Mercurial > hg > nginx-quic
view src/os/unix/ngx_writev_chain.c @ 4569:1db899642518
Upstream: reject upstreams without normal servers.
Such upstreams cause CPU hog later in the code as number of peers isn't
expected to be 0. Currently this may happen either if there are only backup
servers defined in an upstream block, or if server with ipv6 address used
in an upstream block.
author | Maxim Dounin <mdounin@mdounin.ru> |
---|---|
date | Mon, 02 Apr 2012 21:29:35 +0000 |
parents | d620f497c50f |
children | 6cd5d4a279d6 |
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/* * Copyright (C) Igor Sysoev * Copyright (C) Nginx, Inc. */ #include <ngx_config.h> #include <ngx_core.h> #include <ngx_event.h> #if (IOV_MAX > 64) #define NGX_IOVS 64 #else #define NGX_IOVS IOV_MAX #endif ngx_chain_t * ngx_writev_chain(ngx_connection_t *c, ngx_chain_t *in, off_t limit) { u_char *prev; ssize_t n, size, sent; off_t send, prev_send; ngx_uint_t eintr, complete; ngx_err_t err; ngx_array_t vec; ngx_chain_t *cl; ngx_event_t *wev; struct iovec *iov, iovs[NGX_IOVS]; 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; complete = 0; vec.elts = iovs; vec.size = sizeof(struct iovec); vec.nalloc = NGX_IOVS; vec.pool = c->pool; for ( ;; ) { prev = NULL; iov = NULL; eintr = 0; prev_send = send; vec.nelts = 0; /* create the iovec and coalesce the neighbouring bufs */ for (cl = in; cl && vec.nelts < IOV_MAX && send < limit; cl = cl->next) { if (ngx_buf_special(cl->buf)) { continue; } #if 1 if (!ngx_buf_in_memory(cl->buf)) { ngx_debug_point(); } #endif size = cl->buf->last - cl->buf->pos; if (send + size > limit) { size = (ssize_t) (limit - send); } if (prev == cl->buf->pos) { iov->iov_len += size; } else { iov = ngx_array_push(&vec); if (iov == NULL) { return NGX_CHAIN_ERROR; } iov->iov_base = (void *) cl->buf->pos; iov->iov_len = size; } prev = cl->buf->pos + size; send += size; } n = writev(c->fd, vec.elts, vec.nelts); if (n == -1) { err = ngx_errno; switch (err) { case NGX_EAGAIN: break; case NGX_EINTR: eintr = 1; break; default: wev->error = 1; (void) ngx_connection_error(c, err, "writev() failed"); return NGX_CHAIN_ERROR; } ngx_log_debug0(NGX_LOG_DEBUG_EVENT, c->log, err, "writev() not ready"); } sent = n > 0 ? n : 0; ngx_log_debug1(NGX_LOG_DEBUG_EVENT, c->log, 0, "writev: %z", sent); if (send - prev_send == sent) { complete = 1; } c->sent += sent; for (cl = in; cl; cl = cl->next) { if (ngx_buf_special(cl->buf)) { continue; } if (sent == 0) { break; } size = cl->buf->last - cl->buf->pos; if (sent >= size) { sent -= size; cl->buf->pos = cl->buf->last; continue; } cl->buf->pos += sent; break; } if (eintr) { continue; } if (!complete) { wev->ready = 0; return cl; } if (send >= limit || cl == NULL) { return cl; } in = cl; } }