Tell me about the GMP model in Go. How do queues work, what is handoff, work stealing, netpoller?

The GMP model in Go is the foundation of the goroutine scheduler, where:

• G (goroutine) — is a lightweight thread of execution.
• M (machine) — is the system thread of the OS on which goroutines run.
• P (processor) — is a logical processor that connects G and M, managing goroutine execution.

Each P has a run queue of goroutines, where ready-to-run G are placed. M takes G from P's queue and runs them.

Handoff — is a mechanism for transferring a goroutine from one M to another without placing it in the global queue, to minimize delays.

Work stealing — occurs when a P finishes its goroutines and can "steal" tasks from other P's queues to evenly distribute the load.

Netpoller — is an internal mechanism that monitors network events (e.g., socket readiness) and wakes up the corresponding goroutines for processing.

Thus, the GMP model provides efficient and scalable goroutine scheduling with minimal overhead.