Pinso: Precise Isolation of Concurrency Bugs via Delta Triaging

Concurrent programs are known to be difficult to test and maintain. These programs often fail because of concurrency bugs caused by non-deterministic interleavings among shared memory accesses. Even though a concurrency bug can be detected, it is still hard to isolate the root cause of the bug, due to the challenge in understanding the complex thread interleavings or schedules. In this paper, we propose a practical and precise isolation technique for concurrent bugs called Pinso that seeks to exploit the non-deterministic nature of concurrency bugs and accurately find the root causes of program error, to further help developers maintain concurrent programs. Pinso profiles runtime inter-thread interleavings based on a set of summarized memory access patterns, and then, isolates suspicious interleaving patterns in the triaging phase. Using a filtration-oriented scheduler, Pinso effectively eliminates false positives that are irrelevant to the bug. We evaluate Pinso with 11 real-world concurrency bugs, including single- and multi-variable violation, from sever/desktop concurrent applications (MySQL, Apache, and several others). Experiments indicate that our tool accurately isolates the root causes of all the bugs.