From ae0cf2e8311cd2b8cdaa5a0c9f33907a6b82bfeb Mon Sep 17 00:00:00 2001
From: orignal <i2porignal@yandex.ru>
Date: Wed, 20 Oct 2021 21:05:22 -0400
Subject: [PATCH] use memory pool for tunnel messages

---
 libi2pd/I2NPProtocol.cpp | 12 +++---------
 libi2pd/Tunnel.cpp       | 16 +++++++++++++++-
 libi2pd/Tunnel.h         |  6 ++++++
 libi2pd/util.h           | 38 ++++++++++++++++++++++++++++++++------
 4 files changed, 56 insertions(+), 16 deletions(-)

diff --git a/libi2pd/I2NPProtocol.cpp b/libi2pd/I2NPProtocol.cpp
index 0bc721ec..fa4fa7a6 100644
--- a/libi2pd/I2NPProtocol.cpp
+++ b/libi2pd/I2NPProtocol.cpp
@@ -38,20 +38,14 @@ namespace i2p
 
 	std::shared_ptr<I2NPMessage> NewI2NPTunnelMessage (bool endpoint)
 	{
-		I2NPMessage * msg = nullptr;
 		if (endpoint)
-		{
-			// should fit two tunnel message + tunnel gateway header, enough for one garlic encrypted streaming packet
-			msg = new I2NPMessageBuffer<2*i2p::tunnel::TUNNEL_DATA_MSG_SIZE + I2NP_HEADER_SIZE + TUNNEL_GATEWAY_HEADER_SIZE + 28>(); // reserved for alignment and NTCP 16 + 6 + 6
-			msg->Align (6);
-			msg->offset += TUNNEL_GATEWAY_HEADER_SIZE; // reserve room for TunnelGateway header
-		}
+			return i2p::tunnel::tunnels.NewI2NPTunnelMessage ();
 		else
 		{
-			msg = new I2NPMessageBuffer<i2p::tunnel::TUNNEL_DATA_MSG_SIZE + I2NP_HEADER_SIZE + 34>(); // reserved for alignment and NTCP 16 + 6 + 12
+			auto msg = new I2NPMessageBuffer<i2p::tunnel::TUNNEL_DATA_MSG_SIZE + I2NP_HEADER_SIZE + 34>(); // reserved for alignment and NTCP 16 + 6 + 12
 			msg->Align (12);
+			return std::shared_ptr<I2NPMessage>(msg);	
 		}
-		return std::shared_ptr<I2NPMessage>(msg);
 	}
 
 	std::shared_ptr<I2NPMessage> NewI2NPMessage (size_t len)
diff --git a/libi2pd/Tunnel.cpp b/libi2pd/Tunnel.cpp
index c8a1cc99..3de91940 100644
--- a/libi2pd/Tunnel.cpp
+++ b/libi2pd/Tunnel.cpp
@@ -488,7 +488,7 @@ namespace tunnel
 		i2p::util::SetThreadName("Tunnels");
 		std::this_thread::sleep_for (std::chrono::seconds(1)); // wait for other parts are ready
 
-		uint64_t lastTs = 0, lastPoolsTs = 0;
+		uint64_t lastTs = 0, lastPoolsTs = 0, lastMemoryPoolTs = 0;
 		while (m_IsRunning)
 		{
 			try
@@ -564,6 +564,11 @@ namespace tunnel
 						ManageTunnelPools (ts);
 						lastPoolsTs = ts;
 					}	
+					if (ts - lastMemoryPoolTs >= 120) // manage memory pool every 2 minutes
+					{
+						m_I2NPTunnelMessagesMemoryPool.CleanUpMt ();
+						lastMemoryPoolTs = ts;
+					}	
 				}	
 			}
 			catch (std::exception& ex)
@@ -935,6 +940,15 @@ namespace tunnel
 		return outboundTunnel;
 	}
 
+	std::shared_ptr<I2NPMessage> Tunnels::NewI2NPTunnelMessage ()
+	{
+		// should fit two tunnel message + tunnel gateway header, enough for one garlic encrypted streaming packet
+		auto msg = m_I2NPTunnelMessagesMemoryPool.AcquireSharedMt (); 
+		msg->Align (6);
+		msg->offset += TUNNEL_GATEWAY_HEADER_SIZE; // reserve room for TunnelGateway header
+		return msg;
+	}	
+		
 	int Tunnels::GetTransitTunnelsExpirationTimeout ()
 	{
 		int timeout = 0;
diff --git a/libi2pd/Tunnel.h b/libi2pd/Tunnel.h
index 930d0c58..30d9d565 100644
--- a/libi2pd/Tunnel.h
+++ b/libi2pd/Tunnel.h
@@ -18,6 +18,7 @@
 #include <thread>
 #include <mutex>
 #include <memory>
+#include "util.h"
 #include "Queue.h"
 #include "Crypto.h"
 #include "TunnelConfig.h"
@@ -40,6 +41,8 @@ namespace tunnel
 	const int MAX_NUM_RECORDS = 8;
 	const int HIGH_LATENCY_PER_HOP = 250; // in milliseconds
 	
+	const size_t I2NP_TUNNEL_ENPOINT_MESSAGE_SIZE = 2*TUNNEL_DATA_MSG_SIZE + I2NP_HEADER_SIZE + TUNNEL_GATEWAY_HEADER_SIZE + 28; // reserved for alignment and NTCP 16 + 6 + 6 
+	
 	enum TunnelState
 	{
 		eTunnelStatePending,
@@ -219,6 +222,8 @@ namespace tunnel
 			void DeleteTunnelPool (std::shared_ptr<TunnelPool> pool);
 			void StopTunnelPool (std::shared_ptr<TunnelPool> pool);
 
+			std::shared_ptr<I2NPMessage> NewI2NPTunnelMessage ();
+			
 		private:
 
 			template<class TTunnel>
@@ -257,6 +262,7 @@ namespace tunnel
 			std::list<std::shared_ptr<TunnelPool>> m_Pools;
 			std::shared_ptr<TunnelPool> m_ExploratoryPool;
 			i2p::util::Queue<std::shared_ptr<I2NPMessage> > m_Queue;
+			i2p::util::MemoryPoolMt<I2NPMessageBuffer<I2NP_TUNNEL_ENPOINT_MESSAGE_SIZE> > m_I2NPTunnelMessagesMemoryPool;
 			
 			// some stats
 			int m_NumSuccesiveTunnelCreations, m_NumFailedTunnelCreations;
diff --git a/libi2pd/util.h b/libi2pd/util.h
index 282ce7aa..d681829c 100644
--- a/libi2pd/util.h
+++ b/libi2pd/util.h
@@ -56,12 +56,8 @@ namespace util
 
 			void CleanUp ()
 			{
-				while (m_Head)
-				{
-					auto tmp = m_Head;
-					m_Head = static_cast<T*>(*(void * *)m_Head); // next
-					::operator delete ((void *)tmp);
-				}
+				CleanUp (m_Head);
+				m_Head = nullptr;
 			}		
 			
 			template<typename... TArgs>
@@ -98,6 +94,18 @@ namespace util
 					std::bind (&MemoryPool<T>::Release, this, std::placeholders::_1));
 			}
 
+		protected:
+
+			void CleanUp (T * head)
+			{
+				while (head)
+				{
+					auto tmp = head;
+					head = static_cast<T*>(*(void * *)head); // next
+					::operator delete ((void *)tmp);
+				}
+			}	
+			
 		protected:
 
 			T * m_Head;
@@ -131,6 +139,24 @@ namespace util
 					this->Release (it);
 			}
 
+			template<typename... TArgs>
+			std::shared_ptr<T> AcquireSharedMt (TArgs&&... args)
+			{
+				return std::shared_ptr<T>(AcquireMt (std::forward<TArgs>(args)...),
+					std::bind<void (MemoryPoolMt<T>::*)(T *)> (&MemoryPoolMt<T>::ReleaseMt, this, std::placeholders::_1));
+			}
+
+			void CleanUpMt ()
+			{
+				T * head;
+				{
+					std::lock_guard<std::mutex> l(m_Mutex);
+					head = this->m_Head;
+					this->m_Head = nullptr;	
+				}
+				if (head) this->CleanUp (head);
+			}	
+			
 		private:
 
 			std::mutex m_Mutex;