[rfc][icedtea-web] Check online detection even if checked before

[Jie Kang]

----- Original Message -----
> On 01/27/2015 04:37 PM, Jie Kang wrote:
> >
> >
> > ----- Original Message -----
> >> On 01/27/2015 04:16 PM, Jacob Wisor wrote:
> >>> On 01/26/2015 at 12:05 PM, Jiri Vanek wrote:
> >>>> On 01/21/2015 10:28 AM, Jiri Vanek wrote:
> >>>>> On 01/06/2015 09:19 PM, Jacob Wisor wrote:
> >>>>>> On 01/06/2015 at 01:25 PM, Jacob Wisor wrote:
> >>>>>>> On 01/05/2015 at 05:19 PM, Jie Kang wrote:
> >>> […]
> >>>>>> @Jie Kang:
> >>>>>> Thank you for spotting this bug.
> >>>>>>
> >>>>>
> >>>>> Is it really an bug? It actually eliminates the benefits of offline
> >>>>> environment.
> >>>>>
> >>>>>>>> consecutive resources: If for the first resource, we detected
> >>>>>>>> offline,
> >>>>>>>> the
> >>>>>>>> boolean onlineDetected would be set to false. Then for the second
> >>>>>>>> resource,
> >>>>>>>> the detection check would be skipped, even if that resource was able
> >>>>>>>> to be
> >>>>>>>> connected to. This would result in the second resource being unable
> >>>>>>>> to
> >>>>>>>> be
> >>>>>>>> downloaded, even though it definitely could and should be. The patch
> >>>>>>>> fixes
> >>>>>>>> this.
> >>>>>
> >>>>> Thinking about it - how it is possible that first resource could not be
> >>>>> downloaded, but second can
> >>>>> be, and how it is possible that first one can be missed, while second
> >>>>> one
> >>>>> not?
> >>>>>
> >>>>>
> >>>>> Maybe before deciding that environment i onnline/offline - we may try
> >>>>> to
> >>>>> download two or three
> >>>>> resources?
> >>>>
> >>>> One more thing crossed my mind - if the check is done everytime
> >>>> ressource
> >>>> is download.
> >>>>
> >>>> Then the output of isOnline() method is actually prety undetermined.
> >>>
> >>> Is it possible for InetAddress.getByName() to be asynchronious? This
> >>> could
> >>> explain
> >>> isOnline() to return false when called for the first time in some cases.
> >>> Maybe some
> >>> other asynchronious part of the code is causing this effect.
> >>>
> >>> Jacob
> >>>
> >>    I had a different issue in mind:
> >>
> >>   >
> >>   > Resource 1 : Can't download, but it is in cache so we use the cache
> >>   > one.
> >>   >
> >> isOnline will return false if called now
> >>
> >>   >
> >>   > Resource 2 : Not in cache, but we can download, so we download it into
> >>   > cache.
> >>   >
> >> isOnline will now return true.
> >
> >
> > Hello,
> >
> > That isn't true with current implementation of ResourceTracker and
> > JNLPRuntime.
> >
> > See ResourceTracker.initializeResource(), JNLPRuntime.detectOnline() and
> > JNLPRuntime.isOnline().
> >
> >
> Yes I know. But will be valid if we apply your patch. Or not?

Yeah it will be valid with the patch.

> 
> J.
> 
> 

-- 

Jie Kang

OpenJDK Team - Software Engineering Intern