- Curl_write_plain/Curl_read_plain have been eliminated. Last code use
now uses Curl_conn_send/recv so that requests use conn->send/revc
callbacks which defaults to cfilters use.
- Curl_recv_plain/Curl_send_plain have been internalized in cf-socket.c.
- USE_RECV_BEFORE_SEND_WORKAROUND (active on Windows) has been moved
into cf-socket.c. The pre_recv buffer is held at the socket filter
context. `postponed_data` structures have been removed from
`connectdata`.
- the hanger in HTTP/2 request handling was a result of read buffering
on all sends and the multi handling is not prepared for this. The
following happens:
- multi preforms on a HTTP/2 easy handle
- h2 reads and processes data
- this leads to a send of h2 data
- which receives and buffers before the send
- h2 returns
- multi selects on the socket, but no data arrives (its in the buffer already)
the workaround now receives data in a loop as long as there is something in
the buffer. The real fix would be for multi to change, so that `data_pending`
is evaluated before deciding to wait on the socket.
io_buffer, optional, in cf-socket.c, http/2 sets state.drain if lower
filter have pending data.
This io_buffer is only available/used when the
-DUSE_RECV_BEFORE_SEND_WORKAROUND is active, e.g. on Windows
configurations. It also maintains the original checks on protocol
handler being HTTP and conn->send/recv not being replaced.
The HTTP/2 (nghttp2) cfilter now sets data->state.drain when it finds
out that the "lower" filter chain has still pending data at the end of
its IO operation. This prevents the processing from becoming stalled.
Closes#10280
5651a36d1a