Mercurial > hg > nginx
view src/core/ngx_connection.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 | 32b0ba4855a6 |
children | cffaf3f2eec8 ce6d9cf0f567 |
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/* * Copyright (C) Igor Sysoev * Copyright (C) Nginx, Inc. */ #ifndef _NGX_CONNECTION_H_INCLUDED_ #define _NGX_CONNECTION_H_INCLUDED_ #include <ngx_config.h> #include <ngx_core.h> typedef struct ngx_listening_s ngx_listening_t; struct ngx_listening_s { ngx_socket_t fd; struct sockaddr *sockaddr; socklen_t socklen; /* size of sockaddr */ size_t addr_text_max_len; ngx_str_t addr_text; int type; int backlog; int rcvbuf; int sndbuf; #if (NGX_HAVE_KEEPALIVE_TUNABLE) int keepidle; int keepintvl; int keepcnt; #endif /* handler of accepted connection */ ngx_connection_handler_pt handler; void *servers; /* array of ngx_http_in_addr_t, for example */ ngx_log_t log; ngx_log_t *logp; size_t pool_size; /* should be here because of the AcceptEx() preread */ size_t post_accept_buffer_size; ngx_listening_t *previous; ngx_connection_t *connection; ngx_rbtree_t rbtree; ngx_rbtree_node_t sentinel; ngx_uint_t worker; unsigned open:1; unsigned remain:1; unsigned ignore:1; unsigned bound:1; /* already bound */ unsigned inherited:1; /* inherited from previous process */ unsigned nonblocking_accept:1; unsigned listen:1; unsigned nonblocking:1; unsigned shared:1; /* shared between threads or processes */ unsigned addr_ntop:1; unsigned wildcard:1; #if (NGX_HAVE_INET6) unsigned ipv6only:1; #endif unsigned reuseport:1; unsigned add_reuseport:1; unsigned keepalive:2; unsigned deferred_accept:1; unsigned delete_deferred:1; unsigned add_deferred:1; #if (NGX_HAVE_DEFERRED_ACCEPT && defined SO_ACCEPTFILTER) char *accept_filter; #endif #if (NGX_HAVE_SETFIB) int setfib; #endif #if (NGX_HAVE_TCP_FASTOPEN) int fastopen; #endif }; typedef enum { NGX_ERROR_ALERT = 0, NGX_ERROR_ERR, NGX_ERROR_INFO, NGX_ERROR_IGNORE_ECONNRESET, NGX_ERROR_IGNORE_EINVAL } ngx_connection_log_error_e; typedef enum { NGX_TCP_NODELAY_UNSET = 0, NGX_TCP_NODELAY_SET, NGX_TCP_NODELAY_DISABLED } ngx_connection_tcp_nodelay_e; typedef enum { NGX_TCP_NOPUSH_UNSET = 0, NGX_TCP_NOPUSH_SET, NGX_TCP_NOPUSH_DISABLED } ngx_connection_tcp_nopush_e; #define NGX_LOWLEVEL_BUFFERED 0x0f #define NGX_SSL_BUFFERED 0x01 #define NGX_HTTP_V2_BUFFERED 0x02 struct ngx_connection_s { void *data; ngx_event_t *read; ngx_event_t *write; ngx_socket_t fd; ngx_recv_pt recv; ngx_send_pt send; ngx_recv_chain_pt recv_chain; ngx_send_chain_pt send_chain; ngx_listening_t *listening; off_t sent; ngx_log_t *log; ngx_pool_t *pool; int type; struct sockaddr *sockaddr; socklen_t socklen; ngx_str_t addr_text; ngx_proxy_protocol_t *proxy_protocol; #if (NGX_SSL || NGX_COMPAT) ngx_ssl_connection_t *ssl; #endif ngx_udp_connection_t *udp; struct sockaddr *local_sockaddr; socklen_t local_socklen; ngx_buf_t *buffer; ngx_queue_t queue; ngx_atomic_uint_t number; ngx_msec_t start_time; ngx_uint_t requests; unsigned buffered:8; unsigned log_error:3; /* ngx_connection_log_error_e */ unsigned timedout:1; unsigned error:1; unsigned destroyed:1; unsigned idle:1; unsigned reusable:1; unsigned close:1; unsigned shared:1; unsigned sendfile:1; unsigned sndlowat:1; unsigned tcp_nodelay:2; /* ngx_connection_tcp_nodelay_e */ unsigned tcp_nopush:2; /* ngx_connection_tcp_nopush_e */ unsigned need_last_buf:1; unsigned need_flush_buf:1; #if (NGX_HAVE_SENDFILE_NODISKIO || NGX_COMPAT) unsigned busy_count:2; #endif #if (NGX_THREADS || NGX_COMPAT) ngx_thread_task_t *sendfile_task; #endif }; #define ngx_set_connection_log(c, l) \ \ c->log->file = l->file; \ c->log->next = l->next; \ c->log->writer = l->writer; \ c->log->wdata = l->wdata; \ if (!(c->log->log_level & NGX_LOG_DEBUG_CONNECTION)) { \ c->log->log_level = l->log_level; \ } ngx_listening_t *ngx_create_listening(ngx_conf_t *cf, struct sockaddr *sockaddr, socklen_t socklen); ngx_int_t ngx_clone_listening(ngx_cycle_t *cycle, ngx_listening_t *ls); ngx_int_t ngx_set_inherited_sockets(ngx_cycle_t *cycle); ngx_int_t ngx_open_listening_sockets(ngx_cycle_t *cycle); void ngx_configure_listening_sockets(ngx_cycle_t *cycle); void ngx_close_listening_sockets(ngx_cycle_t *cycle); void ngx_close_connection(ngx_connection_t *c); void ngx_close_idle_connections(ngx_cycle_t *cycle); ngx_int_t ngx_connection_local_sockaddr(ngx_connection_t *c, ngx_str_t *s, ngx_uint_t port); ngx_int_t ngx_tcp_nodelay(ngx_connection_t *c); ngx_int_t ngx_connection_error(ngx_connection_t *c, ngx_err_t err, char *text); ngx_connection_t *ngx_get_connection(ngx_socket_t s, ngx_log_t *log); void ngx_free_connection(ngx_connection_t *c); void ngx_reusable_connection(ngx_connection_t *c, ngx_uint_t reusable); #endif /* _NGX_CONNECTION_H_INCLUDED_ */