Fix: report initialization error of client thread

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

diff --git a/src/bin/lttng-sessiond/client.c b/src/bin/lttng-sessiond/client.c
index ea8ffd45fc066c3cfa16b4ac8017400361888e8d..8cf28a9d6323b4859b9563a374422be5489a7484 100644 (file)
--- a/src/bin/lttng-sessiond/client.c
+++ b/src/bin/lttng-sessiond/client.c
@@ -40,31 +40,28 @@
 static bool is_root;
 
 static struct thread_state {
-       pthread_cond_t cond;
-       pthread_mutex_t lock;
-       bool is_running;
-} thread_state = {
-       .cond = PTHREAD_COND_INITIALIZER,
-       .lock = PTHREAD_MUTEX_INITIALIZER,
-       .is_running = false
-};
-
-void set_thread_state_running(void)
+       sem_t ready;
+       bool running;
+} thread_state;
+
+static void set_thread_status(bool running)
 {
-       pthread_mutex_lock(&thread_state.lock);
-        thread_state.is_running = true;
-       pthread_cond_broadcast(&thread_state.cond);
-       pthread_mutex_unlock(&thread_state.lock);
+       DBG("Marking client thread's state as %s", running ? "running" : "error");
+       thread_state.running = running;
+       sem_post(&thread_state.ready);
 }
 
-static void wait_thread_state_running(void)
+static bool wait_thread_status(void)
 {
-       pthread_mutex_lock(&thread_state.lock);
-       while (!thread_state.is_running) {
-               pthread_cond_wait(&thread_state.cond,
-                               &thread_state.lock);
+       DBG("Waiting for client thread to be ready");
+       sem_wait(&thread_state.ready);
+       if (thread_state.running) {
+               DBG("Client thread is ready");
+       } else {
+               ERR("Initialization of client thread failed");
        }
-       pthread_mutex_unlock(&thread_state.lock);
+
+       return thread_state.running;
 }
 
 /*
@@ -2071,6 +2068,11 @@ static void cleanup_client_thread(void *data)
        lttng_pipe_destroy(quit_pipe);
 }
 
+static void thread_init_cleanup(void *data)
+{
+       set_thread_status(false);
+}
+
 /*
  * This thread manage all clients request using the unix client socket for
  * communication.
@@ -2090,6 +2092,7 @@ static void *thread_manage_clients(void *data)
 
        is_root = (getuid() == 0);
 
+       pthread_cleanup_push(thread_init_cleanup, NULL);
        client_sock = create_client_sock();
        if (client_sock < 0) {
                goto error_listen;
@@ -2127,6 +2130,10 @@ static void *thread_manage_clients(void *data)
                goto error;
        }
 
+       /* Set state as running. */
+        set_thread_status(true);
+       pthread_cleanup_pop(0);
+
        /* This testpoint is after we signal readiness to the parent. */
        if (testpoint(sessiond_thread_manage_clients)) {
                goto error;
@@ -2138,9 +2145,6 @@ static void *thread_manage_clients(void *data)
 
        health_code_update();
 
-       /* Set state as running. */
-        set_thread_state_running();
-
        while (1) {
                const struct cmd_completion_handler *cmd_completion_handler;
 
@@ -2362,9 +2366,11 @@ bool shutdown_client_thread(void *thread_data)
 
 struct lttng_thread *launch_client_thread(void)
 {
+       bool thread_running;
        struct lttng_pipe *client_quit_pipe;
        struct lttng_thread *thread;
 
+       sem_init(&thread_state.ready, 0, 0);
        client_quit_pipe = lttng_pipe_open(FD_CLOEXEC);
        if (!client_quit_pipe) {
                goto error;
@@ -2383,8 +2389,11 @@ struct lttng_thread *launch_client_thread(void)
         * This thread is part of the threads that need to be fully
         * initialized before the session daemon is marked as "ready".
         */
-       wait_thread_state_running();
-
+       thread_running = wait_thread_status();
+       if (!thread_running) {
+               lttng_thread_put(thread);
+               thread = NULL;
+       }
        return thread;
 error:
        cleanup_client_thread(client_quit_pipe);