Page  185 ï~~A Run-Time Systen Roger B. Dannei School of Computer Carnegie Mellon Ur Pittsburgh, PA 1521 email: roger.dannenberg( ABSTRACT: run-time organization has b support the high-level, functional, real-time Ian; automatically determines the execution order of propagation from inputs to outputs in a single sa to avoid redundant computations when one expr object-oriented rn-time system also supports S prototype behaviors, which can change signal co

Page  186 ï~~the current value for before the first assignment, I Failure to evaluate expressions in the correct order incI expression were evaluated first, it would see the previo of latency from input x to output A. It turns out that there is no sim e static analy nun-tiefe order evaluation because new assignmen creating new dependencies, and altering the necessary P Arctic expressions are translated into instances of objec These objects respond to the "access" message by com For example, the object for above respon "access" to both B and ramp and combining the result that up-to-date values will be used for both B and ram evaluated, its value and a timestamp are saved in the ol logical time (sample number) does not have re-eval every sample computation, the global time is advanced, a re-evaluation of all expressions upon the next "access A."-a w w

Page  187 ï~~evaluation gurtees dtha the expressions winl elI propagates through all expressions and reaches the ouqF obtained otr systems such Formes [En and Fo, signal dependencies and by manually specifying the ordk The nesting level of "access" method invocatii simple programs. This should not taken t expression ordering has.gnificant bene fit soinc expressions from input to outs order that minimizes latency. ut, latency is substantially In Arctic, the latency is synchronize with*icmn data and one for computatioi Conclusions. We have emented run-t dynamic multiple ordering expression evaluation achieve instances of behavior prototypes. Measureme fast enough support complex real-time control S' implemented by a DSP. Space limitations prevent full discussion I r - -- rE