Fix: auto-resize hash table destroy deadlock

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

diff --git a/include/urcu/rculfhash.h b/include/urcu/rculfhash.h
index cbf513ec848c37744bb084a72ff66dd19f8c1816..fbd33cc3ff346c704ae264d724563977a5ff473f 100644 (file)
--- a/include/urcu/rculfhash.h
+++ b/include/urcu/rculfhash.h
@@ -105,10 +105,20 @@ typedef int (*cds_lfht_match_fct)(struct cds_lfht_node *node, const void *key);
  * (detection of memory corruption).
  */
 static inline
-void cds_lfht_node_init(struct cds_lfht_node *node)
+void cds_lfht_node_init(struct cds_lfht_node *node __attribute__((unused)))
 {
 }
 
+/*
+ * cds_lfht_node_init_deleted - initialize a hash table node to "removed" state
+ * @node: the node to initialize.
+ *
+ * Initialize the node such that cds_lfht_is_node_deleted() can be used
+ * on the node before it is added to a hash table.
+ */
+extern
+void cds_lfht_node_init_deleted(struct cds_lfht_node *node);
+
 /*
  * Hash table creation flags.
  */
@@ -237,16 +247,16 @@ 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.
+ *
  * Prior to liburcu 0.10:
- * - 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 a call_rcu thread
  *   context neither.
  *
  * Starting from liburcu 0.10, rculfhash implements its own worker
- * thread to handle resize operations, which removes RCU requirements on
- * cds_lfht_destroy.
+ * thread to handle resize operations, which removes the above RCU
+ * read-side critical section requirement on cds_lfht_destroy.
  */
 extern
 int cds_lfht_destroy(struct cds_lfht *ht, pthread_attr_t **attr);
@@ -499,7 +509,7 @@ int cds_lfht_del(struct cds_lfht *ht, struct cds_lfht_node *node);
  * This function does not issue any memory barrier.
  */
 extern
-int cds_lfht_is_node_deleted(struct cds_lfht_node *node);
+int cds_lfht_is_node_deleted(const struct cds_lfht_node *node);
 
 /*
  * cds_lfht_resize - Force a hash table resize