This Thread module served as the front end to the old-style thread model,
called 5005threads, that has been removed in version 5.10.
For old code and interim backwards compatibility, the Thread module has been
reworked to function as a front end for the new interpreter threads (ithreads)
model. However, some previous functionality is not available. Further, the
data sharing models between the two thread models are completely different,
and anything to do with data sharing has to be thought differently.
You are strongly encouraged to migrate any existing threaded code to the new
model (i.e., use the threads and threads::shared modules) as soon as possible.
