public void PreCancellationTest()
{
using var ctsScheduler = new CancellationTokenSource();
using var ctsTask = new CancellationTokenSource();
ctsTask.Cancel();
var scheduler = new OrderingScheduler(NumThreads, ctsScheduler.Token);
int N = 100;
var tasks = new Task <int> [100];
var shouldCancels = new bool[100];
for (int i = 0; i < N; ++i)
{
var index = i;
var prio = i % 3;
var thread = i % NumThreads;
var shouldCancel = i % 5 == 0;
var token = ctsTask.Token;
shouldCancels[i] = shouldCancel;
var cancellationToken = shouldCancel ? token : CancellationToken.None;
tasks[i] = scheduler.Run(prio, thread, () =>
{
// should not be here if we should cancel prior
Assert.False(shouldCancel, "throw inside the task; should never get here");
// complete successfully
return(index);
},
// set cancellation token on the task -- this should cancel the task before it starts
cancellationToken);
}
// some tasks should throw
for (var i = 0; i < N; ++i)
{
if (shouldCancels[i])
{
// task should be cancelled BEFORE running, meaning it's CANCELLED, not FAULTED
Assert.Throws <TaskCanceledException>(() => tasks[i].GetAwaiter().GetResult());
Assert.True(tasks[i].IsCanceled);
Assert.False(tasks[i].IsFaulted);
}
else
{
Assert.Equal(i, tasks[i].Result);
}
}
ctsScheduler.Cancel();
scheduler.WaitForShutdown();
}
public void TaskCancellationTest()
{
using var ctsScheduler = new CancellationTokenSource();
using var ctsTask = new CancellationTokenSource();
ctsTask.Cancel();
var scheduler = new OrderingScheduler(NumThreads, ctsScheduler.Token);
int N = 100;
var tasks = new Task <int> [100];
var shouldCancels = new bool[100];
for (int i = 0; i < N; ++i)
{
var index = i;
var prio = i % 3;
var thread = i % NumThreads;
var shouldCancel = i % 5 == 0;
var token = ctsTask.Token;
shouldCancels[i] = shouldCancel;
tasks[i] = scheduler.Run(prio, thread, () =>
{
// throw INSIDE task
if (shouldCancel)
{
token.ThrowIfCancellationRequested();
}
return(index);
});
}
// some tasks should throw
for (var i = 0; i < N; ++i)
{
if (shouldCancels[i])
{
// task should be cancelled WHILE running, meaning it's FAULTED, not CANCELLED
Assert.Throws <OperationCanceledException>(() => tasks[i].GetAwaiter().GetResult());
Assert.False(tasks[i].IsCanceled);
Assert.True(tasks[i].IsFaulted);
}
else
{
Assert.Equal(i, tasks[i].Result);
}
}
ctsScheduler.Cancel();
scheduler.WaitForShutdown();
}
public void LowestPrioNumberCompletesFirst()
{
int PrioLevels = 5;
int NumThreads = 4;
int N = 1000;
using var cts = new CancellationTokenSource();
var scheduler = new OrderingScheduler(NumThreads, cts.Token);
// use this to synchronise start; we don't support asynchronous tasks, so we
// just cause them to block. This is to improve test reliability -- ensure we
// have everything queued before letting them proceed.
var syncStart = new ManualResetEventSlim(false);
// set up 3 sets of prioritised tasks; and queue the least important
// (highest prio number) first to make life more difficult.
Task <(int, int)>[][] tasks = new Task <(int, int)> [PrioLevels][];
public void ExceptionTest()
{
using var cts = new CancellationTokenSource();
var scheduler = new OrderingScheduler(NumThreads, cts.Token);
int N = 100;
var tasks = new Task <int> [100];
var shouldThrows = new bool[100];
for (int i = 0; i < N; ++i)
{
var index = i;
var prio = i % 3;
var thread = i % NumThreads;
var shouldThrow = i % 5 == 0;
shouldThrows[i] = shouldThrow;
tasks[i] = scheduler.Run(prio, thread, () =>
{
if (shouldThrow)
{
throw new MyException();
}
return(index);
});
}
// some tasks should throw
for (var i = 0; i < N; ++i)
{
if (shouldThrows[i])
{
Assert.Throws <MyException>(() => tasks[i].GetAwaiter().GetResult());
}
else
{
Assert.Equal(i, tasks[i].Result);
}
}
cts.Cancel();
scheduler.WaitForShutdown();
}
public SchedulerPerf()
{
_cancellationTokenSource = new CancellationTokenSource();
_orderingScheduler = new OrderingScheduler(Environment.ProcessorCount, _cancellationTokenSource.Token);
_gateScheduler = new GateScheduler(Environment.ProcessorCount);
}