Process Array Example

# This module shows the basic pattern for running an array of
# parallel tasks. array_writer_define_opts loops over a fixed set
# of task identifiers and calls save_opt_list once per iteration,
# so DeBasher schedules one array_writer task per call with its own
# "-id" and "-outf" options. array_reader_define_opts mirrors the
# same loop, reading each writer task's output through
# define_opt_from_proc_task_out. The loop itself is written by hand
# here: compare it with the following example, where the same
# scenario is expressed through DeBasher's array option handler
# convention instead.

array_writer_document()
{
    document_process "Executes an array of 4 tasks. Each task creates a file containing the task index."
}

array_writer_explain_opts()
{
    # -c option
    local description="Sleep time in seconds"
    explain_opt "-c" "<int>" "$description"

    # -id option
    local description="id of writer"
    explain_opt "-id" "<int>" "$description"

    # -outf option
    local description="output file of writer"
    explain_opt "-outf" "<file>" "$description"
}

array_writer_identify_cmdline_opts()
{
    opt_is_cmdline "-c"
}

array_writer_define_opts()
{
    # Initialize variables
    local cmdline=$1
    local process_spec=$2
    local process_name=$3
    local process_outdir=$4
    local optlist=""

    # -c option
    define_cmdline_opt "$cmdline" "-c" optlist || return 1

    # Save option list so as to execute process four times
    for id in 0 1 2 3; do
        local specific_optlist=${optlist}
        define_opt "-id" $id specific_optlist || return 1
        define_opt "-outf" "${process_outdir}/${id}" specific_optlist || return 1
        save_opt_list specific_optlist
    done
}

array_writer()
{
    # Initialize variables
    local sleep_time=$(read_opt_value_from_func_args "-c" "$@")
    local id=$(read_opt_value_from_func_args "-id" "$@")
    local outf=$(read_opt_value_from_func_args "-outf" "$@")

    # Sleep some time
    sleep ${sleep_time}

    # Create file
    echo $id > "${outf}"
}

array_writer_reset_outfiles()
{
    # Initialize variables
    local outf=$(read_opt_value_from_func_args "-outf" "$@")

    # Remove output file
    if [ -f "${outf}" ]; then
        rm "${outf}"
    fi
}

array_reader_document()
{
    document_process "Reads each array_writer task's output file and copies its content to the reader's own output file."
}

array_reader_explain_opts()
{
    # -id option
    local description="id of reader"
    explain_opt "-id" "<int>" "$description"

    # -infile option
    local description="input file"
    explain_opt "-infile" "<file>" "$description"

    # -outdir option
    local description="output directory of reader"
    explain_opt "-outdir" "<dir>" "$description"
}

array_reader_identify_cmdline_opts()
{
    :
}

array_reader_define_opts()
{
    # Initialize variables
    local cmdline=$1
    local process_spec=$2
    local process_name=$3
    local process_outdir=$4
    local optlist=""

    # Save option list so as to execute process four times
    for id in 0 1 2 3; do
        local specific_optlist=${optlist}
        define_opt "-id" $id specific_optlist || return 1
        define_opt_from_proc_task_out "-infile" "array_writer" "${id}" "-outf" specific_optlist || return 1
        define_opt "-outdir" "${process_outdir}" specific_optlist || return 1
        save_opt_list specific_optlist
    done
}

array_reader()
{
    # Initialize variables
    local id=$(read_opt_value_from_func_args "-id" "$@")
    local infile=$(read_opt_value_from_func_args "-infile" "$@")
    local outd=$(read_opt_value_from_func_args "-outdir" "$@")

    # Copy content of infile to auxiliary file
    cat "${infile}" > "${outd}"/${id}_aux

    # Copy content of infile to final file
    cat "${outd}"/${id}_aux > "${outd}"/${id}
}

array_reader_post()
{
    logmsg "Cleaning directory..."

    # Initialize variables
    local id=$(read_opt_value_from_func_args "-id" "$@")
    local outd=$(read_opt_value_from_func_args "-outdir" "$@")

    # Remove auxiliary file
    rm "${outd}"/${id}_aux

    logmsg "Cleaning finished"
}

debasher_array_example_original_program()
{
    add_debasher_process "array_writer" "cpus=1 mem=32 time=00:01:00,00:02:00 throttle=2"
    add_debasher_process "array_reader" "cpus=1 mem=32 time=00:01:00 throttle=4"
}