Dne 24.03.09 22:31, Robert Lor napsal(a):
I think the is-enabled test will address the issues you encountered. I
see a few alternative to fixing this:
1) Only use if (foo_ENABLED()) test for probes with expensive function
call/computation in arguments. This will keep the code clean, and we can
document this in the "Definine New Probes" section in the online doc.
2) Add the if(foo_ENABLED()) test to all probes manually and make this a
requirement for all future probes. This makes the check explicit and
avoid confusion.
3) Post-process probes.h so if(foo_ENABLED()) test is added to every
probe. We're doing some post-processing now by pre-pending TRACE_ to the
macros with a sed script. Personally, I don't like doing complex
post-processing of output from another tool because the script can break
if for some reason DTrace's output is changed.
I prefer option 1 the most and 3 the least.
I prefer also option 1. In many cases if(foo_ENABLED) has same or bigger
performance penalty like disabled probe itself.
Zdenek
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