using System;

using System.Threading;

​

const int N = 1_000_000;

var (r0,dt0) = Test(() =>

{

   int n = 0;

   var th0 = new Thread(() =>

   {

      for (int i = 0; i != N; ++i)

         ++n;

   });

   var th1 = new Thread(() =>

   {

      for (int i = 0; i != N; ++i)

         ++n;

   });

   th0.Start();

   th1.Start();

   th1.Join();

   th0.Join();

   return n;

});

var (r1, dt1) = Test(() =>

{

   int n = 0;

   var mutex = new object();

   var th0 = new Thread(() =>

   {

      for (int i = 0; i != N; ++i)

         lock (mutex)

         {

            ++n;

         }

   });

   var th1 = new Thread(() =>

   {

      for (int i = 0; i != N; ++i)

         lock (mutex)

         {

            ++n;

         }

   });

   th0.Start();

   th1.Start();

   th1.Join();

   th0.Join();

   return n;

});

var (r2, dt2) = Test(() =>

{

   int n = 0;

   var mutex = new object();

   var th0 = new Thread(() =>

   {

      int m = 0;

      for (int i = 0; i != N; ++i)

         ++m;

      lock (mutex)

      {

         n += m;

      }

   });

   var th1 = new Thread(() =>

   {

      int m = 0;

      for (int i = 0; i != N; ++i)

         ++m;

      lock (mutex)

      {

         n += m;

      }

   });

   th0.Start();

   th1.Start();

   th1.Join();

   th0.Join();

   return n;

});

Console.WriteLine($"Sans synchro : {r0} obtenu en {dt0} tics");

Console.WriteLine($"Avec synchro : {r1} obtenu en {dt1} tics");

Console.WriteLine($"Avec synchro : {r2} obtenu en {dt2} tics");

​

static (T,long) Test<T>(Func<T> f)

{

   var sw = new System.Diagnostics.Stopwatch();

   sw.Start();

   T res = f();

   sw.Stop();

   return (res, sw.ElapsedTicks);

}

​