urcu/rculfhash.h

   1 #ifndef _URCU_RCULFHASH_H
   2 #define _URCU_RCULFHASH_H
   3
   4 #include <stdint.h>
   5 #include <urcu-call-rcu.h>
   6
   7 #ifdef __cplusplus
   8 extern "C" {
   9 #endif
  10
  11 /*
  12  * struct rcu_ht_node and struct _rcu_ht_node should be aligned on
  13  * 4-bytes boundaries because the two lower bits are used as flags.
  14  */
  15
  16 struct _rcu_ht_node {
  17         struct rcu_ht_node *next;       /* ptr | DUMMY_FLAG | REMOVED_FLAG */
  18         unsigned long reverse_hash;
  19 };
  20
  21 struct rcu_ht_node {
  22         /* cache-hot for iteration */
  23         struct _rcu_ht_node p;          /* needs to be first field */
  24         void *key;
  25         unsigned int key_len;
  26         /* cache-cold for iteration */
  27         struct rcu_head head;
  28 };
  29
  30 struct rcu_ht;
  31
  32 /*
  33  * Caution !
  34  * Ensure reader and writer threads are registered as urcu readers.
  35  */
  36
  37 typedef unsigned long (*ht_hash_fct)(void *key, size_t length,
  38                                      unsigned long seed);
  39 typedef unsigned long (*ht_compare_fct)(void *key1, size_t key1_len,
  40                                         void *key2, size_t key2_len);
  41
  42 static inline
  43 void ht_node_init(struct rcu_ht_node *node, void *key,
  44                   size_t key_len)
  45 {
  46         node->key = key;
  47         node->key_len = key_len;
  48 }
  49
  50 /*
  51  * init_size must be power of two.
  52  */
  53 struct rcu_ht *ht_new(ht_hash_fct hash_fct,
  54                       ht_compare_fct compare_fct,
  55                       unsigned long hash_seed,
  56                       unsigned long init_size,
  57                       void (*ht_call_rcu)(struct rcu_head *head,
  58                                 void (*func)(struct rcu_head *head)));
  59
  60 int ht_destroy(struct rcu_ht *ht);
  61 /* Count the number of nodes in the hash table. Call with rcu_read_lock held. */
  62 void ht_count_nodes(struct rcu_ht *ht,
  63                 unsigned long *count,
  64                 unsigned long *removed);
  65
  66 /* Call with rcu_read_lock held. */
  67 struct rcu_ht_node *ht_lookup(struct rcu_ht *ht, void *key, size_t key_len);
  68
  69 /* Call with rcu_read_lock held. */
  70 void ht_add(struct rcu_ht *ht, struct rcu_ht_node *node);
  71
  72 /*
  73  * Call with rcu_read_lock held.
  74  * Returns the node added upon success.
  75  * Returns the unique node already present upon failure. If ht_add_unique fails,
  76  * the node passed as parameter should be freed by the caller.
  77  */
  78 struct rcu_ht_node *ht_add_unique(struct rcu_ht *ht, struct rcu_ht_node *node);
  79
  80 /* Call with rcu_read_lock held. */
  81 int ht_remove(struct rcu_ht *ht, struct rcu_ht_node *node);
  82
  83 void ht_resize(struct rcu_ht *ht, int growth);
  84
  85 #ifdef __cplusplus
  86 }
  87 #endif
  88
  89 #endif /* _URCU_RCULFHASH_H */