void pony_asio_event_subscribe(asio_event_t* ev)
{
if((ev == NULL) ||
(ev->flags == ASIO_DISPOSABLE) ||
(ev->flags == ASIO_DESTROYED))
return;
asio_backend_t* b = ponyint_asio_get_backend();
if(ev->noisy)
ponyint_asio_noisy_add();
struct epoll_event ep;
ep.data.ptr = ev;
ep.events = EPOLLRDHUP | EPOLLET;
if(ev->flags & ASIO_READ)
ep.events |= EPOLLIN;
if(ev->flags & ASIO_WRITE)
ep.events |= EPOLLOUT;
if(ev->flags & ASIO_TIMER)
{
ev->fd = timerfd_create(CLOCK_MONOTONIC, TFD_NONBLOCK);
timer_set_nsec(ev->fd, ev->nsec);
ep.events |= EPOLLIN;
}
if(ev->flags & ASIO_SIGNAL)
{
int sig = (int)ev->nsec;
asio_event_t* prev = NULL;
if((sig < MAX_SIGNAL) &&
atomic_compare_exchange_strong_explicit(&b->sighandlers[sig], &prev, ev,
memory_order_release, memory_order_relaxed))
{
signal(sig, signal_handler);
ev->fd = eventfd(0, EFD_NONBLOCK);
ep.events |= EPOLLIN;
} else {
return;
}
}
epoll_ctl(b->epfd, EPOLL_CTL_ADD, ev->fd, &ep);
}
PONY_API void pony_asio_event_subscribe(asio_event_t* ev)
{
if((ev == NULL) ||
(ev->flags == ASIO_DISPOSABLE) ||
(ev->flags == ASIO_DESTROYED))
{
pony_assert(0);
return;
}
asio_backend_t* b = ponyint_asio_get_backend();
pony_assert(b != NULL);
if(ev->noisy)
{
uint64_t old_count = ponyint_asio_noisy_add();
// tell scheduler threads that asio has at least one noisy actor
// if the old_count was 0
if (old_count == 0)
ponyint_sched_noisy_asio(SPECIAL_THREADID_EPOLL);
}
struct epoll_event ep;
ep.data.ptr = ev;
ep.events = EPOLLRDHUP;
if(ev->flags & ASIO_READ)
ep.events |= EPOLLIN;
if(ev->flags & ASIO_WRITE)
ep.events |= EPOLLOUT;
if(ev->flags & ASIO_TIMER)
{
ev->fd = timerfd_create(CLOCK_MONOTONIC, TFD_NONBLOCK);
timer_set_nsec(ev->fd, ev->nsec);
ep.events |= EPOLLIN;
}
if(ev->flags & ASIO_SIGNAL)
{
int sig = (int)ev->nsec;
asio_event_t* prev = NULL;
#ifdef USE_VALGRIND
ANNOTATE_HAPPENS_BEFORE(&b->sighandlers[sig]);
#endif
if((sig < MAX_SIGNAL) &&
atomic_compare_exchange_strong_explicit(&b->sighandlers[sig], &prev, ev,
memory_order_release, memory_order_relaxed))
{
struct sigaction new_action;
new_action.sa_handler = signal_handler;
sigemptyset (&new_action.sa_mask);
// ask to restart interrupted syscalls to match `signal` behavior
new_action.sa_flags = SA_RESTART;
sigaction(sig, &new_action, NULL);
ev->fd = eventfd(0, EFD_NONBLOCK);
ep.events |= EPOLLIN;
} else {
return;
}
}
if(ev->flags & ASIO_ONESHOT)
{
ep.events |= EPOLLONESHOT;
} else {
// Only use edge triggering if one shot isn't enabled.
// This is because of how the runtime gets notifications
// from epoll in this ASIO thread and then notifies the
// appropriate actor to read/write as necessary.
// specifically, it seems there's an edge case/race condition
// with edge triggering where if there is already data waiting
// on the socket, then epoll might not be triggering immediately
// when an edge triggered epoll request is made.
ep.events |= EPOLLET;
}
epoll_ctl(b->epfd, EPOLL_CTL_ADD, ev->fd, &ep);
}