[lttng-tools.git] / lttng-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, unsigned int uid,
		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->consumer_fds_sent = 0;
	lus->uid = uid;
	lus->start_trace = 0;

	/* 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->pathname, PATH_MAX, "%s/ust", path);
	if (ret < 0) {
		PERROR("snprintf kernel traces path");
		goto error_free_session;
	}

	DBG2("UST trace session create successful");

	return lus;

error_free_session:
	free(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 */
	luc->attr.overwrite = chan->attr.overwrite;
	luc->attr.subbuf_size = chan->attr.subbuf_size;
	luc->attr.num_subbuf = chan->attr.num_subbuf;
	luc->attr.switch_timer_interval = chan->attr.switch_timer_interval;
	luc->attr.read_timer_interval = chan->attr.read_timer_interval;
	luc->attr.output = chan->attr.output;

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

	/* 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->pathname, PATH_MAX, "%s", path);
	if (ret < 0) {
		perror("asprintf ust create channel");
		goto error_free_channel;
	}

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

	return luc;

error_free_channel:
	free(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_free_event;
	}

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

	/* Init node */
	hashtable_node_init(&lue->node, (void *) lue->attr.name,
			strlen(lue->attr.name));
	/* Alloc context hash tables */
	lue->ctx = hashtable_new_str(0);

	return lue;

error_free_event:
	free(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 = zmalloc(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 = LTTNG_UST_MMAP;

	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_free_metadata;
	}

	return lum;

error_free_metadata:
	free(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->uid);

	//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, unsigned int uid,
	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->consumer_fds_sent = 0;
	101	lus->uid = uid;
	102	lus->start_trace = 0;
	103
	104	/* Alloc UST domain hash tables */
	105	lus->domain_pid = hashtable_new(0);
	106	lus->domain_exec = hashtable_new_str(0);
	107
	108	/* Alloc UST global domain channels' HT */
	109	lus->domain_global.channels = hashtable_new_str(0);
	110
	111	/* Set session path */
	112	ret = snprintf(lus->pathname, PATH_MAX, "%s/ust", path);
	113	if (ret < 0) {
	114	PERROR("snprintf kernel traces path");
	115	goto error_free_session;
	116	}
	117
	118	DBG2("UST trace session create successful");
	119
	120	return lus;
	121
	122	error_free_session:
	123	free(lus);
	124	error:
	125	return NULL;
	126	}
	127
	128	/*
	129	* Allocate and initialize a ust channel data structure.
	130	*
	131	* Return pointer to structure or NULL.
	132	*/
	133	struct ltt_ust_channel trace_ust_create_channel(struct lttng_channel chan,
	134	char *path)
	135	{
	136	int ret;
	137	struct ltt_ust_channel *luc;
	138
	139	luc = malloc(sizeof(struct ltt_ust_channel));
	140	if (luc == NULL) {
	141	perror("ltt_ust_channel malloc");
	142	goto error;
	143	}
	144
	145	/* Copy UST channel attributes */
	146	luc->attr.overwrite = chan->attr.overwrite;
	147	luc->attr.subbuf_size = chan->attr.subbuf_size;
	148	luc->attr.num_subbuf = chan->attr.num_subbuf;
	149	luc->attr.switch_timer_interval = chan->attr.switch_timer_interval;
	150	luc->attr.read_timer_interval = chan->attr.read_timer_interval;
	151	luc->attr.output = chan->attr.output;
	152
	153	/* Translate to UST output enum */
	154	switch (luc->attr.output) {
	155	default:
	156	luc->attr.output = LTTNG_UST_MMAP;
	157	break;
	158	}
	159
	160	/* Copy channel name */
	161	strncpy(luc->name, chan->name, sizeof(&luc->name));
	162	luc->name[LTTNG_UST_SYM_NAME_LEN - 1] = '\0';
	163
	164	/* Init node */
	165	hashtable_node_init(&luc->node, (void *) luc->name, strlen(luc->name));
	166	/* Alloc hash tables */
	167	luc->events = hashtable_new_str(0);
	168	luc->ctx = hashtable_new_str(0);
	169
	170	/* Set trace output path */
	171	ret = snprintf(luc->pathname, PATH_MAX, "%s", path);
	172	if (ret < 0) {
	173	perror("asprintf ust create channel");
	174	goto error_free_channel;
	175	}
	176
	177	DBG2("Trace UST channel %s created", luc->name);
	178
	179	return luc;
	180
	181	error_free_channel:
	182	free(luc);
	183	error:
	184	return NULL;
	185	}
	186
	187	/*
	188	* Allocate and initialize a ust event. Set name and event type.
	189	*
	190	* Return pointer to structure or NULL.
	191	*/
	192	struct ltt_ust_event trace_ust_create_event(struct lttng_event ev)
	193	{
	194	struct ltt_ust_event *lue;
	195
	196	lue = malloc(sizeof(struct ltt_ust_event));
	197	if (lue == NULL) {
	198	PERROR("ust event malloc");
	199	goto error;
	200	}
	201
	202	switch (ev->type) {
	203	case LTTNG_EVENT_PROBE:
	204	lue->attr.instrumentation = LTTNG_UST_PROBE;
	205	break;
	206	case LTTNG_EVENT_FUNCTION:
	207	lue->attr.instrumentation = LTTNG_UST_FUNCTION;
	208	break;
	209	case LTTNG_EVENT_FUNCTION_ENTRY:
	210	lue->attr.instrumentation = LTTNG_UST_FUNCTION;
	211	break;
	212	case LTTNG_EVENT_TRACEPOINT:
	213	lue->attr.instrumentation = LTTNG_UST_TRACEPOINT;
	214	break;
	215	default:
	216	ERR("Unknown ust instrumentation type (%d)", ev->type);
	217	goto error_free_event;
	218	}
	219
	220	/* Copy event name */
	221	strncpy(lue->attr.name, ev->name, LTTNG_UST_SYM_NAME_LEN);
	222	lue->attr.name[LTTNG_UST_SYM_NAME_LEN - 1] = '\0';
	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(0);
	229
	230	return lue;
	231
	232	error_free_event:
	233	free(lue);
	234	error:
	235	return NULL;
	236	}
	237
	238	/*
	239	* Allocate and initialize a ust metadata.
	240	*
	241	* Return pointer to structure or NULL.
	242	*/
	243	struct ltt_ust_metadata trace_ust_create_metadata(char path)
	244	{
	245	int ret;
	246	struct ltt_ust_metadata *lum;
	247
	248	lum = zmalloc(sizeof(struct ltt_ust_metadata));
	249	if (lum == NULL) {
	250	perror("ust metadata malloc");
	251	goto error;
	252	}
	253
	254	/* Set default attributes */
	255	lum->attr.overwrite = DEFAULT_CHANNEL_OVERWRITE;
	256	lum->attr.subbuf_size = DEFAULT_METADATA_SUBBUF_SIZE;
	257	lum->attr.num_subbuf = DEFAULT_METADATA_SUBBUF_NUM;
	258	lum->attr.switch_timer_interval = DEFAULT_CHANNEL_SWITCH_TIMER;
	259	lum->attr.read_timer_interval = DEFAULT_CHANNEL_READ_TIMER;
	260	lum->attr.output = LTTNG_UST_MMAP;
	261
	262	lum->handle = -1;
	263	/* Set metadata trace path */
	264	ret = snprintf(lum->pathname, PATH_MAX, "%s/metadata", path);
	265	if (ret < 0) {
	266	perror("asprintf ust metadata");
	267	goto error_free_metadata;
	268	}
	269
	270	return lum;
	271
	272	error_free_metadata:
	273	free(lum);
	274	error:
	275	return NULL;
	276	}
	277
	278	/*
	279	* RCU safe free context structure.
	280	*/
	281	static void destroy_context_rcu(struct rcu_head *head)
	282	{
	283	struct cds_lfht_node *node =
	284	caa_container_of(head, struct cds_lfht_node, head);
	285	struct ltt_ust_context *ctx =
	286	caa_container_of(node, struct ltt_ust_context, node);
	287
	288	free(ctx);
	289	}
	290
	291	/*
	292	* Cleanup UST context hash table.
	293	*/
	294	static void destroy_context(struct cds_lfht *ht)
	295	{
	296	int ret;
	297	struct cds_lfht_node *node;
	298	struct cds_lfht_iter iter;
	299
	300	hashtable_get_first(ht, &iter);
	301	while ((node = hashtable_iter_get_node(&iter)) != NULL) {
	302	ret = hashtable_del(ht, &iter);
	303	if (!ret) {
	304	call_rcu(&node->head, destroy_context_rcu);
	305	}
	306	hashtable_get_next(ht, &iter);
	307	}
	308	}
	309
	310	/*
	311	* Cleanup ust event structure.
	312	*/
	313	void trace_ust_destroy_event(struct ltt_ust_event *event)
	314	{
	315	DBG2("Trace destroy UST event %s", event->attr.name);
	316	destroy_context(event->ctx);
	317	free(event);
	318	}
	319
	320	/*
	321	* URCU intermediate call to complete destroy event.
	322	*/
	323	static void destroy_event_rcu(struct rcu_head *head)
	324	{
	325	struct cds_lfht_node *node =
	326	caa_container_of(head, struct cds_lfht_node, head);
	327	struct ltt_ust_event *event =
	328	caa_container_of(node, struct ltt_ust_event, node);
	329
	330	trace_ust_destroy_event(event);
	331	}
	332
	333	/*
	334	* Cleanup ust channel structure.
	335	*/
	336	void trace_ust_destroy_channel(struct ltt_ust_channel *channel)
	337	{
	338	int ret;
	339	struct cds_lfht_node *node;
	340	struct cds_lfht_iter iter;
	341
	342	DBG2("Trace destroy UST channel %s", channel->name);
	343
	344	rcu_read_lock();
	345
	346	hashtable_get_first(channel->events, &iter);
	347	while ((node = hashtable_iter_get_node(&iter)) != NULL) {
	348	ret = hashtable_del(channel->events, &iter);
	349	if (!ret) {
	350	call_rcu(&node->head, destroy_event_rcu);
	351	}
	352	hashtable_get_next(channel->events, &iter);
	353	}
	354
	355	free(channel->events);
	356	destroy_context(channel->ctx);
	357	free(channel);
	358
	359	rcu_read_unlock();
	360	}
	361
	362	/*
	363	* URCU intermediate call to complete destroy channel.
	364	*/
	365	static void destroy_channel_rcu(struct rcu_head *head)
	366	{
	367	struct cds_lfht_node *node =
	368	caa_container_of(head, struct cds_lfht_node, head);
	369	struct ltt_ust_channel *channel =
	370	caa_container_of(node, struct ltt_ust_channel, node);
	371
	372	trace_ust_destroy_channel(channel);
	373	}
	374
	375	/*
	376	* Cleanup ust metadata structure.
	377	*/
	378	void trace_ust_destroy_metadata(struct ltt_ust_metadata *metadata)
	379	{
	380	DBG2("Trace UST destroy metadata %d", metadata->handle);
	381
	382	free(metadata);
	383	}
	384
	385	/*
	386	* Iterate over a hash table containing channels and cleanup safely.
	387	*/
	388	static void destroy_channels(struct cds_lfht *channels)
	389	{
	390	int ret;
	391	struct cds_lfht_node *node;
	392	struct cds_lfht_iter iter;
	393
	394	hashtable_get_first(channels, &iter);
	395	while ((node = hashtable_iter_get_node(&iter)) != NULL) {
	396	ret = hashtable_del(channels, &iter);
	397	if (!ret) {
	398	call_rcu(&node->head, destroy_channel_rcu);
	399	}
	400	hashtable_get_next(channels, &iter);
	401	}
	402	}
	403
	404	/*
	405	* Cleanup UST pid domain.
	406	*/
	407	static void destroy_domain_pid(struct cds_lfht *ht)
	408	{
	409	int ret;
	410	struct cds_lfht_node *node;
	411	struct cds_lfht_iter iter;
	412	struct ltt_ust_domain_pid *d;
	413
	414	hashtable_get_first(ht, &iter);
	415	while ((node = hashtable_iter_get_node(&iter)) != NULL) {
	416	ret = hashtable_del(ht , &iter);
	417	if (!ret) {
	418	d = caa_container_of(node, struct ltt_ust_domain_pid, node);
	419	destroy_channels(d->channels);
	420	}
	421	hashtable_get_next(ht, &iter);
	422	}
	423	}
	424
	425	/*
	426	* Cleanup UST exec name domain.
	427	*/
	428	static void destroy_domain_exec(struct cds_lfht *ht)
	429	{
	430	int ret;
	431	struct cds_lfht_node *node;
	432	struct cds_lfht_iter iter;
	433	struct ltt_ust_domain_exec *d;
	434
	435	hashtable_get_first(ht, &iter);
	436	while ((node = hashtable_iter_get_node(&iter)) != NULL) {
	437	ret = hashtable_del(ht , &iter);
	438	if (!ret) {
	439	d = caa_container_of(node, struct ltt_ust_domain_exec, node);
	440	destroy_channels(d->channels);
	441	}
	442	hashtable_get_next(ht, &iter);
	443	}
	444	}
	445
	446	/*
	447	* Cleanup UST global domain.
	448	*/
	449	static void destroy_domain_global(struct ltt_ust_domain_global *dom)
	450	{
	451	destroy_channels(dom->channels);
	452	}
	453
	454	/*
	455	* Cleanup ust session structure
	456	*/
	457	void trace_ust_destroy_session(struct ltt_ust_session *session)
	458	{
	459	/* Extra safety */
	460	if (session == NULL) {
	461	return;
	462	}
	463
	464	rcu_read_lock();
	465
	466	DBG2("Trace UST destroy session %d", session->uid);
	467
	468	//if (session->metadata != NULL) {
	469	// trace_ust_destroy_metadata(session->metadata);
	470	//}
	471
	472	/* Cleaning up UST domain */
	473	destroy_domain_global(&session->domain_global);
	474	destroy_domain_pid(session->domain_pid);
	475	destroy_domain_exec(session->domain_exec);
	476
	477	free(session);
	478
	479	rcu_read_unlock();
	480	}