|
Besides an expert tour of the inner workings of the Java Virtual Machine (JVM), Programming for the Java Virtual Machine provides a guide to Oolong, a low-level assembly language for Java. Behind Java's "write once, run anywhere" philosophy lies the JVM, an ideal model of a CPU with instructions (called bytecodes), memory, etc. In today's Java compilers, the details of the JVM are invisible, but this book explores how to write the bytecodes directly in Oolong. In the initial stages of the book, the author focuses on the Oolong instruction set, presenting this object-oriented assembly language for Java in a notably clear fashion. The author even demonstrates the basics of Oolong, including classes, using concise examples. The Java verification process, which allows the JVM to check whether a given Java .class file is safe to run, receives detailed attention as do debugging techniques, the Java class loader, and the contents of .class files. The book then offers a thorough description of how Java language elements are compiled into bytecodes, illustrated with Oolong. In a section aimed specifically at researchers, the author shows how other programming languages can be coded in Oolong for use with the JVM, including Scheme, Prolog, and C templates. The book closes with a discussion of performance issues (including optimization techniques), security concerns, and a full listing of the Oolong instruction set. Programming for the Java Virtual Machine is sure to show up on reading lists for computer science students. It shows that assembly language does not disappear on the Java platform, but rather that it can extend the functionality and performance of your Java programs. --Richard Dragan |
