1/* libc-internal interface for thread-specific data. Stub or TLS version.
2 Copyright (C) 1998-2023 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, see
17 <https://www.gnu.org/licenses/>. */
18
19#ifndef _GENERIC_LIBC_TSD_H
20#define _GENERIC_LIBC_TSD_H 1
21
22/* This file defines the following macros for accessing a small fixed
23 set of thread-specific `void *' data used only internally by libc.
24
25 __libc_tsd_define(CLASS, TYPE, KEY) -- Define or declare a datum with TYPE
26 for KEY. CLASS can be `static' for
27 keys used in only one source file,
28 empty for global definitions, or
29 `extern' for global declarations.
30 __libc_tsd_address(TYPE, KEY) -- Return the `TYPE *' pointing to
31 the current thread's datum for KEY.
32 __libc_tsd_get(TYPE, KEY) -- Return the `TYPE' datum for KEY.
33 __libc_tsd_set(TYPE, KEY, VALUE) -- Set the datum for KEY to VALUE.
34
35 The set of available KEY's will usually be provided as an enum,
36 and contains (at least):
37 _LIBC_TSD_KEY_MALLOC
38 _LIBC_TSD_KEY_DL_ERROR
39 _LIBC_TSD_KEY_RPC_VARS
40 All uses must be the literal _LIBC_TSD_* name in the __libc_tsd_* macros.
41 Some implementations may not provide any enum at all and instead
42 using string pasting in the macros. */
43
44#include <tls.h>
45
46/* When full support for __thread variables is available, this interface is
47 just a trivial wrapper for it. Without TLS, this is the generic/stub
48 implementation for wholly single-threaded systems.
49
50 We don't define an enum for the possible key values, because the KEYs
51 translate directly into variables by macro magic. */
52
53#define __libc_tsd_define(CLASS, TYPE, KEY) \
54 CLASS __thread TYPE __libc_tsd_##KEY attribute_tls_model_ie;
55
56#define __libc_tsd_address(TYPE, KEY) (&__libc_tsd_##KEY)
57#define __libc_tsd_get(TYPE, KEY) (__libc_tsd_##KEY)
58#define __libc_tsd_set(TYPE, KEY, VALUE) (__libc_tsd_##KEY = (VALUE))
59
60#endif /* libc-tsd.h */
61