Accessing Opaque Pointers
Clients are able to access the information stored in destinations by using opaque pointers. To use the storage, the client must first call RtmGetOpaqueInformationPointer to obtain the pointer. Whenever a change to the information is necessary, the client must first lock the destination by calling RtmLockDestination with the LockDest parameter set to TRUE. Once the destination is locked, the client can make the necessary change. The destination can be unlocked using another call to RtmLockDestination with the LockDest parameter set to FALSE.
The RtmLockDestination function also allows a client to use either a read lock or a write lock, using the Exclusive parameter. A client should use the write lock only when it is making changes to the information kept using the opaque pointer. Clients can use the read lock to view the opaque pointer information stored in a destination.
For sample code that shows how to use these functions, see Access the Opaque Pointer in a Destination.