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Diffstat (limited to 'gcc/ada/g-locfil.adb')
| -rw-r--r-- | gcc/ada/g-locfil.adb | 134 |
1 files changed, 134 insertions, 0 deletions
diff --git a/gcc/ada/g-locfil.adb b/gcc/ada/g-locfil.adb new file mode 100644 index 000000000..5449dc6e3 --- /dev/null +++ b/gcc/ada/g-locfil.adb @@ -0,0 +1,134 @@ +------------------------------------------------------------------------------ +-- -- +-- GNAT COMPILER COMPONENTS -- +-- -- +-- G N A T . L O C K _ F I L E S -- +-- -- +-- B o d y -- +-- -- +-- Copyright (C) 1998-2009, 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 3, 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. -- +-- -- +-- As a special exception under Section 7 of GPL version 3, you are granted -- +-- additional permissions described in the GCC Runtime Library Exception, -- +-- version 3.1, as published by the Free Software Foundation. -- +-- -- +-- You should have received a copy of the GNU General Public License and -- +-- a copy of the GCC Runtime Library Exception along with this program; -- +-- see the files COPYING3 and COPYING.RUNTIME respectively. If not, see -- +-- <http://www.gnu.org/licenses/>. -- +-- -- +-- 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; |