Ensure SqlDependency was Stopped

Question

SqlDependency starts on application start and stops on app stop. There are can be cases when SqlDependency.Stop() failed (for example, problem with connect to DB). As I understand, the SqlDependency infrastructure will be removed anyway by timeout.

But I don't understand what else SqlDependency.Stop() do?

Does it make sense to call SqlDependency.Stop() before SqlDependency.Start()?

Answer 1

Does it make sense to call SqlDependency.Stop() before SqlDependency.Start()?

If Start() was not called, calling Stop() is a no-op. We can check in the SqlDependency.cs reference source

   internal static bool Stop(string connectionString, string queue, bool useDefaults, bool startFailed) {
            ...
            bool result = false;

            lock (_startStopLock) {
                if (null != _processDispatcher) { // If _processDispatcher null, no Start has been called.
                    ....
                }
            }
            return result;

So it doesn't hurt, but it shouldn't be needed.