X-Git-Url: http://git.efficios.com/?a=blobdiff_plain;f=src%2Fbin%2Flttng-sessiond%2Fust-registry.c;h=384d8030eb1682099c429aaa7327e0f609ac30bb;hb=refs%2Fheads%2Fsow-2020-0002-rev2;hp=6913487d5611aef301313668612d70370d25d5b8;hpb=3b016e589cc2229f0d3be8e6e61e8eeed8b7e9e6;p=lttng-tools.git

diff --git a/src/bin/lttng-sessiond/ust-registry.c b/src/bin/lttng-sessiond/ust-registry.c
index 6913487d5..384d8030e 100644
--- a/src/bin/lttng-sessiond/ust-registry.c
+++ b/src/bin/lttng-sessiond/ust-registry.c
@@ -1,20 +1,11 @@
 /*
- * Copyright (C) 2013 - David Goulet <dgoulet@efficios.com>
+ * Copyright (C) 2013 David Goulet <dgoulet@efficios.com>
  *
- * This program is free software; you can redistribute it and/or modify it
- * under the terms of the GNU General Public License, version 2 only, as
- * published by the Free Software Foundation.
+ * SPDX-License-Identifier: GPL-2.0-only
  *
- * 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., 51
- * Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  */
 
+#include "bin/lttng-sessiond/event-notifier-error-accounting.h"
 #define _LGPL_SOURCE
 #include <assert.h>
 #include <inttypes.h>
@@ -22,18 +13,25 @@
 #include <common/common.h>
 #include <common/hashtable/utils.h>
 #include <lttng/lttng.h>
+#include <lttng/map-key.h>
+#include <lttng/map-key-internal.h>
 
 #include "ust-registry.h"
 #include "ust-app.h"
+#include "ust-field-utils.h"
 #include "utils.h"
+#include "lttng-sessiond.h"
+#include "notification-thread-commands.h"
+
 
 /*
  * Hash table match function for event in the registry.
  */
 static int ht_match_event(struct cds_lfht_node *node, const void *_key)
 {
-	struct ust_registry_event *event;
 	const struct ust_registry_event *key;
+	struct ust_registry_event *event;
+	int i;
 
 	assert(node);
 	assert(_key);
@@ -42,17 +40,39 @@ static int ht_match_event(struct cds_lfht_node *node, const void *_key)
 	assert(event);
 	key = _key;
 
-	/* It has to be a perfect match. */
+	/* It has to be a perfect match. First, compare the event names. */
 	if (strncmp(event->name, key->name, sizeof(event->name))) {
 		goto no_match;
 	}
 
-	/* It has to be a perfect match. */
-	if (strncmp(event->signature, key->signature,
-			strlen(event->signature))) {
+	/* Compare log levels. */
+	if (event->loglevel_value != key->loglevel_value) {
+		goto no_match;
+	}
+
+	/* Compare the number of fields. */
+	if (event->nr_fields != key->nr_fields) {
 		goto no_match;
 	}
 
+	/* Compare each field individually. */
+	for (i = 0; i < event->nr_fields; i++) {
+		if (!match_ustctl_field(&event->fields[i], &key->fields[i])) {
+			goto no_match;
+		}
+	}
+
+	/* Compare model URI. */
+	if (event->model_emf_uri != NULL && key->model_emf_uri == NULL) {
+		goto no_match;
+	} else if(event->model_emf_uri == NULL && key->model_emf_uri != NULL) {
+		goto no_match;
+	} else if (event->model_emf_uri != NULL && key->model_emf_uri != NULL) {
+		if (strcmp(event->model_emf_uri, key->model_emf_uri)) {
+			goto no_match;
+		}
+	}
+
 	/* Match */
 	return 1;
 
@@ -60,17 +80,16 @@ no_match:
 	return 0;
 }
 
-static unsigned long ht_hash_event(void *_key, unsigned long seed)
+static unsigned long ht_hash_event(const void *_key, unsigned long seed)
 {
-	uint64_t xored_key;
-	struct ust_registry_event *key = _key;
+	uint64_t hashed_key;
+	const struct ust_registry_event *key = _key;
 
 	assert(key);
 
-	xored_key = (uint64_t) (hash_key_str(key->name, seed) ^
-			hash_key_str(key->signature, seed));
+	hashed_key = (uint64_t) hash_key_str(key->name, seed);
 
-	return hash_key_u64(&xored_key, seed);
+	return hash_key_u64(&hashed_key, seed);
 }
 
 static int compare_enums(const struct ust_registry_enum *reg_enum_a,
@@ -206,9 +225,20 @@ int validate_event_field(struct ustctl_field *field,
 	case ustctl_atype_sequence:
 	case ustctl_atype_string:
 	case ustctl_atype_variant:
+	case ustctl_atype_array_nestable:
+	case ustctl_atype_sequence_nestable:
+	case ustctl_atype_enum_nestable:
+	case ustctl_atype_variant_nestable:
 		break;
 	case ustctl_atype_struct:
-		if (field->type.u._struct.nr_fields != 0) {
+		if (field->type.u.legacy._struct.nr_fields != 0) {
+			WARN("Unsupported non-empty struct field.");
+			ret = -EINVAL;
+			goto end;
+		}
+		break;
+	case ustctl_atype_struct_nestable:
+		if (field->type.u.struct_nestable.nr_fields != 0) {
 			WARN("Unsupported non-empty struct field.");
 			ret = -EINVAL;
 			goto end;
@@ -216,12 +246,12 @@ int validate_event_field(struct ustctl_field *field,
 		break;
 
 	case ustctl_atype_float:
-		switch (field->type.u.basic._float.mant_dig) {
+		switch (field->type.u._float.mant_dig) {
 		case 0:
 			WARN("UST application '%s' (pid: %d) has unknown float mantissa '%u' "
 				"in field '%s', rejecting event '%s'",
 				app->name, app->pid,
-				field->type.u.basic._float.mant_dig,
+				field->type.u._float.mant_dig,
 				field->name,
 				event_name);
 			ret = -EINVAL;
@@ -257,7 +287,7 @@ int validate_event_fields(size_t nr_fields, struct ustctl_field *fields,
  * registry.
  */
 static struct ust_registry_event *alloc_event(int session_objd,
-		int channel_objd, char *name, char *sig, size_t nr_fields,
+		int container_objd, char *name, char *sig, size_t nr_fields,
 		struct ustctl_field *fields, int loglevel_value,
 		char *model_emf_uri, struct ust_app *app)
 {
@@ -277,7 +307,7 @@ static struct ust_registry_event *alloc_event(int session_objd,
 	}
 
 	event->session_objd = session_objd;
-	event->channel_objd = channel_objd;
+	event->container_objd = container_objd;
 	/* Allocated by ustctl. */
 	event->signature = sig;
 	event->nr_fields = nr_fields;
@@ -325,6 +355,33 @@ static void destroy_event_rcu(struct rcu_head *head)
 	destroy_event(event);
 }
 
+/*
+ * Destroy ust_registry_map_key_ht_entry function call of the call RCU.
+ */
+static void destroy_ust_registry_map_key_ht_entry(struct rcu_head *head)
+{
+	struct lttng_ht_node_u64 *node =
+		caa_container_of(head, struct lttng_ht_node_u64, head);
+	struct ust_registry_map_key_ht_entry *entry =
+		caa_container_of(node, struct ust_registry_map_key_ht_entry, node);
+
+	lttng_map_key_put(entry->key);
+	free(entry);
+}
+
+/*
+ * Destroy ust_registry_map_index_ht_entry function call of the call RCU.
+ */
+static void destroy_ust_registry_map_index_ht_entry(struct rcu_head *head)
+{
+	struct lttng_ht_node_str *node =
+		caa_container_of(head, struct lttng_ht_node_str, head);
+	struct ust_registry_map_index_ht_entry *entry =
+		caa_container_of(node, struct ust_registry_map_index_ht_entry, node);
+
+	free(entry);
+}
+
 /*
  * Find an event using the name and signature in the given registry. RCU read
  * side lock MUST be acquired before calling this function and as long as the
@@ -332,7 +389,7 @@ static void destroy_event_rcu(struct rcu_head *head)
  *
  * On success, the event pointer is returned else NULL.
  */
-struct ust_registry_event *ust_registry_find_event(
+struct ust_registry_event *ust_registry_chan_find_event(
 		struct ust_registry_channel *chan, char *name, char *sig)
 {
 	struct lttng_ht_node_u64 *node;
@@ -371,7 +428,7 @@ end:
  *
  * Should be called with session registry mutex held.
  */
-int ust_registry_create_event(struct ust_registry_session *session,
+int ust_registry_chan_create_event(struct ust_registry_session *session,
 		uint64_t chan_key, int session_objd, int channel_objd, char *name,
 		char *sig, size_t nr_fields, struct ustctl_field *fields,
 		int loglevel_value, char *model_emf_uri, int buffer_type,
@@ -420,7 +477,7 @@ int ust_registry_create_event(struct ust_registry_session *session,
 
 	DBG3("UST registry creating event with event: %s, sig: %s, id: %u, "
 			"chan_objd: %u, sess_objd: %u, chan_id: %u", event->name,
-			event->signature, event->id, event->channel_objd,
+			event->signature, event->id, event->container_objd,
 			event->session_objd, chan->chan_id);
 
 	/*
@@ -445,13 +502,13 @@ int ust_registry_create_event(struct ust_registry_session *session,
 			ERR("UST registry create event add unique failed for event: %s, "
 					"sig: %s, id: %u, chan_objd: %u, sess_objd: %u",
 					event->name, event->signature, event->id,
-					event->channel_objd, event->session_objd);
+					event->container_objd, event->session_objd);
 			ret = -EINVAL;
 			goto error_unlock;
 		}
 	} else {
 		/* Request next event id if the node was successfully added. */
-		event_id = event->id = ust_registry_get_next_event_id(chan);
+		event_id = event->id = ust_registry_channel_get_next_event_id(chan);
 	}
 
 	*event_id_p = event_id;
@@ -479,11 +536,334 @@ error_unlock:
 	return ret;
 }
 
+static
+int format_event_key(const struct lttng_map_key *key,
+		const char *full_event_name, char **formated_key)
+{
+	int ret;
+	char _key[LTTNG_UST_KEY_TOKEN_STRING_LEN_MAX] = {0};
+	enum lttng_map_key_status key_status;
+	unsigned int i, token_count;
+	char *cloned_full_event_name;
+	const char *provider_name, *event_name;
+
+	assert(key);
+	assert(full_event_name);
+
+	cloned_full_event_name = strdup(full_event_name);
+
+	provider_name = strtok(cloned_full_event_name, ":");
+	event_name = strtok(NULL, ":");
+
+	key_status = lttng_map_key_get_token_count(key, &token_count);
+	if (key_status != LTTNG_MAP_KEY_STATUS_OK) {
+		ERR("Error getting map key token count");
+		ret = -1;
+		goto end;
+	}
+
+	if (token_count == 0) {
+		ERR("Map key token number is zero");
+		ret = -1;
+		goto end;
+	}
+
+	for (i = 0; i < token_count; i++) {
+		const struct lttng_map_key_token *token =
+				lttng_map_key_get_token_at_index(key, i);
+		switch (token->type) {
+		case LTTNG_MAP_KEY_TOKEN_TYPE_STRING:
+		{
+			struct lttng_map_key_token_string *str_token =
+					(struct lttng_map_key_token_string *) token;
+			DBG("Appending a string type key token: str = '%s'", str_token->string);
+
+			strcat(_key, lttng_map_key_token_string_get_string(str_token));
+
+			break;
+		}
+		case LTTNG_MAP_KEY_TOKEN_TYPE_VARIABLE:
+		{
+			struct lttng_map_key_token_variable *var_token =
+					(struct lttng_map_key_token_variable *) token;
+
+			switch (var_token->type) {
+			case LTTNG_MAP_KEY_TOKEN_VARIABLE_TYPE_EVENT_NAME:
+				DBG("Serializing a event name variable type key token: event_name = '%s'",
+						event_name);
+				strcat(_key, event_name);
+				break;
+			case LTTNG_MAP_KEY_TOKEN_VARIABLE_TYPE_PROVIDER_NAME:
+				DBG("Serializing a provider name variable type key token: provider_name = '%s'",
+						provider_name);
+				strcat(_key, provider_name);
+				break;
+			default:
+				abort();
+			}
+			break;
+		}
+		default:
+			abort();
+		}
+	}
+
+	*formated_key = strdup(_key);
+
+	ret = 0;
+end:
+	free(cloned_full_event_name);
+	return ret;
+}
+
+static
+const struct lttng_map_key *ust_registry_map_find_key_for_token(
+		struct ust_registry_map *map,
+		uint64_t tracer_token)
+{
+	struct lttng_ht_iter iter;
+	struct lttng_ht_node_u64 *key_node;
+	struct ust_registry_map_key_ht_entry *key_entry;
+	const struct lttng_map_key *key = NULL;;
+
+	assert(map);
+	lttng_ht_lookup(map->tracer_token_to_map_key_ht,
+			(void *) &tracer_token, &iter);
+
+	key_node = lttng_ht_iter_get_node_u64(&iter);
+	if (!key_node) {
+		goto end;
+	}
+
+	/*
+	 * It's already mapped. Return the key we allocated already.
+	 */
+	key_entry = caa_container_of(key_node,
+		struct ust_registry_map_key_ht_entry, node);
+	assert(key_entry);
+
+	key = key_entry->key;
+
+	DBG("Returning map key object associated to the tracer token: key = %p, tracer_token = %"PRIu64,
+		key_entry->key, tracer_token);
+
+end:
+	return key;
+}
+
+int ust_registry_map_add_token_key_mapping(struct ust_registry_session *session,
+		uint64_t map_key, uint64_t tracer_token,
+		struct lttng_map_key *key)
+{
+	int ret;
+	struct ust_registry_map_key_ht_entry *key_entry;
+	struct ust_registry_map *map;
+	const struct lttng_map_key *existing_mapping = NULL;
+
+	rcu_read_lock();
+	map = ust_registry_map_find(session, map_key);
+	if (!map) {
+		ret = -EINVAL;
+		goto end;
+	}
+	rcu_read_unlock();
+
+	/* JORAJ check if the mapping already exist, we might want to *move this
+	 * to the caller or at least provide more check if for some scenario
+	 * (PID) this should never happen
+	 */
+	existing_mapping = ust_registry_map_find_key_for_token(map, tracer_token);
+	if (existing_mapping != NULL) {
+		assert(existing_mapping == key);
+		ret = 0;
+		goto end;
+	}
+
+	key_entry = zmalloc(sizeof(struct ust_registry_map_key_ht_entry));
+	if (!key_entry) {
+		ret = -ENOMEM;
+		goto end;
+	}
+	key_entry->key = key;
+
+	/* Ensure the lifetime of the lttng_map_key object. */
+	lttng_map_key_get(key);
+
+	rcu_read_lock();
+
+	lttng_ht_node_init_u64(&key_entry->node, tracer_token);
+	lttng_ht_add_unique_u64(map->tracer_token_to_map_key_ht,
+			&key_entry->node);
+
+	rcu_read_unlock();
+
+
+	ret = 0;
+end:
+	return ret;
+
+}
+
+static
+int ust_registry_map_find_or_create_index_for_key(struct ust_registry_map *map,
+		const char *formated_key, uint64_t *index)
+{
+	int ret;
+	struct lttng_ht_iter iter;
+	struct lttng_ht_node_str *index_node;
+	struct ust_registry_map_index_ht_entry *index_entry;
+
+	assert(map);
+	assert(formated_key);
+
+	/*
+	 * First try to check if we already mapped this formated key to an
+	 * index.
+	 */
+	lttng_ht_lookup(map->key_string_to_bucket_index_ht,
+			(void *) formated_key, &iter);
+
+	index_node = lttng_ht_iter_get_node_str(&iter);
+	if (index_node) {
+		/*
+		 * It's already mapped. Return the index we allocated already.
+		 */
+		index_entry = caa_container_of(index_node,
+				struct ust_registry_map_index_ht_entry, node);
+		assert(index_entry);
+
+		*index = index_entry->index;
+
+		DBG("Returning an already allocated index for formated key: key = '%s', index = %"PRIu64,
+				formated_key, *index);
+	} else {
+		/*
+		 * It's not mapped. Create a new mapping, add it to the
+		 * hashtable and return it.
+		 */
+		index_entry = zmalloc(sizeof(struct ust_registry_map_index_ht_entry));
+		if (!index_entry) {
+			ret = -1;
+			goto end;
+		}
+
+		index_entry->index = ust_registry_map_get_next_event_id(map);
+		index_entry->formated_key = strdup(formated_key);
+		lttng_ht_node_init_str(&index_entry->node, index_entry->formated_key);
+
+		lttng_ht_add_unique_str(map->key_string_to_bucket_index_ht,
+				&index_entry->node);
+
+		*index = index_entry->index;
+		DBG("Allocated counter index for new formated_key: key = '%s', index = %"PRIu64,
+				formated_key, *index);
+	}
+
+	ret = 0;
+end:
+	return ret;
+}
+
+/*
+ * Create a ust_registry_event from the given parameters and add it to the
+ * registry hash table. If event_id is valid, it is set with the newly created
+ * event id.
+ *
+ * On success, return 0 else a negative value. The created event MUST be unique
+ * so on duplicate entry -EINVAL is returned. On error, event_id is untouched.
+ *
+ * Should be called with session registry mutex held.
+ */
+int ust_registry_map_create_event(struct ust_registry_session *session,
+		uint64_t map_key, int session_objd, int map_objd, char *name,
+		char *sig, size_t nr_fields, struct ustctl_field *fields,
+		int loglevel_value, char *model_emf_uri, int buffer_type,
+		uint64_t tracer_token, uint64_t *counter_index_p,
+		struct ust_app *app)
+{
+	int ret;
+	uint64_t counter_index;
+	struct ust_registry_map *map;
+	char *formated_key;
+	const struct lttng_map_key *key;
+
+	assert(session);
+	assert(name);
+	assert(sig);
+	assert(counter_index_p);
+
+	rcu_read_lock();
+
+	/*
+	 * This should not happen but since it comes from the UST tracer, an
+	 * external party, don't assert and simply validate values.
+	 */
+	if (session_objd < 0 || map_objd < 0) {
+		ret = -EINVAL;
+		goto error_free;
+	}
+
+	map = ust_registry_map_find(session, map_key);
+	if (!map) {
+		ret = -EINVAL;
+		goto error_free;
+	}
+
+	/* Check if we've reached the maximum possible id. */
+	if (ust_registry_is_max_id(map->used_event_id)) {
+		ret = -ENOENT;
+		goto error_free;
+	}
+
+	key = ust_registry_map_find_key_for_token(map, tracer_token);
+	if (!key) {
+		ERR("Tracer token %"PRIu64" not found for map id = %"PRIu32,
+				tracer_token, map->map_id);
+		ret = -EINVAL;
+		goto error_unlock;
+	}
+
+	ret = format_event_key(key, name, &formated_key);
+	if (ret) {
+		ERR("Error formating key");
+		ret = -EINVAL;
+		goto error_unlock;
+	}
+
+	ret = ust_registry_map_find_or_create_index_for_key(map, formated_key,
+			&counter_index);
+	if (ret) {
+		ERR("Error finding or creating index for formated_key = '%s'",
+				formated_key);
+		free(formated_key);
+		ret = -EINVAL;
+		goto error_unlock;
+	}
+
+	DBG3("UST registry allocating counter index %"PRIu64 " to event: %s, "
+		"signature: %s, sess_objd: %u, map_objd: %u, map_id: %u",
+		counter_index, name, sig, session_objd, map_objd, map->map_id);
+
+	*counter_index_p = counter_index;
+
+	rcu_read_unlock();
+	return 0;
+
+error_free:
+	free(sig);
+	free(fields);
+	free(model_emf_uri);
+error_unlock:
+	rcu_read_unlock();
+	return ret;
+}
+
+
 /*
  * For a given event in a registry, delete the entry and destroy the event.
  * This MUST be called within a RCU read side lock section.
  */
-void ust_registry_destroy_event(struct ust_registry_channel *chan,
+void ust_registry_chan_destroy_event(struct ust_registry_channel *chan,
 		struct ust_registry_event *event)
 {
 	int ret;
@@ -502,6 +882,73 @@ void ust_registry_destroy_event(struct ust_registry_channel *chan,
 	return;
 }
 
+/*
+ * This MUST be called within a RCU read side lock section.
+ */
+static void ust_registry_map_key_entry_destroy(struct lttng_ht *ht,
+		struct ust_registry_map_key_ht_entry *entry)
+{
+	int ret;
+	struct lttng_ht_iter iter;
+
+	assert(ht);
+	assert(entry);
+
+	/* Delete the node first. */
+	iter.iter.node = &entry->node.node;
+	ret = lttng_ht_del(ht, &iter);
+	assert(!ret);
+
+	call_rcu(&entry->node.head, destroy_ust_registry_map_key_ht_entry);
+
+	return;
+}
+
+/*
+ * This MUST be called within a RCU read side lock section.
+ */
+static void ust_registry_map_index_ht_entry_destroy(struct lttng_ht *ht,
+		struct ust_registry_map_index_ht_entry *entry)
+{
+	int ret;
+	struct lttng_ht_iter iter;
+
+	assert(ht);
+	assert(entry);
+
+	/* Delete the node first. */
+	iter.iter.node = &entry->node.node;
+	ret = lttng_ht_del(ht, &iter);
+	assert(!ret);
+
+	call_rcu(&entry->node.head, destroy_ust_registry_map_index_ht_entry);
+
+	return;
+}
+
+/*
+ * For a given event in a registry, delete the entry and destroy the event.
+ * This MUST be called within a RCU read side lock section.
+ */
+void ust_registry_map_destroy_event(struct ust_registry_map *map,
+		struct ust_registry_event *event)
+{
+	int ret;
+	struct lttng_ht_iter iter;
+
+	assert(map);
+	assert(event);
+
+	/* Delete the node first. */
+	iter.iter.node = &event->node.node;
+	ret = lttng_ht_del(map->events_ht, &iter);
+	assert(!ret);
+
+	call_rcu(&event->node.head, destroy_event_rcu);
+
+	return;
+}
+
 static void destroy_enum(struct ust_registry_enum *reg_enum)
 {
 	if (!reg_enum) {
@@ -523,8 +970,8 @@ static void destroy_enum_rcu(struct rcu_head *head)
  * Lookup enumeration by name and comparing enumeration entries.
  * Needs to be called from RCU read-side critical section.
  */
-struct ust_registry_enum *
-	ust_registry_lookup_enum(struct ust_registry_session *session,
+static struct ust_registry_enum *ust_registry_lookup_enum(
+		struct ust_registry_session *session,
 		const struct ust_registry_enum *reg_enum_lookup)
 {
 	struct ust_registry_enum *reg_enum = NULL;
@@ -532,8 +979,8 @@ struct ust_registry_enum *
 	struct lttng_ht_iter iter;
 
 	cds_lfht_lookup(session->enums->ht,
-			ht_hash_enum((void *) &reg_enum_lookup, lttng_ht_seed),
-			ht_match_enum, &reg_enum_lookup, &iter.iter);
+			ht_hash_enum((void *) reg_enum_lookup, lttng_ht_seed),
+			ht_match_enum, reg_enum_lookup, &iter.iter);
 	node = lttng_ht_iter_get_node_str(&iter);
 	if (!node) {
 	        goto end;
@@ -655,7 +1102,7 @@ end:
  * the enumeration.
  * This MUST be called within a RCU read side lock section.
  */
-void ust_registry_destroy_enum(struct ust_registry_session *reg_session,
+static void ust_registry_destroy_enum(struct ust_registry_session *reg_session,
 		struct ust_registry_enum *reg_enum)
 {
 	int ret;
@@ -690,26 +1137,108 @@ void destroy_channel_rcu(struct rcu_head *head)
 	free(chan);
 }
 
+/*
+ * We need to execute ht_destroy outside of RCU read-side critical
+ * section and outside of call_rcu thread, so we postpone its execution
+ * using ht_cleanup_push. It is simpler than to mapge the semantic of
+ * the many callers of delete_ust_app_session().
+ */
+static
+void destroy_map_rcu(struct rcu_head *head)
+{
+	struct ust_registry_map *map =
+		caa_container_of(head, struct ust_registry_map, rcu_head);
+
+	if (map->events_ht) {
+		ht_cleanup_push(map->events_ht);
+	}
+
+	if (map->tracer_token_to_map_key_ht) {
+		ht_cleanup_push(map->tracer_token_to_map_key_ht);
+	}
+
+	if (map->key_string_to_bucket_index_ht) {
+		ht_cleanup_push(map->key_string_to_bucket_index_ht);
+	}
+
+	free(map);
+}
+
 /*
  * Destroy every element of the registry and free the memory. This does NOT
  * free the registry pointer since it might not have been allocated before so
  * it's the caller responsability.
  */
-static void destroy_channel(struct ust_registry_channel *chan)
+static void destroy_channel(struct ust_registry_channel *chan, bool notif)
 {
 	struct lttng_ht_iter iter;
 	struct ust_registry_event *event;
+	enum lttng_error_code cmd_ret;
 
 	assert(chan);
 
+	if (notif) {
+		cmd_ret = notification_thread_command_remove_channel(
+				notification_thread_handle, chan->consumer_key,
+				LTTNG_DOMAIN_UST);
+		if (cmd_ret != LTTNG_OK) {
+			ERR("Failed to remove channel from notification thread");
+		}
+	}
+
+	if (chan->ht) {
+		rcu_read_lock();
+		/* Destroy all event associated with this registry. */
+		cds_lfht_for_each_entry(
+				chan->ht->ht, &iter.iter, event, node.node) {
+			/* Delete the node from the ht and free it. */
+			ust_registry_chan_destroy_event(chan, event);
+		}
+		rcu_read_unlock();
+	}
+	call_rcu(&chan->rcu_head, destroy_channel_rcu);
+}
+
+/*
+ * Destroy every element of the registry and free the memory. This does NOT
+ * free the registry pointer since it might not have been allocated before so
+ * it's the caller responsability.
+ */
+static void destroy_map(struct ust_registry_map *map)
+{
+	struct lttng_ht_iter iter;
+	struct ust_registry_event *event;
+	struct ust_registry_map_key_ht_entry *key_entry;
+	struct ust_registry_map_index_ht_entry *index_entry;
+
+	assert(map);
+
 	rcu_read_lock();
-	/* Destroy all event associated with this registry. */
-	cds_lfht_for_each_entry(chan->ht->ht, &iter.iter, event, node.node) {
-		/* Delete the node from the ht and free it. */
-		ust_registry_destroy_event(chan, event);
+	if (map->events_ht) {
+		/* Destroy all event associated with this registry. */
+		cds_lfht_for_each_entry(map->events_ht->ht, &iter.iter, event, node.node) {
+			/* Delete the node from the ht and free it. */
+			ust_registry_map_destroy_event(map, event);
+		}
+	}
+
+	/* Destroy all map_key entries associated with this registry. */
+	cds_lfht_for_each_entry (map->tracer_token_to_map_key_ht->ht,
+			&iter.iter, key_entry, node.node) {
+		ust_registry_map_key_entry_destroy(
+				map->tracer_token_to_map_key_ht,
+				key_entry);
+	}
+
+	/* Destroy all index entry associated with this registry. */
+	cds_lfht_for_each_entry(map->key_string_to_bucket_index_ht->ht,
+			&iter.iter, index_entry, node.node) {
+		ust_registry_map_index_ht_entry_destroy(
+				map->key_string_to_bucket_index_ht,
+				index_entry);
 	}
 	rcu_read_unlock();
-	call_rcu(&chan->rcu_head, destroy_channel_rcu);
+	call_rcu(&map->rcu_head, destroy_map_rcu);
 }
 
 /*
@@ -759,7 +1288,72 @@ int ust_registry_channel_add(struct ust_registry_session *session,
 	return 0;
 
 error:
-	destroy_channel(chan);
+	destroy_channel(chan, false);
+error_alloc:
+	return ret;
+}
+
+/*
+ * Initialize registry map entry with default values.
+ */
+int ust_registry_map_add(struct ust_registry_session *session,
+		uint64_t key)
+{
+	int ret = 0;
+	struct ust_registry_map *map;
+
+	assert(session);
+
+	map = zmalloc(sizeof(*map));
+	if (!map) {
+		PERROR("zmalloc ust registry map");
+		ret = -ENOMEM;
+		goto error_alloc;
+	}
+
+	map->events_ht = lttng_ht_new(0, LTTNG_HT_TYPE_STRING);
+	if (!map->events_ht) {
+		ret = -ENOMEM;
+		goto error;
+	}
+
+	/* Set custom match function. */
+	map->events_ht->match_fct = ht_match_event;
+	map->events_ht->hash_fct = ht_hash_event;
+
+	map->tracer_token_to_map_key_ht = lttng_ht_new(0, LTTNG_HT_TYPE_U64);
+	if (!map->tracer_token_to_map_key_ht) {
+		ret = -ENOMEM;
+		goto error;
+	}
+
+	map->key_string_to_bucket_index_ht = lttng_ht_new(0, LTTNG_HT_TYPE_STRING);
+	if (!map->key_string_to_bucket_index_ht) {
+		ret = -ENOMEM;
+		goto error;
+	}
+
+	/*
+	 * FIXME frdeso: fix this comment
+	 * Assign a map ID right now since the event notification comes
+	 * *before* the map notify so the ID needs to be set at this point so
+	 * the metadata can be dumped for that event.
+	 */
+	if (ust_registry_is_max_id(session->used_map_id)) {
+		ret = -1;
+		goto error;
+	}
+	map->map_id = ust_registry_get_next_map_id(session);
+
+	rcu_read_lock();
+	lttng_ht_node_init_u64(&map->node, key);
+	lttng_ht_add_unique_u64(session->maps, &map->node);
+	rcu_read_unlock();
+
+	return 0;
+
+error:
+	destroy_map(map);
 error_alloc:
 	return ret;
 }
@@ -794,11 +1388,41 @@ end:
 	return chan;
 }
 
+/*
+ * Find a map in the given registry. RCU read side lock MUST be acquired
+ * before calling this function and as long as the event reference is kept by
+ * the caller.
+ *
+ * On success, the pointer is returned else NULL.
+ */
+struct ust_registry_map *ust_registry_map_find(
+		struct ust_registry_session *session, uint64_t key)
+{
+	struct lttng_ht_node_u64 *node;
+	struct lttng_ht_iter iter;
+	struct ust_registry_map *map = NULL;
+
+	assert(session);
+	assert(session->maps);
+
+	DBG3("UST registry map finding key %" PRIu64, key);
+
+	lttng_ht_lookup(session->maps, &key, &iter);
+	node = lttng_ht_iter_get_node_u64(&iter);
+	if (!node) {
+		goto end;
+	}
+	map = caa_container_of(node, struct ust_registry_map, node);
+
+end:
+	return map;
+}
+
 /*
  * Remove channel using key from registry and free memory.
  */
 void ust_registry_channel_del_free(struct ust_registry_session *session,
-		uint64_t key)
+		uint64_t key, bool notif)
 {
 	struct lttng_ht_iter iter;
 	struct ust_registry_channel *chan;
@@ -817,7 +1441,36 @@ void ust_registry_channel_del_free(struct ust_registry_session *session,
 	ret = lttng_ht_del(session->channels, &iter);
 	assert(!ret);
 	rcu_read_unlock();
-	destroy_channel(chan);
+	destroy_channel(chan, notif);
+
+end:
+	return;
+}
+
+/*
+ * Remove map using key from registry and free memory.
+ */
+void ust_registry_map_del_free(struct ust_registry_session *session,
+		uint64_t key)
+{
+	struct lttng_ht_iter iter;
+	struct ust_registry_map *map;
+	int ret;
+
+	assert(session);
+
+	rcu_read_lock();
+	map = ust_registry_map_find(session, key);
+	if (!map) {
+		rcu_read_unlock();
+		goto end;
+	}
+
+	iter.iter.node = &map->node.node;
+	ret = lttng_ht_del(session->maps, &iter);
+	assert(!ret);
+	rcu_read_unlock();
+	destroy_map(map);
 
 end:
 	return;
@@ -844,7 +1497,9 @@ int ust_registry_session_init(struct ust_registry_session **sessionp,
 		const char *root_shm_path,
 		const char *shm_path,
 		uid_t euid,
-		gid_t egid)
+		gid_t egid,
+		uint64_t tracing_id,
+		uid_t tracing_uid)
 {
 	int ret;
 	struct ust_registry_session *session;
@@ -908,7 +1563,7 @@ int ust_registry_session_init(struct ust_registry_session **sessionp,
 
 	session->enums = lttng_ht_new(0, LTTNG_HT_TYPE_STRING);
 	if (!session->enums) {
-		ret = -ENOMEM;
+		ERR("Failed to create enums hash table");
 		goto error;
 	}
 	/* hash/match functions are specified at call site. */
@@ -920,12 +1575,21 @@ int ust_registry_session_init(struct ust_registry_session **sessionp,
 		goto error;
 	}
 
+	session->maps = lttng_ht_new(0, LTTNG_HT_TYPE_U64);
+	if (!session->maps) {
+		lttng_ht_destroy(session->channels);
+		goto error;
+	}
+
 	ret = lttng_uuid_generate(session->uuid);
 	if (ret) {
 		ERR("Failed to generate UST uuid (errno = %d)", ret);
 		goto error;
 	}
 
+	session->tracing_id = tracing_id;
+	session->tracing_uid = tracing_uid;
+
 	pthread_mutex_lock(&session->lock);
 	ret = ust_metadata_session_statedump(session, app, major, minor);
 	pthread_mutex_unlock(&session->lock);
@@ -972,7 +1636,7 @@ void ust_registry_session_destroy(struct ust_registry_session *reg)
 			/* Delete the node from the ht and free it. */
 			ret = lttng_ht_del(reg->channels, &iter);
 			assert(!ret);
-			destroy_channel(chan);
+			destroy_channel(chan, true);
 		}
 		rcu_read_unlock();
 		ht_cleanup_push(reg->channels);
@@ -994,8 +1658,9 @@ void ust_registry_session_destroy(struct ust_registry_session *reg)
 		/*
 		 * Try deleting the directory hierarchy.
 		 */
-		(void) run_as_recursive_rmdir(reg->root_shm_path,
-				reg->uid, reg->gid);
+		(void) run_as_rmdir_recursive(reg->root_shm_path,
+				reg->uid, reg->gid,
+				LTTNG_DIRECTORY_HANDLE_SKIP_NON_EMPTY_FLAG);
 	}
 	/* Destroy the enum hash table */
 	if (reg->enums) {