单声道挂起且MS.Net不会出现的线程问题 [英] A threading problem where mono hangs and MS.Net doesn't
问题描述
我正在预配置Linux端口时用mono测试我的应用程序，但是我遇到了线程问题.我最初考虑在此处粘贴3000条代码行，但最终我设计了一个小小的示例；)
I'm testing my app with mono in prevision of a Linux port, and I have a threading problem. I initially considered pasting 3000 code lines here, but finally I've devised a small minimal example ;)
您有一个带有按钮的窗体(通常命名为Button1)和标签(带有标签(毫无疑问地带有名称Label1)).整个过程都以称为Form1的形式过着幸福的生活.单击Button1将启动无限循环，该循环将递增本地计数器并更新Label1(使用Invoke)以反映其值.
You have a form with a button (poetically named Button1, and a label (which bears, without surprise, the name Label1)). The whole lot is living a happy life on a form called Form1. Clicking Button1 launches an infinite loop that increments a local counter and updates Label1 (using Invoke) to reflect its value.
现在在Mono中，如果您调整窗体的大小，标签将停止更新，永远不会重新启动. MS实施不会发生这种情况. BeginInvoke不能更好地工作；更糟糕的是，这两种情况都会使UI挂起.
Now in Mono, if you resize the form, the label stops updating, never to restart. This doesn't happen with MS implementation. BeginInvoke doesn't work any better; worse, it makes the UI hang in both cases.
您知道这种差异来自何处吗?您将如何解决?最后，为什么BeginInvoke在这里不起作用?我一定是犯了个大错误...但是哪个呢?
Do you know where this discrepancy comes from? How would you solve it? And finally, why doesn't BeginInvoke work here? I must be making a huge mistake... but which?
编辑: 到目前为止取得了一些进展:
EDIT: Some progress so far:
- 实际上，调用BeginInvoke确实可以；只是，UI的刷新速度不够快，因此似乎停止了.
- 在mono上，发生的事情是当您在UI队列中插入一条消息时整个线程挂起(例如，通过调整表单大小).实际上，同步
Invoke调用永不返回.我正试图了解原因. - 有趣的是:即使使用
BeginInvoke，在调整大小操作结束之前，异步调用也不会执行.在MS.Net上，它们在调整大小的同时保持运行.
- Calling BeginInvoke does in fact work; only, the UI just doesn't refresh fast enough, so it seems to stop.
- On mono, what happens is that the whole thread hangs when you insert a message in the UI queue (eg by resizing the form). In fact, the synchronous
Invokecall never returns. I'm trying to understand why. - Of interest: even using
BeginInvoke, the asynchronous calls don't get executed before the resizing operation ends. On MS.Net, they keep running while resizing.
代码看起来像这样(C#版本较低):
The code looks like this (C# version lower):
Public Class Form1
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
Dim T As New Threading.Thread(AddressOf Increment)
T.Start()
End Sub
Sub UpdateLabel(ByVal Text As String)
Label1.Text = Text
End Sub
Delegate Sub UpdateLabelHandler(ByVal Text As String)
Sub Increment()
Dim i As Long = 0
Dim UpdateLabelDelegate As New UpdateLabelHandler(AddressOf UpdateLabel)
Try
While True
i = (i + 1) Mod (Long.MaxValue - 1)
Me.Invoke(UpdateLabelDelegate, New Object() {i.ToString})
End While
Catch Ex As ObjectDisposedException
End Try
End Sub
End Class
或者，在C#中，
public class Form1
{
private void Button1_Click(System.Object sender, System.EventArgs e)
{
System.Threading.Thread T = new System.Threading.Thread(Increment);
T.Start();
}
public void UpdateLabel(string Text)
{
Label1.Text = Text;
}
public delegate void UpdateLabelHandler(string Text);
public void Increment()
{
long i = 0;
UpdateLabelHandler UpdateLabelDelegate = new UpdateLabelHandler(UpdateLabel);
try {
while (true) {
i = (i + 1) % (long.MaxValue - 1);
this.Invoke(UpdateLabelDelegate, new object[] { i.ToString() });
}
} catch (ObjectDisposedException Ex) {
}
}
}
推荐答案
这是mono运行时中的错误，至少我认为是.代码可能不是一个好习惯(我不是线程专家)，但是提示错误的原因是Windows和Linux上的行为不同.
This is a bug in the mono runtime, at least I think it is. The code might not be good practice (I'm not a threading expert), but the thing that suggests a bug is the fact that the behaviour differs on windows and Linux.
在Linux上，mono具有与Windows上的MS.Net完全相同的行为.调整大小时不会挂起，也不会持续更新.
On Linux, mono has exactly the same behaviour as MS.Net has on windows. No hanging, continuous updates even while resizing.
在Windows上，mono显示所有上述问题.我已经在 https://bugzilla.novell.com/show_bug.cgi?id=690400 <上发布了一个错误报告. /a>.
On Windows, mono displays all the aforementioned problems. I've posted a bug report at https://bugzilla.novell.com/show_bug.cgi?id=690400 .
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