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aa350443c5
Due to the built-in tables, __NR_set_tid_address is always defined. Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
47 lines
1.7 KiB
C
47 lines
1.7 KiB
C
/* Setup of nscd worker threads. Linux verison.
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Copyright (C) 2004-2020 Free Software Foundation, Inc.
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This file is part of the GNU C Library.
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Contributed by Ulrich Drepper <drepper@redhat.com>, 2004.
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This program is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published
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by the Free Software Foundation; version 2 of the License, or
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(at your option) any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program; if not, see <https://www.gnu.org/licenses/>. */
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#include <string.h>
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#include <unistd.h>
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#include <nscd.h>
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#include <sysdep.h>
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int
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setup_thread (struct database_dyn *db)
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{
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/* Only supported when NPTL is used. */
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char buf[100];
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if (confstr (_CS_GNU_LIBPTHREAD_VERSION, buf, sizeof (buf)) >= sizeof (buf)
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|| strncmp (buf, "NPTL", 4) != 0)
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return 0;
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/* Do not try this at home, kids. We play with the SETTID address
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even thought the process is multi-threaded. This can only work
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since none of the threads ever terminates. */
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int r = INTERNAL_SYSCALL_CALL (set_tid_address,
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&db->head->nscd_certainly_running);
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if (!INTERNAL_SYSCALL_ERROR_P (r))
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/* We know the kernel can reset this field when nscd terminates.
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So, set the field to a nonzero value which indicates that nscd
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is certainly running and clients can skip the test. */
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return db->head->nscd_certainly_running = 1;
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return 0;
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}
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