EventLoop learning

Summarize your recent work on eventloop Learning from .

Things have to come from js The characteristics of single thread begin to talk about .

Threads and processes

Thread process details
Thread process Ruan Yifeng image details

Yes js This single threaded thing , It's probably just that

But this thing is so bad , The red part is always waiting . So on the one hand, in order to solve the efficiency problem caused by this waiting mechanism ,js We used eventloop The mechanism of .

Event loop

Personal understanding Event loop It is a set of operating mechanism , It is similar to proposing a solution to the single thread blocking problem . For example, in the browser js：
1、js Run the program in the execution stack , Put the macro task and micro task in the process into the macro task queue and micro task queue respectively .
2、 After the execution stack is empty , Take the micro task from the micro task queue and put it into execution
3、 After the micro task runs empty , Take macro task from macro task queue and put it into execution , repeat 2、3.

Figure from https://segmentfault.com/a/1190000016278115