并发程序路径剖析技术研究

Path profiling collects the frequencies of paths during a routine of executions. It analyzes the source code of the target program, encodes all executable paths, instruments the program and collects the data during program running.Related profling techniques mainly focus on single-threaded programs and cannot meet the needs of profiling concurrent programs, which have been wildly used nowadays...The control flow of concurrent program is very complicated because the threads are possible to be spawned, suspended and resumed at various positions during execution. Hence, it is necessary to address the problem that how to trace the concurruent program execution and provide useful information. Based on prior techniques, we focus on applicable and efficient profiling of concurrent programs, and plan to make optimizations over loops, thread interaction and profiling requirements, so as to reduce profiling costs and imporve the value of profiling results. Such optimizations include following parts: (a) on acyclic concurrent programs, we can enumerate all possible executable paths, and use as simple as possible instrumentation to achieve accurate encoding over these paths; (b) on selective profiling, we can identify the uninterested paths during execution, and terminate them as soon as possible for better efficiency, which also makes many static paths unexecutable, and can elimate them from the encoding; (c) on method-level profiling, the control flow is coarse-grained and simpler, and we can perform smarter profiling for this situation; (d) with the information of synchronization, we can identify more unexecutable paths, and improve the profiling efficiency to the next level...Furthermore, we need to design feasible implementation of our algorithm, which can automatically analyze the given concurrent programs, perform instrumentaion, collect the information of execution, and report the profiles, so as to support the empirical study and necessary evaluation.

路径剖析技术通过路径编码、探针语句插装等方式获知程序执行过程中的路径频率信息，其结果广泛应用于软件的分析和优化之中。传统的剖析方法往往集中于单线程程序，随着并发程序的广泛应用，针对并发程序的剖析技术研究日益急迫。并发程序因其生成线程的特点和执行时的灵活性，导致其控制流结构较单线程程序更为复杂和难以跟踪。本课题拟在现有剖析技术的研究成果基础之上，针对如何剖析并发程序之中的路径进行思考和探索，寻找可行、高效、高价值的剖析方案，特别是针对并发程序中的循环情况、线程交互特性和实际需求进行具体分析,依据应用的特点尽可能降低剖析的耗费、提高剖析结果的参考意义，以提高效率和应用空间。. 在此基础之上，我们还需要按照并发程序的特点设计可行的剖析技术实现方式，能够自动地对剖析目标进行分析、插装、信息收集和结果输出，以支持相应的实证研究。

路径剖析技术通过路径编码、探针语句插装等方式获知程序执行过程中的路径频率信息，其结果广泛应用于软件的分析和优化之中。传统的剖析方法往往集中于单线程程序，随着并发程序的广泛应用，针对并发程序的剖析技术研究日益急迫。并发程序因其生成线程的特点和执行时的灵活性，导致其结构和功能较单线程程序更为复杂和难以跟踪。项目在现有剖析技术的研究成果基础之上，针对如何剖析并发程序的问题进行了探索，主要进展包括：（1）并发程序信息提取技术，能够从代码中提取与剖析相关的线程内、线程间两部分信息；（2）并发程序剖析技术，基于提取到的信息构建剖析模型，实现并发程序插装和剖析结果获取；（3）剖析应用技术，将所得并发程序剖析的中间结果和最终结果应用于测试、切片和程序理解等三个方面，改善相应领域的技术的精度和效率。