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Diffstat (limited to 'gcc-4.2.1/gcc/ada/s-tpoben.ads')
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diff --git a/gcc-4.2.1/gcc/ada/s-tpoben.ads b/gcc-4.2.1/gcc/ada/s-tpoben.ads new file mode 100644 index 000000000..53ae4bf50 --- /dev/null +++ b/gcc-4.2.1/gcc/ada/s-tpoben.ads @@ -0,0 +1,200 @@ +------------------------------------------------------------------------------ +-- -- +-- 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 . -- +-- E N T R I E S -- +-- -- +-- S p e c -- +-- -- +-- Copyright (C) 1992-2005, 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, 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, -- +-- 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. -- +-- Extensive contributions were provided by Ada Core Technologies, Inc. -- +-- -- +------------------------------------------------------------------------------ + +-- 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. +-- Any changes to this interface may require corresponding compiler changes. + +with Ada.Finalization; +-- used for Limited_Controlled + +with Unchecked_Conversion; + +package System.Tasking.Protected_Objects.Entries is + pragma Elaborate_Body; + + subtype Positive_Protected_Entry_Index is + Protected_Entry_Index range 1 .. Protected_Entry_Index'Last; + + type Find_Body_Index_Access is access + function + (O : System.Address; + E : Protected_Entry_Index) + return Protected_Entry_Index; + + type Protected_Entry_Body_Array is + array (Positive_Protected_Entry_Index range <>) of Entry_Body; + -- This is an array of the executable code for all entry bodies of + -- a protected type. + + type Protected_Entry_Body_Access is access all Protected_Entry_Body_Array; + + type Protected_Entry_Queue_Array is + array (Protected_Entry_Index range <>) of Entry_Queue; + + -- This type contains the GNARL state of a protected object. The + -- application-defined portion of the state (i.e. private objects) + -- is maintained by the compiler-generated code. + -- note that there is a simplified version of this type declared in + -- System.Tasking.PO_Simple that handle the simple case (no entries). + + type Protection_Entries (Num_Entries : Protected_Entry_Index) is new + Ada.Finalization.Limited_Controlled + with record + L : aliased Task_Primitives.Lock; + -- The underlying lock associated with a Protection_Entries. + -- Note that you should never (un)lock Object.L directly, but instead + -- use Lock_Entries/Unlock_Entries. + + Compiler_Info : System.Address; + -- Pointer to compiler-generated record representing protected object + + Call_In_Progress : Entry_Call_Link; + -- Pointer to the entry call being executed (if any) + + Ceiling : System.Any_Priority; + -- Ceiling priority associated with the protected object + + 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). + + Old_Base_Priority : System.Any_Priority; + -- Task's base priority when the protected operation was called + + Pending_Action : Boolean; + -- Flag indicating that priority has been dipped temporarily in order + -- to avoid violating the priority ceiling of the lock associated with + -- this protected object, in Lock_Server. The flag tells Unlock_Server + -- or Unlock_And_Update_Server to restore the old priority to + -- Old_Base_Priority. This is needed because of situations (bad + -- language design?) where one needs to lock a PO but to do so would + -- violate the priority ceiling. For example, this can happen when an + -- entry call has been requeued to a lower-priority object, and the + -- caller then tries to cancel the call while its own priority is + -- higher than the ceiling of the new PO. + + Finalized : Boolean := False; + -- Set to True by Finalize to make this routine idempotent + + Entry_Bodies : Protected_Entry_Body_Access; + -- Pointer to an array containing the executable code for all entry + -- bodies of a protected type. + + -- The following function maps the entry index in a call (which denotes + -- the queue to the proper entry) into the body of the entry. + + Find_Body_Index : Find_Body_Index_Access; + Entry_Queues : Protected_Entry_Queue_Array (1 .. Num_Entries); + end record; + + -- No default initial values for this type, since call records + -- will need to be re-initialized before every use. + + type Protection_Entries_Access is access all Protection_Entries'Class; + -- See comments in s-tassta.adb about the implicit call to Current_Master + -- generated by this declaration. + + function To_Address is + new Unchecked_Conversion (Protection_Entries_Access, System.Address); + function To_Protection is + new Unchecked_Conversion (System.Address, Protection_Entries_Access); + + function Has_Interrupt_Or_Attach_Handler + (Object : Protection_Entries_Access) return Boolean; + -- Returns True if an Interrupt_Handler or Attach_Handler pragma applies + -- to the protected object. That is to say this primitive returns False for + -- Protection, but is overriden to return True when interrupt handlers are + -- declared so the check required by C.3.1(11) can be implemented in + -- System.Tasking.Protected_Objects.Initialize_Protection. + + 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); + -- Initialize the Object parameter so that it can be used by the runtime + -- to keep track of the runtime state of a protected object. + + procedure Lock_Entries (Object : Protection_Entries_Access); + -- Lock a protected object for write access. Upon return, the caller owns + -- the lock to this object, and no other call to Lock or Lock_Read_Only + -- with the same argument will return until the corresponding call to + -- Unlock has been made by the caller. Program_Error is raised in case of + -- ceiling violation. + + procedure Lock_Entries + (Object : Protection_Entries_Access; Ceiling_Violation : out Boolean); + -- Same as above, but return the ceiling violation status instead of + -- raising Program_Error. + + procedure Lock_Read_Only_Entries (Object : Protection_Entries_Access); + -- Lock a protected object for read access. Upon return, the caller owns + -- the lock for read access, and no other calls to Lock with the same + -- argument will return until the corresponding call to Unlock has been + -- made by the caller. Other calls to Lock_Read_Only may (but need not) + -- return before the call to Unlock, and the corresponding callers will + -- also own the lock for read access. + -- + -- Note: we are not currently using this interface, it is provided for + -- possible future use. At the current time, everyone uses Lock for both + -- read and write locks. + + procedure Unlock_Entries (Object : Protection_Entries_Access); + -- Relinquish ownership of the lock for the object represented by the + -- Object parameter. If this ownership was for write access, or if it was + -- for read access where there are no other read access locks outstanding, + -- one (or more, in the case of Lock_Read_Only) of the tasks waiting on + -- this lock (if any) will be given the lock and allowed to return from + -- the Lock or Lock_Read_Only call. + +private + + procedure Finalize (Object : in out Protection_Entries); + -- Clean up a Protection object; in particular, finalize the associated + -- Lock object. + +end System.Tasking.Protected_Objects.Entries; |