Killing a Task the Proper Way

Question

HI Everybody,

 

Here is the scenario: Suppose that I have two tasks that are making blocking calls to services that are taking a long time to respond.

 

One gets done before the other, so I want that task to kill the others.

 

I know that using abort is bad and evil, so what would be a good way to make this work?

 

This is my test code:

internal void Start ()
{
CancellationTokenSource token_source_01 = new CancellationTokenSource ();
CancellationTokenSource token_source_02 = new CancellationTokenSource ();
CancellationToken CToken_stop_waiting_01 = token_source_01.Token;
CancellationToken CToken_stop_waiting_02 = token_source_02.Token;
Task
do_nothing_task_01 = Task.Run
( () =>
{
Console.WriteLine ("I am pretending to make a blocking call (#1).");
// Pretend that this ReadLine is a call to a service
// that takes a long time to complete.
Console.ReadLine();
token_source_02.Cancel ();
},
CToken_stop_waiting_01
);
Task
do_nothing_task_02 = Task.Run
( () =>
{
Console.WriteLine ("I am pretending to make a blocking call (#2).");
// Pretend that this ReadLine is a call to a service
// that takes a long time to complete.
Console.ReadLine();
token_source_01.Cancel ();
},
CToken_stop_waiting_02
);
Thread.Sleep (TimeSpan.FromSeconds (10));
Console.WriteLine ("This will not actually kill the task.");
token_source_01.Cancel ();
Thread.Sleep (TimeSpan.FromSeconds (10));
token_source_02.Cancel ();
try
{
do_nothing_task_01.Wait ();
do_nothing_task_02.Wait ();
}
catch (TaskCanceledException xcpt)
{
Console.WriteLine($"{nameof(TaskCanceledException)} thrown with message: {xcpt.Message}");
}
catch (OperationCanceledException xcpt)
{
Console.WriteLine($"{nameof(OperationCanceledException)} thrown with message: {xcpt.Message}");
}
finally
{
V_token_source.Dispose();
}
Console.WriteLine (" *** END");
Console.ReadLine();
}

THANKS!