gcc/ada/a-conhel.adb

   1 ------------------------------------------------------------------------------
   2 --                                                                          --
   3 --                         GNAT LIBRARY COMPONENTS                          --
   4 --                                                                          --
   5 --               A D A . C O N T A I N E R S . H E L P E R S                --
   6 --                                                                          --
   7 --                                 B o d y                                  --
   8 --                                                                          --
   9 --           Copyright (C) 2015-2016, 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
  28 package body Ada.Containers.Helpers is
  29
  30    package body Generic_Implementation is
  31
  32       use type SAC.Atomic_Unsigned;
  33
  34       ------------
  35       -- Adjust --
  36       ------------
  37
  38       procedure Adjust (Control : in out Reference_Control_Type) is
  39       begin
  40          if Control.T_Counts /= null then
  41             Lock (Control.T_Counts.all);
  42          end if;
  43       end Adjust;
  44
  45       ----------
  46       -- Busy --
  47       ----------
  48
  49       procedure Busy (T_Counts : in out Tamper_Counts) is
  50       begin
  51          if T_Check then
  52             SAC.Increment (T_Counts.Busy);
  53          end if;
  54       end Busy;
  55
  56       --------------
  57       -- Finalize --
  58       --------------
  59
  60       procedure Finalize (Control : in out Reference_Control_Type) is
  61       begin
  62          if Control.T_Counts /= null then
  63             Unlock (Control.T_Counts.all);
  64             Control.T_Counts := null;
  65          end if;
  66       end Finalize;
  67
  68       --  No need to protect against double Finalize here, because these types
  69       --  are limited.
  70
  71       procedure Finalize (Busy : in out With_Busy) is
  72          pragma Warnings (Off);
  73          pragma Assert (T_Check); -- not called if check suppressed
  74          pragma Warnings (On);
  75       begin
  76          Unbusy (Busy.T_Counts.all);
  77       end Finalize;
  78
  79       procedure Finalize (Lock : in out With_Lock) is
  80          pragma Warnings (Off);
  81          pragma Assert (T_Check); -- not called if check suppressed
  82          pragma Warnings (On);
  83       begin
  84          Unlock (Lock.T_Counts.all);
  85       end Finalize;
  86
  87       ----------------
  88       -- Initialize --
  89       ----------------
  90
  91       procedure Initialize (Busy : in out With_Busy) is
  92          pragma Warnings (Off);
  93          pragma Assert (T_Check); -- not called if check suppressed
  94          pragma Warnings (On);
  95       begin
  96          Generic_Implementation.Busy (Busy.T_Counts.all);
  97       end Initialize;
  98
  99       procedure Initialize (Lock : in out With_Lock) is
 100          pragma Warnings (Off);
 101          pragma Assert (T_Check); -- not called if check suppressed
 102          pragma Warnings (On);
 103       begin
 104          Generic_Implementation.Lock (Lock.T_Counts.all);
 105       end Initialize;
 106
 107       ----------
 108       -- Lock --
 109       ----------
 110
 111       procedure Lock (T_Counts : in out Tamper_Counts) is
 112       begin
 113          if T_Check then
 114             SAC.Increment (T_Counts.Lock);
 115             SAC.Increment (T_Counts.Busy);
 116          end if;
 117       end Lock;
 118
 119       --------------
 120       -- TC_Check --
 121       --------------
 122
 123       procedure TC_Check (T_Counts : Tamper_Counts) is
 124       begin
 125          if T_Check and then T_Counts.Busy > 0 then
 126             raise Program_Error with
 127               "attempt to tamper with cursors";
 128          end if;
 129
 130          --  The lock status (which monitors "element tampering") always
 131          --  implies that the busy status (which monitors "cursor tampering")
 132          --  is set too; this is a representation invariant. Thus if the busy
 133          --  bit is not set, then the lock bit must not be set either.
 134
 135          pragma Assert (T_Counts.Lock = 0);
 136       end TC_Check;
 137
 138       --------------
 139       -- TE_Check --
 140       --------------
 141
 142       procedure TE_Check (T_Counts : Tamper_Counts) is
 143       begin
 144          if T_Check and then T_Counts.Lock > 0 then
 145             raise Program_Error with
 146               "attempt to tamper with elements";
 147          end if;
 148       end TE_Check;
 149
 150       ------------
 151       -- Unbusy --
 152       ------------
 153
 154       procedure Unbusy (T_Counts : in out Tamper_Counts) is
 155       begin
 156          if T_Check then
 157             SAC.Decrement (T_Counts.Busy);
 158          end if;
 159       end Unbusy;
 160
 161       ------------
 162       -- Unlock --
 163       ------------
 164
 165       procedure Unlock (T_Counts : in out Tamper_Counts) is
 166       begin
 167          if T_Check then
 168             SAC.Decrement (T_Counts.Lock);
 169             SAC.Decrement (T_Counts.Busy);
 170          end if;
 171       end Unlock;
 172
 173       -----------------
 174       -- Zero_Counts --
 175       -----------------
 176
 177       procedure Zero_Counts (T_Counts : out Tamper_Counts) is
 178       begin
 179          if T_Check then
 180             T_Counts := (others => <>);
 181          end if;
 182       end Zero_Counts;
 183
 184    end Generic_Implementation;
 185
 186 end Ada.Containers.Helpers;