***********
Performance
***********

.. highlight:: bash

Call :command:`true` 256 times, running 4 processes in parallel:

================= ======== =========
Tool              Version  Time
================= ======== =========
Para              0.11     0.04 secs
Concurrently_     9.1.0    0.13 secs
`GNU Parallel`_   20241022 0.70 secs
rust-parallel_    1.18.1   0.04 secs
================= ======== =========

Times are averages taken from 1,000 runs.


Commands
========

Create a list of 256 :command:`true`'s::

    cmds=
    for _ in $(seq 0 255)
    do cmds="${cmds}true "
    done

Para::

    for _ in $(seq 0 999)
    do command time para -j4 -l0 ${cmds:?}
    done 2>&1 |
    awk 'BEGIN {total=0} {total += $1} END {print (total/NR)}'

Concurrently::

    for _ in $(seq 0 999)
    do command time concurrently -k -m 4 -r ${cmds:?}
    done 2>&1 |
    awk 'BEGIN {total=0} {total += $1} END {print (total/NR)}'

GNU Parallel::

    for _ in $(seq 0 999)
    do command time parallel -j 4 --halt now,fail=1 ::: ${cmds:?}
    done 2>&1 |
    awk 'BEGIN {total=0} {total += $1} END {print (total/NR)}'

rust-parallel::

    for _ in $(seq 0 999)
    do command time rust-parallel -j 4 --exit-on-error ::: ${cmds:?}
    done 2>&1 |
    awk 'BEGIN {total=0} {total += $1} END {print (total/NR)}'