Optional Java Functionality

The ChorusOS operating system offers the following optional Java functionalities.

Java Runtime Environment (JRE)

The ChorusOS Java Runtime Environment (JRE) component allows you to develop and implement Java applications on the ChorusOS operating system. The ChorusOS Java Runtime Environment provides the following services:

Java 2 Platform Micro Edition (J2ME) Compatibility

The ChorusOS JRE offers conformity with the Java 2 Platform Micro Edition (J2ME) specification, and meets the criteria of the Java 2 Technology Conformance Kit (TCK). It supports the APIs for J2ME Connected Device Configuration (CDC) and the Foundation profile. The pre-FCS RMI profile can also be used with source deliveries.

C Virtual Machine (CVM)

A C virtual machine (CVM) allows applications written in the Java programming language to be portable across different hardware environments and operating systems. The CVM mediates between the application and the underlying platform, converting the application's bytecodes into machine-level code appropriate for the hardware and the ChorusOS operating system. The CVM supports all ChorusOS CPUs and it uses native ChorusOS threads with tunable priority levels. It is possible for several CVMs to run simultaneously.

The ChorusOS CVM offers the following characteristics:

• The CVM and user Java applications can be launched directly from an image, embedded in flash or read-only memory. The CVM also offers Execute-in-Place (XIP) functionality, reducing the size of the footprint of your application.

• A Java Native Interface (JNI).

• The CVM uses a generational garbage collector (GC), and supports the fastest CVM locking mode, using atomic operations.

Java Platform Debugger Architecture (JPDA)

The ChorusOS JRE provides debugging support via the Java Platform Debugger Architecture (JPDA). JPDA provides the infrastructure needed to build end-user debugger applications. JPDA consists of the layered APIs:

Java Debug Interface (JDI)

A high-level Java programming language interface, including support for remote debugging.

Java Debug Wire Protocol (JDWP):

Defines the format of information and requests transferred between the debugging process and the debugger front-end.

Java Virtual Machine Debug Interface (JVDMI):

A low-level native interface. Defines the services a Java virtual machine must provide for debugging.

The Sun Forte^TM for Java debugger fully supports JPDA.

Java Dynamic Management Kit (JDMK)

The ChorusOS operating system supports the Java Dynamic Management Kit (JDMK).

JDMK allows you to develop Java technology-based agents on your platform. These agents can access your resources through the Java Native Interface or you can take advantage of the Java programming language to develop new resources in the Java Dynamic Management agent.

The Java Dynamic Management Kit provides scheduling, monitoring, notifications, class loading, and other agent-side services. Agents running in the CVM are completely scalable, meaning that both resources and services may be added or removed dynamically, depending on platform constraints and run-time needs. Connectors and protocol adaptors let you develop Java technology-based management applications that may access and control any number of agents transparently through protocols such as RMI, HTTP, SNMP, and HTML.