Designing a Concurrent Hardware Garbage Collector for Small Embedded Systems

Today more and more functionality is packed into all kinds of embedded systems, making high-level languages, such as Java, increasingly attractive as implementation languages. However, certain aspects, essential to high-level languages are much harder to address in a low performance, small embedded system than on a desktop computer. One of these aspects is memory management with garbage collection. This paper describes the design process behind a concurrent, garbage collector unit (GCU), a coprocessor to the Java Optimised Processor. The GCU, targeting small embedded real-time applications, implements a markcompact algorithm, extended with concurrency support, and tuned for improved performance.