gcc/ada/s-osprim-vms.adb

   1 ------------------------------------------------------------------------------
   2 --                                                                          --
   3 --                 GNAT RUN-TIME LIBRARY (GNARL) COMPONENTS                 --
   4 --                                                                          --
   5 --                  S Y S T E M . O S _ P R I M I T I V E S                 --
   6 --                                                                          --
   7 --                                  B o d y                                 --
   8 --                                                                          --
   9 --          Copyright (C) 1998-2007, 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 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,  51  Franklin  Street,  Fifth  Floor, --
  20 -- Boston, MA 02110-1301, 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 OpenVMS/Alpha version of this file
  35
  36 with System.Aux_DEC;
  37
  38 package body System.OS_Primitives is
  39
  40    --------------------------------------
  41    -- Local functions and declarations --
  42    --------------------------------------
  43
  44    function Get_GMToff return Integer;
  45    pragma Import (C, Get_GMToff, "get_gmtoff");
  46    --  Get the offset from GMT for this timezone
  47
  48    function VMS_Epoch_Offset return Long_Integer;
  49    pragma Inline (VMS_Epoch_Offset);
  50    --  The offset between the Unix Epoch and the VMS Epoch
  51
  52    subtype Cond_Value_Type is System.Aux_DEC.Unsigned_Longword;
  53    --  Condition Value return type
  54
  55    ----------------------
  56    -- VMS_Epoch_Offset --
  57    ----------------------
  58
  59    function VMS_Epoch_Offset return Long_Integer is
  60    begin
  61       return 10_000_000 * (3_506_716_800 + Long_Integer (Get_GMToff));
  62    end VMS_Epoch_Offset;
  63
  64    ----------------
  65    -- Sys_Schdwk --
  66    ----------------
  67    --
  68    --  Schedule Wakeup
  69    --
  70    --  status = returned status
  71    --  pidadr = address of process id to be woken up
  72    --  prcnam = name of process to be woken up
  73    --  daytim = time to wake up
  74    --  reptim = repetition interval of wakeup calls
  75    --
  76
  77    procedure Sys_Schdwk
  78      (
  79       Status : out Cond_Value_Type;
  80       Pidadr : Address := Null_Address;
  81       Prcnam : String := String'Null_Parameter;
  82       Daytim : Long_Integer;
  83       Reptim : Long_Integer := Long_Integer'Null_Parameter
  84      );
  85
  86    pragma Interface (External, Sys_Schdwk);
  87    --  VMS system call to schedule a wakeup event
  88    pragma Import_Valued_Procedure
  89      (Sys_Schdwk, "SYS$SCHDWK",
  90       (Cond_Value_Type, Address, String,         Long_Integer, Long_Integer),
  91       (Value,           Value,   Descriptor (S), Reference,    Reference)
  92      );
  93
  94    ----------------
  95    -- Sys_Gettim --
  96    ----------------
  97    --
  98    --  Get System Time
  99    --
 100    --  status = returned status
 101    --  tim    = current system time
 102    --
 103
 104    procedure Sys_Gettim
 105      (
 106       Status : out Cond_Value_Type;
 107       Tim    : out OS_Time
 108      );
 109    --  VMS system call to get the current system time
 110    pragma Interface (External, Sys_Gettim);
 111    pragma Import_Valued_Procedure
 112      (Sys_Gettim, "SYS$GETTIM",
 113       (Cond_Value_Type, OS_Time),
 114       (Value,           Reference)
 115      );
 116
 117    ---------------
 118    -- Sys_Hiber --
 119    ---------------
 120
 121    --  Hibernate (until woken up)
 122
 123    --  status = returned status
 124
 125    procedure Sys_Hiber (Status : out Cond_Value_Type);
 126    --  VMS system call to hibernate the current process
 127    pragma Interface (External, Sys_Hiber);
 128    pragma Import_Valued_Procedure
 129      (Sys_Hiber, "SYS$HIBER",
 130       (Cond_Value_Type),
 131       (Value)
 132      );
 133
 134    -----------
 135    -- Clock --
 136    -----------
 137
 138    function OS_Clock return OS_Time is
 139       Status : Cond_Value_Type;
 140       T      : OS_Time;
 141    begin
 142       Sys_Gettim (Status, T);
 143       return (T);
 144    end OS_Clock;
 145
 146    -----------
 147    -- Clock --
 148    -----------
 149
 150    function Clock return Duration is
 151    begin
 152       return To_Duration (OS_Clock, Absolute_Calendar);
 153    end Clock;
 154
 155    ----------------
 156    -- Initialize --
 157    ----------------
 158
 159    procedure Initialize is
 160    begin
 161       null;
 162    end Initialize;
 163
 164    ---------------------
 165    -- Monotonic_Clock --
 166    ---------------------
 167
 168    function Monotonic_Clock return Duration renames Clock;
 169
 170    -----------------
 171    -- Timed_Delay --
 172    -----------------
 173
 174    procedure Timed_Delay
 175      (Time : Duration;
 176       Mode : Integer)
 177    is
 178       Sleep_Time : OS_Time;
 179       Status     : Cond_Value_Type;
 180       pragma Unreferenced (Status);
 181
 182    begin
 183       Sleep_Time := To_OS_Time (Time, Mode);
 184       Sys_Schdwk (Status => Status, Daytim => Sleep_Time);
 185       Sys_Hiber (Status);
 186    end Timed_Delay;
 187
 188    -----------------
 189    -- To_Duration --
 190    -----------------
 191
 192    function To_Duration (T : OS_Time; Mode : Integer) return Duration is
 193       pragma Warnings (Off, Mode);
 194    begin
 195       return Duration'Fixed_Value (T - VMS_Epoch_Offset) * 100;
 196    end To_Duration;
 197
 198    ----------------
 199    -- To_OS_Time --
 200    ----------------
 201
 202    function To_OS_Time (D : Duration; Mode : Integer) return OS_Time is
 203    begin
 204       if Mode = Relative then
 205          return -(Long_Integer'Integer_Value (D) / 100);
 206       else
 207          return Long_Integer'Integer_Value (D) / 100 + VMS_Epoch_Offset;
 208       end if;
 209    end To_OS_Time;
 210
 211 end System.OS_Primitives;