Index: libcfa/src/concurrency/io/setup.cfa
===================================================================
--- libcfa/src/concurrency/io/setup.cfa	(revision 2fafe7eaade023aeffc0c15a4090d21980e65706)
+++ libcfa/src/concurrency/io/setup.cfa	(revision 1095ccd2a6aeedf7408f05427dd8313a9fca5e0e)
@@ -388,8 +388,10 @@
 				sq.ready[i] = -1ul32;
 			}
+			sq.prev_ready = 0;
 		}
 		else {
 			sq.ready_cnt = 0;
 			sq.ready = 0p;
+			sq.prev_ready = 0;
 		}
 
Index: libcfa/src/concurrency/io/types.hfa
===================================================================
--- libcfa/src/concurrency/io/types.hfa	(revision 2fafe7eaade023aeffc0c15a4090d21980e65706)
+++ libcfa/src/concurrency/io/types.hfa	(revision 1095ccd2a6aeedf7408f05427dd8313a9fca5e0e)
@@ -23,5 +23,5 @@
       #include "bits/locks.hfa"
 
-	#define LEADER_LOCK
+	// #define LEADER_LOCK
 	struct __leaderlock_t {
 		struct $thread * volatile value;	// ($thread) next_leader | (bool:1) is_locked
@@ -55,4 +55,5 @@
 		volatile __u32 * ready;
 		__u32 ready_cnt;
+		__u32 prev_ready;
 
 		#if defined(LEADER_LOCK)