Method run

src/windows/libwinio.cpp:288–332

{}

Try<Nothing> EventLoop::run()
{
  const Try<long> maxEntries = os::cpus();
  if (maxEntries.isError()) {
    return Error(maxEntries.error());
  }

  bool loop = true;
  std::vector<OVERLAPPED_ENTRY> entries(maxEntries.get());
  while (loop) {
    ULONG dequeued_entries;

    // This function can return in three ways:
    //   1) We get some IO completion events and the function will return true.
    //   2) A timer APC interrupts the function in its alertable wait status,
    //      so the thread will execute the APC. The function will return false
    //      and set the error to `WAIT_IO_COMPLETION`.
    //   3) We get a legitimate error, so we exit early.
    BOOL success = ::GetQueuedCompletionStatusEx(
        iocp_handle_.get(),
        entries.data(),
        maxEntries.get(),
        &dequeued_entries,
        INFINITE,
        TRUE);

    if (!success) {
      // Case 2: Got APC interrupt. We simply continue the loop.
      if (::GetLastError() == WAIT_IO_COMPLETION) {
        continue;
      }

      // We hit case 3, which means we got a serious error.
      return WindowsError();
    }

    // Case 1: Dequeue completion packets and process them. If we get a quit
    // notification, then we will finish the current queue and then exit.
    for (ULONG i = 0; i < dequeued_entries; i++) {
      const bool continue_loop = check_and_handle_completion(entries[i]);
      loop = loop && continue_loop;
    }
  }
  return Nothing();
}


Try<Nothing> EventLoop::stop()