Thesis (M.S.)--West Virginia University, 2000. / Title from document title page. Document formatted into pages; contains vi, 94 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 92-93).

Thesis (M.C.S.) - Carleton University, 2007. / Includes bibliographical references (p. 114-118). Also available in electronic format on the Internet.

Thesis (M.S.)--University of California, Santa Cruz, 1996. / Typescript. Includes bibliographical references (leaf 45).

Thesis (M.S.)--University of California, Santa Cruz, 2000. / Typescript. Includes bibliographical references (leaves 54-56).

Thesis (M.S.)--Montana State University--Bozeman, 2005. / Typescript. Chairperson, Graduate Committee: Gary Harkin. Includes bibliographical references (leaves 38-39).

Thesis (Ph.D.) - University of Queensland, 2005. / Includes bibliography.

Thesis (M.S.)--Rochester Institute of Technology, 2007. / Typescript. Includes bibliographical references (leaves 47-48).

Java’s cross-platform virtual machine arrangement and its special features that make it ideal for writing network applications, also have a tremendous negative impact on its operations. In spite of its relatively weak performance, Java’s success has motivated the search for techniques to enhance its execution. This work presents the JAFARDD (a Java Architecture based on a Folding Algorithm, with Reservation stations, Dynamic translation, and Dual processing) processor designed to accelerate Java processing. JAFARDD dynamically translates Java bytecodes to RISC instructions to facilitate the use of a typical general-purpose RISC core. This enables the exploitation of the instruction level parallelism among the translated instructions using well established techniques, and facilitates the migration to Java-enabled hardware. Designing hardware for Java requires an extensive knowledge and understanding of its instruction set architecture which were acquired through a comprehensive behavioral analysis by benchmarking. Many aspects of the Java workload behavior were collected and the resulting statistics were analyzed. This helped identify performance-critical aspects that are candidates for hardware support. Our analysis surpasses other similar ones in terms of the number of aspects studied and the coverage of the recommendations made. Next, a global analysis of the design space of Java processors was carried out. Different hardware design options and alternatives that are suitable for Java were explored and their trade-offs were examined. We especially focused on the design methodology, execution engine organization, parallelism exploitation, and support for high-level language features. This analysis helped identify innovative design ideas such as the use of a modified Tomasulo’s algorithm. This, in turn, motivated the development of a bytecode folding algorithm that integrates with the reservation station concept in JAFARRD. While examining the behavioral analysis and the design space exploration ideas, a list of global architectural design principles started to emerge. These principles ensure JAFARRD can execute Java efficiently and are taken into consideration while the various instruction pipeline modules were designed. Results from the behavioral analysis also confirmed that Java’s stack architecture creates virtual data dependencies that limit performance and prohibit instruction level parallelism. To overcome this drawback, stack operation folding has been suggested in the literature to enhance performance by grouping contiguous instructions that have true data dependencies into a compound instruction. We have developed a folding algorithm that, unlike existing ones, does not require the folded instructions to be consecutive. To the best of our knowledge, our folding algorithm is the only one that permits nested pattern folding, tolerates variations in folding groups, and detects and resolves folding hazards completely. By incorporating this algorithm into a Java processor, the need for, and therefore the limitations of, a stack are eliminated. In addition to an efficient dual processing configuration (i.e., Java and RISC), JAFARDD is empowered with a number of innovative design features, including: an adaptive feedback fetch policy that copes with the variation in Java instruction size, a smart bytecode queue that compensates for the lack of a stack, an on-chip local variable file to facilitate operand access, an early tag assignment to dispatched instructions to reduce processing delay, and a specialized load/store unit that preprocesses object-oriented instructions. The functionality of JAFARDD has been successfully demonstrated through VHDL modeling and simulation. Furthermore, benchmarking using SPECjvm98 showed that the introduced techniques indeed speed up Java execution. Our bytecode folding algorithm speeds up execution by an average of about 1.29, eliminating an average of 97% of the stack instructions and 50% of the overall instructions. Compared to other proposals, JAFARDD combines Java bytecode folding with dynamic hardware translation, while maintaining the RISC nature of the processor, making this a much more flexible and general approach. / Graduate

Since the introduction of the IP Multimedia Subsystem (IMS) by the Third Generation Partnership Project (3GPP) in 2002, a lot of research has been conducted aimed at designing and implementing IMS capable clients and network elements. Though considerable work has been done in the development of IMS clients, there is no single, free and open source IMS client that provides researchers with all the required functionality needed to test the applications they are developing. For example, several open and closed source SIP/IMS clients are used within the Rhodes University Conver- gence Research Group (RUCRG) to test applications under development, as a result of the fact that the various SIP/IMS clients support different subsets of SIP/IMS features. The lack of a single client and the subsequent use of various clients comes with several problems. Researchers have to know how to deploy, configure, use and at times adapt the various clients to suit their needs. This can be very time consuming and, in fact, contradicts the IMS philosophy (the IMS was proposed to support rapid service creation). This thesis outlines the development of a Java-based, IMS compliant client called RUCRG IMS client, that uses the JAIN SIP Applet Phone (JSAP) as its foundation. JSAP, which originally offered only basic voice calling and instant messaging (IM) capabilities, was modified to be IMS compliant and support video calls, IM and presence using XML Configuration Access Protocol (XCAP).

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