class EventLoop Event Loop. More... Definition #include <eventloop.hh> List of all Methods

Annotated List Files Globals Hierarchy Index

Public Methods

•  EventLoop ()
• void  run ()
• TimerList&  timer_list ()
• SelectorList&  selector_list ()
• XorpTimer  new_oneoff_at (const TimeVal& when, const OneoffTimerCallback& ocb)
• XorpTimer  new_oneoff_after (const TimeVal& wait, const OneoffTimerCallback& ocb)
• XorpTimer  new_oneoff_after_ms (int ms, const OneoffTimerCallback& ocb)
• XorpTimer  new_periodic (int ms, const PeriodicTimerCallback& pcb)
• XorpTimer  set_flag_at (const TimeVal& when, bool* flag_ptr)
• XorpTimer  set_flag_after (const TimeVal& wait, bool* flag_ptr)
• XorpTimer  set_flag_after_ms (int ms, bool* flag_ptr)
• XorpTimer  new_timer (const BasicTimerCallback& cb)
• inline bool  add_selector (int fd, SelectorMask mask, const SelectorCallback& cb)
• void  remove_selector (int fd, SelectorMask event_mask = SEL_ALL)
• size_t  descriptor_count () const
• bool  timers_pending () const
• size_t  timer_list_length () const
• inline void  current_time (TimeVal& now) const

Detailed Description

Co-ordinates interactions between a TimerList and a SelectorList for Xorp processes. All XorpTimer and select operations should be co-ordinated through this interface.

Constructor

Invoke all pending callbacks relating to XorpTimer and file descriptor activity. This function may block if there are no selectors ready. It may block forever if there are no timers pending. The timers_pending method can be used to detect whether there are timers pending, and the descriptor_count method can be used to see if there are any select'able file descriptors.

     EventLoop e;

     ...

     while(e.timers_pending() || e.descriptor_count() > 0) {
         e.run();
     }

Non-xorp processes which use Xorp code should create a periodic timer to prevent the run() function from blocking indefinitely when there are no pending XorpTimer or SelectList objects. The period of the timer will depend on the application's existing needs.

     static bool wakeup_hook(int n) {
        static int count = 0;
	count += n;
	printf("count = %d\n", n);
     	return true;  
     }

     int main() {
     	... // Program initialization

    	// Add a Xorp EventLoop
	EventLoop e;
	XorpTimer wakeywakey = e.new_periodic(100, callback(wakeup_hook, 1));

	// Program's main loop
	for(;;) {
		... do what program does in its main loop ...
		e.run(); // process events
	}
     }

Returns: reference to the TimerList used by the EventLoop instance.

Returns: reference to the SelectorList used by the EventLoop instance.

Add a new one-off timer to the EventLoop.

Parameters:

when	the absolute time when the timer expires.
ocb	callback object that is invoked when timer expires.

Returns: a XorpTimer object that must be assigned to remain scheduled.

Add a new one-off timer to the EventLoop.

Parameters:

wait	the relative time when the timer expires.
ocb	callback object that is invoked when timer expires.

Returns: a XorpTimer object that must be assigned to remain scheduled.

Add a new one-off timer to the EventLoop.

Parameters:

ms	the relative time in milliseconds when the timer expires.
ocb	callback object that is invoked when timer expires.

Returns: a XorpTimer object that must be assigned to remain scheduled.

Add periodic timer to the EventLoop.

Parameters:

ms	the period in milliseconds when the timer expires.
pcb	user callback object that is invoked when timer expires. If the callback returns false the periodic XorpTimer is unscheduled.

Returns: a XorpTimer object that must be assigned to remain scheduled.

Add a flag setting timer to the EventLoop.

Parameters:

when	the absolute time when the timer expires.
flag_ptr	pointer to a boolean variable that is set to false when this function is called and will be set to true when the XorpTimer expires.

Returns: a XorpTimer object that must be assigned to remain scheduled.

Add a flag setting timer to the EventLoop.

Parameters:

wait	the relative time when the timer expires.
flag_ptr	pointer to a boolean variable that is set to false when this function is called and will be set to true when the XorpTimer expires.

Returns: a XorpTimer object that must be assigned to remain scheduled.

Add a flag setting timer to the EventLoop.

Parameters:

ms	the relative time in millisecond when the timer expires.
flag_ptr	pointer to a boolean variable that is set to false when this function is called and will be set to true when the XorpTimer expires.

Returns: a XorpTimer object that must be assigned to remain scheduled.

Create a custom timer associated with the EventLoop.

The XorpTimer object created needs to be explicitly scheduled with the available XorpTimer methods.

Parameters:

cb	user callback object that is invoked when timer expires.

Returns: a XorpTimer object that must be assigned to remain scheduled.

Add a file descriptor and callback to be invoked when descriptor is ready for input or output. A SelectorMask determines what type of I/O event will cause the callback to be invoked.

Only one callback may be associated with each event type, e.g. one callback for read pending, one callback for write pending.

If multiple event types in are associated with the same callback, the callback is only invoked once, but the mask argument passed to the callback shows multiple event types.

Parameters:

fd	the file descriptor.
mask	the SelectorMask of the event types to that will invoke hook.
cb	object to be invoked when file descriptor has I/O pending.

Returns: true on success.

Remove hooks associated with file descriptor.

Parameters:

fd	the file descriptor.
event_mask	mask of event types to clear.

[const]

Returns: the number of file descriptors that have registered callbacks with the EventLoop SelectorList.

[const]

Returns: true if any XorpTimers are present on EventLoop's TimerList.

[const]

Returns: the number of XorpTimers present on EventLoop's TimerList.

[const]

Get current time according to EventLoop's TimerList