sub do_transaction {
    my ($code) = @_;
    &transactions_on;
    eval { $code->() };
    &rollback_and_die if $@;
    &commit;
    &transactions_off;
}

sub rollback_and_die {
    my $commit_error = $@; # save it as rollback could fail
    eval { $_->rollback foreach (AllTables::handles); };
    &transactions_off;    # just to be safe
    die $commit_error;    # and fatal death
}

sub commit {
    eval { $_->commit foreach (AllTables::handles); };
    &rollback_and_die if $@;    # commit failed, so bail
}

sub transactions_on {
    $_->{AutoCommit} = 0 foreach (AllTables::handles);
}

sub transactions_off {
    $_->{AutoCommit} = 1 foreach (AllTables::handles);
}