Bug 970307: Part 3: Reinitialize modules after fork. r=fabrice

dom/apps/AppsServiceChild.jsm

@@ -103,6 +103,12 @@ this.DOMApplicationRegistry = {
       this.cpmm.addMessageListener(aMsgName, this);
     }).bind(this));
 
+    this.resetList();
+
+    Services.obs.addObserver(this, "xpcom-shutdown", false);
+  },
+
+  resetList: function() {
     this.cpmm.sendAsyncMessage("Webapps:RegisterForMessages", {
       messages: APPS_IPC_MSG_NAMES
     });
@@ -110,6 +116,7 @@ this.DOMApplicationRegistry = {
     // We need to prime the cache with the list of apps.
     let list = this.cpmm.sendSyncMessage("Webapps:GetList", { })[0];
     this.webapps = list.webapps;
+
     // We need a fast mapping from localId -> app, so we add an index.
     // We also add the manifest to the app object.
     this.localIdIndex = { };
@@ -118,8 +125,6 @@ this.DOMApplicationRegistry = {
       this.localIdIndex[app.localId] = app;
       app.manifest = list.manifests[id];
     }
-
-    Services.obs.addObserver(this, "xpcom-shutdown", false);
   },
 
   observe: function(aSubject, aTopic, aData) {

dom/ipc/ContentChild.cpp

@@ -507,6 +507,12 @@ NS_IMPL_ISUPPORTS(BackgroundChildPrimer, nsIIPCBackgroundChildCreateCallback)
 
 ContentChild* ContentChild::sSingleton;
 
+static void
+PostForkPreload()
+{
+    TabChild::PostForkPreload();
+}
+
 // Performs initialization that is not fork-safe, i.e. that must be done after
 // forking from the Nuwa process.
 static void
@@ -517,6 +523,7 @@ InitOnContentProcessCreated()
     if (IsNuwaProcess()) {
         return;
     }
+    PostForkPreload();
 #endif
 
     // This will register cross-process observer.
@@ -2081,6 +2088,9 @@ ContentChild::RecvAppInfo(const nsCString& version, const nsCString& buildID,
 #endif
        ) {
         PreloadSlowThings();
+#ifndef MOZ_NUWA_PROCESS
+        PostForkPreload();
+#endif
     }
 
 #ifdef MOZ_NUWA_PROCESS

dom/ipc/TabChild.cpp

@@ -832,6 +832,21 @@ TabChild::PreloadSlowThings()
     ClearOnShutdown(&sPreallocatedTab);
 }
 
+/*static*/ void
+TabChild::PostForkPreload()
+{
+    // Preallocated Tab can be null if we are forked directly from b2g. In such
+    // case we don't need to preload anything, just return.
+    if (!sPreallocatedTab) {
+        return;
+    }
+
+    // Rebuild connections to parent.
+    sPreallocatedTab->RecvLoadRemoteScript(
+      NS_LITERAL_STRING("chrome://global/content/post-fork-preload.js"),
+      true);
+}
+
 /*static*/ already_AddRefed<TabChild>
 TabChild::Create(nsIContentChild* aManager,
                  const TabId& aTabId,

dom/ipc/TabChild.h

@@ -268,6 +268,7 @@ public:
      * on the critical path.
      */
     static void PreloadSlowThings();
+    static void PostForkPreload();
 
     /** Return a TabChild with the given attributes. */
     static already_AddRefed<TabChild>

dom/ipc/jar.mn

@@ -9,3 +9,4 @@ toolkit.jar:
         content/global/BrowserElementChildPreload.js (../browser-element/BrowserElementChildPreload.js)
 *       content/global/BrowserElementPanning.js (../browser-element/BrowserElementPanning.js)
         content/global/preload.js (preload.js)
+        content/global/post-fork-preload.js (post-fork-preload.js)

dom/ipc/post-fork-preload.js

@@ -0,0 +1,20 @@
+/* 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/. */
+
+// Preload some things, in an attempt to make app startup faster.
+//
+// This script is run when the preallocated process starts.  It is injected as
+// a frame script.
+// If Nuwa process is enabled, this script will run in preallocated process
+// forked by Nuwa.
+
+(function (global) {
+  "use strict";
+
+  Components.utils.import("resource://gre/modules/AppsServiceChild.jsm");
+  Components.classes["@mozilla.org/network/protocol-proxy-service;1"].
+    getService(Ci["nsIProtocolProxyService"]);
+
+  DOMApplicationRegistry.resetList();
+})(this);

dom/ipc/preload.js

@@ -6,6 +6,7 @@
 //
 // This script is run when the preallocated process starts.  It is injected as
 // a frame script.
+// If nuwa is enabled, this script will run in Nuwa process before frozen.
 
 const BrowserElementIsPreloaded = true;
 
@@ -53,7 +54,6 @@ const BrowserElementIsPreloaded = true;
   Cc["@mozilla.org/network/idn-service;1"].getService(Ci["nsIIDNService"]);
   Cc["@mozilla.org/network/io-service;1"].getService(Ci["nsIIOService2"]);
   Cc["@mozilla.org/network/mime-hdrparam;1"].getService(Ci["nsIMIMEHeaderParam"]);
-  Cc["@mozilla.org/network/protocol-proxy-service;1"].getService(Ci["nsIProtocolProxyService"]);
   Cc["@mozilla.org/network/socket-transport-service;1"].getService(Ci["nsISocketTransportService"]);
   Cc["@mozilla.org/network/stream-transport-service;1"].getService(Ci["nsIStreamTransportService"]);
   Cc["@mozilla.org/network/url-parser;1?auth=maybe"].getService(Ci["nsIURLParser"]);