File : a-synbar-posix.ads
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 -- --
23 -- --
24 -- --
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
38 with System;
39 private with Ada.Finalization;
40 private with Interfaces.C;
41
42 package 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
54 private
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);
84 end Ada.Synchronous_Barriers;