOADED &&
+ !browser.docShellIsActive &&
+ !this.windowHidden
+ ) {
+ browser.docShellIsActive = true;
+ this.logState(
+ "Set requested tab docshell to active and preserveLayers to false"
+ );
+ // If we minimized the window before the switcher was activated,
+ // we might have set the preserveLayers flag for the current
+ // browser. Let's clear it.
+ browser.preserveLayers(false);
+ }
+ }
+
+ // This function runs before every event. It fixes up the state
+ // to account for closed tabs.
+ preActions() {
+ this.assert(this.tabbrowser._switcher);
+ this.assert(this.tabbrowser._switcher === this);
+
+ for (let i = 0; i < this.tabLayerCache.length; i++) {
+ let tab = this.tabLayerCache[i];
+ if (!tab.linkedBrowser) {
+ this.tabState.delete(tab);
+ this.tabLayerCache.splice(i, 1);
+ i--;
+ }
+ }
+
+ for (let [tab] of this.tabState) {
+ if (!tab.linkedBrowser) {
+ this.tabState.delete(tab);
+ this.unwarmTab(tab);
+ }
+ }
+
+ if (this.lastVisibleTab && !this.lastVisibleTab.linkedBrowser) {
+ this.lastVisibleTab = null;
+ }
+ if (this.lastPrimaryTab && !this.lastPrimaryTab.linkedBrowser) {
+ this.lastPrimaryTab = null;
+ }
+ if (this.blankTab && !this.blankTab.linkedBrowser) {
+ this.blankTab = null;
+ }
+ if (this.spinnerTab && !this.spinnerTab.linkedBrowser) {
+ this.noteSpinnerHidden();
+ this.spinnerTab = null;
+ }
+ if (this.loadingTab && !this.loadingTab.linkedBrowser) {
+ this.maybeClearLoadTimer("preActions");
+ }
+ }
+
+ // This code runs after we've responded to an event or requested a new
+ // tab. It's expected that we've already updated all the principal
+ // state variables. This function takes care of updating any auxilliary
+ // state.
+ postActions(eventString) {
+ // Once we finish loading loadingTab, we null it out. So the state should
+ // always be LOADING.
+ this.assert(
+ !this.loadingTab ||
+ this.getTabState(this.loadingTab) == this.STATE_LOADING
+ );
+
+ // We guarantee that loadingTab is non-null iff loadTimer is non-null. So
+ // the timer is set only when we're loading something.
+ this.assert(!this.loadTimer || this.loadingTab);
+ this.assert(!this.loadingTab || this.loadTimer);
+
+ // If we're switching to a non-remote tab, there's no need to wait
+ // for it to send layers to the compositor, as this will happen
+ // synchronously. Clearing this here means that in the next step,
+ // we can load the non-remote browser immediately.
+ if (!this.requestedTab.linkedBrowser.isRemoteBrowser) {
+ this.maybeClearLoadTimer("postActions");
+ }
+
+ // If we're not loading anything, try loading the requested tab.
+ let stateOfRequestedTab = this.getTabState(this.requestedTab);
+ if (
+ !this.loadTimer &&
+ !this.windowHidden &&
+ (stateOfRequestedTab == this.STATE_UNLOADED ||
+ stateOfRequestedTab == this.STATE_UNLOADING ||
+ this.warmingTabs.has(this.requestedTab))
+ ) {
+ this.assert(stateOfRequestedTab != this.STATE_LOADED);
+ this.loadRequestedTab();
+ }
+
+ let numBackgroundCached = 0;
+ for (let tab of this.tabLayerCache) {
+ if (tab !== this.requestedTab) {
+ numBackgroundCached++;
+ }
+ }
+
+ // See how many tabs still have work to do.
+ let numPending = 0;
+ let numWarming = 0;
+ for (let [tab, state] of this.tabState) {
+ if (!this.shouldDeactivateDocShell(tab.linkedBrowser)) {
+ continue;
+ }
+
+ if (
+ state == this.STATE_LOADED &&
+ tab !== this.requestedTab &&
+ !this.tabLayerCache.includes(tab)
+ ) {
+ numPending++;
+
+ if (tab !== this.visibleTab) {
+ numWarming++;
+ }
+ }
+ if (state == this.STATE_LOADING || state == this.STATE_UNLOADING) {
+ numPending++;
+ }
+ }
+
+ this.updateDisplay();
+
+ // It's possible for updateDisplay to trigger one of our own event
+ // handlers, which might cause finish() to already have been called.
+ // Check for that before calling finish() again.
+ if (!this.tabbrowser._switcher) {
+ return;
+ }
+
+ this.maybeFinishTabSwitch();
+
+ if (numBackgroundCached > 0) {
+ this.deactivateCachedBackgroundTabs();
+ }
+
+ if (numWarming > lazy.gTabWarmingMax) {
+ this.logState("Hit tabWarmingMax");
+ if (this.unloadTimer) {
+ this.clearTimer(this.unloadTimer);
+ }
+ this.unloadNonRequiredTabs();
+ }
+
+ if (numPending == 0) {
+ this.finish();
+ }
+
+ this.logState("/" + eventString);
+ }
+
+ // Fires when we're ready to unload unused tabs.
+ onUnloadTimeout() {
+ this.unloadTimer = null;
+ this.unloadNonRequiredTabs();
+ }
+
+ deactivateCachedBackgroundTabs() {
+ for (let tab of this.tabLayerCache) {
+ if (tab !== this.requestedTab) {
+ let browser = tab.linkedBrowser;
+ browser.preserveLayers(true);
+ browser.docShellIsActive = false;
+ }
+ }
+ }
+
+ // If there are any non-visible and non-requested tabs in
+ // STATE_LOADED, sets them to STATE_UNLOADING. Also queues
+ // up the unloadTimer to run onUnloadTimeout if there are still
+ // tabs in the process of unloading.
+ unloadNonRequiredTabs() {
+ this.warmingTabs = new WeakSet();
+ let numPending = 0;
+
+ // Unload any tabs that can be unloaded.
+ for (let [tab, state] of this.tabState) {
+ if (!this.shouldDeactivateDocShell(tab.linkedBrowser)) {
+ continue;
+ }
+
+ let isInLayerCache = this.tabLayerCache.includes(tab);
+
+ if (
+ state == this.STATE_LOADED &&
+ !this.maybeVisibleTabs.has(tab) &&
+ tab !== this.lastVisibleTab &&
+ tab !== this.loadingTab &&
+ tab !== this.requestedTab &&
+ !isInLayerCache
+ ) {
+ this.setTabState(tab, this.STATE_UNLOADING);
+ }
+
+ if (
+ state != this.STATE_UNLOADED &&
+ tab !== this.requestedTab &&
+ !isInLayerCache
+ ) {
+ numPending++;
+ }
+ }
+
+ if (numPending) {
+ // Keep the timer going since there may be more tabs to unload.
+ this.unloadTimer = this.setTimer(
+ () => this.handleEvent({ type: "unloadTimeout" }),
+ this.UNLOAD_DELAY
+ );
+ }
+ }
+
+ // Fires when an ongoing load has taken too long.
+ onLoadTimeout() {
+ this.maybeClearLoadTimer("onLoadTimeout");
+ }
+
+ // Fires when the layers become available for a tab.
+ onLayersReady(browser) {
+ let tab = this.tabbrowser.getTabForBrowser(browser);
+ if (!tab) {
+ // We probably got a layer update from a tab that got before
+ // the switcher was created, or for browser that's not being
+ // tracked by the async tab switcher (like the preloaded about:newtab).
+ return;
+ }
+
+ this.logState(`onLayersReady(${tab._tPos}, ${browser.isRemoteBrowser})`);
+ this.assert(
+ this.getTabState(tab) == this.STATE_LOADING ||
+ this.getTabState(tab) == this.STATE_LOADED
+ );
+ this.setTabState(tab, this.STATE_LOADED);
+ this.unwarmTab(tab);
+
+ if (this.loadingTab === tab) {
+ this.maybeClearLoadTimer("onLayersReady");
+ }
+ }
+
+ // Fires when we paint the screen. Any tab switches we initiated
+ // previously are done, so there's no need to keep the old layers
+ // around.
+ onPaint(event) {
+ this.addLogFlag(
+ "onPaint",
+ this.switchPaintId != -1,
+ event.transactionId >= this.switchPaintId
+ );
+ this.notePaint(event);
+ this.maybeVisibleTabs.clear();
+ }
+
+ // Called when we're done clearing the layers for a tab.
+ onLayersCleared(browser) {
+ let tab = this.tabbrowser.getTabForBrowser(browser);
+ if (!tab) {
+ return;
+ }
+ this.logState(`onLayersCleared(${tab._tPos})`);
+ this.assert(
+ this.getTabState(tab) == this.STATE_UNLOADING ||
+ this.getTabState(tab) == this.STATE_UNLOADED
+ );
+ this.setTabState(tab, this.STATE_UNLOADED);
+ }
+
+ // Called when a tab switches from remote to non-remote. In this case
+ // a MozLayerTreeReady notification that we requested may never fire,
+ // so we need to simulate it.
+ onRemotenessChange(tab) {
+ this.logState(
+ `onRemotenessChange(${tab._tPos}, ${tab.linkedBrowser.isRemoteBrowser})`
+ );
+ if (!tab.linkedBrowser.isRemoteBrowser) {
+ if (this.getTabState(tab) == this.STATE_LOADING) {
+ this.onLayersReady(tab.linkedBrowser);
+ } else if (this.getTabState(tab) == this.STATE_UNLOADING) {
+ this.onLayersCleared(tab.linkedBrowser);
+ }
+ } else if (this.getTabState(tab) == this.STATE_LOADED) {
+ // A tab just changed from non-remote to remote, which means
+ // that it's gone back into the STATE_LOADING state until
+ // it sends up a layer tree.
+ this.setTabState(tab, this.STATE_LOADING);
+ }
+ }
+
+ onTabRemoved(tab) {
+ if (this.lastVisibleTab == tab) {
+ this.handleEvent({ type: "tabRemoved", tab });
+ }
+ }
+
+ // Called when a tab has been removed, and the browser node is
+ // about to be removed from the DOM.
+ onTabRemovedImpl(tab) {
+ this.lastVisibleTab = null;
+ }
+
+ onVisibilityChange() {
+ if (this.windowHidden) {
+ for (let [tab, state] of this.tabState) {
+ if (!this.shouldDeactivateDocShell(tab.linkedBrowser)) {
+ continue;
+ }
+
+ if (state == this.STATE_LOADING || state == this.STATE_LOADED) {
+ this.setTabState(tab, this.STATE_UNLOADING);
+ }
+ }
+ this.maybeClearLoadTimer("onSizeModeOrOcc");
+ } else {
+ // We're no longer minimized or occluded. This means we might want
+ // to activate the current tab's docShell.
+ this.maybeActivateDocShell(this.tabbrowser.selectedTab);
+ }
+ }
+
+ onSwapDocShells(ourBrowser, otherBrowser) {
+ // This event fires before the swap. ourBrowser is from
+ // our window. We save the state of otherBrowser since ourBrowser
+ // needs to take on that state at the end of the swap.
+
+ let otherTabbrowser = otherBrowser.ownerGlobal.gBrowser;
+ let otherState;
+ if (otherTabbrowser && otherTabbrowser._switcher) {
+ let otherTab = otherTabbrowser.getTabForBrowser(otherBrowser);
+ let otherSwitcher = otherTabbrowser._switcher;
+ otherState = otherSwitcher.getTabState(otherTab);
+ } else {
+ otherState = otherBrowser.docShellIsActive
+ ? this.STATE_LOADED
+ : this.STATE_UNLOADED;
+ }
+ if (!this.swapMap) {
+ this.swapMap = new WeakMap();
+ }
+ this.swapMap.set(otherBrowser, {
+ state: otherState,
+ });
+ }
+
+ onEndSwapDocShells(ourBrowser, otherBrowser) {
+ // The swap has happened. We reset the loadingTab in
+ // case it has been swapped. We also set ourBrowser's state
+ // to whatever otherBrowser's state was before the swap.
+
+ // Clearing the load timer means that we will
+ // immediately display a spinner if ourBrowser isn't
+ // ready yet. Typically it will already be ready
+ // though. If it's not, we're probably in a new window,
+ // in which case we have no other tabs to display anyway.
+ this.maybeClearLoadTimer("onEndSwapDocShells");
+
+ let { state: otherState } = this.swapMap.get(otherBrowser);
+
+ this.swapMap.delete(otherBrowser);
+
+ let ourTab = this.tabbrowser.getTabForBrowser(ourBrowser);
+ if (ourTab) {
+ this.setTabStateNoAction(ourTab, otherState);
+ }
+ }
+
+ /**
+ * Check if the browser should be deactivated. If the browser is a print preivew or
+ * PiP browser then we won't deactive it.
+ * @param browser The browser to check if it should be deactivated
+ * @returns false if a print preview or PiP browser else true
+ */
+ shouldDeactivateDocShell(browser) {
+ return !(
+ this.tabbrowser._printPreviewBrowsers.has(browser) ||
+ lazy.PictureInPicture.isOriginatingBrowser(browser)
+ );
+ }
+
+ shouldActivateDocShell(browser) {
+ let tab = this.tabbrowser.getTabForBrowser(browser);
+ let state = this.getTabState(tab);
+ return state == this.STATE_LOADING || state == this.STATE_LOADED;
+ }
+
+ activateBrowserForPrintPreview(browser) {
+ let tab = this.tabbrowser.getTabForBrowser(browser);
+ let state = this.getTabState(tab);
+ if (state != this.STATE_LOADING && state != this.STATE_LOADED) {
+ this.setTabState(tab, this.STATE_LOADING);
+ this.logState(
+ "Activated browser " + this.tinfo(tab) + " for print preview"
+ );
+ }
+ }
+
+ canWarmTab(tab) {
+ if (!lazy.gTabWarmingEnabled) {
+ return false;
+ }
+
+ if (!tab) {
+ return false;
+ }
+
+ // If the tab is not yet inserted, closing, not remote,
+ // crashed, already visible, or already requested, warming
+ // up the tab makes no sense.
+ if (
+ this.windowHidden ||
+ !tab.linkedPanel ||
+ tab.closing ||
+ !tab.linkedBrowser.isRemoteBrowser ||
+ !tab.linkedBrowser.frameLoader.remoteTab
+ ) {
+ return false;
+ }
+
+ return true;
+ }
+
+ shouldWarmTab(tab) {
+ if (this.canWarmTab(tab)) {
+ // Tabs that are already in STATE_LOADING or STATE_LOADED
+ // have no need to be warmed up.
+ let state = this.getTabState(tab);
+ if (state === this.STATE_UNLOADING || state === this.STATE_UNLOADED) {
+ return true;
+ }
+ }
+
+ return false;
+ }
+
+ unwarmTab(tab) {
+ this.warmingTabs.delete(tab);
+ }
+
+ warmupTab(tab) {
+ if (!this.shouldWarmTab(tab)) {
+ return;
+ }
+
+ this.logState("warmupTab " + this.tinfo(tab));
+
+ this.warmingTabs.add(tab);
+ this.setTabState(tab, this.STATE_LOADING);
+ this.queueUnload(lazy.gTabWarmingUnloadDelayMs);
+ }
+
+ cleanUpTabAfterEviction(tab) {
+ this.assert(tab !== this.requestedTab);
+ let browser = tab.linkedBrowser;
+ if (browser) {
+ browser.preserveLayers(false);
+ }
+ this.setTabState(tab, this.STATE_UNLOADING);
+ }
+
+ evictOldestTabFromCache() {
+ let tab = this.tabLayerCache.shift();
+ this.cleanUpTabAfterEviction(tab);
+ }
+
+ maybePromoteTabInLayerCache(tab) {
+ if (
+ lazy.gTabCacheSize > 1 &&
+ tab.linkedBrowser.isRemoteBrowser &&
+ tab.linkedBrowser.currentURI.spec != "about:blank"
+ ) {
+ let tabIndex = this.tabLayerCache.indexOf(tab);
+
+ if (tabIndex != -1) {
+ this.tabLayerCache.splice(tabIndex, 1);
+ }
+
+ this.tabLayerCache.push(tab);
+
+ if (this.tabLayerCache.length > lazy.gTabCacheSize) {
+ this.evictOldestTabFromCache();
+ }
+ }
+ }
+
+ // Called when the user asks to switch to a given tab.
+ requestTab(tab) {
+ if (tab === this.requestedTab) {
+ return;
+ }
+
+ let tabState = this.getTabState(tab);
+ this.noteTabRequested(tab, tabState);
+
+ this.logState("requestTab " + this.tinfo(tab));
+ this.startTabSwitch();
+
+ let oldBrowser = this.requestedTab.linkedBrowser;
+ oldBrowser.deprioritize();
+ this.requestedTab = tab;
+ if (tabState == this.STATE_LOADED) {
+ this.maybeVisibleTabs.clear();
+ }
+
+ tab.linkedBrowser.setAttribute("primary", "true");
+ if (this.lastPrimaryTab && this.lastPrimaryTab != tab) {
+ this.lastPrimaryTab.linkedBrowser.removeAttribute("primary");
+ }
+ this.lastPrimaryTab = tab;
+
+ this.queueUnload(this.UNLOAD_DELAY);
+ }
+
+ queueUnload(unloadTimeout) {
+ this.handleEvent({ type: "queueUnload", unloadTimeout });
+ }
+
+ onQueueUnload(unloadTimeout) {
+ if (this.unloadTimer) {
+ this.clearTimer(this.unloadTimer);
+ }
+ this.unloadTimer = this.setTimer(
+ () => this.handleEvent({ type: "unloadTimeout" }),
+ unloadTimeout
+ );
+ }
+
+ handleEvent(event, delayed = false) {
+ if (this._processing) {
+ this.setTimer(() => this.handleEvent(event, true), 0);
+ return;
+ }
+ if (delayed && this.tabbrowser._switcher != this) {
+ // if we delayed processing this event, we might be out of date, in which
+ // case we drop the delayed events
+ return;
+ }
+ this._processing = true;
+ try {
+ this.preActions();
+
+ switch (event.type) {
+ case "queueUnload":
+ this.onQueueUnload(event.unloadTimeout);
+ break;
+ case "unloadTimeout":
+ this.onUnloadTimeout();
+ break;
+ case "loadTimeout":
+ this.onLoadTimeout();
+ break;
+ case "tabRemoved":
+ this.onTabRemovedImpl(event.tab);
+ break;
+ case "MozLayerTreeReady": {
+ let browser = event.originalTarget;
+ if (!browser.renderLayers) {
+ // By the time we handle this event, it's possible that something
+ // else has already set renderLayers to false, in which case this
+ // event is stale and we can safely ignore it.
+ return;
+ }
+ this.onLayersReady(browser);
+ break;
+ }
+ case "MozAfterPaint":
+ this.onPaint(event);
+ break;
+ case "MozLayerTreeCleared": {
+ let browser = event.originalTarget;
+ if (browser.renderLayers) {
+ // By the time we handle this event, it's possible that something
+ // else has already set renderLayers to true, in which case this
+ // event is stale and we can safely ignore it.
+ return;
+ }
+ this.onLayersCleared(browser);
+ break;
+ }
+ case "TabRemotenessChange":
+ this.onRemotenessChange(event.target);
+ break;
+ case "visibilitychange":
+ this.onVisibilityChange();
+ break;
+ case "SwapDocShells":
+ this.onSwapDocShells(event.originalTarget, event.detail);
+ break;
+ case "EndSwapDocShells":
+ this.onEndSwapDocShells(event.originalTarget, event.detail);
+ break;
+ }
+
+ this.postActions(event.type);
+ } finally {
+ this._processing = false;
+ }
+ }
+
+ /*
+ * Telemetry and Profiler related helpers for recording tab switch
+ * timing.
+ */
+
+ startTabSwitch() {
+ this.noteStartTabSwitch();
+ this.switchInProgress = true;
+ }
+
+ /**
+ * Something has occurred that might mean that we've completed
+ * the tab switch (layers are ready, paints are done, spinners
+ * are hidden). This checks to make sure all conditions are
+ * satisfied, and then records the tab switch as finished.
+ */
+ maybeFinishTabSwitch() {
+ if (
+ this.switchInProgress &&
+ this.requestedTab &&
+ (this.getTabState(this.requestedTab) == this.STATE_LOADED ||
+ this.requestedTab === this.blankTab)
+ ) {
+ if (this.requestedTab !== this.blankTab) {
+ this.maybePromoteTabInLayerCache(this.requestedTab);
+ }
+
+ this.noteFinishTabSwitch();
+ this.switchInProgress = false;
+
+ let event = new this.window.CustomEvent("TabSwitched", {
+ bubbles: true,
+ detail: {
+ tab: this.requestedTab,
+ },
+ });
+ this.tabbrowser.dispatchEvent(event);
+ }
+ }
+
+ /*
+ * Debug related logging for switcher.
+ */
+ logging() {
+ if (this._useDumpForLogging) {
+ return true;
+ }
+ if (this._logInit) {
+ return this._shouldLog;
+ }
+ let result = Services.prefs.getBoolPref(
+ "browser.tabs.remote.logSwitchTiming",
+ false
+ );
+ this._shouldLog = result;
+ this._logInit = true;
+ return this._shouldLog;
+ }
+
+ tinfo(tab) {
+ if (tab) {
+ return tab._tPos + "(" + tab.linkedBrowser.currentURI.spec + ")";
+ }
+ return "null";
+ }
+
+ log(s) {
+ if (!this.logging()) {
+ return;
+ }
+ if (this._useDumpForLogging) {
+ dump(s + "\n");
+ } else {
+ Services.console.logStringMessage(s);
+ }
+ }
+
+ addLogFlag(flag, ...subFlags) {
+ if (this.logging()) {
+ if (subFlags.length) {
+ flag += `(${subFlags.map(f => (f ? 1 : 0)).join("")})`;
+ }
+ this._logFlags.push(flag);
+ }
+ }
+
+ logState(suffix) {
+ if (!this.logging()) {
+ return;
+ }
+
+ let getTabString = tab => {
+ let tabString = "";
+
+ let state = this.getTabState(tab);
+ let isWarming = this.warmingTabs.has(tab);
+ let isCached = this.tabLayerCache.includes(tab);
+ let isClosing = tab.closing;
+ let linkedBrowser = tab.linkedBrowser;
+ let isActive = linkedBrowser && linkedBrowser.docShellIsActive;
+ let isRendered = linkedBrowser && linkedBrowser.renderLayers;
+ let isPiP =
+ linkedBrowser &&
+ lazy.PictureInPicture.isOriginatingBrowser(linkedBrowser);
+
+ if (tab === this.lastVisibleTab) {
+ tabString += "V";
+ }
+ if (tab === this.loadingTab) {
+ tabString += "L";
+ }
+ if (tab === this.requestedTab) {
+ tabString += "R";
+ }
+ if (tab === this.blankTab) {
+ tabString += "B";
+ }
+ if (this.maybeVisibleTabs.has(tab)) {
+ tabString += "M";
+ }
+
+ let extraStates = "";
+ if (isWarming) {
+ extraStates += "W";
+ }
+ if (isCached) {
+ extraStates += "C";
+ }
+ if (isClosing) {
+ extraStates += "X";
+ }
+ if (isActive) {
+ extraStates += "A";
+ }
+ if (isRendered) {
+ extraStates += "R";
+ }
+ if (isPiP) {
+ extraStates += "P";
+ }
+ if (extraStates != "") {
+ tabString += `(${extraStates})`;
+ }
+
+ switch (state) {
+ case this.STATE_LOADED: {
+ tabString += "(loaded)";
+ break;
+ }
+ case this.STATE_LOADING: {
+ tabString += "(loading)";
+ break;
+ }
+ case this.STATE_UNLOADING: {
+ tabString += "(unloading)";
+ break;
+ }
+ case this.STATE_UNLOADED: {
+ tabString += "(unloaded)";
+ break;
+ }
+ }
+
+ return tabString;
+ };
+
+ let accum = "";
+
+ // This is a bit tricky to read, but what we're doing here is collapsing
+ // identical tab states down to make the overal string shorter and easier
+ // to read, and we move all simply unloaded tabs to the back of the list.
+ // I.e., we turn
+ // "0:(unloaded) 1:(unloaded) 2:(unloaded) 3:(loaded)""
+ // into
+ // "3:(loaded) 0...2:(unloaded)"
+ let tabStrings = this.tabbrowser.tabs.map(t => getTabString(t));
+ let lastMatch = -1;
+ let unloadedTabsStrings = [];
+ for (let i = 0; i <= tabStrings.length; i++) {
+ if (i > 0) {
+ if (i < tabStrings.length && tabStrings[i] == tabStrings[lastMatch]) {
+ continue;
+ }
+
+ if (tabStrings[lastMatch] == "(unloaded)") {
+ if (lastMatch == i - 1) {
+ unloadedTabsStrings.push(lastMatch.toString());
+ } else {
+ unloadedTabsStrings.push(`${lastMatch}...${i - 1}`);
+ }
+ } else if (lastMatch == i - 1) {
+ accum += `${lastMatch}:${tabStrings[lastMatch]} `;
+ } else {
+ accum += `${lastMatch}...${i - 1}:${tabStrings[lastMatch]} `;
+ }
+ }
+
+ lastMatch = i;
+ }
+
+ if (unloadedTabsStrings.length) {
+ accum += `${unloadedTabsStrings.join(",")}:(unloaded) `;
+ }
+
+ accum += "cached: " + this.tabLayerCache.length + " ";
+
+ if (this._logFlags.length) {
+ accum += `[${this._logFlags.join(",")}] `;
+ this._logFlags = [];
+ }
+
+ // It can be annoying to read through the entirety of a log string just
+ // to check if something changed or not. So if we can tell that nothing
+ // changed, just write "unchanged" to save the reader's time.
+ let logString;
+ if (this._lastLogString == accum) {
+ accum = "unchanged";
+ } else {
+ this._lastLogString = accum;
+ }
+ logString = `ATS: ${accum}{${suffix}}`;
+
+ if (this._useDumpForLogging) {
+ dump(logString + "\n");
+ } else {
+ Services.console.logStringMessage(logString);
+ }
+ }
+
+ noteMakingTabVisibleWithoutLayers() {
+ // We're making the tab visible even though we haven't yet got layers for it.
+ // It's hard to know which composite the layers will first be available in (and
+ // the parent process might not even get MozAfterPaint delivered for it), so just
+ // give up measuring this for now. :(
+ Glean.performanceInteraction.tabSwitchComposite.cancel(
+ this._tabswitchTimerId
+ );
+ this._tabswitchTimerId = null;
+ }
+
+ notePaint(event) {
+ if (this.switchPaintId != -1 && event.transactionId >= this.switchPaintId) {
+ if (this._tabswitchTimerId) {
+ Glean.performanceInteraction.tabSwitchComposite.stopAndAccumulate(
+ this._tabswitchTimerId
+ );
+ this._tabswitchTimerId = null;
+ }
+ let { innerWindowId } = this.window.windowGlobalChild;
+ ChromeUtils.addProfilerMarker("AsyncTabSwitch:Composited", {
+ innerWindowId,
+ });
+ this.switchPaintId = -1;
+ }
+ }
+
+ noteTabRequested(tab, tabState) {
+ if (lazy.gTabWarmingEnabled) {
+ let warmingState = "disqualified";
+
+ if (this.canWarmTab(tab)) {
+ if (tabState == this.STATE_LOADING) {
+ warmingState = "stillLoading";
+ } else if (tabState == this.STATE_LOADED) {
+ warmingState = "loaded";
+ } else if (
+ tabState == this.STATE_UNLOADING ||
+ tabState == this.STATE_UNLOADED
+ ) {
+ // At this point, if the tab's browser was being inserted
+ // lazily, we never had a chance to warm it up, and unfortunately
+ // there's no great way to detect that case. Those cases will
+ // end up in the "notWarmed" bucket, along with legitimate cases
+ // where tabs could have been warmed but weren't.
+ warmingState = "notWarmed";
+ }
+ }
+
+ Services.telemetry
+ .getHistogramById("FX_TAB_SWITCH_REQUEST_TAB_WARMING_STATE")
+ .add(warmingState);
+ }
+ }
+
+ noteStartTabSwitch() {
+ TelemetryStopwatch.cancel("FX_TAB_SWITCH_TOTAL_E10S_MS", this.window);
+ TelemetryStopwatch.start("FX_TAB_SWITCH_TOTAL_E10S_MS", this.window);
+
+ if (this._tabswitchTimerId) {
+ Glean.performanceInteraction.tabSwitchComposite.cancel(
+ this._tabswitchTimerId
+ );
+ }
+ this._tabswitchTimerId =
+ Glean.performanceInteraction.tabSwitchComposite.start();
+ let { innerWindowId } = this.window.windowGlobalChild;
+ ChromeUtils.addProfilerMarker("AsyncTabSwitch:Start", { innerWindowId });
+ }
+
+ noteFinishTabSwitch() {
+ // After this point the tab has switched from the content thread's point of view.
+ // The changes will be visible after the next refresh driver tick + composite.
+ let time = TelemetryStopwatch.timeElapsed(
+ "FX_TAB_SWITCH_TOTAL_E10S_MS",
+ this.window
+ );
+ if (time != -1) {
+ TelemetryStopwatch.finish("FX_TAB_SWITCH_TOTAL_E10S_MS", this.window);
+ this.log("DEBUG: tab switch time = " + time);
+ let { innerWindowId } = this.window.windowGlobalChild;
+ ChromeUtils.addProfilerMarker("AsyncTabSwitch:Finish", { innerWindowId });
+ }
+ }
+
+ noteSpinnerDisplayed() {
+ this.assert(!this.spinnerTab);
+ let browser = this.requestedTab.linkedBrowser;
+ this.assert(browser.isRemoteBrowser);
+ TelemetryStopwatch.start("FX_TAB_SWITCH_SPINNER_VISIBLE_MS", this.window);
+ // We have a second, similar probe for capturing recordings of
+ // when the spinner is displayed for very long periods.
+ TelemetryStopwatch.start(
+ "FX_TAB_SWITCH_SPINNER_VISIBLE_LONG_MS",
+ this.window
+ );
+ let { innerWindowId } = this.window.windowGlobalChild;
+ ChromeUtils.addProfilerMarker("AsyncTabSwitch:SpinnerShown", {
+ innerWindowId,
+ });
+ Services.telemetry
+ .getHistogramById("FX_TAB_SWITCH_SPINNER_VISIBLE_TRIGGER")
+ .add(this._loadTimerClearedBy);
+ if (AppConstants.NIGHTLY_BUILD) {
+ Services.obs.notifyObservers(null, "tabswitch-spinner");
+ }
+ }
+
+ noteSpinnerHidden() {
+ this.assert(this.spinnerTab);
+ this.log(
+ "DEBUG: spinner time = " +
+ TelemetryStopwatch.timeElapsed(
+ "FX_TAB_SWITCH_SPINNER_VISIBLE_MS",
+ this.window
+ )
+ );
+ TelemetryStopwatch.finish("FX_TAB_SWITCH_SPINNER_VISIBLE_MS", this.window);
+ TelemetryStopwatch.finish(
+ "FX_TAB_SWITCH_SPINNER_VISIBLE_LONG_MS",
+ this.window
+ );
+ let { innerWindowId } = this.window.windowGlobalChild;
+ ChromeUtils.addProfilerMarker("AsyncTabSwitch:SpinnerHidden", {
+ innerWindowId,
+ });
+ // we do not get a onPaint after displaying the spinner
+ this._loadTimerClearedBy = "none";
+ }
+}