1 ------------------------------------------------------------------------------
3 -- GNAT RUN-TIME COMPONENTS --
5 -- A D A . S Y N C H R O N O U S _ B A R R I E R S --
9 -- Copyright (C) 1992-2024, Free Software Foundation, Inc. --
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. --
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. --
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. --
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/>. --
31 -- GNAT was originally developed by the GNAT team at New York University. --
32 -- Extensive contributions were provided by Ada Core Technologies Inc. --
34 ------------------------------------------------------------------------------
36 package body Ada
.Synchronous_Barriers
with SPARK_Mode
=> Off
is
38 protected body Synchronous_Barrier
is
40 -- The condition "Wait'Count = Release_Threshold" opens the barrier when
41 -- the required number of tasks is reached. The condition "Keep_Open"
42 -- leaves the barrier open while there are queued tasks. While there are
43 -- tasks in the queue no new task will be queued (no new protected
44 -- action can be started on a protected object while another protected
45 -- action on the same protected object is underway, RM 9.5.1 (4)),
46 -- guaranteeing that the barrier will remain open only for those tasks
47 -- already inside the queue when the barrier was open.
49 entry Wait
(Notified
: out Boolean)
50 when Keep_Open
or else Wait
'Count = Release_Threshold
53 -- If we are executing the entry it means that the required number of
54 -- tasks have been queued in the entry. Keep_Open barrier will remain
55 -- true until all queued tasks are out.
57 Keep_Open
:= Wait
'Count > 0;
59 -- The last released task will close the barrier and get the Notified
62 Notified
:= Wait
'Count = 0;
64 end Synchronous_Barrier
;
66 ----------------------
67 -- Wait_For_Release --
68 ----------------------
70 procedure Wait_For_Release
71 (The_Barrier
: in out Synchronous_Barrier
;
72 Notified
: out Boolean)
75 The_Barrier
.Wait
(Notified
);
78 end Ada
.Synchronous_Barriers
;