Hi Think both points are valid actually.
Concretely, such a change has perf impacts, indeed compared to a db init it will be very fast but compared to a driver operation it can be something. Therefore a microbench comparison does not hurt and will at least guarantee it is ok and make people calm about it. When well written lamba are just a static method call so no issue but when not it allocates way more objects and will stress the gc more which is not desired for a pool IMHO. Just my 2cts indeed Le ven. 30 août 2019 à 01:02, Gary Gregory <garydgreg...@gmail.com> a écrit : > On Thu, Aug 29, 2019 at 6:17 PM Phil Steitz <phil.ste...@gmail.com> wrote: > > > > > > > On 8/29/19 6:37 AM, Gary Gregory wrote: > > > Hi All: > > > > > > In https://github.com/apache/commons-dbcp/pull/34, I've reduced a ton > of > > > boilerplate code using lambdas. This also happens to fix a bunch of > > places > > > where we did not call checkOpen() when we should have. > > > > Interesting. I have a couple of comments. > > > > First is a nit - it would make review much easier if you separate the > > formatting changes from the actual code changes in commits. Please try > > to do that. > > > > Second is more important. I am not a jvm expert so this may be a > > non-issue, but I wonder whether these changes will have performance / > > resource utilization impact. If someone can confirm that this all gets > > optimized to the same or equivalent bytecode, there is nothing to worry > > about. If not, I would strongly recommend running benchmarks to > > validate that there is no performance impact. > > > > Hi Phil, > > I understand your concerns but if we step back to the 10k ft level for this > component, let's remember that we are managing _database_ connections here, > and these database operations are typically extremely slow _compared_ to a > Java application: a database app ends up suffering from dealing delays to > do with network IO plus whatever the database is doing. On top of this, any > DBA would not ever consider allowing an app to use 10k connections, even if > the database could handle it. Maybe measurements would be different with an > in-memory database like H2 or HSQLDB, but the database itself is the > bottleneck no matter what, and borrow/return from DBCP is just noise in > comparison IMO. > > My last point is that if I were to write such a component like DBCP > _today_, I would absolutely do it with lambdas, otherwise the duplication > would become a code smell by ignoring a language feature, released in Java > 8 and which should be mature on the eve of Java 13. > > WRT the nit, yeah, that's unfortunate but some of the files have had _so > much_ boilerplate methods edited into "one-liners" and this is going to > mean a lot of changes indeed. Granted, there might be cases where I only > wanted to reformat one method and mistakenly reformatted a whole file, and > for that I offer my apologies. > > Gary > > > > Phil > > > > > > > > > > Gary > > > > > > > > > --------------------------------------------------------------------- > > To unsubscribe, e-mail: dev-unsubscr...@commons.apache.org > > For additional commands, e-mail: dev-h...@commons.apache.org > > > > >
