/// <summary>
/// Asynchronously performs the examples tasks in a loop until the
/// <paramref name="token"/> is canceled.
/// </summary>
/// <returns>
/// A task that when complete contains a tuple with the number of
/// messages published and the number of messages received in total.
/// </returns>
static async Task <(int messagesSent, int messagesReceived)> RunLoopsAsync(
IQueuedMessageSession session,
CancellationToken token)
{
Console.WriteLine("Run Host.vi to send and receive messages from this example.");
Console.WriteLine("Press Ctrl+C to stop.");
Console.WriteLine();
/*
* Begin each loop and wait for both to complete.
*/
var publishLoop = PublishLoopAsync(session, token);
var readLoop = ReadMessageLoopAsync(session, token);
await Task.WhenAll(publishLoop, readLoop).ConfigureAwait(false);
return(publishLoop.Result, readLoop.Result);
}
/// <summary>
/// Asynchronously reads messages from Host.vi until
/// <paramref name="token"/> is canceled.
/// </summary>
/// <returns>A task that when complete contains the number of messages
/// read by the loop.</returns>
static async Task <int> ReadMessageLoopAsync(IQueuedMessageSession session, CancellationToken token)
{
int messagesReceived = 0;
while (!token.IsCancellationRequested)
{
/*
* Try to read a message if one is available. The timeout
* determines the responsiveness of stopping the example,
* because we wait for the read to complete before returning.
*/
var message = await session.ReadAsync(timeoutMilliseconds : 2000)
.ConfigureAwait(false);
if (message == null)
{
// No message has been queued, so loop around to read again.
continue;
}
++messagesReceived;
var date = DateTime.Now.ToString("d", CultureInfo.CurrentCulture);
var time = DateTime.Now.ToString("T", CultureInfo.CurrentCulture);
Console.WriteLine("Received message:");
Console.WriteLine("\tDate: {0}", date);
Console.WriteLine("\tTime: {0}", time);
Console.WriteLine("\tTopic: {0}", message.Topic);
Console.WriteLine("\tMessage: {0}", message.Message);
Console.WriteLine();
/*
* Send a message back to the host to indicate we received
* the message. The reply is sent using a different topic than
* the one on which we received the message.
*/
await session.PublishAsync(HostTopic,
"Replying to " + message.Message).ConfigureAwait(false);
}
return(messagesReceived);
}
