Add per-thread cache to malloc

[thirdparty/glibc.git] / nptl / sem_getvalue.c

diff --git a/nptl/sem_getvalue.c b/nptl/sem_getvalue.c
index 3b17e5962904c4cf02ca69533d4cacdd57ea0e2e..8dfc1cde41ac69113f34ae47a0298ec7a8a1df38 100644 (file)
--- a/nptl/sem_getvalue.c
+++ b/nptl/sem_getvalue.c
@@ -1,4 +1,4 @@
-/* Copyright (C) 2002, 2007 Free Software Foundation, Inc.
+/* Copyright (C) 2002-2017 Free Software Foundation, Inc.
    This file is part of the GNU C Library.
    Contributed by Ulrich Drepper <drepper@redhat.com>, 2002.
 
@@ -13,30 +13,43 @@
    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.  */
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
 
 #include <semaphore.h>
 #include <shlib-compat.h>
 #include "semaphoreP.h"
+#include <atomic.h>
 
 
 int
-__new_sem_getvalue (sem, sval)
-     sem_t *sem;
-     int *sval;
+__new_sem_getvalue (sem_t *sem, int *sval)
 {
   struct new_sem *isem = (struct new_sem *) sem;
 
   /* XXX Check for valid SEM parameter.  */
-
-  *sval = isem->value;
+  /* FIXME This uses relaxed MO, even though POSIX specifies that this function
+     should be linearizable.  However, its debatable whether linearizability
+     is the right requirement.  We need to follow up with POSIX and, if
+     necessary, use a stronger MO here and elsewhere (e.g., potentially
+     release MO in all places where we consume a token).  */
+
+#if __HAVE_64B_ATOMICS
+  *sval = atomic_load_relaxed (&isem->data) & SEM_VALUE_MASK;
+#else
+  *sval = atomic_load_relaxed (&isem->value) >> SEM_VALUE_SHIFT;
+#endif
 
   return 0;
 }
 versioned_symbol (libpthread, __new_sem_getvalue, sem_getvalue, GLIBC_2_1);
 #if SHLIB_COMPAT(libpthread, GLIBC_2_0, GLIBC_2_1)
-strong_alias (__new_sem_getvalue, __old_sem_getvalue)
+int
+__old_sem_getvalue (sem_t *sem, int *sval)
+{
+  struct old_sem *isem = (struct old_sem *) sem;
+  *sval = isem->value;
+  return 0;
+}
 compat_symbol (libpthread, __old_sem_getvalue, sem_getvalue, GLIBC_2_0);
 #endif