Only support ifunc in nptl/pt-vfork.c

[platform/upstream/linaro-glibc.git] / nptl / pthread_cond_signal.c

diff --git a/nptl/pthread_cond_signal.c b/nptl/pthread_cond_signal.c
index e4716f2..22bef3d 100644 (file)
--- a/nptl/pthread_cond_signal.c
+++ b/nptl/pthread_cond_signal.c
@@ -1,4 +1,4 @@
-/* Copyright (C) 2003, 2004, 2007 Free Software Foundation, Inc.
+/* Copyright (C) 2003-2014 Free Software Foundation, Inc.
    This file is part of the GNU C Library.
    Contributed by Martin Schwidefsky <schwidefsky@de.ibm.com>, 2003.
 
@@ -25,6 +25,7 @@
 
 #include <shlib-compat.h>
 #include <kernel-features.h>
+#include <stap-probe.h>
 
 
 int
@@ -34,6 +35,8 @@ __pthread_cond_signal (cond)
   int pshared = (cond->__data.__mutex == (void *) ~0l)
                ? LLL_SHARED : LLL_PRIVATE;
 
+  LIBC_PROBE (cond_signal, 1, cond);
+
   /* Make sure we are alone.  */
   lll_lock (cond->__data.__lock, pshared);
 
@@ -44,12 +47,30 @@ __pthread_cond_signal (cond)
       ++cond->__data.__wakeup_seq;
       ++cond->__data.__futex;
 
-      /* Wake one.  */
-      if (! __builtin_expect (lll_futex_wake_unlock (&cond->__data.__futex, 1,
-                                                    1, &cond->__data.__lock,
-                                                    pshared), 0))
-       return 0;
+#if (defined lll_futex_cmp_requeue_pi \
+     && defined __ASSUME_REQUEUE_PI)
+      pthread_mutex_t *mut = cond->__data.__mutex;
+
+      if (USE_REQUEUE_PI (mut)
+       /* This can only really fail with a ENOSYS, since nobody can modify
+          futex while we have the cond_lock.  */
+         && lll_futex_cmp_requeue_pi (&cond->__data.__futex, 1, 0,
+                                      &mut->__data.__lock,
+                                      cond->__data.__futex, pshared) == 0)
+       {
+         lll_unlock (cond->__data.__lock, pshared);
+         return 0;
+       }
+      else
+#endif
+       /* Wake one.  */
+       if (! __builtin_expect (lll_futex_wake_unlock (&cond->__data.__futex,
+                                                      1, 1,
+                                                      &cond->__data.__lock,
+                                                      pshared), 0))
+         return 0;
 
+      /* Fallback if neither of them work.  */
       lll_futex_wake (&cond->__data.__futex, 1, pshared);
     }