Iot.Device.SocketCan -> TryReadFrame() offer nonblocking mode?

[tkoetting75q]

From what I understand, Linux socket devices can be opened in a blocking or non-blocking mode for reading. Standard is blocking-mode.

=> Flags O_NONBLOCK, MSG_DONTWAIT in the C world

Would it be possible to implement this choice for Iot.Device.SocketCan.CanRaw?

many thanks!

[krwq]

[Triage] @tkoetting75q when I wrote this class it wasn't exactly possible to use Socket + NetworkStream for this - right now it might be possible because we support AddressFamily.ControllerAreaNetwork which means we could rewrite native layer and replace it with NetworkStream where we should get Async for free.

So basically we should replace https://github.com/dotnet/iot/blob/main/src/devices/SocketCan/Interop.cs#L86 with Socket constructor with:

• AddressFamily.ControllerAreaNetwork
• SocketType.Raw
• (ProtocolType)1 // CAN

and wrap that with NetworkStream - it's possible we would be able to get rid of native layer completely but I can't remember.

I probably won't have time to this anytime soon but I can help you with PR if you're interested.

[tkoetting75q]

@krwq thanks for the hints. Since I'm still fairly new to c# I have a hard time following your suggestion. So a very quick and dirty example would be extremely helpful for me at this point.

[krwq]

I believe @pgrawehr might be interested in this work as well. I'm not sure how to write example without actually doing this but I don't have a setup anymore for CAN handy...