gcc/ada/libgnat/s-spsufi.adb

   1 ------------------------------------------------------------------------------
   2 --                                                                          --
   3 --                         GNAT COMPILER COMPONENTS                         --
   4 --                                                                          --
   5 --                SYSTEM.STORAGE_POOLS.SUBPOOLS.FINALIZATION                --
   6 --                                                                          --
   7 --                                 B o d y                                  --
   8 --                                                                          --
   9 --          Copyright (C) 2011-2023, 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 with Ada.Unchecked_Deallocation;
  33
  34 with System.Finalization_Masters; use System.Finalization_Masters;
  35
  36 package body System.Storage_Pools.Subpools.Finalization is
  37
  38    -----------------------------
  39    -- Finalize_And_Deallocate --
  40    -----------------------------
  41
  42    procedure Finalize_And_Deallocate (Subpool : in out Subpool_Handle) is
  43       procedure Free is new Ada.Unchecked_Deallocation (SP_Node, SP_Node_Ptr);
  44
  45    begin
  46       --  Do nothing if the subpool was never created or never used. The latter
  47       --  case may arise with an array of subpool implementations.
  48
  49       if Subpool = null
  50         or else Subpool.Owner = null
  51         or else Subpool.Node = null
  52       then
  53          return;
  54       end if;
  55
  56       --  Clean up all controlled objects chained on the subpool's master
  57
  58       Finalize (Subpool.Master);
  59
  60       --  Remove the subpool from its owner's list of subpools
  61
  62       Detach (Subpool.Node);
  63
  64       --  Destroy the associated doubly linked list node which was created in
  65       --  Set_Pool_Of_Subpools.
  66
  67       Free (Subpool.Node);
  68
  69       --  Dispatch to the user-defined implementation of Deallocate_Subpool. It
  70       --  is important to first set Subpool.Owner to null, because RM-13.11.5
  71       --  requires that "The subpool no longer belongs to any pool" BEFORE
  72       --  calling Deallocate_Subpool. The actual dispatching call required is:
  73       --
  74       --     Deallocate_Subpool(Pool_Of_Subpool(Subpool).all, Subpool);
  75       --
  76       --  but that can't be taken literally, because Pool_Of_Subpool will
  77       --  return null.
  78
  79       declare
  80          Owner : constant Any_Storage_Pool_With_Subpools_Ptr := Subpool.Owner;
  81       begin
  82          Subpool.Owner := null;
  83          Deallocate_Subpool (Owner.all, Subpool);
  84       end;
  85
  86       Subpool := null;
  87    end Finalize_And_Deallocate;
  88
  89 end System.Storage_Pools.Subpools.Finalization;