stat: avoid hang with race in stat thread exit and rusage update

[fio.git] / stat.c

diff --git a/stat.c b/stat.c
index 03dc45880ed73b9a5cb051a59be37cfc29db1e78..3aae76df431e7d9acdb56ec31a2b8a172da195a1 100644 (file)
--- a/stat.c
+++ b/stat.c
@@ -1422,7 +1422,7 @@ void show_run_stats(void)
        fio_mutex_up(stat_mutex);
 }
 
-static void *__show_running_run_stats(void *arg)
+static void __show_running_run_stats(void)
 {
        struct thread_data *td;
        unsigned long long *rt;
@@ -1451,6 +1451,8 @@ static void *__show_running_run_stats(void *arg)
        }
 
        for_each_td(td, i) {
+               if (td->runstate >= TD_EXITED)
+                       continue;
                if (td->rusage_sem) {
                        td->update_rusage = 1;
                        fio_mutex_down(td->rusage_sem);
@@ -1471,34 +1473,6 @@ static void *__show_running_run_stats(void *arg)
 
        free(rt);
        fio_mutex_up(stat_mutex);
-       free(arg);
-       return NULL;
-}
-
-/*
- * Called from signal handler. It _should_ be safe to just run this inline
- * in the sig handler, but we should be disturbing the system less by just
- * creating a thread to do it.
- */
-void show_running_run_stats(void)
-{
-       pthread_t *thread;
-
-       thread = calloc(1, sizeof(*thread));
-       if (!thread)
-               return;
-
-       if (!pthread_create(thread, NULL, __show_running_run_stats, thread)) {
-               int err;
-
-               err = pthread_detach(*thread);
-               if (err)
-                       log_err("fio: DU thread detach failed: %s\n", strerror(err));
-
-               return;
-       }
-
-       free(thread);
 }
 
 static int status_interval_init;
@@ -1917,3 +1891,53 @@ void stat_exit(void)
        fio_mutex_down(stat_mutex);
        fio_mutex_remove(stat_mutex);
 }
+
+static pthread_t si_thread;
+static pthread_cond_t si_cond;
+static pthread_mutex_t si_lock;
+static int si_thread_exit;
+
+/*
+ * Called from signal handler. Wake up status thread.
+ */
+void show_running_run_stats(void)
+{
+       pthread_cond_signal(&si_cond);
+}
+
+static void *si_thread_main(void *unused)
+{
+       while (!si_thread_exit) {
+               pthread_cond_wait(&si_cond, &si_lock);
+               if (si_thread_exit)
+                       break;
+
+               __show_running_run_stats();
+       }
+
+       return NULL;
+}
+
+void create_status_interval_thread(void)
+{
+       int ret;
+
+       pthread_cond_init(&si_cond, NULL);
+       pthread_mutex_init(&si_lock, NULL);
+
+       ret = pthread_create(&si_thread, NULL, si_thread_main, NULL);
+       if (ret) {
+               log_err("Can't create status thread: %s\n", strerror(ret));
+               return;
+       }
+}
+
+void wait_for_status_interval_thread_exit(void)
+{
+       void *ret;
+
+       si_thread_exit = 1;
+       pthread_cond_signal(&si_cond);
+       pthread_join(si_thread, &ret);
+       pthread_cond_destroy(&si_cond);
+}