Multiple Tasks Z

public static async Task executeParallel<T>(this IEnumerable<T> items, int limit, Func<T, Task> actionMethod)
        {
            var allTasks = new List<Task>(); //Store all Tasks
            var activeTasks = new List<Task>();
            foreach (var item in items)
            {
                if (activeTasks.Count >= limit)
                {
                    var completedTask = await Task.WhenAny(activeTasks);
                    activeTasks.Remove(completedTask);
                }
                var task = actionMethod(item);
                allTasks.Add(task);
                activeTasks.Add(task);
            }
            await Task.WhenAll(allTasks); // Wait for all task to complete
        }

public async Task fun(int processId)
       {
           await Task.Run( () =>{
               Random rand = new Random();
               Console.WriteLine("Processing " + processId);
               Thread.Sleep(rand.Next(1500));
               Console.WriteLine("Done processing - " + processId);
           });
       }

  internal async void process(List<int> queue,int limit)
        {
            await queue.executeParallel(limit, fun);
        }

https://www.codeproject.com/Tips/1264928/Throttling-Multiple-Tasks-to-Process-Requests-in-C