//go:build scheduler.none

package task

import "unsafe"

// state is a no-op placeholder. With scheduler.none there is no
// stack switching, so the state struct is empty.
type state struct{}

// currentTask is the single running task.
var currentTask Task

// Current returns the (only) active task.
func Current() *Task {
	return &currentTask
}

// Pause panics — with no scheduler there is nothing to resume us.
func Pause() {
	// Debug: trap to get a stack trace.
	runtimePanic("deadlock: Pause called with no scheduler")
}

// Resume is unreachable with scheduler.none.
func (t *Task) Resume() {
	runtimePanic("deadlock: Resume called with no scheduler")
}

// OnSystemStack returns true — with no scheduler, we're always on
// the system stack.
func OnSystemStack() bool {
	return true
}

// SystemStack returns 0. Never called when OnSystemStack() is true.
func SystemStack() uintptr {
	return 0
}

// start is a no-op under scheduler.none — there are no goroutines to start.
func start(fn uintptr, args unsafe.Pointer, stackSize uintptr) {
	runtimePanic("cannot start goroutine with no scheduler")
}

//go:linkname runtimePanic runtime.runtimePanic
func runtimePanic(str string)