Re: [Qemu-devel] [PATCH v4 4/7] trace: [monitor] Use new event control interface

[Lluís Vilanova]

Stefan Hajnoczi writes:

> On Tue, May 8, 2012 at 3:38 PM, Lluís Vilanova <address@hidden> wrote:
>> Signed-off-by: Lluís Vilanova <address@hidden>
>> ---
>>  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 :)



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