Fix: thread exit vs futex wait/wakeup race

[lttng-tools.git] / src / bin / lttng-sessiond / main.c

diff --git a/src/bin/lttng-sessiond/main.c b/src/bin/lttng-sessiond/main.c
index b29c6745bd51e8ea0cd1c0d9648f0ab8c3fe4198..50eead010a3e2e72b053f4c899a49a2a02f86042 100644 (file)
--- a/src/bin/lttng-sessiond/main.c
+++ b/src/bin/lttng-sessiond/main.c
@@ -605,8 +605,7 @@ static void wait_consumer(struct consumer_data *consumer_data)
        ret = waitpid(consumer_data->pid, &status, 0);
        if (ret == -1) {
                PERROR("consumerd waitpid pid: %d", consumer_data->pid)
-       }
-       if (!WIFEXITED(status)) {
+       } else  if (!WIFEXITED(status)) {
                ERR("consumerd termination with error: %d",
                                WEXITSTATUS(ret));
        }
@@ -1903,6 +1902,8 @@ static void *thread_dispatch_ust_registration(void *data)
                .count = 0,
        };
 
+       rcu_register_thread();
+
        health_register(health_sessiond, HEALTH_SESSIOND_TYPE_APP_REG_DISPATCH);
 
        if (testpoint(sessiond_thread_app_reg_dispatch)) {
@@ -1915,12 +1916,16 @@ static void *thread_dispatch_ust_registration(void *data)
 
        DBG("[thread] Dispatch UST command started");
 
-       while (!CMM_LOAD_SHARED(dispatch_thread_exit)) {
+       for (;;) {
                health_code_update();
 
                /* Atomically prepare the queue futex */
                futex_nto1_prepare(&ust_cmd_queue.futex);
 
+               if (CMM_LOAD_SHARED(dispatch_thread_exit)) {
+                       break;
+               }
+
                do {
                        struct ust_app *app = NULL;
                        ust_cmd = NULL;
@@ -2136,6 +2141,7 @@ error_testpoint:
                ERR("Health error occurred in %s", __func__);
        }
        health_unregister(health_sessiond);
+       rcu_unregister_thread();
        return NULL;
 }