public void Dispose()
{
if (_signal == null)
{
return;
}
BCLDebug.Assert(Thread.CurrentThread == _signal.Thread, "You called Dispose on the wrong thread, or reused your cancellation signal?");
List <CancellationSignal> signals = _signal.Thread.CancellationSignals;
bool tookLock = false;
RuntimeHelpers.PrepareConstrainedRegions();
try {
Monitor.ReliableEnter(signals, out tookLock);
CancellationSignal s = signals[signals.Count - 1];
signals.RemoveAt(signals.Count - 1);
if (!Object.ReferenceEquals(s, _signal))
{
throw new InvalidOperationException(Environment.GetResourceString("InvalidOperation_CancellationRegionLeak"));
}
_signal.Thread = null;
_signal = null;
}
finally {
if (tookLock)
{
Monitor.Exit(signals);
}
Thread.EndThreadAffinity();
}
}
public static void PollForCancellation()
{
Thread t = Thread.CurrentThread;
// Don't go through the property on Thread, but access the field
// directly. We don't want to create the stack if no one in the
// thread is using cancellation.
List <CancellationSignal> signals = t.m_CancellationSignals;
if (signals != null)
{
bool tookLock = false;
RuntimeHelpers.PrepareConstrainedRegions();
try {
Monitor.ReliableEnter(signals, out tookLock);
if (signals.Count > 0)
{
if (signals[signals.Count - 1].CancelRequested)
{
throw new OperationCanceledException();
}
}
}
finally {
if (tookLock)
{
Monitor.Exit(signals);
}
}
}
}
public static void Enter(object obj, ref bool lockTaken)
{
if (lockTaken)
{
Monitor.ThrowLockTakenException();
}
Monitor.ReliableEnter(obj, ref lockTaken);
}
