On Fri, 8 Oct 2021 21:19:36 GMT, XenoAmess <d...@openjdk.java.net> wrote:
> @jmehrens what about this then? > I think it safe now(actually this mechanism is learned from Reader) You should really post your changes to jdk-dev at openjdk.java.net before submitting these so you can know if a change is potentially good or bad. Since jdk pull requests require issue numbers, you can ask people on the list if this is a good idea; if it is, someone on the list may create an issue for you, which probably means your suggestion is valid, and only then you should send a pull request. You need to get a ticket so this pr may get merged. probably through suggesting enhancement on https://bugs.java.com (recommended, takes time but guarantees response) or asking on the mailing list src/java.base/share/classes/java/io/InputStream.java line 550: > 548: > 549: if ((skipBuffer == null) || (skipBuffer.length < size)) { > 550: skipBuffer = new byte[size]; In the `Reader` class, `skipBuffer` access is thread-safe as it's behind a synchronization on the `lock`. This one isn't and is subject to weird java memory models: in extreme cases, if the `skipBuffer` is set to non-null on another thread, it may be non-null on first field read and null on second field read. Hence you should write code like this instead: byte[] skipBuffer = this.skipBuffer; if ((skipBuffer == null) || (skipBuffer.length < size)) { this.skipBuffer = skipBuffer = new byte[size]; } so you only read the field once and get consistent results. ------------- PR: https://git.openjdk.java.net/jdk/pull/5872
