Add missing rcu_cmpxchg_pointer define

[urcu.git] / urcu-qsbr.h

diff --git a/urcu-qsbr.h b/urcu-qsbr.h
index 1dc4ddd6d27a0a59a810c5c7652e984374a0ac91..fdf47124d85f2b170f78410a996f5c3f40e4f8cc 100644 (file)
--- a/urcu-qsbr.h
+++ b/urcu-qsbr.h
@@ -57,6 +57,7 @@
 #define rcu_thread_online      _rcu_thread_online
 
 #define rcu_assign_pointer     _rcu_assign_pointer
+#define rcu_cmpxchg_pointer    _rcu_cmpxchg_pointer
 #define rcu_xchg_pointer       _rcu_xchg_pointer
 #define rcu_publish_content    _rcu_publish_content
 
@@ -66,9 +67,32 @@
  * library wrappers to be used by non-LGPL compatible source code.
  */
 
+/*
+ * QSBR read lock/unlock are guaranteed to be no-ops. Therefore, we expose them
+ * in the LGPL header for any code to use. However, the debug version is not
+ * nops and may contain sanity checks. To activate it, applications must be
+ * recompiled with -DURCU_DEBUG (even non-LGPL/GPL applications). This is the
+ * best trade-off between license/performance/code triviality and
+ * library debugging & tracing features we could come up with.
+ */
+
+#if (!defined(BUILD_QSBR_LIB) && defined(URCU_DEBUG))
+
+static inline void rcu_read_lock(void)
+{
+}
+
+static inline void rcu_read_lock(void)
+{
+}
+
+#else /* !URCU_DEBUG */
+
 extern void rcu_read_lock(void);
 extern void rcu_read_unlock(void);
 
+#endif /* !URCU_DEBUG */
+
 extern void *rcu_dereference(void *p);
 
 extern void rcu_quiescent_state(void);
@@ -80,6 +104,10 @@ extern void *rcu_assign_pointer_sym(void **p, void *v);
 #define rcu_assign_pointer(p, v)                       \
        rcu_assign_pointer_sym((void **)(p), (v))
 
+extern void *rcu_cmpxchg_pointer_sym(void **p, void *old, void *_new);
+#define rcu_cmpxchg_pointer(p, old, _new)              \
+       rcu_cmpxchg_pointer_sym((void **)(p), (old), (_new))
+
 extern void *rcu_xchg_pointer_sym(void **p, void *v);
 #define rcu_xchg_pointer(p, v)                         \
        rcu_xchg_pointer_sym((void **)(p), (v))