Mailing-List: contact users-help@tomcat.apache.org; run by ezmlm
Precedence: bulk
Reply-To: "Tomcat Users List" <users@tomcat.apache.org>
Received-SPF: pass (nike.apache.org: domain of mgainty@hotmail.com designates
 65.55.111.112 as permitted sender)
Message-ID: <BLU172-W44AD0CE1729AAEBCBBB3F8AE9D0@phx.gbl>
Content-Type: multipart/alternative;
	boundary="_5d6e5e69-3e94-432a-aaf2-4122c280b317_"
From: Martin Gainty <mgainty@hotmail.com>
To: Tomcat Users List <users@tomcat.apache.org>
Subject: RE: WebSockets Thread Safety question
Date: Mon, 3 Jun 2013 07:04:09 -0400
Importance: Normal
In-Reply-To: 
 <CAG6aRdUar4R6ZL5CsYvpZXGfti2nsoTrfavHEAWXBqQ=NmaTTA@mail.gmail.com>
References: 
 <CABCN5n0PRRqMyu82FDNkxxZLDjuxQ7hRM+3upkremr9MSRF2Sw@mail.gmail.com>,<CAG6aRdUar4R6ZL5CsYvpZXGfti2nsoTrfavHEAWXBqQ=NmaTTA@mail.gmail.com>
MIME-Version: 1.0

--_5d6e5e69-3e94-432a-aaf2-4122c280b317_
Content-Type: text/plain; charset="iso-8859-1"
Content-Transfer-Encoding: quoted-printable

/java/util>javap Collections | grep synchronized
    public static java.util.Collection synchronizedCollection(java.util.Col=
lecti
on)=3B
    static java.util.Collection synchronizedCollection(java.util.Collection=
=2C jav
a.lang.Object)=3B
    public static java.util.Set synchronizedSet(java.util.Set)=3B
    static java.util.Set synchronizedSet(java.util.Set=2C java.lang.Object)=
=3B
    public static java.util.SortedSet synchronizedSortedSet(java.util.Sorte=
dSet)
=3B
    public static java.util.List synchronizedList(java.util.List)=3B
    static java.util.List synchronizedList(java.util.List=2C java.lang.Obje=
ct)=3B
    public static java.util.Map synchronizedMap(java.util.Map)=3B
    public static java.util.SortedMap synchronizedSortedMap(java.util.Sorte=
dMap)
=3B

use java.util.Collections.synchronizedList=20

Martin=20
______________________________________________=20
Verzicht und Vertraulichkeitanmerkung/Note de d=E9ni et de confidentialit=
=E9

Diese Nachricht ist vertraulich. Sollten Sie nicht der vorgesehene Empfaeng=
er sein=2C so bitten wir hoeflich um eine Mitteilung. Jede unbefugte Weiter=
leitung oder Fertigung einer Kopie ist unzulaessig. Diese Nachricht dient l=
ediglich dem Austausch von Informationen und entfaltet keine rechtliche Bin=
dungswirkung. Aufgrund der leichten Manipulierbarkeit von E-Mails koennen w=
ir keine Haftung fuer den Inhalt uebernehmen.
Ce message est confidentiel et peut =EAtre privil=E9gi=E9. Si vous n'=EAtes=
 pas le destinataire pr=E9vu=2C nous te demandons avec bont=E9 que pour sat=
isfaire informez l'exp=E9diteur. N'importe quelle diffusion non autoris=E9e=
 ou la copie de ceci est interdite. Ce message sert =E0 l'information seule=
ment et n'aura pas n'importe quel effet l=E9galement obligatoire. =C9tant d=
onn=E9 que les email peuvent facilement =EAtre sujets =E0 la manipulation=
=2C nous ne pouvons accepter aucune responsabilit=E9 pour le contenu fourni=
.


> From: chris@derham.me.uk
> Date: Mon=2C 3 Jun 2013 07:42:01 -0300
> Subject: Re: WebSockets Thread Safety question
> To: users@tomcat.apache.org
>=20
> > When I use the syntax from the samples in the onTextMessage() method=2C=
 I get
> > ConcurrentModificationException if I have more than one client sending =
data
> > to the server at the same time:
> >
> >             for(MyMessageInbound mmib: mmiList){
> >                 CharBuffer buffer =3D CharBuffer.wrap(cb)=3B
> >                 mmib.myoutbound.writeTextMessage(buffer)=3B
> >                 mmib.myoutbound.flush()=3B
> >             }
> >
> >
> > Changing it to the following works fine:
> >
> >             for(int i =3D 0=3B i < mmib.size()=3B i++) {
> >                 MyMessageInbound mmib =3D mmiList.get(i)=3B
> >                 CharBuffer buffer =3D CharBuffer.wrap(cb)=3B
> >                 mmib.myoutbound.writeTextMessage(buffer)=3B
> >                 mmib.myoutbound.flush()=3B
> >             }
> >
> > However=2C this approach is not as efficient as to use an Iterator=2C u=
nless I
> > clone the mmiList Collection to iterate over it...
>=20
> Can you explain where is the in-efficiency?
>=20
> Thanks
>=20
> Chris
>=20
> ---------------------------------------------------------------------
> To unsubscribe=2C e-mail: users-unsubscribe@tomcat.apache.org
> For additional commands=2C e-mail: users-help@tomcat.apache.org
>=20
 		 	   		  =

--_5d6e5e69-3e94-432a-aaf2-4122c280b317_--