From 6cb45e931e18f489f1eb202396148529d86470a6 Mon Sep 17 00:00:00 2001 From: =?utf8?q?J=C3=A9r=C3=A9mie=20Galarneau?= Date: Tue, 11 Dec 2018 16:54:01 -0500 Subject: [PATCH] Fix: report initialization error of client thread MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit The health check tests use the testpoints() in the client thread to force a pthread_exit() or simulate a catastrophic error within the client thread. The testpoints were moved before the signal that the thread's initialization was completed by recent changes. This caused the thread to fail to complete its initialization, causing a deadlock of the session daemon. This commit reports initialization errors through the launch_client_thread() function to the "main" thread and shuts down the session daemon. It also moves the testpoints after the thread's initialization to respect the test's intent. Signed-off-by: Jérémie Galarneau --- src/bin/lttng-sessiond/client.c | 59 +++++++++++++++++++-------------- 1 file changed, 34 insertions(+), 25 deletions(-) diff --git a/src/bin/lttng-sessiond/client.c b/src/bin/lttng-sessiond/client.c index ea8ffd45f..8cf28a9d6 100644 --- 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); -- 2.34.1