We found a problem
with deleting step requests in JDI in certain situations. The problem
happens when you step off of the end of one thread, but there are other
threads still running in the program. The step request that got added
to do this ends up with a THREAD_STATUS_ZOMBIE thread status. When any
step event actually occurs we will delete the step request that caused
the event. In the above case we cannot delete that request, since this
step event will never occur. We also have code before adding the next
step request, which removes all the existing step requests
(eventRequestManager.deleteEventRequests(eventRequestManager.stepRequests()))
-- just in case any extra steps are still in the queue, which should
cover the above situation. However, when this is executed in the above
case, we get the following crash:
"instruction at "0x503b10c9" referenced memory at "0x00000003", followed
by the following exception trace:
Exception occurred during event dispatching:
com.sun.jdi.VMDisconnectedException
        at com.sun.tools.jdi.TargetVM.waitForReply(TargetVM.java:282)
        at
com.sun.tools.jdi.VirtualMachineImpl.waitForTargetReply(VirtualMachin
eImpl.java:781)
        at
com.sun.tools.jdi.PacketStream.waitForReply(PacketStream.java:65)
        at
com.sun.tools.jdi.JDWP$EventRequest$Clear.waitForReply(JDWP.java:5024
)
        at
com.sun.tools.jdi.JDWP$EventRequest$Clear.process(JDWP.java:5000)
        at
com.sun.tools.jdi.EventRequestManagerImpl$EventRequestImpl.clear(Even
tRequestManagerImpl.java:183)
        at
com.sun.tools.jdi.EventRequestManagerImpl$EventRequestImpl.setEnabled
(EventRequestManagerImpl.java:141)
        at
com.sun.tools.jdi.EventRequestManagerImpl$EventRequestImpl.disable(Ev
entRequestManagerImpl.java:134)
        at
com.sun.tools.jdi.EventRequestManagerImpl$EventRequestImpl.delete(Eve
ntRequestManagerImpl.java:121)
        at
com.sun.tools.jdi.EventRequestManagerImpl.deleteEventRequests(EventRe
questManagerImpl.java:593)
        at
com.borland.jbuilder.debugger.DebugJavaProcess.step(DebugJavaProcess.
java:334)
        at
com.borland.jbuilder.debugger.DebugJavaProcess.stepOver(DebugJavaProc
ess.java:300)
        at
com.borland.jbuilder.debugger.DebugJavaProcessTracker.stepOver(DebugJ
avaProcessTracker.java:599)
        at
com.borland.jbuilder.debugger.DebuggerActions.stepOverInto_actionPerf
ormed(DebuggerActions.java:88)
        at
com.borland.jbuilder.debugger.DebuggerActions.access$1(DebuggerAction
s.java:34)
        at
com.borland.jbuilder.debugger.DebuggerActions$3.actionPerformed(Debug
gerActions.java:104)
        at
com.borland.primetime.ide.BrowserAction.actionPerformed(BrowserAction
.java:125)
        at
javax.swing.JComponent.processKeyBinding(JComponent.java:1685)
        at
javax.swing.JComponent.processKeyBindings(JComponent.java:1708)
        at javax.swing.JComponent.processKeyEvent(JComponent.java:1610)
        at java.awt.Component.processEvent(Component.java:3014)
        at java.awt.Container.processEvent(Container.java:1015)
        at java.awt.Component.dispatchEventImpl(Component.java:2400)
        at java.awt.Container.dispatchEventImpl(Container.java:1060)
        at java.awt.Component.dispatchEvent(Component.java:2313)
        at
java.awt.LightweightDispatcher.processKeyEvent(Container.java:1791)
        at
java.awt.LightweightDispatcher.dispatchEvent(Container.java:1765)
        at java.awt.Container.dispatchEventImpl(Container.java:1047)
        at java.awt.Window.dispatchEventImpl(Window.java:749)
        at java.awt.Component.dispatchEvent(Component.java:2313)
        at java.awt.EventQueue.dispatchEvent(EventQueue.java:287)
        at
java.awt.EventDispatchThread.pumpOneEvent(EventDispatchThread.java:10
1)
        at
java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:92)
        at java.awt.EventDispatchThread.run(EventDispatchThread.java:83)

Exception occurred during event dispatching:
com.sun.jdi.VMDisconnectedException: Descriptor not a socket: socket
write error

        at com.sun.tools.jdi.TargetVM.send(TargetVM.java:271)
        at
com.sun.tools.jdi.VirtualMachineImpl.sendToTarget(VirtualMachineImpl.
java:777)
        at com.sun.tools.jdi.PacketStream.send(PacketStream.java:55)
        at
com.sun.tools.jdi.JDWP$ThreadReference$SuspendCount.enqueueCommand(JD
WP.java:4017)
        at
com.sun.tools.jdi.JDWP$ThreadReference$SuspendCount.process(JDWP.java
:4003)
        at
com.sun.tools.jdi.ThreadReferenceImpl.suspendCount(ThreadReferenceImp
l.java:161)
        at
com.borland.jbuilder.debugger.DebugJavaProcess.resume(DebugJavaProces
s.java:411)
        at
com.borland.jbuilder.debugger.DebugJavaProcess.checkDebugEvents(Debug
JavaProcess.java:229)
        at
com.borland.jbuilder.debugger.DebugJavaProcess.actionPerformed(DebugJ
avaProcess.java:662)
        at javax.swing.Timer.fireActionPerformed(Timer.java:147)
        at javax.swing.Timer$DoPostEvent.run(Timer.java:105)
        at
javax.swing.SystemEventQueueUtilities.processRunnableEvent(SystemEven
tQueueUtilities.java:399)
        at
javax.swing.SystemEventQueueUtilities.access$0(SystemEventQueueUtilit
ies.java:395)
        at
javax.swing.SystemEventQueueUtilities$RunnableTarget.processEvent(Sys
temEventQueueUtilities.java:436)
        at java.awt.Component.dispatchEventImpl(Component.java:2400)
        at java.awt.Component.dispatchEvent(Component.java:2313)
        at java.awt.EventQueue.dispatchEvent(EventQueue.java:287)
        at
java.awt.EventDispatchThread.pumpOneEvent(EventDispatchThread.java:10
1)
        at
java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:92)
        at java.awt.EventDispatchThread.run(EventDispatchThread.java:83)

If you have Primetime, you can reproduce this problem with the Welcome
Project by putting a breakpoint in the file_exit event handler in
WelcomeFrame, then just stepping through WelcomeApp, and stepping off of
the last line of it. Then select File/Exit on the Welcome app's menu.
After you hit the breakpoint, select "step over" -- boom.