Jaguar: enabling efficient communication and I/O in Java

Implementing efficient communication and I/O mechanisms in Java requires both fast access to lowlevel system resources (such as network and raw disk interfaces) and direct manipulation of memory regions external to the Java heap (such as communication and I/O buffers). Java native methods are too expensive to perform these operations and raise serious protection concerns. We present Jaguar, a new mechanism that provides Java applications with efficient access to system resources while retaining the protection of the Java environment. This is accomplished through compiletime translation of certain Java bytecodes to inlined machine code segments. We demonstrate the use of Jaguar through a Java interface to the VIA fast communications layer, which achieves nearly identical performance to that of C, and Pre-Serialized Objects, a mechanism which greatly reduces the cost of Java object serializa-