Thread blocking based on boolean value

Question

I have a service which processes data from a queue:

while (true)
{
    if(!HaltProcessing)
    { 
        var messages = receivedQueue.GetMessages(MessageGetLimit);

        if (messages.Count() > 0)
        {
            ProcessQueueMessages(messages);
        }
        else
        {
            Task.Delay(PollingInterval);
        }
    }
}

There is a HaltProcessing property which, when set to true, pauses the processing of queue items. I do this through the if statement as seen above.

Is there a better way to block the thread when HaltProcessing is true and unblock when false?

Answer 1

Yes, you can use "WaitHandles".

AutoResetEvent or ManualRestEvent to achieve it.

private ManualRestEvent signal = new ManualRestEvent(false);//or true based on your req
//Setting true is to allow processing and false is to halt the processing

while (true)
{
    signal.WaitOne();
    var messages = receivedQueue.GetMessages(MessageGetLimit);

    if (messages.Count() > 0)
    {
        ProcessQueueMessages(messages);
    }
    else
    {
        Task.Delay(PollingInterval);
    }
}

bool SetHaltProcessing(bool value)
{
    if(value)
       signal.Reset();
    else
       signal.Set();
}

Use case

SetHaltProcessing(true);//To halt the processing
SetHaltProcessing(false);//To start the processing