1 files changed, 44 insertions, 0 deletions
diff --git a/libpthread/nptl/sysdeps/unix/sysv/linux/sem_trywait.c b/libpthread/nptl/sysdeps/unix/sysv/linux/sem_trywait.c
new file mode 100644
index 000000000..3cf1d9a8a
--- /dev/null
+++ b/libpthread/nptl/sysdeps/unix/sysv/linux/sem_trywait.c
@@ -0,0 +1,44 @@
+/* sem_trywait -- wait on a semaphore.  Generic futex-using version.
+   Copyright (C) 2003 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, write to the Free
+   Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
+   02111-1307 USA.  */
+
+#include <errno.h>
+#include <sysdep.h>
+#include <lowlevellock.h>
+#include <internaltypes.h>
+#include <semaphore.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;
+}
+weak_alias(__new_sem_trywait, sem_trywait)