------------------------------------------------------------------------------ -- -- -- 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, 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. -- -- -- -- 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;