Allow MessageFilters to restrict listening to specific message classes

ipc/ipc_channel_proxy_unittest.cc

Index: ipc/ipc_channel_proxy_unittest.cc
diff --git a/ipc/ipc_channel_proxy_unittest.cc b/ipc/ipc_channel_proxy_unittest.cc
new file mode 100644
index 0000000000000000000000000000000000000000..36cf5f64cc710f3c97535a785beb3f95f065b4b3
--- /dev/null
+++ b/ipc/ipc_channel_proxy_unittest.cc
@@ -0,0 +1,268 @@
+// Copyright (c) 2012 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 "build/build_config.h"
+
+#include "base/message_loop/message_loop.h"
+#include "base/pickle.h"
+#include "base/threading/thread.h"
+#include "ipc/ipc_message.h"
+#include "ipc/ipc_message_macros.h"
+#include "ipc/ipc_test_base.h"
+
+namespace {
+
+#if defined(IPC_MESSAGE_START)
+#undef IPC_MESSAGE_START
+#endif
+
+enum Command {
+  SEND,
+  QUIT
+};
+
+static void Send(IPC::Sender* sender,
+                 int message_class,
+                 Command command) {
+  const int IPC_MESSAGE_START = message_class;
+  IPC::Message* message = new IPC::Message(0,
+                                           IPC_MESSAGE_ID(),
+                                           IPC::Message::PRIORITY_NORMAL);
+  message->WriteInt(command);
+  sender->Send(message);
+}
+
+class QuitListener : public IPC::Listener {
+ public:
+  QuitListener() {}
+  virtual ~QuitListener() {}
+
+  virtual bool OnMessageReceived(const IPC::Message& message) OVERRIDE {
+    PickleIterator iter(message);
+
+    int command = SEND;
+    EXPECT_TRUE(iter.ReadInt(&command));
+    if (command == QUIT)
+      base::MessageLoop::current()->QuitWhenIdle();
+
+    return true;
+  }
+};
+
+class ChannelReflectorListener : public IPC::Listener {
+ public:
+  ChannelReflectorListener() : channel_(NULL) {}
+  virtual ~ChannelReflectorListener() {}
+
+  void Init(IPC::Channel* channel) {
+    DCHECK(!channel_);
+    channel_ = channel;
+  }
+
+  virtual bool OnMessageReceived(const IPC::Message& message) OVERRIDE {
+    CHECK(channel_);
+
+    PickleIterator iter(message);
+
+    int command = SEND;
+    EXPECT_TRUE(iter.ReadInt(&command));
+    if (command == QUIT) {
+      channel_->Send(new IPC::Message(message));
+      base::MessageLoop::current()->QuitWhenIdle();
+      return true;
+    }
+
+    channel_->Send(new IPC::Message(message));
+    return true;
+  }
+
+ private:
+  IPC::Channel* channel_;
+};
+
+class MessageCountFilter : public IPC::ChannelProxy::MessageFilter {
+ public:
+  MessageCountFilter()
+      : messages_received_(0),
+        supported_message_class_(0),
+        is_global_filter_(true),
+        filter_removed_(false),
+        message_filtering_enabled_(false) {}
+
+  MessageCountFilter(uint32 supported_message_class_)
+      : messages_received_(0),
+        supported_message_class_(supported_message_class_),
+        is_global_filter_(false),
+        filter_removed_(false),
+        message_filtering_enabled_(false) {}
+
+  virtual void OnFilterRemoved() OVERRIDE {
+    EXPECT_FALSE(filter_removed_);
+    filter_removed_ = true;
+  }
+
+  virtual bool OnMessageReceived(const IPC::Message& message) OVERRIDE {
+    if (!is_global_filter_) {
+      EXPECT_EQ(supported_message_class_, IPC_MESSAGE_CLASS(message));
+    }
+    ++messages_received_;
+    return message_filtering_enabled_;
+  }
+
+  virtual bool GetSupportedMessageClasses(
+      std::vector<uint32>* supported_message_classes) const OVERRIDE {
+    if (is_global_filter_)
+      return false;
+    supported_message_classes->push_back(supported_message_class_);
+    return true;
+  }
+
+  void set_message_filtering_enabled(bool enabled) {
+    message_filtering_enabled_ = enabled;
+  }
+
+  size_t messages_received() const { return messages_received_; }
+  bool filter_removed() const { return filter_removed_; }
+
+ private:
+  virtual ~MessageCountFilter() {}
+
+  size_t messages_received_;
+  uint32 supported_message_class_;
+  bool is_global_filter_;
+  bool filter_removed_;
+  bool message_filtering_enabled_;
+};
+
+class IPCChannelProxyTest : public IPCTestBase {
+ public:
+  IPCChannelProxyTest() {}
+  virtual ~IPCChannelProxyTest() {}
+
+  virtual void SetUp() OVERRIDE {
+    IPCTestBase::SetUp();
+
+    Init("ChannelProxyClient");
+
+    thread_.reset(new base::Thread("ChannelProxyTestServerThread"));
+    base::Thread::Options options;
+    options.message_loop_type = base::MessageLoop::TYPE_IO;
+    thread_->StartWithOptions(options);
+
+    listener_.reset(new QuitListener());
+    CreateChannelProxy(listener_.get(), thread_->message_loop_proxy().get());
+
+    ASSERT_TRUE(StartClient());
+  }
+
+  virtual void TearDown() {
+    DestroyChannelProxy();
+    thread_.reset();
+    listener_.reset();
+    IPCTestBase::TearDown();
+  }
+
+  virtual void QuitAndWaitForIdle() {
+    Send(sender(), -1, QUIT);
+    base::MessageLoop::current()->Run();
+    thread_->message_loop()->RunUntilIdle();

[piman, 2014/02/14 22:05:05]

I don't think this does what you want it to do.
If you look at the implementation, it will create a RunLoop, which will run the
*current* message loop - it makes sense, you can't run another thread's ML on
this thread.
It's already running anyway.

[jdduke (slow), 2014/02/15 02:57:09]

Done.

+    EXPECT_TRUE(WaitForClientShutdown());
+  }
+
+ private:
+  scoped_ptr<base::Thread> thread_;
+  scoped_ptr<QuitListener> listener_;
+};
+
+TEST_F(IPCChannelProxyTest, MessageClassFilters) {
+  // Construct a filter per message class.
+  std::vector<scoped_refptr<MessageCountFilter> > class_filters;
+  for (size_t i = 0; i < LastIPCMsgStart; ++i) {
+    class_filters.push_back(make_scoped_refptr(
+        new MessageCountFilter(i)));
+    channel_proxy()->AddFilter(class_filters.back().get());
+  }
+
+  // Send a message for each class; each filter should receive just one message.
+  for (size_t i = 0; i < class_filters.size(); ++i)
+    Send(sender(), i, SEND);
+
+  // Send a message with an invalid class; this should not reach any filter.
+  Send(sender(), -1, SEND);

[piman, 2014/02/14 22:05:05]

nit: -1 is special (for replies, etc.). You may want to try something like
LastIPCMsgStart+1 too.

[jdduke (slow), 2014/02/15 02:57:09]

Done.

+
+  // All messages should have been received by their respective filter.
+  QuitAndWaitForIdle();
+  for (size_t i = 0; i < class_filters.size(); ++i)
+    EXPECT_EQ(1U, class_filters[i]->messages_received());
+}
+
+TEST_F(IPCChannelProxyTest, GlobalAndMessageClassFilters) {
+  // Add a class and global filter.
+  const int kMessageClass = 7;
+  scoped_refptr<MessageCountFilter> class_filter(
+      new MessageCountFilter(kMessageClass));
+  class_filter->set_message_filtering_enabled(false);
+  channel_proxy()->AddFilter(class_filter.get());
+
+  scoped_refptr<MessageCountFilter> global_filter(new MessageCountFilter());
+  global_filter->set_message_filtering_enabled(false);
+  channel_proxy()->AddFilter(global_filter.get());
+
+  // A message  of class |kMessageClass| should be seen by both the global
+  // filter and |kMessageClass|-specific filter.
+  Send(sender(), kMessageClass, SEND);
+
+  // A message of a different class should be seen only by the global filter.
+  Send(sender(), kMessageClass + 1, SEND);
+
+  // Flush all messages.
+  QuitAndWaitForIdle();
+
+  // The class filter should have received only the class-specific message.
+  EXPECT_EQ(1U, class_filter->messages_received());
+
+  // The global filter should have received both SEND messages, as well as the
+  // final QUIT message.
+  EXPECT_EQ(3U, global_filter->messages_received());
+}
+
+TEST_F(IPCChannelProxyTest, FilterRemoval) {
+  // Add a class and global filter.
+  const int kMessageClass = 7;
+  scoped_refptr<MessageCountFilter> class_filter(
+      new MessageCountFilter(kMessageClass));
+  scoped_refptr<MessageCountFilter> global_filter(new MessageCountFilter());
+
+  // Add and remove both types of filters.
+  channel_proxy()->AddFilter(class_filter.get());
+  channel_proxy()->AddFilter(global_filter.get());
+  channel_proxy()->RemoveFilter(global_filter.get());
+  channel_proxy()->RemoveFilter(class_filter.get());
+
+  // Send some messages; they should not be seen by either filter.
+  Send(sender(), kMessageClass, SEND);
+  Send(sender(), kMessageClass, SEND);
+
+  // Ensure that the filters were removed and did not receive any messages.
+  QuitAndWaitForIdle();
+  EXPECT_TRUE(global_filter->filter_removed());
+  EXPECT_TRUE(class_filter->filter_removed());
+  EXPECT_EQ(0U, class_filter->messages_received());
+  EXPECT_EQ(0U, global_filter->messages_received());
+}
+
+MULTIPROCESS_IPC_TEST_CLIENT_MAIN(ChannelProxyClient) {
+  base::MessageLoopForIO main_message_loop;
+  ChannelReflectorListener listener;
+  IPC::Channel channel(IPCTestBase::GetChannelName("ChannelProxyClient"),
+                       IPC::Channel::MODE_CLIENT,
+                       &listener);
+  CHECK(channel.Connect());
+  listener.Init(&channel);
+
+  base::MessageLoop::current()->Run();
+  return 0;
+}
+
+}  // namespace