gcc/ada/s-memory-vms_64.adb

   1 ------------------------------------------------------------------------------
   2 --                                                                          --
   3 --                         GNAT RUN-TIME COMPONENTS                         --
   4 --                                                                          --
   5 --                         S Y S T E M . M E M O R Y                        --
   6 --                                                                          --
   7 --                                 B o d y                                  --
   8 --                                                                          --
   9 --          Copyright (C) 2001-2010, Free Software Foundation, Inc.         --
  10 --                                                                          --
  11 -- GNAT 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 -- GNAT was originally developed  by the GNAT team at  New York University. --
  28 -- Extensive contributions were provided by Ada Core Technologies Inc.      --
  29 --                                                                          --
  30 ------------------------------------------------------------------------------
  31
  32 --  This is the VMS 64 bit implementation of this package
  33
  34 --  This implementation assumes that the underlying malloc/free/realloc
  35 --  implementation is thread safe, and thus, no additional lock is required.
  36 --  Note that we still need to defer abort because on most systems, an
  37 --  asynchronous signal (as used for implementing asynchronous abort of
  38 --  task) cannot safely be handled while malloc is executing.
  39
  40 --  If you are not using Ada constructs containing the "abort" keyword, then
  41 --  you can remove the calls to Abort_Defer.all and Abort_Undefer.all from
  42 --  this unit.
  43
  44 pragma Compiler_Unit;
  45
  46 with Ada.Exceptions;
  47 with System.Soft_Links;
  48 with System.Parameters;
  49 with System.CRTL;
  50
  51 package body System.Memory is
  52
  53    use Ada.Exceptions;
  54    use System.Soft_Links;
  55
  56    function c_malloc (Size : System.CRTL.size_t) return System.Address
  57     renames System.CRTL.malloc;
  58
  59    procedure c_free (Ptr : System.Address)
  60      renames System.CRTL.free;
  61
  62    function c_realloc
  63      (Ptr : System.Address; Size : System.CRTL.size_t) return System.Address
  64      renames System.CRTL.realloc;
  65
  66    Gnat_Heap_Size : Integer;
  67    pragma Import (C, Gnat_Heap_Size, "__gl_heap_size");
  68    --  Set by Feature logical GNAT$NO_MALLOC_64 and/or Binder switch -Hnn
  69
  70    -----------
  71    -- Alloc --
  72    -----------
  73
  74    function Alloc (Size : size_t) return System.Address is
  75       Result      : System.Address;
  76       Actual_Size : size_t := Size;
  77
  78    begin
  79       if Gnat_Heap_Size = 32 then
  80          return Alloc32 (Size);
  81       end if;
  82
  83       if Size = size_t'Last then
  84          Raise_Exception (Storage_Error'Identity, "object too large");
  85       end if;
  86
  87       --  Change size from zero to non-zero. We still want a proper pointer
  88       --  for the zero case because pointers to zero length objects have to
  89       --  be distinct, but we can't just go ahead and allocate zero bytes,
  90       --  since some malloc's return zero for a zero argument.
  91
  92       if Size = 0 then
  93          Actual_Size := 1;
  94       end if;
  95
  96       if Parameters.No_Abort then
  97          Result := c_malloc (System.CRTL.size_t (Actual_Size));
  98       else
  99          Abort_Defer.all;
 100          Result := c_malloc (System.CRTL.size_t (Actual_Size));
 101          Abort_Undefer.all;
 102       end if;
 103
 104       if Result = System.Null_Address then
 105          Raise_Exception (Storage_Error'Identity, "heap exhausted");
 106       end if;
 107
 108       return Result;
 109    end Alloc;
 110
 111    -------------
 112    -- Alloc32 --
 113    -------------
 114
 115    function Alloc32 (Size : size_t) return System.Address is
 116       Result      : System.Address;
 117       Actual_Size : size_t := Size;
 118
 119    begin
 120       if Size = size_t'Last then
 121          Raise_Exception (Storage_Error'Identity, "object too large");
 122       end if;
 123
 124       --  Change size from zero to non-zero. We still want a proper pointer
 125       --  for the zero case because pointers to zero length objects have to
 126       --  be distinct, but we can't just go ahead and allocate zero bytes,
 127       --  since some malloc's return zero for a zero argument.
 128
 129       if Size = 0 then
 130          Actual_Size := 1;
 131       end if;
 132
 133       if Parameters.No_Abort then
 134          Result := C_malloc32 (Actual_Size);
 135       else
 136          Abort_Defer.all;
 137          Result := C_malloc32 (Actual_Size);
 138          Abort_Undefer.all;
 139       end if;
 140
 141       if Result = System.Null_Address then
 142          Raise_Exception (Storage_Error'Identity, "heap exhausted");
 143       end if;
 144
 145       return Result;
 146    end Alloc32;
 147
 148    ----------
 149    -- Free --
 150    ----------
 151
 152    procedure Free (Ptr : System.Address) is
 153    begin
 154       if Parameters.No_Abort then
 155          c_free (Ptr);
 156       else
 157          Abort_Defer.all;
 158          c_free (Ptr);
 159          Abort_Undefer.all;
 160       end if;
 161    end Free;
 162
 163    -------------
 164    -- Realloc --
 165    -------------
 166
 167    function Realloc
 168      (Ptr  : System.Address;
 169       Size : size_t)
 170       return System.Address
 171    is
 172       Result      : System.Address;
 173       Actual_Size : constant size_t := Size;
 174
 175    begin
 176       if Gnat_Heap_Size = 32 then
 177          return Realloc32 (Ptr, Size);
 178       end if;
 179
 180       if Size = size_t'Last then
 181          Raise_Exception (Storage_Error'Identity, "object too large");
 182       end if;
 183
 184       if Parameters.No_Abort then
 185          Result := c_realloc (Ptr, System.CRTL.size_t (Actual_Size));
 186       else
 187          Abort_Defer.all;
 188          Result := c_realloc (Ptr, System.CRTL.size_t (Actual_Size));
 189          Abort_Undefer.all;
 190       end if;
 191
 192       if Result = System.Null_Address then
 193          Raise_Exception (Storage_Error'Identity, "heap exhausted");
 194       end if;
 195
 196       return Result;
 197    end Realloc;
 198
 199    ---------------
 200    -- Realloc32 --
 201    ---------------
 202
 203    function Realloc32
 204      (Ptr  : System.Address;
 205       Size : size_t)
 206       return System.Address
 207    is
 208       Result      : System.Address;
 209       Actual_Size : constant size_t := Size;
 210
 211    begin
 212       if Size = size_t'Last then
 213          Raise_Exception (Storage_Error'Identity, "object too large");
 214       end if;
 215
 216       if Parameters.No_Abort then
 217          Result := C_realloc32 (Ptr, Actual_Size);
 218       else
 219          Abort_Defer.all;
 220          Result := C_realloc32 (Ptr, Actual_Size);
 221          Abort_Undefer.all;
 222       end if;
 223
 224       if Result = System.Null_Address then
 225          Raise_Exception (Storage_Error'Identity, "heap exhausted");
 226       end if;
 227
 228       return Result;
 229    end Realloc32;
 230 end System.Memory;