Date: Tue, 12 Dec 2000 17:14:25 -0500 From: Dan Jacobs Subject: WebTech Tues 12/19 7pm Waltham - Real-time Java Hi everybody. With the holidays approaching, and time pressures building, it's important to find ways to get everything done in time - including making it to the next WebTech meeting on Tuesday, 12/19/2000, starting at 7pm at the IBM SPC in Waltham. Real-Time Java may be the answer to your problems! Details and directions will be up on the website as soon as the server at ACM becomes available again (don't ask!). This month's presentation will be on Real-Time Java, given by Ben Brosgol of Ada Core Technologies. This is a fascinating topic that covers a lot of very interesting territory. Mark your calendars and don't miss this presentation. It's going to be one of the best! I hope to see you there. -- Dan Jacobs, Chairman ABSTRACT Some of Java's defining characteristics -- such as Object-Oriented Programming, dynamic loading, and garbage collection -- although advantages in general, have proved to be obstacles to the language's spread in the domain of real-time system development. A real-time program's time and space requirements must be predictable, but Java's dynamic underpinnings interfere with that goal. Real-time garbage collection, despite some encouraging recent progress, is still more a research topic than a practical technology. And Java's loose semantics for thread scheduling make it difficult for a developer to ensure that periodic threads will meet their deadlines, and that priority inversions will be avoided. These problems, however, are not intractable, and since early 1999 two independent efforts have been underway to extend the Java platform so as to satisfy the requirements for real-time systems. One specification has been designed by the Real-Time for Java Expert Group (RTJEG) under the auspices of Sun Microsystems' Java Community Process, and the other has been developed by the Real-Time Java Working Group (RTJWG) under the J-Consortium. This talk first discusses the Java platform (language, API, JVM) with respect to real-time support, and then compares and contrasts the two real-time Java specifications with a focus on concurrency / scheduling support, memory management, and asynchrony. BIO SKETCH Dr. Benjamin Brosgol, a senior member of the techical staff at Ada Core Technologies, is a primary member of the Real-Time for Java Expert Group and a reviewer of the J-Consortium specification. He has been delivering Java tutorials and courses regularly since 1997 and has been teaching real-time programming courses for more than ten years. Dr. Brosgol has published several technical papers on Java's OOP and concurrency features and is a co-author of The Real-Time Specification for Java (Addison-Wesley, 2000). In addition to his Java activities he has had a long involvement with the Ada language effort. He participated in both the initial language design and the Ada 95 revision, and he is currently the chair of the ACM's Special Interest Group on Ada (SIGAda).