Retrieve the number of items in the queue.
This is intended to provide a "best guess" count of the number of items in the queue. Depending on the implementation and the setup, the accuracy of the results of this function may vary.
e.g. On a busy system with a large number of consumers and items, the result might only be valid for a fraction of a second and not provide an accurate representation.
An integer estimate of the number of items in the queue.:
modules/ system/ system.queue.inc, line 331
- Queue functionality.
- Static queue implementation.