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------------------------------------------------------------------------------
-- --
-- GNAT RUN-TIME LIBRARY (GNARL) COMPONENTS --
-- --
-- S Y S T E M . O S _ P R I M I T I V E S --
-- --
-- B o d y --
-- --
-- Copyright (C) 1998-2007, Free Software Foundation, Inc. --
-- --
-- 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, 51 Franklin Street, Fifth Floor, --
-- Boston, MA 02110-1301, 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. --
-- Extensive contributions were provided by Ada Core Technologies Inc. --
-- --
------------------------------------------------------------------------------
-- This version uses gettimeofday and select
-- This file is suitable for OpenNT, Dec Unix and SCO UnixWare.
package body System.OS_Primitives is
-- ??? These definitions are duplicated from System.OS_Interface
-- because we don't want to depend on any package. Consider removing
-- these declarations in System.OS_Interface and move these ones in
-- the spec.
type struct_timeval is record
tv_sec : Integer;
tv_usec : Integer;
end record;
pragma Convention (C, struct_timeval);
procedure gettimeofday
(tv : not null access struct_timeval;
tz : Address := Null_Address);
pragma Import (C, gettimeofday, "gettimeofday");
procedure C_select
(n : Integer := 0;
readfds,
writefds,
exceptfds : Address := Null_Address;
timeout : not null access struct_timeval);
pragma Import (C, C_select, "select");
-----------
-- Clock --
-----------
function Clock return Duration is
TV : aliased struct_timeval;
begin
gettimeofday (TV'Access);
return Duration (TV.tv_sec) + Duration (TV.tv_usec) / 10#1#E6;
end Clock;
---------------------
-- Monotonic_Clock --
---------------------
function Monotonic_Clock return Duration renames Clock;
-----------------
-- Timed_Delay --
-----------------
procedure Timed_Delay
(Time : Duration;
Mode : Integer)
is
Rel_Time : Duration;
Abs_Time : Duration;
Base_Time : constant Duration := Clock;
Check_Time : Duration := Base_Time;
timeval : aliased struct_timeval;
begin
if Mode = Relative then
Rel_Time := Time;
Abs_Time := Time + Check_Time;
else
Rel_Time := Time - Check_Time;
Abs_Time := Time;
end if;
if Rel_Time > 0.0 then
loop
timeval.tv_sec := Integer (Rel_Time);
if Duration (timeval.tv_sec) > Rel_Time then
timeval.tv_sec := timeval.tv_sec - 1;
end if;
timeval.tv_usec :=
Integer ((Rel_Time - Duration (timeval.tv_sec)) * 10#1#E6);
C_select (timeout => timeval'Unchecked_Access);
Check_Time := Clock;
exit when Abs_Time <= Check_Time or else Check_Time < Base_Time;
Rel_Time := Abs_Time - Check_Time;
end loop;
end if;
end Timed_Delay;
----------------
-- Initialize --
----------------
procedure Initialize is
begin
null;
end Initialize;
end System.OS_Primitives;
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