Tutorial by Examples

var collection = new BlockingCollection<int>(5); var random = new Random(); var producerTask = Task.Run(() => { for(int item=1; item<=10; item++) { collection.Add(item); Console.WriteLine("Produced: " + item); Thread.Sleep(random.Next(1...

A task can be created by directly instantiating the Task class... var task = new Task(() => { Console.WriteLine("Task code starting..."); Thread.Sleep(2000); Console.WriteLine("...task code ending!"); }); Console.WriteLine("Starting task..."); t...

var tasks = Enumerable.Range(1, 5).Select(n => new Task<int>(() => { Console.WriteLine("I'm task " + n); return n; })).ToArray(); foreach(var task in tasks) task.Start(); Task.WaitAll(tasks); foreach(var task in tasks) Console.WriteLine(task.Result); ...

var allTasks = Enumerable.Range(1, 5).Select(n => new Task<int>(() => n)).ToArray(); var pendingTasks = allTasks.ToArray(); foreach(var task in allTasks) task.Start(); while(pendingTasks.Length > 0) { var finishedTask = pendingTasks[Task.WaitAny(pendingTasks)]; Conso...

var task1 = Task.Run(() => { Console.WriteLine("Task 1 code starting..."); throw new Exception("Oh no, exception from task 1!!"); }); var task2 = Task.Run(() => { Console.WriteLine("Task 2 code starting..."); throw new Exception("Oh ...

var task1 = Task.Run(() => { Console.WriteLine("Task 1 code starting..."); throw new Exception("Oh no, exception from task 1!!"); }); var task2 = Task.Run(() => { Console.WriteLine("Task 2 code starting..."); throw new Exception("Oh ...

var cancellationTokenSource = new CancellationTokenSource(); var cancellationToken = cancellationTokenSource.Token; var task = new Task((state) => { int i = 1; var myCancellationToken = (CancellationToken)state; while(true) { Console.Write...

var random = new Random(); IEnumerable<Task<int>> tasks = Enumerable.Range(1, 5).Select(n => Task.Run(async() => { Console.WriteLine("I'm task " + n); await Task.Delay(random.Next(10,1000)); return n; })); Task<Task<int>> whenAnyTask = Tas...

var random = new Random(); IEnumerable<Task<int>> tasks = Enumerable.Range(1, 5).Select(n => Task.Run(() => { Console.WriteLine("I'm task " + n); return n; })); Task<int[]> task = Task.WhenAll(tasks); int[] results = await task; Console.WriteLine...

var actions = Enumerable.Range(1, 10).Select(n => new Action(() => { Console.WriteLine("I'm task " + n); if((n & 1) == 0) throw new Exception("Exception from task " + n); })).ToArray(); try { Parallel.Invoke(actions); } catch(AggregateExc...

This example uses Parallel.ForEach to calculate the sum of the numbers between 1 and 10000 by using multiple threads. To achieve thread-safety, Interlocked.Add is used to sum the numbers. using System.Threading; int Foo() { int total = 0; var numbers = Enumerable.Range(1, 10000).ToLis...

This example uses Parallel.For to calculate the sum of the numbers between 1 and 10000 by using multiple threads. To achieve thread-safety, Interlocked.Add is used to sum the numbers. using System.Threading; int Foo() { int total = 0; Parallel.For(1, 10001, () => 0, // in...

When you need to pass some data from the parent task to its children tasks, so it logically flows with the execution, use AsyncLocal class: void Main() { AsyncLocal<string> user = new AsyncLocal<string>(); user.Value = "initial user"; // this does not aff...

For Each row As DataRow In FooDataTable.Rows Me.RowsToProcess.Add(row) Next Dim myOptions As ParallelOptions = New ParallelOptions() myOptions.MaxDegreeOfParallelism = environment.processorcount Parallel.ForEach(RowsToProcess, myOptions, Sub(currentRow, state) ...

Task that return a value has return type of Task< TResult > where TResult is the type of value that needs to be returned. You can query the outcome of a Task by its Result property. Task<int> t = Task.Run(() => { int sum = 0; for(int i = 0; i < 500; i++) ...