We present ByteSTM, a virtual machine-level Java STM implementation that is built by extending the Jikes RVM. ByteSTM implements two STM algorithms, TL2 and RingSTM. We modify Jikes RVM’s Optimizing compiler to transparently support implicit transactions. Being implemented at the VM-level, it accesses memory directly and handles memory uniformly, and avoids Java garbage collection by manually m...

We describe the facilities provided by PLATINUM, a multiprocessor micro-kernel, to support user-level exception handling. The principal design goal for these facilities is to provide a very simple mechanism with su cient exibility and e ciency to experiment with the implementation of a wide variety of exception-driven, user-level services in a parallel system. These services provide conventiona...

While many object-oriented languages impose space overhead of only one word per object to support features like virtual method dispatch, Java’s richer functionality has led to implementations that require two or three header words per object. This space overhead increases memory usage and attendant garbage collection costs, reduces cache locality, and constrains programmers who might naturally ...

Side and covert channels (referred to collectively as illicit channels) are an insidious affliction of high security systems brought about by the unwanted and unregulated sharing of state amongst processes. Illicit channels can be effectively broken through isolation, which limits the degree by which processes can interact. The drawback of using isolation as a general mitigation against illicit...

Nowadays cloud computing is very popular for offering services over the Internet. The very important advantage of cloud computing is the ability to provision resources on demand. This avoids the problems of over-provisioning and under-provisioning which are commonly seen with organizations that have widely variable requirements due to increase/decrease, seasonal high and low workload etc. Resou...

Sharing selected data structures among virtual machines of a safe language can improve resource utilization of each participating run-time system. The challenge is to determine what to share and how to share it in order to decrease start-up time and lower memory footprint without compromising the robustness of the system. Furthermore, the engineering effort required to implement the system must...

In IaaS services of cloud the customers demand for hardware resources as a service like memory, processor cycles, disk storage even software. IaaS services of cloud rely heavily on virtualization. The service is provided by means of virtual machine. It is not easy task for cloud users to store their valuable data over cloud because of matter of trust over cloud. Data integrity in cloud environm...

High Level Language Virtual Machines is a core topic of interest for the researchers who are into virtual execution environments. As an open source virtual machine released to 16 universities, as early as 2001, Jikes RVM has been a major drive for many researches. While working on this project, we studied the JIT compilation of Jikes RVM as well as the Garbage Collection (GC) which is handled b...

Current distributed shared memory systems suuer from portability problems which hinder popularity. We present a distributed shared memory system as a distributed implementation of the Java Virtual Machine. The proposed system is unique in that it provides a user-friendly, exible programming model based on pure Java. It is an object-based memory system which maintains the synchronization scope a...

This thesis expands upon an existing system called Golondrina that performs autonomic workload management among a cluster of hardware nodes running operating system-level virtualization. Golondrina works by identifying localized resource stress situations and attempting to dissipate them by reallocating system resources and, if necessary, migrating or replicating virtual machines. It is predict...