Backed out 2 changesets (bug 532150) for test failure

Backed out changeset 57bbbda0dedd (bug 532150)
Backed out changeset 5cab33f5bfbd (bug 532150)

browser/components/sessionstore/nsISessionStartup.idl

@@ -10,15 +10,9 @@
  * - and allows to restore everything into one window.
  */
 
-[scriptable, uuid(35235b39-7098-4b3b-8e28-cd004a88b06f)]
+[scriptable, uuid(170c6857-7f71-46ce-bc9b-185723b1c3a8)]
 interface nsISessionStartup: nsISupports
 {
-  /**
-   * Return a promise that is resolved once initialization
-   * is complete.
-   */
-  readonly attribute jsval onceInitialized;
-
   // Get session state
   readonly attribute jsval state;
 

browser/components/sessionstore/src/Makefile.in

@@ -12,8 +12,8 @@ include $(topsrcdir)/config/config.mk
 
 EXTRA_COMPONENTS = \
   nsSessionStore.manifest \
-  nsSessionStore.js \
+	nsSessionStore.js \
-  nsSessionStartup.js \
+	nsSessionStartup.js \
   $(NULL)
 
 JS_MODULES_PATH := $(FINAL_TARGET)/modules/sessionstore
@@ -22,7 +22,6 @@ EXTRA_JS_MODULES := \
   DocumentUtils.jsm \
   SessionStorage.jsm \
   XPathGenerator.jsm \
-  _SessionFile.jsm \
   $(NULL)
 
 EXTRA_PP_JS_MODULES := \

browser/components/sessionstore/src/SessionStore.jsm

@@ -75,18 +75,14 @@ const TAB_EVENTS = [
 #define BROKEN_WM_Z_ORDER
 #endif
 
-Cu.import("resource://gre/modules/Services.jsm", this);
+Cu.import("resource://gre/modules/Services.jsm");
-Cu.import("resource://gre/modules/XPCOMUtils.jsm", this);
+Cu.import("resource://gre/modules/XPCOMUtils.jsm");
 // debug.js adds NS_ASSERT. cf. bug 669196
-Cu.import("resource://gre/modules/debug.js", this);
+Cu.import("resource://gre/modules/debug.js");
-Cu.import("resource:///modules/TelemetryTimestamps.jsm", this);
+Cu.import("resource:///modules/TelemetryTimestamps.jsm");
-Cu.import("resource://gre/modules/TelemetryStopwatch.jsm", this);
+Cu.import("resource://gre/modules/TelemetryStopwatch.jsm");
-Cu.import("resource://gre/modules/osfile.jsm", this);
+Cu.import("resource://gre/modules/osfile.jsm");
-Cu.import("resource://gre/modules/PrivateBrowsingUtils.jsm", this);
+Cu.import("resource://gre/modules/PrivateBrowsingUtils.jsm");
-Cu.import("resource://gre/modules/commonjs/promise/core.js", this);
-
-XPCOMUtils.defineLazyServiceGetter(this, "gSessionStartup",
-  "@mozilla.org/browser/sessionstartup;1", "nsISessionStartup");
 
 XPCOMUtils.defineLazyModuleGetter(this, "NetUtil",
   "resource://gre/modules/NetUtil.jsm");
@@ -96,8 +92,6 @@ XPCOMUtils.defineLazyModuleGetter(this, "DocumentUtils",
   "resource:///modules/sessionstore/DocumentUtils.jsm");
 XPCOMUtils.defineLazyModuleGetter(this, "SessionStorage",
   "resource:///modules/sessionstore/SessionStorage.jsm");
-XPCOMUtils.defineLazyModuleGetter(this, "_SessionFile",
-  "resource:///modules/sessionstore/_SessionFile.jsm");
 
 #ifdef MOZ_CRASHREPORTER
 XPCOMUtils.defineLazyServiceGetter(this, "CrashReporter",
@@ -296,11 +290,8 @@ let SessionStoreInternal = {
   // session
   _lastSessionState: null,
 
-  // A promise resolved once initialization is complete
+  // Whether we've been initialized
-  _promiseInitialization: Promise.defer(),
+  _initialized: false,
-
-  // Whether session has been initialized
-  _sessionInitialized: false,
 
   // The original "sessionstore.resume_session_once" preference value before it
   // was modified by saveState.  saveState will set the
@@ -335,9 +326,6 @@ let SessionStoreInternal = {
    * Initialize the component
    */
   initService: function ssi_initService() {
-    if (this._sessionInitialized) {
-      return;
-    }
     TelemetryTimestamps.add("sessionRestoreInitialized");
     OBSERVING.forEach(function(aTopic) {
       Services.obs.addObserver(this, aTopic, true);
@@ -370,13 +358,15 @@ let SessionStoreInternal = {
       this._prefBranch.getBoolPref("sessionstore.restore_pinned_tabs_on_demand");
     this._prefBranch.addObserver("sessionstore.restore_pinned_tabs_on_demand", this, true);
 
-    gSessionStartup.onceInitialized.then(
+    // get file references
-      this.initSession.bind(this)
+    this._sessionFile = Services.dirsvc.get("ProfD", Ci.nsILocalFile);
-    );
+    this._sessionFileBackup = this._sessionFile.clone();
-  },
+    this._sessionFile.append("sessionstore.js");
+    this._sessionFileBackup.append("sessionstore.bak");
 
-  initSession: function ssi_initSession() {
+    // get string containing session state
-    let ss = gSessionStartup;
+    var ss = Cc["@mozilla.org/browser/sessionstartup;1"].
+             getService(Ci.nsISessionStartup);
     try {
       if (ss.doRestore() ||
           ss.sessionType == Ci.nsISessionStartup.DEFER_SESSION)
@@ -447,11 +437,14 @@ let SessionStoreInternal = {
     }
 
     if (this._resume_from_crash) {
-      // Launch background copy of the session file. Note that we do
+      // create a backup if the session data file exists
-      // not have race conditions here as _SessionFile guarantees
+      try {
-      // that any I/O operation is completed before proceeding to
+        if (this._sessionFileBackup.exists())
-      // the next I/O operation.
+          this._sessionFileBackup.remove(false);
-      _SessionFile.createBackupCopy();
+        if (this._sessionFile.exists())
+          this._sessionFile.copyTo(null, this._sessionFileBackup.leafName);
+      }
+      catch (ex) { Cu.reportError(ex); } // file was write-locked?
     }
 
     // at this point, we've as good as resumed the session, so we can
@@ -462,9 +455,7 @@ let SessionStoreInternal = {
 
     this._initEncoding();
 
-    // Session is ready.
+    this._initialized = true;
-    this._sessionInitialized = true;
-    this._promiseInitialization.resolve();
   },
 
   _initEncoding : function ssi_initEncoding() {
@@ -504,7 +495,16 @@ let SessionStoreInternal = {
     });
   },
 
-  _initWindow: function ssi_initWindow(aWindow) {
+  /**
+   * Start tracking a window.
+   * This function also initializes the component if it's not already
+   * initialized.
+   */
+  init: function ssi_init(aWindow) {
+    // Initialize the service if needed.
+    if (!this._initialized)
+      this.initService();
+
     if (!aWindow || this._loadState == STATE_RUNNING) {
       // make sure that all browser windows which try to initialize
       // SessionStore are really tracked by it
@@ -524,30 +524,13 @@ let SessionStoreInternal = {
     this.onLoad(aWindow);
   },
 
-  /**
-   * Start tracking a window.
-   *
-   * This function also initializes the component if it is not
-   * initialized yet.
-   */
-  init: function ssi_init(aWindow) {
-    let self = this;
-    this.initService();
-    this._promiseInitialization.promise.then(
-      function onSuccess() {
-        self._initWindow(aWindow);
-      }
-    );
-  },
-
   /**
    * Called on application shutdown, after notifications:
    * quit-application-granted, quit-application
    */
   _uninit: function ssi_uninit() {
     // save all data for session resuming
-    if (this._sessionInitialized)
+    this.saveState(true);
-      this.saveState(true);
 
     // clear out _tabsToRestore in case it's still holding refs
     this._tabsToRestore.priority = null;
@@ -1015,7 +998,7 @@ let SessionStoreInternal = {
    */
   onPurgeSessionHistory: function ssi_onPurgeSessionHistory() {
     var _this = this;
-    _SessionFile.wipe();
+    this._clearDisk();
     // 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.
@@ -1156,7 +1139,7 @@ let SessionStoreInternal = {
         // either create the file with crash recovery information or remove it
         // (when _loadState is not STATE_RUNNING, that file is used for session resuming instead)
         if (!this._resume_from_crash)
-          _SessionFile.wipe();
+          this._clearDisk();
         this.saveState(true);
         break;
       case "sessionstore.restore_on_demand":
@@ -3784,37 +3767,40 @@ let SessionStoreInternal = {
    */
   _saveStateObject: function ssi_saveStateObject(aStateObj) {
     TelemetryStopwatch.start("FX_SESSION_RESTORE_SERIALIZE_DATA_MS");
-    let data = this._toJSONString(aStateObj);
+    var stateString = Cc["@mozilla.org/supports-string;1"].
+                        createInstance(Ci.nsISupportsString);
+    stateString.data = this._toJSONString(aStateObj);
     TelemetryStopwatch.finish("FX_SESSION_RESTORE_SERIALIZE_DATA_MS");
 
-    let stateString = this._createSupportsString(data);
     Services.obs.notifyObservers(stateString, "sessionstore-state-write", "");
-    data = stateString.data;
 
-    // Don't touch the file if an observer has deleted all state data.
+    // don't touch the file if an observer has deleted all state data
-    if (!data) {
+    if (stateString.data)
-      return;
+      this._writeFile(this._sessionFile, stateString.data);
-    }
 
-    let self = this;
+    this._lastSaveTime = Date.now();
-    _SessionFile.write(data).then(
+  },
-      function onSuccess() {
+
-        self._lastSaveTime = Date.now();
+  /**
-        Services.obs.notifyObservers(null, "sessionstore-state-write-complete", "");
+   * delete session datafile and backup
+   */
+  _clearDisk: function ssi_clearDisk() {
+    if (this._sessionFile.exists()) {
+      try {
+        this._sessionFile.remove(false);
       }
-    );
+      catch (ex) { dump(ex + '\n'); } // couldn't remove the file - what now?
+    }
+    if (this._sessionFileBackup.exists()) {
+      try {
+        this._sessionFileBackup.remove(false);
+      }
+      catch (ex) { dump(ex + '\n'); } // couldn't remove the file - what now?
+    }
   },
 
   /* ........ Auxiliary Functions .............. */
 
-  // Wrap a string as a nsISupports
-  _createSupportsString: function ssi_createSupportsString(aData) {
-    let string = Cc["@mozilla.org/supports-string;1"]
-                   .createInstance(Ci.nsISupportsString);
-    string.data = aData;
-    return string;
-  },
-
   /**
    * call a callback for all currently opened browser windows
    * (might miss the most recent one)
@@ -4508,6 +4494,33 @@ let SessionStoreInternal = {
                             removeSHistoryListener(browser.__SS_shistoryListener);
       delete browser.__SS_shistoryListener;
     }
+  },
+
+  /**
+   * write file to disk
+   * @param aFile
+   *        nsIFile
+   * @param aData
+   *        String data
+   */
+  _writeFile: function ssi_writeFile(aFile, aData) {
+    let refObj = {};
+    TelemetryStopwatch.start("FX_SESSION_RESTORE_WRITE_FILE_MS", refObj);
+    let path = aFile.path;
+    let encoded = this._writeFileEncoder.encode(aData);
+    let promise = OS.File.writeAtomic(path, encoded, {tmpPath: path + ".tmp"});
+
+    promise.then(
+      function onSuccess() {
+        TelemetryStopwatch.finish("FX_SESSION_RESTORE_WRITE_FILE_MS", refObj);
+        Services.obs.notifyObservers(null,
+                                      "sessionstore-state-write-complete",
+                                      "");
+      },
+      function onFailure(reason) {
+        TelemetryStopwatch.cancel("FX_SESSION_RESTORE_WRITE_FILE_MS", refObj);
+        Components.reportError("ssi_writeFile failure " + reason);
+      });
   }
 };
 

browser/components/sessionstore/src/_SessionFile.jsm

@@ -1,255 +0,0 @@
-/* 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 = ["_SessionFile"];
-
-/**
- * Implementation of all the disk I/O required by the session store.
- * This is a private API, meant to be used only by the session store.
- * It will change. Do not use it for any other purpose.
- *
- * Note that this module implicitly depends on one of two things:
- * 1. either the asynchronous file I/O system enqueues its requests
- *   and never attempts to simultaneously execute two I/O requests on
- *   the files used by this module from two distinct threads; or
- * 2. the clients of this API are well-behaved and do not place
- *   concurrent requests to the files used by this module.
- *
- * Otherwise, we could encounter bugs, especially under Windows,
- *   e.g. if a request attempts to write sessionstore.js while
- *   another attempts to copy that file.
- *
- * This implementation uses OS.File, which guarantees property 1.
- */
-
-const Cu = Components.utils;
-const Cc = Components.classes;
-const Ci = Components.interfaces;
-
-Cu.import("resource://gre/modules/Services.jsm");
-Cu.import("resource://gre/modules/XPCOMUtils.jsm");
-Cu.import("resource://gre/modules/osfile.jsm");
-Cu.import("resource://gre/modules/commonjs/promise/core.js");
-
-XPCOMUtils.defineLazyModuleGetter(this, "TelemetryStopwatch",
-  "resource://gre/modules/TelemetryStopwatch.jsm");
-XPCOMUtils.defineLazyModuleGetter(this, "NetUtil",
-  "resource://gre/modules/NetUtil.jsm");
-XPCOMUtils.defineLazyModuleGetter(this, "FileUtils",
-  "resource://gre/modules/FileUtils.jsm");
-XPCOMUtils.defineLazyModuleGetter(this, "Task",
-  "resource://gre/modules/Task.jsm");
-
-// An encoder to UTF-8.
-XPCOMUtils.defineLazyGetter(this, "gEncoder", function () {
-  return new TextEncoder();
-});
-
-this._SessionFile = {
-  /**
-   * A promise fulfilled once initialization (either synchronous or
-   * asynchronous) is complete.
-   */
-  promiseInitialized: function SessionFile_initialized() {
-    return SessionFileInternal.promiseInitialized;
-  },
-  /**
-   * Read the contents of the session file, asynchronously.
-   */
-  read: function SessionFile_read() {
-    return SessionFileInternal.read();
-  },
-  /**
-   * Read the contents of the session file, synchronously.
-   */
-  syncRead: function SessionFile_syncRead() {
-    return SessionFileInternal.syncRead();
-  },
-  /**
-   * Write the contents of the session file, asynchronously.
-   */
-  write: function SessionFile_write(aData) {
-    return SessionFileInternal.write(aData);
-  },
-  /**
-   * Create a backup copy, asynchronously.
-   */
-  createBackupCopy: function SessionFile_createBackupCopy() {
-    return SessionFileInternal.createBackupCopy();
-  },
-  /**
-   * Wipe the contents of the session file, asynchronously.
-   */
-  wipe: function SessionFile_wipe() {
-    return SessionFileInternal.wipe();
-  }
-};
-
-Object.freeze(_SessionFile);
-
-/**
- * Utilities for dealing with promises and Task.jsm
- */
-const TaskUtils = {
-  /**
-   * Add logging to a promise.
-   *
-   * @param {Promise} promise
-   * @return {Promise} A promise behaving as |promise|, but with additional
-   * logging in case of uncaught error.
-   */
-  captureErrors: function captureErrors(promise) {
-    return promise.then(
-      null,
-      function onError(reason) {
-        Cu.reportError("Uncaught asynchronous error: " + reason + " at\n" + reason.stack);
-        throw reason;
-      }
-    );
-  },
-  /**
-   * Spawn a new Task from a generator.
-   *
-   * This function behaves as |Task.spawn|, with the exception that it
-   * adds logging in case of uncaught error. For more information, see
-   * the documentation of |Task.jsm|.
-   *
-   * @param {generator} gen Some generator.
-   * @return {Promise} A promise built from |gen|, with the same semantics
-   * as |Task.spawn(gen)|.
-   */
-  spawn: function spawn(gen) {
-    return this.captureErrors(Task.spawn(gen));
-  }
-};
-
-let SessionFileInternal = {
-  /**
-   * A promise fulfilled once initialization is complete
-   */
-  promiseInitialized: Promise.defer(),
-
-  /**
-   * The path to sessionstore.js
-   */
-  path: OS.Path.join(OS.Constants.Path.profileDir, "sessionstore.js"),
-
-  /**
-   * The path to sessionstore.bak
-   */
-  backupPath: OS.Path.join(OS.Constants.Path.profileDir, "sessionstore.bak"),
-
-  /**
-   * Read the sessionstore file synchronously.
-   *
-   * This function is meant to serve as a fallback in case of race
-   * between a synchronous usage of the API and asynchronous
-   * initialization.
-   */
-  syncRead: function ssfi_syncRead() {
-    let text;
-    let exn;
-    TelemetryStopwatch.start("FX_SESSION_RESTORE_SYNC_READ_FILE_MS");
-    try {
-      let file = new FileUtils.File(this.path);
-      if (!file.exists()) {
-        return null;
-      }
-      let chan = NetUtil.newChannel(file);
-      let stream = chan.open();
-      text = NetUtil.readInputStreamToString(stream, stream.available(), {charset: "utf-8"});
-    } catch(ex) {
-      exn = ex;
-    } finally {
-      TelemetryStopwatch.finish("FX_SESSION_RESTORE_SYNC_READ_FILE_MS");
-    }
-    if (exn) {
-      Cu.reportError(exn);
-      return "";
-    }
-    return text;
-  },
-
-  read: function ssfi_read() {
-    let refObj = {};
-    let self = this;
-    return TaskUtils.spawn(function task() {
-      TelemetryStopwatch.start("FX_SESSION_RESTORE_READ_FILE_MS", refObj);
-      let text;
-      try {
-        let bytes = yield OS.File.read(self.path);
-        text = new TextDecoder().decode(bytes);
-        TelemetryStopwatch.finish("FX_SESSION_RESTORE_READ_FILE_MS", refObj);
-      } catch (ex) {
-        if (self._isNoSuchFile(ex)) {
-          // The file does not exist, this is perfectly valid
-          TelemetryStopwatch.finish("FX_SESSION_RESTORE_READ_FILE_MS", refObj);
-        } else {
-          // Any other error: let's not measure with telemetry
-          TelemetryStopwatch.cancel("FX_SESSION_RESTORE_READ_FILE_MS", refObj);
-          Cu.reportError(ex);
-        }
-        text = "";
-      }
-      throw new Task.Result(text);
-    });
-  },
-
-  write: function ssfi_write(aData) {
-    let refObj = {};
-    let self = this;
-    return TaskUtils.spawn(function task() {
-      TelemetryStopwatch.start("FX_SESSION_RESTORE_WRITE_FILE_MS", refObj);
-
-      let bytes = gEncoder.encode(aData);
-
-      try {
-        yield OS.File.writeAtomic(self.path, bytes, {tmpPath: self.path + ".tmp"});
-        TelemetryStopwatch.finish("FX_SESSION_RESTORE_WRITE_FILE_MS", refObj);
-      } catch (ex) {
-        TelemetryStopwatch.cancel("FX_SESSION_RESTORE_WRITE_FILE_MS", refObj);
-        Cu.reportError("Could not write session state file " + self.path
-                       + ": " + aReason);
-      }
-    });
-  },
-
-  createBackupCopy: function ssfi_createBackupCopy() {
-    let self = this;
-    return TaskUtils.spawn(function task() {
-      try {
-        yield OS.File.copy(self.path, self.backupPath);
-      } catch (ex) {
-        if (!self._isNoSuchFile(ex)) {
-          Cu.reportError("Could not backup session state file: " + ex);
-          throw ex;
-        }
-      }
-    });
-  },
-
-  wipe: function ssfi_wipe() {
-    let self = this;
-    return TaskUtils.spawn(function task() {
-      try {
-        yield OS.File.remove(self.path);
-      } catch (ex) {
-        Cu.reportError("Could not remove session state file: " + ex);
-        throw ex;
-      }
-      try {
-        yield OS.File.remove(self.backupPath);
-      } catch (ex) {
-        Cu.reportError("Could not remove session state backup file: " + ex);
-        throw ex;
-      }
-    });
-  },
-
-  _isNoSuchFile: function ssfi_isNoSuchFile(aReason) {
-    return aReason instanceof OS.File.Error && aReason.becauseNoSuchFile;
-  }
-};

browser/components/sessionstore/src/nsSessionStartup.js

@@ -39,20 +39,15 @@ Cu.import("resource://gre/modules/XPCOMUtils.jsm");
 Cu.import("resource://gre/modules/Services.jsm");
 Cu.import("resource://gre/modules/TelemetryStopwatch.jsm");
 Cu.import("resource://gre/modules/PrivateBrowsingUtils.jsm");
-Cu.import("resource://gre/modules/commonjs/promise/core.js");
-
-XPCOMUtils.defineLazyModuleGetter(this, "_SessionFile",
-  "resource:///modules/sessionstore/_SessionFile.jsm");
 
 const STATE_RUNNING_STR = "running";
+const MAX_FILE_SIZE = 100 * 1024 * 1024; // 100 megabytes
 
 function debug(aMsg) {
   aMsg = ("SessionStartup: " + aMsg).replace(/\S{80}/g, "$&\n");
   Services.console.logStringMessage(aMsg);
 }
 
-let gOnceInitializedDeferred = Promise.defer();
-
 /* :::::::: The Service ::::::::::::::: */
 
 function SessionStartup() {
@@ -63,7 +58,6 @@ SessionStartup.prototype = {
   // the state to restore at startup
   _initialState: null,
   _sessionType: Ci.nsISessionStartup.NO_SESSION,
-  _initialized: false,
 
 /* ........ Global Event Handlers .............. */
 
@@ -71,121 +65,95 @@ SessionStartup.prototype = {
    * Initialize the component
    */
   init: function sss_init() {
-    debug("init starting");
     // do not need to initialize anything in auto-started private browsing sessions
     let pbs = Cc["@mozilla.org/privatebrowsing;1"].
               getService(Ci.nsIPrivateBrowsingService);
     if (PrivateBrowsingUtils.permanentPrivateBrowsing ||
         pbs.lastChangedByCommandLine)
       return;
-    // Session state is unknown until we read the file.
-    this._sessionType = null;
-    _SessionFile.read().then(
-      this._onSessionFileRead.bind(this)
-    );
-    debug("init launched");
-  },
 
-  // Wrap a string as a nsISupports
+    let prefBranch = Cc["@mozilla.org/preferences-service;1"].
-  _createSupportsString: function ssfi_createSupportsString(aData) {
+                     getService(Ci.nsIPrefService).getBranch("browser.");
-    let string = Cc["@mozilla.org/supports-string;1"]
-                   .createInstance(Ci.nsISupportsString);
-    string.data = aData;
-    return string;
-  },
 
-  _onSessionFileRead: function sss_onSessionFileRead(aStateString) {
+    // get file references
-    debug("onSessionFileRead ");
+    var dirService = Cc["@mozilla.org/file/directory_service;1"].
-    if (this._initialized) {
+                     getService(Ci.nsIProperties);
-      debug("onSessionFileRead: Initialization is already complete");
+    let sessionFile = dirService.get("ProfD", Ci.nsILocalFile);
-      // Initialization is complete, nothing else to do
+    sessionFile.append("sessionstore.js");
+
+    let doResumeSessionOnce = prefBranch.getBoolPref("sessionstore.resume_session_once");
+    let doResumeSession = doResumeSessionOnce ||
+                          prefBranch.getIntPref("startup.page") == 3;
+
+    // only continue if the session file exists
+    if (!sessionFile.exists())
       return;
-    }
+
+    // get string containing session state
+    let iniString = this._readStateFile(sessionFile);
+    if (!iniString)
+      return;
+
+    // parse the session state into a JS object
+    // remove unneeded braces (added for compatibility with Firefox 2.0 and 3.0)
+    if (iniString.charAt(0) == '(')
+      iniString = iniString.slice(1, -1);
+    let corruptFile = false;
     try {
-      this._initialized = true;
+      this._initialState = JSON.parse(iniString);
-
-      // Let observers modify the state before it is used
-      let supportsStateString = this._createSupportsString(aStateString);
-      Services.obs.notifyObservers(supportsStateString, "sessionstore-state-read", "");
-      aStateString = supportsStateString.data;
-
-      // No valid session found.
-      if (!aStateString) {
-        this._sessionType = Ci.nsISessionStartup.NO_SESSION;
-        return;
-      }
-
-      // parse the session state into a JS object
-      // remove unneeded braces (added for compatibility with Firefox 2.0 and 3.0)
-      if (aStateString.charAt(0) == '(')
-        aStateString = aStateString.slice(1, -1);
-      let corruptFile = false;
-      try {
-        this._initialState = JSON.parse(aStateString);
-      }
-      catch (ex) {
-        debug("The session file contained un-parse-able JSON: " + ex);
-        // This is not valid JSON, but this might still be valid JavaScript,
-        // as used in FF2/FF3, so we need to eval.
-        // evalInSandbox will throw if aStateString is not parse-able.
-        try {
-          var s = new Cu.Sandbox("about:blank", {sandboxName: 'nsSessionStartup'});
-          this._initialState = Cu.evalInSandbox("(" + aStateString + ")", s);
-        } catch(ex) {
-          debug("The session file contained un-eval-able JSON: " + ex);
-          corruptFile = true;
-        }
-      }
-      Services.telemetry.getHistogramById("FX_SESSION_RESTORE_CORRUPT_FILE").add(corruptFile);
-
-      let doResumeSessionOnce = Services.prefs.getBoolPref("browser.sessionstore.resume_session_once");
-      let doResumeSession = doResumeSessionOnce ||
-            Services.prefs.getIntPref("browser.startup.page") == 3;
-
-      // If this is a normal restore then throw away any previous session
-      if (!doResumeSessionOnce)
-        delete this._initialState.lastSessionState;
-
-      let resumeFromCrash = Services.prefs.getBoolPref("browser.sessionstore.resume_from_crash");
-      let lastSessionCrashed =
-        this._initialState && this._initialState.session &&
-        this._initialState.session.state &&
-        this._initialState.session.state == STATE_RUNNING_STR;
-
-      // Report shutdown success via telemetry. Shortcoming here are
-      // being-killed-by-OS-shutdown-logic, shutdown freezing after
-      // session restore was written, etc.
-      Services.telemetry.getHistogramById("SHUTDOWN_OK").add(!lastSessionCrashed);
-
-      // set the startup type
-      if (lastSessionCrashed && resumeFromCrash)
-        this._sessionType = Ci.nsISessionStartup.RECOVER_SESSION;
-      else if (!lastSessionCrashed && doResumeSession)
-        this._sessionType = Ci.nsISessionStartup.RESUME_SESSION;
-      else if (this._initialState)
-        this._sessionType = Ci.nsISessionStartup.DEFER_SESSION;
-      else
-        this._initialState = null; // reset the state
-
-      // wait for the first browser window to open
-      // Don't reset the initial window's default args (i.e. the home page(s))
-      // if all stored tabs are pinned.
-      if (this.doRestore() &&
-          (!this._initialState.windows ||
-           !this._initialState.windows.every(function (win)
-             win.tabs.every(function (tab) tab.pinned))))
-        Services.obs.addObserver(this, "domwindowopened", true);
-
-      Services.obs.addObserver(this, "sessionstore-windows-restored", true);
-
-      if (this._sessionType != Ci.nsISessionStartup.NO_SESSION)
-        Services.obs.addObserver(this, "browser:purge-session-history", true);
-
-    } finally {
-      // We're ready. Notify everyone else.
-      Services.obs.notifyObservers(null, "sessionstore-state-finalized", "");
-      gOnceInitializedDeferred.resolve();
     }
+    catch (ex) {
+      debug("The session file contained un-parse-able JSON: " + ex);
+      // Try to eval.
+      // evalInSandbox will throw if iniString is not parse-able.
+      try {
+        var s = new Cu.Sandbox("about:blank", {sandboxName: 'nsSessionStartup'});
+        this._initialState = Cu.evalInSandbox("(" + iniString + ")", s);
+      } catch(ex) {
+        debug("The session file contained un-eval-able JSON: " + ex);
+        corruptFile = true;
+      }
+    }
+    Services.telemetry.getHistogramById("FX_SESSION_RESTORE_CORRUPT_FILE").add(corruptFile);
+
+    // If this is a normal restore then throw away any previous session
+    if (!doResumeSessionOnce)
+      delete this._initialState.lastSessionState;
+
+    let resumeFromCrash = prefBranch.getBoolPref("sessionstore.resume_from_crash");
+    let lastSessionCrashed =
+      this._initialState && this._initialState.session &&
+      this._initialState.session.state &&
+      this._initialState.session.state == STATE_RUNNING_STR;
+
+    // Report shutdown success via telemetry. Shortcoming here are
+    // being-killed-by-OS-shutdown-logic, shutdown freezing after
+    // session restore was written, etc.
+    Services.telemetry.getHistogramById("SHUTDOWN_OK").add(!lastSessionCrashed);
+
+    // set the startup type
+    if (lastSessionCrashed && resumeFromCrash)
+      this._sessionType = Ci.nsISessionStartup.RECOVER_SESSION;
+    else if (!lastSessionCrashed && doResumeSession)
+      this._sessionType = Ci.nsISessionStartup.RESUME_SESSION;
+    else if (this._initialState)
+      this._sessionType = Ci.nsISessionStartup.DEFER_SESSION;
+    else
+      this._initialState = null; // reset the state
+
+    // wait for the first browser window to open
+    // Don't reset the initial window's default args (i.e. the home page(s))
+    // if all stored tabs are pinned.
+    if (this.doRestore() &&
+        (!this._initialState.windows ||
+        !this._initialState.windows.every(function (win)
+           win.tabs.every(function (tab) tab.pinned))))
+      Services.obs.addObserver(this, "domwindowopened", true);
+
+    Services.obs.addObserver(this, "sessionstore-windows-restored", true);
+
+    if (this._sessionType != Ci.nsISessionStartup.NO_SESSION)
+      Services.obs.addObserver(this, "browser:purge-session-history", true);
   },
 
   /**
@@ -269,15 +237,10 @@ SessionStartup.prototype = {
 
 /* ........ Public API ................*/
 
-  get onceInitialized() {
-    return gOnceInitializedDeferred.promise;
-  },
-
   /**
    * Get the session state as a jsval
    */
   get state() {
-    this._ensureInitialized();
     return this._initialState;
   },
 
@@ -286,7 +249,6 @@ SessionStartup.prototype = {
    * @returns bool
    */
   doRestore: function sss_doRestore() {
-    this._ensureInitialized();
     return this._sessionType == Ci.nsISessionStartup.RECOVER_SESSION ||
            this._sessionType == Ci.nsISessionStartup.RESUME_SESSION;
   },
@@ -295,26 +257,59 @@ SessionStartup.prototype = {
    * Get the type of pending session store, if any.
    */
   get sessionType() {
-    this._ensureInitialized();
     return this._sessionType;
   },
 
-  // Ensure that initialization is complete.
+/* ........ Storage API .............. */
-  // If initialization is not complete yet, fall back to a synchronous
+
-  // initialization and kill ongoing asynchronous initialization
+  /**
-  _ensureInitialized: function sss__ensureInitialized() {
+   * Reads a session state file into a string and lets
+   * observers modify the state before it's being used
+   *
+   * @param aFile is any nsIFile
+   * @returns a session state string
+   */
+  _readStateFile: function sss_readStateFile(aFile) {
+    TelemetryStopwatch.start("FX_SESSION_RESTORE_READ_FILE_MS");
+    var stateString = Cc["@mozilla.org/supports-string;1"].
+                        createInstance(Ci.nsISupportsString);
+    stateString.data = this._readFile(aFile) || "";
+    TelemetryStopwatch.finish("FX_SESSION_RESTORE_READ_FILE_MS");
+
+    Services.obs.notifyObservers(stateString, "sessionstore-state-read", "");
+
+    return stateString.data;
+  },
+
+  /**
+   * reads a file into a string
+   * @param aFile
+   *        nsIFile
+   * @returns string
+   */
+  _readFile: function sss_readFile(aFile) {
     try {
-      debug("_ensureInitialized: " + this._initialState);
+      var stream = Cc["@mozilla.org/network/file-input-stream;1"].
-      if (this._initialized) {
+                   createInstance(Ci.nsIFileInputStream);
-        // Initialization is complete, nothing else to do
+      stream.init(aFile, 0x01, 0, 0);
-        return;
+      var cvstream = Cc["@mozilla.org/intl/converter-input-stream;1"].
-      }
+                     createInstance(Ci.nsIConverterInputStream);
-      let contents = _SessionFile.syncRead();
+
-      this._onSessionFileRead(contents);
+      var fileSize = stream.available();
-    } catch(ex) {
+      if (fileSize > MAX_FILE_SIZE)
-      debug("ensureInitialized: could not read session " + ex + ", " + ex.stack);
+        throw "SessionStartup: sessionstore.js was not processed because it was too large.";
-      throw ex;
+
+      cvstream.init(stream, "UTF-8", fileSize, Ci.nsIConverterInputStream.DEFAULT_REPLACEMENT_CHARACTER);
+      var data = {};
+      cvstream.readString(fileSize, data);
+      var content = data.value;
+      cvstream.close();
+
+      return content.replace(/\r\n?/g, "\n");
     }
+    catch (ex) { Cu.reportError(ex); }
+
+    return null;
   },
 
   /* ........ QueryInterface .............. */

browser/components/sessionstore/test/Makefile.in

@@ -16,10 +16,6 @@ include $(DEPTH)/config/autoconf.mk
 # browser_580512.js is disabled for leaking browser windows (bug 752467)
 # browser_586068-reload.js is disabled due to generally being broken (bug 809123, 797263)
 
-XPCSHELL_TESTS = \
-	unit \
-	$(NULL)
-
 MOCHITEST_BROWSER_FILES = \
 	head.js \
 	browser_form_restore_events.js \

browser/components/sessionstore/test/unit/data/sessionstore_valid.js

@@ -1,3 +0,0 @@
-{
-  "windows": []
-}

browser/components/sessionstore/test/unit/head.js

@@ -1,26 +0,0 @@
-let Cu = Components.utils;
-let Cc = Components.classes;
-let Ci = Components.interfaces;
-
-Components.utils.import("resource://gre/modules/Services.jsm");
-
-// Call a function once initialization of SessionStartup is complete
-let afterSessionStartupInitialization =
-  function afterSessionStartupInitialization(cb) {
-    do_print("Waiting for session startup initialization");
-    let observer = function() {
-      try {
-        do_print("Session startup initialization observed");
-        Services.obs.removeObserver(observer, "sessionstore-state-finalized");
-        cb();
-      } catch (ex) {
-        do_throw(ex);
-      }
-    };
-    let startup = Cc["@mozilla.org/browser/sessionstartup;1"].
-      getService(Ci.nsIObserver);
-    Services.obs.addObserver(startup, "final-ui-startup", false);
-    Services.obs.addObserver(startup, "quit-application", false);
-    Services.obs.notifyObservers(null, "final-ui-startup", "");
-    Services.obs.addObserver(observer, "sessionstore-state-finalized", false);
-};

browser/components/sessionstore/test/unit/test_startup_nosession_async.js

@@ -1,19 +0,0 @@
-/* Any copyright is dedicated to the Public Domain.
-   http://creativecommons.org/publicdomain/zero/1.0/ */
-
-
-// Test nsISessionStartup.sessionType in the following scenario:
-// - no sessionstore.js;
-// - the session store has been loaded, so no need to go
-//    through the synchronous fallback
-
-function run_test() {
-  do_test_pending();
-  let startup = Cc["@mozilla.org/browser/sessionstartup;1"].
-    getService(Ci.nsISessionStartup);
-
-  afterSessionStartupInitialization(function cb() {
-    do_check_eq(startup.sessionType, Ci.nsISessionStartup.NO_SESSION);
-    do_test_finished();
-  });
-}

browser/components/sessionstore/test/unit/test_startup_nosession_sync.js

@@ -1,15 +0,0 @@
-/* Any copyright is dedicated to the Public Domain.
-   http://creativecommons.org/publicdomain/zero/1.0/ */
-
-
-// Test nsISessionStartup.sessionType in the following scenario:
-// - no sessionstore.js;
-// - the session store has not been loaded yet, so we have to trigger
-//    synchronous fallback
-
-function run_test() {
-  do_get_profile();
-  let startup = Cc["@mozilla.org/browser/sessionstartup;1"].
-    getService(Ci.nsISessionStartup);
-  do_check_eq(startup.sessionType, Ci.nsISessionStartup.NO_SESSION);
-}

browser/components/sessionstore/test/unit/test_startup_session_async.js

@@ -1,23 +0,0 @@
-/* Any copyright is dedicated to the Public Domain.
-   http://creativecommons.org/publicdomain/zero/1.0/ */
-
-
-// Test nsISessionStartup.sessionType in the following scenario:
-// - valid sessionstore.js;
-// - the session store has been loaded, so no need to go
-//    through the synchronous fallback
-
-function run_test() {
-  let profd = do_get_profile();
-  let source = do_get_file("data/sessionstore_valid.js");
-  source.copyTo(profd, "sessionstore.js");
-
-  do_test_pending();
-  let startup = Cc["@mozilla.org/browser/sessionstartup;1"].
-    getService(Ci.nsISessionStartup);
-
-  afterSessionStartupInitialization(function cb() {
-    do_check_eq(startup.sessionType, Ci.nsISessionStartup.DEFER_SESSION);
-    do_test_finished();
-  });
-}

browser/components/sessionstore/test/unit/test_startup_session_sync.js

@@ -1,17 +0,0 @@
-/* Any copyright is dedicated to the Public Domain.
-   http://creativecommons.org/publicdomain/zero/1.0/ */
-
-
-// Test nsISessionStartup.sessionType in the following scenario:
-// - valid sessionstore.js;
-// - the session store has not been loaded yet, so we have to trigger
-//    synchronous fallback
-
-function run_test() {
-  let profd = do_get_profile();
-  let source = do_get_file("data/sessionstore_valid.js");
-  source.copyTo(profd, "sessionstore.js");
-  let startup = Cc["@mozilla.org/browser/sessionstartup;1"].
-    getService(Ci.nsISessionStartup);
-  do_check_eq(startup.sessionType, Ci.nsISessionStartup.DEFER_SESSION);
-}

browser/components/sessionstore/test/unit/xpcshell.ini

@@ -1,8 +0,0 @@
-[DEFAULT]
-head = head.js
-tail =
-
-[test_startup_nosession_sync.js]
-[test_startup_nosession_async.js]
-[test_startup_session_sync.js]
-[test_startup_session_async.js]

testing/xpcshell/xpcshell.ini

@@ -97,7 +97,6 @@ skip-if = os == "android"
 [include:browser/components/migration/tests/unit/xpcshell.ini]
 [include:browser/components/places/tests/unit/xpcshell.ini]
 [include:browser/components/privatebrowsing/test/unit/xpcshell.ini]
-[include:browser/components/sessionstore/test/unit/xpcshell.ini]
 [include:browser/components/shell/test/unit/xpcshell.ini]
 [include:browser/devtools/shared/test/unit/xpcshell.ini]
 [include:browser/modules/test/unit/xpcshell.ini]

toolkit/components/telemetry/Histograms.json

@@ -2113,12 +2113,6 @@
     "n_buckets": 10,
     "description": "Session restore: Time to read the session data from the file on disk (ms)"
   },
-  "FX_SESSION_RESTORE_SYNC_READ_FILE_MS": {
-    "kind": "exponential",
-    "high": "3000",
-    "n_buckets": 10,
-    "description": "Session restore: Time to read the session data from the file on disk, using the synchronous fallback (ms)"
-  },
   "FX_SESSION_RESTORE_WRITE_FILE_MS": {
     "kind": "exponential",
     "high": "3000",