A Bug Locating Method for the Debugging of Parallel Discrete Event Simulation

Debugging is critically important for diagnosing bugs of programs. In optimistic Parallel Discrete Event Simulation(PDES), a bug is probably not to be reproduced for the different orders of event processing in different simulation runs, so locating bugs is of great challenge in debugging PDES programs. To solve this problem, we first propose a bug reproducing method based on checkpoint/restart mechanism, which avoids starting the program from scratch when an error emerges. Moreover, our method can change the checkpoint interval dynamically to reduce the overhead of states saving. Then, based on bug reproduction we propose a bug locating method, which aims at searching for these events that cause the bugs likely by comparing the event processing sequences between one passing test case and the failing test case. By doing this, we can focus on the events directly related to the bugs, which will reduce the time of locating a bug.