make fsm's thread safe

direct/src/fsm/FSM.py

@@ -10,6 +10,7 @@ previously called FSM.py (now called ClassicFSM.py).
 from direct.showbase.DirectObject import DirectObject
 from direct.directnotify import DirectNotifyGlobal
 from direct.showbase import PythonUtil
+from direct.stdpy.threading import RLock
 import types
 import string
 
@@ -142,6 +143,7 @@ class FSM(DirectObject):
     defaultTransitions = None
 
     def __init__(self, name):
+        self.lock = RLock()
         self.name = name
         self._serialNum = FSM.SerialNum
         FSM.SerialNum += 1
@@ -166,9 +168,13 @@ class FSM(DirectObject):
     def cleanup(self):
         # A convenience function to force the FSM to clean itself up
         # by transitioning to the "Off" state.
+        self.lock.acquire()
+        try:
             assert self.state
             if self.state != 'Off':
                 self.__setState('Off')
+        finally:
+            self.lock.release()
 
     def setBroadcastStateChanges(self, doBroadcast):
         self._broadcastStateChanges = doBroadcast
@@ -183,18 +189,28 @@ class FSM(DirectObject):
         # Returns the current state if we are in a state now, or the
         # state we are transitioning into if we are currently within
         # the enter or exit function for a state.
+        self.lock.acquire()
+        try:
             if self.state:
                 return self.state
             return self.newState
+        finally:
+            self.lock.release()
 
     def isInTransition(self):
+        self.lock.acquire()
+        try:
             return self.state == None
+        finally:
+            self.lock.release()
     
     def forceTransition(self, request, *args):
         """Changes unconditionally to the indicated state.  This
         bypasses the filterState() function, and just calls
         exitState() followed by enterState()."""
 
+        self.lock.acquire()
+        try:
             assert isinstance(request, types.StringTypes)
             self.notify.debug("%s.forceTransition(%s, %s" % (
                 self.name, request, str(args)[1:]))
@@ -206,6 +222,8 @@ class FSM(DirectObject):
                 return
 
             self.__setState(request, *args)
+        finally:
+            self.lock.release()
 
     def demand(self, request, *args):
         """Requests a state transition, by code that does not expect
@@ -219,6 +237,8 @@ class FSM(DirectObject):
         sequence.
         """
 
+        self.lock.acquire()
+        try:
             assert isinstance(request, types.StringTypes)
             self.notify.debug("%s.demand(%s, %s" % (
                 self.name, request, str(args)[1:]))
@@ -230,6 +250,8 @@ class FSM(DirectObject):
 
             if not self.request(request, *args):
                 raise RequestDenied, "%s (from state: %s)" % (request, self.state)
+        finally:
+            self.lock.release()
 
     def request(self, request, *args):
         """Requests a state transition (or other behavior).  The
@@ -254,6 +276,8 @@ class FSM(DirectObject):
         which will queue these requests up and apply when the
         transition is complete)."""
 
+        self.lock.acquire()
+        try:
             assert isinstance(request, types.StringTypes)
             self.notify.debug("%s.request(%s, %s" % (
                 self.name, request, str(args)[1:]))
@@ -278,6 +302,8 @@ class FSM(DirectObject):
                 self.__setState(*result)
 
             return result
+        finally:
+            self.lock.release()
 
     def defaultEnter(self, *args):
         """ This is the default function that is called if there is no
@@ -353,25 +379,37 @@ class FSM(DirectObject):
 
     def setStateArray(self, stateArray):
         """array of unique states to iterate through"""
+        self.lock.acquire()
+        try:
             self.stateArray = stateArray
+        finally:
+            self.lock.release()
 
     def requestNext(self, *args):
         """request the 'next' state in the predefined state array"""
+        self.lock.acquire()
+        try:
             assert self.state in self.stateArray
 
             curIndex = self.stateArray.index(self.state)
             newIndex = (curIndex + 1) % len(self.stateArray)
 
             self.request(self.stateArray[newIndex], args)
+        finally:
+            self.lock.release()
 
     def requestPrev(self, *args):
         """request the 'previous' state in the predefined state array"""
+        self.lock.acquire()
+        try:
             assert self.state in self.stateArray
 
             curIndex = self.stateArray.index(self.state)
             newIndex = (curIndex - 1) % len(self.stateArray)
 
             self.request(self.stateArray[newIndex], args)
+        finally:
+            self.lock.release()
         
 
     def __setState(self, newState, *args):
@@ -441,9 +479,13 @@ class FSM(DirectObject):
         """
         Print out something useful about the fsm
         """
+        self.lock.acquire()
+        try:
             className = self.__class__.__name__
             if self.state:
                 str = ('%s FSM:%s in state "%s"' % (className, self.name, self.state))
             else:
                 str = ('%s FSM:%s not in any state' % (className, self.name))
             return str
+        finally:
+            self.lock.release()