WDF_CALLBACK_CONSTRAINT enumeration (wudfddi_types.h)

Syntax

typedef enum _WDF_CALLBACK_CONSTRAINT {
  None,
  WdfDeviceLevel,
  WdfLevelReserved,
  WdfLevelMaximum
} WDF_CALLBACK_CONSTRAINT;

Constants

None No callback functions into the driver are synchronized. The driver must handle all synchronization.
WdfDeviceLevel All callback functions into the driver that are associated with the device are synchronized, including all callback functions that are associated with I/O queues. Only one event handler that is associated with the device can run at any given time.
WdfLevelReserved Reserved.
WdfLevelMaximum

Remarks

Note that the above locking models apply only for I/O (that is, open, read, write, and device I/O control) operations and not for Plug and Play (PnP) and power management notifications.

Requirements

Requirement	Value
Minimum UMDF version	1.9
Header	wudfddi_types.h (include Wdf.h)