4.4.2 Event Flag
An event flag is an object used for synchronization, consisting of a pattern of bits used as .ags to indicate the existence of the corresponding event. Functions are provided for creating and deleting an event flag, for event flag setting and clearing, event flag waiting, and event flag status reference. An event flag is identi.ed by an ID number, called an event flag ID.
In addition to the bit pattern indicating the existence of corresponding events, an event flag has a queue of tasks waiting for the event flag. The event flag bit pattern is sometimes called simply event flag. The event noti.er sets or clears the specified bits of the event flag. A task can be made to wait for all or some of the event flag bits to be set. A task waiting for an event flag is put in the queue of that event flag.
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