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Jinbao Chen

Publications and source records attributed to Jinbao Chen.

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An Empirical Study of CGO Usage in Go Projects -- Distribution, Purposes, Patterns and Critical Issues

Multilingual software development integrates multiple languages into a single application, with the Foreign Function Interface (FFI) enabling seamless interaction. While FFI boosts efficiency and extensibility, it also introduces risks. Existing studies focus on FFIs in languages like Python and Java, neglecting CGO, the emerging FFI in Go, which poses unique risks. To address these concerns, we conduct an empirical study of CGO usage across 920 open-source Go projects. Our study aims to reveal the distribution, patterns, purposes, and critical issues associated with CGO, offering insights for developers and the Go team. We develop CGOAnalyzer, a tool to efficiently identify and quantify CGO-related features. Our findings reveal that: (1) 11.3% of analyzed Go projects utilize CGO, with usage concentrated in a subset of projects; (2) CGO serves 4 primary purposes, including system-level interactions and performance optimizations, with 15 distinct usage patterns observed; (3) 19 types of CGO-related issues exist, including one critical issue involving unnecessary pointer checks that pose risks of runtime crashes due to limitations in the current Go compilation toolchain; (4) a temporary solution reduces unnecessary pointer checks, mitigating crash risks, and (5) we submitted a proposal to improve the Go toolchain for a permanent fix, which has been grouped within an accepted proposal for future resolution. Our findings provide valuable insights for developers and the Go team, enhancing development efficiency and reliability while improving the robustness of the Go toolchain.

cs.SE

Utilizing Precise and Complete Code Context to Guide LLM in Automatic False Positive Mitigation

Static Application Security Testing (SAST) tools are critical to software quality, identifying potential code issues early in development. However, they often produce false positive warnings that require manual review, slowing down development. Thus, automating false positive mitigation (FPM) is essential. The advent of Large Language Models (LLMs), with their strong abilities in natural language and code understanding, offers promising avenues for FPM. Yet current LLM-based FPM method faces two major limitations: 1. The warning-related code snippets extracted are overly broad and cluttered with irrelevant control/data flows, reducing precision; 2. Critical code contexts are missing, leading to incomplete representations that can mislead LLMs and cause inaccurate assessments. To overcome these limitations, we propose LLM4FPM , a lightweight and efficient false positive mitigation framework. It features eCPG-Slicer, which builds an extended code property graph (eCPG) to extract precise line-level code contexts for warnings. Furthermore, the integrated FARF algorithm builds a file reference graph to identify all files that are relevant to warnings in linear time. This enables eCPG-Slicer to obtain rich contextual information without resorting to expensive whole-program analysis. LLM4FPM outperforms the existing method on the Juliet dataset (F1 > 99% across various Common Weakness Enumerations) and improves label accuracy on the D2A dataset to 86%. By leveraging a lightweight open-source LLM, LLM4FPM can significantly save inspection costs up to \$2758 per run (\$0.384 per warning) on Juliet with an average inspection time of 4.7s per warning. Moreover, real-world tests on popular C/C++ projects demonstrate its practicality.

cs.SE

All-fiber highly efficient delivery of 2 kW laser over 2.45 km hollow-core fiber

Anti-resonant hollow-core fibers (AR-HCFs) have emerged as an important medium for high-power laser delivery due to their low optical nonlinearity and high damage threshold. However, current delivery systems of high-power laser based on AR-HCFs mainly rely on free-space optical components, which limits long-term stability in dynamic environments. Here, we report an all-fiber delivery of 2 kW laser with 85.3% transmission efficiency over 2.45 km, using a self-fabricated AR-HCF with a record low transmission loss of 0.175 dB/km at 1080 nm. This represents a nearly 500-fold improvement in the power-distance product compared to reported all-fiber AR-HCF-based laser transmission systems, achieving a record transmission distance for high-power laser delivery. Notably, we observed the phenomenon of stimulated Raman scattering amplified within the silica nested tubes in AR-HCF for the first time. By effectively suppressing the Raman noise from the laser source, we achieve an all-fiber laser delivery without stimulated Raman scattering of silica glass. This work marks a significant breakthrough in multi-kilometer and multi-kilowatt power delivery that is potentially useful for industrial manufacturing, nuclear decommissioning, laser drilling of oil, particle acceleration and so on.

physics.optics

Greenplum: A Hybrid Database for Transactional and Analytical Workloads

Demand for enterprise data warehouse solutions to support real-time Online Transaction Processing (OLTP) queries as well as long-running Online Analytical Processing (OLAP) workloads is growing. Greenplum database is traditionally known as an OLAP data warehouse system with limited ability to process OLTP workloads. In this paper, we augment Greenplum into a hybrid system to serve both OLTP and OLAP workloads. The challenge we address here is to achieve this goal while maintaining the ACID properties with minimal performance overhead. In this effort, we identify the engineering and performance bottlenecks such as the under-performing restrictive locking and the two-phase commit protocol. Next we solve the resource contention issues between transactional and analytical queries. We propose a global deadlock detector to increase the concurrency of query processing. When transactions that update data are guaranteed to reside on exactly one segment we introduce one-phase commit to speed up query processing. Our resource group model introduces the capability to separate OLAP and OLTP workloads into more suitable query processing mode. Our experimental evaluation on the TPC-B and CH-benCHmark benchmarks demonstrates the effectiveness of our approach in boosting the OLTP performance without sacrificing the OLAP performance.

cs.DB

Statistical inference methods for cumulative incidence function curves at a fixed point in time

Competing risks data arise frequently in clinical trials. When the proportional subdistribution hazard assumption is violated or two cumulative incidence function (CIF) curves cross, rather than comparing the overall treatment effects, researchers may be interested in focusing on a comparison of clinical utility at some fixed time points. This paper extend a series of tests that are constructed based on a pseudo-value regression technique or different transformation functions for CIFs and their variances based on Gaynor's or Aalen's work, and the differences among CIFs at a given time point are compared.

stat.AP