Performance Evaluation of Exception Handling in I/O Libraries

Lack of data quantifying the performance cost of implementing good exception handling often causes developers to skimp on exception handling based on its overestimated perceived cost. In an effort to remedy this problem we provide performance data on the cost of building good exception handling into software. We use the Safe Fast IO library as a basis for this study. SFIO improves robustness by a factor of 3 to 10 over STDIO without sacrificing performance. We were able to improve the robustness of the critical SFIO functions by another factor of 5, thus quantifying and reducing robustness failure rates by a factor of up to 70 from standard I/O functions, with an average performance penalty of 1% as measured by the original SFIO benchmark scheme. Future processor architecture improvements will further improve checking speed, essentially eliminating performance as an obstacle to improving software robustness.