PM63290; 7.0.0.23: decimalformat clone fails in multi-threaded scenarios

Download Description

PM63290 resolves the following problem:

ERROR DESCRIPTION:
Abstract: com.ibm.icu.text.DecimalFormat.clone creates decimal format instances which operate incorrectly in multi-threaded scenarios. (See ICU ticket #5358.)

Description:
When new instances of com.ibm.icu.text.DecimalFormat are created using DecimalFormat.clone() the new instance shares state with the initial DecimalFormat instance. As a result, use of the initial instance in a first thread is not safe with the concurrent use of the new clone instance in a second thread.

This problem was reported as ICU ticket #5358. For more information,
see: http://bugs.icu-project.org/trac/ticket/5358

LOCAL FIX:
NONE

PROBLEM SUMMARY

USERS AFFECTED:
All users of IBM WebSphere Application Server v7.0 with applications using the ICU4J library

PROBLEM DESCRIPTION:
The NumberFormat parse function can return an incorrect value for a decimal number.

RECOMMENDATION:
None

When parsing a decimal number, NumberFormat can intermittently return an incorrect result which will cause the application to process with an invalid value. The DecimalFormat clone method does not create a new DigitList object for each new DecimalFormat instance, resulting in multiple instances of DecimalFormat sharing the same DigitList. If multiple threads enter parsing simultaneously, this can cause the result on one thread to be corrupted by processing on another thread.

PROBLEM CONCLUSION:
DecimalFormat has been updated to prevent cross thread corruption.

This error will not occur on WebSphere Application Server V8.0 and later due to its use of a later version of ICU4J.

The fix for this APAR is currently targeted for inclusion in fix pack 7.0.0.25. Please refer to the Recommended Updates page for delivery information:
http://www.ibm.com/support/docview.wss?uid=swg27004980