[lttng-tools.git] / src / bin / lttng-sessiond / manage-consumer.c

/*
 * Copyright (C) 2011 EfficiOS Inc.
 * Copyright (C) 2011 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
 * Copyright (C) 2013 Jérémie Galarneau <jeremie.galarneau@efficios.com>
 *
 * SPDX-License-Identifier: GPL-2.0-only
 *
 */

#include <signal.h>

#include <common/pipe.h>
#include <common/utils.h>

#include "manage-consumer.h"
#include "testpoint.h"
#include "health-sessiond.h"
#include "utils.h"
#include "thread.h"
#include "ust-consumer.h"

struct thread_notifiers {
	struct lttng_pipe *quit_pipe;
	struct consumer_data *consumer_data;
	sem_t ready;
	int initialization_result;
};

static void mark_thread_as_ready(struct thread_notifiers *notifiers)
{
	DBG("Marking consumer management thread as ready");
	notifiers->initialization_result = 0;
	sem_post(&notifiers->ready);
}

static void mark_thread_intialization_as_failed(
		struct thread_notifiers *notifiers)
{
	ERR("Consumer management thread entering error state");
	notifiers->initialization_result = -1;
	sem_post(&notifiers->ready);
}

static void wait_until_thread_is_ready(struct thread_notifiers *notifiers)
{
	DBG("Waiting for consumer management thread to be ready");
	sem_wait(&notifiers->ready);
	DBG("Consumer management thread is ready");
}

/*
 * This thread manage the consumer error sent back to the session daemon.
 */
static void *thread_consumer_management(void *data)
{
	int sock = -1, i, ret, pollfd, err = -1, should_quit = 0;
	uint32_t revents, nb_fd;
	enum lttcomm_return_code code;
	struct lttng_poll_event events;
	struct thread_notifiers *notifiers = data;
	struct consumer_data *consumer_data = notifiers->consumer_data;
	const int quit_pipe_read_fd = lttng_pipe_get_readfd(notifiers->quit_pipe);
	struct consumer_socket *cmd_socket_wrapper = NULL;

	DBG("[thread] Manage consumer started");

	rcu_register_thread();
	rcu_thread_online();

	health_register(the_health_sessiond, HEALTH_SESSIOND_TYPE_CONSUMER);

	health_code_update();

	/*
	 * Pass 3 as size here for the thread quit pipe, consumerd_err_sock and the
	 * metadata_sock. Nothing more will be added to this poll set.
	 */
	ret = lttng_poll_create(&events, 3, LTTNG_CLOEXEC);
	if (ret < 0) {
		mark_thread_intialization_as_failed(notifiers);
		goto error_poll;
	}

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

	/*
	 * The error socket here is already in a listening state which was done
	 * just before spawning this thread to avoid a race between the consumer
	 * daemon exec trying to connect and the listen() call.
	 */
	ret = lttng_poll_add(&events, consumer_data->err_sock, LPOLLIN | LPOLLRDHUP);
	if (ret < 0) {
		mark_thread_intialization_as_failed(notifiers);
		goto error;
	}

	health_code_update();

	/* Infinite blocking call, waiting for transmission */
	health_poll_entry();

	if (testpoint(sessiond_thread_manage_consumer)) {
		mark_thread_intialization_as_failed(notifiers);
		goto error;
	}

	ret = lttng_poll_wait(&events, -1);
	health_poll_exit();
	if (ret < 0) {
		mark_thread_intialization_as_failed(notifiers);
		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);

		health_code_update();

		/* Thread quit pipe has been closed. Killing thread. */
		if (pollfd == quit_pipe_read_fd) {
			err = 0;
			mark_thread_intialization_as_failed(notifiers);
			goto exit;
		} else if (pollfd == consumer_data->err_sock) {
			/* Event on the registration socket */
			if (revents & LPOLLIN) {
				continue;
			} else if (revents & (LPOLLERR | LPOLLHUP | LPOLLRDHUP)) {
				ERR("consumer err socket poll error");
				mark_thread_intialization_as_failed(notifiers);
				goto error;
			} else {
				ERR("Unexpected poll events %u for sock %d", revents, pollfd);
				mark_thread_intialization_as_failed(notifiers);
				goto error;
			}
		}
	}

	sock = lttcomm_accept_unix_sock(consumer_data->err_sock);
	if (sock < 0) {
		mark_thread_intialization_as_failed(notifiers);
		goto error;
	}

	/*
	 * Set the CLOEXEC flag. Return code is useless because either way, the
	 * show must go on.
	 */
	(void) utils_set_fd_cloexec(sock);

	health_code_update();

	DBG2("Receiving code from consumer err_sock");

	/* Getting status code from kconsumerd */
	ret = lttcomm_recv_unix_sock(sock, &code,
			sizeof(enum lttcomm_return_code));
	if (ret <= 0) {
		mark_thread_intialization_as_failed(notifiers);
		goto error;
	}

	health_code_update();
	if (code != LTTCOMM_CONSUMERD_COMMAND_SOCK_READY) {
		ERR("consumer error when waiting for SOCK_READY : %s",
				lttcomm_get_readable_code(-code));
		mark_thread_intialization_as_failed(notifiers);
		goto error;
	}

	/* Connect both command and metadata sockets. */
	consumer_data->cmd_sock =
			lttcomm_connect_unix_sock(
				consumer_data->cmd_unix_sock_path);
	consumer_data->metadata_fd =
			lttcomm_connect_unix_sock(
				consumer_data->cmd_unix_sock_path);
	if (consumer_data->cmd_sock < 0 || consumer_data->metadata_fd < 0) {
		PERROR("consumer connect cmd socket");
		mark_thread_intialization_as_failed(notifiers);
		goto error;
	}

	consumer_data->metadata_sock.fd_ptr = &consumer_data->metadata_fd;

	/* Create metadata socket lock. */
	consumer_data->metadata_sock.lock = zmalloc(sizeof(pthread_mutex_t));
	if (consumer_data->metadata_sock.lock == NULL) {
		PERROR("zmalloc pthread mutex");
		mark_thread_intialization_as_failed(notifiers);
		goto error;
	}
	pthread_mutex_init(consumer_data->metadata_sock.lock, NULL);

	DBG("Consumer command socket ready (fd: %d)", consumer_data->cmd_sock);
	DBG("Consumer metadata socket ready (fd: %d)",
			consumer_data->metadata_fd);

	/*
	 * Remove the consumerd error sock since we've established a connection.
	 */
	ret = lttng_poll_del(&events, consumer_data->err_sock);
	if (ret < 0) {
		mark_thread_intialization_as_failed(notifiers);
		goto error;
	}

	/* Add new accepted error socket. */
	ret = lttng_poll_add(&events, sock, LPOLLIN | LPOLLRDHUP);
	if (ret < 0) {
		mark_thread_intialization_as_failed(notifiers);
		goto error;
	}

	/* Add metadata socket that is successfully connected. */
	ret = lttng_poll_add(&events, consumer_data->metadata_fd,
			LPOLLIN | LPOLLRDHUP);
	if (ret < 0) {
		mark_thread_intialization_as_failed(notifiers);
		goto error;
	}

	health_code_update();

	/*
	 * Transfer the write-end of the channel monitoring pipe to the consumer
	 * by issuing a SET_CHANNEL_MONITOR_PIPE command.
	 */
	cmd_socket_wrapper = consumer_allocate_socket(&consumer_data->cmd_sock);
	if (!cmd_socket_wrapper) {
		mark_thread_intialization_as_failed(notifiers);
		goto error;
	}
	cmd_socket_wrapper->lock = &consumer_data->lock;

	pthread_mutex_lock(cmd_socket_wrapper->lock);
	ret = consumer_init(cmd_socket_wrapper, the_sessiond_uuid);
	if (ret) {
		ERR("Failed to send sessiond uuid to consumer daemon");
		mark_thread_intialization_as_failed(notifiers);
		pthread_mutex_unlock(cmd_socket_wrapper->lock);
		goto error;
	}
	pthread_mutex_unlock(cmd_socket_wrapper->lock);

	ret = consumer_send_channel_monitor_pipe(cmd_socket_wrapper,
			consumer_data->channel_monitor_pipe);
	if (ret) {
		mark_thread_intialization_as_failed(notifiers);
		goto error;
	}

	/* Discard the socket wrapper as it is no longer needed. */
	consumer_destroy_socket(cmd_socket_wrapper);
	cmd_socket_wrapper = NULL;

	/* The thread is completely initialized, signal that it is ready. */
	mark_thread_as_ready(notifiers);

	/* Infinite blocking call, waiting for transmission */
	while (1) {
		health_code_update();

		/* Exit the thread because the thread quit pipe has been triggered. */
		if (should_quit) {
			/* Not a health error. */
			err = 0;
			goto exit;
		}

		health_poll_entry();
		ret = lttng_poll_wait(&events, -1);
		health_poll_exit();
		if (ret < 0) {
			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);

			health_code_update();

			/*
			 * Thread quit pipe has been triggered, flag that we should stop
			 * but continue the current loop to handle potential data from
			 * consumer.
			 */
			if (pollfd == quit_pipe_read_fd) {
				should_quit = 1;
			} else if (pollfd == sock) {
				/* Event on the consumerd socket */
				if (revents & (LPOLLERR | LPOLLHUP | LPOLLRDHUP)
						&& !(revents & LPOLLIN)) {
					ERR("consumer err socket second poll error");
					goto error;
				}
				health_code_update();
				/* Wait for any kconsumerd error */
				ret = lttcomm_recv_unix_sock(sock, &code,
						sizeof(enum lttcomm_return_code));
				if (ret <= 0) {
					ERR("consumer closed the command socket");
					goto error;
				}

				ERR("consumer return code : %s",
						lttcomm_get_readable_code(-code));

				goto exit;
			} else if (pollfd == consumer_data->metadata_fd) {
				if (revents & (LPOLLERR | LPOLLHUP | LPOLLRDHUP)
						&& !(revents & LPOLLIN)) {
					ERR("consumer err metadata socket second poll error");
					goto error;
				}
				/* UST metadata requests */
				ret = ust_consumer_metadata_request(
						&consumer_data->metadata_sock);
				if (ret < 0) {
					ERR("Handling metadata request");
					goto error;
				}
			}
			/* No need for an else branch all FDs are tested prior. */
		}
		health_code_update();
	}

exit:
error:
	/*
	 * We lock here because we are about to close the sockets and some other
	 * thread might be using them so get exclusive access which will abort all
	 * other consumer command by other threads.
	 */
	pthread_mutex_lock(&consumer_data->lock);

	/* Immediately set the consumerd state to stopped */
	if (consumer_data->type == LTTNG_CONSUMER_KERNEL) {
		uatomic_set(&the_kernel_consumerd_state, CONSUMER_ERROR);
	} else if (consumer_data->type == LTTNG_CONSUMER64_UST ||
			consumer_data->type == LTTNG_CONSUMER32_UST) {
		uatomic_set(&the_ust_consumerd_state, CONSUMER_ERROR);
	} else {
		/* Code flow error... */
		assert(0);
	}

	if (consumer_data->err_sock >= 0) {
		ret = close(consumer_data->err_sock);
		if (ret) {
			PERROR("close");
		}
		consumer_data->err_sock = -1;
	}
	if (consumer_data->cmd_sock >= 0) {
		ret = close(consumer_data->cmd_sock);
		if (ret) {
			PERROR("close");
		}
		consumer_data->cmd_sock = -1;
	}
	if (consumer_data->metadata_sock.fd_ptr &&
	    *consumer_data->metadata_sock.fd_ptr >= 0) {
		ret = close(*consumer_data->metadata_sock.fd_ptr);
		if (ret) {
			PERROR("close");
		}
	}
	if (sock >= 0) {
		ret = close(sock);
		if (ret) {
			PERROR("close");
		}
	}

	unlink(consumer_data->err_unix_sock_path);
	unlink(consumer_data->cmd_unix_sock_path);
	pthread_mutex_unlock(&consumer_data->lock);

	/* Cleanup metadata socket mutex. */
	if (consumer_data->metadata_sock.lock) {
		pthread_mutex_destroy(consumer_data->metadata_sock.lock);
		free(consumer_data->metadata_sock.lock);
	}
	lttng_poll_clean(&events);

	if (cmd_socket_wrapper) {
		consumer_destroy_socket(cmd_socket_wrapper);
	}
error_poll:
	if (err) {
		health_error();
		ERR("Health error occurred in %s", __func__);
	}
	health_unregister(the_health_sessiond);
	DBG("consumer thread cleanup completed");

	rcu_thread_offline();
	rcu_unregister_thread();

	return NULL;
}

static bool shutdown_consumer_management_thread(void *data)
{
	struct thread_notifiers *notifiers = data;
	const int write_fd = lttng_pipe_get_writefd(notifiers->quit_pipe);

	return notify_thread_pipe(write_fd) == 1;
}

static void cleanup_consumer_management_thread(void *data)
{
	struct thread_notifiers *notifiers = data;

	lttng_pipe_destroy(notifiers->quit_pipe);
	free(notifiers);
}

bool launch_consumer_management_thread(struct consumer_data *consumer_data)
{
	struct lttng_pipe *quit_pipe;
	struct thread_notifiers *notifiers = NULL;
	struct lttng_thread *thread;

	notifiers = zmalloc(sizeof(*notifiers));
	if (!notifiers) {
		goto error_alloc;
	}

	quit_pipe = lttng_pipe_open(FD_CLOEXEC);
	if (!quit_pipe) {
		goto error;
	}
	notifiers->quit_pipe = quit_pipe;
	notifiers->consumer_data = consumer_data;
	sem_init(&notifiers->ready, 0, 0);

	thread = lttng_thread_create("Consumer management",
			thread_consumer_management,
			shutdown_consumer_management_thread,
			cleanup_consumer_management_thread,
			notifiers);
	if (!thread) {
		goto error;
	}
	wait_until_thread_is_ready(notifiers);
	lttng_thread_put(thread);
	if (notifiers->initialization_result) {
		return false;
	}
	return true;
error:
	cleanup_consumer_management_thread(notifiers);
error_alloc:
	return false;
}
Commit	Line	Data
4ec029ed	1	/*
90c106c6	2	* Copyright (C) 2011 EfficiOS Inc.
ab5be9fa MJ	3	* Copyright (C) 2011 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
ab5be9fa MJ	4	* Copyright (C) 2013 Jérémie Galarneau <jeremie.galarneau@efficios.com>
4ec029ed	5	*
ab5be9fa	6	* SPDX-License-Identifier: GPL-2.0-only
4ec029ed	7	*
4ec029ed JG	8	*/
	9
	10	#include <signal.h>
	11
	12	#include <common/pipe.h>
	13	#include <common/utils.h>
	14
	15	#include "manage-consumer.h"
	16	#include "testpoint.h"
	17	#include "health-sessiond.h"
	18	#include "utils.h"
	19	#include "thread.h"
	20	#include "ust-consumer.h"
	21
	22	struct thread_notifiers {
	23	struct lttng_pipe *quit_pipe;
	24	struct consumer_data *consumer_data;
52c50f8f	25	sem_t ready;
4ec029ed JG	26	int initialization_result;
	27	};
	28
	29	static void mark_thread_as_ready(struct thread_notifiers *notifiers)
	30	{
	31	DBG("Marking consumer management thread as ready");
	32	notifiers->initialization_result = 0;
	33	sem_post(&notifiers->ready);
	34	}
	35
	36	static void mark_thread_intialization_as_failed(
	37	struct thread_notifiers *notifiers)
	38	{
52c50f8f	39	ERR("Consumer management thread entering error state");
4ec029ed JG	40	notifiers->initialization_result = -1;
	41	sem_post(&notifiers->ready);
	42	}
	43
	44	static void wait_until_thread_is_ready(struct thread_notifiers *notifiers)
	45	{
	46	DBG("Waiting for consumer management thread to be ready");
	47	sem_wait(&notifiers->ready);
	48	DBG("Consumer management thread is ready");
	49	}
	50
	51	/*
	52	* This thread manage the consumer error sent back to the session daemon.
	53	*/
0e0b3d3a	54	static void thread_consumer_management(void data)
4ec029ed JG	55	{
	56	int sock = -1, i, ret, pollfd, err = -1, should_quit = 0;
	57	uint32_t revents, nb_fd;
	58	enum lttcomm_return_code code;
	59	struct lttng_poll_event events;
	60	struct thread_notifiers *notifiers = data;
	61	struct consumer_data *consumer_data = notifiers->consumer_data;
	62	const int quit_pipe_read_fd = lttng_pipe_get_readfd(notifiers->quit_pipe);
	63	struct consumer_socket *cmd_socket_wrapper = NULL;
	64
	65	DBG("[thread] Manage consumer started");
	66
	67	rcu_register_thread();
	68	rcu_thread_online();
	69
412d7227	70	health_register(the_health_sessiond, HEALTH_SESSIOND_TYPE_CONSUMER);
4ec029ed JG	71
	72	health_code_update();
	73
	74	/*
	75	* Pass 3 as size here for the thread quit pipe, consumerd_err_sock and the
	76	* metadata_sock. Nothing more will be added to this poll set.
	77	*/
	78	ret = lttng_poll_create(&events, 3, LTTNG_CLOEXEC);
	79	if (ret < 0) {
	80	mark_thread_intialization_as_failed(notifiers);
	81	goto error_poll;
	82	}
	83
	84	ret = lttng_poll_add(&events, quit_pipe_read_fd, LPOLLIN \| LPOLLERR);
	85	if (ret < 0) {
	86	mark_thread_intialization_as_failed(notifiers);
	87	goto error;
	88	}
	89
	90	/*
	91	* The error socket here is already in a listening state which was done
	92	* just before spawning this thread to avoid a race between the consumer
	93	* daemon exec trying to connect and the listen() call.
	94	*/
	95	ret = lttng_poll_add(&events, consumer_data->err_sock, LPOLLIN \| LPOLLRDHUP);
	96	if (ret < 0) {
	97	mark_thread_intialization_as_failed(notifiers);
	98	goto error;
	99	}
	100
	101	health_code_update();
	102
	103	/* Infinite blocking call, waiting for transmission */
	104	health_poll_entry();
	105
	106	if (testpoint(sessiond_thread_manage_consumer)) {
	107	mark_thread_intialization_as_failed(notifiers);
	108	goto error;
	109	}
	110
	111	ret = lttng_poll_wait(&events, -1);
	112	health_poll_exit();
	113	if (ret < 0) {
	114	mark_thread_intialization_as_failed(notifiers);
	115	goto error;
	116	}
	117
	118	nb_fd = ret;
	119
	120	for (i = 0; i < nb_fd; i++) {
	121	/* Fetch once the poll data */
	122	revents = LTTNG_POLL_GETEV(&events, i);
	123	pollfd = LTTNG_POLL_GETFD(&events, i);
	124
	125	health_code_update();
	126
4ec029ed JG	127	/* Thread quit pipe has been closed. Killing thread. */
	128	if (pollfd == quit_pipe_read_fd) {
	129	err = 0;
	130	mark_thread_intialization_as_failed(notifiers);
	131	goto exit;
	132	} else if (pollfd == consumer_data->err_sock) {
	133	/* Event on the registration socket */
	134	if (revents & LPOLLIN) {
	135	continue;
	136	} else if (revents & (LPOLLERR \| LPOLLHUP \| LPOLLRDHUP)) {
	137	ERR("consumer err socket poll error");
	138	mark_thread_intialization_as_failed(notifiers);
	139	goto error;
	140	} else {
	141	ERR("Unexpected poll events %u for sock %d", revents, pollfd);
	142	mark_thread_intialization_as_failed(notifiers);
	143	goto error;
	144	}
	145	}
	146	}
	147
	148	sock = lttcomm_accept_unix_sock(consumer_data->err_sock);
	149	if (sock < 0) {
	150	mark_thread_intialization_as_failed(notifiers);
	151	goto error;
	152	}
	153
	154	/*
	155	* Set the CLOEXEC flag. Return code is useless because either way, the
	156	* show must go on.
	157	*/
	158	(void) utils_set_fd_cloexec(sock);
	159
	160	health_code_update();
	161
	162	DBG2("Receiving code from consumer err_sock");
	163
	164	/* Getting status code from kconsumerd */
	165	ret = lttcomm_recv_unix_sock(sock, &code,
	166	sizeof(enum lttcomm_return_code));
	167	if (ret <= 0) {
	168	mark_thread_intialization_as_failed(notifiers);
	169	goto error;
	170	}
	171
	172	health_code_update();
	173	if (code != LTTCOMM_CONSUMERD_COMMAND_SOCK_READY) {
	174	ERR("consumer error when waiting for SOCK_READY : %s",
	175	lttcomm_get_readable_code(-code));
	176	mark_thread_intialization_as_failed(notifiers);
	177	goto error;
	178	}
	179
	180	/* Connect both command and metadata sockets. */
	181	consumer_data->cmd_sock =
	182	lttcomm_connect_unix_sock(
	183	consumer_data->cmd_unix_sock_path);
	184	consumer_data->metadata_fd =
	185	lttcomm_connect_unix_sock(
	186	consumer_data->cmd_unix_sock_path);
	187	if (consumer_data->cmd_sock < 0 \|\| consumer_data->metadata_fd < 0) {
	188	PERROR("consumer connect cmd socket");
	189	mark_thread_intialization_as_failed(notifiers);
	190	goto error;
191	}
192
193	consumer_data->metadata_sock.fd_ptr = &consumer_data->metadata_fd;
194
195	/* Create metadata socket lock. */
196	consumer_data->metadata_sock.lock = zmalloc(sizeof(pthread_mutex_t));
197	if (consumer_data->metadata_sock.lock == NULL) {
198	PERROR("zmalloc pthread mutex");
199	mark_thread_intialization_as_failed(notifiers);
200	goto error;
201	}
202	pthread_mutex_init(consumer_data->metadata_sock.lock, NULL);
203
204	DBG("Consumer command socket ready (fd: %d)", consumer_data->cmd_sock);
205	DBG("Consumer metadata socket ready (fd: %d)",
206	consumer_data->metadata_fd);
207
208	/*
209	* Remove the consumerd error sock since we've established a connection.
210	*/
211	ret = lttng_poll_del(&events, consumer_data->err_sock);
212	if (ret < 0) {
213	mark_thread_intialization_as_failed(notifiers);
214	goto error;
215	}
216
217	/* Add new accepted error socket. */
218	ret = lttng_poll_add(&events, sock, LPOLLIN \| LPOLLRDHUP);
219	if (ret < 0) {
220	mark_thread_intialization_as_failed(notifiers);
221	goto error;
222	}
223
224	/* Add metadata socket that is successfully connected. */
225	ret = lttng_poll_add(&events, consumer_data->metadata_fd,
226	LPOLLIN \| LPOLLRDHUP);
227	if (ret < 0) {
228	mark_thread_intialization_as_failed(notifiers);
229	goto error;
230	}
231
232	health_code_update();
233
234	/*
09ede842 JG	235	* Transfer the write-end of the channel monitoring pipe to the consumer
09ede842 JG	236	* by issuing a SET_CHANNEL_MONITOR_PIPE command.
4ec029ed JG	237	*/
	238	cmd_socket_wrapper = consumer_allocate_socket(&consumer_data->cmd_sock);
	239	if (!cmd_socket_wrapper) {
	240	mark_thread_intialization_as_failed(notifiers);
	241	goto error;
	242	}
	243	cmd_socket_wrapper->lock = &consumer_data->lock;
	244
09ede842	245	pthread_mutex_lock(cmd_socket_wrapper->lock);
412d7227	246	ret = consumer_init(cmd_socket_wrapper, the_sessiond_uuid);
09ede842 JG	247	if (ret) {
	248	ERR("Failed to send sessiond uuid to consumer daemon");
	249	mark_thread_intialization_as_failed(notifiers);
	250	pthread_mutex_unlock(cmd_socket_wrapper->lock);
	251	goto error;
	252	}
	253	pthread_mutex_unlock(cmd_socket_wrapper->lock);
	254
4ec029ed JG	255	ret = consumer_send_channel_monitor_pipe(cmd_socket_wrapper,
	256	consumer_data->channel_monitor_pipe);
	257	if (ret) {
	258	mark_thread_intialization_as_failed(notifiers);
	259	goto error;
	260	}
	261
	262	/* Discard the socket wrapper as it is no longer needed. */
	263	consumer_destroy_socket(cmd_socket_wrapper);
	264	cmd_socket_wrapper = NULL;
	265
	266	/* The thread is completely initialized, signal that it is ready. */
	267	mark_thread_as_ready(notifiers);
	268
	269	/* Infinite blocking call, waiting for transmission */
	270	while (1) {
	271	health_code_update();
	272
	273	/* Exit the thread because the thread quit pipe has been triggered. */
	274	if (should_quit) {
	275	/* Not a health error. */
	276	err = 0;
	277	goto exit;
	278	}
	279
	280	health_poll_entry();
	281	ret = lttng_poll_wait(&events, -1);
	282	health_poll_exit();
	283	if (ret < 0) {
	284	goto error;
	285	}
	286
	287	nb_fd = ret;
	288
	289	for (i = 0; i < nb_fd; i++) {
	290	/* Fetch once the poll data */
	291	revents = LTTNG_POLL_GETEV(&events, i);
	292	pollfd = LTTNG_POLL_GETFD(&events, i);
	293
	294	health_code_update();
	295
4ec029ed JG	296	/*
	297	* Thread quit pipe has been triggered, flag that we should stop
	298	* but continue the current loop to handle potential data from
	299	* consumer.
	300	*/
	301	if (pollfd == quit_pipe_read_fd) {
	302	should_quit = 1;
	303	} else if (pollfd == sock) {
	304	/* Event on the consumerd socket */
	305	if (revents & (LPOLLERR \| LPOLLHUP \| LPOLLRDHUP)
	306	&& !(revents & LPOLLIN)) {
	307	ERR("consumer err socket second poll error");
	308	goto error;
	309	}
	310	health_code_update();
	311	/* Wait for any kconsumerd error */
	312	ret = lttcomm_recv_unix_sock(sock, &code,
	313	sizeof(enum lttcomm_return_code));
	314	if (ret <= 0) {
	315	ERR("consumer closed the command socket");
	316	goto error;
	317	}
	318
	319	ERR("consumer return code : %s",
	320	lttcomm_get_readable_code(-code));
	321
	322	goto exit;
	323	} else if (pollfd == consumer_data->metadata_fd) {
	324	if (revents & (LPOLLERR \| LPOLLHUP \| LPOLLRDHUP)
	325	&& !(revents & LPOLLIN)) {
	326	ERR("consumer err metadata socket second poll error");
	327	goto error;
	328	}
	329	/* UST metadata requests */
	330	ret = ust_consumer_metadata_request(
	331	&consumer_data->metadata_sock);
	332	if (ret < 0) {
	333	ERR("Handling metadata request");
	334	goto error;
	335	}
	336	}
	337	/* No need for an else branch all FDs are tested prior. */
	338	}
	339	health_code_update();
	340	}
	341
	342	exit:
	343	error:
	344	/*
	345	* We lock here because we are about to close the sockets and some other
	346	* thread might be using them so get exclusive access which will abort all
	347	* other consumer command by other threads.
	348	*/
	349	pthread_mutex_lock(&consumer_data->lock);
	350
	351	/* Immediately set the consumerd state to stopped */
	352	if (consumer_data->type == LTTNG_CONSUMER_KERNEL) {
412d7227	353	uatomic_set(&the_kernel_consumerd_state, CONSUMER_ERROR);
4ec029ed JG	354	} else if (consumer_data->type == LTTNG_CONSUMER64_UST \|\|
4ec029ed JG	355	consumer_data->type == LTTNG_CONSUMER32_UST) {
412d7227	356	uatomic_set(&the_ust_consumerd_state, CONSUMER_ERROR);
4ec029ed JG	357	} else {
	358	/* Code flow error... */
	359	assert(0);
	360	}
	361
	362	if (consumer_data->err_sock >= 0) {
	363	ret = close(consumer_data->err_sock);
	364	if (ret) {
	365	PERROR("close");
	366	}
	367	consumer_data->err_sock = -1;
	368	}
	369	if (consumer_data->cmd_sock >= 0) {
	370	ret = close(consumer_data->cmd_sock);
	371	if (ret) {
	372	PERROR("close");
	373	}
	374	consumer_data->cmd_sock = -1;
	375	}
	376	if (consumer_data->metadata_sock.fd_ptr &&
	377	*consumer_data->metadata_sock.fd_ptr >= 0) {
	378	ret = close(*consumer_data->metadata_sock.fd_ptr);
	379	if (ret) {
	380	PERROR("close");
	381	}
	382	}
	383	if (sock >= 0) {
	384	ret = close(sock);
	385	if (ret) {
	386	PERROR("close");
	387	}
	388	}
	389
	390	unlink(consumer_data->err_unix_sock_path);
	391	unlink(consumer_data->cmd_unix_sock_path);
	392	pthread_mutex_unlock(&consumer_data->lock);
	393
	394	/* Cleanup metadata socket mutex. */
	395	if (consumer_data->metadata_sock.lock) {
	396	pthread_mutex_destroy(consumer_data->metadata_sock.lock);
	397	free(consumer_data->metadata_sock.lock);
	398	}
	399	lttng_poll_clean(&events);
	400
	401	if (cmd_socket_wrapper) {
	402	consumer_destroy_socket(cmd_socket_wrapper);
	403	}
	404	error_poll:
	405	if (err) {
	406	health_error();
	407	ERR("Health error occurred in %s", __func__);
	408	}
412d7227	409	health_unregister(the_health_sessiond);
4ec029ed JG	410	DBG("consumer thread cleanup completed");
	411
	412	rcu_thread_offline();
	413	rcu_unregister_thread();
	414
	415	return NULL;
	416	}
	417
	418	static bool shutdown_consumer_management_thread(void *data)
	419	{
	420	struct thread_notifiers *notifiers = data;
	421	const int write_fd = lttng_pipe_get_writefd(notifiers->quit_pipe);
	422
	423	return notify_thread_pipe(write_fd) == 1;
	424	}
	425
	426	static void cleanup_consumer_management_thread(void *data)
	427	{
	428	struct thread_notifiers *notifiers = data;
	429
	430	lttng_pipe_destroy(notifiers->quit_pipe);
	431	free(notifiers);
	432	}
	433
	434	bool launch_consumer_management_thread(struct consumer_data *consumer_data)
	435	{
	436	struct lttng_pipe *quit_pipe;
	437	struct thread_notifiers *notifiers = NULL;
	438	struct lttng_thread *thread;
	439
4ec029ed JG	440	notifiers = zmalloc(sizeof(*notifiers));
4ec029ed JG	441	if (!notifiers) {
21fa020e JG	442	goto error_alloc;
	443	}
	444
	445	quit_pipe = lttng_pipe_open(FD_CLOEXEC);
	446	if (!quit_pipe) {
4ec029ed JG	447	goto error;
	448	}
	449	notifiers->quit_pipe = quit_pipe;
	450	notifiers->consumer_data = consumer_data;
	451	sem_init(&notifiers->ready, 0, 0);
	452
	453	thread = lttng_thread_create("Consumer management",
	454	thread_consumer_management,
	455	shutdown_consumer_management_thread,
	456	cleanup_consumer_management_thread,
	457	notifiers);
	458	if (!thread) {
	459	goto error;
	460	}
	461	wait_until_thread_is_ready(notifiers);
	462	lttng_thread_put(thread);
	463	if (notifiers->initialization_result) {
bd3739b0	464	return false;
4ec029ed JG	465	}
	466	return true;
	467	error:
	468	cleanup_consumer_management_thread(notifiers);
21fa020e	469	error_alloc:
4ec029ed JG	470	return false;
4ec029ed JG	471	}