Back out 5ebd6549bf93 and 73287cb2dc6a (bug 794091) on suspicion of breaking Win64 PGO builds

browser/components/sessionstore/src/SessionStore.jsm

@@ -79,7 +79,6 @@ Cu.import("resource://gre/modules/XPCOMUtils.jsm");
 Cu.import("resource://gre/modules/debug.js");
 Cu.import("resource:///modules/TelemetryTimestamps.jsm");
 Cu.import("resource://gre/modules/TelemetryStopwatch.jsm");
-Cu.import("resource://gre/modules/osfile.jsm");
 
 XPCOMUtils.defineLazyModuleGetter(this, "NetUtil",
   "resource://gre/modules/NetUtil.jsm");
@@ -442,18 +441,9 @@ let SessionStoreInternal = {
         this._prefBranch.getBoolPref("sessionstore.resume_session_once"))
       this._prefBranch.setBoolPref("sessionstore.resume_session_once", false);
 
-    this._initEncoding();
-
     this._initialized = true;
   },
 
-  _initEncoding : function ssi_initEncoding() {
-    // The (UTF-8) encoder used to write to files.
-    XPCOMUtils.defineLazyGetter(this, "_writeFileEncoder", function () {
-      return new TextEncoder();
-    });
-  },
-
   _initPrefs : function() {
     XPCOMUtils.defineLazyGetter(this, "_prefBranch", function () {
       return Services.prefs.getBranch("browser.");
@@ -4445,21 +4435,27 @@ let SessionStoreInternal = {
   _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"});
+    // Initialize the file output stream.
+    var ostream = Cc["@mozilla.org/network/safe-file-output-stream;1"].
+                  createInstance(Ci.nsIFileOutputStream);
+    ostream.init(aFile, 0x02 | 0x08 | 0x20, 0600, ostream.DEFER_OPEN);
 
-    promise.then(
-      function onSuccess() {
+    // Obtain a converter to convert our data to a UTF-8 encoded input stream.
+    var converter = Cc["@mozilla.org/intl/scriptableunicodeconverter"].
+                    createInstance(Ci.nsIScriptableUnicodeConverter);
+    converter.charset = "UTF-8";
+
+    // Asynchronously copy the data to the file.
+    var istream = converter.convertToInputStream(aData);
+    var self = this;
+    NetUtil.asyncCopy(istream, ostream, function(rc) {
+      if (Components.isSuccessCode(rc)) {
         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);
-      });
+                                     "sessionstore-state-write-complete",
+                                     "");
+      }
+    });
   }
 };
 

toolkit/components/osfile/osfile.jsm

@@ -10,26 +10,9 @@ if (typeof Components != "undefined") {
   this.EXPORTED_SYMBOLS = ["OS"];
   Components.utils.import("resource://gre/modules/osfile/osfile_async_front.jsm", this);
 } else {
-  // At this stage, we need to import all sources at once to avoid
-  // a unique failure on tbpl + talos that seems caused by a
-  // what looks like a nested event loop bug (see bug 794091).
 #ifdef XP_WIN
-  importScripts(
-    "resource://gre/modules/osfile/osfile_shared_allthreads.jsm",
-    "resource://gre/modules/osfile/osfile_win_allthreads.jsm",
-    "resource://gre/modules/osfile/ospath_win_back.jsm",
-    "resource://gre/modules/osfile/osfile_win_back.jsm",
-    "resource://gre/modules/osfile/osfile_shared_front.jsm",
-    "resource://gre/modules/osfile/osfile_win_front.jsm"
-  );
+  importScripts("resource://gre/modules/osfile/osfile_win_front.jsm");
 #else
-  importScripts(
-    "resource://gre/modules/osfile/osfile_shared_allthreads.jsm",
-    "resource://gre/modules/osfile/osfile_unix_allthreads.jsm",
-    "resource://gre/modules/osfile/ospath_unix_back.jsm",
-    "resource://gre/modules/osfile/osfile_unix_back.jsm",
-    "resource://gre/modules/osfile/osfile_shared_front.jsm",
-    "resource://gre/modules/osfile/osfile_unix_front.jsm"
-  );
+  importScripts("resource://gre/modules/osfile/osfile_unix_front.jsm");
 #endif
-}
+}

toolkit/components/osfile/osfile_unix_allthreads.jsm

@@ -22,6 +22,9 @@ if (typeof Components != "undefined") {
   this.EXPORTED_SYMBOLS = ["OS"];
   Components.utils.import("resource://gre/modules/ctypes.jsm");
   Components.utils.import("resource://gre/modules/osfile/osfile_shared_allthreads.jsm", this);
+} else {
+  // File is included from a chrome worker
+  importScripts("resource://gre/modules/osfile/osfile_shared_allthreads.jsm");
 }
 
 (function(exports) {

toolkit/components/osfile/osfile_unix_back.jsm

@@ -11,6 +11,8 @@
 
     throw new Error("osfile_unix_back.jsm cannot be used from the main thread yet");
   }
+  importScripts("resource://gre/modules/osfile/osfile_shared_allthreads.jsm");
+  importScripts("resource://gre/modules/osfile/osfile_unix_allthreads.jsm");
   (function(exports) {
      "use strict";
      if (!exports.OS) {

toolkit/components/osfile/osfile_unix_front.jsm

@@ -16,6 +16,9 @@
 
     throw new Error("osfile_unix_front.jsm cannot be used from the main thread yet");
   }
+  importScripts("resource://gre/modules/osfile/osfile_unix_back.jsm");
+  importScripts("resource://gre/modules/osfile/ospath_unix_back.jsm");
+  importScripts("resource://gre/modules/osfile/osfile_shared_front.jsm");
   (function(exports) {
      "use strict";
 

toolkit/components/osfile/osfile_win_allthreads.jsm

@@ -22,6 +22,9 @@ if (typeof Components != "undefined") {
   this.EXPORTED_SYMBOLS = ["OS"];
   Components.utils.import("resource://gre/modules/ctypes.jsm");
   Components.utils.import("resource://gre/modules/osfile/osfile_shared_allthreads.jsm", this);
+} else {
+  // File is included from a chrome worker
+  importScripts("resource://gre/modules/osfile/osfile_shared_allthreads.jsm");
 }
 
 (function(exports) {

toolkit/components/osfile/osfile_win_back.jsm

@@ -28,6 +28,8 @@
 
     throw new Error("osfile_win.jsm cannot be used from the main thread yet");
   }
+  importScripts("resource://gre/modules/osfile/osfile_shared_allthreads.jsm");
+  importScripts("resource://gre/modules/osfile/osfile_win_allthreads.jsm");
 
   (function(exports) {
      "use strict";

toolkit/components/osfile/osfile_win_front.jsm

@@ -16,6 +16,10 @@
     throw new Error("osfile_win_front.jsm cannot be used from the main thread yet");
   }
 
+  importScripts("resource://gre/modules/osfile/osfile_win_back.jsm");
+  importScripts("resource://gre/modules/osfile/ospath_win_back.jsm");
+  importScripts("resource://gre/modules/osfile/osfile_shared_front.jsm");
+
   (function(exports) {
      "use strict";