From 42cca94a7485d62a2594e0f2c95c85eb36982814 Mon Sep 17 00:00:00 2001
From: Ulrich Drepper <drepper@redhat.com>
Date: Sat, 28 Jul 2007 19:31:35 +0000
Subject: [PATCH] (FUTEX_PRIVATE_FLAG, LLL_PRIVATE, LLL_SHARED,
 __lll_private_flag): Define. (lll_futex_wait): Add private argument, define
 as wrapper around lll_futex_timed_wait. (lll_futex_timed_wait,
 lll_futex_wake): Add private argument, use __lll_private_flag macro.
 (lll_robust_mutex_dead, __lll_mutex_unlock, __lll_robust_mutex_unlock,
 __lll_mutex_unlock_force): Pass LLL_SHARED as last arg to lll_futex_*.

---
 sysdeps/unix/sysv/linux/alpha/nptl/lowlevellock.h | 73 ++++++++++++++++-------
 1 file changed, 51 insertions(+), 22 deletions(-)

diff --git a/sysdeps/unix/sysv/linux/alpha/nptl/lowlevellock.h b/sysdeps/unix/sysv/linux/alpha/nptl/lowlevellock.h
index 04ac006..5f08673 100644
--- a/sysdeps/unix/sysv/linux/alpha/nptl/lowlevellock.h
+++ b/sysdeps/unix/sysv/linux/alpha/nptl/lowlevellock.h
@@ -36,34 +36,63 @@
 #define FUTEX_LOCK_PI		6
 #define FUTEX_UNLOCK_PI		7
 #define FUTEX_TRYLOCK_PI	8
+#define FUTEX_PRIVATE_FLAG	128
+
+/* Values for 'private' parameter of locking macros.  Yes, the
+   definition seems to be backwards.  But it is not.  The bit will be
+   reversed before passing to the system call.  */
+#define LLL_PRIVATE	0
+#define LLL_SHARED	FUTEX_PRIVATE_FLAG
+
+
+#if !defined NOT_IN_libc || defined IS_IN_rtld
+/* In libc.so or ld.so all futexes are private.  */
+# ifdef __ASSUME_PRIVATE_FUTEX
+#  define __lll_private_flag(fl, private) \
+  ((fl) | FUTEX_PRIVATE_FLAG)
+# else
+#  define __lll_private_flag(fl, private) \
+  ((fl) | THREAD_GETMEM (THREAD_SELF, header.private_futex))
+# endif
+#else
+# ifdef __ASSUME_PRIVATE_FUTEX
+#  define __lll_private_flag(fl, private) \
+  (((fl) | FUTEX_PRIVATE_FLAG) ^ (private))
+# else
+#  define __lll_private_flag(fl, private) \
+  (__builtin_constant_p (private)					      \
+   ? ((private) == 0							      \
+      ? ((fl) | THREAD_GETMEM (THREAD_SELF, header.private_futex))	      \
+      : (fl))								      \
+   : ((fl) | (((private) ^ FUTEX_PRIVATE_FLAG)				      \
+	      & THREAD_GETMEM (THREAD_SELF, header.private_futex))))
+# endif	      
+#endif
+
 
 /* Initializer for compatibility lock.	*/
 #define LLL_MUTEX_LOCK_INITIALIZER (0)
 
-#define lll_futex_wait(futexp, val) \
-  ({									      \
-    INTERNAL_SYSCALL_DECL (__err);					      \
-    long int __ret;							      \
-    __ret = INTERNAL_SYSCALL (futex, __err, 4,				      \
-			      (futexp), FUTEX_WAIT, (val), 0);		      \
-    INTERNAL_SYSCALL_ERROR_P (__ret, __err)? -__ret : __ret;		      \
-  })
+#define lll_futex_wait(futexp, val, private) \
+  lll_futex_timed_wait (futexp, val, NULL, private)
 
-#define lll_futex_timed_wait(futexp, val, timespec) \
+#define lll_futex_timed_wait(futexp, val, timespec, private) \
   ({									      \
     INTERNAL_SYSCALL_DECL (__err);					      \
     long int __ret;							      \
-    __ret = INTERNAL_SYSCALL (futex, __err, 4,				      \
-			      (futexp), FUTEX_WAIT, (val), (timespec));	      \
+    __ret = INTERNAL_SYSCALL (futex, __err, 4, (futexp),		      \
+			      __lll_private_flag (FUTEX_WAIT, private),	      \
+			      (val), (timespec));			      \
     INTERNAL_SYSCALL_ERROR_P (__ret, __err)? -__ret : __ret;		      \
   })
 
-#define lll_futex_wake(futexp, nr) \
+#define lll_futex_wake(futexp, nr, private) \
   ({									      \
     INTERNAL_SYSCALL_DECL (__err);					      \
     long int __ret;							      \
-    __ret = INTERNAL_SYSCALL (futex, __err, 4,				      \
-			      (futexp), FUTEX_WAKE, (nr), 0);		      \
+    __ret = INTERNAL_SYSCALL (futex, __err, 4, (futexp),		      \
+			      __lll_private_flag (FUTEX_WAKE, private),	      \
+			      (nr), 0);					      \
     INTERNAL_SYSCALL_ERROR_P (__ret, __err)? -__ret : __ret;		      \
   })
 
@@ -72,7 +101,7 @@
     {									      \
       int *__futexp = &(futexv);					      \
       atomic_or (__futexp, FUTEX_OWNER_DIED);				      \
-      lll_futex_wake (__futexp, 1);					      \
+      lll_futex_wake (__futexp, 1, LLL_SHARED);				      \
     }									      \
   while (0)
 
@@ -198,7 +227,7 @@ __lll_mutex_unlock (int *futex)
 {
   int val = atomic_exchange_rel (futex, 0);
   if (__builtin_expect (val > 1, 0))
-    lll_futex_wake (futex, 1);
+    lll_futex_wake (futex, 1, LLL_SHARED);
 }
 #define lll_mutex_unlock(futex) __lll_mutex_unlock(&(futex))
 
@@ -208,7 +237,7 @@ __lll_robust_mutex_unlock (int *futex, int mask)
 {
   int val = atomic_exchange_rel (futex, 0);
   if (__builtin_expect (val & mask, 0))
-    lll_futex_wake (futex, 1);
+    lll_futex_wake (futex, 1, LLL_SHARED);
 }
 #define lll_robust_mutex_unlock(futex) \
   __lll_robust_mutex_unlock(&(futex), FUTEX_WAITERS)
@@ -218,7 +247,7 @@ static inline void __attribute__ ((always_inline))
 __lll_mutex_unlock_force (int *futex)
 {
   (void) atomic_exchange_rel (futex, 0);
-  lll_futex_wake (futex, 1);
+  lll_futex_wake (futex, 1, LLL_SHARED);
 }
 #define lll_mutex_unlock_force(futex) __lll_mutex_unlock_force(&(futex))
 
@@ -252,10 +281,10 @@ typedef int lll_lock_t;
    thread ID while the clone is running and is reset to zero
    afterwards.	*/
 #define lll_wait_tid(tid) \
-  do {					\
-    __typeof (tid) __tid;		\
-    while ((__tid = (tid)) != 0)	\
-      lll_futex_wait (&(tid), __tid);	\
+  do {							\
+    __typeof (tid) __tid;				\
+    while ((__tid = (tid)) != 0)			\
+      lll_futex_wait (&(tid), __tid, LLL_SHARED);	\
   } while (0)
 
 extern int __lll_timedwait_tid (int *, const struct timespec *)
-- 
2.7.4