Mercurial > hg > nginx-quic
view src/os/win32/ngx_wsasend.c @ 8759:56dec0d4e5b1 quic
QUIC: avoid excessive buffer allocations in stream output.
Previously, when a few bytes were send to a QUIC stream by the application, a
4K buffer was allocated for these bytes. Then a STREAM frame was created and
that entire buffer was used as data for that frame. The frame with the buffer
were in use up until the frame was acked by client. Meanwhile, when more
bytes were send to the stream, more buffers were allocated and assigned as
data to newer STREAM frames. In this scenario most buffer memory is unused.
Now the unused part of the stream output buffer is available for further
stream output while earlier parts of the buffer are waiting to be acked.
This is achieved by splitting the output buffer.
author | Roman Arutyunyan <arut@nginx.com> |
---|---|
date | Fri, 24 Dec 2021 18:13:51 +0300 |
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; }