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Java2 Upgrade

Versions

Java and its libraries have been upgraded for security reasons after security advisories were issued by SGI and SUN. SGI has taken the opportunity to rename its Java offerings to conform more closely with the SUN naming conventions. These names are listed in the following table:
 
Old SGI Version Old SUN Name New SGI Version New SUN Name
Java Execution Only Environment (eoe) Java2 JRE 1.2 Java2 v1.3.1_02 Java2 Runtime Environment v1.3.1_02
Java Development Environment (dev) Java2 Development JDK 1.2 Java2 v1.3.1_02 Java2 SDK v1.3.1_02

Implementation Plan

As a result of the advisories the new versions of Java have been installed to new directories. This version will be phased in according to the schedule below. Users are encouraged to switch to the new version of Java as soon as possible.
 
Action Date
New Java installed Thursday, October 3, 2002
New Java becomes the default version of Java Thursday, October 17, 2002
Old Java development libraries (for writing code) are no longer available. Thursday, October 31, 2002

During the transistion period the aliases "newjava" and "oldjava" (without quotes) can be used to move between the two versions of Java. If more details about the Java changes are desired, please use netscape on server.uwindsor.ca (SGI Challenge XL) and open file:/usr/java2v131_02/webdocs/release.html.
 

Installation Location

When writing Java code consider using the JAVA_HOME environment variable to point to the new Java installation location (/usr/java2) and include it in your makefiles as well.  SGI plans the /usr/java2 link to always point to the newest released version from now on. We also plan to make this environment variable work on the replacement system as well.
 

Native and Green Threads

"The default Java threads package on IRIX is known as native threads. It is implemented using POSIX threads, or pthreads, and takes full advantage of multiprocessors when running Java code. The Classic VM also allows the use of green threads. Green threads are user-level threads, implemented within a single Unix process, running on a single processor."

Using the environment variable: THREADS_FLAG

"To specify that native threads or green threads should always be used when running Java software, set the THREADS_FLAG environment variable in one of the following ways:"

       setenv THREADS_FLAG native
       setenv THREADS_FLAG green

To permanently make this change add the appropriate line above to your personal C shell initalization file ~/.cshrc.

Using command line options: -native and -green

To override the setting of the environment variable THREADS_FLAG, use the command line options of "-native" or "-green" (without quotes). Examples follow:

       java -native mypkg.MyClass
       javac -native MyClass.java
       appletviewer -green MyApplet.html

"All the tools in the JDK use native threads by default. This has changed since the previous release, when green threads were used by default." If more details about threads are desired, please use netscape on server.uwindsor.ca (SGI Challenge XL) and open file:/usr/java2v131_02/webdocs/threads.html.

If you have questions or concerns please contact our HelpDesk (email: HelpDesk@UWindsor.Ca or phone: 253-3000 ext. 4440).

Document maintained by Philip Smith. 

Original Date: Tue Oct  1, 2002
Last Revision: Tue Oct  1. 2002