Clean up extension message port data in the renderer.

chrome/renderer/extensions/renderer_extension_bindings.cc

 // Copyright (c) 2009 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "chrome/renderer/extensions/renderer_extension_bindings.h"
 
 #include "app/resource_bundle.h"
 #include "base/basictypes.h"
 #include "base/values.h"
 #include "chrome/common/render_messages.h"
@@ skipping 19 matching lines @@
 namespace {
 
 struct ExtensionData {
   struct PortData {
     int ref_count;  // how many contexts have a handle to this port
     bool disconnected;  // true if this port was forcefully disconnected
     PortData() : ref_count(0), disconnected(false) {}
   };
   std::map<int, PortData> ports;  // port ID -> data
 };
+bool HasPortData(int port_id) {
+  return Singleton<ExtensionData>::get()->ports.find(port_id) !=
+      Singleton<ExtensionData>::get()->ports.end();
+}
 ExtensionData::PortData& GetPortData(int port_id) {
   return Singleton<ExtensionData>::get()->ports[port_id];
 }
+void ClearPortData(int port_id) {
+  Singleton<ExtensionData>::get()->ports.erase(port_id);
+}
 
+const char kPortClosedError[] = "Attempting to use a disconnected port object";
 const char* kExtensionDeps[] = { EventBindings::kName };
 
 class ExtensionImpl : public ExtensionBase {
  public:
   ExtensionImpl()
       : ExtensionBase(RendererExtensionBindings::kName,
                       GetStringResource<IDR_RENDERER_EXTENSION_BINDINGS_JS>(),
                       arraysize(kExtensionDeps), kExtensionDeps) {
   }
   ~ExtensionImpl() {}
@@ skipping 38 matching lines @@
   }
 
   // Sends a message along the given channel.
   static v8::Handle<v8::Value> PostMessage(const v8::Arguments& args) {
     RenderView* renderview = bindings_utils::GetRenderViewForCurrentContext();
     if (!renderview)
       return v8::Undefined();
 
     if (args.Length() >= 2 && args[0]->IsInt32() && args[1]->IsString()) {
       int port_id = args[0]->Int32Value();
+      if (!HasPortData(port_id)) {
+        return v8::ThrowException(v8::Exception::Error(
+          v8::String::New(kPortClosedError)));
+      }
       std::string message = *v8::String::Utf8Value(args[1]->ToString());
       renderview->Send(new ViewHostMsg_ExtensionPostMessage(
           renderview->routing_id(), port_id, message));
     }
     return v8::Undefined();
   }
 
   // Forcefully disconnects a port.
   static v8::Handle<v8::Value> CloseChannel(const v8::Arguments& args) {
     if (args.Length() >= 1 && args[0]->IsInt32()) {
       int port_id = args[0]->Int32Value();
+      if (!HasPortData(port_id)) {

[Aaron Boodman, 2009/10/31 19:21:22]

Maybe we don't want to throw here? It seems nice that you can call close whether
or not the port is open.

[Matt Perry, 2009/11/03 00:39:36]

Done.

+        return v8::ThrowException(v8::Exception::Error(
+          v8::String::New(kPortClosedError)));
+      }
       // Send via the RenderThread because the RenderView might be closing.
       EventBindings::GetRenderThread()->Send(
           new ViewHostMsg_ExtensionCloseChannel(port_id));
-      GetPortData(port_id).disconnected = true;
+      ClearPortData(port_id);
     }
     return v8::Undefined();
   }
 
   // A new port has been created for a context.  This occurs both when script
   // opens a connection, and when a connection is opened to this script.
   static v8::Handle<v8::Value> PortAddRef(const v8::Arguments& args) {
     if (args.Length() >= 1 && args[0]->IsInt32()) {
       int port_id = args[0]->Int32Value();
       ++GetPortData(port_id).ref_count;
     }
     return v8::Undefined();
   }
 
   // The frame a port lived in has been destroyed.  When there are no more
   // frames with a reference to a given port, we will disconnect it and notify
   // the other end of the channel.
   static v8::Handle<v8::Value> PortRelease(const v8::Arguments& args) {
     if (args.Length() >= 1 && args[0]->IsInt32()) {
       int port_id = args[0]->Int32Value();
-      if (!GetPortData(port_id).disconnected &&
-          --GetPortData(port_id).ref_count == 0) {
+      if (HasPortData(port_id) && --GetPortData(port_id).ref_count == 0) {
         // Send via the RenderThread because the RenderView might be closing.
         EventBindings::GetRenderThread()->Send(
             new ViewHostMsg_ExtensionCloseChannel(port_id));
+        ClearPortData(port_id);
       }
     }
     return v8::Undefined();
   }
 };
 
 // Convert a ListValue to a vector of V8 values.
 static std::vector< v8::Handle<v8::Value> > ListValueToV8(
     const ListValue& value) {
   std::vector< v8::Handle<v8::Value> > v8_values;
@@ skipping 48 matching lines @@
   return extension;
 }
 
 void RendererExtensionBindings::Invoke(const std::string& function_name,
                                        const ListValue& args,
                                        RenderView* renderview) {
   v8::HandleScope handle_scope;
   std::vector< v8::Handle<v8::Value> > argv = ListValueToV8(args);
   EventBindings::CallFunction(function_name, argv.size(), &argv[0], renderview);
 }