WORK_QUEUE_TYPE enumeration (wdm.h)

The WORK_QUEUE_TYPE enumeration type indicates the type of system worker thread that handles a work item.

Syntax

typedef enum _WORK_QUEUE_TYPE {
  CriticalWorkQueue,
  DelayedWorkQueue,
  HyperCriticalWorkQueue,
  NormalWorkQueue,
  BackgroundWorkQueue,
  RealTimeWorkQueue,
  SuperCriticalWorkQueue,
  MaximumWorkQueue,
  CustomPriorityWorkQueue
} WORK_QUEUE_TYPE;

Constants

CriticalWorkQueue Indicates a real-time system worker thread. The assigned priority level is 13.
DelayedWorkQueue Indicates an ordinary worker thread. The assigned priority level is 12.
HyperCriticalWorkQueue System priority level. The assigned priority level is 15.
NormalWorkQueue System priority level. The assigned priority level is 8
BackgroundWorkQueue System priority level. The assigned priority level is 7.
RealTimeWorkQueue System priority level. The assigned priority level is18.
SuperCriticalWorkQueue System priority level. The assigned priority level is 14.
MaximumWorkQueue System priority maximum. No priority level assigned.
CustomPriorityWorkQueue The queue has a custom priority level assigned by the caller. The CustomPriorityWorkQueue value is the base priority level for the custom priority queue. Work items are queued at a particular priority by setting QueueType to CustomPriorityWorkQueue + Priority where Priority is the KPRIORITY value for the work item. This queue type is valid starting with Windows 8.1.

Remarks

For drivers targeting Windows 8.1 or later versions of Windows, use of only CustomPriorityWorkQueue with a custom priority level is recommended.

A work queue priority < 17 is advised since queuing
at a higher priority may interfere with work item processing by critical system components.

For more information about system worker threads, see System Worker Threads.

Requirements

Requirement	Value
Header	wdm.h (include Wdm.h, Ntddk.h, Ntifs.h)

See also

IoQueueWorkItem

IoQueueWorkItemEx

IoTryQueueWorkItem