> On Feb. 21, 2015, 12:39 a.m., Maxim Khutornenko wrote: > > src/main/java/org/apache/aurora/scheduler/mesos/MesosSchedulerImpl.java, > > line 199 > > <https://reviews.apache.org/r/31248/diff/1/?file=871335#file871335line199> > > > > Use StringBuilder instead to avoid heap churn. > > Bill Farner wrote: > javac is smart enough here > > > http://stackoverflow.com/questions/11942368/why-use-stringbuilder-explicitly-if-the-compiler-converts-string-concatenation-t > > Maxim Khutornenko wrote: > This is not obvious and may be dependent on particular JVM complier > version/options. I'd rather go with an explicit approach than second guess > JVM internals. > > Bill Farner wrote: > Mind if we wait to observe a problem? This seems like premature > optimization in a relatively infrequent code path, i'd rather favor > readabilty. > > Maxim Khutornenko wrote: > How do you propose we observe the problem? :) It's all these > unaccounted/non-obvious little fragments that may contribute to the churn. > Since it logs on every task status update unconditionally, I'd rather > eliminate the potential problem than deal with possible consequences. > > Bill Farner wrote: > Stepping back, String's javadoc actually documents this behavior [1] > > > The Java language provides special support for the string concatenation > operator ( + ), and for conversion of other objects to strings. String > concatenation is implemented through the StringBuilder(or StringBuffer) class > and its append method. String conversions are implemented through the method > toString, defined by Object and inherited by all classes in Java. For > additional information on string concatenation and conversion, see Gosling, > Joy, and Steele, The Java Language Specification. > > [1] http://docs.oracle.com/javase/7/docs/api/java/lang/String.html
This is better. Though specification is still non-assertive about it: >To increase the performance of repeated string concatenation, a Java compiler >**may use** the StringBuffer class or a similar technique to reduce the number >of intermediate String objects that are created by evaluation of an expression. http://docs.oracle.com/javase/specs/jls/se7/html/jls-15.html#jls-15.18.1 - Maxim ----------------------------------------------------------- This is an automatically generated e-mail. To reply, visit: https://reviews.apache.org/r/31248/#review73351 ----------------------------------------------------------- On Feb. 21, 2015, 1:36 a.m., Bill Farner wrote: > > ----------------------------------------------------------- > This is an automatically generated e-mail. To reply, visit: > https://reviews.apache.org/r/31248/ > ----------------------------------------------------------- > > (Updated Feb. 21, 2015, 1:36 a.m.) > > > Review request for Aurora, Joshua Cohen and Maxim Khutornenko. > > > Bugs: AURORA-1028 > https://issues.apache.org/jira/browse/AURORA-1028 > > > Repository: aurora > > > Description > ------- > > Export stats for source and reason for LOST tasks, and status delivery > latency. > > > Diffs > ----- > > src/main/java/org/apache/aurora/scheduler/events/PubsubEvent.java > 1d8f0128732756db74576ee669f6a2718fecc105 > src/main/java/org/apache/aurora/scheduler/mesos/MesosSchedulerImpl.java > ffc30bb548706df7bec9e1502242890e9b5eb942 > src/main/java/org/apache/aurora/scheduler/mesos/SchedulerDriverModule.java > 59ad9e65589c421cefb76f265446fa2885e6198c > src/main/java/org/apache/aurora/scheduler/mesos/TaskStatusStats.java > PRE-CREATION > src/test/java/org/apache/aurora/scheduler/mesos/MesosSchedulerImplTest.java > d02c6b32841d5d39c5780e7a044079a38729effb > src/test/java/org/apache/aurora/scheduler/mesos/TaskStatusStatsTest.java > PRE-CREATION > > Diff: https://reviews.apache.org/r/31248/diff/ > > > Testing > ------- > > > Thanks, > > Bill Farner > >
