Mercurial > hg > nginx
view src/core/ngx_times.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 | 777202558122 |
children | 76e7e20cda05 |
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/* * Copyright (C) Igor Sysoev * Copyright (C) Nginx, Inc. */ #ifndef _NGX_TIMES_H_INCLUDED_ #define _NGX_TIMES_H_INCLUDED_ #include <ngx_config.h> #include <ngx_core.h> typedef struct { time_t sec; ngx_uint_t msec; ngx_int_t gmtoff; } ngx_time_t; void ngx_time_init(void); void ngx_time_update(void); void ngx_time_sigsafe_update(void); u_char *ngx_http_time(u_char *buf, time_t t); u_char *ngx_http_cookie_time(u_char *buf, time_t t); void ngx_gmtime(time_t t, ngx_tm_t *tp); time_t ngx_next_time(time_t when); #define ngx_next_time_n "mktime()" extern volatile ngx_time_t *ngx_cached_time; #define ngx_time() ngx_cached_time->sec #define ngx_timeofday() (ngx_time_t *) ngx_cached_time extern volatile ngx_str_t ngx_cached_err_log_time; extern volatile ngx_str_t ngx_cached_http_time; extern volatile ngx_str_t ngx_cached_http_log_time; extern volatile ngx_str_t ngx_cached_http_log_iso8601; extern volatile ngx_str_t ngx_cached_syslog_time; /* * milliseconds elapsed since epoch and truncated to ngx_msec_t, * used in event timers */ extern volatile ngx_msec_t ngx_current_msec; #endif /* _NGX_TIMES_H_INCLUDED_ */