1------------------------------------------------------------------------------
2--                                                                          --
3--                         GNAT RUN-TIME COMPONENTS                         --
4--                                                                          --
5--             A D A . S Y N C H R O N O U S _ B A R R I E R S              --
6--                                                                          --
7--                                  S p e c                                 --
8--                                                                          --
9--          Copyright (C) 1992-2011, Free Software Foundation, Inc.         --
10--                                                                          --
11-- This specification is derived from the Ada Reference Manual for use with --
12-- GNAT. The copyright notice above, and the license provisions that follow --
13-- apply solely to the  contents of the part following the private keyword. --
14--                                                                          --
15-- GNAT is free software;  you can  redistribute it  and/or modify it under --
16-- terms of the  GNU General Public License as published  by the Free Soft- --
17-- ware  Foundation;  either version 3,  or (at your option) any later ver- --
18-- sion.  GNAT is distributed in the hope that it will be useful, but WITH- --
19-- OUT ANY WARRANTY;  without even the  implied warranty of MERCHANTABILITY --
20-- or FITNESS FOR A PARTICULAR PURPOSE.                                     --
21--                                                                          --
22-- As a special exception under Section 7 of GPL version 3, you are granted --
23-- additional permissions described in the GCC Runtime Library Exception,   --
24-- version 3.1, as published by the Free Software Foundation.               --
25--                                                                          --
26-- You should have received a copy of the GNU General Public License and    --
27-- a copy of the GCC Runtime Library Exception along with this program;     --
28-- see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see    --
29-- <http://www.gnu.org/licenses/>.                                          --
30--                                                                          --
31-- GNAT was originally developed  by the GNAT team at  New York University. --
32-- Extensive contributions were provided by Ada Core Technologies Inc.      --
33--                                                                          --
34------------------------------------------------------------------------------
35
36--  This is the spec of this package using POSIX barriers
37
38with System;
39private with Ada.Finalization;
40private with Interfaces.C;
41
42package Ada.Synchronous_Barriers is
43   pragma Preelaborate (Synchronous_Barriers);
44
45   subtype Barrier_Limit is Positive range 1 .. Positive'Last;
46
47   type Synchronous_Barrier (Release_Threshold : Barrier_Limit) is
48      limited private;
49
50   procedure Wait_For_Release
51     (The_Barrier : in out Synchronous_Barrier;
52      Notified    : out Boolean);
53
54private
55   --  POSIX barrier data type
56
57   SIZEOF_PTHREAD_BARRIER_T : constant :=
58     (if System.Word_Size = 64 then 32 else 20);
59   --  Value defined according to the linux definition in pthreadtypes.h. On
60   --  other system, e.g. MIPS IRIX, the object is smaller, so it works
61   --  correctly although we are wasting some space.
62
63   type pthread_barrier_t_view is (size_based, align_based);
64
65   type pthread_barrier_t (Kind : pthread_barrier_t_view := size_based) is
66      record
67         case Kind is
68            when size_based =>
69               size : Interfaces.C.char_array (1 .. SIZEOF_PTHREAD_BARRIER_T);
70            when align_based =>
71               align : Interfaces.C.long;
72         end case;
73      end record;
74   pragma Unchecked_Union (pthread_barrier_t);
75
76   type Synchronous_Barrier (Release_Threshold : Barrier_Limit) is
77     new Ada.Finalization.Limited_Controlled with
78        record
79           POSIX_Barrier : aliased pthread_barrier_t;
80        end record;
81
82   overriding procedure Initialize (Barrier : in out Synchronous_Barrier);
83   overriding procedure Finalize   (Barrier : in out Synchronous_Barrier);
84end Ada.Synchronous_Barriers;
85