SMHEntryPoint

The Stream Manager Helper (SMH) messages are exported for use by both device driver and DLL stream handlers through the SMHEntryPoint. The stream handlers use these helper routines to register with the Sync/Stream Manager, report events and synchronization cues, and request or return buffers. They are synchronous calls and are available to Ring 3 DLL stream handlers as a DLL call (Ring 0 stream handlers as an IDC call).