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Auflistung nach Autor:in "Pradel, Michael"

1 - 4 von 4
  • Konferenzbeitrag
    Eventbreak: analyzing the responsiveness of user interfaces through performance-guided test generation
    (Software-engineering and management 2015, 2015) Pradel, Michael; Schuh, Parker; Necula, George; Sen, Koushik
    Event-driven user interface applications typically have a single thread of execution that processes event handlers in response to input events triggered by the user, the network, or other applications. Programmers must ensure that event handlers terminate after a short amount of time because otherwise, the application may become unresponsive. This paper presents EventBreak, a performance-guided test generation technique to identify and analyze event handlers whose execution time may gradually increase while using the application. The key idea is to systematically search for pairs of events where triggering one event increases the execution time of the other event.
  • Konferenzbeitrag
    Monkey See, Monkey Do: Effective Generation of GUI Tests with Inferred Macro Events
    (Software Engineering 2017, 2017) Ermuth, Markus; Pradel, Michael
    Automated testing is an important part of validating the behavior of software with com- plex graphical user interfaces, such as web, mobile, and desktop applications. Despite recent ad- vances in UI-level test generation, existing approaches often fail to create complex sequences of events that represent realistic user interactions. As a result, these approaches cannot reach particular parts of the application under test, which then remain untested. This paper presents a UI-level test generation approach that exploits execution traces of human users to automatically create complex sequences of events that go beyond the recorded traces. The key idea is to infer so-called macro events, i.e., sequences of low-level UI events that correspond to a single logical step of interaction, such as choosing an item of a drop-down menu or filling and submitting a form. The approach builds upon and adapts well-known data mining techniques, in particular frequent subsequence mining and inference of finite state machines. We implement the approach for client-side web applications and apply it to four real-world applications. Our results show that macro-based test generation reaches more pages, exercises more usage scenarios, and covers more code within a fixed testing budget than a purely random test generator.
  • Konferenzbeitrag
    Performance Issues and Optimizations in JavaScript: An Empirical Study
    (Software Engineering 2017, 2017) Selakovic, Marija; Pradel, Michael
    As JavaScript is becoming increasingly popular, the performance of JavaScript programs is crucial to ensure the responsiveness and energy-efficiency of thousands of programs. Yet, little is known about performance issues that developers face in practice and they address these issues. This paper presents an empirical study of 98 fixed performance issues from 16 popular client-side and server-side JavaScript projects. We identify eight root causes of issues and show that inefficient usage of APIs is the most prevalent root cause. Furthermore, we find that most issues are addressed by optimizations that modify only a few lines of code, without significantly affecting the complexity of the source code. By studying the performance impact of optimizations on several versions of the SpiderMonkey and V8 engines, we find that only 42.68% of all optimizations improve performance consistently across all versions of both engines. Finally, we observe that many optimizations are in- stances of patterns applicable across projects, as evidenced by 139 previously unknown optimization opportunities that we find based on the patterns identified during the study. The results of the study help application developers to avoid common mistakes, researchers to develop performance-related techniques that address relevant problems, and engine developers to address prevalent bottleneck patterns.
  • Konferenzbeitrag
    Performance regression testing of concurrent classes
    (Software-engineering and management 2015, 2015) Pradel, Michael; Huggler, Markus; Gross, Thomas
    Developers of thread-safe classes struggle with two opposing goals. The class must be correct, which requires synchronizing concurrent accesses, and the class should provide reasonable performance, which is difficult to realize in the presence of unnecessary synchronization. Validating the performance of a thread-safe class is challenging because it requires diverse workloads that use the class, because existing performance analysis techniques focus on individual bottleneck methods, and because reliably measuring the performance of concurrent executions is difficult. This paper presents SpeedGun