A thread-safe queue to support producer-consumer scenarios where a consumer can await on items to be processed.

AsyncQueue was designed to support an application where there may be multiple producers in background threads sending messages to a single consumer for processing (e.g. sending emails). It's simple to use, essentially supporting just Enqueue and DequeueAsync methods.

        var queue = new AsyncQueue<int>();

        // Simulate some other task posting an item for processing.
        Task.Run(() =>
            {
                Thread.Sleep(10);
                queue.Enqueue(42);
            });

        await queue.DequeueAsync();