message tasklet_service::recv(tasklet& recver)
{
if(_stop)
{
throw stop_exception();
}
bool switched = false;
while (_channel_manager.empty(recver._channel))
{
park(recver);
if (empty_runnables())
{
switch_tasklet(recver);
}
else
{
switch_tasklet(recver, pop_runnable());
}
switched = true;
}
if (!switched)
{
yield(recver);
}
return _channel_manager.fetch(recver._channel);
}
message tasklet_service::recv(tasklet& recver, double timeout)
{
if(_stop)
{
throw stop_exception();
}
if (timeout == infinity)
{
return recv(recver);
}
bool switched = false;
unsigned long long wake_ = now()+(int)(timeout*10);
while (_channel_manager.empty(recver._channel))
{
recver._state = timeout_waitting;
recver._wake = wake_;
_sleepers.insert(&recver);
if (empty_runnables())
{
switch_tasklet(recver);
}
else
{
switch_tasklet(recver, pop_runnable());
}
switched = true;
}
if (!switched)
{
yield(recver);
}
return _channel_manager.fetch(recver._channel);
}
static void schedule(struct thread *t)
{
struct thread *current = current_thread();
/* If t is NULL need to find new runnable thread. */
if (t == NULL) {
if (thread_list_empty(&runnable_threads))
die("Runnable thread list is empty!\n");
t = pop_runnable();
} else {
/* current is still runnable. */
push_runnable(current);
}
switch_to_thread(t->stack_current, ¤t->stack_current);
}
void tasklet_service::yield(tasklet& tasklet_)
{
if(_stop)
{
throw stop_exception();
}
if (empty_runnables())
{
return;
}
push_runnable(tasklet_);
assert(!empty_runnables());
tasklet& next = pop_runnable();
switch_tasklet(tasklet_, next);
}
void tasklet_service::sleep(tasklet& tasklet_, double timeout)
{
if(_stop)
{
throw stop_exception();
}
tasklet_._state = sleeping;
tasklet_._wake = now()+(int)(timeout*10);
_sleepers.insert(&tasklet_);
if (empty_runnables())
{
switch_tasklet(tasklet_);
}
else
{
tasklet& next_tasklet = pop_runnable();
switch_tasklet(tasklet_, next_tasklet);
}
}
tasklet& tasklet_service::pop_tasklet()
{
tasklet* ptasklet = NULL;
while (!ptasklet && !_stop)
{
if (empty_runnables())
{
//这里本来可能引发因为_condition.wait释放_mutex导致的线程安全问题
//但是很幸运的是，pop_tasklet只被threadlet::loop调用，这样就正好不会引发线程安全问题了
_condition.wait();
}
else
{
assert(!empty_runnables());
ptasklet = &pop_runnable();
}
}
if (_stop && !ptasklet)
{
throw stop_exception();
}
return *ptasklet;
}
