在mater进程首先通过调用ngx_start_worker_processes(cycle, ccf->worker_processes,NGX_PROCESS_RESPAWN);函数启动worker进程。

其中ccf->worker_processes代表启动的worker进程个数

1.变量声明。

ngx_int_t i;

ngx_channel_t ch;

2.打印一条启动worker进程的日志。

ngx_log_error(NGX_LOG_NOTICE, cycle->log, 0, "start worker processes");

3.循环调用ngx_spawn_process函数启动worker进程。并初始化ngx_channel_t  ch;

ngx_pass_open_channel，不知道干啥的，一会儿看下。

1 for (i = 0; i < n; i++) { 2  3         ngx_spawn_process(cycle, ngx_worker_process_cycle, 4                           (void *) (intptr_t) i, "worker process", type); 5  6         ch.pid = ngx_processes[ngx_process_slot].pid; 7         ch.slot = ngx_process_slot; 8         ch.fd = ngx_processes[ngx_process_slot].channel[0]; 9 10         ngx_pass_open_channel(cycle, &ch);11     }

 

ngx_spawn_process(cycle, ngx_worker_process_cycle,(void *) (intptr_t) i, "worker process", type);

1.变量初始化

u_long     on;ngx_pid_t  pid;ngx_int_t  s;

2.首先找到ngx_processes列表中是否有已经关掉的进程pid=-1，有的话则继续利用。

3.如果当前启动的进程数大于最大进程数则报错，退出。

4.初始化子父进程通信的消息队列

1 //NGX_PROCESS_DETACHED暂时不知道做什么的 2 if (respawn != NGX_PROCESS_DETACHED) { 3  4         /* Solaris 9 still has no AF_LOCAL */ 5         //打开全双工队列，用于子进程和父进程的通信。 6         if (socketpair(AF_UNIX, SOCK_STREAM, 0, ngx_processes[s].channel) == -1) 7         { 8             ngx_log_error(NGX_LOG_ALERT, cycle->log, ngx_errno, 9                           "socketpair() failed while spawning \"%s\"", name);10             return NGX_INVALID_PID;11         }12 13         ngx_log_debug2(NGX_LOG_DEBUG_CORE, cycle->log, 0,14                        "channel %d:%d",15                        ngx_processes[s].channel[0],16                        ngx_processes[s].channel[1]);17         //ioctl控制消息队列的访问方式，具体还不懂。18         if (ngx_nonblocking(ngx_processes[s].channel[0]) == -1) {19             ngx_log_error(NGX_LOG_ALERT, cycle->log, ngx_errno,20                           ngx_nonblocking_n " failed while spawning \"%s\"",21                           name);22             ngx_close_channel(ngx_processes[s].channel, cycle->log);23             return NGX_INVALID_PID;24         }25         //同上26         if (ngx_nonblocking(ngx_processes[s].channel[1]) == -1) {27             ngx_log_error(NGX_LOG_ALERT, cycle->log, ngx_errno,28                           ngx_nonblocking_n " failed while spawning \"%s\"",29                           name);30             ngx_close_channel(ngx_processes[s].channel, cycle->log);31             return NGX_INVALID_PID;32         }33 34         on = 1;35         if (ioctl(ngx_processes[s].channel[0], FIOASYNC, &on) == -1) {36             ngx_log_error(NGX_LOG_ALERT, cycle->log, ngx_errno,37                           "ioctl(FIOASYNC) failed while spawning \"%s\"", name);38             ngx_close_channel(ngx_processes[s].channel, cycle->log);39             return NGX_INVALID_PID;40         }41 42         if (fcntl(ngx_processes[s].channel[0], F_SETOWN, ngx_pid) == -1) {43             ngx_log_error(NGX_LOG_ALERT, cycle->log, ngx_errno,44                           "fcntl(F_SETOWN) failed while spawning \"%s\"", name);45             ngx_close_channel(ngx_processes[s].channel, cycle->log);46             return NGX_INVALID_PID;47         }48 49         if (fcntl(ngx_processes[s].channel[0], F_SETFD, FD_CLOEXEC) == -1) {50             ngx_log_error(NGX_LOG_ALERT, cycle->log, ngx_errno,51                           "fcntl(FD_CLOEXEC) failed while spawning \"%s\"",52                            name);53             ngx_close_channel(ngx_processes[s].channel, cycle->log);54             return NGX_INVALID_PID;55         }56 57         if (fcntl(ngx_processes[s].channel[1], F_SETFD, FD_CLOEXEC) == -1) {58             ngx_log_error(NGX_LOG_ALERT, cycle->log, ngx_errno,59                           "fcntl(FD_CLOEXEC) failed while spawning \"%s\"",60                            name);61             ngx_close_channel(ngx_processes[s].channel, cycle->log);62             return NGX_INVALID_PID;63         }64 65         ngx_channel = ngx_processes[s].channel[1];66 67     } else {68         ngx_processes[s].channel[0] = -1;69         ngx_processes[s].channel[1] = -1;70     }

5.pid = fork();

fork子进程。

6.子进程执行，父进程退出。

proc(cycle, data);

proc指向的函数是  ngx_worker_process_cycle

data对应worker编号

7.进程进行状态的设置

1     ngx_processes[s].proc = proc; 2     ngx_processes[s].data = data; 3     ngx_processes[s].name = name; 4     ngx_processes[s].exiting = 0; 5  6     switch (respawn) { 7  8     case NGX_PROCESS_NORESPAWN: 9         ngx_processes[s].respawn = 0;10         ngx_processes[s].just_spawn = 0;11         ngx_processes[s].detached = 0;12         break;13 14     case NGX_PROCESS_JUST_SPAWN:15         ngx_processes[s].respawn = 0;16         ngx_processes[s].just_spawn = 1;17         ngx_processes[s].detached = 0;18         break;19 20     case NGX_PROCESS_RESPAWN:21         ngx_processes[s].respawn = 1;22         ngx_processes[s].just_spawn = 0;23         ngx_processes[s].detached = 0;24         break;25 26     case NGX_PROCESS_JUST_RESPAWN:27         ngx_processes[s].respawn = 1;28         ngx_processes[s].just_spawn = 1;29         ngx_processes[s].detached = 0;30         break;31 32     case NGX_PROCESS_DETACHED:33         ngx_processes[s].respawn = 0;34         ngx_processes[s].just_spawn = 0;35         ngx_processes[s].detached = 1;36         break;37     }38 39     if (s == ngx_last_process) {40         ngx_last_process++;41     }42 43     return pid;