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the demo now uses broadcast as well as send/receive.

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git-svn-id: https://yap.svn.sf.net/svnroot/yap/trunk@840 b08c6af1-5177-4d33-ba66-4b1c6b8b522a
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stasinos 2003-07-03 14:58:51 +00:00
parent 2b8b25da07
commit 2334010f7f
1 changed files with 41 additions and 30 deletions
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69
library/mpi/examples/demo1.pl
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@ -2,6 +2,11 @@
%% konstant@let.rug.nl, Thu Jan 24 2002 %% konstant@let.rug.nl, Thu Jan 24 2002
%% %%
% make the `floor' operator return integer values
:- set_prolog_flag(language, iso).
%% %%
%% This the calculation that needs to be performed, in this case %% This the calculation that needs to be performed, in this case
%% the sum of [From..To] %% the sum of [From..To]
@ -19,41 +24,47 @@ calc( From, To, Acc, Res ) :- !,
%% and collects the results. %% and collects the results.
%% %%
do(0, Num):- do(0, NumProc):-
integer(Num), !,
Half is Num // 2,
format( 'Proc 0: Calculating ~q..~q~n', [1, Half] ),
calc( 1, Half, 0, R1 ),
format( 'Proc 0: Done! (~q)~n', [R1] ),
mpi_receive( R2, Source, Tag ), % Receive any Source, any Tag
format( 'Proc ~q said: ~q (Tag: ~q)~n', [Source,R2,Tag] ),
% mpi_receive( R2, 1, 1 ), % Be more particular
Res is R1 + R2,
format( 'Sum(1..~q) = ~q~n', [Num,Res] ).
do(1, Num):-
integer(Num), !,
Half is Num // 2,
format( 'Proc 1: Calculating ~q..~q~n', [Half,Num] ),
calc( Half, Num, 0, Res ),
format( 'Proc 1: Done! (~q)~n', [Res] ),
mpi_send( Res, 0, 1 ).
do(0, _):-
!, !,
% broadcast task
mpi_bcast(10, 0),
set_value(n, NumProc),
set_value(acc, 0),
repeat,
mpi_receive(T, Source, Tag), mpi_receive(T, Source, Tag),
format( '0: Proc ~q said: ~q (Tag: ~q)~n', [Source,T,Tag] ). format( '0: Proc ~q said: ~q (Tag: ~q)~n', [Source,T,Tag] ),
do(1, Term):- % accumulate results
get_value(acc, Acc),
NewAcc is Acc + T,
set_value(acc, NewAcc),
% processors still left
get_value(n, Counter),
NewCounter is Counter - 1,
set_value(n, NewCounter),
NewCounter == 1,
!, !,
mpi_send(Term, 0, 1), format( '0: Result: ~q.~n', [
format( "1: I sent ~q (Tag: 1) to 0~n", [Term] ). do(Rank, NumProc):-
!,
% catch the task broadcast
mpi_bcast(Job, 0),
From is floor(Job * (Rank - 1) / (NumProc - 1)),
To is floor(Job * Rank / (NumProc - 1)) - 1,
format( '~q: I am calculating ~q..~q.~n', [Rank,From,To] ),
% do the job
calc( From, To, 0, Result ),
format( '~q: sending ~q to 0. (Tag: 1)~n', [Rank,Result] ),
% send back the results
mpi_send(Result, 0, 1).
%% %%
%% This is the entry point %% This is the entry point
%% %%
start(Job) :- start:-
mpi_open( Rank, NumProc, ProcName ), mpi_open(Rank, NumProc, ProcName),
format( 'Rank: ~q NumProc: ~q, ProcName: ~q~n', [Rank,NumProc,ProcName] ), format('Rank: ~q NumProc: ~q, ProcName: ~q~n', [Rank,NumProc,ProcName]),
do( Rank, Job ), do(Rank, NumProc),
format( 'Rank ~q finished!~n', [Rank] ). format( 'Rank ~q finished!~n', [Rank] ),
mpi_close.