43 lines
961 B
Perl
43 lines
961 B
Perl
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%% demo2.pl -- Stasinos Konstantopoulos
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%% konstant@let.rug.nl, Tue Feb 12 2002
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%%
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%%
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%% This the calculation that needs to be performed, in this case
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%% the sum of [From..To]
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%%
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calc( From, From, Acc, Res ) :- !,
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Res is Acc + From.
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calc( From, To, Acc, Res ) :- !,
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Acc1 is Acc + To,
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To1 is To - 1,
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calc( From, To1, Acc1, Res ).
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%%
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%% We'll pretend the preprocessing was more complicated, and have the
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%% root broadcast how many numbers each processor should do.
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%% Each processor must then figure out which ones to do and call calc/4.
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%%
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do(0, Num) :-
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!,
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mpi_bcast( Num, 0 ),
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format( 'Proc 0: broadcast ~q.~n', [Num] ).
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do(Rank, _) :-
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!,
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mpi_bcast( Num, 0 ),
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format( 'Proc ~q: had ~q broadcast from 0.~n', [Rank, Num] ).
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%%
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%% This is the entry point
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%%
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start(Num) :-
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mpi_open( Rank, NumProc, ProcName ),
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format( 'Rank: ~q NumProc: ~q, ProcName: ~q~n', [Rank,NumProc,ProcName] ),
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do( Rank, Num ),
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format( 'Rank ~q finished!~n', [Rank] ).
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