Selective capture and replay of program executions

In this paper, we present a technique for selective capture and replay of program executions. Given an application, the technique allows for (1) selecting a subsystem of interest, (2) capturing at runtime all the interactions between such subsystem and the rest of the application, and (3) replaying the recorded interactions on the subsystem in isolation. The technique can be used in several scenarios. For example, it can be used to generate test cases from users' executions, by capturing and collecting partial executions in the field. For another example. it can be used to perform expensive dynamic analyses off-line. For yet another example, it can be used to extract subsystem or unit tests from system tests. Our technique is designed to be efficient, in that we only capture information that is relevant to the considered execution. To this end, we disregard all data that, although flowing through the boundary of the subsystem of interest, do not affect the execution. In the paper, we also present a preliminary evaluation of the technique performed using SCARPE, a prototype tool that implements our approach.