PVM (Parallel Virtual Machine) is a software package which
permits a heterogeneous collection of Unix and/or Windows
computers, connected by a network, to be used as a single
large parallel computer. The
PVM module provides a
S-lang interface to this package. By performing distributed
computations with S-lang one can make better use of available
computer resources yet still retain the advantages of
programming in an interpreted language.
This document briefly describes how to use the S-lang
PVM. It assumes that the reader is
already familiar with the PVM package itself.
For complete details on obtaining, installing and using the
PVM package, see the
PVM documentation. Note that, once the
PVM package is properly installed on your computer, the PVM
man pages will provide detailed documentation on all
the PVM library functions.
Although the S-lang
PVM module functions often have
slightly different interfaces, the differences are usually
minor so the PVM documentation is quite helpful. Because
the S-lang interface is not yet fully documented, it will
be necessary to consult the
PVM documentation directly
to make full use of the S-lang
Because PVM processes require running programs on remote
hosts, it is necessary to provide each host with the full path
to the relevant executables. To simplify this process, it may
be useful to create a directory, e.g.
every host and put relevant executables in that directory so
that the same relative path will work on all machines. This
PVM path may be specified in the
configuration file; for a detailed description of the contents
of this file, see the
pvmd man page.
The usage examples discussed in this manual assume that the PVM has already been initialized by running a command such as
This starts the PVM console and also starts the PVM daemon,
unix> pvm ~/.pvmhosts
pvmd, on each remote host. This daemon runs all PVM slave processes and handles all communications with the parent process and the rest of the PVM.
The execution environment of the PVM slave processes is
inherited from the corresponding
pvmd process which, in
turn, is inherited from the parent process which started the
PVM console. However, it is sometimes useful to
configure the environment of the remote
using a startup script,
$HOME/.pvmprofile. This is a
Bourne shell script which, if present, is run when
is started. For a detailed description of the contents of
this file, see the
pvmd man page.