Speed up loop using multithreading in C# (Question)

Question

Imagine I have an function which goes through one million/billion strings and checks smth in them.

f.ex:

foreach (String item in ListOfStrings)
{
            


        

Answer 1

The Parallel extensions is cool, but this can also be done just by using the threadpool like this:

using System.Collections.Generic;
using System.Threading;

namespace noocyte.Threading
{
    class CalcState
    {
        public CalcState(ManualResetEvent reset, string input) {
            Reset = reset;
            Input = input;
        }
        public ManualResetEvent Reset { get; private set; }
        public string Input { get; set; }
    }

    class CalculateMT
    {
        List result = new List();
        List events = new List();

        private void Calc() {
            List aList = new List();
            aList.Add("test");

            foreach (var item in aList)
            {
                CalcState cs = new CalcState(new ManualResetEvent(false), item);
                events.Add(cs.Reset);
                ThreadPool.QueueUserWorkItem(new WaitCallback(Calculate), cs);
            }
            WaitHandle.WaitAll(events.ToArray());
        }

        private void Calculate(object s)
        {
            CalcState cs = s as CalcState;
            cs.Reset.Set();
            result.Add(cs.Input);
        }
    }
}