> On Sep 26, 2017, at 1:27 PM, mandy chung <mandy.ch...@oracle.com> wrote:
> On 9/25/17 11:37 PM, Kim Barrett wrote:
>> src/java.base/share/classes/java/lang/ClassLoader.java
>> 2394 public void register() {
>> [...]
>> 2406 // register the class loader for cleanup when unloaded
>> 2407 if (loader != getBuiltinPlatformClassLoader() &&
>> 2408 loader != getBuiltinAppClassLoader()) {
>> 2409 CleanerFactory.cleaner()
>> 2410 .register(loader, new Unloader(name, handle,
>> isBuiltin));
>> 2411 }
>>
>> Can anything before the cleanup registration throw?
>
> No within the register method.
I think there are some opportunities for OOME, but I think no worse than before.
And the result would be a loaded library without the unload registration, which
seems like it might perhaps be annoying but probably not fatal.
> I'm considering to separate the JNI_FindClass change to target 18.3 and
> provide a flag to restore the current behavior so that it may help existing
> code to identify its dependency on the current behavior and give time to
> migrate. Then target the finalizer to Cleaner change in 18.9.
>
> It's unknown to us how many existing native libraries are impacted by this
> change (calling FindClass from JNI_OnUnload to load classes visible the class
> loader being unloaded). I suspect it's rare. If FindClass is called when
> the native library is being unloaded and fail to find the class due to this
> change, it is not hard to find out but the code might crash if it does not
> handle the class not found case properly.
>
> Any opinion?
I’m in favor of removing this finalizer sooner rather than later, but you
probably could have guessed that.
