When should I use Shared Locking (Read Locking)

Question

Can someone explain when shared locks should be used. If I understand correctly, shared locks are used when reading and exclusive locks are used while writing.

But why can't I just wait while a mutex is locked when doing a read.

Answer 1

It is for improving performance. Multiple concurrent reads then won't have to happen sequentially, which may be a great bonus if the structure is read frequently. (But still the data read will be consistent and up to date.)