IoAdjustPagingPathCount macro (wdm.h)

  • Article

The IoAdjustPagingPathCount routine increments or decrements a caller-supplied page-file counter as an atomic operation.

Syntax

void IoAdjustPagingPathCount(
  [in]  _count_,
  [in]  _paging_
);

Parameters

[in] _count_

Pointer to a caller-supplied variable that contains a counter. A driver typically stores a page-file counter in the device extension for the device.

[in] _paging_

Specifies whether the counter is to be incremented or decremented. A value of TRUE specifies an increment operation.

Return value

None

Remarks

This routine is useful for maintaining a count of paging files on a device. The operating system notifies a driver that a paging file has been created on, or removed from, one of the driver's devices by sending an IRP. The IRP has the major code IRP_MJ_PNP and the minor code IRP_MN_DEVICE_USAGE_NOTIFICATION.

This routine can be used for other counters, such as counters for hibernation files or crash-dump files.

Requirements

Requirement Value
Minimum supported client Available starting with Windows 2000.
Target Platform Desktop
Header wdm.h (include Wdm.h, Ntddk.h, Ntifs.h)
IRQL Any level

See also

IRP_MJ_PNP

IRP_MN_DEVICE_USAGE_NOTIFICATION