------------------------------------------------------------------------------ -- -- -- 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) 1999-2021, 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 -- -- . -- -- -- -- 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;