What is the implementation principle of golang’s gorout…

The implementation principle of Golang goroutine is based on a model known as M:N scheduling.

In an M:N scheduling model, M represents kernel threads in the operating system and N represents goroutines. In this model, the Go runtime system creates a group of operating system threads known as M thread pools, with each pool typically containing the same number of threads as the CPU cores.

When a coroutine is created, the runtime system schedules it to run on a thread in one of the M thread pools. The switching of coroutines is controlled by the runtime system, not by the operating system kernel, and is based on the characteristics of the coroutine itself and the scheduling strategy of the runtime system.

During the execution of a coroutine, if it encounters an I/O operation or other blocking operation, the runtime system will automatically unbind the coroutine from the thread it is on and place it in a thread pool specifically for handling blocking operations. Once the blocking operation is complete, the coroutine will be rescheduled to continue execution on any available thread.

The advantage of this M:N scheduling model is that it can run a large number of coroutines on a relatively small number of operating system threads, thereby improving concurrency performance. Coroutine switches are also relatively lightweight and do not incur the expensive context switching overhead seen in traditional thread switches.

In summary, the implementation principle of Golang goroutines is based on the M:N scheduling model, which efficiently and lightly achieves concurrency by scheduling goroutines to run on operating system threads.