gcc/ada/a-caldel.adb

   1 ------------------------------------------------------------------------------
   2 --                                                                          --
   3 --                 GNAT RUN-TIME LIBRARY (GNARL) COMPONENTS                 --
   4 --                                                                          --
   5 --                   A D A . C A L E N D A R . D E L A Y S                  --
   6 --                                                                          --
   7 --                                  B o d y                                 --
   8 --                                                                          --
   9 --             Copyright (C) 1991-1994, Florida State University            --
  10 --                     Copyright (C) 1995-2010, AdaCore                     --
  11 --                                                                          --
  12 -- GNAT is free software;  you can  redistribute it  and/or modify it under --
  13 -- terms of the  GNU General Public License as published  by the Free Soft- --
  14 -- ware  Foundation;  either version 3,  or (at your option) any later ver- --
  15 -- sion.  GNAT is distributed in the hope that it will be useful, but WITH- --
  16 -- OUT ANY WARRANTY;  without even the  implied warranty of MERCHANTABILITY --
  17 -- or FITNESS FOR A PARTICULAR PURPOSE.                                     --
  18 --                                                                          --
  19 -- As a special exception under Section 7 of GPL version 3, you are granted --
  20 -- additional permissions described in the GCC Runtime Library Exception,   --
  21 -- version 3.1, as published by the Free Software Foundation.               --
  22 --                                                                          --
  23 -- You should have received a copy of the GNU General Public License and    --
  24 -- a copy of the GCC Runtime Library Exception along with this program;     --
  25 -- see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see    --
  26 -- <http://www.gnu.org/licenses/>.                                          --
  27 --                                                                          --
  28 -- GNARL was developed by the GNARL team at Florida State University.       --
  29 -- Extensive contributions were provided by Ada Core Technologies, Inc.     --
  30 --                                                                          --
  31 ------------------------------------------------------------------------------
  32
  33 with System.OS_Primitives;
  34 with System.Soft_Links;
  35 with System.Traces;
  36 with System.Parameters;
  37
  38 package body Ada.Calendar.Delays is
  39
  40    package OSP renames System.OS_Primitives;
  41    package SSL renames System.Soft_Links;
  42
  43    use type SSL.Timed_Delay_Call;
  44
  45    use System.Traces;
  46
  47    --  Earlier, System.Time_Operations was used to implement the following
  48    --  operations. The idea was to avoid sucking in the tasking packages. This
  49    --  did not work. Logically, we can't have it both ways. There is no way to
  50    --  implement time delays that will have correct task semantics without
  51    --  reference to the tasking run-time system. To achieve this goal, we now
  52    --  use soft links.
  53
  54    -----------------------
  55    -- Local Subprograms --
  56    -----------------------
  57
  58    procedure Timed_Delay_NT (Time : Duration; Mode : Integer);
  59    --  Timed delay procedure used when no tasking is active
  60
  61    ---------------
  62    -- Delay_For --
  63    ---------------
  64
  65    procedure Delay_For (D : Duration) is
  66    begin
  67       if System.Parameters.Runtime_Traces then
  68          Send_Trace_Info (W_Delay, D);
  69       end if;
  70
  71       SSL.Timed_Delay.all (Duration'Min (D, OSP.Max_Sensible_Delay),
  72                            OSP.Relative);
  73
  74       if System.Parameters.Runtime_Traces then
  75          Send_Trace_Info (M_Delay, D);
  76       end if;
  77    end Delay_For;
  78
  79    -----------------
  80    -- Delay_Until --
  81    -----------------
  82
  83    procedure Delay_Until (T : Time) is
  84       D : constant Duration := To_Duration (T);
  85
  86    begin
  87       if System.Parameters.Runtime_Traces then
  88          Send_Trace_Info (WU_Delay, D);
  89       end if;
  90
  91       SSL.Timed_Delay.all (D, OSP.Absolute_Calendar);
  92
  93       if System.Parameters.Runtime_Traces then
  94          Send_Trace_Info (M_Delay, D);
  95       end if;
  96    end Delay_Until;
  97
  98    --------------------
  99    -- Timed_Delay_NT --
 100    --------------------
 101
 102    procedure Timed_Delay_NT (Time : Duration; Mode : Integer) is
 103    begin
 104       OSP.Timed_Delay (Time, Mode);
 105    end Timed_Delay_NT;
 106
 107    -----------------
 108    -- To_Duration --
 109    -----------------
 110
 111    function To_Duration (T : Time) return Duration is
 112    begin
 113       --  Since time has multiple representations on different platforms, a
 114       --  target independent operation in Ada.Calendar is used to perform
 115       --  this conversion.
 116
 117       return Delay_Operations.To_Duration (T);
 118    end To_Duration;
 119
 120 begin
 121    --  Set up the Timed_Delay soft link to the non tasking version if it has
 122    --  not been already set. If tasking is present, Timed_Delay has already set
 123    --  this soft link, or this will be overridden during the elaboration of
 124    --  System.Tasking.Initialization
 125
 126    if SSL.Timed_Delay = null then
 127       SSL.Timed_Delay := Timed_Delay_NT'Access;
 128    end if;
 129
 130 end Ada.Calendar.Delays;