1 ------------------------------------------------------------------------------
3 -- GNAT RUN-TIME LIBRARY (GNARL) COMPONENTS --
5 -- S Y S T E M . O S _ P R I M I T I V E S --
9 -- Copyright (C) 1998-2009, Free Software Foundation, Inc. --
11 -- GNARL is free software; you can redistribute it and/or modify it under --
12 -- terms of the GNU General Public License as published by the Free Soft- --
13 -- ware Foundation; either version 3, or (at your option) any later ver- --
14 -- sion. GNAT is distributed in the hope that it will be useful, but WITH- --
15 -- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
16 -- or FITNESS FOR A PARTICULAR PURPOSE. --
18 -- As a special exception under Section 7 of GPL version 3, you are granted --
19 -- additional permissions described in the GCC Runtime Library Exception, --
20 -- version 3.1, as published by the Free Software Foundation. --
22 -- You should have received a copy of the GNU General Public License and --
23 -- a copy of the GCC Runtime Library Exception along with this program; --
24 -- see the files COPYING3 and COPYING.RUNTIME respectively. If not, see --
25 -- <http://www.gnu.org/licenses/>. --
27 -- GNARL was developed by the GNARL team at Florida State University. --
28 -- Extensive contributions were provided by Ada Core Technologies, Inc. --
30 ------------------------------------------------------------------------------
32 -- This version is for VxWorks targets
34 with System.OS_Interface;
35 -- Since the thread library is part of the VxWorks kernel, using OS_Interface
36 -- is not a problem here, as long as we only use System.OS_Interface as a
37 -- set of C imported routines: using Ada routines from this package would
38 -- create a dependency on libgnarl in libgnat, which is not desirable.
42 package body System.OS_Primitives is
44 use System.OS_Interface;
45 use type Interfaces.C.int;
47 ------------------------
48 -- Internal functions --
49 ------------------------
51 function To_Clock_Ticks (D : Duration) return int;
52 -- Convert a duration value (in seconds) into clock ticks.
53 -- Note that this routine is duplicated from System.OS_Interface since
54 -- as explained above, we do not want to depend on libgnarl
56 function To_Clock_Ticks (D : Duration) return int is
57 Ticks : Long_Long_Integer;
58 Rate_Duration : Duration;
59 Ticks_Duration : Duration;
66 -- Ensure that the duration can be converted to ticks
67 -- at the current clock tick rate without overflowing.
69 Rate_Duration := Duration (sysClkRateGet);
71 if D > (Duration'Last / Rate_Duration) then
72 Ticks := Long_Long_Integer (int'Last);
74 Ticks_Duration := D * Rate_Duration;
75 Ticks := Long_Long_Integer (Ticks_Duration);
77 if Ticks_Duration > Duration (Ticks) then
81 if Ticks > Long_Long_Integer (int'Last) then
82 Ticks := Long_Long_Integer (int'Last);
93 function Clock return Duration is
94 TS : aliased timespec;
97 Result := clock_gettime (CLOCK_REALTIME, TS'Unchecked_Access);
98 pragma Assert (Result = 0);
99 return Duration (TS.ts_sec) + Duration (TS.ts_nsec) / 10#1#E9;
102 ---------------------
103 -- Monotonic_Clock --
104 ---------------------
106 function Monotonic_Clock return Duration renames Clock;
112 procedure Timed_Delay
118 Base_Time : constant Duration := Clock;
119 Check_Time : Duration := Base_Time;
123 pragma Unreferenced (Result);
126 if Mode = Relative then
128 Abs_Time := Time + Check_Time;
130 Rel_Time := Time - Check_Time;
134 if Rel_Time > 0.0 then
136 Ticks := To_Clock_Ticks (Rel_Time);
138 if Mode = Relative and then Ticks < int'Last then
139 -- The first tick will delay anytime between 0 and
140 -- 1 / sysClkRateGet seconds, so we need to add one to
141 -- be on the safe side.
146 Result := taskDelay (Ticks);
149 exit when Abs_Time <= Check_Time or else Check_Time < Base_Time;
151 Rel_Time := Abs_Time - Check_Time;
160 procedure Initialize is
165 end System.OS_Primitives;