1------------------------------------------------------------------------------
2--                                                                          --
3--                 GNAT RUN-TIME LIBRARY (GNARL) COMPONENTS                 --
4--                                                                          --
5--               SYSTEM.TASKING.ASYNC_DELAYS.ENQUEUE_CALENDAR               --
6--                                                                          --
7--                                  B o d y                                 --
8--                                                                          --
9--          Copyright (C) 1998-2019, Free Software Foundation, Inc.         --
10--                                                                          --
11-- GNARL is free software; you can  redistribute it  and/or modify it under --
12-- terms of the  GNU General Public License as published  by the Free Soft- --
13-- ware  Foundation;  either version 3,  or (at your option) any later ver- --
14-- sion.  GNAT is distributed in the hope that it will be useful, but WITH- --
15-- OUT ANY WARRANTY;  without even the  implied warranty of MERCHANTABILITY --
16-- or FITNESS FOR A PARTICULAR PURPOSE.                                     --
17--                                                                          --
18-- As a special exception under Section 7 of GPL version 3, you are granted --
19-- additional permissions described in the GCC Runtime Library Exception,   --
20-- version 3.1, as published by the Free Software Foundation.               --
21--                                                                          --
22-- You should have received a copy of the GNU General Public License and    --
23-- a copy of the GCC Runtime Library Exception along with this program;     --
24-- see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see    --
25-- <http://www.gnu.org/licenses/>.                                          --
26--                                                                          --
27-- GNARL was developed by the GNARL team at Florida State University.       --
28-- Extensive contributions were provided by Ada Core Technologies, Inc.     --
29--                                                                          --
30------------------------------------------------------------------------------
31
32with Ada.Calendar.Delays;
33
34with System.OS_Constants;
35with System.OS_Primitives;
36with System.Task_Primitives.Operations;
37with System.Tasking.Initialization;
38
39function System.Tasking.Async_Delays.Enqueue_Calendar
40  (T : Ada.Calendar.Time;
41   D : Delay_Block_Access) return Boolean
42is
43   use type Ada.Calendar.Time;
44
45   package SOSC renames System.OS_Constants;
46   package STPO renames System.Task_Primitives.Operations;
47
48   RT_T : Duration := Ada.Calendar.Delays.To_Duration (T);
49
50begin
51   if T <= Ada.Calendar.Clock then
52      D.Timed_Out := True;
53      System.Task_Primitives.Operations.Yield;
54      return False;
55   end if;
56
57   --  T is expressed as a duration elapsed since the UNIX epoch, whereas
58   --  Time_Enqueue expects duration elapsed since the epoch of the Ada real-
59   --  time clock: compensate if necessary.
60
61   --  Comparison "SOSC.CLOCK_RT_Ada = SOSC.CLOCK_REALTIME" is compile
62   --  time known, so turn warnings off.
63
64   pragma Warnings (Off);
65
66   if SOSC.CLOCK_RT_Ada /= SOSC.CLOCK_REALTIME then
67      pragma Warnings (On);
68
69      RT_T := RT_T - OS_Primitives.Clock + STPO.Monotonic_Clock;
70   end if;
71
72   System.Tasking.Initialization.Defer_Abort
73     (System.Task_Primitives.Operations.Self);
74   Time_Enqueue (RT_T, D);
75   return True;
76end System.Tasking.Async_Delays.Enqueue_Calendar;
77