C# Thread Synchronization

Synchronization is a technique that allows only one thread to access the resource for the particular time. No other thread can interrupt until the assigned thread finishes its task.

In multithreading program, threads are allowed to access any resource for the required execution time. Threads share resources and executes asynchronously. Accessing shared resources (data) is critical task that sometimes may halt the system. We deal with it by making threads synchronized.

It is mainly used in case of transactions like deposit, withdraw etc.

Advantage of Thread Synchronization

  • Consistency Maintain
  • No Thread Interference

C# Lock

We can use C# lock keyword to execute program synchronously. It is used to get lock for the current thread, execute the task and then release the lock. It ensures that other thread does not interrupt the execution until the execution finish.

Here, we are creating two examples that executes asynchronously and synchronously.

C# Example: Without Synchronization

In this example, we are not using lock. This example executes asynchronously. In other words, there is context-switching between the threads.

snippet
using System;
using System.Threading;
class Printer
{
    public void PrintTable()
    {
        for (int i = 1; i <= 10; i++)
        {
            Thread.Sleep(100);
            Console.WriteLine(i);
        }
    }
}
class Program
{
    public static void Main(string[] args)
    {
        Printer p = new Printer();
        Thread t1 = new Thread(new ThreadStart(p.PrintTable));
        Thread t2 = new Thread(new ThreadStart(p.PrintTable));
        t1.Start();
        t2.Start();
    }
}

Output:

Output
1 1 2 2 3 3 4 4 5 5 6 6 7 7 8 8 9 9 10 10

C# Thread Synchronization Example

In this example, we are using lock. This example executes synchronously. In other words, there is no context-switching between the threads. In the output section, we can see that second thread starts working after first threads finishes its tasks.

snippet
using System;
using System.Threading;
class Printer
{
    public void PrintTable()
    {
        lock (this)
        {
            for (int i = 1; i <= 10; i++)
            {
                Thread.Sleep(100);
                Console.WriteLine(i);
            }
        }
    }
}
class Program
{
    public static void Main(string[] args)
    {
        Printer p = new Printer();
        Thread t1 = new Thread(new ThreadStart(p.PrintTable));
        Thread t2 = new Thread(new ThreadStart(p.PrintTable));
        t1.Start();
        t2.Start();
    }
}

Output:

Output
1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 10
Follow Us
https://www.facebook.com/Rookie-Nerd-638990322793530 https://twitter.com/RookieNerdTutor https://plus.google.com/b/117136517396468545840 #
Contents