Orc.Scheduling

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Find the source at https://github.com/WildGums/Orc.Scheduling.

Allows easily scheduling of (recurring) tasks inside applications.

Quick introduction

Sometimes (recurring) tasks need to be scheduled inside an application. A few examples are maintenance tasks, check for updates, etc. This scheduling library is exposes a simple service to add scheduled tasks so you can easily schedule tasks without having to set up custom timers or remembering about the recurrance of a task.

This library does smart calculations to determine the next important step inside the schedule. It does not simple poll every second but wakes itself up (with a timer) on the next important step so it doesn’t use any unnecessary resources.

Controlling the scheduler

There are a few important methods to control the state of the scheduler. By default the scheduler is enabled.

Starting the scheduler

schedulingService.Start();

Note that starting the service will immediately start tasks that are scheduled in the past

Stopping the scheduler

schedulingService.Stop();

Note that stopping the service will actively cancel all current active tasks

Scheduling tasks

The goal of this library is to make it as easy as possible to schedule simple tasks. Below are a few examples.

Simple tasks

The following examples starts a task 5 minutes from now.

var scheduledTask = new ScheduledTask
{
	Name = "My task",
	Start = DateTime.Now.AddMinutes(5),
	Action = async () =>
	{
		/* logic here */
	}
};

schedulingService.AddScheduledTask(scheduledTask);

Recurring tasks

The following examples starts a task 5 minutes from now, then restarts the task every 1 minute.

var scheduledTask = new ScheduledTask
{
	Name = "My task",
	Start = DateTime.Now.AddMinutes(5),
	Recurring = TimeSpan.FromMinutes(1),
	Action = async () =>
	{
		/* logic here */
	}
};

schedulingService.AddScheduledTask(scheduledTask);

Canceling a running task

To cancel a task, you need a handle to a RunningTask instance. This can be retrieved by the TaskStarted event or the RunningTasks property. This example uses the latter, then cancels the task.

var runningTask = (from task in schedulingService.RunningTasks
				   where task.ScheduledTask.Name == "My task"
				   select task).FirstOrDefault();
if (runningTask != null)
{
	runningTask.CancellationTokenSource.Cancel();
}

Creating custom ScheduledTask implementations

It’s possible to write a custom self-containing task that can handle everything itself. Below is an example of such a self-containing task:

public class CheckForUpdatesScheduledTask : ScheduledTaskBase
{
	private readonly ICommandManager _commandManager;

	public CheckForUpdatesScheduledTask(TimeSpan interval, ICommandManager commandManager)
	{
		Argument.IsNotNull(() => commandManager);

		_commandManager = commandManager;

		Name = "Check for updates";
		Start = DateTime.Now.Add(interval);
		Recurring = interval;
	}

	public override Task InvokeAsync()
	{
		var command = _commandManager.GetCommand(AppCommands.Application.CheckForUpdates);
		if (command != null)
		{
			command.Execute(null);
		}

		return TaskHelper.Completed;
	}

	public override object Clone()
	{
		return new CheckForUpdatesScheduledTask(Recurring ?? TimeSpan.FromMinutes(5), _commandManager);
	}
}

This class can be constructed and added to the scheduling service. This will invoke the check for updates 10 minutes from now and recur every 10 minutes.

var checkForUpdatesScheduledTask = typeFactory.CreateInstanceWithParametersAndAutoCompletion<CheckForUpdatesScheduledTask>(TimeSpan.FromMinutes(10));

schedulingService.AddScheduledTask(checkForUpdatesScheduledTask);

Contributions

We would like to thank the following contributors:

Want to contribute to the documentation? We have a guide for that!

Questions

Have a question about Catel or WildGums controls? Use StackOverflow with the Catel tag!