On Thu, Apr 20, 2017 at 2:53 PM, Gary Gregory <garydgreg...@gmail.com> wrote:
> > On Wed, Apr 19, 2017 at 1:00 PM, Gary Gregory <garydgreg...@gmail.com> > wrote: > >> Related to this, is HttpCore which switch from JCIP style annotations >> (4.x) to @Contract (5.x). I'll ask that ML for the reason/experience. >> > > Acoording to Oleg: > -- > The original JCIP style annotations had to be removed due to ASLv2 > incompatibility with the license of the original work. > > There is a corresponding Jira ticket in LEGAL. > -- > Found these two: https://issues.apache.org/jira/browse/LEGAL-240 https://issues.apache.org/jira/browse/LEGAL-3 Gary > Gary > > >> >> Gary >> >> On Wed, Apr 19, 2017 at 12:14 PM, Oliver Heger < >> oliver.he...@oliver-heger.de> wrote: >> >>> >>> >>> Am 19.04.2017 um 14:06 schrieb Gilles: >>> > On Wed, 19 Apr 2017 09:17:32 +0200, Emmanuel Bourg wrote: >>> >> Le 19/04/2017 à 00:23, Gary Gregory a écrit : >>> >> >>> >>> I'd like to see a real example before we talk about abstract >>> >>> arguments and >>> >>> counter-arguments, which will never end ;-) >>> >> >>> >> Ok, >>> > >>> > Good. [If only...] ;-) >>> > >>> >> here is a slightly more substantial example. The following class is >>> >> immutable but not thread-safe: >>> >> >>> >> public class FileAppender { >>> >> private final File file; >>> >> >>> >> public FileAppender(File file) { >>> >> this.file = file; >>> >> } >>> >> >>> >> public void append(String message) throws IOException { >>> >> try (OutputStream out = new FileOutputStream(file)) { >>> >> out.write(message.getBytes()); >>> >> } >>> >> } >>> >> } >>> >> >>> >> The point is, if the class operates on resources outside the JVM, the >>> >> immutability doesn't ensure the thread safety. Immutability is only a >>> >> thread safety guarantee for data structures, and not for classes with >>> >> operations causing side effects (like writing to files, drawing on the >>> >> screen, playing sounds, calling remote services, accessing off-heap >>> >> memory, etc). >>> > >>> > The consequence should thus be that such classes should not be >>> > documented as thread-safe _because_ such a qualifier would not >>> > bring any actual benefit to the user. >>> > >>> > Documenting/annotating a class as "immutable" or "thread-safe" >>> > must be a _promise_ to the user, and it requires more analysis >>> > than recognizing that all the fields are final. >>> > >>> > To return to the question of which annotation, I'm unfazed by >>> > the possibility of >>> > @ThreadSafe >>> > @NotThreadSafe >>> > because it is an obvious documentation bug, with no more dire >>> > consequences than saying >>> > @ThreadSafe >>> > when, in fact, it is not. >>> > >>> I agree. Let's not forget that the annotations are intended as a tool >>> for documentation. The main responsibility is on the author who is using >>> them. >>> >>> We should not try to be too clever here, especially as we have no way to >>> prevent real documentation errors: classes being marked as @ThreadSafe >>> although they are not, or originally thread-safe classes which are later >>> modified in a way that breaks their thread-safety. >>> >>> Oliver >>> >>> > >>> > Gilles >>> > >>> >> >>> >> Emmanuel Bourg >>> >> >>> >> >>> > >>> > >>> > >>> > --------------------------------------------------------------------- >>> > To unsubscribe, e-mail: dev-unsubscr...@commons.apache.org >>> > For additional commands, e-mail: dev-h...@commons.apache.org >>> > >>> >>> --------------------------------------------------------------------- >>> To unsubscribe, e-mail: dev-unsubscr...@commons.apache.org >>> For additional commands, e-mail: dev-h...@commons.apache.org >>> >>> >> >> >> -- >> E-Mail: garydgreg...@gmail.com | ggreg...@apache.org >> Java Persistence with Hibernate, Second Edition >> <https://www.amazon.com/gp/product/1617290459/ref=as_li_tl?ie=UTF8&camp=1789&creative=9325&creativeASIN=1617290459&linkCode=as2&tag=garygregory-20&linkId=cadb800f39946ec62ea2b1af9fe6a2b8> >> >> <http:////ir-na.amazon-adsystem.com/e/ir?t=garygregory-20&l=am2&o=1&a=1617290459> >> JUnit in Action, Second Edition >> <https://www.amazon.com/gp/product/1935182021/ref=as_li_tl?ie=UTF8&camp=1789&creative=9325&creativeASIN=1935182021&linkCode=as2&tag=garygregory-20&linkId=31ecd1f6b6d1eaf8886ac902a24de418%22> >> >> <http:////ir-na.amazon-adsystem.com/e/ir?t=garygregory-20&l=am2&o=1&a=1935182021> >> Spring Batch in Action >> <https://www.amazon.com/gp/product/1935182951/ref=as_li_tl?ie=UTF8&camp=1789&creative=9325&creativeASIN=1935182951&linkCode=%7B%7BlinkCode%7D%7D&tag=garygregory-20&linkId=%7B%7Blink_id%7D%7D%22%3ESpring+Batch+in+Action> >> <http:////ir-na.amazon-adsystem.com/e/ir?t=garygregory-20&l=am2&o=1&a=1935182951> >> Blog: http://garygregory.wordpress.com >> Home: http://garygregory.com/ >> Tweet! http://twitter.com/GaryGregory >> > > > > -- > E-Mail: garydgreg...@gmail.com | ggreg...@apache.org > Java Persistence with Hibernate, Second Edition > <https://www.amazon.com/gp/product/1617290459/ref=as_li_tl?ie=UTF8&camp=1789&creative=9325&creativeASIN=1617290459&linkCode=as2&tag=garygregory-20&linkId=cadb800f39946ec62ea2b1af9fe6a2b8> > > <http:////ir-na.amazon-adsystem.com/e/ir?t=garygregory-20&l=am2&o=1&a=1617290459> > JUnit in Action, Second Edition > <https://www.amazon.com/gp/product/1935182021/ref=as_li_tl?ie=UTF8&camp=1789&creative=9325&creativeASIN=1935182021&linkCode=as2&tag=garygregory-20&linkId=31ecd1f6b6d1eaf8886ac902a24de418%22> > > <http:////ir-na.amazon-adsystem.com/e/ir?t=garygregory-20&l=am2&o=1&a=1935182021> > Spring Batch in Action > <https://www.amazon.com/gp/product/1935182951/ref=as_li_tl?ie=UTF8&camp=1789&creative=9325&creativeASIN=1935182951&linkCode=%7B%7BlinkCode%7D%7D&tag=garygregory-20&linkId=%7B%7Blink_id%7D%7D%22%3ESpring+Batch+in+Action> > <http:////ir-na.amazon-adsystem.com/e/ir?t=garygregory-20&l=am2&o=1&a=1935182951> > Blog: http://garygregory.wordpress.com > Home: http://garygregory.com/ > Tweet! http://twitter.com/GaryGregory > -- E-Mail: garydgreg...@gmail.com | ggreg...@apache.org Java Persistence with Hibernate, Second Edition <https://www.amazon.com/gp/product/1617290459/ref=as_li_tl?ie=UTF8&camp=1789&creative=9325&creativeASIN=1617290459&linkCode=as2&tag=garygregory-20&linkId=cadb800f39946ec62ea2b1af9fe6a2b8> <http:////ir-na.amazon-adsystem.com/e/ir?t=garygregory-20&l=am2&o=1&a=1617290459> JUnit in Action, Second Edition <https://www.amazon.com/gp/product/1935182021/ref=as_li_tl?ie=UTF8&camp=1789&creative=9325&creativeASIN=1935182021&linkCode=as2&tag=garygregory-20&linkId=31ecd1f6b6d1eaf8886ac902a24de418%22> <http:////ir-na.amazon-adsystem.com/e/ir?t=garygregory-20&l=am2&o=1&a=1935182021> Spring Batch in Action <https://www.amazon.com/gp/product/1935182951/ref=as_li_tl?ie=UTF8&camp=1789&creative=9325&creativeASIN=1935182951&linkCode=%7B%7BlinkCode%7D%7D&tag=garygregory-20&linkId=%7B%7Blink_id%7D%7D%22%3ESpring+Batch+in+Action> <http:////ir-na.amazon-adsystem.com/e/ir?t=garygregory-20&l=am2&o=1&a=1935182951> Blog: http://garygregory.wordpress.com Home: http://garygregory.com/ Tweet! http://twitter.com/GaryGregory
