欢迎关注我的《深入理解MySQL主从原理 32讲 》，如下：
一、问题
是什么
二、找到影响位置
整个寻找过程应该找到key_BINLOG_COND_done这个取值，然后去看他是在那里被定义到相应的mutex/cond上，然后查找mutex/cond的作用即可。
- 定义：
- PSI_cond_info all_server_conds[]=
{
{ &key_PAGE_cond, "PAGE::cond", 0},
{ &key_COND_active, "TC_LOG_MMAP::COND_active", 0},
{ &key_COND_pool, "TC_LOG_MMAP::COND_pool", 0},
{ &key_BINLOG_COND_done, "MYSQL_BIN_LOG::COND_done", 0},
{ &key_BINLOG_update_cond, "MYSQL_BIN_LOG::update_cond", 0},
注册：
register_cond_class- 初始化：
MYSQL_BIN_LOG::set_psi_keys
建立条件变量：
Stage_manager::init
- 使用：
*/
if (!leader) //如果不是 leader
{
mysql_mutex_lock(&m_lock_done);//加锁
while (thd->get_transaction()->m_flags.pending) //唤醒时 设置每个事物的状态 为ture
mysql_cond_wait(&m_cond_done, &m_lock_done);//释放锁 等待条件满足 pending=false
mysql_mutex_unlock(&m_lock_done);//解锁
}- 栈帧
Breakpoint 2, MYSQL_BIN_LOG::set_psi_keys (this=0x2e83640, key_LOCK_index=7, key_LOCK_commit=3, key_LOCK_commit_queue=4, key_LOCK_done=5, key_LOCK_flush_queue=6,
key_LOCK_log=8, key_LOCK_binlog_end_pos=9, key_LOCK_sync=10, key_LOCK_sync_queue=11, key_LOCK_xids=12, key_COND_done=4, key_update_cond=5, key_prep_xids_cond=6,
key_file_log=2, key_file_log_index=4, key_file_log_cache=3, key_file_log_index_cache=5) at /mysqldata/percona-server-locks-detail-5.7.22/sql/binlog.h:539
539 m_key_COND_done= key_COND_done;
(gdb) bt
#0 MYSQL_BIN_LOG::set_psi_keys (this=0x2e83640, key_LOCK_index=7, key_LOCK_commit=3, key_LOCK_commit_queue=4, key_LOCK_done=5, key_LOCK_flush_queue=6,
key_LOCK_log=8, key_LOCK_binlog_end_pos=9, key_LOCK_sync=10, key_LOCK_sync_queue=11, key_LOCK_xids=12, key_COND_done=4, key_update_cond=5, key_prep_xids_cond=6,
key_file_log=2, key_file_log_index=4, key_file_log_cache=3, key_file_log_index_cache=5) at /mysqldata/percona-server-locks-detail-5.7.22/sql/binlog.h:539
#1 0x0000000000edcee4 in init_common_variables () at /mysqldata/percona-server-locks-detail-5.7.22/sql/mysqld.cc:2974
#2 0x0000000000ee117f in mysqld_main (argc=82, argv=0x2f26738) at /mysqldata/percona-server-locks-detail-5.7.22/sql/mysqld.cc:4938
#3 0x0000000000ed8504 in main (argc=4, argv=0x7fffffffe3f8) at /mysqldata/percona-server-locks-detail-5.7.22/sql/main.cc:25
建立条件变量
Breakpoint 3, Stage_manager::init (this=0x2e84858, key_LOCK_flush_queue=6, key_LOCK_sync_queue=11, key_LOCK_commit_queue=4, key_LOCK_done=5, key_COND_done=4)
at /mysqldata/percona-server-locks-detail-5.7.22/sql/binlog.h:156
156 mysql_mutex_init(key_LOCK_done, &m_lock_done, MY_MUTEX_INIT_FAST);
(gdb) bt
#0 Stage_manager::init (this=0x2e84858, key_LOCK_flush_queue=6, key_LOCK_sync_queue=11, key_LOCK_commit_queue=4, key_LOCK_done=5, key_COND_done=4)
at /mysqldata/percona-server-locks-detail-5.7.22/sql/binlog.h:156
#1 0x000000000187cbea in MYSQL_BIN_LOG::init_pthread_objects (this=0x2e83640) at /mysqldata/percona-server-locks-detail-5.7.22/sql/binlog.cc:3601
#2 0x0000000000edcef3 in init_common_variables () at /mysqldata/percona-server-locks-detail-5.7.22/sql/mysqld.cc:2983
#3 0x0000000000ee117f in mysqld_main (argc=82, argv=0x2f26738) at /mysqldata/percona-server-locks-detail-5.7.22/sql/mysqld.cc:4938
#4 0x0000000000ed8504 in main (argc=4, argv=0x7fffffffe3f8) at /mysqldata/percona-server-locks-detail-5.7.22/sql/main.cc:25
