------------------------------------------------------------------------------
-- --
--- GNU ADA RUN-TIME LIBRARY (GNARL) COMPONENTS --
+-- GNAT RUN-TIME LIBRARY (GNARL) COMPONENTS --
-- --
-- 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 --
-- --
-- S p e c --
-- --
--- Copyright (C) 1992-2003, Free Software Foundation, Inc. --
+-- Copyright (C) 1992-2006, Free Software Foundation, Inc. --
-- --
-- GNARL 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- --
-- 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 GNARL; see file COPYING. If not, write --
--- to the Free Software Foundation, 59 Temple Place - Suite 330, Boston, --
--- MA 02111-1307, USA. --
+-- to the Free Software Foundation, 51 Franklin Street, Fifth Floor, --
+-- Boston, MA 02110-1301, 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, --
-- Note: the compiler generates direct calls to this interface, via Rtsfind.
-- Any changes to this interface may require corresponding compiler changes
--- in exp_ch9.adb and possibly exp_ch7.adb
+-- in exp_ch9.adb and possibly exp_ch7.adb and exp_attr.adb
package System.Tasking.Protected_Objects is
pragma Elaborate_Body;
Null_PO : constant Protection_Access := null;
+ function Get_Ceiling
+ (Object : Protection_Access) return System.Any_Priority;
+ -- Returns the new ceiling priority of the protected object
+
procedure Initialize_Protection
(Object : Protection_Access;
Ceiling_Priority : Integer);
-- for possible future use. At the current time, everyone uses Lock
-- for both read and write locks.
+ procedure Set_Ceiling
+ (Object : Protection_Access;
+ Prio : System.Any_Priority);
+ -- Sets the new ceiling priority of the protected object
+
procedure Unlock (Object : Protection_Access);
-- Relinquish ownership of the lock for the object represented by
-- the Object parameter. If this ownership was for write access, or
private
type Protection is record
- L : aliased Task_Primitives.Lock;
+ L : aliased Task_Primitives.Lock;
+ -- Lock used to ensure mutual exclusive access to the protected object
+
Ceiling : System.Any_Priority;
+ -- Ceiling priority associated to the protected object
+
+ New_Ceiling : System.Any_Priority;
+ -- New ceiling priority associated to the protected object. In case
+ -- of assignment of a new ceiling priority to the protected object the
+ -- frontend generates a call to set_ceiling to save the new value in
+ -- this field. After such assignment this value can be read by means
+ -- of the 'Priority attribute, which generates a call to get_ceiling.
+ -- However, the ceiling of the protected object will not be changed
+ -- until completion of the protected action in which the assignment
+ -- has been executed (AARM D.5.2 (10/2)).
+
+ Owner : Task_Id;
+ -- This field contains the protected object's owner. Null_Task
+ -- indicates that the protected object is not currently being used.
+ -- This information is used for detecting the type of potentially
+ -- blocking operations described in the ARM 9.5.1, par. 15 (external
+ -- calls on a protected subprogram with the same target object as that
+ -- of the protected action).
end record;
procedure Finalize_Protection (Object : in out Protection);
- -- Clean up a Protection object; in particular, finalize the associated
- -- Lock object. The compiler generates automatically calls to this
+ -- Clean up a Protection object (in particular, finalize the associated
+ -- Lock object). The compiler generates calls automatically to this
-- procedure
end System.Tasking.Protected_Objects;
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