PM26342: Lock contention may occur with a JAX-RPC application when the BaseSerializerFactory uses Class.forName.

Fixes are available

APAR status

Closed as program error.

Error description

Multiple threads may lock on the Class.forName code when
running a JAX-RPC application.  These locks may reduce overall
system throughput.

Here is an example stack that may be seen within a javacore
file:

Java callstack:
at java/lang/Class.forNameImpl(Native Method)
at java/lang/Class.forName(Class.java:169)
at
com/ibm/ws/webservices/engine/utils/ClassUtils$2.run(ClassUtils.
java:
234)
at
java/security/AccessController.doPrivileged(AccessController.jav
a:202
)
at
com/ibm/ws/security/util/AccessController.doPrivileged(AccessCon
troll
er.java:61)
at
com/ibm/ws/webservices/engine/utils/ClassUtils.loadClass(ClassUt
ils.j
ava:210)
at
com/ibm/ws/webservices/engine/utils/ClassUtils.forName(ClassUtil
s.jav
a:136)
at
com/ibm/ws/webservices/engine/encoding/ser/BaseSerializerFactory
$getS
erializerMethodPRIV.run(BaseSerializerFactory.java:369)
at
java/security/AccessController.doPrivileged(AccessController.jav
a:202
)
at
com/ibm/ws/security/util/AccessController.doPrivileged(AccessCon
troll
er.java:61)
at
com/ibm/ws/webservices/engine/encoding/ser/BaseSerializerFactory
.getS
erializerMethod(BaseSerializerFactory.java:249)


These threads are all trying to load a non-existent class
"java/lang/String_Helper".

Local fix

Problem summary

****************************************************************
* USERS AFFECTED:  IBM WebSphere Application Server users or   *
*                  administrators of JAX-RPC applications      *
****************************************************************
* PROBLEM DESCRIPTION: Lock contention may occur with a        *
*                      JAX-RPC application when the            *
*                      BaseSerializerFactory uses              *
*                      Class.forName.                          *
****************************************************************
* RECOMMENDATION:  Install a fix pack containing this APAR.    *
****************************************************************
Multiple threads may lock on the Class.forName code when
running a JAX-RPC application.  These locks may reduce overall
system throughput.

Here is an example stack that may be seen within a javacore
file:

Java callstack:
at java/lang/Class.forNameImpl(Native Method)
at java/lang/Class.forName(Class.java:169)
at
com/ibm/ws/webservices/engine/utils/ClassUtils$2.run(ClassUtils.
java:
234)
at
java/security/AccessController.doPrivileged(AccessController.jav
a:202
)
at
com/ibm/ws/security/util/AccessController.doPrivileged(AccessCon
troll
er.java:61)
at
com/ibm/ws/webservices/engine/utils/ClassUtils.loadClass(ClassUt
ils.j
ava:210)
at
com/ibm/ws/webservices/engine/utils/ClassUtils.forName(ClassUtil
s.jav
a:136)
at
com/ibm/ws/webservices/engine/encoding/ser/BaseSerializerFactory
$getS
erializerMethodPRIV.run(BaseSerializerFactory.java:369)
at
java/security/AccessController.doPrivileged(AccessController.jav
a:202
)
at
com/ibm/ws/security/util/AccessController.doPrivileged(AccessCon
troll
er.java:61)
at
com/ibm/ws/webservices/engine/encoding/ser/BaseSerializerFactory
.getS
erializerMethod(BaseSerializerFactory.java:249)


These threads are all trying to load a non-existent class
"java/lang/String_Helper".

Problem conclusion

The JAX-RPC runtime loads _Helper classes to assist with the
serialization and deserialization of the JAX-RPC data.

There are some data types (for example, java.lang.String) that
do not have _Helper classes.  The lock contention occurs while
the JAX-RPC runtime searches for these non-existent _Helper
classes.

The JAX-RPC runtime is changed to avoid the _Helper class
lookup for java.lang.String and other common data types.  This
eliminates the lock contention.

The fix for this APAR is currently targeted for inclusion in
fix pack 7.0.0.17  Please refer to the Recommended Updates
page for delivery information:
http://www.ibm.com/support/docview.wss?rs=180&uid=swg27004980

Temporary fix

Comments

APAR Information

APAR number
PM26342
Reported component name
WEBS APP SERV N
Reported component ID
5724H8800
Reported release
700
Status
CLOSED PER
PE
NoPE
HIPER
NoHIPER
Special Attention
NoSpecatt
Submitted date
2010-11-09
Closed date
2010-11-18
Last modified date
2010-11-18

APAR is sysrouted FROM one or more of the following:
APAR is sysrouted TO one or more of the following:

Fix information

Fixed component name
WEBS APP SERV N
Fixed component ID
5724H8800

Applicable component levels

R700 PSY
UP

[{"Business Unit":{"code":"BU059","label":"IBM Software w\/o TPS"},"Product":{"code":"SSEQTP","label":"WebSphere Application Server"},"Platform":[{"code":"PF025","label":"Platform Independent"}],"Version":"7.0","Line of Business":{"code":"LOB45","label":"Automation"}}]

Document Information

Modified date:
27 October 2021

Tips

PM26342: Lock contention may occur with a JAX-RPC application when the BaseSerializerFactory uses Class.forName.

Fixes are available

Subscribe

APAR status

Closed as program error.

Error description

Local fix

Problem summary

Problem conclusion

Temporary fix

Comments

APAR Information

APAR number

Reported component name

Reported component ID

Reported release

Status

PE

HIPER

Special Attention

Submitted date

Closed date

Last modified date

APAR is sysrouted FROM one or more of the following:

APAR is sysrouted TO one or more of the following:

Fix information

Fixed component name

Fixed component ID

Applicable component levels

R700 PSY

Document Information

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