Using Request Object Context

Every framework request object, whether created by the framework or by a driver, can contain driver-defined context space. When a framework-based driver initializes a framework device object, the driver can call WdfDeviceInitSetRequestAttributes to specify a WDF_OBJECT_ATTRIBUTES structure that describes context space for the device's request objects.

The framework allocates context space for request objects as follows:

  • When the framework creates request objects for your driver, it allocates context space with the size that your driver specified when it called WdfDeviceInitSetRequestAttributes.

  • If your driver creates additional request objects by calling WdfRequestCreate, you can specify a context size by providing a WDF_OBJECT_ATTRIBUTES structure.

For more information about allocating and accessing context space for framework objects, see Framework Object Context Space.