+++ /dev/null
-------------------------------------------------------------------------------
--- --
--- 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 --
--- --
--- $Revision: 1.2 $
--- --
--- Copyright (C) 1991-2001, Florida State University --
--- --
--- 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. in cooperation with Florida --
--- State University (http://www.gnat.com). --
--- --
-------------------------------------------------------------------------------
-
--- RT_GNU/Linux version
-
-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 System.OS_Interface;
-
-package System.Task_Primitives is
-
- type Lock is limited private;
- -- Used for implementation of protected objects.
-
- type Lock_Ptr is limited private;
-
- type RTS_Lock is limited private;
- -- 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 RTS_Lock_Ptr is limited private;
-
- 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 RT_GNU_Linux_Lock is record
- Ceiling_Priority : System.Any_Priority;
- Pre_Locking_Priority : System.Any_Priority;
- -- Used to store the task's active priority before it
- -- acquires the lock
-
- Owner : System.Address;
- -- This is really a Task_ID, but we can't use that type
- -- here because this System.Tasking is "with"
- -- the current package -- a circularity.
- end record;
-
- type Lock is new RT_GNU_Linux_Lock;
- type RTS_Lock is new RT_GNU_Linux_Lock;
-
- type RTS_Lock_Ptr is access all RTS_Lock;
- type Lock_Ptr is access all Lock;
-
- type Private_Data is record
- Stack : System.Address;
- -- A stack space needed for the task. the space is allocated
- -- when the task is being created and is deallocated when
- -- the TCB for the task is finalized
-
- Uses_Fp : Integer;
- -- A flag to indicate whether the task is going to use floating-
- -- point unit. It's set to 1, indicating FP unit is always going
- -- to be used. The reason is that it is in this private record and
- -- necessary operation has to be provided for a user to call so as
- -- to change its value
-
- Magic : Integer;
- -- A special value is going to be stored in it when a task is
- -- created. The value is RT_TASK_MAGIC (16#754d2774#) as declared
- -- in System.OS_Interface
-
- State : System.OS_Interface.Rt_Task_States;
- -- Shows whether the task is RT_TASK_READY, RT_TASK_DELAYED or
- -- RT_TASK_DORMANT to support suspend, wait, wakeup.
-
- Stack_Bottom : System.Address;
-
- Active_Priority : System.Any_Priority;
- -- Active priority of the task
-
- Period : System.OS_Interface.RTIME;
- -- Intended originally to store the period of the task, but not used
- -- in the current implementation
-
- Resume_Time : System.OS_Interface.RTIME;
- -- Store the time the task has to be awakened
-
- Next : System.Address;
- -- This really is a Task_ID, used to link the Available_TCBs.
-
- Succ : System.Address;
- pragma Volatile (Succ);
- Pred : System.Address;
- pragma Volatile (Pred);
- -- These really are Task_ID, used to implement a circular doubly
- -- linked list for task queue
-
- L : aliased RTS_Lock;
-
- Outer_Lock : RTS_Lock_Ptr := null;
- -- Used to track which Lock the task is holding is the outermost
- -- one in order to implement priority setting and inheritance
- end record;
-
- -- ???? May need to use pragma Atomic or Volatile on some
- -- components; may also need to specify aliased for some.
-end System.Task_Primitives;
projects / msp430-gcc.git / blobdiff