ndb - bug#19930

  Add mutex surronding sessions, as ndb_mgmd now actively tries to go and  "purge stale sessions"

ndb/include/util/SocketServer.hpp

@@ -105,6 +105,7 @@ public:
   void stopSessions(bool wait = false);
   
   void foreachSession(void (*f)(Session*, void*), void *data);
+  void checkSessions();
   
 private:
   struct SessionInstance {
@@ -116,12 +117,13 @@ private:
     Service * m_service;
     NDB_SOCKET_TYPE m_socket;
   };
-  MutexVector<SessionInstance> m_sessions;
+  NdbLockable m_session_mutex;
+  Vector<SessionInstance> m_sessions;
   MutexVector<ServiceInstance> m_services;
   unsigned m_maxSessions;
   
   void doAccept();
-  void checkSessions();
+  void checkSessionsImpl();
   void startSession(SessionInstance &);
   
   /**

ndb/src/common/util/SocketServer.cpp

@@ -184,9 +184,12 @@ SocketServer::doAccept(){
 	SessionInstance s;
 	s.m_service = si.m_service;
 	s.m_session = si.m_service->newSession(childSock);
-	if(s.m_session != 0){
+	if(s.m_session != 0)
+	{
+	  m_session_mutex.lock();
 	  m_sessions.push_back(s);
 	  startSession(m_sessions.back());
+	  m_session_mutex.unlock();
 	}
 	
 	continue;
@@ -240,10 +243,13 @@ void
 SocketServer::doRun(){
 
   while(!m_stopThread){
-    checkSessions();
+    m_session_mutex.lock();
+    checkSessionsImpl();
     if(m_sessions.size() < m_maxSessions){
+      m_session_mutex.unlock();
       doAccept();
     } else {
+      m_session_mutex.unlock();
       NdbSleep_MilliSleep(200);
     }
   }
@@ -276,17 +282,30 @@ transfer(NDB_SOCKET_TYPE sock){
 void
 SocketServer::foreachSession(void (*func)(SocketServer::Session*, void *), void *data)
 {
+  m_session_mutex.lock();
   for(int i = m_sessions.size() - 1; i >= 0; i--){
     (*func)(m_sessions[i].m_session, data);
   }
-  checkSessions();
+  m_session_mutex.unlock();
 }
 
 void
-SocketServer::checkSessions(){
-  for(int i = m_sessions.size() - 1; i >= 0; i--){
-    if(m_sessions[i].m_session->m_stopped){
-      if(m_sessions[i].m_thread != 0){
+SocketServer::checkSessions()
+{
+  m_session_mutex.lock();
+  checkSessionsImpl();
+  m_session_mutex.unlock();  
+}
+
+void
+SocketServer::checkSessionsImpl()
+{
+  for(int i = m_sessions.size() - 1; i >= 0; i--)
+  {
+    if(m_sessions[i].m_session->m_stopped)
+    {
+      if(m_sessions[i].m_thread != 0)
+      {
 	void* ret;
 	NdbThread_WaitFor(m_sessions[i].m_thread, &ret);
 	NdbThread_Destroy(&m_sessions[i].m_thread);
@@ -301,19 +320,26 @@ SocketServer::checkSessions(){
 void
 SocketServer::stopSessions(bool wait){
   int i;
+  m_session_mutex.lock();
   for(i = m_sessions.size() - 1; i>=0; i--)
   {
     m_sessions[i].m_session->stopSession();
     m_sessions[i].m_session->m_stop = true; // to make sure
   }
+  m_session_mutex.unlock();
+  
   for(i = m_services.size() - 1; i>=0; i--)
     m_services[i].m_service->stopSessions();
   
   if(wait){
+    m_session_mutex.lock();
     while(m_sessions.size() > 0){
-      checkSessions();
+      checkSessionsImpl();
+      m_session_mutex.unlock();
       NdbSleep_MilliSleep(100);
+      m_session_mutex.lock();
     }
+    m_session_mutex.unlock();
   }
 }
 
@@ -348,4 +374,4 @@ sessionThread_C(void* _sc){
 }
 
 template class MutexVector<SocketServer::ServiceInstance>;
-template class MutexVector<SocketServer::SessionInstance>;
+template class Vector<SocketServer::SessionInstance>;

ndb/src/mgmsrv/Services.cpp

@@ -501,6 +501,7 @@ MgmApiSession::get_nodeid(Parser_t::Context &,
         ps.tick= tick;
         m_mgmsrv.get_socket_server()->
           foreachSession(stop_session_if_timed_out,&ps);
+	m_mgmsrv.get_socket_server()->checkSessions();
         error_string = "";
         continue;
       }
@@ -1558,6 +1559,7 @@ MgmApiSession::purge_stale_sessions(Parser_t::Context &ctx,
   ps.free_nodes.bitXORC(NodeBitmask()); // invert connected_nodes to get free nodes
 
   m_mgmsrv.get_socket_server()->foreachSession(stop_session_if_not_connected,&ps);
+  m_mgmsrv.get_socket_server()->checkSessions();
 
   m_output->println("purge stale sessions reply");
   if (str.length() > 0)