rculfhash: document max_nr_buckets = 0

[userspace-rcu.git] / urcu / rculfhash.h

diff --git a/urcu/rculfhash.h b/urcu/rculfhash.h
index 2938e5ec6235883acc9efb9b029e135035f7a10e..6f09ddbde7cbe25f2afd83c85652c3609512f784 100644 (file)
--- a/urcu/rculfhash.h
+++ b/urcu/rculfhash.h
@@ -132,7 +132,8 @@ struct cds_lfht *_cds_lfht_new(unsigned long init_size,
  * @min_nr_alloc_buckets: the minimum number of allocated buckets.
  *                        (must be power of two)
  * @max_nr_buckets: the maximum number of hash table buckets allowed.
- *                  (must be power of two)
+ *                  (must be power of two, 0 is accepted, means
+ *                  "infinite")
  * @flags: hash table creation flags (can be combined with bitwise or: '|').
  *           0: no flags.
  *           CDS_LFHT_AUTO_RESIZE: automatically resize hash table.
@@ -175,6 +176,12 @@ struct cds_lfht *cds_lfht_new(unsigned long init_size,
  *
  * Return 0 on success, negative error value on error.
  * Threads calling this API need to be registered RCU read-side threads.
+ * cds_lfht_destroy should *not* be called from a RCU read-side critical
+ * section. It should *not* be called from call_rcu thread context
+ * neither.
+ * In userspace RCU 0.7.x, for QSBR RCU flavor, cds_lfht_destroy() has a
+ * side-effect: it puts the caller thread in "online" state. This will
+ * be fixed in userspace RCU 0.8.x.
  */
 int cds_lfht_destroy(struct cds_lfht *ht, pthread_attr_t **attr);
 
@@ -424,6 +431,11 @@ int cds_lfht_is_node_deleted(struct cds_lfht_node *node);
  *
  * Threads calling this API need to be registered RCU read-side threads.
  * This function does not (necessarily) issue memory barriers.
+ * cds_lfht_resize should *not* be called from a RCU read-side critical
+ * section.
+ * In userspace RCU 0.7.x, for QSBR RCU flavor, cds_lfht_resize() has a
+ * side-effect: it puts the caller thread in "online" state. This will
+ * be fixed in userspace RCU 0.8.x.
  */
 void cds_lfht_resize(struct cds_lfht *ht, unsigned long new_size);
 
@@ -450,21 +462,21 @@ void cds_lfht_resize(struct cds_lfht *ht, unsigned long new_size);
 #define cds_lfht_for_each_entry(ht, iter, pos, member)                 \
        for (cds_lfht_first(ht, iter),                                  \
                        pos = caa_container_of(cds_lfht_iter_get_node(iter), \
-                                       typeof(*(pos)), member);        \
+                                       __typeof__(*(pos)), member);    \
                &(pos)->member != NULL;                                 \
                cds_lfht_next(ht, iter),                                \
                        pos = caa_container_of(cds_lfht_iter_get_node(iter), \
-                                       typeof(*(pos)), member))
+                                       __typeof__(*(pos)), member))
 
 #define cds_lfht_for_each_entry_duplicate(ht, hash, match, key,                \
                                iter, pos, member)                      \
        for (cds_lfht_lookup(ht, hash, match, key, iter),               \
                        pos = caa_container_of(cds_lfht_iter_get_node(iter), \
-                                       typeof(*(pos)), member);        \
+                                       __typeof__(*(pos)), member);    \
                &(pos)->member != NULL;                                 \
                cds_lfht_next_duplicate(ht, match, key, iter),          \
                        pos = caa_container_of(cds_lfht_iter_get_node(iter), \
-                                       typeof(*(pos)), member))
+                                       __typeof__(*(pos)), member))
 
 #ifdef __cplusplus
 }