fastdebug vs optimized?

[coleen.phillimore at oracle.com]

On 1/31/18 9:43 AM, Thomas Stüfe wrote:
>
>
> On Wed, Jan 31, 2018 at 3:22 PM, <coleen.phillimore at oracle.com 
> <mailto:coleen.phillimore at oracle.com>> wrote:
>
>
>     The idea of optimized was to have the performance of product but
>     the printing and diagnostic options of debug. We used to use it
>     for debugging when we had a lot of race conditions in the vm (a
>     long time ago now there are none J)   We were sensitive to the
>     size of the libjvm.so but since then and since logging, many of
>     the printing functions have been exposed and diagnostic() flags
>     were introduced.
>
>     https://bugs.openjdk.java.net/browse/JDK-8183287
>     <https://bugs.openjdk.java.net/browse/JDK-8183287>
>
>     It's time to remove it and clean up the assert vs. debug macros,
>     but currently unassigned.
>
>     Thanks,
>     Coleen
>
>
> Thanks, Coleen!
>
> So, for me that means probably not to bother with !PRODUCT and just 
> use ASSERT on verification code, right?

Yes, that seems right.

Coleen

>
> ..Thomas
>
>
>     On 1/31/18 8:52 AM, Thomas Stüfe wrote:
>
>         Hi all,
>
>         Sorry for asking the same question again, but I still struggle to
>         understand the difference between fastdebug and optimized
>         builds. Not the
>         technical details, that is clear (I hope):
>
>         optimized: optimized build with !ASSERT !PRODUCT
>         fastdebug: optimized build with ASSERT !PRODUCT
>
>         but what the point is for having two builds with such
>         similarities. What is
>         the optimized build used for?
>
>         When should I guard verification code with ASSERT, when with
>         !PRODUCT? As
>         for the latter, it feels weird to use guarantee and then
>         having to guard it
>         explicitly with !PRODUCT, but that is what I would have to do
>         to get
>         assertions in optimized build while still suppressing them in
>         release
>         builds, yes?
>
>         I always assumed that the optimized build is supposed to be
>         faster than
>         fastdebug, so, expensive verifications should be better left
>         to ASSERT? But
>         then, I see quite some coding contradicting this expectation.
>         The coding
>         itself is no real guideline either, I see both ASSERT and
>         !PRODUCT used
>         without recognizing a clear pattern.
>
>         So, still confused. Can someone enlighten me please :)
>
>         Thanks & Regards, Thomas
>
>
>