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author | Roland McGrath <roland@hack.frob.com> | 2014-07-07 09:28:38 -0700 |
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committer | Roland McGrath <roland@hack.frob.com> | 2014-07-07 09:28:38 -0700 |
commit | 08192659bbeae149e7cb1f4c43547257f7099bb0 (patch) | |
tree | 9f602a4e9f0aefdb06bc15a76be46e958e91a58f /nptl/sem_trywait.c | |
parent | 96baf6ffc57b811bbc424a1fc72ef77dd56d7a18 (diff) | |
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Get rid of nptl/sysdeps/ entirely!
Diffstat (limited to 'nptl/sem_trywait.c')
-rw-r--r-- | nptl/sem_trywait.c | 50 |
1 files changed, 50 insertions, 0 deletions
diff --git a/nptl/sem_trywait.c b/nptl/sem_trywait.c new file mode 100644 index 0000000000..94c323c18e --- /dev/null +++ b/nptl/sem_trywait.c @@ -0,0 +1,50 @@ +/* sem_trywait -- wait on a semaphore. Generic futex-using version. + Copyright (C) 2003-2014 Free Software Foundation, Inc. + This file is part of the GNU C Library. + Contributed by Paul Mackerras <paulus@au.ibm.com>, 2003. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, see + <http://www.gnu.org/licenses/>. */ + +#include <errno.h> +#include <sysdep.h> +#include <lowlevellock.h> +#include <internaltypes.h> +#include <semaphore.h> +#include <atomic.h> + +#include <shlib-compat.h> + + +int +__new_sem_trywait (sem_t *sem) +{ + int *futex = (int *) sem; + int val; + + if (*futex > 0) + { + val = atomic_decrement_if_positive (futex); + if (val > 0) + return 0; + } + + __set_errno (EAGAIN); + return -1; +} +versioned_symbol (libpthread, __new_sem_trywait, sem_trywait, GLIBC_2_1); +#if SHLIB_COMPAT (libpthread, GLIBC_2_0, GLIBC_2_1) +strong_alias (__new_sem_trywait, __old_sem_trywait) +compat_symbol (libpthread, __old_sem_trywait, sem_trywait, GLIBC_2_0); +#endif |