1 ------------------------------------------------------------------------------
3 -- GNAT COMPILER COMPONENTS --
5 -- G N A T . L O C K _ F I L E S --
11 -- Copyright (C) 1995-2001 Ada Core Technologies, Inc. --
13 -- GNAT is free software; you can redistribute it and/or modify it under --
14 -- terms of the GNU General Public License as published by the Free Soft- --
15 -- ware Foundation; either version 2, or (at your option) any later ver- --
16 -- sion. GNAT is distributed in the hope that it will be useful, but WITH- --
17 -- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
18 -- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License --
19 -- for more details. You should have received a copy of the GNU General --
20 -- Public License distributed with GNAT; see file COPYING. If not, write --
21 -- to the Free Software Foundation, 59 Temple Place - Suite 330, Boston, --
22 -- MA 02111-1307, USA. --
24 -- As a special exception, if other files instantiate generics from this --
25 -- unit, or you link this unit with other files to produce an executable, --
26 -- this unit does not by itself cause the resulting executable to be --
27 -- covered by the GNU General Public License. This exception does not --
28 -- however invalidate any other reasons why the executable file might be --
29 -- covered by the GNU Public License. --
31 -- GNAT is maintained by Ada Core Technologies Inc (http://www.gnat.com). --
33 ------------------------------------------------------------------------------
35 -- This package contains the necessary routines for using files for the
36 -- purpose of providing realiable system wide locking capability.
38 package GNAT.Lock_Files is
41 Lock_Error : exception;
42 -- Exception raised if file cannot be locked
46 Lock_File_Name : String;
47 Wait : Duration := 1.0;
48 Retries : Natural := Natural'Last);
49 -- Create a lock file Lock_File_Name in directory Directory. If the file
50 -- cannot be locked because someone already owns the lock, this procedure
51 -- waits Wait seconds and retries at most Retries times. If the file
52 -- still cannot be locked, Lock_Error is raised. The default is to try
53 -- every second, almost forever (Natural'Last times).
56 (Lock_File_Name : String;
57 Wait : Duration := 1.0;
58 Retries : Natural := Natural'Last);
59 -- See above. The full lock file path is given as one string.
61 procedure Unlock_File (Directory : String; Lock_File_Name : String);
64 procedure Unlock_File (Lock_File_Name : String);
65 -- Unlock a file whose full path is given in Lock_File_Name