blob: 4a0aa22fa841cbf9640683a5770a876352e11560 [file] [log] [blame]
------------------------------------------------------------------------------
-- --
-- GNAT COMPILER COMPONENTS --
-- --
-- S Y S T E M . G L O B A L _ L O C K S --
-- --
-- S p e c --
-- --
-- Copyright (C) 1999-2009, Free Software Foundation, Inc. --
-- --
-- GNAT is free software; you can redistribute it and/or modify it under --
-- terms of the GNU General Public License as published by the Free Soft- --
-- ware Foundation; either version 3, or (at your option) any later ver- --
-- sion. GNAT is distributed in the hope that it will be useful, but WITH- --
-- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
-- or FITNESS FOR A PARTICULAR PURPOSE. --
-- --
-- As a special exception under Section 7 of GPL version 3, you are granted --
-- additional permissions described in the GCC Runtime Library Exception, --
-- version 3.1, as published by the Free Software Foundation. --
-- --
-- You should have received a copy of the GNU General Public License and --
-- a copy of the GCC Runtime Library Exception along with this program; --
-- see the files COPYING3 and COPYING.RUNTIME respectively. If not, see --
-- <http://www.gnu.org/licenses/>. --
-- --
-- GNAT was originally developed by the GNAT team at New York University. --
-- Extensive contributions were provided by Ada Core Technologies Inc. --
-- --
------------------------------------------------------------------------------
-- This package contains the necessary routines to provide
-- reliable system wide locking capability.
package System.Global_Locks is
Lock_Error : exception;
-- Exception raised if a request cannot be executed on a lock
type Lock_Type is private;
-- Such a lock is a global lock between partitions. This lock is
-- uniquely defined between the partitions because of its name.
Null_Lock : constant Lock_Type;
-- This needs comments ???
procedure Create_Lock (Lock : out Lock_Type; Name : String);
-- Create or retrieve a global lock for the current partition using
-- its Name.
procedure Acquire_Lock (Lock : in out Lock_Type);
-- If the lock cannot be acquired because someone already owns it, this
-- procedure is supposed to wait and retry forever.
procedure Release_Lock (Lock : in out Lock_Type);
private
type Lock_Type is new Natural;
Null_Lock : constant Lock_Type := 0;
end System.Global_Locks;