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https://issues.apache.org/jira/browse/AXIS-2498?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12751158#action_12751158
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Gautam Singh commented on AXIS-2498:
------------------------------------
Has this been integrated or approved? Can this be used in production?
I
> TypeMappingImpl is not thread safe
> ----------------------------------
>
> Key: AXIS-2498
> URL: https://issues.apache.org/jira/browse/AXIS-2498
> Project: Axis
> Issue Type: Bug
> Components: Serialization/Deserialization
> Affects Versions: 1.4
> Reporter: Manuel Mall
> Attachments: AXIS-2498.patch, SynchronizedMap.java,
> TypeMappingImpl.java
>
>
> This issue originates from
> http://marc.theaimsgroup.com/?l=axis-user&m=114993403032512&w=2.
> Original report and Cyrille's initial response below:
> ================================
> Hello Manuel,
> My understanding is the Stub#createCall invokes methods on an
> instance of TypeMapping that is shared by the AxisEngine via the
> TypeMappingRegistry. Unfortunately, this TypeMappingImpl is not
> threadsafe.
> Here is a a draft patch that should fix it waiting for an official
> patch. Note that I didn't succeed in reproducing the deadlock, I
> patched according to my understanding of the problem.
> Moreover, I preferred to send you this draft/emergency patch before
> doing extensive testings. It works on my samples but I didn't look at
> the impact on performances (it should be limited ).
> HOW TO US THIS PATCH ?
> Here is a draft patch to fix this issue. To use it, the easiest way
> is to unzip axis-1.4-threadSafetyPatch.jar under /WEB-INF/classes
> (classloader order).
> PATCH DESCRIPTION
> TypeMappingImpl.java is the only modified class. Modifications:
> - use synchronized maps instead of plain HashMaps
> - synchronize internalRegister() method to ensure atomicity of access
> to maps in modification
> - synchronize access to "namespaces" variable in setSupportedEncodings
> to ensure atomicity of the clear-add sequence
> Hope this helps,
> Cyrille
> --
> Cyrille Le Clerc
> cyrille.lecl...@pobox.com
> cyrille.lecl...@fr.ibm.com
> +33 6.61.33.69.86
> On 6/10/06, Manuel Mall <man...@apache.org> wrote:
> > I am aware that this topic has been discussed a number of times, e.g.
> > http://marc.theaimsgroup.com/?l=axis-user&m=113771126214607&w=2.
> >
> > I followed the advice that the locator is thread safe but the stub is
> > not and as I have only stateless calls I have therefore a single
> > instance of the serviceLocator and a new instance of the stub for each
> > call.
> >
> > However, when I have many simultaneous client calls I get
> > random "lock-ups" of the system. The threads always end up stuck in the
> > same state, that is in a call to HashMap.containsKey (see below). The
> > trace snippet is taken from a 'kill -3' output. There were around 20
> > threads all with the identical trace. The only difference being the
> > address in the '- locked <...> (a ...)' line, which is to be expected
> > as I have separate instances of the stub.
> >
> > I had hoped that the fix to
> > https://issues.apache.org/jira/browse/AXIS-2284 which is in Axis 1.4
> > had addressed this issue. But even after switching to Axis 1.4 the
> > problem remains. So it seems to me that there is another concurrent
> > HashMap modification problem left in the Axis code in the area of the
> > Type Mapping Registry.
> >
> > Needless to say that the problem only occurs on a multi CPU system.
> >
> > As I am really not familiar enough with the Axis internals I am
> > wondering if anyone with more insight has a suggestion how to avoid
> > this.
> >
> > Thanks
> >
> > Manuel
> > -----
> > "LandataWebPollRequestEventSlave:" prio=1 tid=0x8b48f0a0 nid=0x25cf
> > runnable [0x8ac74000..0x8ac745f0]
> > at java.util.HashMap.containsKey(HashMap.java:349)
> > at java.util.HashMap$KeySet.contains(HashMap.java:873)
> > at
> > org.apache.axis.encoding.TypeMappingImpl.isRegistered(TypeMappingImpl.java:195)
> > at
> > org.apache.axis.encoding.TypeMappingDelegate.isRegistered(TypeMappingDelegate.java:136)
> > at org.apache.axis.client.Call.registerTypeMapping(Call.java:2280)
> > at org.apache.axis.client.Call.registerTypeMapping(Call.java:2322)
> > at
> > au.com.anstat.oscar.landata.webservices.externalwsdl.Portal_340Stub.createCall(Portal_340Stub.java:2494)
> > - locked <0x91cb2dc8> (a
> > au.com.anstat.oscar.landata.webservices.externalwsdl.Portal_340Stub)
> > at
> > au.com.anstat.oscar.landata.webservices.externalwsdl.Portal_340Stub.propertyCertificateList(Portal_340Stub.java:3979)
> > at
> > au.com.anstat.oscar.common.landata.Operation.doPropertyCertificateList(Operation.java:574)
> >
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