Thread: Lock Statement

Lock Statement of C#

I am new in programming word. I am learning # programming language. I am aware about the basic statements of C#. But "lock statement" seems very difficult to understand as I have not at all used this statement. I think this statement is may be used in multithreading concept but I am not sure on this. Please help me.

In C# the 'lock Statement' is defined using 'lock' keyword, this type of C# statement to make important section. This can be getting by applying mutual exclusion lock over class object. Once execution of statement block finally you want to release the applied lock. Following is the syntax for lock statement in C#:

lock(expression) block_of_statement

Follow the below code which is help you to understand Lock Statement of C#:

namespace Lock
{
class Program
{
static void Main(string[] args)
{
Thread[] threads = new Thread[10];
Account acc = new Account(1000);
for (int i = 0; i < 10; i++)
{
Thread t = new Thread(new ThreadStart(acc.MyTransactions));
threads[i] = t;
}
for (int i = 0; i < 10; i++)
{
threads[i].Start();
}
Console.Read();
}
}
class Account
{
private Object myLock = new Object();
int Bal;
Random rnd = new Random();
public Account(int iniAmount)
{
Bal = iniAmount;
}
int Withdraw(int amt)
{
// This condition will never be true unless the lock statement
// is commented out:
if (Bal < 0)
{
throw new Exception("Negative Balance");
}
// Comment out the next line to see the effect of leaving out
// the lock keyword:
lock (myLock)
{
if (Bal >= amt)
{
Console.WriteLine("Balance before Withdrawal : " + Bal);
Console.WriteLine("Amount to Withdraw : -" + amt);
Bal = Bal - amt;
Console.WriteLine("Balance after Withdrawal : " + Bal);
return amt;
}
else
{
return 0; // transaction rejected
}
}
}
public void MyTransactions()
{
for (int i = 0; i < 100; i++)
{
Withdraw(rnd.Next(1, 100));
}
}
}
}