rculfhash: document destroy context limitation

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

diff --git a/urcu/rculfhash.h b/urcu/rculfhash.h
index 03ce5932b4837aa8d4c5f68f6b9cee47dcddcb10..23bd1ce3bded4fd4e83f51e0c63c34b48f788acb 100644 (file)
--- a/urcu/rculfhash.h
+++ b/urcu/rculfhash.h
@@ -175,6 +175,12 @@ 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 +430,11 @@ 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);