[jdk17u-dev] RFR: 8267517: async logging for stdout and stderr [v2]

[Goetz Lindenmaier]

On Tue, 11 Jul 2023 08:36:17 GMT, Xin Liu <xliu at openjdk.org> wrote:

>> This PR backports JDK-8267517 to jdk17u. -Xlog:async will route LogOutput stdout/stderr to the asynchronous logging queue like ordinary log files. The reason we do is that some Java application outputs logs to stdout/stderr and redirect them to files then. 
>> 
>> This is **NOT** a clean backport. It's because jdk17u is missing a few patches, such as JDK-8273471, JDK-8269004. I tried to backport them beforehand, but they both have dependencies.  I manually resolve a couple of conflicts. 
>> 
>> We have verified patch like how we verified for jdk-tip. We output verbose gclog to stdout `-Xlog:gc=trace:stdout` and leverage software flow control to pause our console(C-s). Java threads don't be blocked with '-Xlog:async'. Without this patch, kernel puts Java threads which require GC to 'sleep' state when unified log is blocked.
>> 
>> ---------
>> ### Progress
>> - [ ] Change must be properly reviewed (1 review required, with at least 1 [Reviewer](https://openjdk.org/bylaws#reviewer))
>> - [x] Change must not contain extraneous whitespace
>> - [x] Commit message must refer to an issue
>> 
>> ### Error
>>  ⚠️ The pull request body must not be empty.
>> 
>> 
>> 
>> ### Reviewing
>> <details><summary>Using <code>git</code></summary>
>> 
>> Checkout this PR locally: \
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>> `$ git checkout pull/1555`
>> 
>> Update a local copy of the PR: \
>> `$ git checkout pull/1555` \
>> `$ git pull https://git.openjdk.org/jdk17u-dev.git pull/1555/head`
>> 
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>> 
>> </details>
>
> Xin Liu has updated the pull request incrementally with one additional commit since the last revision:
> 
>   update per feedback

Thanks for this thoroughly documented backport!

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PR Comment: https://git.openjdk.org/jdk17u-dev/pull/1555#issuecomment-1631911271