struct lttng_domain *domain);
/*
- * Destroy a handle. This will simply free(3) the data pointer returned by
- * lttng_create_handle(), rendering it unusable.
+ * Destroy an handle.
+ *
+ * It free(3) the data pointer returned by lttng_create_handle(), rendering it
+ * unusable.
*/
extern void lttng_destroy_handle(struct lttng_handle *handle);
/*
* Create a tracing session using a name and an optional URL.
*
- * If _url_ is NULL, no consumer is created for the session.
+ * If _url_ is NULL, no consumer is created for the session. The name can't be
+ * NULL here.
*/
extern int lttng_create_session(const char *name, const char *url);
*
* The session will not be usable anymore, tracing will be stopped for all
* registered traces, and the tracing buffers will be flushed.
+ *
+ * The name can't be NULL here.
*/
extern int lttng_destroy_session(const char *name);
/*
* Set the tracing group for the *current* flow of execution.
*
- * On success, returns 0, on error, returns -1 (null name) or -ENOMEM.
+ * On success, returns 0 else a negative value on error being a lttng error
+ * code found in lttng-error.h
*/
extern int lttng_set_tracing_group(const char *name);
/*
* Stop tracing for *all* registered traces (kernel and user-space).
+ *
+ * This call will wait for data availability for each domain of the session so
+ * this can take an abritrary amount of time. However, when returning you have
+ * the guarantee that the data is ready to be read and analyse. Use the
+ * _no_wait call below to avoid this behavior.
+ *
+ * The session_name can't be NULL.
*/
extern int lttng_stop_tracing(const char *session_name);
+/*
+ * Behave exactly like lttng_stop_tracing but does not wait for data
+ * availability.
+ */
+extern int lttng_stop_tracing_no_wait(const char *session_name);
+
/*
* Add context to event(s) for a specific channel (or for all).
*
- * 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.
+ * 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.
+ *
+ * Note that whatever event_name value is, a context can not be added to an
+ * event, so we just ignore it for now.
*/
extern int lttng_add_context(struct lttng_handle *handle,
struct lttng_event_context *ctx, const char *event_name,
*
* If the event you are trying to enable does not exist, it will be created,
* else it is enabled.
- * If event_name is NULL, all events are enabled.
* If channel_name is NULL, the default channel is used (channel0).
+ *
+ * The handle and ev params can not be NULL.
*/
extern int lttng_enable_event(struct lttng_handle *handle,
struct lttng_event *ev, const char *channel_name);
/*
- * Apply a filter expression to an event.
+ * Create or enable an event with a specific filter.
*
- * If event_name is NULL, the filter 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 filter is applied to all events of all channels.
- */
-extern int lttng_set_event_filter(struct lttng_handle *handle,
- const char *event_name,
- const char *channel_name,
+ * If the event you are trying to enable does not exist, it will be created,
+ * else it is enabled.
+ * If ev is NULL, all events are enabled with that filter.
+ * If channel_name is NULL, the default channel is used (channel0) and created
+ * if not found.
+ * If filter_expression is NULL, an event without associated filter is
+ * created.
+ */
+extern int lttng_enable_event_with_filter(struct lttng_handle *handle,
+ struct lttng_event *event, const char *channel_name,
const char *filter_expression);
+
/*
* Create or enable a channel.
- * The channel name cannot be NULL.
+ *
+ * The chan and handle params can not be NULL.
*/
extern int lttng_enable_channel(struct lttng_handle *handle,
struct lttng_channel *chan);
/*
* Disable event(s) of a channel and domain.
*
- * If event_name is NULL, all events are disabled.
+ * If name is NULL, all events are disabled.
* If channel_name is NULL, the default channel is used (channel0).
*/
extern int lttng_disable_event(struct lttng_handle *handle,
/*
* Disable channel.
*
- * The channel name cannot be NULL.
*/
extern int lttng_disable_channel(struct lttng_handle *handle,
const char *name);
/*
* Calibrate LTTng overhead.
+ *
+ * The chan and handle params can not be NULL.
*/
extern int lttng_calibrate(struct lttng_handle *handle,
struct lttng_calibrate *calibrate);
* Set the default channel attributes for a specific domain and an allocated
* lttng_channel_attr pointer.
*
- * If either or both of the arguments are NULL, nothing happens.
+ * If one or both arguments are NULL, nothing happens.
*/
extern void lttng_channel_set_default_attr(struct lttng_domain *domain,
struct lttng_channel_attr *attr);
*
* Any other positive value is an lttcomm error which can be translate with
* lttng_strerror().
+ *
+ * Please see lttng-health-check(3) man page for more information.
*/
extern int lttng_health_check(enum lttng_health_component c);
/*
* 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.
+ * or is still being extracted by the consumer(s) (pending) hence not ready to
+ * be used by any readers.
*
- * Return 0 if the data is _NOT_ available else 1 if the data is ready. On
- * error, a negative value is returned and readable by lttng_strerror().
+ * Return 0 if there is _no_ data pending in the buffers thus having a
+ * guarantee that the data can be read safely. Else, return 1 if there is still
+ * traced data is pending. On error, a negative value is returned and readable
+ * by lttng_strerror().
*/
-extern int lttng_data_available(const char *session_name);
+extern int lttng_data_pending(const char *session_name);
#ifdef __cplusplus
}
projects / lttng-tools.git / blobdiff