soemtimes I really wish to rewrite/add some functions in jdk directly... especially for reusing some package private static functions...
Gary Gregory <garydgreg...@gmail.com> 于2020年6月30日周二 上午12:01写道: > I'm not sure talking to the JDK folks is helpful IMO. We are still > targeting Java 8. The customers I deal with are migrating from 8 to 11, and > Java 11 is not everywhere our customers are. So talking about something > that might end up in Java... 25 seems to be not in our user's best or > immediate interest. It might be good for Java in the long oh so long term > of course. > > Gary > > On Mon, Jun 29, 2020 at 8:31 AM Rob Tompkins <chtom...@gmail.com> wrote: > > > At first look, I’m a little surprised we’re trying to take on this > > functionality. Has anyone reached out to the JDK guys to see if they’d be > > interested in having it in the JDK? That said, if we approach it from > that > > path, we would lose the functionality in older versions of java. So > maybe I > > just talked myself out of the idea of putting it in the JDK.... > > > > Just wanted to stream of consciousness my initial gut vibe. > > > > Cheers, > > -Rob > > > > > On Jun 26, 2020, at 10:07 AM, Gary Gregory <garydgreg...@gmail.com> > > wrote: > > > > > > Hi All: > > > > > > I know email is a challenging medium for code reviews, so please > consider > > > these comments coming from my best intentions, constructive and caring > > ;-) > > > Also please excuse the meandering nature of this post. > > > > > > The new class org.apache.commons.lang3.concurrent.Locks.Lock needs > better > > > names IMO, not just the class name. There is already a JRE interface > > called > > > Lock so this class name is confusing (to me.) > > > > > > The Javadoc reads in part: > > > > > > * This class implements a wrapper for a locked (hidden) object, and > > > * provides the means to access it. The basic idea, is that the user > > > * code forsakes all references to the locked object, using only the > > > * wrapper object, and the accessor methods > > > > > > But this is not the case, the object itself is not locked in > > > the traditional sense with a monitor through a synchronized block, so > we > > > need to update the Javadoc as well. > > > > > > To me, this is more about executing blocks of code (through lambdas) > > which > > > then get 'safe' (via locking) access to an underlying object. This > tells > > me > > > the class is more about the functional interfaces than about a domain > > > "Object", hence the name "Lock" is not the best. It's really more of a > > > visitor where the visitation pattern is: Lock, Visit, Unlock. > > > Instead, maybe: > > > - StampledLockVisitor (more specific) > > > - LockingVisitor (more general) > > > - SafeObject (vague) > > > - ObjectLocker (vague) > > > - rejected: LockedObject since the object itself is not locked. > > > - ? > > > > > > What is also confusing IMO is that the instance variable for the object > > is > > > called "lockedObject" but the object is in fact NOT locked all the > time. > > So > > > that needs to be renamed IMO: > > > - object (the simplest) > > > - subject > > > - domain > > > - target > > > - ? > > > > > > In the same vein, the StampedLock is named "lock" which is also > confusing > > > since StampedLock does not implement Lock. > > > > > > Why can't the domain object be null, it's never used by the framework? > > > Why this: > > > if (t == lockedObject) { > > > throw new IllegalStateException("The returned object > > > is, in fact, the hidden object."); > > > } > > > ? > > > This seems like an application specific constraint that has nothing to > do > > > with the framework. > > > > > > Now that I've considered the above, the API Locks.lock(O) is really > > > misnamed, because it does not lock anything, it's a factory method. > > > > > > Stepping back even more, since there is only a static inner class in > > Locks, > > > and no-hint that alternative implementations for different kind of > locks > > > are possible, I would say we do not need Locks, all we need is what is > > now > > > called Lock. > > > > > > It's not clear why some methods are protected, I would make those > > private. > > > It's not like I can use or plugin a Lock, ReentrantReadWriteLock, a > > > ReentrantLock, or any ReadWriteLock instead of a StampedLock. I would > > then > > > make the current Lock class a standalone class which can then be used > > later > > > from a factory class (now Locks) where we can then fill in with > different > > > implementations. > > > > > > The Javadoc talks about a "hidden" object but it is not hidden since it > > is > > > passed to all visitors! > > > > > > This test assumption is wrong: > > > > > > If our threads are running concurrently, then we expect to be > > > faster > > > than running one after the other. > > > > > > The VM or Java spec makes no such guarantee and the tests have no > control > > > over VM scheduling. There are cases where this will fail when under > heavy > > > load for example where the cost of additional threads becomes > > overwhelming. > > > > > > Another item I am quite doubtful about is hiding checked exceptions by > > > rethrowning them as unchecked. I'd consider this an anti-pattern. If I > am > > > using one of our "Failing" interfaces it is because I am expecting it > to > > > fail. Perhaps this could be made smoother by refactoring to pass in a > > > lambda for an exception handler. > > > > > > I've crystallized my thoughts into code here as WIP (Javadoc needs > work): > > > https://github.com/apache/commons-lang/pull/559 > > > > > > Not as important as the above: > > > The example in the Javadoc uses logging as its domain subject, a > > "logging" > > > API (PrintStream) which is not a good example IMO. Logging frameworks > > > today like Log4j handle multi-threaded applications normally without > > having > > > developers meddle in it. Yes, I understand it's a simple example but I > am > > > hoping we can come up with something more realistic or useful. > > > > > > Thank you, > > > Gary > > > > --------------------------------------------------------------------- > > To unsubscribe, e-mail: dev-unsubscr...@commons.apache.org > > For additional commands, e-mail: dev-h...@commons.apache.org > > > > >