ACE_QtReactor Class Reference

An object-oriented event demultiplexor and event handler dispatcher that uses the Qt Library. This class declaration also uses the extension facilities provided by the Qt. So, readers of the class declaration should not be upset with the appearence of the Keywords like Q_OBJECT, private slots etc. They are specific to Qt which uses these as a call back methods implementation mechanism. More...

#include <QtReactor.h>

Inheritance diagram for ACE_QtReactor:

[legend]Collaboration diagram for ACE_QtReactor:

[legend]List of all members.


Public Member Functions
	ACE_QtReactor (QApplication qapp=0, ACE_Sig_Handler =0, ACE_Timer_Queue =0, int disable_notify_pipe=0, ACE_Reactor_Notify notify=0, int mask_signals=1, int s_queue=ACE_SELECT_TOKEN::FIFO)
	Constructor follows .
	ACE_QtReactor (size_t size, QApplication qapp=0, int restart=0, ACE_Sig_Handler =0, ACE_Timer_Queue =0, int disable_notify_pipe=0, ACE_Reactor_Notify notify=0, int mask_signals=1, int s_queue=ACE_SELECT_TOKEN::FIFO)
	Constructor follows .
virtual	~ACE_QtReactor (void)
void	qapplication (QApplication *qapp)
virtual long	schedule_timer (ACE_Event_Handler handler, const void arg, const ACE_Time_Value &delay_time, const ACE_Time_Value &interval)
virtual int	cancel_timer (ACE_Event_Handler *handler, int dont_call_handle_close=1)
virtual int	cancel_timer (long timer_id, const void **arg=0, int dont_call_handle_close=1)
Protected Types
typedef ACE_Map_Manager< ACE_HANDLE, QSocketNotifier *, ACE_Null_Mutex >	MAP
	Typedef of a map.
Protected Member Functions
virtual int	register_handler_i (ACE_HANDLE handle, ACE_Event_Handler *handler, ACE_Reactor_Mask mask)
	Register a single <handler>.
virtual int	register_handler_i (const ACE_Handle_Set &handles, ACE_Event_Handler *handler, ACE_Reactor_Mask mask)
	Register a set of <handlers> with Qt.
virtual int	remove_handler_i (ACE_HANDLE handle, ACE_Reactor_Mask mask)
	Remove the <handler> associated with this <handle>.
virtual int	remove_handler_i (const ACE_Handle_Set &handles, ACE_Reactor_Mask mask)
	Remove a set of <handles>.
virtual int	wait_for_multiple_events (ACE_Select_Reactor_Handle_Set &handle_set, ACE_Time_Value *max_wait_time)
	Wait for events to occur.
virtual int	QtWaitForMultipleEvents (int width, ACE_Select_Reactor_Handle_Set &wait_set, ACE_Time_Value *max_wait_time)
virtual int	bit_ops (ACE_HANDLE handle, ACE_Reactor_Mask mask, ACE_Select_Reactor_Handle_Set &handle_set, int ops)
	Allow manipulation of the <wait_set_> mask and <ready_set_> mask.
int	set_enable_flag_by_mask (int flag_value, ACE_HANDLE handle, ACE_Reactor_Mask mask)
void	create_notifiers_for_handle (ACE_HANDLE handle)
void	destroy_notifiers_for_handle (ACE_HANDLE handle)
Protected Attributes
QApplication *	qapp_
	Some Qt stuff that we need to have.
MAP	read_notifier_
	A notifier for a read.
MAP	write_notifier_
	A write notifier.
MAP	exception_notifier_
	An exception notifier.
QTimer *	qtime_
	The timer class that would provide timer-sgnals & single-shot timers.
Private Slots
void	read_event (int FD)
	Dispatch a Read Event.
void	write_event (int FD)
	Dispatch a Write Event.
void	exception_event (int FD)
	Dispatch an exception event.
void	timeout_event (void)
	Dispach a timeout event.
Private Member Functions
void	reset_timeout (void)
void	reopen_notification_pipe (void)
	reopens notification pipe to create SocketNotifier for it
	ACE_QtReactor (const ACE_QtReactor &)
	Deny access since member-wise won't work...
ACE_QtReactor &	operator= (const ACE_QtReactor &)

Detailed Description

Note:

Marek Brudka <mbrudka@elka.pw.edu.pl>: ACE_QtReactor was quickly bugfixed to meet ACE 5.4.2 (6.0.0?) deadline. While it passes QtReactor_Test now, there is a great room for improvements as the implementation is rather inefficient and obfuscated To be more specific:

reset_timeout always creates and removes qtimer after each timeout event! Obviously, for fast triggering timers this may lead to excessive memory management.
create/destroy_notifiers_for_handle may also be reworked to establish more clean relations between handles and QSocketNotifiers.
read/write_exception_event disable now SocketNotifier for a while to clear pending events. The cost of this operation is high: two hash acces in ACE and at least two next ones in Qt. This makes QtReator slow, but how clear pending events another way ?
there is qapplication() mutator, which sets new qapplication for QtReactor. This mutator violates implicit assumption about the relations between QTimer and QSocketNotifiers and QApplication for this reactor, namely one may expect that after qapplication(), none of QtReactor artifacts is bound to old qapplication. That's not true now, as QTimer and QSocketNotifiers are not reparent to new QApplication. As a result, the sequence: QApplication *old_qapp = new QApplication(..); QtReactor qreactor( old_qapp); // .. register handlers, schedule_timers etc QApplication *new_qapp = new QApplication(..); qreactor.qpplication( new_qapp ); delete old_qapp; almost always leads to problems and memory violation, because QSocketNotifiers are released by old_qapp. Therefore QtReactor should not be reparent now by setting new qapplication.
the lifecycle of Qt objects in ACE contects is rather mysterious and should be made more explicit.
valgrind reports a small memory leak in QtReactor_Test, though as for now it is not clear if the leak is introduced by QtReactor, or rather incorrect memory management in QtReactor_Test.

Member Typedef Documentation

typedef ACE_Map_Manager<ACE_HANDLE, QSocketNotifier *, ACE_Null_Mutex> ACE_QtReactor::MAP [protected]

Typedef of a map.

Constructor & Destructor Documentation

ACE_BEGIN_VERSIONED_NAMESPACE_DECL ACE_QtReactor::ACE_QtReactor	(	QApplication *	qapp = `0`,
		ACE_Sig_Handler *	= `0`,
		ACE_Timer_Queue *	= `0`,
		int	disable_notify_pipe = `0`,
		ACE_Reactor_Notify *	notify = `0`,
		int	mask_signals = `1`,
		int	s_queue = `ACE_SELECT_TOKEN::FIFO`
	)

Constructor follows .

Parameters:

QApplication

*qapp, qapplication which runs events loop

ACE_QtReactor::ACE_QtReactor	(	size_t	size,
		QApplication *	qapp = `0`,
		int	restart = `0`,
		ACE_Sig_Handler *	= `0`,
		ACE_Timer_Queue *	= `0`,
		int	disable_notify_pipe = `0`,
		ACE_Reactor_Notify *	notify = `0`,
		int	mask_signals = `1`,
		int	s_queue = `ACE_SELECT_TOKEN::FIFO`
	)

Constructor follows .

Parameters:

QApplication

*qapp, qapplication which runs events loop

ACE_QtReactor::~ACE_QtReactor ( void ) [virtual]

ACE_QtReactor::ACE_QtReactor ( const ACE_QtReactor & ) [private]

Deny access since member-wise won't work...

Member Function Documentation

int ACE_QtReactor::bit_ops	(	ACE_HANDLE	handle,
		ACE_Reactor_Mask	mask,
		ACE_Select_Reactor_Handle_Set &	handle_set,
		int	ops
	)			`[protected, virtual]`

Allow manipulation of the <wait_set_> mask and <ready_set_> mask.

Reimplemented from ACE_Select_Reactor_Impl.

int ACE_QtReactor::cancel_timer	(	long	timer_id,
		const void **	arg = `0`,
		int	dont_call_handle_close = `1`
	)			`[virtual]`

Cancel the single ACE_Event_Handler that matches the <timer_id> value (which was returned from the <schedule> method). If arg is non-NULL then it will be set to point to the ``magic cookie'' argument passed in when the <Event_Handler> was registered. This makes it possible to free up the memory and avoid memory leaks. If <dont_call_handle_close> is 0 then the <handle_close> method of <event_handler> will be invoked. Returns 1 if cancellation succeeded and 0 if the <timer_id> wasn't found.

Reimplemented from ACE_Select_Reactor_T< ACE_Select_Reactor_Token >.

int ACE_QtReactor::cancel_timer	(	ACE_Event_Handler *	handler,
		int	dont_call_handle_close = `1`
	)			`[virtual]`

Cancel all <event_handlers> that match the address of <event_handler>. If <dont_call_handle_close> is 0 then the <handle_close> method of <event_handler> will be invoked. Returns number of handler's cancelled.

Reimplemented from ACE_Select_Reactor_T< ACE_Select_Reactor_Token >.

void ACE_QtReactor::create_notifiers_for_handle ( ACE_HANDLE handle ) [protected]

void ACE_QtReactor::destroy_notifiers_for_handle ( ACE_HANDLE handle ) [protected]

void ACE_QtReactor::exception_event ( int FD ) [private, slot]

Dispatch an exception event.

ACE_QtReactor& ACE_QtReactor::operator= ( const ACE_QtReactor & ) [private]

void ACE_QtReactor::qapplication ( QApplication * qapp )

int ACE_QtReactor::QtWaitForMultipleEvents	(	int	width,
		ACE_Select_Reactor_Handle_Set &	wait_set,
		ACE_Time_Value *	max_wait_time
	)			`[protected, virtual]`

void ACE_QtReactor::read_event ( int FD ) [private, slot]

Dispatch a Read Event.

int ACE_QtReactor::register_handler_i	(	const ACE_Handle_Set &	handles,
		ACE_Event_Handler *	handler,
		ACE_Reactor_Mask	mask
	)			`[protected, virtual]`

Reimplemented from ACE_Select_Reactor_T< ACE_Select_Reactor_Token >.

int ACE_QtReactor::register_handler_i	(	ACE_HANDLE	handle,
		ACE_Event_Handler *	handler,
		ACE_Reactor_Mask	mask
	)			`[protected, virtual]`

Reimplemented from ACE_Select_Reactor_T< ACE_Select_Reactor_Token >.

int ACE_QtReactor::remove_handler_i	(	const ACE_Handle_Set &	handles,
		ACE_Reactor_Mask	mask
	)			`[protected, virtual]`

Remove a set of <handles>.

Reimplemented from ACE_Select_Reactor_T< ACE_Select_Reactor_Token >.

int ACE_QtReactor::remove_handler_i	(	ACE_HANDLE	handle,
		ACE_Reactor_Mask	mask
	)			`[protected, virtual]`

Remove the <handler> associated with this <handle>.

Reimplemented from ACE_Select_Reactor_T< ACE_Select_Reactor_Token >.

void ACE_QtReactor::reopen_notification_pipe ( void ) [private]

reopens notification pipe to create SocketNotifier for it

void ACE_QtReactor::reset_timeout ( void ) [private]

This method ensures there's an Qt timeout for the first timeout in the Reactor's Timer_Queue.

long ACE_QtReactor::schedule_timer	(	ACE_Event_Handler *	handler,
		const void *	arg,
		const ACE_Time_Value &	delay_time,
		const ACE_Time_Value &	interval
	)			`[virtual]`

Schedule an ACE_Event_Handler that will expire after an amount of time. The return value of this method, a timer_id value, uniquely identifies the event_handler in the ACE_Reactor's internal list of timers. This timer_id value can be used to cancel the timer with the cancel_timer() call.

See also:: cancel_timer()
reset_timer_interval()

Parameters:

	event_handler	Event handler to schedule on reactor
	arg	Argument passed to the handle_timeout() method of event_handler
	delay	Time interval after which the timer will expire
	interval	Time interval after which the timer will be automatically rescheduled