1 ------------------------------------------------------------------------------
3 -- GNAT RUN-TIME LIBRARY (GNARL) COMPONENTS --
5 -- S Y S T E M . T A S K _ P R I M I T I V E S . O P E R A T I O N S . --
10 -- Copyright (C) 1992-2005, Free Software Foundation, Inc. --
12 -- GNARL is free software; you can redistribute it and/or modify it under --
13 -- terms of the GNU General Public License as published by the Free Soft- --
14 -- ware Foundation; either version 2, or (at your option) any later ver- --
15 -- sion. GNARL is distributed in the hope that it will be useful, but WITH- --
16 -- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
17 -- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License --
18 -- for more details. You should have received a copy of the GNU General --
19 -- Public License distributed with GNARL; see file COPYING. If not, write --
20 -- to the Free Software Foundation, 51 Franklin Street, Fifth Floor, --
21 -- Boston, MA 02110-1301, USA. --
23 -- As a special exception, if other files instantiate generics from this --
24 -- unit, or you link this unit with other files to produce an executable, --
25 -- this unit does not by itself cause the resulting executable to be --
26 -- covered by the GNU General Public License. This exception does not --
27 -- however invalidate any other reasons why the executable file might be --
28 -- covered by the GNU Public License. --
30 -- GNARL was developed by the GNARL team at Florida State University. --
31 -- Extensive contributions were provided by Ada Core Technologies, Inc. --
33 ------------------------------------------------------------------------------
35 -- This is a POSIX version of this package where foreign threads are
38 -- Currently, DEC Unix, SCO UnixWare, Solaris pthread, HPUX pthread and
39 -- GNU/Linux threads use this version.
41 separate (System.Task_Primitives.Operations)
42 package body Specific is
48 procedure Initialize (Environment_Task : Task_Id) is
49 pragma Warnings (Off, Environment_Task);
50 Result : Interfaces.C.int;
53 Result := pthread_key_create (ATCB_Key'Access, null);
54 pragma Assert (Result = 0);
61 function Is_Valid_Task return Boolean is
63 return pthread_getspecific (ATCB_Key) /= System.Null_Address;
70 procedure Set (Self_Id : Task_Id) is
71 Result : Interfaces.C.int;
73 Result := pthread_setspecific (ATCB_Key, To_Address (Self_Id));
74 pragma Assert (Result = 0);
81 -- To make Ada tasks and C threads interoperate better, we have added some
82 -- functionality to Self. Suppose a C main program (with threads) calls an
83 -- Ada procedure and the Ada procedure calls the tasking runtime system.
84 -- Eventually, a call will be made to self. Since the call is not coming
85 -- from an Ada task, there will be no corresponding ATCB.
87 -- What we do in Self is to catch references that do not come from
88 -- recognized Ada tasks, and create an ATCB for the calling thread.
90 -- The new ATCB will be "detached" from the normal Ada task master
91 -- hierarchy, much like the existing implicitly created signal-server
94 function Self return Task_Id is
95 Result : System.Address;
98 Result := pthread_getspecific (ATCB_Key);
100 -- If the key value is Null, then it is a non-Ada task.
102 if Result /= System.Null_Address then
103 return To_Task_Id (Result);
105 return Register_Foreign_Thread;