reuse DH keys pairs from failed NTCP sessions

NTCPSession.cpp

@@ -100,6 +100,9 @@ namespace ntcp
 		delete m_Establisher;
 		m_Establisher = nullptr;
 		
+		delete m_DHKeysPair;
+		m_DHKeysPair = nullptr;	
+
 		SendTimeSyncMessage ();
 		SendI2NPMessage (CreateDatabaseStoreMsg ()); // we tell immediately who we are		
 
@@ -154,6 +157,8 @@ namespace ntcp
 		if (ecode)
         {
 			LogPrint ("Phase 1 read error: ", ecode.message ());
+			i2p::transports.ReuseDHKeysPair (m_DHKeysPair);
+			m_DHKeysPair = nullptr;
 			Terminate ();
 		}
 		else
@@ -168,6 +173,8 @@ namespace ntcp
 				if ((m_Establisher->phase1.HXxorHI[i] ^ ident[i]) != digest[i])
 				{
 					LogPrint ("Wrong ident");
+					i2p::transports.ReuseDHKeysPair (m_DHKeysPair);
+					m_DHKeysPair = nullptr;
 					Terminate ();
 					return;
 				}	
@@ -224,6 +231,8 @@ namespace ntcp
         {
 			LogPrint ("Phase 2 read error: ", ecode.message (), ". Wrong ident assumed");
 			GetRemoteRouterInfo ().SetUnreachable (true); // this RouterInfo is not valid
+			i2p::transports.ReuseDHKeysPair (m_DHKeysPair);
+			m_DHKeysPair = nullptr;
 			Terminate ();
 		}
 		else

Transports.cpp

@@ -76,6 +76,12 @@ namespace i2p
 		}
 	}
 
+	void DHKeysPairSupplier::Return (i2p::data::DHKeysPair * pair)
+	{
+		std::unique_lock<std::mutex>  l(m_AcquiredMutex);
+		m_Queue.push (pair);
+	}
+
 	Transports transports;	
 	
 	Transports::Transports (): 
@@ -315,4 +321,9 @@ namespace i2p
 	{
 		return m_DHKeysPairSupplier.Acquire ();
 	}
+
+	void Transports::ReuseDHKeysPair (i2p::data::DHKeysPair * pair)
+	{
+		m_DHKeysPairSupplier.Return (pair);
+	}
 }

Transports.h

@@ -26,6 +26,7 @@ namespace i2p
 			void Start ();
 			void Stop ();
 			i2p::data::DHKeysPair * Acquire ();
+			void Return (i2p::data::DHKeysPair * pair);
 
 		private:
 
@@ -34,7 +35,7 @@ namespace i2p
 
 		private:
 
-			int m_QueueSize;
+			const int m_QueueSize;
 			std::queue<i2p::data::DHKeysPair *> m_Queue;
 
 			bool m_IsRunning;
@@ -55,6 +56,7 @@ namespace i2p
 			
 			boost::asio::io_service& GetService () { return m_Service; };
 			i2p::data::DHKeysPair * GetNextDHKeysPair ();	
+			void ReuseDHKeysPair (i2p::data::DHKeysPair * pair);
 
 			void AddNTCPSession (i2p::ntcp::NTCPSession * session);
 			void RemoveNTCPSession (i2p::ntcp::NTCPSession * session);