a-reatim.ads   [plain text]

------------------------------------------------------------------------------
--                                                                          --
--                         GNAT RUN-TIME COMPONENTS                         --
--                                                                          --
--                         A D A . R E A L _ T I M E                        --
--                                                                          --
--                                  S p e c                                 --
--                                                                          --
--          Copyright (C) 1992-2002 Free Software Foundation, Inc.          --
--                                                                          --
-- This specification is derived from the Ada Reference Manual for use with --
-- GNAT. The copyright notice above, and the license provisions that follow --
-- apply solely to the  contents of the part following the private keyword. --
--                                                                          --
-- GNAT is free software;  you can  redistribute it  and/or modify it under --
-- terms of the  GNU General Public License as published  by the Free Soft- --
-- ware  Foundation;  either version 2,  or (at your option) any later ver- --
-- sion.  GNAT is distributed in the hope that it will be useful, but WITH- --
-- OUT ANY WARRANTY;  without even the  implied warranty of MERCHANTABILITY --
-- or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License --
-- for  more details.  You should have  received  a copy of the GNU General --
-- Public License  distributed with GNAT;  see file COPYING.  If not, write --
-- to  the Free Software Foundation,  59 Temple Place - Suite 330,  Boston, --
-- MA 02111-1307, USA.                                                      --
--                                                                          --
-- As a special exception,  if other files  instantiate  generics from this --
-- unit, or you link  this unit with other files  to produce an executable, --
-- this  unit  does not  by itself cause  the resulting  executable  to  be --
-- covered  by the  GNU  General  Public  License.  This exception does not --
-- however invalidate  any other reasons why  the executable file  might be --
-- covered by the  GNU Public License.                                      --
--                                                                          --
-- GNAT was originally developed  by the GNAT team at  New York University. --
-- Extensive contributions were provided by Ada Core Technologies Inc.      --
--                                                                          --
------------------------------------------------------------------------------

with System.Task_Primitives.Operations;
pragma Elaborate_All (System.Task_Primitives.Operations);

package Ada.Real_Time is

   type Time is private;
   Time_First : constant Time;
   Time_Last  : constant Time;
   Time_Unit  : constant := 10#1.0#E-9;

   type Time_Span is private;
   Time_Span_First : constant Time_Span;
   Time_Span_Last  : constant Time_Span;
   Time_Span_Zero  : constant Time_Span;
   Time_Span_Unit  : constant Time_Span;

   Tick : constant Time_Span;
   function Clock return Time;

   function "+"  (Left : Time;      Right : Time_Span) return Time;
   function "+"  (Left : Time_Span; Right : Time)      return Time;
   function "-"  (Left : Time;      Right : Time_Span) return Time;
   function "-"  (Left : Time;      Right : Time)      return Time_Span;

   function "<"  (Left, Right : Time) return Boolean;
   function "<=" (Left, Right : Time) return Boolean;
   function ">"  (Left, Right : Time) return Boolean;
   function ">=" (Left, Right : Time) return Boolean;

   function "+"  (Left, Right : Time_Span)             return Time_Span;
   function "-"  (Left, Right : Time_Span)             return Time_Span;
   function "-"  (Right : Time_Span)                   return Time_Span;
   function "*"  (Left : Time_Span; Right : Integer)   return Time_Span;
   function "*"  (Left : Integer;   Right : Time_Span) return Time_Span;
   function "/"  (Left, Right : Time_Span)             return Integer;
   function "/"  (Left : Time_Span; Right : Integer)   return Time_Span;

   function "abs" (Right : Time_Span) return Time_Span;

   function "<"  (Left, Right : Time_Span) return Boolean;
   function "<=" (Left, Right : Time_Span) return Boolean;
   function ">"  (Left, Right : Time_Span) return Boolean;
   function ">=" (Left, Right : Time_Span) return Boolean;

   function To_Duration  (TS : Time_Span) return Duration;
   function To_Time_Span (D : Duration)   return Time_Span;

   function Nanoseconds  (NS : Integer) return Time_Span;
   function Microseconds (US : Integer) return Time_Span;
   function Milliseconds (MS : Integer) return Time_Span;

   --  Seconds_Count needs 64 bits, since Time has the full range of
   --  Duration. The delta of Duration is 10 ** (-9), so the maximum
   --  number of seconds is 2**63/10**9 = 8*10**9 which does not quite
   --  fit in 32 bits.

   type Seconds_Count is range -2 ** 63 .. 2 ** 63 - 1;

   procedure Split (T : Time; SC : out Seconds_Count; TS : out Time_Span);
   function Time_Of (SC : Seconds_Count; TS : Time_Span) return Time;

private
   type Time is new Duration;

   Time_First : constant Time := Time'First;

   Time_Last  : constant Time := Time'Last;

   type Time_Span is new Duration;

   Time_Span_First : constant Time_Span := Time_Span'First;

   Time_Span_Last  : constant Time_Span := Time_Span'Last;

   Time_Span_Zero  : constant Time_Span := 0.0;

   Time_Span_Unit  : constant Time_Span := 10#1.0#E-9;

   Tick : constant Time_Span :=
            Time_Span (System.Task_Primitives.Operations.RT_Resolution);

   --  Time and Time_Span are represented in 64-bit Duration value in
   --  in nanoseconds. For example, 1 second and 1 nanosecond is
   --  represented as the stored integer 1_000_000_001.

   pragma Import (Intrinsic, "<");
   pragma Import (Intrinsic, "<=");
   pragma Import (Intrinsic, ">");
   pragma Import (Intrinsic, ">=");
   pragma Import (Intrinsic, "abs");

end Ada.Real_Time;