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_ */