gcc/ada/s-tataat.ads

   1 ------------------------------------------------------------------------------
   2 --                                                                          --
   3 --                GNU ADA RUN-TIME LIBRARY (GNARL) COMPONENTS               --
   4 --                                                                          --
   5 --         S Y S T E M . T A S K I N G . T A S K _ A T T R I B U T E S      --
   6 --                                                                          --
   7 --                                  S p e c                                 --
   8 --                                                                          --
   9 --                             $Revision: 1.9 $
  10 --                                                                          --
  11 --             Copyright (C) 1995-2000 Florida State University             --
  12 --                                                                          --
  13 -- GNARL is free software; you can  redistribute it  and/or modify it under --
  14 -- terms of the  GNU General Public License as published  by the Free Soft- --
  15 -- ware  Foundation;  either version 2,  or (at your option) any later ver- --
  16 -- sion. GNARL is distributed in the hope that it will be useful, but WITH- --
  17 -- OUT ANY WARRANTY;  without even the  implied warranty of MERCHANTABILITY --
  18 -- or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License --
  19 -- for  more details.  You should have  received  a copy of the GNU General --
  20 -- Public License  distributed with GNARL; see file COPYING.  If not, write --
  21 -- to  the Free Software Foundation,  59 Temple Place - Suite 330,  Boston, --
  22 -- MA 02111-1307, USA.                                                      --
  23 --                                                                          --
  24 -- As a special exception,  if other files  instantiate  generics from this --
  25 -- unit, or you link  this unit with other files  to produce an executable, --
  26 -- this  unit  does not  by itself cause  the resulting  executable  to  be --
  27 -- covered  by the  GNU  General  Public  License.  This exception does not --
  28 -- however invalidate  any other reasons why  the executable file  might be --
  29 -- covered by the  GNU Public License.                                      --
  30 --                                                                          --
  31 -- GNARL was developed by the GNARL team at Florida State University. It is --
  32 -- now maintained by Ada Core Technologies Inc. in cooperation with Florida --
  33 -- State University (http://www.gnat.com).                                  --
  34 --                                                                          --
  35 ------------------------------------------------------------------------------
  36
  37 --  This package provides support for the body of Ada.Task_Attributes.
  38
  39 with Ada.Finalization;
  40 --  used for Limited_Controlled
  41
  42 with System.Storage_Elements;
  43 --  used for Integer_Address
  44
  45 package System.Tasking.Task_Attributes is
  46
  47    type Attribute is new Integer;
  48    --  A stand-in for the generic formal type of Ada.Task_Attributes
  49    --  in the following declarations.
  50
  51    type Node;
  52    type Access_Node is access all Node;
  53    type Dummy_Wrapper;
  54    type Access_Dummy_Wrapper is access all Dummy_Wrapper;
  55
  56    type Deallocator is access procedure (P : in out Access_Node);
  57    --  Called to deallocate an Wrapper. P is a pointer to a Node within.
  58
  59    type Instance;
  60
  61    type Access_Instance is access all Instance;
  62
  63    type Instance is new Ada.Finalization.Limited_Controlled with record
  64       Deallocate    : Deallocator;
  65       Initial_Value : aliased System.Storage_Elements.Integer_Address;
  66
  67       Index : Direct_Index;
  68       --  The index of the TCB location used by this instantiation,
  69       --  if it is stored in the TCB, otherwise zero.
  70
  71       Next : Access_Instance;
  72       --  Next instance in All_Attributes list.
  73    end record;
  74
  75    procedure Finalize (X : in out Instance);
  76
  77    type Node is record
  78       Wrapper  : Access_Dummy_Wrapper;
  79       Instance : Access_Instance;
  80       Next     : Access_Node;
  81    end record;
  82
  83    --  The following type is a stand-in for the actual
  84    --  wrapper type, which is different for each instantiation
  85    --  of Ada.Task_Attributes.
  86
  87    type Dummy_Wrapper is record
  88       Noed : aliased Node;
  89
  90       Value : aliased Attribute;
  91       --  The generic formal type, may be controlled
  92    end record;
  93
  94    In_Use : Direct_Index_Vector := 0;
  95    --  is True for direct indices that are already used.
  96
  97    All_Attributes : Access_Instance;
  98    --  A linked list of all indirectly access attributes,
  99    --  which includes all those that require finalization.
 100
 101    All_Attrs_L : aliased System.Task_Primitives.RTS_Lock;
 102    --  Protects In_Use, Next_Indirect_Index, and All_Attributes.
 103    --  Deadlock prevention order of locking:
 104    --    1) All_Attrs_L
 105    --    2) All_Tasks_L
 106    --    3) any TCB.L
 107
 108    procedure Initialize_Attributes (T : Task_ID);
 109    --  Initialize all attributes created via Ada.Task_Attributes for T.
 110    --  This must be called by the creator of the task, inside Create_Task,
 111    --  via soft-link Initialize_Attributes_Link. On entry, abortion must
 112    --  be deferred and the caller must hold no locks
 113
 114    procedure Finalize_Attributes (T : Task_ID);
 115    --  Finalize all attributes created via Ada.Task_Attributes for T.
 116    --  This is to be called by the task after it is marked as terminated
 117    --  (and before it actually dies), inside Vulnerable_Free_Task, via the
 118    --  soft-link Finalize_Attributes_Link. On entry, abortion must be deferred
 119    --  and T.L must be write-locked.
 120
 121 end System.Tasking.Task_Attributes;