Bug 1020831 - Make SessionStore.jsm and SessionFile.jsm share the same run state r=yoric

browser/components/sessionstore/RunState.jsm

@@ -0,0 +1,66 @@
+/* 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/. */
+
+"use strict";
+
+this.EXPORTED_SYMBOLS = ["RunState"];
+
+const Cu = Components.utils;
+
+Cu.import("resource://gre/modules/Services.jsm", this);
+
+const STATE_STOPPED = 0;
+const STATE_RUNNING = 1;
+const STATE_QUITTING = 2;
+
+// We're initially stopped.
+let state = STATE_STOPPED;
+
+function observer(subj, topic) {
+  Services.obs.removeObserver(observer, topic);
+  state = STATE_QUITTING;
+}
+
+// Listen for when the application is quitting.
+Services.obs.addObserver(observer, "quit-application-granted", false);
+
+/**
+ * This module keeps track of SessionStore's current run state. We will
+ * always start out at STATE_STOPPED. After the sessionw as read from disk and
+ * the initial browser window has loaded we switch to STATE_RUNNING. On the
+ * first notice that a browser shutdown was granted we switch to STATE_QUITTING.
+ */
+this.RunState = Object.freeze({
+  // If we're stopped then SessionStore hasn't been initialized yet. As soon
+  // as the session is read from disk and the initial browser window has loaded
+  // the run state will change to STATE_RUNNING.
+  get isStopped() {
+    return state == STATE_STOPPED;
+  },
+
+  // STATE_RUNNING is our default mode of operation that we'll spend most of
+  // the time in. After the session was read from disk and the first browser
+  // window has loaded we remain running until the browser quits.
+  get isRunning() {
+    return state == STATE_RUNNING;
+  },
+
+  // We will enter STATE_QUITTING as soon as we receive notice that a browser
+  // shutdown was granted. SessionStore will use this information to prevent
+  // us from collecting partial information while the browser is shutting down
+  // as well as to allow a last single write to disk and block all writes after
+  // that.
+  get isQuitting() {
+    return state == STATE_QUITTING;
+  },
+
+  // Switch the run state to STATE_RUNNING. This must be called after the
+  // session was read from, the initial browser window has loaded and we're
+  // now ready to restore session data.
+  setRunning() {
+    if (this.isStopped) {
+      state = STATE_RUNNING;
+    }
+  }
+});

browser/components/sessionstore/SessionFile.jsm

@@ -38,6 +38,8 @@ Cu.import("resource://gre/modules/AsyncShutdown.jsm");
 
 XPCOMUtils.defineLazyModuleGetter(this, "console",
   "resource://gre/modules/devtools/Console.jsm");
+XPCOMUtils.defineLazyModuleGetter(this, "RunState",
+  "resource:///modules/sessionstore/RunState.jsm");
 XPCOMUtils.defineLazyModuleGetter(this, "TelemetryStopwatch",
   "resource://gre/modules/TelemetryStopwatch.jsm");
 XPCOMUtils.defineLazyModuleGetter(this, "Task",
@@ -267,7 +269,7 @@ let SessionFileInternal = {
     }
 
     let isFinalWrite = false;
-    if (Services.startup.shuttingDown) {
+    if (RunState.isQuitting) {
       // If shutdown has started, we will want to stop receiving
       // write instructions.
       isFinalWrite = this._isClosed = true;

browser/components/sessionstore/SessionStore.jsm

@@ -11,10 +11,6 @@ const Cc = Components.classes;
 const Ci = Components.interfaces;
 const Cr = Components.results;
 
-const STATE_STOPPED = 0;
-const STATE_RUNNING = 1;
-const STATE_QUITTING = -1;
-
 const TAB_STATE_NEEDS_RESTORE = 1;
 const TAB_STATE_RESTORING = 2;
 
@@ -31,8 +27,7 @@ const MAX_CONCURRENT_TAB_RESTORES = 3;
 // global notifications observed
 const OBSERVING = [
   "browser-window-before-show", "domwindowclosed",
-  "quit-application-requested", "quit-application-granted",
-  "browser-lastwindow-close-granted",
+  "quit-application-requested", "browser-lastwindow-close-granted",
   "quit-application", "browser:purge-session-history",
   "browser:purge-domain-data",
   "gather-telemetry",
@@ -112,6 +107,8 @@ XPCOMUtils.defineLazyModuleGetter(this, "GlobalState",
   "resource:///modules/sessionstore/GlobalState.jsm");
 XPCOMUtils.defineLazyModuleGetter(this, "PrivacyFilter",
   "resource:///modules/sessionstore/PrivacyFilter.jsm");
+XPCOMUtils.defineLazyModuleGetter(this, "RunState",
+  "resource:///modules/sessionstore/RunState.jsm");
 XPCOMUtils.defineLazyModuleGetter(this, "ScratchpadManager",
   "resource:///modules/devtools/scratchpad-manager.jsm");
 XPCOMUtils.defineLazyModuleGetter(this, "SessionSaver",
@@ -288,9 +285,6 @@ let SessionStoreInternal = {
     Ci.nsISupportsWeakReference
   ]),
 
-  // set default load state
-  _loadState: STATE_STOPPED,
-
   _globalState: new GlobalState(),
 
   // During the initial restore and setBrowserState calls tracks the number of
@@ -472,7 +466,7 @@ let SessionStoreInternal = {
 
     // at this point, we've as good as resumed the session, so we can
     // clear the resume_session_once flag, if it's set
-    if (this._loadState != STATE_QUITTING &&
+    if (!RunState.isQuitting &&
         this._prefBranch.getBoolPref("sessionstore.resume_session_once"))
       this._prefBranch.setBoolPref("sessionstore.resume_session_once", false);
 
@@ -531,9 +525,6 @@ let SessionStoreInternal = {
       case "quit-application-requested":
         this.onQuitApplicationRequested();
         break;
-      case "quit-application-granted":
-        this.onQuitApplicationGranted();
-        break;
       case "browser-lastwindow-close-granted":
         this.onLastWindowCloseGranted();
         break;
@@ -739,7 +730,7 @@ let SessionStoreInternal = {
       return;
 
     // ignore windows opened while shutting down
-    if (this._loadState == STATE_QUITTING)
+    if (RunState.isQuitting)
       return;
 
     // Assign the window a unique identifier we can use to reference
@@ -764,8 +755,8 @@ let SessionStoreInternal = {
       this._windows[aWindow.__SSi].isPopup = true;
 
     // perform additional initialization when the first window is loading
-    if (this._loadState == STATE_STOPPED) {
-      this._loadState = STATE_RUNNING;
+    if (RunState.isStopped) {
+      RunState.setRunning();
       SessionSaver.updateLastSaveTime();
 
       // restore a crashed session resp. resume the last session if requested
@@ -1008,7 +999,7 @@ let SessionStoreInternal = {
     let winData = this._windows[aWindow.__SSi];
 
     // Collect window data only when *not* closed during shutdown.
-    if (this._loadState == STATE_RUNNING) {
+    if (RunState.isRunning) {
       // Flush all data queued in the content script before the window is gone.
       TabState.flushWindow(aWindow);
 
@@ -1100,14 +1091,6 @@ let SessionStoreInternal = {
     DirtyWindows.clear();
   },
 
-  /**
-   * On quit application granted
-   */
-  onQuitApplicationGranted: function ssi_onQuitApplicationGranted() {
-    // freeze the data at what we've got (ignoring closing windows)
-    this._loadState = STATE_QUITTING;
-  },
-
   /**
    * On last browser window close
    */
@@ -1141,7 +1124,6 @@ let SessionStoreInternal = {
       LastSession.clear();
     }
 
-    this._loadState = STATE_QUITTING; // just to be sure
     this._uninit();
   },
 
@@ -1153,7 +1135,7 @@ let SessionStoreInternal = {
     // If the browser is shutting down, simply return after clearing the
     // session data on disk as this notification fires after the
     // quit-application notification so the browser is about to exit.
-    if (this._loadState == STATE_QUITTING)
+    if (RunState.isQuitting)
       return;
     LastSession.clear();
     let openWindows = {};
@@ -1179,7 +1161,7 @@ let SessionStoreInternal = {
     var win = this._getMostRecentBrowserWindow();
     if (win) {
       win.setTimeout(() => SessionSaver.run(), 0);
-    } else if (this._loadState == STATE_RUNNING) {
+    } else if (RunState.isRunning) {
       SessionSaver.run();
     }
 
@@ -1237,7 +1219,7 @@ let SessionStoreInternal = {
       }
     }
 
-    if (this._loadState == STATE_RUNNING) {
+    if (RunState.isRunning) {
       SessionSaver.run();
     }
 
@@ -1368,7 +1350,7 @@ let SessionStoreInternal = {
    *        Window reference
    */
   onTabSelect: function ssi_onTabSelect(aWindow) {
-    if (this._loadState == STATE_RUNNING) {
+    if (RunState.isRunning) {
       this._windows[aWindow.__SSi].selected = aWindow.gBrowser.tabContainer.selectedIndex;
 
       let tab = aWindow.gBrowser.selectedTab;
@@ -2033,7 +2015,7 @@ let SessionStoreInternal = {
     var activeWindow = this._getMostRecentBrowserWindow();
 
     TelemetryStopwatch.start("FX_SESSION_RESTORE_COLLECT_ALL_WINDOWS_DATA_MS");
-    if (this._loadState == STATE_RUNNING) {
+    if (RunState.isRunning) {
       // update the data for all windows with activities since the last save operation
       this._forEachBrowserWindow(function(aWindow) {
         if (!this._isWindowLoaded(aWindow)) // window data is still in _statesToRestore
@@ -2090,7 +2072,7 @@ let SessionStoreInternal = {
     //XXXzpao We should do this for _restoreLastWindow == true, but that has
     //        its own check for popups. c.f. bug 597619
     if (nonPopupCount == 0 && lastClosedWindowsCopy.length > 0 &&
-        this._loadState == STATE_QUITTING) {
+        RunState.isQuitting) {
       // prepend the last non-popup browser window, so that if the user loads more tabs
       // at startup we don't accidentally add them to a popup window
       do {
@@ -2155,7 +2137,7 @@ let SessionStoreInternal = {
     if (!this._isWindowLoaded(aWindow))
       return this._statesToRestore[aWindow.__SS_restoreID];
 
-    if (this._loadState == STATE_RUNNING) {
+    if (RunState.isRunning) {
       this._collectWindowData(aWindow);
     }
 
@@ -2637,7 +2619,7 @@ let SessionStoreInternal = {
    */
   restoreNextTab: function ssi_restoreNextTab() {
     // If we call in here while quitting, we don't actually want to do anything
-    if (this._loadState == STATE_QUITTING)
+    if (RunState.isQuitting)
       return;
 
     // Don't exceed the maximum number of concurrent tab restores.

browser/components/sessionstore/moz.build

@@ -31,6 +31,7 @@ EXTRA_JS_MODULES.sessionstore = [
     'PrivacyFilter.jsm',
     'PrivacyLevel.jsm',
     'RecentlyClosedTabsAndWindowsMenuUtils.jsm',
+    'RunState.jsm',
     'SessionCookies.jsm',
     'SessionFile.jsm',
     'SessionHistory.jsm',