Mercurial > hg > nginx
view src/core/ngx_core.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 | e38e9c50a40e |
| children | d27aa9060c95 |
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/* * Copyright (C) Igor Sysoev * Copyright (C) Nginx, Inc. */ #ifndef _NGX_CORE_H_INCLUDED_ #define _NGX_CORE_H_INCLUDED_ #include <ngx_config.h> typedef struct ngx_module_s ngx_module_t; typedef struct ngx_conf_s ngx_conf_t; typedef struct ngx_cycle_s ngx_cycle_t; typedef struct ngx_pool_s ngx_pool_t; typedef struct ngx_chain_s ngx_chain_t; typedef struct ngx_log_s ngx_log_t; typedef struct ngx_open_file_s ngx_open_file_t; typedef struct ngx_command_s ngx_command_t; typedef struct ngx_file_s ngx_file_t; typedef struct ngx_event_s ngx_event_t; typedef struct ngx_event_aio_s ngx_event_aio_t; typedef struct ngx_connection_s ngx_connection_t; typedef struct ngx_thread_task_s ngx_thread_task_t; typedef struct ngx_ssl_s ngx_ssl_t; typedef struct ngx_ssl_connection_s ngx_ssl_connection_t; typedef void (*ngx_event_handler_pt)(ngx_event_t *ev); typedef void (*ngx_connection_handler_pt)(ngx_connection_t *c); #define NGX_OK 0 #define NGX_ERROR -1 #define NGX_AGAIN -2 #define NGX_BUSY -3 #define NGX_DONE -4 #define NGX_DECLINED -5 #define NGX_ABORT -6 #include <ngx_errno.h> #include <ngx_atomic.h> #include <ngx_thread.h> #include <ngx_rbtree.h> #include <ngx_time.h> #include <ngx_socket.h> #include <ngx_string.h> #include <ngx_files.h> #include <ngx_shmem.h> #include <ngx_process.h> #include <ngx_user.h> #include <ngx_dlopen.h> #include <ngx_parse.h> #include <ngx_parse_time.h> #include <ngx_log.h> #include <ngx_alloc.h> #include <ngx_palloc.h> #include <ngx_buf.h> #include <ngx_queue.h> #include <ngx_array.h> #include <ngx_list.h> #include <ngx_hash.h> #include <ngx_file.h> #include <ngx_crc.h> #include <ngx_crc32.h> #include <ngx_murmurhash.h> #if (NGX_PCRE) #include <ngx_regex.h> #endif #include <ngx_radix_tree.h> #include <ngx_times.h> #include <ngx_rwlock.h> #include <ngx_shmtx.h> #include <ngx_slab.h> #include <ngx_inet.h> #include <ngx_cycle.h> #include <ngx_resolver.h> #if (NGX_OPENSSL) #include <ngx_event_openssl.h> #endif #include <ngx_process_cycle.h> #include <ngx_conf_file.h> #include <ngx_module.h> #include <ngx_open_file_cache.h> #include <ngx_os.h> #include <ngx_connection.h> #include <ngx_syslog.h> #include <ngx_proxy_protocol.h> #define LF (u_char) '\n' #define CR (u_char) '\r' #define CRLF "\r\n" #define ngx_abs(value) (((value) >= 0) ? (value) : - (value)) #define ngx_max(val1, val2) ((val1 < val2) ? (val2) : (val1)) #define ngx_min(val1, val2) ((val1 > val2) ? (val2) : (val1)) void ngx_cpuinfo(void); #if (NGX_HAVE_OPENAT) #define NGX_DISABLE_SYMLINKS_OFF 0 #define NGX_DISABLE_SYMLINKS_ON 1 #define NGX_DISABLE_SYMLINKS_NOTOWNER 2 #endif #endif /* _NGX_CORE_H_INCLUDED_ */