150 lines
6.9 KiB
Ada
150 lines
6.9 KiB
Ada
------------------------------------------------------------------------------
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-- --
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-- GNAT RUN-TIME COMPONENTS --
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-- --
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-- G N A T . T H R E A D S --
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-- --
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-- S p e c --
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-- --
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-- Copyright (C) 1998-2010, AdaCore --
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-- --
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-- GNAT 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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-- GNAT was originally developed by the GNAT team at New York 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 package provides facilities for creation or registration of foreign
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-- threads for use as Ada tasks. In order to execute general Ada code, the
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-- run-time system must know about all tasks. This package allows foreign
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-- code, e.g. a C program, to create a thread that the Ada run-time knows
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-- about, or to register the current thread.
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-- For some implementations of GNAT Pro, the registration of foreign threads
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-- is automatic. However, in such implementations, if the Ada program has no
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-- tasks at all and no tasking constructs other than delay, then by default
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-- the non-tasking version of the Ada run-time will be loaded. If foreign
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-- threads are present, it is important to ensure that the tasking version
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-- of the Ada run time is loaded. This may be achieved by adding "with
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-- GNAT.Threads" to any unit in the partition.
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with System;
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with Ada.Task_Identification;
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package GNAT.Threads is
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type Void_Ptr is access all Integer;
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function Create_Thread
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(Code : System.Address; -- pointer
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Parm : Void_Ptr; -- pointer
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Size : Natural; -- int
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Prio : Integer) -- int
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return System.Address;
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pragma Export (C, Create_Thread, "__gnat_create_thread");
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-- Creates a thread with the given (Size) stack size in bytes, and
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-- the given (Prio) priority. The task will execute a call to the
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-- procedure whose address is given by Code. This procedure has
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-- the prototype
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--
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-- void thread_code (void *id, void *parm);
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--
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-- where id is the id of the created task, and parm is the parameter
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-- passed to Create_Thread. The called procedure is the body of the
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-- code for the task, the task will be automatically terminated when
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-- the procedure returns.
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--
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-- This function returns the Ada Id of the created task that can then be
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-- used as a parameter to the procedures below.
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--
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-- C declaration:
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--
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-- extern void *__gnat_create_thread
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-- (void (*code)(void *, void *), void *parm, int size, int prio);
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function Register_Thread return System.Address;
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pragma Export (C, Register_Thread, "__gnat_register_thread");
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-- Create an Ada task Id for the current thread if needed.
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-- If the thread could not be registered, System.Null_Address is returned.
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--
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-- This function returns the Ada Id of the current task that can then be
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-- used as a parameter to the procedures below.
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--
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-- C declaration:
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--
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-- extern void *__gnat_register_thread ();
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--
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-- Here is a typical usage of the Register/Unregister_Thread procedures:
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--
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-- void thread_body ()
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-- {
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-- void *task_id = __gnat_register_thread ();
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-- ... thread body ...
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-- __gnat_unregister_thread ();
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-- }
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procedure Unregister_Thread;
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pragma Export (C, Unregister_Thread, "__gnat_unregister_thread");
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-- Unregister the current task from the GNAT run time and destroy the
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-- memory allocated for its task id.
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--
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-- C declaration:
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--
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-- extern void __gnat_unregister_thread ();
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procedure Unregister_Thread_Id (Thread : System.Address);
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pragma Export (C, Unregister_Thread_Id, "__gnat_unregister_thread_id");
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-- Unregister the task associated with Thread from the GNAT run time and
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-- destroy the memory allocated for its task id.
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-- If no task id is associated with Thread, do nothing.
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--
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-- C declaration:
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--
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-- extern void __gnat_unregister_thread_id (pthread_t *thread);
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procedure Destroy_Thread (Id : System.Address);
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pragma Export (C, Destroy_Thread, "__gnat_destroy_thread");
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-- This procedure may be used to prematurely abort the created thread.
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-- The value Id is the value that was passed to the thread code procedure
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-- at activation time.
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--
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-- C declaration:
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--
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-- extern void __gnat_destroy_thread (void *id);
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procedure Get_Thread (Id : System.Address; Thread : System.Address);
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pragma Export (C, Get_Thread, "__gnat_get_thread");
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-- This procedure is used to retrieve the thread id of a given task.
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-- The value Id is the value that was passed to the thread code procedure
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-- at activation time.
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-- Thread is a pointer to a thread id that will be updated by this
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-- procedure.
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--
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-- C declaration:
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--
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-- extern void __gnat_get_thread (void *id, pthread_t *thread);
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function To_Task_Id
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(Id : System.Address)
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return Ada.Task_Identification.Task_Id;
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-- Ada interface only.
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-- Given a low level Id, as returned by Create_Thread, return a Task_Id,
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-- so that operations in Ada.Task_Identification can be used.
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end GNAT.Threads;
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