ExInterlockedInsertHeadList function

The ExInterlockedInsertHeadList routine atomically inserts an entry at the beginning of a doubly linked list of LIST_ENTRY structures.


NTKERNELAPI PLIST_ENTRY ExInterlockedInsertHeadList(
  PLIST_ENTRY                                  ListHead,
  __drv_aliasesMem PLIST_ENTRY                 ListEntry,
  _Requires_lock_not_held_(*_Curr_)PKSPIN_LOCK Lock



A pointer to the LIST_ENTRY structure that serves as the list header.


A pointer to the LIST_ENTRY structure that represents the entry to be inserted into the list.


A pointer to a KSPIN_LOCK structure that serves as the spin lock used to synchronize access to the list. The storage for the spin lock must be resident and must have been initialized by calling KeInitializeSpinLock. You must use this spin lock only with the ExInterlockedXxxList routines.

Return Value

ExInterlockedInsertHeadList returns a pointer to the first entry of the list before the new entry was inserted. If the list was empty, the routine returns NULL.


ExInterlockedInsertHeadList performs the same operation as InsertHeadList, but atomically. Do not mix atomic and non-atomic calls on the same list.

For more information about using this routine to implement a doubly linked list, see Singly and Doubly Linked Lists.

The ExInterlockedInsertHeadList routine can be called at any IRQL. The storage for the ListHead parameter and the list entries must be resident at all IRQLs.


Windows version Available starting with Windows 2000.
Target Platform Universal
Header wdm.h (include Wdm.h, Ntddk.h, Ntifs.h)
Library NtosKrnl.lib
DLL NtosKrnl.exe
IRQL Any level (see Remarks section)
DDI compliance rules IoAllocateFree, IoReuseIrp, MarkingInterlockedQueuedIrps, RemoveLockCheck, RemoveLockForward, RemoveLockForward2, RemoveLockForwardDeviceControl, RemoveLockForwardDeviceControl2, RemoveLockForwardDeviceControlInternal, RemoveLockForwardDeviceControlInternal2, RemoveLockForwardRead, RemoveLockForwardRead2, RemoveLockForwardWrite, RemoveLockForwardWrite2, RemoveLockRelease2, RemoveLockReleaseCleanup, RemoveLockReleaseClose, RemoveLockReleaseCreate, RemoveLockReleaseDeviceControl, RemoveLockReleaseInternalDeviceControl, RemoveLockReleasePower, RemoveLockReleaseRead, RemoveLockReleaseShutdown, RemoveLockReleaseSystemControl, RemoveLockReleaseWrite

See Also