From 8d71146b819093eb66eea697dd8d8453fa01a6c5 Mon Sep 17 00:00:00 2001
From: Tyler Wilding <xTVaser@users.noreply.github.com>
Date: Sat, 21 May 2022 15:49:01 -0400
Subject: [PATCH] game/deci2: Add a timeout on waiting for a client to connect
 to DECI2 (#1367)

game/deci2: Add a timeout to waiting for a client to connect
---
 common/cross_sockets/XSocket.cpp | 37 ++++++++++++++++++++++++++++++++
 common/cross_sockets/XSocket.h   |  2 ++
 game/system/Deci2Server.cpp      |  5 ++++-
 3 files changed, 43 insertions(+), 1 deletion(-)

diff --git a/common/cross_sockets/XSocket.cpp b/common/cross_sockets/XSocket.cpp
index a65f7077e9..4c60c41a06 100644
--- a/common/cross_sockets/XSocket.cpp
+++ b/common/cross_sockets/XSocket.cpp
@@ -38,6 +38,20 @@ int open_socket(int af, int type, int protocol) {
 int accept_socket(int socket, sockaddr* addr, socklen_t* addrLen) {
   return accept(socket, addr, addrLen);
 }
+int select_and_accept_socket(int socket, sockaddr* addr, socklen_t* addrLen, int microSeconds) {
+  struct timeval timeout;
+  timeout.tv_sec = 0;
+  timeout.tv_usec = microSeconds;
+  // Use select so it can timeout, accept on the returned socket if it is correct
+  fd_set read_sockets;
+  FD_ZERO(&read_sockets);
+  FD_SET(socket, &read_sockets);
+  auto activity = select(socket + 1, &read_sockets, NULL, NULL, &timeout);
+  if (activity > 0) {
+    return accept(socket, addr, addrLen);
+  }
+  return -1;
+}
 #endif
 
 #ifdef _WIN32
@@ -52,6 +66,29 @@ int accept_socket(int socket, sockaddr* addr, int* addrLen) {
   }
   return accept(socket, addr, addrLen);
 }
+
+int select_and_accept_socket(int socket, sockaddr* addr, int* addrLen, int microSeconds) {
+  WSADATA wsaData = {0};
+  int iResult = 0;
+  // Initialize Winsock
+  iResult = WSAStartup(MAKEWORD(2, 2), &wsaData);
+  if (iResult != 0) {
+    printf("WSAStartup failed: %d\n", iResult);
+    return 1;
+  }
+  struct timeval timeout;
+  timeout.tv_sec = 0;
+  timeout.tv_usec = microSeconds;
+  // Use select so it can timeout, accept on the returned socket if it is correct
+  fd_set read_sockets;
+  FD_ZERO(&read_sockets);
+  FD_SET(socket, &read_sockets);
+  auto activity = select(socket + 1, &read_sockets, NULL, NULL, &timeout);
+  if (activity > 0) {
+    return accept(socket, addr, addrLen);
+  }
+  return -1;
+}
 #endif
 
 void close_socket(int sock) {
diff --git a/common/cross_sockets/XSocket.h b/common/cross_sockets/XSocket.h
index 680f80b923..d73306b518 100644
--- a/common/cross_sockets/XSocket.h
+++ b/common/cross_sockets/XSocket.h
@@ -27,8 +27,10 @@ const int TCP_SOCKET_LEVEL = IPPROTO_TCP;
 int open_socket(int af, int type, int protocol);
 #ifdef __linux
 int accept_socket(int socket, sockaddr* addr, socklen_t* addrLen);
+int select_and_accept_socket(int socket, sockaddr* addr, socklen_t* addrLen, int microSeconds);
 #elif _WIN32
 int accept_socket(int socket, sockaddr* addr, int* addrLen);
+int select_and_accept_socket(int socket, sockaddr* addr, int* addrLen, int microSeconds);
 #endif
 void close_socket(int sock);
 int set_socket_option(int socket, int level, int optname, const void* optval, int optlen);
diff --git a/game/system/Deci2Server.cpp b/game/system/Deci2Server.cpp
index 338f64c111..7eae6cefc6 100644
--- a/game/system/Deci2Server.cpp
+++ b/game/system/Deci2Server.cpp
@@ -26,6 +26,8 @@ Deci2Server::~Deci2Server() {
   // Cleanup the accept thread
   if (accept_thread_running) {
     kill_accept_thread = true;
+    // NOTE - if we don't want to wait for the roundtrip timeout to exit the game gracefully
+    // we should just terminate the thread forcefully
     accept_thread.join();
     accept_thread_running = false;
   }
@@ -43,7 +45,8 @@ void Deci2Server::post_init() {
 void Deci2Server::accept_thread_func() {
   socklen_t addr_len = sizeof(addr);
   while (!kill_accept_thread) {
-    accepted_socket = accept_socket(listening_socket, (sockaddr*)&addr, &addr_len);
+    accepted_socket = select_and_accept_socket(listening_socket, (sockaddr*)&addr, &addr_len,
+                                               100000);  // 0.1 second timeout
     if (accepted_socket >= 0) {
       set_socket_timeout(accepted_socket, 100000);
       u32 versions[2] = {versions::GOAL_VERSION_MAJOR, versions::GOAL_VERSION_MINOR};