From 9a3e22bc9c309807858e0675203036c5ef5a44ab Mon Sep 17 00:00:00 2001
From: Andrea Marchesini <amarchesini@mozilla.com>
Date: Wed, 14 Jan 2015 11:50:34 +0000
Subject: [PATCH] Bug 966439 - BroadcastChannel API - patch 2 - close() method,
 r=smaug

---
 dom/broadcastchannel/BroadcastChannel.cpp     | 41 ++++++++++++-
 dom/broadcastchannel/BroadcastChannel.h       | 12 +++-
 dom/broadcastchannel/tests/mochitest.ini      |  1 +
 .../tests/test_broadcastchannel_close.html    | 58 +++++++++++++++++++
 dom/webidl/BroadcastChannel.webidl            |  3 +
 5 files changed, 112 insertions(+), 3 deletions(-)
 create mode 100644 dom/broadcastchannel/tests/test_broadcastchannel_close.html

diff --git a/dom/broadcastchannel/BroadcastChannel.cpp b/dom/broadcastchannel/BroadcastChannel.cpp
index 09b2f9793220..f65fe2b45a55 100644
--- a/dom/broadcastchannel/BroadcastChannel.cpp
+++ b/dom/broadcastchannel/BroadcastChannel.cpp
@@ -219,6 +219,7 @@ BroadcastChannel::BroadcastChannel(nsPIDOMWindow* aWindow,
   , mChannel(aChannel)
   , mIsKeptAlive(false)
   , mInnerID(0)
+  , mState(StateActive)
 {
   // Window can be null in workers
 }
@@ -322,7 +323,18 @@ BroadcastChannel::Constructor(const GlobalObject& aGlobal,
 }
 
 void
-BroadcastChannel::PostMessage(const nsAString& aMessage)
+BroadcastChannel::PostMessage(const nsAString& aMessage, ErrorResult& aRv)
+{
+  if (mState != StateActive) {
+    aRv.Throw(NS_ERROR_FAILURE);
+    return;
+  }
+
+  PostMessageInternal(aMessage);
+}
+
+void
+BroadcastChannel::PostMessageInternal(const nsAString& aMessage)
 {
   if (mActor) {
     nsRefPtr<PostMessageRunnable> runnable =
@@ -338,6 +350,21 @@ BroadcastChannel::PostMessage(const nsAString& aMessage)
   mPendingMessages.AppendElement(aMessage);
 }
 
+void
+BroadcastChannel::Close()
+{
+  if (mState != StateActive) {
+    return;
+  }
+
+  if (mPendingMessages.IsEmpty()) {
+    Shutdown();
+  } else {
+    MOZ_ASSERT(!mActor);
+    mState = StateClosing;
+  }
+}
+
 void
 BroadcastChannel::ActorFailed()
 {
@@ -349,6 +376,10 @@ BroadcastChannel::ActorCreated(ipc::PBackgroundChild* aActor)
 {
   MOZ_ASSERT(aActor);
 
+  if (mState == StateClosed) {
+    return;
+  }
+
   PBroadcastChannelChild* actor =
     aActor->SendPBroadcastChannelConstructor(mPrincipalInfo, mOrigin, mChannel);
 
@@ -359,15 +390,21 @@ BroadcastChannel::ActorCreated(ipc::PBackgroundChild* aActor)
 
   // Flush pending messages.
   for (uint32_t i = 0; i < mPendingMessages.Length(); ++i) {
-    PostMessage(mPendingMessages[i]);
+    PostMessageInternal(mPendingMessages[i]);
   }
 
   mPendingMessages.Clear();
+
+  if (mState == StateClosing) {
+    Shutdown();
+  }
 }
 
 void
 BroadcastChannel::Shutdown()
 {
+  mState = StateClosed;
+
   // If shutdown() is called we have to release the reference if we still keep
   // it.
   if (mIsKeptAlive) {
diff --git a/dom/broadcastchannel/BroadcastChannel.h b/dom/broadcastchannel/BroadcastChannel.h
index 71ebd9d5cf91..ea4656ea38bb 100644
--- a/dom/broadcastchannel/BroadcastChannel.h
+++ b/dom/broadcastchannel/BroadcastChannel.h
@@ -53,7 +53,9 @@ public:
     aName = mChannel;
   }
 
-  void PostMessage(const nsAString& aMessage);
+  void PostMessage(const nsAString& aMessage, ErrorResult& aRv);
+
+  void Close();
 
   EventHandlerNonNull* GetOnmessage();
   void SetOnmessage(EventHandlerNonNull* aCallback);
@@ -81,6 +83,8 @@ private:
 
   ~BroadcastChannel();
 
+  void PostMessageInternal(const nsAString& aMessage);
+
   void UpdateMustKeepAlive();
 
   nsRefPtr<BroadcastChannelChild> mActor;
@@ -95,6 +99,12 @@ private:
   bool mIsKeptAlive;
 
   uint64_t mInnerID;
+
+  enum {
+    StateActive,
+    StateClosing,
+    StateClosed
+  } mState;
 };
 
 } // namespace dom
diff --git a/dom/broadcastchannel/tests/mochitest.ini b/dom/broadcastchannel/tests/mochitest.ini
index 1218751c07ff..5d5aa5bf0099 100644
--- a/dom/broadcastchannel/tests/mochitest.ini
+++ b/dom/broadcastchannel/tests/mochitest.ini
@@ -6,3 +6,4 @@ support-files =
 [test_broadcastchannel_basic.html]
 [test_broadcastchannel_self.html]
 [test_broadcastchannel_worker.html]
+[test_broadcastchannel_close.html]
diff --git a/dom/broadcastchannel/tests/test_broadcastchannel_close.html b/dom/broadcastchannel/tests/test_broadcastchannel_close.html
new file mode 100644
index 000000000000..72b252015e8a
--- /dev/null
+++ b/dom/broadcastchannel/tests/test_broadcastchannel_close.html
@@ -0,0 +1,58 @@
+<!DOCTYPE HTML>
+<html>
+<head>
+  <title>Test for BroadcastChannel</title>
+  <script type="application/javascript" src="/tests/SimpleTest/SimpleTest.js"></script>
+  <link rel="stylesheet" type="text/css" href="/tests/SimpleTest/test.css"/>
+</head>
+<body>
+
+<div id="content"></div>
+
+<script type="application/javascript">
+
+SimpleTest.waitForExplicitFinish();
+
+var receiver = new BroadcastChannel('foo');
+var sequence = [ '2', 'done' ];
+receiver.onmessage = function(e) {
+  if (!sequence.length) {
+    ok (false, 'No more data is expected');
+    return;
+  }
+
+  var data = sequence.shift();
+  is(e.data, data);
+
+  if (!sequence.length) {
+    SimpleTest.executeSoon(function() {
+      SimpleTest.finish();
+    });
+  }
+}
+
+var x = new BroadcastChannel('foo');
+x.close();
+try {
+  x.postMessage('1');
+  ok(false, "PostMessage should throw if called after a close().");
+} catch(e) {
+  ok(true, "PostMessage should throw if called after a close().");
+}
+
+var y = new BroadcastChannel('foo');
+y.postMessage('2');
+y.close();
+try {
+  y.postMessage('3');
+  ok(false, "PostMessage should throw if called after a close().");
+} catch(e) {
+  ok(true, "PostMessage should throw if called after a close().");
+}
+
+var z = new BroadcastChannel('foo');
+z.postMessage('done');
+
+</script>
+</body>
+</html>
diff --git a/dom/webidl/BroadcastChannel.webidl b/dom/webidl/BroadcastChannel.webidl
index 2d611bb0328f..2d128c6a02e5 100644
--- a/dom/webidl/BroadcastChannel.webidl
+++ b/dom/webidl/BroadcastChannel.webidl
@@ -12,7 +12,10 @@
 interface BroadcastChannel : EventTarget {
   readonly attribute DOMString name;
 
+  [Throws]
   void postMessage(DOMString message);
 
+  void close();
+
            attribute EventHandler onmessage;
 };