CASPER the Friendly Daemon

Despite the fact that timing and tracing studies provide tremendous information on the dynamic behavior of software systems, there has been surprisingly little support for these activities under UNIX (R) System V. In this paper, we present a set of tools, called CASPER, packaged as a C library and a pseudo-device driver for UNIX System V, which support timing and tracing of software at both the kernel and user level. Key features of this package are its extreme ease of use, its efficiency, and its ability to time and trace both user and kernel level activities into the same log file. To illustrate its ease of use, we provide some "real life" examples of tracing studies using CASPER.