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I have a program that stores objects into a priority queue, and Dequeue's them at certain times of a day to send over a TCP connection.

Right now, I'm doing this by calling thread.sleep for however many seconds until the next runtime of whatever's coming out next of the priority queue.

        while (MyQueue.NumItems > 0)
        {
            int secondsnow = (int)DateTime.Now.TimeOfDay.TotalSeconds;
            int nextTime = MyQueue.Peek().gettime();
            // Gets the time in seconds when the next object on the queue is to be sent
            Thread.Sleep(TimeSpan.FromSeconds(nextTime - secondsnow));
            // Sleeps until that time
            tcpclient.SendMessage(stream, MyQueue.Dequeue());
            // Send that data over my connection
        }

My next goal is to incorporate a TCP Listener into the program that will sit there waiting for a client to send it data in the form of an object for me to dynamically put into my priority queue while the program is running. The TCP listener itself is a blocking call and needs to unblock whenever the above code needs to dequeue an object at the stated time.

This is a rough idea of the TCP Listener code:

while(true) 
  {
    // Perform a blocking call to accept requests. 

    TcpClient client = server.AcceptTcpClient();            
    Console.WriteLine("Connected!");

    // Get a stream object for reading and writing
    NetworkStream stream = client.GetStream();

    int i;

    // Loop to receive all the data sent by the client. 
    while((i = stream.Read(bytes, 0, bytes.Length))!=0) 
    {   
      // Process data and add to the priority queue
      MyQueue.enqueue(new myObject(bytes));
    }
    // Shutdown and end connection
    client.Close();
  }
}

What's the best way for me to execute both loops at the same time, with one of them being a blocking call and the other being time dependent, while preventing any deadlock situations with both loops accessing the priority queue? I'm new to multithreading so I'm stll pretty confused by the process in which threads start and block.

user2753743
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  • What's the issue? Put each loop in its own thread. The queue isn't going to care. – Idle_Mind Jul 22 '15 at 00:25
  • What deadlock situations are you worried about? Even assuming there's a lock inside your queue implementation, it takes _two_ locks to create deadlock. For general ideas about executing code at intervals, you might benefit from reading [this answer](https://stackoverflow.com/a/30254440/3538012) I wrote for a different question. For this question, without [a good, _minimal_, _complete_ code example](https://stackoverflow.com/help/mcve) that clearly illustrates your scenario, and a _specific_ question, the question is just way too broad. – Peter Duniho Jul 22 '15 at 05:29

0 Answers0