Allow easier control over the thread by providing a dedicated quit pipe.
Signed-off-by: Jonathan Rajotte <[email protected]>
---
src/bin/lttng-sessiond/main.c | 74 ++++++++++++++++++++++++++++++++-----------
1 file changed, 55 insertions(+), 19 deletions(-)
diff --git a/src/bin/lttng-sessiond/main.c b/src/bin/lttng-sessiond/main.c
index 03f695ec..5d7df744 100644
--- a/src/bin/lttng-sessiond/main.c
+++ b/src/bin/lttng-sessiond/main.c
@@ -204,6 +204,7 @@ static int kernel_poll_pipe[2] = { -1, -1 };
* for all threads when receiving an event on the pipe.
*/
static int thread_quit_pipe[2] = { -1, -1 };
+static int thread_health_teardown_trigger_pipe[2] = { -1, -1 };
/*
* This pipe is used to inform the thread managing application communication
@@ -477,6 +478,11 @@ static int init_thread_quit_pipe(void)
return __init_thread_quit_pipe(thread_quit_pipe);
}
+static int init_thread_health_teardown_trigger_pipe(void)
+{
+ return __init_thread_quit_pipe(thread_health_teardown_trigger_pipe);
+}
+
/*
* Stop all threads by closing the thread quit pipe.
*/
@@ -4297,11 +4303,13 @@ static void *thread_manage_health(void *data)
goto error;
}
- /*
- * Pass 2 as size here for the thread quit pipe and client_sock. Nothing
- * more will be added to this poll set.
- */
- ret = sessiond_set_thread_pollset(&events, 2);
+ ret = lttng_poll_create(&events, 2, LTTNG_CLOEXEC);
+ if (ret < 0) {
+ goto error;
+ }
+
+ /* Add teardown trigger */
+ ret = lttng_poll_add(&events, thread_health_teardown_trigger_pipe[0],
LPOLLIN | LPOLLERR);
if (ret < 0) {
goto error;
}
@@ -4343,10 +4351,18 @@ restart:
}
/* 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_health_teardown_trigger_pipe[0]) {
+ if (revents & LPOLLIN) {
+ /* Normal exit */
+ err = 0;
+ goto exit;
+ } else if (revents & LPOLLERR) {
+ ERR("Health teardown poll error");
+ goto error;
+ } else {
+ ERR("Unexpected poll events %u for
teardown sock", revents);
+ goto error;
+ }
}
/* Event on the registration socket */
@@ -4412,8 +4428,13 @@ restart:
}
}
-exit:
error:
+ /*
+ * Perform stop_thread only on error path since in a normal teardown the
+ * health thread is in the last thread to terminate.
+ */
+ stop_threads();
+exit:
if (err) {
ERR("Health error occurred in %s", __func__);
}
@@ -4425,9 +4446,7 @@ error:
PERROR("close");
}
}
-
lttng_poll_clean(&events);
- stop_threads();
rcu_unregister_thread();
return NULL;
}
@@ -5631,6 +5650,7 @@ int main(int argc, char **argv)
*ust64_channel_monitor_pipe = NULL,
*kernel_channel_monitor_pipe = NULL;
bool notification_thread_running = false;
+ bool health_thread_running = false;
init_kernel_workarounds();
@@ -5717,6 +5737,11 @@ int main(int argc, char **argv)
goto exit_init_data;
}
+ if (init_thread_health_teardown_trigger_pipe()) {
+ retval = -1;
+ goto exit_init_data;
+ }
+
/* Check if daemon is UID = 0 */
is_root = !getuid();
@@ -6119,6 +6144,7 @@ int main(int argc, char **argv)
retval = -1;
goto exit_health;
}
+ health_thread_running = true;
/* notification_thread_data acquires the pipes' read side. */
notification_thread_handle = notification_thread_handle_create(
@@ -6311,13 +6337,6 @@ exit_dispatch:
exit_client:
exit_notification:
- ret = pthread_join(health_thread, &status);
- if (ret) {
- errno = ret;
- PERROR("pthread_join health thread");
- retval = -1;
- }
-
exit_health:
exit_init_data:
/*
@@ -6359,6 +6378,20 @@ exit_init_data:
notification_thread_handle_destroy(notification_thread_handle);
}
+ if (health_thread_running) {
+ ret =
notify_thread_pipe(thread_health_teardown_trigger_pipe[1]);
+ if (ret < 0) {
+ ERR("write error on thread quit pipe");
+ }
+
+ ret = pthread_join(health_thread, &status);
+ if (ret) {
+ errno = ret;
+ PERROR("pthread_join health thread");
+ retval = -1;
+ }
+ }
+
rcu_thread_offline();
rcu_unregister_thread();
@@ -6366,6 +6399,9 @@ exit_init_data:
if (ret) {
retval = -1;
}
+
+ /* Health thread teardown pipe cleanup */
+ utils_close_pipe(thread_health_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
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