beremiz

Build by default with optimization level -O2 for GCC

2018-05-25, Andrey Skvortsov
a66062a205ae
Build by default with optimization level -O2 for GCC

before -O0 was used by default, that caused pretty bad performance.

Amd64, i6700k, 4200MHz, GNU/Linux (non-RT kernel), gcc 7.2.0

-------------------------------------
Optimization | EN/ENO |no EN/ENO |
-------------------------------------
default | 11 | 9.5 |
-O3 | 3.9 | 5.2 |
-O2 | 4 | 4.8 |
-Os | 4.1 | 3.5 |
-Ofast | 3.9 | 5.2 |
-------------------------------------

ARM, BBB Cortex-A8, 600Mhz, GNU/Linux, gcc 4.6.3

-------------------------------------
Optimization | EN/ENO |no EN/ENO |
-------------------------------------
default | 273 | 226 |
-O3 | 141.8 | 106.2 |
-O2 | 142 | 107 |
-Os | 152.5 | 112.2 |
-Ofast | 141.7 | 106.2 |
-------------------------------------

For embedded systems with size constaints (like Cortex-Mx, AVR and so
on) I usually use -Os. It gets pretty good results. For
GNU/Linux-based systems -O2 is usually a good choice, as you see the
test results.
Beremiz and Beremiz_service connectors
======================================
To connect a PLC, Beremiz provides 2 types of connectors :
* a Pyro connector
* a WAMP connector
To configure the connection, you have to set the *URI_location* in your project Config tab according to this documentation.
The Pyro connector
----------------------------
Pyro is an advanced and powerful Distributed Object Technology system written entirely in Python.
Beremiz_service spawns a Pyro server, serving a PLCObject (see runtime/PLCObject.py). Therefore, Beremiz acts as a Pyro client.
TODO:: link to PLCObject API documentation
URI_location :
* LOCAL:// is a facility that starts the PLC service locally and connect Beremiz to it via Pyro.
This is intended for use in development stage.
* PYRO://<ip:port> normal connection to a remote PLC. PLC default port is 3000.
* PYROS://<ip:port> SSL connection to a remote PLC, see below.
more information about Pyro can be found on http://pythonhosted.org//Pyro/1-intro.html
===========================
Setup a Pyro SSL connection
===========================
Pyro v3 has a limited TLS/SSL support based on m2crypto. Pyro v4 had dropped it.
In order to have a full and reliable SSL, we recommand to use a TLS/SSL wrapper as nginx, stub or stunnel.
--------------------
TLS-PSK with stunnel
--------------------
In this example, we setup a simple TLS-PSK connection according to rfc4279.
This ciphersuite avoid the need for public key operations and certificate management.
It is perfect for a performance-constrained environments with limited CPU power as a PLC.
Needed :
* stunnel >= 5.09
verify openssl support for PSK cipher::
openssl ciphers -v 'PSK'
----------------------
Client setup (Beremiz)
----------------------
You need to choose an identity for your client, here *client1*.
generate a valid and strong key::
$ echo client1:$(openssl rand -base64 48) > pskclient1.txt
write a stunnel client configuration file *stunnel-client.conf*::
output = stunnel-client.log
client = yes
[beremiz]
accept = 3002
connect = [PLC]:3001
PSKidentity = client1
PSKsecrets = pskclient1.txt
start stunnel client side::
stunnel stunnel-client.conf
You could now connect beremiz with classic URI_location = PYRO://127.0.0.1:3002
--------------------
Server setup (PLC)
--------------------
import the client key in a keyfile psk.txt, concatening all client key.
write a stunnel server configuration file *stunnel-server.conf*::
output = stunnel-server.log
[beremiz]
accept = 3001
connect = 127.0.0.1:3000
PSKsecrets = psk.txt
start stunnel server side::
stunnel stunnel-server.conf
more documentation on stunnel http://www.stunnel.org/docs.html
The WAMP connector
------------------
WAMP is an open standard WebSocket subprotocol that provides two application messaging
patterns in one unified protocol: Remote Procedure Calls + Publish & Subscribe.
Beremiz WAMP connector implementation uses Autobahn and crossbar.
URI_location :
* WAMP://127.0.0.1:8888#Automation#2534667845
more information about WAMP can be found on http://wamp.ws/