Arrays in SHIM: A Proposal

The use of multiprocessor configurations over uniprocessor is rapidly increasing to exploit parallelism instead of frequency scaling for better compute capacity. The multiprocessor architectures being developed will have a major impact on existing software. Current languages provide facilities for concurrent and distributed programming, but are prone to races and non-determinism. SHIM, a deterministic concurrent language, guarantees the behavior of its programs are independent of the scheduling of concurrent operations. The language currently supports atomic arrays only, i.e., parts of arrays cannot be sent to concurrent processes for evaluation (and edition). In this report, we propose a way to add non-atomic arrays to SHIM and describe the semantics that should be considered while allowing concurrent processes to edit parts of the same array