#!/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 threading import Lock, Timer
from time import time as gettime
import wx
REFRESH_PERIOD = 0.1 # Minimum time between 2 refresh
DEBUG_REFRESH_LOCK = Lock() # Common refresh lock for all debug viewers
#-------------------------------------------------------------------------------
# Debug Viewer Class
#-------------------------------------------------------------------------------
"""
Class that implements common behavior of every viewers able to display debug
values
"""
class DebugViewer:
def __init__(self, producer, debug, subscribe_tick=True):
"""
Constructor
@param producer: Object receiving debug value and dispatching them to
consumers
@param debug: Flag indicating that Viewer is debugging
@param subscribe_tick: Flag indicating that viewer need tick value to
synchronize
"""
self.Debug = debug
self.SubscribeTick = subscribe_tick
# Flag indicating that consumer value update inhibited
# (DebugViewer is refreshing)
self.Inhibited = False
# List of data consumers subscribed to DataProducer
self.DataConsumers = {}
# Time stamp indicating when last refresh have been initiated
self.LastRefreshTime = gettime()
# Flag indicating that DebugViewer has acquire common debug lock
self.HasAcquiredLock = False
# Lock for access to the two preceding variable
self.AccessLock = Lock()
# Timer to refresh Debug Viewer one last time in the case that a new
# value have been received during refresh was inhibited and no one
# after refresh was activated
self.LastRefreshTimer = None
# Lock for access to the timer
self.TimerAccessLock = Lock()
# Set DataProducer and subscribe tick if needed
self.SetDataProducer(producer)
def __del__(self):
"""
Destructor
"""
# Unsubscribe all data consumers
self.UnsubscribeAllDataConsumers()
# Delete reference to DataProducer
self.DataProducer = None
# Stop last refresh timer
if self.LastRefreshTimer is not None:
self.LastRefreshTimer.cancel()
# Release Common debug lock if DebugViewer has acquired it
if self.HasAcquiredLock:
DEBUG_REFRESH_LOCK.release()
def SetDataProducer(self, producer):
"""
Set Data Producer
@param producer: Data Producer
"""
# In the case that tick need to be subscribed and DebugViewer is
# debugging
if self.SubscribeTick and self.Debug:
# Subscribe tick to new data producer
if producer is not None:
producer.SubscribeDebugIECVariable("__tick__", self, True)
# Unsubscribe tick from old data producer
if getattr(self, "DataProducer", None) is not None:
self.DataProducer.UnsubscribeDebugIECVariable("__tick__", self)
# Save new data producer
self.DataProducer = producer
def IsDebugging(self):
"""
Get flag indicating if Debug Viewer is debugging
@return: Debugging flag
"""
return self.Debug
def Inhibit(self, inhibit):
"""
Set consumer value update inhibit flag
@param inhibit: Inhibit flag
"""
# Inhibit every data consumers in list
for consumer, iec_path in self.DataConsumers.iteritems():
consumer.Inhibit(inhibit)
# Save inhibit flag
self.Inhibited = inhibit
def AddDataConsumer(self, iec_path, consumer, buffer_list=False):
"""
Subscribe data consumer to DataProducer
@param iec_path: Path in PLC of variable needed by data consumer
@param consumer: Data consumer to subscribe
@return: List of value already received [(tick, data),...] (None if
subscription failed)
"""
# Return immediately if no DataProducer defined
if self.DataProducer is None:
return None
# Subscribe data consumer to DataProducer
result = self.DataProducer.SubscribeDebugIECVariable(
iec_path, consumer, buffer_list)
if result is not None and consumer != self:
# Store data consumer if successfully subscribed and inform
# consumer of variable data type
self.DataConsumers[consumer] = iec_path
consumer.SetDataType(self.GetDataType(iec_path))
return result
def RemoveDataConsumer(self, consumer):
"""
Unsubscribe data consumer from DataProducer
@param consumer: Data consumer to unsubscribe
"""
# Remove consumer from data consumer list
iec_path = self.DataConsumers.pop(consumer, None)
# Unsubscribe consumer from DataProducer
if iec_path is not None:
self.DataProducer.UnsubscribeDebugIECVariable(
iec_path, consumer)
def SubscribeAllDataConsumers(self):
"""
Called to Subscribe all data consumers contained in DebugViewer.
May be overridden by inherited classes.
"""
# Subscribe tick if needed
if self.SubscribeTick and self.Debug and self.DataProducer is not None:
self.DataProducer.SubscribeDebugIECVariable("__tick__", self, True)
def UnsubscribeAllDataConsumers(self, tick=True):
"""
Called to Unsubscribe all data consumers.
"""
if self.DataProducer is not None:
# Unscribe tick if needed
if self.SubscribeTick and tick and self.Debug:
self.DataProducer.UnsubscribeDebugIECVariable("__tick__", self)
# Unsubscribe all data consumers in list
for consumer, iec_path in self.DataConsumers.iteritems():
self.DataProducer.UnsubscribeDebugIECVariable(
iec_path, consumer)
self.DataConsumers = {}
def GetDataType(self, iec_path):
"""
Return variable data type.
@param iec_path: Path in PLC of variable
@return: variable data type (None if not found)
"""
if self.DataProducer is not None:
# Search for variable informations in project compilation files
data_type = self.DataProducer.GetDebugIECVariableType(
iec_path.upper())
if data_type is not None:
return data_type
# Search for variable informations in project data
infos = self.DataProducer.GetInstanceInfos(iec_path)
if infos is not None:
return infos.type
return None
def IsNumType(self, data_type):
"""
Indicate if data type given is a numeric data type
@param data_type: Data type to test
@return: True if data type given is numeric
"""
if self.DataProducer is not None:
return self.DataProducer.IsNumType(data_type)
return False
def ForceDataValue(self, iec_path, value):
"""
Force PLC variable value
@param iec_path: Path in PLC of variable to force
@param value: Value forced
"""
if self.DataProducer is not None:
self.DataProducer.ForceDebugIECVariable(iec_path, value)
def ReleaseDataValue(self, iec_path):
"""
Release PLC variable value
@param iec_path: Path in PLC of variable to release
"""
if self.DataProducer is not None:
self.DataProducer.ReleaseDebugIECVariable(iec_path)
def NewDataAvailable(self, ticks):
"""
Called by DataProducer for each tick captured
@param tick: PLC tick captured
All other parameters are passed to refresh function
"""
# Stop last refresh timer
self.TimerAccessLock.acquire()
if self.LastRefreshTimer is not None:
self.LastRefreshTimer.cancel()
self.LastRefreshTimer=None
self.TimerAccessLock.release()
# Only try to refresh DebugViewer if it is visible on screen and not
# already refreshing
if self.IsShown() and not self.Inhibited:
# Try to get acquire common refresh lock if minimum period between
# two refresh has expired
if gettime() - self.LastRefreshTime > REFRESH_PERIOD and \
DEBUG_REFRESH_LOCK.acquire(False):
self.StartRefreshing()
# If common lock wasn't acquired for any reason, restart last
# refresh timer
else:
self.StartLastRefreshTimer()
# In the case that DebugViewer isn't visible on screen and has already
# acquired common refresh lock, reset DebugViewer
elif not self.IsShown() and self.HasAcquiredLock:
DebugViewer.RefreshNewData(self)
def ShouldRefresh(self):
"""
Callback function called when last refresh timer expired
All parameters are passed to refresh function
"""
# Cancel if DebugViewer is not visible on screen
if self and self.IsShown():
# Try to acquire common refresh lock
if DEBUG_REFRESH_LOCK.acquire(False):
self.StartRefreshing()
# Restart last refresh timer if common refresh lock acquired failed
else:
self.StartLastRefreshTimer()
def StartRefreshing(self):
"""
Called to initiate a refresh of DebugViewer
All parameters are passed to refresh function
"""
# Update last refresh time stamp and flag for common refresh
# lock acquired
self.AccessLock.acquire()
self.HasAcquiredLock = True
self.LastRefreshTime = gettime()
self.AccessLock.release()
# Inhibit data consumer value update
self.Inhibit(True)
# Initiate DebugViewer refresh
wx.CallAfter(self.RefreshNewData)
def StartLastRefreshTimer(self):
"""
Called to start last refresh timer for the minimum time between 2
refresh
All parameters are passed to refresh function
"""
self.TimerAccessLock.acquire()
self.LastRefreshTimer = Timer(
REFRESH_PERIOD, self.ShouldRefresh)
self.LastRefreshTimer.start()
self.TimerAccessLock.release()
def RefreshNewData(self):
"""
Called to refresh DebugViewer according to values received by data
consumers
May be overridden by inherited classes
Can receive any parameters depending on what is needed by inherited
class
"""
if self:
# Activate data consumer value update
self.Inhibit(False)
# Release common refresh lock if acquired and update
# last refresh time
self.AccessLock.acquire()
if self.HasAcquiredLock:
DEBUG_REFRESH_LOCK.release()
self.HasAcquiredLock = False
if gettime() - self.LastRefreshTime > REFRESH_PERIOD:
self.LastRefreshTime = gettime()
self.AccessLock.release()