On Tue, 10 May 2022 04:00:29 GMT, Ioi Lam <ik...@openjdk.org> wrote:
> The `mode` parameter for ` jdk.internal.perf.Perf.attach()` has never
> supported the value `"rw"` since the source code was imported to the openjdk
> repo more than 15 years ago. In fact HotSpot throws
> `IllegalArgumentException` when such a mode is specified.
>
> It's unlikely such a mode will be required for future enhancements. Support
> for `"rw"` is removed. The "mode" parameter is also removed, since now `"r"`
> is the only supported mode.
>
> I also cleaned up related code in the JDK and HotSpot.
>
> Testing:
> - Passed tiers 1 and 2
> - Tiers 3, 4, 5 are in progress
src/jdk.internal.jvmstat/share/classes/sun/jvmstat/perfdata/monitor/protocol/file/PerfDataBuffer.java
line 60:
> 58: FileChannel fc = new RandomAccessFile(f, "r").getChannel();
> 59: ByteBuffer bb = fc.map(FileChannel.MapMode.READ_ONLY, 0L,
> (int)fc.size());
> 60: fc.close(); // doesn't need to remain open
I think you can change this to:
try (FileChannel fc = FileChannel.open(f.toPath())) {
ByteBuffer bb = ...
createPerfDataBuffer(bb, 0);
}
-------------
PR: https://git.openjdk.java.net/jdk/pull/8622
