+#ifdef USE_PTHREADS
+#if USE_REENTRANT
+#include <pthread.h>
+#define _nc_lock_global(name) pthread_mutex_lock(&_nc_globals.mutex_##name)
+#define _nc_unlock_global(name) pthread_mutex_unlock(&_nc_globals.mutex_##name)
+#else
+#error POSIX threads requires --enable-reentrant option
+#endif
+#else
+#define _nc_lock_global(name) /* nothing */
+#define _nc_unlock_global(name) /* nothing */
+#endif
+
+#define _nc_lock_screen(name) /* nothing */
+#define _nc_unlock_screen(name) /* nothing */
+
+#define _nc_lock_window(name) /* nothing */
+#define _nc_unlock_window(name) /* nothing */
+