Previous edit accidentally removed tcp_conn_destroy, timer cancellations,
and etcp_router_cancel_send_ready from conn_free. Without tcp_conn_destroy
the socket was never removed from uasync, causing repeated EPOLLERR →
repeated conn_free on freed memory → double-free crash.
Added debug logs for freed guard entry and u_free.
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.
handle_connect: send first consumer_ack after setting consumer_ack=1
to unblock client router — fixes rq=32/send_q=256 deadlock.
diag_timer_cb: added send_q=N to DIAG line for instant root cause visibility.
read_queue_drain_cb: SOCK:BACKPRESSURE log with send_q count.
write_on_get_cb: SOCK:ACK debug log on each consumer_ack.
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.
External code pushes to write_queue directly (entry_pool + data_pool).
Added queue_set_threshold(write_queue, 32, 0) for write backpressure.
Tests split data into write_chunk_size chunks before queue put.
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
- consumer_ack flag: ACK sent only on consumption, not assembly
- etcp_router_consumer_ack() — called from tcp_proxy_client feed_from_transport
- last_ack_sent_tb: interval-based throttle — send immediately if >=10ms passed,
otherwise timer for remaining time
- timer rules: NULL handle after cancel/fire, NULL check before start
- ROUTER_ACK_INTERVAL_TB 1000→100 (100ms→10ms)
- test_etcp_router_unit: updated test 14 for new immediate-send behavior
- tcp_proxy_client_handle_error: set error flag + send CLOSE once if flag was clear
- tcp_proxy_client_handle_data/handle_close: drop silently, don't send ERROR back
- tcp_proxy_server_handle_data/handle_close: drop silently, don't send ERROR back
- Add recv→send 1MB integration test (3 clients × 3 requests, shell + python)
Evgeny