using System.Reactive.Disposables; using System.Runtime.CompilerServices; using System.Threading; namespace System.Reactive.Concurrency { [System.Runtime.CompilerServices.NullableContext(1)] [System.Runtime.CompilerServices.Nullable(0)] public class SynchronizationContextScheduler : LocalScheduler { private readonly SynchronizationContext _context; private readonly bool _alwaysPost; public SynchronizationContextScheduler(SynchronizationContext context) { if (context == null) throw new ArgumentNullException("context"); _context = context; _alwaysPost = true; } public SynchronizationContextScheduler(SynchronizationContext context, bool alwaysPost) { if (context == null) throw new ArgumentNullException("context"); _context = context; _alwaysPost = alwaysPost; } public override IDisposable Schedule<[System.Runtime.CompilerServices.Nullable(2)] TState>(TState state, Func<IScheduler, TState, IDisposable> action) { if (action == null) throw new ArgumentNullException("action"); if (!_alwaysPost && _context == SynchronizationContext.Current) return action(this, state); SingleAssignmentDisposable d = new SingleAssignmentDisposable(); _context.PostWithStartComplete(delegate { if (!d.IsDisposed) d.Disposable = action(this, state); }); return d; } public override IDisposable Schedule<[System.Runtime.CompilerServices.Nullable(2)] TState>(TState state, TimeSpan dueTime, Func<IScheduler, TState, IDisposable> action) { if (action == null) throw new ArgumentNullException("action"); TimeSpan dueTime2 = Scheduler.Normalize(dueTime); if (dueTime2.Ticks == 0) return Schedule(state, action); return DefaultScheduler.Instance.Schedule(state, dueTime2, (IScheduler _, TState state1) => ((LocalScheduler)this).Schedule<TState>(state1, action)); } } }