/*
 * Thread managing health check socket.
 */
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;
	int is_root;

	DBG("[thread] Manage health check started");

	setup_health_path();

	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(health_unix_sock_path);
	if (sock < 0) {
		ERR("Unable to create health check Unix socket");
		ret = -1;
		goto error;
	}

	is_root = !getuid();
	if (is_root) {
		/* lttng health client socket path permissions */
		ret = chown(health_unix_sock_path, 0,
				utils_get_group_id(tracing_group_name));
		if (ret < 0) {
			ERR("Unable to set group on %s", health_unix_sock_path);
			PERROR("chown");
			ret = -1;
			goto error;
		}

		ret = chmod(health_unix_sock_path,
				S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP);
		if (ret < 0) {
			ERR("Unable to set permissions on %s", health_unix_sock_path);
			PERROR("chmod");
			ret = -1;
			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;
	}

	/* Size is set to 1 for the consumer_channel pipe */
	ret = lttng_poll_create(&events, 2, LTTNG_CLOEXEC);
	if (ret < 0) {
		ERR("Poll set creation failed");
		goto error;
	}

	ret = lttng_poll_add(&events, health_quit_pipe[0], LPOLLIN);
	if (ret < 0) {
		goto error;
	}

	/* Add the application registration socket */
	ret = lttng_poll_add(&events, sock, LPOLLIN | LPOLLPRI);
	if (ret < 0) {
		goto error;
	}

	/* Perform prior memory accesses before decrementing ready */
	cmm_smp_mb__before_uatomic_dec();
	uatomic_dec(&lttng_consumer_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 = check_health_quit_pipe(pollfd, revents);
			if (ret) {
				err = 0;
				goto exit;
			}

			/* Event on the registration socket */
			if (pollfd == sock) {
				if (revents & (LPOLLERR | LPOLLHUP | LPOLLRDHUP)
						&& !(revents & LPOLLIN)) {
					ERR("Health socket poll error");
					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");
			}
			new_sock = -1;
			continue;
		}

		rcu_thread_online();

		assert(msg.cmd == HEALTH_CMD_CHECK);

		memset(&reply, 0, sizeof(reply));
		for (i = 0; i < NR_HEALTH_CONSUMERD_TYPES; i++) {
			/*
			 * health_check_state return 0 if thread is in
			 * error.
			 */
			if (!health_check_state(health_consumerd, i)) {
				reply.ret_code |= 1ULL << i;
			}
		}

		DBG("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");
		}
		new_sock = -1;
	}

exit:
error:
	if (err) {
		ERR("Health error occurred in %s", __func__);
	}
	DBG("Health check thread dying");
	unlink(health_unix_sock_path);
	if (sock >= 0) {
		ret = close(sock);
		if (ret) {
			PERROR("close");
		}
	}

	lttng_poll_clean(&events);

	rcu_unregister_thread();
	return NULL;
}
Example #2
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;
}
Example #3
0
/*
 * Thread managing health check socket.
 */
static void *thread_manage_health(void *data)
{
	const bool is_root = (getuid() == 0);
	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;
	/* Thread-specific quit pipe. */
	struct thread_notifiers *notifiers = data;
	const int quit_pipe_read_fd = lttng_pipe_get_readfd(
			notifiers->quit_pipe);

	DBG("[thread] Manage health check started");

	rcu_register_thread();

	/*
	 * Created with a size of two for:
	 *   - client socket
	 *   - thread quit pipe
	 */
	ret = lttng_poll_create(&events, 2, LTTNG_CLOEXEC);
	if (ret < 0) {
		goto error;
	}

	/* 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 */
		gid_t gid;

		ret = utils_get_group_id(config.tracing_group_name.value, true, &gid);
		if (ret) {
			/* Default to root group. */
			gid = 0;
		}

		ret = chown(config.health_unix_sock_path.value, 0, gid);
		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;
	}

	ret = lttng_poll_add(&events, quit_pipe_read_fd, LPOLLIN | LPOLLERR);
	if (ret < 0) {
		goto error;
	}

	/* Add the application registration socket */
	ret = lttng_poll_add(&events, sock, LPOLLIN | LPOLLPRI);
	if (ret < 0) {
		goto error;
	}

	mark_thread_as_ready(notifiers);
	while (1) {
		DBG("Health check ready");

		/* Infinite 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);

			/* 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;
				}
			} else {
				/* Event on the thread's quit pipe. */
				err = 0;
				goto exit;
			}
		}

		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 = lttcomm_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);
	rcu_unregister_thread();
	return NULL;
}
Example #4
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;
}