1------------------------------------------------------------------------------ 2-- -- 3-- GNAT RUN-TIME COMPONENTS -- 4-- -- 5-- G N A T . T H R E A D S -- 6-- -- 7-- S p e c -- 8-- -- 9-- Copyright (C) 1998-2010, AdaCore -- 10-- -- 11-- GNAT is free software; you can redistribute it and/or modify it under -- 12-- terms of the GNU General Public License as published by the Free Soft- -- 13-- ware Foundation; either version 3, or (at your option) any later ver- -- 14-- sion. GNAT is distributed in the hope that it will be useful, but WITH- -- 15-- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY -- 16-- or FITNESS FOR A PARTICULAR PURPOSE. -- 17-- -- 18-- As a special exception under Section 7 of GPL version 3, you are granted -- 19-- additional permissions described in the GCC Runtime Library Exception, -- 20-- version 3.1, as published by the Free Software Foundation. -- 21-- -- 22-- You should have received a copy of the GNU General Public License and -- 23-- a copy of the GCC Runtime Library Exception along with this program; -- 24-- see the files COPYING3 and COPYING.RUNTIME respectively. If not, see -- 25-- <http://www.gnu.org/licenses/>. -- 26-- -- 27-- GNAT was originally developed by the GNAT team at New York University. -- 28-- Extensive contributions were provided by Ada Core Technologies Inc. -- 29-- -- 30------------------------------------------------------------------------------ 31 32-- This package provides facilities for creation or registration of foreign 33-- threads for use as Ada tasks. In order to execute general Ada code, the 34-- run-time system must know about all tasks. This package allows foreign 35-- code, e.g. a C program, to create a thread that the Ada run-time knows 36-- about, or to register the current thread. 37 38-- For some implementations of GNAT Pro, the registration of foreign threads 39-- is automatic. However, in such implementations, if the Ada program has no 40-- tasks at all and no tasking constructs other than delay, then by default 41-- the non-tasking version of the Ada run-time will be loaded. If foreign 42-- threads are present, it is important to ensure that the tasking version 43-- of the Ada run time is loaded. This may be achieved by adding "with 44-- GNAT.Threads" to any unit in the partition. 45 46with System; 47with Ada.Task_Identification; 48 49package GNAT.Threads is 50 51 type Void_Ptr is access all Integer; 52 53 function Create_Thread 54 (Code : System.Address; -- pointer 55 Parm : Void_Ptr; -- pointer 56 Size : Natural; -- int 57 Prio : Integer) -- int 58 return System.Address; 59 pragma Export (C, Create_Thread, "__gnat_create_thread"); 60 -- Creates a thread with the given (Size) stack size in bytes, and 61 -- the given (Prio) priority. The task will execute a call to the 62 -- procedure whose address is given by Code. This procedure has 63 -- the prototype 64 -- 65 -- void thread_code (void *id, void *parm); 66 -- 67 -- where id is the id of the created task, and parm is the parameter 68 -- passed to Create_Thread. The called procedure is the body of the 69 -- code for the task, the task will be automatically terminated when 70 -- the procedure returns. 71 -- 72 -- This function returns the Ada Id of the created task that can then be 73 -- used as a parameter to the procedures below. 74 -- 75 -- C declaration: 76 -- 77 -- extern void *__gnat_create_thread 78 -- (void (*code)(void *, void *), void *parm, int size, int prio); 79 80 function Register_Thread return System.Address; 81 pragma Export (C, Register_Thread, "__gnat_register_thread"); 82 -- Create an Ada task Id for the current thread if needed. 83 -- If the thread could not be registered, System.Null_Address is returned. 84 -- 85 -- This function returns the Ada Id of the current task that can then be 86 -- used as a parameter to the procedures below. 87 -- 88 -- C declaration: 89 -- 90 -- extern void *__gnat_register_thread (); 91 -- 92 -- Here is a typical usage of the Register/Unregister_Thread procedures: 93 -- 94 -- void thread_body () 95 -- { 96 -- void *task_id = __gnat_register_thread (); 97 -- ... thread body ... 98 -- __gnat_unregister_thread (); 99 -- } 100 101 procedure Unregister_Thread; 102 pragma Export (C, Unregister_Thread, "__gnat_unregister_thread"); 103 -- Unregister the current task from the GNAT run time and destroy the 104 -- memory allocated for its task id. 105 -- 106 -- C declaration: 107 -- 108 -- extern void __gnat_unregister_thread (); 109 110 procedure Unregister_Thread_Id (Thread : System.Address); 111 pragma Export (C, Unregister_Thread_Id, "__gnat_unregister_thread_id"); 112 -- Unregister the task associated with Thread from the GNAT run time and 113 -- destroy the memory allocated for its task id. 114 -- If no task id is associated with Thread, do nothing. 115 -- 116 -- C declaration: 117 -- 118 -- extern void __gnat_unregister_thread_id (pthread_t *thread); 119 120 procedure Destroy_Thread (Id : System.Address); 121 pragma Export (C, Destroy_Thread, "__gnat_destroy_thread"); 122 -- This procedure may be used to prematurely abort the created thread. 123 -- The value Id is the value that was passed to the thread code procedure 124 -- at activation time. 125 -- 126 -- C declaration: 127 -- 128 -- extern void __gnat_destroy_thread (void *id); 129 130 procedure Get_Thread (Id : System.Address; Thread : System.Address); 131 pragma Export (C, Get_Thread, "__gnat_get_thread"); 132 -- This procedure is used to retrieve the thread id of a given task. 133 -- The value Id is the value that was passed to the thread code procedure 134 -- at activation time. 135 -- Thread is a pointer to a thread id that will be updated by this 136 -- procedure. 137 -- 138 -- C declaration: 139 -- 140 -- extern void __gnat_get_thread (void *id, pthread_t *thread); 141 142 function To_Task_Id 143 (Id : System.Address) 144 return Ada.Task_Identification.Task_Id; 145 -- Ada interface only. 146 -- Given a low level Id, as returned by Create_Thread, return a Task_Id, 147 -- so that operations in Ada.Task_Identification can be used. 148 149end GNAT.Threads; 150