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------------------------------------------------------------------------------
-- --
-- GNU ADA RUN-TIME LIBRARY (GNARL) COMPONENTS --
-- --
-- A D A . C A L E N D A R . D E L A Y S --
-- --
-- B o d y --
-- --
-- $Revision: 1.37 $
-- --
-- Copyright (C) 1991-2001 Florida State University --
-- --
-- GNARL 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. GNARL 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 GNARL; 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. --
-- --
-- GNARL was developed by the GNARL team at Florida State University. It is --
-- now maintained by Ada Core Technologies Inc. in cooperation with Florida --
-- State University (http://www.gnat.com). --
-- --
------------------------------------------------------------------------------
with System.OS_Primitives;
-- Used for Delay_Modes
-- Max_Sensible_Delay
with System.Soft_Links;
-- Used for Timed_Delay
package body Ada.Calendar.Delays is
package OSP renames System.OS_Primitives;
package SSL renames System.Soft_Links;
use type SSL.Timed_Delay_Call;
-- Earlier, the following operations were implemented using
-- System.Time_Operations. The idea was to avoid sucking in the tasking
-- packages. This did not work. Logically, we can't have it both ways.
-- There is no way to implement time delays that will have correct task
-- semantics without reference to the tasking run-time system.
-- To achieve this goal, we now use soft links.
-----------------------
-- Local Subprograms --
-----------------------
procedure Timed_Delay_NT (Time : Duration; Mode : Integer);
-- Timed delay procedure used when no tasking is active
---------------
-- Delay_For --
---------------
procedure Delay_For (D : Duration) is
begin
SSL.Timed_Delay.all (Duration'Min (D, OSP.Max_Sensible_Delay),
OSP.Relative);
end Delay_For;
-----------------
-- Delay_Until --
-----------------
procedure Delay_Until (T : Time) is
begin
SSL.Timed_Delay.all (To_Duration (T), OSP.Absolute_Calendar);
end Delay_Until;
--------------------
-- Timed_Delay_NT --
--------------------
procedure Timed_Delay_NT (Time : Duration; Mode : Integer) is
begin
OSP.Timed_Delay (Time, Mode);
end Timed_Delay_NT;
-----------------
-- To_Duration --
-----------------
function To_Duration (T : Time) return Duration is
begin
return Duration (T);
end To_Duration;
begin
-- Set up the Timed_Delay soft link to the non tasking version
-- if it has not been already set.
-- If tasking is present, Timed_Delay has already set this soft
-- link, or this will be overriden during the elaboration of
-- System.Tasking.Initialization
if SSL.Timed_Delay = null then
SSL.Timed_Delay := Timed_Delay_NT'Access;
end if;
end Ada.Calendar.Delays;
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