Rockwell Collins, Inc.

Michael H Masters

David S Hardin

Allen P Mass

John K Gee

David A Greve

Nick M Mykris

T Douglas Hiratzka

Raymond A Kamin

Matthew M Wilding

Multiple Java Virtual Machines (JVMs) operate on a single direct execution JAVA processor with each JVM operating in a separate time slice called a partition. Each JVM has its own data and control structures and is assigned a fixed area of memory. Each partition is also allotted a fixed period of time in which to operate, and, at the end of the allotted time, a context switch is forced to another JVM operating in the next partition. The context switch does not transfer control directly from one JVM to another JVM. Instead, at the end of a partition time period control is switched from the currently operating JVM to a &ldquo;master JVM&rdquo; during a time period called an &ldquo;interstice.&rdquo; The master JVM handles system interrupts and housekeeping duties. At the end of the interstice time period, the master JVM starts a proxy thread associated with the next JVM to become operational. The proxy thread handles JVM-specific interrupts and checks the status of the associated JVM. If the JVM appears operational the proxy thread transfers control to the JVM thread. Time intervals such as partition times and interstice times are enforced by hardware timers and memory accesses are checked by address comparison circuitry to prevent a system failure due to a malfunction in either the master JVM or another JVM.

Real time processor capable of concurrently running multiple independent JAVA machines

An improved computer architecture and system advantageously combine the beneficial characteristics of a high level object oriented programming language with an optimized processor for efficient application to real time embedded computing problems. Additionally, an improved method for resolving symbolic references in code generated by compiling source code written in an object oriented programming language to the corresponding logical memory addresses stores look-up information with the object itself after the first encounter of a given symbolic reference, whereby the logical memory address information is available for subsequent encounters of the symbolic reference, and whereby no modification of the program instructions containing the symbolic reference is necessary. In a preferred embodiment, the Java&trade; programming language is used.

Real time processor optimized for executing JAVA programs

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Cedar Rapids, IA, United States of America

Michael H Masters