Shared Memory Simulations with Triple-Logarithmic Delay
نویسندگان
چکیده
We consider the problem of simulating a PRAM on a distributed memory machine (DMM). Our main result is a randomized algorithm that simulates each step of an n-processor CRCW PRAM on an n-processor DMM with O(log log log n log n) delay, with high probability. This is an exponential improvement on all previously known simulations. It can be extended to a simulation of an (n log log log n log n)-processor EREW PRAM on an n-processor DMM with optimal delay O(log log log n log n), with high probability. Finally a lower bound of (log log log n=log log log log n) expected time is proved for a large class of randomized simulations that includes all known simulations.
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