On Tue, 25 Nov 2025 15:57:56 GMT, David Beaumont <[email protected]> wrote:
>> Plumbing for javac flags, mostly inspired by/copied from test commits made
>> by @lahodaj .
>>
>> There are several things here, mostly entangled, so it's a bit tricky to try
>> splitting this out, but it would be possible if people wanted.
>>
>> The biggest "refactoing" part of this PR is
>> "src/jdk.compiler/share/classes/com/sun/tools/javac/file/JRTIndex.java"
>> which now has a properly controlled lifecycle and disposed its resources
>> correctly. Prior to this, the class used a non-closeable JRT file-system
>> reference, which leads to "persistent open file" issues such as JDK-8357249.
>>
>> This *does* mean that if compilation and the runtime have the same preview
>> mode, then a 2nd JRT file system to the same jimage file is "opened", *but*
>> the file system itself is lightweight, non-caching and both of them will use
>> the underlying SharedImageReader (which is where nodes are cached etc.) so
>> it really shouldn't be an issue (I will make sure javac benchmarks are
>> checked however).
>>
>> The benefit of this is that now, the shared index (which does do some
>> caching) is correctly tracked across all users, and will be closed when the
>> last user closes the lightweight wrapper instance.
>>
>> A lot of the smaller "spot fix" changes in this PR were just copied by me,
>> or at least inspired directly by Jan's work, so I may have missed some
>> semantic subtlety in the code I'm not familiar with. Please evaluate that
>> carefully.
>
> David Beaumont has updated the pull request incrementally with one additional
> commit since the last revision:
>
> Remove note about StableValue (not possible)
src/jdk.compiler/share/classes/com/sun/tools/javac/file/JRTIndex.java line 139:
> 137: /** Close underlying shared resources once no users exist
> (called exactly once). */
> 138: private synchronized void close() throws IOException {
> 139: assert !isClosed;
This should also use `Assert.check(isClosed)`.
In fact, perhaps it might be worth pulling this check out in some `ensureOpen`
method, and call that method whenever you need.
-------------
PR Review Comment:
https://git.openjdk.org/valhalla/pull/1761#discussion_r2606223110
