How does the goroutine interaction process with system calls work in an operating system?

In Go, goroutines are lightweight threads managed by the Go runtime, not directly by the operating system. When a goroutine makes a system call, such as reading from a file or network interaction, the following occurs:

1. The goroutine calls the system call through the runtime.
2. If the system call blocks the thread (OS thread), the Go runtime can temporarily detach this goroutine from the current thread and run another goroutine on the same thread to avoid blocking execution.
3. For this, the runtime uses an M:N model, where M is the number of OS threads, and N is the number of goroutines.
4. When the system call completes, the goroutine resumes work.

Thus, Go efficiently manages blocking system calls, allowing thousands of goroutines to run concurrently on a limited number of OS threads without blocking the entire program.