.Net:后台工作者和多个CPU

Question

我正在使用它BackgroundWorker在后台做一些重要的事情,以便UI不会变得无法响应.

但今天我注意到,当我运行程序时,只使用了两个CPU中的一个.

有没有办法使用所有的 CPU BackgroundWorker？

这是我的简化代码,就好像你很好奇!

---

private System.ComponentModel.BackgroundWorker bwPatchApplier;

this.bwPatchApplier.WorkerReportsProgress = true;
this.bwPatchApplier.DoWork += new System.ComponentModel.DoWorkEventHandler(this.bwPatchApplier_DoWork);
this.bwPatchApplier.ProgressChanged += new System.ComponentModel.ProgressChangedEventHandler(this.bwPatchApplier_ProgressChanged);
this.bwPatchApplier.RunWorkerCompleted += new System.ComponentModel.RunWorkerCompletedEventHandler(this.bwPatchApplier_RunWorkerCompleted);

---

private void bwPatchApplier_DoWork(object sender, DoWorkEventArgs e)
{
    string pc1WorkflowName;
    string pc2WorkflowName;

    if (!GetWorkflowSettings(out pc1WorkflowName, out pc2WorkflowName)) return;

    int progressPercentage = 0;
    var weWorkspaces = (List<WEWorkspace>) e.Argument;

    foreach (WEWorkspace weWorkspace in weWorkspaces)
    {
        using (var spSite = new SPSite(weWorkspace.SiteId))
        {
            foreach (SPWeb web in spSite.AllWebs)
            {
                using (SPWeb spWeb = spSite.OpenWeb(web.ID))
                {
                    PrintHeader(spWeb.ID, spWeb.Title, spWeb.Url, bwPatchApplier);

                    try
                    {
                        for (int index = 0; index < spWeb.Lists.Count; index++)
                        {
                            SPList spList = spWeb.Lists[index];

                            if (spList.Hidden) continue;

                            string listName = spList.Title;

                            if (listName.Equals("PC1") || listName.Equals("PC2"))
                            {
                                #region STEP 1

                                // STEP 1: Remove Workflow

                                #endregion

                                #region STEP 2

                                // STEP 2: Add Events: Adding & Updating

                                #endregion
                            }

                            if ((uint) spList.BaseTemplate == 10135 || (uint) spList.BaseTemplate == 10134)
                            {
                                #region STEP 3

                                // STEP 3: Configure Custom AssignedToEmail Property

                                #endregion

                                #region STEP 4

                                if (enableAssignToEmail)
                                {
                                    // STEP 4: Install AssignedTo events to Work lists
                                }

                                #endregion
                            }

                            #region STEP 5

                            // STEP 5 Install Notification Events

                            #endregion

                            #region STEP 6

                            // STEP 6 Install Report List Events

                            #endregion

                            progressPercentage += TotalSteps;
                            UpdatePercentage(progressPercentage, bwPatchApplier);
                        }
                    }
                    catch (Exception exception)
                    {
                        progressPercentage += TotalSteps;
                        UpdatePercentage(progressPercentage, bwPatchApplier);
                    }
                }
            }
        }
    }

    PrintMessage(string.Empty, bwPatchApplier);
    PrintMessage("*** Process Completed", bwPatchApplier);

    UpdateStatus("Process Completed", bwPatchApplier);
}

---

非常感谢您对此进行调查:)

Answer 1

在BackgroundWorker一个单一的背景(线程池)线内做其工作.因此,如果计算量很大,它将大量使用一个CPU.UI线程仍然在第二个运行,但可能(像大多数用户界面工作一样)花费几乎所有的时间空闲等待输入(这是一件好事).

如果要将工作拆分为使用多个CPU,则需要使用其他一些技术.这可以是多个BackgroundWorker组件,每个组件都可以完成一些工作,也可以直接使用ThreadPool.通过TPL在.NET 4中简化了并行编程,这可能是一个非常好的选择.有关详细信息,您可以在任务并行库的TPL或MSDN页面上查看我的系列.