1# 2# Copyright (C) 2016 The Android Open Source Project 3# 4# Licensed under the Apache License, Version 2.0 (the "License"); 5# you may not use this file except in compliance with the License. 6# You may obtain a copy of the License at 7# 8# http://www.apache.org/licenses/LICENSE-2.0 9# 10# Unless required by applicable law or agreed to in writing, software 11# distributed under the License is distributed on an "AS IS" BASIS, 12# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13# See the License for the specific language governing permissions and 14# limitations under the License. 15# 16 17import logging 18import socket 19import socketserver 20import threading 21 22from vts.runners.host import errors 23from vts.proto import AndroidSystemControlMessage_pb2 as SysMsg 24from vts.proto import ComponentSpecificationMessage_pb2 as CompSpecMsg 25from vts.utils.python.mirror import pb2py 26 27_functions = dict() # Dictionary to hold function pointers 28 29 30class VtsCallbackServerError(errors.VtsError): 31 """Raised when an error occurs in VTS TCP server.""" 32 33 34class CallbackRequestHandler(socketserver.StreamRequestHandler): 35 """The request handler class for our server.""" 36 37 def handle(self): 38 """Receives requests from clients. 39 40 When a callback happens on the target side, a request message is posted 41 to the host side and is handled here. The message is parsed and the 42 appropriate callback function on the host side is called. 43 """ 44 header = self.rfile.readline().strip() 45 try: 46 len = int(header) 47 except ValueError: 48 if header: 49 logging.exception("Unable to convert '%s' into an integer, which " 50 "is required for reading the next message." % 51 header) 52 raise 53 else: 54 logging.error('CallbackRequestHandler received empty message header. Skipping...') 55 return 56 # Read the request message. 57 received_data = self.rfile.read(len) 58 logging.debug("Received callback message: %s", received_data) 59 request_message = SysMsg.AndroidSystemCallbackRequestMessage() 60 request_message.ParseFromString(received_data) 61 logging.debug('Handling callback ID: %s', request_message.id) 62 response_message = SysMsg.AndroidSystemCallbackResponseMessage() 63 # Call the appropriate callback function and construct the response 64 # message. 65 if request_message.id in _functions: 66 callback_args = [] 67 for arg in request_message.arg: 68 callback_args.append(pb2py.Convert(arg)) 69 args = tuple(callback_args) 70 _functions[request_message.id](*args) 71 response_message.response_code = SysMsg.SUCCESS 72 else: 73 logging.error("Callback function ID %s is not registered!", 74 request_message.id) 75 response_message.response_code = SysMsg.FAIL 76 77 # send the response back to client 78 message = response_message.SerializeToString() 79 # self.request is the TCP socket connected to the client 80 self.request.sendall(message) 81 82 83class CallbackServer(object): 84 """This class creates TCPServer in separate thread. 85 86 Attributes: 87 _server: an instance of socketserver.TCPServer. 88 _port: this variable maintains the port number used in creating 89 the server connection. 90 _ip: variable to hold the IP Address of the host. 91 _hostname: IP Address to which initial connection is made. 92 """ 93 94 def __init__(self): 95 self._server = None 96 self._port = 0 # Port 0 means to select an arbitrary unused port 97 self._ip = "" # Used to store the IP address for the server 98 self._hostname = "localhost" # IP address to which initial connection is made 99 100 def RegisterCallback(self, func_id, callback_func): 101 """Registers a callback function. 102 103 Args: 104 func_id: The ID of the callback function. 105 callback_func: The function to register. 106 107 Raises: 108 CallbackServerError is raised if the func_id is already registered. 109 """ 110 if func_id in _functions: 111 raise CallbackServerError( 112 "Function ID '%s' is already registered" % func_id) 113 _functions[func_id] = callback_func 114 115 def UnregisterCallback(self, func_id): 116 """Removes a callback function from the registry. 117 118 Args: 119 func_id: The ID of the callback function to remove. 120 121 Raises: 122 CallbackServerError is raised if the func_id is not registered. 123 """ 124 try: 125 _functions.pop(func_id) 126 except KeyError: 127 raise CallbackServerError( 128 "Can't remove function ID '%s', which is not registered." % 129 func_id) 130 131 def Start(self, port=0): 132 """Starts the server. 133 134 Args: 135 port: integer, number of the port on which the server listens. 136 Default is 0, which means auto-select a port available. 137 138 Returns: 139 IP Address, port number 140 141 Raises: 142 CallbackServerError is raised if the server fails to start. 143 """ 144 try: 145 self._server = socketserver.TCPServer( 146 (self._hostname, port), CallbackRequestHandler) 147 self._ip, self._port = self._server.server_address 148 149 # Start a thread with the server. 150 # Each request will be handled in a child thread. 151 server_thread = threading.Thread(target=self._server.serve_forever) 152 server_thread.daemon = True 153 server_thread.start() 154 logging.info('TcpServer %s started (%s:%s)', server_thread.name, 155 self._ip, self._port) 156 return self._ip, self._port 157 except (RuntimeError, IOError, socket.error) as e: 158 logging.exception(e) 159 raise CallbackServerError( 160 'Failed to start CallbackServer on (%s:%s).' % 161 (self._hostname, port)) 162 163 def Stop(self): 164 """Stops the server. 165 """ 166 self._server.shutdown() 167 self._server.server_close() 168 169 @property 170 def ip(self): 171 return self._ip 172 173 @property 174 def port(self): 175 return self._port 176