Mercurial > hg > nginx
view src/event/ngx_event_acceptex.c @ 7583:efd71d49bde0
Events: available bytes calculation via ioctl(FIONREAD).
This makes it possible to avoid looping for a long time while working
with a fast enough peer when data are added to the socket buffer faster
than we are able to read and process them (ticket #1431). This is
basically what we already do on FreeBSD with kqueue, where information
about the number of bytes in the socket buffer is returned by
the kevent() call.
With other event methods rev->available is now set to -1 when the socket
is ready for reading. Later in ngx_recv() and ngx_recv_chain(), if
full buffer is received, real number of bytes in the socket buffer is
retrieved using ioctl(FIONREAD). Reading more than this number of bytes
ensures that even with edge-triggered event methods the event will be
triggered again, so it is safe to stop processing of the socket and
switch to other connections.
Using ioctl(FIONREAD) only after reading a full buffer is an optimization.
With this approach we only call ioctl(FIONREAD) when there are at least
two recv()/readv() calls.
author | Maxim Dounin <mdounin@mdounin.ru> |
---|---|
date | Thu, 17 Oct 2019 16:02:19 +0300 |
parents | bcd442b585f0 |
children | fdc3d40979b0 |
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/* * Copyright (C) Igor Sysoev * Copyright (C) Nginx, Inc. */ #include <ngx_config.h> #include <ngx_core.h> #include <ngx_event.h> static void ngx_close_posted_connection(ngx_connection_t *c); void ngx_event_acceptex(ngx_event_t *rev) { ngx_listening_t *ls; ngx_connection_t *c; c = rev->data; ls = c->listening; c->log->handler = ngx_accept_log_error; ngx_log_debug1(NGX_LOG_DEBUG_EVENT, c->log, 0, "AcceptEx: %d", c->fd); if (rev->ovlp.error) { ngx_log_error(NGX_LOG_CRIT, c->log, rev->ovlp.error, "AcceptEx() %V failed", &ls->addr_text); return; } /* SO_UPDATE_ACCEPT_CONTEXT is required for shutdown() to work */ if (setsockopt(c->fd, SOL_SOCKET, SO_UPDATE_ACCEPT_CONTEXT, (char *) &ls->fd, sizeof(ngx_socket_t)) == -1) { ngx_log_error(NGX_LOG_CRIT, c->log, ngx_socket_errno, "setsockopt(SO_UPDATE_ACCEPT_CONTEXT) failed for %V", &c->addr_text); /* TODO: close socket */ return; } ngx_getacceptexsockaddrs(c->buffer->pos, ls->post_accept_buffer_size, ls->socklen + 16, ls->socklen + 16, &c->local_sockaddr, &c->local_socklen, &c->sockaddr, &c->socklen); if (ls->post_accept_buffer_size) { c->buffer->last += rev->available; c->buffer->end = c->buffer->start + ls->post_accept_buffer_size; } else { c->buffer = NULL; } if (ls->addr_ntop) { c->addr_text.data = ngx_pnalloc(c->pool, ls->addr_text_max_len); if (c->addr_text.data == NULL) { /* TODO: close socket */ return; } c->addr_text.len = ngx_sock_ntop(c->sockaddr, c->socklen, c->addr_text.data, ls->addr_text_max_len, 0); if (c->addr_text.len == 0) { /* TODO: close socket */ return; } } ngx_event_post_acceptex(ls, 1); c->number = ngx_atomic_fetch_add(ngx_connection_counter, 1); ls->handler(c); return; } ngx_int_t ngx_event_post_acceptex(ngx_listening_t *ls, ngx_uint_t n) { u_long rcvd; ngx_err_t err; ngx_log_t *log; ngx_uint_t i; ngx_event_t *rev, *wev; ngx_socket_t s; ngx_connection_t *c; for (i = 0; i < n; i++) { /* TODO: look up reused sockets */ s = ngx_socket(ls->sockaddr->sa_family, ls->type, 0); ngx_log_debug1(NGX_LOG_DEBUG_EVENT, &ls->log, 0, ngx_socket_n " s:%d", s); if (s == (ngx_socket_t) -1) { ngx_log_error(NGX_LOG_ALERT, &ls->log, ngx_socket_errno, ngx_socket_n " failed"); return NGX_ERROR; } c = ngx_get_connection(s, &ls->log); if (c == NULL) { return NGX_ERROR; } c->pool = ngx_create_pool(ls->pool_size, &ls->log); if (c->pool == NULL) { ngx_close_posted_connection(c); return NGX_ERROR; } log = ngx_palloc(c->pool, sizeof(ngx_log_t)); if (log == NULL) { ngx_close_posted_connection(c); return NGX_ERROR; } c->buffer = ngx_create_temp_buf(c->pool, ls->post_accept_buffer_size + 2 * (ls->socklen + 16)); if (c->buffer == NULL) { ngx_close_posted_connection(c); return NGX_ERROR; } c->local_sockaddr = ngx_palloc(c->pool, ls->socklen); if (c->local_sockaddr == NULL) { ngx_close_posted_connection(c); return NGX_ERROR; } c->sockaddr = ngx_palloc(c->pool, ls->socklen); if (c->sockaddr == NULL) { ngx_close_posted_connection(c); return NGX_ERROR; } *log = ls->log; c->log = log; c->recv = ngx_recv; c->send = ngx_send; c->recv_chain = ngx_recv_chain; c->send_chain = ngx_send_chain; c->listening = ls; rev = c->read; wev = c->write; rev->ovlp.event = rev; wev->ovlp.event = wev; rev->handler = ngx_event_acceptex; rev->ready = 1; wev->ready = 1; rev->log = c->log; wev->log = c->log; if (ngx_add_event(rev, 0, NGX_IOCP_IO) == NGX_ERROR) { ngx_close_posted_connection(c); return NGX_ERROR; } if (ngx_acceptex(ls->fd, s, c->buffer->pos, ls->post_accept_buffer_size, ls->socklen + 16, ls->socklen + 16, &rcvd, (LPOVERLAPPED) &rev->ovlp) == 0) { err = ngx_socket_errno; if (err != WSA_IO_PENDING) { ngx_log_error(NGX_LOG_ALERT, &ls->log, err, "AcceptEx() %V failed", &ls->addr_text); ngx_close_posted_connection(c); return NGX_ERROR; } } } return NGX_OK; } static void ngx_close_posted_connection(ngx_connection_t *c) { ngx_socket_t fd; ngx_free_connection(c); fd = c->fd; c->fd = (ngx_socket_t) -1; if (ngx_close_socket(fd) == -1) { ngx_log_error(NGX_LOG_ALERT, c->log, ngx_socket_errno, ngx_close_socket_n " failed"); } if (c->pool) { ngx_destroy_pool(c->pool); } } u_char * ngx_acceptex_log_error(ngx_log_t *log, u_char *buf, size_t len) { return ngx_snprintf(buf, len, " while posting AcceptEx() on %V", log->data); }