return !must_not_fork;
}
\f
-/* ovsthread_counter.
- *
- * We implement the counter as an array of N_COUNTERS individual counters, each
- * with its own lock. Each thread uses one of the counters chosen based on a
- * hash of the thread's ID, the idea being that, statistically, different
- * threads will tend to use different counters and therefore avoid
- * interfering with each other.
- *
- * Undoubtedly, better implementations are possible. */
-
-/* Basic counter structure. */
-struct ovsthread_counter__ {
- struct ovs_mutex mutex;
- unsigned long long int value;
-};
-
-/* Pad the basic counter structure to 64 bytes to avoid cache line
- * interference. */
-struct ovsthread_counter {
- struct ovsthread_counter__ c;
- char pad[ROUND_UP(sizeof(struct ovsthread_counter__), 64)
- - sizeof(struct ovsthread_counter__)];
-};
-
-#define N_COUNTERS 16
+/* ovsthread_stats. */
-struct ovsthread_counter *
-ovsthread_counter_create(void)
+void
+ovsthread_stats_init(struct ovsthread_stats *stats)
{
- struct ovsthread_counter *c;
int i;
- c = xmalloc(N_COUNTERS * sizeof *c);
- for (i = 0; i < N_COUNTERS; i++) {
- ovs_mutex_init(&c[i].c.mutex);
- c[i].c.value = 0;
+ ovs_mutex_init(&stats->mutex);
+ for (i = 0; i < ARRAY_SIZE(stats->buckets); i++) {
+ stats->buckets[i] = NULL;
}
- return c;
}
void
-ovsthread_counter_destroy(struct ovsthread_counter *c)
+ovsthread_stats_destroy(struct ovsthread_stats *stats)
{
- if (c) {
- int i;
-
- for (i = 0; i < N_COUNTERS; i++) {
- ovs_mutex_destroy(&c[i].c.mutex);
- }
- free(c);
- }
+ ovs_mutex_destroy(&stats->mutex);
}
-void
-ovsthread_counter_inc(struct ovsthread_counter *c, unsigned long long int n)
+void *
+ovsthread_stats_bucket_get(struct ovsthread_stats *stats,
+ void *(*new_bucket)(void))
{
- c = &c[hash_int(ovsthread_id_self(), 0) % N_COUNTERS];
-
- ovs_mutex_lock(&c->c.mutex);
- c->c.value += n;
- ovs_mutex_unlock(&c->c.mutex);
+ unsigned int idx = ovsthread_id_self() & (ARRAY_SIZE(stats->buckets) - 1);
+ void *bucket = stats->buckets[idx];
+ if (!bucket) {
+ ovs_mutex_lock(&stats->mutex);
+ bucket = stats->buckets[idx];
+ if (!bucket) {
+ bucket = stats->buckets[idx] = new_bucket();
+ }
+ ovs_mutex_unlock(&stats->mutex);
+ }
+ return bucket;
}
-unsigned long long int
-ovsthread_counter_read(const struct ovsthread_counter *c)
+size_t
+ovs_thread_stats_next_bucket(const struct ovsthread_stats *stats, size_t i)
{
- unsigned long long int sum;
- int i;
-
- sum = 0;
- for (i = 0; i < N_COUNTERS; i++) {
- ovs_mutex_lock(&c[i].c.mutex);
- sum += c[i].c.value;
- ovs_mutex_unlock(&c[i].c.mutex);
+ for (; i < ARRAY_SIZE(stats->buckets); i++) {
+ if (stats->buckets[i]) {
+ break;
+ }
}
- return sum;
+ return i;
}
+
\f
/* Parses /proc/cpuinfo for the total number of physical cores on this system
* across all CPU packages, not counting hyper-threads.