On Fri, 24 Apr 2026 17:55:18 GMT, Ashay Rane <[email protected]> wrote:
> Prior to this patch, every HTTP request created a new 16KB buffer for > encoding the header, which is typically only a few hundred bytes long. > This increased pressure on the garbage collector when the client created > lots of requests. This patch instead makes the header encoder reuse the > buffer that is created during the handling of the first request. > > The caveat, however, is that the downstream consumers of the header are > asynchronous, so the encoder needs to take special care to ensure that > it doesn't modify or invalidate the buffer after it hands the buffer > over to the downstream asynchronous pipeline. To resolve this, this > patch snapshots the buffer data into compact copies sized to the actual > encoded length. Doing so makes the buffer immediately available for > reuse via `clear()` and `limit()`. > > For typical requests, this reduces per-request allocation from 16KB to > a few hundred bytes (i.e. the size of the compact copy of the encoded > headers), with the 16KB encoding buffer allocated once per connection > instead of once per request. > > --------- > - [x] I confirm that I make this contribution in accordance with the [OpenJDK > Interim AI Policy](https://openjdk.org/legal/ai). Merged the master branch to pull an unrelated build fix. ------------- PR Comment: https://git.openjdk.org/jdk/pull/30931#issuecomment-4316659414
