Nginx HTTP请求流程

http://blog.csdn.net/mikemiller2/article/details/50554183

Nginx HTTP请求流程，有需要的朋友可以参考下。

| \-- ngx_single_process_cycle
##########################################################################
##########################################################################
| | \-- ngx_process_events_and_timers
| | | \-- ngx_event_find_timer
| | | \-- ngx_epoll_process_events //ngx_process_events
                    epoll_wait() //block here //
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
!---> Event: client send first TCP connect request
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
| | | | \-- ngx_time_update
| | | | \-- ngx_event_accept // accept a connection, add the read event and ngx_http_init_request handler to epoll
                        accept() //noblock read, get the new client socket
| | | | | \-- ngx_get_connection
| | | | | \-- ngx_create_pool //create connection pool
| | | | | \-- ngx_nonblocking // nonelock client socket
| | | | | \-- ngx_sock_ntop
| | | | | \-- ngx_http_init_connection //ls->handler, set the next read event handler to ngx_http_init_request
| | | | | | \-- ngx_event_add_timer
| | | | | | \-- ngx_handle_read_event // add the next read event to epoll
| | | | | | | \-- ngx_epoll_add_event
| | | \-- ngx_event_expire_timers
| | | | \-- ngx_rbtree_min
##########################################################################
##########################################################################
| | \-- ngx_process_events_and_timers
| | | \-- ngx_event_find_timer
| | | \-- ngx_epoll_process_events //ngx_process_events
                    epoll_wait() //block here //
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
!---> Event: client send first HTTP request
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
| | | | \-- ngx_time_update
| | | | \-- ngx_http_init_request //call ngx_http_process_request_line, till send out the request
| | | | | \-- ngx_http_process_request_line
| | | | | | \-- ngx_http_read_request_header
| | | | | | \-- ngx_http_parse_request_line //parse method, URL, version
| | | | | | \-- ngx_http_process_request_headers
| | | | | | | \-- ngx_http_read_request_header // read all headers
| | | | | | | \-- ngx_http_parse_header_line // header 1
| | | | | | | \-- ngx_list_push
| | | | | | | \-- ngx_pnalloc
| | | | | | | \-- ngx_hash_find
| | | | | | | \-- ngx_http_process_user_agent //header 1 handler
| | | | | | | \-- ngx_http_parse_header_line // header 2
| | | | | | | \-- ngx_list_push
| | | | | | | \-- ngx_pnalloc
| | | | | | | \-- ngx_hash_find
| | | | | | | \-- ngx_http_process_host //header 2 handler
| | | | | | | \-- ngx_http_parse_header_line //header 3
| | | | | | | \-- ngx_list_push
| | | | | | | \-- ngx_pnalloc
| | | | | | | \-- ngx_hash_find
| | | | | | | \-- ngx_http_parse_header_line // no more header
| | | | | | | \-- ngx_http_process_request_header
| | | | | | | | \-- ngx_http_find_virtual_server
| | | | | | | \-- ngx_http_process_request
| | | | | | | | \-- ngx_event_del_timer
| | | | | | | | \-- ngx_http_handler
| | | | | | | | | \-- ngx_http_core_run_phases
| | | | | | | | | | \-- ngx_http_core_rewrite_phase //phase checker
| | | | | | | | | | | \-- ngx_http_rewrite_handler //phase handler
| | | | | | | | | | \-- ngx_http_core_find_config_phase
| | | | | | | | | | | \-- ngx_http_core_find_location
| | | | | | | | | | | \-- ngx_http_update_location_config
| | | | | | | | | | \-- ngx_http_core_rewrite_phase
| | | | | | | | | | | \-- ngx_http_rewrite_handler
| | | | | | | | | | \-- ngx_http_core_post_rewrite_phase
| | | | | | | | | | \-- ngx_http_core_generic_phase
| | | | | | | | | | | \-- ngx_http_limit_req_handler
| | | | | | | | | | \-- ngx_http_core_generic_phase
| | | | | | | | | | | \-- ngx_http_limit_conn_handler
| | | | | | | | | | \-- ngx_http_core_access_phase
| | | | | | | | | | | \-- ngx_http_access_handler
| | | | | | | | | | \-- ngx_http_core_access_phase
| | | | | | | | | | | \-- ngx_http_auth_basic_handler
| | | | | | | | | | \-- ngx_http_core_post_access_phase
| | | | | | | | | | \-- ngx_http_core_content_phase
| | | | | | | | | | | \-- ngx_http_index_handler
| | | | | | | | | | | | \-- ngx_http_map_uri_to_path
| | | | | | | | | | | | \-- ngx_http_set_disable_symlinks
| | | | | | | | | | | | \-- ngx_open_cached_file
| | | | | | | | | | | | | \-- ngx_file_info_wrapper
| | | | | | | | | | | | \-- ngx_http_internal_redirect
| | | | | | | | | | | | | \-- ngx_http_set_exten
| | | | | | | | | | | | | \-- ngx_http_update_location_config
| | | | | | | | | | | | | \-- ngx_http_handler
| | | | | | | | | | | | | | \-- ngx_http_core_run_phases
| | | | | | | | | | | | | | | \-- ngx_http_core_rewrite_phase
| | | | | | | | | | | | | | | | \-- ngx_http_rewrite_handler
| | | | | | | | | | | | | | | \-- ngx_http_core_find_config_phase
| | | | | | | | | | | | | | | | \-- ngx_http_core_find_location
| | | | | | | | | | | | | | | | \-- ngx_http_update_location_config
| | | | | | | | | | | | | | | \-- ngx_http_core_rewrite_phase
| | | | | | | | | | | | | | | | \-- ngx_http_rewrite_handler
| | | | | | | | | | | | | | | \-- ngx_http_core_post_rewrite_phase
| | | | | | | | | | | | | | | \-- ngx_http_core_generic_phase
| | | | | | | | | | | | | | | | \-- ngx_http_limit_req_handler
| | | | | | | | | | | | | | | \-- ngx_http_core_generic_phase
| | | | | | | | | | | | | | | | \-- ngx_http_limit_conn_handler
| | | | | | | | | | | | | | | \-- ngx_http_core_access_phase
| | | | | | | | | | | | | | | | \-- ngx_http_access_handler
| | | | | | | | | | | | | | | \-- ngx_http_core_access_phase
| | | | | | | | | | | | | | | | \-- ngx_http_auth_basic_handler
| | | | | | | | | | | | | | | \-- ngx_http_core_post_access_phase
| | | | | | | | | | | | | | | \-- ngx_http_core_content_phase
| | | | | | | | | | | | | | | | \-- ngx_http_index_handler
| | | | | | | | | | | | | | | \-- ngx_http_core_content_phase
| | | | | | | | | | | | | | | | \-- ngx_http_autoindex_handler
| | | | | | | | | | | | | | | \-- ngx_http_core_content_phase
| | | | | | | | | | | | | | | | \-- ngx_http_static_handler
| | | | | | | | | | | | | | | | | \-- ngx_http_map_uri_to_path
| | | | | | | | | | | | | | | | | \-- ngx_http_set_disable_symlinks
| | | | | | | | | | | | | | | | | \-- ngx_open_cached_file
| | | | | | | | | | | | | | | | | \-- ngx_http_discard_request_body
| | | | | | | | | | | | | | | | | \-- ngx_http_set_content_type
| | | | | | | | | | | | | | | | | \-- ngx_http_send_header
| | | | | | | | | | | | | | | | | | \-- ngx_http_not_modified_header_filter
| | | | | | | | | | | | | | | | | | | \-- ngx_http_headers_filter
| | | | | | | | | | | | | | | | | | | | \-- ngx_http_userid_filter
| | | | | | | | | | | | | | | | | | | | | \-- ngx_http_charset_header_filter
| | | | | | | | | | | | | | | | | | | | | | \-- ngx_http_destination_charset
| | | | | | | | | | | | | | | | | | | | | | \-- ngx_http_ssi_header_filter
| | | | | | | | | | | | | | | | | | | | | | | \-- ngx_http_gzip_header_filter
| | | | | | | | | | | | | | | | | | | | | | | | \-- ngx_http_range_header_filter
| | | | | | | | | | | | | | | | | | | | | | | | | \-- ngx_list_push
| | | | | | | | | | | | | | | | | | | | | | | | | \-- ngx_http_chunked_header_filter
| | | | | | | | | | | | | | | | | | | | | | | | | | \-- ngx_http_header_filter
| | | | | | | | | | | | | | | | | | | | | | | | | | | \-- ngx_create_temp_buf
| | | | | | | | | | | | | | | | | | | | | | | | | | | \-- ngx_sprintf
| | | | | | | | | | | | | | | | | | | | | | | | | | | \-- ngx_http_time
| | | | | | | | | | | | | | | | | | | | | | | | | | | \-- ngx_http_write_filter
| | | | | | | | | | | | | | | | | | | | | | | | | | | | \-- ngx_alloc_chain_link
| | | | | | | | | | | | | | | | | \-- ngx_http_output_filter
| | | | | | | | | | | | | | | | | | \-- ngx_http_range_body_filter
| | | | | | | | | | | | | | | | | | | \-- ngx_http_copy_filter
| | | | | | | | | | | | | | | | | | | | \-- ngx_output_chain
| | | | | | | | | | | | | | | | | | | | | \-- ngx_output_chain_as_is
| | | | | | | | | | | | | | | | | | | | | \-- ngx_http_charset_body_filter
| | | | | | | | | | | | | | | | | | | | | | \-- ngx_http_ssi_body_filter
| | | | | | | | | | | | | | | | | | | | | | | \-- ngx_http_postpone_filter
| | | | | | | | | | | | | | | | | | | | | | | | \-- ngx_http_gzip_body_filter
| | | | | | | | | | | | | | | | | | | | | | | | | \-- ngx_http_chunked_body_filter
| | | | | | | | | | | | | | | | | | | | | | | | | | \-- ngx_http_write_filter
| | | | | | | | | | | | | | | | | | | | | | | | | | | \-- ngx_alloc_chain_link
| | | | | | | | | | | | | | | | | | | | | | | | | | | \-- ngx_linux_sendfile_chain
| | | | | | | | | | | | | | | | | | | | | | | | | | | | \-- ngx_array_push
                                                                                                                    sendfile() //actually sent out
| | | | | | | | | | | | | | | | \-- ngx_http_finalize_request
| | | | | | | | | | | | | | | | | \-- ngx_http_post_action
| | | | | | | | | | | | | | | | | \-- ngx_http_finalize_connection
| | | | | | | | | | | | | | | | | | \-- ngx_http_close_request
| | | | | | | | | | | \-- ngx_http_finalize_request
| | | | | | | | | | | | \-- ngx_http_finalize_connection
| | | | | | | | | | | | | \-- ngx_http_set_keepalive
| | | | | | | | | | | | | | \-- ngx_http_free_request
| | | | | | | | | | | | | | | \-- ngx_http_log_request
| | | | | | | | | | | | | | | \-- ngx_destroy_pool
| | | | | | | | | | | | | | \-- ngx_event_add_timer //leeplive timeout
| | | | | | | | | | | | | | \-- ngx_handle_read_event //add read event
| | | | | | | | | | | | | | \-- ngx_reusable_connection
| | | | | | | | \-- ngx_http_run_posted_requests
| | | \-- ngx_event_expire_timers
| | | \-- ngx_event_process_posted
| | | | \-- ngx_http_keepalive_handler
| | | | | \-- ngx_palloc
| | | | | | \-- ngx_palloc_large
| | | | | | | \-- ngx_alloc
| | | | | \-- ngx_unix_recv
| | | | | \-- ngx_handle_read_event
| | | | | \-- ngx_pfree
##########################################################################
##########################################################################
| | \-- ngx_process_events_and_timers
| | | \-- ngx_event_find_timer
| | | \-- ngx_epoll_process_events //ngx_process_events
                    epoll_wait() //block here //
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
!---> Event: timeout for the connection
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
| | | | \-- ngx_time_update
| | | | \-- ngx_http_keepalive_handler
| | | | | \-- ngx_unix_recv
| | | | | \-- ngx_http_close_connection
| | | | | | \-- ngx_close_connection
| | | | | | \-- ngx_destroy_pool
| | | \-- ngx_event_expire_timers
##########################################################################
##########################################################################
| | \-- ngx_process_events_and_timers
| | | \-- ngx_event_find_timer
| | | \-- ngx_epoll_process_events //ngx_process_events
                    epoll_wait() //block here //
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
!---> Event: Client send a new TCP connect request
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
| | | | \-- ngx_time_update
| | | | \-- ngx_event_accept
| | | | | \-- ngx_get_connection
| | | | | \-- ngx_create_pool
| | | | | | \-- ngx_memalign
| | | | | \-- ngx_palloc
| | | | | \-- ngx_palloc
| | | | | \-- ngx_nonblocking
| | | | | \-- ngx_atomic_fetch_add
| | | | | \-- ngx_pnalloc
| | | | | \-- ngx_sock_ntop
| | | | | \-- ngx_http_init_connection
| | | | | | \-- ngx_palloc
| | | | | | \-- ngx_event_add_timer
| | | | | | \-- ngx_handle_read_event
| | | | | | | \-- ngx_epoll_add_event
| | | \-- ngx_event_expire_timers
| | | | \-- ngx_rbtree_min
##########################################################################
##########################################################################
| | \-- ngx_process_events_and_timers
| | | \-- ngx_event_find_timer
| | | | \-- ngx_rbtree_min
| | | \-- ngx_epoll_process_events //ngx_process_events
                    epoll_wait() //block here //
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
!---> Event: Client send a new HTTP request
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
| | | | \-- ngx_time_update
| | | | \-- ngx_http_init_request
| | | | | \-- ngx_http_process_request_line
...