#include "dirs.h"
#include "dynamic-string.h"
#include "json.h"
+#include "latch.h"
#include "ofpbuf.h"
+#include "ovs-thread.h"
#include "poll-loop.h"
#include "shash.h"
#include "smap.h"
\f
#define SYSTEM_STATS_INTERVAL (5 * 1000) /* In milliseconds. */
-/* The next time to wake up, or LLONG_MAX if stats are disabled. */
-static long long int next_refresh = LLONG_MAX;
+static pthread_mutex_t mutex = PTHREAD_ADAPTIVE_MUTEX_INITIALIZER;
+static pthread_cond_t cond = PTHREAD_COND_INITIALIZER;
+static struct latch latch;
+static bool enabled;
+static bool started;
+static struct smap *system_stats;
+
+static void *system_stats_thread_func(void *);
+static void discard_stats(void);
/* Enables or disables system stats collection, according to 'enable'. */
void
system_stats_enable(bool enable)
{
- if (!enable) {
- next_refresh = LLONG_MAX;
- } else if (next_refresh == LLONG_MAX) {
- next_refresh = time_msec();
+ if (enabled != enable) {
+ xpthread_mutex_lock(&mutex);
+ if (enable) {
+ if (!started) {
+ xpthread_create(NULL, NULL, system_stats_thread_func, NULL);
+ latch_init(&latch);
+ started = true;
+ }
+ discard_stats();
+ xpthread_cond_signal(&cond);
+ }
+ enabled = enable;
+ xpthread_mutex_unlock(&mutex);
}
}
struct smap *
system_stats_run(void)
{
- if (time_msec() >= next_refresh) {
- struct smap *stats;
+ struct smap *stats = NULL;
- stats = xmalloc(sizeof *stats);
- smap_init(stats);
- get_cpu_cores(stats);
- get_load_average(stats);
- get_memory_stats(stats);
- get_process_stats(stats);
- get_filesys_stats(stats);
-
- next_refresh = time_msec() + SYSTEM_STATS_INTERVAL;
+ xpthread_mutex_lock(&mutex);
+ if (system_stats) {
+ latch_poll(&latch);
- return stats;
+ if (enabled) {
+ stats = system_stats;
+ system_stats = NULL;
+ } else {
+ discard_stats();
+ }
}
+ xpthread_mutex_unlock(&mutex);
- return NULL;
+ return stats;
}
/* Causes poll_block() to wake up when system_stats_run() needs to be
void
system_stats_wait(void)
{
- if (next_refresh != LLONG_MAX) {
- poll_timer_wait_until(next_refresh);
+ if (enabled) {
+ latch_wait(&latch);
+ }
+}
+
+static void
+discard_stats(void)
+{
+ if (system_stats) {
+ smap_destroy(system_stats);
+ free(system_stats);
+ system_stats = NULL;
+ }
+}
+
+static void * NO_RETURN
+system_stats_thread_func(void *arg OVS_UNUSED)
+{
+ pthread_detach(pthread_self());
+
+ for (;;) {
+ long long int next_refresh;
+ struct smap *stats;
+
+ xpthread_mutex_lock(&mutex);
+ while (!enabled) {
+ xpthread_cond_wait(&cond, &mutex);
+ }
+ xpthread_mutex_unlock(&mutex);
+
+ stats = xmalloc(sizeof *stats);
+ smap_init(stats);
+ get_cpu_cores(stats);
+ get_load_average(stats);
+ get_memory_stats(stats);
+ get_process_stats(stats);
+ get_filesys_stats(stats);
+
+ xpthread_mutex_lock(&mutex);
+ discard_stats();
+ system_stats = stats;
+ latch_set(&latch);
+ xpthread_mutex_unlock(&mutex);
+
+ next_refresh = time_msec() + SYSTEM_STATS_INTERVAL;
+ do {
+ poll_timer_wait_until(next_refresh);
+ poll_block();
+ } while (time_msec() < next_refresh);
}
}