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Re: [Oorexx-devel] Shutting down a service
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From: Sahananda (J. W. <sah...@wi...> - 2011-04-22 09:16:38
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I just wanted to report back that I have solved this now and thank everyone for their help. What I kept running into, which floored me was that with rexx\sql you have to run the loadfuncs function, when you start on a new thread, even though rxFuncQuery reports the functions as already loaded. Once I got that into my head, I could load/unload the functions on each invocation of the server and the server could shut itself down (after a suitable quiescent interval - thanks for that hint Rony - saves a great deal of thrashing) Jon On 2 April 2011 19:55, Sahananda (Jon) Wolfers <sah...@wi...>wrote: > Hi Bill, > > this is the conclusion I had come to when I read Mark last. I won't start > the server in the init class method, but anything that uses it will have to > start it and then stop it when they have finished. Starting when already > started will just add to the usage count. Stopping decreases it and when it > is 0 it really stops. It will mean changing my existing code a bit (which I > had hoped to avoid), but it seems the sensible way to go. > > thanks, > > Jon > > PS: thanks Rony - that gave me something to think about. > > > > > On 2 April 2011 19:13, Bill Turner, WB4ALM <wb...@ar...> wrote: > >> Jon, Can you also implement a global "usage count"? When the count is >> zero, the service can shutdown. >> >> That way both A and B increment the count by one when they start, and >> reduce it by one when they terminate when they quit. >> >> if somebody else starts then count goes up one more. Eventually everybody >> will quit and the count becomes zero. >> when it is zero the server shuts its self down. >> >> Using your example, the count could get to four >> >> a script called C calls A (count +1) which calls B (count +1) [count is >> now 2] >> another script D calls B (count +1) then calls A (count +1) [count is >> now 4] >> >> As CAB processes and each called routine terminates, the count becomes >> three and two... >> As DBA processes and each called routine terminates, the count becomes one >> and zero... >> >> This also allows for intertwining... and when the count is zero, the >> server could either decide to terminate >> or go into a "sleep" before terminating. Maybe a count of "-1" means that >> we are getting ready to shutdown, >> so that other routines know to wait before trying to start the server back >> up... >> >> /s/ Bill Turner, wb4alm >> >> >> >> >> >> On 04/02/2011 11:28 AM, Sahananda (Jon) Wolfers wrote: >> >> Hi Mark & Gil, >> >> thank you both for your help, but I think what it points to is I have not >> explained myself. >> >> Both of those aproaches predicate a single client using the server. Let's >> say I have two routines called A & B that both use the server and have >> reqires directives in their scripts. >> >> a script called C calls A which calls B >> another script D calls B then calls A >> >> Whichever way around they are run, the first one 'require'ed will start up >> the server. >> If one of them shuts it down when it terminates, then it is not available >> to the other. >> >> My problem is not shutting it down, but rather knowing when it is >> apropriate to shut it down. >> >> I'm sorry that I'm still worrying away at this on the lists after a year >> >> Jon >> >> On 2 April 2011 16:06, Mark Miesfeld <mie...@gm...> wrote: >> >>> On Sat, Apr 2, 2011 at 7:03 AM, Sahananda (Jon) Wolfers < >>> sah...@wi...> wrote: >>> >>>> I have a question, and I hope it is ok to ask it here. >>>> >>>> It has been brought up by my struggle to move my work to 4.0, but if >>>> solved for me could benefit many people. >>>> >>>> >>>> >>>> My specific problem is about managing to use rexx/sql with ooRexx 4.0 in >>>> a multithreaded environment, but it might b better if I ask the list a more >>>> general question. >>>> >>>> >>>> >>>> That is, where one has to provide one’s applications with a service that >>>> continuously runs, what is the best way to set it up, use it and tear it >>>> down. This question has become more important in 4.0, because there >>>> used to be a loophole in ooDialog that allowed one to run methods on the >>>> ‘main’ thread of a dialog. Now that has gone, it needs to be done >>>> properly. >>>> >>>> >>>> >>>> So for me, because rexx\sql needs to run on the thread that the library >>>> was loaded on, I have built a little server, I queue message objects on the >>>> server, and it performs them on the correct thread. That all works >>>> very well. My problem pertains to how to set it up when it is first >>>> needed, and tear it down when it is finished with. >>>> >>> >>> Well, as always questions like this are hard to answer without knowing >>> what your code is doing. >>> >>> But, one approach comes directly from what you say above. If you are >>> queueing messages to the server, just define a special message that means >>> "shut down". Then when your application is terminating, send it that >>> message. >>> >>> I doubt that there is any one "right" way to do this. >>> >>> Another approach is to have some variable that the server checks each >>> time it enters its processing loop. If the variable is true, it drops out >>> of the loop and the thread terminates. Then when the application is >>> terminating you set the varible and manually force the server to check if it >>> needs to process something. >>> >>> Again, I'd suggest looking at the sysinfo.rex example in trunk. It >>> solves a problem that seems to be similar to yours, every use of OLE has to >>> be done on the same thread. >>> >>> main\samples\windows\oodialog\sysinfo >>> >>> -- >>> Mark Miesfeld >>> >>> >>> >>> ------------------------------------------------------------------------------ >>> Create and publish websites with WebMatrix >>> Use the most popular FREE web apps or write code yourself; >>> WebMatrix provides all the features you need to develop and >>> publish your website. http://p.sf.net/sfu/ms-webmatrix-sf >>> >>> _______________________________________________ >>> Oorexx-devel mailing list >>> Oor...@li... >>> https://lists.sourceforge.net/lists/listinfo/oorexx-devel >>> >>> >> >> ------------------------------------------------------------------------------ >> Create and publish websites with WebMatrix >> Use the most popular FREE web apps or write code yourself; >> WebMatrix provides all the features you need to develop and >> publish your website. http://p.sf.net/sfu/ms-webmatrix-sf >> >> >> _______________________________________________ >> Oorexx-devel mailing lis...@li...https://lists.sourceforge.net/lists/listinfo/oorexx-devel >> >> >> >> >> ------------------------------------------------------------------------------ >> Create and publish websites with WebMatrix >> Use the most popular FREE web apps or write code yourself; >> WebMatrix provides all the features you need to develop and >> publish your website. http://p.sf.net/sfu/ms-webmatrix-sf >> >> _______________________________________________ >> Oorexx-devel mailing list >> Oor...@li... >> https://lists.sourceforge.net/lists/listinfo/oorexx-devel >> >> > |