#include <ExecutionEngine.hpp>

Inheritance diagram for RTT::ExecutionEngine:

Public Member Functions
virtual void	addChild (base::TaskCore *tc)
	ExecutionEngine (base::TaskCore *owner=0)
base::TaskCore *	getParent ()
base::TaskCore *	getTaskCore () const
virtual bool	process (base::DisposableInterface *c)
virtual void	removeChild (base::TaskCore *tc)
virtual bool	removeFunction (base::ExecutableInterface *f)
virtual bool	removeSelfFunction (base::ExecutableInterface *f)
virtual bool	runFunction (base::ExecutableInterface *f)
void	setExceptionTask ()
bool	stopTask (base::TaskCore *task)
void	waitForFunctions (const boost::function< bool(void)> &pred)
void	waitForMessages (const boost::function< bool(void)> &pred)
	~ExecutionEngine ()
Protected Member Functions
virtual bool	breakLoop ()
virtual void	finalize ()
virtual bool	hasWork ()
virtual bool	initialize ()
void	processChildren ()
void	processFunctions ()
void	processMessages ()
virtual void	step ()
void	waitAndProcessFunctions (boost::function< bool(void)> const &pred)
void	waitAndProcessMessages (boost::function< bool(void)> const &pred)
void	waitForMessagesInternal (boost::function< bool(void)> const &pred)
Protected Attributes
std::vector< base::TaskCore * >	children
internal::MWSRQueue < base::ExecutableInterface * > *	f_queue
internal::MWSRQueue < base::DisposableInterface * > *	mqueue
os::Condition	msg_cond
os::Mutex	msg_lock
base::TaskCore *	taskc

Detailed Description

An execution engine serialises (executes one after the other) the execution of all commands, programs, state machines and incomming events for a task. Any function executing in the same execution engine is guaranteed to be thread-safe with respect to other functions executing in the same execution engine.

The ExecutionEngine bundles a internal::CommandProcessor, scripting::ProgramProcessor, scripting::StateMachineProcessor and MessageProcessor.

Changing the Execution Policy: One can subclass this class in order to change the run-time behaviour. Use base::TaskCore::setExecutionEngine in order to install a new ExecutionEngine in a component. All Members of this class are protected and thus accessible in a subclass.

Definition at line 77 of file ExecutionEngine.hpp.

Constructor & Destructor Documentation

RTT::ExecutionEngine::ExecutionEngine ( base::TaskCore * owner = 0 )

Create an execution engine with a internal::CommandProcessor, scripting::ProgramProcessor and StateMachineProcessor.

Parameters:

owner The base::TaskCore in which this execution engine executes. It may be null, in that case no base::TaskCore owns this execution engine.

Definition at line 71 of file ExecutionEngine.cpp.

RTT::ExecutionEngine::~ExecutionEngine ( )

Definition at line 78 of file ExecutionEngine.cpp.

Member Function Documentation

void RTT::ExecutionEngine::addChild ( base::TaskCore * tc ) [virtual]

Add a base::TaskCore to execute.

Definition at line 105 of file ExecutionEngine.cpp.

bool RTT::ExecutionEngine::breakLoop ( ) [protected, virtual]

This method is called by the framework to break out of the loop() method. Reimplement this method to signal loop() to return and return true on success. When this method is not reimplemented by you, it will always return false, denoting that the loop can not be broken. If breakLoop() returns true, the caller will wait until loop() returns.

Returns:: true if the loop could be notified to return.

Reimplemented from RTT::base::RunnableInterface.

Definition at line 391 of file ExecutionEngine.cpp.

void RTT::ExecutionEngine::finalize ( ) [protected, virtual]

The method that will be called after the last periodical execution of step() ( or non periodical execution of loop() ), when the RunnableInterface is stopped.

Implements RTT::base::RunnableInterface.

Definition at line 427 of file ExecutionEngine.cpp.

TaskCore * RTT::ExecutionEngine::getParent ( )

The base::TaskCore which created this ExecutionEngine.

Definition at line 101 of file ExecutionEngine.cpp.

base::TaskCore* RTT::ExecutionEngine::getTaskCore ( ) const [inline]

Returns the owner of this execution engine.

Definition at line 109 of file ExecutionEngine.hpp.

bool RTT::ExecutionEngine::hasWork ( ) [protected, virtual]

This method is for 'intelligent' activity implementations that wish to see if it is required to call step() (again). By default, false is returned. You should only return true in case there is a temporary reason to (re-)run step.

Returns:: true if this object should be run.

See also:: extras::SequentialActivity implementation to see how this can be of use.

Reimplemented from RTT::base::RunnableInterface.

Definition at line 214 of file ExecutionEngine.cpp.

bool RTT::ExecutionEngine::initialize ( ) [protected, virtual]

The method that will be called before the first periodical execution of step() ( or non periodical execution of loop() ), when the thread is started.

Implements RTT::base::RunnableInterface.

Definition at line 209 of file ExecutionEngine.cpp.

bool RTT::ExecutionEngine::process ( base::DisposableInterface * c ) [virtual]

Queue and execute (process) a given message. The message is executed in step() or loop() directly after all other queued ActionInterface objects. The constructor parameter queue_size limits how many messages can be queued in between step()s or loop().

Returns:: true if the message got accepted, false otherwise.; false when the MessageProcessor is not running or does not accept messages.

See also:: acceptMessages

Definition at line 241 of file ExecutionEngine.cpp.

void RTT::ExecutionEngine::processChildren ( ) [protected]

Definition at line 327 of file ExecutionEngine.cpp.

void RTT::ExecutionEngine::processFunctions ( ) [protected]

Definition at line 115 of file ExecutionEngine.cpp.

void RTT::ExecutionEngine::processMessages ( ) [protected]

Definition at line 219 of file ExecutionEngine.cpp.

void RTT::ExecutionEngine::removeChild ( base::TaskCore * tc ) [virtual]

Remove a base::TaskCore from execution.

Definition at line 109 of file ExecutionEngine.cpp.

bool RTT::ExecutionEngine::removeFunction ( base::ExecutableInterface * f ) [virtual]

Remove a running function added with runFunction. This method is only required if the function is to be destroyed and is still present in the Engine.

Definition at line 164 of file ExecutionEngine.cpp.

bool RTT::ExecutionEngine::removeSelfFunction ( base::ExecutableInterface * f ) [virtual]

Self-removal for a running function added with runFunction. You must call this variant in case you want yourself to be removed. Equivalent to returning false in ExecutableInterface::execute().

Definition at line 190 of file ExecutionEngine.cpp.

bool RTT::ExecutionEngine::runFunction ( base::ExecutableInterface * f ) [virtual]

Run a given function in step() or loop(). The function may only be destroyed after the ExecutionEngine is stopped or removeFunction() was invoked. The number of functions the Processor can run in parallel can be increased with setMaxFunctions().

Returns:: false if the Engine is not running or the 'pending' queue is full.

See also:: removeFunction(), setMaxFunctions()

Definition at line 134 of file ExecutionEngine.cpp.

void RTT::ExecutionEngine::setExceptionTask ( )

Set the 'owner' task in the exception state.

Definition at line 412 of file ExecutionEngine.cpp.

void RTT::ExecutionEngine::step ( ) [protected, virtual]

Executes (in that order) Messages, Functions and updateHook() functions of this TaskContext and its children.

Implements RTT::base::RunnableInterface.

Definition at line 321 of file ExecutionEngine.cpp.

bool RTT::ExecutionEngine::stopTask ( base::TaskCore * task )

Stops executing the updateHook of task. This is an explicit synchronisation point, which guarantees that updateHook is no longer executed when this function returns true.

Parameters:

task	The Task calling this function and whose updateHook should no longer be executed.

Returns:: true if it's updateHook() is no longer being executed, false otherwise.

Definition at line 401 of file ExecutionEngine.cpp.

void RTT::ExecutionEngine::waitAndProcessFunctions ( boost::function< bool(void)> const & pred ) [protected]

Call this if you wish to block on a function completing in the Execution Engine and execute it.

Parameters:

pred	As long as !pred() waits and processes functions. If pred() == true when entering this function, then no functions will be processed and this function returns immediately.

This function is for internal use only and is required for asynchronous function invocations.

Note:: waitAndProcessFunctions will call in turn this->processFunctions() and may as a consequence recurse if we get an asynchronous call-back.

Definition at line 303 of file ExecutionEngine.cpp.

void RTT::ExecutionEngine::waitAndProcessMessages ( boost::function< bool(void)> const & pred ) [protected]

Call this if you wish to block on a message arriving in the Execution Engine and execute it.

Parameters:

pred	As long as !pred() waits and processes messages. If pred() == true when entering this function, then no messages will be processed and this function returns immediately.

This function is for internal use only and is required for asynchronous method invocations.

Note:: waitAndProcessMessages will call in turn this->processMessages() and may as a consequence recurse if we get an asynchronous call-back.

Definition at line 285 of file ExecutionEngine.cpp.

void RTT::ExecutionEngine::waitForFunctions ( const boost::function< bool(void)> & pred )

Call this if you wish to block on a function completing in the Execution Engine. Each time a function completes, waitForFunctions will return when pred() returns true.

Parameters:

pred	As long as !pred() blocks the calling thread. If pred() == true when entering this function, returns immediately.

This function is for internal use only and is required for asynchronous function invocations.

Definition at line 264 of file ExecutionEngine.cpp.

void RTT::ExecutionEngine::waitForMessages ( const boost::function< bool(void)> & pred )

Call this if you wish to block on a message arriving in the Execution Engine. Each time one or more messages are processed, waitForMessages will return when pred() returns true.

Parameters:

pred	As long as !pred() blocks the calling thread. If pred() == true when entering this function, returns immediately.

This function is for internal use only and is required for asynchronous method invocations.

Definition at line 255 of file ExecutionEngine.cpp.

void RTT::ExecutionEngine::waitForMessagesInternal ( boost::function< bool(void)> const & pred ) [protected]

Call this if you wish to block on a message arriving in the Execution Engine. Each time one or more messages are processed, waitForMessages will return when pred() returns true.

Parameters:

pred	As long as !pred() blocks the calling thread. If pred() == true when entering this function, the returns immediately.

This function is for internal use only and is required for asynchronous method invocations.

Note:: waitForMessages requires another thread to execute processMessages() and may therefor not be called from within the component's Thread. Use waitAndProcessMessages() instead.

Definition at line 273 of file ExecutionEngine.cpp.