def exitStates(self, enabledTransitions):
statesToExit = OrderedSet()
for t in enabledTransitions:
if t.target:
tstates = self.getTargetStates(t.target)
if t.type == "internal" and isCompoundState(t.source) and all(map(lambda s: isDescendant(s,t.source), tstates)):
ancestor = t.source
else:
ancestor = self.findLCA([t.source] + tstates)
for s in self.configuration:
if isDescendant(s,ancestor):
statesToExit.add(s)
for s in statesToExit:
self.statesToInvoke.delete(s)
statesToExit.sort(key=exitOrder)
for s in statesToExit:
for h in s.history:
if h.type == "deep":
f = lambda s0: isAtomicState(s0) and isDescendant(s0,s)
else:
f = lambda s0: s0.parent == s
self.historyValue[h.id] = filter(f,self.configuration) #+ s.parent
for s in statesToExit:
for content in s.onexit:
self.executeContent(content)
for inv in s.invoke:
self.cancelInvoke(inv)
self.configuration.delete(s)
def __init__(self):
self.running = True
self.configuration = OrderedSet()
self.internalQueue = Queue()
self.externalQueue = Queue()
self.statesToInvoke = OrderedSet()
self.historyValue = {}
self.dm = None
self.invokeId = None
self.parentId = None
self.logger = None
def selectEventlessTransitions(self):
enabledTransitions = OrderedSet()
atomicStates = filter(isAtomicState, self.configuration)
atomicStates = sorted(atomicStates, key=documentOrder)
for state in atomicStates:
done = False
for s in [state] + getProperAncestors(state, None):
if done: break
for t in s.transition:
if not t.event and self.conditionMatch(t):
enabledTransitions.add(t)
done = True
break
filteredTransitions = self.filterPreempted(enabledTransitions)
return filteredTransitions
def __init__(self):
self.running = True
self.exited = False
self.cancelled = False
self.configuration = OrderedSet()
self.internalQueue = Queue()
self.externalQueue = Queue()
self.statesToInvoke = OrderedSet()
self.historyValue = {}
self.dm = None
self.invokeId = None
self.parentId = None
self.logger = None
def selectEventlessTransitions(self):
enabledTransitions = OrderedSet()
atomicStates = filter(isAtomicState, self.configuration)
atomicStates = sorted(atomicStates, key=documentOrder)
for state in atomicStates:
done = False
for s in [state] + getProperAncestors(state, None):
if done: break
for t in s.transition:
if not t.event and self.conditionMatch(t):
enabledTransitions.add(t)
done = True
break
filteredTransitions = self.filterPreempted(enabledTransitions)
return filteredTransitions
def filterPreempted(self, enabledTransitions):
filteredTransitions = []
for t in enabledTransitions:
# does any t2 in filteredTransitions preempt t? if not, add t to filteredTransitions
if not any(map(lambda t2: self.preemptsTransition(t2, t), filteredTransitions)):
filteredTransitions.append(t)
return OrderedSet(filteredTransitions)
def and_rules(name: str, singleton: str, accept_singular: bool = False, first_singleton: Optional[str] = None, last_singleton: Optional[str] = None) -> Set[Rule]:
"""
Creates a mini-grammar of rules that are needed to parse 'A and B',
'A, B and C', 'A, B, C and D', etc. where A, B, C and D all are parseable
using the rule name passed using the singleton argument.
Grammar:
<As> ::= A_helper `and' A_last
<A_helper> ::= A_helper `,' A
<A_helper> ::= A_first
<As> ::= A
"""
if last_singleton is None:
last_singleton = singleton
if first_singleton is None:
first_singleton = singleton
helper = name + "_"
rules = {
# _ and C
Rule(name, [RuleRef(helper), Literal('and'), RuleRef(last_singleton)],
lambda state, data: data[0] + data[2] + Interpretation(local=data[0].local | OrderedSet([data[2].local]))),
# A, B # (allows for 'A, B and C')
Rule(helper, [RuleRef(helper), Literal(','), RuleRef(singleton)],
lambda state, data: data[0] + data[2] + Interpretation(local=data[0].local | OrderedSet([data[2].local]))),
# A (allows for 'A and B')
Rule(helper, [RuleRef(first_singleton)],
lambda state, data: data[0] + Interpretation(local=OrderedSet([data[0].local])))
}
if accept_singular:
rules |= {
Rule(name, [RuleRef(singleton)],
lambda state, data: data[0] + Interpretation(local=OrderedSet([data[0].local])))
}
return rules
def enterStates(self, enabledTransitions):
statesToEnter = OrderedSet()
statesForDefaultEntry = OrderedSet()
for t in enabledTransitions:
if t.target:
tstates = self.getTargetStates(t.target)
if t.type == "internal" and isCompoundState(t.source) and all(map(lambda s: isDescendant(s,t.source), tstates)):
ancestor = t.source
else:
ancestor = self.findLCA([t.source] + tstates)
for s in tstates:
self.addStatesToEnter(s,statesToEnter,statesForDefaultEntry)
for s in tstates:
for anc in getProperAncestors(s,ancestor):
statesToEnter.add(anc)
if isParallelState(anc):
for child in getChildStates(anc):
if not any(map(lambda s: isDescendant(s,child), statesToEnter)):
self.addStatesToEnter(child, statesToEnter,statesForDefaultEntry)
statesToEnter.sort(key=enterOrder)
for s in statesToEnter:
self.statesToInvoke.add(s)
self.configuration.add(s)
if self.doc.binding == "late" and s.isFirstEntry:
s.initDatamodel()
s.isFirstEntry = False
for content in s.onentry:
self.executeContent(content)
if s in statesForDefaultEntry:
self.executeContent(s.initial)
if isFinalState(s):
parent = s.parent
grandparent = parent.parent
self.internalQueue.put(Event(["done", "state", parent.id], s.donedata()))
if isParallelState(grandparent):
if all(map(self.isInFinalState, getChildStates(grandparent))):
self.internalQueue.put(Event(["done", "state", grandparent.id]))
for s in self.configuration:
if isFinalState(s) and isScxmlState(s.parent):
self.running = False;
def exitStates(self, enabledTransitions):
statesToExit = OrderedSet()
for t in enabledTransitions:
if t.target:
tstates = self.getTargetStates(t.target)
if t.type == "internal" and isCompoundState(t.source) and all(map(lambda s: isDescendant(s,t.source), tstates)):
ancestor = t.source
else:
ancestor = self.findLCA([t.source] + tstates)
for s in self.configuration:
if isDescendant(s,ancestor):
statesToExit.add(s)
for s in statesToExit:
self.statesToInvoke.delete(s)
statesToExit.sort(key=exitOrder)
for s in statesToExit:
for h in s.history:
if h.type == "deep":
f = lambda s0: isAtomicState(s0) and isDescendant(s0,s)
else:
f = lambda s0: s0.parent == s
self.historyValue[h.id] = filter(f,self.configuration) #+ s.parent
for s in statesToExit:
for content in s.onexit:
self.executeContent(content)
for inv in s.invoke:
self.cancelInvoke(inv)
self.configuration.delete(s)
def enterStates(self, enabledTransitions):
statesToEnter = OrderedSet()
statesForDefaultEntry = OrderedSet()
for t in enabledTransitions:
if t.target:
tstates = self.getTargetStates(t.target)
if t.type == "internal" and isCompoundState(t.source) and all(map(lambda s: isDescendant(s,t.source), tstates)):
ancestor = t.source
else:
ancestor = self.findLCA([t.source] + tstates)
for s in tstates:
self.addStatesToEnter(s,statesToEnter,statesForDefaultEntry)
for s in tstates:
for anc in getProperAncestors(s,ancestor):
statesToEnter.add(anc)
if isParallelState(anc):
for child in getChildStates(anc):
if not any(map(lambda s: isDescendant(s,child), statesToEnter)):
self.addStatesToEnter(child, statesToEnter,statesForDefaultEntry)
statesToEnter.sort(key=enterOrder)
for s in statesToEnter:
self.statesToInvoke.add(s)
self.configuration.add(s)
if self.doc.binding == "late" and s.isFirstEntry:
s.initDatamodel()
s.isFirstEntry = False
for content in s.onentry:
self.executeContent(content)
if s in statesForDefaultEntry:
self.executeContent(s.initial)
if isFinalState(s):
parent = s.parent
grandparent = parent.parent
self.internalQueue.put(Event(["done", "state", parent.id], s.donedata()))
if isParallelState(grandparent):
if all(map(self.isInFinalState, getChildStates(grandparent))):
self.internalQueue.put(Event(["done", "state", grandparent.id]))
for s in self.configuration:
if isFinalState(s) and isScxmlState(s.parent):
self.running = False;
class Interpreter(object):
'''
The class repsonsible for keeping track of the execution of the
statemachine.
'''
def __init__(self):
self.running = True
self.configuration = OrderedSet()
self.internalQueue = Queue()
self.externalQueue = Queue()
self.statesToInvoke = OrderedSet()
self.historyValue = {}
self.dm = None
self.invokeId = None
self.parentId = None
self.logger = None
def interpret(self, document, invokeId=None):
'''Initializes the interpreter given an SCXMLDocument instance'''
self.doc = document
self.invokeId = invokeId
transition = Transition(document.rootState)
transition.target = document.rootState.initial
transition.exe = document.rootState.initial.exe
self.executeTransitionContent([transition])
self.enterStates([transition])
def mainEventLoop(self):
while self.running:
enabledTransitions = None
stable = False
# now take any newly enabled null transitions and any transitions triggered by internal events
while self.running and not stable:
enabledTransitions = self.selectEventlessTransitions()
if not enabledTransitions:
if self.internalQueue.empty():
stable = True
else:
internalEvent = self.internalQueue.get() # this call returns immediately if no event is available
self.logger.info("internal event found: %s", internalEvent.name)
self.dm["__event"] = internalEvent
enabledTransitions = self.selectTransitions(internalEvent)
if enabledTransitions:
self.microstep(enabledTransitions)
# eventlet.greenthread.sleep()
eventlet.greenthread.sleep()
for state in self.statesToInvoke:
for inv in state.invoke:
inv.invoke(inv)
self.statesToInvoke.clear()
if not self.internalQueue.empty():
continue
externalEvent = self.externalQueue.get() # this call blocks until an event is available
if externalEvent.name == "cancel.invoke.%s" % self.dm.sessionid:
continue
self.logger.info("external event found: %s", externalEvent.name)
self.dm["__event"] = externalEvent
for state in self.configuration:
for inv in state.invoke:
if inv.invokeid == externalEvent.invokeid: # event is the result of an <invoke> in this state
self.applyFinalize(inv, externalEvent)
if inv.autoforward:
inv.send(externalEvent)
enabledTransitions = self.selectTransitions(externalEvent)
if enabledTransitions:
self.microstep(enabledTransitions)
# if we get here, we have reached a top-level final state or some external entity has set running to False
self.exitInterpreter()
def exitInterpreter(self):
statesToExit = sorted(self.configuration, key=exitOrder)
for s in statesToExit:
for content in s.onexit:
self.executeContent(content)
for inv in s.invoke:
self.cancelInvoke(inv)
self.configuration.delete(s)
if isFinalState(s) and isScxmlState(s.parent):
if self.invokeId and self.parentId and self.parentId in self.dm.sessions:
self.send(["done", "invoke", self.invokeId], s.donedata(), self.invokeId, self.dm.sessions[self.parentId].interpreter.externalQueue)
self.logger.info("Exiting interpreter")
dispatcher.send("signal_exit", self, final=s.id)
return
dispatcher.send("signal_exit", self, final=None)
def selectEventlessTransitions(self):
enabledTransitions = OrderedSet()
atomicStates = filter(isAtomicState, self.configuration)
atomicStates = sorted(atomicStates, key=documentOrder)
for state in atomicStates:
done = False
for s in [state] + getProperAncestors(state, None):
if done: break
for t in s.transition:
if not t.event and self.conditionMatch(t):
enabledTransitions.add(t)
done = True
break
filteredTransitions = self.filterPreempted(enabledTransitions)
return filteredTransitions
def selectTransitions(self, event):
enabledTransitions = OrderedSet()
atomicStates = filter(isAtomicState, self.configuration)
atomicStates = sorted(atomicStates, key=documentOrder)
for state in atomicStates:
done = False
for s in [state] + getProperAncestors(state, None):
if done: break
for t in s.transition:
if t.event and nameMatch(t.event, event.name.split(".")) and self.conditionMatch(t):
enabledTransitions.add(t)
done = True
break
filteredTransitions = self.filterPreempted(enabledTransitions)
return filteredTransitions
def preemptsTransition(self, t, t2):
if self.isType1(t): return False
elif self.isType2(t) and self.isType3(t2): return True
elif self.isType3(t): return True
return False
def getCommonParallel(self, states):
ancestors = set(getProperAncestors(states[0], None))
for s in states[1:]:
ancestors = ancestors.intersection(getProperAncestors(s, None))
if ancestors:
return sorted(ancestors, key=exitOrder)[0]
def isType1(self, t):
return not t.target
def isType2(self, t):
source = t.source if t.type == "internal" else t.source.parent
p = self.getCommonParallel([source] + self.getTargetStates(t.target))
return not isScxmlState(p)
def isType3(self, t):
return not self.isType2(t) and not self.isType1(t)
def filterPreempted(self, enabledTransitions):
filteredTransitions = []
for t in enabledTransitions:
# does any t2 in filteredTransitions preempt t? if not, add t to filteredTransitions
if not any(map(lambda t2: self.preemptsTransition(t2, t), filteredTransitions)):
filteredTransitions.append(t)
return OrderedSet(filteredTransitions)
def microstep(self, enabledTransitions):
self.exitStates(enabledTransitions)
self.executeTransitionContent(enabledTransitions)
self.enterStates(enabledTransitions)
self.logger.info("new config: {" + ", ".join([s.id for s in self.configuration if s.id != "__main__"]) + "}")
def exitStates(self, enabledTransitions):
statesToExit = OrderedSet()
for t in enabledTransitions:
if t.target:
tstates = self.getTargetStates(t.target)
if t.type == "internal" and isCompoundState(t.source) and all(map(lambda s: isDescendant(s,t.source), tstates)):
ancestor = t.source
else:
ancestor = self.findLCA([t.source] + tstates)
for s in self.configuration:
if isDescendant(s,ancestor):
statesToExit.add(s)
for s in statesToExit:
self.statesToInvoke.delete(s)
statesToExit.sort(key=exitOrder)
for s in statesToExit:
for h in s.history:
if h.type == "deep":
f = lambda s0: isAtomicState(s0) and isDescendant(s0,s)
else:
f = lambda s0: s0.parent == s
self.historyValue[h.id] = filter(f,self.configuration) #+ s.parent
for s in statesToExit:
for content in s.onexit:
self.executeContent(content)
for inv in s.invoke:
self.cancelInvoke(inv)
self.configuration.delete(s)
def cancelInvoke(self, inv):
inv.cancel()
def executeTransitionContent(self, enabledTransitions):
for t in enabledTransitions:
self.executeContent(t)
def enterStates(self, enabledTransitions):
statesToEnter = OrderedSet()
statesForDefaultEntry = OrderedSet()
for t in enabledTransitions:
if t.target:
tstates = self.getTargetStates(t.target)
if t.type == "internal" and isCompoundState(t.source) and all(map(lambda s: isDescendant(s,t.source), tstates)):
ancestor = t.source
else:
ancestor = self.findLCA([t.source] + tstates)
for s in tstates:
self.addStatesToEnter(s,statesToEnter,statesForDefaultEntry)
for s in tstates:
for anc in getProperAncestors(s,ancestor):
statesToEnter.add(anc)
if isParallelState(anc):
for child in getChildStates(anc):
if not any(map(lambda s: isDescendant(s,child), statesToEnter)):
self.addStatesToEnter(child, statesToEnter,statesForDefaultEntry)
statesToEnter.sort(key=enterOrder)
for s in statesToEnter:
self.statesToInvoke.add(s)
self.configuration.add(s)
if self.doc.binding == "late" and s.isFirstEntry:
s.initDatamodel()
s.isFirstEntry = False
for content in s.onentry:
self.executeContent(content)
if s in statesForDefaultEntry:
self.executeContent(s.initial)
if isFinalState(s):
parent = s.parent
grandparent = parent.parent
self.internalQueue.put(Event(["done", "state", parent.id], s.donedata()))
if isParallelState(grandparent):
if all(map(self.isInFinalState, getChildStates(grandparent))):
self.internalQueue.put(Event(["done", "state", grandparent.id]))
for s in self.configuration:
if isFinalState(s) and isScxmlState(s.parent):
self.running = False;
def addStatesToEnter(self, state,statesToEnter,statesForDefaultEntry):
if isHistoryState(state):
if state.id in self.historyValue:
for s in self.historyValue[state.id]:
self.addStatesToEnter(s, statesToEnter, statesForDefaultEntry)
for anc in getProperAncestors(s,state):
statesToEnter.add(anc)
else:
for t in state.transition:
for s in self.getTargetStates(t.target):
self.addStatesToEnter(s, statesToEnter, statesForDefaultEntry)
else:
statesToEnter.add(state)
if isCompoundState(state):
statesForDefaultEntry.add(state)
for s in self.getTargetStates(state.initial):
self.addStatesToEnter(s, statesToEnter, statesForDefaultEntry)
elif isParallelState(state):
for s in getChildStates(state):
self.addStatesToEnter(s,statesToEnter,statesForDefaultEntry)
def isInFinalState(self, s):
if isCompoundState(s):
return any(map(lambda s: isFinalState(s) and s in self.configuration, getChildStates(s)))
elif isParallelState(s):
return all(map(self.isInFinalState, getChildStates(s)))
else:
return False
def findLCA(self, stateList):
for anc in filter(isCompoundState, getProperAncestors(stateList[0], None)):
# for anc in getProperAncestors(stateList[0], None):
if all(map(lambda(s): isDescendant(s,anc), stateList[1:])):
return anc
class Interpreter(object):
'''
The class repsonsible for keeping track of the execution of the
statemachine.
'''
def __init__(self):
self.running = True
self.exited = False
self.cancelled = False
self.configuration = OrderedSet()
self.internalQueue = Queue()
self.externalQueue = Queue()
self.statesToInvoke = OrderedSet()
self.historyValue = {}
self.dm = None
self.invokeId = None
self.parentId = None
self.logger = None
def interpret(self, document, invokeId=None):
'''Initializes the interpreter given an SCXMLDocument instance'''
self.doc = document
self.invokeId = invokeId
transition = Transition(document.rootState)
transition.target = document.rootState.initial
transition.exe = document.rootState.initial.exe
self.executeTransitionContent([transition])
self.enterStates([transition])
def mainEventLoop(self):
while self.running:
enabledTransitions = None
stable = False
# now take any newly enabled null transitions and any transitions triggered by internal events
while self.running and not stable:
enabledTransitions = self.selectEventlessTransitions()
if not enabledTransitions:
if self.internalQueue.empty():
stable = True
else:
internalEvent = self.internalQueue.get() # this call returns immediately if no event is available
self.logger.info("internal event found: %s", internalEvent.name)
self.dm["__event"] = internalEvent
enabledTransitions = self.selectTransitions(internalEvent)
if enabledTransitions:
self.microstep(enabledTransitions)
# eventlet.greenthread.sleep()
eventlet.greenthread.sleep()
for state in self.statesToInvoke:
for inv in state.invoke:
inv.invoke(inv)
self.statesToInvoke.clear()
if not self.internalQueue.empty():
continue
externalEvent = self.externalQueue.get() # this call blocks until an event is available
# if externalEvent.name == "cancel.invoke.%s" % self.dm.sessionid:
# continue
# our parent session also might cancel us. The mechanism for this is platform specific,
if isCancelEvent(externalEvent):
self.running = False
continue
self.logger.info("external event found: %s", externalEvent.name)
self.dm["__event"] = externalEvent
for state in self.configuration:
for inv in state.invoke:
if inv.invokeid == externalEvent.invokeid: # event is the result of an <invoke> in this state
self.applyFinalize(inv, externalEvent)
if inv.autoforward:
inv.send(externalEvent)
enabledTransitions = self.selectTransitions(externalEvent)
if enabledTransitions:
self.microstep(enabledTransitions)
# if we get here, we have reached a top-level final state or some external entity has set running to False
self.exitInterpreter()
def exitInterpreter(self):
statesToExit = sorted(self.configuration, key=exitOrder)
for s in statesToExit:
for content in s.onexit:
self.executeContent(content)
for inv in s.invoke:
self.cancelInvoke(inv)
self.configuration.delete(s)
if isFinalState(s) and isScxmlState(s.parent):
if self.invokeId and self.parentId and self.parentId in self.dm.sessions:
self.send(["done", "invoke", self.invokeId], s.donedata(), self.invokeId, self.dm.sessions[self.parentId].interpreter.externalQueue)
self.logger.info("Exiting interpreter")
dispatcher.send("signal_exit", self, final=s.id)
self.exited = True
return
self.exited = True
dispatcher.send("signal_exit", self, final=None)
def selectEventlessTransitions(self):
enabledTransitions = OrderedSet()
atomicStates = filter(isAtomicState, self.configuration)
atomicStates = sorted(atomicStates, key=documentOrder)
for state in atomicStates:
done = False
for s in [state] + getProperAncestors(state, None):
if done: break
for t in s.transition:
if not t.event and self.conditionMatch(t):
enabledTransitions.add(t)
done = True
break
filteredTransitions = self.filterPreempted(enabledTransitions)
return filteredTransitions
def selectTransitions(self, event):
enabledTransitions = OrderedSet()
atomicStates = filter(isAtomicState, self.configuration)
atomicStates = sorted(atomicStates, key=documentOrder)
for state in atomicStates:
done = False
for s in [state] + getProperAncestors(state, None):
if done: break
for t in s.transition:
if t.event and nameMatch(t.event, event.name.split(".")) and self.conditionMatch(t):
enabledTransitions.add(t)
done = True
break
filteredTransitions = self.filterPreempted(enabledTransitions)
return filteredTransitions
def preemptsTransition(self, t, t2):
if self.isType1(t): return False
elif self.isType2(t) and self.isType3(t2): return True
elif self.isType3(t): return True
return False
def findLCPA(self, states):
'''
Gets the least common parallel ancestor of states.
Just like findLCA but only for parallel states.
'''
for anc in filter(isParallelState, getProperAncestors(states[0], None)):
if all(map(lambda(s): isDescendant(s,anc), states[1:])):
return anc
