this will block the cpu entirely

cpublock.go

package main

import (
    "fmt"
    "runtime"
    "time"
)

func main() {
    // THIS is totally required; without it, you're blocking the CPU regardless
    // of whether you use LockOSThread or not.
    runtime.GOMAXPROCS(4)

    // arbitrary CPU-blocking function
    go cpublock()
    go cpublock()
    go cpublock()
    go cpublock()

    for {
        fmt.Println("hey")
        time.Sleep(time.Second)
    }
}

func cpublock() {
    x := 0
    for {
        x += 1
    }
}

this will print 'hey' once, then when the time.Sleep yields to the scheduler, the last cpublock goroutine will start.