Game lock up During Scripted Camera Intro/Outro

[MrS-ibra]

Prerequisites

• I have searched for similar issues and confirmed this is not a duplicate

Game Version

• Command & Conquer Generals
• Command & Conquer Generals: Zero Hour
• Other (please specify below)

Bug Description

When playing on maps that have cinematic camera intros/outros, the game sometimes locks up as soon as the camera starts moving.
Can be seen happening on one of Legionnaire's streams here:
https://youtu.be/cOGn2MZjR6s?t=14340

This seems to be introduced by one of the changes as it does not happen on retail.

I have not been able to reproduce it alone, even when running another instance. It only seems to happen when another human player is present in the match, but could be wrong.

Worth noting that this may not happen at all times, and it seems that deleting mapcache or playing the map on a first time transfer does help with reproducing it. though this map I'm attaching does reproduce it reliably (need another human player).

Reproduction Steps

Map with scripted camera intro and reliable reproduction:
hlh the apocalypse version eight.zip

• For this map, human players must be USA in the first and second slot, AI player must be GLA in the third slot and positioned at the top of the map.

Additional Context

camera_hang.mp4

[xezon]

I suspect the game enters an infinite loop somewhere.

[Mauller]

For me this map is throwing a lot of INI file assert errors before crashing out before it even gets into the game.

[Mauller]

[Caball009]

I suspect the game enters an infinite loop somewhere.

This is correct, in W3DDisplay::draw.

The freezeTime logic appears to be the issue. It checks if the game is halted here:

GeneralsGameCode/GeneralsMD/Code/GameEngineDevice/Source/W3DDevice/GameClient/W3DDisplay.cpp

Line 1750 in 746c017

Bool freezeTime = TheFramePacer->isTimeFrozen() || TheFramePacer->isGameHalted();

But it's not possible to break out of the loop if the game had been halted, freezing the game because of the infinite loop:

GeneralsGameCode/GeneralsMD/Code/GameEngineDevice/Source/W3DDevice/GameClient/W3DDisplay.cpp

Lines 1957 to 1962 in 746c017

	if (TheScriptEngine->isTimeFrozenDebug() || TheScriptEngine->isTimeFrozenScript() || TheGameLogic->isGamePaused())
	{
	freezeTime = false; // We're frozen for debug or for pause, and need to continue out of the loop.
	}
	} while (freezeTime && !TheTacticalView->isCameraMovementFinished());

The logic for whether the game is halted resides in GameEngine::isGameHalted; notice the check whether the network is stalling:

GeneralsGameCode/GeneralsMD/Code/GameEngine/Source/Common/GameEngine.cpp

Lines 327 to 341 in 746c017

	Bool GameEngine::isGameHalted()
	{
	if (TheNetwork != NULL)
	{
	if (TheNetwork->isStalling())
	return true;
	}
	else
	{
	if (TheGameLogic != NULL && TheGameLogic->isGamePaused())
	return true;
	}
	return false;
	}

So if a there's a scripted camera move that coincides with the network stalling (e.g. one of the clients has an issue with their connection), the game enters this loop and cannot exit it. As soon as a single client is stuck in this loop, all clients will get stuck in it.

[Caball009]

Simpler and fully reliable reproduction in my experience (also for multiple instances):

1. Use the attached map. It has a single script that moves the camera on map start for 20 seconds.
2. Host game with client01 and join with client02.
3. If the camera plays non-interrupted for 10 seconds or so, suspend one of the clients with something like Windows Resource Monitor (resmon).
   The issue tends to occur in the first 10 seconds without manually triggering it.
4. The other client will notice that the network is stalling and enter an infinite loop, freezing the game.
5. If you resume the suspended client, it'll also enter the infinite loop and be frozen.

camera_intro_test01.zip

[xezon]

Ok nice investigation. Yes this code was added by us as part of the Logic Render decoupling.