gcc/ada/libgnarl/s-osinte__darwin.adb

   1 ------------------------------------------------------------------------------
   2 --                                                                          --
   3 --                 GNAT RUN-TIME LIBRARY (GNARL) COMPONENTS                 --
   4 --                                                                          --
   5 --                   S Y S T E M . O S _ I N T E R F A C E                  --
   6 --                                                                          --
   7 --                                  B o d y                                 --
   8 --                                                                          --
   9 --          Copyright (C) 1999-2018, Free Software Foundation, Inc.         --
  10 --                                                                          --
  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.                                     --
  17 --                                                                          --
  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.               --
  21 --                                                                          --
  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/>.                                          --
  26 --                                                                          --
  27 -- GNARL was developed by the GNARL team at Florida State University.       --
  28 -- Extensive contributions were provided by Ada Core Technologies, Inc.     --
  29 --                                                                          --
  30 ------------------------------------------------------------------------------
  31
  32 --  This is a Darwin Threads version of this package
  33
  34 pragma Polling (Off);
  35 --  Turn off polling, we do not want ATC polling to take place during
  36 --  tasking operations. It causes infinite loops and other problems.
  37
  38 with Interfaces.C.Extensions;
  39
  40 package body System.OS_Interface is
  41    use Interfaces.C;
  42
  43    -----------------
  44    -- To_Duration --
  45    -----------------
  46
  47    function To_Duration (TS : timespec) return Duration is
  48    begin
  49       return Duration (TS.tv_sec) + Duration (TS.tv_nsec) / 10#1#E9;
  50    end To_Duration;
  51
  52    ------------------------
  53    -- To_Target_Priority --
  54    ------------------------
  55
  56    function To_Target_Priority
  57      (Prio : System.Any_Priority) return Interfaces.C.int
  58    is
  59    begin
  60       return Interfaces.C.int (Prio);
  61    end To_Target_Priority;
  62
  63    -----------------
  64    -- To_Timespec --
  65    -----------------
  66
  67    function To_Timespec (D : Duration) return timespec is
  68       S : time_t;
  69       F : Duration;
  70
  71    begin
  72       S := time_t (Long_Long_Integer (D));
  73       F := D - Duration (S);
  74
  75       --  If F has negative value due to a round-up, adjust for positive F
  76       --  value.
  77
  78       if F < 0.0 then
  79          S := S - 1;
  80          F := F + 1.0;
  81       end if;
  82
  83       return timespec'(tv_sec => S,
  84         tv_nsec => long (Long_Long_Integer (F * 10#1#E9)));
  85    end To_Timespec;
  86
  87    -------------------
  88    -- clock_gettime --
  89    -------------------
  90
  91    function clock_gettime
  92      (clock_id : clockid_t;
  93       tp       : access timespec) return int
  94    is
  95       pragma Unreferenced (clock_id);
  96
  97       --  Darwin Threads don't have clock_gettime, so use gettimeofday
  98
  99       use Interfaces;
 100
 101       type timeval is array (1 .. 3) of C.long;
 102       --  The timeval array is sized to contain long_long sec and long usec.
 103       --  If long_long'Size = long'Size then it will be overly large but that
 104       --  won't effect the implementation since it's not accessed directly.
 105
 106       procedure timeval_to_duration
 107         (T    : not null access timeval;
 108          sec  : not null access C.Extensions.long_long;
 109          usec : not null access C.long);
 110       pragma Import (C, timeval_to_duration, "__gnat_timeval_to_duration");
 111
 112       Micro  : constant := 10**6;
 113       sec    : aliased C.Extensions.long_long;
 114       usec   : aliased C.long;
 115       TV     : aliased timeval;
 116       Result : int;
 117
 118       function gettimeofday
 119         (Tv : access timeval;
 120          Tz : System.Address := System.Null_Address) return int;
 121       pragma Import (C, gettimeofday, "gettimeofday");
 122
 123    begin
 124       Result := gettimeofday (TV'Access, System.Null_Address);
 125       pragma Assert (Result = 0);
 126       timeval_to_duration (TV'Access, sec'Access, usec'Access);
 127       tp.all := To_Timespec (Duration (sec) + Duration (usec) / Micro);
 128       return Result;
 129    end clock_gettime;
 130
 131    ------------------
 132    -- clock_getres --
 133    ------------------
 134
 135    function clock_getres
 136      (clock_id : clockid_t;
 137       res      : access timespec) return int
 138    is
 139       pragma Unreferenced (clock_id);
 140
 141       --  Darwin Threads don't have clock_getres.
 142
 143       Nano   : constant := 10**9;
 144       nsec   : int := 0;
 145       Result : int := -1;
 146
 147       function clock_get_res return int;
 148       pragma Import (C, clock_get_res, "__gnat_clock_get_res");
 149
 150    begin
 151       nsec := clock_get_res;
 152       res.all := To_Timespec (Duration (0.0) + Duration (nsec) / Nano);
 153
 154       if nsec > 0 then
 155          Result := 0;
 156       end if;
 157
 158       return Result;
 159    end clock_getres;
 160
 161    -----------------
 162    -- sched_yield --
 163    -----------------
 164
 165    function sched_yield return int is
 166       procedure sched_yield_base (arg : System.Address);
 167       pragma Import (C, sched_yield_base, "pthread_yield_np");
 168
 169    begin
 170       sched_yield_base (System.Null_Address);
 171       return 0;
 172    end sched_yield;
 173
 174    ------------------
 175    -- pthread_init --
 176    ------------------
 177
 178    procedure pthread_init is
 179    begin
 180       null;
 181    end pthread_init;
 182
 183    --------------------
 184    -- Get_Stack_Base --
 185    --------------------
 186
 187    function Get_Stack_Base (thread : pthread_t) return Address is
 188       pragma Unreferenced (thread);
 189    begin
 190       return System.Null_Address;
 191    end Get_Stack_Base;
 192
 193 end System.OS_Interface;