diff --git a/components/checker/checkercomponent.cpp b/components/checker/checkercomponent.cpp
index 12b3bad69..f08436890 100644
--- a/components/checker/checkercomponent.cpp
+++ b/components/checker/checkercomponent.cpp
@@ -53,27 +53,44 @@ void CheckerComponent::Stop(void)
 
 void CheckerComponent::CheckTimerHandler(void)
 {
+	recursive_mutex::scoped_lock lock(Application::GetMutex());
+
 	double now = Utility::GetTime();
 	long tasks = 0;
 
 	int missedServices = 0, missedChecks = 0;
 
-	while (!m_IdleServices.empty()) {
-		typedef nth_index<ServiceSet, 1>::type CheckTimeView;
-		CheckTimeView& idx = boost::get<1>(m_IdleServices);
+	for (;;) {
+		Service::Ptr service;
 
-		CheckTimeView::iterator it = idx.begin();
-		Service::Ptr service = it->lock();
+		{
+			boost::mutex::scoped_lock lock(m_Mutex);
+
+			typedef nth_index<ServiceSet, 1>::type CheckTimeView;
+			CheckTimeView& idx = boost::get<1>(m_IdleServices);
+
+			if (idx.begin() == idx.end())
+				break;
+
+			CheckTimeView::iterator it = idx.begin();
+			service = it->lock();
+
+			if (!service) {
+				idx.erase(it);
+				continue;
+			}
+
+			{
+				ObjectLock olock(service);
+
+				if (service->GetNextCheck() > now)
+					break;
+			}
 
-		if (!service) {
 			idx.erase(it);
-			continue;
 		}
 
-		if (service->GetNextCheck() > now)
-			break;
-
-		idx.erase(it);
+		ObjectLock olock(service);
 
 		/* reschedule the service if checks are currently disabled
 		 * for it and this is not a forced check */
@@ -83,7 +100,14 @@ void CheckerComponent::CheckTimerHandler(void)
 
 				service->UpdateNextCheck();
 
-				idx.insert(service);
+				{
+					boost::mutex::scoped_lock lock(m_Mutex);
+
+					typedef nth_index<ServiceSet, 1>::type CheckTimeView;
+					CheckTimeView& idx = boost::get<1>(m_IdleServices);
+
+					idx.insert(service);
+				}
 
 				continue;
 			}
@@ -136,19 +160,26 @@ void CheckerComponent::CheckTimerHandler(void)
 
 void CheckerComponent::CheckCompletedHandler(const Service::Ptr& service)
 {
-	/* remove the service from the list of pending services; if it's not in the
-	 * list this was a manual (i.e. forced) check and we must not re-add the
-	 * service to the services list because it's already there. */
-	CheckerComponent::ServiceSet::iterator it;
-	it = m_PendingServices.find(service);
-	if (it != m_PendingServices.end()) {
-		m_PendingServices.erase(it);
-		m_IdleServices.insert(service);
+	{
+		boost::mutex::scoped_lock lock(m_Mutex);
+
+		/* remove the service from the list of pending services; if it's not in the
+		 * list this was a manual (i.e. forced) check and we must not re-add the
+		 * service to the services list because it's already there. */
+		CheckerComponent::ServiceSet::iterator it;
+		it = m_PendingServices.find(service);
+		if (it != m_PendingServices.end()) {
+			m_PendingServices.erase(it);
+			m_IdleServices.insert(service);
+		}
 	}
 
 	RescheduleCheckTimer();
 
-	Logger::Write(LogDebug, "checker", "Check finished for service '" + service->GetName() + "'");
+	{
+		ObjectLock olock(service);
+		Logger::Write(LogDebug, "checker", "Check finished for service '" + service->GetName() + "'");
+	}
 }
 
 void CheckerComponent::ResultTimerHandler(void)
@@ -156,20 +187,35 @@ void CheckerComponent::ResultTimerHandler(void)
 	Logger::Write(LogDebug, "checker", "ResultTimerHandler entered.");
 
 	stringstream msgbuf;
-	msgbuf << "Pending services: " << m_PendingServices.size() << "; Idle services: " << m_IdleServices.size();
+
+	{
+		boost::mutex::scoped_lock lock(m_Mutex);
+
+		msgbuf << "Pending services: " << m_PendingServices.size() << "; Idle services: " << m_IdleServices.size();
+	}
+
 	Logger::Write(LogInformation, "checker", msgbuf.str());
 }
 
 void CheckerComponent::CheckerChangedHandler(const Service::Ptr& service)
 {
-	String checker = service->GetChecker();
+	String checker;
+
+	{
+		ObjectLock olock(service);
+		checker = service->GetChecker();
+	}
 
 	if (checker == EndpointManager::GetInstance()->GetIdentity() || checker == m_Endpoint->GetName()) {
+		boost::mutex::scoped_lock lock(m_Mutex);
+
 		if (m_PendingServices.find(service) != m_PendingServices.end())
 			return;
 
 		m_IdleServices.insert(service);
 	} else {
+		boost::mutex::scoped_lock lock(m_Mutex);
+
 		m_IdleServices.erase(service);
 		m_PendingServices.erase(service);
 	}
@@ -177,16 +223,20 @@ void CheckerComponent::CheckerChangedHandler(const Service::Ptr& service)
 
 void CheckerComponent::NextCheckChangedHandler(const Service::Ptr& service)
 {
-	/* remove and re-insert the service from the set in order to force an index update */
-	typedef nth_index<ServiceSet, 0>::type ServiceView;
-	ServiceView& idx = boost::get<0>(m_IdleServices);
+	{
+		boost::mutex::scoped_lock lock(m_Mutex);
 
-	ServiceView::iterator it = idx.find(service);
-	if (it == idx.end())
-		return;
+		/* remove and re-insert the service from the set in order to force an index update */
+		typedef nth_index<ServiceSet, 0>::type ServiceView;
+		ServiceView& idx = boost::get<0>(m_IdleServices);
 
-	idx.erase(it);
-	idx.insert(service);
+		ServiceView::iterator it = idx.find(service);
+		if (it == idx.end())
+			return;
+
+		idx.erase(it);
+		idx.insert(service);
+	}
 
 	RescheduleCheckTimer();
 }
@@ -199,31 +249,40 @@ void CheckerComponent::ObjectRemovedHandler(const DynamicObject::Ptr& object)
 	if (!service)
 		return;
 
-	m_IdleServices.erase(service);
-	m_PendingServices.erase(service);
+	{
+		boost::mutex::scoped_lock lock(m_Mutex);
+
+		m_IdleServices.erase(service);
+		m_PendingServices.erase(service);
+	}
 }
 
 void CheckerComponent::RescheduleCheckTimer(void)
 {
-	if (m_IdleServices.empty())
-		return;
-
-	typedef nth_index<ServiceSet, 1>::type CheckTimeView;
-	CheckTimeView& idx = boost::get<1>(m_IdleServices);
-
 	Service::Ptr service;
 
-	do {
-		CheckTimeView::iterator it = idx.begin();
+	{
+		boost::mutex::scoped_lock lock(m_Mutex);
 
-		if (it == idx.end())
+		if (m_IdleServices.empty())
 			return;
 
-		service = it->lock();
+		typedef nth_index<ServiceSet, 1>::type CheckTimeView;
+		CheckTimeView& idx = boost::get<1>(m_IdleServices);
 
-		if (!service)
-			idx.erase(it);
-	} while (!service);
+		do {
+			CheckTimeView::iterator it = idx.begin();
 
+			if (it == idx.end())
+				return;
+
+			service = it->lock();
+
+			if (!service)
+				idx.erase(it);
+		} while (!service);
+	}
+
+	ObjectLock olock(service);
 	m_CheckTimer->Reschedule(service->GetNextCheck());
 }
diff --git a/components/checker/checkercomponent.h b/components/checker/checkercomponent.h
index f930fa04b..4e4134cde 100644
--- a/components/checker/checkercomponent.h
+++ b/components/checker/checkercomponent.h
@@ -37,7 +37,10 @@ struct ServiceNextCheckExtractor
 		if (!service)
 			return 0;
 
-		return service->GetNextCheck();
+		{
+			ObjectLock olock(service);
+			return service->GetNextCheck();
+		}
 	}
 };
 
@@ -64,6 +67,8 @@ public:
 private:
 	Endpoint::Ptr m_Endpoint;
 
+	boost::mutex m_Mutex;
+
 	ServiceSet m_IdleServices;
 	ServiceSet m_PendingServices;
 
diff --git a/components/checker/i2-checker.h b/components/checker/i2-checker.h
index 9b7a7f49e..f21721915 100644
--- a/components/checker/i2-checker.h
+++ b/components/checker/i2-checker.h
@@ -29,17 +29,6 @@
 #include <i2-base.h>
 #include <i2-icinga.h>
 
-#include <boost/multi_index_container.hpp>
-#include <boost/multi_index/ordered_index.hpp>
-#include <boost/multi_index/key_extractors.hpp>
-
-using boost::multi_index_container;
-using boost::multi_index::indexed_by;
-using boost::multi_index::identity;
-using boost::multi_index::ordered_unique;
-using boost::multi_index::ordered_non_unique;
-using boost::multi_index::nth_index;
-
 #include "checkercomponent.h"
 
 #endif /* I2CHECKER_H */
diff --git a/components/compat/compatcomponent.cpp b/components/compat/compatcomponent.cpp
index ff080e9ac..360a2af89 100644
--- a/components/compat/compatcomponent.cpp
+++ b/components/compat/compatcomponent.cpp
@@ -124,7 +124,6 @@ void CompatComponent::CommandPipeThread(const String& commandPath)
 		}
 	}
 
-
 	if (!fifo_ok && mkfifo(commandPath.CStr(), S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP) < 0)
 		BOOST_THROW_EXCEPTION(PosixException("mkfifo() failed", errno));
 
@@ -154,7 +153,12 @@ void CompatComponent::CommandPipeThread(const String& commandPath)
 				line[strlen(line) - 1] = '\0';
 
 			String command = line;
-			Application::GetEQ().Post(boost::bind(&CompatComponent::ProcessCommand, this, command));
+
+			{
+				recursive_mutex::scoped_lock lock(Application::GetMutex());
+
+				ProcessCommand(command);
+			}
 		}
 
 		fclose(fp);
@@ -412,6 +416,8 @@ void CompatComponent::DumpServiceObject(ofstream& fp, const Service::Ptr& servic
  */
 void CompatComponent::StatusTimerHandler(void)
 {
+	recursive_mutex::scoped_lock lock(Application::GetMutex());
+
 	Logger::Write(LogInformation, "compat", "Writing compat status information");
 
 	String statuspath = GetStatusPath();
diff --git a/components/delegation/delegationcomponent.cpp b/components/delegation/delegationcomponent.cpp
index fb00b4335..4e32271a6 100644
--- a/components/delegation/delegationcomponent.cpp
+++ b/components/delegation/delegationcomponent.cpp
@@ -82,6 +82,8 @@ vector<Endpoint::Ptr> DelegationComponent::GetCheckerCandidates(const Service::P
 
 void DelegationComponent::DelegationTimerHandler(void)
 {
+	recursive_mutex::scoped_lock lock(Application::GetMutex());
+
 	map<Endpoint::Ptr, int> histogram;
 
 	DynamicObject::Ptr object;
diff --git a/components/demo/democomponent.cpp b/components/demo/democomponent.cpp
index e2657d078..07272ad97 100644
--- a/components/demo/democomponent.cpp
+++ b/components/demo/democomponent.cpp
@@ -54,6 +54,8 @@ void DemoComponent::Stop(void)
  */
 void DemoComponent::DemoTimerHandler(void)
 {
+	recursive_mutex::scoped_lock lock(Application::GetMutex());
+
 	Logger::Write(LogInformation, "demo", "Sending multicast 'hello"
 	    " world' message.");
 
diff --git a/components/notification/notificationcomponent.cpp b/components/notification/notificationcomponent.cpp
index d4de1111f..a529ce536 100644
--- a/components/notification/notificationcomponent.cpp
+++ b/components/notification/notificationcomponent.cpp
@@ -53,6 +53,8 @@ void NotificationComponent::Stop(void)
  */
 void NotificationComponent::NotificationTimerHandler(void)
 {
+	recursive_mutex::scoped_lock lock(Application::GetMutex());
+
 	// TODO: implement
 }
 
diff --git a/components/replication/replicationcomponent.cpp b/components/replication/replicationcomponent.cpp
index e35a6e3e5..218ca7ada 100644
--- a/components/replication/replicationcomponent.cpp
+++ b/components/replication/replicationcomponent.cpp
@@ -32,7 +32,7 @@ void ReplicationComponent::Start(void)
 
 	DynamicObject::OnRegistered.connect(boost::bind(&ReplicationComponent::LocalObjectRegisteredHandler, this, _1));
 	DynamicObject::OnUnregistered.connect(boost::bind(&ReplicationComponent::LocalObjectUnregisteredHandler, this, _1));
-	DynamicObject::OnTransactionClosing.connect(boost::bind(&ReplicationComponent::TransactionClosingHandler, this, _1));
+	DynamicObject::OnTransactionClosing.connect(boost::bind(&ReplicationComponent::TransactionClosingHandler, this, _2));
 
 	Endpoint::OnConnected.connect(boost::bind(&ReplicationComponent::EndpointConnectedHandler, this, _1));
 
diff --git a/icinga-app/icinga.cpp b/icinga-app/icinga.cpp
index 08af5900b..1dafdfe95 100644
--- a/icinga-app/icinga.cpp
+++ b/icinga-app/icinga.cpp
@@ -66,23 +66,6 @@ static bool LoadConfigFiles(bool validateOnly)
 	if (hasError)
 		return false;
 
-/*			Logger::Write(LogInformation, "icinga-app", "Validating config items...");
-			DynamicType::Ptr type;
-			BOOST_FOREACH(tie(tuples::ignore, type), DynamicType::GetTypes()) {
-				ConfigType::Ptr ctype = ConfigType::GetByName(type->GetName());
-
-				if (!ctype) {
-					Logger::Write(LogWarning, "icinga-app", "No config type found for type '" + type->GetName() + "'");
-
-					continue;
-				}
-
-				DynamicObject::Ptr object;
-				BOOST_FOREACH(tie(tuples::ignore, object), type->GetObjects()) {
-					ctype->ValidateObject(object);
-				}
-			}*/
-
 	if (validateOnly)
 		return true;
 
@@ -105,8 +88,13 @@ static bool LoadConfigFiles(bool validateOnly)
 static void ReloadConfigTimerHandler(void)
 {
 	if (g_ReloadConfig) {
-		Logger::Write(LogInformation, "icinga-app", "Received SIGHUP. Reloading config files.");
-		LoadConfigFiles(false);
+		{
+			recursive_mutex::scoped_lock lock(Application::GetMutex());
+
+			Logger::Write(LogInformation, "icinga-app", "Received SIGHUP. Reloading config files.");
+			LoadConfigFiles(false);
+		}
+
 		g_ReloadConfig = false;
 	}
 }
@@ -136,10 +124,6 @@ int main(int argc, char **argv)
 	lt_dlinit();
 #endif /* _WIN32 */
 
-	/* This must be done before calling any other functions
-	 * in the base library. */
-	Application::SetMainThread();
-
 	/* Set command-line arguments. */
 	Application::SetArgC(argc);
 	Application::SetArgV(argv);
@@ -252,14 +236,14 @@ int main(int argc, char **argv)
 		return EXIT_FAILURE;
 	}
 
-	DynamicObject::BeginTx();
+	DynamicObject::NewTx();
 
 	bool validateOnly = g_AppParams.count("validate");
 
 	if (!LoadConfigFiles(validateOnly))
 		return EXIT_FAILURE;
 
-	DynamicObject::FinishTx();
+	DynamicObject::NewTx();
 
 	if (validateOnly) {
 		Logger::Write(LogInformation, "icinga-app", "Terminating as requested by --validate.");
@@ -290,4 +274,3 @@ int main(int argc, char **argv)
 
 	return app->Run();
 }
-
diff --git a/lib/base/application.cpp b/lib/base/application.cpp
index 531a8168d..ab91ce35b 100644
--- a/lib/base/application.cpp
+++ b/lib/base/application.cpp
@@ -21,7 +21,7 @@
 
 using namespace icinga;
 
-boost::mutex Application::m_Mutex;
+recursive_mutex Application::m_Mutex;
 Application *Application::m_Instance = NULL;
 bool Application::m_ShuttingDown = false;
 bool Application::m_Debugging = false;
@@ -110,25 +110,26 @@ void Application::SetArgV(char **argv)
 	m_ArgV = argv;
 }
 
-/**
- * Runs one iteration of the event loop.
- *
- * @returns false if we're shutting down, true otherwise.
- */
-bool Application::ProcessEvents(void)
+void Application::NewTxTimerHandler(void)
 {
-	Object::ClearHeldObjects();
+	DynamicObject::NewTx();
+}
 
-	double sleep = Timer::ProcessTimers();
+#ifdef _DEBUG
+void Application::ProfileTimerHandler(void)
+{
+	stringstream msgbuf;
+	msgbuf << "Active objects: " << Object::GetAliveObjectsCount();
+	Logger::Write(LogInformation, "base", msgbuf.str());
 
+	Object::PrintMemoryProfile();
+}
+#endif /* _DEBUG */
+
+void Application::ShutdownTimerHandler(void)
+{
 	if (m_ShuttingDown)
-		return false;
-
-	GetEQ().ProcessEvents(m_Mutex, boost::posix_time::milliseconds(sleep * 1000));
-
-	DynamicObject::FlushTx();
-
-	return true;
+		m_EQ.Stop();
 }
 
 /**
@@ -137,32 +138,31 @@ bool Application::ProcessEvents(void)
  */
 void Application::RunEventLoop(void) const
 {
-	boost::mutex::scoped_lock lock(m_Mutex);
-
-#ifdef _DEBUG
-	double nextProfile = 0;
-#endif /* _DEBUG */
-
 	/* Start the system time watch thread. */
 	thread t(&Application::TimeWatchThreadProc);
 	t.detach();
 
-	while (!m_ShuttingDown) {
-		if (!ProcessEvents())
-			break;
+	/* Set up a timer to periodically flush the tx. */
+	Timer::Ptr newTxTimer = boost::make_shared<Timer>();
+	newTxTimer->OnTimerExpired.connect(boost::bind(&Application::NewTxTimerHandler));
+	newTxTimer->SetInterval(0.5);
+	newTxTimer->Start();
+
+	/* Set up a timer that watches the m_Shutdown flag. */
+	Timer::Ptr shutdownTimer = boost::make_shared<Timer>();
+	shutdownTimer->OnTimerExpired.connect(boost::bind(&Application::ShutdownTimerHandler));
+	shutdownTimer->SetInterval(0.5);
+	shutdownTimer->Start();
 
 #ifdef _DEBUG
-		if (nextProfile < Utility::GetTime()) {
-			stringstream msgbuf;
-			msgbuf << "Active objects: " << Object::GetAliveObjectsCount();
-			Logger::Write(LogInformation, "base", msgbuf.str());
-
-			Object::PrintMemoryProfile();
-
-			nextProfile = Utility::GetTime() + 15.0;
-		}
+	/* Set up a timer that periodically prints some information about the object system. */
+	Timer::Ptr profileTimer = boost::make_shared<Timer>();
+	profileTimer->OnTimerExpired.connect(boost::bind(&Application::ProfileTimerHandler));
+	flushTxTimer->SetInterval(15);
+	flushTxTimer->Start();
 #endif /* _DEBUG */
-	}
+
+	GetEQ().Run();
 }
 
 /**
@@ -186,12 +186,7 @@ void Application::TimeWatchThreadProc(void)
 			       << " in time: " << abs(timeDiff) << " seconds";
 			Logger::Write(LogInformation, "base", msgbuf.str());
 
-			/* in addition to rescheduling the timers this
-			 * causes the event loop to wake up thereby
-			 * solving the problem that timed_wait()
-			 * uses an absolute timestamp for the timeout */
-			GetEQ().Post(boost::bind(&Timer::AdjustTimers,
-			    -timeDiff));
+			Timer::AdjustTimers(-timeDiff);
 		}
 
 		lastLoop = now;
@@ -302,25 +297,6 @@ bool Application::IsDebugging(void)
 	return m_Debugging;
 }
 
-/**
- * Checks whether we're currently on the main thread.
- *
- * @returns true if this is the main thread, false otherwise
- */
-bool Application::IsMainThread(void)
-{
-	return (boost::this_thread::get_id() == m_MainThreadID);
-}
-
-/**
- * Sets the main thread to the currently running thread.
- */
-void Application::SetMainThread(void)
-{
-	m_MainThreadID = boost::this_thread::get_id();
-	m_EQ.SetOwner(m_MainThreadID);
-}
-
 /**
  * Displays a message that tells users what to do when they encounter a bug.
  */
@@ -455,11 +431,11 @@ int Application::Run(void)
 	SetConsoleCtrlHandler(&Application::CtrlHandler, TRUE);
 #endif /* _WIN32 */
 
-	DynamicObject::BeginTx();
+	DynamicObject::NewTx();
 
 	result = Main();
 
-	DynamicObject::FinishTx();
+	DynamicObject::NewTx();
 	DynamicObject::DeactivateObjects();
 
 	return result;
@@ -594,11 +570,11 @@ void Application::SetPkgDataDir(const String& path)
 }
 
 /**
- * Returns the global mutex for the main thread.
+ * Returns the global mutex.
  *
  * @returns The mutex.
  */
-boost::mutex& Application::GetMutex(void)
+recursive_mutex& Application::GetMutex(void)
 {
 	return m_Mutex;
 }
diff --git a/lib/base/application.h b/lib/base/application.h
index 358a8ee2e..f816f7b0e 100644
--- a/lib/base/application.h
+++ b/lib/base/application.h
@@ -62,9 +62,6 @@ public:
 	static void SetDebugging(bool debug);
 	static bool IsDebugging(void);
 
-	static bool IsMainThread(void);
-	static void SetMainThread(void);
-
 	void UpdatePidFile(const String& filename);
 	void ClosePidFile(void);
 
@@ -82,9 +79,7 @@ public:
 	static String GetPkgDataDir(void);
 	static void SetPkgDataDir(const String& path);
 
-	static bool ProcessEvents(void);
-
-	static boost::mutex& GetMutex(void);
+	static recursive_mutex& GetMutex(void);
 
 	static EventQueue& GetEQ(void);
 
@@ -92,7 +87,7 @@ protected:
 	void RunEventLoop(void) const;
 
 private:
-	static boost::mutex m_Mutex; /**< The main thread mutex. */
+	static recursive_mutex m_Mutex; /**< The global mutex. */
 	static Application *m_Instance; /**< The application instance. */
 
 	static bool m_ShuttingDown; /**< Whether the application is in the process of
@@ -120,6 +115,11 @@ private:
 	static void ExceptionHandler(void);
 
 	static void TimeWatchThreadProc(void);
+	static void NewTxTimerHandler(void);
+#ifdef _DEBUG
+	static void ProfileTimerHandler(void)
+#endif /* _DEBUG */
+	static void ShutdownTimerHandler(void);
 };
 
 }
diff --git a/lib/base/asynctask.h b/lib/base/asynctask.h
index ca0f8b3d6..a1941866b 100644
--- a/lib/base/asynctask.h
+++ b/lib/base/asynctask.h
@@ -18,7 +18,7 @@
  ******************************************************************************/
 
 #ifndef ASYNCTASK_H
-#define ASYNCTASK_H 
+#define ASYNCTASK_H
 
 namespace icinga
 {
@@ -79,6 +79,7 @@ public:
 	 */
 	bool IsFinished(void) const
 	{
+		boost::mutex::scoped_lock lock(m_Mutex);
 		return m_Finished;
 	}
 
@@ -133,7 +134,9 @@ public:
 	 */
 	void Wait(void)
 	{
-		Utility::WaitUntil(boost::bind(&AsyncTask<TClass, TResult>::IsFinished, this));
+		boost::mutex::scoped_lock lock(m_Mutex);
+		while (!m_Finished)
+			m_CV.wait(lock);
 	}
 
 protected:
@@ -151,9 +154,14 @@ private:
 	 */
 	void FinishInternal(void)
 	{
-		assert(!m_Finished);
+		{
+			boost::mutex::scoped_lock lock(m_Mutex);
+			assert(!m_Finished);
 
-		m_Finished = true;
+			m_Finished = true;
+
+			m_CV.notify_all();
+		}
 
 		if (!m_CompletionCallback.empty()) {
 			m_CompletionCallback(GetSelf());
@@ -164,6 +172,8 @@ private:
 		}
 	}
 
+	mutable boost::mutex m_Mutex;
+	boost::condition_variable m_CV;
 	CompletionCallback m_CompletionCallback; /**< The completion callback. */
 	TResult m_Result; /**< The task's result. */
 	boost::exception_ptr m_Exception; /**< The task's exception. */
diff --git a/lib/base/component.cpp b/lib/base/component.cpp
index f60ed4f6c..86074b7c7 100644
--- a/lib/base/component.cpp
+++ b/lib/base/component.cpp
@@ -29,8 +29,6 @@ REGISTER_TYPE(Component, NULL);
 Component::Component(const Dictionary::Ptr& properties)
 	: DynamicObject(properties)
 {
-	assert(Application::IsMainThread());
-
 	if (!IsLocal())
 		BOOST_THROW_EXCEPTION(runtime_error("Component objects must be local."));
 
diff --git a/lib/base/connection.h b/lib/base/connection.h
index 4e48d4081..8167e9a73 100644
--- a/lib/base/connection.h
+++ b/lib/base/connection.h
@@ -35,7 +35,7 @@ public:
 
 	void Close(void);
 
-	boost::signal<void (const Connection::Ptr&)> OnClosed;
+	signals2::signal<void (const Connection::Ptr&)> OnClosed;
 
 protected:
 	virtual void ProcessData(void) = 0;
diff --git a/lib/base/dynamicobject.cpp b/lib/base/dynamicobject.cpp
index 10ae87196..4583805c7 100644
--- a/lib/base/dynamicobject.cpp
+++ b/lib/base/dynamicobject.cpp
@@ -23,10 +23,11 @@ using namespace icinga;
 
 double DynamicObject::m_CurrentTx = 0;
 set<DynamicObject *> DynamicObject::m_ModifiedObjects;
+boost::mutex DynamicObject::m_ModifiedObjectsMutex;
 
-boost::signal<void (const DynamicObject::Ptr&)> DynamicObject::OnRegistered;
-boost::signal<void (const DynamicObject::Ptr&)> DynamicObject::OnUnregistered;
-boost::signal<void (const set<DynamicObject *>&)> DynamicObject::OnTransactionClosing;
+signals2::signal<void (const DynamicObject::Ptr&)> DynamicObject::OnRegistered;
+signals2::signal<void (const DynamicObject::Ptr&)> DynamicObject::OnUnregistered;
+signals2::signal<void (double, const set<DynamicObject *>&)> DynamicObject::OnTransactionClosing;
 
 DynamicObject::DynamicObject(const Dictionary::Ptr& serializedObject)
 	: m_ConfigTx(0)
@@ -47,8 +48,12 @@ DynamicObject::DynamicObject(const Dictionary::Ptr& serializedObject)
 	ApplyUpdate(serializedObject, Attribute_Config);
 }
 
+/*
+ * @threadsafety Always.
+ */
 DynamicObject::~DynamicObject(void)
 {
+	boost::mutex::scoped_lock lock(m_ModifiedObjectsMutex);
 	m_ModifiedObjects.erase(this);
 }
 
@@ -193,7 +198,10 @@ void DynamicObject::InternalSetAttribute(const String& name, const Value& data,
 	if (tt.first->second.Type & Attribute_Config)
 		m_ConfigTx = tx;
 
-	m_ModifiedObjects.insert(this);
+	{
+		boost::mutex::scoped_lock lock(m_ModifiedObjectsMutex);
+		m_ModifiedObjects.insert(this);
+	}
 
 	/* Use insert() rather than [] so we don't overwrite
 	 * an existing oldValue if the attribute was previously
@@ -272,7 +280,7 @@ String DynamicObject::GetSource(void) const
 
 void DynamicObject::Register(void)
 {
-	assert(Application::IsMainThread());
+	recursive_mutex::scoped_lock lock(Application::GetMutex());
 
 	DynamicType::Ptr dtype = GetType();
 
@@ -294,7 +302,7 @@ void DynamicObject::Start(void)
 
 void DynamicObject::Unregister(void)
 {
-	assert(Application::IsMainThread());
+	recursive_mutex::scoped_lock lock(Application::GetMutex());
 
 	DynamicType::Ptr dtype = GetType();
 
@@ -331,8 +339,13 @@ ScriptTask::Ptr DynamicObject::InvokeMethod(const String& method,
 	return task;
 }
 
+/*
+ * @threadsafety Always.
+ */
 void DynamicObject::DumpObjects(const String& filename)
 {
+	recursive_mutex::scoped_lock lock(Application::GetMutex());
+
 	Logger::Write(LogInformation, "base", "Dumping program state to file '" + filename + "'");
 
 	String tempFilename = filename + ".tmp";
@@ -391,8 +404,13 @@ void DynamicObject::DumpObjects(const String& filename)
 		BOOST_THROW_EXCEPTION(PosixException("rename() failed", errno));
 }
 
+/*
+ * @threadsafety Always.
+ */
 void DynamicObject::RestoreObjects(const String& filename)
 {
+	recursive_mutex::scoped_lock lock(Application::GetMutex());
+
 	Logger::Write(LogInformation, "base", "Restoring program state from file '" + filename + "'");
 
 	std::fstream fp;
@@ -437,8 +455,13 @@ void DynamicObject::RestoreObjects(const String& filename)
 	Logger::Write(LogDebug, "base", msgbuf.str());
 }
 
+/*
+ * @threadsafety Always.
+ */
 void DynamicObject::DeactivateObjects(void)
 {
+	recursive_mutex::scoped_lock lock(Application::GetMutex());
+
 	DynamicType::TypeMap::iterator tt;
 	for (tt = DynamicType::GetTypes().begin(); tt != DynamicType::GetTypes().end(); tt++) {
 		DynamicType::NameMap::iterator nt;
@@ -451,34 +474,42 @@ void DynamicObject::DeactivateObjects(void)
 	}
 }
 
+/*
+ * @threadsafety Always.
+ */
 double DynamicObject::GetCurrentTx(void)
 {
+	recursive_mutex::scoped_lock lock(Application::GetMutex());
+
 	assert(m_CurrentTx != 0);
 
 	return m_CurrentTx;
 }
 
-void DynamicObject::BeginTx(void)
+/*
+ * @threadsafety Always.
+ */
+void DynamicObject::NewTx(void)
 {
-	m_CurrentTx = Utility::GetTime();
-}
+	set<DynamicObject *> objects;
 
-void DynamicObject::FinishTx(void)
-{
-	BOOST_FOREACH(DynamicObject *object, m_ModifiedObjects) {
+	{
+		boost::mutex::scoped_lock lock(m_ModifiedObjectsMutex);
+
+		/* Some objects may accidentally bleed into the next transaction because
+		 * we're not holding the global mutex while "stealing" the modified objects,
+		 * but that's entirely ok. */
+		m_ModifiedObjects.swap(objects);
+	}
+
+	recursive_mutex::scoped_lock lock(Application::GetMutex());
+
+	BOOST_FOREACH(DynamicObject *object, objects) {
 		object->SendLocalUpdateEvents();
 	}
 
-	OnTransactionClosing(m_ModifiedObjects);
-	m_ModifiedObjects.clear();
-
-	m_CurrentTx = 0;
-}
-
-void DynamicObject::FlushTx(void)
-{
-	FinishTx();
-	BeginTx();
+	OnTransactionClosing(m_CurrentTx, objects);
+	m_CurrentTx = Utility::GetTime();
 }
 
 void DynamicObject::OnInitCompleted(void)
@@ -487,8 +518,13 @@ void DynamicObject::OnInitCompleted(void)
 void DynamicObject::OnAttributeChanged(const String&, const Value&)
 { }
 
+/*
+ * @threadsafety Always.
+ */
 DynamicObject::Ptr DynamicObject::GetObject(const String& type, const String& name)
 {
+	recursive_mutex::scoped_lock lock(Application::GetMutex());
+
 	DynamicType::Ptr dtype = DynamicType::GetByName(type);
 	return dtype->GetObject(name);
 }
diff --git a/lib/base/dynamicobject.h b/lib/base/dynamicobject.h
index 8e02d075d..24377f3bd 100644
--- a/lib/base/dynamicobject.h
+++ b/lib/base/dynamicobject.h
@@ -94,9 +94,9 @@ public:
 
 	void ClearAttributesByType(DynamicAttributeType type);
 
-	static boost::signal<void (const DynamicObject::Ptr&)> OnRegistered;
-	static boost::signal<void (const DynamicObject::Ptr&)> OnUnregistered;
-	static boost::signal<void (const set<DynamicObject *>&)> OnTransactionClosing;
+	static signals2::signal<void (const DynamicObject::Ptr&)> OnRegistered;
+	static signals2::signal<void (const DynamicObject::Ptr&)> OnUnregistered;
+	static signals2::signal<void (double, const set<DynamicObject *>&)> OnTransactionClosing;
 
 	ScriptTask::Ptr InvokeMethod(const String& method,
 	    const vector<Value>& arguments, ScriptTask::CompletionCallback callback);
@@ -127,9 +127,7 @@ public:
 	static void DeactivateObjects(void);
 
 	static double GetCurrentTx(void);
-	static void BeginTx(void);
-	static void FinishTx(void);
-	static void FlushTx(void);
+	static void NewTx(void);
 
 protected:
 	virtual void OnInitCompleted(void);
@@ -149,6 +147,7 @@ private:
 	/* This has to be a set of raw pointers because the DynamicObject
 	 * constructor has to be able to insert objects into this list. */
 	static set<DynamicObject *> m_ModifiedObjects;
+	static boost::mutex m_ModifiedObjectsMutex;
 
 	friend class DynamicType; /* for OnInitCompleted. */
 };
diff --git a/lib/base/dynamictype.cpp b/lib/base/dynamictype.cpp
index 75ec7fae6..1e40c0681 100644
--- a/lib/base/dynamictype.cpp
+++ b/lib/base/dynamictype.cpp
@@ -21,12 +21,19 @@
 
 using namespace icinga;
 
+boost::mutex DynamicType::m_Mutex;
+
 DynamicType::DynamicType(const String& name, const DynamicType::ObjectFactory& factory)
 	: m_Name(name), m_ObjectFactory(factory)
 { }
 
+/**
+ * @threadsafety Always.
+ */
 DynamicType::Ptr DynamicType::GetByName(const String& name)
 {
+	boost::mutex::scoped_lock lock(m_Mutex);
+
 	DynamicType::TypeMap::const_iterator tt = GetTypes().find(name);
 
 	if (tt == GetTypes().end())
@@ -35,12 +42,18 @@ DynamicType::Ptr DynamicType::GetByName(const String& name)
 	return tt->second;
 }
 
+/**
+ * @threadsafety Caller must hold DynamicType::m_Mutex while using the map.
+ */
 DynamicType::TypeMap& DynamicType::GetTypes(void)
 {
 	static DynamicType::TypeMap types;
 	return types;
 }
 
+/**
+ * @threadsafety Caller must hold DynamicType::m_Mutex while using the map.
+ */
 DynamicType::NameMap& DynamicType::GetObjects(void)
 {
 	return m_Objects;
@@ -71,9 +84,16 @@ DynamicObject::Ptr DynamicType::GetObject(const String& name) const
 	return nt->second;
 }
 
+/**
+ * @threadsafety Always.
+ */
 void DynamicType::RegisterType(const DynamicType::Ptr& type)
 {
-	if (GetByName(type->GetName()))
+	boost::mutex::scoped_lock lock(m_Mutex);
+
+	DynamicType::TypeMap::const_iterator tt = GetTypes().find(type->GetName());
+
+	if (tt != GetTypes().end())
 		BOOST_THROW_EXCEPTION(runtime_error("Cannot register class for type '" +
 		    type->GetName() + "': Objects of this type already exist."));
 
@@ -99,6 +119,9 @@ DynamicObject::Ptr DynamicType::CreateObject(const Dictionary::Ptr& serializedUp
 	return obj;
 }
 
+/**
+ * @threadsafety Always.
+ */
 bool DynamicType::TypeExists(const String& name)
 {
 	return (GetByName(name));
diff --git a/lib/base/dynamictype.h b/lib/base/dynamictype.h
index b2bbd6e6b..d97a6c660 100644
--- a/lib/base/dynamictype.h
+++ b/lib/base/dynamictype.h
@@ -47,15 +47,15 @@ public:
 
 	static void RegisterType(const DynamicType::Ptr& type);
 	static bool TypeExists(const String& name);
-	
+
 	DynamicObject::Ptr CreateObject(const Dictionary::Ptr& serializedUpdate) const;
 	DynamicObject::Ptr GetObject(const String& name) const;
 
 	void RegisterObject(const DynamicObject::Ptr& object);
 	void UnregisterObject(const DynamicObject::Ptr& object);
 
-	static TypeMap& GetTypes(void);
-	NameMap& GetObjects(void);
+	/* TODO(thread) make private */ static TypeMap& GetTypes(void);
+	/* TODO(thread) make private */ NameMap& GetObjects(void);
 
 	void AddAttribute(const String& name, DynamicAttributeType type);
 	void RemoveAttribute(const String& name);
@@ -64,6 +64,7 @@ public:
 	void AddAttributes(const AttributeDescription *attributes, int attributeCount);
 
 private:
+	static boost::mutex m_Mutex;
 	String m_Name;
 	ObjectFactory m_ObjectFactory;
 	map<String, DynamicAttributeType> m_Attributes;
diff --git a/lib/base/eventqueue.cpp b/lib/base/eventqueue.cpp
index a236e1cf1..0dc4f40b8 100644
--- a/lib/base/eventqueue.cpp
+++ b/lib/base/eventqueue.cpp
@@ -21,91 +21,95 @@
 
 using namespace icinga;
 
+/**
+ * @threadsafety Always.
+ */
 EventQueue::EventQueue(void)
 	: m_Stopped(false)
 { }
 
-boost::thread::id EventQueue::GetOwner(void) const
+/**
+ * @threadsafety Always.
+ */
+EventQueue::~EventQueue(void)
 {
-	return m_Owner;
-}
-
-void EventQueue::SetOwner(boost::thread::id owner)
-{
-	m_Owner = owner;
+	Stop();
 }
 
+/**
+ * @threadsafety Always.
+ */
 void EventQueue::Stop(void)
 {
 	boost::mutex::scoped_lock lock(m_Mutex);
 	m_Stopped = true;
-	m_EventAvailable.notify_all();
+	m_CV.notify_all();
 }
 
 /**
- * Waits for events using the specified timeout value and processes
- * them.
+ * Spawns worker threads and waits for them to complete.
  *
- * @param mtx The mutex that should be unlocked while waiting. Caller
- * 	      must have this mutex locked.
- * @param timeout The wait timeout.
- * @returns false if the queue has been stopped, true otherwise.
+ * @threadsafety Always.
  */
-bool EventQueue::ProcessEvents(boost::mutex& mtx, millisec timeout)
+void EventQueue::Run(void)
 {
-	vector<Callback> events;
+	thread_group threads;
 
-	mtx.unlock();
+	int cpus = thread::hardware_concurrency();
 
-	{
-		boost::mutex::scoped_lock lock(m_Mutex);
+	if (cpus == 0)
+		cpus = 4;
 
-		while (m_Events.empty() && !m_Stopped) {
-			if (!m_EventAvailable.timed_wait(lock, timeout)) {
-				mtx.lock();
+	for (int i = 0; i < cpus * 4; i++)
+		threads.create_thread(boost::bind(&EventQueue::QueueThreadProc, this));
 
-				return !m_Stopped;
+	threads.join_all();
+}
+
+/**
+ * Waits for events and processes them.
+ *
+ * @threadsafety Always.
+ */
+void EventQueue::QueueThreadProc(void)
+{
+	while (!m_Stopped) {
+		vector<Callback> events;
+
+		{
+			boost::mutex::scoped_lock lock(m_Mutex);
+
+			while (m_Events.empty() && !m_Stopped)
+				m_CV.wait(lock);
+
+			events.swap(m_Events);
+		}
+
+		BOOST_FOREACH(const Callback& ev, events) {
+			double st = Utility::GetTime();
+
+			ev();
+
+			double et = Utility::GetTime();
+
+			if (et - st > 1.0) {
+				stringstream msgbuf;
+				msgbuf << "Event call took " << et - st << " seconds.";
+				Logger::Write(LogWarning, "base", msgbuf.str());
 			}
 		}
-
-		events.swap(m_Events);
 	}
-
-	mtx.lock();
-
-	BOOST_FOREACH(const Callback& ev, events) {
-		double st = Utility::GetTime();
-
-		ev();
-
-		double et = Utility::GetTime();
-
-		if (et - st > 1.0) {
-			stringstream msgbuf;
-			msgbuf << "Event call took " << et - st << " seconds.";
-			Logger::Write(LogWarning, "base", msgbuf.str());
-		}
-	}
-
-	return !m_Stopped;
 }
 
 /**
- * Appends an event to the event queue. Events will be processed in FIFO
- * order on the main thread.
+ * Appends an event to the event queue. Events will be processed in FIFO order.
  *
  * @param callback The callback function for the event.
+ * @threadsafety Always.
  */
 void EventQueue::Post(const EventQueue::Callback& callback)
 {
-	if (boost::this_thread::get_id() == m_Owner) {
-		callback();
-		return;
-	}
-
-	{
-		boost::mutex::scoped_lock lock(m_Mutex);
-		m_Events.push_back(callback);
-		m_EventAvailable.notify_all();
-	}
+	boost::mutex::scoped_lock lock(m_Mutex);
+	m_Events.push_back(callback);
+	m_CV.notify_all();
 }
diff --git a/lib/base/eventqueue.h b/lib/base/eventqueue.h
index 422746482..dec61d21c 100644
--- a/lib/base/eventqueue.h
+++ b/lib/base/eventqueue.h
@@ -34,24 +34,23 @@ public:
 	typedef function<void ()> Callback;
 
 	EventQueue(void);
+	~EventQueue(void);
 
-	bool ProcessEvents(boost::mutex& mtx, millisec timeout = boost::posix_time::milliseconds(30000));
+	void Run(void);
 	void Post(const Callback& callback);
 
 	void Stop(void);
 
-	boost::thread::id GetOwner(void) const;
-	void SetOwner(boost::thread::id owner);
-
-	boost::mutex& GetMutex(void);
-
 private:
 	boost::thread::id m_Owner;
 
 	boost::mutex m_Mutex;
+	condition_variable m_CV;
+
 	bool m_Stopped;
 	vector<Callback> m_Events;
-	condition_variable m_EventAvailable;
+
+	void QueueThreadProc(void);
 };
 
 }
diff --git a/lib/base/i2-base.h b/lib/base/i2-base.h
index 8d10d41cf..04e9684f9 100644
--- a/lib/base/i2-base.h
+++ b/lib/base/i2-base.h
@@ -125,7 +125,7 @@ using std::type_info;
 #include <boost/make_shared.hpp>
 #include <boost/bind.hpp>
 #include <boost/function.hpp>
-#include <boost/signal.hpp>
+#include <boost/signals2.hpp>
 #include <boost/algorithm/string/trim.hpp>
 #include <boost/algorithm/string/split.hpp>
 #include <boost/algorithm/string/compare.hpp>
@@ -139,6 +139,9 @@ using std::type_info;
 #include <boost/uuid/uuid_io.hpp>
 #include <boost/program_options.hpp>
 #include <boost/exception/diagnostic_information.hpp>
+#include <boost/multi_index_container.hpp>
+#include <boost/multi_index/ordered_index.hpp>
+#include <boost/multi_index/key_extractors.hpp>
 
 using boost::shared_ptr;
 using boost::weak_ptr;
@@ -148,6 +151,7 @@ using boost::static_pointer_cast;
 using boost::function;
 using boost::thread;
 using boost::thread_group;
+using boost::recursive_mutex;
 using boost::condition_variable;
 using boost::system_time;
 using boost::posix_time::millisec;
@@ -155,11 +159,18 @@ using boost::tie;
 using boost::rethrow_exception;
 using boost::current_exception;
 using boost::diagnostic_information;
+using boost::multi_index_container;
+using boost::multi_index::indexed_by;
+using boost::multi_index::identity;
+using boost::multi_index::ordered_unique;
+using boost::multi_index::ordered_non_unique;
+using boost::multi_index::nth_index;
 
 namespace tuples = boost::tuples;
+namespace signals2 = boost::signals2;
 
 #if defined(__APPLE__) && defined(__MACH__)
-#	pragma GCC diagnostic ignored "-Wdeprecated-declarations" 
+#	pragma GCC diagnostic ignored "-Wdeprecated-declarations"
 #endif
 
 #include <openssl/bio.h>
diff --git a/lib/base/logger.cpp b/lib/base/logger.cpp
index 42b0551db..b59bbf79e 100644
--- a/lib/base/logger.cpp
+++ b/lib/base/logger.cpp
@@ -81,7 +81,10 @@ void Logger::Write(LogSeverity severity, const String& facility,
 	entry.Facility = facility;
 	entry.Message = message;
 
-	Application::GetEQ().Post(boost::bind(&Logger::ForwardLogEntry, entry));
+	{
+		recursive_mutex::scoped_lock lock(Application::GetMutex());
+		ForwardLogEntry(entry);
+	}
 }
 
 /**
@@ -182,4 +185,3 @@ DynamicObject::Ptr ILogger::GetConfig(void) const
 {
 	return m_Config->GetSelf();
 }
-
diff --git a/lib/base/netstring.cpp b/lib/base/netstring.cpp
index 692c7754e..dc95cf4c3 100644
--- a/lib/base/netstring.cpp
+++ b/lib/base/netstring.cpp
@@ -29,6 +29,7 @@ using namespace icinga;
  * @returns true if a complete String was read from the IOQueue, false otherwise.
  * @exception invalid_argument The input stream is invalid.
  * @see https://github.com/PeterScott/netString-c/blob/master/netString.c
+ * @threadsafety Always.
  */
 bool NetString::ReadStringFromStream(const Stream::Ptr& stream, String *str)
 {
@@ -110,6 +111,7 @@ bool NetString::ReadStringFromStream(const Stream::Ptr& stream, String *str)
  *
  * @param stream The stream.
  * @param str The String that is to be written.
+ * @threadsafety Always.
  */
 void NetString::WriteStringToStream(const Stream::Ptr& stream, const String& str)
 {
diff --git a/lib/base/object.cpp b/lib/base/object.cpp
index 10b591b52..aca652d88 100644
--- a/lib/base/object.cpp
+++ b/lib/base/object.cpp
@@ -25,43 +25,13 @@ using namespace icinga;
  * Default constructor for the Object class.
  */
 Object::Object(void)
-{
-#ifdef _DEBUG
-	boost::mutex::scoped_lock lock(*GetMutex());
-	GetAliveObjects()->insert(this);
-#endif /* _DEBUG */
-}
+{ }
 
 /**
  * Destructor for the Object class.
  */
 Object::~Object(void)
-{
-#ifdef _DEBUG
-	boost::mutex::scoped_lock lock(*GetMutex());
-	GetAliveObjects()->erase(this);
-#endif /* _DEBUG */
-}
-
-/**
- * Temporarily holds onto a reference for an object. This can
- * be used to safely clear the last reference to an object
- * in an event handler.
- */
-void Object::Hold(void)
-{
-	boost::mutex::scoped_lock lock(*GetMutex());
-	GetHeldObjects().push_back(GetSelf());
-}
-
-/**
- * Clears all temporarily held objects.
- */
-void Object::ClearHeldObjects(void)
-{
-	boost::mutex::scoped_lock lock(*GetMutex());
-	GetHeldObjects().clear();
-}
+{ }
 
 /**
  * Returns a reference-counted pointer to this object.
@@ -73,91 +43,14 @@ Object::SharedPtrHolder Object::GetSelf(void)
 	return Object::SharedPtrHolder(shared_from_this());
 }
 
-#ifdef _DEBUG
 /**
- * Retrieves the number of currently alive objects.
+ * Returns the mutex that must be held while calling non-static methods
+ * which have not been explicitly marked as thread-safe.
  *
- * @returns The number of alive objects.
+ * @returns The object's mutex.
+ * @threadsafety Always.
  */
-int Object::GetAliveObjectsCount(void)
+recursive_mutex& Object::GetMutex(void)
 {
-	boost::mutex::scoped_lock lock(*GetMutex());
-	return GetAliveObjects()->size();
+	return m_Mutex;
 }
-
-/**
- * Dumps a memory histogram to the "dictionaries.dump" file.
- */
-void Object::PrintMemoryProfile(void)
-{
-	map<String, int> types;
-
-	ofstream dictfp("dictionaries.dump.tmp");
-
-	{
-		boost::mutex::scoped_lock lock(*GetMutex());
-		set<Object *>::iterator it;
-		BOOST_FOREACH(Object *obj, *GetAliveObjects()) {
-			pair<map<String, int>::iterator, bool> tt;
-			tt = types.insert(make_pair(Utility::GetTypeName(typeid(*obj)), 1));
-			if (!tt.second)
-				tt.first->second++;
-
-			if (typeid(*obj) == typeid(Dictionary)) {
-				Dictionary::Ptr dict = obj->GetSelf();
-				dictfp << Value(dict).Serialize() << std::endl;
-			}
-		}
-	}
-
-#ifdef _WIN32
-	_unlink("dictionaries.dump");
-#endif /* _WIN32 */
-
-	dictfp.close();
-	if (rename("dictionaries.dump.tmp", "dictionaries.dump") < 0)
-		BOOST_THROW_EXCEPTION(PosixException("rename() failed", errno));
-
-	String type;
-	int count;
-	BOOST_FOREACH(tie(type, count), types) {
-		std::cerr << type << ": " << count << std::endl;
-	}
-}
-
-/**
- * Returns currently active objects.
- *
- * @returns currently active objects
- */
-set<Object *> *Object::GetAliveObjects(void)
-{
-	static set<Object *> *aliveObjects = new set<Object *>();
-	return aliveObjects;
-}
-#endif /* _DEBUG */
-
-/**
- * Returns the mutex used for accessing static members.
- *
- * @returns a mutex
- */
-boost::mutex *Object::GetMutex(void)
-{
-	static boost::mutex *mutex = new boost::mutex();
-	return mutex;
-}
-
-/**
- * Returns currently held objects. The caller must be
- * holding the mutex returned by GetMutex().
- *
- * @returns currently held objects
- */
-vector<Object::Ptr>& Object::GetHeldObjects(void)
-{
-	static vector<Object::Ptr> heldObjects;
-	return heldObjects;
-}
-
-
diff --git a/lib/base/object.h b/lib/base/object.h
index fa0fb4c95..c51c05fb6 100644
--- a/lib/base/object.h
+++ b/lib/base/object.h
@@ -31,15 +31,12 @@ class SharedPtrHolder;
  *
  * @ingroup base
  */
-class I2_BASE_API Object : public enable_shared_from_this<Object>, public boost::signals::trackable
+class I2_BASE_API Object : public enable_shared_from_this<Object>
 {
 public:
 	typedef shared_ptr<Object> Ptr;
 	typedef weak_ptr<Object> WeakPtr;
 
-	void Hold(void);
-	static void ClearHeldObjects(void);
-
 	/**
 	 * Holds a shared pointer and provides support for implicit upcasts.
 	 *
@@ -96,10 +93,7 @@ public:
 
 	SharedPtrHolder GetSelf(void);
 
-#ifdef _DEBUG
-	static int GetAliveObjectsCount(void);
-	static void PrintMemoryProfile(void);
-#endif /* _DEBUG */
+	recursive_mutex& GetMutex(void);
 
 protected:
 	Object(void);
@@ -109,9 +103,24 @@ private:
 	Object(const Object& other);
 	Object& operator=(const Object& rhs);
 
-	static boost::mutex *GetMutex(void);
-	static set<Object *> *GetAliveObjects(void);
-	static vector<Object::Ptr>& GetHeldObjects(void);
+	recursive_mutex m_Mutex;
+};
+
+/**
+ * A scoped lock for Objects.
+ */
+struct ObjectLock {
+public:
+	ObjectLock(const Object::Ptr& object)
+		: m_Lock(object->GetMutex())
+	{ }
+
+	ObjectLock(Object *object)
+		: m_Lock(object->GetMutex())
+	{ }
+
+private:
+	recursive_mutex::scoped_lock m_Lock;
 };
 
 /**
diff --git a/lib/base/process-unix.cpp b/lib/base/process-unix.cpp
index d3306e7ee..2331e37c9 100644
--- a/lib/base/process-unix.cpp
+++ b/lib/base/process-unix.cpp
@@ -26,7 +26,7 @@ using namespace icinga;
 int Process::m_TaskFd;
 extern char **environ;
 
-void Process::CreateWorkers(void)
+void Process::Initialize(void)
 {
 	int fds[2];
 
diff --git a/lib/base/process-windows.cpp b/lib/base/process-windows.cpp
index d6db2df03..3dace62fe 100644
--- a/lib/base/process-windows.cpp
+++ b/lib/base/process-windows.cpp
@@ -22,7 +22,7 @@
 
 using namespace icinga;
 
-void Process::CreateWorkers(void)
+void Process::Initialize(void)
 {
 	// TODO: implement
 }
diff --git a/lib/base/process.cpp b/lib/base/process.cpp
index 229a4d7d5..d959c0102 100644
--- a/lib/base/process.cpp
+++ b/lib/base/process.cpp
@@ -21,20 +21,14 @@
 
 using namespace icinga;
 
-bool Process::m_WorkersCreated = false;
+boost::once_flag Process::m_ThreadOnce;
 boost::mutex Process::m_Mutex;
 deque<Process::Ptr> Process::m_Tasks;
 
 Process::Process(const vector<String>& arguments, const Dictionary::Ptr& extraEnvironment)
 	: AsyncTask<Process, ProcessResult>(), m_Arguments(arguments), m_ExtraEnvironment(extraEnvironment)
 {
-	assert(Application::IsMainThread());
-
-	if (!m_WorkersCreated) {
-		CreateWorkers();
-
-		m_WorkersCreated = true;
-	}
+	boost::call_once(&Process::Initialize, m_ThreadOnce);
 
 #ifndef _WIN32
 	m_FD = -1;
diff --git a/lib/base/process.h b/lib/base/process.h
index 2a14c16fc..618acfaa4 100644
--- a/lib/base/process.h
+++ b/lib/base/process.h
@@ -54,8 +54,6 @@ public:
 
 	static vector<String> SplitCommand(const Value& command);
 private:
-	static bool m_WorkersCreated;
-
 	vector<String> m_Arguments;
 	Dictionary::Ptr m_ExtraEnvironment;
 
@@ -76,7 +74,6 @@ private:
 	static int m_TaskFd;
 #endif /* _WIN32 */
 
-	static void CreateWorkers(void);
 	static void NotifyWorker(void);
 
 	void SpawnTask(void);
@@ -89,6 +86,9 @@ private:
 
 	void InitTask(void);
 	bool RunTask(void);
+
+	static boost::once_flag m_ThreadOnce;
+	static void Initialize(void);
 };
 
 }
diff --git a/lib/base/script.cpp b/lib/base/script.cpp
index abf1a6c97..0bcc5ca77 100644
--- a/lib/base/script.cpp
+++ b/lib/base/script.cpp
@@ -32,12 +32,6 @@ Script::Script(const Dictionary::Ptr& properties)
 	: DynamicObject(properties)
 { }
 
-Script::~Script(void)
-{
-	if (m_Interpreter)
-		m_Interpreter->Stop();
-}
-
 void Script::OnInitCompleted(void)
 {
 	SpawnInterpreter();
@@ -63,10 +57,6 @@ void Script::SpawnInterpreter(void)
 {
 	Logger::Write(LogInformation, "base", "Reloading script '" + GetName() + "'");
 
-	if (m_Interpreter)
-		m_Interpreter->Stop();
-
 	ScriptLanguage::Ptr language = ScriptLanguage::GetByName(GetLanguage());
 	m_Interpreter = language->CreateInterpreter(GetSelf());
-	m_Interpreter->Start();
 }
diff --git a/lib/base/script.h b/lib/base/script.h
index 3cae28e3a..daaf288e1 100644
--- a/lib/base/script.h
+++ b/lib/base/script.h
@@ -37,7 +37,6 @@ public:
 	typedef weak_ptr<Script> WeakPtr;
 
 	Script(const Dictionary::Ptr& properties);
-	~Script(void);
 
 	String GetLanguage(void) const;
 	String GetCode(void) const;
diff --git a/lib/base/scriptfunction.cpp b/lib/base/scriptfunction.cpp
index 3a8f5fafa..06ac24294 100644
--- a/lib/base/scriptfunction.cpp
+++ b/lib/base/scriptfunction.cpp
@@ -21,8 +21,8 @@
 
 using namespace icinga;
 
-boost::signal<void (const String&, const ScriptFunction::Ptr&)> ScriptFunction::OnRegistered;
-boost::signal<void (const String&)> ScriptFunction::OnUnregistered;
+signals2::signal<void (const String&, const ScriptFunction::Ptr&)> ScriptFunction::OnRegistered;
+signals2::signal<void (const String&)> ScriptFunction::OnUnregistered;
 
 ScriptFunction::ScriptFunction(const Callback& function)
 	: m_Callback(function)
@@ -31,13 +31,13 @@ ScriptFunction::ScriptFunction(const Callback& function)
 void ScriptFunction::Register(const String& name, const ScriptFunction::Ptr& function)
 {
 	GetFunctions()[name] = function;
-	Application::GetEQ().Post(boost::bind(boost::ref(OnRegistered), name, function));
+	OnRegistered(name, function);
 }
 
 void ScriptFunction::Unregister(const String& name)
 {
 	GetFunctions().erase(name);
-	Application::GetEQ().Post(boost::bind(boost::ref(OnUnregistered), name));
+	OnUnregistered(name);
 }
 
 ScriptFunction::Ptr ScriptFunction::GetByName(const String& name)
diff --git a/lib/base/scriptfunction.h b/lib/base/scriptfunction.h
index 4597acde6..babb62f4a 100644
--- a/lib/base/scriptfunction.h
+++ b/lib/base/scriptfunction.h
@@ -46,10 +46,10 @@ public:
 
 	void Invoke(const shared_ptr<ScriptTask>& task, const vector<Value>& arguments);
 
-	static map<String, ScriptFunction::Ptr>& GetFunctions(void);
+	/* TODO(thread) make private */ static map<String, ScriptFunction::Ptr>& GetFunctions(void);
 
-	static boost::signal<void (const String&, const ScriptFunction::Ptr&)> OnRegistered;
-	static boost::signal<void (const String&)> OnUnregistered;
+	static signals2::signal<void (const String&, const ScriptFunction::Ptr&)> OnRegistered;
+	static signals2::signal<void (const String&)> OnUnregistered;
 
 private:
 	Callback m_Callback;
diff --git a/lib/base/scriptinterpreter.cpp b/lib/base/scriptinterpreter.cpp
index fcfd2ac15..df1ce9c35 100644
--- a/lib/base/scriptinterpreter.cpp
+++ b/lib/base/scriptinterpreter.cpp
@@ -26,55 +26,16 @@ ScriptInterpreter::ScriptInterpreter(const Script::Ptr& script)
 
 ScriptInterpreter::~ScriptInterpreter(void)
 {
-	Stop();
-}
-
-void ScriptInterpreter::Start(void)
-{
-	/* We can't start the thread in the constructor because
-	 * the worker thread might end up calling one of the virtual
-	 * methods before the object is fully constructed. */
-
-	m_Thread = boost::thread(&ScriptInterpreter::ThreadWorkerProc, this);
-}
-
-void ScriptInterpreter::Stop(void)
-{
-	assert(Application::IsMainThread());
-
-	m_EQ.Stop();
-
 	BOOST_FOREACH(const String& function, m_SubscribedFunctions) {
 		ScriptFunction::Unregister(function);
 	}
-
-	m_Thread.join();
-}
-
-void ScriptInterpreter::ThreadWorkerProc(void)
-{
-	m_EQ.SetOwner(boost::this_thread::get_id());
-
-	{
-		boost::mutex::scoped_lock lock(m_Mutex);
-
-		while (m_EQ.ProcessEvents(m_Mutex))
-			; /* empty loop */
-	}
-}
-
-void ScriptInterpreter::ScriptFunctionThunk(const ScriptTask::Ptr& task,
-    const String& function, const vector<Value>& arguments)
-{
-	m_EQ.Post(boost::bind(&ScriptInterpreter::ProcessCall, this,
-	    task, function, arguments));
 }
 
 void ScriptInterpreter::SubscribeFunction(const String& name)
 {
 	m_SubscribedFunctions.insert(name);
 
-	ScriptFunction::Ptr sf = boost::make_shared<ScriptFunction>(boost::bind(&ScriptInterpreter::ScriptFunctionThunk, this, _1, name, _2));
+	ScriptFunction::Ptr sf = boost::make_shared<ScriptFunction>(boost::bind(&ScriptInterpreter::ProcessCall, this, _1, name, _2));
 	ScriptFunction::Register(name, sf);
 }
 
diff --git a/lib/base/scriptinterpreter.h b/lib/base/scriptinterpreter.h
index 0ac0cdb58..6ff25f18c 100644
--- a/lib/base/scriptinterpreter.h
+++ b/lib/base/scriptinterpreter.h
@@ -36,9 +36,6 @@ public:
 
 	~ScriptInterpreter(void);
 
-	void Start(void);
-	void Stop(void);
-
 protected:
 	ScriptInterpreter(const Script::Ptr& script);
 
@@ -49,15 +46,7 @@ protected:
 	void UnsubscribeFunction(const String& name);
 
 private:
-	boost::mutex m_Mutex;
-	EventQueue m_EQ;
 	set<String> m_SubscribedFunctions;
-	boost::thread m_Thread;
-
-	void ThreadWorkerProc(void);
-
-	void ScriptFunctionThunk(const ScriptTask::Ptr& task, const String& function,
-	    const vector<Value>& arguments);
 };
 
 }
diff --git a/lib/base/scriptlanguage.cpp b/lib/base/scriptlanguage.cpp
index 9c131807b..7fb44de30 100644
--- a/lib/base/scriptlanguage.cpp
+++ b/lib/base/scriptlanguage.cpp
@@ -24,18 +24,33 @@ using namespace icinga;
 ScriptLanguage::ScriptLanguage(void)
 { }
 
+/**
+ * @threadsafety Always.
+ */
 void ScriptLanguage::Register(const String& name, const ScriptLanguage::Ptr& language)
 {
+	boost::mutex::scoped_lock lock(GetMutex());
+
 	GetLanguages()[name] = language;
 }
 
+/**
+ * @threadsafety Always.
+ */
 void ScriptLanguage::Unregister(const String& name)
 {
+	boost::mutex::scoped_lock lock(GetMutex());
+
 	GetLanguages().erase(name);
 }
 
+/**
+ * @threadsafety Always.
+ */
 ScriptLanguage::Ptr ScriptLanguage::GetByName(const String& name)
 {
+	boost::mutex::scoped_lock lock(GetMutex());
+
 	map<String, ScriptLanguage::Ptr>::iterator it;
 
 	it = GetLanguages().find(name);
@@ -46,6 +61,12 @@ ScriptLanguage::Ptr ScriptLanguage::GetByName(const String& name)
 	return it->second;
 }
 
+boost::mutex& ScriptLanguage::GetMutex(void)
+{
+	static boost::mutex mutex;
+	return mutex;
+}
+
 map<String, ScriptLanguage::Ptr>& ScriptLanguage::GetLanguages(void)
 {
 	static map<String, ScriptLanguage::Ptr> languages;
diff --git a/lib/base/scriptlanguage.h b/lib/base/scriptlanguage.h
index 4ab9ec912..4c3c903ca 100644
--- a/lib/base/scriptlanguage.h
+++ b/lib/base/scriptlanguage.h
@@ -47,6 +47,7 @@ protected:
 	ScriptLanguage(void);
 
 private:
+	static boost::mutex& GetMutex(void);
 	static map<String, ScriptLanguage::Ptr>& GetLanguages(void);
 };
 
diff --git a/lib/base/socket.cpp b/lib/base/socket.cpp
index f0490577e..d860bf8cf 100644
--- a/lib/base/socket.cpp
+++ b/lib/base/socket.cpp
@@ -532,7 +532,7 @@ void Socket::HandleReadableClient(void)
 	}
 
 	if (new_data)
-		Application::GetEQ().Post(boost::bind(boost::ref(OnDataAvailable), GetSelf()));
+		OnDataAvailable(GetSelf());
 }
 
 void Socket::HandleWritableServer(void)
@@ -557,7 +557,7 @@ void Socket::HandleReadableServer(void)
 
 	TcpSocket::Ptr client = boost::make_shared<TcpSocket>();
 	client->SetFD(fd);
-	Application::GetEQ().Post(boost::bind(boost::ref(OnNewClient), GetSelf(), client));
+	OnNewClient(GetSelf(), client);
 }
 
 /**
diff --git a/lib/base/socket.h b/lib/base/socket.h
index 7d495987e..4d5860243 100644
--- a/lib/base/socket.h
+++ b/lib/base/socket.h
@@ -51,7 +51,7 @@ public:
 
 	void Listen(void);
 
-	boost::signal<void (const Socket::Ptr&, const Socket::Ptr&)> OnNewClient;
+	signals2::signal<void (const Socket::Ptr&, const Socket::Ptr&)> OnNewClient;
 
 protected:
 	Socket(void);
diff --git a/lib/base/stream.cpp b/lib/base/stream.cpp
index 48d0d5b1c..b6e7a03a0 100644
--- a/lib/base/stream.cpp
+++ b/lib/base/stream.cpp
@@ -40,9 +40,9 @@ void Stream::SetConnected(bool connected)
 	m_Connected = connected;
 
 	if (m_Connected)
-		Application::GetEQ().Post(boost::bind(boost::ref(OnConnected), GetSelf()));
+		OnConnected(GetSelf());
 	else
-		Application::GetEQ().Post(boost::bind(boost::ref(OnClosed), GetSelf()));
+		OnClosed(GetSelf());
 }
 
 /**
diff --git a/lib/base/stream.h b/lib/base/stream.h
index cdb01f314..1e868c901 100644
--- a/lib/base/stream.h
+++ b/lib/base/stream.h
@@ -85,9 +85,9 @@ public:
 	boost::exception_ptr GetException(void);
 	void CheckException(void);
 
-	boost::signal<void (const Stream::Ptr&)> OnConnected;
-	boost::signal<void (const Stream::Ptr&)> OnDataAvailable;
-	boost::signal<void (const Stream::Ptr&)> OnClosed;
+	signals2::signal<void (const Stream::Ptr&)> OnConnected;
+	signals2::signal<void (const Stream::Ptr&)> OnDataAvailable;
+	signals2::signal<void (const Stream::Ptr&)> OnClosed;
 
 protected:
 	void SetConnected(bool connected);
diff --git a/lib/base/timer.cpp b/lib/base/timer.cpp
index e02340488..963e25209 100644
--- a/lib/base/timer.cpp
+++ b/lib/base/timer.cpp
@@ -21,76 +21,52 @@
 
 using namespace icinga;
 
-Timer::CollectionType Timer::m_Timers;
+Timer::TimerSet Timer::m_Timers;
+boost::mutex Timer::m_Mutex;
+boost::condition_variable Timer::m_CV;
+boost::once_flag Timer::m_ThreadOnce = BOOST_ONCE_INIT;
 
 /**
- * Constructor for the Timer class.
- */
-Timer::Timer(void)
-	: m_Interval(0)
-{ }
-
-/**
- * Calls expired timers and returned when the next wake-up should happen.
+ * Extracts the next timestamp from a Timer.
  *
- * @returns Time when the next timer is due.
+ * @param wtimer Weak pointer to the timer.
+ * @returns The next timestamp
+ * @threadsafety Caller must hold Timer::m_Mutex.
  */
-double Timer::ProcessTimers(void)
+double TimerNextExtractor::operator()(const Timer::WeakPtr& wtimer)
 {
-	double wakeup = 30; /* wake up at least once after this many seconds */
+	Timer::Ptr timer = wtimer.lock();
 
-	double st = Utility::GetTime();
+	if (!timer)
+		return 0;
 
-	Timer::CollectionType::iterator prev, i;
-	for (i = m_Timers.begin(); i != m_Timers.end(); ) {
-		Timer::Ptr timer = i->lock();
-
-		prev = i;
-		i++;
-
-		if (!timer) {
-			m_Timers.erase(prev);
-			continue;
-		}
-
-		double now = Utility::GetTime();
-
-		if (timer->m_Next <= now) {
-			timer->Call();
-
-			/* time may have changed depending on how long the
-			 * timer call took - we need to fetch the current time */
-			now = Utility::GetTime();
-
-			double next = now + timer->GetInterval();
-
-			if (timer->m_Next <= now || next < timer->m_Next)
-				timer->Reschedule(next);
-		}
-
-		assert(timer->m_Next > now);
-
-		if (timer->m_Next - now < wakeup)
-			wakeup = timer->m_Next - now;
-	}
-
-	assert(wakeup > 0);
-
-	double et = Utility::GetTime();
-
-	if (et - st > 0.01) {
-		stringstream msgbuf;
-		msgbuf << "Timers took " << et - st << " seconds";
-		Logger::Write(LogDebug, "base", msgbuf.str());
-	}
-
-	return wakeup;
+	return timer->m_Next;
 }
 
 /**
- * Calls this timer. Note: the timer delegate must not call
- * Disable() on any other timers than the timer that originally
- * invoked the delegate.
+ * Constructor for the Timer class.
+ *
+ * @threadsafety Always.
+ */
+Timer::Timer(void)
+	: m_Interval(0), m_Next(0)
+{ }
+
+/**
+ * Initializes the timer sub-system.
+ *
+ * @threadsafety Always.
+ */
+void Timer::Initialize(void)
+{
+	thread worker(boost::bind(&Timer::TimerThreadProc));
+	worker.detach();
+}
+
+/**
+ * Calls this timer.
+ *
+ * @threadsafety Always.
  */
 void Timer::Call(void)
 {
@@ -105,15 +81,19 @@ void Timer::Call(void)
 		msgbuf << "Timer call took " << et - st << " seconds.";
 		Logger::Write(LogWarning, "base", msgbuf.str());
 	}
+
+	Reschedule();
 }
 
 /**
  * Sets the interval for this timer.
  *
  * @param interval The new interval.
+ * @threadsafety Always.
  */
 void Timer::SetInterval(double interval)
 {
+	boost::mutex::scoped_lock lock(m_Mutex);
 	m_Interval = interval;
 }
 
@@ -121,44 +101,81 @@ void Timer::SetInterval(double interval)
  * Retrieves the interval for this timer.
  *
  * @returns The interval.
+ * @threadsafety Always.
  */
 double Timer::GetInterval(void) const
 {
+	boost::mutex::scoped_lock lock(m_Mutex);
 	return m_Interval;
 }
 
 /**
  * Registers the timer and starts processing events for it.
+ *
+ * @threadsafety Always.
  */
 void Timer::Start(void)
 {
-	assert(Application::IsMainThread());
+	boost::call_once(&Timer::Initialize, m_ThreadOnce);
 
-	Stop();
-
-	m_Timers.push_back(GetSelf());
-
-	Reschedule(Utility::GetTime() + m_Interval);
+	Reschedule();
 }
 
 /**
  * Unregisters the timer and stops processing events for it.
+ *
+ * @threadsafety Always.
  */
 void Timer::Stop(void)
 {
-	assert(Application::IsMainThread());
+	boost::mutex::scoped_lock lock(m_Mutex);
+	m_Timers.erase(GetSelf());
 
-	m_Timers.remove_if(WeakPtrEqual<Timer>(this));
+	/* Notify the worker thread that we've disabled a timer. */
+	m_CV.notify_all();
 }
 
 /**
  * Reschedules this timer.
  *
- * @param next The time when this timer should be called again.
+ * @param next The time when this timer should be called again. Use -1 to let
+ * 	       the timer figure out a suitable time based on the interval.
+ * @threadsafety Always.
  */
 void Timer::Reschedule(double next)
 {
+	boost::mutex::scoped_lock lock(m_Mutex);
+
+	if (next < 0) {
+		double now = Utility::GetTime();
+		next = m_Next + m_Interval;
+
+		if (next < now)
+			next = now + m_Interval;
+		else
+			next = next;
+	}
+
 	m_Next = next;
+
+	/* Remove and re-add the timer to update the index. */
+	m_Timers.erase(GetSelf());
+	m_Timers.insert(GetSelf());
+
+	/* Notify the worker that we've rescheduled a timer. */
+	m_CV.notify_all();
+}
+
+/**
+ * Retrieves when the timer is next due.
+ *
+ * @returns The timestamp.
+ * @threadsafety Always.
+ */
+double Timer::GetNext(void) const
+{
+	boost::mutex::scoped_lock lock(m_Mutex);
+	return m_Next;
 }
 
 /**
@@ -166,17 +183,76 @@ void Timer::Reschedule(double next)
  * next scheduled timestamp.
  *
  * @param adjustment The adjustment.
+ * @threadsafety Always.
  */
 void Timer::AdjustTimers(double adjustment)
 {
+	boost::mutex::scoped_lock lock(m_Mutex);
+
 	double now = Utility::GetTime();
 
-	Timer::CollectionType::iterator i;
-        for (i = m_Timers.begin(); i != m_Timers.end(); i++) {
-		Timer::Ptr timer = i->lock();
+	typedef nth_index<TimerSet, 1>::type TimerView;
+	TimerView& idx = boost::get<1>(m_Timers);
+
+	TimerView::iterator it;
+	for (it = idx.begin(); it != idx.end(); it++) {
+		Timer::Ptr timer = it->lock();
 
 		if (abs(now - (timer->m_Next + adjustment)) <
-		    abs(now - timer->m_Next))
+		    abs(now - timer->m_Next)) {
 			timer->m_Next += adjustment;
+			m_Timers.erase(timer);
+			m_Timers.insert(timer);
+		    }
+	}
+
+	/* Notify the worker that we've rescheduled some timers. */
+	m_CV.notify_all();
+}
+
+/**
+ * Worker thread proc for Timer objects.
+ *
+ * @threadsafety Always.
+ */
+void Timer::TimerThreadProc(void)
+{
+	for (;;) {
+		boost::mutex::scoped_lock lock(m_Mutex);
+
+		typedef nth_index<TimerSet, 1>::type NextTimerView;
+		NextTimerView& idx = boost::get<1>(m_Timers);
+
+		/* Wait until there is at least one timer. */
+		while (idx.empty())
+			m_CV.wait(lock);
+
+		NextTimerView::iterator it = idx.begin();
+		Timer::Ptr timer = it->lock();
+
+		if (!timer) {
+			/* Remove the timer from the list if it's not alive anymore. */
+			idx.erase(it);
+			continue;
+		}
+
+		double wait = timer->m_Next - Utility::GetTime();
+
+		if (wait > 0) {
+			/* Make sure the timer we just examined can be destroyed while we're waiting. */
+			timer.reset();
+
+			/* Wait for the next timer. */
+			m_CV.timed_wait(lock, boost::posix_time::milliseconds(wait * 1000));
+
+			continue;
+		}
+
+		/* Remove the timer from the list so it doesn't get called again
+		 * until the current call is completed. */
+		m_Timers.erase(timer);
+
+		/* Asynchronously call the timer. */
+		Application::GetEQ().Post(boost::bind(&Timer::Call, timer));
 	}
 }
diff --git a/lib/base/timer.h b/lib/base/timer.h
index ab32c624c..87f554552 100644
--- a/lib/base/timer.h
+++ b/lib/base/timer.h
@@ -24,6 +24,18 @@
 
 namespace icinga {
 
+class Timer;
+
+/**
+ * @ingroup base
+ */
+struct TimerNextExtractor
+{
+	typedef double result_type;
+
+	double operator()(const weak_ptr<Timer>& wtimer);
+};
+
 /**
  * A timer that periodically triggers an event.
  *
@@ -42,23 +54,40 @@ public:
 	void SetInterval(double interval);
 	double GetInterval(void) const;
 
-	static double ProcessTimers(void);
 	static void AdjustTimers(double adjustment);
 
 	void Start(void);
 	void Stop(void);
 
-	void Reschedule(double next);
+	void Reschedule(double next = -1);
+	double GetNext(void) const;
 
-	boost::signal<void(const Timer::Ptr&)> OnTimerExpired;
+	signals2::signal<void(const Timer::Ptr&)> OnTimerExpired;
 
 private:
 	double m_Interval; /**< The interval of the timer. */
 	double m_Next; /**< When the next event should happen. */
 
-	static Timer::CollectionType m_Timers;
+	typedef multi_index_container<
+		Timer::WeakPtr,
+		indexed_by<
+			ordered_unique<identity<Timer::WeakPtr> >,
+			ordered_non_unique<TimerNextExtractor>
+		>
+	> TimerSet;
+
+	static boost::mutex m_Mutex;
+	static boost::condition_variable m_CV;
+	static TimerSet m_Timers;
 
 	void Call(void);
+
+	static boost::once_flag m_ThreadOnce;
+	static void Initialize(void);
+
+	static void TimerThreadProc(void);
+
+	friend struct TimerNextExtractor;
 };
 
 }
diff --git a/lib/base/utility.cpp b/lib/base/utility.cpp
index 0b0a4fa50..2434392c4 100644
--- a/lib/base/utility.cpp
+++ b/lib/base/utility.cpp
@@ -398,17 +398,11 @@ pid_t Utility::GetPid(void)
  */
 void Utility::Sleep(double timeout)
 {
-	if (Application::IsMainThread())
-		Application::GetMutex().unlock();
-
 #ifndef _WIN32
 	usleep(timeout * 1000 * 1000);
 #else /* _WIN32 */
 	::Sleep(timeout * 1000);
 #endif /* _WIN32 */
-
-	if (Application::IsMainThread())
-		Application::GetMutex().lock();
 }
 
 /**
@@ -521,17 +515,6 @@ bool Utility::Glob(const String& pathSpec, const function<void (const String&)>&
 #endif /* _WIN32 */
 }
 
-/**
- * Waits until the given predicate is true. Executes events while waiting.
- *
- * @param predicate The predicate.
- */
-void Utility::WaitUntil(const function<bool (void)>& predicate)
-{
-	while (!predicate())
-		Application::ProcessEvents();
-}
-
 #ifndef _WIN32
 void Utility::SetNonBlocking(int fd)
 {
diff --git a/lib/base/utility.h b/lib/base/utility.h
index fabd99fce..9d0a1f198 100644
--- a/lib/base/utility.h
+++ b/lib/base/utility.h
@@ -58,8 +58,6 @@ public:
 
 	static bool Glob(const String& pathSpec, const function<void (const String&)>& callback);
 
-	static void WaitUntil(const function<bool (void)>& predicate);
-
 	static
 #ifdef _WIN32
 	HMODULE
diff --git a/lib/config/configitem.cpp b/lib/config/configitem.cpp
index 2487a8e27..f5174507b 100644
--- a/lib/config/configitem.cpp
+++ b/lib/config/configitem.cpp
@@ -21,9 +21,10 @@
 
 using namespace icinga;
 
+boost::mutex ConfigItem::m_Mutex;
 ConfigItem::ItemMap ConfigItem::m_Items;
-boost::signal<void (const ConfigItem::Ptr&)> ConfigItem::OnCommitted;
-boost::signal<void (const ConfigItem::Ptr&)> ConfigItem::OnRemoved;
+signals2::signal<void (const ConfigItem::Ptr&)> ConfigItem::OnCommitted;
+signals2::signal<void (const ConfigItem::Ptr&)> ConfigItem::OnRemoved;
 
 /**
  * Constructor for the ConfigItem class.
@@ -295,29 +296,38 @@ DynamicObject::Ptr ConfigItem::GetDynamicObject(void) const
  * @param type The type of the ConfigItem that is to be looked up.
  * @param name The name of the ConfigItem that is to be looked up.
  * @returns The configuration item.
+ * @threadsafety Always.
  */
 ConfigItem::Ptr ConfigItem::GetObject(const String& type, const String& name)
 {
-	ConfigItem::ItemMap::iterator it;
+	{
+		recursive_mutex::scoped_lock lockg(Application::GetMutex());
 
-	ConfigCompilerContext *context = ConfigCompilerContext::GetContext();
+		ConfigCompilerContext *context = ConfigCompilerContext::GetContext();
 
-	if (context) {
-		ConfigItem::Ptr item = context->GetItem(type, name);
+		if (context) {
+			ConfigItem::Ptr item = context->GetItem(type, name);
 
-		if (item)
-			return item;
+			if (item)
+				return item;
 
-		/* ignore already active objects while we're in the compiler
-		 * context and linking to existing items is disabled. */
-		if ((context->GetFlags() & CompilerLinkExisting) == 0)
-			return ConfigItem::Ptr();
+			/* ignore already active objects while we're in the compiler
+			 * context and linking to existing items is disabled. */
+			if ((context->GetFlags() & CompilerLinkExisting) == 0)
+				return ConfigItem::Ptr();
+		}
 	}
 
-	it = m_Items.find(make_pair(type, name));
+	{
+		boost::mutex::scoped_lock lock(m_Mutex);
 
-	if (it != m_Items.end())
-		return it->second;
+		ConfigItem::ItemMap::iterator it;
+
+		it = m_Items.find(make_pair(type, name));
+
+		if (it != m_Items.end())
+			return it->second;
+	}
 
 	return ConfigItem::Ptr();
 }
@@ -351,8 +361,13 @@ void ConfigItem::Dump(ostream& fp) const
 	fp << "}" << "\n";
 }
 
+/**
+ * @threadsafety Caller must hold the global mutex.
+ */
 void ConfigItem::UnloadUnit(const String& unit)
 {
+	boost::mutex::scoped_lock lock(m_Mutex);
+
 	Logger::Write(LogInformation, "config", "Unloading config items from compilation unit '" + unit + "'");
 
 	vector<ConfigItem::Ptr> obsoleteItems;
diff --git a/lib/config/configitem.h b/lib/config/configitem.h
index 14ea0965c..77912962f 100644
--- a/lib/config/configitem.h
+++ b/lib/config/configitem.h
@@ -62,8 +62,8 @@ public:
 
 	static void UnloadUnit(const String& unit);
 
-	static boost::signal<void (const ConfigItem::Ptr&)> OnCommitted;
-	static boost::signal<void (const ConfigItem::Ptr&)> OnRemoved;
+	static signals2::signal<void (const ConfigItem::Ptr&)> OnCommitted;
+	static signals2::signal<void (const ConfigItem::Ptr&)> OnRemoved;
 
 private:
 	void InternalLink(const Dictionary::Ptr& dictionary) const;
@@ -89,6 +89,8 @@ private:
         set<ConfigItem::WeakPtr> m_ChildObjects; /**< Instantiated items
                                                      * that inherit from this item */
 
+	static boost::mutex m_Mutex;
+
 	typedef map<pair<String, String>, ConfigItem::Ptr> ItemMap;
 	static ItemMap m_Items; /**< All registered configuration items. */
 };
diff --git a/lib/config/configtype.cpp b/lib/config/configtype.cpp
index 9fba1d09d..0f6abe805 100644
--- a/lib/config/configtype.cpp
+++ b/lib/config/configtype.cpp
@@ -78,6 +78,9 @@ void ConfigType::ValidateItem(const ConfigItem::Ptr& item) const
 	ValidateDictionary(attrs, ruleLists, locations);
 }
 
+/**
+ * @threadsafety Always.
+ */
 String ConfigType::LocationToString(const vector<String>& locations)
 {
 	bool first = true;
@@ -94,6 +97,9 @@ String ConfigType::LocationToString(const vector<String>& locations)
 	return stack;
 }
 
+/**
+ * @threadsafety Always.
+ */
 void ConfigType::ValidateDictionary(const Dictionary::Ptr& dictionary,
     const vector<TypeRuleList::Ptr>& ruleLists, vector<String>& locations)
 {
@@ -168,4 +174,3 @@ void ConfigType::ValidateDictionary(const Dictionary::Ptr& dictionary,
 		locations.pop_back();
 	}
 }
-
diff --git a/lib/config/expression.cpp b/lib/config/expression.cpp
index 90e6a48c7..8b48f40b2 100644
--- a/lib/config/expression.cpp
+++ b/lib/config/expression.cpp
@@ -160,6 +160,9 @@ void Expression::DumpValue(ostream& fp, int indent, const Value& value, bool inl
 	BOOST_THROW_EXCEPTION(runtime_error("Encountered unknown type while dumping value."));
 }
 
+/**
+ * @threadsafety Always.
+ */
 void Expression::Dump(ostream& fp, int indent) const
 {
 	if (m_Operator == OperatorExecute) {
diff --git a/lib/icinga/api.cpp b/lib/icinga/api.cpp
index 7938094a9..431796906 100644
--- a/lib/icinga/api.cpp
+++ b/lib/icinga/api.cpp
@@ -23,6 +23,9 @@ using namespace icinga;
 
 REGISTER_SCRIPTFUNCTION("GetAnswerToEverything", &API::GetAnswerToEverything);
 
+/**
+ * @threadsafety Always.
+ */
 void API::GetAnswerToEverything(const ScriptTask::Ptr& task, const vector<Value>& arguments)
 {
 	if (arguments.size() < 1)
diff --git a/lib/icinga/cib.cpp b/lib/icinga/cib.cpp
index 6502786f6..3d1f94a5c 100644
--- a/lib/icinga/cib.cpp
+++ b/lib/icinga/cib.cpp
@@ -21,25 +21,42 @@
 
 using namespace icinga;
 
+boost::mutex CIB::m_Mutex;
 RingBuffer CIB::m_ActiveChecksStatistics(15 * 60);
 RingBuffer CIB::m_PassiveChecksStatistics(15 * 60);
 
+/**
+ * @threadsafety Always.
+ */
 void CIB::UpdateActiveChecksStatistics(long tv, int num)
 {
+	boost::mutex::scoped_lock lock(m_Mutex);
 	m_ActiveChecksStatistics.InsertValue(tv, num);
 }
 
+/**
+ * @threadsafety Always.
+ */
 int CIB::GetActiveChecksStatistics(long timespan)
 {
+	boost::mutex::scoped_lock lock(m_Mutex);
 	return m_ActiveChecksStatistics.GetValues(timespan);
 }
 
+/**
+ * @threadsafety Always.
+ */
 void CIB::UpdatePassiveChecksStatistics(long tv, int num)
 {
+	boost::mutex::scoped_lock lock(m_Mutex);
 	m_PassiveChecksStatistics.InsertValue(tv, num);
 }
 
+/**
+ * @threadsafety Always.
+ */
 int CIB::GetPassiveChecksStatistics(long timespan)
 {
+	boost::mutex::scoped_lock lock(m_Mutex);
 	return m_PassiveChecksStatistics.GetValues(timespan);
 }
diff --git a/lib/icinga/cib.h b/lib/icinga/cib.h
index a9eaa907c..e7d5903dc 100644
--- a/lib/icinga/cib.h
+++ b/lib/icinga/cib.h
@@ -39,6 +39,7 @@ public:
 	static int GetPassiveChecksStatistics(long timespan);
 
 private:
+	static boost::mutex m_Mutex;
 	static RingBuffer m_ActiveChecksStatistics;
 	static RingBuffer m_PassiveChecksStatistics;
 };
diff --git a/lib/icinga/externalcommandprocessor.cpp b/lib/icinga/externalcommandprocessor.cpp
index 69c4a0b91..e8cc80a0b 100644
--- a/lib/icinga/externalcommandprocessor.cpp
+++ b/lib/icinga/externalcommandprocessor.cpp
@@ -21,9 +21,13 @@
 
 using namespace icinga;
 
-bool I2_EXPORT ExternalCommandProcessor::m_Initialized;
-map<String, ExternalCommandProcessor::Callback> I2_EXPORT ExternalCommandProcessor::m_Commands;
+boost::once_flag ExternalCommandProcessor::m_InitializeOnce;
+boost::mutex ExternalCommandProcessor::m_Mutex;
+map<String, ExternalCommandProcessor::Callback> ExternalCommandProcessor::m_Commands;
 
+/**
+ * @threadsafety Always.
+ */
 void ExternalCommandProcessor::Execute(const String& line)
 {
 	if (line.IsEmpty())
@@ -54,68 +58,91 @@ void ExternalCommandProcessor::Execute(const String& line)
 	Execute(ts, argv[0], argvExtra);
 }
 
+/**
+ * @threadsafety Always.
+ */
 void ExternalCommandProcessor::Execute(double time, const String& command, const vector<String>& arguments)
 {
-	if (!m_Initialized) {
-		RegisterCommand("PROCESS_SERVICE_CHECK_RESULT", &ExternalCommandProcessor::ProcessServiceCheckResult);
-		RegisterCommand("SCHEDULE_SVC_CHECK", &ExternalCommandProcessor::ScheduleSvcCheck);
-		RegisterCommand("SCHEDULE_FORCED_SVC_CHECK", &ExternalCommandProcessor::ScheduleForcedSvcCheck);
-		RegisterCommand("ENABLE_SVC_CHECK", &ExternalCommandProcessor::EnableSvcCheck);
-		RegisterCommand("DISABLE_SVC_CHECK", &ExternalCommandProcessor::DisableSvcCheck);
-		RegisterCommand("SHUTDOWN_PROCESS", &ExternalCommandProcessor::ShutdownProcess);
-		RegisterCommand("SCHEDULE_FORCED_HOST_SVC_CHECKS", &ExternalCommandProcessor::ScheduleForcedHostSvcChecks);
-		RegisterCommand("SCHEDULE_HOST_SVC_CHECKS", &ExternalCommandProcessor::ScheduleHostSvcChecks);
-		RegisterCommand("ENABLE_HOST_SVC_CHECKS", &ExternalCommandProcessor::EnableHostSvcChecks);
-		RegisterCommand("DISABLE_HOST_SVC_CHECKS", &ExternalCommandProcessor::DisableHostSvcChecks);
-		RegisterCommand("ACKNOWLEDGE_SVC_PROBLEM", &ExternalCommandProcessor::AcknowledgeSvcProblem);
-		RegisterCommand("ACKNOWLEDGE_SVC_PROBLEM_EXPIRE", &ExternalCommandProcessor::AcknowledgeSvcProblemExpire);
-		RegisterCommand("REMOVE_SVC_ACKNOWLEDGEMENT", &ExternalCommandProcessor::RemoveHostAcknowledgement);
-		RegisterCommand("ACKNOWLEDGE_HOST_PROBLEM", &ExternalCommandProcessor::AcknowledgeHostProblem);
-		RegisterCommand("ACKNOWLEDGE_HOST_PROBLEM_EXPIRE", &ExternalCommandProcessor::AcknowledgeHostProblemExpire);
-		RegisterCommand("REMOVE_HOST_ACKNOWLEDGEMENT", &ExternalCommandProcessor::RemoveHostAcknowledgement);
-		RegisterCommand("ENABLE_HOSTGROUP_SVC_CHECKS", &ExternalCommandProcessor::EnableHostgroupSvcChecks);
-		RegisterCommand("DISABLE_HOSTGROUP_SVC_CHECKS", &ExternalCommandProcessor::DisableHostgroupSvcChecks);
-		RegisterCommand("ENABLE_SERVICEGROUP_SVC_CHECKS", &ExternalCommandProcessor::EnableServicegroupSvcChecks);
-		RegisterCommand("DISABLE_SERVICEGROUP_SVC_CHECKS", &ExternalCommandProcessor::DisableServicegroupSvcChecks);
-		RegisterCommand("ENABLE_PASSIVE_SVC_CHECKS", &ExternalCommandProcessor::EnablePassiveSvcChecks);
-		RegisterCommand("DISABLE_PASSIVE_SVC_CHECKS", &ExternalCommandProcessor::DisablePassiveSvcChecks);
-		RegisterCommand("ENABLE_SERVICEGROUP_PASSIVE_SVC_CHECKS", &ExternalCommandProcessor::EnableServicegroupPassiveSvcChecks);
-		RegisterCommand("DISABLE_SERVICEGROUP_PASSIVE_SVC_CHECKS", &ExternalCommandProcessor::DisableServicegroupPassiveSvcChecks);
-		RegisterCommand("ENABLE_HOSTGROUP_PASSIVE_SVC_CHECKS", &ExternalCommandProcessor::EnableHostgroupPassiveSvcChecks);
-		RegisterCommand("DISABLE_HOSTGROUP_PASSIVE_SVC_CHECKS", &ExternalCommandProcessor::DisableHostgroupPassiveSvcChecks);
-		RegisterCommand("PROCESS_FILE", &ExternalCommandProcessor::ProcessFile);
-		RegisterCommand("SCHEDULE_SVC_DOWNTIME", &ExternalCommandProcessor::ScheduleSvcDowntime);
-		RegisterCommand("DEL_SVC_DOWNTIME", &ExternalCommandProcessor::DelSvcDowntime);
-		RegisterCommand("SCHEDULE_HOST_DOWNTIME", &ExternalCommandProcessor::ScheduleHostDowntime);
-		RegisterCommand("DEL_HOST_DOWNTIME", &ExternalCommandProcessor::DelHostDowntime);
-		RegisterCommand("SCHEDULE_HOST_SVC_DOWNTIME", &ExternalCommandProcessor::ScheduleHostSvcDowntime);
-		RegisterCommand("SCHEDULE_HOSTGROUP_HOST_DOWNTIME", &ExternalCommandProcessor::ScheduleHostgroupHostDowntime);
-		RegisterCommand("SCHEDULE_HOSTGROUP_SVC_DOWNTIME", &ExternalCommandProcessor::ScheduleHostgroupSvcDowntime);
-		RegisterCommand("SCHEDULE_SERVICEGROUP_HOST_DOWNTIME", &ExternalCommandProcessor::ScheduleServicegroupHostDowntime);
-		RegisterCommand("SCHEDULE_SERVICEGROUP_SVC_DOWNTIME", &ExternalCommandProcessor::ScheduleServicegroupSvcDowntime);
-		RegisterCommand("ADD_HOST_COMMENT", &ExternalCommandProcessor::AddHostComment);
-		RegisterCommand("DEL_HOST_COMMENT", &ExternalCommandProcessor::DelHostComment);
-		RegisterCommand("ADD_SVC_COMMENT", &ExternalCommandProcessor::AddSvcComment);
-		RegisterCommand("DEL_SVC_COMMENT", &ExternalCommandProcessor::DelSvcComment);
-		RegisterCommand("DEL_ALL_HOST_COMMENTS", &ExternalCommandProcessor::DelAllHostComments);
-		RegisterCommand("DEL_ALL_SVC_COMMENTS", &ExternalCommandProcessor::DelAllSvcComments);
-		RegisterCommand("SEND_CUSTOM_HOST_NOTIFICATION", &ExternalCommandProcessor::SendCustomHostNotification);
-		RegisterCommand("SEND_CUSTOM_SVC_NOTIFICATION", &ExternalCommandProcessor::SendCustomSvcNotification);
+	boost::call_once(m_InitializeOnce, &ExternalCommandProcessor::Initialize);
 
-		m_Initialized = true;
+	Callback callback;
+
+	{
+		boost::mutex::scoped_lock lock(m_Mutex);
+
+		map<String, ExternalCommandProcessor::Callback>::iterator it;
+		it = m_Commands.find(command);
+
+		if (it == m_Commands.end())
+			BOOST_THROW_EXCEPTION(invalid_argument("The external command '" + command + "' does not exist."));
+
+		callback = it->second;
 	}
 
-	map<String, ExternalCommandProcessor::Callback>::iterator it;
-	it = m_Commands.find(command);
+	{
+		recursive_mutex::scoped_lock lock(Application::GetMutex());
+		callback(time, arguments);
+	}
 
-	if (it == m_Commands.end())
-		BOOST_THROW_EXCEPTION(invalid_argument("The external command '" + command + "' does not exist."));
-
-	it->second(time, arguments);
 }
 
+/**
+ * @threadsafety Always.
+ */
+void ExternalCommandProcessor::Initialize(void)
+{
+	RegisterCommand("PROCESS_SERVICE_CHECK_RESULT", &ExternalCommandProcessor::ProcessServiceCheckResult);
+	RegisterCommand("SCHEDULE_SVC_CHECK", &ExternalCommandProcessor::ScheduleSvcCheck);
+	RegisterCommand("SCHEDULE_FORCED_SVC_CHECK", &ExternalCommandProcessor::ScheduleForcedSvcCheck);
+	RegisterCommand("ENABLE_SVC_CHECK", &ExternalCommandProcessor::EnableSvcCheck);
+	RegisterCommand("DISABLE_SVC_CHECK", &ExternalCommandProcessor::DisableSvcCheck);
+	RegisterCommand("SHUTDOWN_PROCESS", &ExternalCommandProcessor::ShutdownProcess);
+	RegisterCommand("SCHEDULE_FORCED_HOST_SVC_CHECKS", &ExternalCommandProcessor::ScheduleForcedHostSvcChecks);
+	RegisterCommand("SCHEDULE_HOST_SVC_CHECKS", &ExternalCommandProcessor::ScheduleHostSvcChecks);
+	RegisterCommand("ENABLE_HOST_SVC_CHECKS", &ExternalCommandProcessor::EnableHostSvcChecks);
+	RegisterCommand("DISABLE_HOST_SVC_CHECKS", &ExternalCommandProcessor::DisableHostSvcChecks);
+	RegisterCommand("ACKNOWLEDGE_SVC_PROBLEM", &ExternalCommandProcessor::AcknowledgeSvcProblem);
+	RegisterCommand("ACKNOWLEDGE_SVC_PROBLEM_EXPIRE", &ExternalCommandProcessor::AcknowledgeSvcProblemExpire);
+	RegisterCommand("REMOVE_SVC_ACKNOWLEDGEMENT", &ExternalCommandProcessor::RemoveHostAcknowledgement);
+	RegisterCommand("ACKNOWLEDGE_HOST_PROBLEM", &ExternalCommandProcessor::AcknowledgeHostProblem);
+	RegisterCommand("ACKNOWLEDGE_HOST_PROBLEM_EXPIRE", &ExternalCommandProcessor::AcknowledgeHostProblemExpire);
+	RegisterCommand("REMOVE_HOST_ACKNOWLEDGEMENT", &ExternalCommandProcessor::RemoveHostAcknowledgement);
+	RegisterCommand("ENABLE_HOSTGROUP_SVC_CHECKS", &ExternalCommandProcessor::EnableHostgroupSvcChecks);
+	RegisterCommand("DISABLE_HOSTGROUP_SVC_CHECKS", &ExternalCommandProcessor::DisableHostgroupSvcChecks);
+	RegisterCommand("ENABLE_SERVICEGROUP_SVC_CHECKS", &ExternalCommandProcessor::EnableServicegroupSvcChecks);
+	RegisterCommand("DISABLE_SERVICEGROUP_SVC_CHECKS", &ExternalCommandProcessor::DisableServicegroupSvcChecks);
+	RegisterCommand("ENABLE_PASSIVE_SVC_CHECKS", &ExternalCommandProcessor::EnablePassiveSvcChecks);
+	RegisterCommand("DISABLE_PASSIVE_SVC_CHECKS", &ExternalCommandProcessor::DisablePassiveSvcChecks);
+	RegisterCommand("ENABLE_SERVICEGROUP_PASSIVE_SVC_CHECKS", &ExternalCommandProcessor::EnableServicegroupPassiveSvcChecks);
+	RegisterCommand("DISABLE_SERVICEGROUP_PASSIVE_SVC_CHECKS", &ExternalCommandProcessor::DisableServicegroupPassiveSvcChecks);
+	RegisterCommand("ENABLE_HOSTGROUP_PASSIVE_SVC_CHECKS", &ExternalCommandProcessor::EnableHostgroupPassiveSvcChecks);
+	RegisterCommand("DISABLE_HOSTGROUP_PASSIVE_SVC_CHECKS", &ExternalCommandProcessor::DisableHostgroupPassiveSvcChecks);
+	RegisterCommand("PROCESS_FILE", &ExternalCommandProcessor::ProcessFile);
+	RegisterCommand("SCHEDULE_SVC_DOWNTIME", &ExternalCommandProcessor::ScheduleSvcDowntime);
+	RegisterCommand("DEL_SVC_DOWNTIME", &ExternalCommandProcessor::DelSvcDowntime);
+	RegisterCommand("SCHEDULE_HOST_DOWNTIME", &ExternalCommandProcessor::ScheduleHostDowntime);
+	RegisterCommand("DEL_HOST_DOWNTIME", &ExternalCommandProcessor::DelHostDowntime);
+	RegisterCommand("SCHEDULE_HOST_SVC_DOWNTIME", &ExternalCommandProcessor::ScheduleHostSvcDowntime);
+	RegisterCommand("SCHEDULE_HOSTGROUP_HOST_DOWNTIME", &ExternalCommandProcessor::ScheduleHostgroupHostDowntime);
+	RegisterCommand("SCHEDULE_HOSTGROUP_SVC_DOWNTIME", &ExternalCommandProcessor::ScheduleHostgroupSvcDowntime);
+	RegisterCommand("SCHEDULE_SERVICEGROUP_HOST_DOWNTIME", &ExternalCommandProcessor::ScheduleServicegroupHostDowntime);
+	RegisterCommand("SCHEDULE_SERVICEGROUP_SVC_DOWNTIME", &ExternalCommandProcessor::ScheduleServicegroupSvcDowntime);
+	RegisterCommand("ADD_HOST_COMMENT", &ExternalCommandProcessor::AddHostComment);
+	RegisterCommand("DEL_HOST_COMMENT", &ExternalCommandProcessor::DelHostComment);
+	RegisterCommand("ADD_SVC_COMMENT", &ExternalCommandProcessor::AddSvcComment);
+	RegisterCommand("DEL_SVC_COMMENT", &ExternalCommandProcessor::DelSvcComment);
+	RegisterCommand("DEL_ALL_HOST_COMMENTS", &ExternalCommandProcessor::DelAllHostComments);
+	RegisterCommand("DEL_ALL_SVC_COMMENTS", &ExternalCommandProcessor::DelAllSvcComments);
+	RegisterCommand("SEND_CUSTOM_HOST_NOTIFICATION", &ExternalCommandProcessor::SendCustomHostNotification);
+	RegisterCommand("SEND_CUSTOM_SVC_NOTIFICATION", &ExternalCommandProcessor::SendCustomSvcNotification);
+}
+
+/**
+ * @threadsafety Always.
+ */
 void ExternalCommandProcessor::RegisterCommand(const String& command, const ExternalCommandProcessor::Callback& callback)
 {
+	boost::mutex::scoped_lock lock(m_Mutex);
 	m_Commands[command] = callback;
 }
 
diff --git a/lib/icinga/externalcommandprocessor.h b/lib/icinga/externalcommandprocessor.h
index 755c36b27..965e2ecf4 100644
--- a/lib/icinga/externalcommandprocessor.h
+++ b/lib/icinga/externalcommandprocessor.h
@@ -28,6 +28,19 @@ public:
 	static void Execute(const String& line);
 	static void Execute(double time, const String& command, const vector<String>& arguments);
 
+private:
+	typedef function<void (double time, const vector<String>& arguments)> Callback;
+
+	static boost::once_flag m_InitializeOnce;
+	static boost::mutex m_Mutex;
+	static map<String, Callback> m_Commands;
+
+	ExternalCommandProcessor(void);
+
+	static void Initialize(void);
+
+	static void RegisterCommand(const String& command, const Callback& callback);
+
 	static void ProcessServiceCheckResult(double time, const vector<String>& arguments);
 	static void ScheduleSvcCheck(double time, const vector<String>& arguments);
 	static void ScheduleForcedSvcCheck(double time, const vector<String>& arguments);
@@ -72,16 +85,6 @@ public:
 	static void DelAllSvcComments(double time, const vector<String>& arguments);
 	static void SendCustomHostNotification(double time, const vector<String>& arguments);
 	static void SendCustomSvcNotification(double time, const vector<String>& arguments);
-
-private:
-	typedef function<void (double time, const vector<String>& arguments)> Callback;
-
-	static bool m_Initialized;
-	static map<String, Callback> m_Commands;
-
-	ExternalCommandProcessor(void);
-
-	static void RegisterCommand(const String& command, const Callback& callback);
 };
 
 }
diff --git a/lib/icinga/host.cpp b/lib/icinga/host.cpp
index 5adcb455e..b01e4b8a5 100644
--- a/lib/icinga/host.cpp
+++ b/lib/icinga/host.cpp
@@ -59,11 +59,17 @@ String Host::GetDisplayName(void) const
 		return GetName();
 }
 
+/**
+ * @threadsafety Always.
+ */
 bool Host::Exists(const String& name)
 {
 	return (DynamicObject::GetObject("Host", name));
 }
 
+/**
+ * @threadsafety Always.
+ */
 Host::Ptr Host::GetByName(const String& name)
 {
 	DynamicObject::Ptr configObject = DynamicObject::GetObject("Host", name);
diff --git a/lib/icinga/hostgroup.cpp b/lib/icinga/hostgroup.cpp
index 7cb5d7d74..48b6cdfb8 100644
--- a/lib/icinga/hostgroup.cpp
+++ b/lib/icinga/hostgroup.cpp
@@ -50,11 +50,17 @@ String HostGroup::GetActionUrl(void) const
 	return Get("action_url");
 }
 
+/**
+ * @threadsafety Always.
+ */
 bool HostGroup::Exists(const String& name)
 {
 	return (DynamicObject::GetObject("HostGroup", name));
 }
 
+/**
+ * @threadsafety Always.
+ */
 HostGroup::Ptr HostGroup::GetByName(const String& name)
 {
 	DynamicObject::Ptr configObject = DynamicObject::GetObject("HostGroup", name);
diff --git a/lib/icinga/macroprocessor.cpp b/lib/icinga/macroprocessor.cpp
index 8e45be9a0..431843ddc 100644
--- a/lib/icinga/macroprocessor.cpp
+++ b/lib/icinga/macroprocessor.cpp
@@ -27,7 +27,7 @@ Value MacroProcessor::ResolveMacros(const Value& cmd, const Dictionary::Ptr& mac
 
 	if (cmd.IsScalar()) {
 		result = InternalResolveMacros(cmd, macros);
-	} else {
+	} else if (cmd.IsObjectType<Dictionary>()) {
 		Dictionary::Ptr resultDict = boost::make_shared<Dictionary>();
 		Dictionary::Ptr dict = cmd;
 
@@ -37,6 +37,8 @@ Value MacroProcessor::ResolveMacros(const Value& cmd, const Dictionary::Ptr& mac
 		}
 
 		result = resultDict;
+	} else {
+		BOOST_THROW_EXCEPTION(invalid_argument("Command is not a string or dictionary."));
 	}
 
 	return result;
diff --git a/lib/icinga/pluginchecktask.cpp b/lib/icinga/pluginchecktask.cpp
index fb8880f48..9e6570ae6 100644
--- a/lib/icinga/pluginchecktask.cpp
+++ b/lib/icinga/pluginchecktask.cpp
@@ -27,9 +27,12 @@ PluginCheckTask::PluginCheckTask(const ScriptTask::Ptr& task, const Process::Ptr
 	: m_Task(task), m_Process(process)
 { }
 
+/**
+ * @threadsafety Always.
+ */
 void PluginCheckTask::ScriptFunc(const ScriptTask::Ptr& task, const vector<Value>& arguments)
 {
-	assert(Application::IsMainThread());
+	recursive_mutex::scoped_lock lock(Application::GetMutex());
 
 	if (arguments.size() < 1)
 		BOOST_THROW_EXCEPTION(invalid_argument("Missing argument: Service must be specified."));
@@ -57,8 +60,13 @@ void PluginCheckTask::ScriptFunc(const ScriptTask::Ptr& task, const vector<Value
 	process->Start(boost::bind(&PluginCheckTask::ProcessFinishedHandler, ct));
 }
 
+/**
+ * @threadsafety Always.
+ */
 void PluginCheckTask::ProcessFinishedHandler(PluginCheckTask ct)
 {
+	recursive_mutex::scoped_lock lock(Application::GetMutex());
+
 	ProcessResult pr;
 
 	try {
diff --git a/lib/icinga/pluginnotificationtask.cpp b/lib/icinga/pluginnotificationtask.cpp
index 7ca023ed6..0168de29f 100644
--- a/lib/icinga/pluginnotificationtask.cpp
+++ b/lib/icinga/pluginnotificationtask.cpp
@@ -28,9 +28,12 @@ PluginNotificationTask::PluginNotificationTask(const ScriptTask::Ptr& task, cons
 	: m_Task(task), m_Process(process), m_ServiceName(service), m_Command(command)
 { }
 
+/**
+ * @threadsafety Always.
+ */
 void PluginNotificationTask::ScriptFunc(const ScriptTask::Ptr& task, const vector<Value>& arguments)
 {
-	assert(Application::IsMainThread());
+	recursive_mutex::scoped_lock lock(Application::GetMutex());
 
 	if (arguments.size() < 1)
 		BOOST_THROW_EXCEPTION(invalid_argument("Missing argument: Notification target must be specified."));
@@ -62,8 +65,13 @@ void PluginNotificationTask::ScriptFunc(const ScriptTask::Ptr& task, const vecto
 	process->Start(boost::bind(&PluginNotificationTask::ProcessFinishedHandler, ct));
 }
 
+/**
+ * @threadsafety Always.
+ */
 void PluginNotificationTask::ProcessFinishedHandler(PluginNotificationTask ct)
 {
+	recursive_mutex::scoped_lock lock(Application::GetMutex());
+
 	ProcessResult pr;
 
 	try {
diff --git a/lib/icinga/service-check.cpp b/lib/icinga/service-check.cpp
index b9cc4cd47..6038a4a08 100644
--- a/lib/icinga/service-check.cpp
+++ b/lib/icinga/service-check.cpp
@@ -25,8 +25,8 @@ const int Service::DefaultMaxCheckAttempts = 3;
 const int Service::DefaultCheckInterval = 5 * 60;
 const int Service::CheckIntervalDivisor = 5;
 
-boost::signal<void (const Service::Ptr&, const String&)> Service::OnCheckerChanged;
-boost::signal<void (const Service::Ptr&, const Value&)> Service::OnNextCheckChanged;
+signals2::signal<void (const Service::Ptr&, const String&)> Service::OnCheckerChanged;
+signals2::signal<void (const Service::Ptr&, const Value&)> Service::OnNextCheckChanged;
 
 Value Service::GetCheckCommand(void) const
 {
@@ -350,7 +350,7 @@ void Service::ApplyCheckResult(const Dictionary::Ptr& cr)
 
 		/* Make sure the notification component sees the updated
 		 * state/state_type attributes. */
-		DynamicObject::FlushTx();
+		DynamicObject::NewTx();
 
 		if (IsReachable() && !IsInDowntime() && !IsAcknowledged())
 			RequestNotifications(NotificationStateChange);
@@ -458,6 +458,8 @@ void Service::BeginExecuteCheck(const function<void (void)>& callback)
 void Service::CheckCompletedHandler(const Dictionary::Ptr& scheduleInfo,
     const ScriptTask::Ptr& task, const function<void (void)>& callback)
 {
+	ObjectLock olock(this);
+
 	Set("current_task", Empty);
 
 	scheduleInfo->Set("execution_end", Utility::GetTime());
@@ -521,7 +523,7 @@ void Service::ProcessCheckResult(const Dictionary::Ptr& cr)
 
 	/* flush the current transaction so other instances see the service's
 	 * new state when they receive the CheckResult message */
-	DynamicObject::FlushTx();
+	DynamicObject::NewTx();
 
 	RequestMessage rm;
 	rm.SetMethod("checker::CheckResult");
diff --git a/lib/icinga/service-comment.cpp b/lib/icinga/service-comment.cpp
index dfeed2388..e3ff4fd6a 100644
--- a/lib/icinga/service-comment.cpp
+++ b/lib/icinga/service-comment.cpp
@@ -210,6 +210,8 @@ void Service::RemoveExpiredComments(void)
 
 void Service::CommentsExpireTimerHandler(void)
 {
+	recursive_mutex::scoped_lock lock(Application::GetMutex());
+
 	DynamicObject::Ptr object;
 	BOOST_FOREACH(tie(tuples::ignore, object), DynamicType::GetByName("Service")->GetObjects()) {
 		Service::Ptr service = dynamic_pointer_cast<Service>(object);
diff --git a/lib/icinga/service-downtime.cpp b/lib/icinga/service-downtime.cpp
index 2c7df0cfe..fa12a93fc 100644
--- a/lib/icinga/service-downtime.cpp
+++ b/lib/icinga/service-downtime.cpp
@@ -275,6 +275,8 @@ void Service::RemoveExpiredDowntimes(void)
 
 void Service::DowntimesExpireTimerHandler(void)
 {
+	recursive_mutex::scoped_lock lock(Application::GetMutex());
+
 	DynamicObject::Ptr object;
 	BOOST_FOREACH(tie(tuples::ignore, object), DynamicType::GetByName("Service")->GetObjects()) {
 		Service::Ptr service = dynamic_pointer_cast<Service>(object);
diff --git a/lib/icinga/service.cpp b/lib/icinga/service.cpp
index 72a09e8c9..bf4e72bf1 100644
--- a/lib/icinga/service.cpp
+++ b/lib/icinga/service.cpp
@@ -67,11 +67,17 @@ String Service::GetDisplayName(void) const
 	return GetName();
 }
 
+/**
+ * @threadsafety Always.
+ */
 bool Service::Exists(const String& name)
 {
 	return (DynamicObject::GetObject("Service", name));
 }
 
+/**
+ * @threadsafety Always.
+ */
 Service::Ptr Service::GetByName(const String& name)
 {
 	DynamicObject::Ptr configObject = DynamicObject::GetObject("Service", name);
@@ -82,9 +88,14 @@ Service::Ptr Service::GetByName(const String& name)
 	return dynamic_pointer_cast<Service>(configObject);
 }
 
+/**
+ * @threadsafety Always.
+ */
 Service::Ptr Service::GetByNamePair(const String& hostName, const String& serviceName)
 {
 	if (!hostName.IsEmpty()) {
+		recursive_mutex::scoped_lock lock(Application::GetMutex());
+
 		Host::Ptr host = Host::GetByName(hostName);
 		return host->GetServiceByShortName(serviceName);
 	} else {
diff --git a/lib/icinga/service.h b/lib/icinga/service.h
index ba76f6cc5..2c3d9e99d 100644
--- a/lib/icinga/service.h
+++ b/lib/icinga/service.h
@@ -180,8 +180,8 @@ public:
 	static ServiceStateType StateTypeFromString(const String& state);
 	static String StateTypeToString(ServiceStateType state);
 
-	static boost::signal<void (const Service::Ptr&, const String&)> OnCheckerChanged;
-	static boost::signal<void (const Service::Ptr&, const Value&)> OnNextCheckChanged;
+	static signals2::signal<void (const Service::Ptr&, const String&)> OnCheckerChanged;
+	static signals2::signal<void (const Service::Ptr&, const Value&)> OnNextCheckChanged;
 
 	/* Downtimes */
 	static int GetNextDowntimeID(void);
diff --git a/lib/icinga/servicegroup.cpp b/lib/icinga/servicegroup.cpp
index e63c13427..c07e940cf 100644
--- a/lib/icinga/servicegroup.cpp
+++ b/lib/icinga/servicegroup.cpp
@@ -50,11 +50,17 @@ String ServiceGroup::GetActionUrl(void) const
 	return Get("action_url");
 }
 
+/**
+ * @threadsafety Always.
+ */
 bool ServiceGroup::Exists(const String& name)
 {
 	return (DynamicObject::GetObject("ServiceGroup", name));
 }
 
+/**
+ * @threadsafety Always.
+ */
 ServiceGroup::Ptr ServiceGroup::GetByName(const String& name)
 {
 	DynamicObject::Ptr configObject = DynamicObject::GetObject("ServiceGroup", name);
diff --git a/lib/python/pythonlanguage.cpp b/lib/python/pythonlanguage.cpp
index 62ab582cf..5c0f0de6a 100644
--- a/lib/python/pythonlanguage.cpp
+++ b/lib/python/pythonlanguage.cpp
@@ -366,7 +366,7 @@ PyObject *PythonLanguage::PyRegisterFunction(PyObject *self, PyObject *args)
 	}
 
 	{
-		boost::mutex::scoped_lock lock(Application::GetMutex());
+		recursive_mutex::scoped_lock lock(Application::GetMutex());
 		interp->RegisterPythonFunction(name, object);
 	}
 
diff --git a/lib/remoting/endpoint.cpp b/lib/remoting/endpoint.cpp
index 32659adb7..d5631cc4e 100644
--- a/lib/remoting/endpoint.cpp
+++ b/lib/remoting/endpoint.cpp
@@ -30,10 +30,10 @@ static AttributeDescription endpointAttributes[] = {
 
 REGISTER_TYPE(Endpoint, endpointAttributes);
 
-boost::signal<void (const Endpoint::Ptr&)> Endpoint::OnConnected;
-boost::signal<void (const Endpoint::Ptr&)> Endpoint::OnDisconnected;
-boost::signal<void (const Endpoint::Ptr&, const String& topic)> Endpoint::OnSubscriptionRegistered;
-boost::signal<void (const Endpoint::Ptr&, const String& topic)> Endpoint::OnSubscriptionUnregistered;
+signals2::signal<void (const Endpoint::Ptr&)> Endpoint::OnConnected;
+signals2::signal<void (const Endpoint::Ptr&)> Endpoint::OnDisconnected;
+signals2::signal<void (const Endpoint::Ptr&, const String& topic)> Endpoint::OnSubscriptionRegistered;
+signals2::signal<void (const Endpoint::Ptr&, const String& topic)> Endpoint::OnSubscriptionUnregistered;
 
 /**
  * Constructor for the Endpoint class.
@@ -201,13 +201,13 @@ void Endpoint::SetSubscriptions(const Dictionary::Ptr& subscriptions)
 
 void Endpoint::RegisterTopicHandler(const String& topic, const function<Endpoint::Callback>& callback)
 {
-	map<String, shared_ptr<boost::signal<Endpoint::Callback> > >::iterator it;
+	map<String, shared_ptr<signals2::signal<Endpoint::Callback> > >::iterator it;
 	it = m_TopicHandlers.find(topic);
 
-	shared_ptr<boost::signal<Endpoint::Callback> > sig;
+	shared_ptr<signals2::signal<Endpoint::Callback> > sig;
 
 	if (it == m_TopicHandlers.end()) {
-		sig = boost::make_shared<boost::signal<Endpoint::Callback> >();
+		sig = boost::make_shared<signals2::signal<Endpoint::Callback> >();
 		m_TopicHandlers.insert(make_pair(topic, sig));
 	} else {
 		sig = it->second;
@@ -271,7 +271,7 @@ void Endpoint::ProcessRequest(const Endpoint::Ptr& sender, const RequestMessage&
 		if (!request.GetMethod(&method))
 			return;
 
-		map<String, shared_ptr<boost::signal<Endpoint::Callback> > >::iterator it;
+		map<String, shared_ptr<signals2::signal<Endpoint::Callback> > >::iterator it;
 		it = m_TopicHandlers.find(method);
 
 		if (it == m_TopicHandlers.end())
diff --git a/lib/remoting/endpoint.h b/lib/remoting/endpoint.h
index 9b8e22eb8..2d337f16f 100644
--- a/lib/remoting/endpoint.h
+++ b/lib/remoting/endpoint.h
@@ -71,11 +71,11 @@ public:
 
 	static Endpoint::Ptr MakeEndpoint(const String& name, bool replicated, bool local = true);
 
-	static boost::signal<void (const Endpoint::Ptr&)> OnConnected;
-	static boost::signal<void (const Endpoint::Ptr&)> OnDisconnected;
+	static signals2::signal<void (const Endpoint::Ptr&)> OnConnected;
+	static signals2::signal<void (const Endpoint::Ptr&)> OnDisconnected;
 
-	static boost::signal<void (const Endpoint::Ptr&, const String& topic)> OnSubscriptionRegistered;
-	static boost::signal<void (const Endpoint::Ptr&, const String& topic)> OnSubscriptionUnregistered;
+	static signals2::signal<void (const Endpoint::Ptr&, const String& topic)> OnSubscriptionRegistered;
+	static signals2::signal<void (const Endpoint::Ptr&, const String& topic)> OnSubscriptionUnregistered;
 
 private:
 	bool m_ReceivedWelcome; /**< Have we received a welcome message
@@ -83,7 +83,7 @@ private:
 	bool m_SentWelcome; /**< Have we sent a welcome message to this
 			         endpoint? */
 
-	map<String, shared_ptr<boost::signal<Callback> > > m_TopicHandlers;
+	map<String, shared_ptr<signals2::signal<Callback> > > m_TopicHandlers;
 
 	void NewMessageHandler(const MessagePart& message);
 	void ClientClosedHandler(void);
diff --git a/lib/remoting/endpointmanager.cpp b/lib/remoting/endpointmanager.cpp
index 3d122a7cf..e7d004bba 100644
--- a/lib/remoting/endpointmanager.cpp
+++ b/lib/remoting/endpointmanager.cpp
@@ -325,6 +325,8 @@ bool EndpointManager::RequestTimeoutLessComparer(const pair<String, PendingReque
 
 void EndpointManager::SubscriptionTimerHandler(void)
 {
+	recursive_mutex::scoped_lock lock(Application::GetMutex());
+
 	Dictionary::Ptr subscriptions = boost::make_shared<Dictionary>();
 
 	DynamicObject::Ptr object;
@@ -349,6 +351,8 @@ void EndpointManager::SubscriptionTimerHandler(void)
 
 void EndpointManager::ReconnectTimerHandler(void)
 {
+	recursive_mutex::scoped_lock lock(Application::GetMutex());
+
 	DynamicObject::Ptr object;
 	BOOST_FOREACH(tie(tuples::ignore, object), DynamicType::GetByName("Endpoint")->GetObjects()) {
 		Endpoint::Ptr endpoint = dynamic_pointer_cast<Endpoint>(object);
@@ -373,6 +377,8 @@ void EndpointManager::ReconnectTimerHandler(void)
 
 void EndpointManager::RequestTimerHandler(void)
 {
+	recursive_mutex::scoped_lock lock(Application::GetMutex());
+
 	map<String, PendingRequest>::iterator it;
 	for (it = m_Requests.begin(); it != m_Requests.end(); it++) {
 		if (it->second.HasTimedOut()) {
diff --git a/lib/remoting/endpointmanager.h b/lib/remoting/endpointmanager.h
index 120f9f57b..bcdb14c14 100644
--- a/lib/remoting/endpointmanager.h
+++ b/lib/remoting/endpointmanager.h
@@ -60,7 +60,7 @@ public:
 
 	void ProcessResponseMessage(const Endpoint::Ptr& sender, const ResponseMessage& message);
 
-	boost::signal<void (const EndpointManager::Ptr&, const Endpoint::Ptr&)> OnNewEndpoint;
+	signals2::signal<void (const EndpointManager::Ptr&, const Endpoint::Ptr&)> OnNewEndpoint;
 
 private:
 	String m_Identity;
diff --git a/lib/remoting/jsonrpcconnection.h b/lib/remoting/jsonrpcconnection.h
index 84589e3bc..9473b8951 100644
--- a/lib/remoting/jsonrpcconnection.h
+++ b/lib/remoting/jsonrpcconnection.h
@@ -38,7 +38,7 @@ public:
 
 	void SendMessage(const MessagePart& message);
 
-	boost::signal<void (const JsonRpcConnection::Ptr&, const MessagePart&)> OnNewMessage;
+	signals2::signal<void (const JsonRpcConnection::Ptr&, const MessagePart&)> OnNewMessage;
 
 protected:
 	virtual void ProcessData(void);