1 /* Setup of nscd worker threads. Linux verison.
2 Copyright (C) 2004-2015 Free Software Foundation, Inc.
3 This file is part of the GNU C Library.
4 Contributed by Ulrich Drepper <drepper@redhat.com>, 2004.
6 This program is free software; you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published
8 by the Free Software Foundation; version 2 of the License, or
9 (at your option) any later version.
11 This program 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
14 GNU General Public License for more details.
16 You should have received a copy of the GNU General Public License
17 along with this program; if not, see <http://www.gnu.org/licenses/>. */
26 setup_thread (struct database_dyn
*db
)
28 #ifdef __NR_set_tid_address
29 /* Only supported when NPTL is used. */
31 if (confstr (_CS_GNU_LIBPTHREAD_VERSION
, buf
, sizeof (buf
)) >= sizeof (buf
)
32 || strncmp (buf
, "NPTL", 4) != 0)
35 /* Do not try this at home, kids. We play with the SETTID address
36 even thought the process is multi-threaded. This can only work
37 since none of the threads ever terminates. */
38 INTERNAL_SYSCALL_DECL (err
);
39 int r
= INTERNAL_SYSCALL (set_tid_address
, err
, 1,
40 &db
->head
->nscd_certainly_running
);
41 if (!INTERNAL_SYSCALL_ERROR_P (r
, err
))
42 /* We know the kernel can reset this field when nscd terminates.
43 So, set the field to a nonzero value which indicates that nscd
44 is certainly running and clients can skip the test. */
45 return db
->head
->nscd_certainly_running
= 1;