static void Main(string[] args)
{
Contoso.Widget w = new Contoso.Widget();
// Perform the same operation two times. The first time, the operation
// is performed by using the default task creation options. The second
// time, the operation is performed by using the DenyChildAttach option
// in the parent task.
Console.WriteLine("Demonstrating parent/child tasks with default options...");
RunWidget(w, TaskCreationOptions.None);
Console.WriteLine();
Console.WriteLine("Demonstrating parent/child tasks with the DenyChildAttach option...");
RunWidget(w, TaskCreationOptions.DenyChildAttach);
}
static void RunWidget(Contoso.Widget widget,
TaskCreationOptions parentTaskOptions)
{
// Record the time required to run the parent
// and child tasks.
Stopwatch stopwatch = new Stopwatch();
stopwatch.Start();
Console.WriteLine("Starting widget as a background task...");
// Run the widget task in the background.
Task <Task> runWidget = Task.Factory.StartNew(() =>
{
Task widgetTask = widget.Run();
// Perform other work while the task runs...
Thread.Sleep(1000);
return(widgetTask);
}, parentTaskOptions);
// Wait for the parent task to finish.
Console.WriteLine("Waiting for parent task to finish...");
runWidget.Wait();
Console.WriteLine("Parent task has finished. Elapsed time is {0} ms.",
stopwatch.ElapsedMilliseconds);
// Perform more work...
Console.WriteLine("Performing more work on the main thread...");
Thread.Sleep(2000);
Console.WriteLine("Elapsed time is {0} ms.", stopwatch.ElapsedMilliseconds);
// Wait for the child task to finish.
Console.WriteLine("Waiting for child task to finish...");
runWidget.Result.Wait();
Console.WriteLine("Child task has finished. Elapsed time is {0} ms.",
stopwatch.ElapsedMilliseconds);
}