An I/O queue notifies a driver when a read request is available for the driver. The I/O queue notifies the driver when an application calls the Microsoft Win32 ReadFile or ReadFileEx function. The driver can handle the notification by registering the IQueueCallbackRead interface.
The IQueueCallbackRead interface inherits from the IUnknown interface. IQueueCallbackRead also has these types of members:
The IQueueCallbackRead interface has these methods.
The OnRead method is called to handle a read request when an application reads information from a device through the Microsoft Win32 ReadFile or ReadFileEx function.
A driver registers the IQueueCallbackRead interface when it calls the IWDFDevice::CreateIoQueue method to create an I/O queue or to configure the default I/O queue. For more information about creating or configuring an I/O queue, see Configuring Dispatch Mode for an I/O Queue.