From 1c8196ae60154bd60e3405e150ac5690a7d42da7 Mon Sep 17 00:00:00 2001
From: Adrian DC <radian.dc@gmail.com>
Date: Thu, 25 Feb 2021 19:59:14 +0100
Subject: [PATCH] fix: resolve #254: resolve double close calls and race
 conditions

---
 src/internal/sio_client_impl.cpp | 23 +++++++++++++----------
 1 file changed, 13 insertions(+), 10 deletions(-)

diff --git a/src/internal/sio_client_impl.cpp b/src/internal/sio_client_impl.cpp
index 1f91d5a9..8cf9ed9c 100644
--- a/src/internal/sio_client_impl.cpp
+++ b/src/internal/sio_client_impl.cpp
@@ -387,15 +387,16 @@ namespace sio
 
     void client_impl::on_fail(connection_hdl)
     {
-        if (m_con_state == con_closing) {
+        con_state m_con_state_was = m_con_state;
+        m_con.reset();
+        m_con_state = con_closed;
+        this->sockets_invoke_void(&sio::socket::on_disconnect);
+
+        if (m_con_state_was == con_closing) {
             LOG("Connection failed while closing." << endl);
-            this->close();
             return;
         }
 
-        m_con.reset();
-        m_con_state = con_closed;
-        this->sockets_invoke_void(&sio::socket::on_disconnect);
         LOG("Connection failed." << endl);
         if(m_reconn_made<m_reconn_attempts)
         {
@@ -415,16 +416,18 @@ namespace sio
     
     void client_impl::on_open(connection_hdl con)
     {
-        if (m_con_state == con_closing) {
+        con_state m_con_state_was = m_con_state;
+        LOG("Connected." << endl);
+        m_con_state = con_opened;
+        m_con = con;
+        m_reconn_made = 0;
+
+        if (m_con_state_was == con_closing) {
             LOG("Connection opened while closing." << endl);
             this->close();
             return;
         }
 
-        LOG("Connected." << endl);
-        m_con_state = con_opened;
-        m_con = con;
-        m_reconn_made = 0;
         this->sockets_invoke_void(&sio::socket::on_open);
         this->socket("");
         if(m_open_listener)m_open_listener();