AI_IPC::DbusTimeouts Class Reference

Object that manages the timeouts for a given dbus connection. More...

#include <DbusTimeouts.h>

Classes
struct	_TimeoutEntry

Public Member Functions
	DbusTimeouts (DBusConnection *conn)
int	fd () const
	Returns the timerfd that the dispatcher should poll on.
void	processEvent (unsigned int pollEvents)
	Called when something has happened on the timerfd event loop. More...

Private Types
typedef struct AI_IPC::DbusTimeouts::_TimeoutEntry	TimeoutEntry

Private Member Functions
dbus_bool_t	addTimeOut (DBusTimeout *timeout)
	Adds the given timeout to the timerfd to poll on. More...
void	toggleTimeOut (DBusTimeout *timeout)
	Toggles the enable / disable state of a timeout. More...
void	removeTimeOut (DBusTimeout *timeout)
	Removes the timeout from the timerfd. More...
struct timespec	calcAbsTime (const struct timespec &base, int milliseconds) const
	Calculates a new time value based on the time now and the supplied millisecond offset. More...
void	updateTimerFd () const
	Writes the item on the head of the expiry queue into the timerfd for the next wake-up time. More...
bool	hasExpired (const struct timespec &expiryTime, const struct timespec &currentTime) const
	Utility function that simply checks if a timespec is after or equal to another timespec. More...

Static Private Member Functions
static dbus_bool_t	addTimeOutCb (DBusTimeout *timeout, void *userData)
static void	toggleTimeOutCb (DBusTimeout *timeout, void *userData)
static void	removeTimeOutCb (DBusTimeout *timeout, void *userData)

Private Attributes
int	mTimerFd
DBusConnection *const	mDbusConnection
bool	mWithinEventHandler
std::list< TimeoutEntry >	mTimeouts
const std::thread::id	mExpectedThreadId

Detailed Description

Object that manages the timeouts for a given dbus connection.

Warning

This class is not thread safe, it is designed to only be called from one thread which is the same thread the libdbus callbacks will be called from. On debug builds an error will be reported if called from any other thread.

Internally it creates an timerfd object and a sorted list of expiry times matched to dbus timeout objects. The expiry item on the head of the list is programmed into the timerfd so the poll loop will wake up when the timer expires.

Although the code is not thread safe (by design) it handles reentrant calls to the installed dbus callbacks while in the processing loop.

Member Function Documentation

addTimeOut()

dbus_bool_t DbusTimeouts::addTimeOut ( DBusTimeout *  timeout )

private

Adds the given timeout to the timerfd to poll on.

Parameters

[in]

timeout

The timeout object to add

Returns

TRUE if the timeout was added, otherwise FALSE.

calcAbsTime()

struct timespec DbusTimeouts::calcAbsTime ( const struct timespec &  base, int  milliseconds  ) const

private

Calculates a new time value based on the time now and the supplied millisecond offset.

Parameters

[in]	base	The base time to calculate the new offset from
[in]	offset	The milliseconds offset

Returns

a timespec that is the base value plus the offset.

hasExpired()

bool DbusTimeouts::hasExpired ( const struct timespec &  expiryTime, const struct timespec &  currentTime  ) const

inlineprivate

Utility function that simply checks if a timespec is after or equal to another timespec.

This is used to determine if a timer has expired or not.

Parameters

[in]	expiryTime	The expiry time point.
[in]	currentTime	The current time point.

Returns

true if expiryTime is less than or equal to the currentTime.

processEvent()

void DbusTimeouts::processEvent

(

unsigned int

pollEvents

)

Called when something has happened on the timerfd event loop.

The main disaptcher loop polls on the timerfd we supply, when anything changes then this method is called.

Parameters

[in]

pollEvents

Bitmask of the poll events that woke the main loop.

removeTimeOut()

void DbusTimeouts::removeTimeOut ( DBusTimeout *  timeout )

private

Removes the timeout from the timerfd.

Parameters

[in]

timeout

The timeout object to remove

toggleTimeOut()

void DbusTimeouts::toggleTimeOut ( DBusTimeout *  timeout )

private

Toggles the enable / disable state of a timeout.

Parameters

[in]

timeout

The timeout object to toggle

updateTimerFd()

void DbusTimeouts::updateTimerFd ( ) const

private

Writes the item on the head of the expiry queue into the timerfd for the next wake-up time.

If the expiry queue is empty then 0 is written into the timerfd which disables it.

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The documentation for this class was generated from the following files:

• AppInfrastructure/IpcService/source/libdbus/DbusTimeouts.h
• AppInfrastructure/IpcService/source/libdbus/DbusTimeouts.cpp