| ------------------------------------------------------------------------------ |
| -- -- |
| -- GNAT COMPILER COMPONENTS -- |
| -- -- |
| -- G N A T . L O C K _ F I L E S -- |
| -- -- |
| -- B o d y -- |
| -- -- |
| -- Copyright (C) 1998-2001 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 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. -- |
| -- -- |
| ------------------------------------------------------------------------------ |
| |
| with System; |
| |
| package body GNAT.Lock_Files is |
| |
| Dir_Separator : Character; |
| pragma Import (C, Dir_Separator, "__gnat_dir_separator"); |
| |
| --------------- |
| -- Lock_File -- |
| --------------- |
| |
| procedure Lock_File |
| (Directory : Path_Name; |
| Lock_File_Name : Path_Name; |
| Wait : Duration := 1.0; |
| Retries : Natural := Natural'Last) |
| is |
| Dir : aliased String := Directory & ASCII.NUL; |
| File : aliased String := Lock_File_Name & ASCII.NUL; |
| |
| function Try_Lock (Dir, File : System.Address) return Integer; |
| pragma Import (C, Try_Lock, "__gnat_try_lock"); |
| |
| begin |
| -- If a directory separator was provided, just remove the one we have |
| -- added above. |
| |
| if Directory (Directory'Last) = Dir_Separator |
| or else Directory (Directory'Last) = '/' |
| then |
| Dir (Dir'Last - 1) := ASCII.Nul; |
| end if; |
| |
| -- Try to lock the file Retries times |
| |
| for I in 0 .. Retries loop |
| if Try_Lock (Dir'Address, File'Address) = 1 then |
| return; |
| end if; |
| |
| exit when I = Retries; |
| delay Wait; |
| end loop; |
| |
| raise Lock_Error; |
| end Lock_File; |
| |
| --------------- |
| -- Lock_File -- |
| --------------- |
| |
| procedure Lock_File |
| (Lock_File_Name : Path_Name; |
| Wait : Duration := 1.0; |
| Retries : Natural := Natural'Last) |
| is |
| begin |
| for J in reverse Lock_File_Name'Range loop |
| if Lock_File_Name (J) = Dir_Separator |
| or else Lock_File_Name (J) = '/' |
| then |
| Lock_File |
| (Lock_File_Name (Lock_File_Name'First .. J - 1), |
| Lock_File_Name (J + 1 .. Lock_File_Name'Last), |
| Wait, |
| Retries); |
| return; |
| end if; |
| end loop; |
| |
| Lock_File (".", Lock_File_Name, Wait, Retries); |
| end Lock_File; |
| |
| ----------------- |
| -- Unlock_File -- |
| ----------------- |
| |
| procedure Unlock_File (Lock_File_Name : Path_Name) is |
| S : aliased String := Lock_File_Name & ASCII.NUL; |
| |
| procedure unlink (A : System.Address); |
| pragma Import (C, unlink, "unlink"); |
| |
| begin |
| unlink (S'Address); |
| end Unlock_File; |
| |
| ----------------- |
| -- Unlock_File -- |
| ----------------- |
| |
| procedure Unlock_File (Directory : Path_Name; Lock_File_Name : Path_Name) is |
| begin |
| if Directory (Directory'Last) = Dir_Separator |
| or else Directory (Directory'Last) = '/' |
| then |
| Unlock_File (Directory & Lock_File_Name); |
| else |
| Unlock_File (Directory & Dir_Separator & Lock_File_Name); |
| end if; |
| end Unlock_File; |
| |
| end GNAT.Lock_Files; |
