Is it possible to pause a goroutine so that it blocks on a specific system thread?

In Go, goroutines are lightweight threads scheduled by the Go runtime onto system threads. It is not possible to suspend a goroutine and bind it directly to a specific system thread, as the Go scheduler dynamically distributes goroutines across threads for optimization.

However, if you need to execute code that must run on a specific system thread (for example, due to interaction with a C library that requires thread affinity), you can use the function runtime.LockOSThread(). This function binds the current goroutine to the system thread on which it is running and prevents the scheduler from moving it to another thread.

Example:

import "runtime"

func main() {
    runtime.LockOSThread() // bind the current goroutine to the system thread
    // now this goroutine will always run on this same system thread
    // ...
}

But note that the goroutine itself is not blocked on the thread — it continues to execute. If you need to suspend execution, you can use channels, timers, or other synchronization mechanisms, but this is not related to binding to a thread.

In summary: you cannot "suspend" a goroutine so that it blocks specifically on a particular system thread, but you can bind a goroutine to a thread using runtime.LockOSThread().