//go:build scheduler.tasks && wasm

package task

import "unsafe"

var systemStack uintptr

// calleeSavedRegs on WASM is empty — WASM manages its own value stack.
// Task switching is done via the asyncify transform or cooperative yields.
type calleeSavedRegs struct{}

// archInit stores the function and args for the task. On WASM, there are no
// hardware registers to initialize — the runtime uses cooperative scheduling.
func (s *state) archInit(r *calleeSavedRegs, fn uintptr, args unsafe.Pointer) {
	s.sp = uintptr(unsafe.Pointer(r))
}

func (s *state) resume() {
	swapTask(s.sp, &systemStack)
}

func (s *state) pause() {
	newStack := systemStack
	systemStack = 0
	swapTask(newStack, &s.sp)
}

func SystemStack() uintptr {
	return systemStack
}