TrackSegment Class Reference

Derived Katabatic::AutoSegment for the router. More...

Inheritance diagram for TrackSegment:

Public Member Functions
virtual bool	isFixed () const
virtual bool	isHorizontal () const
virtual bool	isVertical () const
virtual bool	isLocal () const
virtual bool	isGlobal () const
virtual bool	isBipoint () const
virtual bool	isTerminal () const
virtual bool	isStrap () const
virtual bool	isSlackened () const
virtual bool	isDogleg () const
virtual bool	canDogleg ()
virtual bool	canDogleg (Interval)
virtual bool	canDogleg (Katabatic::GCell *, unsigned int flags=0)
virtual float	getMaxUnderDensity (unsigned int flags) const
virtual unsigned long	getId () const
virtual unsigned int	getDirection () const
virtual Net *	getNet () const
virtual const Layer *	getLayer () const
virtual unsigned long	getFreedomDegree () const
virtual unsigned int	getDoglegLevel () const
virtual TrackElement *	getNext () const
virtual TrackElement *	getPrevious () const
virtual TrackElement *	getParent () const
virtual DbU::Unit	getAxis () const
virtual Interval	getFreeInterval () const
virtual Interval	getSourceConstraints () const
virtual Interval	getTargetConstraints () const
virtual DataNegociate *	getDataNegociate (unsigned int flags=KtDataSelf) const
virtual TrackElement *	getCanonical (Interval &)
virtual size_t	getGCells (Katabatic::GCellVector &) const
virtual TrackElement *	getSourceDogleg ()
virtual TrackElement *	getTargetDogleg ()
virtual TrackElements	getPerpandiculars ()
virtual void	setTrack (Track *)
virtual void	updateFreedomDegree ()
virtual void	setDoglegLevel (unsigned int)
virtual void	swapTrack (TrackElement *)
virtual void	reschedule (unsigned int level)
virtual void	detach ()
virtual void	invalidate ()
virtual void	revalidate ()
virtual void	setAxis (DbU::Unit, unsigned int flags)
virtual TrackElement *	makeDogleg ()
virtual TrackElement *	makeDogleg (Interval, unsigned int &flags)
virtual void	_postDoglegs (TrackElement *&perpandicular, TrackElement *&parallel)
virtual bool	_check () const
Public Member Functions inherited from TrackElement
bool	isCreated () const
bool	isInvalidated () const
bool	isBlockage () const
bool	isLocked () const
bool	isRouted () const
bool	hasSourceDogleg () const
bool	hasTargetDogleg () const
bool	canRipple () const
Track *	getTrack () const
size_t	getIndex () const
Box	getBoundingBox () const
DbU::Unit	getSourceU () const
DbU::Unit	getTargetU () const
DbU::Unit	getLength () const
Interval	getCanonicalInterval () const
void	setFlags (unsigned int)
void	unsetFlags (unsigned int)
void	setIndex (size_t)
virtual void	incOverlapCost (Net *, TrackCost &) const
bool	makeDogleg (Katabatic::GCell *)

Static Public Member Functions
static TrackElement *	create (AutoSegment *, Track *, bool &created)
Static Public Member Functions inherited from TrackElement
static SegmentOverlapCostCB *	setOverlapCostCB (SegmentOverlapCostCB *)

Detailed Description

Derived Katabatic::AutoSegment for the router.

Fig 1: TrackSegment Context

We create one TrackSegment per aligned Katabatic::AutoSegment set, the TrackSegment is associated to the canonical one of the set.

To provide some speedup, the full extention of the aligned segment set is computed once and stored in the TrackSegment itself. The drawback beeing that whenever one segment from the aligned set has it's extention modified, the full extention must be recomputed.

Lazy Revalidate

When the TrackSegment::revalidate() method is called, it only update the cached size of the segment (from the AutoSegment set of aligneds) and the track into which it may be inserted.

The associated DataNegociate and RoutingEvent are not updated.

• The RoutingEvent will be updated when it's key is updated, typically during a requeueing operation and in the SegmentFsm constructor. This should be optimized in the future.
• The DataNegociate is updated only in the SegmentFsm constructor. This is the most costly of the two updates as it perform a perpandicular & parallel connexity exploration.

Dogleg Management

The basic AutoSegment::canDogleg() method is declined in three more dedicated methods in this class:

• TrackSegment::canDogleg(), for locals only, check if a break is possible, never break a segment more than once (to avoid fragmentation).
• TrackSegment::canDogleg(Katabatic::GCell*,unsigned int flags) for globals, check that the segment is breakable in the desired GCell. Never break twice in the first/last GCell (fragmentation limitation), but may reuse an already existing dogleg.
• TrackSegment::canDogleg(Interval), for locals only, direct proxy for the AutoSegment method. Never allow more than one break.

Relationship between AutoSegment and TrackSegment

Figure 2 below, shows an example of dogleg creation:

• At the Katabatic level, AutoSegment id:12 is broken. Thus the creation of AutoSegments id:20 and id:21. The orignal TrackSegment (canonical AutoSegment id:10) remains on the right side (target) of the break.
• But, because the canonical of the former aligned AutoSegment set (10,11,12,13,14) was on the right side of the break, the new parallel TrackSegment will be created on the left side, associated to the newly promoted canonical AutoSegment id:12.

Fig 2: Dogleg Management

The TrackSegment::_postDoglegs() method called by all flavors of TrackSegment::makeDogleg() methods is responsible for creating new TrackSegments for the new doglegs (there may be more than one), it also update the dogleg level and source/target dogleg flags.

This section is not finished. I need to review the parent and doglevel numbering management. There seems to be a risk of infinite fragmentation as the numbering of the original segment is not increased, we should create a break counter separate from deepness.

Global, Weak Global and Local Segments

There's a slight semantic change between Katabatic and Kite about what is local and what is local. This is due to how we consider the intermediate status of WeakGlobal.

A WeakGlobal segment is a local segment which is aligned with a global (though a VTee or an HTee contact).

In Katabatic a local segment is one that is not Global, a local segment can be both Local and WeakGlobal.

In Kite a local segment is one that is neither Global or WeakGlobal. The WeakGlobal sides with Global unlike in Katabatic.

Member Function Documentation

create()

static TrackSegment * create ( AutoSegment *  segment, Track *  track, bool &  created  )

static

Parameters

segment	The Katabatic AutoSegment to decorate.
track	A Track into which insert the TrackSegment (may be NULL).
created	This flag is sets is a new TrackSegment has be created.

Returns

A TrackSegment wrapped around an AutoSegment.

Constructor mainly used at loading time to decorate the Katabatic data-base with the router attributes.

isFixed()

bool isFixed ( ) const

virtual

See also:  Katabatic::AutoSegment::isFixed().

Reimplemented from TrackElement.

isHorizontal()

bool isHorizontal ( ) const

virtual

See also:  Katabatic::AutoSegment::isHorizontal().

Implements TrackElement.

isVertical()

bool isVertical ( ) const

virtual

See also:  Katabatic::AutoSegment::isVertical().

Implements TrackElement.

isLocal()

bool isLocal ( ) const

virtual

See also:  Katabatic::isLocal().

Reimplemented from TrackElement.

isGlobal()

bool isGlobal ( ) const

virtual

See also:  Katabatic::AutoSegment::isGlobal().

Reimplemented from TrackElement.

isBipoint()

bool isBipoint ( ) const

virtual

See also:  Katabatic::AutoSegment::isBipoint().

Reimplemented from TrackElement.

isTerminal()

bool isTerminal ( ) const

virtual

See also:  Katabatic::AutoSegment::isTerminal().

Reimplemented from TrackElement.

isStrap()

bool isStrap ( ) const

virtual

See also:  Katabatic::AutoSegment::isStrap().

Reimplemented from TrackElement.

isSlackened()

bool isSlackened ( ) const

virtual

See also:  Katabatic::AutoSegment::isSlackened().

Reimplemented from TrackElement.

isDogleg()

bool isDogleg ( ) const

virtual

See also:  Katabatic::isDogleg().

Reimplemented from TrackElement.

canDogleg() [1/3]

bool canDogleg ( )

virtual

See also:  AutoSegment::canDogleg(). At Kite level, this variant of the method will apply only on local segments and the segment must not already have a source or target dogleg.

Reimplemented from TrackElement.

canDogleg() [2/3]

bool canDogleg ( Interval  )

virtual

See also:  AutoSegment::canDogleg(). At Kite level, this variant of the method will apply only on local segments and the segment must not already have a source or target dogleg.

Reimplemented from TrackElement.

canDogleg() [3/3]

bool canDogleg ( Katabatic::GCell *  doglegGCell, unsigned int  flags = 0  )

virtual

See also:  AutoSegment::canDogleg(). At kite level, this variant of the method is mainly targeted to global segment. For local segment it behave like TrackElement::canDogleg(Interval). For global segment, make the break in the requested GCell doglegGCell. If it's in the first or last GCell and there is already a dogleg, allow to reuse it if flags contains Kite::KtAllowDoglegReuse.

Reimplemented from TrackElement.

getMaxUnderDensity()

float getMaxUnderDensity ( unsigned int  flags ) const

virtual

Returns: The maximum density of all the GCells under this element.

Reimplemented from TrackElement.

getId()

unsigned long getId ( ) const

virtual

Returns

The Id of the supporting AutoSegment, if there is any. Zero otherwise.

Reimplemented from TrackElement.

getDirection()

unsigned int getDirection ( ) const

virtual

Returns

The direction of the supporting element (should match the preferred direction of the Track).

Implements TrackElement.

getNet()

Net * getNet ( ) const

virtual

Returns: The Net associated to the element (may be NULL).

Implements TrackElement.

getLayer()

const Layer * getLayer ( ) const

virtual

Returns: The Layer of the element (should match the one of the Track).

Implements TrackElement.

getFreedomDegree()

unsigned long getFreedomDegree ( ) const

virtual

Returns: The degree of freedom of the element. It is used as a priority value when sorting TrackElement (in RoutingEvent).

Returns: The degree of freedom of the element. It is used as a priority value when sorting TrackElement (in RoutingEvent).

Currently, it is the slack of the Katabatic::AutoSegment.

Reimplemented from TrackElement.

getDoglegLevel()

unsigned int getDoglegLevel ( ) const

virtual

Returns: The deepness of the dogleg.

Reimplemented from TrackElement.

getNext()

TrackElement * getNext ( ) const

virtual

Returns: The next TrackElement, on the same track and of a different net. See also:  Track::getNext().

Reimplemented from TrackElement.

getPrevious()

TrackElement * getPrevious ( ) const

virtual

Returns: The previous TrackElement, on the same track and of a different net. See also:  Track::getPrevious().

Reimplemented from TrackElement.

getParent()

TrackElement * getParent ( ) const

virtual

Returns: The TrackElement from which the dogleg has been created, if any.

Reimplemented from TrackElement.

getAxis()

DbU::Unit getAxis ( ) const

virtual

Returns: The axis position of the element (must be the same as the Track).

Implements TrackElement.

Referenced by VerticalTrack::getPosition().

getFreeInterval()

Interval getFreeInterval ( ) const

virtual

Returns: The greatest free interval enclosing this element.

Reimplemented from TrackElement.

getSourceConstraints()

Interval getSourceConstraints ( ) const

virtual

See also:  Katabatic::AutoSegment::getSourceConstraints().

Reimplemented from TrackElement.

getTargetConstraints()

Interval getTargetConstraints ( ) const

virtual

See also:  Katabatic::AutoSegment::getTargetConstraints().

Reimplemented from TrackElement.

getDataNegociate()

DataNegociate * getDataNegociate ( unsigned int  flags = KtDataSelf ) const

virtual

Returns: The additional data-structure supplied by the routing algorithm.

Reimplemented from TrackElement.

getCanonical()

TrackElement * getCanonical ( Interval &  i )

virtual

Inner working still unclear to myself.

Reimplemented from TrackElement.

getGCells()

size_t getGCells ( Katabatic::GCellVector &  gcells ) const

virtual

Returns: The table of Katabatic::GCell underneath the element whole span.

Reimplemented from TrackElement.

getSourceDogleg()

TrackElement * getSourceDogleg ( )

virtual

Returns: The source part of the segment from which the dogleg has been created.

Reimplemented from TrackElement.

getTargetDogleg()

TrackElement * getTargetDogleg ( )

virtual

Returns: The target part of the segment from which the dogleg has been created.

Reimplemented from TrackElement.

getPerpandiculars()

TrackElements getPerpandiculars ( )

virtual

Returns: The collection of all element perpandiculars to this one.

Reimplemented from TrackElement.

setTrack()

void setTrack ( Track *  track )

virtual

Insert the element into track, also used as an insertion marker.

Reimplemented from TrackElement.

updateFreedomDegree()

void updateFreedomDegree ( )

virtual

Update, from the element characteristics, it's degree of freedom.

Reimplemented from TrackElement.

setDoglegLevel()

void setDoglegLevel ( unsigned int  level )

virtual

Sets the level of dogleg of the element.

Reimplemented from TrackElement.

swapTrack()

void swapTrack ( TrackElement *  other )

virtual

Swap the tracks of this and other.

Reimplemented from TrackElement.

reschedule()

void reschedule ( unsigned int  level )

virtual

If the TrackElement has already an event scheduled, change the level of this event, otherwise create a new event.

See also:  NegotiateWindow::rescheduleEvent().

Reimplemented from TrackElement.

detach()

void detach ( )

virtual

Remove the link from the TrackElement to it's owning Track, marking it for removal. The removal from the Track's vector is managed by the Track itself during the Session revalidation stage.

Reimplemented from TrackElement.

invalidate()

void invalidate ( )

virtual

See also:  AutoSegment::invalidate().

Reimplemented from TrackElement.

Referenced by TrackSegment::create().

revalidate()

void revalidate ( )

virtual

Actualize the TrackSegment characteristics from the supporting elements (set of AutoSegment).

This method do not update the DataNegociate or the RoutingEvent. This is a lazy update delayed until the constructor of SegmentFsm is called. (see Lazy Revalidate).

Reimplemented from TrackElement.

setAxis()

void setAxis ( DbU::Unit  , unsigned int  flags  )

virtual

Sets the axis of the TrackElement.

Reimplemented from TrackElement.

makeDogleg() [1/2]

TrackElement * makeDogleg ( )

virtual

Create a dogleg on the source end of the TrackSegment. Put the dogleg axis on the source To be further reviewed.

See also:  Dogleg management.

Post-processing done by TrackSegment::_postDoglegs().

Reimplemented from TrackElement.

makeDogleg() [2/2]

TrackElement * makeDogleg ( Interval  interval, unsigned int &  flags  )

virtual

See also:  AutoSegment::makeDogleg(), Dogleg management, the return flags from this method are returned through the flags variable.

Post-processing done by TrackSegment::_postDoglegs().

Reimplemented from TrackElement.

_postDoglegs()

TrackSegment * _postDoglegs ( TrackElement *&  perpandicular, TrackElement *&  parallel  )

virtual

Post-process to be called inside the various dogleg creation or slacken methods. Iterate through the newly created AutoSegments to create, for the perpandicular and the new parallel associateds TrackSegments. Also sets the dogleg levels and flags of the newly created elements.

The session dogleg reset is called at the end of this method. The perpandicular and parallel references to pointers contains the newly created segments for the last dogleg. If more than one was created, you cannot access them (the need has not arised yet).

Reimplemented from TrackElement.

_check()

bool _check ( ) const

virtual

Check the coherency of the element. For a TrackSegment:

• The supporting AutoSegment the canonical one of the set.
• The cached min & max values are identical to the computed ones.

Returns: true on success.

Reimplemented from TrackElement.

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The documentation for this class was generated from the following files:

• TrackSegment.h
• TrackSegment.cpp
• TrackSegment.dox