Index: libcfa/src/concurrency/kernel/private.hfa
===================================================================
--- libcfa/src/concurrency/kernel/private.hfa	(revision b443db063ba041699280cd09c9cdb6cc92a7ed07)
+++ libcfa/src/concurrency/kernel/private.hfa	(revision 7a0f798baa13be83da9201532688ee8da5eb0702)
@@ -161,4 +161,7 @@
 // Blocking acquire
 static inline void __atomic_acquire(volatile bool * ll) {
+	/* paranoid */ verify( ! __preemption_enabled() );
+	/* paranoid */ verify(ll);
+
 	while( __builtin_expect(__atomic_exchange_n(ll, (bool)true, __ATOMIC_SEQ_CST), false) ) {
 		while(__atomic_load_n(ll, (int)__ATOMIC_RELAXED))
@@ -166,8 +169,12 @@
 	}
 	/* paranoid */ verify(*ll);
+	/* paranoid */ verify( ! __preemption_enabled() );
 }
 
 // Non-Blocking acquire
 static inline bool __atomic_try_acquire(volatile bool * ll) {
+	/* paranoid */ verify( ! __preemption_enabled() );
+	/* paranoid */ verify(ll);
+
 	return !__atomic_exchange_n(ll, (bool)true, __ATOMIC_SEQ_CST);
 }
@@ -175,4 +182,6 @@
 // Release
 static inline void __atomic_unlock(volatile bool * ll) {
+	/* paranoid */ verify( ! __preemption_enabled() );
+	/* paranoid */ verify(ll);
 	/* paranoid */ verify(*ll);
 	__atomic_store_n(ll, (bool)false, __ATOMIC_RELEASE);