如不做特殊说明，本博客所使用的 nginx 源码版本是 1.0.14，[] 中是代码所在的文件！
这一节我们分析ngx_worker_process_cycle()，该函数代码比较少，因为它通过调用函数实现功能的，先贴出代码：
[os/unix/ngx_process_cycle.c
761 /* worker_process 所执行的程序，nginx 核心所在 */ 762 static void 763 ngx_worker_process_cycle(ngx_cycle_t *cycle, void *data) 764 { 765 ngx_uint_t i; 766 ngx_connection_t *c; 767 768 ngx_process = NGX_PROCESS_WORKER; 769 770 /* worker 进程初始化 */ 771 ngx_worker_process_init(cycle, 1); 772 773 /* 设置程序名称 */ 774 ngx_setproctitle("worker process");
1. 768 行设置 ngx_process 的值为 NGX_PROCESS_WORKER, 该值会在信号回调函数中有用ngx_signal_handler()[ngx_process.c]，该值表示的是进程模型的类型。
2. 771 行调用 ngx_worker_process_init() 来先对 worker 进程进行一下初始化，该函数的源码如下：
888 /* worker_process 初始化，根据配置来设置一些属性 */ 889 static void 890 ngx_worker_process_init(ngx_cycle_t *cycle, ngx_uint_t priority) 891 { 892 sigset_t set; 893 ngx_int_t n; 894 ngx_uint_t i; 895 struct rlimit rlmt; 896 ngx_core_conf_t *ccf; 897 ngx_listening_t *ls; 898 899 if (ngx_set_environment(cycle, NULL) == NULL) { 900 /* fatal */ 901 exit(2); 902 } 903 904 ccf = (ngx_core_conf_t *) ngx_get_conf(cycle->conf_ctx, ngx_core_module); 905 906 if (priority && ccf->priority != 0) { 907 if (setpriority(PRIO_PROCESS, 0, ccf->priority) == -1) { 908 ngx_log_error(NGX_LOG_ALERT, cycle->log, ngx_errno, 909 "setpriority(%d) failed", ccf->priority); 910 } 911 } 912 913 if (ccf->rlimit_nofile != NGX_CONF_UNSET) { 914 rlmt.rlim_cur = (rlim_t) ccf->rlimit_nofile; 915 rlmt.rlim_max = (rlim_t) ccf->rlimit_nofile; 916 917 if (setrlimit(RLIMIT_NOFILE, &rlmt) == -1) { 918 ngx_log_error(NGX_LOG_ALERT, cycle->log, ngx_errno, 919 "setrlimit(RLIMIT_NOFILE, %i) failed", 920 ccf->rlimit_nofile); 921 } 922 } 923 924 if (ccf->rlimit_core != NGX_CONF_UNSET) { 925 rlmt.rlim_cur = (rlim_t) ccf->rlimit_core; 926 rlmt.rlim_max = (rlim_t) ccf->rlimit_core; 927 928 if (setrlimit(RLIMIT_CORE, &rlmt) == -1) { 929 ngx_log_error(NGX_LOG_ALERT, cycle->log, ngx_errno, 930 "setrlimit(RLIMIT_CORE, %O) failed", 931 ccf->rlimit_core); 932 } 933 } 934 935 #ifdef RLIMIT_SIGPENDING 936 if (ccf->rlimit_sigpending != NGX_CONF_UNSET) { 937 rlmt.rlim_cur = (rlim_t) ccf->rlimit_sigpending; 938 rlmt.rlim_max = (rlim_t) ccf->rlimit_sigpending; 939 940 if (setrlimit(RLIMIT_SIGPENDING, &rlmt) == -1) { 941 ngx_log_error(NGX_LOG_ALERT, cycle->log, ngx_errno, 942 "setrlimit(RLIMIT_SIGPENDING, %i) failed", 943 ccf->rlimit_sigpending); 944 } 945 } 946 #endif 947 948 if (geteuid() == 0) { 949 if (setgid(ccf->group) == -1) { 950 ngx_log_error(NGX_LOG_EMERG, cycle->log, ngx_errno, 951 "setgid(%d) failed", ccf->group); 952 /* fatal */ 953 exit(2); 954 } 955 956 if (initgroups(ccf->username, ccf->group) == -1) { 957 ngx_log_error(NGX_LOG_EMERG, cycle->log, ngx_errno, 958 "initgroups(%s, %d) failed", 959 ccf->username, ccf->group); 960 } 961 962 if (setuid(ccf->user) == -1) { 963 ngx_log_error(NGX_LOG_EMERG, cycle->log, ngx_errno, 964 "setuid(%d) failed", ccf->user); 965 /* fatal */ 966 exit(2); 967 } 968 } 969 970 #if (NGX_HAVE_SCHED_SETAFFINITY) 971 972 if (cpu_affinity) { 973 ngx_log_error(NGX_LOG_NOTICE, cycle->log, 0, 974 "sched_setaffinity(0x%08Xl)", cpu_affinity); 975 976 if (sched_setaffinity(0, sizeof(cpu_affinity), 977 (cpu_set_t *) &cpu_affinity) 978 == -1) 979 { 980 ngx_log_error(NGX_LOG_ALERT, cycle->log, ngx_errno, 981 "sched_setaffinity(0x%08Xl) failed", cpu_affinity); 982 } 983 } 984 985 #endif 986 987 #if (NGX_HAVE_PR_SET_DUMPABLE) 988 989 /* allow coredump after setuid() in Linux 2.4.x */ 990 991 if (prctl(PR_SET_DUMPABLE, 1, 0, 0, 0) == -1) { 992 ngx_log_error(NGX_LOG_ALERT, cycle->log, ngx_errno, 993 "prctl(PR_SET_DUMPABLE) failed"); 994 } 995 996 #endif 997 998 if (ccf->working_directory.len) { 999 if (chdir((char *) ccf->working_directory.data) == -1) { 1000 ngx_log_error(NGX_LOG_ALERT, cycle->log, ngx_errno, 1001 "chdir(\"%s\") failed", ccf->working_directory.data); 1002 /* fatal */ 1003 exit(2); 1004 } 1005 } 1006 1007 sigemptyset(&set); 1008 1009 if (sigprocmask(SIG_SETMASK, &set, NULL) == -1) { 1010 ngx_log_error(NGX_LOG_ALERT, cycle->log, ngx_errno, 1011 "sigprocmask() failed"); 1012 } 1013 1014 /* 1015 * disable deleting previous events for the listening sockets because 1016 * in the worker processes there are no events at all at this point 1017 */ 1018 ls = cycle->listening.elts; 1019 for (i = 0; i < cycle->listening.nelts; i++) { 1020 ls[i].previous = NULL; 1021 } 1022 1023 for (i = 0; ngx_modules[i]; i++) { 1024 if (ngx_modules[i]->init_process) { 1025 /* 如果有模块设置了 init_process 函数 */ 1026 if (ngx_modules[i]->init_process(cycle) == NGX_ERROR) { 1027 /* fatal */ 1028 exit(2); 1029 } 1030 } 1031 } 1032 1033 for (n = 0; n < ngx_last_process; n++) { 1034 1035 if (ngx_processes[n].pid == -1) { 1036 continue; 1037 } 1038 1039 if (n == ngx_process_slot) { 1040 continue; 1041 } 1042 1043 if (ngx_processes[n].channel[1] == -1) { // channel²»ŽæÔÚ£¬Ìø¹ý 1044 continue; 1045 } 1046 1047 if (close(ngx_processes[n].channel[1]) == -1) { 1048 ngx_log_error(NGX_LOG_ALERT, cycle->log, ngx_errno, 1049 "close() channel failed"); 1050 } 1051 } 1052 1053 if (close(ngx_processes[ngx_process_slot].channel[0]) == -1) { 1054 ngx_log_error(NGX_LOG_ALERT, cycle->log, ngx_errno, 1055 "close() channel failed"); 1056 } 1057 1058 #if 0 1059 ngx_last_process = 0; 1060 #endif 1061 /* 貌似要加入读事件 */ 1062 if (ngx_add_channel_event(cycle, ngx_channel, NGX_READ_EVENT, 1063 ngx_channel_handler) 1064 == NGX_ERROR) 1065 { 1066 /* fatal */ 1067 exit(2); 1068 } 1069 }