RFR: 8361639: JFR: Incorrect top frame for I/O events

[Erik Gahlin]

On Tue, 15 Jul 2025 13:38:28 GMT, Alan Bateman <alanb at openjdk.org> wrote:

>> Could I have a review of the change that ensures that the top frame for I/O events is not an internal JDK method, such as FileReadEvent::offer? This change is dependent on [JDK-8361640](https://bugs.openjdk.org/browse/JDK-8361640).
>> 
>> Testing: tier1, tier2 + jdk/jdk/jfr
>> 
>> Thanks
>> Erik
>
> src/jdk.jfr/share/classes/jdk/jfr/events/FileReadEvent.java line 44:
> 
>> 42:               "java.io.DataInputStream",
>> 43:               "java.io.FileInputStream",
>> 44:               "java.io.InputStream",
> 
> Do you have any stack traces handy that could be pasted into the JBS issue or the PR so that it's clear why InputStream and Data*Stream frames are filtered?

It's DataInputStream::readUTF(DataInput in), used by RandomAccessFile::readUTF(), and InputStream::readNBytes(byte[], int, int), which is not overridden by FileInputStream. (FileRead)

DataOutputStream::writeUTF(DataOutput) used by RandomAccessFile::writeUTF (FileWrite)

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PR Review Comment: https://git.openjdk.org/jdk/pull/26211#discussion_r2208184872