Connectivity graphs: a method for proving deadlock freedom based on separation logic

We introduce the notion of a connectivity graph —an abstract representation of the topology of concurrently interacting entities, which allows us to encapsulate generic principles of reasoning about deadlock freedom . Connectivity graphs are parametric in their vertices (representing entities like threads and channels) and their edges (representing references between entities) with labels (representing interaction protocols). We prove deadlock and memory leak freedom in the style of progress and preservation and use separation logic as a meta theoretic tool to treat connectivity graph edges and labels substructurally. To prove preservation locally, we distill generic separation logic rules for local graph transformations that preserve acyclicity of the connectivity graph. To prove global progress locally, we introduce a waiting induction principle for acyclic connectivity graphs. We mechanize our results in Coq, and instantiate our method with a higher-order binary session-typed language to obtain the first mechanized proof of deadlock and leak freedom.

An Ml-Based Memory Leak Detection Scheme for Network Devices

The network is very important to the normal operation of all aspects of society and economy, and the memory leak of network device is a software failure that seriously damages the stability of the system. Some common memory checking tools are not suitable for network devices that are running online, so the operation staff can only constantly monitor the memory usage and infer from experience, which has been proved to be inefficient and unreliable. In this paper we proposed a novel memory leak detection method for network devices based on Machine learning. It first eliminates the impact of large-scale resource table entries on the memory utilization. Then, by analyzing its monotonicity and computing the correlation coefficient with the memory leak sequence sets pre constructed by simulation, the memory leak fault can be found in time. The simulation experiments show that the scheme is computationally efficient and the precision rate is close to 100%, it works well in the actual network environment, and has excellent performance.

Guided Exploration

Many monitoring tools that help developers in analyzing the run-time behavior of their applications share a common shortcoming: they require their users to have a fair amount of experience in monitoring applications to understand the used terminology and the available analysis features. Consequently, novice users who lack this knowledge often struggle to use these tools efficiently. In this paper, we introduce the guided exploration (GE) method that aims to make interactive monitoring tools easier to use and learn. In general, tools that implement GE should provide four support operations on each analysis step: they should automatically (1) detect and (2) highlight the most important information on the screen, (3) explain why it is important, and (4) suggest which next steps are appropriate. This way, tools guide users through their analysis processes, helping them to explore the root cause of a problem. At the same time, users learn the capabilities of the tool and how to use them efficiently. We show how GE can be implemented in new monitoring tools as well as how it can be integrated into existing ones. To demonstrate GE's feasibility and usefulness, we present how we extended the memory monitoring tool AntTracks to provided guided exploration support during memory leak analysis and memory churn analysis. We use these guidances in two user scenarios to inspect and improve the memory behavior of the monitored applications. We hope that our contribution will help usability researchers and developers in making monitoring tools more novice-friendly by improving their usability and learnability.

An Automated Approach of Detection of Memory Leaks for Remote Server Controllers

Memory leaks are a major concern to the long running applications like servers which make the working set to grow with the program. This eventually leads to system crashing. This paper discusses a staged approach to detect leaks in firmware of remote server controller. Remote server controller monitors the server remotely with many processes running in the background. Any memory leak in the long running applications pose a threat to the performance of the system. The approach adopted here filters the processes running in the system with leaks based on time threshold in the first stage. These processes with leaks are passed to the next stage where precise memory leak detection is done using the open source dynamic instrumentation tool Valgrind. The system leverages an automated leak detection approach that invokes the leak detection process on encountering any severity in the system and generates a consolidated leak report. The proposed approach has less impact on the performance of the system and is faster compared to many available systems as there is no need to modify or re-compile the program. In addition, the automated approach offers an effective technique for detecting possible leakages in early software development phases.

Penerapan Agile Unified Process Pada Pengembangan Aplikasi Puasa Ramadhan Berbasis Mobile Android

Bulan Ramadhan merupakan bulan yang istimewa dalam agama Islam, sehingga setiap orang berusaha melakukan ibadah di bulan Ramadhan sebanyak-banyaknya. Keterbatasan waktu dan tempat untuk mengetahui amalan yang ada pada bulan Ramadhan, membuat kurang maksimalnya ibadah yang dilakukan pada bulan Ramadhan. Pengembangan aplikasi Puasa Ramadhan bertujuan guna membantu umat Islam dalam menjalankan puasa Ramadhan. Aplikasi Puasa Ramadhan berbasis Android dikembangkan menggunakan bahasa pemrograman Java dengan metode pengembangan Agile Unified Process (AUP). Penelitian ini menghasilkan sebuah aplikasi Puasa Ramadhan berbasis Android yang dibangun menggunakan metode pengembangan AUP. Hasil pengujian standar ISO 25010 menunjukan apabila aplikasi telah memenuhi pada kriteria compatibility dengan nilai 96.5% atau sangat layak dan performance efficiency berjalan dengan baik tanpa terjadi memory leak atau force close.