random shuffle of tunnels for peer test pairs

libi2pd/TunnelPool.cpp

@@ -361,12 +361,25 @@ namespace tunnel
 
 		// new tests
 		std::vector<std::pair<std::shared_ptr<OutboundTunnel>, std::shared_ptr<InboundTunnel> > > newTests;
+		std::random_device rd;
+		std::mt19937 rnd(rd());
+		std::vector<std::shared_ptr<OutboundTunnel> > outboundTunnels;
 		{
-			std::unique_lock<std::mutex> l1(m_OutboundTunnelsMutex);
-			auto it1 = m_OutboundTunnels.begin ();
-			std::unique_lock<std::mutex> l2(m_InboundTunnelsMutex);
-			auto it2 = m_InboundTunnels.begin ();
-			while (it1 != m_OutboundTunnels.end () && it2 != m_InboundTunnels.end ())
+			std::unique_lock<std::mutex> l(m_OutboundTunnelsMutex);
+			for (auto& it: m_OutboundTunnels)
+				outboundTunnels.push_back (it);
+		}
+		std::shuffle (outboundTunnels.begin(), outboundTunnels.end(), rnd);
+		std::vector<std::shared_ptr<InboundTunnel> > inboundTunnels;
+		{
+			std::unique_lock<std::mutex> l(m_InboundTunnelsMutex);
+			for (auto& it: m_InboundTunnels)
+				inboundTunnels.push_back (it);
+		}
+		std::shuffle (inboundTunnels.begin(), inboundTunnels.end(), rnd);
+		auto it1 = outboundTunnels.begin ();
+		auto it2 = inboundTunnels.begin ();
+		while (it1 != outboundTunnels.end () && it2 != inboundTunnels.end ())
 		{
 			bool failed = false;
 			if ((*it1)->IsFailed ())
@@ -385,7 +398,6 @@ namespace tunnel
 				++it1; ++it2;
 			}
 		}
-		}	
 		for (auto& it: newTests)
 		{
 			uint32_t msgID;