What is C# asynchronous method , does it return to parent method ?

Question

0.00/5 (No votes)

See more:

Hello,

In Asynchronous programming if a method (Child Method) call "Asynchronously"form inside the method (Parent Method),
Then it run parallel. i am not able to understand one thing -

1.Does Parent method have any trace of child method,So that Parent method can be aware about the Child method execution has been Finish.

2.What will be happen to Child Method if Parent Method Execution will finished before the Child Method execution. Does child method will show the output.

What I have tried:

Quote:
using System;
using System.Threading;
namespace Threads
{
public static class Program
{
//parent method as Main()
public static void Main()
{
ThreadPool.QueueUserWorkItem(ChildMethod, 5);
Console.WriteLine("Hi i am in Parent Method.");
// Console.ReadLine();
}

// This method's ChildMethod
private static void ChildMethod(Object state)
{
//wait besacue parrent method has to be finish befor child method.
Thread.Sleep(1000);
Console.WriteLine("Hi i am in Child Method.");
Console.ReadLine();
}
}
}

Posted 14-Mar-18 21:31pm

Siddharth Rai

Updated 14-Mar-18 22:39pm

Add a Solution

Comments

Richard Deeming 15-Mar-18 14:30pm

Much simpler to use async methods:
Asynchronous programming | Microsoft Docs[^]

private static async Task ChildMethod()
{
    await Task.Delay(1000);
    Console.WriteLine("Hi I am in Child Method.");
    Console.ReadLine();
}

static void Main()
{
    Task child = ChildMethod();
    Console.WriteLine("Hi I am in Parent Method.");
    child.GetAwaiter().GetResult();
}

If you're using an up-to-date version of Visual Studio, you can even make the Main method async:

static async Task Main()
{
    Task child = ChildMethod();
    Console.WriteLine("Hi I am in Parent Method.");
    await child;
}

1 solution

Add a Solution

Add your solution here

Treat my content as plain text, not as HTML

Preview 0

…

Existing Members

Sign in to your account

...or Join us

Download, Vote, Comment, Publish.

Your Email
Password
Forgot your password?

Your Email
This email is in use. Do you need your password?
Optional Password

I have read and agree to the Terms of Service and Privacy Policy
Please subscribe me to the CodeProject newsletters

When answering a question please:

Read the question carefully.
Understand that English isn't everyone's first language so be lenient of bad spelling and grammar.
If a question is poorly phrased then either ask for clarification, ignore it, or edit the question and fix the problem. Insults are not welcome.
Don't tell someone to read the manual. Chances are they have and don't get it. Provide an answer or move on to the next question.

Let's work to help developers, not make them feel stupid.

This content, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)

OriginalGriff · Answer 1 · 2018-03-14T22:40:00

Quote:
Does Parent method have any trace of child method,So that Parent method can be aware about the Child method execution has been Finish.

If the state object passed with the second argument does not include some means of telling what is going on, then unless you register a wait handle the "calling task" cannot tell what it happening with the "child task". ThreadPool Class (System.Threading)[^] - see teh "Remarks" section.

Quote:
What will be happen to Child Method if Parent Method Execution will finished before the Child Method execution. Does child method will show the output.

That's a difficult one: it depends on which thread initiates the child process. If it's the main thread - the one that executes from the main method as in your example - then when that thread ends, so will all the child tasks, regardless of their status and all memory and other resources will be recycled back to the OS.
If it isn't, then the child thread will continue.