recvfrom SYSCALL infinite loop

[kldeng]

Hi,
When using jsonrpclib to build a RPC Server.
server = SimpleJSONRPCServer(('0.0.0.0', rpc_listening_port))
server.register_function(floatingip_check, 'floatingip_check')
server.serve_forever()

It's found that the RPC Server process is stucked in a recv_from infinite loop.
recvfrom(4, "", 1, 0, NULL, NULL) = 0
recvfrom(4, "", 1, 0, NULL, NULL) = 0
(output from strace)

It seems rpc server doesn't close the socket normally while recvfrom return zero which indicating the peer has performed an shutdown.

Is this a bug of jsonrpclib or I missed something to make it work.
Thanks a lot.