We mentioned before that the task scheduler needs explicitly defined dependencies between tasks to run them effectively and in the correct order. However, besides this, there is a way to achieve implicit dependency definition; when we create one task inside another, a special parent-child dependency is created for these tasks. By default, this does not affect how these tasks will be executed, but there is a way to make this dependency really important.
We can create a task with the TaskFactory.CreateNew method by providing a special TaskCreationOptions.AttachedToParent parameter. This changes the usual task behavior, and the important differences are as follows:
The parent task will not complete until every child task completes.
If the case child tasks cause any exceptions, they will be translated to the parent task.
The parent task status depends on its child tasks. If any child task fails, the parent task will have the
TaskStatus.Faultedstatus as well.
To illustrate this, we...