On Wed, 14 Dec 2011, Bert Freudenberg wrote:

> On 14.12.2011, at 18:03, Bert Freudenberg wrote:
>
>> On 14.12.2011, at 17:55, Bert Freudenberg wrote:
>>
>>> On 14.12.2011, at 09:07, Andreas Raab wrote:
>>>
>>>> On 12/13/2011 23:30, Eliot Miranda wrote:
>>>>>
>>>>>
>>>>>
>>>>> On Tue, Dec 13, 2011 at 1:36 PM, Lawson English <lenglish5 at cox.net> wrote:
>>>>> That sounds really great.
>>>>>
>>>>> However, there are some broken bits in Squeak that will make learning Smalltalk difficult.
>>>>>
>>>>> Most simple and important example I have right now is the well-known issue that the VM will freeze indefinitely if you input a long running calculation, e.g. x := 100000 factorial. The interrupt key doesn't work, usually.  Newbies like me, like to experiment, and if the VM freezes with every typo, then its hardly worth using.
>>>>>
>>>>> This is interesting because it does *not* freeze in my Qwaq-derived work image.  Here the interrupt key works perfectly with no delay.  I'll see if I can investigate.  Andreas, do you recall doing anything to the debugger to fix issues like this in the Qwaq system?
>>>>
>>>> Nothing I can recall. Also, when I try interrupting 100000 factorial in a 4.2 image with either a Teleplace or OpenQwaq VM I have no trouble interrupting anything. So it doesn't look like it's an issue in the image that is causing it. Wonder if there's anything changed in the support code perhaps...
>>>>
>>>> Cheers,
>>>>   - Andreas
>>>
>>>
>>> I think there may be an error when trying to bring up the user interrupt dialog.
>>>
>>> Pressing Cmd-. during "100000 factorial" does create a SqueakDebug.log file immediately, but does not show the debugger.
>>>
>>> - Bert -
>>
>>
>> Found something: reverting  #openInterrupt:onProcess: from the "mtf 2/5/2011" version to the older "sd 11/20/2005" version restores interruptability
>>
>> - Bert -
>
> ... as does ignoring the CurrentReadOnlySourceFiles exception in the logging code. Levente?

I'm lost. Where does CurrentReadOnlySourceFiles appear and what kind 
of problem does it cause?

Also, reverting #openInterrupt:onProcess: doesn't solve the issue. About 
every second time I interrupt the finalization process, so I won't see a 
debugger till 100000 factorial finishes. Pressing Alt+. one more time can 
interrupt the factorial calculation though.

I benchmarked the log creation and found that it takes anywhere between a 
second and a minute depending on the machine and the state of the 
calculation, so that's the real reason why the debugger doesn't appear 
instantly. I rewrote SmalltalkImage >> #logError:inContext:to: to fork the 
log creation, and the debugger appears instantly (if I'm lucky and the 
right process get interrupted), but I'm not sure if it's a good idea to 
log the context of another process.

logError: errMsg inContext: aContext to: aFilename
 	"Log the error message and a stack trace to the given file."

 	[ [
 		FileStream forceNewFileNamed: aFilename do: [ :file |
 			file
 				nextPutAll: errMsg; cr.
 				aContext errorReportOn: file ] ]
 		on: Error
 		do: [ :err | nil "Can't do much" ] ] forkAt: Processor systemBackgroundPriority

With this change I can easily interrupt [ true ] whileTrue and even [] 
repeat. :)


Levente

>
> - Bert -
>
>
>