X-Git-Url: https://git.lttng.org/?p=lttng-tools.git;a=blobdiff_plain;f=src%2Flib%2Flttng-ctl%2Flttng-ctl.c;h=8f63bf3e85e367285f9c599176040a4cd266dcd5;hp=e4560bb7fb927895d5b11fd84db2338001b0507b;hb=5d2e1e66a968d9e555f9b8b00d0589ebfaf3de32;hpb=ff7ef7b8297ae2e3aa6451a0045d657d91aec7be

diff --git a/src/lib/lttng-ctl/lttng-ctl.c b/src/lib/lttng-ctl/lttng-ctl.c
index e4560bb7f..8f63bf3e8 100644
--- a/src/lib/lttng-ctl/lttng-ctl.c
+++ b/src/lib/lttng-ctl/lttng-ctl.c
@@ -69,8 +69,6 @@ static int connected;
  * Those two variables are used by error.h to silent or control the verbosity of
  * error message. They are global to the library so application linking with it
  * are able to compile correctly and also control verbosity of the library.
- *
- * Note that it is *not* possible to silent ERR() and PERROR() macros.
  */
 int lttng_opt_quiet;
 int lttng_opt_verbose;
@@ -92,7 +90,6 @@ static void set_default_url_attr(struct lttng_uri *uri,
 static ssize_t parse_str_urls_to_uri(const char *ctrl_url, const char *data_url,
 		struct lttng_uri **uris)
 {
-	int ret;
 	unsigned int equal = 1, idx = 0;
 	/* Add the "file://" size to the URL maximum size */
 	char url[PATH_MAX + 7];
@@ -117,6 +114,8 @@ static ssize_t parse_str_urls_to_uri(const char *ctrl_url, const char *data_url,
 	 * Check if first character is a '/' or else reject the URL.
 	 */
 	if (ctrl_url && ctrl_url[0] == '/') {
+		int ret;
+
 		ret = snprintf(url, sizeof(url), "file://%s", ctrl_url);
 		if (ret < 0) {
 			PERROR("snprintf file url");
@@ -185,10 +184,12 @@ static ssize_t parse_str_urls_to_uri(const char *ctrl_url, const char *data_url,
 		/* It's possible the control URIs array contains more than one URI */
 		memcpy(tmp_uris, ctrl_uris, sizeof(struct lttng_uri) * size_ctrl);
 		++idx;
+		free(ctrl_uris);
 	}
 
 	if (data_uris) {
 		memcpy(&tmp_uris[idx], data_uris, sizeof(struct lttng_uri));
+		free(data_uris);
 	}
 
 	*uris = tmp_uris;
@@ -253,7 +254,7 @@ static int send_session_msg(struct lttcomm_session_msg *lsm)
 	int ret;
 
 	if (!connected) {
-		ret = -ENOTCONN;
+		ret = -LTTNG_ERR_NO_SESSIOND;
 		goto end;
 	}
 
@@ -261,6 +262,9 @@ static int send_session_msg(struct lttcomm_session_msg *lsm)
 
 	ret = lttcomm_send_creds_unix_sock(sessiond_socket, lsm,
 			sizeof(struct lttcomm_session_msg));
+	if (ret < 0) {
+		ret = -LTTNG_ERR_FATAL;
+	}
 
 end:
 	return ret;
@@ -277,7 +281,7 @@ static int send_session_varlen(void *data, size_t len)
 	int ret;
 
 	if (!connected) {
-		ret = -ENOTCONN;
+		ret = -LTTNG_ERR_NO_SESSIOND;
 		goto end;
 	}
 
@@ -287,6 +291,9 @@ static int send_session_varlen(void *data, size_t len)
 	}
 
 	ret = lttcomm_send_unix_sock(sessiond_socket, data, len);
+	if (ret < 0) {
+		ret = -LTTNG_ERR_FATAL;
+	}
 
 end:
 	return ret;
@@ -303,11 +310,14 @@ static int recv_data_sessiond(void *buf, size_t len)
 	int ret;
 
 	if (!connected) {
-		ret = -ENOTCONN;
+		ret = -LTTNG_ERR_NO_SESSIOND;
 		goto end;
 	}
 
 	ret = lttcomm_recv_unix_sock(sessiond_socket, buf, len);
+	if (ret < 0) {
+		ret = -LTTNG_ERR_FATAL;
+	}
 
 end:
 	return ret;
@@ -378,13 +388,13 @@ static int try_connect_sessiond(const char *sock_path)
 	ret = access(sock_path, F_OK);
 	if (ret < 0) {
 		/* Not alive */
-		return -1;
+		goto error;
 	}
 
 	ret = lttcomm_connect_unix_sock(sock_path);
 	if (ret < 0) {
 		/* Not alive */
-		return -1;
+		goto error;
 	}
 
 	ret = lttcomm_close_unix_sock(ret);
@@ -393,17 +403,20 @@ static int try_connect_sessiond(const char *sock_path)
 	}
 
 	return 0;
+
+error:
+	return -1;
 }
 
 /*
- * Set sessiond socket path by putting it in the global
- * sessiond_sock_path variable.
- * Returns 0 on success,
- * -ENOMEM on failure (the sessiond socket path is somehow too long)
+ * Set sessiond socket path by putting it in the global sessiond_sock_path
+ * variable.
+ *
+ * Returns 0 on success, negative value on failure (the sessiond socket path
+ * is somehow too long or ENOMEM).
  */
 static int set_session_daemon_path(void)
 {
-	int ret;
 	int in_tgroup = 0;	/* In tracing group */
 	uid_t uid;
 
@@ -420,6 +433,8 @@ static int set_session_daemon_path(void)
 	}
 
 	if (uid != 0) {
+		int ret;
+
 		if (in_tgroup) {
 			/* Tracing group */
 			ret = try_connect_sessiond(sessiond_sock_path);
@@ -437,11 +452,14 @@ static int set_session_daemon_path(void)
 		ret = snprintf(sessiond_sock_path, sizeof(sessiond_sock_path),
 				DEFAULT_HOME_CLIENT_UNIX_SOCK, getenv("HOME"));
 		if ((ret < 0) || (ret >= sizeof(sessiond_sock_path))) {
-			return -ENOMEM;
+			goto error;
 		}
 	}
 end:
 	return 0;
+
+error:
+	return -1;
 }
 
 /*
@@ -455,19 +473,22 @@ static int connect_sessiond(void)
 
 	ret = set_session_daemon_path();
 	if (ret < 0) {
-		return -1; /* set_session_daemon_path() returns -ENOMEM */
+		goto error;
 	}
 
 	/* Connect to the sesssion daemon */
 	ret = lttcomm_connect_unix_sock(sessiond_sock_path);
 	if (ret < 0) {
-		return ret;
+		goto error;
 	}
 
 	sessiond_socket = ret;
 	connected = 1;
 
 	return 0;
+
+error:
+	return -1;
 }
 
 /*
@@ -503,23 +524,27 @@ static int ask_sessiond_varlen(struct lttcomm_session_msg *lsm,
 
 	ret = connect_sessiond();
 	if (ret < 0) {
+		ret = -LTTNG_ERR_NO_SESSIOND;
 		goto end;
 	}
 
 	/* Send command to session daemon */
 	ret = send_session_msg(lsm);
 	if (ret < 0) {
+		/* Ret value is a valid lttng error code. */
 		goto end;
 	}
 	/* Send var len data */
 	ret = send_session_varlen(vardata, varlen);
 	if (ret < 0) {
+		/* Ret value is a valid lttng error code. */
 		goto end;
 	}
 
 	/* Get header from data transmission */
 	ret = recv_data_sessiond(&llm, sizeof(llm));
 	if (ret < 0) {
+		/* Ret value is a valid lttng error code. */
 		goto end;
 	}
 
@@ -553,7 +578,7 @@ static int ask_sessiond_varlen(struct lttcomm_session_msg *lsm,
 	 * this point, an error is returned and data is freed.
 	 */
 	if (buf == NULL) {
-		ret = -1;
+		ret = -LTTNG_ERR_INVALID;
 		free(data);
 		goto end;
 	}
@@ -583,11 +608,15 @@ static int ask_sessiond(struct lttcomm_session_msg *lsm, void **buf)
 struct lttng_handle *lttng_create_handle(const char *session_name,
 		struct lttng_domain *domain)
 {
-	struct lttng_handle *handle;
+	struct lttng_handle *handle = NULL;
+
+	if (domain == NULL) {
+		goto end;
+	}
 
 	handle = malloc(sizeof(struct lttng_handle));
 	if (handle == NULL) {
-		perror("malloc handle");
+		PERROR("malloc handle");
 		goto end;
 	}
 
@@ -607,9 +636,7 @@ end:
  */
 void lttng_destroy_handle(struct lttng_handle *handle)
 {
-	if (handle) {
-		free(handle);
-	}
+	free(handle);
 }
 
 /*
@@ -621,6 +648,10 @@ int lttng_register_consumer(struct lttng_handle *handle,
 {
 	struct lttcomm_session_msg lsm;
 
+	if (handle == NULL || socket_path == NULL) {
+		return -LTTNG_ERR_INVALID;
+	}
+
 	lsm.cmd_type = LTTNG_REGISTER_CONSUMER;
 	copy_string(lsm.session.name, handle->session_name,
 			sizeof(lsm.session.name));
@@ -640,7 +671,7 @@ int lttng_start_tracing(const char *session_name)
 	struct lttcomm_session_msg lsm;
 
 	if (session_name == NULL) {
-		return -1;
+		return -LTTNG_ERR_INVALID;
 	}
 
 	lsm.cmd_type = LTTNG_START_TRACE;
@@ -651,29 +682,79 @@ int lttng_start_tracing(const char *session_name)
 }
 
 /*
- *  Stop tracing for all traces of the session.
- *  Returns size of returned session payload data or a negative error code.
+ * Stop tracing for all traces of the session.
  */
-int lttng_stop_tracing(const char *session_name)
+static int _lttng_stop_tracing(const char *session_name, int wait)
 {
+	int ret, data_ret;
 	struct lttcomm_session_msg lsm;
 
 	if (session_name == NULL) {
-		return -1;
+		return -LTTNG_ERR_INVALID;
 	}
 
 	lsm.cmd_type = LTTNG_STOP_TRACE;
 
 	copy_string(lsm.session.name, session_name, sizeof(lsm.session.name));
 
-	return ask_sessiond(&lsm, NULL);
+	ret = ask_sessiond(&lsm, NULL);
+	if (ret < 0 && ret != -LTTNG_ERR_TRACE_ALREADY_STOPPED) {
+		goto error;
+	}
+
+	if (!wait) {
+		goto end;
+	}
+
+	_MSG("Waiting for data availability");
+
+	/* Check for data availability */
+	do {
+		data_ret = lttng_data_pending(session_name);
+		if (data_ret < 0) {
+			/* Return the data available call error. */
+			ret = data_ret;
+			goto error;
+		}
+
+		/*
+		 * Data sleep time before retrying (in usec). Don't sleep if the call
+		 * returned value indicates availability.
+		 */
+		if (data_ret) {
+			usleep(DEFAULT_DATA_AVAILABILITY_WAIT_TIME);
+			_MSG(".");
+		}
+	} while (data_ret != 0);
+
+	MSG("");
+
+end:
+error:
+	return ret;
+}
+
+/*
+ * Stop tracing and wait for data availability.
+ */
+int lttng_stop_tracing(const char *session_name)
+{
+	return _lttng_stop_tracing(session_name, 1);
+}
+
+/*
+ * Stop tracing but _don't_ wait for data availability.
+ */
+int lttng_stop_tracing_no_wait(const char *session_name)
+{
+	return _lttng_stop_tracing(session_name, 0);
 }
 
 /*
- * Add context to event and/or channel.
- * If event_name is NULL, the context is applied to all events of the channel.
- * If channel_name is NULL, a lookup of the event's channel is done.
- * If both are NULL, the context is applied to all events of all channels.
+ * Add context to a channel.
+ *
+ * If the given channel is NULL, add the contexts to all channels.
+ * The event_name param is ignored.
  *
  * Returns the size of the returned payload data or a negative error code.
  */
@@ -685,7 +766,7 @@ int lttng_add_context(struct lttng_handle *handle,
 
 	/* Safety check. Both are mandatory */
 	if (handle == NULL || ctx == NULL) {
-		return -1;
+		return -LTTNG_ERR_INVALID;
 	}
 
 	memset(&lsm, 0, sizeof(lsm));
@@ -695,9 +776,6 @@ int lttng_add_context(struct lttng_handle *handle,
 	/* Copy channel name */
 	copy_string(lsm.u.context.channel_name, channel_name,
 			sizeof(lsm.u.context.channel_name));
-	/* Copy event name */
-	copy_string(lsm.u.context.event_name, event_name,
-			sizeof(lsm.u.context.event_name));
 
 	copy_lttng_domain(&lsm.domain, &handle->domain);
 
@@ -721,7 +799,7 @@ int lttng_enable_event(struct lttng_handle *handle,
 	struct lttcomm_session_msg lsm;
 
 	if (handle == NULL || ev == NULL) {
-		return -1;
+		return -LTTNG_ERR_INVALID;
 	}
 
 	memset(&lsm, 0, sizeof(lsm));
@@ -751,13 +829,13 @@ int lttng_enable_event(struct lttng_handle *handle,
 }
 
 /*
- * set filter for an event
+ * Create or enable an event with a filter expression.
+ *
  * Return negative error value on error.
  * Return size of returned session payload data if OK.
  */
-
-int lttng_set_event_filter(struct lttng_handle *handle,
-		const char *event_name, const char *channel_name,
+int lttng_enable_event_with_filter(struct lttng_handle *handle,
+		struct lttng_event *event, const char *channel_name,
 		const char *filter_expression)
 {
 	struct lttcomm_session_msg lsm;
@@ -765,13 +843,21 @@ int lttng_set_event_filter(struct lttng_handle *handle,
 	FILE *fmem;
 	int ret = 0;
 
-	/* Safety check. */
-	if (handle == NULL) {
-		return -1;
+	if (!filter_expression) {
+		/*
+		 * Fall back to normal event enabling if no filter
+		 * specified.
+		 */
+		return lttng_enable_event(handle, event, channel_name);
 	}
 
-	if (!filter_expression) {
-		return 0;
+	/*
+	 * Empty filter string will always be rejected by the parser
+	 * anyway, so treat this corner-case early to eliminate
+	 * lttng_fmemopen error for 0-byte allocation.
+	 */
+	if (handle == NULL || filter_expression[0] == '\0') {
+		return -LTTNG_ERR_INVALID;
 	}
 
 	/*
@@ -845,15 +931,17 @@ int lttng_set_event_filter(struct lttng_handle *handle,
 
 	memset(&lsm, 0, sizeof(lsm));
 
-	lsm.cmd_type = LTTNG_SET_FILTER;
+	lsm.cmd_type = LTTNG_ENABLE_EVENT_WITH_FILTER;
 
 	/* Copy channel name */
-	copy_string(lsm.u.filter.channel_name, channel_name,
-			sizeof(lsm.u.filter.channel_name));
+	copy_string(lsm.u.enable.channel_name, channel_name,
+			sizeof(lsm.u.enable.channel_name));
 	/* Copy event name */
-	copy_string(lsm.u.filter.event_name, event_name,
-			sizeof(lsm.u.filter.event_name));
-	lsm.u.filter.bytecode_len = sizeof(ctx->bytecode->b)
+	if (event) {
+		memcpy(&lsm.u.enable.event, event, sizeof(lsm.u.enable.event));
+	}
+
+	lsm.u.enable.bytecode_len = sizeof(ctx->bytecode->b)
 			+ bytecode_get_len(&ctx->bytecode->b);
 
 	copy_lttng_domain(&lsm.domain, &handle->domain);
@@ -862,7 +950,7 @@ int lttng_set_event_filter(struct lttng_handle *handle,
 			sizeof(lsm.session.name));
 
 	ret = ask_sessiond_varlen(&lsm, &ctx->bytecode->b,
-				lsm.u.filter.bytecode_len, NULL);
+				lsm.u.enable.bytecode_len, NULL);
 
 	filter_bytecode_free(ctx);
 	filter_ir_free(ctx);
@@ -895,7 +983,7 @@ int lttng_disable_event(struct lttng_handle *handle, const char *name,
 	struct lttcomm_session_msg lsm;
 
 	if (handle == NULL) {
-		return -1;
+		return -LTTNG_ERR_INVALID;
 	}
 
 	memset(&lsm, 0, sizeof(lsm));
@@ -936,7 +1024,7 @@ int lttng_enable_channel(struct lttng_handle *handle,
 	 * NULL arguments are forbidden. No default values.
 	 */
 	if (handle == NULL || chan == NULL) {
-		return -1;
+		return -LTTNG_ERR_INVALID;
 	}
 
 	memset(&lsm, 0, sizeof(lsm));
@@ -963,7 +1051,7 @@ int lttng_disable_channel(struct lttng_handle *handle, const char *name)
 
 	/* Safety check. Both are mandatory */
 	if (handle == NULL || name == NULL) {
-		return -1;
+		return -LTTNG_ERR_INVALID;
 	}
 
 	memset(&lsm, 0, sizeof(lsm));
@@ -994,7 +1082,7 @@ int lttng_list_tracepoints(struct lttng_handle *handle,
 	struct lttcomm_session_msg lsm;
 
 	if (handle == NULL) {
-		return -1;
+		return -LTTNG_ERR_INVALID;
 	}
 
 	lsm.cmd_type = LTTNG_LIST_TRACEPOINTS;
@@ -1021,7 +1109,7 @@ int lttng_list_tracepoint_fields(struct lttng_handle *handle,
 	struct lttcomm_session_msg lsm;
 
 	if (handle == NULL) {
-		return -1;
+		return -LTTNG_ERR_INVALID;
 	}
 
 	lsm.cmd_type = LTTNG_LIST_TRACEPOINT_FIELDS;
@@ -1051,12 +1139,13 @@ const char *lttng_strerror(int code)
  */
 int lttng_create_session(const char *name, const char *url)
 {
+	int ret;
 	ssize_t size;
 	struct lttcomm_session_msg lsm;
 	struct lttng_uri *uris = NULL;
 
 	if (name == NULL) {
-		return -1;
+		return -LTTNG_ERR_INVALID;
 	}
 
 	memset(&lsm, 0, sizeof(lsm));
@@ -1067,13 +1156,16 @@ int lttng_create_session(const char *name, const char *url)
 	/* There should never be a data URL */
 	size = parse_str_urls_to_uri(url, NULL, &uris);
 	if (size < 0) {
-		return LTTNG_ERR_INVALID;
+		return -LTTNG_ERR_INVALID;
 	}
 
 	lsm.u.uri.size = size;
 
-	return ask_sessiond_varlen(&lsm, uris, sizeof(struct lttng_uri) * size,
+	ret = ask_sessiond_varlen(&lsm, uris, sizeof(struct lttng_uri) * size,
 			NULL);
+
+	free(uris);
+	return ret;
 }
 
 /*
@@ -1085,7 +1177,7 @@ int lttng_destroy_session(const char *session_name)
 	struct lttcomm_session_msg lsm;
 
 	if (session_name == NULL) {
-		return -1;
+		return -LTTNG_ERR_INVALID;
 	}
 
 	lsm.cmd_type = LTTNG_DESTROY_SESSION;
@@ -1128,7 +1220,7 @@ int lttng_list_domains(const char *session_name,
 	struct lttcomm_session_msg lsm;
 
 	if (session_name == NULL) {
-		return -1;
+		return -LTTNG_ERR_INVALID;
 	}
 
 	lsm.cmd_type = LTTNG_LIST_DOMAINS;
@@ -1156,7 +1248,7 @@ int lttng_list_channels(struct lttng_handle *handle,
 	struct lttcomm_session_msg lsm;
 
 	if (handle == NULL) {
-		return -1;
+		return -LTTNG_ERR_INVALID;
 	}
 
 	lsm.cmd_type = LTTNG_LIST_CHANNELS;
@@ -1187,7 +1279,7 @@ int lttng_list_events(struct lttng_handle *handle,
 
 	/* Safety check. An handle and channel name are mandatory */
 	if (handle == NULL || channel_name == NULL) {
-		return -1;
+		return -LTTNG_ERR_INVALID;
 	}
 
 	lsm.cmd_type = LTTNG_LIST_EVENTS;
@@ -1214,11 +1306,11 @@ int lttng_list_events(struct lttng_handle *handle,
 int lttng_set_tracing_group(const char *name)
 {
 	if (name == NULL) {
-		return -1;
+		return -LTTNG_ERR_INVALID;
 	}
 
 	if (asprintf(&tracing_group, "%s", name) < 0) {
-		return -ENOMEM;
+		return -LTTNG_ERR_FATAL;
 	}
 
 	return 0;
@@ -1234,7 +1326,7 @@ int lttng_calibrate(struct lttng_handle *handle,
 
 	/* Safety check. NULL pointer are forbidden */
 	if (handle == NULL || calibrate == NULL) {
-		return -1;
+		return -LTTNG_ERR_INVALID;
 	}
 
 	lsm.cmd_type = LTTNG_CALIBRATE;
@@ -1265,7 +1357,7 @@ void lttng_channel_set_default_attr(struct lttng_domain *domain,
 		attr->switch_timer_interval = DEFAULT_CHANNEL_SWITCH_TIMER;
 		attr->read_timer_interval = DEFAULT_CHANNEL_READ_TIMER;
 
-		attr->subbuf_size = DEFAULT_KERNEL_CHANNEL_SUBBUF_SIZE;
+		attr->subbuf_size = default_get_kernel_channel_subbuf_size();
 		attr->num_subbuf = DEFAULT_KERNEL_CHANNEL_SUBBUF_NUM;
 		attr->output = DEFAULT_KERNEL_CHANNEL_OUTPUT;
 		break;
@@ -1279,7 +1371,7 @@ void lttng_channel_set_default_attr(struct lttng_domain *domain,
 		attr->switch_timer_interval = DEFAULT_CHANNEL_SWITCH_TIMER;
 		attr->read_timer_interval = DEFAULT_CHANNEL_READ_TIMER;
 
-		attr->subbuf_size = DEFAULT_UST_CHANNEL_SUBBUF_SIZE;
+		attr->subbuf_size = default_get_ust_channel_subbuf_size();
 		attr->num_subbuf = DEFAULT_UST_CHANNEL_SUBBUF_NUM;
 		attr->output = DEFAULT_UST_CHANNEL_OUTPUT;
 		break;
@@ -1305,9 +1397,12 @@ int lttng_session_daemon_alive(void)
 		return ret;
 	}
 
-	if (strlen(sessiond_sock_path) == 0) {
-		/* No socket path set. Weird error */
-		return -1;
+	if (*sessiond_sock_path == '\0') {
+		/*
+		 * No socket path set. Weird error which means the constructor was not
+		 * called.
+		 */
+		assert(0);
 	}
 
 	ret = try_connect_sessiond(sessiond_sock_path);
@@ -1328,12 +1423,13 @@ int lttng_session_daemon_alive(void)
 int lttng_set_consumer_url(struct lttng_handle *handle,
 		const char *control_url, const char *data_url)
 {
+	int ret;
 	ssize_t size;
 	struct lttcomm_session_msg lsm;
 	struct lttng_uri *uris = NULL;
 
 	if (handle == NULL || (control_url == NULL && data_url == NULL)) {
-		return -1;
+		return -LTTNG_ERR_INVALID;
 	}
 
 	memset(&lsm, 0, sizeof(lsm));
@@ -1346,57 +1442,32 @@ int lttng_set_consumer_url(struct lttng_handle *handle,
 
 	size = parse_str_urls_to_uri(control_url, data_url, &uris);
 	if (size < 0) {
-		return LTTNG_ERR_INVALID;
+		return -LTTNG_ERR_INVALID;
 	}
 
 	lsm.u.uri.size = size;
 
-	return ask_sessiond_varlen(&lsm, uris, sizeof(struct lttng_uri) * size,
+	ret = ask_sessiond_varlen(&lsm, uris, sizeof(struct lttng_uri) * size,
 			NULL);
+
+	free(uris);
+	return ret;
 }
 
 /*
- * Enable consumer for a session and domain.
- *
- * Return 0 on success, else a negative value.
+ * [OBSELETE]
  */
 int lttng_enable_consumer(struct lttng_handle *handle)
 {
-	struct lttcomm_session_msg lsm;
-
-	if (handle == NULL) {
-		return -1;
-	}
-
-	lsm.cmd_type = LTTNG_ENABLE_CONSUMER;
-
-	copy_string(lsm.session.name, handle->session_name,
-			sizeof(lsm.session.name));
-	copy_lttng_domain(&lsm.domain, &handle->domain);
-
-	return ask_sessiond(&lsm, NULL);
+	return -ENOSYS;
 }
 
 /*
- * Disable consumer for a session and domain.
- *
- * Return 0 on success, else a negative value.
+ * [OBSELETE]
  */
 int lttng_disable_consumer(struct lttng_handle *handle)
 {
-	struct lttcomm_session_msg lsm;
-
-	if (handle == NULL) {
-		return -1;
-	}
-
-	lsm.cmd_type = LTTNG_DISABLE_CONSUMER;
-
-	copy_string(lsm.session.name, handle->session_name,
-			sizeof(lsm.session.name));
-	copy_lttng_domain(&lsm.domain, &handle->domain);
-
-	return ask_sessiond(&lsm, NULL);
+	return -ENOSYS;
 }
 
 /*
@@ -1407,7 +1478,6 @@ int lttng_disable_consumer(struct lttng_handle *handle)
  */
 static int set_health_socket_path(void)
 {
-	int ret;
 	int in_tgroup = 0;	/* In tracing group */
 	uid_t uid;
 	const char *home;
@@ -1425,6 +1495,8 @@ static int set_health_socket_path(void)
 	}
 
 	if (uid != 0) {
+		int ret;
+
 		/*
 		 * With GNU C <  2.1, snprintf returns -1 if the target buffer is too small;
 		 * With GNU C >= 2.1, snprintf returns the required size (excluding closing null)
@@ -1449,11 +1521,9 @@ static int set_health_socket_path(void)
 /*
  * Check session daemon health for a specific health component.
  *
- * Return 0 if health is OK or else 1 if BAD. A return value of -1 indicate
- * that the control library was not able to connect to the session daemon
- * health socket.
+ * Return 0 if health is OK or else 1 if BAD.
  *
- * Any other positive value is an lttcomm error which can be translate with
+ * Any other negative value is a lttng error code which can be translated with
  * lttng_strerror().
  */
 int lttng_health_check(enum lttng_health_component c)
@@ -1465,7 +1535,7 @@ int lttng_health_check(enum lttng_health_component c)
 	/* Connect to the sesssion daemon */
 	sock = lttcomm_connect_unix_sock(health_sock_path);
 	if (sock < 0) {
-		ret = -1;
+		ret = -LTTNG_ERR_NO_SESSIOND;
 		goto error;
 	}
 
@@ -1474,11 +1544,13 @@ int lttng_health_check(enum lttng_health_component c)
 
 	ret = lttcomm_send_unix_sock(sock, (void *)&msg, sizeof(msg));
 	if (ret < 0) {
+		ret = -LTTNG_ERR_FATAL;
 		goto close_error;
 	}
 
 	ret = lttcomm_recv_unix_sock(sock, (void *)&reply, sizeof(reply));
 	if (ret < 0) {
+		ret = -LTTNG_ERR_FATAL;
 		goto close_error;
 	}
 
@@ -1517,43 +1589,72 @@ int _lttng_create_session_ext(const char *name, const char *url,
 	struct lttcomm_session_msg lsm;
 	struct lttng_uri *uris = NULL;
 
-	if (name == NULL || datetime == NULL) {
-		return -1;
+	if (name == NULL || datetime == NULL || url == NULL) {
+		return -LTTNG_ERR_INVALID;
 	}
 
 	memset(&lsm, 0, sizeof(lsm));
 
 	lsm.cmd_type = LTTNG_CREATE_SESSION;
-	if (!strncmp(name, DEFAULT_SESSION_NAME, strlen(DEFAULT_SESSION_NAME))) {
-		ret = snprintf(lsm.session.name, sizeof(lsm.session.name), "%s-%s",
-				name, datetime);
-		if (ret < 0) {
-			PERROR("snprintf session name datetime");
-			return -1;
-		}
-	} else {
-		copy_string(lsm.session.name, name, sizeof(lsm.session.name));
-	}
+	copy_string(lsm.session.name, name, sizeof(lsm.session.name));
 
 	/* There should never be a data URL */
 	size = parse_str_urls_to_uri(url, NULL, &uris);
 	if (size < 0) {
-		return LTTNG_ERR_INVALID;
+		ret = -LTTNG_ERR_INVALID;
+		goto error;
 	}
 
 	lsm.u.uri.size = size;
 
-	if (uris[0].dtype != LTTNG_DST_PATH && strlen(uris[0].subdir) == 0) {
+	if (size > 0 && uris[0].dtype != LTTNG_DST_PATH && strlen(uris[0].subdir) == 0) {
 		ret = snprintf(uris[0].subdir, sizeof(uris[0].subdir), "%s-%s", name,
 				datetime);
 		if (ret < 0) {
 			PERROR("snprintf uri subdir");
-			return -1;
+			ret = -LTTNG_ERR_FATAL;
+			goto error;
 		}
 	}
 
-	return ask_sessiond_varlen(&lsm, uris, sizeof(struct lttng_uri) * size,
+	ret = ask_sessiond_varlen(&lsm, uris, sizeof(struct lttng_uri) * size,
 			NULL);
+
+error:
+	free(uris);
+	return ret;
+}
+
+/*
+ * For a given session name, this call checks if the data is ready to be read
+ * or is still being extracted by the consumer(s) hence not ready to be used by
+ * any readers.
+ */
+int lttng_data_pending(const char *session_name)
+{
+	int ret;
+	struct lttcomm_session_msg lsm;
+
+	if (session_name == NULL) {
+		return -LTTNG_ERR_INVALID;
+	}
+
+	lsm.cmd_type = LTTNG_DATA_PENDING;
+
+	copy_string(lsm.session.name, session_name, sizeof(lsm.session.name));
+
+	ret = ask_sessiond(&lsm, NULL);
+
+	/*
+	 * The ask_sessiond function negate the return code if it's not LTTNG_OK so
+	 * getting -1 means that the reply ret_code was 1 thus meaning that the
+	 * data is available. Yes it is hackish but for now this is the only way.
+	 */
+	if (ret == -1) {
+		ret = 1;
+	}
+
+	return ret;
 }
 
 /*
@@ -1566,3 +1667,11 @@ static void __attribute__((constructor)) init()
 	/* Set socket for health check */
 	(void) set_health_socket_path();
 }
+
+/*
+ * lib destructor
+ */
+static void __attribute__((destructor)) lttng_ctl_exit()
+{
+	free(tracing_group);
+}