Merge remote-tracking branch 'remotes/vivier2/tags/trivial-branch-pull-request' into...

[qemu.git] / util / qht.c

diff --git a/util/qht.c b/util/qht.c
index c190e89f5b3d75d56cf0c6288ee78d634bf2e5bd..aa51be3c52f891dc55990231ba959a9c585b5b77 100644 (file)
--- a/util/qht.c
+++ b/util/qht.c
@@ -236,7 +236,7 @@ static inline void qht_head_init(struct qht_bucket *b)
 }
 
 static inline
-struct qht_bucket *qht_map_to_bucket(struct qht_map *map, uint32_t hash)
+struct qht_bucket *qht_map_to_bucket(const struct qht_map *map, uint32_t hash)
 {
     return &map->buckets[hash & (map->n_buckets - 1)];
 }
@@ -268,7 +268,8 @@ static void qht_map_unlock_buckets(struct qht_map *map)
  * Call with at least a bucket lock held.
  * @map should be the value read before acquiring the lock (or locks).
  */
-static inline bool qht_map_is_stale__locked(struct qht *ht, struct qht_map *map)
+static inline bool qht_map_is_stale__locked(const struct qht *ht,
+                                            const struct qht_map *map)
 {
     return map != ht->map;
 }
@@ -337,12 +338,12 @@ struct qht_bucket *qht_bucket_lock__no_stale(struct qht *ht, uint32_t hash,
     return b;
 }
 
-static inline bool qht_map_needs_resize(struct qht_map *map)
+static inline bool qht_map_needs_resize(const struct qht_map *map)
 {
     return atomic_read(&map->n_added_buckets) > map->n_added_buckets_threshold;
 }
 
-static inline void qht_chain_destroy(struct qht_bucket *head)
+static inline void qht_chain_destroy(const struct qht_bucket *head)
 {
     struct qht_bucket *curr = head->next;
     struct qht_bucket *prev;
@@ -482,10 +483,10 @@ bool qht_reset_size(struct qht *ht, size_t n_elems)
 }
 
 static inline
-void *qht_do_lookup(struct qht_bucket *head, qht_lookup_func_t func,
+void *qht_do_lookup(const struct qht_bucket *head, qht_lookup_func_t func,
                     const void *userp, uint32_t hash)
 {
-    struct qht_bucket *b = head;
+    const struct qht_bucket *b = head;
     int i;
 
     do {
@@ -509,7 +510,7 @@ void *qht_do_lookup(struct qht_bucket *head, qht_lookup_func_t func,
 }
 
 static __attribute__((noinline))
-void *qht_lookup__slowpath(struct qht_bucket *b, qht_lookup_func_t func,
+void *qht_lookup__slowpath(const struct qht_bucket *b, qht_lookup_func_t func,
                            const void *userp, uint32_t hash)
 {
     unsigned int version;
@@ -522,11 +523,11 @@ void *qht_lookup__slowpath(struct qht_bucket *b, qht_lookup_func_t func,
     return ret;
 }
 
-void *qht_lookup_custom(struct qht *ht, const void *userp, uint32_t hash,
+void *qht_lookup_custom(const struct qht *ht, const void *userp, uint32_t hash,
                         qht_lookup_func_t func)
 {
-    struct qht_bucket *b;
-    struct qht_map *map;
+    const struct qht_bucket *b;
+    const struct qht_map *map;
     unsigned int version;
     void *ret;
 
@@ -545,13 +546,16 @@ void *qht_lookup_custom(struct qht *ht, const void *userp, uint32_t hash,
     return qht_lookup__slowpath(b, func, userp, hash);
 }
 
-void *qht_lookup(struct qht *ht, const void *userp, uint32_t hash)
+void *qht_lookup(const struct qht *ht, const void *userp, uint32_t hash)
 {
     return qht_lookup_custom(ht, userp, hash, ht->cmp);
 }
 
-/* call with head->lock held */
-static void *qht_insert__locked(struct qht *ht, struct qht_map *map,
+/*
+ * call with head->lock held
+ * @ht is const since it is only used for ht->cmp()
+ */
+static void *qht_insert__locked(const struct qht *ht, struct qht_map *map,
                                 struct qht_bucket *head, void *p, uint32_t hash,
                                 bool *needs_resize)
 {
@@ -645,7 +649,7 @@ bool qht_insert(struct qht *ht, void *p, uint32_t hash, void **existing)
     return false;
 }
 
-static inline bool qht_entry_is_last(struct qht_bucket *b, int pos)
+static inline bool qht_entry_is_last(const struct qht_bucket *b, int pos)
 {
     if (pos == QHT_BUCKET_ENTRIES - 1) {
         if (b->next == NULL) {
@@ -671,7 +675,7 @@ qht_entry_move(struct qht_bucket *to, int i, struct qht_bucket *from, int j)
 }
 
 /*
- * Find the last valid entry in @head, and swap it with @orig[pos], which has
+ * Find the last valid entry in @orig, and swap it with @orig[pos], which has
  * just been invalidated.
  */
 static inline void qht_bucket_remove_entry(struct qht_bucket *orig, int pos)
@@ -746,7 +750,7 @@ bool qht_remove(struct qht *ht, const void *p, uint32_t hash)
     return ret;
 }
 
-static inline void qht_bucket_iter(struct qht *ht, struct qht_bucket *head,
+static inline void qht_bucket_iter(struct qht_bucket *head,
                                    const struct qht_iter *iter, void *userp)
 {
     struct qht_bucket *b = head;
@@ -759,10 +763,10 @@ static inline void qht_bucket_iter(struct qht *ht, struct qht_bucket *head,
             }
             switch (iter->type) {
             case QHT_ITER_VOID:
-                iter->f.retvoid(ht, b->pointers[i], b->hashes[i], userp);
+                iter->f.retvoid(b->pointers[i], b->hashes[i], userp);
                 break;
             case QHT_ITER_RM:
-                if (iter->f.retbool(ht, b->pointers[i], b->hashes[i], userp)) {
+                if (iter->f.retbool(b->pointers[i], b->hashes[i], userp)) {
                     /* replace i with the last valid element in the bucket */
                     seqlock_write_begin(&head->sequence);
                     qht_bucket_remove_entry(b, i);
@@ -782,14 +786,14 @@ static inline void qht_bucket_iter(struct qht *ht, struct qht_bucket *head,
 }
 
 /* call with all of the map's locks held */
-static inline void qht_map_iter__all_locked(struct qht *ht, struct qht_map *map,
+static inline void qht_map_iter__all_locked(struct qht_map *map,
                                             const struct qht_iter *iter,
                                             void *userp)
 {
     size_t i;
 
     for (i = 0; i < map->n_buckets; i++) {
-        qht_bucket_iter(ht, &map->buckets[i], iter, userp);
+        qht_bucket_iter(&map->buckets[i], iter, userp);
     }
 }
 
@@ -800,8 +804,7 @@ do_qht_iter(struct qht *ht, const struct qht_iter *iter, void *userp)
 
     map = atomic_rcu_read(&ht->map);
     qht_map_lock_buckets(map);
-    /* Note: ht here is merely for carrying ht->mode; ht->map won't be read */
-    qht_map_iter__all_locked(ht, map, iter, userp);
+    qht_map_iter__all_locked(map, iter, userp);
     qht_map_unlock_buckets(map);
 }
 
@@ -825,9 +828,16 @@ void qht_iter_remove(struct qht *ht, qht_iter_bool_func_t func, void *userp)
     do_qht_iter(ht, &iter, userp);
 }
 
-static void qht_map_copy(struct qht *ht, void *p, uint32_t hash, void *userp)
+struct qht_map_copy_data {
+    struct qht *ht;
+    struct qht_map *new;
+};
+
+static void qht_map_copy(void *p, uint32_t hash, void *userp)
 {
-    struct qht_map *new = userp;
+    struct qht_map_copy_data *data = userp;
+    struct qht *ht = data->ht;
+    struct qht_map *new = data->new;
     struct qht_bucket *b = qht_map_to_bucket(new, hash);
 
     /* no need to acquire b->lock because no thread has seen this map yet */
@@ -845,6 +855,7 @@ static void qht_do_resize_reset(struct qht *ht, struct qht_map *new, bool reset)
         .f.retvoid = qht_map_copy,
         .type = QHT_ITER_VOID,
     };
+    struct qht_map_copy_data data;
 
     old = ht->map;
     qht_map_lock_buckets(old);
@@ -859,7 +870,9 @@ static void qht_do_resize_reset(struct qht *ht, struct qht_map *new, bool reset)
     }
 
     g_assert(new->n_buckets != old->n_buckets);
-    qht_map_iter__all_locked(ht, old, &iter, new);
+    data.ht = ht;
+    data.new = new;
+    qht_map_iter__all_locked(old, &iter, &data);
     qht_map_debug__all_locked(new);
 
     atomic_rcu_set(&ht->map, new);
@@ -886,9 +899,9 @@ bool qht_resize(struct qht *ht, size_t n_elems)
 }
 
 /* pass @stats to qht_statistics_destroy() when done */
-void qht_statistics_init(struct qht *ht, struct qht_stats *stats)
+void qht_statistics_init(const struct qht *ht, struct qht_stats *stats)
 {
-    struct qht_map *map;
+    const struct qht_map *map;
     int i;
 
     map = atomic_rcu_read(&ht->map);
@@ -905,8 +918,8 @@ void qht_statistics_init(struct qht *ht, struct qht_stats *stats)
     stats->head_buckets = map->n_buckets;
 
     for (i = 0; i < map->n_buckets; i++) {
-        struct qht_bucket *head = &map->buckets[i];
-        struct qht_bucket *b;
+        const struct qht_bucket *head = &map->buckets[i];
+        const struct qht_bucket *b;
         unsigned int version;
         size_t buckets;
         size_t entries;