#5422: Add unit tests covering the MessageBus behaviour

Author: codereader

test/Makefile.am

@@ -34,6 +34,7 @@ drtest_SOURCES = math/Matrix4.cpp \
                  FacePlane.cpp \
                  Materials.cpp \
                  MapExport.cpp \
+                 MessageBus.cpp \
                  Models.cpp \
                  ModelExport.cpp \
                  ModelScale.cpp \

test/MessageBus.cpp

@@ -0,0 +1,172 @@
+#include "RadiantTest.h"
+
+#include <future>
+#include "imessagebus.h"
+
+namespace test
+{
+
+using MessageBusTest = RadiantTest;
+
+class CustomMessage1 : 
+    public radiant::IMessage
+{
+public:
+    static const std::size_t Id = radiant::IMessage::Type::UserDefinedMessagesGoHigherThanThis + 1000;
+
+    std::size_t getId() const override
+    {
+        return Id;
+    }
+};
+
+class CustomMessage2 :
+    public radiant::IMessage
+{
+public:
+    static const std::size_t Id = radiant::IMessage::Type::UserDefinedMessagesGoHigherThanThis + 1001;
+    
+    std::size_t getId() const override
+    {
+        return Id;
+    }
+};
+
+TEST_F(MessageBusTest, Registration)
+{
+    auto counter1 = 0;
+    auto& messageBus = GlobalRadiantCore().getMessageBus();
+
+    auto listenerId1 = messageBus.addListener(CustomMessage1::Id, [&](radiant::IMessage&) { ++counter1; });
+
+    CustomMessage1 msg1;
+    messageBus.sendMessage(msg1);
+
+    // Counter should have been increased
+    EXPECT_EQ(counter1, 1);
+
+    messageBus.removeListener(listenerId1);
+
+    // Send another message, counter should not increase 
+    messageBus.sendMessage(msg1);
+    
+    EXPECT_EQ(counter1, 1);
+}
+
+TEST_F(MessageBusTest, ChannelHandling)
+{
+    auto counter1 = 0;
+    auto counter2 = 0;
+    auto& messageBus = GlobalRadiantCore().getMessageBus();
+
+    auto listenerId1 = messageBus.addListener(CustomMessage1::Id, [&](radiant::IMessage&) { ++counter1; });
+    auto listenerId2 = messageBus.addListener(CustomMessage2::Id, [&](radiant::IMessage&) { ++counter2; });
+
+    EXPECT_NE(listenerId1, listenerId2);
+
+    CustomMessage1 msg1;
+    messageBus.sendMessage(msg1);
+
+    // Only one counter should have been increased
+    EXPECT_EQ(counter1, 1);
+    EXPECT_EQ(counter2, 0);
+}
+
+TEST_F(MessageBusTest, MultipleListenersOnChannel)
+{
+    auto counter1 = 0;
+    auto& messageBus = GlobalRadiantCore().getMessageBus();
+
+    auto listenerId1 = messageBus.addListener(CustomMessage1::Id, [&](radiant::IMessage&) { ++counter1; });
+    auto listenerId2 = messageBus.addListener(CustomMessage1::Id, [&](radiant::IMessage&) { ++counter1; });
+
+    CustomMessage1 msg1;
+    messageBus.sendMessage(msg1);
+
+    // Counter should have been increased twice
+    EXPECT_EQ(counter1, 2);
+
+    messageBus.removeListener(listenerId1);
+
+    // Send another message, counter should increase only once now
+    messageBus.sendMessage(msg1);
+
+    EXPECT_EQ(counter1, 3);
+}
+
+TEST_F(MessageBusTest, DeregistrationDuringCallback)
+{
+    auto counter1 = 0;
+    auto& messageBus = GlobalRadiantCore().getMessageBus();
+
+    // Two listeners, unsubscribing during callback
+    std::size_t listenerId1 = 0;
+    std::size_t listenerId2 = 0;
+
+    listenerId1 = messageBus.addListener(CustomMessage1::Id, [&](radiant::IMessage&)
+    {
+        ++counter1;
+        messageBus.removeListener(listenerId1);
+    });
+
+    listenerId2 = messageBus.addListener(CustomMessage1::Id, [&](radiant::IMessage&)
+    {
+        ++counter1;
+        messageBus.removeListener(listenerId2);
+    });
+
+    CustomMessage1 msg1;
+    messageBus.sendMessage(msg1);
+
+    // Counter should have been increased twice
+    EXPECT_EQ(counter1, 2);
+
+    // Send another message, counter should not increase anymore
+    messageBus.sendMessage(msg1);
+
+    EXPECT_EQ(counter1, 2);
+}
+
+TEST_F(MessageBusTest, MultipleThreadsCanSendMessages)
+{
+    std::size_t counter = 0;
+    auto& messageBus = GlobalRadiantCore().getMessageBus();
+
+    // Add a handler that launches another thread which in turn is sending messages
+    auto listenerId1 = messageBus.addListener(CustomMessage1::Id, [&](radiant::IMessage&) 
+    {
+        ++counter;
+
+        // Launch a separate thread which is sending messages
+        std::thread innerThread([&]()
+        {
+            CustomMessage2 msg2;
+            messageBus.sendMessage(msg2);
+        });
+
+        // If the sendMessage(CustomMessage2) deadlocks, this will never return
+        innerThread.join();
+
+        ++counter; // finish => counter == 2
+    });
+
+    auto task = std::async(std::launch::async, [&]()
+    {
+        CustomMessage1 msg1;
+        messageBus.sendMessage(msg1);
+    });
+
+    auto result = task.wait_for(std::chrono::seconds(2));
+
+    EXPECT_EQ(counter, 2);
+    EXPECT_EQ(result, std::future_status::ready) << "Inner thread doesn't respond, possibly dead-locked";
+
+    if (result == std::future_status::timeout)
+    {
+        // In case of a deadlock the destructor of the above task
+        // would wait forever, abort the whole test application
+        std::terminate();
+    }
+}
+
+}

tools/msvc/Tests/Tests.vcxproj

@@ -76,6 +76,7 @@
     <ClCompile Include="..\..\..\test\math\Plane3.cpp" />
     <ClCompile Include="..\..\..\test\math\Quaternion.cpp" />
     <ClCompile Include="..\..\..\test\math\Vector3.cpp" />
+    <ClCompile Include="..\..\..\test\MessageBus.cpp" />
     <ClCompile Include="..\..\..\test\ModelExport.cpp" />
     <ClCompile Include="..\..\..\test\Models.cpp" />
     <ClCompile Include="..\..\..\test\ModelScale.cpp" />

tools/msvc/Tests/Tests.vcxproj.filters

@@ -26,6 +26,7 @@
     <ClCompile Include="..\..\..\test\Models.cpp" />
     <ClCompile Include="..\..\..\test\Face.cpp" />
     <ClCompile Include="..\..\..\test\Selection.cpp" />
+    <ClCompile Include="..\..\..\test\MessageBus.cpp" />
   </ItemGroup>
   <ItemGroup>
     <ClInclude Include="..\..\..\test\HeadlessOpenGLContext.h" />