[ltt-dev] [PATCH 5/5] rculfhash: add CDS_LFHT_ACCOUNTING flag

[Mathieu Desnoyers]

Merged as:

commit 5afadd129c36f4778bcc12c8def6f4e3f9604c7b
Author: Lai Jiangshan <laijs at cn.fujitsu.com>
Date:   Fri Oct 28 10:16:34 2011 +0200

    rculfhash: add CDS_LFHT_ACCOUNTING flag
    
    [ Edit by Mathieu Desnoyers: fix null pointer in poison_free. ]
    
    Signed-off-by: Lai Jiangshan <laijs at cn.fujitsu.com>
    Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers at efficios.com>

diff --git a/rculfhash.c b/rculfhash.c
index 668f936..d786a3d 100644
--- a/rculfhash.c
+++ b/rculfhash.c
@@ -486,10 +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)
@@ -530,7 +532,7 @@ static void ht_init_nr_cpus_mask(void)
 #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;
 
@@ -543,13 +545,19 @@ struct ht_items_count *alloc_split_items_count(void)
 	}
 
 	assert(split_count_mask >= 0);
-	return calloc(split_count_mask + 1, sizeof(*count));
+
+	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)
@@ -1334,7 +1342,7 @@ 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;
@@ -1589,7 +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);
@@ -1607,7 +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++) {
@@ -1637,7 +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++) {
diff --git a/tests/test_urcu_hash.c b/tests/test_urcu_hash.c
index 70db8b3..9ae1fa0 100644
--- a/tests/test_urcu_hash.c
+++ b/tests/test_urcu_hash.c
@@ -889,7 +889,8 @@ int main(int argc, char **argv)
 	rcu_register_thread();
 	test_ht = cds_lfht_new(test_hash, test_compare, 0x42UL,
 			init_hash_size, 1,
-			opt_auto_resize ? CDS_LFHT_AUTO_RESIZE : 0, NULL);
+			(opt_auto_resize ? CDS_LFHT_AUTO_RESIZE : 0) |
+			CDS_LFHT_ACCOUNTING, NULL);
       	ret = populate_hash();
 	assert(!ret);
 
diff --git a/urcu/rculfhash.h b/urcu/rculfhash.h
index fd67b6b..9b96104 100644
--- a/urcu/rculfhash.h
+++ b/urcu/rculfhash.h
@@ -94,6 +94,7 @@ void cds_lfht_node_init(struct cds_lfht_node *node, void *key,
  */
 enum {
 	CDS_LFHT_AUTO_RESIZE = (1U << 0),
+	CDS_LFHT_ACCOUNTING = (1U << 1),
 };
 
 /*

-- 
Mathieu Desnoyers
Operating System Efficiency R&D Consultant
EfficiOS Inc.
http://www.efficios.com