--- libmalloc/libmalloc-409.81.2/src/locking.h
+++ libmalloc/libmalloc-140.40.1/src/locking.h
@@ -24,6 +24,8 @@
 #ifndef __LOCKING_H
 #define __LOCKING_H
 
+#if CONFIG_OS_LOCK_UNFAIR
+
 #if OS_UNFAIR_LOCK_INLINE
 #define os_unfair_lock_lock_with_options(lock, options) \
 		os_unfair_lock_lock_with_options_inline(lock, options)
@@ -31,7 +33,7 @@
 		os_unfair_lock_trylock_inline(lock)
 #define os_unfair_lock_unlock(lock) \
 		os_unfair_lock_unlock_inline(lock)
-#endif // OS_UNFAIR_LOCK_INLINE
+#endif
 
 typedef os_unfair_lock _malloc_lock_s;
 #define _MALLOC_LOCK_INIT OS_UNFAIR_LOCK_INIT
@@ -45,7 +47,7 @@
 MALLOC_ALWAYS_INLINE
 static inline void
 _malloc_lock_lock(_malloc_lock_s *lock) {
-	return os_unfair_lock_lock_with_options(lock, OS_UNFAIR_LOCK_ADAPTIVE_SPIN |
+	return os_unfair_lock_lock_with_options(lock,
 			OS_UNFAIR_LOCK_DATA_SYNCHRONIZATION);
 }
 
@@ -61,10 +63,51 @@
     return os_unfair_lock_unlock(lock);
 }
 
+#else // CONFIG_OS_LOCK_UNFAIR
+#if CONFIG_OS_LOCK_HANDOFF
+
+typedef os_lock_handoff_s _malloc_lock_s;
+#define _MALLOC_LOCK_INIT OS_LOCK_HANDOFF_INIT
+
+__attribute__((always_inline))
+static inline void
+_malloc_lock_init(_malloc_lock_s *lock) {
+    const os_lock_handoff_s _os_lock_handoff_init = OS_LOCK_HANDOFF_INIT;
+    *lock = _os_lock_handoff_init;
+}
+
+#else //CONFIG_OS_LOCK_HANDOFF
+
+typedef os_lock_spin_s _malloc_lock_s;
+#define _MALLOC_LOCK_INIT OS_LOCK_SPIN_INIT
+
 MALLOC_ALWAYS_INLINE
 static inline void
-_malloc_lock_assert_owner(_malloc_lock_s *lock) {
-	os_unfair_lock_assert_owner(lock);
+_malloc_lock_init(_malloc_lock_s *lock) {
+    const os_lock_spin_s _os_lock_spin_init = OS_LOCK_SPIN_INIT;
+    *lock = _os_lock_spin_init;
 }
 
+#endif
+
+MALLOC_ALWAYS_INLINE
+static inline void
+_malloc_lock_lock(_malloc_lock_s *lock) {
+    return os_lock_lock(lock);
+}
+
+MALLOC_ALWAYS_INLINE
+static inline bool
+_malloc_lock_trylock(_malloc_lock_s *lock) {
+    return os_lock_trylock(lock);
+}
+
+MALLOC_ALWAYS_INLINE
+static inline void
+_malloc_lock_unlock(_malloc_lock_s *lock) {
+    return os_lock_unlock(lock);
+}
+
+#endif // !CONFIG_OS_LOCK_UNFAIR
+
 #endif // __LOCKING_H