RFR: 8307403: java/util/zip/DeInflate.java timed out

[Jaikiran Pai]

On Mon, 15 May 2023 15:10:06 GMT, Volker Simonis <simonis at openjdk.org> wrote:

>> Can I please get a review of this test only change which addresses the issue noted in https://bugs.openjdk.org/browse/JDK-8307403?
>> 
>> When we recently did a change in https://bugs.openjdk.org/browse/JDK-8299748, there was a oversight that the `deflate.deflate(tempBuffer)` could potentially end up taking in a zero sized array. That would then mean the loop in which this `deflate` happens, would never exit leading to the test timing out.
>> I've added additional details as a comment to the JBS issue https://bugs.openjdk.org/browse/JDK-8307403?focusedCommentId=14581202&page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel#comment-14581202.
>> 
>> The commit in this PR uses a fixed size temporary buffer, unrelated to the input length, to get past this problem. The use of fixed size here will not re-introduce the original issue which https://bugs.openjdk.org/browse/JDK-8299748 fixed, because unlike previously, this is just a temporary size and we continue to deflate the content into a dynamically growing `ByteArrayOutputStream` till the deflater is "finished".
>> 
>> Additionally I've added a log message to help debug any future issues in this call.
>
> test/jdk/java/util/zip/DeInflate.java line 146:
> 
>> 144:         def.finish();
>> 145: 
>> 146:         try (ByteArrayOutputStream baos = new ByteArrayOutputStream()) {
> 
> I don't think this is really required because the `ByteArrayOutputStream` will grow dynamically anyway, even if initialized to zero but for all other cases `len` is probably a better estimation than the default size of `32`. But I leave it up to you if you want to change it back.

Hello Volker, you are right that even initializing this with `len` should be fine since the `ByteArrayOutputStream` will grow if/when needed. However, the reason I decided to remove the usage of `len` here was to avoid any kind of confusion and make it easier to read that `len` is only for the input length (as noted in the javadoc of that method) and plays no other role in deciding sizes of (temporary) outputs.

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PR Review Comment: https://git.openjdk.org/jdk/pull/13955#discussion_r1194498736