Linux runtime: overrun detection for real-time timers and for plc execution.
If real-time timer wakes-up PLC thread too late (10% over period), then
warning is logged.
If PLC code (IO retreive, execution, IO publish) takes longer than requested
PLC execution cycle, then warning is logged, and CPU hoogging is mitigated
by delaying next PLC execution a few cylces more until having at least
1ms minimal idle time.
#!/usr/bin/env python
# -*- coding: utf-8 -*-
#
# See COPYING.Runtime file for copyrights details.
#
from __future__ import absolute_import
import ctypes
from ctypes import *
from datetime import timedelta as td
ctypes.pythonapi.PyString_AsString.argtypes = (ctypes.c_void_p,)
ctypes.pythonapi.PyString_AsString.restype = ctypes.POINTER(ctypes.c_char)
class IEC_STRING(Structure):
"""
Must be changed according to changes in iec_types.h
"""
_fields_ = [("len", c_uint8),
("body", c_char * 126)]
class IEC_TIME(Structure):
"""
Must be changed according to changes in iec_types.h
"""
_fields_ = [("s", c_long), # tv_sec
("ns", c_long)] # tv_nsec
def _t(t, u=lambda x: x.value, p=lambda t, x: t(x)):
return (t, u, p)
def _ttime():
return (IEC_TIME,
lambda x: td(0, x.s, x.ns/1000.0),
lambda t, x: t(x.days * 24 * 3600 + x.seconds, x.microseconds*1000))
SameEndianessTypeTranslator = {
"BOOL": _t(c_uint8, lambda x: x.value != 0),
"STEP": _t(c_uint8),
"TRANSITION": _t(c_uint8),
"ACTION": _t(c_uint8),
"SINT": _t(c_int8),
"USINT": _t(c_uint8),
"BYTE": _t(c_uint8),
"STRING": (IEC_STRING,
lambda x: x.body[:x.len],
lambda t, x: t(len(x), x)),
"INT": _t(c_int16),
"UINT": _t(c_uint16),
"WORD": _t(c_uint16),
"DINT": _t(c_int32),
"UDINT": _t(c_uint32),
"DWORD": _t(c_uint32),
"LINT": _t(c_int64),
"ULINT": _t(c_uint64),
"LWORD": _t(c_uint64),
"REAL": _t(c_float),
"LREAL": _t(c_double),
"TIME": _ttime(),
"TOD": _ttime(),
"DATE": _ttime(),
"DT": _ttime(),
}
SwapedEndianessTypeTranslator = {
# TODO
}
TypeTranslator = SameEndianessTypeTranslator
# Construct debugger natively supported types
DebugTypesSize = dict([(key, sizeof(t)) for key, (t, p, u) in SameEndianessTypeTranslator.iteritems() if t is not None])
def UnpackDebugBuffer(buff, indexes):
res = []
buffoffset = 0
buffsize = len(buff)
buffptr = cast(ctypes.pythonapi.PyString_AsString(id(buff)), c_void_p).value
for iectype in indexes:
c_type, unpack_func, _pack_func = \
TypeTranslator.get(iectype, (None, None, None))
cursor = c_void_p(buffptr + buffoffset)
if iectype == "STRING":
# strlen is stored in c_uint8 and sizeof(c_uint8) is 1
# first check we can read size
if (buffoffset + 1) <= buffsize:
size = 1 + cast(cursor,POINTER(c_type)).contents.len
else:
return None
else:
size = sizeof(c_type)
if c_type is not None and (buffoffset + size) <= buffsize:
value = unpack_func(cast(cursor,
POINTER(c_type)).contents)
buffoffset += size
res.append(value)
else:
return None
if buffoffset and buffoffset == buffsize:
return res
return None