55 lines
2.1 KiB
C#
55 lines
2.1 KiB
C#
//------------------------------------------------------------------------------
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// <copyright file="PageAsyncTaskManager.cs" company="Microsoft">
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// Copyright (c) Microsoft Corporation. All rights reserved.
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// </copyright>
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//------------------------------------------------------------------------------
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namespace System.Web.UI {
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using System;
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using System.Collections.Generic;
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using System.Threading;
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using System.Threading.Tasks;
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using System.Web;
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// Handles execution of asynchronous tasks that are registered with a Page
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internal sealed class PageAsyncTaskManager {
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private bool _executeTasksAsyncHasCompleted = false;
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private readonly Queue<IPageAsyncTask> _registeredTasks = new Queue<IPageAsyncTask>();
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public void EnqueueTask(IPageAsyncTask task) {
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if (_executeTasksAsyncHasCompleted) {
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// don't allow multiple calls to the execution routine
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throw new InvalidOperationException(SR.GetString(SR.PageAsyncManager_CannotEnqueue));
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}
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_registeredTasks.Enqueue(task);
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}
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public async Task ExecuteTasksAsync(object sender, EventArgs e, CancellationToken cancellationToken, AspNetSynchronizationContextBase syncContext, IRequestCompletedNotifier requestCompletedNotifier) {
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try {
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while (_registeredTasks.Count > 0) {
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// if canceled, propagate exception to caller and stop executing tasks
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cancellationToken.ThrowIfCancellationRequested();
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// if request finished, stop executing tasks
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if (requestCompletedNotifier.IsRequestCompleted) {
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return;
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}
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// execute this task
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IPageAsyncTask task = _registeredTasks.Dequeue();
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using (syncContext.AllowVoidAsyncOperationsBlock()) {
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await task.ExecuteAsync(sender, e, cancellationToken);
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}
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}
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}
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finally {
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_executeTasksAsyncHasCompleted = true;
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}
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}
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}
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}
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