[Feature][ZXW-33]merge ZXW 0428 version
Change-Id: I11f167edfea428d9fab198ff00ff1364932d1b0b
diff --git a/ap/libc/glibc/glibc-2.23/sysdeps/nacl/lowlevellock.h b/ap/libc/glibc/glibc-2.23/sysdeps/nacl/lowlevellock.h
new file mode 100644
index 0000000..330c726
--- /dev/null
+++ b/ap/libc/glibc/glibc-2.23/sysdeps/nacl/lowlevellock.h
@@ -0,0 +1,41 @@
+/* Low-level lock implementation. NaCl version.
+ Copyright (C) 2015-2016 Free Software Foundation, Inc.
+ This file is part of the GNU C Library.
+
+ The GNU C Library is free software; you can redistribute it and/or
+ modify it under the terms of the GNU Lesser General Public
+ License as published by the Free Software Foundation; either
+ version 2.1 of the License, or (at your option) any later version.
+
+ The GNU C Library is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ Lesser General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public
+ License along with the GNU C Library. If not, see
+ <http://www.gnu.org/licenses/>. */
+
+#ifndef _LOWLEVELLOCK_H
+
+/* Everything except the exit handling is the same as the generic code. */
+# include <sysdeps/nptl/lowlevellock.h>
+
+/* See exit-thread.h for details. */
+# define NACL_EXITING_TID 1
+
+# undef lll_wait_tid
+# define lll_wait_tid(tid) \
+ do { \
+ __typeof (tid) __tid; \
+ volatile __typeof (tid) *__tidp = &(tid); \
+ while ((__tid = atomic_load_relaxed (__tidp)) != 0) \
+ { \
+ if (__tid == NACL_EXITING_TID) \
+ atomic_spin_nop (); \
+ else \
+ lll_futex_wait (__tidp, __tid, LLL_PRIVATE); \
+ } \
+ } while (0)
+
+#endif /* lowlevellock.h */