Co-authored-by: Jonathan Swoboda <swoboda1337@users.noreply.github.com>
Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>
Co-authored-by: pre-commit-ci-lite[bot] <117423508+pre-commit-ci-lite[bot]@users.noreply.github.com>
On ESP32 with CONFIG_LWIP_TCPIP_CORE_LOCKING, bypass lwip_setsockopt()
for TCP_NODELAY by directly modifying tcp_pcb->flags under the TCPIP
core lock. This eliminates ~1091 bytes of overhead per call (socket
lookups, hook, switch cascade, refcounting) for what is just a single
bit flip.
The API frame helper toggles Nagle's algorithm on every message send
via set_nodelay_for_message(), making this a hot path. The fast path
reduces set_nodelay_raw_ from calling the full lwip_setsockopt to just
acquiring the mutex, loading 3 pointers, and flipping the TF_NODELAY
bit.
Only enabled when both USE_LWIP_FAST_SELECT (cached lwip_sock pointer)
and CONFIG_LWIP_TCPIP_CORE_LOCKING (real mutex protection) are
available. Falls back to the standard setsockopt call otherwise.
Defensively free pb when err != ERR_OK but pb != nullptr in both
recv_fn and s_queued_recv_fn. In practice lwip never sends data
with an error code, but this prevents a leak if it ever does.
Also add comment noting tcp_recved is deferred to read().
Defensively free pb when err != ERR_OK but pb != nullptr in both
recv_fn and s_queued_recv_fn. In practice lwip never sends data
with an error code, but this prevents a leak if it ever does.
Also add comment noting tcp_recved is deferred to read().
Consolidate the dequeue + shift + tcp_arg update into a single while
loop that skips null entries (freed by lwip while queued) and returns
the first valid PCB. Eliminates the duplicated shift/update logic.
Consolidate the dequeue + shift + tcp_arg update into a single while
loop that skips null entries (freed by lwip while queued) and returns
the first valid PCB. Eliminates the duplicated shift/update logic.
When LWIPRawImpl creation was deferred to the main-loop accept(),
the queued PCB had no recv callback registered. lwip's default
tcp_recv_null handler ACKs incoming data but drops it silently.
On ESP8266, lwip processes TCP segments in batches — if the SYN
completion and first data packet arrive in the same batch, the
API handshake data is lost, causing SocketClosedAPIError (EOF).
Fix: register temporary recv/err callbacks on queued PCBs that
buffer any data received before accept() creates the LWIPRawImpl.
The buffered data is transferred to the new socket via init().
J. Nick Koston