-/*
- * This thread manage application registration.
- */
-static void *thread_registration_apps(void *data)
-{
- int sock = -1, i, ret, pollfd, err = -1;
- uint32_t revents, nb_fd;
- struct lttng_poll_event events;
- /*
- * Get allocated in this thread, enqueued to a global queue, dequeued and
- * freed in the manage apps thread.
- */
- struct ust_command *ust_cmd = NULL;
-
- DBG("[thread] Manage application registration started");
-
- health_register(health_sessiond, HEALTH_SESSIOND_TYPE_APP_REG);
-
- if (testpoint(sessiond_thread_registration_apps)) {
- goto error_testpoint;
- }
-
- ret = lttcomm_listen_unix_sock(apps_sock);
- if (ret < 0) {
- goto error_listen;
- }
-
- /*
- * Pass 2 as size here for the thread quit pipe and apps socket. Nothing
- * more will be added to this poll set.
- */
- ret = sessiond_set_thread_pollset(&events, 2);
- if (ret < 0) {
- goto error_create_poll;
- }
-
- /* Add the application registration socket */
- ret = lttng_poll_add(&events, apps_sock, LPOLLIN | LPOLLRDHUP);
- if (ret < 0) {
- goto error_poll_add;
- }
-
- /* Notify all applications to register */
- ret = notify_ust_apps(1);
- if (ret < 0) {
- ERR("Failed to notify applications or create the wait shared memory.\n"
- "Execution continues but there might be problem for already\n"
- "running applications that wishes to register.");
- }
-
- while (1) {
- DBG("Accepting application registration");
-
- /* Inifinite blocking call, waiting for transmission */
- restart:
- health_poll_entry();
- ret = lttng_poll_wait(&events, -1);
- health_poll_exit();
- if (ret < 0) {
- /*
- * Restart interrupted system call.
- */
- if (errno == EINTR) {
- goto restart;
- }
- goto error;
- }
-
- nb_fd = ret;
-
- for (i = 0; i < nb_fd; i++) {
- health_code_update();
-
- /* 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 == apps_sock) {
- if (revents & LPOLLIN) {
- sock = lttcomm_accept_unix_sock(apps_sock);
- if (sock < 0) {
- goto error;
- }
-
- /*
- * Set socket timeout for both receiving and ending.
- * app_socket_timeout is in seconds, whereas
- * lttcomm_setsockopt_rcv_timeout and
- * lttcomm_setsockopt_snd_timeout expect msec as
- * parameter.
- */
- if (config.app_socket_timeout >= 0) {
- (void) lttcomm_setsockopt_rcv_timeout(sock,
- config.app_socket_timeout * 1000);
- (void) lttcomm_setsockopt_snd_timeout(sock,
- config.app_socket_timeout * 1000);
- }
-
- /*
- * Set the CLOEXEC flag. Return code is useless because
- * either way, the show must go on.
- */
- (void) utils_set_fd_cloexec(sock);
-
- /* Create UST registration command for enqueuing */
- ust_cmd = zmalloc(sizeof(struct ust_command));
- if (ust_cmd == NULL) {
- PERROR("ust command zmalloc");
- ret = close(sock);
- if (ret) {
- PERROR("close");
- }
- goto error;
- }
-
- /*
- * Using message-based transmissions to ensure we don't
- * have to deal with partially received messages.
- */
- ret = lttng_fd_get(LTTNG_FD_APPS, 1);
- if (ret < 0) {
- ERR("Exhausted file descriptors allowed for applications.");
- free(ust_cmd);
- ret = close(sock);
- if (ret) {
- PERROR("close");
- }
- sock = -1;
- continue;
- }
-
- health_code_update();
- ret = ust_app_recv_registration(sock, &ust_cmd->reg_msg);
- if (ret < 0) {
- free(ust_cmd);
- /* Close socket of the application. */
- ret = close(sock);
- if (ret) {
- PERROR("close");
- }
- lttng_fd_put(LTTNG_FD_APPS, 1);
- sock = -1;
- continue;
- }
- health_code_update();
-
- ust_cmd->sock = sock;
- sock = -1;
-
- DBG("UST registration received with pid:%d ppid:%d uid:%d"
- " gid:%d sock:%d name:%s (version %d.%d)",
- ust_cmd->reg_msg.pid, ust_cmd->reg_msg.ppid,
- ust_cmd->reg_msg.uid, ust_cmd->reg_msg.gid,
- ust_cmd->sock, ust_cmd->reg_msg.name,
- ust_cmd->reg_msg.major, ust_cmd->reg_msg.minor);
-
- /*
- * Lock free enqueue the registration request. The red pill
- * has been taken! This apps will be part of the *system*.
- */
- cds_wfcq_enqueue(&ust_cmd_queue.head, &ust_cmd_queue.tail, &ust_cmd->node);
-
- /*
- * Wake the registration queue futex. Implicit memory
- * barrier with the exchange in cds_wfcq_enqueue.
- */
- futex_nto1_wake(&ust_cmd_queue.futex);
- } else if (revents & (LPOLLERR | LPOLLHUP | LPOLLRDHUP)) {
- ERR("Register apps socket poll error");
- goto error;
- } else {
- ERR("Unexpected poll events %u for sock %d", revents, pollfd);
- goto error;
- }
- }
- }
- }
-
-exit:
-error:
- /* Notify that the registration thread is gone */
- notify_ust_apps(0);
-
- if (apps_sock >= 0) {
- ret = close(apps_sock);
- if (ret) {
- PERROR("close");
- }
- }
- if (sock >= 0) {
- ret = close(sock);
- if (ret) {
- PERROR("close");
- }
- lttng_fd_put(LTTNG_FD_APPS, 1);
- }
- unlink(config.apps_unix_sock_path.value);
-
-error_poll_add:
- lttng_poll_clean(&events);
-error_listen:
-error_create_poll:
-error_testpoint:
- DBG("UST Registration thread cleanup complete");
- if (err) {
- health_error();
- ERR("Health error occurred in %s", __func__);
- }
- health_unregister(health_sessiond);
-
- return NULL;
-}
-