1/* libc-internal interface for thread-specific data.  Stub or TLS version.
2   Copyright (C) 1998,2001,02 Free Software Foundation, Inc.
3   This file is part of the GNU C Library.
4
5   The GNU C Library is free software; you can redistribute it and/or
6   modify it under the terms of the GNU Lesser General Public
7   License as published by the Free Software Foundation; either
8   version 2.1 of the License, or (at your option) any later version.
9
10   The GNU C Library is distributed in the hope that it will be useful,
11   but WITHOUT ANY WARRANTY; without even the implied warranty of
12   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
13   Lesser General Public License for more details.
14
15   You should have received a copy of the GNU Lesser General Public
16   License along with the GNU C Library; if not, write to the Free
17   Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
18   02111-1307 USA.  */
19
20#ifndef _GENERIC_BITS_LIBC_TSD_H
21#define _GENERIC_BITS_LIBC_TSD_H 1
22
23/* This file defines the following macros for accessing a small fixed
24   set of thread-specific `void *' data used only internally by libc.
25
26   __libc_tsd_define(CLASS, KEY)	-- Define or declare a `void *' datum
27   					   for KEY.  CLASS can be `static' for
28					   keys used in only one source file,
29					   empty for global definitions, or
30					   `extern' for global declarations.
31   __libc_tsd_address(KEY)		-- Return the `void **' pointing to
32   					   the current thread's datum for KEY.
33   __libc_tsd_get(KEY)			-- Return the `void *' datum for KEY.
34   __libc_tsd_set(KEY, VALUE)		-- Set the datum for KEY to VALUE.
35
36   The set of available KEY's will usually be provided as an enum,
37   and contains (at least):
38		_LIBC_TSD_KEY_MALLOC
39		_LIBC_TSD_KEY_DL_ERROR
40		_LIBC_TSD_KEY_RPC_VARS
41   All uses must be the literal _LIBC_TSD_* name in the __libc_tsd_* macros.
42   Some implementations may not provide any enum at all and instead
43   using string pasting in the macros.  */
44
45#include <TLS.h>
46
47/* When full support for __thread variables is available, this interface is
48   just a trivial wrapper for it.  Without TLS, this is the generic/stub
49   implementation for wholly single-threaded systems.
50
51   We don't define an enum for the possible key values, because the KEYs
52   translate directly into variables by macro magic.  */
53
54#if USE___THREAD
55# define __libc_tsd_define(CLASS, KEY)	\
56  CLASS __thread void *__libc_tsd_##KEY attribute_tls_model_ie;
57
58# define __libc_tsd_address(KEY)	(&__libc_tsd_##KEY)
59# define __libc_tsd_get(KEY)		(__libc_tsd_##KEY)
60# define __libc_tsd_set(KEY, VALUE)	(__libc_tsd_##KEY = (VALUE))
61#else
62# define __libc_tsd_define(CLASS, KEY)	CLASS void *__libc_tsd_##KEY##_data;
63
64# define __libc_tsd_address(KEY)	(&__libc_tsd_##KEY##_data)
65# define __libc_tsd_get(KEY)		(__libc_tsd_##KEY##_data)
66# define __libc_tsd_set(KEY, VALUE)	(__libc_tsd_##KEY##_data = (VALUE))
67#endif
68
69#endif	/* bits/libc-tsd.h */
70