- Windows Driver Foundation (WDF)
- Kernel Mode Objects
- User Mode Objects
- Summary
User Mode Objects
UMDF objects are based on the component object model (COM). The UMDF uses a small subset of COM for query-interface and reference counting features. In the UMDF driver, both the driver and the framework implement and expose the COM-style interface. Handles are not required because the interfaces are abstract base classes and thus identify the object.
The UMDF defines fewer objects than the KMDF because User Mode Driver cannot directly access hardware and therefore does not perform direct memory access (DMA) or handle interrupts. The following is a list of interfaces that expose the UMDF object types:
Object Interface Name |
Usage |
IWDFObject |
Defines the base WDF object type |
IWDFDriver |
Represents the driver object |
IWDFDevice |
Represents a device object |
IWDFFile |
Represents a file object |
IWDFIoQueue |
Represents a queue of I/O requests |
IWDFIoRequest |
Describes an I/O request |
IWDFIoTarget |
Represents the driver that is the target of an I/O request |
IWDFMemory |
Provides access to an area of memory |