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
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