X-Git-Url: https://git.liburcu.org/?p=urcu.git;a=blobdiff_plain;f=rculfhash-mm-order.c;fp=rculfhash-mm-order.c;h=69e2b622a6eeb4020b06980818e8951120a92af7;hp=0000000000000000000000000000000000000000;hb=0b6aa0018b42d0b101c617ef6c6d34d0f4dd2258;hpb=7b3893e462472cd25a19ac6f5ebc09aeb031ea60

diff --git a/rculfhash-mm-order.c b/rculfhash-mm-order.c
new file mode 100644
index 0000000..69e2b62
--- /dev/null
+++ b/rculfhash-mm-order.c
@@ -0,0 +1,101 @@
+/*
+ * rculfhash-mm-order.c
+ *
+ * Order based memory management for Lock-Free RCU Hash Table
+ *
+ * Copyright 2011 - Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
+ * Copyright 2011 - Lai Jiangshan <laijs@cn.fujitsu.com>
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#include <rculfhash-internal.h>
+
+static
+void cds_lfht_alloc_bucket_table(struct cds_lfht *ht, unsigned long order)
+{
+	if (order == 0) {
+		ht->tbl_order[0] = calloc(ht->min_nr_alloc_buckets,
+			sizeof(struct cds_lfht_node));
+		assert(ht->tbl_order[0]);
+	} else if (order > ht->min_alloc_buckets_order) {
+		ht->tbl_order[order] = calloc(1UL << (order -1),
+			sizeof(struct cds_lfht_node));
+		assert(ht->tbl_order[order]);
+	}
+	/* Nothing to do for 0 < order && order <= ht->min_alloc_buckets_order */
+}
+
+/*
+ * cds_lfht_free_bucket_table() should be called with decreasing order.
+ * When cds_lfht_free_bucket_table(0) is called, it means the whole
+ * lfht is destroyed.
+ */
+static
+void cds_lfht_free_bucket_table(struct cds_lfht *ht, unsigned long order)
+{
+	if (order == 0)
+		poison_free(ht->tbl_order[0]);
+	else if (order > ht->min_alloc_buckets_order)
+		poison_free(ht->tbl_order[order]);
+	/* Nothing to do for 0 < order && order <= ht->min_alloc_buckets_order */
+}
+
+static
+struct cds_lfht_node *bucket_at(struct cds_lfht *ht, unsigned long index)
+{
+	unsigned long order;
+
+	if (index < ht->min_nr_alloc_buckets) {
+		dbg_printf("bucket index %lu order 0 aridx 0\n", index);
+		return &ht->tbl_order[0][index];
+	}
+	/*
+	 * equivalent to get_count_order_ulong(index + 1), but optimizes
+	 * away the non-existing 0 special-case for
+	 * get_count_order_ulong.
+	 */
+	order = fls_ulong(index);
+	dbg_printf("bucket index %lu order %lu aridx %lu\n",
+		   index, order, index & ((1UL << (order - 1)) - 1));
+	return &ht->tbl_order[order][index & ((1UL << (order - 1)) - 1)];
+}
+
+static
+struct cds_lfht *alloc_cds_lfht(unsigned long min_nr_alloc_buckets,
+		unsigned long max_nr_buckets)
+{
+	struct cds_lfht *ht;
+
+	ht = calloc(1, sizeof(struct cds_lfht));
+	assert(ht);
+
+	ht->mm = &cds_lfht_mm_order;
+
+	ht->min_nr_alloc_buckets = min_nr_alloc_buckets;
+	ht->min_alloc_buckets_order = get_count_order_ulong(min_nr_alloc_buckets);
+	ht->max_nr_buckets = max_nr_buckets;
+
+	ht->bucket_at = bucket_at;
+
+	return ht;
+}
+
+const struct cds_lfht_mm_type cds_lfht_mm_order = {
+	.alloc_cds_lfht = alloc_cds_lfht,
+	.alloc_bucket_table = cds_lfht_alloc_bucket_table,
+	.free_bucket_table = cds_lfht_free_bucket_table,
+	.bucket_at = bucket_at,
+};