<box begindoc>**This is automatically generated documentation.**  Edit after the "[[#COMMENTS|COMMENTS]]" heading; changes to the main body will be lost.</box>

====== Queue Element Documentation ======

===== NAME =====

**Queue** -- Click element;
stores packets in a FIFO queue

===== SYNOPSIS =====

Queue\\ Queue(CAPACITY)

**Ports**: 1 input, 1-2 outputs\\ 
**Package**: standard (core)\\ 

===== DESCRIPTION =====

Stores incoming packets in a first-in-first-out queue.
Drops incoming packets if the queue already holds CAPACITY packets.
The default for CAPACITY is 1000.
Queue notifies interested parties when it becomes empty and when a
formerly-empty queue receives a packet.  The empty notification takes place
some time after the queue goes empty, to prevent thrashing for queues that
hover around 1 or 2 packets long.  This behavior is the same as that of
[[NotifierQueue]].  Queue additionally notifies interested parties that it is
non-full, and when a formerly-full queue gains some free space.  In all
respects but notification, Queue behaves exactly like [[SimpleQueue]].
You may also use the old element name "FullNoteQueue".
**Multithreaded Click note:** Queue is designed to be used in an environment
with at most one concurrent pusher and at most one concurrent puller.  Thus,
at most one thread pushes to the Queue at a time and at most one thread pulls
from the Queue at a time.  Different threads can push to and pull from the
Queue concurrently, however.  See [[ThreadSafeQueue]] for a queue that can support
multiple concurrent pushers and pullers.


===== ELEMENT HANDLERS =====


 ? **length (read-only)**
 ! Returns the current number of packets in the queue.

 ? **highwater_length (read-only)**
 ! Returns the maximum number of packets that have ever been in the queue at once.

 ? **capacity (read/write)**
 ! Returns or sets the queue's capacity.

 ? **drops (read-only)**
 ! Returns the number of packets dropped by the queue so far.

 ? **reset_counts (write-only)**
 ! When written, resets the ''drops'' and ''highwater_length'' counters.

 ? **reset (write-only)**
 ! When written, drops all packets in the queue.


===== SEE ALSO =====

[[ThreadSafeQueue]], [[SimpleQueue]], [[NotifierQueue]], [[MixedQueue]], [[FrontDropQueue]]


Generated by 'click-elem2man' from '../elements/standard/fullnotequeue.hh' on 7/Mar/2009.


===== COMMENTS =====