[tip:perf/core] tools lib traceevent: Man pages for find field APIs

tip-bot for Tzvetomir Stoyanov
2019-05-18T09:12:09Z

Commit-ID: 0b51220ee0c3f6634b9fcf9208cc0764d5861163
Gitweb: https://git.kernel.org/tip/0b51220ee0c3f6634b9fcf9208cc0764d5861163
Author: Tzvetomir Stoyanov <tstoyanov@vmware.com>
AuthorDate: Fri, 10 May 2019 15:56:24 -0400
Committer: Arnaldo Carvalho de Melo <acme@redhat.com>
CommitDate: Wed, 15 May 2019 16:36:48 -0300

tools lib traceevent: Man pages for find field APIs

Create man pages for libtraceevent APIs:

tep_find_common_field(),
tep_find_field()
tep_find_any_field()

Signed-off-by: Tzvetomir Stoyanov <tstoyanov@vmware.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: linux-trace-devel@vger.kernel.org
Link: http://lore.kernel.org/linux-trace-devel/20190503091119.23399-18-tstoyanov@vmware.com
Link: http://lkml.kernel.org/r/20190510200108.721589427@goodmis.org
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---
.../Documentation/libtraceevent-field_find.txt | 118 +++++++++++++++++++++
1 file changed, 118 insertions(+)

diff --git a/tools/lib/traceevent/Documentation/libtraceevent-field_find.txt b/tools/lib/traceevent/Documentation/libtraceevent-field_find.txt
new file mode 100644
index 000000000000..0896af5b9eff
--- /dev/null
+++ b/tools/lib/traceevent/Documentation/libtraceevent-field_find.txt
@@ -0,0 +1,118 @@
+libtraceevent(3)
+================
+
+NAME
+----
+tep_find_common_field, tep_find_field, tep_find_any_field -
+Search for a field in an event.
+
+SYNOPSIS
+--------
+[verse]
+--
+*#include <event-parse.h>*
+
+struct tep_format_field pass:[*]*tep_find_common_field*(struct tep_event pass:[*]_event_, const char pass:[*]_name_);
+struct tep_format_field pass:[*]*tep_find_field*(struct tep_event_ormat pass:[*]_event_, const char pass:[*]_name_);
+struct tep_format_field pass:[*]*tep_find_any_field*(struct tep_event pass:[*]_event_, const char pass:[*]_name_);
+--
+
+DESCRIPTION
+-----------
+These functions search for a field with given name in an event. The field
+returned can be used to find the field content from within a data record.
+
+The _tep_find_common_field()_ function searches for a common field with _name_
+in the _event_.
+
+The _tep_find_field()_ function searches for an event specific field with
+_name_ in the _event_.
+
+The _tep_find_any_field()_ function searches for any field with _name_ in the
+_event_.
+
+RETURN VALUE
+------------
+The _tep_find_common_field(), _tep_find_field()_ and _tep_find_any_field()_
+functions return a pointer to the found field, or NULL in case there is no field
+with the requested name.
+
+EXAMPLE
+-------
+[source,c]
+--
+#include <event-parse.h>
+...
+void get_htimer_info(struct tep_handle *tep, struct tep_record *record)
+{
+ struct tep_format_field *field;
+ struct tep_event *event;
+ long long softexpires;
+ int mode;
+ int pid;
+
+ event = tep_find_event_by_name(tep, "timer", "hrtimer_start");
+
+ field = tep_find_common_field(event, "common_pid");
+ if (field == NULL) {
+ /* Cannot find "common_pid" field in the event */
+ } else {
+ /* Get pid from the data record */
+ pid = tep_read_number(tep, record->data + field->offset,
+ field->size);
+ }
+
+ field = tep_find_field(event, "softexpires");
+ if (field == NULL) {
+ /* Cannot find "softexpires" event specific field in the event */
+ } else {
+ /* Get softexpires parameter from the data record */
+ softexpires = tep_read_number(tep, record->data + field->offset,
+ field->size);
+ }
+
+ field = tep_find_any_field(event, "mode");
+ if (field == NULL) {
+ /* Cannot find "mode" field in the event */
+ } else
+ {
+ /* Get mode parameter from the data record */
+ mode = tep_read_number(tep, record->data + field->offset,
+ field->size);