SkyPat is a C++ performance analysis toolkit. SkyPat combines unit tests and perf_event to give programmers the power of accomplishing reliability and performance test simultaneously. Unlike traditional tools that manipulate entire program as a black-box, SkyPat works on a region of code like a white-box. It is used as a normal unit test library. It provides macros and assertions, into which perf_events are embedded, to ensure correctness and to evaluate performance of a region of code. With perf_events, SkyPat can evaluate running time precisely without interference to scheduler. Moreover, perf_event also gives SkyPat accurate cycle counts that are useful for tools that are sensitive to variance of timing, such as compilers.