X-Git-Url: https://git.lttng.org/?p=lttng-tools.git;a=blobdiff_plain;f=include%2Flttng%2Flttng.h;h=5a826aad78bd3262063de1f14011c5d06f01a5c4;hp=515e07c4e9703653c600e633d887ccae6f194957;hb=b2068598da7219137071ddd7f83ae72232060fe3;hpb=52df24019c3998b87870fb8371fa20fb33449a0d diff --git a/include/lttng/lttng.h b/include/lttng/lttng.h index 515e07c4e..5a826aad7 100644 --- a/include/lttng/lttng.h +++ b/include/lttng/lttng.h @@ -33,6 +33,10 @@ extern "C" { #endif +#ifndef LTTNG_PACKED +#define LTTNG_PACKED __attribute__((__packed__)) +#endif + /* * Event symbol length. Copied from LTTng kernel ABI. */ @@ -156,7 +160,7 @@ struct lttng_domain { char exec_name[NAME_MAX]; char padding[LTTNG_DOMAIN_PADDING2]; } attr; -}; +} LTTNG_PACKED; /* * Perf counter attributes @@ -170,7 +174,7 @@ struct lttng_event_perf_counter_ctx { char name[LTTNG_SYMBOL_NAME_LEN]; char padding[LTTNG_PERF_EVENT_PADDING1]; -}; +} LTTNG_PACKED; /* * Event/channel context @@ -187,7 +191,7 @@ struct lttng_event_context { struct lttng_event_perf_counter_ctx perf_counter; char padding[LTTNG_EVENT_CONTEXT_PADDING2]; } u; -}; +} LTTNG_PACKED; /* * Event probe. @@ -204,7 +208,7 @@ struct lttng_event_probe_attr { char symbol_name[LTTNG_SYMBOL_NAME_LEN]; char padding[LTTNG_EVENT_PROBE_PADDING1]; -}; +} LTTNG_PACKED; /* * Function tracer @@ -216,7 +220,7 @@ struct lttng_event_function_attr { char symbol_name[LTTNG_SYMBOL_NAME_LEN]; char padding[LTTNG_EVENT_FUNCTION_PADDING1]; -}; +} LTTNG_PACKED; /* * Generic lttng event @@ -245,7 +249,7 @@ struct lttng_event { char padding[LTTNG_EVENT_PADDING2]; } attr; -}; +} LTTNG_PACKED; enum lttng_event_field_type { LTTNG_EVENT_FIELD_OTHER = 0, @@ -262,7 +266,7 @@ struct lttng_event_field { char padding[LTTNG_EVENT_FIELD_PADDING]; struct lttng_event event; int nowrite; -}; +} LTTNG_PACKED; /* * Tracer channel attributes. For both kernel and user-space. @@ -279,7 +283,7 @@ struct lttng_channel_attr { enum lttng_event_output output; /* splice, mmap */ char padding[LTTNG_CHANNEL_ATTR_PADDING1]; -}; +} LTTNG_PACKED; /* * Channel information structure. For both kernel and user-space. @@ -293,14 +297,14 @@ struct lttng_channel { struct lttng_channel_attr attr; char padding[LTTNG_CHANNEL_PADDING1]; -}; +} LTTNG_PACKED; #define LTTNG_CALIBRATE_PADDING1 16 struct lttng_calibrate { enum lttng_calibrate_type type; char padding[LTTNG_CALIBRATE_PADDING1]; -}; +} LTTNG_PACKED; /* * Basic session information. @@ -319,7 +323,7 @@ struct lttng_session { uint32_t enabled; /* enabled/started: 1, disabled/stopped: 0 */ char padding[LTTNG_SESSION_PADDING1]; -}; +} LTTNG_PACKED; /* * Handle used as a context for commands. @@ -332,7 +336,7 @@ struct lttng_handle { struct lttng_domain domain; char padding[LTTNG_HANDLE_PADDING1]; -}; +} LTTNG_PACKED; /* * Public LTTng control API @@ -360,15 +364,18 @@ extern struct lttng_handle *lttng_create_handle(const char *session_name, 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); @@ -377,6 +384,8 @@ 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); @@ -443,7 +452,8 @@ extern int lttng_session_daemon_alive(void); /* * 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); @@ -477,6 +487,8 @@ extern int lttng_start_tracing(const char *session_name); * 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); @@ -489,9 +501,11 @@ 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, @@ -502,8 +516,9 @@ extern int lttng_add_context(struct lttng_handle *handle, * * 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); @@ -513,7 +528,7 @@ extern int lttng_enable_event(struct lttng_handle *handle, * * 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 with that filter. + * 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 @@ -525,7 +540,8 @@ extern int lttng_enable_event_with_filter(struct lttng_handle *handle, /* * 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); @@ -533,7 +549,7 @@ extern int lttng_enable_channel(struct lttng_handle *handle, /* * 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, @@ -542,13 +558,14 @@ 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); @@ -557,7 +574,7 @@ extern int lttng_calibrate(struct lttng_handle *handle, * 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); @@ -593,6 +610,8 @@ extern int lttng_disable_consumer(struct lttng_handle *handle); * * 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);