You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
186 lines
6.3 KiB
186 lines
6.3 KiB
using System;
|
|
using System.Collections.Generic;
|
|
using System.Collections.Concurrent;
|
|
using System.Linq;
|
|
using System.Text;
|
|
using System.Threading;
|
|
using System.Threading.Tasks;
|
|
|
|
namespace IPA.Utilities.Async
|
|
{
|
|
/// <summary>
|
|
/// A single-threaded task scheduler that runs all of its tasks on the same thread.
|
|
/// </summary>
|
|
public class SingleThreadTaskScheduler : TaskScheduler, IDisposable
|
|
{
|
|
private readonly Thread runThread = new Thread(ExecuteTasksS);
|
|
private readonly BlockingCollection<Task> tasks = new BlockingCollection<Task>();
|
|
private readonly CancellationTokenSource exitTokenSource = new CancellationTokenSource();
|
|
|
|
/// <summary>
|
|
/// Gets whether or not the underlying thread has been started.
|
|
/// </summary>
|
|
/// <exception cref="ObjectDisposedException">Thrown if this object has already been disposed.</exception>
|
|
public bool IsRunning
|
|
{
|
|
get
|
|
{
|
|
ThrowIfDisposed();
|
|
return runThread.IsAlive;
|
|
}
|
|
}
|
|
|
|
/// <summary>
|
|
/// Starts the thread that executes tasks scheduled with this <see cref="TaskScheduler"/>
|
|
/// </summary>
|
|
/// <exception cref="ObjectDisposedException">Thrown if this object has already been disposed.</exception>
|
|
public void Start()
|
|
{
|
|
ThrowIfDisposed();
|
|
|
|
runThread.Start(this);
|
|
}
|
|
|
|
/// <summary>
|
|
/// Terminates the runner thread, and waits for the currently running task to complete.
|
|
/// </summary>
|
|
/// <remarks>
|
|
/// After this method returns, this object has been disposed and is no longer in a valid state.
|
|
/// </remarks>
|
|
/// <returns>an <see cref="IEnumerable{T}"/> of <see cref="Task"/>s that did not execute</returns>
|
|
/// <exception cref="ObjectDisposedException">Thrown if this object has already been disposed.</exception>
|
|
public IEnumerable<Task> Exit()
|
|
{
|
|
ThrowIfDisposed();
|
|
|
|
tasks.CompleteAdding();
|
|
exitTokenSource.Cancel();
|
|
runThread.Join();
|
|
|
|
var retTasks = new List<Task>();
|
|
retTasks.AddRange(tasks);
|
|
|
|
return retTasks;
|
|
}
|
|
|
|
/// <summary>
|
|
/// Waits for the runner thread to complete all tasks in the queue, then exits.
|
|
/// </summary>
|
|
/// <remarks>
|
|
/// After this method returns, this object has been disposed and is no longer in a valid state.
|
|
/// </remarks>
|
|
/// <exception cref="ObjectDisposedException">Thrown if this object has already been disposed.</exception>
|
|
public void Join()
|
|
{
|
|
ThrowIfDisposed();
|
|
|
|
tasks.CompleteAdding();
|
|
runThread.Join();
|
|
}
|
|
|
|
/// <summary>
|
|
/// Throws a <see cref="NotSupportedException"/>.
|
|
/// </summary>
|
|
/// <returns>nothing</returns>
|
|
/// <exception cref="NotSupportedException">Always.</exception>
|
|
protected override IEnumerable<Task> GetScheduledTasks()
|
|
{
|
|
// this is only for debuggers which we can't use sooooo
|
|
throw new NotSupportedException();
|
|
}
|
|
|
|
/// <summary>
|
|
/// Queues a given <see cref="Task"/> to this scheduler. The <see cref="Task"/> <i>must></i> be
|
|
/// scheduled for this <see cref="TaskScheduler"/> by the runtime.
|
|
/// </summary>
|
|
/// <param name="task">the <see cref="Task"/> to queue</param>
|
|
/// <exception cref="ObjectDisposedException">Thrown if this object has already been disposed.</exception>
|
|
protected override void QueueTask(Task task)
|
|
{
|
|
ThrowIfDisposed();
|
|
|
|
tasks.Add(task);
|
|
}
|
|
|
|
/// <summary>
|
|
/// Rejects any attempts to execute a task inline.
|
|
/// </summary>
|
|
/// <remarks>
|
|
/// This task scheduler <i>always</i> runs its tasks on the thread that it manages, therefore it doesn't
|
|
/// make sense to run it inline.
|
|
/// </remarks>
|
|
/// <param name="task">the task to attempt to execute</param>
|
|
/// <param name="taskWasPreviouslyQueued">whether the task was previously queued to this scheduler</param>
|
|
/// <returns><see langword="false"/></returns>
|
|
/// <exception cref="ObjectDisposedException">Thrown if this object has already been disposed.</exception>
|
|
protected override bool TryExecuteTaskInline(Task task, bool taskWasPreviouslyQueued)
|
|
{
|
|
ThrowIfDisposed();
|
|
|
|
return false;
|
|
}
|
|
|
|
private void ThrowIfDisposed()
|
|
{
|
|
if (disposedValue)
|
|
throw new ObjectDisposedException(nameof(SingleThreadTaskScheduler));
|
|
}
|
|
|
|
private void ExecuteTasks()
|
|
{
|
|
ThrowIfDisposed();
|
|
|
|
var token = exitTokenSource.Token;
|
|
|
|
try
|
|
{
|
|
// while we are still accepting tasks, and we can pull out a task with an infinite wait duration
|
|
while (!tasks.IsCompleted && tasks.TryTake(out var task, -1, token))
|
|
{
|
|
TryExecuteTask(task);
|
|
}
|
|
}
|
|
catch (OperationCanceledException)
|
|
{
|
|
// TryTake was cancelled, we'll just leave
|
|
}
|
|
}
|
|
|
|
private static void ExecuteTasksS(object param)
|
|
{
|
|
var self = param as SingleThreadTaskScheduler;
|
|
self.ExecuteTasks();
|
|
}
|
|
|
|
#region IDisposable Support
|
|
private bool disposedValue = false; // To detect redundant calls
|
|
|
|
/// <summary>
|
|
/// Disposes this object.
|
|
/// </summary>
|
|
/// <param name="disposing">whether or not to dispose managed objects</param>
|
|
protected virtual void Dispose(bool disposing)
|
|
{
|
|
if (!disposedValue)
|
|
{
|
|
if (disposing)
|
|
{
|
|
exitTokenSource.Dispose();
|
|
tasks.Dispose();
|
|
}
|
|
|
|
disposedValue = true;
|
|
}
|
|
}
|
|
|
|
/// <summary>
|
|
/// Disposes this object. This puts the object into an unusable state.
|
|
/// </summary>
|
|
public void Dispose()
|
|
{
|
|
// Do not change this code. Put cleanup code in Dispose(bool disposing) above.
|
|
Dispose(true);
|
|
}
|
|
#endregion
|
|
}
|
|
}
|