MySQL：半同步（二）主库端回调函数

作者简介：高鹏，笔名八怪。《深入理解MySQL主从原理》图书作者，同时运营个人公众号“MySQL学习”，持续分享遇到的有趣case以及代码解析！

源码版本5.7.29。主库端的回调函数比较多，比较复杂。

一、回调函数：repl_semi_binlog_dump_start

调用线程：dump线程

#0  repl_semi_binlog_dump_start (param=0x7fffe8150ba0, log_file=0x7fffe81520c0 "", log_pos=4) at /home/mysql/soft/percona-server-5.7.29-32/plugin/semisync/semisync_master_plugin.cc:127 #1  0x00000000013dca8e in Binlog_transmit_delegate::transmit_start (this=0x2d1c980 , thd=0x7ffdec000b90, flags=0, log_file=0x7fffe81520c0 "", log_pos=4,      observe_transmission=0x7fffe8151e24) at /home/mysql/soft/percona-server-5.7.29-32/sql/rpl_handler.cc:726 #2  0x000000000182233e in Binlog_sender::init (this=0x7fffe8151490) at /home/mysql/soft/percona-server-5.7.29-32/sql/rpl_binlog_sender.cc:119 #3  0x0000000001822611 in Binlog_sender::run (this=0x7fffe8151490) at /home/mysql/soft/percona-server-5.7.29-32/sql/rpl_binlog_sender.cc:208 #4  0x000000000182040a in mysql_binlog_send (thd=0x7ffdec000b90, log_ident=0x7fffe81520c0 "", pos=4, slave_gtid_executed=0x7fffe8151e90, flags=0)     at /home/mysql/soft/percona-server-5.7.29-32/sql/rpl_master.cc:421 #5  0x00000000018202d6 in com_binlog_dump_gtid (thd=0x7ffdec000b90, packet=0x7ffdec00a8b1 "", packet_length=123) at /home/mysql/soft/percona-server-5.7.29-32/sql/rpl_master.cc:405 #6  0x00000000014b76ef in dispatch_command (thd=0x7ffdec000b90, com_data=0x7fffe8152c90, command=COM_BINLOG_DUMP_GTID) at /home/mysql/soft/percona-server-5.7.29-32/sql/sql_parse.cc:1754 #7  0x00000000014b5a94 in do_command (thd=0x7ffdec000b90) at /home/mysql/soft/percona-server-5.7.29-32/sql/sql_parse.cc:1060 #8  0x00000000015e9d32 in handle_connection (arg=0x7019220) at /home/mysql/soft/percona-server-5.7.29-32/sql/conn_handler/connection_handler_per_thread.cc:325 #9  0x00000000018b97f2 in pfs_spawn_thread (arg=0x6f595f0) at /home/mysql/soft/percona-server-5.7.29-32/storage/perfschema/pfs.cc:2198 #10 0x00007ffff7bc6ea5 in start_thread () from /lib64/libpthread.so.0 #11 0x00007ffff5f2b8dd in clone () from /lib64/libc.so.6