On Tue, 12 Apr 2022 13:02:44 GMT, Alan Bateman <al...@openjdk.org> wrote:
>> src/java.base/share/classes/java/io/BufferedReader.java line 101:
>>
>>> 99: */
>>> 100: public BufferedReader(Reader in, int sz) {
>>> 101: Objects.requireNonNull(in);
>>
>> Not sure if that even matters - but there will be a slight change of
>> behaviour here if `InternalLock.CAN_USE_INTERNAL_LOCK` is ever `false`.
>> Instead of synchronizing on `in`, the `BufferedReader` will synchronize on
>> `this`.
>> Now that I think of it - it probably does matter since even if
>> CAN_USE_INTERNAL_LOCK is true, untrusted subclasses of BufferedReader
>> calling this constructor might expect the locking to be performed on `in`?
>
>> Not sure if that even matters - but there will be a slight change of
>> behaviour here if `InternalLock.CAN_USE_INTERNAL_LOCK` is ever `false`.
>> Instead of synchronizing on `in`, the `BufferedReader` will synchronize on
>> `this`.
>
> Good! We can change this so that depends on whether BufferedReader is
> extended and whether the given Reader is trusted. It's not clear if anyone
> could reliably depend on undocumented behavior like this but we have to be
> cautious at the same time.
Thanks - the same issue appears with `BufferedWriter`/`Writer`.
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PR: https://git.openjdk.java.net/jdk/pull/8166
