Stop the application registration thread before orphaned threads

The application registration thread receives new connections from
applications, provides them to the dispatch thread. The dispatch
thread, in turn, forwards the command and notification sockets of
applications (liblttng-ust) to the application management and
application notification threads.

Not shutting down the application registration thread is problematic
since application connections will be accepted but not associated
to an "ust_app" structure as the following threads are no longer
present.

The remaining threads can then be safely torn down as part of the
orphaned threads.

Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>

diff --git a/src/bin/lttng-sessiond/main.c b/src/bin/lttng-sessiond/main.c
index 5f7600c0c0b200f4608903e4c2bd1069f105ea82..a96dc51952eb6ef84f127c027499795cfefcda76 100644 (file)
--- a/src/bin/lttng-sessiond/main.c
+++ b/src/bin/lttng-sessiond/main.c
@@ -1354,6 +1354,7 @@ int main(int argc, char **argv)
        struct rotation_thread_timer_queue *rotation_timer_queue = NULL;
        struct lttng_thread *client_thread = NULL;
        struct lttng_thread *notification_thread = NULL;
+       struct lttng_thread *register_apps_thread = NULL;
 
        init_kernel_workarounds();
 
@@ -1747,7 +1748,9 @@ int main(int argc, char **argv)
        }
 
        /* Create thread to manage application registration. */
-       if (!launch_application_registration_thread(&ust_cmd_queue)) {
+       register_apps_thread = launch_application_registration_thread(
+                       &ust_cmd_queue);
+       if (!register_apps_thread) {
                retval = -1;
                goto exit_reg_apps;
        }
@@ -1815,6 +1818,10 @@ exit_kernel:
 exit_agent_reg:
 exit_apps_notify:
 exit_apps:
+       if (register_apps_thread) {
+               lttng_thread_shutdown(register_apps_thread);
+               lttng_thread_put(register_apps_thread);
+       }
 exit_reg_apps:
 exit_dispatch:
 exit_client:

diff --git a/src/bin/lttng-sessiond/register.c b/src/bin/lttng-sessiond/register.c
index b75db4ed9533f9c0e73025602b3729514d89d111..6776019c68d3cdef3cfd4439906363a56b345c39 100644 (file)
--- a/src/bin/lttng-sessiond/register.c
+++ b/src/bin/lttng-sessiond/register.c
@@ -361,7 +361,7 @@ static bool shutdown_application_registration_thread(void *data)
        return notify_thread_pipe(write_fd) == 1;
 }
 
-bool launch_application_registration_thread(
+struct lttng_thread *launch_application_registration_thread(
                struct ust_cmd_queue *cmd_queue)
 {
        struct lttng_pipe *quit_pipe;
@@ -388,9 +388,8 @@ bool launch_application_registration_thread(
        if (!thread) {
                goto error;
        }
-       lttng_thread_put(thread);
-       return true;
+       return thread;
 error:
        cleanup_application_registration_thread(notifiers);
-       return false;
+       return NULL;
 }

diff --git a/src/bin/lttng-sessiond/register.h b/src/bin/lttng-sessiond/register.h
index 71bb4de1e502a1978338deb613aa13908be7f344..d9bd0515523b58094b480e8ff1a2831ae37d04c6 100644 (file)
--- a/src/bin/lttng-sessiond/register.h
+++ b/src/bin/lttng-sessiond/register.h
@@ -23,6 +23,7 @@
 #include <stdbool.h>
 #include "lttng-sessiond.h"
 
-bool launch_application_registration_thread(struct ust_cmd_queue *cmd_queue);
+struct lttng_thread *launch_application_registration_thread(
+               struct ust_cmd_queue *cmd_queue);
 
 #endif /* SESSIOND_APPLICATION_REGISTRATION_THREAD_H */