fixed startup race conditions

arangod/Cluster/ClusterComm.cpp

@@ -47,8 +47,7 @@ using namespace triagens::arango;
 ////////////////////////////////////////////////////////////////////////////////
 
 void triagens::arango::ClusterCommRestCallback(string& coordinator, 
-                             triagens::rest::HttpResponse* response)
-{
+                             triagens::rest::HttpResponse* response) {
   ClusterComm::instance()->asyncAnswer(coordinator, response);
 }
 
@@ -80,22 +79,13 @@ ClusterComm::~ClusterComm () {
   cleanupAllQueues();
 }
 
-////////////////////////////////////////////////////////////////////////////////
-/// @brief the actual singleton instance
-////////////////////////////////////////////////////////////////////////////////
-
-ClusterComm* ClusterComm::_theinstance = 0;
-
 ////////////////////////////////////////////////////////////////////////////////
 /// @brief getter for our singleton instance
 ////////////////////////////////////////////////////////////////////////////////
 
 ClusterComm* ClusterComm::instance () {
-  // This does not have to be thread-safe, because we guarantee that
-  // this is called very early in the startup phase when there is still
-  // a single thread.
-  assert(_theinstance != 0);
-  return _theinstance;
+  static ClusterComm* Instance = new ClusterComm();
+  return Instance;
 }
 
 ////////////////////////////////////////////////////////////////////////////////
@@ -103,10 +93,19 @@ ClusterComm* ClusterComm::instance () {
 ////////////////////////////////////////////////////////////////////////////////
 
 void ClusterComm::initialise () {
-  assert(_theinstance == 0);
-  _theinstance = new ClusterComm();  // this now happens exactly once
- 
-  _theinstance->startBackgroundThread(); 
+  auto* i = instance();
+  i->startBackgroundThread(); 
+}
+
+////////////////////////////////////////////////////////////////////////////////
+/// @brief cleanup function to call once when shutting down
+////////////////////////////////////////////////////////////////////////////////
+        
+void ClusterComm::cleanup () {
+  auto i = instance();
+  assert(i != nullptr);
+
+  delete i;
 }
 
 ////////////////////////////////////////////////////////////////////////////////

arangod/Cluster/ClusterComm.h

@@ -254,10 +254,7 @@ void ClusterCommRestCallback(string& coordinator, rest::HttpResponse* response);
 /// @brief cleanup function to call once when shutting down
 ////////////////////////////////////////////////////////////////////////////////
         
-        static void cleanup () {
-          delete _theinstance;
-          _theinstance = 0;
-        }
+        static void cleanup ();
 
 ////////////////////////////////////////////////////////////////////////////////
 /// @brief whether or not connection errors should be logged as errors

arangod/Cluster/ClusterInfo.cpp

@@ -236,18 +236,13 @@ void CollectionInfoCurrent::copyAllJsons () {
 // --SECTION--                                                   private methods
 // -----------------------------------------------------------------------------
 
-ClusterInfo* ClusterInfo::_theinstance = 0;
-
 ////////////////////////////////////////////////////////////////////////////////
 /// @brief returns an instance of the cluster info class
 ////////////////////////////////////////////////////////////////////////////////
 
 ClusterInfo* ClusterInfo::instance () {
-  // This does not have to be thread-safe, because we guarantee that
-  // this is called very early in the startup phase when there is still
-  // a single thread.
-  assert(_theinstance != 0);
-  return _theinstance;
+  static ClusterInfo* Instance = new ClusterInfo();
+  return Instance;
 }
 
 ////////////////////////////////////////////////////////////////////////////////
@@ -255,8 +250,18 @@ ClusterInfo* ClusterInfo::instance () {
 ////////////////////////////////////////////////////////////////////////////////
 
 void ClusterInfo::initialise () {
-  assert(_theinstance == 0);
-  _theinstance = new ClusterInfo();  // this now happens exactly once
+  instance();
+}
+
+////////////////////////////////////////////////////////////////////////////////
+/// @brief cleanup function to call once when shutting down
+////////////////////////////////////////////////////////////////////////////////
+        
+void ClusterInfo::cleanup () {
+  auto i = instance();
+  assert(i != nullptr);
+
+  delete i;
 }
 
 ////////////////////////////////////////////////////////////////////////////////

arangod/Cluster/ClusterInfo.h

@@ -751,10 +751,7 @@ namespace triagens {
 /// @brief cleanup function to call once when shutting down
 ////////////////////////////////////////////////////////////////////////////////
         
-        static void cleanup () {
-          delete _theinstance;
-          _theinstance = 0;
-        }
+        static void cleanup ();
 
 // -----------------------------------------------------------------------------
 // --SECTION--                                                    public methods

arangod/Cluster/ServerState.cpp

@@ -65,19 +65,13 @@ ServerState::~ServerState () {
 // --SECTION--                                             public static methods
 // -----------------------------------------------------------------------------
 
-////////////////////////////////////////////////////////////////////////////////
-/// @brief the actual singleton instance
-////////////////////////////////////////////////////////////////////////////////
-
-ServerState* ServerState::_theinstance = 0;
-
 ////////////////////////////////////////////////////////////////////////////////
 /// @brief create the (sole) instance
 ////////////////////////////////////////////////////////////////////////////////
 
 ServerState* ServerState::instance () {
-  assert(_theinstance != 0);
-  return _theinstance;
+  static ServerState* Instance = new ServerState();
+  return Instance;
 }
 
 ////////////////////////////////////////////////////////////////////////////////
@@ -85,8 +79,18 @@ ServerState* ServerState::instance () {
 ////////////////////////////////////////////////////////////////////////////////
 
 void ServerState::initialise () {
-  assert(_theinstance == 0);
-  _theinstance = new ServerState();  // this now happens exactly once
+  instance();
+}
+
+////////////////////////////////////////////////////////////////////////////////
+/// @brief cleanup function to call once when shutting down
+////////////////////////////////////////////////////////////////////////////////
+        
+void ServerState::cleanup () {
+  auto i = instance();
+  assert(i != nullptr);
+
+  delete i;
 }
 
 ////////////////////////////////////////////////////////////////////////////////

arangod/Cluster/ServerState.h

@@ -117,10 +117,7 @@ namespace triagens {
 /// @brief cleanup function to call once when shutting down
 ////////////////////////////////////////////////////////////////////////////////
         
-        static void cleanup () {
-          delete _theinstance;
-          _theinstance = 0;
-        }
+        static void cleanup ();
 
 ////////////////////////////////////////////////////////////////////////////////
 /// @brief get the string representation of a role