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 specified 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 values 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)