def js_run()

in horovod/runner/js_run.py [0:0]

• 40 lines of code
• 14 McCabe index (conditional complexity)

def js_run(settings, nics, env, command, stdout=None, stderr=None):
    """
    Runs Horovod with jsrun.

    Args:
        settings: Settings for running jsrun.
                  Note: settings.num_proc and settings.hosts must not be None.
        nics: Interfaces to include by jsrun.
        env: Environment dictionary to use for running jsrun.
        command: Command and arguments to run as a list of string.
        stdout: Stdout of the mpi process.
                Only used when settings.run_func_mode is True.
        stderr: Stderr of the mpi process.
                Only used when settings.run_func_mode is True.
    """
    mpi_impl_flags, _ = _get_mpi_implementation_flags(settings.tcp_flag, env=env)
    if mpi_impl_flags is None:
        raise Exception(_MPI_NOT_FOUND_ERROR_MSG)

    if not is_jsrun_installed():
        raise Exception(
            'horovod does not find the jsrun command.\n\n'
            'Please, make sure you are running on a cluster with jsrun installed or '
            'use one of the other launchers.')

    if nics and 'NCCL_SOCKET_IFNAME' not in env:
        env['NCCL_SOCKET_IFNAME'] = ','.join(nics)

    smpiargs = ' '.join(mpi_impl_flags)
    if settings.extra_mpi_args:
        smpiargs += ' ' + settings.extra_mpi_args

    if settings.binding_args:
        binding_args = settings.binding_args
    else:
        rf = generate_jsrun_rankfile(settings)
        if settings.verbose >= 2:
            safe_shell_exec.execute('cat {rf}'.format(rf=rf))
        binding_args = '--erf_input {rf}'.format(rf=rf)

    jsrun_command = (
        'jsrun {binding_args} '
        '{output_filename_arg} '
        '{smpiargs} '
        '{command}'
        .format(binding_args = binding_args,
                output_filename_arg='--stdio_stderr {file} --stdio_stdout {file}'.format(file=settings.output_filename)
                                    if settings.output_filename else '',
                smpiargs= '--smpiargs {args}'.format(args=quote(smpiargs)) if smpiargs else '',
                command=' '.join(quote(par) for par in command))
    )

    if settings.verbose >= 2:
        print(jsrun_command)

    # Execute the jsrun command.
    if settings.run_func_mode:
        exit_code = safe_shell_exec.execute(jsrun_command, env=env, stdout=stdout, stderr=stderr)
        if exit_code != 0:
            raise RuntimeError("jsrun failed with exit code {exit_code}".format(exit_code=exit_code))
    else:
        os.execve('/bin/sh', ['/bin/sh', '-c', jsrun_command], env)