# Executive Support Routines

This section contains references, in alphabetical order, for the subset of system-supplied ExXxx support routines that can be used by kernel-mode file systems and file system filter drivers, but not by device drivers.

In addition to the routines documented here, file systems and file system filter drivers can also call any of the ExXxx routines that are described in the Kernel-Mode Driver Architecture Reference section that are declared in Ntifs.h.

## In this section

TopicDescription

Reserved for system use.

Reserved for system use.

Reserved for system use.

ExInitializeWorkItem initializes a work-queue item with a caller-supplied context and callback routine to be queued for execution when a system worker thread is given control.

Note  Use this routine with extreme caution. (See the following Remarks section.)

Obsolete.

ExQueueWorkItem inserts a given work item into a queue from which a system worker thread removes the item and gives control to the routine that the caller supplied to ExInitializeWorkItem.

Note  Use this routine with extreme caution. (See the following Remarks section.)