Re: Logging code and Garbage Collection

[Mark Mahieu]

Adam Jenkins wrote:
I understand the motivation for large scale stuff like that...but your 
thoughts on simple concats?

e.g. log.debug("Here is some stuff that happened" + someStuff);
Just out of interests, did your profiling pick up less or more time 
spent in that than wrapping it in a debug?

Our conclusion was that it was best just to get into the habit of 
wrapping all log statements (except maybe error and warning depending on 
your p.o.v).  In an example like yours, even if the message isn't output 
3 things happen:

1) The creation of new (temporary) objects
2) Entering the method and executing any code there
3) Garbage collection of the temporary objects
While point 2 may be pretty insignificant depending on the actual 
logging library in use (and other factors) points 1 and 3 certainly aren't.

After all, all that the VM has to do if you wrap the code is check a 
boolean (which it may well have inlined).  If it's false it doesn't do 
1, 2 or 3.

Mark