Gracefully handle debugger accept thread already running

src/xenia/debug/debugger.cc

@@ -58,7 +58,8 @@ Breakpoint::~Breakpoint() = default;
 Debugger::Debugger(Emulator* emulator)
     : emulator_(emulator),
       listen_socket_(INVALID_SOCKET),
-      client_socket_(INVALID_SOCKET) {
+      client_socket_(INVALID_SOCKET),
+      accept_thread_running_(false) {
   WSADATA wsa_data;
   WSAStartup(MAKEWORD(2, 2), &wsa_data);
 }
@@ -134,6 +135,8 @@ void SendResponse(SOCKET client_socket, flatbuffers::FlatBufferBuilder& fbb,
 }
 
 void Debugger::PreLaunch() {
+  if (!accept_thread_running_) {
+    accept_thread_running_ = true;
     accept_thread_ = std::thread([this]() {
       xe::threading::set_name("Debugger Server");
 
@@ -176,8 +179,8 @@ void Debugger::PreLaunch() {
 
             // Read body.
             std::vector<uint8_t> body(length);
-          r = recv(client_socket_, reinterpret_cast<char*>(body.data()), length,
+            r = recv(client_socket_, reinterpret_cast<char*>(body.data()),
-                   MSG_WAITALL);
+                     length, MSG_WAITALL);
             if (r != length) {
               // Failed?
               XELOGE("Failed to recv debug data body - dead connection?");
@@ -195,6 +198,7 @@ void Debugger::PreLaunch() {
         // This will WaitForClient if it was waiting.
       }
     });
+  }
 
   if (FLAGS_wait_for_debugger) {
     // Wait for the first client.

src/xenia/debug/debugger.h

@@ -111,6 +111,7 @@ class Debugger {
   Emulator* emulator_;
 
   uintptr_t listen_socket_;
+  bool accept_thread_running_;
   std::thread accept_thread_;
   xe::threading::Fence accept_fence_;
   uintptr_t client_socket_;