ABC++- CONCURRENCY BY INHERITANCE IN C++

Many attempts have been made to add concurrency to C++, often by exten sive compiler extensions, but much of the work has not exploited the p ower of C++. This paper shows how the object-oriented facilities of C+ are powerful enough to encapsulate concurrency creation and control. We have developed a concurrent C++-based prototype system (ABC++) and describe how we can provide, with a standard compiler, almost all of the functionality offered by a new or extended language. Active object s, object distribution, selective method acceptance, and synchronous a nd asynchronous object interaction are supported. Concurrency control and synchronization are encapsulated at the active object level. The g oal of ABC++ is to allow users to write concurrent programs without de aling with explicit synchronization and mutual exclusion constructs, w ith as few restrictions on the use of C++ as possible. ABC++ can be im plemented on either a shared memory multiprocessor or a cluster of hom ogeneous workstations. It is presently implemented on a network of RIS C System/6000(R) processors and on the IBM Scalable POWERparallel(TM) System 1 (SP1(TM)).