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) 1999-2019, 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
34pragma 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
38with Interfaces.C.Extensions;
39
40package 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
193end System.OS_Interface;
194