lock Statement of C sharp

[Sonam Goenka]

Hello friends,

I am new to the C sharp programming. I am ware about the basic statements of sharp. But "lock statement" seems very complicated to understand as I have never used this statement. I think this statement is may be used in multithreading concept but I am not sure on this. So please let me know about the "lock Statement" i.e about it's syntax, it's use and example. I am waiting for your reply.

[kelfro]

Hi,

In C sharp the 'lock Statement' is defined using 'lock' keyword, This type of c sharp statement to make critical section. This can be achieved by applying mutual exclusion lock over class object. After execution of statement block finally you need to release the applied lock. Following is the syntax for lock statement in C sharp:

lock(expression) block_of_statement

[Zecho]

Hi,

If you want know about the use of lock Statement in C sharp, then please refer following C sharp example.

using System.Threading;
using System;

class ProgramDM
{
    static readonly object _objectT = new object();

    static void AR()
    {
       
        lock (_objectT)
        {
            Thread.Sleep(100);
            Console.WriteLine(Environment.TickCount);
        }
    }

    static void Main()
    {
        
        for (int ix = 0; ix < 10; ix++)
        {
            ThreadStart start = new ThreadStart(AR);
            new Thread(start).Start();
        }
    }
}

[Reegan]

The lock Statement of C sharp is used only with the 'reference object', otherwise you can't use this statement. The functionality of this statement is identical to the critical functions of C sharp. The basic use of lock statement is to apply lock on critical code of program. lock statement make sure that thread doesn't enter a critical section when other thread is present in the critical section.

[opaper]

Below is the example of lock statement of C sharp, try to run this program and see what output it shows:

class AccountGH
{   int balanceM;
   Random r = new Random();
   public Account(int initial) 
   {      balanceM = initial;
   }
   int Withdraw(int amount) 
   {    if (balanceM < 0) 
      {throw new Exception("Negative balanceM");   }
       lock (this)
      {
         if (balanceM >= amount) 
         {
            Console.WriteLine("balanceM before Withdrawal :  " + balanceM);
            Console.WriteLine("Amount to Withdraw        : -" + amount); 
            balanceM = balanceM - amount;
            Console.WriteLine("balanceM after Withdrawal  :  " + balanceM);
            return amount;
         }
         else 
         {     return 0; 
         }  }   }

   public void DoTransactions() 
   {
      for (int i = 0; i < 100; i++) 
      {
         Withdraw(r.Next(1, 100));
      }
   }
}