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------------------------------------------------------------------------------
-- --
-- GNAT RUN-TIME COMPONENTS --
-- --
-- S Y S T E M . O S _ P R I M I T I V E S. T I M E D _ D E L A Y --
-- --
-- B o d y --
-- --
-- Copyright (C) 2012-2021, AdaCore --
-- --
-- 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 3, 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. --
-- --
-- As a special exception under Section 7 of GPL version 3, you are granted --
-- additional permissions described in the GCC Runtime Library Exception, --
-- version 3.1, as published by the Free Software Foundation. --
-- --
-- You should have received a copy of the GNU General Public License and --
-- a copy of the GCC Runtime Library Exception along with this program; --
-- see the files COPYING3 and COPYING.RUNTIME respectively. If not, see --
-- <http://www.gnu.org/licenses/>. --
-- --
-- GNAT was originally developed by the GNAT team at New York University. --
-- Extensive contributions were provided by Ada Core Technologies Inc. --
-- --
------------------------------------------------------------------------------
-- This is the Posix, Posix2008, and LynxOS version of this procedure.
separate (System.OS_Primitives)
procedure Timed_Delay
(Time : Duration;
Mode : Integer)
is
Request : aliased timespec;
Remaind : aliased timespec;
Rel_Time : Duration;
Abs_Time : Duration;
Base_Time : constant Duration := Clock;
Check_Time : Duration := Base_Time;
Time_Chunk : Duration;
Result : Integer;
pragma Unreferenced (Result);
begin
if Mode = Relative then
Rel_Time := Time;
Abs_Time := Time + Check_Time;
else
Rel_Time := Time - Check_Time;
Abs_Time := Time;
end if;
-- To keep a sensible Max_Sensible_Delay on a target whose system
-- maximum is less than sensible, we split the delay into manageable
-- chunks of time less than or equal to the Max_System_Delay.
if Rel_Time > 0.0 then
Time_Chunk := Rel_Time;
loop
pragma Warnings (Off, "condition is always *");
if Max_System_Delay < Max_Sensible_Delay and then
Time_Chunk > Max_System_Delay
then
Time_Chunk := Max_System_Delay;
end if;
pragma Warnings (On);
Request := To_Timespec (Time_Chunk);
Result := nanosleep (Request'Access, Remaind'Access);
Check_Time := Clock;
exit when Abs_Time <= Check_Time or else Check_Time < Base_Time;
Time_Chunk := Abs_Time - Check_Time;
end loop;
end if;
end Timed_Delay;