gcc/ada/libgnarl/a-sytaco.adb

   1 ------------------------------------------------------------------------------
   2 --                                                                          --
   3 --                         GNAT RUN-TIME COMPONENTS                         --
   4 --                                                                          --
   5 --         A D A . S Y N C H R O N O U S _ T A S K _ C O N T R O L          --
   6 --                                                                          --
   7 --                                 B o d y                                  --
   8 --                                                                          --
   9 --          Copyright (C) 1992-2018, Free Software Foundation, Inc.         --
  10 --                                                                          --
  11 -- GNAT 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 -- GNAT was originally developed  by the GNAT team at  New York 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.Synchronous_Task_Control with
  38   SPARK_Mode => Off
  39 is
  40
  41    ----------------
  42    -- Initialize --
  43    ----------------
  44
  45    procedure Initialize (S : in out Suspension_Object) is
  46    begin
  47       System.Task_Primitives.Operations.Initialize (S.SO);
  48    end Initialize;
  49
  50    --------------
  51    -- Finalize --
  52    --------------
  53
  54    procedure Finalize (S : in out Suspension_Object) is
  55    begin
  56       System.Task_Primitives.Operations.Finalize (S.SO);
  57    end Finalize;
  58
  59    -------------------
  60    -- Current_State --
  61    -------------------
  62
  63    function Current_State (S : Suspension_Object) return Boolean is
  64    begin
  65       return System.Task_Primitives.Operations.Current_State (S.SO);
  66    end Current_State;
  67
  68    ---------------
  69    -- Set_False --
  70    ---------------
  71
  72    procedure Set_False (S : in out Suspension_Object) is
  73    begin
  74       System.Task_Primitives.Operations.Set_False (S.SO);
  75    end Set_False;
  76
  77    --------------
  78    -- Set_True --
  79    --------------
  80
  81    procedure Set_True (S : in out Suspension_Object) is
  82    begin
  83       System.Task_Primitives.Operations.Set_True (S.SO);
  84    end Set_True;
  85
  86    ------------------------
  87    -- Suspend_Until_True --
  88    ------------------------
  89
  90    procedure Suspend_Until_True (S : in out Suspension_Object) is
  91    begin
  92       --  This is a potentially blocking (see ARM D.10, par. 10), so that
  93       --  if pragma Detect_Blocking is active then Program_Error must be
  94       --  raised if this operation is called from a protected action.
  95
  96       if System.Tasking.Detect_Blocking
  97         and then System.Tasking.Self.Common.Protected_Action_Nesting > 0
  98       then
  99          Ada.Exceptions.Raise_Exception
 100            (Program_Error'Identity, "potentially blocking operation");
 101       end if;
 102
 103       System.Task_Primitives.Operations.Suspend_Until_True (S.SO);
 104    end Suspend_Until_True;
 105
 106 end Ada.Synchronous_Task_Control;