ADDHOSTS(3PVM)							  PVM Version 3.4						    ADDHOSTS(3PVM)

NAME

       pvm_addhosts - Add hosts to the virtual machine.

SYNOPSIS

       C    int info = pvm_addhosts( char **hosts, int nhost, int *infos )

       Fortran	 call pvmfaddhost( host, info )

PARAMETERS

       hosts   An  array  of strings naming the hosts to be added.  Pvmd must already be installed and the user must have an account on the speci-
	       fied hosts.

       nhost   Integer specifying the length of array hosts.

       infos   Integer array of length nhost which returns the status for each host.  Values less than zero indicate an error, while positive val-
	       ues are TIDs of the new hosts.

       host    Character string naming the host to be added.

       info    Integer	status	code  returned	by  the routine.  Values less than nhost indicate partial failure, and values less than 1 indicate
	       total failure.

DESCRIPTION

       The routine pvm_addhosts adds the computers named in hosts to the configuration of computers making up  the  virtual  machine.	The  names
       should have the same syntax as lines of a pvmd hostfile (see man page for pvmd3): A hostname followed by options of the form xx=y.

       If  pvm_addhosts is successful, info will be equal to nhost.  Partial success is indicated by 0 < info < nhost, and total failure by info <
       1.  The array infos can be checked to determine which host caused the error.

       The Fortran routine pvmfaddhost adds a single host to the configuration with each call.	info will be 1 if successful or < 0 if error.

       The status of hosts can be requested by the application using pvm_mstat and pvm_config.	If a host fails it will be  automatically  deleted
       from  the  configuration.   Using  pvm_addhosts a replacement host can be added by the application, however it is the responsibility of the
       application developer to make his application tolerant of host failure.	Another use of this feature would be to add  more  hosts  as  they
       become available, for example on a weekend, or if the application dynamically determines it could use more computational power.

EXAMPLES

       C:
	    static char *hosts[] = {
		"sparky",
		"thud.cs.utk.edu",
	    };
	    info = pvm_addhosts( hosts, 2, infos );

       Fortran:
	    CALL PVMFADDHOST( 'azure', INFO )

ERRORS

       The following error conditions can be returned by pvm_addhosts:

       PvmBadParam
	      giving an invalid argument value.

       PvmAlready
	      another task is currently adding hosts.

       PvmSysErr
	      local pvmd is not responding.

       and in the infos vector:

       PvmBadParam
	      bad hostname syntax.

       PvmNoHost
	      no such host.

       PvmCantStart
	      failed to start pvmd on host.

       PvmDupHost
	      host already configured.

       PvmBadVersion
	      pvmd protocol versions don't match.

       PvmOutOfRes
	      PVM has run out of system resources.

SEE ALSO

       pvm_pvmd3(1PVM), pvm_delhosts(3PVM), pvm_start_pvmd(3PVM), pvm_config(3PVM), pvm_mstat(3PVM)

								 22 February, 1994						    ADDHOSTS(3PVM)