Re: [PATCH v3 3/3] perf script/python: Pass event/thread/dso nameand symbol info to event handler in python

[Arnaldo Carvalho de Melo]

 Em Mon, Jun 18, 2012 at 02:10:39PM +0800, Feng Tang escreveu:
> Also as suggested by Arnaldo, pack all these parameters to a dictionary,
> which is more expandable for adding new parameters while keep the
> compatibility for old scripts.
> 
> Signed-off-by: Feng Tang <feng.tang@xxxxxxxxx>
> ---
>  .../util/scripting-engines/trace-event-python.c    |   32 +++++++++++++++----
>  1 files changed, 25 insertions(+), 7 deletions(-)
> 
> diff --git a/tools/perf/util/scripting-engines/trace-event-python.c b/tools/perf/util/scripting-engines/trace-event-python.c
> index 97f4fad..e8ac480 100644
> --- a/tools/perf/util/scripting-engines/trace-event-python.c
> +++ b/tools/perf/util/scripting-engines/trace-event-python.c
> @@ -336,15 +336,23 @@ static void python_process_general_event(union perf_event *pevent __unused,
>  				 struct machine *machine __unused,
>  				 struct addr_location *al)
>  {
> -	PyObject *handler, *retval, *t;
> +	PyObject *handler, *retval, *t, *dict;
>  	static char handler_name[64];
>  	unsigned n = 0;
> -	void *data = sample->raw_data;
> +	struct thread *thread = al->thread;
>  
> +	/*
> +	 * Use the MAX_FIELDS to make the function expandable, though
> +	 * currently there is only one itme for the tuple.
> +	 */
>  	t = PyTuple_New(MAX_FIELDS);
>  	if (!t)
>  		Py_FatalError("couldn't create Python tuple");
>  
> +	dict = PyDict_New();
> +	if (!dict)
> +		Py_FatalError("couldn't create Python dictionary");
> +
>  	snprintf(handler_name, sizeof(handler_name), "%s", "process_event");
>  
>  	handler = PyDict_GetItemString(main_dict, handler_name);
> @@ -353,14 +361,23 @@ static void python_process_general_event(union perf_event *pevent __unused,
>  		goto exit;
>  	}
>  
> -	/* Pass 4 parameters: event_attr, perf_sample, raw data, thread name */
> -	PyTuple_SetItem(t, n++, PyString_FromStringAndSize(
> +	PyDict_SetItemString(dict, "ev_name", PyString_FromString(event_name(evsel)));
> +	PyDict_SetItemString(dict, "attr", PyString_FromStringAndSize(
>  			(const char *)&evsel->attr, sizeof(evsel->attr)));
> -	PyTuple_SetItem(t, n++, PyString_FromStringAndSize(
> +	PyDict_SetItemString(dict, "sample", PyString_FromStringAndSize(
>  			(const char *)sample, sizeof(*sample)));
> -	PyTuple_SetItem(t, n++, PyString_FromStringAndSize(
> -			data, sample->raw_size));
> +	PyDict_SetItemString(dict, "raw_buf", PyString_FromStringAndSize(
> +			(const char *)sample->raw_data, sample->raw_size));
> +	PyDict_SetItemString(dict, "comm",
> +			PyString_FromString(thread->comm));
> +	PyDict_SetItemString(dict, "dso",
> +			PyString_FromString(al->map->dso->name));
> +	if (al->sym) {
> +		PyDict_SetItemString(dict, "symbol",
> +			PyString_FromString(al->sym->name));
> +	}
>  
> +	PyTuple_SetItem(t, n++, dict);

Now old scrips will break, as the tuple they expect:

 (attr, sample, raw_data)

will not be there.

To not break those scripts you must leave it there and add the new ones
in a python compatible way. I.e. have you tested the existing scripts
using the new perf tool with your patches applied? They must continue to
work.

I.e. leave the old tuple and add the dict at the end somehow.

The first two patches in this series don't apply anymore, please find
them attached fixed, please check if they work as expected.

- Arnaldo