diff --git a/src/backend/threadpool.c b/src/backend/threadpool.c
index ea88b4503..9de1e6d81 100644
--- a/src/backend/threadpool.c
+++ b/src/backend/threadpool.c
@@ -39,6 +39,7 @@ static lumiera_threadpool threadpool;
  */
 NOBUG_DEFINE_FLAG_PARENT (threadpool, threads_dbg); /*TODO insert a suitable/better parent flag here */
 
+LUMIERA_ERROR_DEFINE(THREADPOOL_OFFLINE, "tried to acquire thread while threadpool is not available");
 
 //code goes here//
 
@@ -56,6 +57,7 @@ lumiera_threadpool_init(void)
       llist_init (&threadpool.pool[i].idle_list);
       threadpool.pool[i].thread_count = 0;
       threadpool.pool[i].idle_thread_count = 0;
+      threadpool.pool[i].status = LUMIERA_THREADPOOL_ONLINE;
 
       //TODO: configure each pools' pthread_attrs appropriately
       pthread_attr_init (&threadpool.pool[i].pthread_attrs);
@@ -70,9 +72,27 @@ lumiera_threadpool_destroy(void)
 {
   TRACE (threadpool);
 
+  /* set all threadpools offline must be done first, since running threads may attempt to start new ones */
+  for (int i = 0; i < LUMIERA_THREADCLASS_COUNT; ++i)
+    LUMIERA_CONDITION_SECTION (threadpool, &threadpool.pool[i].sync)
+      threadpool.pool[i].status = LUMIERA_THREADPOOL_OFFLINE;
+
+  /* wait that all theads have finished */
+  for (int i = 0; i < LUMIERA_THREADCLASS_COUNT; ++i)
+    {
+      LUMIERA_CONDITION_SECTION (threadpool, &threadpool.pool[i].sync)
+        {
+          TODO ("check threads deadlines, kill them when they are stalled");
+          TODO ("for threads without deadline use a timeout from config system, 500ms or so by default");
+          LUMIERA_CONDITION_WAIT(llist_is_empty (&threadpool.pool[i].working_list));
+        }
+    }
+
+  /* now we can delete all threads */
   for (int i = 0; i < LUMIERA_THREADCLASS_COUNT; ++i)
     {
       TRACE (threadpool, "destroying individual pool #%d", i);
+
       LUMIERA_CONDITION_SECTION (threadpool, &threadpool.pool[i].sync)
         {
           REQUIRE (threadpool.pool[i].thread_count
@@ -100,11 +120,14 @@ lumiera_threadpool_destroy(void)
     }
 }
 
-
+/**
+ *
+ * @return thread handle or NULL on error (lumiera error will be set)
+ */
 LumieraThread
-lumiera_threadpool_acquire_thread(enum lumiera_thread_class kind,
-                                  const char* purpose,
-                                  struct nobug_flag* flag)
+lumiera_threadpool_acquire_thread (enum lumiera_thread_class kind,
+                                   const char* purpose,
+                                   struct nobug_flag* flag)
 {
   TRACE (threadpool);
   LumieraThread ret = NULL;
@@ -113,34 +136,39 @@ lumiera_threadpool_acquire_thread(enum lumiera_thread_class kind,
 
   LUMIERA_CONDITION_SECTION (threadpool, &threadpool.pool[kind].sync)
     {
-      if (llist_is_empty (&threadpool.pool[kind].idle_list))
+      if (threadpool.pool[kind].status != LUMIERA_THREADPOOL_ONLINE)
+        LUMIERA_ERROR_SET_WARNING (threadpool, THREADPOOL_OFFLINE, purpose);
+      else
         {
-          ret = lumiera_thread_new (kind, purpose, flag,
-                                    &threadpool.pool[kind].pthread_attrs);
-          ENSURE (ret, "did not create a valid thread");
-          TODO ("no error handing, let the resourcecollector do it, no need when returning the thread");
-          threadpool.pool[kind].thread_count++;
-          LUMIERA_CONDITION_WAIT (!llist_is_empty (&threadpool.pool[kind].idle_list));
+          if (llist_is_empty (&threadpool.pool[kind].idle_list))
+            {
+              ret = lumiera_thread_new (kind, purpose, flag,
+                                        &threadpool.pool[kind].pthread_attrs);
+              ENSURE (ret, "did not create a valid thread");
+              TODO ("no error handing, let the resourcecollector do it, no need when returning the thread");
+              threadpool.pool[kind].thread_count++;
+              LUMIERA_CONDITION_WAIT (!llist_is_empty (&threadpool.pool[kind].idle_list));
+            }
+          // use an existing thread, pick the first one
+          // remove it from the pool's list
+          ret = (LumieraThread) (llist_head (&threadpool.pool[kind].idle_list));
+
+          ENSURE (ret, "did not find a valid thread");
+
+          REQUIRE (ret->state == LUMIERA_THREADSTATE_IDLE, "trying to return a non-idle thread (state=%s)", lumiera_threadstate_names[ret->state]);
+
+          // move thread to the working_list
+          llist_insert_head (&threadpool.pool[kind].working_list, &ret->node);
+
+          threadpool.pool[kind].idle_thread_count--; // cheaper than using llist_count
+          REQUIRE ((int)(llist_count (&threadpool.pool[kind].working_list)
+                         + llist_count (&threadpool.pool[kind].idle_list))
+                   == threadpool.pool[kind].thread_count,
+                   "threadpool counter miscalculation (working_list count = %u, idle_list count = %u, thread_count = %d )",
+                   llist_count (&threadpool.pool[kind].working_list),
+                   llist_count (&threadpool.pool[kind].idle_list),
+                   threadpool.pool[kind].thread_count);
         }
-      // use an existing thread, pick the first one
-      // remove it from the pool's list
-      ret = (LumieraThread) (llist_head (&threadpool.pool[kind].idle_list));
-
-      ENSURE (ret, "did not find a valid thread");
-
-      REQUIRE (ret->state == LUMIERA_THREADSTATE_IDLE, "trying to return a non-idle thread (state=%s)", lumiera_threadstate_names[ret->state]);
-
-      // move thread to the working_list
-      llist_insert_head (&threadpool.pool[kind].working_list, &ret->node);
-
-      threadpool.pool[kind].idle_thread_count--; // cheaper than using llist_count
-      REQUIRE ((int)(llist_count (&threadpool.pool[kind].working_list)
-                     + llist_count (&threadpool.pool[kind].idle_list))
-               == threadpool.pool[kind].thread_count,
-               "threadpool counter miscalculation (working_list count = %u, idle_list count = %u, thread_count = %d )",
-               llist_count (&threadpool.pool[kind].working_list),
-               llist_count (&threadpool.pool[kind].idle_list),
-               threadpool.pool[kind].thread_count);
     }
   return ret;
 }
diff --git a/src/backend/threadpool.h b/src/backend/threadpool.h
index 47d90e6fc..5a3455d39 100644
--- a/src/backend/threadpool.h
+++ b/src/backend/threadpool.h
@@ -64,6 +64,11 @@ lumiera_threadpool_release_thread(LumieraThread thread);
 typedef struct lumiera_threadpool_struct lumiera_threadpool;
 typedef lumiera_threadpool* LumieraThreadpool;
 
+enum lumiera_threadpool_state {
+  LUMIERA_THREADPOOL_OFFLINE,
+  LUMIERA_THREADPOOL_ONLINE
+};
+
 struct lumiera_threadpool_struct
 {
   struct
@@ -74,6 +79,7 @@ struct lumiera_threadpool_struct
     int idle_thread_count;
     pthread_attr_t pthread_attrs;
     lumiera_condition sync;
+    enum lumiera_threadpool_state status;
   } pool[LUMIERA_THREADCLASS_COUNT];
 };
 
diff --git a/tests/backend/test-threadpool.c b/tests/backend/test-threadpool.c
index 2acb8b861..952bfac2b 100644
--- a/tests/backend/test-threadpool.c
+++ b/tests/backend/test-threadpool.c
@@ -172,8 +172,6 @@ TEST ("no-function")
 			  &NOBUG_FLAG(NOBUG_ON));
 
   // cleanup
-  ECHO("wait 1 sec");
-  usleep(1000000);
   ECHO("finished waiting");
   lumiera_threadpool_destroy();
 }
@@ -195,8 +193,6 @@ TEST ("process-function")
 			  &NOBUG_FLAG(NOBUG_ON)); // struct nobug_flag* flag)
 
   // cleanup
-  ECHO("wait 1 sec");
-  usleep(1000000);
   ECHO("finished waiting");
   lumiera_threadpool_destroy();
 }