#pypp 0
#include "kernel.hh"

void Thread::run ():
	if flags & THREAD_FLAG_RUNNING:
		return
	flags |= THREAD_FLAG_RUNNING
	if flags & THREAD_FLAG_WAITING:
		return
	schedule_next = first_scheduled
	if schedule_next:
		schedule_next->schedule_prev = this
	first_scheduled = this

void Thread::unrun ():
	if !(flags & THREAD_FLAG_RUNNING):
		return
	flags &= ~THREAD_FLAG_RUNNING
	if !(flags & THREAD_FLAG_WAITING):
		if current == this:
			current = schedule_next
		if schedule_prev:
			schedule_prev->schedule_next = schedule_next
		else:
			first_scheduled = schedule_next
		if schedule_next:
			schedule_next->schedule_prev = schedule_prev

void Thread::wait ():
	if flags & THREAD_FLAG_WAITING:
		return
	if flags & THREAD_FLAG_RUNNING:
		unrun ()
	flags |= THREAD_FLAG_WAITING
	// Try to receive a message from a Receiver immediately.
	for Receiver *r = receivers; r; r = r->next_owned:
		if r->try_deliver ():
			break

void Thread::unwait ():
	if !(flags & THREAD_FLAG_WAITING):
		return
	flags &= ~THREAD_FLAG_WAITING
	if flags & THREAD_FLAG_RUNNING:
		flags &= ~THREAD_FLAG_RUNNING
		run ()

void schedule ():
	Thread *old = current
	if current:
		current = current->schedule_next
	if !current:
		current = first_scheduled
		if !current:
			current = &idle