1 ------------------------------------------------------------------------------
3 -- GNAT COMPILER COMPONENTS --
5 -- G N A T . L O C K _ F I L E S --
9 -- Copyright (C) 1995-2023, AdaCore --
11 -- GNAT is free software; you can redistribute it and/or modify it under --
12 -- terms of the GNU General Public License as published by the Free Soft- --
13 -- ware Foundation; either version 3, or (at your option) any later ver- --
14 -- sion. GNAT is distributed in the hope that it will be useful, but WITH- --
15 -- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
16 -- or FITNESS FOR A PARTICULAR PURPOSE. --
18 -- As a special exception under Section 7 of GPL version 3, you are granted --
19 -- additional permissions described in the GCC Runtime Library Exception, --
20 -- version 3.1, as published by the Free Software Foundation. --
22 -- You should have received a copy of the GNU General Public License and --
23 -- a copy of the GCC Runtime Library Exception along with this program; --
24 -- see the files COPYING3 and COPYING.RUNTIME respectively. If not, see --
25 -- <http://www.gnu.org/licenses/>. --
27 -- GNAT was originally developed by the GNAT team at New York University. --
28 -- Extensive contributions were provided by Ada Core Technologies Inc. --
30 ------------------------------------------------------------------------------
32 -- This package contains the necessary routines for using files for the
33 -- purpose of providing reliable system wide locking capability.
35 package GNAT
.Lock_Files
is
38 Lock_Error
: exception;
39 -- Exception raised if file cannot be locked
41 subtype Path_Name
is String;
42 -- Pathname is used by all services provided in this unit to specify
43 -- directory name and file name. On DOS based systems both directory
44 -- separators are handled (i.e. slash and backslash).
47 (Directory
: Path_Name
;
48 Lock_File_Name
: Path_Name
;
49 Wait
: Duration := 1.0;
50 Retries
: Natural := Natural'Last);
51 -- Create a lock file Lock_File_Name in directory Directory. If the file
52 -- cannot be locked because someone already owns the lock, this procedure
53 -- waits Wait seconds and retries at most Retries times. If the file
54 -- still cannot be locked, Lock_Error is raised. The default is to try
55 -- every second, almost forever (Natural'Last times). The full path of
56 -- the file is constructed by concatenating Directory and Lock_File_Name.
57 -- Directory can optionally terminate with a directory separator.
60 (Lock_File_Name
: Path_Name
;
61 Wait
: Duration := 1.0;
62 Retries
: Natural := Natural'Last);
63 -- See above. The full lock file path is given as one string
65 procedure Unlock_File
(Directory
: Path_Name
; Lock_File_Name
: Path_Name
);
66 -- Unlock a file. Directory can optionally terminate with a directory
69 procedure Unlock_File
(Lock_File_Name
: Path_Name
);
70 -- Unlock a file whose full path is given in Lock_File_Name