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 -*-
# This file is part of Beremiz, a Integrated Development Environment for
# programming IEC 61131-3 automates supporting plcopen standard and CanFestival.
#
# Copyright (C) 2007: Edouard TISSERANT and Laurent BESSARD
#
# See COPYING file for copyrights details.
#
# This program is free software; you can redistribute it and/or
# modify it under the terms of the GNU General Public License
# as published by the Free Software Foundation; either version 2
# of the License, or (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
from __future__ import absolute_import
import os
import sys
import subprocess
import ctypes
import time
from threading import Timer, Lock, Thread, Semaphore, Condition
import signal
_debug = os.path.exists("BEREMIZ_DEBUG")
class outputThread(Thread):
"""
Thread is used to print the output of a command to the stdout
"""
def __init__(self, Proc, fd, callback=None, endcallback=None):
Thread.__init__(self)
self.killed = False
self.finished = False
self.retval = None
self.Proc = Proc
self.callback = callback
self.endcallback = endcallback
self.fd = fd
def run(self):
outchunk = None
self.retval = None
while self.retval is None and not self.killed:
if self.endcallback:
self.retval = self.Proc.poll()
else:
self.retval = self.Proc.returncode
outchunk = self.fd.readline()
if self.callback:
self.callback(outchunk)
while outchunk != '' and not self.killed:
outchunk = self.fd.readline()
if self.callback:
self.callback(outchunk)
if self.endcallback:
try:
err = self.Proc.wait()
except Exception:
err = self.retval
self.finished = True
self.endcallback(self.Proc.pid, err)
class ProcessLogger(object):
def __init__(self, logger, Command, finish_callback=None,
no_stdout=False, no_stderr=False, no_gui=True,
timeout=None, outlimit=None, errlimit=None,
endlog=None, keyword=None, kill_it=False, cwd=None,
encoding=None, output_encoding=None):
self.logger = logger
if not isinstance(Command, list):
self.Command_str = Command
self.Command = []
for i, word in enumerate(Command.replace("'", '"').split('"')):
if i % 2 == 0:
word = word.strip()
if len(word) > 0:
self.Command.extend(word.split())
else:
self.Command.append(word)
else:
self.Command = Command
self.Command_str = subprocess.list2cmdline(self.Command)
fsencoding = sys.getfilesystemencoding()
self.output_encoding = output_encoding
if encoding is None:
encoding = fsencoding
self.Command = [self.Command[0].encode(fsencoding)]+map(
lambda x: x.encode(encoding), self.Command[1:])
self.finish_callback = finish_callback
self.no_stdout = no_stdout
self.no_stderr = no_stderr
self.startupinfo = None
self.errlen = 0
self.outlen = 0
self.errlimit = errlimit
self.outlimit = outlimit
self.exitcode = None
self.outdata = []
self.errdata = []
self.keyword = keyword
self.kill_it = kill_it
self.startsem = Semaphore(0)
self.finishsem = Semaphore(0)
self.endlock = Lock()
popenargs = {
"cwd": os.getcwd() if cwd is None else cwd,
"stdin": subprocess.PIPE,
"stdout": subprocess.PIPE,
"stderr": subprocess.PIPE
}
if no_gui and os.name in ("nt", "ce"):
self.startupinfo = subprocess.STARTUPINFO()
self.startupinfo.dwFlags |= subprocess.STARTF_USESHOWWINDOW
popenargs["startupinfo"] = self.startupinfo
elif os.name == 'posix':
popenargs["shell"] = False
if timeout:
self.timeout = Timer(timeout, self.endlog)
self.timeout.start()
else:
self.timeout = None
if _debug and self.logger:
self.logger.write("(DEBUG) launching:\n" + self.Command_str + "\n")
self.Proc = subprocess.Popen(self.Command, **popenargs)
self.outt = outputThread(
self.Proc,
self.Proc.stdout,
self.output,
self.finish)
self.outt.start()
self.errt = outputThread(
self.Proc,
self.Proc.stderr,
self.errors)
self.errt.start()
self.startsem.release()
self.spinwakeuplock = Lock()
self.spinwakeupcond = Condition(self.spinwakeuplock)
self.spinwakeuptimer = None
def output(self, v):
if v and self.output_encoding:
v = v.decode(self.output_encoding)
self.outdata.append(v)
self.outlen += 1
if self.logger and not self.no_stdout:
self.logger.write(v)
if (self.keyword and v.find(self.keyword) != -1) or (self.outlimit and self.outlen > self.outlimit):
self.endlog()
def errors(self, v):
if v and self.output_encoding:
v = v.decode(self.output_encoding)
self.errdata.append(v)
self.errlen += 1
if self.logger and not self.no_stderr:
self.logger.write_warning(v)
if self.errlimit and self.errlen > self.errlimit:
self.endlog()
def log_the_end(self, ecode, pid):
if self.logger is not None:
self.logger.write(self.Command_str + "\n")
self.logger.write_warning(_("exited with status {a1} (pid {a2})\n").format(a1=str(ecode), a2=str(pid)))
def finish(self, pid, ecode):
# avoid running function before start is finished
self.startsem.acquire()
self.startsem.release()
if self.timeout:
self.timeout.cancel()
self.exitcode = ecode
if self.exitcode != 0:
self.log_the_end(ecode, pid)
if self.finish_callback is not None:
self.finish_callback(self, ecode, pid)
self.errt.join()
self.finishsem.release()
self.spinwakeup()
def kill(self, gently=True):
# avoid running kill before start is finished
self.startsem.acquire()
self.startsem.release()
self.outt.killed = True
self.errt.killed = True
if os.name in ("nt", "ce"):
PROCESS_TERMINATE = 1
handle = ctypes.windll.kernel32.OpenProcess(PROCESS_TERMINATE, False, self.Proc.pid)
ctypes.windll.kernel32.TerminateProcess(handle, -1)
ctypes.windll.kernel32.CloseHandle(handle)
else:
if gently:
sig = signal.SIGTERM
else:
sig = signal.SIGKILL
try:
os.kill(self.Proc.pid, sig)
except Exception:
pass
self.outt.join()
self.errt.join()
def endlog(self):
if self.endlock.acquire(False):
if not self.outt.finished and self.kill_it:
self.kill()
self.finishsem.release()
self.spinwakeup()
def spinwakeup(self):
with self.spinwakeuplock:
if self.spinwakeuptimer is not None:
self.spinwakeuptimer.cancel()
self.spinwakeuptimer = None
self.spinwakeupcond.notify()
def spin(self):
start = time.time()
if self.logger:
while not self.finishsem.acquire(0):
with self.spinwakeuplock:
self.spinwakeuptimer = Timer(0.1, self.spinwakeup)
self.spinwakeuptimer.start()
self.spinwakeupcond.wait()
self.logger.progress("%.3fs"%(time.time() - start))
else:
self.finishsem.acquire()
return [self.exitcode, "".join(self.outdata), "".join(self.errdata)]