using System;
using System.Linq;
using System.Collections.Generic;
using System.Collections.Concurrent;
using System.Reflection;
using System.Linq.Expressions;
using System.Threading;
using System.Threading.Tasks;

var queue = new ConcurrentQueue<int>(new[] { 0, 1 });
using var peeked = new Barrier(2);
int[] seen = new int[2], removed = new int[2];
void Consume(int index)
{
    if (!queue.TryPeek(out seen[index])) throw new InvalidOperationException();
    if (!peeked.SignalAndWait(TimeSpan.FromSeconds(5))) throw new TimeoutException();
    if (!queue.TryDequeue(out removed[index])) throw new InvalidOperationException();
}
OwnedThreads.Run(() => Consume(0), () => Consume(1));
Console.WriteLine($"same-peek:{seen[0] == 0 && seen[1] == 0}");
Console.WriteLine($"distinct-removals:{removed.Distinct().Count() == 2}");
Console.WriteLine($"remaining:{queue.Count}");

public static class OwnedThreads
{
    public static void Run(params Action[] actions)
    {
        var errors = new ConcurrentQueue<Exception>();
        var threads = actions.Select(action => new Thread(() => { try { action(); } catch (Exception error) { errors.Enqueue(error); } }) { IsBackground = true }).ToArray();
        foreach (var thread in threads) thread.Start();
        foreach (var thread in threads) if (!thread.Join(TimeSpan.FromSeconds(8))) throw new TimeoutException("Owned worker did not finish");
        if (!errors.IsEmpty) throw new AggregateException(errors);
    }
}