--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/gcc/ada/libgnat/s-gloloc.ads	Fri Oct 27 22:46:09 2017 +0900
@@ -0,0 +1,63 @@
+------------------------------------------------------------------------------
+--                                                                          --
+--                         GNAT COMPILER COMPONENTS                         --
+--                                                                          --
+--                  S Y S T E M . G L O B A L _ L O C K S                   --
+--                                                                          --
+--                                 S p e c                                  --
+--                                                                          --
+--          Copyright (C) 1999-2017, Free Software Foundation, Inc.         --
+--                                                                          --
+-- GNAT is free software;  you can  redistribute it  and/or modify it under --
+-- terms of the  GNU General Public License as published  by the Free Soft- --
+-- ware  Foundation;  either version 3,  or (at your option) any later ver- --
+-- sion.  GNAT is distributed in the hope that it will be useful, but WITH- --
+-- OUT ANY WARRANTY;  without even the  implied warranty of MERCHANTABILITY --
+-- or FITNESS FOR A PARTICULAR PURPOSE.                                     --
+--                                                                          --
+-- As a special exception under Section 7 of GPL version 3, you are granted --
+-- additional permissions described in the GCC Runtime Library Exception,   --
+-- version 3.1, as published by the Free Software Foundation.               --
+--                                                                          --
+-- You should have received a copy of the GNU General Public License and    --
+-- a copy of the GCC Runtime Library Exception along with this program;     --
+-- see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see    --
+-- <http://www.gnu.org/licenses/>.                                          --
+--                                                                          --
+-- GNAT was originally developed  by the GNAT team at  New York University. --
+-- Extensive contributions were provided by Ada Core Technologies Inc.      --
+--                                                                          --
+------------------------------------------------------------------------------
+
+   --  This package contains the necessary routines to provide
+   --  reliable system wide locking capability.
+
+package System.Global_Locks is
+
+   Lock_Error : exception;
+   --  Exception raised if a request cannot be executed on a lock
+
+   type Lock_Type is private;
+   --  Such a lock is a global lock between partitions. This lock is
+   --  uniquely defined between the partitions because of its name.
+
+   Null_Lock : constant Lock_Type;
+   --  This needs comments ???
+
+   procedure Create_Lock (Lock : out Lock_Type; Name : String);
+   --  Create or retrieve a global lock for the current partition using
+   --  its Name.
+
+   procedure Acquire_Lock (Lock : in out Lock_Type);
+   --  If the lock cannot be acquired because someone already owns it, this
+   --  procedure is supposed to wait and retry forever.
+
+   procedure Release_Lock (Lock : in out Lock_Type);
+
+private
+
+   type Lock_Type is new Natural;
+
+   Null_Lock : constant Lock_Type := 0;
+
+end System.Global_Locks;