Debugger/Highlighter Freezes Image

>Wolfgang Mayer wrote:
>> I've experienced the VW7.4 debugger freeze twice this week, usually
>> after forking another debugger from the current one using "debug it"
>> or when editing a method within the debugger.  Unfortunately, I have
>> not been able to reproduce this.
>>
>> From the stack trace it seems that this may be related to the
>> RBCodeHighlighter?
>
>Not really, the RBCodeHighlighter process is trying to grow a write
>stream. During this process it become:'s one string to a larger one.
>#become: then tries to swap the event tables for the two strings.
>However, the EventTable's recursion lock is locked, so it waits. Looking
>at the various processes, I see two others that are waiting on the same
>recursion lock, but I didn't see anyone that is in the middle of the
>critical: block for the event table.
>
>
>John Brant

> Alan Knight wrote:
>
>> This might be another manifestion of the general problem that if a
>> process is terminated while an unwind block is in the process of
>> running, then that unwind block does not finish running. This is a
>> known issue, but also a good reason to be very careful using
>> #terminate.
>
>
> Do you have a way to be sufficiently careful using #terminate to avoid
> this problem in the general case?
>
> I haven't been able to determine any way to safely terminate any process
> that uses unwind blocks. And essentially all processes use unwind blocks.
>
> I'd really like to see this bug fixed. Is the AR scheduled for work
> anytime soon?
>
> We do a lot of multi-process work, and we've been running into this
> lately. For a particularly nasty example, see my mail on "Single-process
> deadlock" of Jan 25.
>
> In looking at the existing code, I find it simple and elegant. However,
> it does not behave correctly. Inability to safely terminate a process
> leaves major hole in the Process model. I don't see an obvious way to
> fix this without complicating the unwind code, but I think this is
> serious enough to warrant being tackled soon.
>
> -Martin
>
>
>

> The best way to terminate a process is to carefully design the process
> so you can end it via mechanisms *other* than #terminate.  The best
> techniques are those that cause the process to terminate itself.  Some
> examples:
>
> 1. The process reads "requests" from a SharedQueue.  To stop the
> process, put a special request on the SharedQueue that the process
> recognizes and ends itself.
>
> 2. Assume some object creates the process and holds a reference to it in
> an instance variable.  The process stays alive as long as that instance
> variable refers to itself.  When the reference changes, the process
> stops itself.  To stop the process simply change the instance variable
> to nil (or anything else).
>
> 3. The process begins with a top-level exception handler that handles a
> specially defined exception.  To stop the process, send #interruptWith:
> aBlock to it, where the block does something like: "SpecialException
> raiseSignal". HOWEVER, this will cause a walkback if the process was
> already terminated. There are some application-specific ways around this.
>

> -----Original Message-----
> From: Wolfgang Mayer [mailto:[hidden email]]
> Sent: Tuesday, January 31, 2006 1:12 AM
> To: VWNC List
> Subject: Debugger/Highlighter Freezes Image
>
> I've experienced the VW7.4 debugger freeze twice this week, usually
> after forking another debugger from the current one using "debug it"
> or when editing a method within the debugger.  Unfortunately, I have
> not been able to reproduce this.
>
>  From the stack trace it seems that this may be related to the
> RBCodeHighlighter?
>
> We use a slightly modified version of the RBCodeHighlighter that
> redraws only the portion of the text view where there emphasis has
> actually changed. To compute this, we compare the highlighted copied
> text to the original to find spans with changed emphasis. We then find
> and invalidate the view coordinates including those characters. Except
> for a few helper methods, the main change to
> HighlightingTextEditorController>>startHighlighting is as follows:
>
> Instead of
>
>          [localText string = self text string
> ifTrue:
> [self text setString: self text string

> text]].
>
> The helpers are implemented in terms of Text>>emphasisAt:,
> Text>>sameEmphasisAs:,
> self view invalidateRectangle:repairNow:true, and self view
> characterBlockForIndex:.
>
>
> Any chances that this could be causing the lockups?
>
>
> Anyway, here's the stack trace [gdb, dumpAllProcesses(1)]. Maybe there is
> something obvious I don't see:
> [Platform: Ubuntu Linux, kernel 2.6.15-12-686, glibc 2.3.6, X11 Xorg
> 6.8.2]
>
>
> Any hints would be appreciated.
>
>
> - Wolfgang
>
>
>
> process 0x81dfb28
>
> frame 0xbfdc9750 a(n) Semaphore waitIfCurtailedSignal
> frame 0xbfdc9768 a(n) Semaphore critical:
> frame 0xbfdc9784 a(n) RecursionLock critical:
> frame 0xbfdc97a8 a(n) EphemeronDictionary at:ifAbsent:
> frame 0xbfdc97bc a(n) ByteString myEventTable
> frame 0xbfdc97e4 a(n) ByteString become:
> frame 0xbfdc9800 a(n) ByteString changeSizeTo:
> frame 0xbfdc9818 a(n) ByteString growToAtLeast:
> frame 0xbfdc9830 a(n) WriteStream pastEndPut:
> frame 0xbfdc9848 a(n) WriteStream nextPut:
> frame 0xbfdc985c a(n) CodeHighlightingScanner step
> frame 0xbfdc9870 a(n) CodeHighlightingScanner scanForToken
> frame 0xbfdc9884 a(n) CodeHighlightingScanner next
> frame 0xbfdc9898 a(n) CodeHighlightingParser getNextToken
> frame 0xbfdc98b0 a(n) CodeHighlightingParser performParsingLoop
> frame 0xbfdc98c4 a(n) CodeHighlightingParser parse
> frame 0xbfdc98dc a(n) BlockClosure [] in CodeHighlightingParser
> class>>formatMethod:forClass:namespace:
> frame 0xbfdc98f8 a(n) BlockClosure on:do:
> frame 0xbfdc9918 a Class (CodeHighlightingParser)
> formatMethod:forClass:namespace:
> frame 0xbfdc9954 a(n) BlockClosure [] in
> HighlightingTextEditorController>>startHighlighting:
> frame 0xbfdc9970 a(n) BlockClosure on:do:
> frame 0xbfdc9988 a(n) BlockClosure [] in Process class>>forBlock:priority:
>
> process 0x8cde7a4
> suspendedContext is nil
>
> process 0x8de8940
>
> frame 0xbfdcd974 a(n) Semaphore wait
> frame 0xbfdcd988 a(n) BlockClosure [] in Delay
> class>>initializeTimingProcess
> context 0x08df9e54 BlockClosure>>on:do:
> context 0x08df9434 [] in Process class>>forBlock:priority:
>
> process 0x95a19d8
>
> context 0xb79b82dc Process>>resume
> context 0xb79c6370 BlockClosure>>forkAt:
> context 0x097a3590 Process>>suspendResumable:do:
> context 0xb79b7b98 DebuggerService class>>openOn:exception:interrupted:
> context 0xb79c6358 DebuggerService class>>openOnException:
> context 0x097a31a0 DebuggerService class>>openException:
> context 0x097a3188 Notifier class>>openException:
> context 0x097a3170 UnhandledException>>defaultAction
> context 0x097a3158 UnhandledException(GenericException)>>performHandler:
> context 0x097a30b0
> UnhandledException(GenericException)>>propagatePrivateFrom:
> context 0xb79b7b68 UnhandledException(GenericException)>>propagateFrom:
> context 0xb79c6340 UnhandledException(GenericException)>>propagate
> context 0xb79b7b5c UnhandledException(GenericException)>>raiseSignal
> context 0xb79c6328 BreakInterrupt(GenericException)>>noHandler
> context 0x097a32f0 BreakInterrupt(GenericException)>>defaultAction
> context 0x097a32d8 BreakInterrupt(GenericException)>>performHandler:
> context 0x097a3278 BreakInterrupt(GenericException)>>propagatePrivateFrom:
> context 0xb79b7b50 BreakInterrupt(GenericException)>>propagateFrom:
> context 0xb79c6310 BreakInterrupt(GenericException)>>propagate
> context 0xb79b7b44 BreakInterrupt(GenericException)>>raiseSignal
> context 0xb79b7a6c BreakInterrupt class(GenericException
> class)>>raiseRequestWith:errorString:
> context 0xb79b7b74 CodeProbe(Object)>>breakOn:label:
> context 0x095a772c CodeProbe>>actOn:
> context 0xb79b821c IndexTreeMutator>>unboundMethod
> ...
> context 0xb79b0374 BlockClosure>>ensure:
> context 0xb79b0368 Cursor>>showWhile:
> context 0xb79b035c LoggingDebugger>>debugAndPrintEvents
> context 0xb79b0350 [] in LoggingDebugger>>debug
> context 0xb79b0344 LoggingDebugger>>runAndMeasureTime:
> context 0xb79b0338 LoggingDebugger>>debug                       // <-
> entry
> point of my application
> context 0xb79b032c UndefinedObject>>unboundMethod
> context 0xb79b0320 UndefinedObject(Object)>>performMethod:arguments:
> context 0xb79b0314 UndefinedObject(Object)>>performMethod:
> context 0xb79b0308
> HighlightingTextEditorController(ParagraphEditor)>>evaluateCompiled:
> context 0xb79b02fc [] in ParagraphEditor>>evaluateSelection
> context 0xb79c9a60 BlockClosure>>ensure:
> context 0xb79b02f0 Cursor>>showWhile:
> context 0xb79b02e4
> HighlightingTextEditorController(ParagraphEditor)>>evaluateSelection
> context 0xb79b02d8 [] in ParagraphEditor>>doIt
> context 0xb79d8970 BlockClosure>>on:do:
> context 0xb79b02cc HighlightingTextEditorController(ParagraphEditor)>>doIt
> context 0xb79b02c0
> HighlightingTextEditorController(TextEditorController)>>dispatchMenuSymbol
> :
> context 0xb79b02b4
> HighlightingTextEditorController(TextEditorController)>>dispatchMenuSelect
> ion:
> context 0xb79b02a8
> HighlightingTextEditorController(ControllerWithMenu)>>processMenu:at:cente
> red:
> context 0xb79b029c
> HighlightingTextEditorController(ControllerWithMenu)>>processMenuAt:center
> ed:
> context 0xb79b0290
> HighlightingTextEditorController(ControllerWithMenu)>>yellowButtonPressedE
> vent:
> context 0xb79b0284
> HighlightingTextEditorController(ParagraphEditor)>>yellowButtonPressedEven
> t:
> context 0xb79b0278
> HighlightingTextEditorController(TextEditorController)>>yellowButtonPresse
> dEvent:
> context 0xb79b026c YellowButtonPressedEvent>>dispatchTo:
> context 0xb79b0260
> HighlightingTextEditorController(ControllerWithMenu)>>handleEvent:
> context 0xb79b0254 EventDispatcher>>dispatch:to:
> context 0xb79b023c EventDispatcher>>dispatchEvent:
> context 0xb79b0230 YellowButtonPressedEvent(Event)>>dispatch
> context 0xb79b0218
> YellowButtonPressedEvent(Event)>>dispatchForWindowManager:
> context 0xb79b020c [] in WindowManager>>safelyDispatchForWindowManager:
> context 0xb79d891c BlockClosure>>on:do:
> context 0xb79b0200 WindowManager>>safelyDispatchForWindowManager:
> context 0xb79b01f4 WindowManager>>processNextEvent
> context 0x095e5478 [] in WindowManager>>newProcess
> context 0x095e53e8 BlockClosure>>on:do:
> context 0x095e53c4 [] in WindowManager>>newProcess
> context 0x095e5340 BlockClosure>>on:do:
> context 0x095a1708 [] in Process class>>forBlock:priority:
>
> process 0x95a2440
>
> context 0x095ae5d8 Semaphore>>wait
> context 0x095ab260 EventQueue>>next
> context 0x095ab248 WindowManager>>processNextEvent
> context 0xb79dc1bc [] in WindowManager>>newProcess
> context 0xb79db6e8 BlockClosure>>on:do:
> context 0xb79c04f0 [] in WindowManager>>newProcess
> context 0x097a8234 BlockClosure>>on:do:
> context 0x095a78c4 [] in Process class>>forBlock:priority:
>
> process 0x95b9474
>
> context 0xb79dfc18 Semaphore>>wait
> context 0xb79b34b8 EventQueue>>next
> context 0xb79b63a4 WindowManager>>processNextEvent
> context 0xb79d057c [] in WindowManager>>newProcess
> context 0x095d4438 BlockClosure>>on:do:
> context 0x095b2694 [] in WindowManager>>newProcess
> context 0x095d4444 BlockClosure>>on:do:
> context 0x095b585c [] in Process class>>forBlock:priority:
>
> process 0x95c8360
> suspendedContext is nil
>
> process 0x95cc5f0
> suspendedContext is nil
>
> process 0x95da0e4
>
> context 0x095ab698 Semaphore>>wait
> context 0x095a9a54 EventQueue>>next
> context 0x095a9a3c WindowManager>>processNextEvent
> context 0xb79d02d0 [] in WindowManager>>newProcess
> context 0x095d7e40 BlockClosure>>on:do:
> context 0xb79cfe8c [] in WindowManager>>newProcess
> context 0x095d7e34 BlockClosure>>on:do:
> context 0x095da0cc [] in Process class>>forBlock:priority:
>
> process 0x95e1938
> suspendedContext is nil
>
> process 0x967753c
> suspendedContext is nil
>
> process 0x96dfab0
>
> context 0x095ab680 Semaphore>>wait
> context 0x095a9b80 EventQueue>>next
> context 0x095a9b5c WindowManager>>processNextEvent
> context 0x097795e4 [] in WindowManager>>newProcess
> context 0x0977ae44 BlockClosure>>on:do:
> context 0x09779e60 [] in WindowManager>>newProcess
> context 0x0977ae50 BlockClosure>>on:do:
> context 0x096dff18 [] in Process class>>forBlock:priority:
>
> process 0x96e248c
> suspendedContext is nil
>
> process 0x96ea238
>
> frame 0xbfdc86d8 a(n) Semaphore waitIfCurtailedSignal
> frame 0xbfdc86f0 a(n) Semaphore critical:
> frame 0xbfdc870c a(n) RecursionLock critical:
> frame 0xbfdc8730 a(n) EphemeronDictionary at:ifAbsent:
> frame 0xbfdc8744 a(n) OrderedCollection myEventTable
> frame 0xbfdc876c a(n) OrderedCollection become:
> frame 0xbfdc8790 a(n) OrderedCollection changeCapacityTo:
> frame 0xbfdc87a4 a(n) OrderedCollection increaseCapacity
> frame 0xbfdc87cc a(n) OrderedCollection makeRoomAtLast
> frame 0xbfdc87e4 a(n) OrderedCollection addLast:
> frame 0xbfdc8808 a(n) BlockClosure [] in EventQueue>>nextPut:collapse:
> frame 0xbfdc8824 a(n) BlockClosure ensure:
> frame 0xbfdc883c a(n) Semaphore critical:
> frame 0xbfdc8860 a(n) BlockClosure [] in EventQueue>>nextPut:collapse:
> frame 0xbfdc887c a(n) BlockClosure ensure:
> frame 0xbfdc8894 a(n) Semaphore critical:
> frame 0xbfdc88ac a(n) Process uninterruptablyDo:
> frame 0xbfdc88c0 a(n) BlockClosure valueUninterruptably
> frame 0xbfdc88e0 a(n) EventQueue nextPut:collapse:
> frame 0xbfdc88fc a(n) WindowManager addEvent:collapse:
> frame 0xbfdc8914 a(n) EventSensor addCollapsedMetaInput:
> frame 0xbfdc892c a(n) EventSensor eventMouseMoved:
> frame 0xbfdc894c a(n) InputState send:eventMouseMoved:
> frame 0xbfdc8970 a(n) InputState process:
> frame 0xbfdc8988 a(n) InputState 0x0 no selector
> context 0x096f7ed0 [] in InputState class>>install
> context 0x096f2de8 BlockClosure>>on:do:
> context 0x096ea070 [] in Process class>>forBlock:priority:
>
> process 0x9755944
>
> frame 0xbfdca974 a(n) Semaphore wait
> frame 0xbfdca988 a Class (ObjectMemory) 0x0 no selector
> context 0x0977a2c8 [] in ObjectMemory class>>installIdleLoopProcess
> context 0x09777868 BlockClosure>>on:do:
> context 0x09707e24 [] in Process class>>forBlock:priority:
>
> process 0x97559bc
>
> context 0x081c0c7c Semaphore>>wait
> context 0x096e9fd4 ObjectMemory class>>lowSpaceLoop
> context 0x097ba114 [] in ObjectMemory class>>installLowSpaceProcess
> context 0x097bb8a8 BlockClosure>>on:do:
> context 0x09707f08 [] in Process class>>forBlock:priority:
>
> process 0x9755a28
>
> context 0x096ea1c0 Semaphore>>wait
> context 0x097be77c [] in ExternalProcess class>>startReaper
> context 0x0979fd38 BlockClosure>>on:do:
> context 0x09707ed8 [] in Process class>>forBlock:priority:
>
> process 0x9755a34
>
> frame 0xbfdd096c a(n) Semaphore wait
> frame 0xbfdd0988 a(n) BlockClosure [] in ObjectMemory
> class>>installScavengeNotification
> context 0x097915a8 BlockClosure>>on:do:
> context 0x09707e6c [] in Process class>>forBlock:priority:
>
> process 0x9793d2c
>
> context 0x081c0c58 Semaphore>>wait
> context 0x09799e64 WeakArray class>>outerFinalizationLoop
> context 0x09799e58 [] in WeakArray class>>installFinalizationMechanism
> context 0x09799744 BlockClosure>>on:do:
> context 0x097b898c [] in Process class>>forBlock:priority:
>
> process 0x97ab69c
>
> context 0xb79def70 Semaphore>>wait
> context 0xb79dd914 EventQueue>>next
> context 0xb79b0128 WindowManager>>processNextEvent
> context 0x096f81d0 [] in WindowManager>>newProcess
> context 0x096f81dc BlockClosure>>on:do:
> context 0x096f8200 [] in WindowManager>>newProcess
> context 0x096f8218 BlockClosure>>on:do:
> context 0x09799ea0 [] in Process class>>forBlock:priority:
>
> process 0x97b5c2c
>
> context 0x096ea130 Semaphore>>wait
> context 0x0978eb24 [] in CCallback class>>installForeignCallbackProcess
> context 0x0978eb0c BlockClosure>>on:do:
> context 0x097b5c38 [] in Process class>>forBlock:priority:
>
> process 0x97b5ca4
>
> context 0x096ea13c Semaphore>>wait
> context 0x0975be24 [] in CCallback class>>installCallbackProcess
> context 0x0975be78 BlockClosure>>on:do:
> context 0x0975beb4 [] in CCallback class>>installCallbackProcess
> context 0x0975bed8 BlockClosure>>on:do:
> context 0x0975bf20 [] in CCallback class>>installCallbackProcess
> context 0x0975bf74 BlockClosure>>on:do:
> context 0x097b5cb0 [] in Process class>>forBlock:priority:
>
> process 0xb79af78c
>
> frame 0xbfdc7534 a(n) Semaphore waitIfCurtailedSignal
> frame 0xbfdc754c a(n) Semaphore critical:
> frame 0xbfdc7568 a(n) RecursionLock critical:
> frame 0xbfdc758c a(n) EphemeronDictionary at:ifAbsent:
> frame 0xbfdc75a0 a(n) Set myEventTable
> frame 0xbfdc75c8 a(n) Set become:
> frame 0xbfdc75e4 a(n) Set changeCapacityTo:
> frame 0xbfdc75f8 a(n) Set grow
> frame 0xbfdc7614 a(n) Set fullCheck
> frame 0xbfdc7630 a(n) Set atNewIndex:put:
> frame 0xbfdc764c a(n) Set add:
> frame 0xbfdc7668 a(n) BlockClosure [] in CompiledCode>>allSymbolLiterals
> frame 0xbfdc768c a(n) BlockClosure [] in
> CompiledCode>>allSymbolLiteralsDo:
> frame 0xbfdc76b0 a(n) InstructionStream scanFor:
> frame 0xbfdc76dc a(n) ProbedCompiledMethod allSymbolLiteralsDo:
> frame 0xbfdc76f4 a(n) ProbedCompiledMethod allSymbolLiterals
> frame 0xbfdc7720 a(n) DebuggerClient querySubmenuSending:
> frame 0xbfdc7738 a(n) BlockClosure [] in
> DebuggerClient>>setQuerySubmenuBlocksIn:
> frame 0xbfdc774c a(n) MenuItemAdornment submenu
> frame 0xbfdc7760 a(n) MenuItem submenu
> frame 0xbfdc7788 a(n) BlockClosure [] in BlockClosure>>unboundMethod
> frame 0xbfdc77a8 a(n) Array do:
> frame 0xbfdc77c4 a(n) MotifMenuView menuItemForShortcutKey:inMenu:
> frame 0xbfdc77dc a(n) MotifMenuView menuItemForShortcutKey:
> frame 0xbfdc7804 a(n) MotifMenuBarButtonView
> processShortcutKeyEventAsMenuItemAccessor:
> frame 0xbfdc7820 a(n) BlockClosure [] in BlockClosure>>unboundMethod
> frame 0xbfdc7840 a(n) OrderedCollection do:
> frame 0xbfdc7858 a(n) MotifMenuBar processShortcutKeyEventInMenuBar:
> frame 0xbfdc7880 a(n) KeyboardProcessor processShortcutKeyEvent:
> frame 0xbfdc789c a(n) KeyboardProcessor processKeyboardEvent:
> frame 0xbfdc78bc a(n) KeyboardProcessor processKeyboardEvent:for:
> frame 0xbfdc78dc a(n) EventDispatcher dispatchEvent:
> frame 0xbfdc78f0 a(n) KeyPressedEvent dispatch
> frame 0xbfdc7908 a(n) KeyPressedEvent dispatchForWindowManager:
> frame 0xbfdc7924 a(n) BlockClosure [] in
> WindowManager>>safelyDispatchForWindowManager:
> frame 0xbfdc7940 a(n) BlockClosure on:do:
> frame 0xbfdc7958 a(n) WindowManager safelyDispatchForWindowManager:
> frame 0xbfdc7970 a(n) WindowManager processNextEvent
> frame 0xbfdc7988 a(n) BlockClosure [] in WindowManager>>newProcess
> context 0xb79e1b08 BlockClosure>>on:do:
> context 0xb79b69ec [] in WindowManager>>newProcess
> context 0xb79e1afc BlockClosure>>on:do:
> context 0x095d17ec [] in Process class>>forBlock:priority:
>
> process 0xb79b84a4
> suspendedContext is nil
>
> process 0xb79b9800
>
> context 0xb79e1b80 Semaphore>>wait
> context 0xb79da830 EventQueue>>next
> context 0xb79da68c WindowManager>>processNextEvent
> context 0xb79c4924 [] in WindowManager>>newProcess
> context 0xb79e1700 BlockClosure>>on:do:
> context 0xb79e1664 [] in WindowManager>>newProcess
> context 0xb79e1628 BlockClosure>>on:do:
> context 0xb79b97f4 [] in Process class>>forBlock:priority:
>
> process 0xb79bd76c
>
> context 0xb79e1970 Semaphore>>wait
> context 0x096ecd28 EventQueue>>next
> context 0xb79ccb14 WindowManager>>processNextEvent
> context 0xb79e1a84 [] in WindowManager>>newProcess
> context 0xb79e1a78 BlockClosure>>on:do:
> context 0xb79d93fc [] in WindowManager>>newProcess
> context 0xb79c5044 BlockClosure>>on:do:
> context 0xb79b6c20 [] in Process class>>forBlock:priority:
>
> process 0xb79c5974
>
> context 0xb79e0e24 Semaphore>>signal
> context 0xb79e0e18 [] in ProcessHandle>>performDebugOperation:
>
> process 0xb79d120c
> suspendedContext is nil
>
> process 0xb79d6a80
> suspendedContext is nil
>
> process 0xb79dc018
> suspendedContext is nil
>
> process 0xb79dc300
> suspendedContext is nil
>
> process 0xb79dc54c
> suspendedContext is nil
>
> process 0xb79e1a0c
> suspendedContext is nil
>
> --- Last modified: <06/01/31 16:37:53
> [hidden email]> ---

> -----Original Message-----
> From: Wolfgang Mayer [mailto:[hidden email]]
> Sent: Tuesday, January 31, 2006 7:59 PM
> To: VWNC List
> Subject: Re: Debugger/Highlighter Freezes Image
>
> Alan Knight wrote:
> > This might be another manifestion of the general problem that if a
> process
> > is terminated while an unwind block is in the process of running, then
> that
> > unwind block does not finish running. This is a known issue, but also a
> good
> > reason to be very careful using #terminate. If that's the problem, it
> may be
> > because some of the modifications that people made to  the
> RBCodeHighlighter
> > or some other code that's accessing the event table is terminating
> > processes.
>
> I've played around a bit more and I can now reproduce the deadlock in a
> fresh
> visualnc.im [VW7.3.1, VW7.4]:
>
> "doit in a workspace"
> [Object new myEventTable] repeat.
>
> If this code is interrupted by pressing Ctrl-Y, the deadlock occurs. (If
> not at
> the first time, proceed and try again. For me, it always locks at the
> first or
> second attempt.) I suspect that a similar scenario happens with my
> application
> (I don't use processes at all).
>
>
> Is there any way to avoid this? While it should be feasible to avoid
> #terminate
> and cleanup gracefully for "regular" use of processes, I cannot see how
> this
> can be done safely for User Interrupts while debugging. (Maybe this is
> trivial,
> my understanding of processes and concurrency in VW is not very deep.)
>
> Also, is it possible to #signal the locked semaphore from within an
> attached
> gdb session to revive the image? Apologies if this is in the
> documentation, I
> couldn't find the relevant section.
>
>
> Regards,
>
> - Wolfgang
>
>
>
> process 0x8dd8b5c
> suspendedContext is nil
>
> process 0x8e5de4c
> suspendedContext is nil
>
> process 0x8ee2cf8
>
> context 0xb7a940d0 Semaphore>>wait
> context 0x08ef4218 [] in Delay class>>initializeTimingProcess
> context 0x08ef420c BlockClosure>>on:do:
> context 0x08ef37ec [] in Process class>>forBlock:priority:
>
> process 0x8f0ed44
>
> frame 0xbf81aa0c a(n) Semaphore wait
> frame 0xbf81aa28 a(n) EventQueue next
> frame 0xbf81aa40 a(n) WindowManager processNextEvent
> frame 0xbf81aa58 a(n) BlockClosure [] in WindowManager>>newProcess
> context 0x08f1b02c BlockClosure>>on:do:
> context 0x08c8de84 [] in WindowManager>>newProcess
> context 0x08f1b044 BlockClosure>>on:do:
> context 0x08f1b05c [] in Process class>>forBlock:priority:
>
> process 0x8f36f50
> suspendedContext is nil
>
> process 0x8f38da4
> suspendedContext is nil
>
> process 0x8f46250
> suspendedContext is nil
>
> process 0x8fcca40
> suspendedContext is nil
>
> process 0x8fccbc0
> suspendedContext is nil
>
> process 0x8fcccc8
> suspendedContext is nil
>
> process 0x8fd14d4
>
> context 0x08fd625c Semaphore>>wait
> context 0x08fdf9a0 [] in CCallback class>>installForeignCallbackProcess
> context 0x08fdfcf4 BlockClosure>>on:do:
> context 0x08fd1ce4 [] in Process class>>forBlock:priority:
>
> process 0x8fd1504
> suspendedContext is nil
>
> process 0x8fd6688
> suspendedContext is nil
>
> process 0x8fdf508
> suspendedContext is nil
>
> process 0x90ff254
>
> context 0x090ff11c Semaphore>>wait
> context 0x0910124c [] in CCallback class>>installCallbackProcess
> context 0x091013d8 BlockClosure>>on:do:
> context 0x0910142c [] in CCallback class>>installCallbackProcess
> context 0x09101744 BlockClosure>>on:do:
> context 0x09101aa4 [] in CCallback class>>installCallbackProcess
> context 0x09101b94 BlockClosure>>on:do:
> context 0x090ff188 [] in Process class>>forBlock:priority:
>
> process 0x90ff260
>
> context 0x090ff0d4 Semaphore>>wait
> context 0x091013f0 [] in CCallback class>>installForeignCallbackProcess
> context 0x09101444 BlockClosure>>on:do:
> context 0x090ff104 [] in Process class>>forBlock:priority:
>
> process 0x90ff5a8
>
> frame 0xbf8197a0 a(n) Semaphore waitIfCurtailedSignal
> frame 0xbf8197b8 a(n) Semaphore critical:
> frame 0xbf8197d4 a(n) RecursionLock critical:
> frame 0xbf8197f8 a(n) EphemeronDictionary at:ifAbsent:
> frame 0xbf81980c a(n) OrderedCollection myEventTable
> frame 0xbf819834 a(n) OrderedCollection become:
> frame 0xbf819858 a(n) OrderedCollection changeCapacityTo:
> frame 0xbf81986c a(n) OrderedCollection increaseCapacity
> frame 0xbf819894 a(n) OrderedCollection makeRoomAtLast
> frame 0xbf8198ac a(n) OrderedCollection addLast:
> frame 0xbf8198c8 a(n) BlockClosure [] in EventQueue>>nextPut:
> frame 0xbf8198e4 a(n) BlockClosure ensure:
> frame 0xbf8198fc a(n) Semaphore critical:
> frame 0xbf819918 a(n) BlockClosure [] in EventQueue>>nextPut:
> frame 0xbf819934 a(n) BlockClosure ensure:
> frame 0xbf81994c a(n) Semaphore critical:
> frame 0xbf819964 a(n) Process uninterruptablyDo:
> frame 0xbf819978 a(n) BlockClosure valueUninterruptably
> frame 0xbf819990 a(n) EventQueue nextPut:
> frame 0xbf8199a8 a(n) WindowManager addEvent:
> frame 0xbf8199c0 a(n) ApplicationWindow addEvent:
> frame 0xbf8199d8 a(n) EventSensor addMetaInput:
> frame 0xbf819a00 a(n) EventSensor eventResize:
> frame 0xbf819a1c a(n) InputState send:eventResize:
> frame 0xbf819a40 a(n) InputState process:
> frame 0xbf819a58 a(n) InputState 0x0 no selector
> context 0xb7a94a30 [] in InputState class>>install
> context 0xb7a910f4 BlockClosure>>on:do:
> context 0x090ff0bc [] in Process class>>forBlock:priority:
>
> process 0x91011f8
>
> context 0xb7a8fec4 Semaphore>>wait
> context 0x09106250 WeakArray class>>outerFinalizationLoop
> context 0x09106268 [] in WeakArray class>>installFinalizationMechanism
> context 0x09106f34 BlockClosure>>on:do:
> context 0x09107594 [] in Process class>>forBlock:priority:
>
> process 0x9106688
>
> frame 0xbf8159a0 a(n) Semaphore waitIfCurtailedSignal
> frame 0xbf8159b8 a(n) Semaphore critical:
> frame 0xbf8159d4 a(n) RecursionLock critical:
> frame 0xbf8159f8 a(n) EphemeronDictionary at:ifAbsent:
> frame 0xbf815a0c a(n) OrderedCollection myEventTable
> frame 0xbf815a34 a(n) OrderedCollection become:
> frame 0xbf815a58 a(n) OrderedCollection changeCapacityTo:
> frame 0xbf81d374 a(n) OrderedCollection increaseCapacity
> frame 0xbf81d39c a(n) OrderedCollection makeRoomAtLast
> frame 0xbf81d3b4 a(n) OrderedCollection addLast:
> frame 0xbf81d3cc a(n) OrderedCollection add:
> frame 0xbf81d3f4 a Class (UnixFilename) components:
> frame 0xbf81d420 a Class (UnixFilename) canonicalize:
> frame 0xbf81d43c a Class (UnixFilename) createInstanceNamed:
> frame 0xbf81d454 a Class (Filename) named:
> frame 0xbf81d468 a(n) ByteString asFilename
> frame 0xbf81d47c a(n) PortableFilename asFilename
> frame 0xbf81d490 a(n) FileConnection name
> frame 0xbf81d4a4 a(n) ExternalReadStream name
> frame 0xbf81d4b8 a(n) EncodedStream name
> frame 0xbf81d4d8 a(n) XMLParser wrapDataSource:
> frame 0xbf81d4f0 a(n) XMLParser on:
> frame 0xbf81d508 a(n) XMLParser parseElement:
> frame 0xbf81d538 a(n) BlockClosure [] in
> XMLSourceFileFormat>>methodSourceAt:in:
> frame 0xbf81d554 a(n) BlockClosure on:do:
> frame 0xbf81d574 a(n) XMLSourceFileFormat methodSourceAt:in:
> frame 0xbf81d5a4 a(n) BlockClosure [] in
> SourceFileManager>>retrieveMethodSourceAt:using:ifAbsent:
> frame 0xbf81d5c0 a(n) BlockClosure on:do:
> frame 0xbf81d5e4 a(n) SourceFileManager
> retrieveMethodSourceAt:using:ifAbsent:
> frame 0xbf81d608 a(n) SourceFileManager methodSourceAt:ifAbsent:
> frame 0xbf81d61c a(n) CompiledMethod methodSources
> frame 0xbf81d634 a(n) CompiledMethod getSource
> frame 0xbf81d648 a(n) CompiledBlock getSource
> frame 0xbf81d668 a(n) CompiledBlock getSourceForUserIfNone:
> frame 0xbf81d680 a(n) BlockClosure [] in BlockClosure>>unboundMethod
> frame 0xbf81d69c a(n) BlockClosure on:do:
> frame 0xbf81d6b0 <Hybrid Block Context> sourceCode
> frame 0xbf81d6d0 <Hybrid Block Context> selector
> frame 0xbf81d6ec a(n) DebuggerService context:
> frame 0xbf81d704 a(n) DebuggerService selectContext:
> frame 0xbf81d71c a(n) DebuggerService selectContextAt:
> frame 0xbf81d734 a(n) DebuggerService onHandle:
> frame 0xbf81d750 a(n) DebuggerService process:context:interrupted:
> frame 0xbf81d778 a Class (DebuggerService)
> context:proceedable:interrupted:
> frame 0xbf81d7a0 a Class (DebuggerService) openOn:exception:interrupted:
> frame 0xbf81d7c0 a Class (DebuggerService) openOnException:
> frame 0xbf81d7d8 a Class (DebuggerService) openException:
> frame 0xbf81d7f0 a Class (Notifier) openException:
> frame 0xbf81d808 a(n) UnhandledException defaultAction
> frame 0xbf81d828 a(n) UnhandledException performHandler:
> frame 0xbf81d844 a(n) UnhandledException propagatePrivateFrom:
> frame 0xbf81d85c a(n) UnhandledException propagateFrom:
> frame 0xbf81d870 a(n) UnhandledException propagate
> frame 0xbf81d884 a(n) UnhandledException raiseSignal
> frame 0xbf81d898 a(n) UserInterrupt noHandler
> frame 0xbf81d8ac a(n) UserInterrupt defaultAction
> frame 0xbf81d8cc a(n) UserInterrupt performHandler:
> frame 0xbf81d8e8 a(n) UserInterrupt propagatePrivateFrom:
> frame 0xbf81d900 a(n) UserInterrupt propagateFrom:
> frame 0xbf81d914 a(n) UserInterrupt propagate
> frame 0xbf81d928 a(n) UserInterrupt raiseSignal
> frame 0xbf81d944 a Class (UserInterrupt) interruptWith:errorString:
> frame 0xbf81d958 a(n) BlockClosure [] in DebuggerService
> class>>interruptActiveUserProcess
> frame 0xbf81d978 a(n) BlockClosure [] in Process>>interruptWith:
> frame 0xbf81d98c a(n) BlockClosure [] in RecursionLock>>critical:
> frame 0xbf81d9a8 a(n) BlockClosure ensure:
> frame 0xbf81d9c0 a(n) Semaphore critical:
> frame 0xbf81d9dc a(n) RecursionLock critical:
> frame 0xbf81da00 a(n) EphemeronDictionary at:ifAbsent:
> frame 0xbf81da14 a(n) Object myEventTable
> frame 0xbf81da2c a(n) Object actionForEvent:
> frame 0xbf81da44 a(n) Object triggerEvent:
> frame 0xbf81da58 <nil> 0x0 no selector
> context 0xb7a93eb4 UndefinedObject(Object)>>performMethod:arguments:
> context 0xb7a93ea8 UndefinedObject(Object)>>performMethod:
> context 0xb7a93e9c
> TextEditorController(ParagraphEditor)>>evaluateCompiled:
> context 0xb7a93e84 [] in ParagraphEditor>>evaluateSelection
> context 0xb7a93e6c BlockClosure>>ensure:
> context 0xb7a93e60 Cursor>>showWhile:
> context 0xb7a93e54
> TextEditorController(ParagraphEditor)>>evaluateSelection
> context 0xb7a93e48 [] in ParagraphEditor>>doIt
> context 0xb7a94880 BlockClosure>>on:do:
> context 0xb7a93e3c TextEditorController(ParagraphEditor)>>doIt
> context 0xb7a93e30 TextEditorController>>dispatchMenuSymbol:
> context 0xb7a93e24 TextEditorController>>dispatchMenuSelection:
> context 0xb7a93e18
> TextEditorController(ControllerWithMenu)>>processMenu:at:centered:
> context 0xb7a93e0c
> TextEditorController(ControllerWithMenu)>>processMenuAt:centered:
> context 0xb7a93e00
> TextEditorController(ControllerWithMenu)>>yellowButtonPressedEvent:
> context 0xb7a93df4
> TextEditorController(ParagraphEditor)>>yellowButtonPressedEvent:
> context 0xb7a93de8 TextEditorController>>yellowButtonPressedEvent:
> context 0xb7a93ddc YellowButtonPressedEvent>>dispatchTo:
> context 0xb7a93dd0 TextEditorController(ControllerWithMenu)>>handleEvent:
> context 0xb7a93dc4 EventDispatcher>>dispatch:to:
> context 0xb7a93db8 EventDispatcher>>dispatchEvent:
> context 0xb7a93dac YellowButtonPressedEvent(Event)>>dispatch
> context 0xb7a93da0
> YellowButtonPressedEvent(Event)>>dispatchForWindowManager:
> context 0xb7a93d94 [] in WindowManager>>safelyDispatchForWindowManager:
> context 0xb7a94874 BlockClosure>>on:do:
> context 0xb7a93d88 WindowManager>>safelyDispatchForWindowManager:
> context 0xb7a93d7c WindowManager>>processNextEvent
> context 0xb7a94a54 [] in WindowManager>>newProcess
> context 0xb7a94a48 BlockClosure>>on:do:
> context 0xb7a909a4 [] in WindowManager>>newProcess
> context 0xb7a8f3b4 BlockClosure>>on:do:
> context 0xb7a8f3a8 [] in Process class>>forBlock:priority:
>
> process 0xb7905550
>
> frame 0xbf81ea3c a(n) Semaphore wait
> frame 0xbf81ea58 a(n) BlockClosure [] in ObjectMemory
> class>>installScavengeNotification
> context 0xb7a94a00 BlockClosure>>on:do:
> context 0xb7908580 [] in Process class>>forBlock:priority:
>
> process 0xb790555c
>
> frame 0xbf818a44 a(n) Semaphore wait
> frame 0xbf818a58 a Class (ObjectMemory) 0x0 no selector
> context 0xb7a94a18 [] in ObjectMemory class>>installIdleLoopProcess
> context 0xb7a94754 BlockClosure>>on:do:
> context 0xb7908598 [] in Process class>>forBlock:priority:
>
> process 0xb79085c8
>
> frame 0xbf81ba44 a(n) Semaphore wait
> frame 0xbf81ba58 a Class (ObjectMemory) 0x0 no selector
> context 0x090ff578 [] in ObjectMemory class>>installLowSpaceProcess
> context 0x090ff590 BlockClosure>>on:do:
> context 0xb79085d4 [] in Process class>>forBlock:priority:
>
> process 0xb79085ec
>
> context 0x090ff194 Semaphore>>wait
> context 0x09101234 [] in ExternalProcess class>>startReaper
> context 0x091013b4 BlockClosure>>on:do:
> context 0xb79085f8 [] in Process class>>forBlock:priority:
>
> process 0xb7a8cb34
>
> frame 0xbf81c9a4 a(n) Semaphore wait
> frame 0xbf81c9c0 a(n) EventQueue next
> frame 0xbf81c9d8 a(n) WindowManager processNextEvent
> frame 0xbf81c9f0 a(n) BlockClosure [] in WindowManager>>newProcess
> frame 0xbf81ca0c a(n) BlockClosure on:do:
> frame 0xbf81ca24 a(n) BlockClosure [] in WindowManager>>newProcess
> frame 0xbf81ca40 a(n) BlockClosure on:do:
> frame 0xbf81ca58 a(n) BlockClosure [] in Process class>>forBlock:priority:
>
> process 0xb7a8e4c0
>
> frame 0xbf817668 a(n) Semaphore waitIfCurtailedSignal
> frame 0xbf817680 a(n) Semaphore critical:
> frame 0xbf81769c a(n) RecursionLock critical:
> frame 0xbf8176c0 a(n) EphemeronDictionary at:ifAbsent:
> frame 0xbf8176d4 a(n) OrderedCollection myEventTable
> frame 0xbf8176fc a(n) OrderedCollection become:
> frame 0xbf817720 a(n) OrderedCollection changeCapacityTo:
> frame 0xbf817734 a(n) OrderedCollection increaseCapacity
> frame 0xbf81775c a(n) OrderedCollection makeRoomAtLast
> frame 0xbf817774 a(n) OrderedCollection addLast:
> frame 0xbf81778c a(n) OrderedCollection add:
> frame 0xbf8177c8 a(n) TabControlBarView displayOn:
> frame 0xbf8177e0 a(n) BoundedWrapper displayOn:
> frame 0xbf817808 a(n) TabControlComposite displayOn:
> frame 0xbf817820 a(n) BoundedWrapper displayOn:
> frame 0xbf817838 a(n) SpecWrapper displayOn:
> frame 0xbf817854 a(n) SpecWrapper displayOn:
> frame 0xbf81787c a(n) CompositePart displayOn:
> frame 0xbf817894 a(n) BoundedWrapper displayOn:
> frame 0xbf8178bc a(n) ReComposingComposite displayOn:
> frame 0xbf8178f0 a(n) WindowDisplayPolicy displayDamageList:in:
> frame 0xbf817908 a(n) ApplicationWindow displayDamageEvent:
> frame 0xbf817920 a(n) ApplicationWindow checkForEvents
> frame 0xbf81793c a(n) BlockClosure [] in
> WindowManager>>repairDamagesExcept:
> frame 0xbf81795c a(n) OrderedCollection do:
> frame 0xbf817978 a(n) BlockClosure [] in
> WindowManager>>repairDamagesExcept:
> frame 0xbf817994 a(n) BlockClosure on:do:
> frame 0xbf8179ac a(n) WindowManager repairDamagesExcept:
> frame 0xbf8179c0 a(n) WindowManager repairDamages
> frame 0xbf8179d8 a(n) WindowManager processNextEvent
> frame 0xbf8179f0 a(n) BlockClosure [] in WindowManager>>newProcess
> frame 0xbf817a0c a(n) BlockClosure on:do:
> frame 0xbf817a24 a(n) BlockClosure [] in WindowManager>>newProcess
> frame 0xbf817a40 a(n) BlockClosure on:do:
> frame 0xbf817a58 a(n) BlockClosure [] in Process class>>forBlock:priority:
>
> process 0x8dd8b5c
> suspendedContext is nil
>
> process 0x8e5de4c
> suspendedContext is nil
>
> process 0x8ee2cf8
>
> frame 0xbface084 a(n) Semaphore wait
> frame 0xbface098 a(n) BlockClosure [] in Delay
> class>>initializeTimingProcess
> context 0x08ef420c BlockClosure>>on:do:
> context 0x08ef37ec [] in Process class>>forBlock:priority:
>
> process 0x8f0ed44
>
> frame 0xbfad504c a(n) Semaphore wait
> frame 0xbfad5068 a(n) EventQueue next
> frame 0xbfad5080 a(n) WindowManager processNextEvent
> frame 0xbfad5098 a(n) BlockClosure [] in WindowManager>>newProcess
> context 0x08f1b02c BlockClosure>>on:do:
> context 0x08c8de84 [] in WindowManager>>newProcess
> context 0x08f1b044 BlockClosure>>on:do:
> context 0x08f1b05c [] in Process class>>forBlock:priority:
>
> process 0x8f36f50
> suspendedContext is nil
>
> process 0x8f38da4
> suspendedContext is nil
>
> process 0x8f46250
> suspendedContext is nil
>
> process 0x8fcca40
> suspendedContext is nil
>
> process 0x8fccbc0
> suspendedContext is nil
>
> process 0x8fcccc8
> suspendedContext is nil
>
> process 0x8fd14d4
>
> context 0x08fd625c Semaphore>>wait
> context 0x08fdf9a0 [] in CCallback class>>installForeignCallbackProcess
> context 0x08fdfcf4 BlockClosure>>on:do:
> context 0x08fd1ce4 [] in Process class>>forBlock:priority:
>
> process 0x8fd1504
> suspendedContext is nil
>
> process 0x8fd6688
> suspendedContext is nil
>
> process 0x8fdf508
> suspendedContext is nil
>
> process 0x916575c
>
> context 0x091715ac Semaphore>>wait
> context 0x081c2bf8 [] in CCallback class>>installCallbackProcess
> context 0x081c5f4c BlockClosure>>on:do:
> context 0x081c8028 [] in CCallback class>>installCallbackProcess
> context 0x081c93e8 BlockClosure>>on:do:
> context 0x081c9adc [] in CCallback class>>installCallbackProcess
> context 0x081d8efc BlockClosure>>on:do:
> context 0x09171540 [] in Process class>>forBlock:priority:
>
> process 0x91657b0
>
> context 0x0916620c Semaphore>>wait
> context 0x091992e4 [] in CCallback class>>installForeignCallbackProcess
> context 0xb79b6810 BlockClosure>>on:do:
> context 0x091715c4 [] in Process class>>forBlock:priority:
>
> process 0x916bed0 (activeProcess)
>
> frame 0xbfad0d6c a(n) RecursionLock critical:
> frame 0xbfad0d90 a(n) EphemeronDictionary at:ifAbsent:
> frame 0xbfad0da4 a(n) Object myEventTable
> frame 0xbfad0db8 <nil> 0x0 no selector
> frame 0xbfad0dd4 <nil> performMethod:arguments:
> frame 0xbfad0dec <nil> performMethod:
> frame 0xbfad0e08 a(n) TextEditorController evaluateCompiled:
> frame 0xbfad0e24 a(n) BlockClosure [] in
> ParagraphEditor>>evaluateSelection
> frame 0xbfad0e40 a(n) BlockClosure ensure:
> frame 0xbfad0e5c a(n) Cursor showWhile:
> frame 0xbfad0e78 a(n) TextEditorController evaluateSelection
> frame 0xbfad0e90 a(n) BlockClosure [] in ParagraphEditor>>doIt
> frame 0xbfad0eac a(n) BlockClosure on:do:
> frame 0xbfad0ec0 a(n) TextEditorController doIt
> frame 0xbfad0ed8 a(n) TextEditorController dispatchMenuSymbol:
> frame 0xbfad0ef0 a(n) TextEditorController dispatchMenuSelection:
> frame 0xbfad0f10 a(n) TextEditorController processMenu:at:centered:
> frame 0xbfad0f34 a(n) TextEditorController processMenuAt:centered:
> frame 0xbfad0f4c a(n) TextEditorController yellowButtonPressedEvent:
> frame 0xbfad0f64 a(n) TextEditorController yellowButtonPressedEvent:
> frame 0xbfad0f7c a(n) TextEditorController yellowButtonPressedEvent:
> frame 0xbfad0f94 a(n) YellowButtonPressedEvent dispatchTo:
> frame 0xbfad0fac a(n) TextEditorController handleEvent:
> frame 0xbfad0fcc a(n) EventDispatcher dispatch:to:
> frame 0xbfad0fec a(n) EventDispatcher dispatchEvent:
> frame 0xbfad1000 a(n) YellowButtonPressedEvent dispatch
> frame 0xbfad1018 a(n) YellowButtonPressedEvent dispatchForWindowManager:
> frame 0xbfad1034 a(n) BlockClosure [] in
> WindowManager>>safelyDispatchForWindowManager:
> frame 0xbfad1050 a(n) BlockClosure on:do:
> frame 0xbfad1068 a(n) WindowManager safelyDispatchForWindowManager:
> frame 0xbfad1080 a(n) WindowManager processNextEvent
> frame 0xbfad1098 a(n) BlockClosure [] in WindowManager>>newProcess
> context 0xb79b28ec BlockClosure>>on:do:
> context 0xb79b2910 [] in WindowManager>>newProcess
> context 0xb79b2934 BlockClosure>>on:do:
> context 0xb79b2958 [] in Process class>>forBlock:priority:
>
> process 0xb79b29d0
>
> frame 0xbfad2084 a(n) Semaphore wait
> frame 0xbfad2098 a Class (ObjectMemory) 0x0 no selector
> context 0xb7b4aae4 [] in ObjectMemory class>>installIdleLoopProcess
> context 0xb7b4a9ac BlockClosure>>on:do:
> context 0xb79b67ec [] in Process class>>forBlock:priority:
>
> process 0xb79b2b98
>
> frame 0xbfad407c a(n) Semaphore wait
> frame 0xbfad4098 a(n) BlockClosure [] in ObjectMemory
> class>>installScavengeNotification
> context 0xb79bb6a0 BlockClosure>>on:do:
> context 0xb79b67bc [] in Process class>>forBlock:priority:
>
> process 0xb79b2ba4
>
> context 0x091714e0 Semaphore>>wait
> context 0x081c221c [] in ExternalProcess class>>startReaper
> context 0x081c535c BlockClosure>>on:do:
> context 0xb79b67a4 [] in Process class>>forBlock:priority:
>
> process 0xb79b6750
>
> frame 0xbfad3084 a(n) Semaphore wait
> frame 0xbfad3098 a Class (ObjectMemory) 0x0 no selector
> context 0xb79e5a24 [] in ObjectMemory class>>installLowSpaceProcess
> context 0x09165a8c BlockClosure>>on:do:
> context 0xb79b675c [] in Process class>>forBlock:priority:
>
> process 0xb79e47d0
>
> frame 0xbfacd080 a(n) Semaphore wait
> frame 0xbfacd098 a(n) InputState 0x0 no selector
> context 0xb7b4ab08 [] in InputState class>>install
> context 0xb7b4a928 BlockClosure>>on:do:
> context 0xb79e4794 [] in Process class>>forBlock:priority: