RTT::base::TaskCore Class Reference

#include <TaskCore.hpp>

Inheritance diagram for RTT::base::TaskCore:

Public Types
enum	TaskState {   Init, PreOperational, FatalError, Exception,   Stopped, Running, RunTimeError }

Public Member Functions
const ExecutionEngine *	engine () const
ExecutionEngine *	engine ()
unsigned int	getCycleCounter () const
unsigned int	getIOCounter () const
virtual TaskState	getTargetState () const
virtual TaskState	getTaskState () const
unsigned int	getTimeOutCounter () const
unsigned int	getTriggerCounter () const
	TaskCore (TaskState initial_state=Stopped, const std::string &name=std::string())
virtual	~TaskCore ()
Operations
These TaskCore functions are exported in a TaskContext as script methods and are for configuration, starting and stopping its ExecutionEngine.
virtual bool	configure ()
virtual bool	activate ()
virtual bool	start ()
virtual bool	stop ()
virtual bool	cleanup ()
virtual bool	isConfigured () const
virtual bool	isActive () const
virtual bool	isRunning () const
virtual Seconds	getPeriod () const
virtual bool	setPeriod (Seconds s)
virtual unsigned	getCpuAffinity () const
virtual bool	setCpuAffinity (unsigned cpu)
virtual bool	inFatalError () const
virtual bool	inException () const
virtual bool	inRunTimeError () const
virtual bool	update ()
virtual bool	trigger ()
virtual void	error ()
virtual bool	recover ()

Protected Member Functions
virtual bool	breakUpdateHook ()
virtual void	cleanupHook ()
virtual bool	configureHook ()
virtual void	errorHook ()
virtual void	exception ()
virtual void	exceptionHook ()
virtual void	fatal ()
virtual bool	startHook ()
virtual void	stopHook ()
virtual void	updateHook ()

Protected Attributes
ExecutionEngine *	ee
unsigned int	mCycleCounter
unsigned int	mIOCounter
std::string	mName
TaskState	mTaskState
unsigned int	mTimeOutCounter
unsigned int	mTriggerCounter
bool	mTriggerOnStart

Private Member Functions
	TaskCore (TaskCore &)

Private Attributes
TaskState const	mInitialState
TaskState	mTargetState

Friends
class	::RTT::ExecutionEngine
class	TaskContext

Detailed Description

The minimal Orocos task. It has a state and an ExecutionEngine to process messages and user functions.

Definition at line 54 of file TaskCore.hpp.

Member Enumeration Documentation

enum RTT::base::TaskCore::TaskState

Describes the different states a component can have. When a TaskContext is being constructed, it is in the Init state. After the construction ends, the component arrives in the PreOperational (additional configuration required) or the Stopped (ready to run) state. Invoking start() will make a transition to the Running state and stop() back to the Stopped state. The Running state executes updateHook(). Finally, there is an FatalError state, in which the component can enter by calling the protected method fatal(). In this state, the ExecutionEngine is stopped and updateHook() is no longer called. The object should then be disposed by a supervision system.

Next to the fatal error, one run-time error level is available in the Running state as well. This level allows 'automatic' recovery by the component in case the problem is temporal. In case of problems, one may call the protected method error() when the component is Running. The component will enter the RunTimeError state and will cause the errorHook() to be called instead of updateHook(). When recover() is called, this run-time error state is left and the nominal Running state is entered again.

In order to check if these transitions are allowed, hook functions are executed, which can be filled in by the component builder.

• A transition from PreOperational to Stopped is checked by calling the configureHook() method. If this method returns true, the transition is made, otherwise, the state remains PreOperational.
• A transition from Stopped to Running is checked by calling the startHook() method. If this method returns true, the transition is made, otherwise, the state remains Stopped.
• A transition from Running to Stopped is always allowed and the stopHook() method is called to inform the component of this transtion.
• A transition from Stopped to PreOperational is always allowed and the cleanupHook() method is called to inform the component of this transtion.

Enumerator
Init	The state during component construction.
PreOperational	The state indicating additional configuration is required.
FatalError	The state indicating the component encountered a fatal error and is unable to execute.
Exception	The state indicating the component encountered a C++ exception.
Stopped	The state indicating the component is ready to run.
Running	The state indicating the component is running [green].
RunTimeError	The state indicating that a run-time error has occured [red] and needs attention.

Definition at line 99 of file TaskCore.hpp.

Constructor & Destructor Documentation

RTT::TaskCore::TaskCore	(	TaskState	initial_state = Stopped,
		const std::string &	name = std::string()
	)

Create a TaskCore. It's ExecutionEngine will be newly constructed with private processing of commands, events, programs and state machines.

Parameters

initial_state

Provide the PreOperational parameter flag here to force users in calling configure(), before they call start().

Definition at line 53 of file TaskCore.cpp.

RTT::TaskCore::~TaskCore ( )

virtual

Definition at line 67 of file TaskCore.cpp.

RTT::base::TaskCore::TaskCore ( TaskCore &  )

private

Member Function Documentation

bool RTT::TaskCore::activate ( )

virtual

This method starts the ExecutionEngine of this component in case it was not running. Normally, it is always running. There is no way to deactivate it from the public interface.

Returns

true if the ExecutionEngine is running (again) and false if it could not be started.

Reimplemented in RTT::corba::TaskContextProxy.

Definition at line 258 of file TaskCore.cpp.

bool RTT::TaskCore::breakUpdateHook ( )

protectedvirtual

Implement this function if your code might block for long times inside the updateHook() function. Insert in this hook the code to wake up that code or signal it otherwise that updateHook() is requested to return (for example by setting a flag). The method returns false by default.

Returns

true if well received and updateHook() will soon return. False otherwise.

Reimplemented in Reader< T, PortType >, Writer< T, PortType >, and StatesTC.

Definition at line 327 of file TaskCore.cpp.

bool RTT::TaskCore::cleanup ( )

virtual

This method instructs a stopped component to enter the pre-operational state again. It calls cleanupHook().

Returns

true if the component was in the Stopped state.

Reimplemented in RTT::corba::TaskContextProxy.

Definition at line 130 of file TaskCore.cpp.

void RTT::TaskCore::cleanupHook ( )

protectedvirtual

Implement this method such that it contains the code which will be executed when cleanup() is called. The default implementation is an empty function.

Reimplemented in TestFileDescriptor, and StatesTC.

Definition at line 263 of file TaskCore.cpp.

bool RTT::TaskCore::configure ( )

virtual

This method instructs the component to (re-)read configuration data and try to enter the Stopped state. This can only succeed if the component is not running and configureHook() returns true.

Reimplemented in RTT::corba::TaskContextProxy.

Definition at line 96 of file TaskCore.cpp.

bool RTT::TaskCore::configureHook ( )

protectedvirtual

Implement this method such that it contains the code which will be executed when configure() is called. The default implementation is an empty function which returns true.

Return values

true	to indicate that configuration succeeded and the Stopped state may be entered.
false	to indicate that configuration failed and the Preoperational state is entered.

Reimplemented in TaskCore_bails_out_if_configureHook_returns_true_but_exception_was_called, StatesTC, and TestFileDescriptor.

Definition at line 311 of file TaskCore.cpp.

const ExecutionEngine* RTT::base::TaskCore::engine ( ) const

inline

Get a const pointer to the ExecutionEngine of this Task.

Definition at line 306 of file TaskCore.hpp.

ExecutionEngine* RTT::base::TaskCore::engine ( )

inline

Get a pointer to the ExecutionEngine of this Task.

Definition at line 314 of file TaskCore.hpp.

void RTT::TaskCore::error ( )

virtual

Call this method in a Running state to indicate a run-time error condition. errorHook() will be called instead of updateHook(). If the error condition is solved, call recover().

Definition at line 156 of file TaskCore.cpp.

void RTT::TaskCore::errorHook ( )

protectedvirtual

Implement this method to contain code that must be executed in the RunTimeError state, instead of updateHook(). This allows you to specify the behaviour in an erroneous component. errorHook() is called as long as the component is not recover()'ed. After recover()'ed, the updateHook() is called again.

Reimplemented in errorHook_is_not_called_after_an_exit_transition_Task, calling_recover_does_not_override_a_stop_transition_Task, calling_error_does_not_override_a_stop_transition_Task, and StatesTC.

Definition at line 320 of file TaskCore.cpp.

void RTT::TaskCore::exception ( )

protectedvirtual

Call this method to indicate a run-time exception happend. First the TaskState is set to Exception. Next, if the taskstate was >= Running, stopHook() is called. Next, if the taskstate was >= Stopped, cleanupHook() is called. Finally, exceptionHook() is called. If any exception happens in exceptionHook(), fatal() is called.

Definition at line 163 of file TaskCore.cpp.

void RTT::TaskCore::exceptionHook ( )

protectedvirtual

Implement this method to contain code that must be executed when transitioning to the Exception state. This allows you to specify the last actions in an erroneous component, after stopHook() and cleanupHook() were called.

See also

recover() to leave the Exception state.

Reimplemented in StatesTC.

Definition at line 332 of file TaskCore.cpp.

void RTT::TaskCore::fatal ( )

protectedvirtual

Call this method from any place to indicate that this component encountered a fatal error. It calls no hooks, the ExecutionEngine is stopped and the component waits destruction.

Definition at line 151 of file TaskCore.cpp.

unsigned RTT::TaskCore::getCpuAffinity ( ) const

virtual

Get the configured cpu affinity of this component.

See also

ActivityInterface::getCpuAffinity()

Definition at line 301 of file TaskCore.cpp.

unsigned int RTT::base::TaskCore::getCycleCounter ( ) const

inline

For each update cycle, this counter increments by one. You can use this to check across (callback) functions if we're still in the same cycle or in a new one.

Definition at line 324 of file TaskCore.hpp.

unsigned int RTT::base::TaskCore::getIOCounter ( ) const

inline

Number of cycles that were caused by IOReady triggers.

Definition at line 332 of file TaskCore.hpp.

Seconds RTT::TaskCore::getPeriod ( ) const

virtual

Get the configured execution period of this component. Note that this value only is used when the component isActive() or isRunning().

Return values

0.0	if the component is non-periodic (event based).
a	negative number when the component is not executable.
a	positive value when the component is periodic. The period is expressed in seconds.

Todo:

: add a bool setPeriod(double) function to allow changing the period at run-time.

Definition at line 291 of file TaskCore.cpp.

TaskCore::TaskState RTT::TaskCore::getTargetState ( ) const

virtual

Returns the state this TaskCore is going to, or in case no transition is taking place, returns getTaskState(). For example, before start(), this function returns Stopped. During startHook(), it returns Running and after start() it also returns Running.

If getTaskState() != getTargetState, a transition is taking place.

See also

getTaskState()

Definition at line 82 of file TaskCore.cpp.

TaskCore::TaskState RTT::TaskCore::getTaskState ( ) const

virtual

Returns the current state of the TaskCore. For example, before start(), this function returns Stopped. During startHook() it returns Stopped, and after start() it returns Running.

See also

getTargetState()

Reimplemented in RTT::corba::TaskContextProxy.

Definition at line 78 of file TaskCore.cpp.

unsigned int RTT::base::TaskCore::getTimeOutCounter ( ) const

inline

Number of cycles that were caused by TimeOut triggers.

Definition at line 336 of file TaskCore.hpp.

unsigned int RTT::base::TaskCore::getTriggerCounter ( ) const

inline

Number of cycles that were caused by Trigger triggers.

Definition at line 328 of file TaskCore.hpp.

bool RTT::TaskCore::inException ( ) const

virtual

Inspect if the component is in the Exception state.

Reimplemented in RTT::corba::TaskContextProxy.

Definition at line 278 of file TaskCore.cpp.

bool RTT::TaskCore::inFatalError ( ) const

virtual

Inspect if the component is in the FatalError state. There is no possibility to recover from this state. You need to destroy and recreate your component.

Reimplemented in RTT::corba::TaskContextProxy.

Definition at line 274 of file TaskCore.cpp.

bool RTT::TaskCore::inRunTimeError ( ) const

virtual

Inspect if the component is in the RunTimeError state.

Reimplemented in RTT::corba::TaskContextProxy.

Definition at line 282 of file TaskCore.cpp.

bool RTT::TaskCore::isActive ( ) const

virtual

Inspect if the component's ExecutionEngine is processing requests. Normally this is always the case, but user code could stop the ExecutionEngine manually.

Reimplemented in RTT::corba::TaskContextProxy.

Definition at line 286 of file TaskCore.cpp.

bool RTT::TaskCore::isConfigured ( ) const

virtual

Inspect if the component is configured, i.e. in the Stopped, Active or Running state.

Reimplemented in RTT::corba::TaskContextProxy.

Definition at line 270 of file TaskCore.cpp.

bool RTT::TaskCore::isRunning ( ) const

virtual

Inspect if the component is in the Running or RunTimeError state. As RunTimeError is a substate of Running, this method also returns true when the component is in one of these states. See inRunTimeError() or testing the run-time error state.

Reimplemented in RTT::corba::TaskContextProxy.

Definition at line 266 of file TaskCore.cpp.

bool RTT::TaskCore::recover ( )

virtual

Call this method in a RunTimeError or Exception state to indicate that the run-time error conditions are gone and nominal operation is resumed. Makes transition to Running or PreOperational, depending on the state it was in.

Returns

false if not applicable in the current state.

Reimplemented in RTT::corba::TaskContextProxy.

Definition at line 186 of file TaskCore.cpp.

bool RTT::TaskCore::setCpuAffinity ( unsigned  cpu )

virtual

Sets the cpu affinity of this component.

Returns

false if not allowed by the component's activity.

See also

ActivityInterface::setCpuAffinity()

Definition at line 306 of file TaskCore.cpp.

bool RTT::TaskCore::setPeriod ( Seconds  s )

virtual

Sets the period of this component. You may call this at any time, it is simply forwarded to the component's activity object.

Returns

false if not allowed by the component's activity.

See also

ActivityInterface::setPeriod()

Definition at line 296 of file TaskCore.cpp.

bool RTT::TaskCore::start ( )

virtual

This method starts the execution of the updateHook() with each trigger or period. This function calls the user function startHook(), which must return true in order to allow this component to run.

Return values

false	if startHook() returned false if the component was not Stopped
true	if the Running state was entered.

Reimplemented in RTT::TaskContext, and RTT::corba::TaskContextProxy.

Definition at line 198 of file TaskCore.cpp.

bool RTT::TaskCore::startHook ( )

protectedvirtual

Implement this method such that it contains the code which will be executed when start() is called. The default implementation is an empty function which returns true.

Return values

true	to indicate that the component may run and the Running state may be entered.
false	to indicate that the component may not run and the Stopped state is entered.

Reimplemented in TaskCore_bails_out_if_startHook_returns_true_but_exception_was_called, StatesTC, and TestFileDescriptor.

Definition at line 315 of file TaskCore.cpp.

bool RTT::TaskCore::stop ( )

virtual

This method stops the execution of updateHook() of this component. You can override this method to do something else or in addition. This function calls stopHook() as well.

Returns

false if the component was not Running or not Active.

Reimplemented in RTT::TaskContext, and RTT::corba::TaskContextProxy.

Definition at line 232 of file TaskCore.cpp.

void RTT::TaskCore::stopHook ( )

protectedvirtual

Implement this method such that it contains the code which will be executed when stop() is called. The default implementation is an empty function.

Reimplemented in errorHook_is_not_called_after_an_exit_transition_Task, and StatesTC.

Definition at line 335 of file TaskCore.cpp.

bool RTT::TaskCore::trigger ( )

virtual

Invoke this method to trigger the thread of this TaskContext to execute its ExecutionEngine and the update() method.

Return values

false	if this->engine()->getActivity()->trigger() == false
true	otherwise.

Definition at line 91 of file TaskCore.cpp.

bool RTT::TaskCore::update ( )

virtual

Invoke this method to execute the ExecutionEngine and the update() method.

Return values

false	if this->engine()->getActivity()->execute() == false
true	otherwise.

Definition at line 86 of file TaskCore.cpp.

void RTT::TaskCore::updateHook ( )

protectedvirtual

Function where the user must insert his 'application' code. When the ExecutionEngine's Activity is a periodic, this function is called by the ExecutionEngine in each periodic step after all messages are processed. When it is executed by a non periodic activity, this function is called after a message is received and executed. It should not loop forever, since no commands or events are processed when this function executes. The default implementation is an empty function.

Reimplemented in Reader< T, PortType >, Writer< T, PortType >, errorHook_is_not_called_after_an_exit_transition_Task, calling_recover_does_not_override_a_stop_transition_Task, calling_error_does_not_override_a_stop_transition_Task, StatesTC, TestFileDescriptor, TheServer, OperationCallerComponent, TheServer, EventPortsTC, and MasterComponent.

Definition at line 323 of file TaskCore.cpp.

Friends And Related Function Documentation

friend class ::RTT::ExecutionEngine

friend

Definition at line 438 of file TaskCore.hpp.

friend class TaskContext

friend

Definition at line 463 of file TaskCore.hpp.

Member Data Documentation

ExecutionEngine* RTT::base::TaskCore::ee

protected

The execution engine which calls update() and processes our commands, events etc.

Definition at line 444 of file TaskCore.hpp.

unsigned int RTT::base::TaskCore::mCycleCounter

protected

For each update cycle, this counter increments by one. You can use this to check across (callback) functions if we're still in the same cycle or in a new one.

Definition at line 476 of file TaskCore.hpp.

TaskState const RTT::base::TaskCore::mInitialState

private

Store the component's initial state here so that we can transition to it when recovering from Exception

Definition at line 453 of file TaskCore.hpp.

unsigned int RTT::base::TaskCore::mIOCounter

protected

Number of cycles that were caused by IOReady triggers.

Definition at line 480 of file TaskCore.hpp.

std::string RTT::base::TaskCore::mName

protected

The name of this task. This is used only for debugging / tracing purposes

Definition at line 493 of file TaskCore.hpp.

TaskState RTT::base::TaskCore::mTargetState

private

We need this to be able to detect transitions from mTaskState to mTargetState.

Definition at line 458 of file TaskCore.hpp.

TaskState RTT::base::TaskCore::mTaskState

protected

Definition at line 446 of file TaskCore.hpp.

unsigned int RTT::base::TaskCore::mTimeOutCounter

protected

Number of cycles that were caused by TimeOut triggers.

Definition at line 484 of file TaskCore.hpp.

unsigned int RTT::base::TaskCore::mTriggerCounter

protected

Number of cycles that were caused by Trigger triggers.

Definition at line 488 of file TaskCore.hpp.

bool RTT::base::TaskCore::mTriggerOnStart

protected

Set to false in order to not trigger() when calling start().

Definition at line 469 of file TaskCore.hpp.

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

• TaskCore.hpp
• TaskCore.cpp