[lttng-dev] [RFC PATCH v2 04/13] Order termination of thread_manage_apps after dispatch_thread

[Jérémie Galarneau]

On 18 September 2017 at 18:51, Jonathan Rajotte
<jonathan.rajotte-julien at efficios.com> wrote:
> This ensure that no registration are ongoing when thread_manage_apps

registration -> registrations

> perform it's cleanup and termination.

perform -> performs

>
> Signed-off-by: Jonathan Rajotte <jonathan.rajotte-julien at efficios.com>
> ---
>  src/bin/lttng-sessiond/main.c | 46 +++++++++++++++++++++++++++++++++++++------
>  1 file changed, 40 insertions(+), 6 deletions(-)
>
> diff --git a/src/bin/lttng-sessiond/main.c b/src/bin/lttng-sessiond/main.c
> index 0ca72ec8..8d9b14b5 100644
> --- a/src/bin/lttng-sessiond/main.c
> +++ b/src/bin/lttng-sessiond/main.c
> @@ -205,6 +205,7 @@ static int kernel_poll_pipe[2] = { -1, -1 };
>   */
>  static int thread_quit_pipe[2] = { -1, -1 };
>  static int thread_health_teardown_trigger_pipe[2] = { -1, -1 };
> +static int thread_apps_teardown_trigger_pipe[2] = { -1, -1 };
>
>  /*
>   * This pipe is used to inform the thread managing application communication
> @@ -483,6 +484,11 @@ static int init_thread_health_teardown_trigger_pipe(void)
>         return __init_thread_quit_pipe(thread_health_teardown_trigger_pipe);
>  }
>
> +static int init_thread_apps_teardown_trigger_pipe(void)
> +{
> +       return __init_thread_quit_pipe(thread_apps_teardown_trigger_pipe);
> +}
> +
>  /*
>   * Stop all threads by closing the thread quit pipe.
>   */
> @@ -496,7 +502,6 @@ static void stop_threads(void)
>         if (ret < 0) {
>                 ERR("write error on thread quit pipe");
>         }
> -
>  }
>
>  /*
> @@ -1634,11 +1639,17 @@ static void *thread_manage_apps(void *data)
>
>         health_code_update();
>
> -       ret = sessiond_set_thread_pollset(&events, 2);
> +       ret = lttng_poll_create(&events, 2, LTTNG_CLOEXEC);
>         if (ret < 0) {
>                 goto error_poll_create;
>         }
>
> +       /* Add quit pipe */
> +       ret = lttng_poll_add(&events, thread_apps_teardown_trigger_pipe[0], LPOLLIN | LPOLLERR);
> +       if (ret < 0) {
> +               goto error;
> +       }
> +
>         ret = lttng_poll_add(&events, apps_cmd_pipe[0], LPOLLIN | LPOLLRDHUP);
>         if (ret < 0) {
>                 goto error;
> @@ -1685,10 +1696,18 @@ static void *thread_manage_apps(void *data)
>                         }
>
>                         /* Thread quit pipe has been closed. Killing thread. */
> -                       ret = sessiond_check_thread_quit_pipe(pollfd, revents);
> -                       if (ret) {
> -                               err = 0;
> -                               goto exit;
> +                       if (pollfd == thread_apps_teardown_trigger_pipe[0]) {
> +                               if (revents & LPOLLIN) {
> +                                       /* Normal exit */
> +                                       err = 0;
> +                                       goto exit;
> +                               } else if (revents & LPOLLERR) {
> +                                       ERR("Quit pipe error");
> +                                       goto error;
> +                               } else {
> +                                       ERR("Unknown poll events %u for quit pipe", revents);
> +                                       goto error;
> +                               }
>                         }
>
>                         /* Inspect the apps cmd pipe */
> @@ -5739,6 +5758,11 @@ int main(int argc, char **argv)
>                 goto exit_init_data;
>         }
>
> +       if (init_thread_apps_teardown_trigger_pipe()) {
> +               retval = -1;
> +               goto exit_init_data;
> +       }
> +
>         /* Check if daemon is UID = 0 */
>         is_root = !getuid();
>
> @@ -6302,6 +6326,7 @@ exit_client:
>                 PERROR("pthread_join registration app" );
>                 retval = -1;
>         }
> +
>  exit_reg_apps:
>         /* Instruct the dispatch thread to quit */
>         CMM_STORE_SHARED(dispatch_thread_exit, 1);
> @@ -6315,6 +6340,12 @@ exit_reg_apps:
>         }
>
>  exit_dispatch:
> +       /* Instruct the apps thread to quit */
> +       ret = notify_thread_pipe(thread_apps_teardown_trigger_pipe[1]);
> +       if (ret < 0) {
> +               ERR("write error on thread quit pipe");
> +       }
> +
>         ret = pthread_join(apps_thread, &status);
>         if (ret) {
>                 errno = ret;
> @@ -6397,6 +6428,9 @@ exit_init_data:
>
>         /* Health thread teardown pipe cleanup */
>         utils_close_pipe(thread_health_teardown_trigger_pipe);
> +       /* Apps thread teardown pipe cleanup */
> +       utils_close_pipe(thread_apps_teardown_trigger_pipe);
> +
>         lttng_pipe_destroy(ust32_channel_monitor_pipe);
>         lttng_pipe_destroy(ust64_channel_monitor_pipe);
>         lttng_pipe_destroy(kernel_channel_monitor_pipe);
> --
> 2.11.0
>



-- 
Jérémie Galarneau
EfficiOS Inc.
http://www.efficios.com