Revert "wait for 2 seconds on disconnect" changes

CHANGELOG.md

@@ -3,6 +3,7 @@
 ## [1.7.2] - Unreleased
 
 - Fixed: [#5834](https://github.com/ethereum/aleth/pull/5834) Fix segmentation fault during sync.
+- Fixed: [#5841](https://github.com/ethereum/aleth/pull/5841) Revert the change introduced in 1.7.0 to wait 2 secods after sending `Disconnect` to peer before closing the socket, as it caused instabilty during sync.
 
 ## [1.7.1] - 2019-11-18
 

libp2p/Host.cpp

@@ -1200,11 +1200,3 @@ void Host::forEachPeer(
             return;
 }
 
-std::unique_ptr<ba::steady_timer> Host::createTimer(std::chrono::seconds const& _expiryDelay,
-    std::function<void(const boost::system::error_code& error)>&& _f)
-{
-    std::unique_ptr<ba::steady_timer> timer{new ba::steady_timer{m_ioContext}};
-    timer->expires_after(_expiryDelay);
-    timer->async_wait(_f);
-    return timer;
-}

libp2p/Host.h

@@ -266,11 +266,6 @@ class Host: public Worker
 
     std::shared_ptr<CapabilityHostFace> capabilityHost() const { return m_capabilityHost; }
 
-    /// Execute work on the network thread after an @a _expiryDelay delay.
-    /// Returned timer should be kept alive until delay is over.
-    std::unique_ptr<ba::steady_timer> createTimer(std::chrono::seconds const& _expiryDelay,
-        std::function<void(const boost::system::error_code& error)>&& _f);
-
 protected:
     /*
      * Used by the host to run a capability's background work loop

libp2p/Session.cpp

@@ -206,9 +206,6 @@ bool Session::checkPacket(bytesConstRef _msg)
 
 void Session::send(bytes&& _msg)
 {
-    if (m_dropped)
-        return;
-
     bytesConstRef msg(&_msg);
     LOG(m_netLoggerDetail) << capabilityPacketTypeToString(_msg[0]) << " to";
     if (!checkPacket(msg))
@@ -279,6 +276,16 @@ void Session::drop(DisconnectReason _reason)
 {
     if (m_dropped)
         return;
+    bi::tcp::socket& socket = m_socket->ref();
+    if (socket.is_open())
+        try
+        {
+            boost::system::error_code ec;
+            LOG(m_netLoggerDetail) << "Closing (" << reasonOf(_reason) << ") connection with";
+            socket.shutdown(boost::asio::ip::tcp::socket::shutdown_both, ec);
+            socket.close();
+        }
+        catch (...) {}
 
     m_peer->m_lastDisconnect = _reason;
     if (_reason == BadProtocol)
@@ -291,22 +298,14 @@ void Session::drop(DisconnectReason _reason)
 
 void Session::disconnect(DisconnectReason _reason)
 {
-    if (m_dropped)
-        return;
-
     clog(VerbosityTrace, "p2pcap") << "Disconnecting (our reason: " << reasonOf(_reason) << ") from " << m_logSuffix;
 
-    RLPStream s;
-    prep(s, DisconnectPacket, 1) << (int)_reason;
-    sealAndSend(s);
-
-    auto self(shared_from_this());
-    // The empty handler will keep the Session alive for the supplied amount of time, after
-    // which Host will garbage-collect the Session which will invoke the Session dtor and close the
-    // socket
-    m_disconnectTimer =
-        m_server->createTimer(std::chrono::seconds(2), [self](boost::system::error_code) {});
-
+    if (m_socket->ref().is_open())
+    {
+        RLPStream s;
+        prep(s, DisconnectPacket, 1) << (int)_reason;
+        sealAndSend(s);
+    }
     drop(_reason);
 }
 

libp2p/Session.h

@@ -84,7 +84,7 @@ class Session: public SessionFace, public std::enable_shared_from_this<SessionFa
 
     void ping() override;
 
-    bool isConnected() const override { return !m_dropped; }
+    bool isConnected() const override { return m_socket->ref().is_open(); }
 
     NodeID id() const override;
 
@@ -177,8 +177,6 @@ class Session: public SessionFace, public std::enable_shared_from_this<SessionFa
 
     std::set<std::string> m_disabledCapabilities;
 
-    std::unique_ptr<ba::steady_timer> m_disconnectTimer;
-
     std::string m_logSuffix;
 
     Logger m_netLogger{createLogger(VerbosityDebug, "net")};