beremiz

Add retain basic implementation on GNU/Linux

2018-06-07, Andrey Skvortsov
976841968d74
Add retain basic implementation on GNU/Linux

Retain is saved in file and backup of this file is done every time.
File isn't saved on every PLC cycle to avoid high I/O load.
By default, retain is saved every second and on PLC stop/shutdown.
It's possible to override retain flush period by using CFLAGS option
in project's settings. For example, for 0.5 seconds period
use "-DFILE_RETAIN_SAVE_PERIOD_S=0.5".
#!/usr/bin/env python
# -*- coding: utf-8 -*-
#
# See COPYING.Runtime file for copyrights details.
#
from __future__ import absolute_import
from ctypes import CDLL, RTLD_GLOBAL, pointer, c_int, POINTER, c_char, create_string_buffer
def TryPreloadXenomai():
"""
Xenomai 3 (at least for version <= 3.0.6) do not handle properly dlclose
of shared objects whose dlopen did trigger xenomai_init.
As a workaround, this pre-loads xenomai libraries that need to be
initialized and call xenomai_init once for all.
Xenomai auto init of libs MUST be disabled (see --auto-init-solib in xeno-config)
"""
try:
for name in ["cobalt", "modechk", "copperplate", "alchemy"]:
globals()[name] = CDLL("lib"+name+".so", mode=RTLD_GLOBAL)
cobalt.xenomai_init(pointer(c_int(0)), pointer((POINTER(c_char)*2)(create_string_buffer("prog_name"), None)))
except Exception:
pass