gcc/ada/a-retide.adb

   1 ------------------------------------------------------------------------------
   2 --                                                                          --
   3 --                  GNAT RUN-TIME LIBRARY (GNARL) COMPONENTS                --
   4 --                                                                          --
   5 --                   A D A . R E A L _ T I M E . D E L A Y S                --
   6 --                                                                          --
   7 --                                  B o d y                                 --
   8 --                                                                          --
   9 --         Copyright (C) 1992-2009, 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
  32 with Ada.Exceptions;
  33
  34 with System.Tasking;
  35 with System.Task_Primitives.Operations;
  36
  37 package body Ada.Real_Time.Delays is
  38
  39    package STPO renames System.Task_Primitives.Operations;
  40
  41    ----------------
  42    -- Local Data --
  43    ----------------
  44
  45    Absolute_RT : constant := 2;
  46
  47    -----------------
  48    -- Delay_Until --
  49    -----------------
  50
  51    procedure Delay_Until (T : Time) is
  52       Self_Id : constant System.Tasking.Task_Id := STPO.Self;
  53
  54    begin
  55       --  If pragma Detect_Blocking is active, Program_Error must be
  56       --  raised if this potentially blocking operation is called from a
  57       --  protected action.
  58
  59       if System.Tasking.Detect_Blocking
  60         and then Self_Id.Common.Protected_Action_Nesting > 0
  61       then
  62          Ada.Exceptions.Raise_Exception
  63            (Program_Error'Identity, "potentially blocking operation");
  64       else
  65          STPO.Timed_Delay (Self_Id, To_Duration (T), Absolute_RT);
  66       end if;
  67    end Delay_Until;
  68
  69    -----------------
  70    -- To_Duration --
  71    -----------------
  72
  73    function To_Duration (T : Time) return Duration is
  74    begin
  75       return To_Duration (Time_Span (T));
  76    end To_Duration;
  77
  78 begin
  79    --  Ensure that the tasking run time is initialized when using delay
  80    --  operations. The initialization routine has the required machinery to
  81    --  prevent multiple calls to Initialize.
  82
  83    System.Tasking.Initialize;
  84 end Ada.Real_Time.Delays;