Integrated: 8307944: ClassFileDumper should only load java.nio.file.Path if enabled

[Mandy Chung]

On Thu, 25 May 2023 20:23:27 GMT, Mandy Chung <mchung at openjdk.org> wrote:

> Change `ClassFileDumper` constructor to take a `String` rather than `Path` to avoid the file system implementation classes loaded during startup.  In addition, `FilePermission` also causes the default file system to be initialized. 
> 
> This patch changes `ClassFileDumper` to validate the given path only if it's enabled and not to use limited `doPrivileged` to avoid the initialization of `FilePermission` class and the file system implementation classes by default.
> 
> This patch also changes `ClassFileDumper::write` to use `File` instead of `Path` because of JDK-8306678.  `OperatingSystem::<clinit>` causes `Enum::valueOf` to be called which calls core reflection which in turns invokes method handles.   If `-Djdk.invoke.MethodHandle.dumpMethodHandleInternals` is set, VM initialization would fail because `BootLoader::<clinit>` causes `ClassLoaderHelper` to initialize which in turn causes `OperatingSystem` be initialized.   If additional LFs are spinned and dumped, if `ClassFileDumper` uses `Path` for writing, `FileSystems::getDefault` would fail with `NullPointerException` because it calls `BootLoader.loadLibrary` which is not fully initialized. 
> 
> A separate issue will be filed to follow up the startup overhead of `OperatingSystem`.

This pull request has now been integrated.

Changeset: de7fd1c3
Author:    Mandy Chung <mchung at openjdk.org>
URL:       https://git.openjdk.org/jdk/commit/de7fd1c3061cfbfdbd5d7cc2b1ba0ee8d432ee0a
Stats:     167 lines in 6 files changed: 75 ins; 58 del; 34 mod

8307944: ClassFileDumper should only load java.nio.file.Path if enabled

Reviewed-by: rriggs

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PR: https://git.openjdk.org/jdk/pull/14160