- u_async.c: process immediate_queue BEFORE epoll_wait in uasync_poll
- stcp_link.c: defensive NULL etcp_conn/etcp_link in stcp_link_close
- utun_instance.c: move stcp_server_list_destroy_all to Phase J (before ETCP),
add deferred drain in both Phase J and L
- stcp.h/c: STCP_HS_ENC_CLIENT 6→38, STCP_HS_ENC_SERVER 7→39,
exchange ed25519_pubkey in both handshake directions
- etcp_connections.c: copy peer_ed25519 from STCP to ETCP_CONN in
etcp_link_enter_ready_tcp; guard link->etcp in tcp_link_close_cb
- chat_sync.c: fix lk->conn NULL dereference for TCP links
- test_stcp.c: update stcp_server_create/stcp_client_connect callsites
- tools/chat_tcp_test: change transport udp→tcp
Root cause: accept queue overflow (backlog=32) caused kernel SYN drops.
Children waited ~1s for SYN retransmit timeout (5 gaps × 1s = 5s out of 7.2s).
With backlog=1024 the timeout drops from ~7.2s to ~0.065s (110× faster).
В одном epoll_wait batch три события для fd: EPOLLERR (освобождает tc),
EPOLLIN (read_cb), EPOLLOUT (write_cb). read_cb/write_cb guard проверяет
tc->sock==SOCKET_INVALID, но sock обнулялся ПОСЛЕ on_error.
Перенос sock=SOCKET_INVALID до on_error защищает от use-after-free.
Доказано: без фикса segfault на tcp_io.c:374 (write_cb → tc->connected).
С фиксом тест работает без крашей.
- pkt_normalizer: save recvpart->len before queue_data_put (may free synchronously)
- ll_queue: save uasync_call_soon handle in queue_waiter_handle, cancel on free
- uasync: generation counter in epoll data.u64 to skip stale events after fd reuse
- uasync: keep fd_to_index mapping after socket_array_remove for inactive nodes
- test: test_uasync_socket_race — 4 children × 200 iterations, currently flaky
evgeny
Evgeny