Persistant compile identifier. As an alternative to passing the same compile_id to each and every function call, you can set this compile_id and it will be used implicitly thereafter.永久的编译鉴别号.作为一个可选办法将相同的编译号传递给每个函数调用,你可以设置这个编译id,随后此id将会被隐含地使用.
