Reproducible Execution of POSIX Programs with DiOS

In this paper, we describe DiOS, a lightweight model operating system which can be used to execute programs that make use of POSIX APIs. Such executions are fully reproducible: running the same program with the same inputs twice will result in two exactly identical instruction traces, even if the program uses threads for parallelism. DiOS is implemented almost entirely in portable C and C++: although its primary platform is DiVM, a verification-oriented virtual machine, it can be configured to also run in KLEE, a symbolic executor. Finally, it can be compiled into machine code to serve as a user-mode kernel. Additionally, DiOS is modular and extensible. Its various components can be combined to match both the capabilities of the underlying platform and to provide services required by a particular program. New components can be added to cover additional system calls or APIs. The experimental evaluation has two parts. DiOS is first evaluated as a component of a program verification platform based on DiVM. In the second part, we consider its portability and modularity by combining it with the symbolic executor KLEE

2009 Sixth International Conference on Information Technology: New Generations Automated Testing of Environment-Dependent Programs − A case study of modeling the File System for Pex

Programs that interact with the file system are a classical challenge for automated software testing. A common approach to handling this problem is to insert an abstraction layer between the application and the file system. However, even with a well-defined abstraction layer, the burden on the software developer or tester is still high: they have to understand the subtleties of the file system to craft a meaningful set of test cases. The file system is accessed through a complex API, which often causes developers to overlook obscure yet possible corner cases. In this paper, we present a parameterized model of the file system that can be used in conjunction with Pex, an automated test generation tool, to test code that depends on the file system