EvtDriverUnload function

[Applies to KMDF and UMDF]

A driver's EvtDriverUnload event callback function performs operations that must take place before the driver is unloaded.

Syntax


EVT_WDF_DRIVER_UNLOAD EvtDriverUnload;

VOID EvtDriverUnload(
  _In_  WDFDRIVER Driver
)
{ ... }

Parameters

Driver [in]

A handle to a framework driver object.

Return value

None

Remarks

The EvtDriverUnload callback function must deallocate any non-device-specific system resources that the driver's DriverEntry routine allocated.

The framework does not call a driver's EvtDriverUnload callback function if the driver's DriverEntry routine returns an error status value.

You must declare the function by using the EVT_WDF_DRIVER_UNLOAD type. For more information, see the following Example section.

Examples

To define an EvtDriverUnload callback function, you must first provide a function declaration that identifies the type of callback function you’re defining. Windows provides a set of callback function types for drivers. Declaring a function using the callback function types helps Code Analysis for Drivers, Static Driver Verifier (SDV), and other verification tools find errors, and it’s a requirement for writing drivers for the Windows operating system.

For example, to define an EvtDriverUnload callback function that is named MyDriverUnload, use the EVT_WDF_DRIVER_UNLOAD type as shown in this code example:


EVT_WDF_DRIVER_UNLOAD  MyDriverUnload;

Then, implement your callback function as follows:


_Use_decl_annotations_
VOID 
MyDriverUnload (
    WDFDRIVER Driver
    )
  {...}

The EVT_WDF_DRIVER_UNLOAD function type is defined in the WdfDriver.h header file. To more accurately identify errors when you run the code analysis tools, be sure to add the _Use_decl_annotations_ annotation to your function definition. The _Use_decl_annotations_ annotation ensures that the annotations that are applied to the EVT_WDF_DRIVER_UNLOAD function type in the header file are used. For more information about the requirements for function declarations, see Declaring Functions by Using Function Role Types for KMDF Drivers. For information about _Use_decl_annotations_, see Annotating Function Behavior.

Requirements

Minimum KMDF version

1.0

Minimum UMDF version

2.0

Header

Wdfdriver.h (include Wdf.h)

IRQL

PASSIVE_LEVEL

See also

DriverEntry

 

 

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