112 lines
5.2 KiB
Ada
112 lines
5.2 KiB
Ada
------------------------------------------------------------------------------
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-- --
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-- GNAT RUN-TIME LIBRARY (GNARL) COMPONENTS --
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-- --
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-- S Y S T E M . T A S K _ P R I M I T I V E S --
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-- --
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-- S p e c --
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-- --
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-- Copyright (C) 1991-2020, Free Software Foundation, Inc. --
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-- --
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-- GNARL is free software; you can redistribute it and/or modify it under --
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-- terms of the GNU General Public License as published by the Free Soft- --
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-- ware Foundation; either version 3, or (at your option) any later ver- --
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-- sion. GNAT is distributed in the hope that it will be useful, but WITH- --
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-- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
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-- or FITNESS FOR A PARTICULAR PURPOSE. --
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-- --
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-- As a special exception under Section 7 of GPL version 3, you are granted --
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-- additional permissions described in the GCC Runtime Library Exception, --
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-- version 3.1, as published by the Free Software Foundation. --
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-- --
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-- You should have received a copy of the GNU General Public License and --
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-- a copy of the GCC Runtime Library Exception along with this program; --
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-- see the files COPYING3 and COPYING.RUNTIME respectively. If not, see --
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-- <http://www.gnu.org/licenses/>. --
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-- --
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-- GNARL was developed by the GNARL team at Florida State University. --
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-- Extensive contributions were provided by Ada Core Technologies, Inc. --
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-- --
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------------------------------------------------------------------------------
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-- This is a HP-UX version of this package
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-- This package provides low-level support for most tasking features
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with System.OS_Interface;
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package System.Task_Primitives is
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pragma Preelaborate;
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type Lock is limited private;
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-- Should be used for implementation of protected objects
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type RTS_Lock is limited private;
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-- Should be used inside the runtime system. The difference between Lock
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-- and the RTS_Lock is that the later one serves only as a semaphore so
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-- that do not check for ceiling violations.
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type Suspension_Object is limited private;
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-- Should be used for the implementation of Ada.Synchronous_Task_Control
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type Task_Body_Access is access procedure;
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-- Pointer to the task body's entry point (or possibly a wrapper
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-- declared local to the GNARL).
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type Private_Data is limited private;
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-- Any information that the GNULLI needs maintained on a per-task basis.
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-- A component of this type is guaranteed to be included in the
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-- Ada_Task_Control_Block.
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subtype Task_Address is System.Address;
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Task_Address_Size : constant := Standard'Address_Size;
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-- Type used for task addresses and its size
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Alternate_Stack_Size : constant := 0;
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-- No alternate signal stack is used on this platform
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private
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type Lock is record
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L : aliased System.OS_Interface.pthread_mutex_t;
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Priority : Integer;
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Owner_Priority : Integer;
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end record;
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type RTS_Lock is new System.OS_Interface.pthread_mutex_t;
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type Suspension_Object is record
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State : Boolean;
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pragma Atomic (State);
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-- Boolean that indicates whether the object is open. This field is
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-- marked Atomic to ensure that we can read its value without locking
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-- the access to the Suspension_Object.
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Waiting : Boolean;
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-- Flag showing if there is a task already suspended on this object
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L : aliased System.OS_Interface.pthread_mutex_t;
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-- Protection for ensuring mutual exclusion on the Suspension_Object
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CV : aliased System.OS_Interface.pthread_cond_t;
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-- Condition variable used to queue threads until condition is signaled
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end record;
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type Private_Data is record
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Thread : aliased System.OS_Interface.pthread_t;
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-- pragma Atomic (Thread);
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-- Unfortunately, the above fails because Thread is 64 bits.
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-- Thread field may be updated by two different threads of control.
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-- (See, Enter_Task and Create_Task in s-taprop.adb). They put the
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-- same value (thr_self value). We do not want to use lock on those
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-- operations and the only thing we have to make sure is that they
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-- are updated in atomic fashion.
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CV : aliased System.OS_Interface.pthread_cond_t;
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L : aliased RTS_Lock;
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-- Protection for all components is lock L
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end record;
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end System.Task_Primitives;
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