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

[Jie Kang]

----- 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().


Regards,

> 
> 
> J.
> 
> 
> 
> 

-- 

Jie Kang

OpenJDK Team - Software Engineering Intern