private void RegisterWithSource(CancellationSource source)
{
if (source == null)
{
return; //todo: throw?
}
source.Register(Cancel);
}
/// <summary>
/// Merges two CancellationSources. Treat null as NON-cancellable.
/// </summary>
/// <param name="source1"></param>
/// <param name="source2"></param>
/// <returns></returns>
public static CancellationSource Merge(CancellationSource source1, CancellationSource source2)
{
if (source1 == null)
{
return(source2);
}
return(source2 == null ? source1 : new Merged(source1, source2));
}
public void MergeNullSources_Fact()
{
CancellationSource.Merge(null, null)
.ShouldBeNull();
CancellationSource.Merge(CancellationSource.Canceled, null)
.ShouldEqual(CancellationSource.Canceled);
CancellationSource.Merge(null, CancellationSource.Canceled)
.ShouldEqual(CancellationSource.Canceled);
}
public void RegisterBeforeCancel_Fact()
{
object callbackCreated = null;
var source = new CancellationSource();
source.Token.Register(() => callbackCreated = new object());
callbackCreated.ShouldBeNull();
source.Cancel();
callbackCreated.ShouldNotBeNull();
}
public void MergeAndCancelSecond_Fact()
{
var source1 = new CancellationSource();
var source2 = new CancellationSource();
var merged = CancellationSource.Merge(source1, source2);
source2.Cancel();
source1.IsCancelationRequested.ShouldBeFalse();
source2.IsCancelationRequested.ShouldBeTrue();
merged.IsCancelationRequested.ShouldBeTrue();
//ensure safety in calling other cancels
source1.Cancel();
merged.Cancel();
}
public void DisposedThrows_Fact()
{
CancellationSource source;
using (source = new CancellationSource()) {
source.IsCancelationRequested.ShouldBeFalse();
}
try {
source.Cancel();
}
catch (ObjectDisposedException) {
return;
}
throw new Exception("CancellationSource not disposed.");
}
public void CancelationSourceLifecycle_Fact()
{
CancellationSource source;
using (source = new CancellationSource()) {
source.IsCancelationRequested.ShouldBeFalse();
source.IsDisposed.ShouldBeFalse();
source.Cancel();
source.IsCancelationRequested.ShouldBeTrue();
source.IsDisposed.ShouldBeFalse();
source.Cancel();
source.IsCancelationRequested.ShouldBeTrue();
source.IsDisposed.ShouldBeFalse();
}
source.IsDisposed.ShouldBeTrue();
}
public void WaitTimeoutOccurs_Fact()
{
var cancellationSource = new CancellationSource();
var task = Task.Run(token => {
while (!token.IsCancellationRequested)
{
Thread.Sleep(10);
}
},
cancellationSource);
bool waitSuccess = task.Wait(15);
waitSuccess.ShouldBeFalse();
cancellationSource.Cancel();
EnsureQuietDisposal(task);
}
public void CancelActionTask_NoisyWait_Fact()
{
var cancellationSource = new CancellationSource();
var task = Task.Run(token => {
for (int i = 0; i < 1000000; i++)
{
token.ThrowIfCancellationRequested();
Thread.Sleep(10);
}
},
cancellationSource);
Thread.Sleep(15);
cancellationSource.Cancel();
var waitException = Trap.WaitException(task);
ValidateCancellationException(waitException);
ValidateCanceledTask(task);
EnsureQuietDisposal(task);
}
public void CancelActionTask_QuietBackground_Fact()
{
var cancellationSource = new CancellationSource();
var task = Task.Run(token => {
for (int i = 0; i < 1000000; i++)
{
token.ThrowIfCancellationRequested();
Thread.Sleep(10);
}
},
cancellationSource);
Thread.Sleep(15);
cancellationSource.Cancel();
while (!task.IsComplete)
{
Thread.Sleep(5);
}
ValidateCanceledTask(task);
EnsureQuietDisposal(task);
}
public void ActionTask_CancelTaskAndActionContinuation_Fact()
{
var cs = new CancellationSource();
var task = Task.Run(token => {
cs.Cancel();
Thread.Sleep(10);
token.ThrowIfCancellationRequested();
throw new Exception("We should have been canceled, and never see this.");
},
cs);
var continuation = task.ContinueWith((previous, token) => {
// we should never see the following exception
throw new Exception("Pre canceled continuation should not run");
},
cs);
continuation.Wait();
task.Status.ShouldEqual(TaskStatus.Canceled);
continuation.Status.ShouldEqual(TaskStatus.Canceled);
EnsureQuietDisposal(task);
EnsureQuietDisposal(continuation);
}
public Merged(CancellationSource source1, CancellationSource source2)
{
RegisterWithSource(source1);
RegisterWithSource(source2);
}
public static CancellationSource operator +(CancellationToken token1, CancellationToken token2)
{
return(CancellationSource.Merge(token1._source, token2._source));
}
internal CancellationToken(CancellationSource source)
{
_source = source;
}