/// <summary>Initializes a new <see cref="WorkItemTask"/> with the work to be done by that task, and an optional
/// <see cref="TaskCancellationEvent"/> allowing the task to be canceled along with other tasks that share the same
/// cancellation event.
/// </summary>
public WorkItemTask(TaskDelegate work, TaskCancellationEvent cancellationEvent) : base(cancellationEvent)
{
if (work == null)
{
throw new ArgumentNullException();
}
this.work = work;
}
/// <summary>Runs a number of instances of a work item simultaneously, and returns the results from all instances when they've
/// completed or been canceled using the given cancellation event.
/// </summary>
/// <include file="documentation.xml" path="/Utilities/Tasks/ParallelismRemarks/*"/>
public static T[] Parallelize <T>(TaskDelegate <T> work, int instanceCount, TaskCancellationEvent cancellationEvent)
{
using (CompositeTask task = CreateParallel(work, instanceCount, cancellationEvent))
{
task.Run();
return(task.GetResults <T>());
}
}
/// <summary>Creates and returns a task that represents the running of a number of instances of a work item simultaneously.
/// The method accepts an optional cancellation event that can be associated with all instances of the work item, as well as
/// the aggregate task that encapsulates them.
/// </summary>
/// <include file="documentation.xml" path="/Utilities/Tasks/ParallelismRemarks/*"/>
public static Task CreateParallel(TaskDelegate work, int instanceCount, TaskCancellationEvent cancellationEvent)
{
if (instanceCount <= 0)
{
throw new ArgumentOutOfRangeException();
}
if (instanceCount == 1)
{
return(new WorkItemTask(work, cancellationEvent));
}
else
{
Task[] tasks = new Task[instanceCount];
for (int i = 0; i < tasks.Length; i++)
{
tasks[i] = new WorkItemTask(work, cancellationEvent);
}
return(new CompositeTask(tasks, cancellationEvent));
}
}
/// <summary>Initializes a new <see cref="CompositeTask"/> with the set of other tasks to perform and an optional
/// <see cref="TaskCancellationEvent"/> allowing the task to be canceled along with other tasks that share the same
/// <see cref="TaskCancellationEvent"/>.
/// </summary>
public CompositeTask(IEnumerable <Task> tasks, TaskCancellationEvent cancellationEvent) : base(cancellationEvent)
{
if (tasks == null)
{
throw new ArgumentNullException();
}
List <Task> taskList = new List <Task>();
foreach (Task task in tasks)
{
if (task == null)
{
throw new ArgumentException("A task was null.");
}
task.Completed += task_Completed;
taskList.Add(task);
}
this.tasks = taskList.ToArray();
}
/// <summary>Initializes a new <see cref="Task"/> with an optional <see cref="TaskCancellationEvent"/> allowing the task to be
/// canceled along with other tasks that share the same cancellation event.
/// </summary>
protected Task(TaskCancellationEvent cancellationEvent)
{
this.cancellationEvent = cancellationEvent;
}
/// <summary>Runs an instance of a work item on each hardware thread, and returns the results from all instances when they've
/// completed or been canceled using the given cancellation event.
/// </summary>
/// <include file="documentation.xml" path="/Utilities/Tasks/ParallelismRemarks/*"/>
public static T[] Parallelize <T>(TaskDelegate <T> work, TaskCancellationEvent cancellationEvent)
{
return(Parallelize(work, SystemInformation.GetAvailableCpuThreads(), cancellationEvent));
}
/// <summary>Runs a number of instances of a work item simultaneously, and returns when all instances have completed or been
/// canceled using the given cancellation event.
/// </summary>
/// <include file="documentation.xml" path="/Utilities/Tasks/ParallelismRemarks/*"/>
public static void Parallelize(TaskDelegate work, int instanceCount, TaskCancellationEvent cancellationEvent)
{
using (Task task = CreateParallel(work, instanceCount, cancellationEvent)) task.Run();
}
/// <summary>Runs an instance of a work item on each hardware thread, and returns when all instances have completed or been
/// canceled using the given cancellation event.
/// </summary>
/// <include file="documentation.xml" path="/Utilities/Tasks/ParallelismRemarks/*"/>
public static void Parallelize(TaskDelegate work, TaskCancellationEvent cancellationEvent)
{
Parallelize(work, SystemInformation.GetAvailableCpuThreads(), cancellationEvent);
}
/// <summary>Creates and returns a task that represents the running of an instance of a work item on each hardware thread. The
/// method accepts an optional cancellation event that can be associated with all instances of the work item, as well as the
/// aggregate task that encapsulates them.
/// </summary>
/// <include file="documentation.xml" path="/Utilities/Tasks/ParallelismRemarks/*"/>
public static CompositeTask CreateParallel <T>(TaskDelegate <T> work, TaskCancellationEvent cancellationEvent)
{
return(CreateParallel(work, SystemInformation.GetAvailableCpuThreads(), cancellationEvent));
}
