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