File : s-tadeca.adb
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) 1998-2015, 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 -- --
19 -- --
20 -- --
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
32 with Ada.Calendar.Delays;
33
34 with System.OS_Constants;
35 with System.OS_Primitives;
36 with System.Task_Primitives.Operations;
37 with System.Tasking.Initialization;
38
39 function System.Tasking.Async_Delays.Enqueue_Calendar
40 (T : Ada.Calendar.Time;
41 D : Delay_Block_Access) return Boolean
42 is
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
50 begin
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;
76 end System.Tasking.Async_Delays.Enqueue_Calendar;