[cpp-threads] pthreads cancellation

[Doug Lea]

Kevlin Henney wrote:

> 
> What was the specific issue you had in mind? I had envisaged that 
> cancellation is something that is carried out through joiners (or the 
> currently opaque thread identity returned from threadof).
> 
> Kevlin

There are two sorts of use cases here:


1. You created the task but now want to kill it.
(example: someone hits a cancel button.)

2. You originally wanted to wait for it but now longer want to.
(example: parallel database lookups. Kill others after
the first returns.)


Can you show what these might look like under your proposal?

-Doug