Java调试器：是否可以选择性地挂起线程？ [英] Java Debugger: Is it possible selectively suspend threads?

问题描述

在过去的一段时间里，作为一个C / C ++程序员，有可能在某些平台上调试器组合以选择性地挂起线程。击中断点之后，可以发出命令（或者在GUI中点击东西）来冰/除冰（挂起/唤醒）线程。在进一步的step / next / run / continue命令后，挂起的线程将不会执行任何指令。

今天可以使用任何JVM或Java IDE吗？我使用IntelliJ，我没有看到该功能，也没有通过Google找到任何信息。

澄清：

1. 我不是询问断点的线程策略，例如挂起当前线程或所有线程。我知道这个JVM调试器功能。


2. 开发环境是香草：我使用IntelliJ Java IDE，我可以访问有问题的源代码。

最后，我意识到Java调试器是一个有点模糊的术语。 AFAIK，Sun发布了调试器用于与JVM通信的线上调试格式。也许每个JVM（IBM vs Sun vs IcedTea vs ???）都支持不同的调试功能，但我只熟悉Sun / Oracle JVM。

解决方案

你可以在jdb中挂起一个线程（见下文）。我喜欢IntelliJ作为Java编辑器。另一方面，它的调试器并不可怕，但关闭。

 初始化jdb ... 
>运行
没有任何挂起。 
>线程
组系统：
（java.lang.ref.Reference $ ReferenceHandler）0x141参考处理程序cond。等待
（java.lang.ref.Finalizer $ FinalizerThread）0x140 Finalizer cond。等待
（java.lang.Thread）0x13f信号调度程序运行
（java.lang.Thread）0x401 Java2D Disposer cond。等待
（java.lang.Thread）0x804 TimerQueue cond。等待
组主要：
（java.lang.Thread）0x322 AWT-AppKit运行
（java.lang.Thread）0x323 AWT-Shutdown cond。等待
（java.awt.EventDispatchThread）0x5ec AWT-EventQueue-0 cond。等待
（java.util.TimerThread）0x750 Timer-0 cond。等待
（java.lang.Thread）0x7fd DestroyJavaVM运行
>暂停0x5ec 
>线程
组系统：
（java.lang.ref.Reference $ ReferenceHandler）0x141参考处理程序cond。等待
（java.lang.ref.Finalizer $ FinalizerThread）0x140 Finalizer cond。等待
（java.lang.Thread）0x13f信号调度程序运行
（java.lang.Thread）0x401 Java2D Disposer cond。等待
（java.lang.Thread）0x804 TimerQueue cond。等待
组主要：
（java.lang.Thread）0x322 AWT-AppKit运行
（java.lang.Thread）0x323 AWT-Shutdown cond。等待
（java.awt.EventDispatchThread）0x5ec AWT-EventQueue-0在监视器中等待
（java.util.TimerThread）0x750 Timer-0 cond。等待
（java.lang.Thread）0x7fd DestroyJavaVM运行
>其中0x5ec 
 [1] java.lang.Object.wait（本机方法）
 [2] java.lang.Object.wait（Object.java:485）
 [3] java。 awt.EventQueue.getNextEvent（EventQueue.java:558）
 [4] java.awt.EventDispatchThread.pumpOneEventForFilters（EventDispatchThread.java:263）
 [5] java.awt.EventDispatchThread.pumpEventsForFilter（EventDispatchThread。 java：211）
 [6] java.awt.EventDispatchThread.pumpEventsForHierarchy（EventDispatchThread.java:201）
 [7] java.awt.EventDispatchThread.pumpEvents（EventDispatchThread.java:196）
 [8] java.awt.EventDispatchThread.pumpEvents（EventDispatchThread.java:188）
 [9] java.awt.EventDispatchThread.run（EventDispatchThread.java:122）
 AWT-EventQueue-0 [1]其中0x322 
当前线程不被挂起。 
 AWT-AppKit [1] resume 0x5ec 
 AWT-AppKit [1]其中0x5ec 
当前线程未挂起。 
 AWT-EventQueue-0 [1] 
  

In my past life as a C/C++ programmer, it was possible on some platforms & debugger combinations to selectively suspend threads. After hitting a breakpoint, one could issue commands (or click stuff in the GUI) to ice/de-ice (suspend / wake) a thread. Upon further step/next/run/continue commands, suspended threads would not execute any instructions.

Is this possible with any JVM or Java IDE today? I use IntelliJ and I don't see the feature, nor can I find any information via Google.

To clarify:

1. I am not asking about the thread policy for a breakpoint, e.g, suspend current thread or all threads. I am aware of that JVM debugger feature.
2. The dev environment is vanilla: I use IntelliJ Java IDE, and I have access to the source code in question.

Finally, I realise the "Java debugger" is a somewhat vague term. AFAIK, Sun published a debug-on-the-wire format that debuggers use to communicate with the JVM. Perhaps each JVM (IBM vs Sun vs IcedTea vs ???) supports different debug capabilities, but I am only familiar with the Sun/Oracle JVM.

解决方案

You can definitely suspend a single thread in jdb (see below). I love IntelliJ as a Java editor. On the other side its debugger is not terrible, but close.

Initializing jdb ...
> run
Nothing suspended.
> threads
Group system:
  (java.lang.ref.Reference$ReferenceHandler)0x141 Reference Handler cond. waiting
  (java.lang.ref.Finalizer$FinalizerThread)0x140  Finalizer         cond. waiting
  (java.lang.Thread)0x13f                         Signal Dispatcher running
  (java.lang.Thread)0x401                         Java2D Disposer   cond. waiting
  (java.lang.Thread)0x804                         TimerQueue        cond. waiting
Group main:
  (java.lang.Thread)0x322                         AWT-AppKit        running
  (java.lang.Thread)0x323                         AWT-Shutdown      cond. waiting
  (java.awt.EventDispatchThread)0x5ec             AWT-EventQueue-0  cond. waiting
  (java.util.TimerThread)0x750                    Timer-0           cond. waiting
  (java.lang.Thread)0x7fd                         DestroyJavaVM     running
> suspend 0x5ec             
> threads
Group system:
  (java.lang.ref.Reference$ReferenceHandler)0x141 Reference Handler cond. waiting
  (java.lang.ref.Finalizer$FinalizerThread)0x140  Finalizer         cond. waiting
  (java.lang.Thread)0x13f                         Signal Dispatcher running
  (java.lang.Thread)0x401                         Java2D Disposer   cond. waiting
  (java.lang.Thread)0x804                         TimerQueue        cond. waiting
Group main:
  (java.lang.Thread)0x322                         AWT-AppKit        running
  (java.lang.Thread)0x323                         AWT-Shutdown      cond. waiting
  (java.awt.EventDispatchThread)0x5ec             AWT-EventQueue-0  waiting in a monitor
  (java.util.TimerThread)0x750                    Timer-0           cond. waiting
  (java.lang.Thread)0x7fd                         DestroyJavaVM     running
> where 0x5ec
  [1] java.lang.Object.wait (native method)
  [2] java.lang.Object.wait (Object.java:485)
  [3] java.awt.EventQueue.getNextEvent (EventQueue.java:558)
  [4] java.awt.EventDispatchThread.pumpOneEventForFilters (EventDispatchThread.java:263)
  [5] java.awt.EventDispatchThread.pumpEventsForFilter (EventDispatchThread.java:211)
  [6] java.awt.EventDispatchThread.pumpEventsForHierarchy (EventDispatchThread.java:201)
  [7] java.awt.EventDispatchThread.pumpEvents (EventDispatchThread.java:196)
  [8] java.awt.EventDispatchThread.pumpEvents (EventDispatchThread.java:188)
  [9] java.awt.EventDispatchThread.run (EventDispatchThread.java:122)
AWT-EventQueue-0[1] where 0x322
Current thread isn't suspended.
AWT-AppKit[1] resume 0x5ec
AWT-AppKit[1] where 0x5ec
Current thread isn't suspended.
AWT-EventQueue-0[1]

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