The following example creates five child processes and uses them simultaneously to compute the second integral homology of each of the 267 groups of order 64. The final command shows that
H_2(G, Z)= Z_2^15
for the 267-th group G in GAP's library of small groups.
gap> Processes:=List([1..5],i->ChildProcess());; gap> fn:=function(i);return GroupHomology(SmallGroup(64,i),2);end;; gap> for p in Processes do > ChildPut(fn,"fn",p); > od; gap> NrSmallGroups(64); 267 gap> L:=ParallelList([1..267],"fn",Processes);; gap> L[267]; [ 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2 ]
The function ParallelList()
is built from HAP's six core functions for parallel computation.
The following commands use core functions to compute the product A=M× N of two random matrices by distributing the work over two processors.
gap> M:=RandomMat(2000,2000);; gap> N:=RandomMat(2000,2000);; gap> s:=ChildProcess();; gap> Mtop:=M{[1..1000]};; gap> Mbottom:=M{[1001..2000]};; gap> ChildPut(Mtop,"Mtop",s); gap> ChildPut(N,"N",s); gap> NextAvailableChild([s]);; gap> ChildCommand("Atop:=Mtop*N;;",s);; gap> Abottom:=Mbottom*N;; gap> A:=ChildGet("Atop",s);; gap> Append(A,Abottom);;
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