### How to share memory in a distributed systemHow to share memory in a distributed system

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 Author Upfal, Eli ♦ Wigderson, Avi Source ACM Digital Library Content type Text Publisher Association for Computing Machinery (ACM) File Format PDF Copyright Year ©1987 Language English
 Subject Domain (in DDC) Computer science, information & general works ♦ Data processing & computer science Abstract The power of shared-memory in models of parallel computation is studied, and a novel distributed data structure that eliminates the need for shared memory without significantly increasing the run time of the parallel computation is described. More specifically, it is shown how a complete network of processors can deterministically simulate one PRAM step in $\textit{O}(log$ $\textit{n}/(log$ log $\textit{n})2)$ time when both models use $\textit{n}$ processors and the size of the PRAM's shared memory is polynomial in $\textit{n}.$ (The best previously known upper bound was the trivial $\textit{O}(\textit{n})).$ It is established that this upper bound is nearly optimal, and it is proved that an on-line simulation of $\textit{T}$ PRAM steps by a complete network of processors requires $&OHgr;(\textit{T}(log$ $\textit{n/}$ log log $\textit{n}))$ time.A simple consequence of the upper bound is that an Ultracomputer (the currently feasible general-purpose parallel machine) can simulate one step of a PRAM (the most convenient parallel model to program) in $\textit{O}((log$ $\textit{n})2log$ log $\textit{n})$ steps. ISSN 00045411 Age Range 18 to 22 years ♦ above 22 year Educational Use Research Education Level UG and PG Learning Resource Type Article Publisher Date 1987-01-01 Publisher Place New York e-ISSN 1557735X Journal Journal of the ACM (JACM) Volume Number 34 Issue Number 1 Page Count 12 Starting Page 116 Ending Page 127

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Source: ACM Digital Library