Index: abi/include/abi/synch.h
===================================================================
--- abi/include/abi/synch.h	(revision 8338a81e441a841d8987874fd886687c76a0c0b0)
+++ abi/include/abi/synch.h	(revision ab6edb66478acf791a711b3f91d2a5a370fb7a0c)
@@ -45,4 +45,6 @@
 /** Interruptible operation. */
 #define SYNCH_FLAGS_INTERRUPTIBLE  (1 << 1)
+/** Futex operation (makes sleep with timeout composable). */
+#define SYNCH_FLAGS_FUTEX          (1 << 2)
 
 #endif