Yes, synchronizing in this way could potentially be bad. On Sat, Sep 18, 2010 at 8:36 AM, Norbert Hirneisen <no...@s2you.de> wrote:
> Just another question regarding this context: > > the original code has been written by a colleague. > Now I´m intrigued if setting the execute-Method in the base class within a > synchronized block makes sense ?! > As far as I´m understanding the action classes behave like servlets and > multiple > request can be served parallel by using multi-threading. > So synchronzing the execute-Methode would slow down the performance > significantly ??! Is my understanding correct ? > > Thanks, > Norbert > > > > -----Ursprüngliche Nachricht----- > Von: Dave Newton [mailto:davelnew...@gmail.com] > Gesendet: Samstag, 18. September 2010 14:07 > An: Struts Users Mailing List; no...@s2you.de > Betreff: Re: AW: Struts 1 and thread safety > > > No, I meant actual ThreadLocals, but what you're saying would work too. > > The best way to go about doing it depends on what's being done in the > subclasses. > > Dave > > > On Sat, Sep 18, 2010 at 7:53 AM, Norbert Hirneisen <no...@s2you.de> wrote: > > > Thanks, Dave. > > Using the data local means to call > > long projectId = Project.getIdFromRequest(request); > > in every subclass because there is no thread-safe way to use a class field > in > the super-class ? > > Would it be thread-safe to use a local variable in the super-class and > store the > data in the session ? > Is that what you mean with "passing the data around" ? > > Thanks in advance, > Norbert > > > > -----Ursprüngliche Nachricht----- > Von: Dave Newton [mailto:davelnew...@gmail.com] > Gesendet: Samstag, 18. September 2010 13:47 > An: no...@s2you.de; Struts Users Mailing List > Betreff: Re: AW: Struts 1 and thread safety > > > > > No, it's not thread safe. Actions should be treated like servlets in this > regard, and designed better. > > Consider either passing the required data around, or using thread locals. > > Dave > > On Sep 18, 2010 6:42 AM, "Norbert Hirneisen" <no...@s2you.de> wrote: > > Nobody here who can help ? > > > >> -----Ursprüngliche Nachricht----- > >> Von: Norbert Hirneisen [mailto:no...@s2you.de] > >> Gesendet: Freitag, 17. September 2010 11:01 > >> An: user@struts.apache.org > >> Betreff: Struts 1 and thread safety > >> > >> > >> Hello, > >> > >> I have al large Struts 1 application with a modified > >> DispatchAction class. Most > >> action classes are derivatives from this class. > >> In the webapp I have several projects defined. The project > >> can be determined by > >> analysing the URL. > >> This is done in the central DispatchAction-class by using > >> class fields declared > >> as volatile. The execute-Method is declared as synchronized. > >> After reading a lot about thread safety now I´m not sure if > >> this approach is > >> thread safe on a request level. > >> Abbreviated example: > >> > >> public abstract class DispatchAction extends Action { > >> .... > >> protected volatile long projectId = -1; > >> .... > >> > >> @Override > >> synchronized public ActionForward execute( > >> ActionMapping mapping, > >> ActionForm form, > >> HttpServletRequest request, > >> HttpServletResponse response) > >> throws Exception { > >> ... > >> long projectId = Project.getIdFromRequest(request); > >> ... > >> return forward; > >> } > >> > >> When I access projectId from a derived class is this thread > >> safe or have I to > >> implement in the doExecute-Method of each derived action > >> class ? This would be > >> thread safe but comes with a lot of redundant code. > >> > >> Any help would be helpful. > >> > >> Best regards, > >> Norbert > >> > >> > >> > >> Norbert Hirneisen > >> > >> science4you Online-Monitoring > >> http://www.science4you.org > >> email: no...@s2you.de > >> > >> Die Falternacht: www.falternacht.de > >> Werden Sie Falterzähler: www.falterfunde.de > >> Wanderfalter: www.science4you.org/platform/monitoring/index.do > >> Tagfalter-Monitoring Deutschland: > >> www.science4you.org/platform/tmd/tmd-top/index.do > >> Infos über geschützte Arten ? http://www.wisia.de > >> > >> Norbert Hirneisen > >> Science & Communications > >> > >> von-Müllenark-Str. 19 > >> 53179 Bonn > >> Tel. 0228/6194930 > >> Ust.ID-Nr. DE237150377 > >> > >> Der Inhalt dieser Mitteilung ist nur für obigen Adressaten > >> bestimmt und streng > >> vertraulich. Eine Weitergabe oder Vervielfältigung durch > >> andere als den > >> Adressaten ist verboten! 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