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)