On Thu, 22 Jan 2026 12:09:28 GMT, Alan Bateman <[email protected]> wrote:
> Can you please provide an example where IOException is thrown?
I could not produce IOException, but it might occur if filesystem is broken.
AccessDeniedException would happen as following. We can see it easy on attach
to rootless container.
# ./jcmd 1 VM.version
1:
java.nio.file.AccessDeniedException: /proc/1/root/tmp
at
java.base/sun.nio.fs.UnixException.translateToIOException(UnixException.java:90)
at
java.base/sun.nio.fs.UnixException.rethrowAsIOException(UnixException.java:108)
at
java.base/sun.nio.fs.UnixException.rethrowAsIOException(UnixException.java:113)
at
java.base/sun.nio.fs.UnixFileSystemProvider.isSameFile(UnixFileSystemProvider.java:391)
at java.base/java.nio.file.Files.isSameFile(Files.java:1418)
at
jdk.attach/sun.tools.attach.VirtualMachineImpl.findTargetProcessTmpDirectory(VirtualMachineImpl.java:280)
at
jdk.attach/sun.tools.attach.VirtualMachineImpl.findSocketFile(VirtualMachineImpl.java:236)
at
jdk.attach/sun.tools.attach.VirtualMachineImpl.<init>(VirtualMachineImpl.java:87)
at
jdk.attach/sun.tools.attach.AttachProviderImpl.attachVirtualMachine(AttachProviderImpl.java:56)
at
jdk.attach/com.sun.tools.attach.VirtualMachine.attach(VirtualMachine.java:201)
at jdk.jcmd/sun.tools.jcmd.JCmd.executeCommandForPid(JCmd.java:113)
at jdk.jcmd/sun.tools.jcmd.JCmd.main(JCmd.java:97)
> It would be useful to get an example or two of when MonitorException is
> thrown.
As I said before, I cannot find out the location to throw MonitorException in
JDK source around attach mechanism, but it might happen if the user uses custom
attach provider. Anyway it is checked exception, so it shouldn't ignore or
raise assertion error.
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PR Review Comment: https://git.openjdk.org/jdk/pull/29355#discussion_r2716993417
