Skip site navigation (1)Skip section navigation (2)

FreeBSD Manual Pages

  
 
  

home | help
alarm_handler(3)	   Erlang Module Definition	      alarm_handler(3)

NAME
       alarm_handler - An Alarm	Handling Process

DESCRIPTION
       The  alarm  handler  process is a gen_event event manager process which
       receives	alarms in the system. This process is not  intended  to	 be  a
       complete	alarm handler. It defines a place to which alarms can be sent.
       One simple event	handler	is installed in	the alarm handler at start-up,
       but users are encouraged	to write and install their own handlers.

       The  simple event handler sends all alarms as info reports to the error
       logger, and saves all of	them in	a list which can be passed to  a  user
       defined	event  handler,	 which	may be installed at a later stage. The
       list can	grow large if many alarms are generated. So it is a good  rea-
       son to install a	better user defined handler.

       There  are  functions to	set and	clear alarms. The format of alarms are
       defined by the user. For	example, an event handler for  SNMP  could  be
       defined,	together with an alarm MIB.

       The alarm handler is part of the	SASL application.

       When  writing  new  event handlers for the alarm	handler, the following
       events must be handled:

	 {set_alarm, {AlarmId, AlarmDescr}}:
	   This	event is generated by alarm_handler:set_alarm({AlarmId,	 Alar-
	   mDecsr}).

	 {clear_alarm, AlarmId}:
	   This	event is generated by alarm_handler:clear_alarm(AlarmId).

       The  default  simple  handler is	called alarm_handler and it may	be ex-
       changed	by  calling  gen_event:swap_handler/3  as  gen_event:swap_han-
       dler(alarm_handler, {alarm_handler, swap}, {NewHandler, Args}). NewHan-
       dler:init({Args,	 {alarm_handler,  Alarms}})  is	  called.   Refer   to
       gen_event(3) for	further	details.

EXPORTS
       clear_alarm(AlarmId) -> void()

	      Types:

		 AlarmId = term()

	      Sends the	clear_alarm event to all event handlers.

	      When receiving this event, the default simple handler clears the
	      latest received alarm with id AlarmId.

       get_alarms() -> [alarm()]

	      Returns a	list of	all active alarms. This	function can  only  be
	      used when	the simple handler is installed.

       set_alarm(alarm())

	      Types:

		 alarm() = {AlarmId, AlarmDescription}
		 AlarmId = term()
		 AlarmDescription = term()

	      Sends the	set_alarm event	to all event handlers.

	      When receiving this event, the default simple handler stores the
	      alarm. The AlarmId identifies the	alarm and  is  used  when  the
	      alarm is cleared.

SEE ALSO
       error_logger(3),	gen_event(3)

Ericsson AB			  sasl 2.4.1		      alarm_handler(3)

NAME | DESCRIPTION | EXPORTS | SEE ALSO

Want to link to this manual page? Use this URL:
<https://www.freebsd.org/cgi/man.cgi?query=alarm_handler&sektion=3&manpath=FreeBSD+12.1-RELEASE+and+Ports>

home | help