Index: cfox/lib/FXReadWriteLock.cpp
--- cfox/lib/FXReadWriteLock.cpp.orig
+++ cfox/lib/FXReadWriteLock.cpp
@@ -70,7 +70,9 @@ FXReadWriteLock::FXReadWriteLock(){
   FXASSERT_STATIC(sizeof(data)>=sizeof(pthread_rwlock_t));
   pthread_rwlockattr_t rwlockatt;
   pthread_rwlockattr_init(&rwlockatt);
+#if defined(__GLIBC__)
   pthread_rwlockattr_setkind_np(&rwlockatt,PTHREAD_RWLOCK_PREFER_WRITER_NP);
+#endif
   pthread_rwlock_init((pthread_rwlock_t*)data,&rwlockatt);
   pthread_rwlockattr_destroy(&rwlockatt);
 #else
