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 --
9 -- Copyright (C) 1991-1994, Florida State University --
10 -- Copyright (C) 1995-2005, Ada Core Technologies --
12 -- GNARL is free software; you can redistribute it and/or modify it under --
13 -- terms of the GNU General Public License as published by the Free Soft- --
14 -- ware Foundation; either version 2, or (at your option) any later ver- --
15 -- sion. GNARL is distributed in the hope that it will be useful, but WITH- --
16 -- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
17 -- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License --
18 -- for more details. You should have received a copy of the GNU General --
19 -- Public License distributed with GNARL; see file COPYING. If not, write --
20 -- to the Free Software Foundation, 59 Temple Place - Suite 330, Boston, --
21 -- MA 02111-1307, USA. --
23 -- As a special exception, if other files instantiate generics from this --
24 -- unit, or you link this unit with other files to produce an executable, --
25 -- this unit does not by itself cause the resulting executable to be --
26 -- covered by the GNU General Public License. This exception does not --
27 -- however invalidate any other reasons why the executable file might be --
28 -- covered by the GNU Public License. --
30 -- GNARL was developed by the GNARL team at Florida State University. --
31 -- Extensive contributions were provided by Ada Core Technologies, Inc. --
33 ------------------------------------------------------------------------------
36 -- Turn off polling, we do not want ATC polling to take place during
37 -- tasking operations. It causes infinite loops and other problems.
39 with System.Task_Primitives.Operations;
40 -- used for Write_Lock
44 with System.Parameters;
45 -- used for Runtime_Traces
48 -- used for Send_Trace_Info
50 with System.Soft_Links.Tasking;
51 -- Used for Init_Tasking_Soft_Links
53 package body System.Tasking.Protected_Objects is
55 use System.Task_Primitives.Operations;
58 -------------------------
59 -- Finalize_Protection --
60 -------------------------
62 procedure Finalize_Protection (Object : in out Protection) is
64 Finalize_Lock (Object.L'Unrestricted_Access);
65 end Finalize_Protection;
67 ---------------------------
68 -- Initialize_Protection --
69 ---------------------------
71 procedure Initialize_Protection
72 (Object : Protection_Access;
73 Ceiling_Priority : Integer)
75 Init_Priority : Integer := Ceiling_Priority;
77 if Init_Priority = Unspecified_Priority then
78 Init_Priority := System.Priority'Last;
81 Initialize_Lock (Init_Priority, Object.L'Access);
82 Object.Ceiling := System.Any_Priority (Init_Priority);
83 end Initialize_Protection;
89 procedure Lock (Object : Protection_Access) is
90 Ceiling_Violation : Boolean;
93 -- The lock is made without defering abort
95 -- Therefore the abort has to be deferred before calling this routine.
96 -- This means that the compiler has to generate a Defer_Abort call
97 -- before the call to Lock.
99 -- The caller is responsible for undeferring abort, and compiler
100 -- generated calls must be protected with cleanup handlers to ensure
101 -- that abort is undeferred in all cases.
103 Write_Lock (Object.L'Access, Ceiling_Violation);
105 if Parameters.Runtime_Traces then
106 Send_Trace_Info (PO_Lock);
109 if Ceiling_Violation then
113 -- We are entering in a protected action, so that we increase the
114 -- protected object nesting level (if pragma Detect_Blocking is
117 if Detect_Blocking then
119 Self_Id : constant Task_Id := Self;
121 Self_Id.Common.Protected_Action_Nesting :=
122 Self_Id.Common.Protected_Action_Nesting + 1;
131 procedure Lock_Read_Only (Object : Protection_Access) is
132 Ceiling_Violation : Boolean;
135 Read_Lock (Object.L'Access, Ceiling_Violation);
137 if Parameters.Runtime_Traces then
138 Send_Trace_Info (PO_Lock);
141 if Ceiling_Violation then
145 -- We are entering in a protected action, so that we increase the
146 -- protected object nesting level (if pragma Detect_Blocking is
149 if Detect_Blocking then
151 Self_Id : constant Task_Id := Self;
153 Self_Id.Common.Protected_Action_Nesting :=
154 Self_Id.Common.Protected_Action_Nesting + 1;
163 procedure Unlock (Object : Protection_Access) is
165 -- We are exiting from a protected action, so that we decrease the
166 -- protected object nesting level (if pragma Detect_Blocking is
169 if Detect_Blocking then
171 Self_Id : constant Task_Id := Self;
174 -- Cannot call this procedure without being within a protected
177 pragma Assert (Self_Id.Common.Protected_Action_Nesting > 0);
179 Self_Id.Common.Protected_Action_Nesting :=
180 Self_Id.Common.Protected_Action_Nesting - 1;
184 Unlock (Object.L'Access);
186 if Parameters.Runtime_Traces then
187 Send_Trace_Info (PO_Unlock);
192 -- Ensure that tasking soft links are set when using protected objects
194 System.Soft_Links.Tasking.Init_Tasking_Soft_Links;
195 end System.Tasking.Protected_Objects;