TmReferenceEnlistmentKey function (wdm.h)

Article
02/22/2024

The TmReferenceEnlistmentKey routine increments the reference count for the key of a specified enlistment object and retrieves the key.

Syntax

NTSTATUS TmReferenceEnlistmentKey(
  [in]  PKENLISTMENT Enlistment,
  [out] PVOID        *Key
);

Parameters

[in] Enlistment

A pointer to an enlistment object. Your component can receive this pointer as input to a ResourceManagerNotification callback routine. Alternatively, your component can call ObReferenceObjectByHandle and supply the object handle that a previous call to ZwCreateEnlistment, TmCreateEnlistment, or ZwOpenEnlistment provided.

[out] Key

A pointer to a variable that receives the enlistment object's enlistment key. The caller assigns an enlistment key when it calls ZwCreateEnlistment or TmCreateEnlistment.

Return value

TmReferenceEnlistmentKey returns STATUS_SUCCESS if the operation succeeds. Otherwise, this routine might return one of the following values:

Return code	Description
STATUS_INVALID_PARAMETER	The Key parameter's value is NULL.
STATUS_UNSUCCESSFUL	The reference count of the specified enlistment object has been decremented to zero, so the reference count cannot be incremented.
STATUS_INSUFFICIENT_RESOURCES	The reference count is at its maximum value (0xFFFFFFFF) and cannot be incremented.

The routine might return other NTSTATUS values.

Remarks

The TmReferenceEnlistmentKey routine increments the reference count for an enlistment object's key value, and the TmDereferenceEnlistmentKey routine decrements the count.

If a resource manager has defined a key value for an enlistment, the resource manager receives the key value when it calls ZwGetNotificationResourceManager or when KTM calls the ResourceManagerNotification callback routine.

While a resource manager is processing a notification, it might use the key as a pointer to a temporary memory allocation, and it might use the reference count to determine when it should deallocate the memory.

For information about when to use KTM's TmXxx routines instead of ZwXxx routines, see Using TmXxx Routines.

Requirements

Requirement	Value
Minimum supported client	Available in Windows Vista and later operating system versions.
Target Platform	Universal
Header	wdm.h (include Wdm.h, Ntddk.h, Ntifs.h)
Library	NtosKrnl.lib
DLL	NtosKrnl.exe
IRQL	<= DISPATCH_LEVEL