Mercurial > hg > nginx
view src/core/ngx_core.h @ 8045:aa28c802409f
Resolver: make TCP write timer event cancelable.
Similar to 70e65bf8dfd7, the change is made to ensure that the ability to
cancel resolver tasks is fully controlled by the caller. As mentioned in the
referenced commit, it is safe to make this timer cancelable because resolve
tasks can have their own timeouts that are not cancelable.
The scenario where this may become a problem is a periodic background resolve
task (not tied to a specific request or a client connection), which receives a
response with short TTL, large enough to warrant fallback to a TCP query.
With each event loop wakeup, we either have a previously set write timer
instance or schedule a new one. The non-cancelable write timer can delay or
block graceful shutdown of a worker even if the ngx_resolver_ctx_t->cancelable
flag is set by the API user, and there are no other tasks or connections.
We use the resolver API in this way to maintain the list of upstream server
addresses specified with the 'resolve' parameter, and there could be third-party
modules implementing similar logic.
author | Aleksei Bavshin <a.bavshin@f5.com> |
---|---|
date | Wed, 01 Jun 2022 20:17:23 -0700 |
parents | 06b01840bd42 |
children | 5d91389e0fd3 |
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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_proxy_protocol_s ngx_proxy_protocol_t; typedef struct ngx_ssl_connection_s ngx_ssl_connection_t; typedef struct ngx_udp_connection_s ngx_udp_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_ */