Keep MessagePort wrappers alive for the life-time of the corresponding

MessageChannel.

I create the MessagePort wrappers when a MessageChannel is constructed
and put references to them in internal fields in the MessageChannel.

This is a fix for 
  http://code.google.com/p/chromium/issues/detail?id=4195
Review URL: http://codereview.chromium.org/9508

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@5006 0039d316-1c4b-4281-b951-d872f2087c98

5 files changed, 45 insertions, 19 deletions

diff --git a/webkit/port/bindings/v8/v8_custom.cpp b/webkit/port/bindings/v8/v8_custom.cpp
index 23a226d..c8b4743 100644
--- a/webkit/port/bindings/v8/v8_custom.cpp
+++ b/webkit/port/bindings/v8/v8_custom.cpp
@@ -262,9 +262,6 @@ CALLBACK_FUNC_DECL(DOMParserConstructor) {
                                      DOMParser>(args);
 }
 
-// TODO(mbelshe): merge this with the XHR Constructor.
-//   The only difference is that this one takes an argument to its
-//   create call, the XHR does not.
 CALLBACK_FUNC_DECL(MessageChannelConstructor) {
   INC_STATS(L"DOM.MessageChannel.Constructor");
   if (!args.IsConstructCall()) {
@@ -282,11 +279,32 @@ CALLBACK_FUNC_DECL(MessageChannelConstructor) {
   // Note: it's OK to let this RefPtr go out of scope because we also call
   // SetDOMWrapper(), which effectively holds a reference to obj.
   RefPtr<MessageChannel> obj = MessageChannel::create(document);
-  V8Proxy::SetDOMWrapper(args.Holder(), V8ClassIndex::MESSAGECHANNEL,
-      obj.get());
+  
+  // Create wrappers for the two associated MessagePorts.
+  v8::Handle<v8::Value> port1_wrapper =
+    V8Proxy::ToV8Object(V8ClassIndex::MESSAGEPORT,
+                        static_cast<Peerable*>(obj->port1()));
+  v8::Handle<v8::Value> port2_wrapper =
+    V8Proxy::ToV8Object(V8ClassIndex::MESSAGEPORT,
+                        static_cast<Peerable*>(obj->port2()));
+  
+  v8::Handle<v8::Object> wrapper_object = args.Holder();
+
+  // Setup the standard wrapper object internal fields.
+  V8Proxy::SetDOMWrapper(
+      wrapper_object, V8ClassIndex::MESSAGECHANNEL, obj.get());
   V8Proxy::SetJSWrapperForDOMObject(
-      obj.get(), v8::Persistent<v8::Object>::New(args.Holder()));
-  return args.Holder();
+      obj.get(), v8::Persistent<v8::Object>::New(wrapper_object));  
+
+  // Create references from the MessageChannel wrapper to the two
+  // MessagePort wrappers to make sure that the MessagePort wrappers
+  // stay alive as long as the MessageChannel wrapper is around.
+  wrapper_object->SetInternalField(kMessageChannelPort1Index, port1_wrapper);
+  wrapper_object->SetInternalField(kMessageChannelPort2Index, port2_wrapper);
+
+  // Return the wrapper object which will be the result of the call to
+  // new.
+  return wrapper_object;
 }
 
 
diff --git a/webkit/port/bindings/v8/v8_custom.h b/webkit/port/bindings/v8/v8_custom.h
index 6ce3239..d3bee4c 100644
--- a/webkit/port/bindings/v8/v8_custom.h
+++ b/webkit/port/bindings/v8/v8_custom.h
@@ -54,6 +54,13 @@ class V8Custom {
   static const int kXMLHttpRequestInternalFieldCount =
                       kDefaultWrapperInternalFieldCount + 1;
 
+  static const int kMessageChannelPort1Index = 
+                      kDefaultWrapperInternalFieldCount + 0;
+  static const int kMessageChannelPort2Index = 
+                      kDefaultWrapperInternalFieldCount + 1;
+  static const int kMessageChannelInternalFieldCount =
+                      kDefaultWrapperInternalFieldCount + 2;
+
   static const int kMessagePortRequestCacheIndex =
                       kDefaultWrapperInternalFieldCount + 0;
   static const int kMessagePortInternalFieldCount =
diff --git a/webkit/port/bindings/v8/v8_proxy.cpp b/webkit/port/bindings/v8/v8_proxy.cpp
index eb6250a..0833a3b 100644
--- a/webkit/port/bindings/v8/v8_proxy.cpp
+++ b/webkit/port/bindings/v8/v8_proxy.cpp
@@ -1384,11 +1384,20 @@ v8::Persistent<v8::FunctionTemplate> V8Proxy::GetTemplate(
       break;
     }
 
-    case V8ClassIndex::MESSAGECHANNEL:
-      desc->SetCallHandler(USE_CALLBACK(MessageChannelConstructor));
-      break;
+    case V8ClassIndex::MESSAGECHANNEL: {
+        // Reserve two more internal fields for referencing the port1
+        // and port2 wrappers.  This ensures that the port wrappers are
+        // kept alive when the channel wrapper is.
+        desc->SetCallHandler(USE_CALLBACK(MessageChannelConstructor));
+        v8::Local<v8::ObjectTemplate> instance_template =
+          desc->InstanceTemplate();
+        instance_template->SetInternalFieldCount(
+            V8Custom::kMessageChannelInternalFieldCount);
+        break;
+    }
+
     case V8ClassIndex::MESSAGEPORT: {
-      // Reserve one more internal field for keeping event listeners.
+        // Reserve one more internal field for keeping event listeners.
         v8::Local<v8::ObjectTemplate> instance_template =
             desc->InstanceTemplate();
         instance_template->SetInternalFieldCount(
diff --git a/webkit/tools/layout_tests/test_lists/mac/tests_fixable.txt b/webkit/tools/layout_tests/test_lists/mac/tests_fixable.txt
index f8508de..5bd754e 100644
--- a/webkit/tools/layout_tests/test_lists/mac/tests_fixable.txt
+++ b/webkit/tools/layout_tests/test_lists/mac/tests_fixable.txt
@@ -682,10 +682,6 @@ V8 # LayoutTests/fast/js/date-set-to-nan.html = FAIL
 # http://crbug.com/2844
 V8 # SKIP : LayoutTests/http/tests/appcache = TIMEOUT | FAIL
 
-# GC issue with MessageChannels.
-# http://code.google.com/p/chromium/issues/detail?id=4195
-V8 # LayoutTests/fast/events/message-channel-gc.html = PASS | FAIL
-
 # Depends on postMessage in a way we don't support:
 # http://code.google.com/p/chromium/issues/detail?id=2857
 V8 # LayoutTests/http/tests/security/dataURL/xss-DENIED-to-data-url-sub-frame-uppercase.html = FAIL
diff --git a/webkit/tools/layout_tests/test_lists/win/tests_fixable.txt b/webkit/tools/layout_tests/test_lists/win/tests_fixable.txt
index b3cb9b4..8bf329c 100644
--- a/webkit/tools/layout_tests/test_lists/win/tests_fixable.txt
+++ b/webkit/tools/layout_tests/test_lists/win/tests_fixable.txt
@@ -669,10 +669,6 @@ V8 # LayoutTests/fast/js/date-set-to-nan.html = FAIL
 # http://crbug.com/2844
 V8 # SKIP : LayoutTests/http/tests/appcache = TIMEOUT | FAIL
 
-# GC issue with MessageChannels.
-# http://code.google.com/p/chromium/issues/detail?id=4195
-V8 # LayoutTests/fast/events/message-channel-gc.html = PASS | FAIL
-
 # Depends on postMessage in a way we don't support:
 # http://code.google.com/p/chromium/issues/detail?id=2857
 V8 # LayoutTests/http/tests/security/dataURL/xss-DENIED-to-data-url-sub-frame-uppercase.html = FAIL