1 /* MT support function to get address of `errno' variable, linuxthreads
2 version.
3 Copyright (C) 1996, 1998, 2002, 2003, 2004 Free Software Foundation, Inc.
4 This file is part of the GNU C Library.
5
6 The GNU C Library is free software; you can redistribute it and/or
7 modify it under the terms of the GNU Lesser General Public
8 License as published by the Free Software Foundation; either
9 version 2.1 of the License, or (at your option) any later version.
10
11 The GNU C Library is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 Lesser General Public License for more details.
15
16 You should have received a copy of the GNU Lesser General Public
17 License along with the GNU C Library; if not, write to the Free
18 Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
19 02111-1307 USA. */
20
21 #include <errno.h>
22 #include "internals.h"
23 #include <pt-machine.h>
24 //#include <sysdep-cancel.h>
25 #if defined USE_TLS && USE_TLS
26 #define USE___THREAD 1
27 #endif
28
29 #define SINGLE_THREAD_P \
30 __builtin_expect (THREAD_GETMEM (thread_self(), \
31 p_header.data.multiple_threads) == 0, 1)
32
33 #if ! USE___THREAD && !RTLD_PRIVATE_ERRNO
34 #undef errno
35 extern int errno;
36 #endif
37
38 int *
39 #if ! USE___THREAD
40 weak_const_function
41 #endif
__errno_location(void)42 __errno_location (void)
43 {
44 #if ! USE___THREAD && !defined NOT_IN_libc
45 if (! SINGLE_THREAD_P)
46 {
47 pthread_descr self = thread_self();
48 return LIBC_THREAD_GETMEM (self, p_errnop);
49 }
50 #endif
51 return &errno;
52 }
53 libc_hidden_def (__errno_location)
54