using System;
using System.Threading;
-#if NET_4_0 || BOOTSTRAP_NET_4_0
+#if NET_4_0 || MOBILE
namespace System.Threading
{
+ [System.Diagnostics.DebuggerDisplay ("IsCancellationRequested = {IsCancellationRequested}")]
public struct CancellationToken
{
+ bool canBeCanceled;
+ bool initialized;
+ CancellationTokenSource source;
+
public CancellationToken (bool canceled)
: this ()
{
- // dummy, this is actually set by CancellationTokenSource when the token is created
- Source = null;
+ initialized = true;
+ canBeCanceled = canceled;
+ // This is correctly set later if token originates from a Source
+ source = canceled ? CancellationTokenSource.CanceledSource : CancellationTokenSource.NoneSource;
}
public static CancellationToken None {
public void ThrowIfCancellationRequested ()
{
- if (Source.IsCancellationRequested)
+ if (initialized && Source.IsCancellationRequested)
throw new OperationCanceledException (this);
}
return this.Source == other.Source;
}
- public override bool Equals (object obj)
+ public override bool Equals (object other)
{
- return (obj is CancellationToken) ? Equals ((CancellationToken)obj) : false;
+ return (other is CancellationToken) ? Equals ((CancellationToken)other) : false;
}
public override int GetHashCode ()
return Source.GetHashCode ();
}
- public static bool operator == (CancellationToken lhs, CancellationToken rhs)
+ public static bool operator == (CancellationToken left, CancellationToken right)
{
- return lhs.Equals (rhs);
+ return left.Equals (right);
}
- public static bool operator != (CancellationToken lhs, CancellationToken rhs)
+ public static bool operator != (CancellationToken left, CancellationToken right)
{
- return !lhs.Equals (rhs);
+ return !left.Equals (right);
}
public bool CanBeCanceled {
get {
- return true;
+ return canBeCanceled;
}
}
public bool IsCancellationRequested {
get {
- return Source.IsCancellationRequested;
+ return initialized && Source.IsCancellationRequested;
}
}
}
internal CancellationTokenSource Source {
- get;
- set;
+ get {
+ if (!initialized)
+ CorrectlyInitialize ();
+ return source;
+ }
+ set {
+ source = value;
+ }
+ }
+
+ void CorrectlyInitialize ()
+ {
+ Source = CancellationTokenSource.NoneSource;
+ initialized = true;
}
}
}