1------------------------------------------------------------------------------
2--                                                                          --
3--                 GNU ADA 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) 1997-2002 Free Software Foundation             --
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 2,  or (at your option) any later ver- --
14-- sion. GNARL 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.  See the GNU General Public License --
17-- for  more details.  You should have  received  a copy of the GNU General --
18-- Public License  distributed with GNARL; see file COPYING.  If not, write --
19-- to  the Free Software Foundation,  59 Temple Place - Suite 330,  Boston, --
20-- MA 02111-1307, USA.                                                      --
21--                                                                          --
22-- As a special exception,  if other files  instantiate  generics from this --
23-- unit, or you link  this unit with other files  to produce an executable, --
24-- this  unit  does not  by itself cause  the resulting  executable  to  be --
25-- covered  by the  GNU  General  Public  License.  This exception does not --
26-- however invalidate  any other reasons why  the executable file  might be --
27-- covered by the  GNU Public License.                                      --
28--                                                                          --
29-- GNARL was developed by the GNARL team at Florida State University.       --
30-- Extensive contributions were provided by Ada Core Technologies, Inc.     --
31--                                                                          --
32------------------------------------------------------------------------------
33
34--  This is the VxWorks version.
35
36--  This package encapsulates all direct interfaces to OS services
37--  that are needed by children of System.
38
39pragma Polling (Off);
40--  Turn off polling, we do not want ATC polling to take place during
41--  tasking operations. It causes infinite loops and other problems.
42
43package body System.OS_Interface is
44
45   use type Interfaces.C.int;
46
47   Low_Priority : constant := 255;
48   --  VxWorks native (default) lowest scheduling priority.
49
50   -------------
51   -- sigwait --
52   -------------
53
54   function sigwait
55     (set : access sigset_t;
56      sig : access Signal) return int
57   is
58      Result : int;
59
60      function sigwaitinfo
61        (set : access sigset_t; sigvalue : System.Address) return int;
62      pragma Import (C, sigwaitinfo, "sigwaitinfo");
63
64   begin
65      Result := sigwaitinfo (set, System.Null_Address);
66
67      if Result /= -1 then
68         sig.all := Signal (Result);
69         return 0;
70      else
71         sig.all := 0;
72         return errno;
73      end if;
74   end sigwait;
75
76   -----------------
77   -- To_Duration --
78   -----------------
79
80   function To_Duration (TS : timespec) return Duration is
81   begin
82      return Duration (TS.ts_sec) + Duration (TS.ts_nsec) / 10#1#E9;
83   end To_Duration;
84
85   -----------------
86   -- To_Timespec --
87   -----------------
88
89   function To_Timespec (D : Duration) return timespec is
90      S : time_t;
91      F : Duration;
92   begin
93      S := time_t (Long_Long_Integer (D));
94      F := D - Duration (S);
95
96      --  If F has negative value due to a round-up, adjust for positive F
97      --  value.
98      if F < 0.0 then
99         S := S - 1;
100         F := F + 1.0;
101      end if;
102
103      return timespec'(ts_sec  => S,
104                       ts_nsec => long (Long_Long_Integer (F * 10#1#E9)));
105   end To_Timespec;
106
107   -------------------------
108   -- To_VxWorks_Priority --
109   -------------------------
110
111   function To_VxWorks_Priority (Priority : in int) return int is
112   begin
113      return Low_Priority - Priority;
114   end To_VxWorks_Priority;
115
116   --------------------
117   -- To_Clock_Ticks --
118   --------------------
119
120   --  ??? - For now, we'll always get the system clock rate
121   --  since it is allowed to be changed during run-time in
122   --  VxWorks. A better method would be to provide an operation
123   --  to set it that so we can always know its value.
124   --
125   --  Another thing we should probably allow for is a resultant
126   --  tick count greater than int'Last. This should probably
127   --  be a procedure with two output parameters, one in the
128   --  range 0 .. int'Last, and another representing the overflow
129   --  count.
130
131   function To_Clock_Ticks (D : Duration) return int is
132      Ticks          : Long_Long_Integer;
133      Rate_Duration  : Duration;
134      Ticks_Duration : Duration;
135
136   begin
137      if D < 0.0 then
138         return -1;
139      end if;
140
141      --  Ensure that the duration can be converted to ticks
142      --  at the current clock tick rate without overflowing.
143
144      Rate_Duration := Duration (sysClkRateGet);
145
146      if D > (Duration'Last / Rate_Duration) then
147         Ticks := Long_Long_Integer (int'Last);
148      else
149         Ticks_Duration := D * Rate_Duration;
150         Ticks := Long_Long_Integer (Ticks_Duration);
151
152         if Ticks_Duration > Duration (Ticks) then
153            Ticks := Ticks + 1;
154         end if;
155
156         if Ticks > Long_Long_Integer (int'Last) then
157            Ticks := Long_Long_Integer (int'Last);
158         end if;
159      end if;
160
161      return int (Ticks);
162   end To_Clock_Ticks;
163
164end System.OS_Interface;
165