CODEWITHSUNDEEP
c#taskbackgroundworker
Dennis V
Dennis V

Reputation: 13

Backgroundworker and Task.Run have a big delay before action

Have 1 main BackgroundWorker and many of other. In time of starting other workers in main worker Task.Run not running in expected time. How to modify code to do all tasks(or threads) parallel?

static List<System.ComponentModel.BackgroundWorker> workers;
static System.ComponentModel.BackgroundWorker mainWorker;

static void Main(string[] args)
{
    mainWorker = new System.ComponentModel.BackgroundWorker();
    mainWorker.DoWork += MainWorker_DoWork;
    mainWorker.RunWorkerAsync();
    workers = new List<System.ComponentModel.BackgroundWorker>();

    for (int i = 0; i < 50; i++)
    {
        workers.Add(new System.ComponentModel.BackgroundWorker());
        workers[i].DoWork += FastAnalizWorker_DoWork;
        workers[i].RunWorkerAsync(i);
        System.Threading.Thread.Sleep(0);
    }
}

static void MainWorker_DoWork(object sender,
    System.ComponentModel.DoWorkEventArgs e)
{
    while (true)
    {
        System.Threading.Thread.Sleep(1000);
        Task.Run(() => ShowMessage("main"));
    }
}

static void FastAnalizWorker_DoWork(object sender,
    System.ComponentModel.DoWorkEventArgs e)
{
    int index = (int)e.Argument;
    System.Threading.Thread.Sleep(index * 1000);
    ShowMessage(index.ToString());
}

static void ShowMessage(string message)
{
    Console.WriteLine(string.Format("{0:mm ss}: {1}", DateTime.UtcNow, message));
}

Console result: Screenshot

Upvotes: 1

Views: 218

Answers (1)

Jes&#250;s L&#243;pez
Jes&#250;s L&#243;pez

Reputation: 9221

Task.Run have a big delay because you are causing thread pool starvation.

Both BackgroundWorker and Task.Run use the thread pool to do their job.

The thread pool starvation is caused because:

  • You are calling Thread.Sleep() that blocks the current thread.
  • You are concurrently running more BackgroundWorker's than the thread pool size

Upvotes: 2

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