Mercurial > hg > nginx
view src/os/win32/ngx_wsasend.c @ 9086:f68fdb017141 quic
QUIC: optimized sending stream response.
When a stream is created by client, it's often the case that nginx will send
immediate response on that stream. An example is HTTP/3 request stream, which
in most cases quickly replies with at least HTTP headers.
QUIC stream init handlers are called from a posted event. Output QUIC
frames are also sent to client from a posted event, called the push event.
If the push event is posted before the stream init event, then output produced
by stream may trigger sending an extra UDP datagram. To address this, push
event is now re-posted when a new stream init event is posted.
An example is handling 0-RTT packets. Client typically sends an init packet
coalesced with a 0-RTT packet. Previously, nginx replied with a padded CRYPTO
datagram, followed by a 1-RTT stream reply datagram. Now CRYPTO and STREAM
packets are coalesced in one reply datagram, which saves bandwidth.
Other examples include coalescing 1-RTT first stream response, and
MAX_STREAMS/STREAM sent in response to ACK/STREAM.
author | Roman Arutyunyan <arut@nginx.com> |
---|---|
date | Mon, 03 Apr 2023 16:17:12 +0400 |
parents | 53eb1e67e432 |
children |
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/* * Copyright (C) Igor Sysoev * Copyright (C) Nginx, Inc. */ #include <ngx_config.h> #include <ngx_core.h> #include <ngx_event.h> ssize_t ngx_wsasend(ngx_connection_t *c, u_char *buf, size_t size) { int n; u_long sent; ngx_err_t err; ngx_event_t *wev; WSABUF wsabuf; wev = c->write; if (!wev->ready) { return NGX_AGAIN; } /* * WSABUF must be 4-byte aligned otherwise * WSASend() will return undocumented WSAEINVAL error. */ wsabuf.buf = (char *) buf; wsabuf.len = size; sent = 0; n = WSASend(c->fd, &wsabuf, 1, &sent, 0, NULL, NULL); ngx_log_debug4(NGX_LOG_DEBUG_EVENT, c->log, 0, "WSASend: fd:%d, %d, %ul of %uz", c->fd, n, sent, size); if (n == 0) { if (sent < size) { wev->ready = 0; } c->sent += sent; return sent; } err = ngx_socket_errno; if (err == WSAEWOULDBLOCK) { ngx_log_debug0(NGX_LOG_DEBUG_EVENT, c->log, err, "WSASend() not ready"); wev->ready = 0; return NGX_AGAIN; } wev->error = 1; ngx_connection_error(c, err, "WSASend() failed"); return NGX_ERROR; } ssize_t ngx_overlapped_wsasend(ngx_connection_t *c, u_char *buf, size_t size) { int n; u_long sent; ngx_err_t err; ngx_event_t *wev; LPWSAOVERLAPPED ovlp; WSABUF wsabuf; wev = c->write; if (!wev->ready) { return NGX_AGAIN; } ngx_log_debug1(NGX_LOG_DEBUG_EVENT, c->log, 0, "wev->complete: %d", wev->complete); if (!wev->complete) { /* post the overlapped WSASend() */ /* * WSABUFs must be 4-byte aligned otherwise * WSASend() will return undocumented WSAEINVAL error. */ wsabuf.buf = (char *) buf; wsabuf.len = size; sent = 0; ovlp = (LPWSAOVERLAPPED) &c->write->ovlp; ngx_memzero(ovlp, sizeof(WSAOVERLAPPED)); n = WSASend(c->fd, &wsabuf, 1, &sent, 0, ovlp, NULL); ngx_log_debug4(NGX_LOG_DEBUG_EVENT, c->log, 0, "WSASend: fd:%d, %d, %ul of %uz", c->fd, n, sent, size); wev->complete = 0; if (n == 0) { if (ngx_event_flags & NGX_USE_IOCP_EVENT) { /* * if a socket was bound with I/O completion port then * GetQueuedCompletionStatus() would anyway return its status * despite that WSASend() was already complete */ wev->active = 1; return NGX_AGAIN; } if (sent < size) { wev->ready = 0; } c->sent += sent; return sent; } err = ngx_socket_errno; if (err == WSA_IO_PENDING) { ngx_log_debug0(NGX_LOG_DEBUG_EVENT, c->log, err, "WSASend() posted"); wev->active = 1; return NGX_AGAIN; } wev->error = 1; ngx_connection_error(c, err, "WSASend() failed"); return NGX_ERROR; } /* the overlapped WSASend() complete */ wev->complete = 0; wev->active = 0; if (ngx_event_flags & NGX_USE_IOCP_EVENT) { if (wev->ovlp.error) { ngx_connection_error(c, wev->ovlp.error, "WSASend() failed"); return NGX_ERROR; } sent = wev->available; } else { if (WSAGetOverlappedResult(c->fd, (LPWSAOVERLAPPED) &wev->ovlp, &sent, 0, NULL) == 0) { ngx_connection_error(c, ngx_socket_errno, "WSASend() or WSAGetOverlappedResult() failed"); return NGX_ERROR; } } ngx_log_debug3(NGX_LOG_DEBUG_EVENT, c->log, 0, "WSAGetOverlappedResult: fd:%d, %ul of %uz", c->fd, sent, size); if (sent < size) { wev->ready = 0; } c->sent += sent; return sent; }