[Bluej-discuss] Terminal Window .. safety belt needed...

[Todd O'Bryan]

Just to throw this into the mix...my district IT department doesn't  
give student accounts access to the Task Manager at all on Windows.  
You'd be amazed how often we have to restart as a result.

Todd

On Apr 4, 2006, at 10:38 AM, Michael Kölling wrote:

> Hi Gordon,
>
> That seems like a good idea.
>
> I just tried it to see how it behaves on my machine (MacOS X).
>
> I also could not stop the execution from within BlueJ. The problem
> is, I think, that the system spends all its time in the character
> output, which is handled by the screen painter thread, which is also
> needed to get the barber pole's menu up...
>
> I could, however, kill BlueJ through the equivalent of the Task
> Manager without problems.
>
> I agree that BlueJ has a problem there, but I would also argue that
> the fact that Win XP couldn't kill it is a clear Windows problem. No
> application (not even BlueJ) should have the ability to deadlock your
> OS.
>
> But that's another matter.
>
> Now, I could claim that the experience of hanging your computer is a
> valuable learning experience... ("See what you can do with bad
> programming?") .. but of course you are right: a "Do you really want
> to continue" - dialogue after a loooooong output would be a very nice
> thing.
>
> Michael
>
>
> On 4 Apr 2006, at 14:46, Gordon Royle wrote:
>
>> After this afternoon's student lab, I realize that there is one
>> feature I would like for the Terminal Window .. a safety feature...
>>
>> I am getting my students just to do some routine for-loop tasks such
>> as printing out to the terminal window something like
>>
>> 10 9 8 7 6 5 4 3 2 1
>>
>> so they can get used to writing i-- instead of i++ and so on.
>>
>> But of course, they try things like
>>
>> for (int i=10; i>0; i++) {
>>    System.out.print(i);
>> }
>>
>> which in this case (or rather these cases!) led to major system
>> meltdown..
>>
>>
>> Not only could I not stop the system with the BlueJ features
>> (Terminate Thread or Reset VM) because there was simply no response
>> from clicking on the barber's pole, but I couldn't even stop it with
>> Task Manager (these particular students had chosen to use Win XP) and
>> indeed could not even do Shut Down so ended up having to power-cycle
>> the computer. One guy ended up doing it four times, though to be fair
>> he is not the sharpest tool in the shed...
>>
>>
>> So, maybe the Terminal Window could come with an optional limit on
>> the amount of output from a single method call.... if this limit (say
>> 10K characters or something like that) is exceeded then it could
>> either just stop trying to display it, or even fancier, pop up a
>> dialog and ask the user if they wish to continue or to terminate the
>> thread...
>>
>>
>> Cheers
>>
>> Gordon
>> _______________________________________________
>> mailing list bluej-discuss at bluej.org
>> To unsubscribe or change your preferences, go to
>> http://lists.bluej.org/mailman/listinfo/bluej-discuss
>
> _______________________________________________
> mailing list bluej-discuss at bluej.org
> To unsubscribe or change your preferences, go to
> http://lists.bluej.org/mailman/listinfo/bluej-discuss