Net::SIP::Dispatcher::Eventloop(3pm)			User Contributed Perl Documentation		      Net::SIP::Dispatcher::Eventloop(3pm)

NAME

       Net::SIP::Dispatcher::Eventloop - simple event loop for Net::SIP::Dispatcher

SYNOPSIS

	 my $loop = Net::SIP::Dispatcher::Eventloop->new;
	 $loop->addFD( $fd, $callback );
	 $loop->add_timer( 10,$callback );
	 $loop->loop;

DESCRIPTION

       The package implements a simple event loop. It's not optimized for speed but it is provided as a simple implementation in case the users
       application does not has an event loop yet.

       Because the eventloop object can be given in the constructor of Net::SIP::Dispatcher you might provide an alternative implementation, which
       implemented the described methods.

CONSTRUCTOR

       new Creates new event loop, returns created object

METHODS

       addFD ( HANDLE, CALLBACK, ?NAME )
	   Adds file handle HANDLE to the event loop, so that CALLBACK gets triggered if HANDLE is readable. CALLBACK is a callback accepted by
	   invoke_callback in Net::SIP::Util. The callback will be invoked with HANDLE as an additional argument.

	   NAME can be used to aid debugging, it will be shown in the debug messages once the FD gets ready.

	   If there was already a callback for HANDLE it gets replaced by the new one.

	   IMPORTANT NOTE: CALLBACK gets triggered if HANDLE *is* readable inside the loop, not if HANDLE *gets* readable. Unlike with Event::Lib
	   or similar the CALLBACK is not triggered by the edge, but by the level (like poll(2) or select(2)). So if 2 bytes come in at the handle
	   and one reads only 1 byte in the callback the callback gets triggered again for more data.  You have to watch this, if you want to
	   integrate Net::SIP with your existing event loop.

       delFD ( HANDLE )
	   Removes HANDLE from loop, e.g. no more checking for readability will be done.

       add_timer( WHEN, CALLBACK, [ REPEAT ] )
	   Adds timer which gets triggered at WHEN or "now + WHEN". Depending on the value of WHEN it gets interpreted as the number of seconds
	   since 1970-01-01 (when it's really big) or as a relative time (when it's not that big).  WHEN can be floating point for subseconds
	   resolution.

	   CALLBACK is a callback accepted by invoke_callback in Net::SIP::Util.  It gets invoked with the timer object (see later) as an
	   additional argument, which has a method cancel for canceling the (repeating) timer.

	   REPEAT is the number of seconds between each invocation of the timer. If greater then 0 (subsection resulution possible) the callback
	   will be called each REPEAT seconds, after it was called the first time at WHEN.

	   The method will return an object which has a method cancel which can be used to cancel the timer before it gets triggered (or gets
	   triggered the next time in case of repeating timers).

       looptime
	   Returns the current loop time in subseconds resolution (using gettimeofday from Time::HiRes). This is not the current time, but the
	   time, when the last event in the loop occured (e.g. when the select(2) call returned)

       loop ( [ TIMEOUT, @STOPVAR ] )
	   The main loop, e.g. continuiosly checks timers and file handles for the events and calls callbacks.

	   If TIMEOUT is given it will run the loop for at most TIMEOUT seconds, then the method will return. Undefined TIMEOUT means that it will
	   never return because of timeout and TIMEOUT of 0 means that it will check all timers and handles only once and then return.

	   @STOPVAR is a list of scalar references. These scalars are expected to be changed from the callbacks, so it will check after each loop
	   cycle, e.g.	after all callbacks are called (timers and handles) if any of these scalars is TRUE, in which case it will end the loop.

	   The behavior with STOPVAR cannot be found in most existing event loops.  If you want to integrate Net::SIP with your own event loop you
	   migth simply wrap all callbacks given in addFD and add_timer in another callback which at the end checks the stopvars and terminates
	   the 3rd-party loop in a loop-specific way.

perl v5.14.2							    2009-01-23				      Net::SIP::Dispatcher::Eventloop(3pm)