shutdown threads earlier

naemon unloads modules at the end of the shutdown process, so we
need to shutdown threads earlier already when receiving the end of
eventloop event. After that event, we must not access objects anymore.

src/module.c

@@ -100,6 +100,7 @@ time_t g_last_log_rotation = -1;
 int g_eventloopstarted = false;
 
 void *client_thread(void *data __attribute__ ((__unused__)));
+void deregister_callbacks();
 
 static void reap_client_threads()
 {
@@ -371,8 +372,10 @@ void close_socket()
 {
     if (!g_use_inet_socket)
         unlink(g_socket_addr);
-    iobroker_close(nagios_iobs, g_socket_fd);
-    g_socket_fd = -1;
+    if (g_socket_fd != -1) {
+        iobroker_close(nagios_iobs, g_socket_fd);
+        g_socket_fd = -1;
+    }
 }
 
 int broker_host(int event_type __attribute__ ((__unused__)), void *data __attribute__ ((__unused__)))
@@ -483,9 +486,33 @@ static void schedule_timeperiods_cache_update(struct nm_event_execution_properti
     return;
 }
 
+void shutdown_threads() {
+    size_t i;
+
+    g_should_terminate = true;
+    close_socket();
+
+    /*
+    * Make sure all client connections are terminated before
+    * returning control. Since we touch global naemon state everywhere,
+    * this is strictly mandatory.
+    */
+    if(g_client_threads != NULL) {
+        for (i = 0; i < g_num_client_threads; ++i) {
+            if (pthread_join(*(g_client_threads[i]), NULL) != 0) {
+                logger(LG_ERR, "Failed to join with client thread");
+            }
+            free(g_client_threads[i]);
+        }
+        free(g_client_threads);
+        g_client_threads = NULL;
+    }
+}
+
 int broker_process(int event_type __attribute__ ((__unused__)), void *data)
 {
     int ret;
+
     struct nebstruct_process_struct *ps = (struct nebstruct_process_struct *)data;
     if (ps->type == NEBTYPE_PROCESS_EVENTLOOPSTART) {
         g_eventloopstarted = true;
@@ -498,6 +525,12 @@ int broker_process(int event_type __attribute__ ((__unused__)), void *data)
             return ERROR;
         }
     }
+    if (ps->type == NEBTYPE_PROCESS_EVENTLOOPEND) {
+        logger(LG_INFO, "deinitializing");
+        g_eventloopstarted = false;
+        deregister_callbacks();
+        shutdown_threads();
+    }
     return OK;
 }
 
@@ -810,26 +843,8 @@ int nebmodule_init(int flags __attribute__ ((__unused__)), char *args, void *han
 
 int nebmodule_deinit(int flags __attribute__ ((__unused__)), int reason __attribute__ ((__unused__)))
 {
-    size_t i;
-    logger(LG_INFO, "deinitializing");
-    g_should_terminate = true;
-    close_socket();
-
-    /*
-     * Make sure all client connections are terminated before
-     * returning control. Since we touch global naemon state everywhere,
-     * this is strictly mandatory.
-     */
-    for (i = 0; i < g_num_client_threads; ++i) {
-        if (pthread_join(*(g_client_threads[i]), NULL) != 0) {
-            logger(LG_ERR, "Failed to join with client thread");
-        }
-        free(g_client_threads[i]);
-    }
-    free(g_client_threads);
-
+    shutdown_threads();
     store_deinit();
-    deregister_callbacks();
     close_logfile();
     return 0;
 }