3 tracker中的recv_notify_read

一、recv_notify_read

由第一篇文章中知道，一旦accept一个连接，就会指定一个工作线程调用这个函数。（注意：工作线程一直调用event_base_loop在循环等待事件）

void recv_notify_read(int sock, short event, void *arg){int bytes;int incomesock;int result;struct tracker_thread_data *pThreadData;struct fast_task_info *pTask;char szClientIp[IP_ADDRESS_SIZE];in_addr_t client_addr;while (1){if ((bytes=read(sock, &incomesock, sizeof(incomesock))) < 0) //得到incomesock。{if (!(errno == EAGAIN || errno == EWOULDBLOCK)){}break;}else if (bytes == 0){break;}if (incomesock < 0){struct timeval tv;                        tv.tv_sec = 1;                        tv.tv_usec = 0;pThreadData = g_thread_data + (-1 * incomesock - 1) % \g_work_threads;event_base_loopexit(pThreadData->ev_base, &tv);return;}client_addr = getPeerIpaddr(incomesock, \szClientIp, IP_ADDRESS_SIZE);if (g_allow_ip_count >= 0){if (bsearch(&client_addr, g_allow_ip_addrs, \g_allow_ip_count, sizeof(in_addr_t), \cmp_by_ip_addr_t) == NULL){close(incomesock);continue;}}if (tcpsetnonblockopt(incomesock) != 0){close(incomesock);continue;}pTask = free_queue_pop();  //从队列中取出一个结构体来处理。该队列在tracker_service_init中初始化。if (pTask == NULL){close(incomesock);continue;}pThreadData = g_thread_data + incomesock % g_work_threads; //管理该线程的结构体strcpy(pTask->client_ip, szClientIp);event_set(&pTask->ev_read, incomesock, EV_READ, \client_sock_read, pTask);          //对该线程设置读事件if (event_base_set(pThreadData->ev_base, &pTask->ev_read) != 0){task_finish_clean_up(pTask);close(incomesock);continue;}event_set(&pTask->ev_write, incomesock, EV_WRITE, \client_sock_write, pTask);        //对该线程设置写事件（注意尚未添加）if ((result=event_base_set(pThreadData->ev_base, \&pTask->ev_write)) != 0){task_finish_clean_up(pTask);close(incomesock);continue;}if (event_add(&pTask->ev_read, &g_network_tv) != 0)  //添加读事件(含超时)，注意还没有添加写事件{task_finish_clean_up(pTask);close(incomesock);continue;}}}

二、client_sock_read

上文添加的读事件发生或超时时会回调该函数。

static void client_sock_read(int sock, short event, void *arg){int bytes;int recv_bytes;struct fast_task_info *pTask;pTask = (struct fast_task_info *)arg;if (event == EV_TIMEOUT){if (pTask->offset == 0 && pTask->req_count > 0)  //req_count为request count.（？）{if (event_add(&pTask->ev_read, &g_network_tv) != 0) //重新设置等待事件{close(pTask->ev_read.ev_fd);task_finish_clean_up(pTask);}}else{close(pTask->ev_read.ev_fd);task_finish_clean_up(pTask);}return;}while (1){if (pTask->length == 0) //recv header{recv_bytes = sizeof(TrackerHeader) - pTask->offset;}else{recv_bytes = pTask->length - pTask->offset;}bytes = recv(sock, pTask->data + pTask->offset, recv_bytes, 0);if (bytes < 0){if (errno == EAGAIN || errno == EWOULDBLOCK){if(event_add(&pTask->ev_read, &g_network_tv)!=0){close(pTask->ev_read.ev_fd);task_finish_clean_up(pTask);}}else{close(pTask->ev_read.ev_fd);task_finish_clean_up(pTask);}return;}else if (bytes == 0){close(pTask->ev_read.ev_fd);task_finish_clean_up(pTask);return;}if (pTask->length == 0) //header{if (pTask->offset + bytes < sizeof(TrackerHeader)){if (event_add(&pTask->ev_read, &g_network_tv)!=0){close(pTask->ev_read.ev_fd);}pTask->offset += bytes;return;}pTask->length = buff2long(((TrackerHeader *) \pTask->data)->pkg_len);if (pTask->length < 0){close(pTask->ev_read.ev_fd);task_finish_clean_up(pTask);return;}pTask->length += sizeof(TrackerHeader);if (pTask->length > TRACKER_MAX_PACKAGE_SIZE){close(pTask->ev_read.ev_fd);task_finish_clean_up(pTask);return;}}pTask->offset += bytes;if (pTask->offset >= pTask->length) //recv done{pTask->req_count++;   //rec_count++，请求个数+1tracker_deal_task(pTask);return;}}return;}

三、tracker_deal_task

int tracker_deal_task(struct fast_task_info *pTask){TrackerHeader *pHeader;int result;pHeader = (TrackerHeader *)pTask->data;switch(pHeader->cmd){case TRACKER_PROTO_CMD_STORAGE_BEAT:TRACKER_CHECK_LOGINED(pTask)result = tracker_deal_storage_beat(pTask);break;case TRACKER_PROTO_CMD_STORAGE_SYNC_REPORT:TRACKER_CHECK_LOGINED(pTask)result = tracker_deal_storage_sync_report(pTask);break;case TRACKER_PROTO_CMD_STORAGE_REPORT_DISK_USAGE:TRACKER_CHECK_LOGINED(pTask)result = tracker_deal_storage_df_report(pTask);break;case TRACKER_PROTO_CMD_STORAGE_JOIN:result = tracker_deal_storage_join(pTask);break;case TRACKER_PROTO_CMD_STORAGE_REPORT_STATUS:result = tracker_deal_storage_report_status(pTask);break;case TRACKER_PROTO_CMD_STORAGE_GET_STATUS:result = tracker_deal_server_get_storage_status(pTask);break;case TRACKER_PROTO_CMD_STORAGE_GET_SERVER_ID:result = tracker_deal_get_storage_id(pTask);break;case TRACKER_PROTO_CMD_STORAGE_FETCH_STORAGE_IDS:result = tracker_deal_fetch_storage_ids(pTask);break;case TRACKER_PROTO_CMD_STORAGE_REPLICA_CHG:TRACKER_CHECK_LOGINED(pTask)result = tracker_deal_storage_replica_chg(pTask);break;case TRACKER_PROTO_CMD_SERVICE_QUERY_FETCH_ONE:result = tracker_deal_service_query_fetch_update( \pTask, pHeader->cmd);break;case TRACKER_PROTO_CMD_SERVICE_QUERY_UPDATE:result = tracker_deal_service_query_fetch_update( \pTask, pHeader->cmd);break;case TRACKER_PROTO_CMD_SERVICE_QUERY_FETCH_ALL:result = tracker_deal_service_query_fetch_update( \pTask, pHeader->cmd);break;case TRACKER_PROTO_CMD_SERVICE_QUERY_STORE_WITHOUT_GROUP_ONE:result = tracker_deal_service_query_storage( \pTask, pHeader->cmd);break;case TRACKER_PROTO_CMD_SERVICE_QUERY_STORE_WITH_GROUP_ONE:result = tracker_deal_service_query_storage( \pTask, pHeader->cmd);break;case TRACKER_PROTO_CMD_SERVICE_QUERY_STORE_WITHOUT_GROUP_ALL:result = tracker_deal_service_query_storage( \pTask, pHeader->cmd);break;case TRACKER_PROTO_CMD_SERVICE_QUERY_STORE_WITH_GROUP_ALL:result = tracker_deal_service_query_storage( \pTask, pHeader->cmd);break;case TRACKER_PROTO_CMD_SERVER_LIST_ONE_GROUP:result = tracker_deal_server_list_one_group(pTask);break;case TRACKER_PROTO_CMD_SERVER_LIST_ALL_GROUPS:result = tracker_deal_server_list_all_groups(pTask);break;case TRACKER_PROTO_CMD_SERVER_LIST_STORAGE:result = tracker_deal_server_list_group_storages(pTask);break;case TRACKER_PROTO_CMD_STORAGE_SYNC_SRC_REQ:result = tracker_deal_storage_sync_src_req(pTask);break;case TRACKER_PROTO_CMD_STORAGE_SYNC_DEST_REQ:TRACKER_CHECK_LOGINED(pTask)result = tracker_deal_storage_sync_dest_req(pTask);break;case TRACKER_PROTO_CMD_STORAGE_SYNC_NOTIFY:result = tracker_deal_storage_sync_notify(pTask);break;case TRACKER_PROTO_CMD_STORAGE_SYNC_DEST_QUERY:result = tracker_deal_storage_sync_dest_query(pTask);break;case TRACKER_PROTO_CMD_SERVER_DELETE_STORAGE:result = tracker_deal_server_delete_storage(pTask);break;case TRACKER_PROTO_CMD_SERVER_SET_TRUNK_SERVER:result = tracker_deal_server_set_trunk_server(pTask);break;case TRACKER_PROTO_CMD_STORAGE_REPORT_IP_CHANGED:result = tracker_deal_storage_report_ip_changed(pTask);break;case TRACKER_PROTO_CMD_STORAGE_CHANGELOG_REQ:result = tracker_deal_changelog_req(pTask);break;case TRACKER_PROTO_CMD_STORAGE_PARAMETER_REQ:result = tracker_deal_parameter_req(pTask);break;case FDFS_PROTO_CMD_QUIT:close(pTask->ev_read.ev_fd);task_finish_clean_up(pTask);return 0;case FDFS_PROTO_CMD_ACTIVE_TEST:result = tracker_deal_active_test(pTask);break;case TRACKER_PROTO_CMD_TRACKER_GET_STATUS:result = tracker_deal_get_tracker_status(pTask);break;case TRACKER_PROTO_CMD_TRACKER_GET_SYS_FILES_START:result = tracker_deal_get_sys_files_start(pTask);break;case TRACKER_PROTO_CMD_TRACKER_GET_ONE_SYS_FILE:result = tracker_deal_get_one_sys_file(pTask);break;case TRACKER_PROTO_CMD_TRACKER_GET_SYS_FILES_END:result = tracker_deal_get_sys_files_end(pTask);break;case TRACKER_PROTO_CMD_STORAGE_REPORT_TRUNK_FID:TRACKER_CHECK_LOGINED(pTask)result = tracker_deal_report_trunk_fid(pTask);break;case TRACKER_PROTO_CMD_STORAGE_FETCH_TRUNK_FID:TRACKER_CHECK_LOGINED(pTask)result = tracker_deal_get_trunk_fid(pTask);break;case TRACKER_PROTO_CMD_STORAGE_REPORT_TRUNK_FREE:TRACKER_CHECK_LOGINED(pTask)result = tracker_deal_report_trunk_free_space(pTask);break;case TRACKER_PROTO_CMD_TRACKER_PING_LEADER:result = tracker_deal_ping_leader(pTask);break;case TRACKER_PROTO_CMD_TRACKER_NOTIFY_NEXT_LEADER:result = tracker_deal_notify_next_leader(pTask);break;case TRACKER_PROTO_CMD_TRACKER_COMMIT_NEXT_LEADER:result = tracker_deal_commit_next_leader(pTask);break;default:logError("file: "__FILE__", line: %d, "  \"client ip: %s, unkown cmd: %d", \__LINE__, pTask->client_ip, \pHeader->cmd);result = EINVAL;break;}pHeader = (TrackerHeader *)pTask->data;pHeader->status = result;pHeader->cmd = TRACKER_PROTO_CMD_RESP;long2buff(pTask->length - sizeof(TrackerHeader), pHeader->pkg_len);send_add_event(pTask); //调用client_sock_write(pTask->ev_write.ev_fd, EV_WRITE, pTask);直接发送。                               //注意到之前只初始化了写事件，并没有event_add写事件。return 0;}

四、client_sock_write

//在send数据之后，调用以下部分：if (pTask->offset >= pTask->length){pTask->offset = 0;pTask->length  = 0;if ((result=event_add(&pTask->ev_read, \&g_network_tv)) != 0) //一轮发送任务完成，继续监听读事件。{close(pTask->ev_read.ev_fd);task_finish_clean_up(pTask);return;}return;}