Am 23.06.2014 um 23:20 schrieb Nicolas Cellier <nicolas.cellier.aka.n...@gmail.com>:
> > > > 2014-06-23 22:50 GMT+02:00 Nicolas Cellier > <nicolas.cellier.aka.n...@gmail.com>: > > > > 2014-06-23 22:38 GMT+02:00 Norbert Hartl <norb...@hartl.name>: > > Hmmm, > > I'm trying to write a test for it and I wonder why > > testDynamicVariableAccessFromDifferentProcess > | process sem1 result | > > sem1 := Semaphore new. > process := [ > TestDynamicVariable > value: 123 > during: [ sem1 wait ] ] fork. > > Processor activeProcess > evaluate: [ result := TestDynamicVariable value ] > onBehalfOf: process. > sem1 signal. > self assert: result = 123 > > does not work. The variable accessing is in > > DynamicVariable>>#value: anObject during: aBlock > | p oldValue | > p := Processor activeProcess. > oldValue := (p psValueAt: index) ifNil: [ self default ]. > ^ [ > p psValueAt: index put: anObject. > aBlock value ] ensure: [ p psValueAt: index put: oldValue ] > > Any ideas? > > But what happens when you immediately fork, are you sure the forked process > immediately pre-empts the activeProcess? > What if you introduce Processor activeProcess yield after the fork? > > > Ah, I just tried, it's Processor yield. > > [Transcript cr; show: 'A' ] fork. > Processor yield. > Transcript cr; show: 'B' . > > produces the required transcripting order. > Without yielding, B comes before A. > I knew it was something simple I forgot. Thank you very much, Norbert > > > Norbert > > Am 23.06.2014 um 21:29 schrieb Eliot Miranda <eliot.mira...@gmail.com>: > >> >> >> >> On Mon, Jun 23, 2014 at 12:05 PM, Norbert Hartl <norb...@hartl.name> 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 <eliot.mira...@gmail.com>: >> >>> and here are the changes I've just committed to Squeak trunk. >>> >>> >>> On Mon, Jun 23, 2014 at 10:05 AM, Eliot Miranda<eliot.mira...@gmail.com> >>> 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 <norb...@hartl.name>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 > > >
