Refactoring GrPPI:Generic Refactoring for Generic Parallelism in C++

Funding: EU Horizon 2020 project, TeamPlay (https://www.teamplay-xh2020.eu), Grant Number 779882, UK EPSRC Discovery, grant number EP/P020631/1, and Madrid Regional Government, CABAHLA-CM (ConvergenciA Big dAta-Hpc: de Los sensores a las Aplicaciones) Grant Number S2018/TCS-4423.The Generic Reusable Parallel Pattern Interface (GrPPI) is a very useful abstraction over different parallel pattern libraries, allowing the programmer to write generic patterned parallel code that can easily be compiled to different backends such as FastFlow, OpenMP, Intel TBB and C++ threads. However, rewriting legacy code to use GrPPI still involves code transformations that can be highly non-trivial, especially for programmers who are not experts in parallelism. This paper describes software refactorings to semi-automatically introduce instances of GrPPI patterns into sequential C++ code, as well as safety checking static analysis mechanisms which verify that introducing patterns into the code does not introduce concurrency-related bugs such as race conditions. We demonstrate the refactorings and safety-checking mechanisms on four simple benchmark applications, showing that we are able to obtain, with little effort, GrPPI-based parallel versions that accomplish good speedups (comparable to those of manually-produced parallel versions) using different pattern backends.Publisher PDFPeer reviewe

Exercise training has greater effects on insulin sensitivity in daughters of patients with type 2 diabetes than in women with no family history of diabetes

Aims/hypothesis. Sedentary offspring of patients with type 2 diabetes are often more insulin-resistant than persons with no family history of diabetes, but when active or fit offspring of type 2 diabetic patients are compared with non-diabetic persons, differences in insulin resistance are less evident. This study aimed to determine the effects of an exercise training intervention on insulin sensitivity in both groups. Methods. Women offspring (n=34) of type 2 diabetic patients (offspring age 35.6+/-7.0 years, BMI 28.1+/-5.1 kg/m(2)) and 36 matched female controls (age 33.6+/-6.1 years, BMI 27.3+/-4.7 kg/m(2)) participated. Body composition, fitness and metabolic measurements were made at baseline and after a controlled 7 week exercise intervention. Results. At baseline, insulin sensitivity index (ISI) was 22% lower in offspring than controls (p < 0.05), despite similar body fat and maximal oxygen uptake ((V)over dotO(2max)) values in the two groups. ISI increased by 23% (p < 0.05) in offspring following the exercise intervention, compared with 7% (NS) in the controls. Increases in ((V)over dotO(2max))were similar in both groups (controls 12%, offspring 15%, p < 0.05 for both). Plasma leptin concentrations decreased significantly in the offspring (-24%, p < 0.01) but not in controls (0%, NS). Change in ISI correlated significantly with baseline ISI (r=-0.47, p < 0.0005) and change in leptin (r=-0.43, p < 0.0005). The latter relationship was not attenuated by adjustment for changes in body fat. Conclusions/interpretation. Offspring, but not controls, significantly increased ISI in response to an exercise intervention, indicating that insulin sensitivity is more highly modulated by physical activity in daughters of patients with type 2 diabetes than in women with no family history of the disease