Lluís Vilanova writes:
> Stefan Hajnoczi writes:
>> On Tue, May 8, 2012 at 3:38 PM, Lluís Vilanova <vilan...@ac.upc.edu> wrote:
>>> Signed-off-by: Lluís Vilanova <vilan...@ac.upc.edu>
>>> ---
>>> monitor.c | 15 ++++++++++++---
>>> 1 file changed, 12 insertions(+), 3 deletions(-)
>>>
>>> diff --git a/monitor.c b/monitor.c
>>> index 8946a10..86c2538 100644
>>> --- a/monitor.c
>>> +++ b/monitor.c
>>> @@ -625,10 +625,19 @@ static void do_trace_event_set_state(Monitor *mon,
>>> const QDict *qdict)
>>> {
>>> const char *tp_name = qdict_get_str(qdict, "name");
>>> bool new_state = qdict_get_bool(qdict, "option");
>>> - int ret = trace_event_set_state(tp_name, new_state);
>>>
>>> - if (!ret) {
>>> - monitor_printf(mon, "unknown event name \"%s\"\n", tp_name);
>>> + if (trace_event_is_pattern(tp_name)) {
>>> + TraceEvent *ev = NULL;
>>> + while ((ev = trace_event_pattern(tp_name, ev)) != NULL) {
>>> + trace_event_set_state_dynamic(ev, new_state);
>>> + }
>>> + } else {
>>> + TraceEvent *ev = trace_event_name(tp_name);
>>> + if (ev == NULL) {
>>> + monitor_printf(mon, "unknown event name \"%s\"\n", tp_name);
>>> + } else {
>>> + trace_event_set_state_dynamic(ev, new_state);
>>> + }
>> Why check for a pattern and split the code in two? How about just:
>> while ((ev = trace_event_pattern(tp_name, ev)) != NULL) {
>> ...
>> }
>> That should cover both the single trace event name case and the wildcard
>> case.
> That's true... it's just that somehow I thought it was abusive to use pattern
> matching on a string without patterns :)
When going through the code to add your comments I realized why it made sense to
use 'trace_event_name' instead of 'trace_event_pattern'.
In the case the string contains no pattern, not finding a result is an error in
'trace_backend_init_events' (when reading the list of events given in the
commandline file), as well as in 'do_trace_event_set_state' (when setting the
state from the monitor, although here the error is not fatal).
In comparison, setting by pattern never fails.
Lluis
--
"And it's much the same thing with knowledge, for whenever you learn
something new, the whole world becomes that much richer."
-- The Princess of Pure Reason, as told by Norton Juster in The Phantom
Tollbooth
