------------------------------------------------------------------------------ -- -- -- GNU ADA RUN-TIME LIBRARY (GNARL) COMPONENTS -- -- -- -- SYSTEM.TASKING.PROTECTED_OBJECTS.ENTRIES -- -- -- -- B o d y -- -- -- -- -- -- Copyright (C) 1998-2001, 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- -- -- 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. -- -- -- -- 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. -- -- -- -- GNARL was developed by the GNARL team at Florida State University. It is -- -- now maintained by Ada Core Technologies, Inc. (http://www.gnat.com). -- -- -- ------------------------------------------------------------------------------ -- This package contains all the simple primitives related to -- Protected_Objects with entries (i.e init, lock, unlock). -- The handling of protected objects with no entries is done in -- System.Tasking.Protected_Objects, the complex routines for protected -- objects with entries in System.Tasking.Protected_Objects.Operations. -- The split between Entries and Operations is needed to break circular -- dependencies inside the run time. -- Note: the compiler generates direct calls to this interface, via Rtsfind. with Ada.Exceptions; -- used for Exception_Occurrence_Access with System.Task_Primitives.Operations; -- used for Initialize_Lock -- Write_Lock -- Unlock -- Get_Priority -- Wakeup with System.Tasking.Initialization; -- used for Defer_Abort, -- Undefer_Abort, -- Change_Base_Priority pragma Elaborate_All (System.Tasking.Initialization); -- this insures that tasking is initialized if any protected objects are -- created. with System.Parameters; -- used for Single_Lock package body System.Tasking.Protected_Objects.Entries is package STPO renames System.Task_Primitives.Operations; use Parameters; use Task_Primitives.Operations; use Ada.Exceptions; Locking_Policy : Character; pragma Import (C, Locking_Policy, "__gl_locking_policy"); -------------- -- Finalize -- -------------- procedure Finalize (Object : in out Protection_Entries) is Entry_Call : Entry_Call_Link; Caller : Task_ID; Ceiling_Violation : Boolean; Self_ID : constant Task_ID := STPO.Self; Old_Base_Priority : System.Any_Priority; begin if Object.Finalized then return; end if; STPO.Write_Lock (Object.L'Unrestricted_Access, Ceiling_Violation); if Single_Lock then Lock_RTS; end if; if Ceiling_Violation then -- Dip our own priority down to ceiling of lock. -- See similar code in Tasking.Entry_Calls.Lock_Server. STPO.Write_Lock (Self_ID); Old_Base_Priority := Self_ID.Common.Base_Priority; Self_ID.New_Base_Priority := Object.Ceiling; Initialization.Change_Base_Priority (Self_ID); STPO.Unlock (Self_ID); if Single_Lock then Unlock_RTS; end if; STPO.Write_Lock (Object.L'Unrestricted_Access, Ceiling_Violation); if Ceiling_Violation then Raise_Exception (Program_Error'Identity, "Ceiling Violation"); end if; if Single_Lock then Lock_RTS; end if; Object.Old_Base_Priority := Old_Base_Priority; Object.Pending_Action := True; end if; -- Send program_error to all tasks still queued on this object. for E in Object.Entry_Queues'Range loop Entry_Call := Object.Entry_Queues (E).Head; while Entry_Call /= null loop Caller := Entry_Call.Self; Entry_Call.Exception_To_Raise := Program_Error'Identity; STPO.Write_Lock (Caller); Initialization.Wakeup_Entry_Caller (Self_ID, Entry_Call, Done); STPO.Unlock (Caller); exit when Entry_Call = Object.Entry_Queues (E).Tail; Entry_Call := Entry_Call.Next; end loop; end loop; Object.Finalized := True; if Single_Lock then Unlock_RTS; end if; STPO.Unlock (Object.L'Unrestricted_Access); STPO.Finalize_Lock (Object.L'Unrestricted_Access); end Finalize; ------------------------------------- -- Has_Interrupt_Or_Attach_Handler -- ------------------------------------- function Has_Interrupt_Or_Attach_Handler (Object : Protection_Entries_Access) return Boolean is pragma Warnings (Off, Object); begin return False; end Has_Interrupt_Or_Attach_Handler; ----------------------------------- -- Initialize_Protection_Entries -- ----------------------------------- procedure Initialize_Protection_Entries (Object : Protection_Entries_Access; Ceiling_Priority : Integer; Compiler_Info : System.Address; Entry_Bodies : Protected_Entry_Body_Access; Find_Body_Index : Find_Body_Index_Access) is Init_Priority : Integer := Ceiling_Priority; Self_ID : constant Task_ID := STPO.Self; begin if Init_Priority = Unspecified_Priority then Init_Priority := System.Priority'Last; end if; if Locking_Policy = 'C' and then Has_Interrupt_Or_Attach_Handler (Object) and then Init_Priority not in System.Interrupt_Priority then -- Required by C.3.1(11) raise Program_Error; end if; Initialization.Defer_Abort (Self_ID); Initialize_Lock (Init_Priority, Object.L'Access); Initialization.Undefer_Abort (Self_ID); Object.Ceiling := System.Any_Priority (Init_Priority); Object.Compiler_Info := Compiler_Info; Object.Pending_Action := False; Object.Call_In_Progress := null; Object.Entry_Bodies := Entry_Bodies; Object.Find_Body_Index := Find_Body_Index; for E in Object.Entry_Queues'Range loop Object.Entry_Queues (E).Head := null; Object.Entry_Queues (E).Tail := null; end loop; end Initialize_Protection_Entries; ------------------ -- Lock_Entries -- ------------------ procedure Lock_Entries (Object : Protection_Entries_Access; Ceiling_Violation : out Boolean) is begin if Object.Finalized then Raise_Exception (Program_Error'Identity, "Protected Object is finalized"); end if; -- The lock is made without defering abortion. -- Therefore the abortion has to be deferred before calling this -- routine. This means that the compiler has to generate a Defer_Abort -- call before the call to Lock. -- The caller is responsible for undeferring abortion, and compiler -- generated calls must be protected with cleanup handlers to ensure -- that abortion is undeferred in all cases. pragma Assert (STPO.Self.Deferral_Level > 0); Write_Lock (Object.L'Access, Ceiling_Violation); end Lock_Entries; procedure Lock_Entries (Object : Protection_Entries_Access) is Ceiling_Violation : Boolean; begin if Object.Finalized then Raise_Exception (Program_Error'Identity, "Protected Object is finalized"); end if; pragma Assert (STPO.Self.Deferral_Level > 0); Write_Lock (Object.L'Access, Ceiling_Violation); if Ceiling_Violation then Raise_Exception (Program_Error'Identity, "Ceiling Violation"); end if; end Lock_Entries; ---------------------------- -- Lock_Read_Only_Entries -- ---------------------------- procedure Lock_Read_Only_Entries (Object : Protection_Entries_Access) is Ceiling_Violation : Boolean; begin if Object.Finalized then Raise_Exception (Program_Error'Identity, "Protected Object is finalized"); end if; Read_Lock (Object.L'Access, Ceiling_Violation); if Ceiling_Violation then Raise_Exception (Program_Error'Identity, "Ceiling Violation"); end if; end Lock_Read_Only_Entries; -------------------- -- Unlock_Entries -- -------------------- procedure Unlock_Entries (Object : Protection_Entries_Access) is begin Unlock (Object.L'Access); end Unlock_Entries; end System.Tasking.Protected_Objects.Entries;