Index: kernel/generic/include/proc/thread.h
===================================================================
--- kernel/generic/include/proc/thread.h	(revision a35b458e9db1ca95e679799dc7c1b12c83359ca3)
+++ kernel/generic/include/proc/thread.h	(revision 2fc9bfdff4f7f7961c56c7e4f3521ee05f4582e8)
@@ -112,4 +112,12 @@
 	/** If true, the thread can be interrupted from sleep. */
 	bool sleep_interruptible;
+
+	/**
+	 * If true, and this thread's sleep returns without a wakeup
+	 * (timed out or interrupted), waitq ignores the next wakeup.
+	 * This is necessary for futex to be able to handle those conditions.
+	 */
+	bool sleep_composable;
+
 	/** Wait queue in which this thread sleeps. */
 	waitq_t *sleep_queue;