tools lib traceevent: Man pages for print field APIs
Create man pages for libtraceevent APIs: tep_print_field(), tep_print_fields(), tep_print_num_field(), tep_print_func_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/20190503091119.23399-20-tstoyanov@vmware.com Link: http://lkml.kernel.org/r/20190510200109.054708419@goodmis.org Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>hifive-unleashed-5.2
Tzvetomir Stoyanov
Arnaldo Carvalho de Melo
parent
96e75ef97d
commit
6dfe6849b6
|
|
@ -0,0 +1,126 @@
|
|||
libtraceevent(3)
|
||||
================
|
||||
|
||||
NAME
|
||||
----
|
||||
tep_print_field, tep_print_fields, tep_print_num_field, tep_print_func_field -
|
||||
Print the field content.
|
||||
|
||||
SYNOPSIS
|
||||
--------
|
||||
[verse]
|
||||
--
|
||||
*#include <event-parse.h>*
|
||||
*#include <trace-seq.h>*
|
||||
|
||||
void *tep_print_field*(struct trace_seq pass:[*]_s_, void pass:[*]_data_, struct tep_format_field pass:[*]_field_);
|
||||
void *tep_print_fields*(struct trace_seq pass:[*]_s_, void pass:[*]_data_, int _size_, struct tep_event pass:[*]_event_);
|
||||
int *tep_print_num_field*(struct trace_seq pass:[*]_s_, const char pass:[*]_fmt_, struct tep_event pass:[*]_event_, const char pass:[*]_name_, struct tep_record pass:[*]_record_, int _err_);
|
||||
int *tep_print_func_field*(struct trace_seq pass:[*]_s_, const char pass:[*]_fmt_, struct tep_event pass:[*]_event_, const char pass:[*]_name_, struct tep_record pass:[*]_record_, int _err_);
|
||||
--
|
||||
|
||||
DESCRIPTION
|
||||
-----------
|
||||
These functions print recorded field's data, according to the field's type.
|
||||
|
||||
The _tep_print_field()_ function extracts from the recorded raw _data_ value of
|
||||
the _field_ and prints it into _s_, according to the field type.
|
||||
|
||||
The _tep_print_fields()_ prints each field name followed by the record's field
|
||||
value according to the field's type:
|
||||
[verse]
|
||||
--
|
||||
"field1_name=field1_value field2_name=field2_value ..."
|
||||
--
|
||||
It iterates all fields of the _event_, and calls _tep_print_field()_ for each of
|
||||
them.
|
||||
|
||||
The _tep_print_num_field()_ function prints a numeric field with given format
|
||||
string. A search is performed in the _event_ for a field with _name_. If such
|
||||
field is found, its value is extracted from the _record_ and is printed in the
|
||||
_s_, according to the given format string _fmt_. If the argument _err_ is
|
||||
non-zero, and an error occures - it is printed in the _s_.
|
||||
|
||||
The _tep_print_func_field()_ function prints a function field with given format
|
||||
string. A search is performed in the _event_ for a field with _name_. If such
|
||||
field is found, its value is extracted from the _record_. The value is assumed
|
||||
to be a function address, and a search is perform to find the name of this
|
||||
function. The function name (if found) and its address are printed in the _s_,
|
||||
according to the given format string _fmt_. If the argument _err_ is non-zero,
|
||||
and an error occures - it is printed in _s_.
|
||||
|
||||
RETURN VALUE
|
||||
------------
|
||||
The _tep_print_num_field()_ and _tep_print_func_field()_ functions return 1
|
||||
on success, -1 in case of an error or 0 if the print buffer _s_ is full.
|
||||
|
||||
EXAMPLE
|
||||
-------
|
||||
[source,c]
|
||||
--
|
||||
#include <event-parse.h>
|
||||
#include <trace-seq.h>
|
||||
...
|
||||
struct tep_handle *tep = tep_alloc();
|
||||
...
|
||||
struct trace_seq seq;
|
||||
trace_seq_init(&seq);
|
||||
struct tep_event *event = tep_find_event_by_name(tep, "timer", "hrtimer_start");
|
||||
...
|
||||
void process_record(struct tep_record *record)
|
||||
{
|
||||
struct tep_format_field *field_pid = tep_find_common_field(event, "common_pid");
|
||||
|
||||
trace_seq_reset(&seq);
|
||||
|
||||
/* Print the value of "common_pid" */
|
||||
tep_print_field(&seq, record->data, field_pid);
|
||||
|
||||
/* Print all fields of the "hrtimer_start" event */
|
||||
tep_print_fields(&seq, record->data, record->size, event);
|
||||
|
||||
/* Print the value of "expires" field with custom format string */
|
||||
tep_print_num_field(&seq, " timer expires in %llu ", event, "expires", record, 0);
|
||||
|
||||
/* Print the address and the name of "function" field with custom format string */
|
||||
tep_print_func_field(&seq, " timer function is %s ", event, "function", record, 0);
|
||||
}
|
||||
...
|
||||
--
|
||||
|
||||
FILES
|
||||
-----
|
||||
[verse]
|
||||
--
|
||||
*event-parse.h*
|
||||
Header file to include in order to have access to the library APIs.
|
||||
*trace-seq.h*
|
||||
Header file to include in order to have access to trace sequences related APIs.
|
||||
Trace sequences are used to allow a function to call several other functions
|
||||
to create a string of data to use.
|
||||
*-ltraceevent*
|
||||
Linker switch to add when building a program that uses the library.
|
||||
--
|
||||
|
||||
SEE ALSO
|
||||
--------
|
||||
_libtraceevent(3)_, _trace-cmd(1)_
|
||||
|
||||
AUTHOR
|
||||
------
|
||||
[verse]
|
||||
--
|
||||
*Steven Rostedt* <rostedt@goodmis.org>, author of *libtraceevent*.
|
||||
*Tzvetomir Stoyanov* <tz.stoyanov@gmail.com>, author of this man page.
|
||||
--
|
||||
REPORTING BUGS
|
||||
--------------
|
||||
Report bugs to <linux-trace-devel@vger.kernel.org>
|
||||
|
||||
LICENSE
|
||||
-------
|
||||
libtraceevent is Free Software licensed under the GNU LGPL 2.1
|
||||
|
||||
RESOURCES
|
||||
---------
|
||||
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
|
||||
Loading…
Reference in New Issue