5 files changed, 442 insertions, 326 deletions

diff --git a/src/OSSupport/CMakeLists.txt b/src/OSSupport/CMakeLists.txt
index 8454279fe..167afb784 100644
--- a/src/OSSupport/CMakeLists.txt
+++ b/src/OSSupport/CMakeLists.txt
@@ -13,6 +13,7 @@ SET (SRCS
 	IsThread.cpp
 	ListenThread.cpp
 	Network.cpp
+	NetworkSingleton.cpp
 	Semaphore.cpp
 	Socket.cpp
 	SocketThreads.cpp
@@ -28,6 +29,7 @@ SET (HDRS
 	IsThread.h
 	ListenThread.h
 	Network.h
+	NetworkSingleton.h
 	Queue.h
 	Semaphore.h
 	Socket.h
diff --git a/src/OSSupport/Network.cpp b/src/OSSupport/Network.cpp
index decd111ea..359206632 100644
--- a/src/OSSupport/Network.cpp
+++ b/src/OSSupport/Network.cpp
@@ -13,6 +13,7 @@
 #include <thread>
 #include "Event.h"
 #include "CriticalSection.h"
+#include "NetworkSingleton.h"
 
 
 
@@ -232,102 +233,6 @@ protected:
 
 
 
-class cNetworkSingleton
-{
-	friend class cHostnameLookup;    // Needs access to m_DNSBase
-	friend class cIPLookup;          // Needs access to m_DNSBase
-	friend class cTCPLinkImpl;       // Needs access to m_EventBase and m_DNSBase
-	friend class cServerHandleImpl;  // Needs access to m_EventBase
-
-public:
-	/** Returns the singleton instance of this class */
-	static cNetworkSingleton & Get(void);
-
-
-	// The following functions are implementations for the cNetwork class
-
-	/** Queues a DNS query to resolve the specified hostname to IP address.
-	Calls one of the callbacks when the resolving succeeds, or when it fails.
-	Returns true if queueing was successful, false if not.
-	Note that the return value doesn't report the success of the actual lookup; the lookup happens asynchronously on the background. */
-	bool HostnameToIP(
-		const AString & a_Hostname,
-		cNetwork::cResolveNameCallbacksPtr a_Callbacks
-	);
-
-
-	/** Queues a DNS query to resolve the specified IP address to a hostname.
-	Calls one of the callbacks when the resolving succeeds, or when it fails.
-	Returns true if queueing was successful, false if not.
-	Note that the return value doesn't report the success of the actual lookup; the lookup happens asynchronously on the background. */
-	bool IPToHostName(
-		const AString & a_IP,
-		cNetwork::cResolveNameCallbacksPtr a_Callbacks
-	);
-
-protected:
-
-	/** The main LibEvent container for driving the event loop. */
-	event_base * m_EventBase;
-
-	/** The LibEvent handle for doing DNS lookups. */
-	evdns_base * m_DNSBase;
-
-	/** Container for all client connections, including ones with pending-connect. */
-	cTCPLinkImplPtrs m_Connections;
-
-	/** Container for all servers that are currently active. */
-	cServerHandleImplPtrs m_Servers;
-
-	/** Container for all pending hostname lookups. */
-	cHostnameLookupPtrs m_HostnameLookups;
-
-	/** Container for all pending IP lookups. */
-	cIPLookupPtrs m_IPLookups;
-
-	/** Mutex protecting all containers against multithreaded access. */
-	cCriticalSection m_CS;
-
-
-	/** Initializes the LibEvent internals. */
-	cNetworkSingleton(void);
-
-	/** Converts LibEvent-generated log events into log messages in MCS log. */
-	static void LogCallback(int a_Severity, const char * a_Msg);
-
-	/** Implements the thread that runs LibEvent's event dispatcher loop. */
-	static void RunEventLoop(cNetworkSingleton * a_Self);
-
-	/** Removes the specified hostname lookup from m_HostnameLookups.
-	Used by the underlying lookup implementation when the lookup is finished. */
-	void RemoveHostnameLookup(const cHostnameLookup * a_HostnameLookup);
-
-	/** Removes the specified IP lookup from m_IPLookups.
-	Used by the underlying lookup implementation when the lookup is finished. */
-	void RemoveIPLookup(const cIPLookup * a_IPLookup);
-
-	/** Adds the specified link to m_Connections.
-	Used by the underlying link implementation when a new link is created. */
-	void AddLink(cTCPLinkImplPtr a_Link);
-
-	/** Removes the specified link from m_Connections.
-	Used by the underlying link implementation when the link is closed / errored. */
-	void RemoveLink(const cTCPLinkImpl * a_Link);
-
-	/** Adds the specified link to m_Servers.
-	Used by the underlying server handle implementation when a new listening server is created.
-	Only servers that succeed in listening are added. */
-	void AddServer(cServerHandleImplPtr a_Server);
-
-	/** Removes the specified server from m_Servers.
-	Used by the underlying server handle implementation when the server is closed. */
-	void RemoveServer(const cServerHandleImpl * a_Server);
-};
-
-
-
-
-
 ////////////////////////////////////////////////////////////////////////////////
 // Globals:
 
@@ -357,7 +262,7 @@ cHostnameLookup::cHostnameLookup(const AString & a_Hostname, cNetwork::cResolveN
 	hints.ai_socktype = SOCK_STREAM;
 	hints.ai_family = AF_UNSPEC;
 	hints.ai_flags = EVUTIL_AI_CANONNAME;
-	evdns_getaddrinfo(cNetworkSingleton::Get().m_DNSBase, a_Hostname.c_str(), nullptr, &hints, Callback, this);
+	evdns_getaddrinfo(cNetworkSingleton::Get().GetDNSBase(), a_Hostname.c_str(), nullptr, &hints, Callback, this);
 }
 
 
@@ -440,13 +345,13 @@ cIPLookup::cIPLookup(const AString & a_IP, cNetwork::cResolveNameCallbacksPtr a_
 		case AF_INET:
 		{
 			sockaddr_in * sa4 = reinterpret_cast<sockaddr_in *>(&sa);
-			evdns_base_resolve_reverse(cNetworkSingleton::Get().m_DNSBase, &(sa4->sin_addr), 0, Callback, this);
+			evdns_base_resolve_reverse(cNetworkSingleton::Get().GetDNSBase(), &(sa4->sin_addr), 0, Callback, this);
 			break;
 		}
 		case AF_INET6:
 		{
 			sockaddr_in6 * sa6 = reinterpret_cast<sockaddr_in6 *>(&sa);
-			evdns_base_resolve_reverse_ipv6(cNetworkSingleton::Get().m_DNSBase, &(sa6->sin6_addr), 0, Callback, this);
+			evdns_base_resolve_reverse_ipv6(cNetworkSingleton::Get().GetDNSBase(), &(sa6->sin6_addr), 0, Callback, this);
 			break;
 		}
 		default:
@@ -492,7 +397,7 @@ void cIPLookup::Callback(int a_Result, char a_Type, int a_Count, int a_Ttl, void
 
 cTCPLinkImpl::cTCPLinkImpl(cTCPLink::cCallbacksPtr a_LinkCallbacks):
 	super(a_LinkCallbacks),
-	m_BufferEvent(bufferevent_socket_new(cNetworkSingleton::Get().m_EventBase, -1, BEV_OPT_CLOSE_ON_FREE)),
+	m_BufferEvent(bufferevent_socket_new(cNetworkSingleton::Get().GetEventBase(), -1, BEV_OPT_CLOSE_ON_FREE)),
 	m_Server(nullptr)
 {
 	// Create the LibEvent handle, but don't assign a socket to it yet (will be assigned within Connect() method):
@@ -506,7 +411,7 @@ cTCPLinkImpl::cTCPLinkImpl(cTCPLink::cCallbacksPtr a_LinkCallbacks):
 
 cTCPLinkImpl::cTCPLinkImpl(evutil_socket_t a_Socket, cTCPLink::cCallbacksPtr a_LinkCallbacks, cServerHandleImpl * a_Server, const sockaddr * a_Address, int a_AddrLen):
 	super(a_LinkCallbacks),
-	m_BufferEvent(bufferevent_socket_new(cNetworkSingleton::Get().m_EventBase, a_Socket, BEV_OPT_CLOSE_ON_FREE)),
+	m_BufferEvent(bufferevent_socket_new(cNetworkSingleton::Get().GetEventBase(), a_Socket, BEV_OPT_CLOSE_ON_FREE)),
 	m_Server(a_Server)
 {
 	// Update the endpoint addresses:
@@ -568,7 +473,7 @@ cTCPLinkImplPtr cTCPLinkImpl::Connect(const AString & a_Host, UInt16 a_Port, cTC
 	}
 
 	// a_Host is a hostname, connect after a lookup:
-	if (bufferevent_socket_connect_hostname(res->m_BufferEvent, cNetworkSingleton::Get().m_DNSBase, AF_UNSPEC, a_Host.c_str(), a_Port) == 0)
+	if (bufferevent_socket_connect_hostname(res->m_BufferEvent, cNetworkSingleton::Get().GetDNSBase(), AF_UNSPEC, a_Host.c_str(), a_Port) == 0)
 	{
 		// Success
 		return res;
@@ -932,7 +837,7 @@ bool cServerHandleImpl::Listen(UInt16 a_Port)
 		evutil_closesocket(MainSock);
 		return false;
 	}
-	m_ConnListener = evconnlistener_new(cNetworkSingleton::Get().m_EventBase, Callback, this, LEV_OPT_CLOSE_ON_FREE | LEV_OPT_REUSEABLE, 0, MainSock);
+	m_ConnListener = evconnlistener_new(cNetworkSingleton::Get().GetEventBase(), Callback, this, LEV_OPT_CLOSE_ON_FREE | LEV_OPT_REUSEABLE, 0, MainSock);
 
 	// If a secondary socket is required (WinXP dual-stack), create it here:
 	if (NeedsTwoSockets)
@@ -943,7 +848,7 @@ bool cServerHandleImpl::Listen(UInt16 a_Port)
 		{
 			if (evutil_make_socket_nonblocking(SecondSock) == 0)
 			{
-				m_SecondaryConnListener = evconnlistener_new(cNetworkSingleton::Get().m_EventBase, Callback, this, LEV_OPT_CLOSE_ON_FREE | LEV_OPT_REUSEABLE, 0, SecondSock);
+				m_SecondaryConnListener = evconnlistener_new(cNetworkSingleton::Get().GetEventBase(), Callback, this, LEV_OPT_CLOSE_ON_FREE | LEV_OPT_REUSEABLE, 0, SecondSock);
 			}
 			else
 			{
@@ -1070,224 +975,3 @@ cTCPLink::cTCPLink(cCallbacksPtr a_Callbacks):
 
 
 
-////////////////////////////////////////////////////////////////////////////////
-// cNetworkSingleton:
-
-cNetworkSingleton::cNetworkSingleton(void)
-{
-	// Windows: initialize networking:
-	#ifdef _WIN32
-		WSADATA wsaData;
-		memset(&wsaData, 0, sizeof(wsaData));
-		int res = WSAStartup (MAKEWORD(2, 2), &wsaData);
-		if (res != 0)
-		{
-			int err = WSAGetLastError();
-			LOGWARNING("WSAStartup failed: %d, WSAGLE = %d (%s)", res, err, evutil_socket_error_to_string(err));
-			exit(1);
-		}
-	#endif  // _WIN32
-
-	// Initialize LibEvent logging:
-	event_set_log_callback(LogCallback);
-
-	// Initialize threading:
-	#if defined(EVTHREAD_USE_WINDOWS_THREADS_IMPLEMENTED)
-		evthread_use_windows_threads();
-	#elif defined(EVTHREAD_USE_PTHREADS_IMPLEMENTED)
-		evthread_use_pthreads();
-	#else
-		#error No threading implemented for EVTHREAD
-	#endif
-
-	// Create the main event_base:
-	m_EventBase = event_base_new();
-	if (m_EventBase == nullptr)
-	{
-		LOGERROR("Failed to initialize LibEvent. The server will now terminate.");
-		abort();
-	}
-
-	// Create the DNS lookup helper:
-	m_DNSBase = evdns_base_new(m_EventBase, 1);
-	if (m_DNSBase == nullptr)
-	{
-		LOGERROR("Failed to initialize LibEvent's DNS subsystem. The server will now terminate.");
-		abort();
-	}
-
-	// Create the event loop thread:
-	std::thread EventLoopThread(RunEventLoop, this);
-	EventLoopThread.detach();
-}
-
-
-
-
-
-cNetworkSingleton & cNetworkSingleton::Get(void)
-{
-	static cNetworkSingleton Instance;
-	return Instance;
-}
-
-
-
-
-
-bool cNetworkSingleton::HostnameToIP(
-	const AString & a_Hostname,
-	cNetwork::cResolveNameCallbacksPtr a_Callbacks
-)
-{
-	try
-	{
-		cCSLock Lock(m_CS);
-		m_HostnameLookups.push_back(std::make_shared<cHostnameLookup>(a_Hostname, a_Callbacks));
-	}
-	catch (...)
-	{
-		return false;
-	}
-	return true;
-}
-
-
-
-
-bool cNetworkSingleton::IPToHostName(
-	const AString & a_IP,
-	cNetwork::cResolveNameCallbacksPtr a_Callbacks
-)
-{
-	try
-	{
-		cCSLock Lock(m_CS);
-		m_IPLookups.push_back(std::make_shared<cIPLookup>(a_IP, a_Callbacks));
-	}
-	catch (...)
-	{
-		return false;
-	}
-	return true;
-}
-
-
-
-
-void cNetworkSingleton::LogCallback(int a_Severity, const char * a_Msg)
-{
-	switch (a_Severity)
-	{
-		case _EVENT_LOG_DEBUG: LOGD      ("LibEvent: %s", a_Msg); break;
-		case _EVENT_LOG_MSG:   LOG       ("LibEvent: %s", a_Msg); break;
-		case _EVENT_LOG_WARN:  LOGWARNING("LibEvent: %s", a_Msg); break;
-		case _EVENT_LOG_ERR:   LOGERROR  ("LibEvent: %s", a_Msg); break;
-		default:
-		{
-			LOGWARNING("LibEvent: Unknown log severity (%d): %s", a_Severity, a_Msg);
-			break;
-		}
-	}
-}
-
-
-
-
-
-void cNetworkSingleton::RunEventLoop(cNetworkSingleton * a_Self)
-{
-	event_base_loop(a_Self->m_EventBase, EVLOOP_NO_EXIT_ON_EMPTY);
-}
-
-
-
-
-
-void cNetworkSingleton::RemoveHostnameLookup(const cHostnameLookup * a_HostnameLookup)
-{
-	cCSLock Lock(m_CS);
-	for (auto itr = m_HostnameLookups.begin(), end = m_HostnameLookups.end(); itr != end; ++itr)
-	{
-		if (itr->get() == a_HostnameLookup)
-		{
-			m_HostnameLookups.erase(itr);
-			return;
-		}
-	}  // for itr - m_HostnameLookups[]
-}
-
-
-
-
-
-void cNetworkSingleton::RemoveIPLookup(const cIPLookup * a_IPLookup)
-{
-	cCSLock Lock(m_CS);
-	for (auto itr = m_IPLookups.begin(), end = m_IPLookups.end(); itr != end; ++itr)
-	{
-		if (itr->get() == a_IPLookup)
-		{
-			m_IPLookups.erase(itr);
-			return;
-		}
-	}  // for itr - m_IPLookups[]
-}
-
-
-
-
-
-void cNetworkSingleton::AddLink(cTCPLinkImplPtr a_Link)
-{
-	cCSLock Lock(m_CS);
-	m_Connections.push_back(a_Link);
-}
-
-
-
-
-
-void cNetworkSingleton::RemoveLink(const cTCPLinkImpl * a_Link)
-{
-	cCSLock Lock(m_CS);
-	for (auto itr = m_Connections.begin(), end = m_Connections.end(); itr != end; ++itr)
-	{
-		if (itr->get() == a_Link)
-		{
-			m_Connections.erase(itr);
-			return;
-		}
-	}  // for itr - m_Connections[]
-}
-
-
-
-
-
-void cNetworkSingleton::AddServer(cServerHandleImplPtr a_Server)
-{
-	cCSLock Lock(m_CS);
-	m_Servers.push_back(a_Server);
-}
-
-
-
-
-
-void cNetworkSingleton::RemoveServer(const cServerHandleImpl * a_Server)
-{
-	cCSLock Lock(m_CS);
-	for (auto itr = m_Servers.begin(), end = m_Servers.end(); itr != end; ++itr)
-	{
-		if (itr->get() == a_Server)
-		{
-			m_Servers.erase(itr);
-			return;
-		}
-	}  // for itr - m_Servers[]
-}
-
-
-
-
diff --git a/src/OSSupport/NetworkSingleton.cpp b/src/OSSupport/NetworkSingleton.cpp
new file mode 100644
index 000000000..552abad64
--- /dev/null
+++ b/src/OSSupport/NetworkSingleton.cpp
@@ -0,0 +1,281 @@
+
+// NetworkSingleton.cpp
+
+// Implements the cNetworkSingleton class representing the storage for global data pertaining to network API
+// such as a list of all connections, all listening sockets and the LibEvent dispatch thread.
+
+#include "Globals.h"
+#include "NetworkSingleton.h"
+#include <event2/event.h>
+#include <event2/thread.h>
+#include <event2/bufferevent.h>
+#include <event2/dns.h>
+#include <event2/listener.h>
+
+
+
+
+
+////////////////////////////////////////////////////////////////////////////////
+// Class definitions:
+
+/** Holds information about an in-progress Hostname-to-IP lookup. */
+class cHostnameLookup
+{
+	/** The callbacks to call for resolved names / errors. */
+	cNetwork::cResolveNameCallbacksPtr m_Callbacks;
+
+	/** The hostname that was queried (needed for the callbacks). */
+	AString m_Hostname;
+
+	static void Callback(int a_ErrCode, struct evutil_addrinfo * a_Addr, void * a_Self);
+
+public:
+	cHostnameLookup(const AString & a_Hostname, cNetwork::cResolveNameCallbacksPtr a_Callbacks);
+};
+typedef SharedPtr<cHostnameLookup> cHostnameLookupPtr;
+typedef std::vector<cHostnameLookupPtr> cHostnameLookupPtrs;
+
+
+
+
+
+/** Holds information about an in-progress IP-to-Hostname lookup. */
+class cIPLookup
+{
+	/** The callbacks to call for resolved names / errors. */
+	cNetwork::cResolveNameCallbacksPtr m_Callbacks;
+
+	/** The IP that was queried (needed for the callbacks). */
+	AString m_IP;
+
+	static void Callback(int a_Result, char a_Type, int a_Count, int a_Ttl, void * a_Addresses, void * a_Self);
+
+public:
+	cIPLookup(const AString & a_IP, cNetwork::cResolveNameCallbacksPtr a_Callbacks);
+};
+typedef SharedPtr<cIPLookup> cIPLookupPtr;
+typedef std::vector<cIPLookupPtr> cIPLookupPtrs;
+
+
+
+
+
+cNetworkSingleton::cNetworkSingleton(void)
+{
+	// Windows: initialize networking:
+	#ifdef _WIN32
+		WSADATA wsaData;
+		memset(&wsaData, 0, sizeof(wsaData));
+		int res = WSAStartup (MAKEWORD(2, 2), &wsaData);
+		if (res != 0)
+		{
+			int err = WSAGetLastError();
+			LOGWARNING("WSAStartup failed: %d, WSAGLE = %d (%s)", res, err, evutil_socket_error_to_string(err));
+			exit(1);
+		}
+	#endif  // _WIN32
+
+	// Initialize LibEvent logging:
+	event_set_log_callback(LogCallback);
+
+	// Initialize threading:
+	#if defined(EVTHREAD_USE_WINDOWS_THREADS_IMPLEMENTED)
+		evthread_use_windows_threads();
+	#elif defined(EVTHREAD_USE_PTHREADS_IMPLEMENTED)
+		evthread_use_pthreads();
+	#else
+		#error No threading implemented for EVTHREAD
+	#endif
+
+	// Create the main event_base:
+	m_EventBase = event_base_new();
+	if (m_EventBase == nullptr)
+	{
+		LOGERROR("Failed to initialize LibEvent. The server will now terminate.");
+		abort();
+	}
+
+	// Create the DNS lookup helper:
+	m_DNSBase = evdns_base_new(m_EventBase, 1);
+	if (m_DNSBase == nullptr)
+	{
+		LOGERROR("Failed to initialize LibEvent's DNS subsystem. The server will now terminate.");
+		abort();
+	}
+
+	// Create the event loop thread:
+	std::thread EventLoopThread(RunEventLoop, this);
+	EventLoopThread.detach();
+}
+
+
+
+
+
+cNetworkSingleton & cNetworkSingleton::Get(void)
+{
+	static cNetworkSingleton Instance;
+	return Instance;
+}
+
+
+
+
+
+bool cNetworkSingleton::HostnameToIP(
+	const AString & a_Hostname,
+	cNetwork::cResolveNameCallbacksPtr a_Callbacks
+)
+{
+	try
+	{
+		cCSLock Lock(m_CS);
+		m_HostnameLookups.push_back(std::make_shared<cHostnameLookup>(a_Hostname, a_Callbacks));
+	}
+	catch (...)
+	{
+		return false;
+	}
+	return true;
+}
+
+
+
+
+bool cNetworkSingleton::IPToHostName(
+	const AString & a_IP,
+	cNetwork::cResolveNameCallbacksPtr a_Callbacks
+)
+{
+	try
+	{
+		cCSLock Lock(m_CS);
+		m_IPLookups.push_back(std::make_shared<cIPLookup>(a_IP, a_Callbacks));
+	}
+	catch (...)
+	{
+		return false;
+	}
+	return true;
+}
+
+
+
+
+void cNetworkSingleton::LogCallback(int a_Severity, const char * a_Msg)
+{
+	switch (a_Severity)
+	{
+		case _EVENT_LOG_DEBUG: LOGD      ("LibEvent: %s", a_Msg); break;
+		case _EVENT_LOG_MSG:   LOG       ("LibEvent: %s", a_Msg); break;
+		case _EVENT_LOG_WARN:  LOGWARNING("LibEvent: %s", a_Msg); break;
+		case _EVENT_LOG_ERR:   LOGERROR  ("LibEvent: %s", a_Msg); break;
+		default:
+		{
+			LOGWARNING("LibEvent: Unknown log severity (%d): %s", a_Severity, a_Msg);
+			break;
+		}
+	}
+}
+
+
+
+
+
+void cNetworkSingleton::RunEventLoop(cNetworkSingleton * a_Self)
+{
+	event_base_loop(a_Self->m_EventBase, EVLOOP_NO_EXIT_ON_EMPTY);
+}
+
+
+
+
+
+void cNetworkSingleton::RemoveHostnameLookup(const cHostnameLookup * a_HostnameLookup)
+{
+	cCSLock Lock(m_CS);
+	for (auto itr = m_HostnameLookups.begin(), end = m_HostnameLookups.end(); itr != end; ++itr)
+	{
+		if (itr->get() == a_HostnameLookup)
+		{
+			m_HostnameLookups.erase(itr);
+			return;
+		}
+	}  // for itr - m_HostnameLookups[]
+}
+
+
+
+
+
+void cNetworkSingleton::RemoveIPLookup(const cIPLookup * a_IPLookup)
+{
+	cCSLock Lock(m_CS);
+	for (auto itr = m_IPLookups.begin(), end = m_IPLookups.end(); itr != end; ++itr)
+	{
+		if (itr->get() == a_IPLookup)
+		{
+			m_IPLookups.erase(itr);
+			return;
+		}
+	}  // for itr - m_IPLookups[]
+}
+
+
+
+
+
+void cNetworkSingleton::AddLink(cTCPLinkImplPtr a_Link)
+{
+	cCSLock Lock(m_CS);
+	m_Connections.push_back(a_Link);
+}
+
+
+
+
+
+void cNetworkSingleton::RemoveLink(const cTCPLinkImpl * a_Link)
+{
+	cCSLock Lock(m_CS);
+	for (auto itr = m_Connections.begin(), end = m_Connections.end(); itr != end; ++itr)
+	{
+		if (itr->get() == a_Link)
+		{
+			m_Connections.erase(itr);
+			return;
+		}
+	}  // for itr - m_Connections[]
+}
+
+
+
+
+
+void cNetworkSingleton::AddServer(cServerHandleImplPtr a_Server)
+{
+	cCSLock Lock(m_CS);
+	m_Servers.push_back(a_Server);
+}
+
+
+
+
+
+void cNetworkSingleton::RemoveServer(const cServerHandleImpl * a_Server)
+{
+	cCSLock Lock(m_CS);
+	for (auto itr = m_Servers.begin(), end = m_Servers.end(); itr != end; ++itr)
+	{
+		if (itr->get() == a_Server)
+		{
+			m_Servers.erase(itr);
+			return;
+		}
+	}  // for itr - m_Servers[]
+}
+
+
+
+
diff --git a/src/OSSupport/NetworkSingleton.h b/src/OSSupport/NetworkSingleton.h
new file mode 100644
index 000000000..d5a4ec279
--- /dev/null
+++ b/src/OSSupport/NetworkSingleton.h
@@ -0,0 +1,138 @@
+
+// NetworkSingleton.h
+
+// Declares the cNetworkSingleton class representing the storage for global data pertaining to network API
+// such as a list of all connections, all listening sockets and the LibEvent dispatch thread.
+
+#pragma once
+
+#include "Network.h"
+#include "CriticalSection.h"
+
+
+
+
+
+// fwd:
+struct event_base;
+struct evdns_base;
+class cServerHandleImpl;
+class cTCPLinkImpl;
+class cHostnameLookup;
+class cIPLookup;
+typedef SharedPtr<cTCPLinkImpl> cTCPLinkImplPtr;
+typedef std::vector<cTCPLinkImplPtr> cTCPLinkImplPtrs;
+typedef SharedPtr<cServerHandleImpl> cServerHandleImplPtr;
+typedef std::vector<cServerHandleImplPtr> cServerHandleImplPtrs;
+typedef SharedPtr<cHostnameLookup> cHostnameLookupPtr;
+typedef std::vector<cHostnameLookupPtr> cHostnameLookupPtrs;
+typedef SharedPtr<cIPLookup> cIPLookupPtr;
+typedef std::vector<cIPLookupPtr> cIPLookupPtrs;
+
+
+
+
+
+class cNetworkSingleton
+{
+public:
+	/** Returns the singleton instance of this class */
+	static cNetworkSingleton & Get(void);
+
+
+	// The following functions are implementations for the cNetwork class
+
+	/** Queues a DNS query to resolve the specified hostname to IP address.
+	Calls one of the callbacks when the resolving succeeds, or when it fails.
+	Returns true if queueing was successful, false if not.
+	Note that the return value doesn't report the success of the actual lookup; the lookup happens asynchronously on the background.
+	TODO: Move this out into a separate file with cHostnameLookup. */
+	bool HostnameToIP(
+		const AString & a_Hostname,
+		cNetwork::cResolveNameCallbacksPtr a_Callbacks
+	);
+
+
+	/** Queues a DNS query to resolve the specified IP address to a hostname.
+	Calls one of the callbacks when the resolving succeeds, or when it fails.
+	Returns true if queueing was successful, false if not.
+	Note that the return value doesn't report the success of the actual lookup; the lookup happens asynchronously on the background.
+	TODO: Move this out into a separate file with cIPLookup. */
+	bool IPToHostName(
+		const AString & a_IP,
+		cNetwork::cResolveNameCallbacksPtr a_Callbacks
+	);
+
+	/** Returns the main LibEvent handle for event registering. */
+	event_base * GetEventBase(void) { return m_EventBase; }
+
+	/** Returns the LibEvent handle for DNS lookups. */
+	evdns_base * GetDNSBase(void) { return m_DNSBase; }
+
+	/** Removes the specified hostname lookup from m_HostnameLookups.
+	Used by the underlying lookup implementation when the lookup is finished. */
+	void RemoveHostnameLookup(const cHostnameLookup * a_HostnameLookup);
+
+	/** Removes the specified IP lookup from m_IPLookups.
+	Used by the underlying lookup implementation when the lookup is finished. */
+	void RemoveIPLookup(const cIPLookup * a_IPLookup);
+
+	/** Adds the specified link to m_Connections.
+	Used by the underlying link implementation when a new link is created. */
+	void AddLink(cTCPLinkImplPtr a_Link);
+
+	/** Removes the specified link from m_Connections.
+	Used by the underlying link implementation when the link is closed / errored. */
+	void RemoveLink(const cTCPLinkImpl * a_Link);
+
+	/** Adds the specified link to m_Servers.
+	Used by the underlying server handle implementation when a new listening server is created.
+	Only servers that succeed in listening are added. */
+	void AddServer(cServerHandleImplPtr a_Server);
+
+	/** Removes the specified server from m_Servers.
+	Used by the underlying server handle implementation when the server is closed. */
+	void RemoveServer(const cServerHandleImpl * a_Server);
+
+protected:
+
+	/** The main LibEvent container for driving the event loop. */
+	event_base * m_EventBase;
+
+	/** The LibEvent handle for doing DNS lookups. */
+	evdns_base * m_DNSBase;
+
+	/** Container for all client connections, including ones with pending-connect. */
+	cTCPLinkImplPtrs m_Connections;
+
+	/** Container for all servers that are currently active. */
+	cServerHandleImplPtrs m_Servers;
+
+	/** Container for all pending hostname lookups. */
+	cHostnameLookupPtrs m_HostnameLookups;
+
+	/** Container for all pending IP lookups. */
+	cIPLookupPtrs m_IPLookups;
+
+	/** Mutex protecting all containers against multithreaded access. */
+	cCriticalSection m_CS;
+
+
+	/** Initializes the LibEvent internals. */
+	cNetworkSingleton(void);
+
+	/** Converts LibEvent-generated log events into log messages in MCS log. */
+	static void LogCallback(int a_Severity, const char * a_Msg);
+
+	/** Implements the thread that runs LibEvent's event dispatcher loop. */
+	static void RunEventLoop(cNetworkSingleton * a_Self);
+};
+
+
+
+
+
+
+
+
+
diff --git a/tests/Network/CMakeLists.txt b/tests/Network/CMakeLists.txt
index 9d0dcdc24..6bf291544 100644
--- a/tests/Network/CMakeLists.txt
+++ b/tests/Network/CMakeLists.txt
@@ -6,10 +6,13 @@ include_directories(${CMAKE_SOURCE_DIR}/src/)
 include_directories(${CMAKE_SOURCE_DIR}/lib/libevent/include)
 
 add_definitions(-DTEST_GLOBALS=1)
+
+# Create a single Network library that contains all the networking code:
 add_library(Network
-	${CMAKE_SOURCE_DIR}/src/OSSupport/Network.cpp
 	${CMAKE_SOURCE_DIR}/src/OSSupport/CriticalSection.cpp
 	${CMAKE_SOURCE_DIR}/src/OSSupport/Event.cpp
+	${CMAKE_SOURCE_DIR}/src/OSSupport/Network.cpp
+	${CMAKE_SOURCE_DIR}/src/OSSupport/NetworkSingleton.cpp
 	${CMAKE_SOURCE_DIR}/src/StringUtils.cpp
 )
 
@@ -18,12 +21,20 @@ if (MSVC)
 	target_link_libraries(Network ws2_32.lib)
 endif()
 
+
+
+
+# Define individual tests:
+
+# Google: download the google.com frontpage using http client socket:
 add_executable(Google-exe Google.cpp)
 target_link_libraries(Google-exe Network)
 add_test(NAME Google-test COMMAND Google-exe)
 
+# EchoServer: Listen on port 9876, echo everything back:
 add_executable(EchoServer EchoServer.cpp)
 target_link_libraries(EchoServer Network)
 
+# NameLookup: Lookup hostname-to-IP and IP-to-hostname:
 add_executable(NameLookup NameLookup.cpp)
 target_link_libraries(NameLookup Network)