129 lines
6.2 KiB
Ada
129 lines
6.2 KiB
Ada
------------------------------------------------------------------------------
|
|
-- --
|
|
-- 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: 1.1 $ --
|
|
-- --
|
|
-- Copyright (C) 1991-1997, 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. in cooperation with Florida --
|
|
-- State University (http://www.gnat.com). --
|
|
-- --
|
|
------------------------------------------------------------------------------
|
|
|
|
-- This is the FreeBSD PTHREADS version of this package. Contributed
|
|
-- by Daniel M. Eischen (eischen@vigrid.com).
|
|
|
|
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.C;
|
|
-- used for int
|
|
-- size_t
|
|
|
|
with System.OS_Interface;
|
|
-- used for pthread_mutex_t
|
|
-- pthread_cond_t
|
|
-- pthread_t
|
|
|
|
package System.Task_Primitives is
|
|
|
|
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 new System.OS_Interface.pthread_mutex_t;
|
|
type RTS_Lock is new System.OS_Interface.pthread_mutex_t;
|
|
|
|
type Private_Data is record
|
|
Thread : aliased System.OS_Interface.pthread_t;
|
|
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.
|
|
|
|
LWP : aliased System.Address;
|
|
-- This field is not relevant on all targets. Currently only SGI and
|
|
-- AiX updates it. The purpose of this field is to provide a better
|
|
-- tasking support on gdb. The order of the two first fields (Thread
|
|
-- and LWP) is important.
|
|
|
|
CV : aliased System.OS_Interface.pthread_cond_t;
|
|
|
|
L : aliased RTS_Lock;
|
|
-- Protection for all components is lock L
|
|
|
|
Current_Priority : Interfaces.C.int := 0;
|
|
-- Active priority, except that the effects of protected object
|
|
-- priority ceilings are not reflected. This only reflects explicit
|
|
-- priority changes and priority inherited through task activation
|
|
-- and rendezvous.
|
|
--
|
|
-- Ada 95 notes: In Ada 95, this field will be transferred to the
|
|
-- Priority field of an Entry_Calls component when an entry call
|
|
-- is initiated. The Priority of the Entry_Calls component will not
|
|
-- change for the duration of the call. The accepting task can
|
|
-- use it to boost its own priority without fear of its changing in
|
|
-- the meantime.
|
|
--
|
|
-- This can safely be used in the priority ordering
|
|
-- of entry queues. Once a call is queued, its priority does not
|
|
-- change.
|
|
--
|
|
-- Since an entry call cannot be made while executing
|
|
-- a protected action, the priority of a task will never reflect a
|
|
-- priority ceiling change at the point of an entry call.
|
|
--
|
|
-- Protection: Only written by Self, and only accessed when Acceptor
|
|
-- accepts an entry or when Created activates, at which points Self is
|
|
-- suspended.
|
|
|
|
Stack_Size : Interfaces.C.size_t;
|
|
-- Requested stack size.
|
|
-- Protection: Only used by Self.
|
|
end record;
|
|
|
|
end System.Task_Primitives;
|