SelectorBase Class Reference

Reports activity on a set of devices. More...

#include <Pt/System/Selector.h>

Inheritance diagram for SelectorBase:

List of all members.

Public Member Functions

virtual ~SelectorBase ()

Destructor.

void add (Selectable &s)

Adds an IOResult.

void remove (Selectable &s)

Cancel an IOResult.

void add (Timer &timer)

Adds a Timer.

void remove (Timer &timer)

Removes a Timer.

bool wait (std::size_t msecs=WaitInfinite)

Wait for activity.

void wake ()

Wakes the selctor from waiting.

Static Public Attributes

static const std::size_t WaitInfinite = static_cast<const std::size_t>(-1)

Protected Member Functions

SelectorBase ()

Default constructor.

void onAddTimer (Timer &timer)

void onRemoveTimer (Timer &timer)

void onTimerChanged (Timer &timer)

virtual void onAdd (Selectable &)=0

virtual void onRemove (Selectable &)=0

virtual void onChanged (Selectable &s)=0

virtual bool onWait (std::size_t msecs)=0

virtual void onWake ()=0

Friends

class Selectable

class Timer

Detailed Description

A Selector can be used to monitor a set of Selectables and Timers and wait for activity on them. The wait call can be performed with a timeout and the respective timeout signal is sent if it occurs. Clients can be notified about Timer and Selectable activity by connecting to the appropriate signals of the Timer and Selectable classes.

The following example uses a Selector to wait on acitvity on a Timer, which is set to time-out after 1000 msecs.

        // slot to handle timer activity
        void onTimer();

        int main()
        {
            using cxxtools::System;

            Timer timer;
            timer.start(1000);
            connect(timer.timeout, ontimer);

            Selector selector;
            selector.addTimer(timer);
            selector wait();

            return 0;
        }

A Selector is the heart of the EventLoop, which calls Selector::wait continously. The EventLoop and Application classes provide the same API as the Selector itself.

Member Function Documentation

void add ( Selectable & s )

Adds an IOResult to the selector. IOResult are removed automatically when they get destroyed.

void add ( Timer & timer )

Adds a Timer to the selector. Timers are removed automatically when they get destroyed.

Parameters:

timer

The device to add

void remove ( Timer & timer )

Parameters:

timer

The timer to remove

bool wait ( std::size_t msecs = WaitInfinite )

This method will wait for activity on the registered Selectables and Timers. Use Selector::WaitInfinite to wait without timeout.

Parameters:

msecs

timeout in miliseconds

void wake ( )

This method can be used to end a Selector::wait call before the timeout expires. It is supposed to be used from another thread and thus is thread-safe.


Public Member Functions
virtual	~SelectorBase ()
	Destructor.
void	add (Selectable &s)
	Adds an IOResult.
void	remove (Selectable &s)
	Cancel an IOResult.
void	add (Timer &timer)
	Adds a Timer.
void	remove (Timer &timer)
	Removes a Timer.
bool	wait (std::size_t msecs=WaitInfinite)
	Wait for activity.
void	wake ()
	Wakes the selctor from waiting.
Static Public Attributes
static const std::size_t	WaitInfinite = static_cast<const std::size_t>(-1)
Protected Member Functions
	SelectorBase ()
	Default constructor.
void	onAddTimer (Timer &timer)
void	onRemoveTimer (Timer &timer)
void	onTimerChanged (Timer &timer)
virtual void	onAdd (Selectable &)=0
virtual void	onRemove (Selectable &)=0
virtual void	onChanged (Selectable &s)=0
virtual bool	onWait (std::size_t msecs)=0
virtual void	onWake ()=0
Friends
class	Selectable
class	Timer