DotnetPrimeNumbers

using System;
using System.Linq;
using System.Threading;
using System.Threading.Channels;

namespace DataStructuresAlgorithms.ParallelCourseWork
{
    public class Parallel
    {
        public static bool IsPrime(int number)
        {
            const int threadCount = 4;
            var threads = new Thread[threadCount];
            var parameters = new Parameters[threadCount];

            var square = (int) Math.Sqrt(number);
            var intervalWidth = (square - 2) / threadCount;

            for (var i = 0; i < threadCount; i++)
            {
                var threadStart = new ParameterizedThreadStart(Routine);
                parameters[i] = new Parameters
                {
                    Start = i == 0 ? 2 : intervalWidth * i,
                    End = intervalWidth * (i + 1),
                    Number = number
                };

                threads[i] = new Thread(threadStart);
                threads[i].Start(parameters[i]);
            }

            foreach (var thread in threads)
            {
                thread.Join();
            }

            var result = parameters.Aggregate((bool?) null, (current, parameter) => current == null ? parameter.Result : current.Value && parameter.Result.Value);

            return result.Value;
        }

        private static void Routine(object parameters)
        {
            var p = parameters as Parameters;
            var d = p.Start;

            while (d <= p.End)
            {
                if (p.Number % d == 0)
                {
                    p.Result = false;
                    return;
                }

                d++;
            }

            p.Result = true;
        }

        public class Parameters
        {
            public int Start { get; set; }
            public int End { get; set; }
            public int Number { get; set; }
            public bool? Result { get; set; }
        }
    }
}