coroutine-main-run-loop.c

static void deltask(schd_t* const schd, task_t* const t)
{
	if (t->prev)
		t->prev->next = t->next;
	else
		schd->head = t->next;
	if (t->next)
		t->next->prev = t->prev;
	else
		schd->tail = t->prev;
}

static void* schdmain(void* userdata)
{
	schd_t* const schd = (schd_t*)userdata;
	for (;;) {
		pthread_mutex_lock(&schd->mutex);
		// No one is waiting, and no more tasks. exit.
		if (schd->head == 0 && schd->count.suspend == 0)
		{
			pthread_mutex_unlock(&schd->mutex);
			break;
		}
		if (schd->head == 0)
		{
			pthread_cond_wait(&schd->cv, &schd->mutex);
			pthread_mutex_unlock(&schd->mutex);
			continue;
		}
		task_t* const t = schd->head;
		deltask(schd, t);
		pthread_mutex_unlock(&schd->mutex);
		swapcontext(&schd->caller, &t->context);
		t->context = schd->callee;
		if (t->done)
			taskfree(t);
	}
	return 0;
}