WaitAll.cs

static bool WaitAll(Task[] tasks, int timeout, CancellationToken token)
{
    var cts = CancellationTokenSource.CreateLinkedTokenSource(token);

    foreach (var task in tasks)
    {
        task.ContinueWith(t => {
            if (t.IsFaulted) cts.Cancel();
        }, 
        cts.Token, 
        TaskContinuationOptions.ExecuteSynchronously, 
        TaskScheduler.Current));
    }

    return Task.WaitAll(tasks, timeout, cts.Token);
}