Mercurial > hg > nginx
view src/core/ngx_rbtree.h @ 6806:75dbab4ea930
Events: improved error event handling for UDP sockets.
Normally, the epoll module calls the read and write handlers depending
on whether EPOLLIN and EPOLLOUT are reported by epoll_wait(). No error
processing is done in the module, the handlers are expected to get an
error when doing I/O.
If an error event is reported without EPOLLIN and EPOLLOUT, the module
set both EPOLLIN and EPOLLOUT to ensure the error event is handled at
least in one active handler.
This works well unless the error is delivered along with only one of
EPOLLIN or EPOLLOUT, and the corresponding handler does not do any I/O.
For example, it happened when getting EPOLLERR|EPOLLOUT from
epoll_wait() upon receiving "ICMP port unreachable" while proxying UDP.
As the write handler had nothing to send it was not able to detect and
log an error, and did not switch to the next upstream.
The fix is to unconditionally set EPOLLIN and EPOLLOUT in case of an
error event. In the aforementioned case, this causes the read handler
to be called which does recv() and detects an error.
In addition to the epoll module, analogous changes were made in
devpoll/eventport/poll.
author | Dmitry Volyntsev <xeioex@nginx.com> |
---|---|
date | Mon, 21 Nov 2016 16:03:42 +0300 |
parents | 1f513d7f1b45 |
children | e0cc454aafe4 |
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/* * Copyright (C) Igor Sysoev * Copyright (C) Nginx, Inc. */ #ifndef _NGX_RBTREE_H_INCLUDED_ #define _NGX_RBTREE_H_INCLUDED_ #include <ngx_config.h> #include <ngx_core.h> typedef ngx_uint_t ngx_rbtree_key_t; typedef ngx_int_t ngx_rbtree_key_int_t; typedef struct ngx_rbtree_node_s ngx_rbtree_node_t; struct ngx_rbtree_node_s { ngx_rbtree_key_t key; ngx_rbtree_node_t *left; ngx_rbtree_node_t *right; ngx_rbtree_node_t *parent; u_char color; u_char data; }; typedef struct ngx_rbtree_s ngx_rbtree_t; typedef void (*ngx_rbtree_insert_pt) (ngx_rbtree_node_t *root, ngx_rbtree_node_t *node, ngx_rbtree_node_t *sentinel); struct ngx_rbtree_s { ngx_rbtree_node_t *root; ngx_rbtree_node_t *sentinel; ngx_rbtree_insert_pt insert; }; #define ngx_rbtree_init(tree, s, i) \ ngx_rbtree_sentinel_init(s); \ (tree)->root = s; \ (tree)->sentinel = s; \ (tree)->insert = i void ngx_rbtree_insert(ngx_rbtree_t *tree, ngx_rbtree_node_t *node); void ngx_rbtree_delete(ngx_rbtree_t *tree, ngx_rbtree_node_t *node); void ngx_rbtree_insert_value(ngx_rbtree_node_t *root, ngx_rbtree_node_t *node, ngx_rbtree_node_t *sentinel); void ngx_rbtree_insert_timer_value(ngx_rbtree_node_t *root, ngx_rbtree_node_t *node, ngx_rbtree_node_t *sentinel); #define ngx_rbt_red(node) ((node)->color = 1) #define ngx_rbt_black(node) ((node)->color = 0) #define ngx_rbt_is_red(node) ((node)->color) #define ngx_rbt_is_black(node) (!ngx_rbt_is_red(node)) #define ngx_rbt_copy_color(n1, n2) (n1->color = n2->color) /* a sentinel must be black */ #define ngx_rbtree_sentinel_init(node) ngx_rbt_black(node) static ngx_inline ngx_rbtree_node_t * ngx_rbtree_min(ngx_rbtree_node_t *node, ngx_rbtree_node_t *sentinel) { while (node->left != sentinel) { node = node->left; } return node; } #endif /* _NGX_RBTREE_H_INCLUDED_ */