Low-overhead memory leak detection using adaptive statistical profiling

Abstract

Sampling has been successfully used to identify performance optimization opportunities. We would like to apply similar techniques to check program correctness. Unfortunately, sampling provides poor coverage of infrequently executed code, where bugs often lurk. We describe an adaptive profiling scheme that addresses this by sampling executions of code segments at a rate inversely proportional to their execution frequency.To validate our ideas, we have implemented SWAT, a novel memory leak detection tool. SWAT traces program allocations/ frees to construct a heap model and uses our adaptive profiling infrastructure to monitor loads/stores to these objects with low overhead. SWAT reports 'stale' objects that have not been accessed for a 'long' time as leaks. This allows it to find all leaks that manifest during the current program execution. Since SWAT has low runtime overhead (< 5%), and low space overhead (< 10% in most cases and often less than 5%), it can be used to track leaks in production code that take days to manifest. In addition to identifying the allocations that leak memory, SWAT exposes where the program last accessed the leaked data, which facilitates debugging and fixing the leak. SWAT has been used by several product groups at Microsoft for the past 18 months and has proved effective at detecting leaks with a low false positive rate (<10%).

Runtime Verification with State Estimation

“…If the original program executes in time R, and the instrumented program executes in time R + M with monitoring, we say that the monitoring overhead is M R . Recently, a number of techniques have been developed to mitigate the overhead due to RV [13,9,1,14,5]. Common to these approaches is the use of event sampling to reduce overhead.…”

Safe Memory-Leak Fixing for C Programs

“…The most widelyused dynamic approach to handling memory leaks is garbage collection [35,36,37,38], which adds runtime overhead to the program. There is also research on dynamic memoryleak detection [39,40,41,42,43,44,45], which provides the location of an allocation which will be leaked later. However, as discussed before, this information alone is still far away from fixing the leak.…”

Memory Leaks Detection in Java by Bi-abductive Inference

“…Different from static approaches as the above and ours there are dynamic techniques for memory leak detection [10,16,11,23]. The main drawback with dynamic techniques is that they cannot give guarantees.…”