Abstract not found

Atomic blocks allow programmers to delimit sections of code as ‘atomic’, leaving the language’s implementation to enforce atomicity. Existing work has shown how to implement atomic blocks over word-based transactional memory that provides scalable multiprocessor performance without requiring changes to the basic structure of objects in the heap. However, these implementations perform poorly because they interpose on all accesses to shared memory in the atomic block, redirecting updates to a thread-private log which must be searched by reads in the block and later reconciled with the heap when leaving the block. This paper takes a four-pronged approach to improving performance: (1) we introduce a new ‘direct access ’ implementation that avoids searching thread-private logs, (2) we develop compiler optimizations to reduce the amount of logging (e.g. when a thread accesses the same data repeatedly in an atomic block), (3) we use runtime filtering to detect duplicate log entries that are missed statically, and (4) we present a series of GC-time techniques to compact the logs generated by long-running atomic blocks. Our implementation supports short-running scalable concurrent benchmarks with less than 50 % overhead over a non-thread-safe baseline. We support long atomic blocks containing millions of shared memory accesses with a 2.5-4.5x slowdown. Categories and Subject Descriptors D.3.3 [Programming Languages]:

Category theorists invented monads in the 1960's to concisely express certain aspects of universal algebra. Functional programmers invented list comprehensions in the 1970's to concisely express certain programs involving lists. This paper shows how list comprehensions may be generalised to an arbitrary monad, and how the resulting programming feature can concisely express in a pure functional language some programs that manipulate state, handle exceptions, parse text, or invoke continuations. A new solution to the old problem of destructive array update is also presented. No knowledge of category theory is assumed.

A simple cosmological model with only six parameters (matter density, Ωmh 2, baryon density, Ωbh 2, Hubble Constant, H0, amplitude of fluctuations, σ8, optical

Writing papers has always been a miracle. The most inspiring person for me in this respect is Simon Peyton Jones, a researcher working for Microsoft Research who has shown 'How to write a good research paper ' [1], among other very inter-esting guidelines [2][3]. In short, Peyton Jones

Programming is a notoriously error-prone process, and a great deal of evidence in practice has demonstrated that the use of a type system in a programming language can effectively detect program errors at compile-time. Moreover, some recent studies have indicated that the use of types can lead to significant enhancement of program performance at run-time. For the sake of practicality of type-checking, most type systems developed for general purpose programming languages tend to be simple and coarse, and this leaves ample room for improvement. As an advocate of types, this thesis addresses the issue of designing a type system for practical programming in which a notion of dependent types is available, leading to more accurate capture of program invariants with types. In contrast to developing a type theory with dependent types and then designing upon it a functional programming language, we study practical methods for extending the type systems of existing programming languages with dep...

this paper). It is a simple, weakly-typed, pure lazy functional language with no pattern-matching or user-dened types. After parsing, the Ginger compiler transforms the source tree into a set of supercombinators (functions in which no free variables occur, see Section 13.2.1 of Peyton Jones (1987)

Haskell (Peyton Jones, 2003) is often used as a host for another language. Typically, the abstract syntax of the guest language is defined by a bunch of data type declarations; parsers and pretty-printers convert between the concrete syntax and its abstract representation. A quote

Haskell (Peyton Jones, 2003) is often used as a host language for embedding other languages. Typically, the abstract syntax of the guest language is defined by a collection of datatype declarations; parsers and pretty-printers convert between the concrete syntax and its abstract representation. A

We show how a set of building blocks can be used to construct programming language interpreters, and present implementations of such building blocks capable of supporting many commonly known features, including simple expressions, three different function call mechanisms (call-by-name, callby -value and lazy evaluation), references and assignment, nondeterminism, first-class continuations, and program tracing. The underlying mechanism of our system is monad transformers, a simple form of abstraction for introducing a wide range of computational behaviors, such as state, I/O, continuations, and exceptions. Our work is significant in the following respects. First, we have succeeded in designing a fully modular interpreter based on monad transformers that includes features missing from Steele's, Espinosa's, and Wadler's earlier efforts. Second, we have found new ways to lift monad operations through monad transformers, in particular difficult cases not achieved in Moggi's original work. ...