[9] RFR of 8042377: BufferedWriter and FilteredOutputStream.close throw IAE if flush and close throw equal exceptions

[Brian Burkhalter]

Hi Peter,

Thanks for the code change suggestion. I have modified the patch to use its logic and to revert to the original boolean instance variable instead of the contentious AtomicBoolean:

http://cr.openjdk.java.net/~bpb/8042377/webrev.02/

The test passes unchanged.

Push will be withheld until there’s an imprimatur from a JDK 9 Reviewer.

Thanks,

Brian

On Jun 25, 2015, at 1:31 AM, Peter Levart <peter.levart at gmail.com> wrote:

> Modified code is a little different semantically from try-with resources. in case both flush() and out.close() throw, try-with resources propagates the exception thrown from flush() while modified code propagates exception thrown from out.close(). But that, I think, is actually preferable in this case, since we are calling method close() on FilterOutputStream.
> 
> The other semantic difference is when flush() and/or out.close() throw unchecked exception. In try-with-resources case, unchecked exception from out.close() is always added as suppressed to the exception from flush() while in modified code, unchecked exception from flush() is ignored when out.close() also throws. Also, IOExceptio from flush() is ignored if out.close() throws unchecked exception. Here's how both exceptions can be considered regardless of whether they are IOException or unchecked:
> 
>     public void close() throws IOException {
>         if (closed.compareAndSet(false, true)) {
>             Throwable flushException = null;
>             try {
>                 flush();
>             } catch (Throwable e) {
>                 flushException = e;
>                 throw e;
>             } finally {
>                 if (flushException == null) {
>                     out.close();
>                 } else {
>                     try {
>                         out.close();
>                     } catch (Throwable closeException) {
>                         if (flushException != closeException) {
>                             closeException.addSuppressed(flushException);
>                         }
>                         throw closeException;
>                     }
>                 }
>             }
>         }
>     }