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------------------------------------------------------------------------------
-- --
-- GNU ADA 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) 1998-2001 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, 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). --
-- --
------------------------------------------------------------------------------
-- This version is for VxWorks targets
with System.OS_Interface;
-- Since the thread library is part of the VxWorks kernel, using OS_Interface
-- is not a problem here, as long as we only use System.OS_Interface as a
-- set of C imported routines: using Ada routines from this package would
-- create a dependency on libgnarl in libgnat, which is not desirable.
with Interfaces.C;
-- used for type int
package body System.OS_Primitives is
use System.OS_Interface;
--------------------------
-- Internal functions --
--------------------------
function To_Clock_Ticks (D : Duration) return int;
-- Convert a duration value (in seconds) into clock ticks.
-- Note that this routine is duplicated from System.OS_Interface since
-- as explained above, we do not want to depend on libgnarl
function To_Clock_Ticks (D : Duration) return int is
Ticks : Long_Long_Integer;
Rate_Duration : Duration;
Ticks_Duration : Duration;
begin
-- Ensure that the duration can be converted to ticks
-- at the current clock tick rate without overflowing.
Rate_Duration := Duration (sysClkRateGet);
if D > (Duration'Last / Rate_Duration) then
Ticks := Long_Long_Integer (int'Last);
else
-- We always want to round up to the nearest clock tick.
Ticks_Duration := D * Rate_Duration;
Ticks := Long_Long_Integer (Ticks_Duration);
if Ticks_Duration > Duration (Ticks) then
Ticks := Ticks + 1;
end if;
if Ticks > Long_Long_Integer (int'Last) then
Ticks := Long_Long_Integer (int'Last);
end if;
end if;
return int (Ticks);
end To_Clock_Ticks;
-----------
-- Clock --
-----------
function Clock return Duration is
TS : aliased timespec;
Result : int;
use type Interfaces.C.int;
begin
Result := clock_gettime (CLOCK_REALTIME, TS'Unchecked_Access);
pragma Assert (Result = 0);
return Duration (TS.ts_sec) + Duration (TS.ts_nsec) / 10#1#E9;
end Clock;
---------------------
-- Monotonic_Clock --
---------------------
function Monotonic_Clock return Duration renames Clock;
-----------------
-- Timed_Delay --
-----------------
procedure Timed_Delay
(Time : Duration;
Mode : Integer)
is
Result : int;
Rel_Time : Duration;
Abs_Time : Duration;
Check_Time : Duration := Clock;
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
Result := taskDelay (To_Clock_Ticks (Rel_Time));
Check_Time := Clock;
exit when Abs_Time <= Check_Time;
Rel_Time := Abs_Time - Check_Time;
end loop;
end if;
end Timed_Delay;
end System.OS_Primitives;
|
