- * Thread managing health check socket.
- */
-static void *thread_manage_health(void *data)
-{
- int sock = -1, new_sock = -1, ret, i, pollfd, err = -1;
- uint32_t revents, nb_fd;
- struct lttng_poll_event events;
- struct health_comm_msg msg;
- struct health_comm_reply reply;
-
- DBG("[thread] Manage health check started");
-
- rcu_register_thread();
-
- /* We might hit an error path before this is created. */
- lttng_poll_init(&events);
-
- /* Create unix socket */
- sock = lttcomm_create_unix_sock(config.health_unix_sock_path.value);
- if (sock < 0) {
- ERR("Unable to create health check Unix socket");
- goto error;
- }
-
- if (is_root) {
- /* lttng health client socket path permissions */
- ret = chown(config.health_unix_sock_path.value, 0,
- utils_get_group_id(config.tracing_group_name.value));
- if (ret < 0) {
- ERR("Unable to set group on %s", config.health_unix_sock_path.value);
- PERROR("chown");
- goto error;
- }
-
- ret = chmod(config.health_unix_sock_path.value,
- S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP);
- if (ret < 0) {
- ERR("Unable to set permissions on %s", config.health_unix_sock_path.value);
- PERROR("chmod");
- goto error;
- }
- }
-
- /*
- * Set the CLOEXEC flag. Return code is useless because either way, the
- * show must go on.
- */
- (void) utils_set_fd_cloexec(sock);
-
- ret = lttcomm_listen_unix_sock(sock);
- if (ret < 0) {
- 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);
- if (ret < 0) {
- goto error;
- }
-
- /* Add the application registration socket */
- ret = lttng_poll_add(&events, sock, LPOLLIN | LPOLLPRI);
- if (ret < 0) {
- goto error;
- }
-
- sessiond_notify_ready();
-
- while (1) {
- DBG("Health check ready");
-
- /* Inifinite blocking call, waiting for transmission */
-restart:
- ret = lttng_poll_wait(&events, -1);
- if (ret < 0) {
- /*
- * Restart interrupted system call.
- */
- if (errno == EINTR) {
- goto restart;
- }
- goto error;
- }
-
- nb_fd = ret;
-
- for (i = 0; i < nb_fd; i++) {
- /* Fetch once the poll data */
- revents = LTTNG_POLL_GETEV(&events, i);
- pollfd = LTTNG_POLL_GETFD(&events, i);
-
- if (!revents) {
- /* No activity for this FD (poll implementation). */
- continue;
- }
-
- /* Thread quit pipe has been closed. Killing thread. */
- ret = sessiond_check_thread_quit_pipe(pollfd, revents);
- if (ret) {
- err = 0;
- goto exit;
- }
-
- /* Event on the registration socket */
- if (pollfd == sock) {
- if (revents & LPOLLIN) {
- continue;
- } else if (revents & (LPOLLERR | LPOLLHUP | LPOLLRDHUP)) {
- ERR("Health socket poll error");
- goto error;
- } else {
- ERR("Unexpected poll events %u for sock %d", revents, pollfd);
- goto error;
- }
- }
- }
-
- new_sock = lttcomm_accept_unix_sock(sock);
- if (new_sock < 0) {
- goto error;
- }
-
- /*
- * Set the CLOEXEC flag. Return code is useless because either way, the
- * show must go on.
- */
- (void) utils_set_fd_cloexec(new_sock);
-
- DBG("Receiving data from client for health...");
- ret = lttcomm_recv_unix_sock(new_sock, (void *)&msg, sizeof(msg));
- if (ret <= 0) {
- DBG("Nothing recv() from client... continuing");
- ret = close(new_sock);
- if (ret) {
- PERROR("close");
- }
- continue;
- }
-
- rcu_thread_online();
-
- memset(&reply, 0, sizeof(reply));
- for (i = 0; i < NR_HEALTH_SESSIOND_TYPES; i++) {
- /*
- * health_check_state returns 0 if health is
- * bad.
- */
- if (!health_check_state(health_sessiond, i)) {
- reply.ret_code |= 1ULL << i;
- }
- }
-
- DBG2("Health check return value %" PRIx64, reply.ret_code);
-
- ret = send_unix_sock(new_sock, (void *) &reply, sizeof(reply));
- if (ret < 0) {
- ERR("Failed to send health data back to client");
- }
-
- /* End of transmission */
- ret = close(new_sock);
- if (ret) {
- PERROR("close");
- }
- }
-
-exit:
-error:
- if (err) {
- ERR("Health error occurred in %s", __func__);
- }
- DBG("Health check thread dying");
- unlink(config.health_unix_sock_path.value);
- if (sock >= 0) {
- ret = close(sock);
- if (ret) {
- PERROR("close");
- }
- }
-
- lttng_poll_clean(&events);
- stop_threads();
- rcu_unregister_thread();
- return NULL;
-}
-
-/*
- * This thread manage all clients request using the unix client socket for
- * communication.