# Lesson 2- Eventloops

* call\_soon
* call\_later
* run\_forever - loops

![](https://4253921594-files.gitbook.io/~/files/v0/b/gitbook-legacy-files/o/assets%2F-MhiOx8KkYnYxHHqfUbB%2F-MiNN9_pa0pXbWthn_e7%2F-MiNNXmw1pz0i3CapTrm%2Fimage.png?alt=media\&token=9dbe3a98-c852-4cba-a108-c58b903e9a2e)

Select operations

Eventloops can run only one things at a time. There is usually a :

selector or proactor

Reactors - reacts based on notifications used by reactors

twisted calls eventloops

I/0 completion Ports - changes. In windows you can use proactors and selctors. In Unix you can use selectors

![](https://4253921594-files.gitbook.io/~/files/v0/b/gitbook-legacy-files/o/assets%2F-MhiOx8KkYnYxHHqfUbB%2F-Mj2K3S86a3zlK49S08Z%2F-Mj2KnVUeZHGAV5w1iF-%2Fimage.png?alt=media\&token=22caca50-e229-45c5-badd-3bb3ac529aa3)

Base\_events - consists of base events, yet there is only while loops there

![](https://4253921594-files.gitbook.io/~/files/v0/b/gitbook-legacy-files/o/assets%2F-MhiOx8KkYnYxHHqfUbB%2F-Mj2K3S86a3zlK49S08Z%2F-Mj2N7F1aFQXjBgOKSY-%2Fimage.png?alt=media\&token=c7960704-cd37-415a-9a91-152d05ef86e2)

Python 3.5 implementation, then in \`*run*once\`

![](https://4253921594-files.gitbook.io/~/files/v0/b/gitbook-legacy-files/o/assets%2F-MhiOx8KkYnYxHHqfUbB%2F-Mj2K3S86a3zlK49S08Z%2F-Mj2NMmhvUXVvkd4_HTm%2Fimage.png?alt=media\&token=db36d931-69af-4311-8dca-d5081b3997ae)

Heart of heart of asyncio is select\_once method which calls the proactors and is having selector.select(timeout) method

![](https://4253921594-files.gitbook.io/~/files/v0/b/gitbook-legacy-files/o/assets%2F-MhiOx8KkYnYxHHqfUbB%2F-Mj2K3S86a3zlK49S08Z%2F-Mj2O9k_kzQoIArmTQs9%2Fimage.png?alt=media\&token=8f85df27-4725-416f-b8b7-d4a9338f9fe1)

![](https://4253921594-files.gitbook.io/~/files/v0/b/gitbook-legacy-files/o/assets%2F-MhiOx8KkYnYxHHqfUbB%2F-Mj2K3S86a3zlK49S08Z%2F-Mj2OKkm6F5F_wc8n3kL%2Fimage.png?alt=media\&token=811d9b52-0b89-475a-8b5f-f9132151baf1)

![](https://4253921594-files.gitbook.io/~/files/v0/b/gitbook-legacy-files/o/assets%2F-MhiOx8KkYnYxHHqfUbB%2F-Mj2K3S86a3zlK49S08Z%2F-Mj2OLiTA_ZjKkwfQjmo%2Fimage.png?alt=media\&token=8442f823-eb7e-4e6e-b694-f155d9db6340)

Uvloop for production, as it's doing a lot of magic and improvement in results. As it's fastest implementation with similar performance to NodeJS

Eventloop is just a normal function for handling netoworks requests and is used to handle callbacks. By what?

![](https://4253921594-files.gitbook.io/~/files/v0/b/gitbook-legacy-files/o/assets%2F-MhiOx8KkYnYxHHqfUbB%2F-Mj2K3S86a3zlK49S08Z%2F-Mj2Pledle4i1Vyi9898%2Fimage.png?alt=media\&token=d1159ac3-1e94-4dff-af76-925807d6281d)

Eventloop is not magical, it's just a loop which handles network events and executes as callbacks one by one. It can handle many networks events concurrently with a selector or a proactor. While it can handle many callback, but only run one callback at a time. Some callbacks, run and come again with a trick called traumpaline

callsoon, calllater is difficult to run. But it's usually run using coroutine. These coroutines make asynchrnous programs easy and magical