Mercurial > hg > nginx-quic
view src/os/unix/ngx_readv_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 | 4be36d5e78ae |
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/* * Copyright (C) Igor Sysoev * Copyright (C) Nginx, Inc. */ #include <ngx_config.h> #include <ngx_core.h> #include <ngx_event.h> #define NGX_IOVS 16 #if (NGX_HAVE_KQUEUE) ssize_t ngx_readv_chain(ngx_connection_t *c, ngx_chain_t *chain) { u_char *prev; ssize_t n, size; ngx_err_t err; ngx_array_t vec; ngx_event_t *rev; struct iovec *iov, iovs[NGX_IOVS]; rev = c->read; if (ngx_event_flags & NGX_USE_KQUEUE_EVENT) { ngx_log_debug3(NGX_LOG_DEBUG_EVENT, c->log, 0, "readv: eof:%d, avail:%d, err:%d", rev->pending_eof, rev->available, rev->kq_errno); if (rev->available == 0) { if (rev->pending_eof) { rev->ready = 0; rev->eof = 1; ngx_log_error(NGX_LOG_INFO, c->log, rev->kq_errno, "kevent() reported about an closed connection"); if (rev->kq_errno) { rev->error = 1; ngx_set_socket_errno(rev->kq_errno); return NGX_ERROR; } return 0; } else { return NGX_AGAIN; } } } prev = NULL; iov = NULL; size = 0; vec.elts = iovs; vec.nelts = 0; vec.size = sizeof(struct iovec); vec.nalloc = NGX_IOVS; vec.pool = c->pool; /* coalesce the neighbouring bufs */ while (chain) { if (prev == chain->buf->last) { iov->iov_len += chain->buf->end - chain->buf->last; } else { iov = ngx_array_push(&vec); if (iov == NULL) { return NGX_ERROR; } iov->iov_base = (void *) chain->buf->last; iov->iov_len = chain->buf->end - chain->buf->last; } size += chain->buf->end - chain->buf->last; prev = chain->buf->end; chain = chain->next; } ngx_log_debug2(NGX_LOG_DEBUG_EVENT, c->log, 0, "readv: %d, last:%d", vec.nelts, iov->iov_len); rev = c->read; do { n = readv(c->fd, (struct iovec *) vec.elts, vec.nelts); if (n >= 0) { if (ngx_event_flags & NGX_USE_KQUEUE_EVENT) { rev->available -= n; /* * rev->available may be negative here because some additional * bytes may be received between kevent() and recv() */ if (rev->available <= 0) { if (!rev->pending_eof) { rev->ready = 0; } if (rev->available < 0) { rev->available = 0; } } if (n == 0) { /* * on FreeBSD recv() may return 0 on closed socket * even if kqueue reported about available data */ #if 0 ngx_log_error(NGX_LOG_ALERT, c->log, 0, "readv() returned 0 while kevent() reported " "%d available bytes", rev->available); #endif rev->eof = 1; rev->available = 0; } return n; } if (n < size) { rev->ready = 0; } if (n == 0) { rev->eof = 1; } return n; } err = ngx_socket_errno; if (err == NGX_EAGAIN || err == NGX_EINTR) { ngx_log_debug0(NGX_LOG_DEBUG_EVENT, c->log, err, "readv() not ready"); n = NGX_AGAIN; } else { n = ngx_connection_error(c, err, "readv() failed"); break; } } while (err == NGX_EINTR); rev->ready = 0; if (n == NGX_ERROR) { c->read->error = 1; } return n; } #else /* ! NGX_HAVE_KQUEUE */ ssize_t ngx_readv_chain(ngx_connection_t *c, ngx_chain_t *chain) { u_char *prev; ssize_t n, size; ngx_err_t err; ngx_array_t vec; ngx_event_t *rev; struct iovec *iov, iovs[NGX_IOVS]; prev = NULL; iov = NULL; size = 0; vec.elts = iovs; vec.nelts = 0; vec.size = sizeof(struct iovec); vec.nalloc = NGX_IOVS; vec.pool = c->pool; /* coalesce the neighbouring bufs */ while (chain) { if (prev == chain->buf->last) { iov->iov_len += chain->buf->end - chain->buf->last; } else { iov = ngx_array_push(&vec); if (iov == NULL) { return NGX_ERROR; } iov->iov_base = (void *) chain->buf->last; iov->iov_len = chain->buf->end - chain->buf->last; } size += chain->buf->end - chain->buf->last; prev = chain->buf->end; chain = chain->next; } ngx_log_debug2(NGX_LOG_DEBUG_EVENT, c->log, 0, "readv: %d:%d", vec.nelts, iov->iov_len); rev = c->read; do { n = readv(c->fd, (struct iovec *) vec.elts, vec.nelts); if (n == 0) { rev->ready = 0; rev->eof = 1; return n; } else if (n > 0) { if (n < size && !(ngx_event_flags & NGX_USE_GREEDY_EVENT)) { rev->ready = 0; } return n; } err = ngx_socket_errno; if (err == NGX_EAGAIN || err == NGX_EINTR) { ngx_log_debug0(NGX_LOG_DEBUG_EVENT, c->log, err, "readv() not ready"); n = NGX_AGAIN; } else { n = ngx_connection_error(c, err, "readv() failed"); break; } } while (err == NGX_EINTR); rev->ready = 0; if (n == NGX_ERROR) { c->read->error = 1; } return n; } #endif /* NGX_HAVE_KQUEUE */