Mercurial > hg > nginx-quic
view src/os/unix/ngx_udp_sendmsg_chain.c @ 6949:ff0c8e11edbc
Simplified and improved sendfile() code on Linux.
The ngx_linux_sendfile() function is now used for both normal sendfile()
and sendfile in threads. The ngx_linux_sendfile_thread() function was
modified to use the same interface as ngx_linux_sendfile(), and is simply
called from ngx_linux_sendfile() when threads are enabled.
Special return code NGX_DONE is used to indicate that a thread task was
posted and no further actions are needed.
If number of bytes sent is less that what we were sending, we now always
retry sending. This is needed for sendfile() in threads as the number
of bytes we are sending might have been changed since the thread task
was posted. And this is also needed for Linux 4.3+, as sendfile() might
be interrupted at any time and provides no indication if it was interrupted
or not (ticket #1174).
author | Maxim Dounin <mdounin@mdounin.ru> |
---|---|
date | Tue, 28 Mar 2017 18:15:39 +0300 |
parents | 56fc55e32f23 |
children | dbb0c854e308 |
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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 ngx_chain_t *ngx_udp_output_chain_to_iovec(ngx_iovec_t *vec, ngx_chain_t *in, ngx_log_t *log); static ssize_t ngx_sendmsg(ngx_connection_t *c, ngx_iovec_t *vec); ngx_chain_t * ngx_udp_unix_sendmsg_chain(ngx_connection_t *c, ngx_chain_t *in, off_t limit) { ssize_t n; off_t send; ngx_chain_t *cl; ngx_event_t *wev; ngx_iovec_t vec; struct iovec iovs[NGX_IOVS_PREALLOCATE]; wev = c->write; if (!wev->ready) { return in; } #if (NGX_HAVE_KQUEUE) if ((ngx_event_flags & NGX_USE_KQUEUE_EVENT) && wev->pending_eof) { (void) ngx_connection_error(c, wev->kq_errno, "kevent() reported about an closed connection"); wev->error = 1; return NGX_CHAIN_ERROR; } #endif /* the maximum limit size is the maximum size_t value - the page size */ if (limit == 0 || limit > (off_t) (NGX_MAX_SIZE_T_VALUE - ngx_pagesize)) { limit = NGX_MAX_SIZE_T_VALUE - ngx_pagesize; } send = 0; vec.iovs = iovs; vec.nalloc = NGX_IOVS_PREALLOCATE; for ( ;; ) { /* create the iovec and coalesce the neighbouring bufs */ cl = ngx_udp_output_chain_to_iovec(&vec, in, c->log); if (cl == NGX_CHAIN_ERROR) { return NGX_CHAIN_ERROR; } if (cl && cl->buf->in_file) { ngx_log_error(NGX_LOG_ALERT, c->log, 0, "file buf in sendmsg " "t:%d r:%d f:%d %p %p-%p %p %O-%O", cl->buf->temporary, cl->buf->recycled, cl->buf->in_file, cl->buf->start, cl->buf->pos, cl->buf->last, cl->buf->file, cl->buf->file_pos, cl->buf->file_last); ngx_debug_point(); return NGX_CHAIN_ERROR; } if (cl == in) { return in; } send += vec.size; n = ngx_sendmsg(c, &vec); if (n == NGX_ERROR) { return NGX_CHAIN_ERROR; } if (n == NGX_AGAIN) { wev->ready = 0; return in; } c->sent += n; in = ngx_chain_update_sent(in, n); if (send >= limit || in == NULL) { return in; } } } static ngx_chain_t * ngx_udp_output_chain_to_iovec(ngx_iovec_t *vec, ngx_chain_t *in, ngx_log_t *log) { size_t total, size; u_char *prev; ngx_uint_t n, flush; ngx_chain_t *cl; struct iovec *iov; cl = in; iov = NULL; prev = NULL; total = 0; n = 0; flush = 0; for ( /* void */ ; in && !flush; in = in->next) { if (in->buf->flush || in->buf->last_buf) { flush = 1; } if (ngx_buf_special(in->buf)) { continue; } if (in->buf->in_file) { break; } if (!ngx_buf_in_memory(in->buf)) { ngx_log_error(NGX_LOG_ALERT, log, 0, "bad buf in output chain " "t:%d r:%d f:%d %p %p-%p %p %O-%O", in->buf->temporary, in->buf->recycled, in->buf->in_file, in->buf->start, in->buf->pos, in->buf->last, in->buf->file, in->buf->file_pos, in->buf->file_last); ngx_debug_point(); return NGX_CHAIN_ERROR; } size = in->buf->last - in->buf->pos; if (prev == in->buf->pos) { iov->iov_len += size; } else { if (n == vec->nalloc) { ngx_log_error(NGX_LOG_ALERT, log, 0, "too many parts in a datagram"); return NGX_CHAIN_ERROR; } iov = &vec->iovs[n++]; iov->iov_base = (void *) in->buf->pos; iov->iov_len = size; } prev = in->buf->pos + size; total += size; } if (!flush) { #if (NGX_SUPPRESS_WARN) vec->size = 0; vec->count = 0; #endif return cl; } vec->count = n; vec->size = total; return in; } static ssize_t ngx_sendmsg(ngx_connection_t *c, ngx_iovec_t *vec) { ssize_t n; ngx_err_t err; struct msghdr msg; ngx_memzero(&msg, sizeof(struct msghdr)); if (c->socklen) { msg.msg_name = c->sockaddr; msg.msg_namelen = c->socklen; } msg.msg_iov = vec->iovs; msg.msg_iovlen = vec->count; eintr: n = sendmsg(c->fd, &msg, 0); ngx_log_debug2(NGX_LOG_DEBUG_EVENT, c->log, 0, "sendmsg: %z of %uz", n, vec->size); if (n == -1) { err = ngx_errno; switch (err) { case NGX_EAGAIN: ngx_log_debug0(NGX_LOG_DEBUG_EVENT, c->log, err, "sendmsg() not ready"); return NGX_AGAIN; case NGX_EINTR: ngx_log_debug0(NGX_LOG_DEBUG_EVENT, c->log, err, "sendmsg() was interrupted"); goto eintr; default: c->write->error = 1; ngx_connection_error(c, err, "sendmsg() failed"); return NGX_ERROR; } } return n; }