--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/gcc/ada/libgnarl/g-semaph.adb	Fri Oct 27 22:46:09 2017 +0900
@@ -0,0 +1,84 @@
+------------------------------------------------------------------------------
+--                                                                          --
+--                         GNAT LIBRARY COMPONENTS                          --
+--                                                                          --
+--                      G N A T . S E M A P H O R E S                       --
+--                                                                          --
+--                                 B o d y                                  --
+--                                                                          --
+--                     Copyright (C) 2003-2017, AdaCore                     --
+--                                                                          --
+-- 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. --
+-- It is now maintained by Ada Core Technologies Inc (http://www.gnat.com). --
+--                                                                          --
+------------------------------------------------------------------------------
+
+package body GNAT.Semaphores is
+
+   ------------------------
+   -- Counting_Semaphore --
+   ------------------------
+
+   protected body Counting_Semaphore is
+
+      -----------
+      -- Seize --
+      -----------
+
+      entry Seize when Count > 0 is
+      begin
+         Count := Count - 1;
+      end Seize;
+
+      -------------
+      -- Release --
+      -------------
+
+      procedure Release is
+      begin
+         Count := Count + 1;
+      end Release;
+   end Counting_Semaphore;
+
+   ----------------------
+   -- Binary_Semaphore --
+   ----------------------
+
+   protected body Binary_Semaphore is
+
+      -----------
+      -- Seize --
+      -----------
+
+      entry Seize when Available is
+      begin
+         Available := False;
+      end Seize;
+
+      -------------
+      -- Release --
+      -------------
+
+      procedure Release is
+      begin
+         Available := True;
+      end Release;
+   end Binary_Semaphore;
+
+end GNAT.Semaphores;