[dmd-concurrency] CSP: Communicating sequential processes

[Andrei Alexandrescu]

Sean Kelly wrote:
> It doesn't currently allow upgrading read locks to write locks, though I think this wouldn't be difficult to add.  More importantly I suppose is that acquiring a concurrent read lock may be more expensive than you'd expect, so you really only want to use a ReadWriteMutex if the read operations take a reasonable amount of time to complete.

I think pthreads don't allow the upgrade.

Andrei