RFR: 8351594: JFR: Rate-limited sampling of Java events [v8]

[Alan Bateman]

On Thu, 5 Jun 2025 09:41:10 GMT, Erik Gahlin <egahlin at openjdk.org> wrote:

>> Could I have review of an enhancement that adds rate-limited sampling to Java events, including five events in the JDK (SocketRead, SocketWrite, FileRead, FileWrite, and JavaExceptionThrow).
>> 
>> Testing: test/jdk/jdk/jfr
>> 
>> Thanks
>> Erik
>
> Erik Gahlin has updated the pull request incrementally with two additional commits since the last revision:
> 
>  - Remove the mistakenly added file.
>  - Fix whitespace

src/java.base/share/classes/sun/nio/ch/FileChannelImpl.java line 1252:

> 1250:         } finally {
> 1251:             long bytes = bytesWritten > 0 ? bytesWritten : 0;
> 1252:             FileWriteEvent.offer(start, path, bytes);

The number of bytes written is >=0, it can't be < 0, so I'm not sure why the existing code checks bytesWritten > 0.

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PR Review Comment: https://git.openjdk.org/jdk/pull/25559#discussion_r2128429546