A compile time based approach for solving out-of-order communication in Kahn process networks

The Compaan compiler framework automates the transformation of DSP applications written in Matlab into Kahn process networks (KPNs). These KPNs express the signal processing applications in a parallel distributed way, making them more suitable for mapping onto parallel architectures. A simple instance of a generated KPN by Compaan is a producer process that communicates with a consumer process via a FIFO buffer with the consumer reading data from the FIFO using a blocking read. When the sequence of producing data is different from the sequence of consuming data, a simple FIFO is not sufficient to implement the communication. For such a case, extra storage and control are needed at the consumer side. This paper presents a novel approach that determines at compile time whether a FIFO buffer is sufficient for every producer/consumer pair of a Compaan-generated KPN. For the case when the additional memory is required, we also provide an address generation mechanism at compile time. The presented approach is based on the Ehrhart theory.