-- --
-- 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 I N G L E _ E N T R Y --
+-- SYSTEM.TASKING.PROTECTED_OBJECTS.SINGLE_ENTRY --
-- --
-- B o d y --
-- --
--- Copyright (C) 1998-2005, Free Software Foundation, Inc. --
+-- Copyright (C) 1998-2009, 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- --
--- ware Foundation; either version 2, or (at your option) any later ver- --
--- sion. GNARL is distributed in the hope that it will be useful, but WITH- --
+-- 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. 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. --
+-- or FITNESS FOR A PARTICULAR PURPOSE. --
-- --
--- As a special exception, if other files instantiate generics from this --
--- unit, or you link this unit with other files to produce an executable, --
--- this unit does not by itself cause the resulting executable to be --
--- covered by the GNU General Public License. This exception does not --
--- however invalidate any other reasons why the executable file might be --
--- covered by the GNU Public License. --
+-- 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/>. --
-- --
-- GNARL was developed by the GNARL team at Florida State University. --
-- Extensive contributions were provided by Ada Core Technologies, Inc. --
------------------------------------------------------------------------------
pragma Style_Checks (All_Checks);
--- Turn off subprogram ordering check, since restricted GNARLI
--- subprograms are gathered together at end.
+-- Turn off subprogram ordering check, since restricted GNARLI subprograms are
+-- gathered together at end.
-- This package provides an optimized version of Protected_Objects.Operations
-- and Protected_Objects.Entries making the following assumptions:
-- operations. It can cause infinite loops and other problems.
pragma Suppress (All_Checks);
-
-with System.Task_Primitives.Operations;
--- used for Self
--- Finalize_Lock
--- Write_Lock
--- Unlock
+-- Why is this required ???
with Ada.Exceptions;
--- used for Exception_Id
--- Raise_Exception
+with System.Task_Primitives.Operations;
with System.Parameters;
--- used for Single_Lock
package body System.Tasking.Protected_Objects.Single_Entry is
use type Ada.Exceptions.Exception_Id;
E : constant Ada.Exceptions.Exception_Id :=
- Entry_Call.Exception_To_Raise;
+ Entry_Call.Exception_To_Raise;
begin
if E /= Ada.Exceptions.Null_Id then
is
Self_Id : constant Task_Id := Entry_Call.Self;
Timedout : Boolean;
+
Yielded : Boolean;
+ pragma Unreferenced (Yielded);
use type Ada.Exceptions.Exception_Id;
STPO.Timed_Sleep
(Self_Id, Wakeup_Time, Mode, Entry_Caller_Sleep, Timedout, Yielded);
- if Timedout then
- Entry_Call.State := Cancelled;
- else
- Entry_Call.State := Done;
- end if;
-
+ Entry_Call.State := (if Timedout then Cancelled else Done);
Self_Id.Common.State := Runnable;
end Wait_For_Completion_With_Timeout;
Compiler_Info : System.Address;
Entry_Body : Entry_Body_Access)
is
- Init_Priority : Integer := Ceiling_Priority;
begin
- if Init_Priority = Unspecified_Priority then
- Init_Priority := System.Priority'Last;
- end if;
+ Initialize_Protection (Object.Common'Access, Ceiling_Priority);
- STPO.Initialize_Lock (Init_Priority, Object.L'Access);
- Object.Ceiling := System.Any_Priority (Init_Priority);
- Object.Owner := Null_Task;
Object.Compiler_Info := Compiler_Info;
Object.Call_In_Progress := null;
Object.Entry_Body := Entry_Body;
-- Do not call this procedure from within the run-time system.
procedure Lock_Entry (Object : Protection_Entry_Access) is
- Ceiling_Violation : Boolean;
-
begin
- -- If pragma Detect_Blocking is active then, as described in the ARM
- -- 9.5.1, par. 15, we must check whether this is an external call on a
- -- protected subprogram with the same target object as that of the
- -- protected action that is currently in progress (i.e., if the caller
- -- is already the protected object's owner). If this is the case hence
- -- Program_Error must be raised.
-
- if Detect_Blocking and then Object.Owner = Self then
- raise Program_Error;
- end if;
-
- STPO.Write_Lock (Object.L'Access, Ceiling_Violation);
-
- if Ceiling_Violation then
- raise Program_Error;
- end if;
-
- -- We are entering in a protected action, so that we increase the
- -- protected object nesting level (if pragma Detect_Blocking is
- -- active), and update the protected object's owner.
-
- if Detect_Blocking then
- declare
- Self_Id : constant Task_Id := Self;
-
- begin
- -- Update the protected object's owner
-
- Object.Owner := Self_Id;
-
- -- Increase protected object nesting level
-
- Self_Id.Common.Protected_Action_Nesting :=
- Self_Id.Common.Protected_Action_Nesting + 1;
- end;
- end if;
+ Lock (Object.Common'Access);
end Lock_Entry;
--------------------------
-- Do not call this procedure from within the runtime system
procedure Lock_Read_Only_Entry (Object : Protection_Entry_Access) is
- Ceiling_Violation : Boolean;
-
begin
- -- If pragma Detect_Blocking is active then, as described in the ARM
- -- 9.5.1, par. 15, we must check whether this is an external call on a
- -- protected subprogram with the same target object as that of the
- -- protected action that is currently in progress (i.e., if the caller
- -- is already the protected object's owner). If this is the case hence
- -- Program_Error must be raised.
-
- -- Note that in this case (getting read access), several tasks may
- -- have read ownership of the protected object, so that this method of
- -- storing the (single) protected object's owner does not work
- -- reliably for read locks. However, this is the approach taken for two
- -- major reasosn: first, this function is not currently being used (it
- -- is provided for possible future use), and second, it largely
- -- simplifies the implementation.
-
- if Detect_Blocking and then Object.Owner = Self then
- raise Program_Error;
- end if;
-
- STPO.Read_Lock (Object.L'Access, Ceiling_Violation);
-
- if Ceiling_Violation then
- raise Program_Error;
- end if;
-
- -- We are entering in a protected action, so that we increase the
- -- protected object nesting level (if pragma Detect_Blocking is
- -- active), and update the protected object's owner.
-
- if Detect_Blocking then
- declare
- Self_Id : constant Task_Id := Self;
-
- begin
- -- Update the protected object's owner
-
- Object.Owner := Self_Id;
-
- -- Increase protected object nesting level
-
- Self_Id.Common.Protected_Action_Nesting :=
- Self_Id.Common.Protected_Action_Nesting + 1;
- end;
- end if;
+ Lock_Read_Only (Object.Common'Access);
end Lock_Read_Only_Entry;
--------------------
Uninterpreted_Data : System.Address;
Mode : Call_Modes)
is
- Self_Id : constant Task_Id := STPO.Self;
- Entry_Call : Entry_Call_Record renames Self_Id.Entry_Calls (1);
- Ceiling_Violation : Boolean;
-
+ Self_Id : constant Task_Id := STPO.Self;
+ Entry_Call : Entry_Call_Record renames Self_Id.Entry_Calls (1);
begin
-- If pragma Detect_Blocking is active then Program_Error must be
-- raised if this potentially blocking operation is called from a
if Detect_Blocking
and then Self_Id.Common.Protected_Action_Nesting > 0
then
- Ada.Exceptions.Raise_Exception
- (Program_Error'Identity, "potentially blocking operation");
+ raise Program_Error with "potentially blocking operation";
end if;
- STPO.Write_Lock (Object.L'Access, Ceiling_Violation);
-
- if Ceiling_Violation then
- raise Program_Error;
- end if;
+ Lock_Entry (Object);
Entry_Call.Mode := Mode;
Entry_Call.State := Now_Abortable;
-- Timed_Protected_Single_Entry_Call --
---------------------------------------
- -- Compiler interface only. Do not call from within the RTS.
+ -- Compiler interface only (do not call from within the RTS)
procedure Timed_Protected_Single_Entry_Call
(Object : Protection_Entry_Access;
is
Self_Id : constant Task_Id := STPO.Self;
Entry_Call : Entry_Call_Record renames Self_Id.Entry_Calls (1);
- Ceiling_Violation : Boolean;
begin
-- If pragma Detect_Blocking is active then Program_Error must be
if Detect_Blocking
and then Self_Id.Common.Protected_Action_Nesting > 0
then
- Ada.Exceptions.Raise_Exception
- (Program_Error'Identity, "potentially blocking operation");
+ raise Program_Error with "potentially blocking operation";
end if;
- STPO.Write_Lock (Object.L'Access, Ceiling_Violation);
-
- if Ceiling_Violation then
- raise Program_Error;
- end if;
+ Lock (Object.Common'Access);
Entry_Call.Mode := Timed_Call;
Entry_Call.State := Now_Abortable;
procedure Unlock_Entry (Object : Protection_Entry_Access) is
begin
- -- We are exiting from a protected action, so that we decrease the
- -- protected object nesting level (if pragma Detect_Blocking is
- -- active), and remove ownership of the protected object.
-
- if Detect_Blocking then
- declare
- Self_Id : constant Task_Id := Self;
-
- begin
- -- Calls to this procedure can only take place when being within
- -- a protected action and when the caller is the protected
- -- object's owner.
-
- pragma Assert (Self_Id.Common.Protected_Action_Nesting > 0
- and then Object.Owner = Self_Id);
-
- -- Remove ownership of the protected object
-
- Object.Owner := Null_Task;
-
- Self_Id.Common.Protected_Action_Nesting :=
- Self_Id.Common.Protected_Action_Nesting - 1;
- end;
- end if;
-
- STPO.Unlock (Object.L'Access);
+ Unlock (Object.Common'Access);
end Unlock_Entry;
end System.Tasking.Protected_Objects.Single_Entry;
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