Nginx: Start Process

First, the master boot process

1. flow chart
   
2. The main function

• ngx_get_options
  parse command parameters
• ngx_process_options
  configuration prefix, the prefix, configuration files, configuration parameters string
• ngx_add_inherited_sockets
  carrying out a smooth upgrade, will be passed to the new process by "NGINX" environment variable listening fd, for cycle- new process initialization> listening structures.
• ngx_init_cycle

  • When the update server and the time zone
    TP = ngx_timeofday ();
    the tp-> = 0 sec;
    ngx_time_update ();

  • Assign a new pool and Cycle
    pool = ngx_create_pool (NGX_CYCLE_POOL_SIZE, log);
    Cycle = ngx_pcalloc (pool, the sizeof (ngx_cycle_t));

  • Initial configuration prefix, the prefix, configuration files, configuration parameters string from the old copy of some data inside old_cycle cycle objects to
    initialize an array of paths
    ngx_array_init (& cycle-> paths, pool , n, sizeof (ngx_path_t *);
    save all nginx directory to be operated, if the directory does not exist, it is created, the creation fails nginx fails to start, call ngx_add_path add .eg.proxy_temp_path as defined directory to store temporary files bearing receives from the proxy server to the data, the path needs to be added to the array path .

  • 初始化config_dump数组
    ngx_array_init(&cycle->config_dump, pool, 1, sizeof(ngx_conf_dump_t);
    ngx_rbtree_init(&cycle->config_dump_rbtree, &cycle->config_dump_sentinel,
    ngx_str_rbtree_insert_value);

  • Open_files initialize an array
    ngx_list_init (& cycle-> open_files, pool , n, sizeof (ngx_open_file_t);
    save the file to open nginx, call ngx_conf_open_file add .eg.nginx log file path interface needs to be saved in the array.

  • Initialization shared_memory list
    ngx_list_init (& cycle-> shared_memory, pool , n, sizeof (ngx_shm_zone_t);
    save the shared memory information nginx to use, the interface call ngx_shared_memory_add added.

  • According listening old_cycle, and initialize the new cycle-> listening.
    IF (ngx_array_init (& cycle-> Listening, the pool, n-, the sizeof (ngx_listening_t))
    = NGX_OK!)
    {
    ngx_destroy_pool (the pool);
    return NULL;
    }

  • Initialization resuable_connections_queue queue.
    ngx_queue_init (& cycle-> reusable_connections_queue);

  • Call the core module of create_conf (), the configuration is stored in an array conf_ctx cycle, the key is the index number compiled kernel modules.
    IF (module-> create_conf) {
    RV = module-> create_conf (Cycle);
    IF (RV == NULL) {
    ngx_destroy_pool (the pool);
    return NULL;
    }
    // [core module] configured as an index for the module id
    cycle-> conf_ctx [cycle-> modules [I] -> index] = RV;
    }

  • Configuration parsing

  • Each file and the list traversal open_files open
    File [I] = .FD ngx_o
    pen_file (File [I] .name.data,
    NGX_FILE_APPEND,
    NGX_FILE_CREATE_OR_OPEN,
    NGX_FILE_DEFAULT_ACCESS);

  • Create a shared memory and initialize (compare the old and new shared_memory the list, the same shared memory retention, old different shared memory is released and the new is created).

  • Create a new listening socket on old_cycle existing sockets inherit, to be non-existent New.
    IF (! ngx_open_listening_sockets (Cycle) = NGX_OK) {
    GOTO failed;}

  • Submit a new cycle configuration, and call all init_module modules (actually only ngx_event_core_module module defines the callback, that only ngx_event_module_init () is called).
    IF (! ngx_init_modules (Cycle) = NGX_OK) {
    / * * fatal /
    Exit (. 1);
    }

  • Old_cycle release excess shared_memory.

  • Old_cycle release listening socket is not in use.

  • Old_cycle release excess open_files.

  • old_cycle cleanup.

Two, master process

1. ngx_master_process_cycle process

• 信号屏蔽
  if (sigprocmask(SIG_BLOCK, &set, NULL) == -1) {
  ngx_log_error(NGX_LOG_ALERT, cycle->log, ngx_errno,
  “sigprocmask() failed”);
  }

  sigemptyset(&set);

• Modify process name
  ngx_setproctitle (title);

• 启动worker进程
  ngx_start_worker_processes(cycle, ccf->worker_processes,
  NGX_PROCESS_RESPAWN);
  ngx_start_cache_manager_processes(cycle, 0);

• Enter the main loop

2. The main loop flow chart
   

Three, worker process

1. ngx_worker_process_init initialization

• Initializing variables change into
  ngx_set_environment (cycle, NULL);

• Set process priority
  setpriority (PRIO_PROCESS, 0, ccf-> priority);

• Number setting file handle limit
  setrlimit (RLIMIT_NOFILE, & rlmt);

• Provided core_file file
  setrlimit (RLIMIT_CORE, & rlmt);

• User group
  setgid (CCF> Group);
  initgroups (CCF> username, CCF> Group);
  the setuid (CCF> User);

• 设置cpu亲和
  ngx_get_cpu_affinity(worker);
  ngx_setaffinity(cpu_affinity, cycle->log);

• Disposed signal shielding
  sigemptyset (& SET);
  the sigprocmask (SIG_SETMASK, & SET, NULL);

• 调用init_process()
  cycle->modules[i]->init_process(cycle);

• channel setting off others fd [1], retention of others fd [0] to communicate with each other. Own fd [1] message received master process. channel events added epoll.

  for (n = 0; n <ngx_last_process; n ++) {
  close (ngx_processes [n] .channel [1]);
  }
  Close (ngx_processes [ngx_process_slot] .channel [0]);
  ngx_add_channel_event (Cycle, ngx_channel, NGX_READ_EVENT,
  ngx_channel_handler)