ExclusiveTaskQueue

ExclusiveTaskQueue.cs

using System;
using System.Threading.Tasks;

namespace Sample
{
    internal class ExclusiveTaskQueue
    {
        private readonly object exclusiveTaskLock = new object();
        private Task exclusiveTask = Task.FromResult(true);

        public Task Schedule(Func<Task> func)
        {
            lock (exclusiveTaskLock) return exclusiveTask = exclusiveTask.ContinueWith(t => func()).Unwrap();
        }

        public Task<TResult> Schedule<TResult>(Func<Task<TResult>> func)
        {
            lock (exclusiveTaskLock)
            {
                var res = exclusiveTask.ContinueWith(t => func()).Unwrap();
                exclusiveTask = res;
                return res;
            }
        }
    }
}