Link between two components. More...

#include <link.h>

Inheritance diagram for SST::Link:

Data Structures
class	AttachPoint
	Attach point for inspecting, modifying or dropping events sent on the Link. More...

Public Member Functions
void	addSendLatency (int cycles, const std::string &timebase)
	Set additional Latency to be added to events being sent out of this Link.
void	addSendLatency (SimTime_t cycles, TimeConverter timebase)
	Set additional Latency to be added to events being sent out of this Link.
void	addRecvLatency (int cycles, const std::string &timebase)
	Set additional latency to be added on to events coming in on this Link.
void	addRecvLatency (SimTime_t cycles, TimeConverter timebase)
	Set additional latency to be added on to events coming in on this Link.
void	setFunctor (Event::HandlerBase *functor)
	Set the callback function to be called when a message is delivered.
void	replaceFunctor (Event::HandlerBase *functor)
	Replace the callback function to be called when a message is delivered.
Event::HandlerBase *	getFunctor ()
	Get the callback function to be called when a message is delivered.
void	send (SimTime_t delay, TimeConverter tc, Event *event)
	Sends an Event over a Link with an additional delay specified with a TimeConverter.
void	send (SimTime_t delay, Event *event)
	Sends an event over a Link with additional delay specified by the Link's default timebase.
void	send (Event *event)
	Send an Event with no additional delay.
Event *	recv ()
	Retrieve a pending Event from the Link.
void	setDefaultTimeBase (TimeConverter tc)
	Manually set the default defaultTimeBase.
TimeConverter	getDefaultTimeBase ()
	Return the default timebase for this Link.
LinkId_t	getId ()
	Return the ID of this Link.
void	sendUntimedData (Event *data)
	Send data during the init() or complete() phase.
Event *	recvUntimedData ()
	Receive an Event (if any) during the init() or complete() phase.
bool	isConfigured ()
	Return whether Link has been configured.

Protected Member Functions
void	setAsSyncLink ()
void	setDeliveryInfo (uintptr_t info)
	Set the delivery_info for the Link.
void	setTag (uint32_t new_tag)
	Set the tag field for event link ordering.
SimTime_t	getLatency ()
	Get the latency on the link in units of core atomic time base.
uintptr_t	getDeliveryInfo ()
	Get the delivery_info for the link.
Link *	getPairLink ()
	Get the pair_link.
void	send_impl (SimTime_t delay, Event *event)
	Sends an Event over a Link with an additional delay specified with a TimeConverter.

Static Protected Member Functions
static void	updateEventDeliveryInfo (Event *event, uintptr_t delivery_info)
	Updates the delivery info in an event.

Protected Attributes
ActivityQueue *	send_queue
	Queue of events to be received by the owning component.
uintptr_t	delivery_info
	Holds the delivery information.
SimTime_t	defaultTimeBase
	Timebase used if no other timebase is specified.
SimTime_t	latency
	Latency of the Link.
Link *	pair_link
	Pointer to the opposite side of this Link.

Static Protected Attributes
static bool	is_restart_same_parallelism = false
	Variable used by Link restarts to know whether stored rank data for remote links is still valid (i.e.

Friends
class	*SST::Core::Serialization::serialize_impl< Link >**
class	LinkPair
class	RankSync
class	ThreadSync
class	Simulation
class	SyncManager
class	ComponentInfo
class	BaseComponent

Detailed Description

Link between two components.

Carries events

Member Function Documentation

◆ addRecvLatency() [1/2]

void SST::Link::addRecvLatency	(	int	cycles,
		const std::string &	timebase )

Set additional latency to be added on to events coming in on this Link.

Parameters

cycles	Number of cycles to be added
timebase	Base units of cycles

References SST::TimeLord::getSimCycles(), SST::Simulation::getSimulation(), SST::Simulation::getTimeLord(), and pair_link.

◆ addRecvLatency() [2/2]

void SST::Link::addRecvLatency	(	SimTime_t	cycles,
		TimeConverter	timebase )

Set additional latency to be added on to events coming in on this Link.

Parameters

cycles	Number of cycles to be added
timebase	Base units of cycles

References SST::TimeConverter::convertToCoreTime(), and pair_link.

◆ addSendLatency() [1/2]

void SST::Link::addSendLatency	(	int	cycles,
		const std::string &	timebase )

Set additional Latency to be added to events being sent out of this Link.

Parameters

cycles	Number of cycles to be added
timebase	Base units of cycles

References SST::TimeLord::getSimCycles(), SST::Simulation::getSimulation(), SST::Simulation::getTimeLord(), and latency.

◆ addSendLatency() [2/2]

void SST::Link::addSendLatency	(	SimTime_t	cycles,
		TimeConverter	timebase )

Set additional Latency to be added to events being sent out of this Link.

Parameters

cycles	Number of cycles to be added
timebase	Base units of cycles

References SST::TimeConverter::convertToCoreTime(), and latency.

◆ getDefaultTimeBase()

TimeConverter SST::Link::getDefaultTimeBase ( )

Return the default timebase for this Link.

Returns: the default timebase for this Link

References defaultTimeBase, SST::Simulation::getSimulation(), SST::TimeLord::getTimeConverter(), and SST::Simulation::getTimeLord().

◆ getFunctor()

Event::HandlerBase * SST::Link::getFunctor ( )

Get the callback function to be called when a message is delivered.

Polling Links will return nullptr.

Returns: Functor used for event delivery

References pair_link.

◆ getId()

LinkId_t SST::Link::getId ( )

inline

Return the ID of this Link.

Returns: the unique ID for this Link

References attached_tools, and id.

Referenced by SST::RankSyncParallelSkip::registerLink(), SST::RankSyncSerialSkip::registerLink(), and SST::ThreadSyncSimpleSkip::registerLink().

◆ getLatency()

SimTime_t SST::Link::getLatency ( )

inlineprotected

Get the latency on the link in units of core atomic time base.

NOTE: This is a core only API and not part of the public stable API

References latency.

◆ isConfigured()

bool SST::Link::isConfigured ( )

inline

Return whether Link has been configured.

Returns: True if Link has been configured, false otherwise

◆ recv()

Event * SST::Link::recv ( )

Retrieve a pending Event from the Link.

For Links which do not have a set event handler, they can be polled with this function. Returns nullptr if there is no pending Event. Not available for HANDLER-type Links.

Returns: Event if one is available, nullptr if no Event is available

References SST::Output::fatal(), SST::Simulation::getCurrentSimCycle(), SST::Activity::getDeliveryTime(), SST::Simulation::getSimulation(), SST::Simulation::getSimulationOutput(), and pair_link.

◆ recvUntimedData()

Event * SST::Link::recvUntimedData ( )

Receive an Event (if any) during the init() or complete() phase.

Returns: Event if one is available, nullptr if no Event is available

References SST::Activity::getDeliveryTime(), SST::Simulation::getSimulation(), and pair_link.

◆ replaceFunctor()

void SST::Link::replaceFunctor ( Event::HandlerBase * functor )

Replace the callback function to be called when a message is delivered.

Any previous handler will be deleted. Not available for Polling Links.

Parameters

functor Functor to call when message is delivered

References SST::Output::fatal(), SST::Simulation::getSimulation(), SST::Simulation::getSimulationOutput(), pair_link, and SST::SSTHandlerBase< returnT, argT >::transferAttachedToolInfo().

◆ send() [1/3]

void SST::Link::send ( Event * event )

inline

Send an Event with no additional delay.

Parameters

event Event to send

References send_impl().

◆ send() [2/3]

void SST::Link::send	(	SimTime_t	delay,
		Event *	event )

inline

Sends an event over a Link with additional delay specified by the Link's default timebase.

Parameters

delay	The additional delay, in units of the Link's default timebase
event	Event to send

References defaultTimeBase, and send_impl().

◆ send() [3/3]

void SST::Link::send	(	SimTime_t	delay,
		TimeConverter	tc,
		Event *	event )

inline

Sends an Event over a Link with an additional delay specified with a TimeConverter.

I.e. the total delay is the Link's delay + the additional specified delay.

Parameters

delay	Additional delay
tc	TimeConverter to specify timebase for the additional delay
event	Event to send

References SST::TimeConverter::convertToCoreTime(), and send_impl().

◆ send_impl()

void SST::Link::send_impl	(	SimTime_t	delay,
		Event *	event )

protected

Sends an Event over a Link with an additional delay specified with a TimeConverter.

I.e. the total delay is the Link's delay + the additional specified delay.

Parameters

delay	Additional total delay to add in units of the core timebase
event	Event to send

References attached_tools, delivery_info, SST::Output::fatal(), SST::Simulation::getSimulation(), SST::Simulation::getSimulationOutput(), latency, pair_link, and send_queue.

Referenced by send(), send(), and send().

◆ sendUntimedData()

void SST::Link::sendUntimedData ( Event * data )

Send data during the init() or complete() phase.

Parameters

Data	event to send

References delivery_info, SST::Output::fatal(), SST::Simulation::getSimulation(), SST::Simulation::getSimulationOutput(), pair_link, send_queue, and SST::Activity::setDeliveryTime().

◆ setDefaultTimeBase()

void SST::Link::setDefaultTimeBase ( TimeConverter tc )

Manually set the default defaultTimeBase.

Parameters

tc	TimeConverter object for the timebase

References defaultTimeBase, and SST::TimeConverter::getFactor().

◆ setFunctor()

void SST::Link::setFunctor ( Event::HandlerBase * functor )

Set the callback function to be called when a message is delivered.

Not available for Polling Links.

Parameters

functor Functor to call when message is delivered

References SST::Output::fatal(), SST::Simulation::getSimulation(), SST::Simulation::getSimulationOutput(), and pair_link.

◆ setTag()

void SST::Link::setTag ( uint32_t new_tag )

inlineprotected

Set the tag field for event link ordering.

Parameters

new_tag New order tag to use for the Link

References pair_link.

◆ updateEventDeliveryInfo()

void SST::Link::updateEventDeliveryInfo	(	Event *	event,
		uintptr_t	delivery_info )

inlinestaticprotected

Updates the delivery info in an event.

This is used during a restart and is implemented here because Link is a friend of Event.

Parameters

event	Event to update
delivery_info	New delivery info (pointer to handler cast as uintptr_t)

References delivery_info.

Field Documentation

◆ attached_tools

ToolList* SST::Link::attached_tools

This stores any tools connected to the Link::AttachPoint.

The first entry in the list will always contain the Link id since the pointer to the attached_tools list is now using that memory location.

Referenced by getId(), and send_impl().

◆ defaultTimeBase

SimTime_t SST::Link::defaultTimeBase

protected

Timebase used if no other timebase is specified.

Used to specify the units for added delays when sending, such as in Link::send(). Often set by the Component::registerClock() function if the regAll argument is true.

Referenced by getDefaultTimeBase(), send(), and setDefaultTimeBase().

◆ delivery_info

uintptr_t SST::Link::delivery_info

protected

Holds the delivery information.

This is stored as a uintptr_t, but is actually a pointer converted using reinterpret_cast. For Links connected to a Component/SubComponent, this holds a pointer to the delivery functor. For Links connected to a Sync object, this holds a pointer to the remote Link to send the event on after synchronization.

Referenced by getDeliveryInfo(), SST::ThreadSync::getDeliveryInfo(), send_impl(), sendUntimedData(), setDeliveryInfo(), and updateEventDeliveryInfo().

◆ id

LinkId_t SST::Link::id

The Link id is a globally unique id.

For serial loads, the ids start at 1 and increment for each new Link.

On a parallel load, the top 32-bits is filled with the MPI rank and the bottom 32-bits start at 1 and increment for each new rank. The ids for links that cross a rank boundary need to be reconciled so that the Link objects on both ranks agree on the ID. This is done by having the "lower" rank send the Link name and it's id for the Link to the "higher" rank, which will then use that id for the Link. "Higher" and "lower" are determined in a way that hopefully spreads out the MPI traffic across all the ranks and isn't just a direct greater/less than comparison. It is determined as follows:

1 - A rank is lower than the N/2 ranks after it, wrapping around to 0 when needed.

2 - A rank is higher than the N/2 ranks before it, wrapping around to N-1 when needed.

The id is used in several places:

When exchanging Link pointers to put in the delivery_info field
As the global name for connecting links on a restart from checkpoint

Referenced by getId().

◆ is_restart_same_parallelism

bool SST::Link::is_restart_same_parallelism = false

staticprotected

Variable used by Link restarts to know whether stored rank data for remote links is still valid (i.e.

did we restart with the exact same rank/thread count or not).

◆ latency

SimTime_t SST::Link::latency

protected

Latency of the Link.

It is used by the partitioner as the weight. This latency is added to the delay put on the event by the component.

Referenced by addSendLatency(), addSendLatency(), getLatency(), SST::ThreadSync::getLatency(), and send_impl().

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

src/sst/core/link.h
src/sst/core/link.cc

Data Structures

Public Member Functions

Protected Member Functions

Static Protected Member Functions

Protected Attributes

Static Protected Attributes

Friends

Detailed Description

Member Function Documentation

◆ addRecvLatency() [1/2]

◆ addRecvLatency() [2/2]

◆ addSendLatency() [1/2]

◆ addSendLatency() [2/2]

◆ getDefaultTimeBase()

◆ getFunctor()

◆ getId()

◆ getLatency()

◆ isConfigured()

◆ recv()

◆ recvUntimedData()

◆ replaceFunctor()

◆ send() [1/3]

◆ send() [2/3]

◆ send() [3/3]

◆ send_impl()

◆ sendUntimedData()

◆ setDefaultTimeBase()

◆ setFunctor()

◆ setTag()

◆ updateEventDeliveryInfo()

Field Documentation

◆ attached_tools

◆ defaultTimeBase

◆ delivery_info

◆ id

◆ is_restart_same_parallelism

◆ latency