PK26512: FINDBUGS TOOL THROWS DC_DOUBLECHECK ON JAVA FILE GENERATED BY WSDL2JAVA.

6.1.0.1: WebSphere Application Server V6.1.0 Fix Pack 1 for HP-UX
6.1.0.1: WebSphere Application Server V6.1.0 Fix Pack 1 for AIX
6.1.0.1: WebSphere Application Server V6.1.0 Fix Pack 1 for Windows
6.1.0.1: WebSphere Application Server V6.1.0 Fix Pack 1 for Linux
6.1.0.1: WebSphere Application Server V6.1.0 Fix Pack 1 for i5/OS
6.1.0.1: WebSphere Application Server V6.1.0 Fix Pack 1 for Solaris

APAR status

• Closed as program error.

Error description

• FindBugs tool throws DC_DOUBLECHECK on java file generated by
  WSDL2java.  The java file shows:
  
   if (!_equals) { return false; }
   if (__history == null) {
       synchronized (this) {
           if (__history == null) {
               __history = new java.lang.ThreadLocal();
           }
       }
   }
  
  This could cause some performance issue.
  

Local fix

• n/a
  

Problem summary

• ****************************************************************
  * USERS AFFECTED: WebSphere Application Server version 6       *
  *                 users of web services.                       *
  ****************************************************************
  * PROBLEM DESCRIPTION: WSDL2Java Issue:                        *
  *                      FindBugs tool throws DC_DOUBLECHECK     *
  *                      on java file generated by WSDL2Java.    *
  ****************************************************************
  * RECOMMENDATION:                                              *
  ****************************************************************
  The WSDL2Java tool, when used with the "-genEquals yes"
  option, generates java code that demonstrates the undesireable
  version of the double-checked locking technique.
  
  An example of the generated java code is as follows:
  
  private transient java.lang.ThreadLocal __history;
  
  public boolean equals(java.lang.Object obj) {
  
      if (obj == null) { return false; }
  
      if (obj.getClass() != this.getClass()) { return false;}
  
      ....other code.....
      if (__history == null) {
  
          synchronized (this) {       <========================
  double-checked locking
  
              if (__history == null) {
  
                  __history = new java.lang.ThreadLocal();
  
              }
  
          }
  
      }
      ...other code....
  
  }
  
  
  
  private transient java.lang.ThreadLocal __hashHistory;
  
  public int hashCode() {
  
      if (__hashHistory == null) {
  
          synchronized (this) {       <========================
  double-checked locking
  
              if (__hashHistory == null) {
  
                  __hashHistory = new java.lang.ThreadLocal();
  
              }
  
          }
  
      }
  
      ....other code....
  }
  

Problem conclusion

• The fix is to change the code that the WSDL2Java facility
  generates for the -genEquals option.  This code cannot use the
  double-checked locking technique.  Instead, the code must use
  a synchronized  accessor/initializer method.
  
  The fix for this APAR is currently targeted for inclusion
  in cumulative fix 6.0.2.13 and 6.1.0.1.
  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 is sysrouted FROM one or more of the following:

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

Modules/Macros

• WEBSRVC
  

Fix information

• Fixed component name

  WEBSPH APP SERV

• Fixed component ID

  5724J0800

Applicable component levels

• R60A PSY

     UP

• R60H PSY

     UP

• R60I PSY

     UP

• R60P PSY

     UP

• R60S PSY

     UP

• R60W PSY

     UP

• R60Z PSY

     UP

• R61A PSY

     UP

• R61H PSY

     UP

• R61I PSY

     UP

• R61P PSY

     UP

• R61S PSY

     UP

• R61W PSY

     UP

• R61Z PSY

     UP