Buffer Optimization and Dispatching Scheme for Embedded Systems with Behavioral Transparency

Abstract

This article presents a buffer minimization scheme with low dispatching overhead for embedded software processes. To accomplish this, we exploit behavioral transparency in the model of computation. In such a model (e.g., synchronous dataflow), the state of buffer requirements is determined completely by the firing sequence of the actors without requiring functional simulation of the actors. Fine-grained buffer allocation incurs high and code pointer overhead while coarse-grained allocation suffers from memory fragmentation. Instead, we propose a medium-grained, “access-contiguous” buffer allocation scheme that minimizes the total buffer space and pointer overhead. We formulate the buffer allocation problem as 2D tiles that represent the lifetime of the buffers to minimize their memory occupation spatially and temporally. Experimental results show that our scheme uses less data memory than existing techniques by 26% on average, or up to 57% in the best case. Our technique retains code modularity for dynamic configuration and, more importantly, enables many more applications that otherwise would not fit if implemented using previous state-of-the-art techniques.