Bug 588630 - "When invoking TabCandy/Panorama with many open blank tabs, Firefox hangs & then pops up "Unresponsive Script" dialog" [r=dietrich, a=blocking]

--HG--
extra : rebase_source : 6a7a920136de79d479dd4ee67060f0274ee26759

browser/base/content/tabview/groupitems.js

@@ -1047,6 +1047,10 @@ GroupItem.prototype = Utils.extend(new Item(), new Subscribable(), {
   // Parameters:
   //   options - passed to <Items.arrange> or <_stackArrange>
   arrange: function GroupItem_arrange(options) {
+    if (GroupItems._arrangePaused) {
+      GroupItems.pushArrange(this, options);
+      return;
+    }
     if (this.expanded) {
       this.topChild = null;
       var box = new Rect(this.expanded.bounds);
@@ -1490,6 +1494,8 @@ let GroupItems = {
   _activeGroupItem: null,
   _activeOrphanTab: null,
   _cleanupFunctions: [],
+  _arrangePaused: false,
+  _arrangesPending: [],
 
   // ----------
   // Function: init
@@ -1521,6 +1527,51 @@ let GroupItems = {
     this.groupItems = null;
   },
 
+  // ----------
+  // Function: pauseArrange
+  // Bypass arrange() calls and collect for resolution in
+  // resumeArrange()
+  pauseArrange: function GroupItems_pauseArrange() {
+    Utils.assert(this._arrangePaused == false, 
+      "pauseArrange has been called while already paused");
+    Utils.assert(this._arrangesPending.length == 0, 
+      "There are bypassed arrange() calls that haven't been resolved");
+    this._arrangePaused = true;
+  },
+
+  // ----------
+  // Function: pushArrange
+  // Push an arrange() call and its arguments onto an array
+  // to be resolved in resumeArrange()
+  pushArrange: function GroupItems_pushArrange(groupItem, options) {
+    Utils.assert(this._arrangePaused, 
+      "Ensure pushArrange() called while arrange()s aren't paused"); 
+    let i;
+    for (i = 0; i < this._arrangesPending.length; i++)
+      if (this._arrangesPending[i].groupItem === groupItem)
+        break;
+    let arrangeInfo = {
+      groupItem: groupItem,
+      options: options
+    };
+    if (i < this._arrangesPending.length)
+      this._arrangesPending[i] = arrangeInfo;
+    else
+      this._arrangesPending.push(arrangeInfo);
+  },
+
+  // ----------
+  // Function: resumeArrange
+  // Resolve bypassed and collected arrange() calls
+  resumeArrange: function GroupItems_resumeArrange() {
+    for (let i = 0; i < this._arrangesPending.length; i++) {
+      let g = this._arrangesPending[i];
+      g.groupItem.arrange(g.options);
+    }
+    this._arrangesPending = [];
+    this._arrangePaused = false;
+  },
+
   // ----------
   // Function: _handleAttrModified
   // watch for icon changes on app tabs

browser/base/content/tabview/search.js

@@ -132,7 +132,7 @@ var TabUtils = {
   // Function: favURLOf
   // Given a <TabItem> or a <xul:tab> returns the URL of tab's favicon.
   faviconURLOf: function TabUtils_faviconURLOf(tab) {
-    return tab.image != undefined ? tab.image : tab.favEl.src;
+    return tab.image != undefined ? tab.image : tab.favImgEl.src;
   },
   
   // ---------

browser/base/content/tabview/tabitems.js

@@ -70,8 +70,10 @@ function TabItem(tab, options) {
 
   this.canvasSizeForced = false;
   this.isShowingCachedData = false;
-  this.favEl = (iQ('.favicon>img', $div))[0];
+  this.favEl = (iQ('.favicon', $div))[0];
+  this.favImgEl = (iQ('.favicon>img', $div))[0];
   this.nameEl = (iQ('.tab-title', $div))[0];
+  this.thumbEl = (iQ('.thumb', $div))[0];
   this.canvasEl = (iQ('.thumb canvas', $div))[0];
   this.cachedThumbEl = (iQ('img.cached-thumb', $div))[0];
 
@@ -194,6 +196,7 @@ function TabItem(tab, options) {
   iQ("<div>")
     .addClass('close')
     .appendTo($div);
+  this.closeEl = (iQ(".close", $div))[0];
 
   iQ("<div>")
     .addClass('expander')
@@ -322,10 +325,10 @@ TabItem.prototype = Utils.extend(new Item(), new Subscribable(), {
       this.bounds.copy(rect);
     else {
       var $container = iQ(this.container);
-      var $title = iQ('.tab-title', $container);
-      var $thumb = iQ('.thumb', $container);
-      var $close = iQ('.close', $container);
-      var $fav   = iQ('.favicon', $container);
+      var $title = iQ(this.nameEl);
+      var $thumb = iQ(this.thumbEl);
+      var $close = iQ(this.closeEl);
+      var $fav   = iQ(this.favEl);
       var css = {};
 
       const fontSizeRange = new Range(8,15);
@@ -802,8 +805,8 @@ let TabItems = {
       if (iconUrl == null)
         iconUrl = Utils.defaultFaviconURL;
 
-      if (iconUrl != tabItem.favEl.src)
-        tabItem.favEl.src = iconUrl;
+      if (iconUrl != tabItem.favImgEl.src)
+        tabItem.favImgEl.src = iconUrl;
 
       // ___ URL
       let tabUrl = tab.linkedBrowser.currentURI.spec;

browser/base/content/tabview/ui.js

@@ -171,6 +171,7 @@ let UI = {
 
       // ___ Storage
 
+      GroupItems.pauseArrange();
       GroupItems.init();
 
       let firstTime = true;
@@ -221,9 +222,11 @@ let UI = {
       // initialized.
       let event = document.createEvent("Events");
       event.initEvent("tabviewframeinitialized", true, false);
-      dispatchEvent(event);
+      dispatchEvent(event);      
     } catch(e) {
       Utils.log(e);
+    } finally {
+      GroupItems.resumeArrange();
     }
   },