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authorRoland McGrath <roland@hack.frob.com>2014-10-17 14:30:16 -0700
committerRoland McGrath <roland@hack.frob.com>2014-10-17 14:30:16 -0700
commit184ee94010786a9e0952aff3af39eba1d72287d3 (patch)
treeb7f4a680b4340f565951a599a6d86f88e61a1711 /nptl/pthread_mutex_lock.c
parent327ae2570744dabf7f065a6b529d16cc22438603 (diff)
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NPTL: Conditionalize direct futex syscall uses.
Diffstat (limited to 'nptl/pthread_mutex_lock.c')
-rw-r--r--nptl/pthread_mutex_lock.c13
1 files changed, 9 insertions, 4 deletions
diff --git a/nptl/pthread_mutex_lock.c b/nptl/pthread_mutex_lock.c
index d94f4c9483..6d4acd40c6 100644
--- a/nptl/pthread_mutex_lock.c
+++ b/nptl/pthread_mutex_lock.c
@@ -276,6 +276,10 @@ __pthread_mutex_lock_full (pthread_mutex_t *mutex)
       THREAD_SETMEM (THREAD_SELF, robust_head.list_op_pending, NULL);
       break;
 
+    /* The PI support requires the Linux futex system call.  If that's not
+       available, pthread_mutex_init should never have allowed the type to
+       be set.  So it will get the default case for an invalid type.  */
+#ifdef __NR_futex
     case PTHREAD_MUTEX_PI_RECURSIVE_NP:
     case PTHREAD_MUTEX_PI_ERRORCHECK_NP:
     case PTHREAD_MUTEX_PI_NORMAL_NP:
@@ -321,9 +325,9 @@ __pthread_mutex_lock_full (pthread_mutex_t *mutex)
 	  }
 
 	int newval = id;
-#ifdef NO_INCR
+# ifdef NO_INCR
 	newval |= FUTEX_WAITERS;
-#endif
+# endif
 	oldval = atomic_compare_and_exchange_val_acq (&mutex->__data.__lock,
 						      newval, 0);
 
@@ -377,9 +381,9 @@ __pthread_mutex_lock_full (pthread_mutex_t *mutex)
 	       incremented which is not correct because the old owner
 	       has to be discounted.  If we are not supposed to
 	       increment __nusers we actually have to decrement it here.  */
-#ifdef NO_INCR
+# ifdef NO_INCR
 	    --mutex->__data.__nusers;
-#endif
+# endif
 
 	    return EOWNERDEAD;
 	  }
@@ -409,6 +413,7 @@ __pthread_mutex_lock_full (pthread_mutex_t *mutex)
 	  }
       }
       break;
+#endif  /* __NR_futex.  */
 
     case PTHREAD_MUTEX_PP_RECURSIVE_NP:
     case PTHREAD_MUTEX_PP_ERRORCHECK_NP: