And this will make logging faster because there is less locking in
multi-threaded apps?

Gary

On Sat, Sep 12, 2015 at 1:10 PM, Ralph Goers <[email protected]>
wrote:

> Are you talking about making this change in signalCompletionIfShutdown()?
> If so I am OK with what you are proposing.
>
> Ralph
>
> > On Sep 12, 2015, at 11:19 AM, Remko Popma <[email protected]> wrote:
> >
> > I want to run this by you:
> >
> > LoggerConfig currently always takes a lock after logging a log event.
> > Within this lock it checks if the shutdown flag has been set.
> > Can we do it the other way around? First check if the shutdown flag has
> been set and then take the lock (to notify the other thread)?
> >
> > I think it is safe to do this:
> >
> > public void log(final LogEvent event) {
> >     counter.incrementAndGet();
> >     try {
> >         if (!isFiltered(event)) {
> >             processLogEvent(event);
> >         }
> >     } finally {
> >         // FIRST update counter, THEN check shutdown flag;
> >         // these are atomic and will not get re-ordered.
> >         // So we don't need the lock to check the shutdown flag.
> >         if (counter.decrementAndGet() == 0 && shutdown.get()) {
> >             // ONLY take the lock if the shutdown flag was set
> >             shutdownLock.lock();
> >             try {
> >                 noLogEvents.signalAll(); // lock required to call
> signal()
> >             } finally {
> >                 shutdownLock.unlock();
> >             }
> >         }
> >     }
> > }
> >
> > // keep this method unchanged
> > private void waitForCompletion() {
> >     shutdownLock.lock();
> >     try {
> >         // NOTE: FIRST the shutdown flag is set
> >         if (shutdown.compareAndSet(false, true)) {
> >             int retries = 0;
> >             // NOTE: THEN the counter is read
> >             while (counter.get() > 0) {
> >                 try {
> >                     noLogEvents.await(retries + 1, TimeUnit.SECONDS);
> >                 } catch (final InterruptedException ie) {
> >                     if (++retries > MAX_RETRIES) {
> >                         break;
> >                     }
> >                 }
> >             }
> >         }
> >     } finally {
> >         shutdownLock.unlock();
> >     }
> > }
> >
> >
>
>
>
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