mysql主从

  DBUG_PRINT("info", ("Creating new slave thread"));
  if (mysql_thread_create(thread_key, &th, &connection_attrib, h_func,
                          (void *)mi)) {
    LogErr(ERROR_LEVEL, ER_RPL_CANT_CREATE_SLAVE_THREAD,
           mi->get_for_channel_str());
    my_error(ER_SLAVE_THREAD, MYF(0));
    goto err;
  }

slave 线程

/**
  Slave SQL thread entry point.

  @param arg Pointer to Relay_log_info object that holds information
  for the SQL thread.

  @return Always 0.
*/
extern "C" void *handle_slave_sql(void *arg) {
  THD *thd; /* needs to be first for thread_stack */
  bool thd_added = false;
  bool main_loop_error = false;
  char llbuff[22], llbuff1[22];