PollSet::poll on Windows always returns immediately after first connection, due to bad event socket implementation

[obiltschnig]

PollSet uses and event fd to interrupt an ongoing poll() in wakeUp(). On POSIX platforms this uses eventfd() and works fine. On Windows, a ServerSocket is created (either as Unix domain socket or TCP socket) instead. The problem is that when that event fd is signaled, the implementation attempts to receive from it. Which is not going to work as it's a ServerSocket. So this eventfd stays signaled forever, causing high CPU load as poll() always returns immediately.

[lanthora]

The commit that fixes this problem should also solve the problem that the
Poco::Net::ServiceNotFoundException exception is thrown when creating a PollSet with a Chinese username in Windows.

// TemporaryFile path contains Chinese characters
_pSockFile.reset(new TemporaryFile);
// SocketAddress throw ServiceNotFoundException
_pSocket.reset(new ServerSocket(SocketAddress(_pSockFile->path())));