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) 1997-2019, 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 AIX (Native) version of this package
33
34pragma Polling (Off);
35--  Turn off polling, we do not want ATC polling to take place during tasking
36--  operations. It causes infinite loops and other problems.
37
38package body System.OS_Interface is
39
40   use Interfaces.C;
41
42   -----------------
43   -- To_Duration --
44   -----------------
45
46   function To_Duration (TS : timespec) return Duration is
47   begin
48      return Duration (TS.tv_sec) + Duration (TS.tv_nsec) / 10#1#E9;
49   end To_Duration;
50
51   ------------------------
52   -- To_Target_Priority --
53   ------------------------
54
55   function To_Target_Priority
56     (Prio : System.Any_Priority) return Interfaces.C.int
57   is
58      Dispatching_Policy : Character;
59      pragma Import (C, Dispatching_Policy, "__gl_task_dispatching_policy");
60
61      Time_Slice_Val : Integer;
62      pragma Import (C, Time_Slice_Val, "__gl_time_slice_val");
63
64   begin
65      --  For the case SCHED_OTHER the only valid priority across all supported
66      --  versions of AIX is 1 (note that the scheduling policy can be set
67      --  with the pragma Task_Dispatching_Policy or setting the time slice
68      --  value). Otherwise, for SCHED_RR and SCHED_FIFO, the system defines
69      --  priorities in the range 1 .. 127. This means that we must map
70      --  System.Any_Priority in the range 0 .. 126 to 1 .. 127.
71
72      if Dispatching_Policy = ' ' and then Time_Slice_Val < 0 then
73         return 1;
74      else
75         return Interfaces.C.int (Prio) + 1;
76      end if;
77   end To_Target_Priority;
78
79   -----------------
80   -- To_Timespec --
81   -----------------
82
83   function To_Timespec (D : Duration) return timespec is
84      S : time_t;
85      F : Duration;
86
87   begin
88      S := time_t (Long_Long_Integer (D));
89      F := D - Duration (S);
90
91      --  If F is negative due to a round-up, adjust for positive F value
92
93      if F < 0.0 then
94         S := S - 1;
95         F := F + 1.0;
96      end if;
97
98      return timespec'(tv_sec => S,
99                       tv_nsec => long (Long_Long_Integer (F * 10#1#E9)));
100   end To_Timespec;
101
102   -----------------
103   -- sched_yield --
104   -----------------
105
106   --  AIX Thread does not have sched_yield;
107
108   function sched_yield return int is
109      procedure pthread_yield;
110      pragma Import (C, pthread_yield, "sched_yield");
111   begin
112      pthread_yield;
113      return 0;
114   end sched_yield;
115
116   --------------------
117   -- Get_Stack_Base --
118   --------------------
119
120   function Get_Stack_Base (thread : pthread_t) return Address is
121      pragma Warnings (Off, thread);
122   begin
123      return Null_Address;
124   end Get_Stack_Base;
125
126   --------------------------
127   -- PTHREAD_PRIO_INHERIT --
128   --------------------------
129
130   AIX_Version : Integer := 0;
131   --  AIX version in the form xy for AIX version x.y (0 means not set)
132
133   SYS_NMLN : constant := 32;
134   --  AIX system constant used to define utsname, see sys/utsname.h
135
136   subtype String_NMLN is String (1 .. SYS_NMLN);
137
138   type utsname is record
139      sysname    : String_NMLN;
140      nodename   : String_NMLN;
141      release    : String_NMLN;
142      version    : String_NMLN;
143      machine    : String_NMLN;
144      procserial : String_NMLN;
145   end record;
146   pragma Convention (C, utsname);
147
148   procedure uname (name : out utsname);
149   pragma Import (C, uname);
150
151   function PTHREAD_PRIO_INHERIT return int is
152      name : utsname;
153
154      function Val (C : Character) return Integer;
155      --  Transform a numeric character ('0' .. '9') to an integer
156
157      ---------
158      -- Val --
159      ---------
160
161      function Val (C : Character) return Integer is
162      begin
163         return Character'Pos (C) - Character'Pos ('0');
164      end Val;
165
166   --  Start of processing for PTHREAD_PRIO_INHERIT
167
168   begin
169      if AIX_Version = 0 then
170
171         --  Set AIX_Version
172
173         uname (name);
174         AIX_Version := Val (name.version (1)) * 10 + Val (name.release (1));
175      end if;
176
177      if AIX_Version < 53 then
178
179         --  Under AIX < 5.3, PTHREAD_PRIO_INHERIT is defined as 0 in pthread.h
180
181         return 0;
182
183      else
184         --  Under AIX >= 5.3, PTHREAD_PRIO_INHERIT is defined as 3
185
186         return 3;
187      end if;
188   end PTHREAD_PRIO_INHERIT;
189
190end System.OS_Interface;
191