Automatic Non-functional Testing of Code Generators Families

International audienceThe intensive use of generative programming techniques provides an elegant engineering solution to deal with the heterogeneity of platforms and technological stacks. The use of domain-specific languages for example, leads to the creation of numerous code generators that automatically translate highlevel system specifications into multi-target executable code. Producing correct and efficient code generator is complex and error-prone. Although software designers provide generally high-level test suites to verify the functional outcome of generated code, it remains challenging and tedious to verify the behavior of produced code in terms of non-functional properties. This paper describes a practical approach based on a runtime monitoring infrastructure to automatically check the potential inefficient code generators. This infrastructure, based on system containers as execution platforms, allows code-generator developers to evaluate the generated code performance. We evaluate our approach by analyzing the performance of Haxe, a popular high-level programming language that involves a set of cross-platform code generators. Experimental results show that our approach is able to detect some performance inconsistencies that reveal real issues in Haxe code generators

A multidimensional empirical study on refactoring activity

Abstract In this paper we present an empirical study on the refactoring activity in three well-known projects. We have studied five research questions that explore the different types of refactorings applied to different types of sources, the individual contribution of team members on refactoring activities, the alignment of refactoring activity with release dates and testing periods, and the motivation behind the applied refactorings. The studied projects have a history of 12, 7, and 6 years, respectively. We have found that there is very little variation in the types of refactorings applied on test code, since the majority of the refactorings focus on the reorganization and renaming of classes. Additionally, we have identified that the refactoring decision making and application is often performed by individual refactoring "managers". We have found a strong alignment between refactoring activity and release dates. Moreover, we found that the development teams apply a considerable amount of refactorings during testing periods. Finally, we have also found that in addition to code smell resolution the main drivers for applying refactorings are the introduction of extension points, and the resolution of backward compatibility issues

Detecting Cognitive Ability Changes in Patients With Moderate Dementia Using a Modified ''Whack-a-Mole'' Game

This paper presents the results from a one-year study of 12 patients with moderate dementia in an adult day program who played a novel whack-a-mole game-based measurement instrument for cognitive behavior and performance. The ongoing measurement of cognition and changes associated with dementia is a challenge for healthcare providers. Measurement methods based on a tablet-based instrument are proposed. Partnership with the adult day program greatly eased recruitment: all but 1 eligible participant joined our study, compared to one in five, or lower, for previous studies with similar populations. There are three unique aspects to the design of our game: first, it has two distinct targets requiring different actions, which increases the cognitive processing for the users; second, each level is systematically more difficult; third, it records and analyzes player performance. The results show that the patients' game performance improves over the first few weeks; this indicates that they are learning the game and retaining ability gains from week-to-week, suggesting some procedural learning is still intact. Over the year, 4 participants showed cognitive decline, 4 were stable and 3 improved based on their Minimental State Exam (MMSE) score. Two measures are proposed based on level progression within the sessions and mole hit performance. The level progression measure identifies declining participants with one false negative (FN) and one false positive error. The mole hit performance measure identifies declining participants with one FN error. These results demonstrate the potential for the proposed instrument to provide an ongoing measurement as an alternative for the repeated application of the MMSE

Monitoring cognitive ability in patients with moderate dementia using a modified 'whack-a-mole'

This paper presents results from the first 2 months of a 1-year study of 12 moderate dementia patients that participate in a weekly adult day program within a local community-care access center. The 12 patients are using a tablet-based whack-a-mole game, instrumented to record the user's behavior; this record is analyzed to extract indicators, as potential proxies of cognitive ability. Our partnership with the adult day program greatly eased recruitment: all but 1 eligible participant joined our study. The measurements recorded by the game include the detailed user progression through the game levels. There are two unique aspects to the design of our game: first, it includes two distinct targets requiring different actions, which increases the cognitive processing in the tap task for the users; second, each level is systematically more difficult than the last. The results show that the patients' performance within the game improves over the first few weeks; this indicates that they are learning the game and retaining ability gains from week to week, which is unexpected in dementia patients. Subsequently they appear to reach a performance plateau, with consistent performance from one week to the next. The performance levels are compared to their MMSE Total score and MMSE Orientation for Time sub-score and they are shown to have a maximum correlation of 0.465 and 0.654 respectively. These results demonstrate the potential for the whack-a-mole game to provide an ongoing measurement alternative for the MMSE and specifically the Orientation for Time sub-score that is a predictor of future decline