Fix: add missing destroy functions to queues/stack APIs

[urcu.git] / urcu / static / lfstack.h

diff --git a/urcu/static/lfstack.h b/urcu/static/lfstack.h
index 0be959436e7d4577c4e6e7673dad6b49fae74469..05d0bb478b8b169a03864272810d1b5c76bfa4f8 100644 (file)
--- a/urcu/static/lfstack.h
+++ b/urcu/static/lfstack.h
@@ -66,7 +66,8 @@ void _cds_lfs_node_init(struct cds_lfs_node *node)
 }
 
 /*
- * cds_lfs_init: initialize lock-free stack.
+ * cds_lfs_init: initialize lock-free stack (with lock). Pair with
+ * cds_lfs_destroy().
  */
 static inline
 void _cds_lfs_init(struct cds_lfs_stack *s)
@@ -78,6 +79,27 @@ void _cds_lfs_init(struct cds_lfs_stack *s)
        assert(!ret);
 }
 
+/*
+ * cds_lfs_destroy: destroy lock-free stack (with lock). Pair with
+ * cds_lfs_init().
+ */
+static inline
+void _cds_lfs_destroy(struct cds_lfs_stack *s)
+{
+        int ret = pthread_mutex_destroy(&s->lock);
+       assert(!ret);
+}
+
+/*
+ * ___cds_lfs_init: initialize lock-free stack (without lock).
+ * Don't pair with any destroy function.
+ */
+static inline
+void ___cds_lfs_init(struct __cds_lfs_stack *s)
+{
+       s->head = NULL;
+}
+
 static inline
 bool ___cds_lfs_empty_head(struct cds_lfs_head *head)
 {
@@ -90,9 +112,9 @@ bool ___cds_lfs_empty_head(struct cds_lfs_head *head)
  * No memory barrier is issued. No mutual exclusion is required.
  */
 static inline
-bool _cds_lfs_empty(struct cds_lfs_stack *s)
+bool _cds_lfs_empty(cds_lfs_stack_ptr_t s)
 {
-       return ___cds_lfs_empty_head(CMM_LOAD_SHARED(s->head));
+       return ___cds_lfs_empty_head(CMM_LOAD_SHARED(s._s->head));
 }
 
 /*
@@ -125,9 +147,10 @@ bool _cds_lfs_empty(struct cds_lfs_stack *s)
  * Returns non-zero otherwise.
  */
 static inline
-bool _cds_lfs_push(struct cds_lfs_stack *s,
+bool _cds_lfs_push(cds_lfs_stack_ptr_t u_s,
                  struct cds_lfs_node *node)
 {
+       struct __cds_lfs_stack *s = u_s._s;
        struct cds_lfs_head *head = NULL;
        struct cds_lfs_head *new_head =
                caa_container_of(node, struct cds_lfs_head, node);
@@ -148,7 +171,7 @@ bool _cds_lfs_push(struct cds_lfs_stack *s,
                if (old_head == head)
                        break;
        }
-       return ___cds_lfs_empty_head(head);
+       return !___cds_lfs_empty_head(head);
 }
 
 /*
@@ -159,17 +182,23 @@ bool _cds_lfs_push(struct cds_lfs_stack *s,
  * __cds_lfs_pop needs to be synchronized using one of the following
  * techniques:
  *
- * 1) Calling __cds_lfs_pop under rcu read lock critical section. The
- *    caller must wait for a grace period to pass before freeing the
- *    returned node or modifying the cds_lfs_node structure.
+ * 1) Calling __cds_lfs_pop under rcu read lock critical section.
+ *    Both __cds_lfs_pop and __cds_lfs_pop_all callers must wait for a
+ *    grace period to pass before freeing the returned node or pushing
+ *    the node back into the stack. It is valid to overwrite the content
+ *    of cds_lfs_node immediately after __cds_lfs_pop and
+ *    __cds_lfs_pop_all. No RCU read-side critical section is needed
+ *    around __cds_lfs_pop_all.
  * 2) Using mutual exclusion (e.g. mutexes) to protect __cds_lfs_pop
  *    and __cds_lfs_pop_all callers.
  * 3) Ensuring that only ONE thread can call __cds_lfs_pop() and
  *    __cds_lfs_pop_all(). (multi-provider/single-consumer scheme).
  */
 static inline
-struct cds_lfs_node *___cds_lfs_pop(struct cds_lfs_stack *s)
+struct cds_lfs_node *___cds_lfs_pop(cds_lfs_stack_ptr_t u_s)
 {
+       struct __cds_lfs_stack *s = u_s._s;
+
        for (;;) {
                struct cds_lfs_head *head, *next_head;
                struct cds_lfs_node *next;
@@ -201,18 +230,22 @@ struct cds_lfs_node *___cds_lfs_pop(struct cds_lfs_stack *s)
  * matching the technique used to synchronize __cds_lfs_pop:
  *
  * 1) If __cds_lfs_pop is called under rcu read lock critical section,
- *    both __cds_lfs_pop and cds_lfs_pop_all callers must wait for a
- *    grace period to pass before freeing the returned node or modifying
- *    the cds_lfs_node structure. However, no RCU read-side critical
- *    section is needed around __cds_lfs_pop_all.
+ *    both __cds_lfs_pop and __cds_lfs_pop_all callers must wait for a
+ *    grace period to pass before freeing the returned node or pushing
+ *    the node back into the stack. It is valid to overwrite the content
+ *    of cds_lfs_node immediately after __cds_lfs_pop and
+ *    __cds_lfs_pop_all. No RCU read-side critical section is needed
+ *    around __cds_lfs_pop_all.
  * 2) Using mutual exclusion (e.g. mutexes) to protect __cds_lfs_pop and
  *    __cds_lfs_pop_all callers.
  * 3) Ensuring that only ONE thread can call __cds_lfs_pop() and
  *    __cds_lfs_pop_all(). (multi-provider/single-consumer scheme).
  */
 static inline
-struct cds_lfs_head *___cds_lfs_pop_all(struct cds_lfs_stack *s)
+struct cds_lfs_head *___cds_lfs_pop_all(cds_lfs_stack_ptr_t u_s)
 {
+       struct __cds_lfs_stack *s = u_s._s;
+
        /*
         * Implicit memory barrier after uatomic_xchg() matches implicit
         * memory barrier before uatomic_cmpxchg() in cds_lfs_push. It