C# – Multithreading

The Main Thread

using System;
using System.Threading;

namespace MultithreadingApplication {
   class MainThreadProgram {
      static void Main(string[] args) {
         Thread th = Thread.CurrentThread;
         th.Name = "MainThread";
         
         Console.WriteLine("This is {0}", th.Name);
         Console.ReadKey();
      }
   }
}

Sr.No.	Property & Description
1	CurrentContext Gets the current context in which the thread is executing.
2	CurrentCulture Gets or sets the culture for the current thread.
3	CurrentPrinciple Gets or sets the thread’s current principal (for role-based security).
4	CurrentThread Gets the currently running thread.
5	CurrentUICulture Gets or sets the current culture used by the Resource Manager to look up culture-specific resources at run-time.
6	ExecutionContext Gets an ExecutionContext object that contains information about the various contexts of the current thread.
7	IsAlive Gets a value indicating the execution status of the current thread.
8	IsBackground Gets or sets a value indicating whether or not a thread is a background thread.
9	IsThreadPoolThread Gets a value indicating whether or not a thread belongs to the managed thread pool.
10	ManagedThreadId Gets a unique identifier for the current managed thread.
11	Name Gets or sets the name of the thread.
12	Priority Gets or sets a value indicating the scheduling priority of a thread.
13	ThreadState Gets a value containing the states of the current thread.

Creating Threads

using System;
using System.Threading;

namespace MultithreadingApplication {
   class ThreadCreationProgram {
      public static void CallToChildThread() {
         Console.WriteLine("Child thread starts");
      }
      static void Main(string[] args) {
         ThreadStart childref = new ThreadStart(CallToChildThread);
         Console.WriteLine("In Main: Creating the Child thread");
         Thread childThread = new Thread(childref);
         childThread.Start();
         childThread.Join(1000);
         Console.ReadKey();
      }

Thread Pool

List<string> urls = new(){
    "https://www.google.com/",
    "https://www.duckduckgo.com/",
    "https://www.yahoo.com/",
};

foreach (var url in urls)
{
    ThreadPool.QueueUserWorkItem((state) => CheckHttpStatus(url));
}

async and await

static void Main()
    {
        Task task = new Task(CallMethod);
        task.Start();
        task.Wait();
        Console.ReadLine();
    }

    static async void CallMethod()
    {
        string filePath = "E:\\sampleFile.txt";
        Task<int> task = ReadFile(filePath);

        Console.WriteLine(" Other Work 1");
        Console.WriteLine(" Other Work 2");
        Console.WriteLine(" Other Work 3");

        int length = await task;
        Console.WriteLine(" Total length: " + length);

        Console.WriteLine(" After work 1");
        Console.WriteLine(" After work 2");
    }

    static async Task<int> ReadFile(string file)
    {
        int length = 0;

        Console.WriteLine(" File reading is stating");
        using (StreamReader reader = new StreamReader(file))
        {
            // Reads all characters from the current position to the end of the stream asynchronously
            // and returns them as one string.
            string s = await reader.ReadToEndAsync();

            length = s.Length;
        }
        Console.WriteLine(" File reading is completed");
        return length;
    }

static async Task Main(string[] args)
   {
     await callMethod();
     Console.ReadKey();
   }

   public static async Task callMethod()
   {
     Method2();
     var count = await Method1();
     Method3(count);
   }

   public static async Task<int> Method1()
   {
     int count = 0;
     await Task.Run(() =>
     {
       for (int i = 0; i < 100; i++)
       {
         Console.WriteLine(" Method 1");
         count += 1;
       }
     });
     return count;
   }

   public static void Method2()
   {
     for (int i = 0; i < 25; i++)
     {
       Console.WriteLine(" Method 2");
     }
   }

   public static void Method3(int count)
   {
     Console.WriteLine("Total count is " + count);
   }