X-Git-Url: http://git.liburcu.org/?a=blobdiff_plain;f=rculfhash.c;h=da37e97d38554c6def88699590be83439385e82f;hb=b5d6b20fb518bce4a39c256ac89dcb376a5f971a;hp=e94b9b224422e8e316c5dbeea4be0aff0b002b36;hpb=4c42f1b8ad898738bf5caae2682e18c57dce91d3;p=urcu.git

diff --git a/rculfhash.c b/rculfhash.c
index e94b9b2..da37e97 100644
--- a/rculfhash.c
+++ b/rculfhash.c
@@ -179,6 +179,7 @@
  * tables and machines lacking per-cpu data suppport.
  */
 #define COUNT_COMMIT_ORDER		10
+#define DEFAULT_SPLIT_COUNT_MASK	0xFUL
 #define CHAIN_LEN_TARGET		1
 #define CHAIN_LEN_RESIZE_THRESHOLD	3
 
@@ -485,10 +486,12 @@ int get_count_order_ulong(unsigned long x)
 }
 
 #ifdef POISON_FREE
-#define poison_free(ptr)				\
-	do {						\
-		memset(ptr, 0x42, sizeof(*(ptr)));	\
-		free(ptr);				\
+#define poison_free(ptr)					\
+	do {							\
+		if (ptr) {					\
+			memset(ptr, 0x42, sizeof(*(ptr)));	\
+			free(ptr);				\
+		}						\
 	} while (0)
 #else
 #define poison_free(ptr)	free(ptr)
@@ -497,14 +500,6 @@ int get_count_order_ulong(unsigned long x)
 static
 void cds_lfht_resize_lazy(struct cds_lfht *ht, unsigned long size, int growth);
 
-/*
- * If the sched_getcpu() and sysconf(_SC_NPROCESSORS_CONF) calls are
- * available, then we support hash table item accounting.
- * In the unfortunate event the number of CPUs reported would be
- * inaccurate, we use modulo arithmetic on the number of CPUs we got.
- */
-#if defined(HAVE_SCHED_GETCPU) && defined(HAVE_SYSCONF)
-
 static
 void cds_lfht_resize_lazy_count(struct cds_lfht *ht, unsigned long size,
 				unsigned long count);
@@ -512,6 +507,7 @@ void cds_lfht_resize_lazy_count(struct cds_lfht *ht, unsigned long size,
 static long nr_cpus_mask = -1;
 static long split_count_mask = -1;
 
+#if defined(HAVE_SYSCONF)
 static void ht_init_nr_cpus_mask(void)
 {
 	long maxcpus;
@@ -528,53 +524,72 @@ static void ht_init_nr_cpus_mask(void)
 	maxcpus = 1UL << get_count_order_ulong(maxcpus);
 	nr_cpus_mask = maxcpus - 1;
 }
+#else /* #if defined(HAVE_SYSCONF) */
+static void ht_init_nr_cpus_mask(void)
+{
+	nr_cpus_mask = -2;
+}
+#endif /* #else #if defined(HAVE_SYSCONF) */
 
 static
-struct ht_items_count *alloc_split_items_count(void)
+void alloc_split_items_count(struct cds_lfht *ht)
 {
 	struct ht_items_count *count;
 
 	if (nr_cpus_mask == -1)	{
 		ht_init_nr_cpus_mask();
-		split_count_mask = nr_cpus_mask;
+		if (nr_cpus_mask < 0)
+			split_count_mask = DEFAULT_SPLIT_COUNT_MASK;
+		else
+			split_count_mask = nr_cpus_mask;
 	}
 
-	if (split_count_mask < 0)
-		return NULL;
-	else
-		return calloc(split_count_mask + 1, sizeof(*count));
+	assert(split_count_mask >= 0);
+
+	if (ht->flags & CDS_LFHT_ACCOUNTING) {
+		ht->split_count = calloc(split_count_mask + 1, sizeof(*count));
+		assert(ht->split_count);
+	} else {
+		ht->split_count = NULL;
+	}
 }
 
 static
-void free_split_items_count(struct ht_items_count *count)
+void free_split_items_count(struct cds_lfht *ht)
 {
-	poison_free(count);
+	poison_free(ht->split_count);
 }
 
+#if defined(HAVE_SCHED_GETCPU)
 static
-int ht_get_split_count_index(void)
+int ht_get_split_count_index(unsigned long hash)
 {
 	int cpu;
 
 	assert(split_count_mask >= 0);
 	cpu = sched_getcpu();
 	if (unlikely(cpu < 0))
-		return cpu;
+		return hash & split_count_mask;
 	else
 		return cpu & split_count_mask;
 }
+#else /* #if defined(HAVE_SCHED_GETCPU) */
+static
+int ht_get_split_count_index(unsigned long hash)
+{
+	return hash & split_count_mask;
+}
+#endif /* #else #if defined(HAVE_SCHED_GETCPU) */
 
 static
-void ht_count_add(struct cds_lfht *ht, unsigned long size)
+void ht_count_add(struct cds_lfht *ht, unsigned long size, unsigned long hash)
 {
 	unsigned long split_count;
 	int index;
 
 	if (unlikely(!ht->split_count))
 		return;
-	index = ht_get_split_count_index();
-	if (unlikely(index < 0))
-		return;
+	index = ht_get_split_count_index(hash);
 	split_count = uatomic_add_return(&ht->split_count[index].add, 1);
 	if (unlikely(!(split_count & ((1UL << COUNT_COMMIT_ORDER) - 1)))) {
 		long count;
@@ -594,16 +609,14 @@ void ht_count_add(struct cds_lfht *ht, unsigned long size)
 }
 
 static
-void ht_count_del(struct cds_lfht *ht, unsigned long size)
+void ht_count_del(struct cds_lfht *ht, unsigned long size, unsigned long hash)
 {
 	unsigned long split_count;
 	int index;
 
 	if (unlikely(!ht->split_count))
 		return;
-	index = ht_get_split_count_index();
-	if (unlikely(index < 0))
-		return;
+	index = ht_get_split_count_index(hash);
 	split_count = uatomic_add_return(&ht->split_count[index].del, 1);
 	if (unlikely(!(split_count & ((1UL << COUNT_COMMIT_ORDER) - 1)))) {
 		long count;
@@ -628,35 +641,6 @@ void ht_count_del(struct cds_lfht *ht, unsigned long size)
 	}
 }
 
-#else /* #if defined(HAVE_SCHED_GETCPU) && defined(HAVE_SYSCONF) */
-
-static const long nr_cpus_mask = -2;
-static const long split_count_mask = -2;
-
-static
-struct ht_items_count *alloc_split_items_count(void)
-{
-	return NULL;
-}
-
-static
-void free_split_items_count(struct ht_items_count *count)
-{
-}
-
-static
-void ht_count_add(struct cds_lfht *ht, unsigned long size)
-{
-}
-
-static
-void ht_count_del(struct cds_lfht *ht, unsigned long size)
-{
-}
-
-#endif /* #else #if defined(HAVE_SCHED_GETCPU) && defined(HAVE_SYSCONF) */
-
-
 static
 void check_resize(struct cds_lfht *ht, unsigned long size, uint32_t chain_len)
 {
@@ -1346,6 +1330,7 @@ struct cds_lfht *_cds_lfht_new(cds_lfht_hash_fct hash_fct,
 	init_size = max(init_size, min_alloc_size);
 	ht = calloc(1, sizeof(struct cds_lfht));
 	assert(ht);
+	ht->flags = flags;
 	ht->hash_fct = hash_fct;
 	ht->compare_fct = compare_fct;
 	ht->hash_seed = hash_seed;
@@ -1358,10 +1343,9 @@ struct cds_lfht *_cds_lfht_new(cds_lfht_hash_fct hash_fct,
 	ht->cds_lfht_rcu_register_thread = cds_lfht_rcu_register_thread;
 	ht->cds_lfht_rcu_unregister_thread = cds_lfht_rcu_unregister_thread;
 	ht->resize_attr = attr;
-	ht->split_count = alloc_split_items_count();
+	alloc_split_items_count(ht);
 	/* this mutex should not nest in read-side C.S. */
 	pthread_mutex_init(&ht->resize_mutex, NULL);
-	ht->flags = flags;
 	order = get_count_order_ulong(init_size);
 	ht->t.resize_target = 1UL << order;
 	cds_lfht_create_dummy(ht, 1UL << order);
@@ -1490,7 +1474,7 @@ void cds_lfht_add(struct cds_lfht *ht, struct cds_lfht_node *node)
 
 	size = rcu_dereference(ht->t.size);
 	_cds_lfht_add(ht, size, node, NULL, 0);
-	ht_count_add(ht, size);
+	ht_count_add(ht, size, hash);
 }
 
 struct cds_lfht_node *cds_lfht_add_unique(struct cds_lfht *ht,
@@ -1505,7 +1489,7 @@ struct cds_lfht_node *cds_lfht_add_unique(struct cds_lfht *ht,
 	size = rcu_dereference(ht->t.size);
 	_cds_lfht_add(ht, size, node, &iter, 0);
 	if (iter.node == node)
-		ht_count_add(ht, size);
+		ht_count_add(ht, size, hash);
 	return iter.node;
 }
 
@@ -1522,7 +1506,7 @@ struct cds_lfht_node *cds_lfht_add_replace(struct cds_lfht *ht,
 	for (;;) {
 		_cds_lfht_add(ht, size, node, &iter, 0);
 		if (iter.node == node) {
-			ht_count_add(ht, size);
+			ht_count_add(ht, size, hash);
 			return NULL;
 		}
 
@@ -1543,13 +1527,15 @@ int cds_lfht_replace(struct cds_lfht *ht, struct cds_lfht_iter *old_iter,
 
 int cds_lfht_del(struct cds_lfht *ht, struct cds_lfht_iter *iter)
 {
-	unsigned long size;
+	unsigned long size, hash;
 	int ret;
 
 	size = rcu_dereference(ht->t.size);
 	ret = _cds_lfht_del(ht, size, iter->node, 0);
-	if (!ret)
-		ht_count_del(ht, size);
+	if (!ret) {
+		hash = bit_reverse_ulong(iter->node->p.reverse_hash);
+		ht_count_del(ht, size, hash);
+	}
 	return ret;
 }
 
@@ -1611,7 +1597,7 @@ int cds_lfht_destroy(struct cds_lfht *ht, pthread_attr_t **attr)
 	ret = cds_lfht_delete_dummy(ht);
 	if (ret)
 		return ret;
-	free_split_items_count(ht->split_count);
+	free_split_items_count(ht);
 	if (attr)
 		*attr = ht->resize_attr;
 	poison_free(ht);
@@ -1629,7 +1615,7 @@ void cds_lfht_count_nodes(struct cds_lfht *ht,
 	unsigned long nr_dummy = 0;
 
 	*approx_before = 0;
-	if (split_count_mask >= 0) {
+	if (ht->split_count) {
 		int i;
 
 		for (i = 0; i < split_count_mask + 1; i++) {
@@ -1659,7 +1645,7 @@ void cds_lfht_count_nodes(struct cds_lfht *ht,
 	} while (!is_end(node));
 	dbg_printf("number of dummy nodes: %lu\n", nr_dummy);
 	*approx_after = 0;
-	if (split_count_mask >= 0) {
+	if (ht->split_count) {
 		int i;
 
 		for (i = 0; i < split_count_mask + 1; i++) {
@@ -1796,8 +1782,6 @@ void cds_lfht_resize_lazy(struct cds_lfht *ht, unsigned long size, int growth)
 	}
 }
 
-#if defined(HAVE_SCHED_GETCPU) && defined(HAVE_SYSCONF)
-
 static
 void cds_lfht_resize_lazy_count(struct cds_lfht *ht, unsigned long size,
 				unsigned long count)
@@ -1822,5 +1806,3 @@ void cds_lfht_resize_lazy_count(struct cds_lfht *ht, unsigned long size,
 		CMM_STORE_SHARED(ht->t.resize_initiated, 1);
 	}
 }
-
-#endif