标签:
第一次这么近距离的接触源码,有点兴奋,又有点不知所措,尼玛随便一个源文件都有几千行,你说怎么看,还有一些数不清的数据结构,函数,类等乱七八糟的东西。
我装的mysql版本是5.7.12,然后运行平台是centos 6.5 x64 (应该是x64)。
启动gdb
gdb --args /usr/local/mysql-5.7.12/bin/mysqld
也可以用如下,如果你设置了链接的话
gdb --args mysqld
然后你就进入了gdb的环境中
在此呢,我们可以用b 函数名来添加断点
这个个断点是我在mysqld.cc的源文件中找的一个函数,随便瞎找的一个。
然后用下面的这个命令来启动mysqld
然后就是gdb c,c的意思是继续的意思,刚刚run --defaults-file=/etc/my.cnf --user=root已经运行了,而且到达设置的断点mysqld_main
如果此时我们用另一个客户端service mysql status一下的话
发现mysql的服务并没有启动
于是我们继续在gdb中输入命令c
...
并且这里是等待模式,没有出现(gdb)
然后在另一可以客户端继续service mysql status一下的话
会发现mysql的服务已经启动了
继续在这个客户端操作,登录mysql
mysql -uroot -hlocalhost -p
发现可以成功的登录进去了
然后再看看调试环境下
可以发现出现了一个新的线程,应该是客户端连接的线程吧。
然后退出mysql,exit,发现gdb环境下没啥变化,没有说线程结束了什么的。
但是如果我们重新开一个客户端登录mysql,又会多出一个线程
关闭了客户端仍然没有发现这两个线程退出的迹象。
当在一个客户端关闭mysql服务的时候,service mysql stop,
会发现在gdb出现了这个
然后
Shutting down MySQL......................................这个点点无限循环下去
于是在gdb环境下,输入命令c
(gdb) c Continuing. 2016-05-03T10:49:28.524672Z 0 [Note] InnoDB: page_cleaner: 1000ms intended loop took 180093ms. The settings might not be optimal. (flushed=0 and evicted=0, during the time.) [Thread 0x7fff957fb700 (LWP 4113) exited] [Thread 0x7fffb8c82700 (LWP 4162) exited] 2016-05-03T10:49:28.569814Z 0 [Note] Giving 0 client threads a chance to die gracefully 2016-05-03T10:49:28.569875Z 0 [Note] Shutting down slave threads 2016-05-03T10:49:28.569896Z 0 [Note] Forcefully disconnecting 0 remaining clients 2016-05-03T10:49:28.569912Z 0 [Note] Event Scheduler: Purging the queue. 0 events [Thread 0x7fffb8cc3700 (LWP 4135) exited] 2016-05-03T10:49:28.578091Z 0 [Note] Binlog end 2016-05-03T10:49:28.581076Z 0 [Note] Shutting down plugin ‘ngram‘ 2016-05-03T10:49:28.581127Z 0 [Note] Shutting down plugin ‘ARCHIVE‘ 2016-05-03T10:49:28.581135Z 0 [Note] Shutting down plugin ‘partition‘ 2016-05-03T10:49:28.581139Z 0 [Note] Shutting down plugin ‘BLACKHOLE‘ 2016-05-03T10:49:28.581170Z 0 [Note] Shutting down plugin ‘CSV‘ 2016-05-03T10:49:28.581180Z 0 [Note] Shutting down plugin ‘MEMORY‘ 2016-05-03T10:49:28.581189Z 0 [Note] Shutting down plugin ‘MyISAM‘ 2016-05-03T10:49:28.581240Z 0 [Note] Shutting down plugin ‘MRG_MYISAM‘ 2016-05-03T10:49:28.581250Z 0 [Note] Shutting down plugin ‘PERFORMANCE_SCHEMA‘ 2016-05-03T10:49:28.581321Z 0 [Note] Shutting down plugin ‘INNODB_SYS_VIRTUAL‘ 2016-05-03T10:49:28.581337Z 0 [Note] Shutting down plugin ‘INNODB_SYS_DATAFILES‘ 2016-05-03T10:49:28.581341Z 0 [Note] Shutting down plugin ‘INNODB_SYS_TABLESPACES‘ 2016-05-03T10:49:28.581345Z 0 [Note] Shutting down plugin ‘INNODB_SYS_FOREIGN_COLS‘ 2016-05-03T10:49:28.581349Z 0 [Note] Shutting down plugin ‘INNODB_SYS_FOREIGN‘ 2016-05-03T10:49:28.581352Z 0 [Note] Shutting down plugin ‘INNODB_SYS_FIELDS‘ 2016-05-03T10:49:28.581356Z 0 [Note] Shutting down plugin ‘INNODB_SYS_COLUMNS‘ 2016-05-03T10:49:28.581363Z 0 [Note] Shutting down plugin ‘INNODB_SYS_INDEXES‘ 2016-05-03T10:49:28.581367Z 0 [Note] Shutting down plugin ‘INNODB_SYS_TABLESTATS‘ 2016-05-03T10:49:28.581370Z 0 [Note] Shutting down plugin ‘INNODB_SYS_TABLES‘ 2016-05-03T10:49:28.581374Z 0 [Note] Shutting down plugin ‘INNODB_FT_INDEX_TABLE‘ 2016-05-03T10:49:28.581377Z 0 [Note] Shutting down plugin ‘INNODB_FT_INDEX_CACHE‘ 2016-05-03T10:49:28.581381Z 0 [Note] Shutting down plugin ‘INNODB_FT_CONFIG‘ 2016-05-03T10:49:28.581411Z 0 [Note] Shutting down plugin ‘INNODB_FT_BEING_DELETED‘ 2016-05-03T10:49:28.581417Z 0 [Note] Shutting down plugin ‘INNODB_FT_DELETED‘ 2016-05-03T10:49:28.581420Z 0 [Note] Shutting down plugin ‘INNODB_FT_DEFAULT_STOPWORD‘ 2016-05-03T10:49:28.581424Z 0 [Note] Shutting down plugin ‘INNODB_METRICS‘ 2016-05-03T10:49:28.581428Z 0 [Note] Shutting down plugin ‘INNODB_TEMP_TABLE_INFO‘ 2016-05-03T10:49:28.581431Z 0 [Note] Shutting down plugin ‘INNODB_BUFFER_POOL_STATS‘ 2016-05-03T10:49:28.581435Z 0 [Note] Shutting down plugin ‘INNODB_BUFFER_PAGE_LRU‘ 2016-05-03T10:49:28.581438Z 0 [Note] Shutting down plugin ‘INNODB_BUFFER_PAGE‘ 2016-05-03T10:49:28.581442Z 0 [Note] Shutting down plugin ‘INNODB_CMP_PER_INDEX_RESET‘ 2016-05-03T10:49:28.581445Z 0 [Note] Shutting down plugin ‘INNODB_CMP_PER_INDEX‘ 2016-05-03T10:49:28.581449Z 0 [Note] Shutting down plugin ‘INNODB_CMPMEM_RESET‘ 2016-05-03T10:49:28.581452Z 0 [Note] Shutting down plugin ‘INNODB_CMPMEM‘ 2016-05-03T10:49:28.581456Z 0 [Note] Shutting down plugin ‘INNODB_CMP_RESET‘ 2016-05-03T10:49:28.581459Z 0 [Note] Shutting down plugin ‘INNODB_CMP‘ 2016-05-03T10:49:28.581463Z 0 [Note] Shutting down plugin ‘INNODB_LOCK_WAITS‘ 2016-05-03T10:49:28.581466Z 0 [Note] Shutting down plugin ‘INNODB_LOCKS‘ 2016-05-03T10:49:28.581470Z 0 [Note] Shutting down plugin ‘INNODB_TRX‘ 2016-05-03T10:49:28.581473Z 0 [Note] Shutting down plugin ‘InnoDB‘ [Thread 0x7fffb8d04700 (LWP 4112) exited] 2016-05-03T10:49:28.581822Z 0 [Note] InnoDB: FTS optimize thread exiting. 2016-05-03T10:49:28.590938Z 0 [Note] InnoDB: Starting shutdown... [Thread 0x7fff96bfd700 (LWP 4110) exited] [Thread 0x7fff975fe700 (LWP 4109) exited] 2016-05-03T10:49:28.691896Z 0 [Note] InnoDB: Dumping buffer pool(s) to /usr/local/mysql-5.7.12/data/ib_buffer_pool 2016-05-03T10:49:28.692817Z 0 [Note] InnoDB: Buffer pool(s) dump completed at 160503 18:49:28 [Thread 0x7fffb0dbd700 (LWP 4101) exited] [Thread 0x7fff961fc700 (LWP 4111) exited] [Thread 0x7fffb17be700 (LWP 4100) exited] [Thread 0x7fff97fff700 (LWP 4108) exited] [Thread 0x7fffabfff700 (LWP 4102) exited] [Thread 0x7fffa8dfa700 (LWP 4107) exited] [Thread 0x7fffaabfd700 (LWP 4104) exited] [Thread 0x7fffa97fb700 (LWP 4106) exited] [Thread 0x7fffaa1fc700 (LWP 4105) exited] [Thread 0x7fffb23e5700 (LWP 4098) exited] [Thread 0x7fffab5fe700 (LWP 4103) exited] [Thread 0x7fffb37e7700 (LWP 4096) exited] [Thread 0x7fffb2de6700 (LWP 4097) exited] [Thread 0x7fffb87ef700 (LWP 4088) exited] [Thread 0x7fffb41e8700 (LWP 4095) exited] [Thread 0x7fffb4be9700 (LWP 4094) exited] [Thread 0x7fffb55ea700 (LWP 4093) exited] [Thread 0x7fffb69ec700 (LWP 4091) exited] [Thread 0x7fffb5feb700 (LWP 4092) exited] [Thread 0x7fffb73ed700 (LWP 4090) exited] [Thread 0x7fffb7dee700 (LWP 4089) exited] 2016-05-03T10:49:29.967622Z 0 [Note] InnoDB: Shutdown completed; log sequence number 2739027 2016-05-03T10:49:29.970363Z 0 [Note] InnoDB: Removed temporary tablespace data file: "ibtmp1" 2016-05-03T10:49:29.970416Z 0 [Note] Shutting down plugin ‘sha256_password‘ 2016-05-03T10:49:29.970422Z 0 [Note] Shutting down plugin ‘mysql_native_password‘ 2016-05-03T10:49:29.970683Z 0 [Note] Shutting down plugin ‘binlog‘ 2016-05-03T10:49:29.971711Z 0 [Note] /usr/local/mysql-5.7.12/bin/mysqld: Shutdown complete [Thread 0x7fffeeeec700 (LWP 4087) exited] Program exited normally. (gdb)
然后即使就是程序退出是的各种动作,哗啦啦一片。
然后再看那个关闭mysql服务的客户端
可以发现mysql服务已经彻底关闭了。
上面是初次用gdb来运行mysqld的过程,只能算是初涉吧。
标签:
原文地址:http://www.cnblogs.com/tuhooo/p/5454432.html