From a1c9a718987fcb489c44ca4e101b071b5e72a700 Mon Sep 17 00:00:00 2001
From: arcattack <arcattackmusic@gmail.com>
Date: Wed, 22 Jul 2026 08:24:30 -0500
Subject: [PATCH] Join wait: non-blocking dial -- the spinner no longer
 stutters

User-reported after the waiting-screen fix: "the animation keeps hanging."
Cause: RelayDialTcp used a BLOCKING connect() -- against a down/unreachable
operator each attempt froze the window thread for the OS SYN-retry window
(seconds), so the spinner ran only during the 2s sleep between attempts.

RelayDialTcp now connects NON-blocking and select()s in 100ms slices,
pumping the message loop + repainting the waiting screen every slice (both
in-flight and between retry attempts).  The success path already returned a
non-blocking socket (FIONBIO), so caller semantics are unchanged; the other
dial sites (console dial, game-socket dial) inherit the smooth behavior.

Verified: 4 window captures at 400ms intervals during a dead-host dial all
differ in the spinner region (uniform diff energy == continuous animation)
and IsHungAppWindow reads false on every sample.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
---
 engine/MUNGA_L4/L4NET.CPP | 74 +++++++++++++++++++++++++++++++++++----
 1 file changed, 68 insertions(+), 6 deletions(-)

diff --git a/engine/MUNGA_L4/L4NET.CPP b/engine/MUNGA_L4/L4NET.CPP
index eefad11..00384f8 100644
--- a/engine/MUNGA_L4/L4NET.CPP
+++ b/engine/MUNGA_L4/L4NET.CPP
@@ -1663,6 +1663,16 @@ SOCKET L4NetworkManager::RelayDialTcp(
 	const SOCKADDR_IN &endpoint,
 	int timeout_seconds)
 {
+	//
+	// NON-BLOCKING dial (2026-07-22, the "spinner keeps hanging" fix): the
+	// old blocking connect() froze the window thread for the OS SYN-retry
+	// window (seconds) per attempt -- the waiting screen stuttered.  Connect
+	// non-blocking and select() in 100ms slices, pumping the message loop +
+	// repainting the waiting screen each slice (RelayWaitTick).  The success
+	// path always returned a NON-blocking socket anyway (FIONBIO set below),
+	// so callers see identical semantics.
+	//
+	extern void BTWaitScreenPaint(const char *, const char *);
 	unsigned long deadline = GetTickCount() + (unsigned long)timeout_seconds * 1000UL;
 	for (;;)
 	{
@@ -1671,16 +1681,58 @@ SOCKET L4NetworkManager::RelayDialTcp(
 		{
 			return INVALID_SOCKET;
 		}
-		if (connect(sock, (const sockaddr *)&endpoint, sizeof(endpoint)) == 0)
+		unsigned long enable = 1;
+		ioctlsocket(sock, FIONBIO, &enable);
+		int rc = connect(sock, (const sockaddr *)&endpoint, sizeof(endpoint));
+		int wsa_error = (rc == 0) ? 0 : WSAGetLastError();
+		int connected = (rc == 0);
+		if (!connected && wsa_error == WSAEWOULDBLOCK)
+		{
+			// in flight: watch writability (success) / except (refusal),
+			// animating between slices
+			for (;;)
+			{
+				fd_set write_set, except_set;
+				FD_ZERO(&write_set);   FD_SET(sock, &write_set);
+				FD_ZERO(&except_set);  FD_SET(sock, &except_set);
+				timeval tv;
+				tv.tv_sec = 0;
+				tv.tv_usec = 100000;
+				int ready = select(0, NULL, &write_set, &except_set, &tv);
+				if (ready == 1 || ready == 2)
+				{
+					if (FD_ISSET(sock, &write_set))
+					{
+						connected = 1;
+					}
+					else
+					{
+						wsa_error = WSAECONNREFUSED;
+					}
+					break;
+				}
+				if (GetTickCount() >= deadline)
+				{
+					wsa_error = WSAETIMEDOUT;
+					break;
+				}
+				MSG msg;
+				while (PeekMessageA(&msg, NULL, 0, 0, PM_REMOVE))
+				{
+					TranslateMessage(&msg);
+					DispatchMessageA(&msg);
+				}
+				BTWaitScreenPaint("WAITING FOR THE OPERATOR'S SESSION",
+					"connecting...");
+			}
+		}
+		if (connected)
 		{
-			unsigned long enable = 1;
-			ioctlsocket(sock, FIONBIO, &enable);
 			BOOL noDelay = TRUE;
 			setsockopt(sock, IPPROTO_TCP, TCP_NODELAY,
 				(char *)&noDelay, sizeof(noDelay));
-			return sock;
+			return sock;						// already non-blocking (FIONBIO above)
 		}
-		int wsa_error = WSAGetLastError();
 		closesocket(sock);
 		if (GetTickCount() >= deadline
 			|| (wsa_error != WSAECONNREFUSED && wsa_error != WSAETIMEDOUT))
@@ -1689,7 +1741,17 @@ SOCKET L4NetworkManager::RelayDialTcp(
 				<< ")\n" << std::flush;
 			return INVALID_SOCKET;
 		}
-		Sleep(250);
+		{
+			MSG msg;
+			while (PeekMessageA(&msg, NULL, 0, 0, PM_REMOVE))
+			{
+				TranslateMessage(&msg);
+				DispatchMessageA(&msg);
+			}
+			BTWaitScreenPaint("WAITING FOR THE OPERATOR'S SESSION",
+				"connecting...");
+			Sleep(100);
+		}
 	}
 }