In node js, what is libuv and does it use all core?

Question

As far as I know, all IO requests and other asynchronous tasks are done by libuv in nodejs. I want to know if libuv is using threading. If it is, is it using all available core or not?

Answer 1

The libuv module has a responsibility that is relevant for some particular functions in the standard library. for SOME standard library function calls, the node C++ side and libuv decide to do expensive calculations outside of the event loop entirely.They make something called a thread pool that thread pool is a series of four threads that can be used for running computationally intensive tasks such as hashing functions.

By default libuv creates four threads in this thread pool. Thread Pool in the picture is organized by the Libuv So that means that in addition to that thread used for the event loop there are four other threads that can be used to offload expensive calculations that need to occur inside of our application. Many of the functions include in the node standard library will automatically make use of this thread pool.

Network (Network IO) is responsible for api requests, File system (File IO) is fs module. so node.js single thread delegates those heavy work to the libuv

If you have too many function calls, It will use all of the cores. CPU cores do not actually speed up the processing function calls, they just allow for some amount of concurrency inside of the work that you are doing.