X-Git-Url: https://git.liburcu.org/?p=urcu.git;a=blobdiff_plain;f=rculfhash.c;h=7d39388f494700a1b06a5df885d5a5350cdf42a8;hp=6e12db1013f6c58d70ee3119a67a068fadc3d80e;hb=e53ab1eb49ad61eddcc9481bd6a6fbaf1b257439;hpb=a1e5e232288fc2bc58502f5161e9ae4460b7133c

diff --git a/rculfhash.c b/rculfhash.c
index 6e12db1..7d39388 100644
--- a/rculfhash.c
+++ b/rculfhash.c
@@ -563,6 +563,7 @@ 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;
+static int split_count_order = -1;
 
 #if defined(HAVE_SYSCONF)
 static void ht_init_nr_cpus_mask(void)
@@ -597,6 +598,8 @@ void alloc_split_items_count(struct cds_lfht *ht)
 			split_count_mask = DEFAULT_SPLIT_COUNT_MASK;
 		else
 			split_count_mask = nr_cpus_mask;
+		split_count_order =
+			cds_lfht_get_count_order_ulong(split_count_mask + 1);
 	}
 
 	assert(split_count_mask >= 0);
@@ -713,14 +716,39 @@ void check_resize(struct cds_lfht *ht, unsigned long size, uint32_t chain_len)
 	 * Use bucket-local length for small table expand and for
 	 * environments lacking per-cpu data support.
 	 */
-	if (count >= (1UL << COUNT_COMMIT_ORDER))
+	if (count >= (1UL << (COUNT_COMMIT_ORDER + split_count_order)))
 		return;
 	if (chain_len > 100)
 		dbg_printf("WARNING: large chain length: %u.\n",
 			   chain_len);
-	if (chain_len >= CHAIN_LEN_RESIZE_THRESHOLD)
-		cds_lfht_resize_lazy_grow(ht, size,
-			cds_lfht_get_count_order_u32(chain_len - (CHAIN_LEN_TARGET - 1)));
+	if (chain_len >= CHAIN_LEN_RESIZE_THRESHOLD) {
+		int growth;
+
+		/*
+		 * Ideal growth calculated based on chain length.
+		 */
+		growth = cds_lfht_get_count_order_u32(chain_len
+				- (CHAIN_LEN_TARGET - 1));
+		if ((ht->flags & CDS_LFHT_ACCOUNTING)
+				&& (size << growth)
+					>= (1UL << (COUNT_COMMIT_ORDER
+						+ split_count_order))) {
+			/*
+			 * If ideal growth expands the hash table size
+			 * beyond the "small hash table" sizes, use the
+			 * maximum small hash table size to attempt
+			 * expanding the hash table. This only applies
+			 * when node accounting is available, otherwise
+			 * the chain length is used to expand the hash
+			 * table in every case.
+			 */
+			growth = COUNT_COMMIT_ORDER + split_count_order
+				- cds_lfht_get_count_order_ulong(size);
+			if (growth <= 0)
+				return;
+		}
+		cds_lfht_resize_lazy_grow(ht, size, growth);
+	}
 }
 
 static
@@ -1745,6 +1773,13 @@ int cds_lfht_destroy(struct cds_lfht *ht, pthread_attr_t **attr)
 	was_online = ht->flavor->read_ongoing();
 	if (was_online)
 		ht->flavor->thread_offline();
+	/* Calling with RCU read-side held is an error. */
+	if (ht->flavor->read_ongoing()) {
+		ret = -EINVAL;
+		if (was_online)
+			ht->flavor->thread_online();
+		goto end;
+	}
 	while (uatomic_read(&ht->in_progress_resize))
 		poll(NULL, 0, 100);	/* wait for 100ms */
 	if (was_online)
@@ -1756,6 +1791,7 @@ int cds_lfht_destroy(struct cds_lfht *ht, pthread_attr_t **attr)
 	if (attr)
 		*attr = ht->resize_attr;
 	poison_free(ht);
+end:
 	return ret;
 }
 
@@ -1886,14 +1922,26 @@ void cds_lfht_resize(struct cds_lfht *ht, unsigned long new_size)
 {
 	int was_online;
 
-	resize_target_update_count(ht, new_size);
-	CMM_STORE_SHARED(ht->resize_initiated, 1);
 	was_online = ht->flavor->read_ongoing();
 	if (was_online)
 		ht->flavor->thread_offline();
+	/* Calling with RCU read-side held is an error. */
+	if (ht->flavor->read_ongoing()) {
+		static int print_once;
+
+		if (!CMM_LOAD_SHARED(print_once))
+			fprintf(stderr, "[error] rculfhash: cds_lfht_resize "
+				"called with RCU read-side lock held.\n");
+		CMM_STORE_SHARED(print_once, 1);
+		assert(0);
+		goto end;
+	}
+	resize_target_update_count(ht, new_size);
+	CMM_STORE_SHARED(ht->resize_initiated, 1);
 	pthread_mutex_lock(&ht->resize_mutex);
 	_do_cds_lfht_resize(ht);
 	pthread_mutex_unlock(&ht->resize_mutex);
+end:
 	if (was_online)
 		ht->flavor->thread_online();
 }