AirSim crashes when requested an image

[marco-stephan]

When requesting an image from AirSim using simGetImage(...) or simGetImages(...), AirSim occasionally crashes. This only happens on one of my computers.

simGetImage(...)

Reproduction steps

1. Connect to AirSim
2. Request image(s)

Code:

MultirotorRpcLibClient* airSim = new MultirotorRpcLibClient();
while (airSim->getConnectionState() != RpcLibClientBase::ConnectionState::Connected);

while (1)
{
	const std::vector<uint8_t> image = airSim->simGetImage("0", ImageCaptureBase::ImageType::Scene);
}

Error

DelegateSignatureImpl.inl at line 1045

The data of the DelegateInstanceInterface variable is unaccessable ("Unable to read memory")

simGetImages(...)

Reproduction steps

1. Connect to AirSim
2. Request image(s)

Code:

MultirotorRpcLibClient* airSim = new MultirotorRpcLibClient();
while (airSim->getConnectionState() != RpcLibClientBase::ConnectionState::Connected);

while (1)
{
	const std::vector<ImageCaptureBase::ImageRequest> imageRequests = {
		ImageCaptureBase::ImageRequest("0", ImageCaptureBase::ImageType::Scene, false, false)
	};
	const std::vector<ImageCaptureBase::ImageResponse>& imageResponses = airSim->simGetImages(imageRequests);
}

Error

RenderRequest.cpp at line 84

The game_viewport variable is of value 0x0000000000000001 and its data is unaccessable ("Unable to read memory")

Software Information

AirSim commit: bd8ee6b (latest master)

Hardware Information

CPU: Intel i5-7300HQ
GPU 1: Intel HD Graphics 630
GPU 2: NVIDIA GTX 1050Ti
RAM: 8GB

[rajat2004]

Which version of UE are you using? And this is happening only on Windows? (I'm assuming here that multiple systems includes different OS also)
The first one is happening from inside UE code, so can't really do much about that, maybe a later version can help
As for the second one, that doesn't make much sense, game_viewport_ is being used multiple times before this as well in the same function, so if it's null, should be exited in the beginning itself

[marco-stephan]

I am using UE 4.24.3 on both computes and both machines are running on Windows 10 (10.0.19041.388).

I was able to fix both crashes in https://github.com/marco-stephan/AirSim/tree/fix-get-images. Note that I have very little experience with AirSim's source code and the Unreal Engine itself so the fix committed is most likely not optimal.

[rajat2004]

The crash was somewhat reproducible and this fixed the problem? There's an already existing wait_signal_ which does the same thing, so instead of adding a new one, it might be better to move the call of wait_signal_->signal() from the end of Execute to the end of the lambda function where you right now added wait_signal2_->signal()
Anyways, a PR would be great

[marco-stephan]

The crashes were pretty reproducible meaning they appeared within 2 to 3 seconds when executing the code above. I wasn't sure if the proposed fix is the right way to go so I did not open a PR for this. That being said, I will open a PR with only one signal.

[stale]

This issue has been automatically marked as stale because it has not had activity from the community in the last year. It will be closed if no further activity occurs within 20 days.