memcached conn thread

每个thread一个连接队列，conn很庞大，你可以理解它囊括了连接包含的所有信息，小宇宙。

typedef struct { pthread_t thread_id; /* unique ID of this thread */ struct event_base *base; /* libevent handle this thread uses */ struct event notify_event; /* listen event for notify pipe */ int notify_receive_fd; /* receiving end of notify pipe */ int notify_send_fd; /* sending end of notify pipe */

    CQ  new_conn_queue;         

/* queue of new connections to handle */

} LIBEVENT_THREAD;

 

typedef struct conn_queue CQ; struct conn_queue { CQ_ITEM *head; CQ_ITEM *tail; pthread_mutex_t lock

;
    pthread_cond_t  cond;
};

 

typedef struct conn_queue_item CQ_ITEM; struct conn_queue_item { int sfd; int init_state; int event_flags; int read_buffer_size; int is_udp; CQ_ITEM *

next;
};

• thread_init
• 分配LIBEVENT_THREAD *threads;
• setup_thread注册回调函数thread_libevent_process
• create_worker->worker_libevent->event_base_loop
• thread_libevent_process
• 取出LIBEVENT_THREAD里边连接队列的一个元素CQ_ITEM
• CQ_ITEM的成员来初始化一个conn
• accept_new_conns
• update_event：event_set(&c->event, c->sfd, new_flags, event_handler, (void *)c);
• event_handler
• drive_machine
• conn_listening
• accept_new_conns
• conn_read
• try_read_network
• conn_write
• conn_nread
• conn_swallow
• conn_closing
• conn_mwrite