Introduction Asynchronous and non-Blocking I/O Coroutines Queue example - a concurrent web spider Structure of a Tornado web application Templates and UI Authentication and security Running and deploying server Coroutines and concurrency tornado.gen — Simplify asynchronous code tornado.concurrent — Work with threads and futures tornado.locks – Synchronization primitives tornado.queues – Queues for coroutines Parallelism Interleaving Looping Running in the background Queue example - a concurrent web spider Structure of a Tornado web application The Application object Subclassing RequestHandler Handling request

Introduction Asynchronous and non-Blocking I/O Coroutines Queue example - a concurrent web spider Structure of a Tornado web application Templates and UI Authentication and security Running and deploying Utilities tornado.autoreload — Automatically detect code changes in development tornado.concurrent — Work with Future objects tornado.log — Logging support tornado.options — Command-line parsing tornado.stack_context Parallelism Interleaving Looping Running in the background Queue example - a concurrent web spider Structure of a Tornado web application The Application object Subclassing RequestHandler Handling request

Introduction Asynchronous and non-Blocking I/O Coroutines Queue example - a concurrent web spider Structure of a Tornado web application Templates and UI Authentication and security Running and deploying Utilities tornado.autoreload — Automatically detect code changes in development tornado.concurrent — Work with Future objects tornado.log — Logging support tornado.options — Command-line parsing tornado.testing Parallelism Interleaving Looping Running in the background Queue example - a concurrent web spider Structure of a Tornado web application The main coroutine The Application object Subclassing RequestHandler

Introduction Asynchronous and non-Blocking I/O Coroutines Queue example - a concurrent web spider Structure of a Tornado web application Templates and UI Authentication and security Running and deploying Utilities tornado.autoreload — Automatically detect code changes in development tornado.concurrent — Work with Future objects tornado.log — Logging support tornado.options — Command-line parsing tornado.testing Parallelism Interleaving Looping Running in the background Queue example - a concurrent web spider Structure of a Tornado web application The main coroutine The Application object Subclassing RequestHandler

Introduction Asynchronous and non-Blocking I/O Coroutines Queue example - a concurrent web spider Structure of a Tornado web application Templates and UI Authentication and security Running and deploying Utilities tornado.autoreload — Automatically detect code changes in development tornado.concurrent — Work with Future objects tornado.log — Logging support tornado.options — Command-line parsing tornado.testing Parallelism Interleaving Looping Running in the background Queue example - a concurrent web spider Structure of a Tornado web application The main coroutine The Application object Subclassing RequestHandler

Introduction Asynchronous and non-Blocking I/O Coroutines Queue example - a concurrent web spider Structure of a Tornado web application Templates and UI Authentication and security Running and deploying Utilities tornado.autoreload — Automatically detect code changes in development tornado.concurrent — Work with Future objects tornado.log — Logging support tornado.options — Command-line parsing tornado.testing Parallelism Interleaving Looping Running in the background Queue example - a concurrent web spider Structure of a Tornado web application The main coroutine The Application object Subclassing RequestHandler

Introduction Asynchronous and non-Blocking I/O Coroutines Queue example - a concurrent web spider Structure of a Tornado web application Templates and UI Authentication and security Running and deploying Utilities tornado.autoreload — Automatically detect code changes in development tornado.concurrent — Work with Future objects tornado.log — Logging support tornado.options — Command-line parsing tornado.testing Parallelism Interleaving Looping Running in the background Queue example - a concurrent web spider Structure of a Tornado web application The main coroutine The Application object Subclassing RequestHandler

Introduction Asynchronous and non-Blocking I/O Coroutines Queue example - a concurrent web spider Structure of a Tornado web application Templates and UI Authentication and security Running and deploying Utilities tornado.autoreload — Automatically detect code changes in development tornado.concurrent — Work with Future objects tornado.log — Logging support tornado.options — Command-line parsing tornado.testing Parallelism Interleaving Looping Running in the background Queue example - a concurrent web spider Structure of a Tornado web application The main coroutine The Application object Subclassing RequestHandler

Introduction Asynchronous and non-Blocking I/O Coroutines Queue example - a concurrent web spider Structure of a Tornado web application Templates and UI Authentication and security Running and deploying Utilities tornado.autoreload — Automatically detect code changes in development tornado.concurrent — Work with Future objects tornado.log — Logging support tornado.options — Command-line parsing tornado.testing Parallelism Interleaving Looping Running in the background Queue example - a concurrent web spider Structure of a Tornado web application The Application object Subclassing RequestHandler Handling request

Asynchronous An asynchronous function returns before it is finished, and generally causes some work to happen in the background before triggering some future action in the application (as opposed to futures. You can use tornado.gen.convert_yielded to convert anything that would work with yield into a form that will work with await: async def f(): executor = concurrent.futures.ThreadPoolExecutor() once. Eventually, a worker fetches a page whose URLs have all been seen before, and there is also no work left in the queue. Thus that worker’s call to task_done decrements the counter to zero. The main coroutine