Hoare-style Specifications as Correctness Conditions for Non-linearizable Concurrent Objects

Designing scalable concurrent objects, which can be efficiently used on multicore processors, often requires one to abandon standard specification techniques, such as linearizability, in favor of more relaxed consistency requirements. However, the variety of alternative correctness conditions makes it difficult to choose which one to employ in a particular case, and to compose them when using objects whose behaviors are specified via different criteria. The lack of syntactic verification methods for most of these criteria poses challenges in their systematic adoption and application. In this paper, we argue for using Hoare-style program logics as an alternative and uniform approach for specification and compositional formal verification of safety properties for concurrent objects and their client programs. Through a series of case studies, we demonstrate how an existing program logic for concurrency can be employed off-the-shelf to capture important state and history invariants, allowing one to explicitly quantify over interference of environment threads and provide intuitive and expressive Hoare-style specifications for several non-linearizable concurrent objects that were previously specified only via dedicated correctness criteria. We illustrate the adequacy of our specifications by verifying a number of concurrent client scenarios, that make use of the previously specified concurrent objects, capturing the essence of such correctness conditions as concurrency-aware linearizability, quiescent, and quantitative quiescent consistency. All examples described in this paper are verified mechanically in Coq.Comment: 18 page

Openness and Total Factor Productivity: Test of Temporal Coincidence of the Structural Breaks for Latin America and the Caribbean

We study the existence of structural break in TFP and in several indicators of openness for a sample of 20 Latin American and Caribbean economies for the period 1960-2005. For this purpose, it has been used the test of Zivot and Andrews (1992) on series of TFP computed from a development accounting exercise (Hsieh and Klenow, 2010) and alternative measures of openness with different characters: openness policies, openness as result, and measure of deviation (Wacziarg, 2001). The accumulation of cases, both potential and significant breaks in TFP are in line with the Oil Crisis of 1973/4 and 1979/80, and the Mexican Crisis of 1982. The cases of breaks on TFP during the consolidation process of openness in the region (1985-95) are not significant. Shocks in openness seem to have effects on the rate of growth of TFPApertura, Productividad Total de los Factores, America Latina y el Caribe

Apertura y Productividad Total de los Factores: Análisis de la contemporaneidad en los quiebres estructurales para América Latina y el Caribe

We study the existence of structural break in TFP and in several indicators of openness for a sample of 20 Latin American and Caribbean economies for the period 1960-2005. For this purpose, it has been used the test of Zivot and Andrews (1992) on series of TFP computed from a development accounting exercise (Hsieh and Klenow, 2010) and alternative measures of openness with different characters: openness policies, openness as result, and measure of deviation (Wacziarg, 2001). The accumulation of cases, both potential and significant breaks in TFP are in line with the Oil Crisis of 1973/4 and 1979/80, and the Mexican Crisis of 1982. The cases of breaks on TFP during the consolidation process of openness in the region (1985-95) are not significant. Shocks in openness seem to have effects on the rate of growth of TF

Apertura y productividad total de los factores: análisis de la contemporaneidad en los quiebres estructurales para América Latina y el Caribe.

Se ha estudiado la existencia de quiebres estructurales en la PTF y en varios indicadores de apertura para una muestra de 20 economías latinoamericanas y del Caribe para el período 1960-2005. Se han utilizado los tests de Zivot y Andrews (1992) y el de Bai Perron (1998) sobre una serie de PTF computada a partir de un ejercicio de contabilidad del desarrollo (Hsieh y Klenow, 2010) y sobre medidas alternativas de apertura con diferentes caracteres (Wacziarg, 2001). Los casos de quiebre en la PTF durante el proceso de consolidación de la apertura en la región (1985-1995) no son significativos. Los resultados parecen indicar que los shocks en la apertura operan sobre las tasas de crecimiento de la PTF.Openness, Total Factor Productivity, Latin America and the Caribbean