[Go] LockOsThread

Reference:
https://github.com/golang/go/wiki/LockOSThread

package sdl

// Arrange that main.main runs on main thread.
func init() {
 runtime.LockOSThread()
}

// Main runs the main SDL service loop.
// The binary's main.main must call sdl.Main() to run this loop.
// Main does not return. If the binary needs to do other work, it
// must do it in separate goroutines.
func Main() {
 for f := range mainfunc {
  f()
 }
}

// queue of work to run in main thread.
var mainfunc = make(chan func())

// do runs f on the main thread.
func do(f func()) {
 done := make(chan bool, 1)
 mainfunc <- func() {
  f()
  done <- true
 }
 <-done
}

func Beep() {
 do(func() {
  // whatever must run in main thread
 })
}