# HG changeset patch
# User Jonathan G Rennison <j.g.rennison@gmail.com>
# Date 2020-05-06 22:41:25
# Node ID c20a6e3dcfe0e09bf918833a809d8bdbbbb8a7af
# Parent  970d51c47b55f5ac29bcb3f0d33eb958dc2b14bc

Fix: Racy use of flags in TCPConnecter::CheckCallbacks

conected and aborted flags are used concurrently from multiple threads.

diff --git a/src/network/core/tcp.h b/src/network/core/tcp.h
--- a/src/network/core/tcp.h
+++ b/src/network/core/tcp.h
@@ -15,6 +15,8 @@
 #include "address.h"
 #include "packet.h"
 
+#include <atomic>
+
 /** The states of sending the packets. */
 enum SendPacketsState {
 	SPS_CLOSED,      ///< The connection got closed.
@@ -61,8 +63,8 @@ public:
  */
 class TCPConnecter {
 private:
-	bool connected;             ///< Whether we succeeded in making the connection
-	bool aborted;               ///< Whether we bailed out (i.e. connection making failed)
+	std::atomic<bool> connected;///< Whether we succeeded in making the connection
+	std::atomic<bool> aborted;  ///< Whether we bailed out (i.e. connection making failed)
 	bool killed;                ///< Whether we got killed
 	SOCKET sock;                ///< The socket we're connecting with
 
diff --git a/src/network/core/tcp_connect.cpp b/src/network/core/tcp_connect.cpp
--- a/src/network/core/tcp_connect.cpp
+++ b/src/network/core/tcp_connect.cpp
@@ -66,19 +66,21 @@ void TCPConnecter::Connect()
 {
 	for (auto iter = _tcp_connecters.begin(); iter < _tcp_connecters.end(); /* nothing */) {
 		TCPConnecter *cur = *iter;
-		if ((cur->connected || cur->aborted) && cur->killed) {
+		const bool connected = cur->connected.load();
+		const bool aborted = cur->aborted.load();
+		if ((connected || aborted) && cur->killed) {
 			iter = _tcp_connecters.erase(iter);
 			if (cur->sock != INVALID_SOCKET) closesocket(cur->sock);
 			delete cur;
 			continue;
 		}
-		if (cur->connected) {
+		if (connected) {
 			iter = _tcp_connecters.erase(iter);
 			cur->OnConnect(cur->sock);
 			delete cur;
 			continue;
 		}
-		if (cur->aborted) {
+		if (aborted) {
 			iter = _tcp_connecters.erase(iter);
 			cur->OnFailure();
 			delete cur;