[8] Review Request for 8007292 : Add JavaFX internal packages to package.access

Bernd Eckenfels bernd-pirat at eckenfels.net
Wed Oct 9 20:49:41 PDT 2013


While you discuss TWR hazards, be aware that closing a sink (OutputStream)  
as part of a "finally" branch which hides exceptions is dangerous in some  
I/O scenarios because hardware write errors could be delayed until the  
close. NFS for example has this tendency, but also some virtual  
filesystems do a lot of commit work on close. So typically you add a close  
inside the try as well.


Am 10.10.2013, 04:36 Uhr, schrieb Joseph Darcy <joe.darcy at oracle.com>:
> It is a hazard (I thought I had published a blog entry on this very  
> tropic, but apparently not). The most robust pattern is
> try(OriginalResource r1 = new OriginalResource;
>      WrappingResource r2 = new WrappingResource(r1);
>      AnnotherWrappingResource r3 = new WrappingResource(r2)) { ...}
> One thing to watch out for in this pattern is a non-idempotent close.  
> Calling close on r3 will presumably propagate a close call to r2, and  
> then r2 to r1. So give the desguaring the try-with-resource and the  
> expected behavior of the wrapping in a normal termination situation,  
> close on r3 gets called once, close on r2 gets called twice (first from  
> the close on r3, second close from try-with-resources), and close on r1  
> gets called three times.
> HTH,
> -Joe


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