Task Factory and,Task Parallelism (Task Parallel Library) in C#

Represented by:

System.Threading.Tasks.TaskFactory which has no return type object.
System.Threading.Tasks.TaskFactory<TResult> which has TResult as return type.

Important Note:

Runs the task immediately after creating the task .This type of execution is known as Task Parallelism.
Runs the task in a pre-defined order. This type of execution is known as Continuation Tasks.
Running the task by pair. That is in Asynchronous programming model.

Now let’s look deep into Task Parallelism.

Task parallel library is used to perform asynchronous operation.
The task that are invoked by Task Parallelism is invoked by are independent of one another.
1. Parallel.Invoke(() => Console.WriteLine("Perform Operatrion 1"), () =>Console.WriteLine("Perform Operatrion 2"));
The Task are separated by “,”. They are independent of one another.
These task are actually queued in ThreadPool.
It provides many enhancements such as waiting, cancellation, continuations, exception handling, detailed status, custom scheduling, and more.
It takes Action delegate as input, that is the return type is always void.
Task.Run method create and start a task in one operation, that is in one step.
TaskFactory.StartNew is also used to create and start a task in one operation.

Code sample

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
namespace Task_Parallel_Library {
class Program {
static void Main(string[] args) {
runoperation obj = new runoperation();
Console.WriteLine("Creating and running tasks implicitly");
obj.parallelinvoke_implicitly();
Console.WriteLine();
Console.WriteLine("Creating and running tasks explicity");
obj.parallelinvoke_explicity_01();
Console.WriteLine();
Console.WriteLine("Creating and running tasks explicity by referencing action delegate");
obj.parallelinvoke_explicity_03();
Console.ReadLine();
}
}
class runoperation {
static runoperation() {}
public void parallelinvoke_implicitly() {
//Creating and running tasks implicitly
// This way of running mutiple task at same time is known as implicit task
// both operation are exxecuted parallelly
//Retun type is always void for parallel invoke. In technical term the input of parallel invoke is always action delegate
Parallel.Invoke(() = > Console.WriteLine("Perform Operatrion 1"), () = > Console.WriteLine("Perform Operatrion 2"));
}
public void parallelinvoke_explicity_01() {
Parallel.Invoke(() = > dowork("Task- One"), () = > dowork("Task- Two"), () = > dowork("Task- Three"));
}
private void dowork(string input) {
Console.WriteLine("I have been called by '{0}'", input);
}
public void parallelinvoke_explicity_03() {
// parallel invoke with action delegate as input
Parallel.Invoke(action1);
}
/// <summary>
/// Following is an action delegate with one input of type string
/// </summary>
Action action1 = new Action(delegate {
Console.WriteLine("Hi.... I am action Delegate.... I am inline coded with anonymous type");
});
}
}