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a88c926368
2003-02-05 Ulrich Drepper <drepper@redhat.com> * sysdeps/pthread/bits/libc-lock.h (__libc_once): Set control variable for non-libpthread case to the same value the pthread_once function would use.
50 lines
1.6 KiB
C
50 lines
1.6 KiB
C
/* Copyright (C) 2003 Free Software Foundation, Inc.
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This file is part of the GNU C Library.
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Contributed by Martin Schwidefsky <schwidefsky@de.ibm.com>, 2003.
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The GNU C Library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Lesser General Public
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License as published by the Free Software Foundation; either
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version 2.1 of the License, or (at your option) any later version.
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The GNU C Library 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 GNU
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Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public
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License along with the GNU C Library; if not, write to the Free
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Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
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02111-1307 USA. */
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#include <errno.h>
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#include <sysdep.h>
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#include <lowlevelsem.h>
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#include <internaltypes.h>
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#include <shlib-compat.h>
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int
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__new_sem_trywait (sem_t *sem)
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{
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int oldval;
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int newval;
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/* Atomically decrement sem counter if it is > 0. */
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lll_compare_and_swap ((int *) sem, oldval, newval,
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"ltr %2,%1; jnp 1f; ahi %2,-1");
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/* oldval != newval if the semaphore count has been decremented. */
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if (oldval == newval)
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{
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__set_errno (EAGAIN);
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return -1;
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}
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return 0;
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}
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versioned_symbol (libpthread, __new_sem_trywait, sem_trywait, GLIBC_2_1);
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#if SHLIB_COMPAT(libpthread, GLIBC_2_0, GLIBC_2_1)
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strong_alias (__new_sem_trywait, __old_sem_trywait)
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compat_symbol (libpthread, __old_sem_trywait, sem_trywait, GLIBC_2_0);
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#endif
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