C # thread synchronization SemaphoreSlim class presentation

SemaphoreSlim class limits the number of threads simultaneously access a resource

code show as below:

. 1    static SemaphoreSlim SemaphoreSlim = new new SemaphoreSlim ( . 4 );
 2  
. 3          static  void AccessDatabase ( String name, int seconds The)
 . 4          {
 . 5              Console.WriteLine ($ " {name} waiting for access to the database " );
 . 6              semaphoreSlim.Wait ();
 . 7              Console .WriteLine ($ " {} is authorized to access the database name " );
 . 8              the Thread.Sleep (TimeSpan.FromSeconds (seconds the));
 . 9              Console.WriteLine ($ "{name} has finished accessing the database " );
 10              semaphoreSlim.Release ();
 . 11          }
 12 is  
13 is          static  void the Main ( String [] args)
 14          {
 15              for ( int I = . 1 ; I <= . 6 ; I ++ )
 16              {
 . 17                  String threadName $ = " thread} I { " ;
 18 is                  int SecondsToWait = 2 + 2 * I;
 . 19                  var T = new new Thread(() => AccessDatabase(threadName, secondsToWait));
20                 t.Start();
21             }
22             Console.ReadLine();
23         }

operation result: