DropHeadQueue

simple module

This is a limited packet queue which drops packets at the head of the queue.

Inheritance diagram

The following diagram shows inheritance relationships for this type. Unresolved types are missing from the diagram.

Extends

Name	Type	Description
PacketQueue	simple module	This module implements a widely configurable packet queue, which is suitable among others, to be used in MAC protocols, traffic conditioning, and quality of services. This module can be used on its own, but it's also often supplemented by additional queueing components such as servers, classifiers, schedulers, multiplexers, etc. This kind of composition allows to form a larger module which can act as a packet queue with more complex behavior.

Parameters

Name	Type	Default value	Description
displayStringTextFormat	string	"contains %p pk (%l) pushed %u\npopped %o removed %r dropped %d"	determines display string text above the submodule
packetCapacity	int	100	maximum number of packets in the queue, no limit by default
dataCapacity	int	-1b	maximum total length of packets in the queue, no limit by default
dropperClass	string	"inet::queueing::PacketAtCollectionBeginDropper"	determines which packets are dropped when the queue is overloaded, packets are not dropped by default; the parameter must be the name of a C++ class which implements the IPacketDropperFunction C++ interface and is registered via Register_Class
comparatorClass	string	""	determines the order of packets in the queue, insertion order by default; the parameter must be the name of a C++ class which implements the IPacketComparatorFunction C++ interface and is registered via Register_Class
bufferModule	string	""	relative module path to the IPacketBuffer module used by this queue, implicit buffer by default

Properties

Name	Value	Description
display	i=block/queue
class	PacketQueue

Gates

Name	Direction	Size	Description
in	input
out	output

Signals

Name	Type	Unit
packetRemoved	inet::Packet
packetPushed	inet::Packet
packetDropped	inet::Packet
packetPopped	inet::Packet

Statistics

Name	Title	Source	Record	Unit	Interpolation Mode
packetRemoved	packets removed		count, sum(packetBytes), vector(packetBytes)		none
queueLength	queue length	count(packetPushed) - count(packetPopped) - count(packetRemoved) - count(packetDropped)	max, timeavg, vector		sample-hold
queueingTime	queueing times	queueingTime(packetPopped)	histogram, vector	s	none
packetPushed	packet pushed		count, sum(packetBytes), vector(packetBytes)		none
packetDropQueueOverflow	packet drops: queue overflow	packetDropReasonIsQueueOverflow(packetDropped)	count, sum(packetBytes), vector(packetBytes)		none
packetPopped	packet popped		count, sum(packetBytes), vector(packetBytes)		none

Source code

//
// This is a limited packet queue which drops packets at the head of the queue.
//
simple DropHeadQueue extends PacketQueue
{
    parameters:
        packetCapacity = default(100);
        dropperClass = default("inet::queueing::PacketAtCollectionBeginDropper");
}

File: src/inet/queueing/queue/DropHeadQueue.ned