Refresh both AGENTS guides and clarify module purpose, usage, ownership, threading, return values and wire formats in headers. Remove the unused timeout_heap freed_count field and unimplemented getter.
- 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
Added #ifdef __cplusplus / extern "C" { ... } / #endif to ~65 headers
in src/ and lib/, enabling the C library to be linked into C++ code (chatgui).
Fixed packet_dump.h (added missing header guard) and etcp_bbr.h
(#pragma once guard).
waiter-based backpressure (commit ba14e31e) could starve HTTPS CONNECT
worker under concurrent 4-worker load — send_q never drained below threshold
fast enough for the waiter to fire before curl timed out (exit=28).
Add retry_timer (500ms, force=1) alongside etcp_router_on_send_ready
waiter: waiter gives instant wake when send_q drains, timer guarantees
delivery via force=1 if waiter hasn't fired in time.
Also improve socks_proxy DEBUG diagnostics in backpressure branches.
- tcp_proxy_server: drain_cb uses etcp_router_on_send_ready instead of retry_timer
- socks_proxy: on_read_cb + tx_waiter_cb use etcp_router_on_send_ready instead of waiter_register
- Result: FIFO round-robin via ll_queue waiters on send_q, all streams get fair share
- No timers — wakeup is event-driven via queue_data_get → check_waiters
- TCP backpressure: read_queue callback_suspended prevents over-reading
error_cb can fire twice for the same fd in one epoll batch,
or conn_free called from multiple callbacks during restart/shutdown.
freed flag makes conn_free idempotent.
tcp_conn_destroy: set read/write queue callbacks to NULL before
queue_free to stop deferred autofetch (drain_cb on freed rc).
write_on_get_cb: throttle consumer_ack to every 8th write_queue
dequeue instead of every single one (was 30+ ACK/sec).
ack_batch field in tcp_proxy_server_conn.
etcp_router: new etcp_router_conn_restart(inst, node_id, svc_id) — closes
all rconns for the peer, notifies service via cb(NULL, entry) with
node_id, resets seq state.
seq=0 detection in etcp_router_recv_cb: when rx_seq >= 256 (MAX_INFLIGHT)
and a data packet arrives with seq=0, detect peer restart and reset rconn.
tcp_proxy_client: handle TCP_PROXY_SUBCMD_RESTART — clear all client conns
and server conns for the restarted peer.
Threshold prevents false positives on in-window seq=0 duplicates.
1-sec diag_timer_cb prints rq/wq counts+bytes, outstanding pool
allocations, tcp kernel buffer sizes (SO_RCVBUF/SO_SNDBUF).
Started in handle_connect, cancelled in conn_free.
lib/u_async: uasync_set_socket_read/write — O(1) EPOLL_CTL_MOD toggle per socket
lib/ll_queue: queue_set_empty_callback — one-shot deferred callback on queue drain
lib/tcp_io: TCP connection management via uasync + ll_queue with pool alloc
- read: direct recv into pool buffer, high/low water flow control
- write: autofetch via ll_queue callback, partial send via write_buf
- on_fin/on_error/on_flushed callbacks, FIN deferred until read_queue drained
- getpeername for pre-connected socket detection
tcp_proxy_server: migrated to tcp_io (22→13 fields, 437→270 lines, -7 functions)
tests: test_tcp_io (5 tests), test_tcp_proxy_server rewritten for tcp_conn
evgeny