RTT::Timer Class Reference

This class allows to define a timer object which can be armed in single shot and periodic mode. More...

#include <rtt/Timer.hpp>

Inheritance diagram for RTT::Timer:
RTT::RunnableInterface RTT::OS::RunnableInterface

List of all members.

Public Types

typedef int TimerId
 A positive numeric ID representing a timer.

Public Member Functions

 Timer (TimerId max_timers, int scheduler=-1, int priority=0)
 Create a timer object which can hold max_timers timers.
virtual void timeout (TimerId timer_id)
 This function is called each time an armed or periodic timer expires.
void setMaxTimers (TimerId max)
 Change the maximum number of timers in this object.
bool startTimer (TimerId timer_id, Seconds period)
 Start a periodic timer which starts first over period seconds and then every period seconds.
bool arm (TimerId timer_id, Seconds wait_time)
 Arm a timer to fire once over wait_time seconds.
TimeService::Seconds timeRemaining (TimerId timer_id) const
 Returns the remaining time before this timer elapses.
bool isArmed (TimerId timer_id) const
 Check if a given timer id is armed.
bool killTimer (TimerId timer_id)
 Disable an armed timer.
virtual bool hasWork ()
 This method is for 'intelligent' activity implementations that wish to see if it is required to call step() (again).
ActivityInterface * getActivity () const
 Query for the task this interface is run in.
virtual void setActivity (ActivityInterface *task)
 Set the task this interface is run in.
virtual OS::ThreadInterface * getThread () const
 Get the thread this object is run in.
virtual void setThread (ThreadInterface *t)
 Set the thread this object will be run in.

Protected Types

typedef TimeService::nsecs Time
typedef std::vector< std::pair
< Time, Time > > 		TimerIds
 Index in vector is the timer id.

Protected Member Functions

bool initialize ()
 The method that will be called before the first periodical execution of step() ( or non periodical execution of loop() ), when the thread is started.
void finalize ()
 The method that will be called after the last periodical execution of step() ( or non periodical execution of loop() ), when the RunnableInterface is stopped.
void step ()
 The method that will be periodically executed when this class RTT_API is run in a periodic thread.
void loop ()
 The method that will be executed once when this class RTT_API is run in a non periodic thread.
bool breakLoop ()
 This method is called by the framework to break out of the loop() method.

Protected Attributes

TimeService * mTimeserv
OS::ThreadInterface * mThread
OS::Semaphore msem
OS::Mutex m
TimerIds mtimers
bool mdo_quit

Detailed Description

This class allows to define a timer object which can be armed in single shot and periodic mode.

In Order to use this class, derive your class from Timer and implement the timeout() method. The resolution of this class depends completely on the timer resolution of the underlying operating system.

If you do not attach an activity, the Timer will create a thread of its own and start it. That thread will be stopped and cleaned up when the Timer is destroyed.

Definition at line 65 of file Timer.hpp.

Member Typedef Documentation

typedef std::vector<std::pair<Time, Time> > RTT::Timer::TimerIds [protected]

Index in vector is the timer id.

1st Time is the absolute time upon which the timer expires. 2nd Time is the optional period of the timer.

Definition at line 84 of file Timer.hpp.

Constructor & Destructor Documentation

RTT::Timer::Timer ( TimerId  max_timers,
int  scheduler = -1,
int  priority = 0 
)

Create a timer object which can hold max_timers timers.

A Timer must be executed in a non periodic thread (or the main thread) or it will refuse to start. If scheduler is set to -1 (default) no thread is created and you need to attach a thread yourself to this Timer.

Parameters:
max_timers The initial amount of timers this Timer can monitor. Keep as low as possible. See also setMaxTimers().
scheduler The Orocos scheduler type for this timer. ORO_SCHED_OTHER or ORO_SCHED_RT or -1 to attach your own thread.
priority The priority within the scheduler of this timer.

Member Function Documentation

bool RTT::Timer::arm ( TimerId  timer_id,
Seconds  wait_time 
)

Arm a timer to fire once over wait_time seconds.

Parameters:
timer_id The number of the timer, starting from zero.
wait_time The time in seconds from now, when the timer should expire. This is a floating point number.
See also:
killTimer to disable it before it fires.
bool RTT::Timer::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::OS::RunnableInterface.

ActivityInterface * RTT::RunnableInterface::getActivity (  )  const [inline, inherited]

Query for the task this interface is run in.

Zero denotes that no task is present to run it, and hence no detailed information is available.

Returns:
The Activity which runs this RunnableInterface.

Definition at line 106 of file RunnableInterface.hpp.

virtual OS::ThreadInterface* RTT::RunnableInterface::getThread (  )  const [virtual, inherited]

Get the thread this object is run in.

Returns:
a pointer to the thread or 0 if not run by a thread.

Reimplemented from RTT::OS::RunnableInterface.

virtual bool RTT::RunnableInterface::hasWork (  )  [virtual, inherited]

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

Reimplemented in RTT::CommandProcessor, RTT::EventProcessor, and RTT::ExecutionEngine.

bool RTT::Timer::isArmed ( TimerId  timer_id  )  const

Check if a given timer id is armed.

Parameters:
timer_id The number of the timer, starting from zero.
bool RTT::Timer::killTimer ( TimerId  timer_id  ) 

Disable an armed timer.

Parameters:
timer_id The number of the timer, starting from zero.
void RTT::Timer::loop (  )  [protected, virtual]

The method that will be executed once when this class RTT_API is run in a non periodic thread.

The default implementation calls step() once.

Reimplemented from RTT::OS::RunnableInterface.

virtual void RTT::RunnableInterface::setActivity ( ActivityInterface *  task  )  [virtual, inherited]

Set the task this interface is run in.

A Zero means no task is running it.

Parameters:
task The ActivityInterface running this interface.

Reimplemented in RTT::ExecutionEngine.

void RTT::Timer::setMaxTimers ( TimerId  max  ) 

Change the maximum number of timers in this object.

Any added timer with id >= max will be removed.

bool RTT::Timer::startTimer ( TimerId  timer_id,
Seconds  period 
)

Start a periodic timer which starts first over period seconds and then every period seconds.

Parameters:
timer_id The number of the timer, starting from zero.
period The period when the timer should expire. This is a floating point number.
See also:
killTimer to disable it again.
virtual void RTT::Timer::timeout ( TimerId  timer_id  )  [virtual]

This function is called each time an armed or periodic timer expires.

The user must implement this method to catch the time outs.

Parameters:
timer_id The number of the timer that expired.
TimeService::Seconds RTT::Timer::timeRemaining ( TimerId  timer_id  )  const

Returns the remaining time before this timer elapses.

Return values:
0.0 if the timer is not armed or has already elapsed.
Returns:
the remaining time in seconds.
The documentation for this class was generated from the following file:
Generated on Thu Dec 23 13:22:45 2010 for Orocos Real-Time Toolkit by  doxygen 1.6.3