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

FreeBSD Manual Pages

  
 
  

home | help
ADVISE(3PVM)			 PVM Version 3.4		    ADVISE(3PVM)

NAME
     pvm_advise() - Controls use of direct task-to-task routing.
     [In Version 3.2: Replaced by pvm_setopt]

SYNOPSIS
     C	  int info = pvm_advise( int route )

     Fortran   call pvmfadvise( route, info )

PARAMETERS
     route   Integer advising PVM to set up direct task-to-task links.
					route options
	     PvmDontRoute	 1    Don't allow direct links to this task
	     PvmAllowDirect	 2    Allow but don't request direct links
	     PvmRouteDirect	 3    Request direct links

     info    Integer returning error status.

DESCRIPTION
     The routine pvm_advise advises PVM on whether or not to set up direct task-
     to-task  links (using TCP) for all subsequent communication. Once a link is
     established it remains until the application finishes.  If  a  direct  link
     can  not  be established because one of the two tasks has requested PvmDon-
     tRoute or because no  resources  are  available,  then  the  default  route
     through  the  PVM daemons is used.  pvm_advise can be called multiple times
     to selectively establish direct links, but is typically set only once  near
     the  beginning of each task.  PvmAllowDirect is the default advise setting.
     This setting on task A allows other tasks to set  up  direct  links  to  A.
     Once  a direct link is established between tasks both tasks will use it for
     sending messages.	pvm_advise returns the error status in info.   The  per-
     formance  of  direct task-to-task links can be up to a factor of two better
     than the default route. The draw back is a lack of scalability of	the  di-
     rect  links.   Some  versions  of UNIX limit the number of links to no more
     than 30.

EXAMPLES
     C:
			 info = pvm_advise( PvmRouteDirect );

     Fortran:
			 CALL PVMFADVISE( PVMROUTEDIRECT, INFO )

ERRORS
     This error condition can be returned by pvm_advise

     PvmBadParam
	    giving an invalid route value.

SEE ALSO
     pvm_setopt(3PVM)

				 30 August, 1993		    ADVISE(3PVM)

Want to link to this manual page? Use this URL:
<https://man.freebsd.org/cgi/man.cgi?query=pvmfadvise&sektion=3&manpath=FreeBSD+Ports+15.1.quarterly>

home | help