public void CancelAfter(int millisecondsDelay)
{
if (millisecondsDelay < -1)
{
throw new ArgumentOutOfRangeException("millisecondsDelay");
}
CheckDisposed();
if (IsCancellationRequested || millisecondsDelay == Timeout.Infinite)
{
return;
}
if (timer == null)
{
// Have to be carefull not to create secondary background timer
var t = new Timer(timer_callback, this, Timeout.Infinite, Timeout.Infinite);
if (CustomInterlocked.CompareExchange(ref timer, t, null) != null)
{
t.Dispose();
}
}
Timer.Change(millisecondsDelay, Timeout.Infinite);
}
internal CancellationTokenRegistration Register(Action callback, bool useSynchronizationContext)
{
CheckDisposed();
var tokenReg = new CancellationTokenRegistration(CustomInterlocked.Increment(ref currId), this);
/* If the source is already canceled we execute the callback immediately
* if not, we try to add it to the queue and if it is currently being processed
* we try to execute it back ourselves to be sure the callback is ran
*/
if (IsCancellationRequested)
{
callback();
}
else
{
callbacks.TryAdd(tokenReg, callback);
if (IsCancellationRequested && callbacks.TryRemove(tokenReg, out callback))
{
callback();
}
}
return(tokenReg);
}
protected virtual void Dispose(bool disposing)
{
if (disposing && (state & StateDisposed) == 0)
{
if (CustomInterlocked.CompareExchange(ref state, StateDisposed, StateValid) == StateValid)
{
UnregisterLinkedTokens();
callbacks = null;
}
else
{
if (handle != null)
{
handle.WaitOne();
}
state |= StateDisposed;
Thread.MemoryBarrier();
}
if (timer != null)
{
Timer.Dispose();
}
((IDisposable)handle).Dispose();
handle = null;
}
}
long UpdateStateWithOp(bool set)
{
int oldValue, newValue;
do
{
oldValue = state;
newValue = (int)(((oldValue >> 1) + 1) << 1) | (set ? 1 : 0);
} while (CustomInterlocked.CompareExchange(ref state, newValue, oldValue) != oldValue);
return(newValue);
}
void UnregisterLinkedTokens()
{
var registrations = CustomInterlocked.Exchange(ref _linkedTokens, null);
if (registrations == null)
{
return;
}
foreach (var linked in (CancellationTokenRegistration[])registrations)
{
linked.Dispose();
}
}
void CommitChangeToHandle(long stamp)
{
CustomInterlocked.Increment(ref used);
var tmpHandle = Handle;
if (tmpHandle != null)
{
// First in all case we carry the operation we were called for
if ((stamp & 1) == 1)
{
tmpHandle.Set();
}
else
{
tmpHandle.Reset();
}
/* Then what may happen is that the two suboperations (state change and handle change)
* overlapped with others. In our case it doesn't matter if the two suboperations aren't
* executed together at the same time, the only thing we have to make sure of is that both
* state and handle are synchronized on the last visible state change.
*
* For instance if S is state change and H is handle change, for 3 concurrent operations
* we may have the following serialized timeline: S1 S2 H2 S3 H3 H1
* Which is perfectly fine (all S were converted to H at some stage) but in that case
* we have a mismatch between S and H at the end because the last operations done were
* S3/H1. We thus need to repeat H3 to get to the desired final state.
*/
int currentState;
do
{
currentState = state;
if (currentState != stamp && (stamp & 1) != (currentState & 1))
{
if ((currentState & 1) == 1)
{
tmpHandle.Set();
}
else
{
tmpHandle.Reset();
}
}
} while (currentState != state);
}
CustomInterlocked.Decrement(ref used);
}
protected virtual void Dispose(bool disposing)
{
if (!disposed.TryRelaxedSet())
{
return;
}
if (handle != null)
{
var tmpHandle = CustomInterlocked.Exchange(ref handle, null);
if (used > 0)
{
// A tiny wait (just a few cycles normally) before releasing
SpinWait wait = new SpinWait();
while (used > 0)
{
wait.SpinOnce();
}
}
((IDisposable)tmpHandle).Dispose();
}
}
bool ApplyOperation(int num, out int newValue)
{
int oldCount;
do
{
oldCount = initialCount;
if (oldCount == 0)
{
newValue = 0;
return(false);
}
newValue = oldCount + num;
if (newValue < 0)
{
return(false);
}
} while (CustomInterlocked.CompareExchange(ref initialCount, newValue, oldCount) != oldCount);
return(true);
}
void Cancellation(bool throwOnFirstException)
{
if (CustomInterlocked.CompareExchange(ref state, StateCanceled, StateValid) != StateValid)
{
return;
}
handle.Set();
if (linkedTokens != null)
{
UnregisterLinkedTokens();
}
var cbs = callbacks;
if (cbs == null)
{
return;
}
List <Exception> exceptions = null;
try {
Action cb;
for (int id = currId; id != int.MinValue; id--)
{
if (!cbs.TryRemove(new CancellationTokenRegistration(id, this), out cb))
{
continue;
}
if (cb == null)
{
continue;
}
if (throwOnFirstException)
{
cb();
}
else
{
try {
cb();
} catch (Exception e) {
if (exceptions == null)
{
exceptions = new List <Exception> ();
}
exceptions.Add(e);
}
}
}
} finally {
cbs.Clear();
}
if (exceptions != null)
{
throw new AggregateException(exceptions);
}
}
