Prepare for post-2.2.0 (2.2.90).

[sliver-openvswitch.git] / lib / ovs-thread.c

diff --git a/lib/ovs-thread.c b/lib/ovs-thread.c
index 0dc5585..19edf8f 100644 (file)
--- a/lib/ovs-thread.c
+++ b/lib/ovs-thread.c
@@ -240,7 +240,10 @@ xpthread_barrier_wait(pthread_barrier_t *barrier)
 {
     int error;
 
+    ovsrcu_quiesce_start();
     error = pthread_barrier_wait(barrier);
+    ovsrcu_quiesce_end();
+
     if (error && OVS_UNLIKELY(error != PTHREAD_BARRIER_SERIAL_THREAD)) {
         ovs_abort(error, "pthread_barrier_wait failed");
     }
@@ -253,6 +256,7 @@ DEFINE_EXTERN_PER_THREAD_DATA(ovsthread_id, 0);
 struct ovsthread_aux {
     void *(*start)(void *);
     void *arg;
+    char name[16];
 };
 
 static void *
@@ -270,13 +274,18 @@ ovsthread_wrapper(void *aux_)
     aux = *auxp;
     free(auxp);
 
+    /* The order of the following calls is important, because
+     * ovsrcu_quiesce_end() saves a copy of the thread name. */
+    set_subprogram_name("%s%u", aux.name, id);
     ovsrcu_quiesce_end();
+
     return aux.start(aux.arg);
 }
 
-void
-xpthread_create(pthread_t *threadp, pthread_attr_t *attr,
-                void *(*start)(void *), void *arg)
+/* Starts a thread that calls 'start(arg)'.  Sets the thread's name to 'name'
+ * (suffixed by its ovsthread_id()).  Returns the new thread's pthread_t. */
+pthread_t
+ovs_thread_create(const char *name, void *(*start)(void *), void *arg)
 {
     struct ovsthread_aux *aux;
     pthread_t thread;
@@ -289,12 +298,13 @@ xpthread_create(pthread_t *threadp, pthread_attr_t *attr,
     aux = xmalloc(sizeof *aux);
     aux->start = start;
     aux->arg = arg;
+    ovs_strlcpy(aux->name, name, sizeof aux->name);
 
-    error = pthread_create(threadp ? threadp : &thread, attr,
-                           ovsthread_wrapper, aux);
+    error = pthread_create(&thread, NULL, ovsthread_wrapper, aux);
     if (error) {
         ovs_abort(error, "pthread_create failed");
     }
+    return thread;
 }
 \f
 bool
@@ -379,83 +389,53 @@ may_fork(void)
     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. */
+/* ovsthread_stats. */
 
-/* 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
-
-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.