[lttng-tools.git] / ltt-sessiond / trace-ust.c

/*
 * Copyright (C) 2011 - David Goulet <david.goulet@polymtl.ca>
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License as published by the Free
 * Software Foundation; only version 2 of the License.
 *
 * This program is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
 * more details.
 *
 * You should have received a copy of the GNU General Public License along with
 * this program; if not, write to the Free Software Foundation, Inc., 59 Temple
 * Place - Suite 330, Boston, MA  02111-1307, USA.
 */

#define _GNU_SOURCE
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>

#include <lttngerr.h>
#include <lttng-share.h>

#include "hashtable.h"
#include "trace-ust.h"

/*
 * Find the channel in the hashtable.
 */
struct ltt_ust_channel *trace_ust_find_channel_by_name(struct cds_lfht *ht,
		char *name)
{
	struct cds_lfht_node *node;
	struct cds_lfht_iter iter;

	rcu_read_lock();
	node = hashtable_lookup(ht, (void *) name, strlen(name), &iter);
	if (node == NULL) {
		rcu_read_unlock();
		goto error;
	}
	rcu_read_unlock();

	DBG2("Trace UST channel %s found by name", name);

	return caa_container_of(node, struct ltt_ust_channel, node);

error:
	DBG2("Trace UST channel %s not found by name", name);
	return NULL;
}

/*
 * Find the event in the hashtable.
 */
struct ltt_ust_event *trace_ust_find_event_by_name(struct cds_lfht *ht,
		char *name)
{
	struct cds_lfht_node *node;
	struct cds_lfht_iter iter;

	rcu_read_lock();
	node = hashtable_lookup(ht, (void *) name, strlen(name), &iter);
	if (node == NULL) {
		rcu_read_unlock();
		goto error;
	}
	rcu_read_unlock();

	DBG2("Found UST event by name %s", name);

	return caa_container_of(node, struct ltt_ust_event, node);

error:
	return NULL;
}

/*
 * Allocate and initialize a ust session data structure.
 *
 * Return pointer to structure or NULL.
 */
struct ltt_ust_session *trace_ust_create_session(char *path, pid_t pid,
		struct lttng_domain *domain)
{
	int ret;
	struct ltt_ust_session *lus;

	/* Allocate a new ltt ust session */
	lus = malloc(sizeof(struct ltt_ust_session));
	if (lus == NULL) {
		perror("create ust session malloc");
		goto error;
	}

	/* Init data structure */
	lus->handle = -1;
	lus->enabled = 1;
	lus->consumer_fds_sent = 0;
	lus->metadata = NULL;

	/* Alloc UST domain hash tables */
	lus->domain_pid = hashtable_new(0);
	lus->domain_exec = hashtable_new_str(0);

	/* Alloc UST global domain channels' HT */
	lus->domain_global.channels = hashtable_new_str(0);

	/* Set session path */
	ret = snprintf(lus->path, PATH_MAX, "%s/ust_%d", path, pid);
	if (ret < 0) {
		PERROR("snprintf kernel traces path");
		goto error;
	}

	DBG2("UST trace session create successful");

	return lus;

error:
	return NULL;
}

/*
 * Allocate and initialize a ust channel data structure.
 *
 * Return pointer to structure or NULL.
 */
struct ltt_ust_channel *trace_ust_create_channel(struct lttng_channel *chan,
		char *path)
{
	int ret;
	struct ltt_ust_channel *luc;

	luc = malloc(sizeof(struct ltt_ust_channel));
	if (luc == NULL) {
		perror("ltt_ust_channel malloc");
		goto error;
	}

	/* Copy UST channel attributes */
	memcpy(&luc->attr, &chan->attr, sizeof(struct lttng_ust_channel));

	/* Translate to UST output enum */
	switch (luc->attr.output) {
	default:
		luc->attr.output = LTTNG_UST_MMAP;
		break;
	}

	luc->handle = -1;
	luc->enabled = 1;

	/* Copy channel name */
	strncpy(luc->name, chan->name, sizeof(&luc->name));
	luc->name[LTTNG_UST_SYM_NAME_LEN - 1] = '\0';

	/* Init node */
	hashtable_node_init(&luc->node, (void *) luc->name, strlen(luc->name));
	/* Alloc hash tables */
	luc->events = hashtable_new_str(0);
	luc->ctx = hashtable_new_str(0);

	/* Set trace output path */
	ret = snprintf(luc->trace_path, PATH_MAX, "%s", path);
	if (ret < 0) {
		perror("asprintf ust create channel");
		goto error;
	}
	CDS_INIT_LIST_HEAD(&luc->stream_list.head);

	DBG2("Trace UST channel %s created", luc->name);

	return luc;

error:
	return NULL;
}

/*
 * Allocate and initialize a ust event. Set name and event type.
 *
 * Return pointer to structure or NULL.
 */
struct ltt_ust_event *trace_ust_create_event(struct lttng_event *ev)
{
	struct ltt_ust_event *lue;

	lue = malloc(sizeof(struct ltt_ust_event));
	if (lue == NULL) {
		PERROR("ust event malloc");
		goto error;
	}

	switch (ev->type) {
	case LTTNG_EVENT_PROBE:
		lue->attr.instrumentation = LTTNG_UST_PROBE;
		break;
	case LTTNG_EVENT_FUNCTION:
		lue->attr.instrumentation = LTTNG_UST_FUNCTION;
		break;
	case LTTNG_EVENT_FUNCTION_ENTRY:
		lue->attr.instrumentation = LTTNG_UST_FUNCTION;
		break;
	case LTTNG_EVENT_TRACEPOINT:
		lue->attr.instrumentation = LTTNG_UST_TRACEPOINT;
		break;
	default:
		ERR("Unknown ust instrumentation type (%d)", ev->type);
		goto error;
	}

	/* Copy event name */
	strncpy(lue->attr.name, ev->name, LTTNG_UST_SYM_NAME_LEN);
	lue->attr.name[LTTNG_UST_SYM_NAME_LEN - 1] = '\0';

	/* Setting up a ust event */
	lue->handle = -1;
	lue->enabled = 1;

	/* Init node */
	hashtable_node_init(&lue->node, (void *) lue->attr.name,
			strlen(lue->attr.name));
	/* Alloc context hash tables */
	lue->ctx = hashtable_new_str(5);

	return lue;

error:
	return NULL;
}

/*
 * Allocate and initialize a ust metadata.
 *
 * Return pointer to structure or NULL.
 */
struct ltt_ust_metadata *trace_ust_create_metadata(char *path)
{
	int ret;
	struct ltt_ust_metadata *lum;

	lum = malloc(sizeof(struct ltt_ust_metadata));
	if (lum == NULL) {
		perror("ust metadata malloc");
		goto error;
	}

	/* Set default attributes */
	lum->attr.overwrite = DEFAULT_CHANNEL_OVERWRITE;
	lum->attr.subbuf_size = DEFAULT_METADATA_SUBBUF_SIZE;
	lum->attr.num_subbuf = DEFAULT_METADATA_SUBBUF_NUM;
	lum->attr.switch_timer_interval = DEFAULT_CHANNEL_SWITCH_TIMER;
	lum->attr.read_timer_interval = DEFAULT_CHANNEL_READ_TIMER;
	lum->attr.output = DEFAULT_UST_CHANNEL_OUTPUT;

	lum->handle = -1;
	/* Set metadata trace path */
	ret = snprintf(lum->pathname, PATH_MAX, "%s/metadata", path);
	if (ret < 0) {
		perror("asprintf ust metadata");
		goto error;
	}

	return lum;

error:
	return NULL;
}

/*
 * RCU safe free context structure.
 */
static void destroy_context_rcu(struct rcu_head *head)
{
	struct cds_lfht_node *node =
		caa_container_of(head, struct cds_lfht_node, head);
	struct ltt_ust_context *ctx =
		caa_container_of(node, struct ltt_ust_context, node);

	free(ctx);
}

/*
 * Cleanup UST context hash table.
 */
static void destroy_context(struct cds_lfht *ht)
{
	int ret;
	struct cds_lfht_node *node;
	struct cds_lfht_iter iter;

	hashtable_get_first(ht, &iter);
	while ((node = hashtable_iter_get_node(&iter)) != NULL) {
		ret = hashtable_del(ht, &iter);
		if (!ret) {
			call_rcu(&node->head, destroy_context_rcu);
		}
		hashtable_get_next(ht, &iter);
	}
}

/*
 * Cleanup ust event structure.
 */
void trace_ust_destroy_event(struct ltt_ust_event *event)
{
	DBG2("Trace destroy UST event %s", event->attr.name);
	destroy_context(event->ctx);
	free(event);
}

/*
 * URCU intermediate call to complete destroy event.
 */
static void destroy_event_rcu(struct rcu_head *head)
{
	struct cds_lfht_node *node =
		caa_container_of(head, struct cds_lfht_node, head);
	struct ltt_ust_event *event =
		caa_container_of(node, struct ltt_ust_event, node);

	trace_ust_destroy_event(event);
}

/*
 * Cleanup ust channel structure.
 */
void trace_ust_destroy_channel(struct ltt_ust_channel *channel)
{
	int ret;
	struct cds_lfht_node *node;
	struct cds_lfht_iter iter;

	DBG2("Trace destroy UST channel %s", channel->name);

	rcu_read_lock();

	hashtable_get_first(channel->events, &iter);
	while ((node = hashtable_iter_get_node(&iter)) != NULL) {
		ret = hashtable_del(channel->events, &iter);
		if (!ret) {
			call_rcu(&node->head, destroy_event_rcu);
		}
		hashtable_get_next(channel->events, &iter);
	}

	free(channel->events);
	destroy_context(channel->ctx);
	free(channel);

	rcu_read_unlock();
}

/*
 * URCU intermediate call to complete destroy channel.
 */
static void destroy_channel_rcu(struct rcu_head *head)
{
	struct cds_lfht_node *node =
		caa_container_of(head, struct cds_lfht_node, head);
	struct ltt_ust_channel *channel =
		caa_container_of(node, struct ltt_ust_channel, node);

	trace_ust_destroy_channel(channel);
}

/*
 * Cleanup ust metadata structure.
 */
void trace_ust_destroy_metadata(struct ltt_ust_metadata *metadata)
{
	DBG2("Trace UST destroy metadata %d", metadata->handle);

	free(metadata);
}

/*
 * Iterate over a hash table containing channels and cleanup safely.
 */
static void destroy_channels(struct cds_lfht *channels)
{
	int ret;
	struct cds_lfht_node *node;
	struct cds_lfht_iter iter;

	hashtable_get_first(channels, &iter);
	while ((node = hashtable_iter_get_node(&iter)) != NULL) {
		ret = hashtable_del(channels, &iter);
		if (!ret) {
			call_rcu(&node->head, destroy_channel_rcu);
		}
		hashtable_get_next(channels, &iter);
	}
}

/*
 * Cleanup UST pid domain.
 */
static void destroy_domain_pid(struct cds_lfht *ht)
{
	int ret;
	struct cds_lfht_node *node;
	struct cds_lfht_iter iter;
	struct ltt_ust_domain_pid *d;

	hashtable_get_first(ht, &iter);
	while ((node = hashtable_iter_get_node(&iter)) != NULL) {
		ret = hashtable_del(ht , &iter);
		if (!ret) {
			d = caa_container_of(node, struct ltt_ust_domain_pid, node);
			destroy_channels(d->channels);
		}
		hashtable_get_next(ht, &iter);
	}
}

/*
 * Cleanup UST exec name domain.
 */
static void destroy_domain_exec(struct cds_lfht *ht)
{
	int ret;
	struct cds_lfht_node *node;
	struct cds_lfht_iter iter;
	struct ltt_ust_domain_exec *d;

	hashtable_get_first(ht, &iter);
	while ((node = hashtable_iter_get_node(&iter)) != NULL) {
		ret = hashtable_del(ht , &iter);
		if (!ret) {
			d = caa_container_of(node, struct ltt_ust_domain_exec, node);
			destroy_channels(d->channels);
		}
		hashtable_get_next(ht, &iter);
	}
}

/*
 * Cleanup UST global domain.
 */
static void destroy_domain_global(struct ltt_ust_domain_global *dom)
{
	destroy_channels(dom->channels);
}

/*
 * Cleanup ust session structure
 */
void trace_ust_destroy_session(struct ltt_ust_session *session)
{
	/* Extra safety */
	if (session == NULL) {
		return;
	}

	rcu_read_lock();

	DBG2("Trace UST destroy session %d", session->handle);

	if (session->metadata != NULL) {
		trace_ust_destroy_metadata(session->metadata);
	}

	/* Cleaning up UST domain */
	destroy_domain_global(&session->domain_global);
	destroy_domain_pid(session->domain_pid);
	destroy_domain_exec(session->domain_exec);

	free(session);

	rcu_read_unlock();
}
Commit	Line	Data
	1	/*
	2	* Copyright (C) 2011 - David Goulet <david.goulet@polymtl.ca>
	3	*
	4	* This program is free software; you can redistribute it and/or modify it
	5	* under the terms of the GNU General Public License as published by the Free
	6	* Software Foundation; only version 2 of the License.
	7	*
	8	* This program is distributed in the hope that it will be useful, but WITHOUT
	9	* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
	10	* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
	11	* more details.
	12	*
	13	* You should have received a copy of the GNU General Public License along with
	14	* this program; if not, write to the Free Software Foundation, Inc., 59 Temple
	15	* Place - Suite 330, Boston, MA 02111-1307, USA.
	16	*/
	17
	18	#define _GNU_SOURCE
	19	#include <stdio.h>
	20	#include <stdlib.h>
	21	#include <string.h>
	22	#include <unistd.h>
	23
	24	#include <lttngerr.h>
	25	#include <lttng-share.h>
	26
	27	#include "hashtable.h"
	28	#include "trace-ust.h"
	29
	30	/*
	31	* Find the channel in the hashtable.
	32	*/
	33	struct ltt_ust_channel trace_ust_find_channel_by_name(struct cds_lfht ht,
	34	char *name)
	35	{
	36	struct cds_lfht_node *node;
	37	struct cds_lfht_iter iter;
	38
	39	rcu_read_lock();
	40	node = hashtable_lookup(ht, (void *) name, strlen(name), &iter);
	41	if (node == NULL) {
	42	rcu_read_unlock();
	43	goto error;
	44	}
	45	rcu_read_unlock();
	46
	47	DBG2("Trace UST channel %s found by name", name);
	48
	49	return caa_container_of(node, struct ltt_ust_channel, node);
	50
	51	error:
	52	DBG2("Trace UST channel %s not found by name", name);
	53	return NULL;
	54	}
	55
	56	/*
	57	* Find the event in the hashtable.
	58	*/
	59	struct ltt_ust_event trace_ust_find_event_by_name(struct cds_lfht ht,
	60	char *name)
	61	{
	62	struct cds_lfht_node *node;
	63	struct cds_lfht_iter iter;
	64
	65	rcu_read_lock();
	66	node = hashtable_lookup(ht, (void *) name, strlen(name), &iter);
	67	if (node == NULL) {
	68	rcu_read_unlock();
	69	goto error;
	70	}
	71	rcu_read_unlock();
	72
	73	DBG2("Found UST event by name %s", name);
	74
	75	return caa_container_of(node, struct ltt_ust_event, node);
	76
	77	error:
	78	return NULL;
	79	}
	80
	81	/*
	82	* Allocate and initialize a ust session data structure.
	83	*
	84	* Return pointer to structure or NULL.
	85	*/
	86	struct ltt_ust_session trace_ust_create_session(char path, pid_t pid,
	87	struct lttng_domain *domain)
	88	{
	89	int ret;
	90	struct ltt_ust_session *lus;
	91
	92	/* Allocate a new ltt ust session */
	93	lus = malloc(sizeof(struct ltt_ust_session));
	94	if (lus == NULL) {
	95	perror("create ust session malloc");
	96	goto error;
	97	}
	98
	99	/* Init data structure */
	100	lus->handle = -1;
	101	lus->enabled = 1;
	102	lus->consumer_fds_sent = 0;
	103	lus->metadata = NULL;
	104
	105	/* Alloc UST domain hash tables */
	106	lus->domain_pid = hashtable_new(0);
	107	lus->domain_exec = hashtable_new_str(0);
	108
	109	/* Alloc UST global domain channels' HT */
	110	lus->domain_global.channels = hashtable_new_str(0);
	111
	112	/* Set session path */
	113	ret = snprintf(lus->path, PATH_MAX, "%s/ust_%d", path, pid);
	114	if (ret < 0) {
	115	PERROR("snprintf kernel traces path");
	116	goto error;
	117	}
	118
	119	DBG2("UST trace session create successful");
	120
	121	return lus;
	122
	123	error:
	124	return NULL;
	125	}
	126
	127	/*
	128	* Allocate and initialize a ust channel data structure.
	129	*
	130	* Return pointer to structure or NULL.
	131	*/
	132	struct ltt_ust_channel trace_ust_create_channel(struct lttng_channel chan,
	133	char *path)
	134	{
	135	int ret;
	136	struct ltt_ust_channel *luc;
	137
	138	luc = malloc(sizeof(struct ltt_ust_channel));
	139	if (luc == NULL) {
	140	perror("ltt_ust_channel malloc");
	141	goto error;
	142	}
	143
	144	/* Copy UST channel attributes */
	145	memcpy(&luc->attr, &chan->attr, sizeof(struct lttng_ust_channel));
	146
	147	/* Translate to UST output enum */
	148	switch (luc->attr.output) {
	149	default:
	150	luc->attr.output = LTTNG_UST_MMAP;
	151	break;
	152	}
	153
	154	luc->handle = -1;
	155	luc->enabled = 1;
	156
	157	/* Copy channel name */
	158	strncpy(luc->name, chan->name, sizeof(&luc->name));
	159	luc->name[LTTNG_UST_SYM_NAME_LEN - 1] = '\0';
	160
	161	/* Init node */
	162	hashtable_node_init(&luc->node, (void *) luc->name, strlen(luc->name));
	163	/* Alloc hash tables */
	164	luc->events = hashtable_new_str(0);
	165	luc->ctx = hashtable_new_str(0);
	166
	167	/* Set trace output path */
	168	ret = snprintf(luc->trace_path, PATH_MAX, "%s", path);
	169	if (ret < 0) {
	170	perror("asprintf ust create channel");
	171	goto error;
	172	}
	173	CDS_INIT_LIST_HEAD(&luc->stream_list.head);
	174
	175	DBG2("Trace UST channel %s created", luc->name);
	176
	177	return luc;
	178
	179	error:
	180	return NULL;
	181	}
	182
	183	/*
	184	* Allocate and initialize a ust event. Set name and event type.
	185	*
	186	* Return pointer to structure or NULL.
	187	*/
	188	struct ltt_ust_event trace_ust_create_event(struct lttng_event ev)
	189	{
	190	struct ltt_ust_event *lue;
	191
	192	lue = malloc(sizeof(struct ltt_ust_event));
	193	if (lue == NULL) {
	194	PERROR("ust event malloc");
	195	goto error;
	196	}
	197
	198	switch (ev->type) {
	199	case LTTNG_EVENT_PROBE:
	200	lue->attr.instrumentation = LTTNG_UST_PROBE;
	201	break;
	202	case LTTNG_EVENT_FUNCTION:
	203	lue->attr.instrumentation = LTTNG_UST_FUNCTION;
	204	break;
	205	case LTTNG_EVENT_FUNCTION_ENTRY:
	206	lue->attr.instrumentation = LTTNG_UST_FUNCTION;
	207	break;
	208	case LTTNG_EVENT_TRACEPOINT:
	209	lue->attr.instrumentation = LTTNG_UST_TRACEPOINT;
	210	break;
	211	default:
	212	ERR("Unknown ust instrumentation type (%d)", ev->type);
	213	goto error;
	214	}
	215
	216	/* Copy event name */
	217	strncpy(lue->attr.name, ev->name, LTTNG_UST_SYM_NAME_LEN);
	218	lue->attr.name[LTTNG_UST_SYM_NAME_LEN - 1] = '\0';
	219
	220	/* Setting up a ust event */
	221	lue->handle = -1;
	222	lue->enabled = 1;
	223
	224	/* Init node */
	225	hashtable_node_init(&lue->node, (void *) lue->attr.name,
	226	strlen(lue->attr.name));
	227	/* Alloc context hash tables */
	228	lue->ctx = hashtable_new_str(5);
	229
	230	return lue;
	231
	232	error:
	233	return NULL;
	234	}
	235
	236	/*
	237	* Allocate and initialize a ust metadata.
	238	*
	239	* Return pointer to structure or NULL.
	240	*/
	241	struct ltt_ust_metadata trace_ust_create_metadata(char path)
	242	{
	243	int ret;
	244	struct ltt_ust_metadata *lum;
	245
	246	lum = malloc(sizeof(struct ltt_ust_metadata));
	247	if (lum == NULL) {
	248	perror("ust metadata malloc");
	249	goto error;
	250	}
	251
	252	/* Set default attributes */
	253	lum->attr.overwrite = DEFAULT_CHANNEL_OVERWRITE;
	254	lum->attr.subbuf_size = DEFAULT_METADATA_SUBBUF_SIZE;
	255	lum->attr.num_subbuf = DEFAULT_METADATA_SUBBUF_NUM;
	256	lum->attr.switch_timer_interval = DEFAULT_CHANNEL_SWITCH_TIMER;
	257	lum->attr.read_timer_interval = DEFAULT_CHANNEL_READ_TIMER;
	258	lum->attr.output = DEFAULT_UST_CHANNEL_OUTPUT;
	259
	260	lum->handle = -1;
	261	/* Set metadata trace path */
	262	ret = snprintf(lum->pathname, PATH_MAX, "%s/metadata", path);
	263	if (ret < 0) {
	264	perror("asprintf ust metadata");
	265	goto error;
	266	}
	267
	268	return lum;
	269
	270	error:
	271	return NULL;
	272	}
	273
	274	/*
	275	* RCU safe free context structure.
	276	*/
	277	static void destroy_context_rcu(struct rcu_head *head)
	278	{
	279	struct cds_lfht_node *node =
	280	caa_container_of(head, struct cds_lfht_node, head);
	281	struct ltt_ust_context *ctx =
	282	caa_container_of(node, struct ltt_ust_context, node);
	283
	284	free(ctx);
	285	}
	286
	287	/*
	288	* Cleanup UST context hash table.
	289	*/
	290	static void destroy_context(struct cds_lfht *ht)
	291	{
	292	int ret;
	293	struct cds_lfht_node *node;
	294	struct cds_lfht_iter iter;
	295
	296	hashtable_get_first(ht, &iter);
	297	while ((node = hashtable_iter_get_node(&iter)) != NULL) {
	298	ret = hashtable_del(ht, &iter);
	299	if (!ret) {
	300	call_rcu(&node->head, destroy_context_rcu);
	301	}
	302	hashtable_get_next(ht, &iter);
	303	}
	304	}
	305
	306	/*
	307	* Cleanup ust event structure.
	308	*/
	309	void trace_ust_destroy_event(struct ltt_ust_event *event)
	310	{
	311	DBG2("Trace destroy UST event %s", event->attr.name);
	312	destroy_context(event->ctx);
	313	free(event);
	314	}
	315
	316	/*
	317	* URCU intermediate call to complete destroy event.
	318	*/
	319	static void destroy_event_rcu(struct rcu_head *head)
	320	{
	321	struct cds_lfht_node *node =
	322	caa_container_of(head, struct cds_lfht_node, head);
	323	struct ltt_ust_event *event =
	324	caa_container_of(node, struct ltt_ust_event, node);
	325
	326	trace_ust_destroy_event(event);
	327	}
	328
	329	/*
	330	* Cleanup ust channel structure.
	331	*/
	332	void trace_ust_destroy_channel(struct ltt_ust_channel *channel)
	333	{
	334	int ret;
	335	struct cds_lfht_node *node;
	336	struct cds_lfht_iter iter;
	337
	338	DBG2("Trace destroy UST channel %s", channel->name);
	339
	340	rcu_read_lock();
	341
	342	hashtable_get_first(channel->events, &iter);
	343	while ((node = hashtable_iter_get_node(&iter)) != NULL) {
	344	ret = hashtable_del(channel->events, &iter);
	345	if (!ret) {
	346	call_rcu(&node->head, destroy_event_rcu);
	347	}
	348	hashtable_get_next(channel->events, &iter);
	349	}
	350
	351	free(channel->events);
	352	destroy_context(channel->ctx);
	353	free(channel);
	354
	355	rcu_read_unlock();
	356	}
	357
	358	/*
	359	* URCU intermediate call to complete destroy channel.
	360	*/
	361	static void destroy_channel_rcu(struct rcu_head *head)
	362	{
	363	struct cds_lfht_node *node =
	364	caa_container_of(head, struct cds_lfht_node, head);
	365	struct ltt_ust_channel *channel =
	366	caa_container_of(node, struct ltt_ust_channel, node);
	367
	368	trace_ust_destroy_channel(channel);
	369	}
	370
	371	/*
	372	* Cleanup ust metadata structure.
	373	*/
	374	void trace_ust_destroy_metadata(struct ltt_ust_metadata *metadata)
	375	{
	376	DBG2("Trace UST destroy metadata %d", metadata->handle);
	377
	378	free(metadata);
	379	}
	380
	381	/*
	382	* Iterate over a hash table containing channels and cleanup safely.
	383	*/
	384	static void destroy_channels(struct cds_lfht *channels)
	385	{
	386	int ret;
	387	struct cds_lfht_node *node;
	388	struct cds_lfht_iter iter;
	389
	390	hashtable_get_first(channels, &iter);
	391	while ((node = hashtable_iter_get_node(&iter)) != NULL) {
	392	ret = hashtable_del(channels, &iter);
	393	if (!ret) {
	394	call_rcu(&node->head, destroy_channel_rcu);
	395	}
	396	hashtable_get_next(channels, &iter);
	397	}
	398	}
	399
	400	/*
	401	* Cleanup UST pid domain.
	402	*/
	403	static void destroy_domain_pid(struct cds_lfht *ht)
	404	{
	405	int ret;
	406	struct cds_lfht_node *node;
	407	struct cds_lfht_iter iter;
	408	struct ltt_ust_domain_pid *d;
	409
	410	hashtable_get_first(ht, &iter);
	411	while ((node = hashtable_iter_get_node(&iter)) != NULL) {
	412	ret = hashtable_del(ht , &iter);
	413	if (!ret) {
	414	d = caa_container_of(node, struct ltt_ust_domain_pid, node);
	415	destroy_channels(d->channels);
	416	}
	417	hashtable_get_next(ht, &iter);
	418	}
	419	}
	420
	421	/*
	422	* Cleanup UST exec name domain.
	423	*/
	424	static void destroy_domain_exec(struct cds_lfht *ht)
	425	{
	426	int ret;
	427	struct cds_lfht_node *node;
	428	struct cds_lfht_iter iter;
	429	struct ltt_ust_domain_exec *d;
	430
	431	hashtable_get_first(ht, &iter);
	432	while ((node = hashtable_iter_get_node(&iter)) != NULL) {
	433	ret = hashtable_del(ht , &iter);
	434	if (!ret) {
	435	d = caa_container_of(node, struct ltt_ust_domain_exec, node);
	436	destroy_channels(d->channels);
	437	}
	438	hashtable_get_next(ht, &iter);
	439	}
	440	}
	441
	442	/*
	443	* Cleanup UST global domain.
	444	*/
	445	static void destroy_domain_global(struct ltt_ust_domain_global *dom)
	446	{
	447	destroy_channels(dom->channels);
	448	}
	449
	450	/*
	451	* Cleanup ust session structure
	452	*/
	453	void trace_ust_destroy_session(struct ltt_ust_session *session)
	454	{
	455	/* Extra safety */
	456	if (session == NULL) {
	457	return;
	458	}
	459
	460	rcu_read_lock();
	461
	462	DBG2("Trace UST destroy session %d", session->handle);
	463
	464	if (session->metadata != NULL) {
	465	trace_ust_destroy_metadata(session->metadata);
	466	}
	467
	468	/* Cleaning up UST domain */
	469	destroy_domain_global(&session->domain_global);
	470	destroy_domain_pid(session->domain_pid);
	471	destroy_domain_exec(session->domain_exec);
	472
	473	free(session);
	474
	475	rcu_read_unlock();
	476	}