------------------------------------------------------------------------------ -- -- -- GNAT RUNTIME COMPONENTS -- -- -- -- G N A T . T H R E A D S -- -- -- -- S p e c -- -- -- -- Copyright (C) 1998-2003 Ada Core Technologies, Inc. -- -- -- -- GNAT 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. GNAT 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 GNAT; 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. -- -- -- -- GNAT was originally developed by the GNAT team at New York University. -- -- Extensive contributions were provided by Ada Core Technologies Inc. -- -- -- ------------------------------------------------------------------------------ -- This package provides facilities for creation of foreign threads for -- use as Ada tasks. In order to execute general Ada code, the run-time -- system must know about all tasks. This package allows foreign code, -- e.g. a C program, to create a thread that the Ada run-time knows about. with System; with Ada.Task_Identification; package GNAT.Threads is type Void_Ptr is access all Integer; function Create_Thread (Code : System.Address; -- pointer Parm : Void_Ptr; -- pointer Size : Natural; -- int Prio : Integer) -- int return System.Address; pragma Export (C, Create_Thread, "__gnat_create_thread"); -- Creates a thread with the given (Size) stack size in bytes, and -- the given (Prio) priority. The task will execute a call to the -- procedure whose address is given by Code. This procedure has -- the prototype -- -- void thread_code (void *id, void *parm); -- -- where id is the id of the created task, and parm is the parameter -- passed to Create_Thread. The called procedure is the body of the -- code for the task, the task will be automatically terminated when -- the procedure returns. -- -- This function returns the Ada Id of the created task that can then be -- used as a parameter to the procedures below. -- -- C declaration: -- -- extern void *__gnat_create_thread -- (void (*code)(void *, void *), void *parm, int size, int prio); function Register_Thread return System.Address; pragma Export (C, Register_Thread, "__gnat_register_thread"); -- Create an Ada task Id for the current thread if needed. -- If the thread could not be registered, System.Null_Address is returned. -- -- This function returns the Ada Id of the current task that can then be -- used as a parameter to the procedures below. -- -- C declaration: -- -- extern void *__gnat_register_thread (); -- -- Here is a typical usage of the Register/Unregister_Thread procedures: -- -- void thread_body () -- { -- void *task_id = __gnat_register_thread (); -- ... thread body ... -- __gnat_unregister_thread (); -- } procedure Unregister_Thread; pragma Export (C, Unregister_Thread, "__gnat_unregister_thread"); -- Unregister the current task from the GNAT run time and destroy the -- memory allocated for its task id. -- -- C declaration: -- -- extern void __gnat_unregister_thread (); procedure Unregister_Thread_Id (Thread : System.Address); pragma Export (C, Unregister_Thread_Id, "__gnat_unregister_thread_id"); -- Unregister the task associated with Thread from the GNAT run time and -- destroy the memory allocated for its task id. -- If no task id is associated with Thread, do nothing. -- -- C declaration: -- -- extern void __gnat_unregister_thread_id (pthread_t *thread); procedure Destroy_Thread (Id : System.Address); pragma Export (C, Destroy_Thread, "__gnat_destroy_thread"); -- This procedure may be used to prematurely abort the created thread. -- The value Id is the value that was passed to the thread code procedure -- at activation time. -- -- C declaration: -- -- extern void __gnat_destroy_thread (void *id); procedure Get_Thread (Id : System.Address; Thread : System.Address); pragma Export (C, Get_Thread, "__gnat_get_thread"); -- This procedure is used to retrieve the thread id of a given task. -- The value Id is the value that was passed to the thread code procedure -- at activation time. -- Thread is a pointer to a thread id that will be updated by this -- procedure. -- -- C declaration: -- -- extern void __gnat_get_thread (void *id, pthread_t *thread); function To_Task_Id (Id : System.Address) return Ada.Task_Identification.Task_Id; -- Ada interface only. -- Given a low level Id, as returned by Create_Thread, return a Task_Id, -- so that operations in Ada.Task_Identification can be used. end GNAT.Threads;