BACnetClient is not thread safe about bacnet HOT 6 OPEN

Hey @minzdrav, just wondering if that worked for you? Did you manage to run a client per thread without issue?

Hi @MatthijsvdVeer
Yes.

from bacnet.

Yup, can confirm the reads are not threadsafe. It has to do with InvokeId, a uint8 that gets added to every request like a correlation ID, it gets incremented every request, and if you send too many requests it can quickly roll over and cause problems.

Update: On further investigation the reads cause a thread to be blocked waiting for reply because of the use of ManualResetEvent, this is actually a much bigger problem, as the non thread-safe client can be wrapped in a mutex, and multiple clients started in parallel, however, the reads will quickly eat up worker threads.

Fortunately a solution could be to replace ManualResetEvent with a TaskCompletionSource which doesn't block a thread. The rest of the code seems to be non-blocking which is great.

from bacnet.

Hi Guys,
I have same problem with https://github.com/ela-compil/BACnet/tree/v2-netstandard brunch.
Could you please try to fix?

from bacnet.

Unfortunatelly the client was not written to be thread safe. Try using a lock each time before you use it or write a wrapper that would do it for you for each atomic operation. Since BACnet operations have identifiers it should be possible to allow multiple requests to be sent out in the same time. I will leave this issue open to try to address it in the future.

from bacnet.

Hi @gralin
Thank you.
Yes, it's working fine with locks.
I have 1 thread per device and customer want to read properties and values from many devices. I'll try to create BACnet client per thread. Should work faster than locks.

from bacnet.

Hey @minzdrav, just wondering if that worked for you? Did you manage to run a client per thread without issue?

from bacnet.