Question

I need to run a list of methods synchronously, with the ability to stop the execution list. It’s easy to stop the loop before execution using a reset event (see first line in Execute).

How can I wait for a response from action.Execute() and action.Execute() at the same time?

private ManualResetEvent _abortingToken = new ManualResetEvent(false);
private List<IAction> _actions;

public void Abort()
{
    _abortingToken.Set();
}

public void Execute()
{
    foreach (var action in _actions)
    {
        if (_abortingToken.WaitOne(0))
            break; // Execution aborted.

        action.Execute(); // Somehow, I need to call this without blocking

        while (/*Execute not finished*/)
        {
            if (_abortingToken.WaitOne(1))
                action.Abort();
        }
    }
}

I think it would be easy to preform using Tasks, but unfortunately I’m using .net 3.5.

---

Edit: solution inspired by SLaks answer:

public void Execute()
{
    Action execute = null;
    IAsyncResult result = null;

    foreach (var action in _actions)
    {
        execute = new Action(scriptCommand.Execute);

        if (_abortingToken.WaitOne(0))
            break; // Execution aborted.

        result = execute.BeginInvoke(null, null);

        while (!result.IsCompleted)
        {
            if (_abortingToken.WaitOne(10))
            {
                action.Abort();
                break;
            }
        }

        execute.EndInvoke(result);
    }
}

Answer 1

That’s the opposite of synchronicity.
You need to run the method on a background thread.

For example, you can call the method using Delegate.BeginInvoke, then check IAsyncResult.IsCompleted. (and make sure to call EndInvoke afterwards)