rculfhash: add comment about hash seed randomness within test program

[urcu.git] / tests / test_urcu_hash.c

diff --git a/tests/test_urcu_hash.c b/tests/test_urcu_hash.c
index c696533db612502c2af74cd3b0d2afb4b13d0670..adeac3c27df7561ba065a2ab9aad89a0e0bd07e5 100644 (file)
--- a/tests/test_urcu_hash.c
+++ b/tests/test_urcu_hash.c
@@ -41,6 +41,12 @@
 #define DEFAULT_MIN_ALLOC_SIZE 1
 #define DEFAULT_RAND_POOL      1000000
 
+/*
+ * Note: the hash seed should be a random value for hash tables
+ * targeting production environments to provide protection against
+ * denial of service attacks. We keep it a static value within this test
+ * program to compare identical benchmark runs.
+ */
 #define TEST_HASH_SEED 0x42UL
 
 /* Make this big enough to include the POWER5+ L3 cacheline size of 256B */
@@ -454,7 +460,7 @@ void *thr_count(void *arg)
        rcu_register_thread();
 
        for (;;) {
-               unsigned long count, removed;
+               unsigned long count;
                long approx_before, approx_after;
                ssize_t len;
                char buf[1];
@@ -470,15 +476,15 @@ void *thr_count(void *arg)
                printf("Counting nodes... ");
                fflush(stdout);
                rcu_read_lock();
-               cds_lfht_count_nodes(test_ht, &approx_before, &count, &removed,
+               cds_lfht_count_nodes(test_ht, &approx_before, &count,
                                &approx_after);
                rcu_read_unlock();
                printf("done.\n");
                printf("Approximation before node accounting: %ld nodes.\n",
                        approx_before);
                printf("Accounting of nodes in the hash table: "
-                       "%lu nodes + %lu logically removed.\n",
-                       count, removed);
+                       "%lu nodes.\n",
+                       count);
                printf("Approximation after node accounting: %ld nodes.\n",
                        approx_after);
        }
@@ -610,7 +616,7 @@ void *thr_writer(void *_count)
                        cds_lfht_test_lookup(test_ht,
                                (void *)(((unsigned long) rand_r(&rand_lookup) % write_pool_size) + write_pool_offset),
                                sizeof(void *), &iter);
-                       ret = cds_lfht_del(test_ht, &iter);
+                       ret = cds_lfht_del(test_ht, cds_lfht_iter_get_node(&iter));
                        rcu_read_unlock();
                        if (ret == 0) {
                                node = cds_lfht_iter_get_test_node(&iter);
@@ -715,7 +721,7 @@ void test_delete_all_nodes(struct cds_lfht *ht)
        cds_lfht_for_each_entry(ht, &iter, node, node) {
                int ret;
 
-               ret = cds_lfht_del(test_ht, &iter);
+               ret = cds_lfht_del(test_ht, cds_lfht_iter_get_node(&iter));
                assert(!ret);
                call_rcu(&node->head, free_node_cb);
                count++;
@@ -763,7 +769,7 @@ int main(int argc, char **argv)
        struct wr_count *count_writer;
        unsigned long long tot_reads = 0, tot_writes = 0,
                tot_add = 0, tot_add_exist = 0, tot_remove = 0;
-       unsigned long count, removed;
+       unsigned long count;
        long approx_before, approx_after;
        int i, a, ret;
        struct sigaction act;
@@ -1086,18 +1092,17 @@ int main(int argc, char **argv)
        rcu_thread_online();
        rcu_read_lock();
        printf("Counting nodes... ");
-       cds_lfht_count_nodes(test_ht, &approx_before, &count, &removed,
-               &approx_after);
+       cds_lfht_count_nodes(test_ht, &approx_before, &count, &approx_after);
        printf("done.\n");
        test_delete_all_nodes(test_ht);
        rcu_read_unlock();
        rcu_thread_offline();
-       if (count || removed) {
+       if (count) {
                printf("Approximation before node accounting: %ld nodes.\n",
                        approx_before);
                printf("Nodes deleted from hash table before destroy: "
-                       "%lu nodes + %lu logically removed.\n",
-                       count, removed);
+                       "%lu nodes.\n",
+                       count);
                printf("Approximation after node accounting: %ld nodes.\n",
                        approx_after);
        }