| """RPC Implemention, originally written for the Python Idle IDE |
| |
| For security reasons, GvR requested that Idle's Python execution server process |
| connect to the Idle process, which listens for the connection. Since Idle has |
| has only one client per server, this was not a limitation. |
| |
| +---------------------------------+ +-------------+ |
| | SocketServer.BaseRequestHandler | | SocketIO | |
| +---------------------------------+ +-------------+ |
| ^ | register() | |
| | | unregister()| |
| | +-------------+ |
| | ^ ^ |
| | | | |
| | + -------------------+ | |
| | | | |
| +-------------------------+ +-----------------+ |
| | RPCHandler | | RPCClient | |
| | [attribute of RPCServer]| | | |
| +-------------------------+ +-----------------+ |
| |
| The RPCServer handler class is expected to provide register/unregister methods. |
| RPCHandler inherits the mix-in class SocketIO, which provides these methods. |
| |
| See the Idle run.main() docstring for further information on how this was |
| accomplished in Idle. |
| |
| """ |
| |
| import sys |
| import os |
| import socket |
| import select |
| import SocketServer |
| import struct |
| import cPickle as pickle |
| import threading |
| import Queue |
| import traceback |
| import copy_reg |
| import types |
| import marshal |
| |
| |
| def unpickle_code(ms): |
| co = marshal.loads(ms) |
| assert isinstance(co, types.CodeType) |
| return co |
| |
| def pickle_code(co): |
| assert isinstance(co, types.CodeType) |
| ms = marshal.dumps(co) |
| return unpickle_code, (ms,) |
| |
| # XXX KBK 24Aug02 function pickling capability not used in Idle |
| # def unpickle_function(ms): |
| # return ms |
| |
| # def pickle_function(fn): |
| # assert isinstance(fn, type.FunctionType) |
| # return repr(fn) |
| |
| copy_reg.pickle(types.CodeType, pickle_code, unpickle_code) |
| # copy_reg.pickle(types.FunctionType, pickle_function, unpickle_function) |
| |
| BUFSIZE = 8*1024 |
| LOCALHOST = '127.0.0.1' |
| |
| class RPCServer(SocketServer.TCPServer): |
| |
| def __init__(self, addr, handlerclass=None): |
| if handlerclass is None: |
| handlerclass = RPCHandler |
| SocketServer.TCPServer.__init__(self, addr, handlerclass) |
| |
| def server_bind(self): |
| "Override TCPServer method, no bind() phase for connecting entity" |
| pass |
| |
| def server_activate(self): |
| """Override TCPServer method, connect() instead of listen() |
| |
| Due to the reversed connection, self.server_address is actually the |
| address of the Idle Client to which we are connecting. |
| |
| """ |
| self.socket.connect(self.server_address) |
| |
| def get_request(self): |
| "Override TCPServer method, return already connected socket" |
| return self.socket, self.server_address |
| |
| def handle_error(self, request, client_address): |
| """Override TCPServer method |
| |
| Error message goes to __stderr__. No error message if exiting |
| normally or socket raised EOF. Other exceptions not handled in |
| server code will cause os._exit. |
| |
| """ |
| try: |
| raise |
| except SystemExit: |
| raise |
| except: |
| erf = sys.__stderr__ |
| print>>erf, '\n' + '-'*40 |
| print>>erf, 'Unhandled server exception!' |
| print>>erf, 'Thread: %s' % threading.currentThread().getName() |
| print>>erf, 'Client Address: ', client_address |
| print>>erf, 'Request: ', repr(request) |
| traceback.print_exc(file=erf) |
| print>>erf, '\n*** Unrecoverable, server exiting!' |
| print>>erf, '-'*40 |
| os._exit(0) |
| |
| #----------------- end class RPCServer -------------------- |
| |
| objecttable = {} |
| request_queue = Queue.Queue(0) |
| response_queue = Queue.Queue(0) |
| |
| |
| class SocketIO: |
| |
| nextseq = 0 |
| |
| def __init__(self, sock, objtable=None, debugging=None): |
| self.sockthread = threading.currentThread() |
| if debugging is not None: |
| self.debugging = debugging |
| self.sock = sock |
| if objtable is None: |
| objtable = objecttable |
| self.objtable = objtable |
| self.responses = {} |
| self.cvars = {} |
| |
| def close(self): |
| sock = self.sock |
| self.sock = None |
| if sock is not None: |
| sock.close() |
| |
| def exithook(self): |
| "override for specific exit action" |
| os._exit() |
| |
| def debug(self, *args): |
| if not self.debugging: |
| return |
| s = self.location + " " + str(threading.currentThread().getName()) |
| for a in args: |
| s = s + " " + str(a) |
| print>>sys.__stderr__, s |
| |
| def register(self, oid, object): |
| self.objtable[oid] = object |
| |
| def unregister(self, oid): |
| try: |
| del self.objtable[oid] |
| except KeyError: |
| pass |
| |
| def localcall(self, seq, request): |
| self.debug("localcall:", request) |
| try: |
| how, (oid, methodname, args, kwargs) = request |
| except TypeError: |
| return ("ERROR", "Bad request format") |
| if not self.objtable.has_key(oid): |
| return ("ERROR", "Unknown object id: %r" % (oid,)) |
| obj = self.objtable[oid] |
| if methodname == "__methods__": |
| methods = {} |
| _getmethods(obj, methods) |
| return ("OK", methods) |
| if methodname == "__attributes__": |
| attributes = {} |
| _getattributes(obj, attributes) |
| return ("OK", attributes) |
| if not hasattr(obj, methodname): |
| return ("ERROR", "Unsupported method name: %r" % (methodname,)) |
| method = getattr(obj, methodname) |
| try: |
| if how == 'CALL': |
| ret = method(*args, **kwargs) |
| if isinstance(ret, RemoteObject): |
| ret = remoteref(ret) |
| return ("OK", ret) |
| elif how == 'QUEUE': |
| request_queue.put((seq, (method, args, kwargs))) |
| return("QUEUED", None) |
| else: |
| return ("ERROR", "Unsupported message type: %s" % how) |
| except SystemExit: |
| raise |
| except socket.error: |
| raise |
| except: |
| self.debug("localcall:EXCEPTION") |
| traceback.print_exc(file=sys.__stderr__) |
| return ("EXCEPTION", None) |
| |
| def remotecall(self, oid, methodname, args, kwargs): |
| self.debug("remotecall:asynccall: ", oid, methodname) |
| seq = self.asynccall(oid, methodname, args, kwargs) |
| return self.asyncreturn(seq) |
| |
| def remotequeue(self, oid, methodname, args, kwargs): |
| self.debug("remotequeue:asyncqueue: ", oid, methodname) |
| seq = self.asyncqueue(oid, methodname, args, kwargs) |
| return self.asyncreturn(seq) |
| |
| def asynccall(self, oid, methodname, args, kwargs): |
| request = ("CALL", (oid, methodname, args, kwargs)) |
| seq = self.newseq() |
| if threading.currentThread() != self.sockthread: |
| cvar = threading.Condition() |
| self.cvars[seq] = cvar |
| self.debug(("asynccall:%d:" % seq), oid, methodname, args, kwargs) |
| self.putmessage((seq, request)) |
| return seq |
| |
| def asyncqueue(self, oid, methodname, args, kwargs): |
| request = ("QUEUE", (oid, methodname, args, kwargs)) |
| seq = self.newseq() |
| if threading.currentThread() != self.sockthread: |
| cvar = threading.Condition() |
| self.cvars[seq] = cvar |
| self.debug(("asyncqueue:%d:" % seq), oid, methodname, args, kwargs) |
| self.putmessage((seq, request)) |
| return seq |
| |
| def asyncreturn(self, seq): |
| self.debug("asyncreturn:%d:call getresponse(): " % seq) |
| response = self.getresponse(seq, wait=0.05) |
| self.debug(("asyncreturn:%d:response: " % seq), response) |
| return self.decoderesponse(response) |
| |
| def decoderesponse(self, response): |
| how, what = response |
| if how == "OK": |
| return what |
| if how == "QUEUED": |
| return None |
| if how == "EXCEPTION": |
| self.debug("decoderesponse: EXCEPTION") |
| return None |
| if how == "EOF": |
| self.debug("decoderesponse: EOF") |
| self.decode_interrupthook() |
| return None |
| if how == "ERROR": |
| self.debug("decoderesponse: Internal ERROR:", what) |
| raise RuntimeError, what |
| raise SystemError, (how, what) |
| |
| def decode_interrupthook(self): |
| "" |
| raise EOFError |
| |
| def mainloop(self): |
| """Listen on socket until I/O not ready or EOF |
| |
| pollresponse() will loop looking for seq number None, which |
| never comes, and exit on EOFError. |
| |
| """ |
| try: |
| self.getresponse(myseq=None, wait=0.05) |
| except EOFError: |
| self.debug("mainloop:return") |
| return |
| |
| def getresponse(self, myseq, wait): |
| response = self._getresponse(myseq, wait) |
| if response is not None: |
| how, what = response |
| if how == "OK": |
| response = how, self._proxify(what) |
| return response |
| |
| def _proxify(self, obj): |
| if isinstance(obj, RemoteProxy): |
| return RPCProxy(self, obj.oid) |
| if isinstance(obj, types.ListType): |
| return map(self._proxify, obj) |
| # XXX Check for other types -- not currently needed |
| return obj |
| |
| def _getresponse(self, myseq, wait): |
| self.debug("_getresponse:myseq:", myseq) |
| if threading.currentThread() is self.sockthread: |
| # this thread does all reading of requests or responses |
| while 1: |
| response = self.pollresponse(myseq, wait) |
| if response is not None: |
| return response |
| else: |
| # wait for notification from socket handling thread |
| cvar = self.cvars[myseq] |
| cvar.acquire() |
| while not self.responses.has_key(myseq): |
| cvar.wait() |
| response = self.responses[myseq] |
| self.debug("_getresponse:%s: thread woke up: response: %s" % |
| (myseq, response)) |
| del self.responses[myseq] |
| del self.cvars[myseq] |
| cvar.release() |
| return response |
| |
| def newseq(self): |
| self.nextseq = seq = self.nextseq + 2 |
| return seq |
| |
| def putmessage(self, message): |
| self.debug("putmessage:%d:" % message[0]) |
| try: |
| s = pickle.dumps(message) |
| except pickle.PicklingError: |
| print >>sys.__stderr__, "Cannot pickle:", repr(message) |
| raise |
| s = struct.pack("<i", len(s)) + s |
| while len(s) > 0: |
| try: |
| r, w, x = select.select([], [self.sock], []) |
| n = self.sock.send(s[:BUFSIZE]) |
| except (AttributeError, socket.error): |
| # socket was closed |
| raise IOError |
| else: |
| s = s[n:] |
| |
| buffer = "" |
| bufneed = 4 |
| bufstate = 0 # meaning: 0 => reading count; 1 => reading data |
| |
| def pollpacket(self, wait): |
| self._stage0() |
| if len(self.buffer) < self.bufneed: |
| r, w, x = select.select([self.sock.fileno()], [], [], wait) |
| if len(r) == 0: |
| return None |
| try: |
| s = self.sock.recv(BUFSIZE) |
| except socket.error: |
| raise EOFError |
| if len(s) == 0: |
| raise EOFError |
| self.buffer += s |
| self._stage0() |
| return self._stage1() |
| |
| def _stage0(self): |
| if self.bufstate == 0 and len(self.buffer) >= 4: |
| s = self.buffer[:4] |
| self.buffer = self.buffer[4:] |
| self.bufneed = struct.unpack("<i", s)[0] |
| self.bufstate = 1 |
| |
| def _stage1(self): |
| if self.bufstate == 1 and len(self.buffer) >= self.bufneed: |
| packet = self.buffer[:self.bufneed] |
| self.buffer = self.buffer[self.bufneed:] |
| self.bufneed = 4 |
| self.bufstate = 0 |
| return packet |
| |
| def pollmessage(self, wait): |
| packet = self.pollpacket(wait) |
| if packet is None: |
| return None |
| try: |
| message = pickle.loads(packet) |
| except pickle.UnpicklingError: |
| print >>sys.__stderr__, "-----------------------" |
| print >>sys.__stderr__, "cannot unpickle packet:", repr(packet) |
| traceback.print_stack(file=sys.__stderr__) |
| print >>sys.__stderr__, "-----------------------" |
| raise |
| return message |
| |
| def pollresponse(self, myseq, wait): |
| """Handle messages received on the socket. |
| |
| Some messages received may be asynchronous 'call' or 'queue' requests, |
| and some may be responses for other threads. |
| |
| 'call' requests are passed to self.localcall() with the expectation of |
| immediate execution, during which time the socket is not serviced. |
| |
| 'queue' requests are used for tasks (which may block or hang) to be |
| processed in a different thread. These requests are fed into |
| request_queue by self.localcall(). Responses to queued requests are |
| taken from response_queue and sent across the link with the associated |
| sequence numbers. Messages in the queues are (sequence_number, |
| request/response) tuples and code using this module removing messages |
| from the request_queue is responsible for returning the correct |
| sequence number in the response_queue. |
| |
| pollresponse() will loop until a response message with the myseq |
| sequence number is received, and will save other responses in |
| self.responses and notify the owning thread. |
| |
| """ |
| while 1: |
| # send queued response if there is one available |
| try: |
| qmsg = response_queue.get(0) |
| except Queue.Empty: |
| pass |
| else: |
| seq, response = qmsg |
| message = (seq, ('OK', response)) |
| self.putmessage(message) |
| # poll for message on link |
| try: |
| message = self.pollmessage(wait) |
| if message is None: # socket not ready |
| return None |
| except EOFError: |
| self.handle_EOF() |
| return None |
| except AttributeError: |
| return None |
| seq, resq = message |
| how = resq[0] |
| self.debug("pollresponse:%d:myseq:%s" % (seq, myseq)) |
| # process or queue a request |
| if how in ("CALL", "QUEUE"): |
| self.debug("pollresponse:%d:localcall:call:" % seq) |
| response = self.localcall(seq, resq) |
| self.debug("pollresponse:%d:localcall:response:%s" |
| % (seq, response)) |
| if how == "CALL": |
| self.putmessage((seq, response)) |
| elif how == "QUEUE": |
| # don't acknowledge the 'queue' request! |
| pass |
| continue |
| # return if completed message transaction |
| elif seq == myseq: |
| return resq |
| # must be a response for a different thread: |
| else: |
| cv = self.cvars.get(seq, None) |
| # response involving unknown sequence number is discarded, |
| # probably intended for prior incarnation of server |
| if cv is not None: |
| cv.acquire() |
| self.responses[seq] = resq |
| cv.notify() |
| cv.release() |
| continue |
| |
| def handle_EOF(self): |
| "action taken upon link being closed by peer" |
| self.EOFhook() |
| self.debug("handle_EOF") |
| for key in self.cvars: |
| cv = self.cvars[key] |
| cv.acquire() |
| self.responses[key] = ('EOF', None) |
| cv.notify() |
| cv.release() |
| # call our (possibly overridden) exit function |
| self.exithook() |
| |
| def EOFhook(self): |
| "Classes using rpc client/server can override to augment EOF action" |
| pass |
| |
| #----------------- end class SocketIO -------------------- |
| |
| class RemoteObject: |
| # Token mix-in class |
| pass |
| |
| def remoteref(obj): |
| oid = id(obj) |
| objecttable[oid] = obj |
| return RemoteProxy(oid) |
| |
| class RemoteProxy: |
| |
| def __init__(self, oid): |
| self.oid = oid |
| |
| class RPCHandler(SocketServer.BaseRequestHandler, SocketIO): |
| |
| debugging = False |
| location = "#S" # Server |
| |
| def __init__(self, sock, addr, svr): |
| svr.current_handler = self ## cgt xxx |
| SocketIO.__init__(self, sock) |
| SocketServer.BaseRequestHandler.__init__(self, sock, addr, svr) |
| |
| def handle(self): |
| "handle() method required by SocketServer" |
| self.mainloop() |
| |
| def get_remote_proxy(self, oid): |
| return RPCProxy(self, oid) |
| |
| class RPCClient(SocketIO): |
| |
| debugging = False |
| location = "#C" # Client |
| |
| nextseq = 1 # Requests coming from the client are odd numbered |
| |
| def __init__(self, address, family=socket.AF_INET, type=socket.SOCK_STREAM): |
| self.listening_sock = socket.socket(family, type) |
| self.listening_sock.setsockopt(socket.SOL_SOCKET, |
| socket.SO_REUSEADDR, 1) |
| self.listening_sock.bind(address) |
| self.listening_sock.listen(1) |
| |
| def accept(self): |
| working_sock, address = self.listening_sock.accept() |
| if self.debugging: |
| print>>sys.__stderr__, "****** Connection request from ", address |
| if address[0] == LOCALHOST: |
| SocketIO.__init__(self, working_sock) |
| else: |
| print>>sys.__stderr__, "** Invalid host: ", address |
| raise socket.error |
| |
| def get_remote_proxy(self, oid): |
| return RPCProxy(self, oid) |
| |
| class RPCProxy: |
| |
| __methods = None |
| __attributes = None |
| |
| def __init__(self, sockio, oid): |
| self.sockio = sockio |
| self.oid = oid |
| |
| def __getattr__(self, name): |
| if self.__methods is None: |
| self.__getmethods() |
| if self.__methods.get(name): |
| return MethodProxy(self.sockio, self.oid, name) |
| if self.__attributes is None: |
| self.__getattributes() |
| if not self.__attributes.has_key(name): |
| raise AttributeError, name |
| |
| def __getattributes(self): |
| self.__attributes = self.sockio.remotecall(self.oid, |
| "__attributes__", (), {}) |
| |
| def __getmethods(self): |
| self.__methods = self.sockio.remotecall(self.oid, |
| "__methods__", (), {}) |
| |
| def _getmethods(obj, methods): |
| # Helper to get a list of methods from an object |
| # Adds names to dictionary argument 'methods' |
| for name in dir(obj): |
| attr = getattr(obj, name) |
| if callable(attr): |
| methods[name] = 1 |
| if type(obj) == types.InstanceType: |
| _getmethods(obj.__class__, methods) |
| if type(obj) == types.ClassType: |
| for super in obj.__bases__: |
| _getmethods(super, methods) |
| |
| def _getattributes(obj, attributes): |
| for name in dir(obj): |
| attr = getattr(obj, name) |
| if not callable(attr): |
| attributes[name] = 1 |
| |
| class MethodProxy: |
| |
| def __init__(self, sockio, oid, name): |
| self.sockio = sockio |
| self.oid = oid |
| self.name = name |
| |
| def __call__(self, *args, **kwargs): |
| value = self.sockio.remotecall(self.oid, self.name, args, kwargs) |
| return value |
| |
| |
| # XXX KBK 09Sep03 We need a proper unit test for this module. Previously |
| # existing test code was removed at Rev 1.27. |