This document summarizes the functionality and issues of the Sun Java Real-Time System (Java RTS) 2.1. Java RTS is Sun's implementation of the Real-Time Specification for Java (RTSJ). The specification details for this implementation are described in Java RTS Implementation Details. Java RTS 2.1 complies with JSR-01 Technology Compatibility Kit (TCK) 1.0.2 version SE 3.0.11c, which tests the behavior of implementations of RTSJ version 1.0.2. Readme File: Links to all the Java RTS technical documents ContentsOperating System Support for Solaris OS Operating System Support for Solaris OSJava RTS 2.1 is supported on an UltraSPARC® processor or on a Sun x86/x64 platform running one of the following operating systems:
Refer to the content of the /etc/release file to determine the exact version of Solaris that is installed on your machine. The OS kernel version is reported by the command Note: Drivers are specific to a particular version of the Solaris Operating System. If you attempt to install a package on a version of Solaris OS where it is not certified, that is, not in the above list, you will receive a warning message. You can continue the installation on that version, but such an installation constitutes an unsupported configuration. In this case, incompatibilities in the cyclic driver package and Solaris OS version may adversely affect the behavior of the operating system. Operating System Support for Linux OSJava RTS 2.1 was tested on the x86/x64 platform running one of the following operating systems:
Our initial test and support plans do not include other Linux distributions. However, since this release of Java RTS uses the real-time POSIX programming interface, it is possible that other properly configured Linux distributions that implement this interface can also run Java RTS 2.1. Temporal correctness is still being worked on by the Linux community, but currently the OS configuration needs to include a 2.6.21 Linux kernel or later with the latest RT patch. (See the site http://www.kernel.org/pub/linux/kernel/projects/rt/ to obtain the appropriate RT patch.) In addition, Java RTS will not run on a system with a glibc version prior to 2.4; furthermore, to reduce issues with priority inversion, Java RTS needs either a system with glibc 2.5 or later, or else a system that has explicitly patched glibc with the necessary priority-inheritance mutex support from 2.5. Known IssuesWith SUSE Linux Enterprise Real Time 10 Service Pack 2 (SP2), Java RTS 2.1 for Linux is impacted by the following bugs:
With Red Hat Enterprise MRG 1.0.1 Errata, Java RTS 2.1 for Linux is impacted by the following bugs:
(Solaris OS only) When DTrace is used to monitor the Java RTS VM, timestamps produced by DTrace can sometimes have wrong values due to the following bugs:
Java Virtual Machine SupportJava RTS provides only the 32-bit "client" version of the Java virtual machine; the 64-bit version is not supported, and using the-server option has no effect.
For the best temporal performance, we recommend installing Java RTS on a machine featuring at least two processors. Functionality and Issues of Java SE 5.0Java RTS 2.1 is generally based on the Java Platform, Standard Edition (Java SE) version 5.0 Update 16. Java SE 5.0 (also known as J2SE 5.0 or 1.5.0) is a major release of the Java platform containing new features and enhancements in many functional areas. Update releases are bug fix releases, which can include reliability, performance, and security fixes. The features, bugs, and workarounds of the Java SE 5.0 release and the additional fixes provided by Update 16 can be found at the J2SE 5.0 Release Notes web site. We are aware of the CR 6682380 (Foreach loop with generics inside finally block crashes javac with -target 1.5). This is a compiler bug, which is fixed in a future version of Java SE. (See http://bugs.sun.com/view_bug.do?bug_id=6682380.) Enhancements in This Java RTS ReleaseJava RTS 2.1 provides the following enhancements to the previous version:
General Differences from Java HotSpot VMGeneral differences in the behavior of Java RTS as compared with the Java HotSpot Virtual Machine are as follows:
Functionality and Issues Specific to Java RTSJava RTS differs in functionality from Java SE and the Java HotSpot VM in a number of areas, including clocks, timers, class initialization, memory management, and scheduling. In addition, certain issues, such as programming considerations, limitations, bugs, and workarounds, are applicable only to Java RTS. The Technical Information document summarizes the functionality and issues that are specific to Java RTS. Contact UsPlease report any problems or bugs you might encounter to the Java RTS team. |