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Diffstat (limited to 'gcc-4.4.3/gcc/ada/s-gloloc.adb')
| -rw-r--r-- | gcc-4.4.3/gcc/ada/s-gloloc.adb | 149 |
1 files changed, 149 insertions, 0 deletions
diff --git a/gcc-4.4.3/gcc/ada/s-gloloc.adb b/gcc-4.4.3/gcc/ada/s-gloloc.adb new file mode 100644 index 000000000..331e67ffb --- /dev/null +++ b/gcc-4.4.3/gcc/ada/s-gloloc.adb @@ -0,0 +1,149 @@ +------------------------------------------------------------------------------ +-- -- +-- GNAT COMPILER COMPONENTS -- +-- -- +-- S Y S T E M . G L O B A L _ L O C K S -- +-- -- +-- B o d y -- +-- -- +-- Copyright (C) 1999-2009, 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.Soft_Links; + +package body System.Global_Locks is + + type String_Access is access String; + + Dir_Separator : Character; + pragma Import (C, Dir_Separator, "__gnat_dir_separator"); + + type Lock_File_Entry is record + Dir : String_Access; + File : String_Access; + end record; + + Last_Lock : Lock_Type := Null_Lock; + Lock_Table : array (Lock_Type range 1 .. 15) of Lock_File_Entry; + + procedure Lock_File + (Dir : String; + File : String; + Wait : Duration := 0.1; + Retries : Natural := Natural'Last); + -- Create a lock file File in directory Dir. If the file cannot be + -- locked because someone already owns the lock, this procedure + -- waits Wait seconds and retries at most Retries times. If the file + -- still cannot be locked, Lock_Error is raised. The default is to try + -- every second, almost forever (Natural'Last times). + + ------------------ + -- Acquire_Lock -- + ------------------ + + procedure Acquire_Lock (Lock : in out Lock_Type) is + begin + Lock_File + (Lock_Table (Lock).Dir.all, + Lock_Table (Lock).File.all); + end Acquire_Lock; + + ----------------- + -- Create_Lock -- + ----------------- + + procedure Create_Lock (Lock : out Lock_Type; Name : String) is + L : Lock_Type; + + begin + System.Soft_Links.Lock_Task.all; + Last_Lock := Last_Lock + 1; + L := Last_Lock; + System.Soft_Links.Unlock_Task.all; + + if L > Lock_Table'Last then + raise Lock_Error; + end if; + + for J in reverse Name'Range loop + if Name (J) = Dir_Separator then + Lock_Table (L).Dir := new String'(Name (Name'First .. J - 1)); + Lock_Table (L).File := new String'(Name (J + 1 .. Name'Last)); + exit; + end if; + end loop; + + if Lock_Table (L).Dir = null then + Lock_Table (L).Dir := new String'("."); + Lock_Table (L).File := new String'(Name); + end if; + + Lock := L; + end Create_Lock; + + --------------- + -- Lock_File -- + --------------- + + procedure Lock_File + (Dir : String; + File : String; + Wait : Duration := 0.1; + Retries : Natural := Natural'Last) + is + C_Dir : aliased String := Dir & ASCII.NUL; + C_File : aliased String := File & ASCII.NUL; + + function Try_Lock (Dir, File : System.Address) return Integer; + pragma Import (C, Try_Lock, "__gnat_try_lock"); + + begin + for I in 0 .. Retries loop + if Try_Lock (C_Dir'Address, C_File'Address) = 1 then + return; + end if; + + exit when I = Retries; + delay Wait; + end loop; + + raise Lock_Error; + end Lock_File; + + ------------------ + -- Release_Lock -- + ------------------ + + procedure Release_Lock (Lock : in out Lock_Type) is + S : aliased String := + Lock_Table (Lock).Dir.all & Dir_Separator & + Lock_Table (Lock).File.all & ASCII.NUL; + + procedure unlink (A : System.Address); + pragma Import (C, unlink, "unlink"); + + begin + unlink (S'Address); + end Release_Lock; + +end System.Global_Locks; |