Implementation, Compilation, Optimization of Object-Oriented Languages, Programs and Systems - Report on the Workshop ICOOOLPS'2006 at ECOOP'06

ICOOOLPS'2006 was the first edition of ECOOP-ICOOOLPS workshop. It intended to bring researchers and practitioners both from academia and industry together, with a spirit of openness, to try and identify and begin to address the numerous and very varied issues of optimization. This succeeded, as can be seen from the papers, the attendance and the liveliness of the discussions that took place during and after the workshop, not to mention a few new cooperations or postdoctoral contracts. The 22 talented people from different groups who participated were unanimous to appreciate this first edition and recommend that ICOOOLPS be continued next year. A community is thus beginning to form, and should be reinforced by a second edition next year, with all the improvements this first edition made emerge.Comment: The original publication is available at http://www.springerlink.co

Cooking the Books: Formalizing JMM Implementation Recipes

The Java Memory Model (JMM) is intended to characterize the meaning of concurrent Java programs. Because of the model\u27s complexity, however, its definition cannot be easily transplanted within an optimizing Java compiler, even though an important rationale for its design was to ensure Java compiler optimizations are not unduly hampered because of the language\u27s concurrency features. In response, Lea\u27s JSR-133 Cookbook for Compiler Writers, an informal guide to realizing the principles underlying the JMM on different (relaxed-memory) platforms was developed. The goal of the cookbook is to give compiler writers a relatively simple, yet reasonably efficient, set of reordering-based recipes that satisfy JMM constraints. In this paper, we present the first formalization of the cookbook, providing a semantic basis upon which the relationship between the recipes defined by the cookbook and the guarantees enforced by the JMM can be rigorously established. Notably, one artifact of our investigation is that the rules defined by the cookbook for compiling Java onto Power are inconsistent with the requirements of the JMM, a surprising result, and one which justifies our belief in the need for formally provable definitions to reason about sophisticated (and racy) concurrency patterns in Java, and their implementation on modern-day relaxed-memory hardware. Our formalization enables simulation arguments between an architecture-independent intermediate representation of the kind suggested by Lea with machine abstractions for Power and x86. Moreover, we provide fixes for cookbook recipes that are inconsistent with the behaviors admitted by the target platform, and prove the correctness of these repairs

One Stack to Run Them All Reducing Concurrent Analysis to Sequential Analysis Under Priority Scheduling

Abstract. We present a reduction from a concurrent real-time program with priority preemptive scheduling to a sequential program that has the same set of behaviors. Whereas many static analyses of concurrent programs are undecidable, our reduction enables the application of any sequential program analysis to be applied to a concurrent real-time program with priority preemptive scheduling.

On Julia\u27s Efficient Algorithm for Subtyping Union Types and Covariant Tuples (Artifact)

This is the artifact for the pearl paper "On Julia\u27s efficient algorithm for subtyping union types and covariant tuples.

Frangibility Quantification of Frangible Bullet upon Impact on a Hard Target

The article presents a new method of quantitative evaluation of the degree of disintegration, called frangibility of frangible bullets, based on shooting experiments. On the basis of the dependence of the Frangibility Factor of the bullet on its impact velocity, the frangibility index is determined as a quantifier of the projectile’s ability to disintegrate into fragments applied for a certain range of interest. The method can be used to assess the ability to disintegrate into fragments of various types of bullets, preferably frangible bullets produced by powder metallurgy technologies. The proposed method was used to quantify the frangibility of five experimental frangible bullets