Question

我有两个窗口来测试使用威胁的性能

我循环播放500

For i As Integer = 1 To 500
    'Form 1 scenario
    Dim Thread1 As New System.Threading.Thread(AddressOf InsertRecord1)
    Thread1.Start(RunningID)
    Dim Thread2 As New System.Threading.Thread(AddressOf InsertRecord1)
    Thread2.Start(RunningID)
    Dim Thread3 As New System.Threading.Thread(AddressOf InsertRecord1)
    Thread3.Start(RunningID)
    Dim Thread4 As New System.Threading.Thread(AddressOf InsertRecord1)
    Thread4.Start(RunningID)
Next

表格2场景

For i As Integer = 1 To 500
    'Form 2 scenario
    Dim Thread1 As New System.Threading.Thread(AddressOf InsertRecord1)
    Thread1.Start(RunningID)
    Dim Thread2 As New System.Threading.Thread(AddressOf InsertRecord1)
    Thread2.Start(RunningID)
    Dim Thread3 As New System.Threading.Thread(AddressOf InsertRecord1)
    Thread3.Start(RunningID)
    Dim Thread4 As New System.Threading.Thread(AddressOf InsertRecord1)
    Thread4.Start(RunningID)
    Thread1.Join()
    Thread2.Join()
    Thread3.Join()
    Thread4.Join()
Next

显然情景2比情景1快。为什么??

这是收集的数据

Scenario 1 take (milliseconds): 2578   3188   3078   2984   3250
Scenario 2 take (milliseconds): 1890   1969   1828   1938   1860

Answer 1

我认为这只是表明你的插页不能很好地扩展。您的第一个scanario启动2000个线程并等待它们完成 - 第二个场景启动4个线程并等待它们完成500次。

使用线程会增加执行的开销，如果所有线程都进入同一个无法处理许多连接的数据库，执行时间会变得更糟，那么本身可能会降低代码速度。也许您可以在没有多个线程的情况下测试您的示例，将调用直接放入循环并查看数字，这可能会更快地运行。

为什么线程在Visual Basic .Net中使用thread.Join运行得更快

1 个答案: