internal CbParker(ParkerCallback pkcb) : base(1) { callback = pkcb; }
internal CbParker (ParkerCallback pkcb, bool useSynchronizationContext, bool useExecutionContext) : base (1) { callback = pkcb; if (useSynchronizationContext) { sctx = SynchronizationContext.Current; } if (useExecutionContext) { ectx = ExecutionContext.Capture (); } }