It appears that the ": locked" attribute will be eradicated from Perl in 5.10 / Ponie. However, I liked the functionality (previously unknown to me), so I've just implemented Thread::Synchronize which introduces the ": synchronize" code attribute.

NAME

Thread::Synchronize - synchronize subroutine calls between threads

SYNOPSIS

use Thread::Synchronize;  # activate :synchronize attribute

sub foo : synchronize { } # only one subroutine running at a time

DESCRIPTION

This module currently adds one feature to threaded pro- grams: the ":synchronize" subroutine attribute which causes calls to that subroutine to be automatically syn- chronized between threads (only one thread can execute that subroutine at a time).

Actually, this implementation uses a source filter, so no actual attribute handling is involved during runtime.

Liz

Update:
Changed the name of the module to Thread::Synchronized.