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authorRoland McGrath <roland@hack.frob.com>2014-07-07 09:28:38 -0700
committerRoland McGrath <roland@hack.frob.com>2014-07-07 09:28:38 -0700
commit08192659bbeae149e7cb1f4c43547257f7099bb0 (patch)
tree9f602a4e9f0aefdb06bc15a76be46e958e91a58f /nptl/sem_post.c
parent96baf6ffc57b811bbc424a1fc72ef77dd56d7a18 (diff)
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Get rid of nptl/sysdeps/ entirely!
Diffstat (limited to 'nptl/sem_post.c')
-rw-r--r--nptl/sem_post.c80
1 files changed, 80 insertions, 0 deletions
diff --git a/nptl/sem_post.c b/nptl/sem_post.c
new file mode 100644
index 0000000000..4906adf332
--- /dev/null
+++ b/nptl/sem_post.c
@@ -0,0 +1,80 @@
+/* sem_post -- post to a POSIX semaphore. Generic futex-using version.
+ Copyright (C) 2003-2014 Free Software Foundation, Inc.
+ This file is part of the GNU C Library.
+ Contributed by Jakub Jelinek <jakub@redhat.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 <atomic.h>
+#include <errno.h>
+#include <sysdep.h>
+#include <lowlevellock.h>
+#include <internaltypes.h>
+#include <semaphore.h>
+
+#include <shlib-compat.h>
+
+int
+__new_sem_post (sem_t *sem)
+{
+ struct new_sem *isem = (struct new_sem *) sem;
+
+ __typeof (isem->value) cur;
+ do
+ {
+ cur = isem->value;
+ if (isem->value == SEM_VALUE_MAX)
+ {
+ __set_errno (EOVERFLOW);
+ return -1;
+ }
+ }
+ while (atomic_compare_and_exchange_bool_rel (&isem->value, cur + 1, cur));
+
+ atomic_full_barrier ();
+ if (isem->nwaiters > 0)
+ {
+ int err = lll_futex_wake (&isem->value, 1,
+ isem->private ^ FUTEX_PRIVATE_FLAG);
+ if (__builtin_expect (err, 0) < 0)
+ {
+ __set_errno (-err);
+ return -1;
+ }
+ }
+ return 0;
+}
+versioned_symbol (libpthread, __new_sem_post, sem_post, GLIBC_2_1);
+
+
+#if SHLIB_COMPAT (libpthread, GLIBC_2_0, GLIBC_2_1)
+int
+attribute_compat_text_section
+__old_sem_post (sem_t *sem)
+{
+ int *futex = (int *) sem;
+
+ (void) atomic_increment_val (futex);
+ /* We always have to assume it is a shared semaphore. */
+ int err = lll_futex_wake (futex, 1, LLL_SHARED);
+ if (__builtin_expect (err, 0) < 0)
+ {
+ __set_errno (-err);
+ return -1;
+ }
+ return 0;
+}
+compat_symbol (libpthread, __old_sem_post, sem_post, GLIBC_2_0);
+#endif