urcu-bp: allow weak linking

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>

diff --git a/urcu-bp.c b/urcu-bp.c
index 4c0ab54a28e71b47947905d6f5f42354de0135cd..99fcb0cdffddc1cc6c4cc7c5c864eb6ac5921a9d 100644 (file)
--- a/urcu-bp.c
+++ b/urcu-bp.c
@@ -421,5 +421,23 @@ void rcu_bp_after_fork_child(void)
        assert(!ret);
 }
 
+void *rcu_set_pointer_sym_bp(void **p, void *v)
+{
+       cmm_wmb();
+       return uatomic_set(p, v);
+}
+
+void *rcu_xchg_pointer_sym_bp(void **p, void *v)
+{
+       cmm_wmb();
+       return uatomic_xchg(p, v);
+}
+
+void *rcu_cmpxchg_pointer_sym_bp(void **p, void *old, void *_new)
+{
+       cmm_wmb();
+       return uatomic_cmpxchg(p, old, _new);
+}
+
 #include "urcu-call-rcu-impl.h"
 #include "urcu-defer-impl.h"

diff --git a/urcu-bp.h b/urcu-bp.h
index 451bedb8dd4700b2f69c788682695005ef71af36..34f7a5c0929299385bedd48b04141dc339835b74 100644 (file)
--- a/urcu-bp.h
+++ b/urcu-bp.h
@@ -37,12 +37,6 @@
 #include <stdlib.h>
 #include <pthread.h>
 
-/*
- * See urcu-pointer.h and urcu/static/urcu-pointer.h for pointer
- * publication headers.
- */
-#include <urcu-pointer.h>
-
 #ifdef __cplusplus
 extern "C" {
 #endif
@@ -57,6 +51,12 @@ extern "C" {
  * rcu_unregister_thread() should be called before the thread exits.
  */
 
+/*
+ * See urcu-pointer.h and urcu/static/urcu-pointer.h for pointer
+ * publication headers.
+ */
+#include <urcu-pointer.h>
+
 #ifdef _LGPL_SOURCE
 
 #include <urcu/static/urcu-bp.h>
@@ -75,6 +75,11 @@ extern "C" {
 #define rcu_read_lock_bp               _rcu_read_lock
 #define rcu_read_unlock_bp             _rcu_read_unlock
 
+#define rcu_dereference_bp             rcu_dereference
+#define rcu_cmpxchg_pointer_bp         rcu_cmpxchg_pointer
+#define rcu_xchg_pointer_bp            rcu_xchg_pointer
+#define rcu_set_pointer_bp             rcu_set_pointer
+
 #else /* !_LGPL_SOURCE */
 
 /*
@@ -82,8 +87,54 @@ extern "C" {
  * See LGPL-only urcu/static/urcu-pointer.h for documentation.
  */
 
-extern void rcu_read_lock(void);
-extern void rcu_read_unlock(void);
+extern void rcu_read_lock(void)
+       __attribute__((weak));
+extern void rcu_read_unlock(void)
+       __attribute__((weak));
+
+extern void *rcu_dereference_sym_bp(void *p)
+       __attribute__((weak));
+#define rcu_dereference_bp(p)                                               \
+       ({                                                                   \
+               typeof(p) _________p1 = URCU_FORCE_CAST(typeof(p),           \
+                       rcu_dereference_sym_bp(URCU_FORCE_CAST(void *, p))); \
+               (_________p1);                                               \
+       })
+
+extern void *rcu_cmpxchg_pointer_sym_bp(void **p, void *old, void *_new)
+       __attribute__((weak));
+#define rcu_cmpxchg_pointer_bp(p, old, _new)                                \
+       ({                                                                   \
+               typeof(*(p)) _________pold = (old);                          \
+               typeof(*(p)) _________pnew = (_new);                         \
+               typeof(*(p)) _________p1 = URCU_FORCE_CAST(typeof(*(p)),     \
+                       rcu_cmpxchg_pointer_sym_bp(URCU_FORCE_CAST(void **, p),\
+                                               _________pold,               \
+                                               _________pnew));             \
+               (_________p1);                                               \
+       })
+
+extern void *rcu_xchg_pointer_sym_bp(void **p, void *v)
+       __attribute__((weak));
+#define rcu_xchg_pointer_bp(p, v)                                           \
+       ({                                                                   \
+               typeof(*(p)) _________pv = (v);                              \
+               typeof(*(p)) _________p1 = URCU_FORCE_CAST(typeof(*(p)),     \
+                       rcu_xchg_pointer_sym_bp(URCU_FORCE_CAST(void **, p), \
+                                            _________pv));                  \
+               (_________p1);                                               \
+       })
+
+extern void *rcu_set_pointer_sym_bp(void **p, void *v)
+       __attribute__((weak));
+#define rcu_set_pointer_bp(p, v)                                            \
+       ({                                                                   \
+               typeof(*(p)) _________pv = (v);                              \
+               typeof(*(p)) _________p1 = URCU_FORCE_CAST(typeof(*(p)),     \
+                       rcu_set_pointer_sym_bp(URCU_FORCE_CAST(void **, p),  \
+                                           _________pv));                   \
+               (_________p1);                                               \
+       })
 
 #endif /* !_LGPL_SOURCE */