Is there a way to stop a NpgsqlConnection from being in waiting state and meanwhile ensure to not loose any notifications when waiting?

Question

In PostgreSql, I wrote generic code to be notify on table update.

Doing so, I have to wait for the connection. Not waiting, I receive no notification from the Database. So I wait like this:

conn.Wait(Timeout.Infinite);

I could have used Wait without any parameter in a loop be I was afraid to miss some notifications by concurrency. For example when 2 notifications enter simultanously, when wait is called without parameter and is released by receiving the first notification, we can miss the second one (before returning in the wait state). So I used "Timeout.Infinite".

To stop th connection from another thread, I tried to close it with:

conn.Close()

But I receive an exception:

Npgsql.NpgsqlOperationInProgressException: 'The connection is already in state 'Waiting''

So the question is :

Is there any way to stop the connection from being in waiting state and meanwhile ensure to not loose any notifications when waiting?

Note: I think (only my opinion) it is missing a CancellationToken from the PostgreSql "Connection.Wait" function. We should be able to cancel the waiting either when waiting for the next change.

Answer 1

Use the WaitAsync function, which accepts a CancellationToken.

await conn.WaitAsync(someToken);

Obviously this must be done in an async function, which should never be called using .Wait or .Result as you could deadlock. Instead do async all the way down.