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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 --
-- --
-- $Revision: 1.2 $
-- --
-- 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 is the OpenVMS/Alpha version of this file
with System.Aux_DEC;
package body System.OS_Primitives is
--------------------------------------
-- Local functions and declarations --
--------------------------------------
function Get_GMToff return Integer;
pragma Import (C, Get_GMToff, "get_gmtoff");
-- Get the offset from GMT for this timezone
VMS_Epoch_Offset : constant Long_Integer :=
10_000_000 *
(3_506_716_800 + Long_Integer (Get_GMToff));
-- The offset between the Unix Epoch and the VMS Epoch
subtype Cond_Value_Type is System.Aux_DEC.Unsigned_Longword;
-- Condition Value return type
----------------
-- Sys_Schdwk --
----------------
--
-- Schedule Wakeup
--
-- status = returned status
-- pidadr = address of process id to be woken up
-- prcnam = name of process to be woken up
-- daytim = time to wake up
-- reptim = repitition interval of wakeup calls
--
procedure Sys_Schdwk
(
Status : out Cond_Value_Type;
Pidadr : in Address := Null_Address;
Prcnam : in String := String'Null_Parameter;
Daytim : in Long_Integer;
Reptim : in Long_Integer := Long_Integer'Null_Parameter
);
pragma Interface (External, Sys_Schdwk);
-- VMS system call to schedule a wakeup event
pragma Import_Valued_Procedure
(Sys_Schdwk, "SYS$SCHDWK",
(Cond_Value_Type, Address, String, Long_Integer, Long_Integer),
(Value, Value, Descriptor (S), Reference, Reference)
);
----------------
-- Sys_Gettim --
----------------
--
-- Get System Time
--
-- status = returned status
-- tim = current system time
--
procedure Sys_Gettim
(
Status : out Cond_Value_Type;
Tim : out OS_Time
);
-- VMS system call to get the current system time
pragma Interface (External, Sys_Gettim);
pragma Import_Valued_Procedure
(Sys_Gettim, "SYS$GETTIM",
(Cond_Value_Type, OS_Time),
(Value, Reference)
);
---------------
-- Sys_Hiber --
---------------
--
-- Hibernate (until woken up)
--
-- status = returned status
--
procedure Sys_Hiber (Status : out Cond_Value_Type);
-- VMS system call to hibernate the current process
pragma Interface (External, Sys_Hiber);
pragma Import_Valued_Procedure
(Sys_Hiber, "SYS$HIBER",
(Cond_Value_Type),
(Value)
);
-----------
-- Clock --
-----------
function OS_Clock return OS_Time is
Status : Cond_Value_Type;
T : OS_Time;
begin
Sys_Gettim (Status, T);
return (T);
end OS_Clock;
-----------
-- Clock --
-----------
function Clock return Duration is
begin
return To_Duration (OS_Clock, Absolute_Calendar);
end Clock;
---------------------
-- Monotonic_Clock --
---------------------
function Monotonic_Clock return Duration renames Clock;
-----------------
-- Timed_Delay --
-----------------
procedure Timed_Delay
(Time : Duration;
Mode : Integer)
is
Sleep_Time : OS_Time;
Status : Cond_Value_Type;
begin
Sleep_Time := To_OS_Time (Time, Mode);
Sys_Schdwk (Status => Status, Daytim => Sleep_Time);
Sys_Hiber (Status);
end Timed_Delay;
-----------------
-- To_Duration --
-----------------
function To_Duration (T : OS_Time; Mode : Integer) return Duration is
begin
return Duration'Fixed_Value (T - VMS_Epoch_Offset) * 100;
end To_Duration;
----------------
-- To_OS_Time --
----------------
function To_OS_Time (D : Duration; Mode : Integer) return OS_Time is
begin
if Mode = Relative then
return -(Long_Integer'Integer_Value (D) / 100);
else
return Long_Integer'Integer_Value (D) / 100 + VMS_Epoch_Offset;
end if;
end To_OS_Time;
end System.OS_Primitives;