Exemplo n.º 1
0
void *thread_ht_cleanup(void *data)
{
	int ret, i, pollfd, err = -1;
	ssize_t size_ret;
	uint32_t revents, nb_fd;
	struct lttng_poll_event events;

	DBG("[ht-thread] startup.");

	rcu_register_thread();
	rcu_thread_online();

	health_register(health_sessiond, HEALTH_SESSIOND_TYPE_HT_CLEANUP);

	health_code_update();

	ret = sessiond_set_thread_pollset(&events, 2);
	if (ret < 0) {
		goto error_poll_create;
	}

	/* Add pipe to the pollset. */
	ret = lttng_poll_add(&events, ht_cleanup_pipe[0], LPOLLIN | LPOLLERR);
	if (ret < 0) {
		goto error;
	}

	health_code_update();

	while (1) {
		DBG3("[ht-thread] Polling on %d fds.",
			LTTNG_POLL_GETNB(&events));

		/* 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++) {
			struct lttng_ht *ht;

			health_code_update();

			/* Fetch once the poll data */
			revents = LTTNG_POLL_GETEV(&events, i);
			pollfd = LTTNG_POLL_GETFD(&events, i);

			/* Thread quit pipe has been closed. Killing thread. */
			ret = sessiond_check_thread_quit_pipe(pollfd, revents);
			if (ret) {
				err = 0;
				goto exit;
			}
			assert(pollfd == ht_cleanup_pipe[0]);

			if (revents & (LPOLLERR | LPOLLHUP | LPOLLRDHUP)) {
				ERR("ht cleanup pipe error");
				goto error;
			} else if (!(revents & LPOLLIN)) {
				/* No POLLIN and not a catched error, stop the thread. */
				ERR("ht cleanup failed. revent: %u", revents);
				goto error;
			}

			/* Get socket from dispatch thread. */
			size_ret = lttng_read(ht_cleanup_pipe[0], &ht,
					sizeof(ht));
			if (size_ret < sizeof(ht)) {
				PERROR("ht cleanup notify pipe");
				goto error;
			}
			health_code_update();
			/*
			 * The whole point of this thread is to call
			 * lttng_ht_destroy from a context that is NOT:
			 * 1) a read-side RCU lock,
			 * 2) a call_rcu thread.
			 */
			lttng_ht_destroy(ht);

			health_code_update();
		}
	}

exit:
error:
	lttng_poll_clean(&events);
error_poll_create:
	utils_close_pipe(ht_cleanup_pipe);
	ht_cleanup_pipe[0] = ht_cleanup_pipe[1] = -1;
	DBG("[ust-thread] cleanup complete.");
	if (err) {
		health_error();
		ERR("Health error occurred in %s", __func__);
	}
	health_unregister(health_sessiond);
	rcu_thread_offline();
	rcu_unregister_thread();
	return NULL;
}
Exemplo n.º 2
0
/*
 * This thread manage application notify communication.
 */
void *ust_thread_manage_notify(void *data)
{
	int i, ret, pollfd, err = -1;
	ssize_t size_ret;
	uint32_t revents, nb_fd;
	struct lttng_poll_event events;

	DBG("[ust-thread] Manage application notify command");

	rcu_register_thread();
	rcu_thread_online();

	health_register(health_sessiond,
		HEALTH_SESSIOND_TYPE_APP_MANAGE_NOTIFY);

	if (testpoint(sessiond_thread_app_manage_notify)) {
		goto error_testpoint;
	}

	health_code_update();

	ret = sessiond_set_thread_pollset(&events, 2);
	if (ret < 0) {
		goto error_poll_create;
	}

	/* Add notify pipe to the pollset. */
	ret = lttng_poll_add(&events, apps_cmd_notify_pipe[0], LPOLLIN | LPOLLERR);
	if (ret < 0) {
		goto error;
	}

	health_code_update();

	while (1) {
		DBG3("[ust-thread] Manage notify polling on %d fds",
				LTTNG_POLL_GETNB(&events));

		/* 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);

			/* Thread quit pipe has been closed. Killing thread. */
			ret = sessiond_check_thread_quit_pipe(pollfd, revents);
			if (ret) {
				err = 0;
				goto exit;
			}

			/* Inspect the apps cmd pipe */
			if (pollfd == apps_cmd_notify_pipe[0]) {
				int sock;

				if (revents & (LPOLLERR | LPOLLHUP | LPOLLRDHUP)) {
					ERR("Apps notify command pipe error");
					goto error;
				} else if (!(revents & LPOLLIN)) {
					/* No POLLIN and not a catched error, stop the thread. */
					ERR("Notify command pipe failed. revent: %u", revents);
					goto error;
				}

				/* Get socket from dispatch thread. */
				size_ret = lttng_read(apps_cmd_notify_pipe[0],
						&sock, sizeof(sock));
				if (size_ret < sizeof(sock)) {
					PERROR("read apps notify pipe");
					goto error;
				}
				health_code_update();

				ret = lttng_poll_add(&events, sock,
						LPOLLIN | LPOLLERR | LPOLLHUP | LPOLLRDHUP);
				if (ret < 0) {
					/*
					 * It's possible we've reached the max poll fd allowed.
					 * Let's close the socket but continue normal execution.
					 */
					ret = close(sock);
					if (ret) {
						PERROR("close notify socket %d", sock);
					}
					lttng_fd_put(LTTNG_FD_APPS, 1);
					continue;
				}
				DBG3("UST thread notify added sock %d to pollset", sock);
			} else {
				/*
				 * At this point, we know that a registered application
				 * triggered the event.
				 */
				if (revents & (LPOLLERR | LPOLLHUP | LPOLLRDHUP)) {
					/* Removing from the poll set */
					ret = lttng_poll_del(&events, pollfd);
					if (ret < 0) {
						goto error;
					}

					/* The socket is closed after a grace period here. */
					ust_app_notify_sock_unregister(pollfd);
				} else if (revents & (LPOLLIN | LPOLLPRI)) {
					ret = ust_app_recv_notify(pollfd);
					if (ret < 0) {
						/*
						 * If the notification failed either the application is
						 * dead or an internal error happened. In both cases,
						 * we can only continue here. If the application is
						 * dead, an unregistration will follow or else the
						 * application will notice that we are not responding
						 * on that socket and will close it.
						 */
						continue;
					}
				} else {
					ERR("Unknown poll events %u for sock %d", revents, pollfd);
					continue;
				}
				health_code_update();
			}
		}
	}

exit:
error:
	lttng_poll_clean(&events);
error_poll_create:
error_testpoint:
	utils_close_pipe(apps_cmd_notify_pipe);
	apps_cmd_notify_pipe[0] = apps_cmd_notify_pipe[1] = -1;
	DBG("Application notify communication apps thread cleanup complete");
	if (err) {
		health_error();
		ERR("Health error occurred in %s", __func__);
	}
	health_unregister(health_sessiond);
	rcu_thread_offline();
	rcu_unregister_thread();
	return NULL;
}