handler and consumer handler objects that run in separate threads and route messages from one or more remote suppliers to one or more remote consumers, respectively. When a supplier handler thread receives a message from a remote supplier, it uses an address field in the message to determine the corresponding consumer handler, whose thread then delivers the message to its remote consumer. When ...

We explore the semantics and analysis of a new kind of control structure called a versioning exception that ensures the state of the program, at the point when an exception handler is invoked, reflects the program state at the point when the handler is installed. Versioning exceptions provide a transaction-like versioning semantics to the code protected by a handler: modifications performed wit...

Over the last few decades, distributed systems have demonstrated architectural evolvement. One recent evolutionary step is Service-Oriented Architecture (SOA). The SOA model is perfectly engendered in Web services, which provide software platforms to build applications as services. Web services utilize supportive capabilities such as security, reliability, and monitoring. These capabilities are...

Over the last couple of decades, distributed systems have been demonstrated an architectural evolvement based on models including client/server, multi-tier, distributed objects, messaging and peer-to-peer. One recent evolutionary step is Service Oriented Architecture (SOA), whose goal is to achieve loose-coupling among the interacting software applications for scalability and interoperability. ...

A good design of human-computer interface can make the communication more effective, more easily and less mistaking guidance for users. In order to realize the rapid construction and dynamic reconfiguration of human-computer interface, a rapid developing model based on component assembly was proposed recurring to an assistant design tool developed self-owned, as well as the assembly models of d...

This paper presents a software architecture that enables the application-specific processing of messages on network processors attached to cluster machines. Such processing is performed by stream handlers executed on such attached network processors (ANPs) and able to manipulate both message headers and their data content. Handler execution can be associated with the ANPs’ receive side, its tra...

Memory virtualization by means of demand paging is a crucial component of every modern operating system. The formal verification is challenging since reasoning about the page fault handler has to cover two concurrent computational sources: the processor and the hard disk. We accurately model the interleaved executions of devices and the page fault handler, which is written in a high-level progr...

Figure 1. Traditional vs. Multithreaded Exception Handling. Six instructions have been fetched when an exception is detected on the fourth. Traditionally (a), instructions 4-6 are squashed and must be refetched after the exception handler is fetched. With our multithreaded mechanism (b), a second thread fetches the exception handler (AD), and then the main thread continues to fetch (7,8). The e...

All practical MPC implementations should have a means to recover from infeasibility. We present a recently developed infeasibility handler which computes optimal relaxations of the relaxable constraints subject to a user-de ned prioritization, by solving only a single linear program on-line in addition to the standard quadratic programming problem on-line. A stability result for this infeasibil...