Optimizing a CORBA Internet Inter-ORB protocol (IIOP) engine for minimal footprint embedded multimedia systems

To support the quality-of-service (QoS) requirements of embedded multimedia applications, such as real-time audio and video, electronic mail and fax, and Internet telephony, off-the-shelf middleware like common object request broker architecture (CORBA) must be flexible, efficient, and predictable. Moreover, stringent memory constraints imposed by embedded system hardware necessitates a minimal footprint for middleware that supports multimedia ap plications. This paper provides three contributions toward developing effic ient object request brokers (ORB's) middleware to support embedded multimed ia applications. First, we describe the optimization principle patterns use d to develop a time and space-efficient CORBA Inter-ORE Protocol (IIOP) int erpreter for the adaptive communication environment (ACE)-ORB (TAO), which is our high-performance, real-time ORE. Second, we describe the optimizatio ns applied to TAO's interface definition language (IDL) compiler to generat e efficient and small stubs/skeletons used in TAO's IIOP protocol engine, T hird, we empirically compare the performance and memory footprint of interp retive (de)marshaling versus compiled (de)marshaling for a nide range of ID L data types. Applying our optimization principle patterns to TAO's IIOP pr otocol engine improved its interpretive (de)marshaling performance to the p oint where it is now comparable to the performance of compiled (de)marshali ng. Moreover, our IDL compiler optimizations generate interpreted stubs/ske letons whose footprint is substantially smaller than compiled stubs/skeleto ns. Our results illustrate that careful application of optimization princip le patterns can yield both time and space-efficient standards-based middlew are.