Re: [infinispan-dev] trace vs log.isTraceEnabled

Manik, I believe the constants are interned the moment the class is loaded, so there's no extra work to pass int to the trace method. În data de 07.12.2011 12:43, "Manik Surtani"<manik(a)jboss.org> a scris: > Bringing this thread up again, is it really true to say that > > if (trace) log.trace("blah") > > is as cheap as > > log.trace("blah") > > ? > > In the former, with tracing disabled, nothing happens after the condition > check. In the latter, you still construct a String "blah", and even if > there is no complex interpolation or message construction, the basic String > message is still constructed (and starts to take up PermGen space too, as > literals are interned [1]). > > So the case for the if (trace) pattern still stands IMO. > > Cheers > Manik > > [1] > http://docs.oracle.com/javase/1.4.2/docs/api/java/lang/String.html#intern() > "All literal strings and string-valued constant expressions are interned." > > On 28 Sep 2011, at 17:41, David M. Lloyd wrote: > >> On 09/28/2011 11:35 AM, Mircea Markus wrote: >>> Hi, >>> >>> I'm not aware of any convention on using trace vs log.isTraceEnabled() > to guard the trace statements. >>> >>> if (trace) log.trace("some request related stuff") >>> vs >>> if (log.isTraceEnabled()) log.trace("some request related stuff"); >>> >>> The former is more efficient, but cannot be managed at runtime. It > seems to be the preferred form, so shall we stick with it? >> >> If you're using the jboss-logging API, and your log statement does not >> do any interpolation, then it is just as fast to do any of the following >> (with no if): >> >> log.trace("blah"); >> log.tracef("the %s happened to %s", foo, bar); >> log.tracev("the {0} happened to {1}", foo, bar); >> >> In the case where trace logging is disabled, these are exactly as >> efficient as the if (log.isTraceEnabled()) variants. In the case where >> it is enabled, it is marginally more efficient (though the trace log >> itself is substantially more expensive of course). >> >> Overall I'd avoid the "if" forms unless you're doing complex > interpolation: >> >> log.trace("Foo " + bar + " baz " + zap); >> log.tracef("the %s happened to %s", fooMethod().barMethod(), bar); >> >> ...both of which incur the expense of the expression resolution even if >> the log message is ultimately discarded. >> -- >> - DML >> _______________________________________________ >> infinispan-dev mailing list >> infinispan-dev(a)lists.jboss.org >> https://lists.jboss.org/mailman/listinfo/infinispan-dev > > -- > Manik Surtani > manik(a)jboss.org > twitter.com/maniksurtani > > Lead, Infinispan > http://www.infinispan.org > > > > > _______________________________________________ > infinispan-dev mailing list > infinispan-dev(a)lists.jboss.org > https://lists.jboss.org/mailman/listinfo/infinispan-dev > _______________________________________________ infinispan-dev mailing list infinispan-dev(a)lists.jboss.org https://lists.jboss.org/mailman/listinfo/infinispan-dev