| ------------------------------------------------------------------------------ |
| -- -- |
| -- GNAT RUN-TIME COMPONENTS -- |
| -- -- |
| -- G N A T . T H R E A D S -- |
| -- -- |
| -- S p e c -- |
| -- -- |
| -- Copyright (C) 1998-2022, AdaCore -- |
| -- -- |
| -- 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 3, 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. -- |
| -- -- |
| -- As a special exception under Section 7 of GPL version 3, you are granted -- |
| -- additional permissions described in the GCC Runtime Library Exception, -- |
| -- version 3.1, as published by the Free Software Foundation. -- |
| -- -- |
| -- You should have received a copy of the GNU General Public License and -- |
| -- a copy of the GCC Runtime Library Exception along with this program; -- |
| -- see the files COPYING3 and COPYING.RUNTIME respectively. If not, see -- |
| -- <http://www.gnu.org/licenses/>. -- |
| -- -- |
| -- 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 or registration 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, or to register the current thread. |
| |
| -- For some implementations of GNAT Pro, the registration of foreign threads |
| -- is automatic. However, in such implementations, if the Ada program has no |
| -- tasks at all and no tasking constructs other than delay, then by default |
| -- the non-tasking version of the Ada run-time will be loaded. If foreign |
| -- threads are present, it is important to ensure that the tasking version |
| -- of the Ada run time is loaded. This may be achieved by adding "with |
| -- GNAT.Threads" to any unit in the partition. |
| |
| 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"); |
| procedure Get_Thread |
| (Id : Ada.Task_Identification.Task_Id; Thread : System.Address); |
| -- 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 or a Task_Id. |
| -- 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. |
| |
| function Make_Independent return Boolean; |
| -- If a procedure loads a shared library containing tasks, and that |
| -- procedure is considered to be a master by the compiler (because it |
| -- contains tasks or class-wide objects that might contain tasks), |
| -- then the tasks in the shared library need to call Make_Independent |
| -- because otherwise they will depend on the procedure that loaded the |
| -- shared library. |
| -- |
| -- See System.Tasking.Utilities.Make_Independent in s-tasuti.ads for |
| -- further documentation. |
| |
| end GNAT.Threads; |
