Co-optimization of buffer requirement and response time for SDF graph

Synchronous data flow graph (SDF) is a model of computation that has been widely used in block diagram 'digit signal processing (DSP) programming environment. Many existing schedule methods of SDF have been developed to reduce run-time costs including the amount of memories used by executing codes and the response time of the target system. But because these methods deal with amount of memories and response time independently, they often generate contradicting results about these two kinds of run-time costs. For example, these methods reduce the amount of memory consumption but increasing response time. By contrast, earliest deadline first (EDF) reduce the response time, without considering the buffer requirement of the system. However, by adding a judging condition to EDF, on the one hand, we could schedule the SDF with an efficient response time, on the other hand, we could schedule the system with an efficient buffer requirement, while keeping the same response time. Hence, our improved EDF effectively makes up the deficiencies of SDF and EDF, thereby enhancing the utility of SDF and EDF.