__TimerEvent class

Article
01/07/2021

The __TimerEvent system class is reports an event generated by WMI in response to a consumer's request for an interval timer event or an absolute timer event. An interval timer event is an event that occurs at regular intervals. An absolute timer event is an event that occurs at a specific time. Timer events can occur in any namespace.

The following syntax is simplified from Managed Object Format (MOF) code and includes all inherited properties. Properties are listed in alphabetic order, not MOF order.

Syntax

class __TimerEvent : __Event
{
  uint32 NumFirings;
  uint8  SECURITY_DESCRIPTOR[];
  string TimerId;
  uint64 TIME_CREATED;
};

Members

The __TimerEvent class has these types of members:

Properties

Properties

The __TimerEvent class has these properties.

NumFirings

Data type: uint32
Access type: Read-only

Number of times the event occurred before a notification was delivered to the consumer.

SECURITY_DESCRIPTOR

Data type: uint8 array
Access type: Read-only

Descriptor used by the event provider to determine which users can receive the event. This property is inherited from __Event.

TIME_CREATED

Data type: uint64
Access type: Read-only

Unique value that indicates the time at which the event was generated. This is a 64-bit value that represents the number of 100-nanosecond intervals after January 1, 1601. The information is in the Coordinated Universal Times (UTC) format. This property is inherited from __Event.

For more information about using uint64 values in scripts, see Scripting in WMI.

TimerId

Data type: string
Access type: Read-only

Instance of the __TimerInstruction subclass that caused WMI to fire this event. Consumers specify a timer identification in the TimerId property of the __TimerInstruction subclass that they create to register.

Remarks

The __TimerEvent class is derived from __Event.

Event consumers register for an absolute timer event by creating an instance of the __AbsoluteTimerInstruction system class. They register for an interval timer event by creating an instance of the __IntervalTimerInstruction system class.

During normal operation, the NumFirings property is set to 1. When it is not possible to reach the consumer or the firing interval is much quicker than the ability to deliver the event, NumFirings is set to a number greater than 1. When NumFirings is greater than 1, WMI automatically merges many timer events into the same event. This merging is similar to what occurs with WM_TIMER messages in Windows programming.

Requirements

Requirement	Value
Minimum supported client	Windows Vista
Minimum supported server	Windows Server 2008
Namespace	All WMI namespaces