From e81aea0fc96a2eb44e09d3aa0aad1e7d11878cae Mon Sep 17 00:00:00 2001
From: dec05eba <0xdec05eba@gmail.com>
Date: Sun, 21 Oct 2018 08:52:53 +0200
Subject: Fix concurrent connection to the same address

---
 src/DirectConnection.cpp | 107 ++++++++++++++++++++++++++---------------------
 1 file changed, 59 insertions(+), 48 deletions(-)

(limited to 'src')

diff --git a/src/DirectConnection.cpp b/src/DirectConnection.cpp
index 010b8af..3ffff22 100644
--- a/src/DirectConnection.cpp
+++ b/src/DirectConnection.cpp
@@ -109,58 +109,77 @@ namespace sibs
     {
         connect(address, true, true, connectCallbackFunc, receiveDataCallbackFunc, true);
     }
+
+    static bool isReady(const std::shared_future<PubSubConnectResult> &connectionResultFuture)
+    {
+        return connectionResultFuture.wait_for(std::chrono::seconds(0)) == std::future_status::ready;
+    }
     
     void DirectConnections::connect(const Ipv4 &address, bool rendezvous, bool reuseAddr, PubSubConnectCallback connectCallbackFunc, PubSubReceiveDataCallback receiveDataCallbackFunc, bool bind)
     {
-        std::thread([this, address, rendezvous, reuseAddr, connectCallbackFunc, receiveDataCallbackFunc, bind]()
+        connectionResultsMutex.lock();
+        auto it = connectionResults.find(address);
+        if(it != connectionResults.end())
         {
-            std::shared_ptr<DirectConnectionPeer> peer = getPeerByAddress(address);
-            if(peer)
+            std::shared_future<PubSubConnectResult> connectionResultFuture = it->second;
+            connectionResultsMutex.unlock();
+            if(isReady(connectionResultFuture))
             {
-                // this doesn't really matter, we always call connect with same callback function
-                peer->receiveDataCallbackFunc = receiveDataCallbackFunc;
+                PubSubConnectResult connectResult = connectionResultFuture.get();
                 if(connectCallbackFunc)
-                    connectCallbackFunc(peer, PubSubResult::OK, "");
-                return;
+                    connectCallbackFunc(connectResult.peer, connectResult.result, connectResult.resultStr);
             }
             else
             {
-                peer = std::make_shared<DirectConnectionPeer>();
-                peerByAddressMap[address] = peer;
-            }
-            
-            std::unique_ptr<Socket> socket;
-            try
-            {
-                socket = createSocket(Ipv4(nullptr, port), rendezvous, reuseAddr, bind);
-            }
-            catch(SocketCreateException &e)
-            {
-                if(connectCallbackFunc)
-                    connectCallbackFunc(peer, PubSubResult::ERROR, e.what());
-                return;
+                std::thread([connectCallbackFunc, connectionResultFuture]()
+                {
+                    PubSubConnectResult connectResult = connectionResultFuture.get();
+                    if(connectCallbackFunc)
+                        connectCallbackFunc(connectResult.peer, connectResult.result, connectResult.resultStr);
+                }).detach();
             }
-            
-            Log::debug("DirectConnections: Connecting to peer (ip: %s, port: %d, rendezvous: %s)", address.getAddress().c_str(), address.getPort(), rendezvous ? "yes" : "no");
-            if(UDT::connect(socket->udtSocket, (sockaddr*)&address.address, sizeof(address.address)) == UDT::ERROR)
+        }
+        else
+        {
+            connectionResults[address] = std::async(std::launch::async, [this, address, rendezvous, reuseAddr, connectCallbackFunc, receiveDataCallbackFunc, bind]()
             {
+                std::shared_ptr<DirectConnectionPeer> peer = std::make_shared<DirectConnectionPeer>();
+                std::unique_ptr<Socket> socket;
+
+                try
+                {
+                    socket = createSocket(Ipv4(nullptr, port), rendezvous, reuseAddr, bind);
+                }
+                catch(SocketCreateException &e)
+                {
+                    if(connectCallbackFunc)
+                        connectCallbackFunc(peer, PubSubResult::ERROR, e.what());
+                    return PubSubConnectResult { peer, PubSubResult::ERROR, e.what() };
+                }
+                
+                Log::debug("DirectConnections: Connecting to peer (ip: %s, port: %d, rendezvous: %s)", address.getAddress().c_str(), address.getPort(), rendezvous ? "yes" : "no");
+                if(UDT::connect(socket->udtSocket, (sockaddr*)&address.address, sizeof(address.address)) == UDT::ERROR)
+                {
+                    if(connectCallbackFunc)
+                        connectCallbackFunc(peer, PubSubResult::ERROR, UDT::getlasterror_desc());
+                    return PubSubConnectResult{ peer, PubSubResult::ERROR, UDT::getlasterror_desc() };
+                }
+                
+                UDT::epoll_add_usock(eid, socket->udtSocket);
+                socket->eid = eid;
+                peersMutex.lock();
+                peers[socket->udtSocket] = peer;
+                peer->socket = std::move(socket);
+                peer->address = address;
+                peer->receiveDataCallbackFunc = receiveDataCallbackFunc;
+                peersMutex.unlock();
+                
                 if(connectCallbackFunc)
-                    connectCallbackFunc(peer, PubSubResult::ERROR, UDT::getlasterror_desc());
-                return;
-            }
-            
-            UDT::epoll_add_usock(eid, socket->udtSocket);
-            socket->eid = eid;
-            peersMutex.lock();
-            peers[socket->udtSocket] = peer;
-            peer->socket = std::move(socket);
-            peer->address = address;
-            peer->receiveDataCallbackFunc = receiveDataCallbackFunc;
-            peersMutex.unlock();
-            
-            if(connectCallbackFunc)
-                connectCallbackFunc(peer, PubSubResult::OK, "");
-        }).detach();
+                    connectCallbackFunc(peer, PubSubResult::OK, "");
+                return PubSubConnectResult { peer, PubSubResult::OK, "" };
+            });
+            connectionResultsMutex.unlock();
+        }
     }
     
     bool DirectConnections::send(const std::shared_ptr<DirectConnectionPeer> peer, std::shared_ptr<Message> data, PubSubSendDataCallback sendDataCallbackFunc)
@@ -241,14 +260,6 @@ namespace sibs
         }
         peersMutex.unlock();
     }
-
-    std::shared_ptr<DirectConnectionPeer> DirectConnections::getPeerByAddress(const Ipv4 &address) const
-    {
-        auto it = peerByAddressMap.find(address);
-        if(it != peerByAddressMap.end())
-            return it->second;
-        return nullptr;
-    }
     
     void DirectConnections::receiveData()
     {
-- 
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