rculfstack: LGPL-ize

[urcu.git] / urcu / rculfstack.h

diff --git a/urcu/rculfstack.h b/urcu/rculfstack.h
index 8cf7d13b35cc09ffc79f6646dd9c0d2c75b3e9b5..a33fcb1a7eaa29a7d80b798906c84b6303048623 100644 (file)
--- a/urcu/rculfstack.h
+++ b/urcu/rculfstack.h
@@ -27,10 +27,6 @@
 extern "C" {
 #endif
 
-#if (!defined(_GNU_SOURCE) && !defined(_LGPL_SOURCE))
-#error "Dynamic loader LGPL wrappers not implemented yet"
-#endif
-
 struct rcu_lfs_node {
        struct rcu_lfs_node *next;
 };
@@ -39,69 +35,29 @@ struct rcu_lfs_stack {
        struct rcu_lfs_node *head;
 };
 
-void rcu_lfs_node_init(struct rcu_lfs_node *node)
-{
-}
+#ifdef _LGPL_SOURCE
 
-void rcu_lfs_init(struct rcu_lfs_stack *s)
-{
-       s->head = NULL;
-}
+#include <urcu/rculfstack-static.h>
 
-void rcu_lfs_push(struct rcu_lfs_stack *s, struct rcu_lfs_node *node)
-{
-       for (;;) {
-               struct rcu_lfs_node *head;
+#define rcu_lfs_node_init      _rcu_lfs_node_init
+#define rcu_lfs_init           _rcu_lfs_init
+#define rcu_lfs_push           _rcu_lfs_push
+#define rcu_lfs_pop            _rcu_lfs_pop
 
-               rcu_read_lock();
-               head = rcu_dereference(s->head);
-               node->next = head;
-               /*
-                * uatomic_cmpxchg() implicit memory barrier orders earlier
-                * stores to node before publication.
-                */
-               if (uatomic_cmpxchg(&s->head, head, node) == head) {
-                       rcu_read_unlock();
-                       return;
-               } else {
-                       /* Failure to prepend. Retry. */
-                       rcu_read_unlock();
-                       continue;
-               }
-       }
-}
+#else /* !_LGPL_SOURCE */
+
+extern void rcu_lfs_node_init(struct rcu_lfs_node *node);
+extern void rcu_lfs_init(struct rcu_lfs_stack *s);
+extern void rcu_lfs_push(struct rcu_lfs_stack *s, struct rcu_lfs_node *node);
 
 /*
  * The caller must wait for a grace period to pass before freeing the returned
  * node or modifying the rcu_lfs_node structure.
  * Returns NULL if stack is empty.
  */
-struct rcu_lfs_node *
-rcu_lfs_pop(struct rcu_lfs_stack *s)
-{
-       for (;;) {
-               struct rcu_lfs_node *head;
+extern struct rcu_lfs_node *rcu_lfs_pop(struct rcu_lfs_stack *s);
 
-               rcu_read_lock();
-               head = rcu_dereference(s->head);
-               if (head) {
-                       struct rcu_lfs_node *next = rcu_dereference(head->next);
-
-                       if (uatomic_cmpxchg(&s->head, head, next) == head) {
-                               rcu_read_unlock();
-                               return head;
-                       } else {
-                               /* Concurrent modification. Retry. */
-                               rcu_read_unlock();
-                               continue;
-                       }
-               } else {
-                       /* Empty stack */
-                       rcu_read_unlock();
-                       return NULL;
-               }
-       }
-}
+#endif /* !_LGPL_SOURCE */
 
 #ifdef __cplusplus
 }