ABCL/onEM-4
Masahiro Yasugi, Satoshi Matsuoka, Akinori Yonezawa · 1992
The trend towards object-oriented software construction is becoming more and more prevalent, and parallel programming cannot be an exception. In the context of parallel computation, it is often natural to model the computation as message passing between autonomous, concurrently active objects. The problem was, as some previous studies had indicated, that the overhead from message reception to dynamic method dispatching consumes a significant amount of execution time (e.g., as much as 4000 machine cycles or 500 μseconds at 8 MHz block for some language/hardware combination). Our ABCL/onEM-4, a software/hardware implementation architecture for a concurrent object-oriented language, overcomes this problem with technologies such as address-specifiable reactive packet-driven architecture, zero-overhead context switching, and packet-driven allocation of message boxes. Preliminary performance measurements on a real hardware EM-4 confirm our claim, achieving the performance of up to nearly 10 μseconds (130 clocks) total for a remote object-creation followed by a request message send to the created object and a reply reception from the object, for a 12.5 MHz clock speed. Our results indicate that the concurrent object-oriented computational model and languages are highly viable with proper implementational software/hardware architectures.