How do I use Semaphore in C#?

How do I use Semaphore in C#?

In C#, a Semaphore is used to control access to a resource by multiple threads. You can create a Semaphore by specifying the maximum number of threads that can access the resource at the same time.

Can you show me a code example?

Sure! Here's a simple example:

using System;
using System.Threading;

class Program
{
    static Semaphore semaphore = new Semaphore(2, 2);

    static void AccessResource(int threadNumber)
    {
        Console.WriteLine($"Thread {threadNumber} is waiting to access the resource.");
        semaphore.WaitOne(); // Wait until it is safe to enter.
        Console.WriteLine($"Thread {threadNumber} has entered the resource.");
        Thread.Sleep(2000); // Simulate some work.
        Console.WriteLine($"Thread {threadNumber} is leaving the resource.");
        semaphore.Release(); // Release the semaphore.
    }

    static void Main()
    {
        for (int i = 1; i <= 5; i++)
        {
            int threadNumber = i;
            new Thread(() => AccessResource(threadNumber)).Start();
        }
    }
}

What happens if more threads try to access the resource than allowed?

If more threads try to access the resource than the allowed count, they will be blocked and will wait until a thread releases the semaphore.