sub foo {
    my @arr = ();
    my %hash = ();
    ....
    %hash = ....  # key/values populated by some API

    push(@arr, \%hash);
    bar(\@arr, <other_args>);  # @arr contains only one item

}

sub bar {
    my $array_ref = shift;
    .... other function args are accessed here
    foreach my $i (.....) {
       ....  %some_hash initialized here for each iteration of the for-loop
       push (@$array_ref, \%some_hash); 
    }

    zzz($array_ref);   # zzz() will do some read-only operations with this array
}