gcc/ada/s-gloloc.ads

   1 ------------------------------------------------------------------------------
   2 --                                                                          --
   3 --                         GNAT COMPILER COMPONENTS                         --
   4 --                                                                          --
   5 --                  S Y S T E M . G L O B A L _ L O C K S                   --
   6 --                                                                          --
   7 --                                 S p e c                                  --
   8 --                                                                          --
   9 --          Copyright (C) 1999-2009, 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 package contains the necessary routines to provide
  33    --  reliable system wide locking capability.
  34
  35 package System.Global_Locks is
  36
  37    Lock_Error : exception;
  38    --  Exception raised if a request cannot be executed on a lock
  39
  40    type Lock_Type is private;
  41    --  Such a lock is a global lock between partitions. This lock is
  42    --  uniquely defined between the partitions because of its name.
  43
  44    Null_Lock : constant Lock_Type;
  45    --  This needs comments ???
  46
  47    procedure Create_Lock (Lock : out Lock_Type; Name : String);
  48    --  Create or retrieve a global lock for the current partition using
  49    --  its Name.
  50
  51    procedure Acquire_Lock (Lock : in out Lock_Type);
  52    --  If the lock cannot be acquired because someone already owns it, this
  53    --  procedure is supposed to wait and retry forever.
  54
  55    procedure Release_Lock (Lock : in out Lock_Type);
  56
  57 private
  58
  59    type Lock_Type is new Natural;
  60
  61    Null_Lock : constant Lock_Type := 0;
  62
  63 end System.Global_Locks;