Http3

Memory leak and correctness fixes

• Fixed a heap leak where stream readable sides were never consumed on GET requests — heap dropped from 358MB to 5.4MB after 1M requests.
• Fixed silent data loss at 8 call sites where fatal send errors were swallowed; now properly emits EVENT_ERROR to JS.
• Fixed partial-write data loss in borrow-based stream_send.
• Fixed io_uring RX buffer ring exhaustion with stop-and-wait cross-thread echo protocol.

Performance (+21.8% H3 sustained throughput)

• RecyclableBuffer for inbound data — napi_create_external_buffer with finalize callbacks that return buffers to the worker pool via crossbeam, eliminating malloc fragmentation.
• ChunkPool with 1KB/2KB/4KB size classes for outbound sends, with auto-recycle on drop.
• Zero-copy H3 send via send_body_owned() wrapping Vec in ArcBuf without copying.
• Event shape normalization — all JsH3Event objects now present the same set of JS properties, reducing V8 hidden classes from 6-8 to 2.
• Lazy BackpressureState — per-stream state deferred until first backpressure, saving ~69K allocations/s.
• Combined sendResponse — new respondWithBody() sends headers + body + FIN in 1 NAPI call instead of 3.

Shutdown lifecycle fix

• Fixed a deadlock in close() on all four event loop types (H3 server/client, QUIC server/client) caused by synchronous thread join blocking the JS event loop.
• Split shutdown() into requestShutdown() + joinWorker(), safe for all transport drivers (io_uring, kqueue, poll).

Transport drivers

• io_uring: RX buffer ring exhaustion fix, waker resubmit, sendmsg EAGAIN handling.
• kqueue: pending-write drain fixes, waker reliability.
• Driver-tracing feature gate for optional per-event diagnostics.

Test infrastructure

• 545 tests (161 Rust unit, 53 integration, 8 packet loss, 325 TypeScript).
• 34 e2e scenarios (REST CRUD, file serving, SSE, streaming, concurrency, datagrams, server push).
• 5-minute longhaul: H3 sustained at 24.6K req/s, QUIC at 45.6K streams/s (0 errors).
• FFI boundary stress, packet loss simulation, heap profiling scripts.

Dependencies

Rust 1.94, napi-rs 3.8, quiche 0.26.1 (BoringSSL), pnpm.

Full changelog: https://github.com/currentspace/http3/blob/main/CHANGELOG.md#070