Ok, thanks. That helps! I think for NetRexx, I am going the Streams route, as spun of threads are just jvm threads, as are the ‘address’ed shells - well processes, but to NetRexx they still run on a jvm thread.
Best regards, René. > On 21 Jan 2022, at 16:59, Rick McGuire <object.r...@gmail.com> wrote: > > > > >> On Fri, Jan 21, 2022 at 10:26 AM rvjan...@xs4all.nl <rvjan...@xs4all.nl> >> wrote: >> We used to call these Control Blocks, as in the interface to the OS. In Rexx >> we can address environments. One of these is the OS shell, these have data >> to exchange information with the addressed environments, like for example >> how they can update the Rexx variable pool. I just wondered if these all are >> instance variables, or whether there is some other method needed to >> synchronise acces, for example to make sure they are not garbage collected >> prematurely, but are when the thread using them has ended. > > Still not sure what you are looking for. If the external environment is the > system one, the command gets spun off as a separate process so interactions > like the variable pool are not possible. For other environments, the APIs > that allow those interactions have to first obtain the global interpreter > lock before accessing any internal data. ooRexx isn't fully multithreaded but > rather uses cooperative multithreading. While code runs on separate threads, > only one thread actually has access to the internals of the interpreter at > one time. The only thing close to "a variable that controls access" is the > kernel semaphore that controls access. > > Rick > >> >> René. >> >>>> On 21 Jan 2022, at 16:12, Rick McGuire <object.r...@gmail.com> wrote: >>>> >>> >>> >>> >>>> On Fri, Jan 21, 2022 at 9:44 AM rvjan...@xs4all.nl <rvjan...@xs4all.nl> >>>> wrote: >>>> Thank you Rick, >>>> >>>> What I meant with the last question is, are the blocks that control an >>>> ADDRESS environment also instance variables? >>> >>> And I still don't understand what you are asking for. What do you mean by >>> "blocks". I suspect you're assuming something that probably doesn't exist. >>> >>> Rick >>> >>>> >>>> René. >>>> >>>>>> On 21 Jan 2022, at 15:39, Rick McGuire <object.r...@gmail.com> wrote: >>>>>> >>>>> >>>>> All access to the standard handles are done via Stream object instances, >>>>> and all of the methods are guarded so the synchronization between threads >>>>> is automatic. I'm not sure what you are asking with the last question. >>>>> >>>>> Rick >>>>> >>>>> >>>>>> On Fri, Jan 21, 2022 at 9:31 AM rvjan...@xs4all.nl <rvjan...@xs4all.nl> >>>>>> wrote: >>>>>> Hi, >>>>>> >>>>>> Some questions: >>>>>> >>>>>> Can anybody point me to the relevant source code that shows how ooRexx >>>>>> ‘handles’ (no pun intended) multithreaded access to file handles; more >>>>>> specificly (and also) how the access to the standard shell handles is >>>>>> guarded (if at all) in the case multiple threads want to use stdin, >>>>>> stdout and stderr. I seem to remember that say can be rerouted: are the >>>>>> handles protected at that moment? >>>>>> >>>>>> In NetRexx these handles are static, so cause a bit of trouble when we >>>>>> re-route in a heavily multithreaded environment/application like >>>>>> Pipelines. >>>>>> The JSR223 interface suffers likewise, as it seems to require that every >>>>>> thread going through it can assign its own file handles. >>>>>> >>>>>> Also, what happens when we ‘address’ an external environment - do all >>>>>> threads assume their own I/O handles, or are they using the same set >>>>>> that is set centrally? >>>>>> >>>>>> Many thanks in advance. >>>>>> >>>>>> René. >>>>>> _______________________________________________ >>>>>> Oorexx-devel mailing list >>>>>> Oorexx-devel@lists.sourceforge.net >>>>>> https://lists.sourceforge.net/lists/listinfo/oorexx-devel >>>>> _______________________________________________ >>>>> Oorexx-devel mailing list >>>>> Oorexx-devel@lists.sourceforge.net >>>>> https://lists.sourceforge.net/lists/listinfo/oorexx-devel >>>> _______________________________________________ >>>> Oorexx-devel mailing list >>>> Oorexx-devel@lists.sourceforge.net >>>> https://lists.sourceforge.net/lists/listinfo/oorexx-devel >>> _______________________________________________ >>> Oorexx-devel mailing list >>> Oorexx-devel@lists.sourceforge.net >>> https://lists.sourceforge.net/lists/listinfo/oorexx-devel >> _______________________________________________ >> Oorexx-devel mailing list >> Oorexx-devel@lists.sourceforge.net >> https://lists.sourceforge.net/lists/listinfo/oorexx-devel > _______________________________________________ > Oorexx-devel mailing list > Oorexx-devel@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/oorexx-devel
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