public async Task CompletionSourceCompletesResultAsynchronously(bool runAsync)
{
var steps = new Steps();
var control = new SemaphoreSlim(0);
var control2 = new SemaphoreSlim(0);
steps.Add("main.start");
var options = runAsync ? TaskCreationOptions.RunContinuationsAsynchronously : TaskCreationOptions.None;
var taskCompletionSource = new TaskCompletionSource <int>(options);
var task = Task.Run(async() =>
{
steps.Add("task.start");
// some delay to ensure we do not SetResult before awaiting the task completion source,
// thus forcing the await on that task to actually await asynchronously
//await control.WaitAsync().CfAwait();
control.Wait();
//await Task.Delay(2000).CfAwait();
Thread.Sleep(2000);
steps.Add("task.complete");
taskCompletionSource.SetResult(42);
steps.Add("task.continue");
// keep running for a while - on the same thread!
//await Task.Delay(200).CfAwait();
Thread.Sleep(200);
steps.Add("task.end");
});
steps.Add("main.wait");
control.Release();
await taskCompletionSource.Task.CfAwait();
steps.Add("main.resume");
// keep running for a while - on the same thread!
//await Task.Delay(200).CfAwait();
Thread.Sleep(200);
steps.Add("main.continue");
await Task.Yield();
await task.CfAwait();
steps.Add("main.end");
Console.WriteLine(steps);
// FIXME why does it *have* to be "not same thread"? this test can fail on some occasions
// task.complete thread 18 == main.resume thread 18 -- for runAsync = true
// task.complete and task.continue always run on same thread
// task.complete and main.wait always run on different threads
steps.AssertSameThread("task.complete", "task.continue");
steps.AssertNotSameThread("task.complete", "main.wait");
// task.complete and main.resume
if (runAsync)
{
steps.AssertNotSameThread("task.complete", "main.resume"); // run on different threads
}
else
{
steps.AssertSameThread("task.complete", "main.resume"); // run on same thread
}
// FIXME if async, order here is not specified!
//if (runAsync)
// steps.AssertOrder("task.continue", "main.resume"); // main.resume after task.continue since different thread
//else
if (!runAsync)
{
steps.AssertOrder("main.resume", "task.continue"); // main.resume before task.continue since same thread
}
steps.AssertOrder("main.resume", "main.end");
}