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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) 1998-2009, 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 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/>. --
-- --
-- GNARL was developed by the GNARL team at Florida State University. --
-- Extensive contributions were provided by Ada Core Technologies, Inc. --
-- --
------------------------------------------------------------------------------
-- This version is for POSIX-like operating systems
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 time_t is new Long_Long_Integer;
type timespec is record
tv_sec : time_t;
tv_nsec : Long_Long_Integer;
end record;
pragma Convention (C, timespec);
function nanosleep (rqtp, rmtp : not null access timespec) return Integer;
pragma Import (C, nanosleep, "nanosleep");
-----------
-- Clock --
-----------
function Clock return Duration is
type timeval is array (1 .. 2) of Long_Long_Integer;
procedure timeval_to_duration
(T : not null access timeval;
sec : not null access Long_Integer;
usec : not null access Long_Integer);
pragma Import (C, timeval_to_duration, "__gnat_timeval_to_duration");
Micro : constant := 10**6;
sec : aliased Long_Integer;
usec : aliased Long_Integer;
TV : aliased timeval;
Result : Integer;
pragma Unreferenced (Result);
function gettimeofday
(Tv : access timeval;
Tz : System.Address := System.Null_Address) return Integer;
pragma Import (C, gettimeofday, "gettimeofday");
begin
-- The return codes for gettimeofday are as follows (from man pages):
-- EPERM settimeofday is called by someone other than the superuser
-- EINVAL Timezone (or something else) is invalid
-- EFAULT One of tv or tz pointed outside accessible address space
-- None of these codes signal a potential clock skew, hence the return
-- value is never checked.
Result := gettimeofday (TV'Access, System.Null_Address);
timeval_to_duration (TV'Access, sec'Access, usec'Access);
return Duration (sec) + Duration (usec) / Micro;
end Clock;
---------------------
-- Monotonic_Clock --
---------------------
function Monotonic_Clock return Duration renames Clock;
-----------------
-- To_Timespec --
-----------------
function To_Timespec (D : Duration) return timespec;
function To_Timespec (D : Duration) return timespec is
S : time_t;
F : Duration;
begin
S := time_t (Long_Long_Integer (D));
F := D - Duration (S);
-- If F has negative value due to a round-up, adjust for positive F
-- value.
if F < 0.0 then
S := S - 1;
F := F + 1.0;
end if;
return
timespec'(tv_sec => S,
tv_nsec => Long_Long_Integer (F * 10#1#E9));
end To_Timespec;
-----------------
-- Timed_Delay --
-----------------
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;
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;
if Rel_Time > 0.0 then
loop
Request := To_Timespec (Rel_Time);
Result := nanosleep (Request'Access, Remaind'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;
|
