nginx 通过ngx_get_conf获取conf信息，ngx_set_worker_processes通过cmd-＞set(cf, cmd, conf)被调用
1.获取conf信息：
ccf = (ngx_core_conf_t *) ngx_get_conf(cycle->conf_ctx, ngx_core_module);
ngx_get_conf的原型为：
#define ngx_get_conf(conf_ctx, module) conf_ctx[module.index]
所以module.index实际上是ngx_core_module.NGX_MODULE_V1.NGX_MODULE_UNSET_INDEX
ngx_module_t ngx_core_module = {
NGX_MODULE_V1,
&ngx_core_module_ctx, /* module context /
ngx_core_commands, / module directives /
NGX_CORE_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
};
从下面的宏定义中将 NGX_MODULE_V1展开
#define NGX_MODULE_V1 为：
NGX_MODULE_UNSET_INDEX,
NGX_MODULE_UNSET_INDEX,
NULL,
0,
0,
nginx_version,
NGX_MODULE_SIGNATURE
typedef struct {
ngx_str_t name;
void *(*create_conf)(ngx_cycle_t *cycle);
char *(*init_conf)(ngx_cycle_t *cycle, void *conf);
} ngx_core_module_t;
struct ngx_command_s {
ngx_str_t name;
ngx_uint_t type;
char *(*set)(ngx_conf_t *cf, ngx_command_t *cmd, void *conf);
ngx_uint_t conf;
ngx_uint_t offset;
void *post;
};
由于：typedef struct ngx_module_s ngx_module_t;
所以ngx_core_module原型为：
struct ngx_module_s {
ngx_uint_t ctx_index;
ngx_uint_t index; //typedef uintptr_t ngx_uint_t;
char *name;
ngx_uint_t spare0;
ngx_uint_t spare1;
ngx_uint_t version;
const char *signature;
void *ctx;
ngx_command_t *commands;
ngx_uint_t type;
ngx_int_t (*init_master)(ngx_log_t *log);
ngx_int_t (*init_module)(ngx_cycle_t *cycle);
ngx_int_t (*init_process)(ngx_cycle_t *cycle);
ngx_int_t (*init_thread)(ngx_cycle_t *cycle);
void (*exit_thread)(ngx_cycle_t *cycle);
void (*exit_process)(ngx_cycle_t *cycle);
void (*exit_master)(ngx_cycle_t *cycle);
uintptr_t spare_hook0;
uintptr_t spare_hook1;
uintptr_t spare_hook2;
uintptr_t spare_hook3;
uintptr_t spare_hook4;
uintptr_t spare_hook5;
uintptr_t spare_hook6;
uintptr_t spare_hook7;
};
ngx_core_conf_t原型为：
typedef struct {
ngx_flag_t daemon;
ngx_flag_t master;
ngx_msec_t timer_resolution;
ngx_int_t worker_processes;
ngx_int_t debug_points;
ngx_int_t rlimit_nofile;
off_t rlimit_core;
int priority;
ngx_uint_t cpu_affinity_auto;
ngx_uint_t cpu_affinity_n;
ngx_cpuset_t *cpu_affinity;
char *username;
ngx_uid_t user;
ngx_gid_t group;
ngx_str_t working_directory;
ngx_str_t lock_file;
ngx_str_t pid;
ngx_str_t oldpid;
ngx_array_t env;
char **environment;
} ngx_core_conf_t;
conf_ctx原型其实是一个空的4阶指针：
struct ngx_cycle_s {
void ****conf_ctx;
ngx_pool_t *pool;
ngx_log_t *log;
ngx_log_t new_log;
ngx_uint_t log_use_stderr; /* unsigned log_use_stderr:1; */
ngx_connection_t **files;
ngx_connection_t *free_connections;
ngx_uint_t free_connection_n;
ngx_module_t **modules;
ngx_uint_t modules_n;
ngx_uint_t modules_used; /* unsigned modules_used:1; */
ngx_queue_t reusable_connections_queue;
ngx_array_t listening;
ngx_array_t paths;
ngx_array_t config_dump;
ngx_list_t open_files;
ngx_list_t shared_memory;
ngx_uint_t connection_n;
ngx_uint_t files_n;
ngx_connection_t *connections;
ngx_event_t *read_events;
ngx_event_t *write_events;
ngx_cycle_t *old_cycle;
ngx_str_t conf_file;
ngx_str_t conf_param;
ngx_str_t conf_prefix;
ngx_str_t prefix;
ngx_str_t lock_file;
ngx_str_t hostname;
};
struct ngx_cycle_s {
void ****conf_ctx;
ngx_pool_t *pool;
ngx_log_t *log;
ngx_log_t new_log;
ngx_uint_t log_use_stderr; /* unsigned log_use_stderr:1; */
ngx_connection_t **files;
ngx_connection_t *free_connections;
ngx_uint_t free_connection_n;
ngx_module_t **modules;
ngx_uint_t modules_n;
ngx_uint_t modules_used; /* unsigned modules_used:1; */
ngx_queue_t reusable_connections_queue;
ngx_array_t listening;
ngx_array_t paths;
ngx_array_t config_dump;
ngx_list_t open_files;
ngx_list_t shared_memory;
ngx_uint_t connection_n;
ngx_uint_t files_n;
ngx_connection_t *connections;
ngx_event_t *read_events;
ngx_event_t *write_events;
ngx_cycle_t *old_cycle;
ngx_str_t conf_file;
ngx_str_t conf_param;
ngx_str_t conf_prefix;
ngx_str_t prefix;
ngx_str_t lock_file;
ngx_str_t hostname;
};
2.ngx_set_worker_processes通过cmd->set(cf, cmd, conf)调用。
/**
* 配置文件设置值；
* conf为配置的指针地址;
* cmd为命令结构；
* conf为配置指针地址 一般情况下 conf为模块自定义的配置文件数据结构地址
*
*/
rv = cmd->set(cf, cmd, conf);
typedef struct ngx_command_s ngx_command_t;
struct ngx_command_s {
ngx_str_t name;
ngx_uint_t type;
char *(*set)(ngx_conf_t *cf, ngx_command_t *cmd, void *conf);
ngx_uint_t conf;
ngx_uint_t offset;
void *post;
};
static ngx_command_t ngx_core_commands[] = {
…
{ ngx_string(“worker_processes”),
NGX_MAIN_CONF|NGX_DIRECT_CONF|NGX_CONF_TAKE1,
ngx_set_worker_processes,
0,
0,
NULL },
}
static char *
ngx_set_worker_processes(ngx_conf_t *cf, ngx_command_t *cmd, void *conf)
{
ngx_str_t *value;
ngx_core_conf_t *ccf;
ccf = (ngx_core_conf_t *) conf;
if (ccf->worker_processes != NGX_CONF_UNSET) {
return "is duplicate";
}
value = cf->args->elts;
if (ngx_strcmp(value[1].data, "auto") == 0) {
ccf->worker_processes = ngx_ncpu;
return NGX_CONF_OK;
}
ccf->worker_processes = ngx_atoi(value[1].data, value[1].len);
if (ccf->worker_processes == NGX_ERROR) {
return "invalid value";
}
return NGX_CONF_OK;
}