启动redis命令：src/redis-server redis.conf
30408:C 13 Jan 2021 17:29:52.662 # oO0OoO0OoO0Oo Redis is starting oO0OoO0OoO0Oo
30408:C 13 Jan 2021 17:29:52.662 # Redis version=5.0.4, bits=64, commit=00000000, modified=0, pid=30408, just started
30408:C 13 Jan 2021 17:29:52.662 # Configuration loaded 第二步 加载配置_._                                                  _.-``__ ''-._                                             _.-``    `.  `_.  ''-._           Redis 5.0.4 (00000000/0) 64 bit.-`` .-```.  ```/    _.,_ ''-._                                   (    '      ,       .-`  | `,    )     Running in standalone mode|`-._`-...-` __...-.``-._|'` _.-'|     Port: 6379   redis服务器的端口号|    `-._   `._    /     _.-'    |     PID: 30408    redis的进程号`-._    `-._  `-./  _.-'    _.-'                                   |`-._`-._    `-.__.-'    _.-'_.-'|                                  |    `-._`-._        _.-'_.-'    |           http://redis.io        `-._    `-._`-.__.-'_.-'    _.-'                                   |`-._`-._    `-.__.-'    _.-'_.-'|                                  |    `-._`-._        _.-'_.-'    |                                  `-._    `-._`-.__.-'_.-'    _.-'                                   `-._    `-.__.-'    _.-'                                       `-._        _.-'                                           `-.__.-'                                               30408:M 13 Jan 2021 17:29:52.664 # WARNING: The TCP backlog setting of 511 cannot be enforced because /proc/sys/net/core/somaxconn is set to the lower value of 128.
30408:M 13 Jan 2021 17:29:52.664 # Server initialized  第三步 执行initServer函数，初始化服务器的数据结构
30408:M 13 Jan 2021 17:29:52.664 # WARNING overcommit_memory is set to 0! Background save may fail under low memory condition. To fix this issue add 'vm.overcommit_memory = 1' to /etc/sysctl.conf and then reboot or run the command 'sysctl vm.overcommit_memory=1' for this to take effect.
30408:M 13 Jan 2021 17:29:52.664 # WARNING you have Transparent Huge Pages (THP) support enabled in your kernel. This will create latency and memory usage issues with Redis. To fix this issue run the command 'echo never > /sys/kernel/mm/transparent_hugepage/enabled' as root, and add it to your /etc/rc.local in order to retain the setting after a reboot. Redis must be restarted after THP is disabled.
30408:M 13 Jan 2021 17:29:52.664 * DB loaded from disk: 0.000 seconds  第四步操作结束后，会打印
30408:M 13 Jan 2021 17:29:52.664 * Ready to accept connections 第五步操作结束后，会打印      

30408:C 13 Jan 2021 17:29:52.662 # Configuration loaded

               _._                                                  _.-``__ ''-._                                             _.-``    `.  `_.  ''-._           Redis 5.0.4 (00000000/0) 64 bit.-`` .-```.  ```/    _.,_ ''-._                                   (    '      ,       .-`  | `,    )     Running in standalone mode|`-._`-...-` __...-.``-._|'` _.-'|     Port: 6379   redis服务器的端口号|    `-._   `._    /     _.-'    |     PID: 30408    redis的进程号`-._    `-._  `-./  _.-'    _.-'                                   |`-._`-._    `-.__.-'    _.-'_.-'|                                  |    `-._`-._        _.-'_.-'    |           http://redis.io        `-._    `-._`-.__.-'_.-'    _.-'                                   |`-._`-._    `-.__.-'    _.-'_.-'|                                  |    `-._`-._        _.-'_.-'    |                                  `-._    `-._`-.__.-'_.-'    _.-'                                   `-._    `-.__.-'    _.-'                                       `-._        _.-'                                           `-.__.-'                                               30408:M 13 Jan 2021 17:29:52.664 # WARNING: The TCP backlog setting of 511 cannot be enforced because /proc/sys/net/core/somaxconn is set to the lower value of 128.
30408:M 13 Jan 2021 17:29:52.664 # Server initialized

30408:M 13 Jan 2021 17:29:52.664 * DB loaded from disk: 0.000 seconds

30408:M 13 Jan 2021 17:29:52.664 * Ready to accept connections

int main(int argc, char **argv) {第一步：省略很多代码...initServerConfig();第二步：省略很多代码...loadServerConfig(server.configfile, config_from_stdin, options);第三步：省略很多代码...initServer();第四步：省略很多代码...loadDataFromDisk();serverLog(LL_NOTICE,"DB loaded from disk: %.3f seconds",(float)(ustime()-start)/1000000);第五步：省略很多代码...serverLog(LL_NOTICE,"Ready to accept connections");
}

void initServerConfig(void) {int j;pthread_mutex_init(&server.next_client_id_mutex,NULL);pthread_mutex_init(&server.lruclock_mutex,NULL);pthread_mutex_init(&server.unixtime_mutex,NULL);updateCachedTime(1);getRandomHexChars(server.runid,CONFIG_RUN_ID_SIZE);server.runid[CONFIG_RUN_ID_SIZE] = '0';  //运行idchangeReplicationId();clearReplicationId2();server.timezone = getTimeZone(); /* Initialized by tzset(). */  时间server.configfile = NULL;server.executable = NULL;server.hz = server.config_hz = CONFIG_DEFAULT_HZ; 默认频率，这个用来控制serverCron函数，每秒执行的次数server.dynamic_hz = CONFIG_DEFAULT_DYNAMIC_HZ;server.arch_bits = (sizeof(long) == 8) ? 64 : 32;server.port = CONFIG_DEFAULT_SERVER_PORT; 端口server.tcp_backlog = CONFIG_DEFAULT_TCP_BACKLOG;server.bindaddr_count = 0;...省略很多代码，真的超级无敌多,但都是初始化默认值}

void initServer(void) {int j;signal(SIGHUP, SIG_IGN);signal(SIGPIPE, SIG_IGN);setupSignalHandlers();if (server.syslog_enabled) {openlog(server.syslog_ident, LOG_PID | LOG_NDELAY | LOG_NOWAIT,server.syslog_facility);}server.hz = server.config_hz;   频率server.pid = getpid();   进程idserver.current_client = NULL;server.fixed_time_expire = 0;server.clients = listCreate();server.clients_index = raxNew();server.clients_to_close = listCreate();server.slaves = listCreate();server.monitors = listCreate();server.clients_pending_write = listCreate();server.slaveseldb = -1; /* Force to emit the first SELECT command. */server.unblocked_clients = listCreate();server.ready_keys = listCreate();server.clients_waiting_acks = listCreate();server.get_ack_from_slaves = 0;server.clients_paused = 0;server.system_memory_size = zmalloc_get_memory_size();...省略很多代码}

void loadDataFromDisk(void) {long long start = ustime();if (server.aof_state == AOF_ON) {  首先，判断AOF是否开启，如果开启，就尝试加载AOF文件if (loadAppendOnlyFile(server.aof_filename) == C_OK)serverLog(LL_NOTICE,"DB loaded from append only file: %.3f seconds",(float)(ustime()-start)/1000000);} else {rdbSaveInfo rsi = RDB_SAVE_INFO_INIT;  加载RDB文件if (rdbLoad(server.rdb_filename,&rsi) == C_OK) {serverLog(LL_NOTICE,"DB loaded from disk: %.3f seconds",(float)(ustime()-start)/1000000);   这个就是打印出来的日志/* Restore the replication ID / offset from the RDB file. */if ((server.masterhost ||(server.cluster_enabled &&nodeIsSlave(server.cluster->myself))) &&rsi.repl_id_is_set &&rsi.repl_offset != -1 &&/* Note that older implementations may save a repl_stream_db* of -1 inside the RDB file in a wrong way, see more* information in function rdbPopulateSaveInfo. */rsi.repl_stream_db != -1){memcpy(server.replid,rsi.repl_id,sizeof(server.replid));server.master_repl_offset = rsi.repl_offset;/* If we are a slave, create a cached master from this* information, in order to allow partial resynchronizations* with masters. */replicationCacheMasterUsingMyself();selectDb(server.cached_master,rsi.repl_stream_db);}} else if (errno != ENOENT) {serverLog(LL_WARNING,"Fatal error loading the DB: %s. Exiting.",strerror(errno));exit(1);}}
}