If you setlink to null, a new database connection is created.
如果将link设为null，就会创建一个新的数据库连接。
2
You can setlink as a reference to an existing database connection link or object.
而link则可被设为对现有数据库连接或对象的一个引用。
3
BRSL stands for "branch relative and setlink." This branches to the function entry point and sets the link register (LR) to the next instruction for the return address.
brsl代表“branch relative and set link”，用来分支到函数的入口点并将链接寄存器(LR)设置为返回地址的下一个指令。