On Mon, Jun 23, 2014 at 12:05 PM, Norbert Hartl <[email protected]> wrote:

> Hi Eliot,
>
> thank you very much. I imported your changes in a pharo 3 image and it
> works awesome. So I'm preparing a slice for pharo.
>
> Thanks again, a very annoying problem seems to be solved,
>

glad to hear it, and thanks for your prompting me as it's now in Squeak
trunk too.


>
> Norbert
>
> Am 23.06.2014 um 19:29 schrieb Eliot Miranda <[email protected]>:
>
> and here are the changes I've just committed to Squeak trunk.
>
>
> On Mon, Jun 23, 2014 at 10:05 AM, Eliot Miranda <[email protected]>
> wrote:
>
>> Hi Norbert,
>>
>>     [ let me try again.  never try and get code out too early in the
>> morning ;-) ]
>>
>>     it is the debugger that needs fixing, not your code !! :-).  The
>> debugger needs to respect process identity.  Andreas and I (mostly Andreas)
>> came up with the following changes at Qwaq.  Your message is a good
>> reminder that I need to add this to Squeak asap.
>>
>> The idea is for Process to have an additional inst var 'effectiveProcess'
>> that holds the actual process running code.  For the most part this is
>> self, but in the debugger we substitute the process being debugged:
>>
>> *Process methods for accessing*
>> *effectiveProcess*
>> "effectiveProcess is a mechanism to allow process-faithful debugging.
>>  The debugger executes code
>>  on behalf of processes, so unless some effort is made the identity of
>> Processor activeProcess is not
>>   correctly maintained when debugging code.  The debugger uses
>> evaluate:onBehalfOf: to assign the
>>  debugged process as the effectiveProcess of the process executing the
>> code, preserving process
>>   identity."
>> ^effectiveProcess ifNil: [self]
>>
>> then the relevant methods in Process and processorScheduler defer to
>> effectiveProcess, e.g.
>>
>> *ProcessorScheduler methods for process state change*
>> *terminateActive*
>> "Terminate the process that is currently running."
>>
>> activeProcess effectiveProcess terminate
>>
>> and the debugging methods use evaluate:onBehalfOf: to install the process
>> being debugged:
>>
>> *Process methods for private*
>> *evaluate: aBlock onBehalfOf: aProcess*
>> "Evaluate aBlock setting effectiveProcess to aProcess.  Used
>>  in the execution simulation machinery to ensure that
>>   Processor activeProcess evaluates correctly when debugging."
>> | oldEffectiveProcess |
>> oldEffectiveProcess := effectiveProcess.
>>  effectiveProcess := aProcess.
>> ^aBlock ensure: [effectiveProcess := oldEffectiveProcess]
>>
>> *Process methods for changing suspended state*
>> *step*
>>
>> ^Processor activeProcess
>>  evaluate: [suspendedContext := suspendedContext step]
>> onBehalfOf: self
>>
>> *stepToCallee*
>>  "Step until top context changes"
>>
>> Processor activeProcess
>> evaluate:
>>  [| ctxt |
>> ctxt := suspendedContext.
>> [ctxt == suspendedContext] whileTrue: [
>>  suspendedContext := suspendedContext step]]
>> onBehalfOf: self.
>> ^suspendedContext
>>
>> etc.  Changes from a Qwaq image attached.
>>
>> HTH
>>
>>
>> On Mon, Jun 23, 2014 at 4:50 AM, Norbert Hartl <[email protected]>
>> wrote:
>>
>>> In my code I'm using a DynamicVariable to request a context object when
>>> needed. Until now I knew the name DynamicVariable only from seaside. There
>>> it is called WADynamicVariable and it is an exception. So I blindly assumed
>>> the pharo DynamicVariable works the same.
>>> I thought this might be a good optimization not to travel the stack all
>>> the time but put in the process.
>>> Now that I am using it I can see the difference. I find it real hard
>>> using it because I don't know how to debug/step in code. DynamicVariable is
>>> a process specific variable but as soon as a debugger opens it is very
>>> likely to be in another process. This makes stepping in method using the
>>> DynamicVariable impossible. The only way round is to set break points after
>>> the dynamic lookup and step from there. But this feels just wrong.
>>> What would be the best way to have DynamicVariable and be able to debug
>>> anything? Or is there a variant that uses the stack instead of the "active"
>>> process?
>>>
>>> thanks,
>>>
>>> Norbert
>>>
>>>
>>>
>>
>>
>> --
>> best,
>> Eliot
>>
>
>
>
> --
> best,
> Eliot
>  <trunk4.6EffectiveProcessMethods.st>
>
>
>


-- 
best,
Eliot

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