aboutsummaryrefslogtreecommitdiff
path: root/nptl/sem_trywait.c
diff options
context:
space:
mode:
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_trywait.c
parent96baf6ffc57b811bbc424a1fc72ef77dd56d7a18 (diff)
downloadglibc-08192659bbeae149e7cb1f4c43547257f7099bb0.tar
glibc-08192659bbeae149e7cb1f4c43547257f7099bb0.tar.gz
glibc-08192659bbeae149e7cb1f4c43547257f7099bb0.tar.bz2
glibc-08192659bbeae149e7cb1f4c43547257f7099bb0.zip
Get rid of nptl/sysdeps/ entirely!
Diffstat (limited to 'nptl/sem_trywait.c')
-rw-r--r--nptl/sem_trywait.c50
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