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Updates to IBM Java runtime for z/TPF are now available (SR6 FP25)

By Peter Lemieszewski posted 28 days ago

There are updates made to the IBM® 64-bit Runtime Environment for z/TPF, Java™ Technology Edition, Version 8 to address various product security vulnerabilities.  For more information, see the security bulletin.

The SR6 FP25 update to the runtime environment is required to make use of PJ46404, MMAP private allocator for Java. There is an associated blog post for APAR PJ46404.

Since jar file /sys/tpf_pbfiles/opt/ibm/java-s390x-80/jre/lib/tools/monitoring-api.jar is now included in SR6 FP25, this update is also required for use with z/TPF system monitoring for Java applications (APARs PJ46312 & PJ46275). There is an associated blog post for these APARs.

Updates to the runtime environment include improvements to run time performance of the Just In Time (JIT) compiler. The JIT was also updated to use malloc64() when requesting incidental heap storage. 

There are additional z/TPF updates provided with APAR PJ46432. One notable update is that, during startup, the JVM will call user exit ujvm_jvm_startup_hook(). This user exit is included in new shared object UJVM.  Here, you can call a set of z/TPF C/C++ programming services to tailor the Java runtime environment for your z/TPF system. For example, a user can call tpf_easetc() to change the priority class attribute for all ECBs defined as JIT threads in the JVM. See base/rt/ujvm.cpp for more details about this user exit. For more information about PJ46432, see the APEDIT.

Download and install the PJ46432_ibm-java-jre-8.0-6.25 package from the IBM 64-bit Runtime Environment for z/TPF, Java Technology Edition, Version 8 download page. This update, including the associated changes made for APAR PJ46432, replaces the runtime environment provided with APAR PJ46358.