NOTIFY(3PVM)							 NOTIFY(3PVM)

NAME
  pvm_notify - Request notification of PVM event such as host failure.

SYNOPSIS
  C	  int info = pvm_notify( int what, int msgtag, int cnt,	int *tids )

  Fortran call pvmfnotify( what, msgtag, cnt, tids, info )

PARAMETERS

  what	  Type of event	to trigger the notification.  Presently	one of:
	       Value		   Meaning
	       PvmTaskExit	   Task	exits or is killed
	       PvmHostDelete	   Host	is deleted or crashes
	       PvmHostAdd	   New host is added

  msgtag  Message tag to be used in notification.

  cnt	  For PvmTaskExit and PvmHostDelete, specifies the length of the tids
	  array.  For PvmHostAdd, specifies the	number of times	to notify.

  tids	  For PvmTaskExit and PvmHostDelete, an	array of length	cnt of task
	  or pvmd TIDs to be notified about.  The array	is not used with the
	  PvmHostAdd option.

  info	  Integer status code returned by the routine.	Values less than zero
	  indicate an error.

DISCUSSION
  The routine pvm_notify requests PVM to notify	the caller on detecting	cer-
  tain events.	One or more notify messages (see below)	are sent by PVM	back
  to the calling task.	The messages have tag msgtag supplied to notify.

  The notification messages have the following format:

  PvmTaskExit
       One notify message for each TID requested.  The message body contains
       a single	TID of exited task.

  PvmHostDelete
       One notify message for each TID requested.  The message body contains
       a single	pvmd-TID of exited pvmd.

  PvmHostAdd
       cnt notify messages are sent, one each time the local pvmd's host
       table is	updated.  The message body contains an integer length fol-
       lowed by	a list of pvmd-TIDs of new pvmds.  The counter of PvmHostAdd
       messages	yet to be sent is replaced by successive calls to pvm_notify.
       Specifying a cnt	of -1 turns on PvmHostAdd messages until a future
       notify; a count of zero disables	them.

  TIDs in the notify messages are packed as integers.

  The calling task is responsible for receiving	messages with the specified
  tag and taking appropriate action.

  Future versions of PVM may expand the	list of	available notification
  events.

EXAMPLES
  C:
       info = pvm_notify( PvmTaskExit, 9999, ntask, tids )

  Fortran:
       CALL PVMFNOTIFY(	PVMHOSTDELETE, 1111, NUMHOSTS, DTIDS, INFO )

ERRORS
       PvmSysErr      pvmd not responding.
       PvmBadParam    giving an	invalid	argument value.

SEE ALSO
  pvm_tasks(3PVM), pvm_config(3PVM)