Avalonia/src/Avalonia.Controls/PullToRefresh/RefreshCompletionDeferral.cs

using System;
using System.Threading;

namespace Avalonia.Controls
{
    /// <summary>
    /// Deferral class for notify that a work done in RefreshRequested event is done.
    /// </summary>
    public class RefreshCompletionDeferral
    {
        private Action _deferredAction;
        private int _deferCount;

        public RefreshCompletionDeferral(Action deferredAction)
        {
            _deferredAction = deferredAction;
        }

        public void Complete()
        {
            Interlocked.Decrement(ref _deferCount);

            if (_deferCount == 0)
            {
                _deferredAction?.Invoke();
            }
        }

        public RefreshCompletionDeferral Get()
        {
            Interlocked.Increment(ref _deferCount);

            return this;
        }
    }
}