Function waitForReadiness

3rdparty/Amalgamate/juce_core_amalgam.cpp:7107–7158

	}

	static int waitForReadiness (const int handle, const bool forReading, const int timeoutMsecs) noexcept
	{
		struct timeval timeout;
		struct timeval* timeoutp;

		if (timeoutMsecs >= 0)
		{
			timeout.tv_sec = timeoutMsecs / 1000;
			timeout.tv_usec = (timeoutMsecs % 1000) * 1000;
			timeoutp = &timeout;
		}
		else
		{
			timeoutp = 0;
		}

		fd_set rset, wset;
		FD_ZERO (&rset);
		FD_SET (handle, &rset);
		FD_ZERO (&wset);
		FD_SET (handle, &wset);

		fd_set* const prset = forReading ? &rset : nullptr;
		fd_set* const pwset = forReading ? nullptr : &wset;

	   #if JUCE_WINDOWS
		if (select (handle + 1, prset, pwset, 0, timeoutp) < 0)
			return -1;
	   #else
		{
			int result;
			while ((result = select (handle + 1, prset, pwset, 0, timeoutp)) < 0
					&& errno == EINTR)
			{
			}

			if (result < 0)
				return -1;
		}
	   #endif

		{
			int opt;
			juce_socklen_t len = sizeof (opt);

			if (getsockopt (handle, SOL_SOCKET, SO_ERROR, (char*) &opt, &len) < 0
				 || opt != 0)
				return -1;
		}

		return FD_ISSET (handle, forReading ? &rset : &wset) ? 1 : 0;
	}

	static bool setSocketBlockingState (const int handle, const bool shouldBlock) noexcept
	{