1 ------------------------------------------------------------------------------
3 -- GNU ADA RUN-TIME LIBRARY (GNARL) COMPONENTS --
5 -- S Y S T E M . T A S K I N G . P R O T E C T E D _ O B J E C T S --
11 -- Copyright (C) 1991-2001 Florida State University --
13 -- GNARL is free software; you can redistribute it and/or modify it under --
14 -- terms of the GNU General Public License as published by the Free Soft- --
15 -- ware Foundation; either version 2, or (at your option) any later ver- --
16 -- sion. GNARL is distributed in the hope that it will be useful, but WITH- --
17 -- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
18 -- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License --
19 -- for more details. You should have received a copy of the GNU General --
20 -- Public License distributed with GNARL; see file COPYING. If not, write --
21 -- to the Free Software Foundation, 59 Temple Place - Suite 330, Boston, --
22 -- MA 02111-1307, USA. --
24 -- As a special exception, if other files instantiate generics from this --
25 -- unit, or you link this unit with other files to produce an executable, --
26 -- this unit does not by itself cause the resulting executable to be --
27 -- covered by the GNU General Public License. This exception does not --
28 -- however invalidate any other reasons why the executable file might be --
29 -- covered by the GNU Public License. --
31 -- GNARL was developed by the GNARL team at Florida State University. It is --
32 -- now maintained by Ada Core Technologies Inc. in cooperation with Florida --
33 -- State University (http://www.gnat.com). --
35 ------------------------------------------------------------------------------
38 -- Turn off polling, we do not want ATC polling to take place during
39 -- tasking operations. It causes infinite loops and other problems.
41 with System.Task_Primitives.Operations;
42 -- used for Write_Lock
45 package body System.Tasking.Protected_Objects is
47 use System.Task_Primitives.Operations;
49 -------------------------
50 -- Finalize_Protection --
51 -------------------------
53 procedure Finalize_Protection (Object : in out Protection) is
55 Finalize_Lock (Object.L'Unrestricted_Access);
56 end Finalize_Protection;
58 ---------------------------
59 -- Initialize_Protection --
60 ---------------------------
62 procedure Initialize_Protection
63 (Object : Protection_Access;
64 Ceiling_Priority : Integer)
66 Init_Priority : Integer := Ceiling_Priority;
68 if Init_Priority = Unspecified_Priority then
69 Init_Priority := System.Priority'Last;
72 Initialize_Lock (Init_Priority, Object.L'Access);
73 Object.Ceiling := System.Any_Priority (Init_Priority);
74 end Initialize_Protection;
80 procedure Lock (Object : Protection_Access) is
81 Ceiling_Violation : Boolean;
83 -- The lock is made without defering abortion.
85 -- Therefore the abortion has to be deferred before calling this
86 -- routine. This means that the compiler has to generate a Defer_Abort
87 -- call before the call to Lock.
89 -- The caller is responsible for undeferring abortion, and compiler
90 -- generated calls must be protected with cleanup handlers to ensure
91 -- that abortion is undeferred in all cases.
93 Write_Lock (Object.L'Access, Ceiling_Violation);
95 if Ceiling_Violation then
104 procedure Lock_Read_Only (Object : Protection_Access) is
105 Ceiling_Violation : Boolean;
107 Read_Lock (Object.L'Access, Ceiling_Violation);
109 if Ceiling_Violation then
118 procedure Unlock (Object : Protection_Access) is
120 Unlock (Object.L'Access);
123 end System.Tasking.Protected_Objects;