Support information for IBM® SDK, Java™ Technology Edition, Version 6 that is not available in the user documentation.
The information to support IBM SDK, Java Technology Edition, Version 6 is available in the product documentation. Supplementary information is available for the following updates to this release:
- Service refresh 13, fix pack 2
- Service refresh 13, fix pack 1
- Service refresh 13
- Service refresh 12
- Service refresh 10, fix pack 1
For information about security fixes, see Security Alerts.
For a list of the IBM fixes included, see IBM SDK, Java Technology Edition, Version 6 fixes.
To download the latest service refresh, see IBM developer kits.
For information about the daylight saving time changes included in service refreshes and fix pack levels, see Olson time zone updates in the IBM SDK for Java. Later updates can by applied using the IBM Time Zone Update Utility for Java (JTZU).
Service refresh 13, fix pack 2
This fix pack includes a change to the default value for the RMI property java.rmi.server.useCodebaseOnly from false to true, which might cause unexpected errors for applications that use RMI. For more information, see http://docs.oracle.com/javase/7/docs/technotes/guides/rmi/enhancements-7.html.
On Windows, improvements are made to the way that Runtime.exec decodes command strings. However, applications specifying commands that contain spaces in the program name, or that use quotation marks incorrectly, might fail to start. For more information, including guidance on resolving problems, see http://www.oracle.com/technetwork/java/javase/7u21-relnotes-1932873.html#jaruntime.
Service refresh 13, fix pack 1
This fix pack contains a security fix for the Oracle security vulnerability, CVE-2013-0169. For any further security fixes in this release, see Security alerts.
A security enhancement is included to correctly validate certificates on jar files of applications. After upgrading, a CertificateException occurs for any applications in one of the following scenarios:
- The application jar is not properly signed.
- The application jar has incorrect certificates.
- A certificate in the certificate chain is revoked.
To avoid these exceptions, make sure that your application jars are signed with valid certificates before upgrading from an earlier release. This issue relates to APAR IV38456.
Service refresh 13
Non-blocking registration of interested operations with selectors on the AIX operating system
In this release, the implementation of the registration of interested operations with the java.nio.channels.Selector class has been modified to avoid blocked threads.
In previous releases, this implementation could cause blocking of threads on the AIX® operating system. If a Java application used the java.nio.channels.SelectionKey.interestOps() method to register an interested operation with a Selector object that was engaged in a polling operation, the registering thread could be blocked. A thread that is blocked in this way can cause the application to hang or timeout. The following Java stack traces from such a situation show that the first thread is performing a poll operation, and the second thread is blocked:
3XMTHREADINFO "Thread-2" TID:0x31E65800, j9thread_t:0x31C9764C, state:R, prio=5
3XMTHREADINFO1 (native thread ID:0x2AA00A5, native priority:0x5, native policy:UNKNOWN)
4XESTACKTRACE at sun/nio/ch/PollArrayWrapper.poll0(Native Method)
4XESTACKTRACE at sun/nio/ch/PollArrayWrapper.poll(PollArrayWrapper.java:116)
4XESTACKTRACE at sun/nio/ch/PollSelectorImpl.doSelect(PollSelectorImpl.java:57)
4XESTACKTRACE at sun/nio/ch/SelectorImpl.lockAndDoSelect(SelectorImpl.java:69)
4XESTACKTRACE at sun/nio/ch/SelectorImpl.select(SelectorImpl.java:80)
4XESTACKTRACE at sun/nio/ch/SelectorImpl.select(SelectorImpl.java:84)
4XESTACKTRACE at BlockIntOpsReg.run(BlockIntOpsReg.java:18)
4XESTACKTRACE at java/lang/Thread.run(Thread.java:735)
3XMTHREADINFO "main" TID:0x30A65500, j9thread_t:0x301162D4, state:B, prio=5
3XMTHREADINFO1 (native thread ID:0x14A005F, native priority:0x5, native policy:UNKNOWN)
4XESTACKTRACE at sun/nio/ch/SelectionKeyImpl.nioInterestOps(SelectionKeyImpl.java:103)
4XESTACKTRACE at sun/nio/ch/SelectionKeyImpl.interestOps(SelectionKeyImpl.java:65)
4XESTACKTRACE at BlockIntOpsReg.main(BlockIntOpsReg.java:40)
This thread blocking was caused by the pollset implementation using a Java cache of limited size to store requests for registration of interested operations. When the cache reached its size limit, the implementation attempted to register all the requests in the Java cache into the native AIX pollset cache, which could result in blocked threads. From this release, the Java cache size is unlimited, and interested operations are registered just before the next poll operation, to avoid blocking of threads.
For more information about I/O polling on the AIX operating system, see the following developerWorks article: Efficient I/O event polling through the pollset interface on AIX.
Service refresh 12
PKCS11 security provider
A new library is available that allows the IBMPKCS11Impl provider to run on the Linux AMD64 platform.
Service refresh 10, fix pack 1
The following Oracle change is included with IBM SDK for Java version 6 service refresh 10, fix pack 1:
This change relates to Oracle security vulnerability CVE-2012-0502.
The KeyboardFocusManager specification explicitly allows a single, global KeyboardFocusManager for all applets. Some public methods are unsafe for such implementations.
As a result of the fix, the following methods now throw a java.lang.SecurityException if they are invoked on a java.awt.KeyboardFocusManager that is not the current java.awt.KeyboardFocusManager for the calling thread's context:
- java.awt.KeyboardFocusManager.setGlobalFocusOwner(Component focusOwner)
- java.awt.KeyboardFocusManager.setGlobalPermanentFocusOwner(Component PermanentFocusOwner)
- java.awt.KeyboardFocusManager.setGlobalFocusedWindow(Window focusedWindow)
- java.awt.KeyboardFocusManager.setGlobalActiveWindow(Window activeWindow)
- java.awt.KeyboardFocusManager.setGlobalCurrentFocusCycleRoot(Container newFocusCycleRoot)
Tuning options for the Generational Concurrent (gencon) Garbage Collection policy
The -Xgc option can be used with a number of parameters to fine-tune garbage collection. The following options apply to the gencon policy:
This option turns off the adaptive tenure age in the generational concurrent GC policy. The initial age that is set is maintained throughout the run time of the Java™ virtual machine. See scvTenureAge.
This option sets the initial scavenger tenure age in the generational concurrent GC policy. The range is 1 - 14 and the default value is 10.
For more information about tenure age and the -Xgc option in the product documentation.
Comparative Oracle build levels
The following table indicates the Oracle FCS build level that has comparative functionality to recent releases of the IBM SDK:
|IBM SDK 6||Oracle Java 6 FCS build|
|GA||Update 04 Build 04|
|Service Refresh 1||Update 05 Build 13|
|Service Refresh 2||Update 07 Build 02|
|Service Refresh 3||Update 07 Build 02|
|Service Refresh 4||Update 07 Build 02|
|Service Refresh 5||Update 10 Build 33|
|Service Refresh 6||Update 14 Build 07|
|Service Refresh 7||Update 17 Build 02|
|Service Refresh 8||Update 18 Build 07|
|Service Refresh 9||Update 21 Build 06|
|Service Refresh 10||Update 27 Build 05|
|Service Refresh 11||Update 32 Build 05|
|Service Refresh 12||Update 32 Build 05|
|Service Refresh 13||Update 39 Build 02|
|Service Refresh 14||Update 51 Build 09|
|Service Refresh 15||Update 65 Build 11|
|Service Refresh 16||Update 75 Build 13|
|Service Refresh 16 Fix pack 1||Update 81 Build 08|
|Service Refresh 16 Fix pack 2||Update 85 Build 13|