A packet queue is a class that holds deferred packets and later sends them using the associated slave port or master port. More...

#include <packet_queue.hh>

Inheritance diagram for PacketQueue:

Classes
class	DeferredPacket
	A deferred packet, buffered to transmit later. More...

Public Member Functions
virtual const std::string	name () const =0
	Provide a name to simplify debugging. More...

size_t	size () const
	Get the size of the queue. More...

Tick	deferredPacketReadyTime () const
	Get the next packet ready time. More...

bool	hasAddr (Addr addr) const
	Check if a packets address exists in the queue. More...

bool	checkFunctional (PacketPtr pkt)
	Check the list of buffered packets against the supplied functional request. More...

void	schedSendEvent (Tick when)
	Schedule a send event if we are not already waiting for a retry. More...

void	schedSendTiming (PacketPtr pkt, Tick when, bool force_order=false)
	Add a packet to the transmit list, and schedule a send event. More...

void	retry ()
	Retry sending a packet from the queue. More...

void	disableSanityCheck ()
	This allows a user to explicitly disable the sanity check on the size of the transmitList, which is enabled by default. More...

DrainState	drain () override
	Notify an object that it needs to drain its state. More...

Public Member Functions inherited from Drainable
DrainState	drainState () const
	Return the current drain state of an object. More...

virtual void	notifyFork ()
	Notify a child process of a fork. More...

Protected Member Functions
bool	deferredPacketReady () const
	Check whether we have a packet ready to go on the transmit list. More...

virtual void	sendDeferredPacket ()
	Attempt to send a packet. More...

virtual bool	sendTiming (PacketPtr pkt)=0
	Send a packet using the appropriate method for the specific subclass (reuest, response or snoop response). More...

	PacketQueue (EventManager &_em, const std::string &_label, bool disable_sanity_check=false)
	Create a packet queue, linked to an event manager, and a label that will be used for functional print request packets. More...

virtual	~PacketQueue ()
	Virtual desctructor since the class may be used as a base class. More...

Protected Member Functions inherited from Drainable
	Drainable ()

virtual	~Drainable ()

virtual void	drainResume ()
	Resume execution after a successful drain. More...

void	signalDrainDone () const
	Signal that an object is drained. More...

Protected Attributes
const std::string	label
	Label to use for print request packets label stack. More...

bool	waitingOnRetry
	Remember whether we're awaiting a retry. More...

Private Types
typedef std::list< DeferredPacket >	DeferredPacketList

Private Member Functions
void	processSendEvent ()
	Used to schedule sending of deferred packets. More...

Private Attributes
DeferredPacketList	transmitList
	A list of outgoing packets. More...

EventManager &	em
	The manager which is used for the event queue. More...

EventWrapper< PacketQueue,&PacketQueue::processSendEvent >	sendEvent
	Event used to call processSendEvent. More...

bool	_disableSanityCheck

Detailed Description

A packet queue is a class that holds deferred packets and later sends them using the associated slave port or master port.

Definition at line 65 of file packet_queue.hh.

Member Typedef Documentation

typedef std::list<DeferredPacket> PacketQueue::DeferredPacketList

private

Definition at line 78 of file packet_queue.hh.

Constructor & Destructor Documentation

PacketQueue::PacketQueue	(	EventManager &	_em,
		const std::string &	_label,
		bool	disable_sanity_check = `false`
	)

protected

Create a packet queue, linked to an event manager, and a label that will be used for functional print request packets.

Parameters

_em	Event manager used for scheduling this queue
_label	Label to push on the label stack for print request packets
disable_sanity_check	Flag used to disable the sanity check on the size of the transmitList. The check is enabled by default.

Definition at line 52 of file packet_queue.cc.

PacketQueue::~PacketQueue ( )

protectedvirtual

Virtual desctructor since the class may be used as a base class.

Definition at line 59 of file packet_queue.cc.

Member Function Documentation

bool PacketQueue::checkFunctional ( PacketPtr pkt )

Check the list of buffered packets against the supplied functional request.

Definition at line 85 of file packet_queue.cc.

References Packet::checkFunctional(), ArmISA::i, label, Packet::popLabel(), Packet::pushLabel(), and transmitList.

Referenced by QueuedSlavePort::checkFunctional(), QueuedMasterPort::checkFunctional(), and SimpleTimingPort::recvFunctional().

bool PacketQueue::deferredPacketReady ( ) const

inlineprotected

Check whether we have a packet ready to go on the transmit list.

Definition at line 108 of file packet_queue.hh.

References curTick(), and transmitList.

Referenced by sendDeferredPacket().

Tick PacketQueue::deferredPacketReadyTime ( ) const

inline

Get the next packet ready time.

Definition at line 161 of file packet_queue.hh.

References MaxTick, and transmitList.

Referenced by Cache::CacheReqPacketQueue::checkConflictingSnoop(), and sendDeferredPacket().

void PacketQueue::disableSanityCheck ( )

inline

This allows a user to explicitly disable the sanity check on the size of the transmitList, which is enabled by default.

Users must use this function to explicitly disable the sanity check.

Definition at line 206 of file packet_queue.hh.

References _disableSanityCheck.

DrainState PacketQueue::drain ( )

overridevirtual

Notify an object that it needs to drain its state.

If the object does not need further simulation to drain internal buffers, it returns DrainState::Drained and automatically switches to the Drained state. If the object needs more simulation, it returns DrainState::Draining and automatically enters the Draining state. Other return values are invalid.

Note: An object that has entered the Drained state can be disturbed by other objects in the system and consequently stop being drained. These perturbations are not visible in the drain state. The simulator therefore repeats the draining process until all objects return DrainState::Drained on the first call to drain().

Returns: DrainState::Drained if the object is drained at this point in time, DrainState::Draining if it needs further simulation.

Implements Drainable.

Definition at line 228 of file packet_queue.cc.

References DPRINTF, Drained, Draining, and transmitList.

bool PacketQueue::hasAddr ( Addr addr ) const

Check if a packets address exists in the queue.

Definition at line 73 of file packet_queue.cc.

References addr, MipsISA::p, and transmitList.

Referenced by Cache::CacheReqPacketQueue::checkConflictingSnoop().

virtual const std::string PacketQueue::name ( ) const

pure virtual

Provide a name to simplify debugging.

Returns: A complete name, appended to module and port

Implemented in RespPacketQueue, SnoopRespPacketQueue, and ReqPacketQueue.

Referenced by retry(), and schedSendTiming().

void PacketQueue::processSendEvent ( )

private

Used to schedule sending of deferred packets.

Definition at line 221 of file packet_queue.cc.

References sendDeferredPacket(), and waitingOnRetry.

void PacketQueue::retry ( )

Retry sending a packet from the queue.

Note that this is not necessarily the same packet if something has been added with an earlier time stamp.

Definition at line 64 of file packet_queue.cc.

References DPRINTF, name(), sendDeferredPacket(), and waitingOnRetry.

Referenced by QueuedMasterPort::recvReqRetry(), QueuedSlavePort::recvRespRetry(), and QueuedMasterPort::recvRetrySnoopResp().

void PacketQueue::schedSendEvent ( Tick when )

Schedule a send event if we are not already waiting for a retry.

If the requested time is before an already scheduled send event, the event will be rescheduled. If MaxTick is passed, no event is scheduled. Instead, if we are idle and asked to drain then check and signal drained.

Parameters

when	time to schedule an event

Definition at line 155 of file packet_queue.cc.

References curTick(), DPRINTF, Draining, Drainable::drainState(), em, MaxTick, EventManager::reschedule(), EventManager::schedule(), Event::scheduled(), sendEvent, Drainable::signalDrainDone(), transmitList, waitingOnRetry, and Event::when().

Referenced by Cache::CacheReqPacketQueue::checkConflictingSnoop(), BaseCache::CacheMasterPort::schedSendEvent(), schedSendTiming(), and sendDeferredPacket().

void PacketQueue::schedSendTiming	(	PacketPtr	pkt,
		Tick	when,
		bool	force_order = `false`
	)

Add a packet to the transmit list, and schedule a send event.

Parameters

pkt	Packet to send
when	Absolute time (in ticks) to send packet
force_order	Force insertion order for packets with same address

Definition at line 105 of file packet_queue.cc.

References _disableSanityCheck, Packet::cmdString(), curTick(), DPRINTF, Packet::getAddr(), Packet::getSize(), ArmISA::i, Packet::isExpressSnoop(), name(), panic, schedSendEvent(), and transmitList.

Referenced by QueuedMasterPort::schedTimingReq(), QueuedSlavePort::schedTimingResp(), and QueuedMasterPort::schedTimingSnoopResp().

void PacketQueue::sendDeferredPacket ( )

protectedvirtual

Attempt to send a packet.

Note that a subclass of the PacketQueue can override this method and thus change the behaviour (as done by the cache for the request queue). The default implementation sends the head of the transmit list. The caller must guarantee that the list is non-empty and that the head packet is scheduled for curTick() (or earlier).

Reimplemented in Cache::CacheReqPacketQueue.

Definition at line 191 of file packet_queue.cc.

References deferredPacketReady(), deferredPacketReadyTime(), PacketQueue::DeferredPacket::pkt, schedSendEvent(), sendTiming(), transmitList, and waitingOnRetry.

Referenced by processSendEvent(), and retry().

virtual bool PacketQueue::sendTiming ( PacketPtr pkt )

protectedpure virtual

Send a packet using the appropriate method for the specific subclass (reuest, response or snoop response).

Implemented in RespPacketQueue, SnoopRespPacketQueue, and ReqPacketQueue.

Referenced by sendDeferredPacket().

size_t PacketQueue::size ( ) const

inline

Get the size of the queue.