X-Git-Url: https://git.lttng.org/?p=lttng-tools.git;a=blobdiff_plain;f=src%2Fbin%2Flttng-sessiond%2Fust-app.c;h=c81f6e8f5597e1531292cfee2e4f5b5f57faf0dd;hp=c8c653134f7528e2cea26f0d333fc655881fe9e0;hb=025faf73cdb6942ebf437dc4c4f6631f0134b128;hpb=00e2e675d54dc726a7c8f8887c889cc8ef022003

diff --git a/src/bin/lttng-sessiond/ust-app.c b/src/bin/lttng-sessiond/ust-app.c
index c8c653134..c81f6e8f5 100644
--- a/src/bin/lttng-sessiond/ust-app.c
+++ b/src/bin/lttng-sessiond/ust-app.c
@@ -25,13 +25,100 @@
 #include <sys/types.h>
 #include <unistd.h>
 #include <urcu/compiler.h>
+#include <lttng/ust-error.h>
 
 #include <common/common.h>
+#include <common/sessiond-comm/sessiond-comm.h>
 
+#include "fd-limit.h"
+#include "health.h"
 #include "ust-app.h"
 #include "ust-consumer.h"
 #include "ust-ctl.h"
-#include "fd-limit.h"
+
+/*
+ * Match function for the hash table lookup.
+ *
+ * It matches an ust app event based on three attributes which are the event
+ * name, the filter bytecode and the loglevel.
+ */
+static int ht_match_ust_app_event(struct cds_lfht_node *node, const void *_key)
+{
+	struct ust_app_event *event;
+	const struct ust_app_ht_key *key;
+
+	assert(node);
+	assert(_key);
+
+	event = caa_container_of(node, struct ust_app_event, node.node);
+	key = _key;
+
+	/* Match the 3 elements of the key: name, filter and loglevel. */
+
+	/* Event name */
+	if (strncmp(event->attr.name, key->name, sizeof(event->attr.name)) != 0) {
+		goto no_match;
+	}
+
+	/* Event loglevel. */
+	if (event->attr.loglevel != key->loglevel) {
+		if (event->attr.loglevel_type == LTTNG_UST_LOGLEVEL_ALL
+				&& key->loglevel == 0 && event->attr.loglevel == -1) {
+			/*
+			 * Match is accepted. This is because on event creation, the
+			 * loglevel is set to -1 if the event loglevel type is ALL so 0 and
+			 * -1 are accepted for this loglevel type since 0 is the one set by
+			 * the API when receiving an enable event.
+			 */
+		} else {
+			goto no_match;
+		}
+	}
+
+	/* One of the filters is NULL, fail. */
+	if ((key->filter && !event->filter) || (!key->filter && event->filter)) {
+		goto no_match;
+	}
+
+	if (key->filter && event->filter) {
+		/* Both filters exists, check length followed by the bytecode. */
+		if (event->filter->len != key->filter->len ||
+				memcmp(event->filter->data, key->filter->data,
+					event->filter->len) != 0) {
+			goto no_match;
+		}
+	}
+
+	/* Match. */
+	return 1;
+
+no_match:
+	return 0;
+}
+
+/*
+ * Unique add of an ust app event in the given ht. This uses the custom
+ * ht_match_ust_app_event match function and the event name as hash.
+ */
+static void add_unique_ust_app_event(struct lttng_ht *ht,
+		struct ust_app_event *event)
+{
+	struct cds_lfht_node *node_ptr;
+	struct ust_app_ht_key key;
+
+	assert(ht);
+	assert(ht->ht);
+	assert(event);
+
+	key.name = event->attr.name;
+	key.filter = event->filter;
+	key.loglevel = event->attr.loglevel;
+
+	node_ptr = cds_lfht_add_unique(ht->ht,
+			ht->hash_fct(event->node.key, lttng_ht_seed),
+			ht_match_ust_app_event, &key, &event->node.node);
+	assert(node_ptr == &event->node.node);
+}
 
 /*
  * Delete ust context safely. RCU read lock must be held before calling
@@ -54,18 +141,7 @@ void delete_ust_app_ctx(int sock, struct ust_app_ctx *ua_ctx)
 static
 void delete_ust_app_event(int sock, struct ust_app_event *ua_event)
 {
-	int ret;
-	struct lttng_ht_iter iter;
-	struct ust_app_ctx *ua_ctx;
-
-	/* Destroy each context of event */
-	cds_lfht_for_each_entry(ua_event->ctx->ht, &iter.iter, ua_ctx,
-			node.node) {
-		ret = lttng_ht_del(ua_event->ctx, &iter);
-		assert(!ret);
-		delete_ust_app_ctx(sock, ua_ctx);
-	}
-	lttng_ht_destroy(ua_event->ctx);
+	free(ua_event->filter);
 
 	if (ua_event->obj != NULL) {
 		ustctl_release_object(sock, ua_event->obj);
@@ -322,7 +398,6 @@ struct ust_app_event *alloc_ust_app_event(char *name,
 	ua_event->enabled = 1;
 	strncpy(ua_event->name, name, sizeof(ua_event->name));
 	ua_event->name[sizeof(ua_event->name) - 1] = '\0';
-	ua_event->ctx = lttng_ht_new(0, LTTNG_HT_TYPE_ULONG);
 	lttng_ht_node_init_str(&ua_event->node, ua_event->name);
 
 	/* Copy attributes */
@@ -361,6 +436,29 @@ error:
 	return ua_ctx;
 }
 
+/*
+ * Allocate a filter and copy the given original filter.
+ *
+ * Return allocated filter or NULL on error.
+ */
+static struct lttng_ust_filter_bytecode *alloc_copy_ust_app_filter(
+		struct lttng_ust_filter_bytecode *orig_f)
+{
+	struct lttng_ust_filter_bytecode *filter = NULL;
+
+	/* Copy filter bytecode */
+	filter = zmalloc(sizeof(*filter) + orig_f->len);
+	if (!filter) {
+		PERROR("zmalloc alloc ust app filter");
+		goto error;
+	}
+
+	memcpy(filter, orig_f, sizeof(*filter) + orig_f->len);
+
+error:
+	return filter;
+}
+
 /*
  * Find an ust_app using the sock and return it. RCU read side lock must be
  * held before calling this helper function.
@@ -384,6 +482,42 @@ error:
 	return NULL;
 }
 
+/*
+ * Lookup for an ust app event based on event name, filter bytecode and the
+ * event loglevel.
+ *
+ * Return an ust_app_event object or NULL on error.
+ */
+static struct ust_app_event *find_ust_app_event(struct lttng_ht *ht,
+		char *name, struct lttng_ust_filter_bytecode *filter, int loglevel)
+{
+	struct lttng_ht_iter iter;
+	struct lttng_ht_node_str *node;
+	struct ust_app_event *event = NULL;
+	struct ust_app_ht_key key;
+
+	assert(name);
+	assert(ht);
+
+	/* Setup key for event lookup. */
+	key.name = name;
+	key.filter = filter;
+	key.loglevel = loglevel;
+
+	/* Lookup using the event name as hash and a custom match fct. */
+	cds_lfht_lookup(ht->ht, ht->hash_fct((void *) name, lttng_ht_seed),
+			ht_match_ust_app_event, &key, &iter.iter);
+	node = lttng_ht_iter_get_node_str(&iter);
+	if (node == NULL) {
+		goto end;
+	}
+
+	event = caa_container_of(node, struct ust_app_event, node);
+
+end:
+	return event;
+}
+
 /*
  * Create the channel context on the tracer.
  */
@@ -393,6 +527,8 @@ int create_ust_channel_context(struct ust_app_channel *ua_chan,
 {
 	int ret;
 
+	health_code_update(&health_thread_cmd);
+
 	ret = ustctl_add_context(app->sock, &ua_ctx->ctx,
 			ua_chan->obj, &ua_ctx->obj);
 	if (ret < 0) {
@@ -404,29 +540,36 @@ int create_ust_channel_context(struct ust_app_channel *ua_chan,
 	DBG2("UST app context created successfully for channel %s", ua_chan->name);
 
 error:
+	health_code_update(&health_thread_cmd);
 	return ret;
 }
 
 /*
- * Create the event context on the tracer.
+ * Set the filter on the tracer.
  */
 static
-int create_ust_event_context(struct ust_app_event *ua_event,
-		struct ust_app_ctx *ua_ctx, struct ust_app *app)
+int set_ust_event_filter(struct ust_app_event *ua_event,
+		struct ust_app *app)
 {
 	int ret;
 
-	ret = ustctl_add_context(app->sock, &ua_ctx->ctx,
-			ua_event->obj, &ua_ctx->obj);
-	if (ret < 0) {
+	health_code_update(&health_thread_cmd);
+
+	if (!ua_event->filter) {
+		ret = 0;
 		goto error;
 	}
 
-	ua_ctx->handle = ua_ctx->obj->handle;
+	ret = ustctl_set_filter(app->sock, ua_event->filter,
+			ua_event->obj);
+	if (ret < 0) {
+		goto error;
+	}
 
-	DBG2("UST app context created successfully for event %s", ua_event->name);
+	DBG2("UST filter set successfully for event %s", ua_event->name);
 
 error:
+	health_code_update(&health_thread_cmd);
 	return ret;
 }
 
@@ -438,6 +581,8 @@ static int disable_ust_event(struct ust_app *app,
 {
 	int ret;
 
+	health_code_update(&health_thread_cmd);
+
 	ret = ustctl_disable(app->sock, ua_event->obj);
 	if (ret < 0) {
 		ERR("UST app event %s disable failed for app (pid: %d) "
@@ -450,6 +595,7 @@ static int disable_ust_event(struct ust_app *app,
 			ua_event->attr.name, app->pid);
 
 error:
+	health_code_update(&health_thread_cmd);
 	return ret;
 }
 
@@ -461,6 +607,8 @@ static int disable_ust_channel(struct ust_app *app,
 {
 	int ret;
 
+	health_code_update(&health_thread_cmd);
+
 	ret = ustctl_disable(app->sock, ua_chan->obj);
 	if (ret < 0) {
 		ERR("UST app channel %s disable failed for app (pid: %d) "
@@ -473,6 +621,7 @@ static int disable_ust_channel(struct ust_app *app,
 			ua_chan->name, app->pid);
 
 error:
+	health_code_update(&health_thread_cmd);
 	return ret;
 }
 
@@ -484,6 +633,8 @@ static int enable_ust_channel(struct ust_app *app,
 {
 	int ret;
 
+	health_code_update(&health_thread_cmd);
+
 	ret = ustctl_enable(app->sock, ua_chan->obj);
 	if (ret < 0) {
 		ERR("UST app channel %s enable failed for app (pid: %d) "
@@ -498,6 +649,7 @@ static int enable_ust_channel(struct ust_app *app,
 			ua_chan->name, app->pid);
 
 error:
+	health_code_update(&health_thread_cmd);
 	return ret;
 }
 
@@ -509,6 +661,8 @@ static int enable_ust_event(struct ust_app *app,
 {
 	int ret;
 
+	health_code_update(&health_thread_cmd);
+
 	ret = ustctl_enable(app->sock, ua_event->obj);
 	if (ret < 0) {
 		ERR("UST app event %s enable failed for app (pid: %d) "
@@ -521,6 +675,7 @@ static int enable_ust_event(struct ust_app *app,
 			ua_event->attr.name, app->pid);
 
 error:
+	health_code_update(&health_thread_cmd);
 	return ret;
 }
 
@@ -533,6 +688,8 @@ static int open_ust_metadata(struct ust_app *app,
 	int ret;
 	struct lttng_ust_channel_attr uattr;
 
+	health_code_update(&health_thread_cmd);
+
 	uattr.overwrite = ua_sess->metadata->attr.overwrite;
 	uattr.subbuf_size = ua_sess->metadata->attr.subbuf_size;
 	uattr.num_subbuf = ua_sess->metadata->attr.num_subbuf;
@@ -560,6 +717,7 @@ static int open_ust_metadata(struct ust_app *app,
 	ua_sess->metadata->handle = ua_sess->metadata->obj->handle;
 
 error:
+	health_code_update(&health_thread_cmd);
 	return ret;
 }
 
@@ -571,6 +729,8 @@ static int create_ust_stream(struct ust_app *app,
 {
 	int ret;
 
+	health_code_update(&health_thread_cmd);
+
 	/* We are going to receive 2 fds, we need to reserve them. */
 	ret = lttng_fd_get(LTTNG_FD_APPS, 2);
 	if (ret < 0) {
@@ -585,6 +745,7 @@ static int create_ust_stream(struct ust_app *app,
 	}
 
 error:
+	health_code_update(&health_thread_cmd);
 	return ret;
 }
 
@@ -596,6 +757,8 @@ static int create_ust_channel(struct ust_app *app,
 {
 	int ret;
 
+	health_code_update(&health_thread_cmd);
+
 	/* TODO: remove cast and use lttng-ust-abi.h */
 
 	/* We are going to receive 2 fds, we need to reserve them. */
@@ -604,6 +767,9 @@ static int create_ust_channel(struct ust_app *app,
 		ERR("Exhausted number of available FD upon create channel");
 		goto error;
 	}
+
+	health_code_update(&health_thread_cmd);
+
 	ret = ustctl_create_channel(app->sock, ua_sess->handle,
 			(struct lttng_ust_channel_attr *)&ua_chan->attr, &ua_chan->obj);
 	if (ret < 0) {
@@ -620,6 +786,8 @@ static int create_ust_channel(struct ust_app *app,
 	DBG2("UST app channel %s created successfully for pid:%d and sock:%d",
 			ua_chan->name, app->pid, app->sock);
 
+	health_code_update(&health_thread_cmd);
+
 	/* If channel is not enabled, disable it on the tracer */
 	if (!ua_chan->enabled) {
 		ret = disable_ust_channel(app, ua_sess, ua_chan);
@@ -629,6 +797,7 @@ static int create_ust_channel(struct ust_app *app,
 	}
 
 error:
+	health_code_update(&health_thread_cmd);
 	return ret;
 }
 
@@ -641,14 +810,12 @@ int create_ust_event(struct ust_app *app, struct ust_app_session *ua_sess,
 {
 	int ret = 0;
 
+	health_code_update(&health_thread_cmd);
+
 	/* Create UST event on tracer */
 	ret = ustctl_create_event(app->sock, &ua_event->attr, ua_chan->obj,
 			&ua_event->obj);
 	if (ret < 0) {
-		if (ret == -EEXIST || ret == -EPERM) {
-			ret = 0;
-			goto error;
-		}
 		ERR("Error ustctl create event %s for app pid: %d with ret %d",
 				ua_event->attr.name, app->pid, ret);
 		goto error;
@@ -659,6 +826,16 @@ int create_ust_event(struct ust_app *app, struct ust_app_session *ua_sess,
 	DBG2("UST app event %s created successfully for pid:%d",
 			ua_event->attr.name, app->pid);
 
+	health_code_update(&health_thread_cmd);
+
+	/* Set filter if one is present. */
+	if (ua_event->filter) {
+		ret = set_ust_event_filter(ua_event, app);
+		if (ret < 0) {
+			goto error;
+		}
+	}
+
 	/* If event not enabled, disable it on the tracer */
 	if (ua_event->enabled == 0) {
 		ret = disable_ust_event(app, ua_sess, ua_event);
@@ -669,10 +846,10 @@ int create_ust_event(struct ust_app *app, struct ust_app_session *ua_sess,
 			 * just created it.
 			 */
 			switch (ret) {
-			case -EPERM:
+			case -LTTNG_UST_ERR_PERM:
 				/* Code flow problem */
 				assert(0);
-			case -EEXIST:
+			case -LTTNG_UST_ERR_EXIST:
 				/* It's OK for our use case. */
 				ret = 0;
 				break;
@@ -684,6 +861,7 @@ int create_ust_event(struct ust_app *app, struct ust_app_session *ua_sess,
 	}
 
 error:
+	health_code_update(&health_thread_cmd);
 	return ret;
 }
 
@@ -693,10 +871,6 @@ error:
 static void shadow_copy_event(struct ust_app_event *ua_event,
 		struct ltt_ust_event *uevent)
 {
-	struct lttng_ht_iter iter;
-	struct ltt_ust_context *uctx;
-	struct ust_app_ctx *ua_ctx;
-
 	strncpy(ua_event->name, uevent->attr.name, sizeof(ua_event->name));
 	ua_event->name[sizeof(ua_event->name) - 1] = '\0';
 
@@ -705,16 +879,10 @@ static void shadow_copy_event(struct ust_app_event *ua_event,
 	/* Copy event attributes */
 	memcpy(&ua_event->attr, &uevent->attr, sizeof(ua_event->attr));
 
-	cds_lfht_for_each_entry(uevent->ctx->ht, &iter.iter, uctx, node.node) {
-		ua_ctx = alloc_ust_app_ctx(&uctx->ctx);
-		if (ua_ctx == NULL) {
-			/* malloc() failed. We should simply stop */
-			return;
-		}
-
-		lttng_ht_node_init_ulong(&ua_ctx->node,
-				(unsigned long) ua_ctx->ctx.ctx);
-		lttng_ht_add_unique_ulong(ua_event->ctx, &ua_ctx->node);
+	/* Copy filter bytecode */
+	if (uevent->filter) {
+		ua_event->filter = alloc_copy_ust_app_filter(uevent->filter);
+		/* Filter might be NULL here in case of ENONEM. */
 	}
 }
 
@@ -725,7 +893,6 @@ static void shadow_copy_channel(struct ust_app_channel *ua_chan,
 		struct ltt_ust_channel *uchan)
 {
 	struct lttng_ht_iter iter;
-	struct lttng_ht_node_str *ua_event_node;
 	struct ltt_ust_event *uevent;
 	struct ltt_ust_context *uctx;
 	struct ust_app_event *ua_event;
@@ -752,11 +919,9 @@ static void shadow_copy_channel(struct ust_app_channel *ua_chan,
 
 	/* Copy all events from ltt ust channel to ust app channel */
 	cds_lfht_for_each_entry(uchan->events->ht, &iter.iter, uevent, node.node) {
-		struct lttng_ht_iter uiter;
-
-		lttng_ht_lookup(ua_chan->events, (void *) uevent->attr.name, &uiter);
-		ua_event_node = lttng_ht_iter_get_node_str(&uiter);
-		if (ua_event_node == NULL) {
+		ua_event = find_ust_app_event(ua_chan->events, uevent->attr.name,
+				uevent->filter, uevent->attr.loglevel);
+		if (ua_event == NULL) {
 			DBG2("UST event %s not found on shadow copy channel",
 					uevent->attr.name);
 			ua_event = alloc_ust_app_event(uevent->attr.name, &uevent->attr);
@@ -764,7 +929,7 @@ static void shadow_copy_channel(struct ust_app_channel *ua_chan,
 				continue;
 			}
 			shadow_copy_event(ua_event, uevent);
-			lttng_ht_add_unique_str(ua_chan->events, &ua_event->node);
+			add_unique_ust_app_event(ua_chan->events, ua_event);
 		}
 	}
 
@@ -877,6 +1042,8 @@ static struct ust_app_session *create_ust_app_session(
 	int ret;
 	struct ust_app_session *ua_sess;
 
+	health_code_update(&health_thread_cmd);
+
 	ua_sess = lookup_session_by_app(usess, app);
 	if (ua_sess == NULL) {
 		DBG2("UST app pid: %d session id %d not found, creating it",
@@ -889,13 +1056,16 @@ static struct ust_app_session *create_ust_app_session(
 		shadow_copy_session(ua_sess, usess, app);
 	}
 
+	health_code_update(&health_thread_cmd);
+
 	if (ua_sess->handle == -1) {
 		ret = ustctl_create_session(app->sock);
 		if (ret < 0) {
 			ERR("Creating session for app pid %d", app->pid);
+			delete_ust_app_session(-1, ua_sess);
 			/* This means that the tracer is gone... */
 			ua_sess = (void*) -1UL;
-			goto error;
+			goto end;
 		}
 
 		ua_sess->handle = ret;
@@ -908,11 +1078,8 @@ static struct ust_app_session *create_ust_app_session(
 	}
 
 end:
+	health_code_update(&health_thread_cmd);
 	return ua_sess;
-
-error:
-	delete_ust_app_session(-1, ua_sess);
-	return NULL;
 }
 
 /*
@@ -956,47 +1123,6 @@ error:
 	return ret;
 }
 
-/*
- * Create an UST context and enable it for the event on the tracer.
- */
-static
-int create_ust_app_event_context(struct ust_app_session *ua_sess,
-		struct ust_app_event *ua_event, struct lttng_ust_context *uctx,
-		struct ust_app *app)
-{
-	int ret = 0;
-	struct lttng_ht_iter iter;
-	struct lttng_ht_node_ulong *node;
-	struct ust_app_ctx *ua_ctx;
-
-	DBG2("UST app adding context to event %s", ua_event->name);
-
-	lttng_ht_lookup(ua_event->ctx, (void *)((unsigned long)uctx->ctx), &iter);
-	node = lttng_ht_iter_get_node_ulong(&iter);
-	if (node != NULL) {
-		ret = -EEXIST;
-		goto error;
-	}
-
-	ua_ctx = alloc_ust_app_ctx(uctx);
-	if (ua_ctx == NULL) {
-		/* malloc failed */
-		ret = -1;
-		goto error;
-	}
-
-	lttng_ht_node_init_ulong(&ua_ctx->node, (unsigned long) ua_ctx->ctx.ctx);
-	lttng_ht_add_unique_ulong(ua_event->ctx, &ua_ctx->node);
-
-	ret = create_ust_event_context(ua_event, ua_ctx, app);
-	if (ret < 0) {
-		goto error;
-	}
-
-error:
-	return ret;
-}
-
 /*
  * Enable on the tracer side a ust app event for the session and channel.
  */
@@ -1116,7 +1242,7 @@ static struct ust_app_channel *create_ust_app_channel(
 	ret = create_ust_channel(app, ua_sess, ua_chan);
 	if (ret < 0) {
 		/* Not found previously means that it does not exist on the tracer */
-		assert(ret != -EEXIST);
+		assert(ret != -LTTNG_UST_ERR_EXIST);
 		goto error;
 	}
 
@@ -1142,14 +1268,12 @@ int create_ust_app_event(struct ust_app_session *ua_sess,
 		struct ust_app *app)
 {
 	int ret = 0;
-	struct lttng_ht_iter iter;
-	struct lttng_ht_node_str *ua_event_node;
 	struct ust_app_event *ua_event;
 
 	/* Get event node */
-	lttng_ht_lookup(ua_chan->events, (void *)uevent->attr.name, &iter);
-	ua_event_node = lttng_ht_iter_get_node_str(&iter);
-	if (ua_event_node != NULL) {
+	ua_event = find_ust_app_event(ua_chan->events, uevent->attr.name,
+			uevent->filter, uevent->attr.loglevel);
+	if (ua_event != NULL) {
 		ret = -EEXIST;
 		goto end;
 	}
@@ -1167,11 +1291,11 @@ int create_ust_app_event(struct ust_app_session *ua_sess,
 	ret = create_ust_event(app, ua_sess, ua_chan, ua_event);
 	if (ret < 0) {
 		/* Not found previously means that it does not exist on the tracer */
-		assert(ret != -EEXIST);
+		assert(ret != -LTTNG_UST_ERR_EXIST);
 		goto error;
 	}
 
-	lttng_ht_add_unique_str(ua_chan->events, &ua_event->node);
+	add_unique_ust_app_event(ua_chan->events, ua_event);
 
 	DBG2("UST app create event %s for PID %d completed", ua_event->name,
 			app->pid);
@@ -1291,8 +1415,10 @@ int ust_app_register(struct ust_register_msg *msg, int sock)
 	struct ust_app *lta;
 	int ret;
 
-	if ((msg->bits_per_long == 64 && ust_consumerd64_fd == -EINVAL)
-			|| (msg->bits_per_long == 32 && ust_consumerd32_fd == -EINVAL)) {
+	if ((msg->bits_per_long == 64 &&
+				(uatomic_read(&ust_consumerd64_fd) == -EINVAL))
+			|| (msg->bits_per_long == 32 &&
+				(uatomic_read(&ust_consumerd32_fd) == -EINVAL))) {
 		ERR("Registration failed: application \"%s\" (pid: %d) has "
 			"%d-bit long, but no consumerd for this long size is available.\n",
 			msg->name, msg->pid, msg->bits_per_long);
@@ -1394,8 +1520,16 @@ void ust_app_unregister(int sock)
 	/* Assign second node for deletion */
 	iter.iter.node = &lta->pid_n.node;
 
+	/*
+	 * Ignore return value since the node might have been removed before by an
+	 * add replace during app registration because the PID can be reassigned by
+	 * the OS.
+	 */
 	ret = lttng_ht_del(ust_app_ht, &iter);
-	assert(!ret);
+	if (ret) {
+		DBG3("Unregister app by PID %d failed. This can happen on pid reuse",
+				lta->pid);
+	}
 
 	/* Free memory */
 	call_rcu(&lta->pid_n.head, delete_ust_app_rcu);
@@ -1443,6 +1577,8 @@ int ust_app_list_events(struct lttng_event **events)
 	cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
 		struct lttng_ust_tracepoint_iter uiter;
 
+		health_code_update(&health_thread_cmd);
+
 		if (!app->compatible) {
 			/*
 			 * TODO: In time, we should notice the caller of this error by
@@ -1458,14 +1594,18 @@ int ust_app_list_events(struct lttng_event **events)
 		}
 
 		while ((ret = ustctl_tracepoint_list_get(app->sock, handle,
-						&uiter)) != -ENOENT) {
+					&uiter)) != -LTTNG_UST_ERR_NOENT) {
+			health_code_update(&health_thread_cmd);
 			if (count >= nbmem) {
+				/* In case the realloc fails, we free the memory */
+				void *tmp_ptr = (void *) tmp;
 				DBG2("Reallocating event list from %zu to %zu entries", nbmem,
 						2 * nbmem);
 				nbmem *= 2;
 				tmp = realloc(tmp, nbmem * sizeof(struct lttng_event));
 				if (tmp == NULL) {
 					PERROR("realloc ust app events");
+					free(tmp_ptr);
 					ret = -ENOMEM;
 					goto rcu_error;
 				}
@@ -1487,6 +1627,7 @@ int ust_app_list_events(struct lttng_event **events)
 rcu_error:
 	rcu_read_unlock();
 error:
+	health_code_update(&health_thread_cmd);
 	return ret;
 }
 
@@ -1514,6 +1655,8 @@ int ust_app_list_event_fields(struct lttng_event_field **fields)
 	cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
 		struct lttng_ust_field_iter uiter;
 
+		health_code_update(&health_thread_cmd);
+
 		if (!app->compatible) {
 			/*
 			 * TODO: In time, we should notice the caller of this error by
@@ -1529,14 +1672,18 @@ int ust_app_list_event_fields(struct lttng_event_field **fields)
 		}
 
 		while ((ret = ustctl_tracepoint_field_list_get(app->sock, handle,
-						&uiter)) != -ENOENT) {
+					&uiter)) != -LTTNG_UST_ERR_NOENT) {
+			health_code_update(&health_thread_cmd);
 			if (count >= nbmem) {
+				/* In case the realloc fails, we free the memory */
+				void *tmp_ptr = (void *) tmp;
 				DBG2("Reallocating event field list from %zu to %zu entries", nbmem,
 						2 * nbmem);
 				nbmem *= 2;
 				tmp = realloc(tmp, nbmem * sizeof(struct lttng_event_field));
 				if (tmp == NULL) {
 					PERROR("realloc ust app event fields");
+					free(tmp_ptr);
 					ret = -ENOMEM;
 					goto rcu_error;
 				}
@@ -1544,6 +1691,7 @@ int ust_app_list_event_fields(struct lttng_event_field **fields)
 
 			memcpy(tmp[count].field_name, uiter.field_name, LTTNG_UST_SYM_NAME_LEN);
 			tmp[count].type = uiter.type;
+			tmp[count].nowrite = uiter.nowrite;
 
 			memcpy(tmp[count].event.name, uiter.event_name, LTTNG_UST_SYM_NAME_LEN);
 			tmp[count].event.loglevel = uiter.loglevel;
@@ -1562,6 +1710,7 @@ int ust_app_list_event_fields(struct lttng_event_field **fields)
 rcu_error:
 	rcu_read_unlock();
 error:
+	health_code_update(&health_thread_cmd);
 	return ret;
 }
 
@@ -1571,21 +1720,22 @@ error:
 void ust_app_clean_list(void)
 {
 	int ret;
+	struct ust_app *app;
 	struct lttng_ht_iter iter;
-	struct lttng_ht_node_ulong *node;
 
 	DBG2("UST app cleaning registered apps hash table");
 
 	rcu_read_lock();
 
-	cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, node, node) {
+	cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
 		ret = lttng_ht_del(ust_app_ht, &iter);
 		assert(!ret);
-		call_rcu(&node->head, delete_ust_app_rcu);
+		call_rcu(&app->pid_n.head, delete_ust_app_rcu);
 	}
 
 	/* Cleanup socket hash table */
-	cds_lfht_for_each_entry(ust_app_ht_by_sock->ht, &iter.iter, node, node) {
+	cds_lfht_for_each_entry(ust_app_ht_by_sock->ht, &iter.iter, app,
+			sock_n.node) {
 		ret = lttng_ht_del(ust_app_ht_by_sock, &iter);
 		assert(!ret);
 	}
@@ -1847,6 +1997,7 @@ int ust_app_disable_all_event_glb(struct ltt_ust_session *usess,
 int ust_app_create_channel_glb(struct ltt_ust_session *usess,
 		struct ltt_ust_channel *uchan)
 {
+	int ret = 0;
 	struct lttng_ht_iter iter;
 	struct ust_app *app;
 	struct ust_app_session *ua_sess;
@@ -1878,9 +2029,11 @@ int ust_app_create_channel_glb(struct ltt_ust_session *usess,
 		ua_sess = create_ust_app_session(usess, app);
 		if (ua_sess == NULL) {
 			/* The malloc() failed. */
+			ret = -1;
 			goto error;
 		} else if (ua_sess == (void *) -1UL) {
 			/* The application's socket is not valid. Contiuing */
+			ret = -1;
 			continue;
 		}
 
@@ -1888,16 +2041,15 @@ int ust_app_create_channel_glb(struct ltt_ust_session *usess,
 		ua_chan = create_ust_app_channel(ua_sess, uchan, app);
 		if (ua_chan == NULL) {
 			/* Major problem here and it's maybe the tracer or malloc() */
+			ret = -1;
 			goto error;
 		}
 	}
 
 	rcu_read_unlock();
 
-	return 0;
-
 error:
-	return -1;
+	return ret;
 }
 
 /*
@@ -1908,7 +2060,7 @@ int ust_app_enable_event_glb(struct ltt_ust_session *usess,
 {
 	int ret = 0;
 	struct lttng_ht_iter iter, uiter;
-	struct lttng_ht_node_str *ua_chan_node, *ua_event_node;
+	struct lttng_ht_node_str *ua_chan_node;
 	struct ust_app *app;
 	struct ust_app_session *ua_sess;
 	struct ust_app_channel *ua_chan;
@@ -1946,14 +2098,14 @@ int ust_app_enable_event_glb(struct ltt_ust_session *usess,
 
 		ua_chan = caa_container_of(ua_chan_node, struct ust_app_channel, node);
 
-		lttng_ht_lookup(ua_chan->events, (void*)uevent->attr.name, &uiter);
-		ua_event_node = lttng_ht_iter_get_node_str(&uiter);
-		if (ua_event_node == NULL) {
+		/* Get event node */
+		ua_event = find_ust_app_event(ua_chan->events, uevent->attr.name,
+				uevent->filter, uevent->attr.loglevel);
+		if (ua_event == NULL) {
 			DBG3("UST app enable event %s not found for app PID %d."
 					"Skipping app", uevent->attr.name, app->pid);
 			continue;
 		}
-		ua_event = caa_container_of(ua_event_node, struct ust_app_event, node);
 
 		ret = enable_ust_app_event(ua_sess, ua_event, app);
 		if (ret < 0) {
@@ -2008,7 +2160,7 @@ int ust_app_create_event_glb(struct ltt_ust_session *usess,
 
 		ret = create_ust_app_event(ua_sess, ua_chan, uevent, app);
 		if (ret < 0) {
-			if (ret != -EEXIST) {
+			if (ret != -LTTNG_UST_ERR_EXIST) {
 				/* Possible value at this point: -ENOMEM. If so, we stop! */
 				break;
 			}
@@ -2033,7 +2185,7 @@ int ust_app_start_trace(struct ltt_ust_session *usess, struct ust_app *app)
 	struct ust_app_session *ua_sess;
 	struct ust_app_channel *ua_chan;
 	struct ltt_ust_stream *ustream;
-	int consumerd_fd;
+	struct consumer_socket *socket;
 
 	DBG("Starting tracing for ust app pid %d", app->pid);
 
@@ -2053,11 +2205,26 @@ int ust_app_start_trace(struct ltt_ust_session *usess, struct ust_app *app)
 		goto skip_setup;
 	}
 
+	/* Create directories if consumer is LOCAL and has a path defined. */
+	if (usess->consumer->type == CONSUMER_DST_LOCAL &&
+			strlen(usess->consumer->dst.trace_path) > 0) {
+		ret = run_as_mkdir_recursive(usess->consumer->dst.trace_path,
+				S_IRWXU | S_IRWXG, usess->uid, usess->gid);
+		if (ret < 0) {
+			if (ret != -EEXIST) {
+				ERR("Trace directory creation error");
+				ret = -1;
+				goto error_rcu_unlock;
+			}
+		}
+	}
+
 	/* Indicate that the session has been started once */
 	ua_sess->started = 1;
 
 	ret = create_ust_app_metadata(ua_sess, usess->pathname, app);
 	if (ret < 0) {
+		ret = LTTNG_ERR_UST_META_FAIL;
 		goto error_rcu_unlock;
 	}
 
@@ -2080,20 +2247,27 @@ int ust_app_start_trace(struct ltt_ust_session *usess, struct ust_app *app)
 				free(ustream);
 				goto error_rcu_unlock;
 			}
+
+			health_code_update(&health_thread_cmd);
+
 			ret = ustctl_create_stream(app->sock, ua_chan->obj,
 					&ustream->obj);
 			if (ret < 0) {
 				/* Got all streams */
 				lttng_fd_put(LTTNG_FD_APPS, 2);
 				free(ustream);
+				ret = LTTNG_ERR_UST_STREAM_FAIL;
 				break;
 			}
 			ustream->handle = ustream->obj->handle;
 
+			health_code_update(&health_thread_cmd);
+
 			/* Order is important */
 			cds_list_add_tail(&ustream->list, &ua_chan->streams.head);
 			ret = snprintf(ustream->name, sizeof(ustream->name), "%s_%u",
-					ua_chan->name, ua_chan->streams.count++);
+					ua_chan->name, ua_chan->streams.count);
+			ua_chan->streams.count++;
 			if (ret < 0) {
 				PERROR("asprintf UST create stream");
 				/*
@@ -2105,14 +2279,24 @@ int ust_app_start_trace(struct ltt_ust_session *usess, struct ust_app *app)
 			DBG2("UST stream %d ready (handle: %d)", ua_chan->streams.count,
 					ustream->handle);
 		}
+
+		health_code_update(&health_thread_cmd);
 	}
 
 	switch (app->bits_per_long) {
 	case 64:
-		consumerd_fd = ust_consumerd64_fd;
+		socket = consumer_find_socket(uatomic_read(&ust_consumerd64_fd),
+				usess->consumer);
+		if (socket == NULL) {
+			goto skip_setup;
+		}
 		break;
 	case 32:
-		consumerd_fd = ust_consumerd32_fd;
+		socket = consumer_find_socket(uatomic_read(&ust_consumerd32_fd),
+				usess->consumer);
+		if (socket == NULL) {
+			goto skip_setup;
+		}
 		break;
 	default:
 		ret = -EINVAL;
@@ -2120,11 +2304,13 @@ int ust_app_start_trace(struct ltt_ust_session *usess, struct ust_app *app)
 	}
 
 	/* Setup UST consumer socket and send fds to it */
-	ret = ust_consumer_send_session(consumerd_fd, ua_sess, usess->consumer);
+	ret = ust_consumer_send_session(ua_sess, usess->consumer, socket);
 	if (ret < 0) {
 		goto error_rcu_unlock;
 	}
 
+	health_code_update(&health_thread_cmd);
+
 skip_setup:
 	/* This start the UST tracing */
 	ret = ustctl_start_session(app->sock, ua_sess->handle);
@@ -2133,15 +2319,19 @@ skip_setup:
 		goto error_rcu_unlock;
 	}
 
+	health_code_update(&health_thread_cmd);
+
 	/* Quiescent wait after starting trace */
 	ustctl_wait_quiescent(app->sock);
 
 end:
 	rcu_read_unlock();
+	health_code_update(&health_thread_cmd);
 	return 0;
 
 error_rcu_unlock:
 	rcu_read_unlock();
+	health_code_update(&health_thread_cmd);
 	return -1;
 }
 
@@ -2176,6 +2366,8 @@ int ust_app_stop_trace(struct ltt_ust_session *usess, struct ust_app *app)
 	 */
 	assert(ua_sess->started == 1);
 
+	health_code_update(&health_thread_cmd);
+
 	/* This inhibits UST tracing */
 	ret = ustctl_stop_session(app->sock, ua_sess->handle);
 	if (ret < 0) {
@@ -2183,12 +2375,17 @@ int ust_app_stop_trace(struct ltt_ust_session *usess, struct ust_app *app)
 		goto error_rcu_unlock;
 	}
 
+	health_code_update(&health_thread_cmd);
+
 	/* Quiescent wait after stopping trace */
 	ustctl_wait_quiescent(app->sock);
 
+	health_code_update(&health_thread_cmd);
+
 	/* Flushing buffers */
 	cds_lfht_for_each_entry(ua_sess->channels->ht, &iter.iter, ua_chan,
 			node.node) {
+		health_code_update(&health_thread_cmd);
 		ret = ustctl_sock_flush_buffer(app->sock, ua_chan->obj);
 		if (ret < 0) {
 			ERR("UST app PID %d channel %s flush failed with ret %d",
@@ -2198,6 +2395,8 @@ int ust_app_stop_trace(struct ltt_ust_session *usess, struct ust_app *app)
 		}
 	}
 
+	health_code_update(&health_thread_cmd);
+
 	/* Flush all buffers before stopping */
 	ret = ustctl_sock_flush_buffer(app->sock, ua_sess->metadata->obj);
 	if (ret < 0) {
@@ -2207,10 +2406,12 @@ int ust_app_stop_trace(struct ltt_ust_session *usess, struct ust_app *app)
 
 end:
 	rcu_read_unlock();
+	health_code_update(&health_thread_cmd);
 	return 0;
 
 error_rcu_unlock:
 	rcu_read_unlock();
+	health_code_update(&health_thread_cmd);
 	return -1;
 }
 
@@ -2246,8 +2447,10 @@ int ust_app_destroy_trace(struct ltt_ust_session *usess, struct ust_app *app)
 	obj.shm_fd = -1;
 	obj.wait_fd = -1;
 	obj.memory_map_size = 0;
+	health_code_update(&health_thread_cmd);
 	ustctl_release_object(app->sock, &obj);
 
+	health_code_update(&health_thread_cmd);
 	delete_ust_app_session(app->sock, ua_sess);
 
 	/* Quiescent wait after stopping trace */
@@ -2255,10 +2458,12 @@ int ust_app_destroy_trace(struct ltt_ust_session *usess, struct ust_app *app)
 
 end:
 	rcu_read_unlock();
+	health_code_update(&health_thread_cmd);
 	return 0;
 
 error_rcu_unlock:
 	rcu_read_unlock();
+	health_code_update(&health_thread_cmd);
 	return -1;
 }
 
@@ -2374,7 +2579,8 @@ void ust_app_global_update(struct ltt_ust_session *usess, int sock)
 	}
 
 	ua_sess = create_ust_app_session(usess, app);
-	if (ua_sess == NULL) {
+	if (ua_sess == NULL || ua_sess == (void *) -1UL) {
+		/* Tracer is gone for this session and has been freed */
 		goto error;
 	}
 
@@ -2410,14 +2616,10 @@ void ust_app_global_update(struct ltt_ust_session *usess, int sock)
 				continue;
 			}
 
-			/* Add context on events. */
-			cds_lfht_for_each_entry(ua_event->ctx->ht, &iter_ctx.iter,
-					ua_ctx, node.node) {
-				ret = create_ust_event_context(ua_event, ua_ctx, app);
-				if (ret < 0) {
-					/* FIXME: Should we quit here or continue... */
-					continue;
-				}
+			ret = set_ust_event_filter(ua_event, app);
+			if (ret < 0) {
+				/* FIXME: Should we quit here or continue... */
+				continue;
 			}
 		}
 	}
@@ -2483,63 +2685,6 @@ int ust_app_add_ctx_channel_glb(struct ltt_ust_session *usess,
 	return ret;
 }
 
-/*
- * Add context to a specific event in a channel for global UST domain.
- */
-int ust_app_add_ctx_event_glb(struct ltt_ust_session *usess,
-		struct ltt_ust_channel *uchan, struct ltt_ust_event *uevent,
-		struct ltt_ust_context *uctx)
-{
-	int ret = 0;
-	struct lttng_ht_node_str *ua_chan_node, *ua_event_node;
-	struct lttng_ht_iter iter, uiter;
-	struct ust_app_session *ua_sess;
-	struct ust_app_event *ua_event;
-	struct ust_app_channel *ua_chan = NULL;
-	struct ust_app *app;
-
-	rcu_read_lock();
-
-	cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
-		if (!app->compatible) {
-			/*
-			 * TODO: In time, we should notice the caller of this error by
-			 * telling him that this is a version error.
-			 */
-			continue;
-		}
-		ua_sess = lookup_session_by_app(usess, app);
-		if (ua_sess == NULL) {
-			continue;
-		}
-
-		/* Lookup channel in the ust app session */
-		lttng_ht_lookup(ua_sess->channels, (void *)uchan->name, &uiter);
-		ua_chan_node = lttng_ht_iter_get_node_str(&uiter);
-		if (ua_chan_node == NULL) {
-			continue;
-		}
-		ua_chan = caa_container_of(ua_chan_node, struct ust_app_channel,
-				node);
-
-		lttng_ht_lookup(ua_chan->events, (void *)uevent->attr.name, &uiter);
-		ua_event_node = lttng_ht_iter_get_node_str(&uiter);
-		if (ua_event_node == NULL) {
-			continue;
-		}
-		ua_event = caa_container_of(ua_event_node, struct ust_app_event,
-				node);
-
-		ret = create_ust_app_event_context(ua_sess, ua_event, &uctx->ctx, app);
-		if (ret < 0) {
-			continue;
-		}
-	}
-
-	rcu_read_unlock();
-	return ret;
-}
-
 /*
  * Enable event for a channel from a UST session for a specific PID.
  */
@@ -2548,7 +2693,7 @@ int ust_app_enable_event_pid(struct ltt_ust_session *usess,
 {
 	int ret = 0;
 	struct lttng_ht_iter iter;
-	struct lttng_ht_node_str *ua_chan_node, *ua_event_node;
+	struct lttng_ht_node_str *ua_chan_node;
 	struct ust_app *app;
 	struct ust_app_session *ua_sess;
 	struct ust_app_channel *ua_chan;
@@ -2582,16 +2727,14 @@ int ust_app_enable_event_pid(struct ltt_ust_session *usess,
 
 	ua_chan = caa_container_of(ua_chan_node, struct ust_app_channel, node);
 
-	lttng_ht_lookup(ua_chan->events, (void *)uevent->attr.name, &iter);
-	ua_event_node = lttng_ht_iter_get_node_str(&iter);
-	if (ua_event_node == NULL) {
+	ua_event = find_ust_app_event(ua_chan->events, uevent->attr.name,
+			uevent->filter, uevent->attr.loglevel);
+	if (ua_event == NULL) {
 		ret = create_ust_app_event(ua_sess, ua_chan, uevent, app);
 		if (ret < 0) {
 			goto error;
 		}
 	} else {
-		ua_event = caa_container_of(ua_event_node, struct ust_app_event, node);
-
 		ret = enable_ust_app_event(ua_sess, ua_event, app);
 		if (ret < 0) {
 			goto error;
@@ -2677,29 +2820,33 @@ int ust_app_validate_version(int sock)
 	app = find_app_by_sock(sock);
 	assert(app);
 
+	health_code_update(&health_thread_cmd);
+
 	ret = ustctl_tracer_version(sock, &app->version);
 	if (ret < 0) {
 		goto error;
 	}
 
 	/* Validate version */
-	if (app->version.major > UST_APP_MAJOR_VERSION) {
+	if (app->version.major != UST_APP_MAJOR_VERSION) {
 		goto error;
 	}
 
-	DBG2("UST app PID %d is compatible with major version %d "
-			"(supporting <= %d)", app->pid, app->version.major,
+	DBG2("UST app PID %d is compatible with internal major version %d "
+			"(supporting == %d)", app->pid, app->version.major,
 			UST_APP_MAJOR_VERSION);
 	app->compatible = 1;
 	rcu_read_unlock();
+	health_code_update(&health_thread_cmd);
 	return 0;
 
 error:
-	DBG2("UST app PID %d is not compatible with major version %d "
-			"(supporting <= %d)", app->pid, app->version.major,
+	DBG2("UST app PID %d is not compatible with internal major version %d "
+			"(supporting == %d)", app->pid, app->version.major,
 			UST_APP_MAJOR_VERSION);
 	app->compatible = 0;
 	rcu_read_unlock();
+	health_code_update(&health_thread_cmd);
 	return -1;
 }
 
@@ -2723,6 +2870,8 @@ int ust_app_calibrate_glb(struct lttng_ust_calibrate *calibrate)
 			continue;
 		}
 
+		health_code_update(&health_thread_cmd);
+
 		ret = ustctl_calibrate(app->sock, calibrate);
 		if (ret < 0) {
 			switch (ret) {
@@ -2743,5 +2892,7 @@ int ust_app_calibrate_glb(struct lttng_ust_calibrate *calibrate)
 
 	rcu_read_unlock();
 
+	health_code_update(&health_thread_cmd);
+
 	return ret;
 }