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lib/IPC/ConcurrencyLimit/WithLatestStandby.pm  view on Meta::CPAN

                # we failed to get the lock, which means there is a newer
                # process that can replace us so return/exit - this frees up
                # our lock and lets the newer process to move into our position.
                $0 = "$old_oh - no-lock-retired"
                    if $self->{process_name_change};
                return;
            }
        }

        # nope - the lock to our left is being held so sleep a while before
        # we try again. We use the rand and the formula so that items to the
        # right poll faster than items to the left, and to reduce the chance
        # that lock holder 1 and lock holder 3 poll lock 2 at the same time
        # forever. The formula guarantees that items to the left poll faster,
        # and the rand ensures there is jitter.
        sleep rand(($poll_time / $locker_id)*2);
    }

    # assert that $locker_id is 0 at this point.
    die "panic: We should not reach this point with \$locker_id larger than 0, got $locker_id"
        if $locker_id;

    $self->_diag("Got $names->[$locker_id] lock, we are allowed to do work.")
        if $self->{debug};