| Message ID | 20211130050057.336228-3-tz.stoyanov@gmail.com (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | New tracefs APIs | expand |
On Tue, 30 Nov 2021 07:00:55 +0200 "Tzvetomir Stoyanov (VMware)" <tz.stoyanov@gmail.com> wrote: > A new API is proposed, to get tep event describing given dynamic event: [blank line] > tracefs_dynevent_get_event() [blank line] > The API detects any newly created dynamic events, but does not detect > the deletion. > > Signed-off-by: Tzvetomir Stoyanov (VMware) <tz.stoyanov@gmail.com> > --- > Documentation/libtracefs-dynevents.txt | 14 +++++++++++-- > include/tracefs.h | 2 ++ > src/tracefs-dynevents.c | 29 ++++++++++++++++++++++++++ > 3 files changed, 43 insertions(+), 2 deletions(-) > > diff --git a/Documentation/libtracefs-dynevents.txt b/Documentation/libtracefs-dynevents.txt > index a374651..7de06be 100644 > --- a/Documentation/libtracefs-dynevents.txt > +++ b/Documentation/libtracefs-dynevents.txt > @@ -4,8 +4,8 @@ libtracefs(3) > NAME > ---- > tracefs_dynevent_create, tracefs_dynevent_destroy, tracefs_dynevent_destroy_all, > -tracefs_dynevent_free, tracefs_dynevent_list_free, tracefs_dynevent_get_all, tracefs_dynevent_info - > -Create, destroy, free and get dynamic events. > +tracefs_dynevent_free, tracefs_dynevent_list_free, tracefs_dynevent_get_all, tracefs_dynevent_info, > +tracefs_dynevent_get_event - Create, destroy, free and get dynamic events. > > SYNOPSIS > -------- > @@ -23,6 +23,7 @@ void *tracefs_dynevent_list_free*(struct tracefs_dynevent pass:[*]pass:[*]_event > struct tracefs_dynevent pass:[*]*tracefs_dynevent_get*(enum tracefs_dynevent_type _type_, const char pass:[*]_system_, const char pass:[*]_event_); > struct tracefs_dynevent pass:[*]pass:[*]*tracefs_dynevent_get_all*(unsigned int _types_, const char pass:[*]_system_); > enum tracefs_dynevent_type *tracefs_dynevent_info*(struct tracefs_dynevent pass:[*]_dynevent_, char pass:[*]pass:[*]_system_, char pass:[*]pass:[*]_event_, char pass:[*]pass:[*]_prefix_, char pass:[*]pass:[*]_addr_, char pass:[*]pass:[*]_format_); > +struct tep_event pass:[*]*tracefs_dynevent_get_event*(struct tep_handle pass:[*]_tep_, struct tracefs_dynevent pass:[*]_dynevent_); > -- > > DESCRIPTION > @@ -68,6 +69,11 @@ if relevant for this event type. If _format_ is non NULL, it will hold the forma > dynamic event. Note, that the content in _group_, _event_, _prefix_, _addr_, and _format_ must be > freed with free(3) if they are set. > > +The *tracefs_dynevent_get_event*() function returns tep event, describing the given dynamic event. "returns a tep event" > +If the dynamic event is newly created and not yet loaded in the @tep, the dynamic event system is "loaded in @tep" > +rescanned for any new events. The returned pointer to tep event is controlled by @tep and must not > +be freed. > + > RETURN VALUE > ------------ > > @@ -88,6 +94,10 @@ in case of an error or in case there are no events in the system. That array mus > on error. If _system_, _event_, _prefix_, _addr_, or _format_ are non NULL, they will contain > allocated strings that must be freed by free(3). > > +The *tracefs_dynevent_get_event*() function returns pointer to tep event or NULL in case of an error "returns a pointer to a tep event' > +or if the requested dynamic event is missing. The returned pointer to tep event is controlled by > +@tep and must not be freed. > + > ERRORS > ------ > The following errors are for all the above calls: > diff --git a/include/tracefs.h b/include/tracefs.h > index 9662603..fbd7d31 100644 > --- a/include/tracefs.h > +++ b/include/tracefs.h > @@ -262,6 +262,8 @@ tracefs_dynevent_get(enum tracefs_dynevent_type type, const char *system, const > enum tracefs_dynevent_type > tracefs_dynevent_info(struct tracefs_dynevent *dynevent, char **system, > char **event, char **prefix, char **addr, char **format); > +struct tep_event * > +tracefs_dynevent_get_event(struct tep_handle *tep, struct tracefs_dynevent *dynevent); > > struct tracefs_dynevent * > tracefs_eprobe_alloc(const char *system, const char *event, > diff --git a/src/tracefs-dynevents.c b/src/tracefs-dynevents.c > index ea07d13..2ff3c87 100644 > --- a/src/tracefs-dynevents.c > +++ b/src/tracefs-dynevents.c > @@ -752,3 +752,32 @@ error: > > return TRACEFS_DYNEVENT_UNKNOWN; > } > + > +/** > + * tracefs_dynevent_get_event - return tep event, representing the given dynamic event remove the comma. > + * @tep: a handle to the trace event parser context, that holds the events remove the comma. > + * @dynevent: a dynamic event context, describing given dynamic event. remove the comma ;-) > + * > + * Returns pointer to tep event, describing the given dynamic event. The pointer "Returns a pointer to a tep event describing the given dynamic event". > + * is managed by @tep handle and must not be freed. In case of an error, or in case "by the @tep handle" > + * the requested dynamic event is missing in the @tep handler - NULL is returned. > + */ > +struct tep_event * > +tracefs_dynevent_get_event(struct tep_handle *tep, struct tracefs_dynevent *dynevent) > +{ > + struct tep_event *event; > + > + if (!tep || !dynevent || !dynevent->event) > + return NULL; > + > + /* If the dynamic event is already loaded in the tep, return it */ > + event = tep_find_event_by_name(tep, dynevent->system, dynevent->event); > + if (event) > + return event; > + > + /* Try to load any new events from the given system */ > + if (trace_load_events(tep, NULL, dynevent->system)) Does this refresh, or does just append? That is, if there are already dynamic events, wouldn't this re-add the existing events that are already there? Perhaps we need an interface in libtraceevent that rescans, and checks for duplicates. -- Steve > + return NULL; > + > + return tep_find_event_by_name(tep, dynevent->system, dynevent->event); > +}
On Wed, Dec 1, 2021 at 11:04 PM Steven Rostedt <rostedt@goodmis.org> wrote: > [ ... ] > > > + * the requested dynamic event is missing in the @tep handler - NULL is returned. > > + */ > > +struct tep_event * > > +tracefs_dynevent_get_event(struct tep_handle *tep, struct tracefs_dynevent *dynevent) > > +{ > > + struct tep_event *event; > > + > > + if (!tep || !dynevent || !dynevent->event) > > + return NULL; > > + > > + /* If the dynamic event is already loaded in the tep, return it */ > > + event = tep_find_event_by_name(tep, dynevent->system, dynevent->event); > > + if (event) > > + return event; > > + > > + /* Try to load any new events from the given system */ > > + if (trace_load_events(tep, NULL, dynevent->system)) > > Does this refresh, or does just append? > This calls tep_parse_event() for all events in the given system, so it only appends. > That is, if there are already dynamic events, wouldn't this re-add the > existing events that are already there? I just realized that there is a bug, there will be duplicates. > > Perhaps we need an interface in libtraceevent that rescans, and checks for > duplicates. Yes, that logic should be in libtraceevent, there should be new API. > > -- Steve > > > + return NULL; > > + > > + return tep_find_event_by_name(tep, dynevent->system, dynevent->event); > > +} >
diff --git a/Documentation/libtracefs-dynevents.txt b/Documentation/libtracefs-dynevents.txt index a374651..7de06be 100644 --- a/Documentation/libtracefs-dynevents.txt +++ b/Documentation/libtracefs-dynevents.txt @@ -4,8 +4,8 @@ libtracefs(3) NAME ---- tracefs_dynevent_create, tracefs_dynevent_destroy, tracefs_dynevent_destroy_all, -tracefs_dynevent_free, tracefs_dynevent_list_free, tracefs_dynevent_get_all, tracefs_dynevent_info - -Create, destroy, free and get dynamic events. +tracefs_dynevent_free, tracefs_dynevent_list_free, tracefs_dynevent_get_all, tracefs_dynevent_info, +tracefs_dynevent_get_event - Create, destroy, free and get dynamic events. SYNOPSIS -------- @@ -23,6 +23,7 @@ void *tracefs_dynevent_list_free*(struct tracefs_dynevent pass:[*]pass:[*]_event struct tracefs_dynevent pass:[*]*tracefs_dynevent_get*(enum tracefs_dynevent_type _type_, const char pass:[*]_system_, const char pass:[*]_event_); struct tracefs_dynevent pass:[*]pass:[*]*tracefs_dynevent_get_all*(unsigned int _types_, const char pass:[*]_system_); enum tracefs_dynevent_type *tracefs_dynevent_info*(struct tracefs_dynevent pass:[*]_dynevent_, char pass:[*]pass:[*]_system_, char pass:[*]pass:[*]_event_, char pass:[*]pass:[*]_prefix_, char pass:[*]pass:[*]_addr_, char pass:[*]pass:[*]_format_); +struct tep_event pass:[*]*tracefs_dynevent_get_event*(struct tep_handle pass:[*]_tep_, struct tracefs_dynevent pass:[*]_dynevent_); -- DESCRIPTION @@ -68,6 +69,11 @@ if relevant for this event type. If _format_ is non NULL, it will hold the forma dynamic event. Note, that the content in _group_, _event_, _prefix_, _addr_, and _format_ must be freed with free(3) if they are set. +The *tracefs_dynevent_get_event*() function returns tep event, describing the given dynamic event. +If the dynamic event is newly created and not yet loaded in the @tep, the dynamic event system is +rescanned for any new events. The returned pointer to tep event is controlled by @tep and must not +be freed. + RETURN VALUE ------------ @@ -88,6 +94,10 @@ in case of an error or in case there are no events in the system. That array mus on error. If _system_, _event_, _prefix_, _addr_, or _format_ are non NULL, they will contain allocated strings that must be freed by free(3). +The *tracefs_dynevent_get_event*() function returns pointer to tep event or NULL in case of an error +or if the requested dynamic event is missing. The returned pointer to tep event is controlled by +@tep and must not be freed. + ERRORS ------ The following errors are for all the above calls: diff --git a/include/tracefs.h b/include/tracefs.h index 9662603..fbd7d31 100644 --- a/include/tracefs.h +++ b/include/tracefs.h @@ -262,6 +262,8 @@ tracefs_dynevent_get(enum tracefs_dynevent_type type, const char *system, const enum tracefs_dynevent_type tracefs_dynevent_info(struct tracefs_dynevent *dynevent, char **system, char **event, char **prefix, char **addr, char **format); +struct tep_event * +tracefs_dynevent_get_event(struct tep_handle *tep, struct tracefs_dynevent *dynevent); struct tracefs_dynevent * tracefs_eprobe_alloc(const char *system, const char *event, diff --git a/src/tracefs-dynevents.c b/src/tracefs-dynevents.c index ea07d13..2ff3c87 100644 --- a/src/tracefs-dynevents.c +++ b/src/tracefs-dynevents.c @@ -752,3 +752,32 @@ error: return TRACEFS_DYNEVENT_UNKNOWN; } + +/** + * tracefs_dynevent_get_event - return tep event, representing the given dynamic event + * @tep: a handle to the trace event parser context, that holds the events + * @dynevent: a dynamic event context, describing given dynamic event. + * + * Returns pointer to tep event, describing the given dynamic event. The pointer + * is managed by @tep handle and must not be freed. In case of an error, or in case + * the requested dynamic event is missing in the @tep handler - NULL is returned. + */ +struct tep_event * +tracefs_dynevent_get_event(struct tep_handle *tep, struct tracefs_dynevent *dynevent) +{ + struct tep_event *event; + + if (!tep || !dynevent || !dynevent->event) + return NULL; + + /* If the dynamic event is already loaded in the tep, return it */ + event = tep_find_event_by_name(tep, dynevent->system, dynevent->event); + if (event) + return event; + + /* Try to load any new events from the given system */ + if (trace_load_events(tep, NULL, dynevent->system)) + return NULL; + + return tep_find_event_by_name(tep, dynevent->system, dynevent->event); +}
A new API is proposed, to get tep event describing given dynamic event: tracefs_dynevent_get_event() The API detects any newly created dynamic events, but does not detect the deletion. Signed-off-by: Tzvetomir Stoyanov (VMware) <tz.stoyanov@gmail.com> --- Documentation/libtracefs-dynevents.txt | 14 +++++++++++-- include/tracefs.h | 2 ++ src/tracefs-dynevents.c | 29 ++++++++++++++++++++++++++ 3 files changed, 43 insertions(+), 2 deletions(-)