With help from several members of the Perl5 Porters team, I have added to the threads module the capability to send signals to individual threads. This new funtionality is well-documented in the POD along with a couple of (highly simplistic) examples on using thread signalling to implement thread cancelling, and suspend/resume operations.

This new version (1.27) of the threads modules will be available from CPAN shortly. This functionality has also been integrated into blead.