Do not join lru and slab maintainer threads if they do not exist

If no_modern option was supplied then these threads did not run
but memcached still attempted to join them, which resulted in a
segfault.

resolve #685

1 files changed, 10 insertions, 6 deletions

diff --git a/thread.c b/thread.c
index f162d26..abbfca1 100644
--- a/thread.c
+++ b/thread.c
@@ -226,12 +226,16 @@ void stop_threads(void) {
     stop_item_crawler_thread(CRAWLER_WAIT);
     if (settings.verbose > 0)
         fprintf(stderr, "stopped lru crawler\n");
-    stop_lru_maintainer_thread();
-    if (settings.verbose > 0)
-        fprintf(stderr, "stopped maintainer\n");
-    stop_slab_maintenance_thread();
-    if (settings.verbose > 0)
-        fprintf(stderr, "stopped slab mover\n");
+    if (settings.lru_maintainer_thread) {
+        stop_lru_maintainer_thread();
+        if (settings.verbose > 0)
+            fprintf(stderr, "stopped maintainer\n");
+    }
+    if (settings.slab_reassign) {
+        stop_slab_maintenance_thread();
+        if (settings.verbose > 0)
+            fprintf(stderr, "stopped slab mover\n");
+    }
     logger_stop();
     if (settings.verbose > 0)
         fprintf(stderr, "stopped logger thread\n");