FIX: wait_for_fd in epoll should atleast put into sleep for a tiny mo…

…ment

io/epoll.cpp

@@ -301,7 +301,9 @@ ok: entry.interests |= eint;
  return rm_interest({fd, EVENT_RWE| ONE_SHOT, 0}); // remove fd from epoll
  int ret = add_interest({fd, interest | ONE_SHOT, CURRENT});
  if (ret < 0) LOG_ERROR_RETURN(0, -1, "failed to add event interest");
- ret = thread_usleep(timeout);
+ // if timeout is just simple 0, wait for a tiny little moment
+ // so that events can be collect.
+ ret = thread_usleep(timeout.timeout() ? timeout : Timeout(10));
  ERRNO err;
  if (ret == -1 && err.no == EOK) {
  return 0; // Event arrived

net/pooled_socket.cpp

@@ -121,9 +121,10 @@ class TCPSocketPool : public ForwardSocketClient {
  photon::Timer timer;
 
  // all fd < 0 treated as socket not based on fd
- // and always alive. Using such socket needs user
+ // and always reuseable. Using such socket needs user
  // to check if connected socket is still usable.
- bool stream_alive(int fd) {
+ // if there still have unread bytes in strema, it should be closed.
+ bool stream_reusable(int fd) {
  return (fd < 0) || (wait_for_fd_readable(fd, 0) != 0);
  }
 
@@ -196,7 +197,7 @@ class TCPSocketPool : public ForwardSocketClient {
  if (!stream) {
  stream = m_underlay->connect(remote, local);
  if (!stream) return nullptr;
- } else if (!stream_alive(stream->get_underlay_fd())) {
+ } else if (!stream_reusable(stream->get_underlay_fd())) {
  delete stream;
  goto again;
  }
@@ -231,7 +232,7 @@ class TCPSocketPool : public ForwardSocketClient {
  bool release(const EndPoint& ep, ISocketStream* stream) {
  auto fd = stream->get_underlay_fd();
  ERRNO err;
- if (!stream_alive(fd)) return false;
+ if (!stream_reusable(fd)) return false;
  auto node = new StreamListNode(ep, stream, fd, TTL_us);
  push_into_pool(node);
  errno = err.no;