/* 启动缓存管理进程 */
static void
ngx_start_cache_manager_processes(ngx_cycle_t *cycle, ngx_uint_t respawn)
{
ngx_uint_t i, manager, loader;
ngx_path_t **path;
ngx_channel_t ch;
manager = 0;
loader = 0;
path = ngx_cycle->paths.elts;
for (i = 0; i < ngx_cycle->paths.nelts; i++) {
/* 判断管理句柄 */
if (path[i]->manager) {
manager = 1;
}
/* 判断加载句柄 */
if (path[i]->loader) {
loader = 1;
}
}
if (manager == 0) {
return;
}
/* 启动缓存管理进程 */
ngx_spawn_process(cycle, ngx_cache_manager_process_cycle,
&ngx_cache_manager_ctx, "cache manager process",
respawn ? NGX_PROCESS_JUST_RESPAWN : NGX_PROCESS_RESPAWN);
ngx_memzero(&ch, sizeof(ngx_channel_t));
ch.command = NGX_CMD_OPEN_CHANNEL;
ch.pid = ngx_processes[ngx_process_slot].pid;
ch.slot = ngx_process_slot;
ch.fd = ngx_processes[ngx_process_slot].channel[0];
/* 通知其他worker进程和缓存管理进程的通信fd */
ngx_pass_open_channel(cycle, &ch);
if (loader == 0) {
return;
}
/* 启动缓存加载进程 */
ngx_spawn_process(cycle, ngx_cache_manager_process_cycle,
&ngx_cache_loader_ctx, "cache loader process",
respawn ? NGX_PROCESS_JUST_SPAWN : NGX_PROCESS_NORESPAWN);
ch.command = NGX_CMD_OPEN_CHANNEL;
ch.pid = ngx_processes[ngx_process_slot].pid;
ch.slot = ngx_process_slot;
ch.fd = ngx_processes[ngx_process_slot].channel[0];
ngx_pass_open_channel(cycle, &ch);
}
/*启动缓存索引重建进程，该进程在整个Nginx服务器运行过程中只存在很短的时间，主要用来遍历磁盘上的缓存数据，在内存中建立数据索引，提高Nginx服务器检索缓存的效率*/
static void
ngx_start_cache_manager_processes(ngx_cycle_t *cycle, ngx_uint_t respawn)
{
ngx_uint_t i, manager, loader;
ngx_path_t **path;
ngx_channel_t ch;
manager = 0;
loader = 0;
path = ngx_cycle->paths.elts;
for (i = 0; i < ngx_cycle->paths.nelts; i++) {
if (path[i]->manager) {
manager = 1;
}
if (path[i]->loader) {
loader = 1;
}
}
if (manager == 0) {
return;
}
/*创建缓存索引管理进程Cache Manager Process，此时respawn=0，所以传入的参数是NGX_PROCESS_JUST_RESPAWN*/
ngx_spawn_process(cycle, ngx_cache_manager_process_cycle,
&ngx_cache_manager_ctx, "cache manager process",
respawn ? NGX_PROCESS_JUST_RESPAWN : NGX_PROCESS_RESPAWN);
ngx_memzero(&ch, sizeof(ngx_channel_t));
ch.command = NGX_CMD_OPEN_CHANNEL;
ch.pid = ngx_processes[ngx_process_slot].pid;
ch.slot = ngx_process_slot;
ch.fd = ngx_processes[ngx_process_slot].channel[0];
/*创建进程间通信管道*/
ngx_pass_open_channel(cycle, &ch);
if (loader == 0) {
return;
}
/*创建缓存索引管理进程Cache Loader Process，此时respawn=0，所以传入的参数是NGX_PROCESS_JUST_SPAWN*/
ngx_spawn_process(cycle, ngx_cache_manager_process_cycle,
&ngx_cache_loader_ctx, "cache loader process",
respawn ? NGX_PROCESS_JUST_SPAWN : NGX_PROCESS_NORESPAWN);
ch.command = NGX_CMD_OPEN_CHANNEL;
ch.pid = ngx_processes[ngx_process_slot].pid;
ch.slot = ngx_process_slot;
ch.fd = ngx_processes[ngx_process_slot].channel[0];
/*创建进程间通信管道*/
ngx_pass_open_channel(cycle, &ch);
}
static void
ngx_start_cache_manager_processes(ngx_cycle_t *cycle, ngx_uint_t respawn)
{
ngx_uint_t i, manager, loader;
ngx_path_t **path;
ngx_channel_t ch;
manager = 0;
loader = 0;
path = ngx_cycle->pathes.elts;
for (i = 0; i < ngx_cycle->pathes.nelts; i++) {
if (path[i]->manager) {
manager = 1;
}
if (path[i]->loader) {
loader = 1;
}
}
if (manager == 0) {
return;
}
ngx_spawn_process(cycle, ngx_cache_manager_process_cycle,
&ngx_cache_manager_ctx, "cache manager process",
respawn ? NGX_PROCESS_JUST_RESPAWN : NGX_PROCESS_RESPAWN);
ch.command = NGX_CMD_OPEN_CHANNEL;
ch.pid = ngx_processes[ngx_process_slot].pid;
ch.slot = ngx_process_slot;
ch.fd = ngx_processes[ngx_process_slot].channel[0];
ngx_pass_open_channel(cycle, &ch);
if (loader == 0) {
return;
}
ngx_spawn_process(cycle, ngx_cache_manager_process_cycle,
&ngx_cache_loader_ctx, "cache loader process",
respawn ? NGX_PROCESS_JUST_SPAWN : NGX_PROCESS_NORESPAWN);
ch.command = NGX_CMD_OPEN_CHANNEL;
ch.pid = ngx_processes[ngx_process_slot].pid;
ch.slot = ngx_process_slot;
ch.fd = ngx_processes[ngx_process_slot].channel[0];
ngx_pass_open_channel(cycle, &ch);
}
/*启动工作进程：两个任务，1是设置父子进程通信，2是根据配置循环创建所有的工作进程*/
static void
ngx_start_worker_processes(ngx_cycle_t *cycle, ngx_int_t n, ngx_int_t type)
{
ngx_int_t i;
ngx_channel_t ch;
ngx_log_error(NGX_LOG_NOTICE, cycle->log, 0, "start worker processes");
//传递给其他子进程的命令，打开channel
ch.command = NGX_CMD_OPEN_CHANNEL;
//创建n个worker进程
for (i = 0; i < n; i++) {
cpu_affinity = ngx_get_cpu_affinity(i);
//[p]fork新进程的具体工作，ngx_worker_process_cycle函数是工作进程要执行的具体工作
ngx_spawn_process(cycle, ngx_worker_process_cycle, NULL,
"worker process", type);
//全局数组,定义在src/os/unix/ngx_process.c文件中，存储元素类型是ngx_process_t。
//注意，ngx_process_slot在spawn函数中已经赋值完毕，就是当前子进程的位置
ch.pid = ngx_processes[ngx_process_slot].pid;
ch.slot = ngx_process_slot;
ch.fd = ngx_processes[ngx_process_slot].channel[0];
//建立通道,用于进程通信
ngx_pass_open_channel(cycle, &ch);
}
}
static void
ngx_start_worker_processes(ngx_cycle_t *cycle, ngx_int_t n, ngx_int_t type)
{
ngx_int_t i;
ngx_channel_t ch;
ngx_log_error(NGX_LOG_NOTICE, cycle->log, 0, "start worker processes");
ngx_memzero(&ch, sizeof(ngx_channel_t));
ch.command = NGX_CMD_OPEN_CHANNEL;
for (i = 0; i < n; i++) {
/*打开主进程和工作进程通信的管道，并fork出子进程，在子进程中运行ngx_worker_process_cycle函数*/
ngx_spawn_process(cycle, ngx_worker_process_cycle,
(void *) (intptr_t) i, "worker process", type);
ch.pid = ngx_processes[ngx_process_slot].pid;
ch.slot = ngx_process_slot;
ch.fd = ngx_processes[ngx_process_slot].channel[0];
/*循环遍历所有的工作进程信息，将新打开的进程的PID、slot（也就是下标）、channel[0]发送给其他的进程*/
ngx_pass_open_channel(cycle, &ch);
}
}
static void
ngx_start_worker_processes(ngx_cycle_t *cycle, ngx_int_t n, ngx_int_t type)
{
ngx_int_t i;
ngx_channel_t ch;
ngx_log_error(NGX_LOG_NOTICE, cycle->log, 0, "start worker processes");
ngx_memzero(&ch, sizeof(ngx_channel_t));
ch.command = NGX_CMD_OPEN_CHANNEL;
for (i = 0; i < n; i++) {
ngx_spawn_process(cycle, ngx_worker_process_cycle,
(void *) (intptr_t) i, "worker process", type);
ch.pid = ngx_processes[ngx_process_slot].pid;
ch.slot = ngx_process_slot;
ch.fd = ngx_processes[ngx_process_slot].channel[0];
//父进程将ngx_spawn_process新创建的进程的channel[0] 传递给进程表中的其他进程
ngx_pass_open_channel(cycle, &ch);
}
}
/* master进程启动n个子进程 */
static void
ngx_start_worker_processes(ngx_cycle_t *cycle, ngx_int_t n, ngx_int_t type)
{
ngx_int_t i;
ngx_channel_t ch;
ngx_log_error(NGX_LOG_NOTICE, cycle->log, 0, "start worker processes");
ngx_memzero(&ch, sizeof(ngx_channel_t));
ch.command = NGX_CMD_OPEN_CHANNEL;
/* 创建n个worker进程 */
for (i = 0; i < n; i++) {
/* ngx_worker_process_cycle用来初始化worker进程的主循环 */
ngx_spawn_process(cycle, ngx_worker_process_cycle,
(void *) (intptr_t) i, "worker process", type);
ch.pid = ngx_processes[ngx_process_slot].pid;
ch.slot = ngx_process_slot;
/* 将子进程的0通道通知其他在前创建的进程，1通道是接收信息的 */
ch.fd = ngx_processes[ngx_process_slot].channel[0];
/* 把创建的子进程的相关信息通知前面已经生成的子进程，
* 注意这里是父进程把刚创建的子进程的相关信息发送给其他子进程，
* 而不是子进程自己发送的
*/
ngx_pass_open_channel(cycle, &ch);
}
}
// 被ngx_master_process_cycle()调用
// 启动worker进程，数量由配置决定，即worker_processes指令
// 调用时传递的是#define NGX_PROCESS_RESPAWN -3
static void
ngx_start_worker_processes(ngx_cycle_t *cycle, ngx_int_t n, ngx_int_t type)
{
ngx_int_t i;
ngx_channel_t ch;
ngx_log_error(NGX_LOG_NOTICE, cycle->log, 0, "start worker processes");
ngx_memzero(&ch, sizeof(ngx_channel_t));
// unix channel
ch.command = NGX_CMD_OPEN_CHANNEL;
for (i = 0; i < n; i++) {
// os/unix/ngx_process.c产生进程，执行ngx_worker_process_cycle
// 创建的进程都在ngx_processes数组里
// 定义在os/unix/ngx_process.c
// ngx_process_t ngx_processes[NGX_MAX_PROCESSES];
ngx_spawn_process(cycle, ngx_worker_process_cycle,
(void *) (intptr_t) i, "worker process", type);
// 设置channel信息
ch.pid = ngx_processes[ngx_process_slot].pid;
ch.slot = ngx_process_slot;
ch.fd = ngx_processes[ngx_process_slot].channel[0];
// 建立channel，用于进程间通信
ngx_pass_open_channel(cycle, &ch);
}
}
static void
ngx_start_session_manager_processes(ngx_cycle_t *cycle, ngx_uint_t respawn)
{
ngx_channel_t ch;
if (!cycle->session_enabled) {
return;
}
ngx_spawn_process(cycle, ngx_session_manager_process_cycle,
&ngx_session_manager_ctx, "session manager process",
respawn ? NGX_PROCESS_JUST_RESPAWN : NGX_PROCESS_RESPAWN);
ch.command = NGX_CMD_OPEN_CHANNEL;
ch.pid = ngx_processes[ngx_process_slot].pid;
ch.slot = ngx_process_slot;
ch.fd = ngx_processes[ngx_process_slot].channel[0];
ngx_pass_open_channel(cycle, &ch);
}
static void
ngx_start_ip_blacklist_manager_processes(ngx_cycle_t *cycle, ngx_uint_t respawn)
{
ngx_channel_t ch;
if (!cycle->ip_blacklist_enabled) {
/* ip blacklist not enabled, don't start the helper */
return;
}
ngx_spawn_process(cycle, ngx_ip_blacklist_manager_process_cycle,
&ngx_ip_blacklist_manager_ctx,
"IP blacklist manager process",
respawn ? NGX_PROCESS_JUST_RESPAWN : NGX_PROCESS_RESPAWN);
ch.command = NGX_CMD_OPEN_CHANNEL;
ch.pid = ngx_processes[ngx_process_slot].pid;
ch.slot = ngx_process_slot;
ch.fd = ngx_processes[ngx_process_slot].channel[0];
ngx_pass_open_channel(cycle, &ch);
}
static void
ngx_start_worker_processes(ngx_cycle_t *cycle, ngx_int_t n, ngx_int_t type)
{
ngx_int_t i;
ngx_channel_t ch;
ngx_log_error(NGX_LOG_NOTICE, cycle->log, 0, "start worker processes");
// 传递给子进程的命令
ch.command = NGX_CMD_OPEN_CHANNEL;
for (i = 0; i < n; i++) {
// fork子进程
ngx_spawn_process(cycle, ngx_worker_process_cycle,
(void *) (intptr_t) i, "worker process", type);
// 初始化channel，ngx_process_slot在ngx_spawn_process中已经赋值
ch.pid = ngx_processes[ngx_process_slot].pid;
ch.slot = ngx_process_slot;
ch.fd = ngx_processes[ngx_process_slot].channel[0];
ngx_pass_open_channel(cycle, &ch);
}
}
static void
ngx_start_worker_processes(ngx_cycle_t *cycle, ngx_int_t n, ngx_int_t type)
{
ngx_int_t i;
ngx_channel_t ch;
ngx_log_error(NGX_LOG_NOTICE, cycle->log, 0, "start worker processes");
ch.command = NGX_CMD_OPEN_CHANNEL;
for (i = 0; i < n; i++) {
cpu_affinity = ngx_get_cpu_affinity(i);
ngx_spawn_process(cycle, ngx_worker_process_cycle, NULL,
"worker process", type);
ch.pid = ngx_processes[ngx_process_slot].pid;
ch.slot = ngx_process_slot;
ch.fd = ngx_processes[ngx_process_slot].channel[0];
ngx_pass_open_channel(cycle, &ch);
}
}
static ngx_uint_t
ngx_reap_children(ngx_cycle_t *cycle)
{
ngx_int_t i, n;
ngx_uint_t live;
ngx_channel_t ch;
ngx_core_conf_t *ccf;
ngx_memzero(&ch, sizeof(ngx_channel_t));
ch.command = NGX_CMD_CLOSE_CHANNEL;
ch.fd = -1;
live = 0;
for (i = 0; i < ngx_last_process; i++) {
ngx_log_debug7(NGX_LOG_DEBUG_EVENT, cycle->log, 0,
"child: %d %P e:%d t:%d d:%d r:%d j:%d",
i,
ngx_processes[i].pid,
ngx_processes[i].exiting,
ngx_processes[i].exited,
ngx_processes[i].detached,
ngx_processes[i].respawn,
ngx_processes[i].just_spawn);
if (ngx_processes[i].pid == -1) {
continue;
}
if (ngx_processes[i].exited) {
if (!ngx_processes[i].detached) {
ngx_close_channel(ngx_processes[i].channel, cycle->log);
ngx_processes[i].channel[0] = -1;
ngx_processes[i].channel[1] = -1;
ch.pid = ngx_processes[i].pid;
ch.slot = i;
for (n = 0; n < ngx_last_process; n++) {
if (ngx_processes[n].exited
|| ngx_processes[n].pid == -1
|| ngx_processes[n].channel[0] == -1)
{
continue;
}
ngx_log_debug3(NGX_LOG_DEBUG_CORE, cycle->log, 0,
"pass close channel s:%i pid:%P to:%P",
ch.slot, ch.pid, ngx_processes[n].pid);
/* TODO: NGX_AGAIN */
ngx_write_channel(ngx_processes[n].channel[0],
&ch, sizeof(ngx_channel_t), cycle->log);
}
}
if (ngx_processes[i].respawn
&& !ngx_processes[i].exiting
&& !ngx_terminate
&& !ngx_quit)
{
if (ngx_spawn_process(cycle, ngx_processes[i].proc,
ngx_processes[i].data,
ngx_processes[i].name, i)
== NGX_INVALID_PID)
{
ngx_log_error(NGX_LOG_ALERT, cycle->log, 0,
"could not respawn %s",
ngx_processes[i].name);
continue;
}
ch.command = NGX_CMD_OPEN_CHANNEL;
ch.pid = ngx_processes[ngx_process_slot].pid;
ch.slot = ngx_process_slot;
ch.fd = ngx_processes[ngx_process_slot].channel[0];
ngx_pass_open_channel(cycle, &ch);
live = 1;
continue;
}
if (ngx_processes[i].pid == ngx_new_binary) {
ccf = (ngx_core_conf_t *) ngx_get_conf(cycle->conf_ctx,
ngx_core_module);
if (ngx_rename_file((char *) ccf->oldpid.data,
(char *) ccf->pid.data)
== NGX_FILE_ERROR)
{
ngx_log_error(NGX_LOG_ALERT, cycle->log, ngx_errno,
ngx_rename_file_n " %s back to %s failed "
"after the new binary process \"%s\" exited",
ccf->oldpid.data, ccf->pid.data, ngx_argv[0]);
}
ngx_new_binary = 0;
if (ngx_noaccepting) {
ngx_restart = 1;
ngx_noaccepting = 0;
}
}
if (i == ngx_last_process - 1) {
ngx_last_process--;
} else {
ngx_processes[i].pid = -1;
}
} else if (ngx_processes[i].exiting || !ngx_processes[i].detached) {
live = 1;
}
}
return live;
}