Abstract Most of the performance bench‐marks for compilers do not give detailed performance characteristics that might be useful to a programmer. The goal of most bench‐marks seems to be to produce a single number. A set of bench‐mark tools that measure individual language features of C and generate a large number of measurements has been designed to create a detailed performance profile of any C compiler. There is an emphasis on the detailed statement‐level measurements of both CPU and I/O aspects of C, but there is also a range of routine and program‐level bench‐marks that seek to measure the interaction of CPU and I/O in actual application programs. The programs are portable, parametrized, and openended so that additional measurements can be added with little effort. With some additional effort, the tools could be adapted to other languages.

A buffer has been analyzed in a computer communication system with Poisson arrivals, periodic opportunities for service, and random blocking of service. The solution obtained reflects the waiting a customer must do until a service opportunity arises. Compared to previous solutions for this problem, the average queue length and the variance of queue length are larger by a factor which depends on the arrival rate.