Inductive Proof Outlines for Monitors in Java

Abstract. The research concerning Java’s semantics and proof theory has mainly focussed on various aspects of sequential sub-languages. Java, however, integrates features of a class-based object-oriented language with the notion of multi-threading, where multiple threads can concurrently execute and exchange information via shared instance variables. Furthermore, each object can act as a monitor to assure mutual exclusion or to coordinate between threads. In this paper we present a sound and relatively complete assertional proof system for Java’s monitor concept, which generates verification conditions for a concurrent sublanguage JavaMT of Java. This work extends previous results by incorporating Java’s monitor methods

Assignment as the Sole Means of Updating Objects

this paper, no differentiation is made between functions and procedures. All programs are called routines, some of these may return values

The Relationship between Syntactic Structure Analysis Features, Histological Grade and High-Risk HPV DNA in Cervical Intraepithelial Neoplasia

Aim: To assess the correlation between syntactic structure analysis (SSA) features, revised dysplasia grade and the presence of high‐risk human papillomavirus DNA in cervical intraepithelial neoplasia (CIN). Materials and methods: HPV polymerase chain reaction (PCR) was assessed in 101 consecutive biopsies and consensus in CIN grade between the experts occurred in 88 cases (CIN1=16, CIN2=27, CIN3=45). SSA was performed in the diagnostic histological section of the CIN lesions in these patients and SSA features were compared with the blind review CIN grade, and presence/absence of high‐risk HPV DNA. Results: One of the SSA features (points from which the surrounding surfaces has 4 edges, PECO‐4) was significantly different between all three consensus CIN grades. Many more features revealed significant differences between CIN1 and CIN2 or between CIN2 and CIN3 cases. With stepwise discriminant analysis, the best multivariate combination of features to distinguish the different CIN grades were the Maximum MST Line Length (MML) and the Area Disorder. Crude overall classification of the consensus grades with these features was 69%. The MML and the Area Disorder is also the best combination to distinguish cases with and without high‐risk HPV DNA (77% correct classifications). Conclusions: SSA features are correlated with both CIN grade and presence of high‐risk HPV DNA, but the discrimination power is not good enough to be used as a routine method for quality control of subjective grade or as a surrogate marker for high‐risk HPV DNA presence

Weak Fairness Semantic Drawbacks in Java Multithreading

International audienceWith the development of embedded and mobile systems, Java is being widely used for application programs and is also considered for implementing systems kernel or application platforms. It is the aim of this paper to exemplify some subtle programming errors that may result from the process queuing and awaking policy, which corresponds to a weak fairness semantic and which has been chosen for implementing the monitor concept in this language. Two examples show some subtle deadlocks resulting from this policy. The first example deals with process synchronization: processes seeking after partners for a peer-to-peer communication call a symmetrical rendezvous server. The second example concerns resource sharing according to a solution of the dining philosophers paradigm. In this example, several implementations are presented, the last ones aiming to provide deterministic process awakening. All these examples have been validated and simulated and this allows comparing their concurrency complexity and effectiveness. Our conclusion is, first, that the use of Java for multithreading programming necessitates sometimes additional shielding code for developing correct programs and, second, that a good acquaintance with several styles of concurrent programming helps designing more robust Java solutions, once the choice of the implementation language is irrevocable

Action-Oriented Exception Handling in Cooperative and Competitive Concurrent Object-Oriented Systems

. The chief aim of this survey is to discuss exception handling models which have been developed for concurrent object systems. In conducting this discussion we rely on the following fundamental principles: exception handling should be associated with structuring techniques; concurrent systems require exception handling which is different from that used in sequential systems; concurrent systems are best structured out of (nested) actions; atomicity of actions is crucial for developing complex systems. In this survey we adhere to the wellknown classification of concurrent systems, developed in the 70s by C.A.R. Hoare, J.J. Horning and B. Randell, into cooperative, competitive and disjoint ones. Competitive systems are structured using atomic transactions. Atomic actions are used for structuring cooperative systems. Complex systems in which components can compete and cooperate are structured using Coordinated Atomic actions. The focus of the survey is on outlining models and ..