NdisCancelTimerObject function (ndis.h)
The NdisCancelTimerObject function cancels a timer object that is associated with a previous call to the NdisSetTimerObject function.
Syntax
BOOLEAN NdisCancelTimerObject(
[in] NDIS_HANDLE TimerObject
);
Parameters
[in] TimerObject
A handle to a timer object that NDIS provides when a driver calls the NdisAllocateTimerObject function.
Return value
NdisCancelTimerObject returns TRUE if the specified timer object is in the system timer queue; otherwise, it returns FALSE.
Remarks
A call to NdisCancelTimerObject cancels execution of a NetTimerCallback function, provided that the last specified timeout interval has not yet expired.
NDIS drivers should call NdisCancelTimerObject first when they are halting or unloading to ensure that a NetTimerCallback function does not attempt to access resources that the driver has already released.
If a nonzero value was specified in the MillisecondsPeriod parameter of the NdisSetTimerObject function, the timer is known as a periodic timer. If a zero value was specified in the MillisecondsPeriod parameter, the timer is known as a one-shot timer. The following points apply to canceling both types of timers:
- If the caller of NdisCancelTimerObject is canceling a periodic timer, it must be running at IRQL = PASSIVE_LEVEL. Otherwise, the caller of NdisCancelTimerObject should be running at IRQL <= DISPATCH_LEVEL.
-
If the caller of
NdisCancelTimerObject is canceling a periodic timer, NdisCancelTimerObject calls KeFlushQueuedDpcs to ensure that the timer is not currently running. Therefore, the caller is not required to have a separate synchronization mechanism to ensure that the timer is not currently being executed on another processor.
If the caller of NdisCancelTimerObject is canceling a one-shot timer, the caller is required to have a separate synchronization mechanism to ensure the timer is not currently running on another processor. For example, the caller could call NDIS_WAIT_FOR_MUTEX in order to wait for the timer thread to signal a mutex object when the thread is about to complete.
For more information, see Synchronization and Notification in Network Drivers.
Requirements
| Requirement | Value |
|---|---|
| Minimum supported client | Supported in NDIS 6.0 and later. |
| Target Platform | Universal |
| Header | ndis.h (include Ndis.h) |
| Library | Ndis.lib |
| IRQL | See Remarks section |
| DDI compliance rules | Irql_Timer_Function(ndis), PeriodicTimer(ndis) |