| ------------------------------------------------------------------------------ |
| -- -- |
| -- GNAT COMPILER COMPONENTS -- |
| -- -- |
| -- G N A T . L O C K _ F I L E S -- |
| -- -- |
| -- S p e c -- |
| -- -- |
| -- Copyright (C) 1995-2001 Ada Core Technologies, 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 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, 59 Temple Place - Suite 330, Boston, -- |
| -- MA 02111-1307, 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; |
