------------------------------------------------------------------------------ -- -- -- GNAT COMPILER COMPONENTS -- -- -- -- G N A T . L O C K _ F I L E S -- -- -- -- S p e c -- -- -- -- Copyright (C) 1995-2005, AdaCore -- -- -- -- 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 2, 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. See the GNU General Public License -- -- for more details. You should have received a copy of the GNU General -- -- Public License distributed with GNAT; see file COPYING. If not, write -- -- to the Free Software Foundation, 51 Franklin Street, Fifth Floor, -- -- Boston, MA 02110-1301, USA. -- -- -- -- As a special exception, if other files instantiate generics from this -- -- unit, or you link this unit with other files to produce an executable, -- -- this unit does not by itself cause the resulting executable to be -- -- covered by the GNU General Public License. This exception does not -- -- however invalidate any other reasons why the executable file might be -- -- covered by the GNU Public License. -- -- -- -- 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 for using files for the -- purpose of providing realiable system wide locking capability. package GNAT.Lock_Files is pragma Preelaborate; Lock_Error : exception; -- Exception raised if file cannot be locked subtype Path_Name is String; -- Pathname is used by all services provided in this unit to specified -- directory name and file name. On DOS based systems both directory -- separators are handled (i.e. slash and backslash). procedure Lock_File (Directory : Path_Name; Lock_File_Name : Path_Name; Wait : Duration := 1.0; Retries : Natural := Natural'Last); -- Create a lock file Lock_File_Name in directory Directory. If the file -- cannot be locked because someone already owns the lock, this procedure -- waits Wait seconds and retries at most Retries times. If the file -- still cannot be locked, Lock_Error is raised. The default is to try -- every second, almost forever (Natural'Last times). The full path of -- the file is constructed by concatenating Directory and Lock_File_Name. -- Directory can optionally terminate with a directory separator. procedure Lock_File (Lock_File_Name : Path_Name; Wait : Duration := 1.0; Retries : Natural := Natural'Last); -- See above. The full lock file path is given as one string procedure Unlock_File (Directory : Path_Name; Lock_File_Name : Path_Name); -- Unlock a file. Directory can optionally terminate with a directory -- separator. procedure Unlock_File (Lock_File_Name : Path_Name); -- Unlock a file whose full path is given in Lock_File_Name end GNAT.Lock_Files;