Merge lp:~jan-ellenbeck/openwns-library/fixForBug661367 into lp:openwns-library

[Jan]

Provides a fix/workaround to Bug #661367 by adding a method to check whether the wns::simulator::Singleton is (still) valid. This is checked for in the PeriodicTimeout destructor to avoid situations where the simulator core is already gone when destroying the class derived from PeriodicTimeout (e.g. a Singleton that gets destroyed std::atexit). As this check is only performed in the destructor, there is no performance impact whatsoever.

[Maciej Muehleisen (mue-comnets)]

Thank you for the effort but I prefer a clean solution by getting rid of std::atexit and using the simulator end event to shutdown singletons. I'll try to take care of that before X-mas.

review: Disapprove

Unmerged revisions

242. By Jan on 2010-12-22

Fixes bug 661367 which occurs at shutdown when a Singleton is also derived from PeriodicTimeout

=== modified file 'src/events/PeriodicTimeout.cpp'
--- src/events/PeriodicTimeout.cpp	2008-10-14 23:51:59 +0000
+++ src/events/PeriodicTimeout.cpp	2010-12-22 00:48:10 +0000
@@ -74,8 +74,14 @@
 {
 	if(this->hasPeriodicTimeoutSet())
 	{
-		this->cancelPeriodicTimeout();
-	}
+        // check whether event scheduler still exists because if called
+        // from a Singleton, the event scheduler would already be destroyed at
+        // the time the Singletong gets destroyed and thus this destructor gets called
+        if (wns::simulator::getSingleton().hasValidInstance())
+        {
+            this->cancelPeriodicTimeout();
+        }
+    }
 }
 
 

=== modified file 'src/simulator/ISimulator.cpp'
--- src/simulator/ISimulator.cpp	2010-04-07 15:03:35 +0000
+++ src/simulator/ISimulator.cpp	2010-12-22 00:48:10 +0000
@@ -120,6 +120,12 @@
     return simulator_.get();
 }
 
+bool
+Singleton::hasValidInstance()
+{
+    return simulator_.get() != NULL;
+}
+
 void
 Singleton::setInstance(ISimulator* simulator)
 {

=== modified file 'src/simulator/ISimulator.hpp'
--- src/simulator/ISimulator.hpp	2010-04-07 15:03:35 +0000
+++ src/simulator/ISimulator.hpp	2010-12-22 00:48:10 +0000
@@ -216,6 +216,12 @@
         ~Singleton();
 
         /**
+         * @brief Check whether the global instance of ISimulator exists
+         */
+        bool
+        hasValidInstance();
+        
+        /**
          * @brief Retrieve the global instance of ISimulator
          * @pre An instance must be set
          */
@@ -223,7 +229,7 @@
         getInstance();
 
         /**
-         * @brief Retrieve set the global instance of ISimulator
+         * @brief Set the global instance of ISimulator
          * @pre No instance must be set
          */
         void