Contrary to popular believe Oracle latches were significantly evolved through the last decade. Not only additional statistics appeared (and disappeared) and new (shared) latch type was introduced, the latch itself was changed
It is interesting to see how the latch was organized in the past and contemporary versions.
To see the latch in-memory seems hard, since latches typically held for a small amount of time. Hopefully Oracle gives us a possibility to call any its kernel function using oradebug call utility. We only need to know that Oracle itself uses kslgetl(laddr, wait, why, where) function to acquire the exclusive latch. Recently I blogged about this function and its parameters.
This function can be also used to artificially acquire any latch for demonstration by:
SQL> oradebug call kslgetl <latch address> <wait> <why> >where>