cbits::CallbackTimer Class Reference

A timer object that invokes a user-supplied callback when it expires. More...

#include <CallbackTimer.h>

Inheritance diagram for cbits::CallbackTimer:

[legend]Collaboration diagram for cbits::CallbackTimer:[legend]List of all members.

Public Types
enum	Type { SINGLE = 1, PERIODIC = 2 }
	Timer types. More...
Public Methods
virtual	~CallbackTimer ()
	Destructor. More...
const bool	start ()
	Start the timer. More...
const bool	stop ()
	Stop the timer. More...
virtual void	run ()
	Runnable implementation. More...
const bool	isStopped () const
	Test if the timer is stopped or expired. More...
const Thread *const	getThread () const
	Accessor for the cbits::Thread object that's executing this timer. More...
Static Public Methods
CallbackTimer *	create (const Type t, const long tm, CallbackTimerListener &cl)
	Create a callback timer instance. More...
Protected Methods
	CallbackTimer (const Type t, const long tm, CallbackTimerListener &cl)
	Constructor. More...
virtual const bool	impl_lock_obj () const=0
	Lock the object. More...
virtual const bool	impl_unlock_obj () const=0
	Unlock the object. More...
virtual const bool	impl_wait (const long msec)=0
	Wait for the timer to expire. More...
virtual const bool	impl_signal ()=0
	Abort the timer. More...
Private Attributes
Type	_type
	Type of this timer. More...
long	_tm_msec
	Timer period. More...
CallbackTimerListener &	_client
	Callback. More...
Thread *	_timer
	timer and callback thread. More...
bool	_halt
	true if timer is stopped. More...

Detailed Description

A timer object that invokes a user-supplied callback when it expires.

If a PERIODIC timer is created, the user callback will be called at the end of each interval with the clock being 'reset' when the callback completes.

For instance, to create a timer objec that fires after 10 seconds:

	CallbackTimerListener cb = ...;
	CallbackTimer* timer = CallbackTimer::create( SINGLE, 10000, cb );
	timer->getThread()->join();
	// ...

The 'join' method will return after the timer has fired and invoked the user supplied callback. If the CallbackTimer is of type PERIODIC, though, the join method will not return (in the example above).

Implementation Note:

A CallbackTimer derived class must be implemented for each new platform. The protected, pure virtual impl_XXX methods (see below) must be implemented in the derived class.

Member Enumeration Documentation

enum cbits::CallbackTimer::Type

Timer types.

Enumeration values:

SINGLE Execute one interval.

PERIODIC Execute repeatedly.

Constructor & Destructor Documentation

CallbackTimer::~CallbackTimer ( ) [virtual]

Destructor.
If the timer is running, it is stopped and the callback will not be executed.

CallbackTimer::CallbackTimer ( const Type t,

const long tm,

CallbackTimerListener & cl

) [protected]

Constructor.
Create an initialized timer. The timer must not 'run' until the start method is invoked.
Parameters:

t Type

tm timer interval

cl callback

Member Function Documentation

CallbackTimer * CallbackTimer::create ( const Type t,

const long tm,

CallbackTimerListener & cl

) [static]

Create a callback timer instance.
Create an initialized timer. The timer must not 'run' until the start method is invoked.

Returns:
a new callback timer.
@raises CallbackTimerException if the timer can not be created.
Parameters:

t Timer type.

tm interval (msec)

cl Callback object.

const Thread* const cbits::CallbackTimer::getThread ( ) const [inline]

Accessor for the cbits::Thread object that's executing this timer.

virtual const bool cbits::CallbackTimer::impl_lock_obj ( ) const [protected, pure virtual]

Lock the object.
The implementation should protect the object against concurrent access by, for instance, locking an instance-scoped mutex.

Returns:
true if the object was successfully locked; otherwise, false.

Implemented in cbits::CallbackTimer_PTHREAD.

virtual const bool cbits::CallbackTimer::impl_signal ( ) [protected, pure virtual]

Abort the timer.
The implementation must stop the timer, causing the impl_wait method to return with a value of false if the time interval has not expired.
Implemented in cbits::CallbackTimer_PTHREAD.

virtual const bool cbits::CallbackTimer::impl_unlock_obj ( ) const [protected, pure virtual]

Unlock the object.
The implementation should release the 'lock' that was acquired by the 'lock' method.
Implemented in cbits::CallbackTimer_PTHREAD.

virtual const bool cbits::CallbackTimer::impl_wait ( const long msec ) [protected, pure virtual]

Wait for the timer to expire.
The implementation must block the current thread for the time interval specified in the method call.
Parameters:

msec the length of time to block the current thread.

Returns:
true if the time interval has expired, false for any other reason.

Implemented in cbits::CallbackTimer_PTHREAD.

const bool CallbackTimer::isStopped ( ) const

Test if the timer is stopped or expired.

void CallbackTimer::run ( ) [virtual]

Runnable implementation.
Not for client use.
Implements cbits::Runnable.

const bool CallbackTimer::start ( )

Start the timer.

Returns:
true if the timer was successfully started; otherwise, false.

const bool CallbackTimer::stop ( )

Stop the timer.

Returns:
true if the timer was stopped; otherwise, false.

Member Data Documentation

CallbackTimerListener& cbits::CallbackTimer::_client [private]

Callback.

bool cbits::CallbackTimer::_halt [private]

true if timer is stopped.

Thread* cbits::CallbackTimer::_timer [private]

timer and callback thread.

long cbits::CallbackTimer::_tm_msec [private]

Timer period.

Type cbits::CallbackTimer::_type [private]

Type of this timer.

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cbits::CallbackTimer Class Reference

Public Types

Public Methods

Static Public Methods

Protected Methods

Private Attributes

Detailed Description

Member Enumeration Documentation

Constructor & Destructor Documentation

Member Function Documentation

Member Data Documentation