| ------------------------------------------------------------------------------ |
| -- -- |
| -- GNU ADA RUN-TIME LIBRARY (GNARL) COMPONENTS -- |
| -- -- |
| -- S Y S T E M . T A S K _ P R I M I T I V E S -- |
| -- -- |
| -- S p e c -- |
| -- -- |
| -- Copyright (C) 1991-1994, Florida State University -- |
| -- Copyright (C) 1995-2003, Ada Core Technologies -- |
| -- -- |
| -- 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. -- |
| -- Extensive contributions were provided by Ada Core Technologies, Inc. -- |
| -- -- |
| ------------------------------------------------------------------------------ |
| |
| -- This is an OS/2 version of this package. |
| |
| -- This package provides low-level support for most tasking features. |
| |
| pragma Polling (Off); |
| -- Turn off polling, we do not want ATC polling to take place during |
| -- tasking operations. It causes infinite loops and other problems. |
| |
| with Interfaces.OS2Lib.Threads; |
| with Interfaces.OS2Lib.Synchronization; |
| |
| package System.Task_Primitives is |
| |
| pragma Preelaborate; |
| |
| -- type Lock is limited private; |
| -- Should be used for implementation of protected objects. |
| |
| -- type RTS_Lock is limited private; |
| -- Should be used inside the runtime system. |
| -- The difference between Lock and the RTS_Lock is that the later |
| -- one serves only as a semaphore so that do not check for |
| -- ceiling violations. |
| |
| type Task_Body_Access is access procedure; |
| -- Pointer to the task body's entry point (or possibly a wrapper |
| -- declared local to the GNARL). |
| |
| -- type Private_Data is limited private; |
| -- Any information that the GNULLI needs maintained on a per-task |
| -- basis. A component of this type is guaranteed to be included |
| -- in the Ada_Task_Control_Block. |
| |
| -- private |
| |
| type Lock is record |
| Mutex : aliased Interfaces.OS2Lib.Synchronization.HMTX; |
| Priority : Integer; |
| Owner_Priority : Integer; |
| Owner_ID : Address; |
| end record; |
| |
| type RTS_Lock is new Lock; |
| |
| type Private_Data is record |
| Thread : aliased Interfaces.OS2Lib.Threads.TID; |
| pragma Atomic (Thread); |
| -- Thread field may be updated by two different threads of control. |
| -- (See, Enter_Task and Create_Task in s-taprop.adb). |
| -- They put the same value (thr_self value). We do not want to |
| -- use lock on those operations and the only thing we have to |
| -- make sure is that they are updated in atomic fashion. |
| |
| CV : aliased Interfaces.OS2Lib.Synchronization.HEV; |
| |
| L : aliased RTS_Lock; |
| -- Protection for all components is lock L |
| |
| Current_Priority : Integer := -1; |
| -- The Current_Priority is the actual priority of a thread. |
| -- This field is needed because it is only possible to set a |
| -- delta priority in OS/2. The only places where this field should |
| -- be set are Set_Priority, Create_Task and Initialize (Environment). |
| |
| Wrapper : Interfaces.OS2Lib.Threads.PFNTHREAD; |
| -- This is the original wrapper passed by Operations.Create_Task. |
| -- When installing an exception handler in a thread, the thread |
| -- starts executing the Exception_Wrapper which calls Wrapper |
| -- when the handler has been installed. The handler is removed when |
| -- wrapper returns. |
| end record; |
| |
| end System.Task_Primitives; |
