On 17/07/2023 11:08, Alan Bateman wrote:
On 15/07/2023 17:53, Daohan Qu wrote:
:
Although the |assert| keyword has been around for a long time and
is handy for invariant checks, it does not seem to be widely used.
For example, in the famous |j.u.c| packages, nearly all |assert|
statements are commented out [1].
My questions are, should |assert| be heavily used in Java programs,
especially in production code? And should we enable them in the
production code?
Asserts are very useful during development or when testing, e.g. the
JDK tests run with -esa and can periodically help catch issues when
testing a change.
You will find places in the JDK code, esp. in performance critical
code, where assertions are commented out. The reason is that asserts,
even if disabled, increase the method size and can impact inlining by
the compiler at run-time. So while useful when debugging some issue
in such code, they are commended out to avoid increasing the method size.
I believe this can be partially alleviated by extracting the asserts to
a method (partially as the call also increases method size). The
optimizer seems to be smart enough to not call the method if it does
nothing (when ea is disabled).
--John
