From 67b8186658a72def4e63d6e62313be39f5bf1fa1 Mon Sep 17 00:00:00 2001
From: Eberhard Graether <egraether@gmail.com>
Date: Fri, 12 Dec 2014 17:09:16 +0100
Subject: [PATCH] logic: added sleep time of 25ms to messaging loop

---
 src/lib/utility/messaging/MessageQueue.cpp | 30 +++++++++++++++++++---
 src/lib/utility/messaging/MessageQueue.h   |  8 +++---
 src/test/MessageQueueTestSuite.h           |  5 +++-
 3 files changed, 35 insertions(+), 8 deletions(-)

diff --git a/src/lib/utility/messaging/MessageQueue.cpp b/src/lib/utility/messaging/MessageQueue.cpp
index e9ecb6e6..c9eb52fd 100644
--- a/src/lib/utility/messaging/MessageQueue.cpp
+++ b/src/lib/utility/messaging/MessageQueue.cpp
@@ -1,5 +1,6 @@
 #include "utility/messaging/MessageQueue.h"
 
+#include <chrono>
 #include <thread>
 
 #include "utility/logging/logging.h"
@@ -97,6 +98,9 @@ void MessageQueue::startMessageLoop()
 		}
 
 		processMessages();
+
+		const int SLEEP_TIME_MS = 25;
+		std::this_thread::sleep_for(std::chrono::milliseconds(SLEEP_TIME_MS));
 	}
 }
 
@@ -118,6 +122,13 @@ bool MessageQueue::loopIsRunning() const
 	return m_loopIsRunning;
 }
 
+bool MessageQueue::hasMessagesQueued() const
+{
+	std::lock_guard<std::mutex> lock(m_frontMessageBufferMutex);
+	std::lock_guard<std::mutex> lock2(m_backMessageBufferMutex);
+	return m_backMessageBuffer->size() + m_frontMessageBuffer->size() > 0;
+}
+
 std::shared_ptr<MessageQueue> MessageQueue::s_instance;
 
 MessageQueue::MessageQueue()
@@ -132,14 +143,25 @@ MessageQueue::MessageQueue()
 void MessageQueue::processMessages()
 {
 	{
-		std::lock_guard<std::mutex> lock(m_backMessageBufferMutex);
+		std::lock_guard<std::mutex> lock(m_frontMessageBufferMutex);
+		std::lock_guard<std::mutex> lock2(m_backMessageBufferMutex);
 		m_backMessageBuffer.swap(m_frontMessageBuffer);
 	}
 
-	while (m_frontMessageBuffer->size())
+	while (true)
 	{
-		std::shared_ptr<MessageBase> message = m_frontMessageBuffer->front();
-		m_frontMessageBuffer->pop();
+		std::shared_ptr<MessageBase> message;
+		{
+			std::lock_guard<std::mutex> lock(m_frontMessageBufferMutex);
+
+			if (!m_frontMessageBuffer->size())
+			{
+				break;
+			}
+
+			message = m_frontMessageBuffer->front();
+			m_frontMessageBuffer->pop();
+		}
 
 		std::lock_guard<std::mutex> lock(m_listenersMutex);
 
diff --git a/src/lib/utility/messaging/MessageQueue.h b/src/lib/utility/messaging/MessageQueue.h
index b836ae81..0059f02d 100644
--- a/src/lib/utility/messaging/MessageQueue.h
+++ b/src/lib/utility/messaging/MessageQueue.h
@@ -23,9 +23,10 @@ public:
 	void stopMessageLoop();
 
 	bool loopIsRunning() const;
+	bool hasMessagesQueued() const;
 
 private:
-	typedef std::queue<std::shared_ptr<MessageBase> > MessageBufferType;
+	typedef std::queue<std::shared_ptr<MessageBase>> MessageBufferType;
 
 	static std::shared_ptr<MessageQueue> s_instance;
 
@@ -43,8 +44,9 @@ private:
 	size_t m_listenersLength;
 	bool m_loopIsRunning;
 
-	std::mutex m_backMessageBufferMutex;
-	std::mutex m_listenersMutex;
+	mutable std::mutex m_frontMessageBufferMutex;
+	mutable std::mutex m_backMessageBufferMutex;
+	mutable std::mutex m_listenersMutex;
 	mutable std::mutex m_loopMutex;
 };
 
diff --git a/src/test/MessageQueueTestSuite.h b/src/test/MessageQueueTestSuite.h
index e7ddaa44..ad80cc1d 100644
--- a/src/test/MessageQueueTestSuite.h
+++ b/src/test/MessageQueueTestSuite.h
@@ -240,6 +240,9 @@ private:
 	void waitForThread() const
 	{
 		static const int THREAD_WAIT_TIME_MS = 5;
-		std::this_thread::sleep_for(std::chrono::milliseconds(THREAD_WAIT_TIME_MS));
+		while (MessageQueue::getInstance()->hasMessagesQueued())
+		{
+			std::this_thread::sleep_for(std::chrono::milliseconds(THREAD_WAIT_TIME_MS));
+		}
 	}
 };