// nextTask returns taskInfo.sp for next task or 0.
// TODO: better scheduler
func nextTask(sp uintptr) uintptr {
n := tasker.forceNext
if n >= 0 {
tasker.forceNext = -1
} else {
again:
if ereg := atomic.SwapUintptr((*uintptr)(&eventReg), 0); ereg != 0 {
tasker.deliverEvent(Event(ereg))
}
n = tasker.curTask
for {
if n++; n == len(tasker.tasks) {
n = 0
}
if tasker.tasks[n].state() == taskReady {
break
}
if n == tasker.curTask {
// No task to run.
sleep.WFE()
goto again
}
}
if n == tasker.curTask {
return 0
}
}
tasker.tasks[tasker.curTask].sp = sp
tasker.curTask = n
return tasker.tasks[n].sp
}
func SwapUintptr(addr *uintptr, new uintptr) uintptr {
return orig.SwapUintptr(addr, new)
}