DREAM::Task

DREAM::Task Class Reference

#include <Task.h>

Inheritance diagram for DREAM::Task:


Public Member Functions
	Task (const std::string &id, DREAM::Thread *thread_ptr, uint wcet, uint deadline)
	Constructor.
	Task (const std::string &id, DREAM::Thread *thread_ptr, uint wcet, uint deadline, uint subpriority)
	Constructor.
	Task (const std::string &id, DREAM::Thread *thread_ptr, uint wcet, uint bcet, uint deadline, uint subpriority)
	Constructor.
	Task (const DREAM::Task &task)
	Copy constructor for Tasks.
virtual	~Task ()
	Destructor.
virtual void	operator= (const DREAM::Task &task)
	Operator overloading.
virtual bool	operator== (const DREAM::Task &task)
	Operator overloading.
virtual uint	bcet () const
	Returns the best case execution time of the task.
virtual void	bcet (uint bcet)
	Sets the best case execution time of the task .
virtual void	branching_point ()
	Sets the new execution time if branching points were found.
virtual DREAM::Context	context () const
	Returns whether the Task uses the best case or worst case time for the simulation.
virtual void	context (DREAM::Context context)
	Sets the Task to use the specified context (e.g.
virtual double	clock_dl () const
	Returns the value of the deadline clock - clock_dl_.
virtual void	clock_dl_reset ()
	Resets deadline clock value - clock_dl_.
virtual void	clock_exec_reset ()
	Resets execution clock value - clock_exec_.
virtual void	clock_step (double clock_step)
	Models the passing of time - increments local clock.
virtual void	consume ()
	Consumes an event received from an event source.
virtual uint	deadline () const
	Returns the deadline of the task.
virtual void	deadline (uint deadline)
	Sets the deadline of the task.
virtual void	execute ()
	Schedules the Task for execution.
virtual bool	isidle () const
	Returns true if the Task is idle (used by Channels).
virtual double	next_event ()
	Tells when the Task will generate the next event.
virtual void	next_et (double next_et)
	Sets the next execution time when the context is branchingpoint.
virtual void	preempt ()
	Models the preemption of the task.
virtual uint	priority () const
	Returns the priority of the Task - the priority of the Thread which executes it.
virtual void	priority (uint priority)
	Sets the priority of the Task.
virtual void	publish ()
	Publishes an event to dependent tasks.
virtual void	reset ()
	Resets task (after a frame overrun or when restarting the simulation).
virtual uint	subpriority () const
	Returns the sub-priority of the Task - subpriority_.
virtual void	subpriority (uint subpriority)
	Sets the subpriority of the Task.
virtual void	take_transitions ()
	Takes state transitions.
virtual void	visitor_if (DREAM::NODE_MAP task_map, DREAM::NODE_MAP channel_map, DREAM::NODE_MAP *timer_map, std::ofstream &f_stream)
	This function is part of the IF system description generator.
virtual void	visitor_map (DREAM::NODE_MAP task_map, DREAM::NODE_MAP channel_map, DREAM::NODE_MAP *timer_map)
	This function fills the IDs (names) of tasks, channels and timers to the parameter lists.
virtual void	visitor_task_avltree (DREAM::TASK_AVLTREE *task_avltree)
	This function builds the task list for manipulation.
virtual void	visitor_update_task_avltree (DREAM::TASK_AVLTREE *task_avltree)
	This function updates task values in the system.
virtual void	visitor_uppaal (DREAM::NODE_MAP task_map, DREAM::NODE_MAP channel_map, DREAM::NODE_MAP *timer_map, std::ofstream &f_stream)
	This function is part of the Uppaal system description generator.
virtual uint	wcet () const
	Returns the worst case execution time of the task.
virtual void	wcet (uint wcet)
	Sets the worst case execution time of the task.
virtual bool	zero_delay_race_condition (DREAM::System *system_ptr)
	Returns true if all of the sources of the task are zero-delay channels.
Protected Member Functions
	Task (const std::string &id, DREAM::Thread *thread_ptr, uint wcet, uint bcet, uint deadline, uint subpriority, DREAM::Context context, double et, DREAM::State state, double clock_dl)
	Constructor.
Protected Attributes
uint	bcet_
	Best case execution time.
DREAM::Context	context_
	Specifies whether best case, worst case, or a random value is used for the execution time during the simulation.
double	clock_dl_
	Deadline clock.
uint	deadline_
	Deadline.
double	et_
	The execution time.
double	next_et_
	The next execution time when the context is branchingpoint.
DREAM::State	state_
	State of the Task as specified by the DRE Semantic Domain.
uint	subpriority_
	Sub-priority.
uint	wcet_
	Worst case execution time.
uint	zero_delay_race_condition_
	This variable is used to speed up the search whether all sources are zero-delay.

Detailed Description

Real-time Task.

This class is the implementation of the Task in the DRE Semantic Domain.

Definition at line 856 of file Task.h.

Constructor & Destructor Documentation

DREAM::Task::Task	(	const std::string &	id,
		DREAM::Thread *	thread_ptr,
		uint	wcet,
		uint	deadline
	)

Constructor.

Parameters:

	id	specifies the name of the Task.
	thread_ptr	defines the mapping of the Task to a platform processor.
	wcet	is the worst case execution time parameter of the Task.
	deadline	is the deadline of the task - deadlines are counted from the time when the task becomes enabled.

Definition at line 1221 of file Task.cpp.

DREAM::Task::Task	(	const std::string &	id,
		DREAM::Thread *	thread_ptr,
		uint	wcet,
		uint	deadline,
		uint	subpriority
	)

Constructor.

Parameters:

	id	specifies the name of the Task.
	thread_ptr	defines the mapping of the Task to a platform processor.
	wcet	is the worst case execution time parameter of the Task.
	deadline	is the deadline of the task - deadlines are counted from the time when the task becomes enabled.
	subpriority	is the subpriority of the task. Subpriorities can be used to model the queueing policies (FIFO, MUF etc.)

Definition at line 1239 of file Task.cpp.

DREAM::Task::Task	(	const std::string &	id,
		DREAM::Thread *	thread_ptr,
		uint	wcet,
		uint	bcet,
		uint	deadline,
		uint	subpriority
	)

Constructor.

Parameters:

	id	specifies the name of the Task.
	thread_ptr	defines the mapping of the Task to a platform processor.
	bcet	is the best case execution time parameter of the Task.
	wcet	is the worst case execution time parameter of the Task.
	deadline	is the deadline of the task - deadlines are counted from the time when the task becomes enabled.
	subpriority	is the subpriority of the task. Subpriorities can be used to model the queueing policies (FIFO, MUF etc.)

Definition at line 1258 of file Task.cpp.

DREAM::Task::Task ( const DREAM::Task & task )

Copy constructor for Tasks.

Used in genetic algorithms.

Definition at line 1302 of file Task.cpp.

DREAM::Task::~Task ( ) [virtual]

Destructor.

Definition at line 1321 of file Task.cpp.

DREAM::Task::Task	(	const std::string &	id,
		DREAM::Thread *	thread_ptr,
		uint	wcet,
		uint	bcet,
		uint	deadline,
		uint	subpriority,
		DREAM::Context	context,
		double	et,
		DREAM::State	state,
		double	clock_dl
	)			`[protected]`

Constructor.

This contructor is only to be used by the copy constructors of derived classes.

Parameters:

	id	specifies the name of the Task.
	thread_ptr	defines the mapping of the Task to a platform processor.
	bcet	is the best case execution time parameter of the Task.
	wcet	is the worst case execution time parameter of the Task.
	deadline	is the deadline of the task - deadlines are counted from the time when the task becomes enabled.
	subpriority	is the subpriority of the task. Subpriorities can be used to model the queueing policies (FIFO, MUF etc.)
	context	specifies the context of the Task.
	et	specifies the actual execution time of the Task.
	state	specifies the state of the Task.
	clock_dl	specifies the deadline clock of the Task.

Definition at line 1280 of file Task.cpp.

Member Function Documentation

void DREAM::Task::operator= ( const DREAM::Task & task ) [virtual]

Operator overloading.

The Task will be copied except for the thread_ptr_.

Parameters:

task

is the Task to be copied.

Definition at line 1325 of file Task.cpp.

References bcet_, clock_dl_, context_, deadline_, DREAM::Node::id_, next_et_, state_, subpriority_, and wcet_.

bool DREAM::Task::operator== ( const DREAM::Task & task ) [virtual]

Operator overloading.

Parameters:

task

is the Task to be compared with this class.

Definition at line 1342 of file Task.cpp.

References DREAM::Node::id_.

uint DREAM::Task::bcet ( ) const [inline, virtual]

Returns the best case execution time of the task.

Returns:: the best case execution time bcet_.

Reimplemented from DREAM::Node.

Definition at line 1362 of file Task.cpp.

void DREAM::Task::bcet ( uint bcet ) [inline, virtual]

Sets the best case execution time of the task .

Parameters:

bcet

is the best case execution time parameter of the Task.

Reimplemented from DREAM::Node.

Definition at line 1372 of file Task.cpp.

void DREAM::Task::branching_point ( ) [inline, virtual]

Sets the new execution time if branching points were found.

Reimplemented from DREAM::Node.

Definition at line 1383 of file Task.cpp.

References DREAM::bestcase, and DREAM::branchingpoint.

DREAM::Context DREAM::Task::context ( ) const [inline, virtual]

Returns whether the Task uses the best case or worst case time for the simulation.

Returns:: the context of the Timer.

Reimplemented from DREAM::Node.

Definition at line 1404 of file Task.cpp.

void DREAM::Task::context ( DREAM::Context context ) [inline, virtual]

Sets the Task to use the specified context (e.g.

in the simulation).

Parameters:

context

is the context assumed.

Reimplemented from DREAM::Node.

Definition at line 1414 of file Task.cpp.

double DREAM::Task::clock_dl ( ) const [inline, virtual]

Returns the value of the deadline clock - clock_dl_.

Reimplemented from DREAM::Node.

Definition at line 1424 of file Task.cpp.

void DREAM::Task::clock_dl_reset ( ) [inline, virtual]

Resets deadline clock value - clock_dl_.

Definition at line 1430 of file Task.cpp.

References clock_dl_.

Referenced by reset().

void DREAM::Task::clock_exec_reset ( ) [inline, virtual]

Resets execution clock value - clock_exec_.

Reimplemented from DREAM::Node.

Definition at line 1435 of file Task.cpp.

References bcet_, DREAM::bestcase, DREAM::Node::clock_exec_, context_, et_, DREAM::random(), DREAM::randomcase, wcet_, and DREAM::worstcase.

Referenced by reset().

void DREAM::Task::clock_step ( double clock_step ) [inline, virtual]

Models the passing of time - increments local clock.

Parameters:

clock_step

specifies by how much do we have to increment the time.

Reimplemented from DREAM::Node.

Definition at line 1448 of file Task.cpp.

References bcet_, Option::branching_, DREAM::branchingpoint, clock_dl_, DREAM::Node::clock_exec_, context_, DREAM::enabled, et_, DREAM::executing, DREAM::Node::id_, next_et_, DREAM::preempted, DREAM::System::relevant_event(), DREAM::Node::remote_dep_, DREAM::Thread::scheduler(), state_, DREAM::Scheduler::system(), DREAM::Node::thread_ptr_, DREAM::Thread::trace(), wcet_, and DREAM::worstcase.

void DREAM::Task::consume ( ) [inline, virtual]

Consumes an event received from an event source.

This function is called by the publish () function of the event source and triggers state transitions. The take_transitions () function will take the enabled transitions.

Reimplemented from DREAM::Node.

Definition at line 1486 of file Task.cpp.

References DREAM::enabled, DREAM::error, DREAM::executing, and DREAM::idle.

uint DREAM::Task::deadline ( ) const [inline, virtual]

Returns the deadline of the task.

Returns:: deadline of the clock deadline_.

Reimplemented from DREAM::Node.

Definition at line 1513 of file Task.cpp.

Referenced by DREAM::Scheduler::add_error().

void DREAM::Task::deadline ( uint deadline ) [inline, virtual]

Sets the deadline of the task.

Deadlines are counted from the time when the task becomes enabled.

Parameters:

deadline

is the deadline of the task.

Reimplemented from DREAM::Node.

Definition at line 1523 of file Task.cpp.

void DREAM::Task::execute ( ) [inline, virtual]

Schedules the Task for execution.

This function will schedule the Task for execution.

Reimplemented from DREAM::Node.

Definition at line 1533 of file Task.cpp.

References DREAM::branchingpoint, DREAM::enabled, DREAM::executing, and DREAM::preempted.

Referenced by DREAM::FixedPriorityScheduler::schedule().

bool DREAM::Task::isidle ( ) const [inline, virtual]

Returns true if the Task is idle (used by Channels).

Reimplemented from DREAM::Node.

Definition at line 1575 of file Task.cpp.

References DREAM::idle.

double DREAM::Task::next_event ( ) [inline, virtual]

Tells when the Task will generate the next event.

Returns:: Time remaining till the next event generation.

Reimplemented from DREAM::Node.

Definition at line 1581 of file Task.cpp.

References DREAM::Node::clock_exec_, et_, DREAM::executing, and state_.

void DREAM::Task::next_et ( double next_et ) [inline, virtual]

Sets the next execution time when the context is branchingpoint.

Reimplemented from DREAM::Node.

Definition at line 1593 of file Task.cpp.

void DREAM::Task::preempt ( ) [inline, virtual]

Models the preemption of the task.

This function will take the state transition to the preempted state as specified by the DRE Semantic Domain. It does not require calling the take_transition () function.

Reimplemented from DREAM::Node.

Definition at line 1604 of file Task.cpp.

References DREAM::executing, and DREAM::preempted.

uint DREAM::Task::priority ( ) const [inline, virtual]

Returns the priority of the Task - the priority of the Thread which executes it.

Reimplemented from DREAM::Node.

Definition at line 1615 of file Task.cpp.

Referenced by DREAM::Solution::fitness().

void DREAM::Task::priority ( uint priority ) [inline, virtual]

Sets the priority of the Task.

This function looks up whether there is a Thread with the requested priority on the actual CPU. If yes, it redeploys the Task to that Thread. If not, returns with an Exception. This function is used by the genetic algorithm when assigning priorities.

Parameters:

priority

is the priority of the task.

Reimplemented from DREAM::Node.

Definition at line 1625 of file Task.cpp.

void DREAM::Task::publish ( ) [inline, virtual]

Publishes an event to dependent tasks.

This function models synchronous event propagation by calling the consume () functions of all the dependent Nodes.

Reimplemented from DREAM::Node.

Definition at line 1635 of file Task.cpp.

References DREAM::executing, and DREAM::idle.

void DREAM::Task::reset ( ) [inline, virtual]

Resets task (after a frame overrun or when restarting the simulation).

Reimplemented from DREAM::Node.

Definition at line 1653 of file Task.cpp.

References clock_dl_reset(), clock_exec_reset(), DREAM::Node::executed(), DREAM::idle, and state_.

uint DREAM::Task::subpriority ( ) const [inline, virtual]

Returns the sub-priority of the Task - subpriority_.

Reimplemented from DREAM::Node.

Definition at line 1665 of file Task.cpp.

Referenced by DREAM::Scheduler::add_error(), DREAM::Solution::fitness(), and DREAM::FixedPriorityScheduler::schedule().

void DREAM::Task::subpriority ( uint subpriority ) [inline, virtual]

Sets the subpriority of the Task.

Parameters:

subpriority

is the subpriority of the task. Subpriorities can be used to model the queueing policies (FixedPriority, FIFO, MUF etc.)

Reimplemented from DREAM::Node.

Definition at line 1675 of file Task.cpp.

void DREAM::Task::take_transitions ( ) [inline, virtual]

Takes state transitions.

This function implements the state transitions of a Task as specified by the DRE Semantic Domain. Transitions can be triggered by events coming from other Tasks, Timers, event Channels or Schedulers.

Reimplemented from DREAM::Node.

Definition at line 1685 of file Task.cpp.

References DREAM::error, DREAM::executing, and Option::verbose1_.

void DREAM::Task::visitor_if	(	DREAM::NODE_MAP *	task_map,
		DREAM::NODE_MAP *	channel_map,
		DREAM::NODE_MAP *	timer_map,
		std::ofstream &	f_stream
	)			`[virtual]`

This function is part of the IF system description generator.

Parameters:

	task_map	stores the Task pointers.
	channel_map	stores the Channel pointers.
	timer_map	stores the Timer pointers.
	f_stream	is the output stream to be written to.

Reimplemented from DREAM::Node.

Definition at line 1747 of file Task.cpp.

void DREAM::Task::visitor_map	(	DREAM::NODE_MAP *	task_map,
		DREAM::NODE_MAP *	channel_map,
		DREAM::NODE_MAP *	timer_map
	)			`[virtual]`

This function fills the IDs (names) of tasks, channels and timers to the parameter lists.

The function is used to generate output for model checkers.

Parameters:

	task_map	stores the Task pointers.
	channel_map	stores the Channel pointers.
	timer_map	stores the Timer pointers.

Reimplemented from DREAM::Node.

Definition at line 1989 of file Task.cpp.

void DREAM::Task::visitor_task_avltree ( DREAM::TASK_AVLTREE * task_avltree ) [virtual]

This function builds the task list for manipulation.

The function is used by genetic algorithms.

Parameters:

task_avltree

stores the Task pointers.

Reimplemented from DREAM::Node.

Definition at line 1997 of file Task.cpp.

References DREAM::AVLTree< key_type, item_type >::insert().

void DREAM::Task::visitor_update_task_avltree ( DREAM::TASK_AVLTREE * task_avltree ) [virtual]

This function updates task values in the system.

The function is used by genetic algorithms.

Parameters:

task_avltree

stores the Task pointers.

Reimplemented from DREAM::Node.

Definition at line 2005 of file Task.cpp.

References DREAM::AVLTree< key_type, item_type >::begin(), and DREAM::AVLTree< key_type, item_type >::end().

void DREAM::Task::visitor_uppaal	(	DREAM::NODE_MAP *	task_map,
		DREAM::NODE_MAP *	channel_map,
		DREAM::NODE_MAP *	timer_map,
		std::ofstream &	f_stream
	)			`[virtual]`

This function is part of the Uppaal system description generator.

Parameters:

	task_map	stores the Task pointers.
	channel_map	stores the Channel pointers.
	timer_map	stores the Timer pointers.
	f_stream	is the output stream to be written to.