aiorwlock provides read write lock for asyncio . A RWLock maintains a pair of
associated locks, one for read-only operations and one for writing. The read
lock may be held simultaneously by multiple reader tasks, so long as there are
no writers. The write lock is exclusive.

Whether or not a read-write lock will improve performance over the use of a
mutual exclusion lock depends on the frequency that the data is read compared to
being modified. For example, a collection that is initially populated with data
and thereafter infrequently modified, while being frequently searched is an
ideal candidate for the use of a read-write lock. However, if updates become
frequent then the data spends most of its time being exclusively locked and
there is little, if any increase in concurrency.