[lttng-tools.git] / src / lib / lttng-ctl / lttng-ctl-health.c

/*
 * lttng-ctl-health.c
 *
 * Linux Trace Toolkit Health Control Library
 *
 * Copyright (C) 2011 David Goulet <david.goulet@polymtl.ca>
 * Copyright (C) 2013 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
 *
 * SPDX-License-Identifier: LGPL-2.1-only
 *
 */

#define _LGPL_SOURCE
#include <unistd.h>
#include <sys/types.h>
#include <stdint.h>
#include <limits.h>
#include <string.h>
#include <lttng/health-internal.h>

#include <bin/lttng-sessiond/health-sessiond.h>
#include <bin/lttng-consumerd/health-consumerd.h>
#include <bin/lttng-relayd/health-relayd.h>
#include <common/defaults.h>
#include <common/utils.h>
#include <common/compat/errno.h>

#include "lttng-ctl-helper.h"

enum health_component {
	HEALTH_COMPONENT_SESSIOND,
	HEALTH_COMPONENT_CONSUMERD,
	HEALTH_COMPONENT_RELAYD,

	NR_HEALTH_COMPONENT,
};

struct lttng_health_thread {
	struct lttng_health *p;
	int state;
};

struct lttng_health {
	enum health_component component;
	uint64_t state;
	unsigned int nr_threads;
	char health_sock_path[PATH_MAX];
	/* For consumer health only */
	enum lttng_health_consumerd consumerd_type;
	struct lttng_health_thread thread[];
};

static
const char *sessiond_thread_name[NR_HEALTH_SESSIOND_TYPES] = {
	[ HEALTH_SESSIOND_TYPE_CMD ] = "Session daemon command",
	[ HEALTH_SESSIOND_TYPE_APP_MANAGE ] = "Session daemon application manager",
	[ HEALTH_SESSIOND_TYPE_APP_REG ] = "Session daemon application registration",
	[ HEALTH_SESSIOND_TYPE_KERNEL ] = "Session daemon kernel",
	[ HEALTH_SESSIOND_TYPE_CONSUMER ] = "Session daemon consumer manager",
	[ HEALTH_SESSIOND_TYPE_HT_CLEANUP ] = "Session daemon hash table cleanup",
	[ HEALTH_SESSIOND_TYPE_APP_MANAGE_NOTIFY ] = "Session daemon application notification manager",
	[ HEALTH_SESSIOND_TYPE_APP_REG_DISPATCH ] = "Session daemon application registration dispatcher",
	[ HEALTH_SESSIOND_TYPE_ROTATION ] = "Session daemon rotation manager",
	[ HEALTH_SESSIOND_TYPE_TIMER ] = "Session daemon timer manager",
	[ HEALTH_SESSIOND_TYPE_ACTION_EXECUTOR ] = "Session daemon trigger action executor",
};

static
const char *consumerd_thread_name[NR_HEALTH_CONSUMERD_TYPES] = {
	[ HEALTH_CONSUMERD_TYPE_CHANNEL ] = "Consumer daemon channel",
	[ HEALTH_CONSUMERD_TYPE_METADATA ] = "Consumer daemon metadata",
	[ HEALTH_CONSUMERD_TYPE_DATA ] = "Consumer daemon data",
	[ HEALTH_CONSUMERD_TYPE_SESSIOND ] = "Consumer daemon session daemon command manager",
	[ HEALTH_CONSUMERD_TYPE_METADATA_TIMER ] = "Consumer daemon metadata timer",
};

static
const char *relayd_thread_name[NR_HEALTH_RELAYD_TYPES] = {
	[ HEALTH_RELAYD_TYPE_DISPATCHER ] = "Relay daemon dispatcher",
	[ HEALTH_RELAYD_TYPE_WORKER ] = "Relay daemon worker",
	[ HEALTH_RELAYD_TYPE_LISTENER ] = "Relay daemon listener",
	[ HEALTH_RELAYD_TYPE_LIVE_DISPATCHER ] = "Relay daemon live dispatcher",
	[ HEALTH_RELAYD_TYPE_LIVE_WORKER ] = "Relay daemon live worker",
	[ HEALTH_RELAYD_TYPE_LIVE_LISTENER ] = "Relay daemon live listener",
};

static
const char **thread_name[NR_HEALTH_COMPONENT] = {
	[ HEALTH_COMPONENT_SESSIOND ] = sessiond_thread_name,
	[ HEALTH_COMPONENT_CONSUMERD] = consumerd_thread_name,
	[ HEALTH_COMPONENT_RELAYD ] = relayd_thread_name,
};

/*
 * Set health socket path.
 *
 * Returns 0 on success or a negative errno.
 */
static
int set_health_socket_path(struct lttng_health *lh,
		int tracing_group)
{
	uid_t uid;
	const char *home;
	int ret;
	/* Global and home format strings */
	const char *global_str, *home_str;

	switch (lh->component) {
	case HEALTH_COMPONENT_SESSIOND:
		global_str = DEFAULT_GLOBAL_HEALTH_UNIX_SOCK;
		home_str = DEFAULT_HOME_HEALTH_UNIX_SOCK;
		break;
	case HEALTH_COMPONENT_CONSUMERD:
		switch (lh->consumerd_type) {
		case LTTNG_HEALTH_CONSUMERD_UST_32:
			global_str = DEFAULT_GLOBAL_USTCONSUMER32_HEALTH_UNIX_SOCK;
			home_str = DEFAULT_HOME_USTCONSUMER32_HEALTH_UNIX_SOCK;
			break;
		case LTTNG_HEALTH_CONSUMERD_UST_64:
			global_str = DEFAULT_GLOBAL_USTCONSUMER64_HEALTH_UNIX_SOCK;
			home_str = DEFAULT_HOME_USTCONSUMER64_HEALTH_UNIX_SOCK;
			break;
		case LTTNG_HEALTH_CONSUMERD_KERNEL:
			global_str = DEFAULT_GLOBAL_KCONSUMER_HEALTH_UNIX_SOCK;
			home_str = DEFAULT_HOME_KCONSUMER_HEALTH_UNIX_SOCK;
			break;
		default:
			return -EINVAL;
		}
		break;
	case HEALTH_COMPONENT_RELAYD:
		if (lh->health_sock_path[0] == '\0') {
			return -EINVAL;
		} else {
			return 0;
		}
		break;	/* Unreached */
	default:
		return -EINVAL;
	}

	uid = getuid();

	if (uid == 0 || tracing_group) {
		ret = lttng_strncpy(lh->health_sock_path,
				global_str,
				sizeof(lh->health_sock_path));
		return ret == 0 ? 0 : -EINVAL;
	}

	/*
	 * With GNU C <  2.1, snprintf returns -1 if the target buffer
	 * is too small; With GNU C >= 2.1, snprintf returns the
	 * required size (excluding closing null).
	 */
	home = utils_get_home_dir();
	if (home == NULL) {
		/* Fallback in /tmp */
		home = "/tmp";
	}

	ret = snprintf(lh->health_sock_path, sizeof(lh->health_sock_path),
			home_str, home);
	if ((ret < 0) || (ret >= sizeof(lh->health_sock_path))) {
		return -ENOMEM;
	}

	return 0;
}

static
struct lttng_health *lttng_health_create(enum health_component hc,
		unsigned int nr_threads)
{
	struct lttng_health *lh;
	int i;

	lh = zmalloc(sizeof(*lh) + sizeof(lh->thread[0]) * nr_threads);
	if (!lh) {
		return NULL;
	}

	lh->component = hc;
	lh->state = UINT64_MAX;		/* All bits in error initially */
	lh->nr_threads = nr_threads;
	for (i = 0; i < nr_threads; i++) {
		lh->thread[i].p = lh;
	}
	return lh;
}

struct lttng_health *lttng_health_create_sessiond(void)
{
	struct lttng_health *lh;

	lh = lttng_health_create(HEALTH_COMPONENT_SESSIOND,
			NR_HEALTH_SESSIOND_TYPES);
	if (!lh) {
		return NULL;
	}
	return lh;
}

struct lttng_health *
	lttng_health_create_consumerd(enum lttng_health_consumerd consumerd)
{
	struct lttng_health *lh;

	lh = lttng_health_create(HEALTH_COMPONENT_CONSUMERD,
			NR_HEALTH_CONSUMERD_TYPES);
	if (!lh) {
		return NULL;
	}
	lh->consumerd_type = consumerd;
	return lh;
}

struct lttng_health *lttng_health_create_relayd(const char *path)
{
	int ret;
	struct lttng_health *lh = NULL;

	if (!path) {
		goto error;
	}

	lh = lttng_health_create(HEALTH_COMPONENT_RELAYD,
			NR_HEALTH_RELAYD_TYPES);
	if (!lh) {
		goto error;
	}

	ret = lttng_strncpy(lh->health_sock_path, path,
			sizeof(lh->health_sock_path));
	if (ret) {
		goto error;
	}

	return lh;

error:
	free(lh);
	return NULL;
}

void lttng_health_destroy(struct lttng_health *lh)
{
	free(lh);
}

int lttng_health_query(struct lttng_health *health)
{
	int sock, ret, i, tracing_group;
	struct health_comm_msg msg;
	struct health_comm_reply reply;

	if (!health) {
		return -EINVAL;
	}

	tracing_group = lttng_check_tracing_group();
retry:
	ret = set_health_socket_path(health, tracing_group);
	if (ret) {
		goto error;
	}
	/* Connect to component */
	sock = lttcomm_connect_unix_sock(health->health_sock_path);
	if (sock < 0) {
		if (tracing_group) {
			/* For tracing group, fallback to per-user */
			tracing_group = 0;
			goto retry;
		}
		ret = -1;
		goto error;
	}

	memset(&msg, 0, sizeof(msg));
	msg.cmd = HEALTH_CMD_CHECK;

	ret = lttcomm_send_unix_sock(sock, (void *)&msg, sizeof(msg));
	if (ret < 0) {
		ret = -1;
		goto close_error;
	}

	ret = lttcomm_recv_unix_sock(sock, (void *)&reply, sizeof(reply));
	if (ret < 0) {
		ret = -1;
		goto close_error;
	}

	health->state = reply.ret_code;
	for (i = 0; i < health->nr_threads; i++) {
		if (health->state & (1ULL << i)) {
			health->thread[i].state = -1;
		} else {
			health->thread[i].state = 0;
		}
	}

close_error:
	{
		int closeret;

		closeret = close(sock);
		assert(!closeret);
	}

error:
	if (ret >= 0)
		ret = 0;
	return ret;
}

int lttng_health_state(const struct lttng_health *health)
{
	if (!health) {
		return -EINVAL;
	}

	if (health->state == 0) {
		return 0;
	} else {
		return -1;
	}
}

int lttng_health_get_nr_threads(const struct lttng_health *health)
{
	if (!health) {
		return -EINVAL;
	}
	return health->nr_threads;
}

const struct lttng_health_thread *
	lttng_health_get_thread(const struct lttng_health *health,
		unsigned int nth_thread)
{
	if (!health || nth_thread >= health->nr_threads) {
		return NULL;
	}
	return &health->thread[nth_thread];
}

int lttng_health_thread_state(const struct lttng_health_thread *thread)
{
	if (!thread) {
		return -EINVAL;
	}
	return thread->state;
}

const char *lttng_health_thread_name(const struct lttng_health_thread *thread)
{
	unsigned int nr;

	if (!thread) {
		return NULL;
	}
	nr = thread - &thread->p->thread[0];
	return thread_name[thread->p->component][nr];
}
Commit	Line	Data
6c71277b MD	1	/*
	2	* lttng-ctl-health.c
	3	*
	4	* Linux Trace Toolkit Health Control Library
	5	*
	6	* Copyright (C) 2011 David Goulet <david.goulet@polymtl.ca>
	7	* Copyright (C) 2013 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
	8	*
ab5be9fa	9	* SPDX-License-Identifier: LGPL-2.1-only
6c71277b	10	*
6c71277b MD	11	*/
6c71277b MD	12
6c1c0768	13	#define _LGPL_SOURCE
6c71277b MD	14	#include <unistd.h>
	15	#include <sys/types.h>
	16	#include <stdint.h>
	17	#include <limits.h>
73d8fe3e	18	#include <string.h>
6c71277b MD	19	#include <lttng/health-internal.h>
	20
	21	#include <bin/lttng-sessiond/health-sessiond.h>
	22	#include <bin/lttng-consumerd/health-consumerd.h>
	23	#include <bin/lttng-relayd/health-relayd.h>
	24	#include <common/defaults.h>
	25	#include <common/utils.h>
edf4b93e	26	#include <common/compat/errno.h>
6c71277b MD	27
	28	#include "lttng-ctl-helper.h"
	29
	30	enum health_component {
	31	HEALTH_COMPONENT_SESSIOND,
	32	HEALTH_COMPONENT_CONSUMERD,
	33	HEALTH_COMPONENT_RELAYD,
	34
	35	NR_HEALTH_COMPONENT,
	36	};
	37
	38	struct lttng_health_thread {
	39	struct lttng_health *p;
	40	int state;
	41	};
	42
	43	struct lttng_health {
	44	enum health_component component;
	45	uint64_t state;
	46	unsigned int nr_threads;
	47	char health_sock_path[PATH_MAX];
	48	/* For consumer health only */
	49	enum lttng_health_consumerd consumerd_type;
	50	struct lttng_health_thread thread[];
	51	};
	52
	53	static
	54	const char *sessiond_thread_name[NR_HEALTH_SESSIOND_TYPES] = {
	55	[ HEALTH_SESSIOND_TYPE_CMD ] = "Session daemon command",
	56	[ HEALTH_SESSIOND_TYPE_APP_MANAGE ] = "Session daemon application manager",
	57	[ HEALTH_SESSIOND_TYPE_APP_REG ] = "Session daemon application registration",
	58	[ HEALTH_SESSIOND_TYPE_KERNEL ] = "Session daemon kernel",
	59	[ HEALTH_SESSIOND_TYPE_CONSUMER ] = "Session daemon consumer manager",
	60	[ HEALTH_SESSIOND_TYPE_HT_CLEANUP ] = "Session daemon hash table cleanup",
	61	[ HEALTH_SESSIOND_TYPE_APP_MANAGE_NOTIFY ] = "Session daemon application notification manager",
	62	[ HEALTH_SESSIOND_TYPE_APP_REG_DISPATCH ] = "Session daemon application registration dispatcher",
db66e574	63	[ HEALTH_SESSIOND_TYPE_ROTATION ] = "Session daemon rotation manager",
d086f507	64	[ HEALTH_SESSIOND_TYPE_TIMER ] = "Session daemon timer manager",
f2b3ef9f	65	[ HEALTH_SESSIOND_TYPE_ACTION_EXECUTOR ] = "Session daemon trigger action executor",
6c71277b MD	66	};
	67
	68	static
	69	const char *consumerd_thread_name[NR_HEALTH_CONSUMERD_TYPES] = {
	70	[ HEALTH_CONSUMERD_TYPE_CHANNEL ] = "Consumer daemon channel",
	71	[ HEALTH_CONSUMERD_TYPE_METADATA ] = "Consumer daemon metadata",
	72	[ HEALTH_CONSUMERD_TYPE_DATA ] = "Consumer daemon data",
	73	[ HEALTH_CONSUMERD_TYPE_SESSIOND ] = "Consumer daemon session daemon command manager",
	74	[ HEALTH_CONSUMERD_TYPE_METADATA_TIMER ] = "Consumer daemon metadata timer",
	75	};
	76
	77	static
	78	const char *relayd_thread_name[NR_HEALTH_RELAYD_TYPES] = {
	79	[ HEALTH_RELAYD_TYPE_DISPATCHER ] = "Relay daemon dispatcher",
	80	[ HEALTH_RELAYD_TYPE_WORKER ] = "Relay daemon worker",
	81	[ HEALTH_RELAYD_TYPE_LISTENER ] = "Relay daemon listener",
e7b0d526 MD	82	[ HEALTH_RELAYD_TYPE_LIVE_DISPATCHER ] = "Relay daemon live dispatcher",
	83	[ HEALTH_RELAYD_TYPE_LIVE_WORKER ] = "Relay daemon live worker",
	84	[ HEALTH_RELAYD_TYPE_LIVE_LISTENER ] = "Relay daemon live listener",
6c71277b MD	85	};
	86
	87	static
	88	const char **thread_name[NR_HEALTH_COMPONENT] = {
	89	[ HEALTH_COMPONENT_SESSIOND ] = sessiond_thread_name,
	90	[ HEALTH_COMPONENT_CONSUMERD] = consumerd_thread_name,
	91	[ HEALTH_COMPONENT_RELAYD ] = relayd_thread_name,
	92	};
	93
	94	/*
	95	* Set health socket path.
	96	*
e1b624d0	97	* Returns 0 on success or a negative errno.
6c71277b MD	98	*/
	99	static
	100	int set_health_socket_path(struct lttng_health *lh,
	101	int tracing_group)
	102	{
	103	uid_t uid;
	104	const char *home;
	105	int ret;
	106	/* Global and home format strings */
	107	const char global_str, home_str;
	108
	109	switch (lh->component) {
	110	case HEALTH_COMPONENT_SESSIOND:
	111	global_str = DEFAULT_GLOBAL_HEALTH_UNIX_SOCK;
	112	home_str = DEFAULT_HOME_HEALTH_UNIX_SOCK;
	113	break;
	114	case HEALTH_COMPONENT_CONSUMERD:
	115	switch (lh->consumerd_type) {
	116	case LTTNG_HEALTH_CONSUMERD_UST_32:
	117	global_str = DEFAULT_GLOBAL_USTCONSUMER32_HEALTH_UNIX_SOCK;
	118	home_str = DEFAULT_HOME_USTCONSUMER32_HEALTH_UNIX_SOCK;
	119	break;
	120	case LTTNG_HEALTH_CONSUMERD_UST_64:
	121	global_str = DEFAULT_GLOBAL_USTCONSUMER64_HEALTH_UNIX_SOCK;
	122	home_str = DEFAULT_HOME_USTCONSUMER64_HEALTH_UNIX_SOCK;
	123	break;
	124	case LTTNG_HEALTH_CONSUMERD_KERNEL:
	125	global_str = DEFAULT_GLOBAL_KCONSUMER_HEALTH_UNIX_SOCK;
	126	home_str = DEFAULT_HOME_KCONSUMER_HEALTH_UNIX_SOCK;
	127	break;
	128	default:
	129	return -EINVAL;
	130	}
	131	break;
	132	case HEALTH_COMPONENT_RELAYD:
	133	if (lh->health_sock_path[0] == '\0') {
	134	return -EINVAL;
	135	} else {
	136	return 0;
	137	}
	138	break; /* Unreached */
	139	default:
	140	return -EINVAL;
	141	}
	142
	143	uid = getuid();
	144
	145	if (uid == 0 \|\| tracing_group) {
e1b624d0	146	ret = lttng_strncpy(lh->health_sock_path,
6c71277b MD	147	global_str,
6c71277b MD	148	sizeof(lh->health_sock_path));
e1b624d0	149	return ret == 0 ? 0 : -EINVAL;
6c71277b MD	150	}
	151
	152	/*
	153	* With GNU C < 2.1, snprintf returns -1 if the target buffer
	154	* is too small; With GNU C >= 2.1, snprintf returns the
	155	* required size (excluding closing null).
	156	*/
	157	home = utils_get_home_dir();
	158	if (home == NULL) {
	159	/* Fallback in /tmp */
	160	home = "/tmp";
	161	}
	162
	163	ret = snprintf(lh->health_sock_path, sizeof(lh->health_sock_path),
	164	home_str, home);
	165	if ((ret < 0) \|\| (ret >= sizeof(lh->health_sock_path))) {
	166	return -ENOMEM;
	167	}
	168
	169	return 0;
	170	}
	171
	172	static
	173	struct lttng_health *lttng_health_create(enum health_component hc,
	174	unsigned int nr_threads)
	175	{
	176	struct lttng_health *lh;
	177	int i;
	178
	179	lh = zmalloc(sizeof(lh) + sizeof(lh->thread[0]) nr_threads);
	180	if (!lh) {
	181	return NULL;
	182	}
	183
	184	lh->component = hc;
	185	lh->state = UINT64_MAX; /* All bits in error initially */
	186	lh->nr_threads = nr_threads;
	187	for (i = 0; i < nr_threads; i++) {
	188	lh->thread[i].p = lh;
	189	}
	190	return lh;
	191	}
	192
	193	struct lttng_health *lttng_health_create_sessiond(void)
	194	{
	195	struct lttng_health *lh;
	196
	197	lh = lttng_health_create(HEALTH_COMPONENT_SESSIOND,
	198	NR_HEALTH_SESSIOND_TYPES);
	199	if (!lh) {
	200	return NULL;
	201	}
	202	return lh;
	203	}
	204
	205	struct lttng_health *
	206	lttng_health_create_consumerd(enum lttng_health_consumerd consumerd)
	207	{
	208	struct lttng_health *lh;
	209
	210	lh = lttng_health_create(HEALTH_COMPONENT_CONSUMERD,
	211	NR_HEALTH_CONSUMERD_TYPES);
	212	if (!lh) {
	213	return NULL;
214	}
215	lh->consumerd_type = consumerd;
216	return lh;
217	}
218
219	struct lttng_health lttng_health_create_relayd(const char path)
220	{
e1b624d0 JG	221	int ret;
e1b624d0 JG	222	struct lttng_health *lh = NULL;
6c71277b MD	223
6c71277b MD	224	if (!path) {
e1b624d0	225	goto error;
6c71277b MD	226	}
	227
	228	lh = lttng_health_create(HEALTH_COMPONENT_RELAYD,
	229	NR_HEALTH_RELAYD_TYPES);
	230	if (!lh) {
e1b624d0	231	goto error;
6c71277b	232	}
e1b624d0	233
336a72eb JG	234	ret = lttng_strncpy(lh->health_sock_path, path,
336a72eb JG	235	sizeof(lh->health_sock_path));
e1b624d0 JG	236	if (ret) {
	237	goto error;
	238	}
	239
6c71277b	240	return lh;
e1b624d0 JG	241
	242	error:
	243	free(lh);
	244	return NULL;
6c71277b MD	245	}
	246
	247	void lttng_health_destroy(struct lttng_health *lh)
	248	{
	249	free(lh);
	250	}
	251
	252	int lttng_health_query(struct lttng_health *health)
	253	{
	254	int sock, ret, i, tracing_group;
	255	struct health_comm_msg msg;
	256	struct health_comm_reply reply;
	257
	258	if (!health) {
	259	return -EINVAL;
	260	}
	261
	262	tracing_group = lttng_check_tracing_group();
	263	retry:
	264	ret = set_health_socket_path(health, tracing_group);
	265	if (ret) {
	266	goto error;
	267	}
71d01237	268	/* Connect to component */
6c71277b MD	269	sock = lttcomm_connect_unix_sock(health->health_sock_path);
	270	if (sock < 0) {
	271	if (tracing_group) {
	272	/* For tracing group, fallback to per-user */
	273	tracing_group = 0;
	274	goto retry;
	275	}
	276	ret = -1;
	277	goto error;
	278	}
	279
53efb85a	280	memset(&msg, 0, sizeof(msg));
6c71277b MD	281	msg.cmd = HEALTH_CMD_CHECK;
	282
	283	ret = lttcomm_send_unix_sock(sock, (void *)&msg, sizeof(msg));
	284	if (ret < 0) {
	285	ret = -1;
	286	goto close_error;
	287	}
	288
	289	ret = lttcomm_recv_unix_sock(sock, (void *)&reply, sizeof(reply));
	290	if (ret < 0) {
	291	ret = -1;
	292	goto close_error;
	293	}
	294
	295	health->state = reply.ret_code;
	296	for (i = 0; i < health->nr_threads; i++) {
	297	if (health->state & (1ULL << i)) {
	298	health->thread[i].state = -1;
	299	} else {
	300	health->thread[i].state = 0;
	301	}
	302	}
	303
	304	close_error:
	305	{
	306	int closeret;
	307
	308	closeret = close(sock);
	309	assert(!closeret);
	310	}
	311
	312	error:
	313	if (ret >= 0)
	314	ret = 0;
	315	return ret;
	316	}
	317
	318	int lttng_health_state(const struct lttng_health *health)
	319	{
	320	if (!health) {
	321	return -EINVAL;
	322	}
	323
	324	if (health->state == 0) {
	325	return 0;
	326	} else {
	327	return -1;
	328	}
	329	}
	330
	331	int lttng_health_get_nr_threads(const struct lttng_health *health)
	332	{
	333	if (!health) {
	334	return -EINVAL;
	335	}
	336	return health->nr_threads;
	337	}
	338
	339	const struct lttng_health_thread *
	340	lttng_health_get_thread(const struct lttng_health *health,
	341	unsigned int nth_thread)
	342	{
	343	if (!health \|\| nth_thread >= health->nr_threads) {
	344	return NULL;
345	}
346	return &health->thread[nth_thread];
347	}
348
349	int lttng_health_thread_state(const struct lttng_health_thread *thread)
350	{
351	if (!thread) {
352	return -EINVAL;
353	}
354	return thread->state;
355	}
356
357	const char lttng_health_thread_name(const struct lttng_health_thread thread)
358	{
359	unsigned int nr;
360
361	if (!thread) {
362	return NULL;
363	}
364	nr = thread - &thread->p->thread[0];
365	return thread_name[thread->p->component][nr];
366	}