Using Java Technology to Standardize Real-Time Development

Abstract

With the recently released Real-Time Specification for Java^TM (RTSJ), developed through the Java Community Process^SM by the Real-Time Expert Group, the real-time embedded software developer will be able to use the Java programming language in applications where predictable/hard real-time behavior is a must. Device manufacturers with time constraint requirements will be able to take full advantage of the benefits offered by the Java Technology Model, helping get better products to market faster. The extensions can be utilized by many industries for numerous applications. A few examples include computer networking and telecommunications equipment, industrial robots, automotive controllers, medical and scientific measurement devices, and industrial controllers.

Java Technology Model with Real-Time Extensions

The Java Technology Model with Real-Time Extensions further leverages the capabilities of a real-time operating system (RTOS) to achieve the promise of hard real-time computing. By coupling the Real-Time Java Virtual Machine with an RTOS and giving the developer new mechanisms to separate hard real-time and soft real-time threads, objects and memory, Java Technology will be capable of addressing the requirements faced by real-time and non-real-time applications.

The extensions do not introduce new keywords or make syntactic extensions to the Java programming language, allowing the developer to utilize current tools. However, there are new memory models introduced. With these memory models, developers will be able to define areas that can or cannot be affected by non-deterministic events such as garbage collection. Additionally, physical memory or memory mapped I/O will be accessible.

Advantages of the Java Technology Model

Because of the advantages provided by the Java technology model, there has been a tremendous shift towards using the Java programming language in software development. Many companies are experiencing shorter development schedules and reduced costs by developing products using the Java programming language.

The Java programming language offers several distinct advantages:

• Simplicity. Most notably, the Java programming language is easy to learn and use. The language also brings the productivity enhancements from object oriented methodologies. There is a large, and rapidly growing supply of developer talent in the industry, making it easier to staff new projects.

• Security. For distributed, networked applications, the Java programming language features robust security. The run-time environment creates a "sandbox" where applications can execute safely, with fine-grained access restrictions on system resources. The lack of pointers also eliminates direct memory access, resulting in fewer bugs.

• Portability. By using an underlying Java run-time environment, applications can be easily developed on a desktop system using standard software development tools. By taking into account the underlying target hardware characteristics, developers can then move applications with minimal effort to the target device.

As a result, applications written in the Java programming language are easily migrated across product lines, greatly simplifying porting and development efforts, even if the deployment target or underlying RTOS changes. In this way, the Java programming language can provide a much higher degree of standardization in the real-time world.

Since the Java APIs have been developed with involvement from many companies in the computing industry, the platform has gained a level of acceptance and maturity that promises a long lifespan. For device manufacturers concerned with long product life cycles, the longevity of the language will facilitate better on-going support and maintenance.

Real-Time Specification for Java Background

The process of developing real-time extensions for the Java platform, followed a defined methodology for expanding the Java APIs known as the Java Community Process. The Java Community Process is an open one, involving collaboration and consensus-building among academic and industry experts. The process is subject to review by an independent auditor, ensuring that it remains open and is not controlled by any one vendor. The goal of the process is to produce Java extension specifications, as well as reference implementations and conformance tests for those specifications, which will enable all vendors to deliver compliant products.

The Real-Time Expert Group is led by Dr. Greg Bollella of IBM and is comprised of numerous experts in the real-time industry. In addition, over forty companies have signed up to participate as expert consultants and to review draft specifications prior to public release. James Gosling, "father" of the Java programming language is Sun`s representative to the Expert Group.

Summary

Today, the Java programming language is helping many companies achieve faster time-to-market and lower development costs for their products. This is true within the embedded device market as well, where manufacturers can reuse code across product lines, simplifying development and thus saving valuable development time and cost.

The specification for extending the Java platform with real-time capabilities will promote standardization and provide direction on using the Java programming language for real-time applications. The real-time industry has stepped up to participate in the open Java Community Process for developing the real-time API, and has welcomed the Real-Time Expert Group`s efforts as a means of providing a productive, more standardized real-time development environment.