C# : How to use Parallel.Invoke to execute the parallel operations

In nowadays we have multiple core CPU machine that enables to process the multiple thread on same time/simultaneously. .NET framework provides class library and runtime support to write efficient the parallel programming code. For more information about the parallel programming architecture please visit Parallel Programming in .NET.

In this article, we will discuss about the Parallel.Invoke method and how to write the parallel programming code with help of this.

Parallel.Invoke method provides a simple way in which a number of Tasks may be created and executed in parallel and we don’t need to create a complicated threading code.

Here is syntax:

public static void Invoke(params Action[] actions);

Parallel.Invoke takes as array of delegates of method and it execute each of provided methods in parallel.

public static void Invoke(System.Threading.Tasks.ParallelOptions parallelOptions, params Action[] actions);

In second method, we have more control over execution of parallel operations. With help of additional parameter parallelOptions, we can control the max degrees of parallelism means the maximum number of concurrent tasks and we can also cancel the operation by using CancellationToken property.

Here is a simple example of Parallel.Invoke method:

static void Main()

        {

            List requests = GetRequests();

            ParallelOptions parallelOptions = new ParallelOptions();

            parallelOptions.MaxDegreeOfParallelism = 10;

            foreach (Request request in requests)

            {

                Parallel.Invoke(parallelOptions, async() => await ProcessRequest(request));

            }

           

        }

static async Task ProcessRequest(Request request)

        {

            // Process Request and produce response asynchronously

        }

In above example, we are controlling execution of parallel operations and only 10 max concurrent tasks are allowed.