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This article mainly introduces "what is the execution process of nginx startup initialization code". In daily operation, I believe that many people have doubts about what is the execution process of nginx startup initialization code. Xiaobian consulted all kinds of materials and sorted out simple and easy-to-use operation methods. I hope it will be helpful to answer the doubts of "what is the execution process of nginx startup initialization code?" Next, please follow the editor to study!

Code execution process

Ngx_event_process_init: traverses connections, initializes the callback function of listenfd, and adds event listener

Static ngx_int_t

Ngx_event_process_init (ngx_cycle_t * cycle)

{

...

Cycle- > connections =

Ngx_alloc (sizeof (ngx_connection_t) * cycle- > connection_n, cycle- > log)

Cycle- > read_events = ngx_alloc (sizeof (ngx_event_t) * cycle- > connection_n

Cycle- > log)

...

Ls = cycle- > listening.elts

For (I = 0; I)

< cycle->

Listening.nelts; iTunes +) {

C = ngx_get_connection (ls[ I] .fd, cycle- > log)

C-> listening = & LS [I]

Rev = c-> read

}

...

Rev- > handler = ngx_event_accept

Ngx_add_event (rev, NGX_READ_EVENT, 0)

...

}

Ngx_event_accept: call the callback function of ngx_listening_t

Void

Ngx_event_accept (ngx_event_t * ev)

{

...

Lc = ev- > data

Ls = lc- > listening

...

S = accept (lc- > fd, (struct sockaddr *) sa, & socklen)

C = ngx_get_connection (s, ev- > log)

Ngx_add_conn (c)

Ls- > handler (c)

...

}

Find the location of ls- > handler (c)

Static char *

Ngx_http_block (ngx_conf_t * cf, ngx_command_t * cmd, void * conf)

{

...

If (ngx_http_optimize_servers (cf, cmcf, cmcf- > ports)! = NGX_OK) {

Return NGX_CONF_ERROR

}

...

}

Static ngx_int_t

Ngx_http_optimize_servers (ngx_conf_t * cf, ngx_http_core_main_conf_t * cmcf

Ngx_array_t * ports)

{

...

If (ngx_http_init_listening (cf, & port [p])! = NGX_OK) {

Return NGX_ERROR

}

...

}

Static ngx_int_t

Ngx_http_init_listening (ngx_conf_t * cf, ngx_http_conf_port_t * port)

{

...

Ls = ngx_http_add_listening (cf, & addr [I])

If (ls = = NULL) {

Return NGX_ERROR

}

...

}

Static ngx_listening_t *

Ngx_http_add_listening (ngx_conf_t * cf, ngx_http_conf_addr_t * addr)

{

...

Ls- > handler = ngx_http_init_connection

...

}

Third-party module (output):

Server {

Listen 0.0.0.0:70

Location / {

Root / usr/local/nginx/html/bak/

Limit_req zone=req10k burst=5 nodelay

Shuchu "helloworld"

}

}

The three cores of a module

Static ngx_command_t ngx_http_shuchu_commands [] = {

{

Ngx_string ("shuchu")

NGX_HTTP_LOC_CONF | NGX_CONF_TAKE1

Ngx_http_shuchu

NGX_HTTP_LOC_CONF_OFFSET

Offsetof (ngx_http_shuchu_loc_conf_t, content)

NULL

}

Ngx_null_command

}

Static ngx_http_module_t ngx_http_shuchu_ctx = {

NULL

Ngx_http_shuchu_init

NULL

NULL

NULL

NULL

Ngx_http_shuchu_create_loc_conf

Ngx_http_shuchu_merge_loc_conf

}

Ngx_module_t ngx_http_shuchu_module = {

NGX_MODULE_V1

& ngx_http_shuchu_ctx, / * module context * /

Ngx_http_shuchu_commands, / * module directives * /

NGX_HTTP_MODULE, / * module type * /

NULL, / * init master * /

NULL, / * init module * /

NULL, / * init process * /

NULL, / * init thread * /

NULL, / * exit thread * /

NULL, / * exit process * /

NULL, / * exit master * /

NGX_MODULE_V1_PADDING

}

Ngx_conf_parse: parsing configuration

Char *

Ngx_conf_parse (ngx_conf_t * cf, ngx_str_t * filename)

{

...

Type = parse_file

Fd = ngx_open_file (filename- > data, NGX_FILE_RDONLY, NGX_FILE_OPEN, 0)

Rc = ngx_conf_read_token (cf)

Omit the determination of the combination of rc and type

Rc = ngx_conf_handler (cf, rc)

...

}

Ngx_conf_handler: processing instructions

Static ngx_int_t

Ngx_conf_handler (ngx_conf_t * cf, ngx_int_t last)

{

...

For (I = 0; ngx_ modules [I]; iTunes +) {

Cmd = ngx_ modules [I]-> commands

For (/ * void * /; cmd- > name.len; cmd++) {

If (cmd- > type & NGX_DIRECT_CONF) {

Conf = ((void * *) cf- > ctx) [ngx_ modules [I]-> index]

} else if (cmd- > type & NGX_MAIN_CONF) {

Conf = & ((void * *) cf- > ctx) [ngx_ modules [I]-> index])

} else if (cf- > ctx) {

Confp = * (void * *) ((char *) cf- > ctx + cmd- > conf)

If (confp) {

Conf = confp [NGX _ modules [I]-> ctx_index]

}

}

Rv = cmd- > set (cf, cmd, conf)

}

}

...

}

Ngx_http_block

Static char *

Ngx_http_block (ngx_conf_t * cf, ngx_command_t * cmd, void * conf)

{

...

Ctx- > main_conf = ngx_pcalloc (cf- > pool, sizeof (void *) * ngx_http_max_module)

Ctx- > srv_conf = ngx_pcalloc (cf- > pool, sizeof (void *) * ngx_http_max_module)

Ctx- > loc_conf = ngx_pcalloc (cf- > pool, sizeof (void *) * ngx_http_max_module)

For (m = 0; ngx_ modules [m]; masks +) {

If (ngx_ modules [m]-> type! = NGX_HTTP_MODULE) {

Continue

}

Module = ngx_ modules [m]-> ctx

Mi = ngx_ modules [m]-> ctx_index

If (module- > create_main_conf) {

Ctx- > main_ confession [mi] = module- > create_main_conf (cf)

If (ctx- > main_ confi [mi] = = NULL) {

Return NGX_CONF_ERROR

}

}

If (module- > create_srv_conf) {

Ctx- > srv_ confession [mi] = module- > create_srv_conf (cf)

If (ctx- > srv_ confi [mi] = = NULL) {

Return NGX_CONF_ERROR

}

}

If (module- > create_loc_conf) {

Ctx- > loc_ confession [mi] = module- > create_loc_conf (cf)

If (ctx- > loc_ confi [mi] = = NULL) {

Return NGX_CONF_ERROR

}

}

}

Pcf = * cf

Cf- > ctx = ctx

...

/ * parse inside the http {} block * /

Cf- > module_type = NGX_HTTP_MODULE

Cf- > cmd_type = NGX_HTTP_MAIN_CONF

Rv = ngx_conf_parse (cf, NULL)

...

}

Ngx_http_core_server

Static char *

Ngx_http_core_server (ngx_conf_t * cf, ngx_command_t * cmd, void * dummy)

{

...

Ctx = ngx_pcalloc (cf- > pool, sizeof (ngx_http_conf_ctx_t))

If (ctx = = NULL) {

Return NGX_CONF_ERROR

}

Http_ctx = cf- > ctx

Ctx- > main_conf = http_ctx- > main_conf

Ctx- > srv_conf = ngx_pcalloc (cf- > pool, sizeof (void *) * ngx_http_max_module)

Ctx- > loc_conf = ngx_pcalloc (cf- > pool, sizeof (void *) * ngx_http_max_module)

...

Cscf = ctx- > srv_ confession [NGX _ http_core_module.ctx_index]

Cscf- > ctx = ctx

Cmcf = ctx- > main_ confession [NGX _ http_core_module.ctx_index]

Cscfp = ngx_array_push (& cmcf- > servers)

If (cscfp = = NULL) {

Return NGX_CONF_ERROR

}

* cscfp = cscf

/ * parse inside server {} * /

Pcf = * cf

Cf- > ctx = ctx

Cf- > cmd_type = NGX_HTTP_SRV_CONF

Rv = ngx_conf_parse (cf, NULL)

...

}

Ngx_http_core_listen

Static char *

Ngx_http_core_listen (ngx_conf_t * cf, ngx_command_t * cmd, void * conf)

{

...

Cscf- > listen = 1

Value = cf- > args- > elts

Ngx_memzero (& u, sizeof (ngx_url_t))

U.url = value [1]

Ngx_parse_url (cf- > pool, & u)

If (ngx_http_add_listen (cf, cscf, & lsopt) = = NGX_OK) {

Return NGX_CONF_OK

}

...

}

Ngx_http_add_listen

Ngx_int_t

Ngx_http_add_listen (ngx_conf_t * cf, ngx_http_core_srv_conf_t * cscf

Ngx_http_listen_opt_t * lsopt)

{

...

Cmcf = ngx_http_conf_get_module_main_conf (cf, ngx_http_core_module)

If (cmcf- > ports = = NULL) {

Cmcf- > ports = ngx_array_create (cf- > temp_pool, 2

Sizeof (ngx_http_conf_port_t))

If (cmcf- > ports = = NULL) {

Return NGX_ERROR

}

}

Sin = & lsopt- > u.sockaddr_in

P = sin- > sin_port

Port = ngx_array_push (cmcf- > ports)

Port- > family = sa- > sa_family

Port- > port = p

Port- > addrs.elts = NULL

Ngx_http_add_address (cf, cscf, port, lsopt)

...

}

Ngx_http_add_address

Static ngx_int_t

Ngx_http_add_address (ngx_conf_t * cf, ngx_http_core_srv_conf_t * cscf

Ngx_http_conf_port_t * port, ngx_http_listen_opt_t * lsopt)

{

...

Addr = ngx_array_push (& port- > addrs)

Addr- > opt = * lsopt

Addr- > default_server = cscf

...}

Ngx_http_add_server

Static ngx_int_t

Ngx_http_add_server (ngx_conf_t * cf, ngx_http_core_srv_conf_t * cscf

Ngx_http_conf_addr_t * addr)

{

...

Server = ngx_array_push (& addr- > servers)

* server = cscf

...

}

So far, the basic architecture of the whole configuration has been set up. There are multiple listening addresses (ngx_http_conf_addr_t) hanging under the port (ngx_http_conf_port_t). The opt after each address is currently read in the configuration and contains the listener information, and the listening address (ngx_http_conf_addr_t) is followed by a server block (ngx_http_core_srv_conf_t) where the listening address exists. The next step is to finally do something in optmize, do something in opt, and then do hash:

Ngx_http_optimize_servers

Static ngx_int_t

Ngx_http_optimize_servers (ngx_conf_t * cf, ngx_http_core_main_conf_t * cmcf

Ngx_array_t * ports)

{

...

Port = ports- > elts

For (p = 0; p

< ports->

Nelts; packs +) {

Addr = port [p] .addrs.elts

For (a = 0; a)

< port[p].addrs.nelts; a++) { if (ngx_http_server_names(cf, cmcf, &addr[a]) != NGX_OK) { return NGX_ERROR; } } if (ngx_http_init_listening(cf, &port[p]) != NGX_OK) { return NGX_ERROR; } } ... } ngx_http_server_names:整理addr中的servers，将sn和对应的srv_conf对应起来 static ngx_int_t ngx_http_optimize_servers(ngx_conf_t *cf, ngx_http_core_main_conf_t *cmcf, ngx_array_t *ports) { ... ha.pool = cf->

Pool

Cscfp = addr- > servers.elts

For (s = 0; s)

< addr->

Servers.nelts; slots +) {

Name = cscfp [s]-> server_names.elts

For (n = 0; n)

< cscfp[s]->

Server_names.nelts; nasty +) {

Rc = ngx_hash_add_key (& ha, & name [n] .name, name [n] .server

NGX_HASH_WILDCARD_KEY)

}

...

Hash.hash = & addr- > hash

Ngx_hash_init (& hash, ha.keys.elts, ha.keys.nelts)

}

...

}

Ngx_http_add_listening

Static ngx_listening_t *

Ngx_http_add_listening (ngx_conf_t * cf, ngx_http_conf_addr_t * addr)

{

...

Ls = ngx_create_listening (cf, & addr- > opt.u.sockaddr, addr- > opt.socklen)

Ls- > handler = ngx_http_init_connection

...

}

Instance

Every time get_connection reverses instance, s is the socket obtained by accept, which is an int, which is assigned to c-> fd

Ngx_connection_t *

Ngx_get_connection (ngx_socket_t s, ngx_log_t * log)

{

...

C = ngx_cycle- > free_connections

Ngx_cycle- > free_connections = c-> data

Ngx_cycle- > free_connection_n--

Rev = c-> read

Wev = c-> write

Ngx_memzero (c, sizeof (ngx_connection_t))

C-> read = rev

C-> write = wev

C-> fd = s

Rev- > instance =! instance

Wev- > instance =! instance

Rev- > data = c

Wev- > data = c

Return c

...

}

While in free, only move the linked list, empty the files, and make the current linked list available.

Void

Ngx_free_connection (ngx_connection_t * c)

{

...

C-> data = ngx_cycle- > free_connections

Ngx_cycle- > free_connections = c

Ngx_cycle- > free_connection_n++

If (ngx_cycle- > files) {

Ngx_cycle- > Files [c-> fd] = NULL

...

}

And both add_event and add_connection point the epoll directly to instance, and when process_events, take out the event to point to.

Static ngx_int_t

Ngx_epoll_add_event (ngx_event_t * ev, ngx_int_t event, ngx_uint_t flags)

{

...

Ee.data.ptr = (void *) ((uintptr_t) c | ev- > instance)

...

}

Static ngx_int_t

Ngx_epoll_process_events (ngx_cycle_t * cycle, ngx_msec_t timer, ngx_uint_t flags)

{

...

C = event_ list [I] .data.ptr

Instance = (uintptr_t) c & 1

If (c-> fd = =-1 | | rev- > instance! = instance) {

...

}

At this point, the study on "what is the execution process of nginx startup initialization code" is over. I hope to be able to solve your doubts. The collocation of theory and practice can better help you learn, go and try it! If you want to continue to learn more related knowledge, please continue to follow the website, the editor will continue to work hard to bring you more practical articles!

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