def launch_gateway()

in pypaimon/py4j/java_gateway.py [0:0]

• 26 lines of code
• 4 McCabe index (conditional complexity)

def launch_gateway():
    # type: () -> JavaGateway
    """
    launch jvm gateway
    """

    # Create a temporary directory where the gateway server should write the connection information.
    conn_info_dir = tempfile.mkdtemp()
    try:
        fd, conn_info_file = tempfile.mkstemp(dir=conn_info_dir)
        os.close(fd)
        os.unlink(conn_info_file)

        env = dict(os.environ)
        env[constants.PYPAIMON_CONN_INFO_PATH] = conn_info_file

        p = launch_gateway_server_process(env)

        while not p.poll() and not os.path.isfile(conn_info_file):
            time.sleep(0.1)

        if not os.path.isfile(conn_info_file):
            stderr_info = p.stderr.read().decode('utf-8')
            raise RuntimeError(
                "Java gateway process exited before sending its port number.\nStderr:\n"
                + stderr_info
            )

        with open(conn_info_file, "rb") as info:
            gateway_port = struct.unpack("!I", info.read(4))[0]
    finally:
        shutil.rmtree(conn_info_dir)

    # Connect to the gateway
    gateway = JavaGateway(
        gateway_parameters=GatewayParameters(port=gateway_port, auto_convert=True),
        callback_server_parameters=CallbackServerParameters(
            port=0, daemonize=True, daemonize_connections=True))

    return gateway