concurrency problem 2005-04-11 - By Kalra, Ashwani
Back
hi,
Thanks for this info. I have also found the problem. There was another call
going for different method at the same time which was not synchronised.
Regds
Ashwani
> -- --Original Message-- --
> From: An interest list for Sun Java Center J2EE Pattern Catalog
> [mailto:J2EEPATTERNS-INTEREST@(protected)]On Behalf Of Glenn Phillips
> Sent: Saturday, April 09, 2005 12:14 AM
> To: J2EEPATTERNS-INTEREST@(protected)
> Subject: Re: concurrency problem
>
>
> For what it is worth, try using request.getSession(false)
> instead. You may
> have been running into a situation where you were not
> synchronizing on a
> unique object. I'm not sure which server you are using, but it may be
> returning a new session object instance (not logical
> instance) when there is
> an exclusive hold on the prior session instance.
>
> My two cents,
>
> Glenn
>
> >From: "Kalra, Ashwani"
> <ashwani.kalra@(protected)>
> >Reply-To: An interest list for Sun Java Center J2EE
> Pattern Catalog
> <J2EEPATTERNS-INTEREST@(protected)>
> >To: J2EEPATTERNS-INTEREST@(protected)
> >Subject: concurrency problem
> >Date: Fri, 8 Apr 2005 16:53:22 +0530
> >MIME-Version: 1.0
> >Received: from swjscmail2.java.sun.com ([192.18.99.108]) by
> mc1-f4.hotmail.com with Microsoft SMTPSVC(6.0.3790.211); Fri,
> 8 Apr 2005
> 04:33:53 -0700
> >Received: from swjscmail1 (swjscmail1.Sun.COM [192.18.99.107])by
> swjscmail2.java.sun.com (Postfix) with ESMTPid 93C7D21548;
> Fri, 8 Apr 2005
> 05:25:51 -0600 (MDT)
> >Received: from JAVA.SUN.COM by JAVA.SUN.COM
> (LISTSERV-TCP/IP release
> 1.8e) with spool id 60503412 for
> J2EEPATTERNS-INTEREST@(protected); Fri, 8 Apr 2005
> 05:20:06 -0600
> >Received: from mxeorb01.capgemini.com (mxeorb01.capgemini.com
> [198.184.232.82]) by swjscmail1.java.sun.com
> (Postfix) with ESMTP
> id EB5F848EC for
> <J2EEPATTERNS-INTEREST@(protected)>; Fri,
> 8 Apr 2005 05:10:04 -0600 (MDT)
> >Received: from mxiorb01.capgemini.com (crayfish
> [205.223.236.82]) by
> mxeorb01.capgemini.com (8.13.3/8.12.11) with ESMTP id
> j38BNYrK000092
> for <J2EEPATTERNS-INTEREST@(protected)>; Fri,
> 8 Apr 2005
> 13:23:34 +0200 (MEST)
> >Received: from mxiorb01.capgemini.com (localhost [127.0.0.1]) by
> mxiorb01.capgemini.com (8.13.3/8.12.11) with ESMTP id j38BNYYH012071
> for <J2EEPATTERNS-INTEREST@(protected)>; Fri, 8
> Apr 2005 13:23:34
> +0200 (MEST)
> >Received: from ntbomexmta.corp.capgemini.com (ntbomexmta
> [10.48.144.55])
> by mxiorb01.capgemini.com (8.13.3/8.13.3) with ESMTP id
> j38BNIvu011860 for
> <J2EEPATTERNS-INTEREST@(protected)>; Fri,
> 8 Apr 2005 13:23:33 +0200 (MEST)
> >Received: from BOMEX001.corp.capgemini.com ([10.48.144.53]) by
> ntbomexmta.corp.capgemini.com with Microsoft SMTPSVC(6.0.3790.211);
> Fri, 8 Apr 2005 16:53:25 +0530
> >X-Message-Info: nNbrIwMvXSSAJPzo4M4qM2xyKJV3NDtps+cNnG9EuGE> >X
-Original-To: J2EEPATTERNS-INTEREST@(protected)
> >Delivered-To: J2EEPATTERNS-INTEREST@(protected)
> >X-MimeOLE: Produced By Microsoft Exchange V6.5.7226.0
> >Content-class: urn:content-classes:message
> >X-MS-Has-Attach:
> >X-MS-TNEF-Correlator:
> >Thread-Topic: concurrency problem
> >Thread-Index: AcU8LV+wY1ytqkN/SOyzTMyr9o8W7w=> >X-OriginalArrivalTime:
08 Apr 2005 11:23:25.0588 (UTC)
> FILETIME=[61706D40:01C53C2D]
> >Precedence: list
> >Return-Path: owner-j2eepatterns-interest@(protected)
> >
> >
> >I am facing concurrency problem in following scenario.
> >
> >
> >
> >All our action classes call same stateful session bean .
> Each action
> class obtains the reference from HTTPSession object and calls
> one and only
> one business method.
> >
> >To prevent the concurrent access to this instance which
> occurs when user
> immediately presses two links quickly in succession I am
> using the following
> code block
> >
> >
> >
> >execute(...) //execute methods of Action class
> >
> >{
> >
> >.....
> >
> >.....
> >
> >//Obtain the session from Request.User will always be in
> session here
> >
> >session=request.getSession()
> >
> >Synchronised(session)
> >
> >{
> >
> >//call ejb's business method.
> >
> >}
> >
> >
> >
> >}
> >
> >However sometimes more than one thread is able to pass
> through, And I
> get exception from Appserver. As 2 threads are not allowed
> for statefull
> Session bean.
> >
> >Can there be problem in above code. Is it ok to
> synchronise on session
> object.
> >
> >Thanks & Regds
> > Ashwani
> >
> >Ext: 1860
> >
> >
> >
> >
> >
> >
> >
> >This message contains information that may be privileged
> or confidential
> and is the property of the Capgemini Group. It is intended
> only for the
> person to whom it is addressed. If you are not the intended
> recipient, you
> are not authorized to read, print, retain, copy, disseminate,
> distribute,
> or use this message or any part thereof. If you receive this
> message in
> error, please notify the sender immediately and delete all
> copies of this
> message.
> >
> >=========================================================> =========> >
;Companion Site: http://www.corej2eepatterns.com
> >J2EE BluePrints: http://java.sun.com/blueprints/corej2eepatterns
> >List Archive:
> http://archives.java.sun.com/archives/j2eepatterns-interest.html
> >Unsubscribing: email "signoff J2EEPATTERNS-INTEREST" to
> listserv@(protected)
>
> ===================================================================>
Companion Site: http://www.corej2eepatterns.com
> J2EE BluePrints: http://java.sun.com/blueprints/corej2eepatterns
> List Archive:
> http://archives.java.sun.com/archives/j2eepatterns-interest.html
> Unsubscribing: email "signoff J2EEPATTERNS-INTEREST" to
> listserv@(protected)
>
This message contains information that may be privileged or confidential and is
the property of the Capgemini Group. It is intended only for the person to whom
it is addressed. If you are not the intended recipient, you are not authorized
to read, print, retain, copy, disseminate, distribute, or use this message or
any part thereof. If you receive this message in error, please notify the
sender immediately and delete all copies of this message.
===================================================================Companion
Site: http://www.corej2eepatterns.com
J2EE BluePrints: http://java.sun.com/blueprints/corej2eepatterns
List Archive: http://archives.java.sun.com/archives/j2eepatterns-interest.html
Unsubscribing: email "signoff J2EEPATTERNS-INTEREST" to listserv@(protected)
|
|
