TxsConnectTask: Try avoid cylic references with the callback instance. Set the oParent member to None when deregistering it. Also, deregister the callback as soon as the task is done to speed up this process.

git-svn-id: https://www.virtualbox.org/svn/vbox/trunk@66960 cfe28804-0f27-0410-a406-dd0f0b0b656f

1 files changed, 16 insertions, 5 deletions

diff --git a/src/VBox/ValidationKit/testdriver/vboxwrappers.py b/src/VBox/ValidationKit/testdriver/vboxwrappers.py
index c6d3370c1d7..cc13e5fa4ee 100644
--- a/src/VBox/ValidationKit/testdriver/vboxwrappers.py
+++ b/src/VBox/ValidationKit/testdriver/vboxwrappers.py
@@ -2835,7 +2835,9 @@ class TxsConnectTask(TdTaskBase):
             reporter.log2('onGuestPropertyChange(,%s,%s,%s,%s)' % (sMachineId, sName, sValue, sFlags));
             if    sMachineId == self.sMachineId \
               and sName  == '/VirtualBox/GuestInfo/Net/0/V4/IP':
-                self.oParentTask._setIp(sValue);                                # pylint: disable=W0212
+                oParentTask = self.oParentTask;
+                if oParentTask:
+                    oParentTask._setIp(sValue);                                # pylint: disable=W0212
 
 
     def __init__(self, oSession, cMsTimeout, sIpAddr, sMacAddr, fReversedSetup):
@@ -2845,10 +2847,10 @@ class TxsConnectTask(TdTaskBase):
         self.sNextIpAddr        = None;
         self.sMacAddr           = sMacAddr;
         self.fReversedSetup     = fReversedSetup;
-        self.oVBox              = oSession.oVBox;
+        self.oVBox              = oSession.oVBox;       ## @todo who needs this?
         self.oVBoxEventHandler  = None;
         self.oTxsSession        = None;
-        self.fpApiVer           = oSession.fpApiVer;
+        self.fpApiVer           = oSession.fpApiVer;    ## @todo who needs this?
 
         # Skip things we don't implement.
         if sMacAddr is not None:
@@ -2903,9 +2905,11 @@ class TxsConnectTask(TdTaskBase):
     def _deregisterEventHandler(self):
         """Deregisters the event handler."""
         fRc = True;
-        if self.oVBoxEventHandler is not None:
-            fRc = self.oVBoxEventHandler.unregister();
+        oVBoxEventHandler = self.oVBoxEventHandler;
+        if oVBoxEventHandler is not None:
             self.oVBoxEventHandler = None;
+            fRc = oVBoxEventHandler.unregister();
+            oVBoxEventHandler.oParentTask = None; # Try avoid cylic deps.
         return fRc;
 
     def _setIp(self, sIpAddr, fInitCall = False):
@@ -2971,15 +2975,21 @@ class TxsConnectTask(TdTaskBase):
             fSuccess = False;
 
         # Signal done, or retry?
+        fDeregister = False;
         if   fSuccess \
           or self.fReversedSetup \
           or self.getAgeAsMs() >= self.cMsTimeout:
             self.signalTaskLocked();
+            fDeregister = True;
         else:
             sIpAddr = self.sNextIpAddr if self.sNextIpAddr is not None else self.sIpAddr;
             self._openTcpSession(sIpAddr, cMsIdleFudge = 5000);
 
         self.oCv.release();
+
+        # If we're done, deregister the callback (w/o owning lock).  It will
+        if fDeregister:
+            self._deregisterEventHandler();
         return True;
 
     #
@@ -3001,6 +3011,7 @@ class TxsConnectTask(TdTaskBase):
 
     def cancelTask(self):
         """ Cancels the task. """
+        self._deregisterEventHandler(); # (make sure to avoid cyclic fun)
         self.oCv.acquire();
         if not self.fSignalled:
             oTxsSession = self.oTxsSession;