Tornado’s own interfaces (such as tornado.web) directly instead of using WSGI. In general, Tornado code is not thread-safe. The only method in Tornado that is safe to call from other threads is IOLoop.add_callback referencing any Tornado objects. run_in_executor is the recommended way to interact with blocking code. 7Tornado Documentation, Release 6.5.1 8 Chapter 3. Threads and WSGICHAPTER FOUR ASYNCIO INTEGRATION concurrent connections, Tornado uses a single-threaded event loop. This means that all appli- cation code should aim to be asynchronous and non-blocking because only one operation can be active at a time

Tornado’s own interfaces (such as tornado.web) directly instead of using WSGI. In general, Tornado code is not thread-safe. The only method in Tornado that is safe to call from other threads is IOLoop.add_callback referencing any Tornado objects. run_in_executor is the recommended way to interact with blocking code. asyncio Integration Tornado is integrated with the standard library asyncio [https://docs.python asyncio — Bridge between asyncio and Tornado Utilities tornado.autoreload — Automatically detect code changes in development tornado.concurrent — Work with Future objects tornado.log — Logging support

关键字和结构体名开头并后跟元组中的类型。例如，下面是两 个分别叫做 Color 和 Point 元组结构体的定义和用法： 文件名：src/main.rs struct Color(i32, i32, i32); struct Point(i32, i32, i32); fn main() { let black = Color(0, 0, 0); let origin = Point(0 0, 0); } 注意 black 和 origin 值的类型不同，因为它们是不同的元组结构体的实例。你定义的每一个 结构体有其自己的类型，即使结构体中的字段可能有着相同的类型。例如，一个获取 Color 类 型参数的函数不能接受 Point 作为参数，即便这两个类型都由三个 i32 值组成。除此之外， 元组结构体实例类似于元组，你可以将它们解构为单独的部分，也可以使用 . 后跟索引来访问 单独的 会成为这些值的所有者，如示例 8-22 所示： use std::collections::HashMap; let field_name = String::from("Favorite color"); let field_value = String::from("Blue"); let mut map = HashMap::new(); map.insert(field_name