.. rst-class:: mini-api
- :mini:`type rwlock`
- A read-write lock for synchronizing concurrent code.
- :mini:`fun rwlock(): rwlock`
- Returns a new read-write lock.
- :mini:`meth (Lock: rwlock):rdlock`
- Locks :mini:`Lock` for reading, waiting if there are any writers using or waiting to use :mini:`Lock`.
- :mini:`meth (Lock: rwlock):unlock`
- Unlocks :mini:`Lock`, resuming any waiting writers or readers (giving preference to writers).
- :mini:`meth (Lock: rwlock):wrlock`
- Locks :mini:`Lock` for reading, waiting if there are any readers or other writers using :mini:`Lock`.