protected override void RunLoop()
{
using (var redisClient = clientsManager.GetReadOnlyClient())
{
using (var subscription = redisClient.CreateSubscription())
{
subscription.OnUnSubscribe = channel => Log.Debug("OnUnSubscribe: " + channel);
subscription.OnMessage = (channel, msg) =>
{
if (msg == WorkerStatus.StopCommand)
{
Log.Debug("Stop Command Issued");
if (Interlocked.CompareExchange(ref status, WorkerStatus.Stopped, WorkerStatus.Started) != WorkerStatus.Started)
Interlocked.CompareExchange(ref status, WorkerStatus.Stopped, WorkerStatus.Stopping);
Log.Debug("UnSubscribe From All Channels...");
subscription.UnSubscribeFromAllChannels(); //Un block thread.
return;
}
this.IncrementMessageCount(1);
var messageReceivedArgs = new MessageReceivedArgs {QueueName = msg};
this.MqServer.NotifyMessageReceived(messageReceivedArgs);
};
subscription.SubscribeToChannels(QueueNames.TopicIn); //blocks thread
}
}
}
// IList<WaitHandle> manualResetEvents = new List<WaitHandle>();
public override void NotifyMessageReceived(MessageReceivedArgs messageReceivedArgs)
{
var handlerThreadCount = this.MessageHandlerRegister.RegisteredHandlers[messageReceivedArgs.MessageType].Configuration.NoOfThreads;
if (handlerThreadCount == 0) //// 0 => Threadpool
{
// Threadpool
// Queue the item to execute using the thread pool.
// TODO: Use Wait and Pulse; Use a incremental lock counter to ensure that all queued work items complete.
// var manualResetEvent = new ManualResetEvent(false);
// lock (manualResetEvents)
// {
// TODO: Verify that a lock is not required.
// manualResetEvents.Add(manualResetEvent);
Interlocked.Increment(ref threadPoolWorkItemCount);
ThreadPool.QueueUserWorkItem(new WaitCallback(ExecuteUsingQueuedWorkItem), messageReceivedArgs);
// TODO: How to wait for all tasks to complete using this method?
// }
/*
* // TODO: Change Project Framework to 3.5
* // TODO: Wait for all queued work items to complete when stop is called, in DISPOSE method.
* lock (manualResetEvents)
* {
* // After stop is called, set a flag that indicates pulse should be called when count == 0
* // TODO: Loop until count is 0; then pulse (Or, if already 0; pulse instantly)
* WaitHandle.WaitAll(manualResetEvents.ToArray());
* }*/
}
else
{
// Static Thread
base.NotifyMessageReceived(messageReceivedArgs);
}
}
protected override void RunLoop()
{
// Use Long-Polling to retrieve messages from a specific SQS queue.
while (Interlocked.CompareExchange(ref status, 0, 0) == WorkerStatus.Started)
{
Log.DebugFormat("Polling SQS Queue '{0}' for messages.", this.QueueName);
var response = this.SqsClient.ReceiveMessage(this.QueueUrl, this.WaitTimeInSeconds, this.MaxNumberOfMessages, this.MessageVisibilityTimeout, "ApproximateReceiveCount"); // Blocks until timout, or msg received
if (response.IsSetReceiveMessageResult() && response.ReceiveMessageResult.Message.Count > 0)
{
// Place the item in the ready to process queue, and notify workers that a new msg has arrived.
Log.DebugFormat("Received {0} Message(s) from Queue '{1}'.", response.ReceiveMessageResult.Message.Count, this.QueueName);
// Thread-safe local queue -> Provides access to msg reponse, and retrieving multiple msgs!
foreach (var sqsMessage in response.ReceiveMessageResult.Message)
{
// TODO: Remember; Need to code so no problem if same message received twice... consider cache?
// TODO: Need to verify Message MD5, and use 'IsSet()' methods to ensure the msg is valid. Earlier in process.
if (sqsMessage.IsSetMD5OfBody() && !MessageSecurity.IsMd5Valid(sqsMessage.Body, sqsMessage.MD5OfBody))
{
Log.WarnFormat("Message '{0}' has invalid MD5 signature, will not be processed.");
continue;
}
var messageBytes = Convert.FromBase64String(sqsMessage.Body);
// Set standard message properties
var message = messageBytes.ToMessage(this.MessageType);
if (sqsMessage.IsSetAttribute() && sqsMessage.Attribute.Count > 0)
{
foreach (var attribute in sqsMessage.Attribute)
{
if (attribute.Name == "ApproximateReceiveCount")
{
message.RetryAttempts = int.Parse(attribute.Value);
break;
}
}
}
// Set SQS message properties
var sqsMessageBody = message.Body as ISqsMessageBody;
if (sqsMessageBody != null)
{
sqsMessageBody.ReceiptHandle = sqsMessage.ReceiptHandle;
sqsMessageBody.QueueUrl = this.QueueUrl;
sqsMessageBody.QueueName = this.QueueName;
sqsMessageBody.VisibilityTimeout = this.MessageVisibilityTimeout;
message.RetryAttempts += sqsMessageBody.PreviousRetryAttempts;
}
else
{
Log.WarnFormat("The message type '{0}' is using the AwsSqsQueueHandler, but does not implement 'ISqsMessageBody'. No AwsSqsMessageHandlerRegister pre,post or error message handlers will be executed.", this.MessageType.Name);
}
// =====================
this.MessageCoordinator.EnqueMessage(this.QueueName, message, this.MessageType);
this.IncrementMessageCount(1);
var messageReceivedArgs = new MessageReceivedArgs { MessageType = this.MessageType, QueueName = this.QueueName, MessageId = sqsMessage.MessageId };
this.MqServer.NotifyMessageReceived(messageReceivedArgs);
}
}
}
Log.DebugFormat("Stopped polling SQS queue: {0}", this.QueueName);
}
